diff options
Diffstat (limited to 'net')
33 files changed, 2801 insertions, 3863 deletions
diff --git a/net/dccp/Kconfig b/net/dccp/Kconfig index 206c16ad9c3..7aa2a7acc7e 100644 --- a/net/dccp/Kconfig +++ b/net/dccp/Kconfig @@ -25,6 +25,9 @@ config INET_DCCP_DIAG def_tristate y if (IP_DCCP = y && INET_DIAG = y) def_tristate m +config IP_DCCP_ACKVEC + bool + source "net/dccp/ccids/Kconfig" menu "DCCP Kernel Hacking" diff --git a/net/dccp/Makefile b/net/dccp/Makefile index 0c1c9af2bf7..f4f8793aaff 100644 --- a/net/dccp/Makefile +++ b/net/dccp/Makefile @@ -1,7 +1,6 @@ obj-$(CONFIG_IP_DCCP) += dccp.o dccp_ipv4.o -dccp-y := ccid.o feat.o input.o minisocks.o options.o \ - qpolicy.o output.o proto.o timer.o ackvec.o +dccp-y := ccid.o feat.o input.o minisocks.o options.o output.o proto.o timer.o dccp_ipv4-y := ipv4.o @@ -9,6 +8,8 @@ dccp_ipv4-y := ipv4.o obj-$(subst y,$(CONFIG_IP_DCCP),$(CONFIG_IPV6)) += dccp_ipv6.o dccp_ipv6-y := ipv6.o +dccp-$(CONFIG_IP_DCCP_ACKVEC) += ackvec.o + obj-$(CONFIG_INET_DCCP_DIAG) += dccp_diag.o obj-$(CONFIG_NET_DCCPPROBE) += dccp_probe.o diff --git a/net/dccp/ackvec.c b/net/dccp/ackvec.c index 41819848bdd..1e8be246ad1 100644 --- a/net/dccp/ackvec.c +++ b/net/dccp/ackvec.c @@ -1,375 +1,445 @@ /* * net/dccp/ackvec.c * - * An implementation of Ack Vectors for the DCCP protocol - * Copyright (c) 2007 University of Aberdeen, Scotland, UK + * An implementation of the DCCP protocol * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; version 2 of the License; */ + +#include "ackvec.h" #include "dccp.h" + +#include <linux/dccp.h> +#include <linux/init.h> +#include <linux/errno.h> #include <linux/kernel.h> +#include <linux/skbuff.h> #include <linux/slab.h> +#include <net/sock.h> + static struct kmem_cache *dccp_ackvec_slab; static struct kmem_cache *dccp_ackvec_record_slab; -struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority) +static struct dccp_ackvec_record *dccp_ackvec_record_new(void) { - struct dccp_ackvec *av = kmem_cache_zalloc(dccp_ackvec_slab, priority); + struct dccp_ackvec_record *avr = + kmem_cache_alloc(dccp_ackvec_record_slab, GFP_ATOMIC); - if (av != NULL) { - av->av_buf_head = av->av_buf_tail = DCCPAV_MAX_ACKVEC_LEN - 1; - INIT_LIST_HEAD(&av->av_records); - } - return av; + if (avr != NULL) + INIT_LIST_HEAD(&avr->avr_node); + + return avr; } -static void dccp_ackvec_purge_records(struct dccp_ackvec *av) +static void dccp_ackvec_record_delete(struct dccp_ackvec_record *avr) { - struct dccp_ackvec_record *cur, *next; - - list_for_each_entry_safe(cur, next, &av->av_records, avr_node) - kmem_cache_free(dccp_ackvec_record_slab, cur); - INIT_LIST_HEAD(&av->av_records); + if (unlikely(avr == NULL)) + return; + /* Check if deleting a linked record */ + WARN_ON(!list_empty(&avr->avr_node)); + kmem_cache_free(dccp_ackvec_record_slab, avr); } -void dccp_ackvec_free(struct dccp_ackvec *av) +static void dccp_ackvec_insert_avr(struct dccp_ackvec *av, + struct dccp_ackvec_record *avr) { - if (likely(av != NULL)) { - dccp_ackvec_purge_records(av); - kmem_cache_free(dccp_ackvec_slab, av); + /* + * AVRs are sorted by seqno. Since we are sending them in order, we + * just add the AVR at the head of the list. + * -sorbo. + */ + if (!list_empty(&av->av_records)) { + const struct dccp_ackvec_record *head = + list_entry(av->av_records.next, + struct dccp_ackvec_record, + avr_node); + BUG_ON(before48(avr->avr_ack_seqno, head->avr_ack_seqno)); } + + list_add(&avr->avr_node, &av->av_records); } -/** - * dccp_ackvec_update_records - Record information about sent Ack Vectors - * @av: Ack Vector records to update - * @seqno: Sequence number of the packet carrying the Ack Vector just sent - * @nonce_sum: The sum of all buffer nonces contained in the Ack Vector - */ -int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seqno, u8 nonce_sum) +int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) { + struct dccp_sock *dp = dccp_sk(sk); + struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec; + /* Figure out how many options do we need to represent the ackvec */ + const u16 nr_opts = DIV_ROUND_UP(av->av_vec_len, DCCP_MAX_ACKVEC_OPT_LEN); + u16 len = av->av_vec_len + 2 * nr_opts, i; + u32 elapsed_time; + const unsigned char *tail, *from; + unsigned char *to; struct dccp_ackvec_record *avr; + suseconds_t delta; + + if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) + return -1; + + delta = ktime_us_delta(ktime_get_real(), av->av_time); + elapsed_time = delta / 10; - avr = kmem_cache_alloc(dccp_ackvec_record_slab, GFP_ATOMIC); + if (elapsed_time != 0 && + dccp_insert_option_elapsed_time(sk, skb, elapsed_time)) + return -1; + + avr = dccp_ackvec_record_new(); if (avr == NULL) - return -ENOBUFS; + return -1; + + DCCP_SKB_CB(skb)->dccpd_opt_len += len; + + to = skb_push(skb, len); + len = av->av_vec_len; + from = av->av_buf + av->av_buf_head; + tail = av->av_buf + DCCP_MAX_ACKVEC_LEN; + + for (i = 0; i < nr_opts; ++i) { + int copylen = len; + + if (len > DCCP_MAX_ACKVEC_OPT_LEN) + copylen = DCCP_MAX_ACKVEC_OPT_LEN; + + *to++ = DCCPO_ACK_VECTOR_0; + *to++ = copylen + 2; + + /* Check if buf_head wraps */ + if (from + copylen > tail) { + const u16 tailsize = tail - from; + + memcpy(to, from, tailsize); + to += tailsize; + len -= tailsize; + copylen -= tailsize; + from = av->av_buf; + } + + memcpy(to, from, copylen); + from += copylen; + to += copylen; + len -= copylen; + } - avr->avr_ack_seqno = seqno; - avr->avr_ack_ptr = av->av_buf_head; - avr->avr_ack_ackno = av->av_buf_ackno; - avr->avr_ack_nonce = nonce_sum; - avr->avr_ack_runlen = dccp_ackvec_runlen(av->av_buf + av->av_buf_head); - /* - * When the buffer overflows, we keep no more than one record. This is - * the simplest way of disambiguating sender-Acks dating from before the - * overflow from sender-Acks which refer to after the overflow; a simple - * solution is preferable here since we are handling an exception. - */ - if (av->av_overflow) - dccp_ackvec_purge_records(av); /* - * Since GSS is incremented for each packet, the list is automatically - * arranged in descending order of @ack_seqno. + * From RFC 4340, A.2: + * + * For each acknowledgement it sends, the HC-Receiver will add an + * acknowledgement record. ack_seqno will equal the HC-Receiver + * sequence number it used for the ack packet; ack_ptr will equal + * buf_head; ack_ackno will equal buf_ackno; and ack_nonce will + * equal buf_nonce. */ - list_add(&avr->avr_node, &av->av_records); + avr->avr_ack_seqno = DCCP_SKB_CB(skb)->dccpd_seq; + avr->avr_ack_ptr = av->av_buf_head; + avr->avr_ack_ackno = av->av_buf_ackno; + avr->avr_ack_nonce = av->av_buf_nonce; + avr->avr_sent_len = av->av_vec_len; - dccp_pr_debug("Added Vector, ack_seqno=%llu, ack_ackno=%llu (rl=%u)\n", + dccp_ackvec_insert_avr(av, avr); + + dccp_pr_debug("%s ACK Vector 0, len=%d, ack_seqno=%llu, " + "ack_ackno=%llu\n", + dccp_role(sk), avr->avr_sent_len, (unsigned long long)avr->avr_ack_seqno, - (unsigned long long)avr->avr_ack_ackno, - avr->avr_ack_runlen); + (unsigned long long)avr->avr_ack_ackno); return 0; } -static struct dccp_ackvec_record *dccp_ackvec_lookup(struct list_head *av_list, - const u64 ackno) +struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority) { - struct dccp_ackvec_record *avr; - /* - * Exploit that records are inserted in descending order of sequence - * number, start with the oldest record first. If @ackno is `before' - * the earliest ack_ackno, the packet is too old to be considered. - */ - list_for_each_entry_reverse(avr, av_list, avr_node) { - if (avr->avr_ack_seqno == ackno) - return avr; - if (before48(ackno, avr->avr_ack_seqno)) - break; + struct dccp_ackvec *av = kmem_cache_alloc(dccp_ackvec_slab, priority); + + if (av != NULL) { + av->av_buf_head = DCCP_MAX_ACKVEC_LEN - 1; + av->av_buf_ackno = UINT48_MAX + 1; + av->av_buf_nonce = 0; + av->av_time = ktime_set(0, 0); + av->av_vec_len = 0; + INIT_LIST_HEAD(&av->av_records); } - return NULL; + + return av; } -/* - * Buffer index and length computation using modulo-buffersize arithmetic. - * Note that, as pointers move from right to left, head is `before' tail. - */ -static inline u16 __ackvec_idx_add(const u16 a, const u16 b) +void dccp_ackvec_free(struct dccp_ackvec *av) { - return (a + b) % DCCPAV_MAX_ACKVEC_LEN; + if (unlikely(av == NULL)) + return; + + if (!list_empty(&av->av_records)) { + struct dccp_ackvec_record *avr, *next; + + list_for_each_entry_safe(avr, next, &av->av_records, avr_node) { + list_del_init(&avr->avr_node); + dccp_ackvec_record_delete(avr); + } + } + + kmem_cache_free(dccp_ackvec_slab, av); } -static inline u16 __ackvec_idx_sub(const u16 a, const u16 b) +static inline u8 dccp_ackvec_state(const struct dccp_ackvec *av, + const u32 index) { - return __ackvec_idx_add(a, DCCPAV_MAX_ACKVEC_LEN - b); + return av->av_buf[index] & DCCP_ACKVEC_STATE_MASK; } -u16 dccp_ackvec_buflen(const struct dccp_ackvec *av) +static inline u8 dccp_ackvec_len(const struct dccp_ackvec *av, + const u32 index) { - if (unlikely(av->av_overflow)) - return DCCPAV_MAX_ACKVEC_LEN; - return __ackvec_idx_sub(av->av_buf_tail, av->av_buf_head); + return av->av_buf[index] & DCCP_ACKVEC_LEN_MASK; } -/** - * dccp_ackvec_update_old - Update previous state as per RFC 4340, 11.4.1 - * @av: non-empty buffer to update - * @distance: negative or zero distance of @seqno from buf_ackno downward - * @seqno: the (old) sequence number whose record is to be updated - * @state: state in which packet carrying @seqno was received +/* + * If several packets are missing, the HC-Receiver may prefer to enter multiple + * bytes with run length 0, rather than a single byte with a larger run length; + * this simplifies table updates if one of the missing packets arrives. */ -static void dccp_ackvec_update_old(struct dccp_ackvec *av, s64 distance, - u64 seqno, enum dccp_ackvec_states state) +static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av, + const unsigned int packets, + const unsigned char state) { - u16 ptr = av->av_buf_head; + unsigned int gap; + long new_head; - BUG_ON(distance > 0); - if (unlikely(dccp_ackvec_is_empty(av))) - return; + if (av->av_vec_len + packets > DCCP_MAX_ACKVEC_LEN) + return -ENOBUFS; - do { - u8 runlen = dccp_ackvec_runlen(av->av_buf + ptr); + gap = packets - 1; + new_head = av->av_buf_head - packets; - if (distance + runlen >= 0) { - /* - * Only update the state if packet has not been received - * yet. This is OK as per the second table in RFC 4340, - * 11.4.1; i.e. here we are using the following table: - * RECEIVED - * 0 1 3 - * S +---+---+---+ - * T 0 | 0 | 0 | 0 | - * O +---+---+---+ - * R 1 | 1 | 1 | 1 | - * E +---+---+---+ - * D 3 | 0 | 1 | 3 | - * +---+---+---+ - * The "Not Received" state was set by reserve_seats(). - */ - if (av->av_buf[ptr] == DCCPAV_NOT_RECEIVED) - av->av_buf[ptr] = state; - else - dccp_pr_debug("Not changing %llu state to %u\n", - (unsigned long long)seqno, state); - break; + if (new_head < 0) { + if (gap > 0) { + memset(av->av_buf, DCCP_ACKVEC_STATE_NOT_RECEIVED, + gap + new_head + 1); + gap = -new_head; } + new_head += DCCP_MAX_ACKVEC_LEN; + } - distance += runlen + 1; - ptr = __ackvec_idx_add(ptr, 1); + av->av_buf_head = new_head; - } while (ptr != av->av_buf_tail); -} + if (gap > 0) + memset(av->av_buf + av->av_buf_head + 1, + DCCP_ACKVEC_STATE_NOT_RECEIVED, gap); -/* Mark @num entries after buf_head as "Not yet received". */ -static void dccp_ackvec_reserve_seats(struct dccp_ackvec *av, u16 num) -{ - u16 start = __ackvec_idx_add(av->av_buf_head, 1), - len = DCCPAV_MAX_ACKVEC_LEN - start; - - /* check for buffer wrap-around */ - if (num > len) { - memset(av->av_buf + start, DCCPAV_NOT_RECEIVED, len); - start = 0; - num -= len; - } - if (num) - memset(av->av_buf + start, DCCPAV_NOT_RECEIVED, num); + av->av_buf[av->av_buf_head] = state; + av->av_vec_len += packets; + return 0; } -/** - * dccp_ackvec_add_new - Record one or more new entries in Ack Vector buffer - * @av: container of buffer to update (can be empty or non-empty) - * @num_packets: number of packets to register (must be >= 1) - * @seqno: sequence number of the first packet in @num_packets - * @state: state in which packet carrying @seqno was received +/* + * Implements the RFC 4340, Appendix A */ -static void dccp_ackvec_add_new(struct dccp_ackvec *av, u32 num_packets, - u64 seqno, enum dccp_ackvec_states state) +int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, + const u64 ackno, const u8 state) { - u32 num_cells = num_packets; + /* + * Check at the right places if the buffer is full, if it is, tell the + * caller to start dropping packets till the HC-Sender acks our ACK + * vectors, when we will free up space in av_buf. + * + * We may well decide to do buffer compression, etc, but for now lets + * just drop. + * + * From Appendix A.1.1 (`New Packets'): + * + * Of course, the circular buffer may overflow, either when the + * HC-Sender is sending data at a very high rate, when the + * HC-Receiver's acknowledgements are not reaching the HC-Sender, + * or when the HC-Sender is forgetting to acknowledge those acks + * (so the HC-Receiver is unable to clean up old state). In this + * case, the HC-Receiver should either compress the buffer (by + * increasing run lengths when possible), transfer its state to + * a larger buffer, or, as a last resort, drop all received + * packets, without processing them whatsoever, until its buffer + * shrinks again. + */ - if (num_packets > DCCPAV_BURST_THRESH) { - u32 lost_packets = num_packets - 1; + /* See if this is the first ackno being inserted */ + if (av->av_vec_len == 0) { + av->av_buf[av->av_buf_head] = state; + av->av_vec_len = 1; + } else if (after48(ackno, av->av_buf_ackno)) { + const u64 delta = dccp_delta_seqno(av->av_buf_ackno, ackno); - DCCP_WARN("Warning: large burst loss (%u)\n", lost_packets); /* - * We received 1 packet and have a loss of size "num_packets-1" - * which we squeeze into num_cells-1 rather than reserving an - * entire byte for each lost packet. - * The reason is that the vector grows in O(burst_length); when - * it grows too large there will no room left for the payload. - * This is a trade-off: if a few packets out of the burst show - * up later, their state will not be changed; it is simply too - * costly to reshuffle/reallocate/copy the buffer each time. - * Should such problems persist, we will need to switch to a - * different underlying data structure. + * Look if the state of this packet is the same as the + * previous ackno and if so if we can bump the head len. */ - for (num_packets = num_cells = 1; lost_packets; ++num_cells) { - u8 len = min(lost_packets, (u32)DCCPAV_MAX_RUNLEN); - - av->av_buf_head = __ackvec_idx_sub(av->av_buf_head, 1); - av->av_buf[av->av_buf_head] = DCCPAV_NOT_RECEIVED | len; + if (delta == 1 && + dccp_ackvec_state(av, av->av_buf_head) == state && + dccp_ackvec_len(av, av->av_buf_head) < DCCP_ACKVEC_LEN_MASK) + av->av_buf[av->av_buf_head]++; + else if (dccp_ackvec_set_buf_head_state(av, delta, state)) + return -ENOBUFS; + } else { + /* + * A.1.2. Old Packets + * + * When a packet with Sequence Number S <= buf_ackno + * arrives, the HC-Receiver will scan the table for + * the byte corresponding to S. (Indexing structures + * could reduce the complexity of this scan.) + */ + u64 delta = dccp_delta_seqno(ackno, av->av_buf_ackno); + u32 index = av->av_buf_head; - lost_packets -= len; + while (1) { + const u8 len = dccp_ackvec_len(av, index); + const u8 av_state = dccp_ackvec_state(av, index); + /* + * valid packets not yet in av_buf have a reserved + * entry, with a len equal to 0. + */ + if (av_state == DCCP_ACKVEC_STATE_NOT_RECEIVED && + len == 0 && delta == 0) { /* Found our + reserved seat! */ + dccp_pr_debug("Found %llu reserved seat!\n", + (unsigned long long)ackno); + av->av_buf[index] = state; + goto out; + } + /* len == 0 means one packet */ + if (delta < len + 1) + goto out_duplicate; + + delta -= len + 1; + if (++index == DCCP_MAX_ACKVEC_LEN) + index = 0; } } - if (num_cells + dccp_ackvec_buflen(av) >= DCCPAV_MAX_ACKVEC_LEN) { - DCCP_CRIT("Ack Vector buffer overflow: dropping old entries\n"); - av->av_overflow = true; - } - - av->av_buf_head = __ackvec_idx_sub(av->av_buf_head, num_packets); - if (av->av_overflow) - av->av_buf_tail = av->av_buf_head; - - av->av_buf[av->av_buf_head] = state; - av->av_buf_ackno = seqno; + av->av_buf_ackno = ackno; + av->av_time = ktime_get_real(); +out: + return 0; - if (num_packets > 1) - dccp_ackvec_reserve_seats(av, num_packets - 1); +out_duplicate: + /* Duplicate packet */ + dccp_pr_debug("Received a dup or already considered lost " + "packet: %llu\n", (unsigned long long)ackno); + return -EILSEQ; } -/** - * dccp_ackvec_input - Register incoming packet in the buffer - */ -void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb) +static void dccp_ackvec_throw_record(struct dccp_ackvec *av, + struct dccp_ackvec_record *avr) { - u64 seqno = DCCP_SKB_CB(skb)->dccpd_seq; - enum dccp_ackvec_states state = DCCPAV_RECEIVED; + struct dccp_ackvec_record *next; - if (dccp_ackvec_is_empty(av)) { - dccp_ackvec_add_new(av, 1, seqno, state); - av->av_tail_ackno = seqno; + /* sort out vector length */ + if (av->av_buf_head <= avr->avr_ack_ptr) + av->av_vec_len = avr->avr_ack_ptr - av->av_buf_head; + else + av->av_vec_len = DCCP_MAX_ACKVEC_LEN - 1 - + av->av_buf_head + avr->avr_ack_ptr; - } else { - s64 num_packets = dccp_delta_seqno(av->av_buf_ackno, seqno); - u8 *current_head = av->av_buf + av->av_buf_head; - - if (num_packets == 1 && - dccp_ackvec_state(current_head) == state && - dccp_ackvec_runlen(current_head) < DCCPAV_MAX_RUNLEN) { + /* free records */ + list_for_each_entry_safe_from(avr, next, &av->av_records, avr_node) { + list_del_init(&avr->avr_node); + dccp_ackvec_record_delete(avr); + } +} - *current_head += 1; - av->av_buf_ackno = seqno; +void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk, + const u64 ackno) +{ + struct dccp_ackvec_record *avr; - } else if (num_packets > 0) { - dccp_ackvec_add_new(av, num_packets, seqno, state); - } else { - dccp_ackvec_update_old(av, num_packets, seqno, state); - } + /* + * If we traverse backwards, it should be faster when we have large + * windows. We will be receiving ACKs for stuff we sent a while back + * -sorbo. + */ + list_for_each_entry_reverse(avr, &av->av_records, avr_node) { + if (ackno == avr->avr_ack_seqno) { + dccp_pr_debug("%s ACK packet 0, len=%d, ack_seqno=%llu, " + "ack_ackno=%llu, ACKED!\n", + dccp_role(sk), 1, + (unsigned long long)avr->avr_ack_seqno, + (unsigned long long)avr->avr_ack_ackno); + dccp_ackvec_throw_record(av, avr); + break; + } else if (avr->avr_ack_seqno > ackno) + break; /* old news */ } } -/** - * dccp_ackvec_clear_state - Perform house-keeping / garbage-collection - * This routine is called when the peer acknowledges the receipt of Ack Vectors - * up to and including @ackno. While based on on section A.3 of RFC 4340, here - * are additional precautions to prevent corrupted buffer state. In particular, - * we use tail_ackno to identify outdated records; it always marks the earliest - * packet of group (2) in 11.4.2. - */ -void dccp_ackvec_clear_state(struct dccp_ackvec *av, const u64 ackno) - { - struct dccp_ackvec_record *avr, *next; - u8 runlen_now, eff_runlen; - s64 delta; +static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av, + struct sock *sk, u64 *ackno, + const unsigned char len, + const unsigned char *vector) +{ + unsigned char i; + struct dccp_ackvec_record *avr; - avr = dccp_ackvec_lookup(&av->av_records, ackno); - if (avr == NULL) + /* Check if we actually sent an ACK vector */ + if (list_empty(&av->av_records)) return; - /* - * Deal with outdated acknowledgments: this arises when e.g. there are - * several old records and the acks from the peer come in slowly. In - * that case we may still have records that pre-date tail_ackno. - */ - delta = dccp_delta_seqno(av->av_tail_ackno, avr->avr_ack_ackno); - if (delta < 0) - goto free_records; - /* - * Deal with overlapping Ack Vectors: don't subtract more than the - * number of packets between tail_ackno and ack_ackno. - */ - eff_runlen = delta < avr->avr_ack_runlen ? delta : avr->avr_ack_runlen; - runlen_now = dccp_ackvec_runlen(av->av_buf + avr->avr_ack_ptr); + i = len; /* - * The run length of Ack Vector cells does not decrease over time. If - * the run length is the same as at the time the Ack Vector was sent, we - * free the ack_ptr cell. That cell can however not be freed if the run - * length has increased: in this case we need to move the tail pointer - * backwards (towards higher indices), to its next-oldest neighbour. + * XXX + * I think it might be more efficient to work backwards. See comment on + * rcv_ackno. -sorbo. */ - if (runlen_now > eff_runlen) { + avr = list_entry(av->av_records.next, struct dccp_ackvec_record, avr_node); + while (i--) { + const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK; + u64 ackno_end_rl; - av->av_buf[avr->avr_ack_ptr] -= eff_runlen + 1; - av->av_buf_tail = __ackvec_idx_add(avr->avr_ack_ptr, 1); + dccp_set_seqno(&ackno_end_rl, *ackno - rl); - /* This move may not have cleared the overflow flag. */ - if (av->av_overflow) - av->av_overflow = (av->av_buf_head == av->av_buf_tail); - } else { - av->av_buf_tail = avr->avr_ack_ptr; /* - * We have made sure that avr points to a valid cell within the - * buffer. This cell is either older than head, or equals head - * (empty buffer): in both cases we no longer have any overflow. + * If our AVR sequence number is greater than the ack, go + * forward in the AVR list until it is not so. */ - av->av_overflow = 0; - } - - /* - * The peer has acknowledged up to and including ack_ackno. Hence the - * first packet in group (2) of 11.4.2 is the successor of ack_ackno. - */ - av->av_tail_ackno = ADD48(avr->avr_ack_ackno, 1); + list_for_each_entry_from(avr, &av->av_records, avr_node) { + if (!after48(avr->avr_ack_seqno, *ackno)) + goto found; + } + /* End of the av_records list, not found, exit */ + break; +found: + if (between48(avr->avr_ack_seqno, ackno_end_rl, *ackno)) { + const u8 state = *vector & DCCP_ACKVEC_STATE_MASK; + if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED) { + dccp_pr_debug("%s ACK vector 0, len=%d, " + "ack_seqno=%llu, ack_ackno=%llu, " + "ACKED!\n", + dccp_role(sk), len, + (unsigned long long) + avr->avr_ack_seqno, + (unsigned long long) + avr->avr_ack_ackno); + dccp_ackvec_throw_record(av, avr); + break; + } + /* + * If it wasn't received, continue scanning... we might + * find another one. + */ + } -free_records: - list_for_each_entry_safe_from(avr, next, &av->av_records, avr_node) { - list_del(&avr->avr_node); - kmem_cache_free(dccp_ackvec_record_slab, avr); + dccp_set_seqno(ackno, ackno_end_rl - 1); + ++vector; } } -/* - * Routines to keep track of Ack Vectors received in an skb - */ -int dccp_ackvec_parsed_add(struct list_head *head, u8 *vec, u8 len, u8 nonce) +int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, + u64 *ackno, const u8 opt, const u8 *value, const u8 len) { - struct dccp_ackvec_parsed *new = kmalloc(sizeof(*new), GFP_ATOMIC); - - if (new == NULL) - return -ENOBUFS; - new->vec = vec; - new->len = len; - new->nonce = nonce; + if (len > DCCP_MAX_ACKVEC_OPT_LEN) + return -1; - list_add_tail(&new->node, head); + /* dccp_ackvector_print(DCCP_SKB_CB(skb)->dccpd_ack_seq, value, len); */ + dccp_ackvec_check_rcv_ackvector(dccp_sk(sk)->dccps_hc_rx_ackvec, sk, + ackno, len, value); return 0; } -EXPORT_SYMBOL_GPL(dccp_ackvec_parsed_add); - -void dccp_ackvec_parsed_cleanup(struct list_head *parsed_chunks) -{ - struct dccp_ackvec_parsed *cur, *next; - - list_for_each_entry_safe(cur, next, parsed_chunks, node) - kfree(cur); - INIT_LIST_HEAD(parsed_chunks); -} -EXPORT_SYMBOL_GPL(dccp_ackvec_parsed_cleanup); int __init dccp_ackvec_init(void) { @@ -379,9 +449,10 @@ int __init dccp_ackvec_init(void) if (dccp_ackvec_slab == NULL) goto out_err; - dccp_ackvec_record_slab = kmem_cache_create("dccp_ackvec_record", - sizeof(struct dccp_ackvec_record), - 0, SLAB_HWCACHE_ALIGN, NULL); + dccp_ackvec_record_slab = + kmem_cache_create("dccp_ackvec_record", + sizeof(struct dccp_ackvec_record), + 0, SLAB_HWCACHE_ALIGN, NULL); if (dccp_ackvec_record_slab == NULL) goto out_destroy_slab; diff --git a/net/dccp/ackvec.h b/net/dccp/ackvec.h index 6cdca79a99f..bcb64fb4ace 100644 --- a/net/dccp/ackvec.h +++ b/net/dccp/ackvec.h @@ -3,134 +3,156 @@ /* * net/dccp/ackvec.h * - * An implementation of Ack Vectors for the DCCP protocol - * Copyright (c) 2007 University of Aberdeen, Scotland, UK + * An implementation of the DCCP protocol * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@mandriva.com> + * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ -#include <linux/dccp.h> #include <linux/compiler.h> +#include <linux/ktime.h> #include <linux/list.h> #include <linux/types.h> -/* - * Ack Vector buffer space is static, in multiples of %DCCP_SINGLE_OPT_MAXLEN, - * the maximum size of a single Ack Vector. Setting %DCCPAV_NUM_ACKVECS to 1 - * will be sufficient for most cases of low Ack Ratios, using a value of 2 gives - * more headroom if Ack Ratio is higher or when the sender acknowledges slowly. - * The maximum value is bounded by the u16 types for indices and functions. - */ -#define DCCPAV_NUM_ACKVECS 2 -#define DCCPAV_MAX_ACKVEC_LEN (DCCP_SINGLE_OPT_MAXLEN * DCCPAV_NUM_ACKVECS) - -/* Estimated minimum average Ack Vector length - used for updating MPS */ -#define DCCPAV_MIN_OPTLEN 16 - -/* Threshold for coping with large bursts of losses */ -#define DCCPAV_BURST_THRESH (DCCPAV_MAX_ACKVEC_LEN / 8) - -enum dccp_ackvec_states { - DCCPAV_RECEIVED = 0x00, - DCCPAV_ECN_MARKED = 0x40, - DCCPAV_RESERVED = 0x80, - DCCPAV_NOT_RECEIVED = 0xC0 -}; -#define DCCPAV_MAX_RUNLEN 0x3F +/* Read about the ECN nonce to see why it is 253 */ +#define DCCP_MAX_ACKVEC_OPT_LEN 253 +/* We can spread an ack vector across multiple options */ +#define DCCP_MAX_ACKVEC_LEN (DCCP_MAX_ACKVEC_OPT_LEN * 2) -static inline u8 dccp_ackvec_runlen(const u8 *cell) -{ - return *cell & DCCPAV_MAX_RUNLEN; -} +#define DCCP_ACKVEC_STATE_RECEIVED 0 +#define DCCP_ACKVEC_STATE_ECN_MARKED (1 << 6) +#define DCCP_ACKVEC_STATE_NOT_RECEIVED (3 << 6) -static inline u8 dccp_ackvec_state(const u8 *cell) -{ - return *cell & ~DCCPAV_MAX_RUNLEN; -} +#define DCCP_ACKVEC_STATE_MASK 0xC0 /* 11000000 */ +#define DCCP_ACKVEC_LEN_MASK 0x3F /* 00111111 */ -/** struct dccp_ackvec - Ack Vector main data structure +/** struct dccp_ackvec - ack vector + * + * This data structure is the one defined in RFC 4340, Appendix A. * - * This implements a fixed-size circular buffer within an array and is largely - * based on Appendix A of RFC 4340. + * @av_buf_head - circular buffer head + * @av_buf_tail - circular buffer tail + * @av_buf_ackno - ack # of the most recent packet acknowledgeable in the + * buffer (i.e. %av_buf_head) + * @av_buf_nonce - the one-bit sum of the ECN Nonces on all packets acked + * by the buffer with State 0 * - * @av_buf: circular buffer storage area - * @av_buf_head: head index; begin of live portion in @av_buf - * @av_buf_tail: tail index; first index _after_ the live portion in @av_buf - * @av_buf_ackno: highest seqno of acknowledgeable packet recorded in @av_buf - * @av_tail_ackno: lowest seqno of acknowledgeable packet recorded in @av_buf - * @av_buf_nonce: ECN nonce sums, each covering subsequent segments of up to - * %DCCP_SINGLE_OPT_MAXLEN cells in the live portion of @av_buf - * @av_overflow: if 1 then buf_head == buf_tail indicates buffer wraparound - * @av_records: list of %dccp_ackvec_record (Ack Vectors sent previously) + * Additionally, the HC-Receiver must keep some information about the + * Ack Vectors it has recently sent. For each packet sent carrying an + * Ack Vector, it remembers four variables: + * + * @av_records - list of dccp_ackvec_record + * @av_ack_nonce - the one-bit sum of the ECN Nonces for all State 0. + * + * @av_time - the time in usecs + * @av_buf - circular buffer of acknowledgeable packets */ struct dccp_ackvec { - u8 av_buf[DCCPAV_MAX_ACKVEC_LEN]; - u16 av_buf_head; - u16 av_buf_tail; - u64 av_buf_ackno:48; - u64 av_tail_ackno:48; - bool av_buf_nonce[DCCPAV_NUM_ACKVECS]; - u8 av_overflow:1; + u64 av_buf_ackno; struct list_head av_records; + ktime_t av_time; + u16 av_buf_head; + u16 av_vec_len; + u8 av_buf_nonce; + u8 av_ack_nonce; + u8 av_buf[DCCP_MAX_ACKVEC_LEN]; }; -/** struct dccp_ackvec_record - Records information about sent Ack Vectors +/** struct dccp_ackvec_record - ack vector record * - * These list entries define the additional information which the HC-Receiver - * keeps about recently-sent Ack Vectors; again refer to RFC 4340, Appendix A. + * ACK vector record as defined in Appendix A of spec. * - * @avr_node: the list node in @av_records - * @avr_ack_seqno: sequence number of the packet the Ack Vector was sent on - * @avr_ack_ackno: the Ack number that this record/Ack Vector refers to - * @avr_ack_ptr: pointer into @av_buf where this record starts - * @avr_ack_runlen: run length of @avr_ack_ptr at the time of sending - * @avr_ack_nonce: the sum of @av_buf_nonce's at the time this record was sent + * The list is sorted by avr_ack_seqno * - * The list as a whole is sorted in descending order by @avr_ack_seqno. + * @avr_node - node in av_records + * @avr_ack_seqno - sequence number of the packet this record was sent on + * @avr_ack_ackno - sequence number being acknowledged + * @avr_ack_ptr - pointer into av_buf where this record starts + * @avr_ack_nonce - av_ack_nonce at the time this record was sent + * @avr_sent_len - lenght of the record in av_buf */ struct dccp_ackvec_record { struct list_head avr_node; - u64 avr_ack_seqno:48; - u64 avr_ack_ackno:48; + u64 avr_ack_seqno; + u64 avr_ack_ackno; u16 avr_ack_ptr; - u8 avr_ack_runlen; - u8 avr_ack_nonce:1; + u16 avr_sent_len; + u8 avr_ack_nonce; }; -extern int dccp_ackvec_init(void); +struct sock; +struct sk_buff; + +#ifdef CONFIG_IP_DCCP_ACKVEC +extern int dccp_ackvec_init(void); extern void dccp_ackvec_exit(void); extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority); extern void dccp_ackvec_free(struct dccp_ackvec *av); -extern void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb); -extern int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seq, u8 sum); -extern void dccp_ackvec_clear_state(struct dccp_ackvec *av, const u64 ackno); -extern u16 dccp_ackvec_buflen(const struct dccp_ackvec *av); +extern int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, + const u64 ackno, const u8 state); + +extern void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, + struct sock *sk, const u64 ackno); +extern int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, + u64 *ackno, const u8 opt, + const u8 *value, const u8 len); -static inline bool dccp_ackvec_is_empty(const struct dccp_ackvec *av) +extern int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb); + +static inline int dccp_ackvec_pending(const struct dccp_ackvec *av) +{ + return av->av_vec_len; +} +#else /* CONFIG_IP_DCCP_ACKVEC */ +static inline int dccp_ackvec_init(void) { - return av->av_overflow == 0 && av->av_buf_head == av->av_buf_tail; + return 0; } -/** - * struct dccp_ackvec_parsed - Record offsets of Ack Vectors in skb - * @vec: start of vector (offset into skb) - * @len: length of @vec - * @nonce: whether @vec had an ECN nonce of 0 or 1 - * @node: FIFO - arranged in descending order of ack_ackno - * This structure is used by CCIDs to access Ack Vectors in a received skb. - */ -struct dccp_ackvec_parsed { - u8 *vec, - len, - nonce:1; - struct list_head node; -}; +static inline void dccp_ackvec_exit(void) +{ +} + +static inline struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority) +{ + return NULL; +} + +static inline void dccp_ackvec_free(struct dccp_ackvec *av) +{ +} + +static inline int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk, + const u64 ackno, const u8 state) +{ + return -1; +} -extern int dccp_ackvec_parsed_add(struct list_head *head, - u8 *vec, u8 len, u8 nonce); -extern void dccp_ackvec_parsed_cleanup(struct list_head *parsed_chunks); +static inline void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, + struct sock *sk, const u64 ackno) +{ +} + +static inline int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb, + const u64 *ackno, const u8 opt, + const u8 *value, const u8 len) +{ + return -1; +} + +static inline int dccp_insert_option_ackvec(const struct sock *sk, + const struct sk_buff *skb) +{ + return -1; +} + +static inline int dccp_ackvec_pending(const struct dccp_ackvec *av) +{ + return 0; +} +#endif /* CONFIG_IP_DCCP_ACKVEC */ #endif /* _ACKVEC_H */ diff --git a/net/dccp/ccid.c b/net/dccp/ccid.c index e3fb52b4f5c..4809753d12a 100644 --- a/net/dccp/ccid.c +++ b/net/dccp/ccid.c @@ -13,13 +13,6 @@ #include "ccid.h" -static u8 builtin_ccids[] = { - DCCPC_CCID2, /* CCID2 is supported by default */ -#if defined(CONFIG_IP_DCCP_CCID3) || defined(CONFIG_IP_DCCP_CCID3_MODULE) - DCCPC_CCID3, -#endif -}; - static struct ccid_operations *ccids[CCID_MAX]; #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT) static atomic_t ccids_lockct = ATOMIC_INIT(0); @@ -93,47 +86,6 @@ static void ccid_kmem_cache_destroy(struct kmem_cache *slab) } } -/* check that up to @array_len members in @ccid_array are supported */ -bool ccid_support_check(u8 const *ccid_array, u8 array_len) -{ - u8 i, j, found; - - for (i = 0, found = 0; i < array_len; i++, found = 0) { - for (j = 0; !found && j < ARRAY_SIZE(builtin_ccids); j++) - found = (ccid_array[i] == builtin_ccids[j]); - if (!found) - return false; - } - return true; -} - -/** - * ccid_get_builtin_ccids - Provide copy of `builtin' CCID array - * @ccid_array: pointer to copy into - * @array_len: value to return length into - * This function allocates memory - caller must see that it is freed after use. - */ -int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len) -{ - *ccid_array = kmemdup(builtin_ccids, sizeof(builtin_ccids), gfp_any()); - if (*ccid_array == NULL) - return -ENOBUFS; - *array_len = ARRAY_SIZE(builtin_ccids); - return 0; -} - -int ccid_getsockopt_builtin_ccids(struct sock *sk, int len, - char __user *optval, int __user *optlen) -{ - if (len < sizeof(builtin_ccids)) - return -EINVAL; - - if (put_user(sizeof(builtin_ccids), optlen) || - copy_to_user(optval, builtin_ccids, sizeof(builtin_ccids))) - return -EFAULT; - return 0; -} - int ccid_register(struct ccid_operations *ccid_ops) { int err = -ENOBUFS; @@ -196,41 +148,22 @@ int ccid_unregister(struct ccid_operations *ccid_ops) EXPORT_SYMBOL_GPL(ccid_unregister); -/** - * ccid_request_module - Pre-load CCID module for later use - * This should be called only from process context (e.g. during connection - * setup) and is necessary for later calls to ccid_new (typically in software - * interrupt), so that it has the modules available when they are needed. - */ -static int ccid_request_module(u8 id) -{ - if (!in_atomic()) { - ccids_read_lock(); - if (ccids[id] == NULL) { - ccids_read_unlock(); - return request_module("net-dccp-ccid-%d", id); - } - ccids_read_unlock(); - } - return 0; -} - -int ccid_request_modules(u8 const *ccid_array, u8 array_len) -{ -#ifdef CONFIG_KMOD - while (array_len--) - if (ccid_request_module(ccid_array[array_len])) - return -1; -#endif - return 0; -} - struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx, gfp_t gfp) { struct ccid_operations *ccid_ops; struct ccid *ccid = NULL; ccids_read_lock(); +#ifdef CONFIG_KMOD + if (ccids[id] == NULL) { + /* We only try to load if in process context */ + ccids_read_unlock(); + if (gfp & GFP_ATOMIC) + goto out; + request_module("net-dccp-ccid-%d", id); + ccids_read_lock(); + } +#endif ccid_ops = ccids[id]; if (ccid_ops == NULL) goto out_unlock; @@ -272,6 +205,20 @@ out_module_put: EXPORT_SYMBOL_GPL(ccid_new); +struct ccid *ccid_hc_rx_new(unsigned char id, struct sock *sk, gfp_t gfp) +{ + return ccid_new(id, sk, 1, gfp); +} + +EXPORT_SYMBOL_GPL(ccid_hc_rx_new); + +struct ccid *ccid_hc_tx_new(unsigned char id,struct sock *sk, gfp_t gfp) +{ + return ccid_new(id, sk, 0, gfp); +} + +EXPORT_SYMBOL_GPL(ccid_hc_tx_new); + static void ccid_delete(struct ccid *ccid, struct sock *sk, int rx) { struct ccid_operations *ccid_ops; diff --git a/net/dccp/ccid.h b/net/dccp/ccid.h index d27054ba215..fdeae7b5731 100644 --- a/net/dccp/ccid.h +++ b/net/dccp/ccid.h @@ -60,18 +60,22 @@ struct ccid_operations { void (*ccid_hc_tx_exit)(struct sock *sk); void (*ccid_hc_rx_packet_recv)(struct sock *sk, struct sk_buff *skb); - int (*ccid_hc_rx_parse_options)(struct sock *sk, u8 pkt, - u8 opt, u8 *val, u8 len); + int (*ccid_hc_rx_parse_options)(struct sock *sk, + unsigned char option, + unsigned char len, u16 idx, + unsigned char* value); int (*ccid_hc_rx_insert_options)(struct sock *sk, struct sk_buff *skb); void (*ccid_hc_tx_packet_recv)(struct sock *sk, struct sk_buff *skb); - int (*ccid_hc_tx_parse_options)(struct sock *sk, u8 pkt, - u8 opt, u8 *val, u8 len); + int (*ccid_hc_tx_parse_options)(struct sock *sk, + unsigned char option, + unsigned char len, u16 idx, + unsigned char* value); int (*ccid_hc_tx_send_packet)(struct sock *sk, struct sk_buff *skb); void (*ccid_hc_tx_packet_sent)(struct sock *sk, - unsigned int len); + int more, unsigned int len); void (*ccid_hc_rx_get_info)(struct sock *sk, struct tcp_info *info); void (*ccid_hc_tx_get_info)(struct sock *sk, @@ -99,78 +103,31 @@ static inline void *ccid_priv(const struct ccid *ccid) return (void *)ccid->ccid_priv; } -extern bool ccid_support_check(u8 const *ccid_array, u8 array_len); -extern int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len); -extern int ccid_getsockopt_builtin_ccids(struct sock *sk, int len, - char __user *, int __user *); - -extern int ccid_request_modules(u8 const *ccid_array, u8 array_len); extern struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx, gfp_t gfp); -static inline int ccid_get_current_rx_ccid(struct dccp_sock *dp) -{ - struct ccid *ccid = dp->dccps_hc_rx_ccid; - - if (ccid == NULL || ccid->ccid_ops == NULL) - return -1; - return ccid->ccid_ops->ccid_id; -} - -static inline int ccid_get_current_tx_ccid(struct dccp_sock *dp) -{ - struct ccid *ccid = dp->dccps_hc_tx_ccid; - - if (ccid == NULL || ccid->ccid_ops == NULL) - return -1; - return ccid->ccid_ops->ccid_id; -} +extern struct ccid *ccid_hc_rx_new(unsigned char id, struct sock *sk, + gfp_t gfp); +extern struct ccid *ccid_hc_tx_new(unsigned char id, struct sock *sk, + gfp_t gfp); extern void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk); extern void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk); -/* - * Congestion control of queued data packets via CCID decision. - * - * The TX CCID performs its congestion-control by indicating whether and when a - * queued packet may be sent, using the return code of ccid_hc_tx_send_packet(). - * The following modes are supported via the symbolic constants below: - * - timer-based pacing (CCID returns a delay value in milliseconds); - * - autonomous dequeueing (CCID internally schedules dccps_xmitlet). - */ - -enum ccid_dequeueing_decision { - CCID_PACKET_SEND_AT_ONCE = 0x00000, /* "green light": no delay */ - CCID_PACKET_DELAY_MAX = 0x0FFFF, /* maximum delay in msecs */ - CCID_PACKET_DELAY = 0x10000, /* CCID msec-delay mode */ - CCID_PACKET_WILL_DEQUEUE_LATER = 0x20000, /* CCID autonomous mode */ - CCID_PACKET_ERR = 0xF0000, /* error condition */ -}; - -static inline int ccid_packet_dequeue_eval(const int return_code) -{ - if (return_code < 0) - return CCID_PACKET_ERR; - if (return_code == 0) - return CCID_PACKET_SEND_AT_ONCE; - if (return_code <= CCID_PACKET_DELAY_MAX) - return CCID_PACKET_DELAY; - return return_code; -} - static inline int ccid_hc_tx_send_packet(struct ccid *ccid, struct sock *sk, struct sk_buff *skb) { + int rc = 0; if (ccid->ccid_ops->ccid_hc_tx_send_packet != NULL) - return ccid->ccid_ops->ccid_hc_tx_send_packet(sk, skb); - return CCID_PACKET_SEND_AT_ONCE; + rc = ccid->ccid_ops->ccid_hc_tx_send_packet(sk, skb); + return rc; } static inline void ccid_hc_tx_packet_sent(struct ccid *ccid, struct sock *sk, - unsigned int len) + int more, unsigned int len) { if (ccid->ccid_ops->ccid_hc_tx_packet_sent != NULL) - ccid->ccid_ops->ccid_hc_tx_packet_sent(sk, len); + ccid->ccid_ops->ccid_hc_tx_packet_sent(sk, more, len); } static inline void ccid_hc_rx_packet_recv(struct ccid *ccid, struct sock *sk, @@ -187,31 +144,27 @@ static inline void ccid_hc_tx_packet_recv(struct ccid *ccid, struct sock *sk, ccid->ccid_ops->ccid_hc_tx_packet_recv(sk, skb); } -/** - * ccid_hc_tx_parse_options - Parse CCID-specific options sent by the receiver - * @pkt: type of packet that @opt appears on (RFC 4340, 5.1) - * @opt: the CCID-specific option type (RFC 4340, 5.8 and 10.3) - * @val: value of @opt - * @len: length of @val in bytes - */ static inline int ccid_hc_tx_parse_options(struct ccid *ccid, struct sock *sk, - u8 pkt, u8 opt, u8 *val, u8 len) + unsigned char option, + unsigned char len, u16 idx, + unsigned char* value) { - if (ccid->ccid_ops->ccid_hc_tx_parse_options == NULL) - return 0; - return ccid->ccid_ops->ccid_hc_tx_parse_options(sk, pkt, opt, val, len); + int rc = 0; + if (ccid->ccid_ops->ccid_hc_tx_parse_options != NULL) + rc = ccid->ccid_ops->ccid_hc_tx_parse_options(sk, option, len, idx, + value); + return rc; } -/** - * ccid_hc_rx_parse_options - Parse CCID-specific options sent by the sender - * Arguments are analogous to ccid_hc_tx_parse_options() - */ static inline int ccid_hc_rx_parse_options(struct ccid *ccid, struct sock *sk, - u8 pkt, u8 opt, u8 *val, u8 len) + unsigned char option, + unsigned char len, u16 idx, + unsigned char* value) { - if (ccid->ccid_ops->ccid_hc_rx_parse_options == NULL) - return 0; - return ccid->ccid_ops->ccid_hc_rx_parse_options(sk, pkt, opt, val, len); + int rc = 0; + if (ccid->ccid_ops->ccid_hc_rx_parse_options != NULL) + rc = ccid->ccid_ops->ccid_hc_rx_parse_options(sk, option, len, idx, value); + return rc; } static inline int ccid_hc_rx_insert_options(struct ccid *ccid, struct sock *sk, diff --git a/net/dccp/ccids/Kconfig b/net/dccp/ccids/Kconfig index fb168be2cb4..12275943eab 100644 --- a/net/dccp/ccids/Kconfig +++ b/net/dccp/ccids/Kconfig @@ -1,8 +1,10 @@ menu "DCCP CCIDs Configuration (EXPERIMENTAL)" + depends on EXPERIMENTAL config IP_DCCP_CCID2 - tristate "CCID2 (TCP-Like)" + tristate "CCID2 (TCP-Like) (EXPERIMENTAL)" def_tristate IP_DCCP + select IP_DCCP_ACKVEC ---help--- CCID 2, TCP-like Congestion Control, denotes Additive Increase, Multiplicative Decrease (AIMD) congestion control with behavior @@ -34,7 +36,7 @@ config IP_DCCP_CCID2_DEBUG If in doubt, say N. config IP_DCCP_CCID3 - tristate "CCID3 (TCP-Friendly)" + tristate "CCID3 (TCP-Friendly) (EXPERIMENTAL)" def_tristate IP_DCCP select IP_DCCP_TFRC_LIB ---help--- @@ -62,9 +64,9 @@ config IP_DCCP_CCID3 If in doubt, say M. -if IP_DCCP_CCID3 config IP_DCCP_CCID3_DEBUG bool "CCID3 debugging messages" + depends on IP_DCCP_CCID3 ---help--- Enable CCID3-specific debugging messages. @@ -74,29 +76,10 @@ config IP_DCCP_CCID3_DEBUG If in doubt, say N. -choice - prompt "Select method for measuring the packet size s" - default IP_DCCP_CCID3_MEASURE_S_AS_MPS - -config IP_DCCP_CCID3_MEASURE_S_AS_MPS - bool "Always use MPS in place of s" - ---help--- - This use is recommended as it is consistent with the initialisation - of X and suggested when s varies (rfc3448bis, (1) in section 4.1). -config IP_DCCP_CCID3_MEASURE_S_AS_AVG - bool "Use moving average" - ---help--- - An alternative way of tracking s, also supported by rfc3448bis. - This used to be the default for CCID-3 in previous kernels. -config IP_DCCP_CCID3_MEASURE_S_AS_MAX - bool "Track the maximum payload length" - ---help--- - An experimental method based on tracking the maximum packet size. -endchoice - config IP_DCCP_CCID3_RTO int "Use higher bound for nofeedback timer" default 100 + depends on IP_DCCP_CCID3 && EXPERIMENTAL ---help--- Use higher lower bound for nofeedback timer expiration. @@ -123,7 +106,6 @@ config IP_DCCP_CCID3_RTO The purpose of the nofeedback timer is to slow DCCP down when there is serious network congestion: experimenting with larger values should therefore not be performed on WANs. -endif # IP_DCCP_CCID3 config IP_DCCP_TFRC_LIB tristate diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c index fa713227c66..9a430734530 100644 --- a/net/dccp/ccids/ccid2.c +++ b/net/dccp/ccids/ccid2.c @@ -25,7 +25,7 @@ /* * This implementation should follow RFC 4341 */ -#include "../feat.h" + #include "../ccid.h" #include "../dccp.h" #include "ccid2.h" @@ -34,8 +34,51 @@ #ifdef CONFIG_IP_DCCP_CCID2_DEBUG static int ccid2_debug; #define ccid2_pr_debug(format, a...) DCCP_PR_DEBUG(ccid2_debug, format, ##a) + +static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx) +{ + int len = 0; + int pipe = 0; + struct ccid2_seq *seqp = hctx->ccid2hctx_seqh; + + /* there is data in the chain */ + if (seqp != hctx->ccid2hctx_seqt) { + seqp = seqp->ccid2s_prev; + len++; + if (!seqp->ccid2s_acked) + pipe++; + + while (seqp != hctx->ccid2hctx_seqt) { + struct ccid2_seq *prev = seqp->ccid2s_prev; + + len++; + if (!prev->ccid2s_acked) + pipe++; + + /* packets are sent sequentially */ + BUG_ON(dccp_delta_seqno(seqp->ccid2s_seq, + prev->ccid2s_seq ) >= 0); + BUG_ON(time_before(seqp->ccid2s_sent, + prev->ccid2s_sent)); + + seqp = prev; + } + } + + BUG_ON(pipe != hctx->ccid2hctx_pipe); + ccid2_pr_debug("len of chain=%d\n", len); + + do { + seqp = seqp->ccid2s_prev; + len++; + } while (seqp != hctx->ccid2hctx_seqh); + + ccid2_pr_debug("total len=%d\n", len); + BUG_ON(len != hctx->ccid2hctx_seqbufc * CCID2_SEQBUF_LEN); +} #else #define ccid2_pr_debug(format, a...) +#define ccid2_hc_tx_check_sanity(hctx) #endif static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx) @@ -44,7 +87,8 @@ static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx) int i; /* check if we have space to preserve the pointer to the buffer */ - if (hctx->seqbufc >= sizeof(hctx->seqbuf) / sizeof(struct ccid2_seq *)) + if (hctx->ccid2hctx_seqbufc >= (sizeof(hctx->ccid2hctx_seqbuf) / + sizeof(struct ccid2_seq*))) return -ENOMEM; /* allocate buffer and initialize linked list */ @@ -60,35 +104,38 @@ static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx) seqp->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1]; /* This is the first allocation. Initiate the head and tail. */ - if (hctx->seqbufc == 0) - hctx->seqh = hctx->seqt = seqp; + if (hctx->ccid2hctx_seqbufc == 0) + hctx->ccid2hctx_seqh = hctx->ccid2hctx_seqt = seqp; else { /* link the existing list with the one we just created */ - hctx->seqh->ccid2s_next = seqp; - seqp->ccid2s_prev = hctx->seqh; + hctx->ccid2hctx_seqh->ccid2s_next = seqp; + seqp->ccid2s_prev = hctx->ccid2hctx_seqh; - hctx->seqt->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1]; - seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = hctx->seqt; + hctx->ccid2hctx_seqt->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1]; + seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = hctx->ccid2hctx_seqt; } /* store the original pointer to the buffer so we can free it */ - hctx->seqbuf[hctx->seqbufc] = seqp; - hctx->seqbufc++; + hctx->ccid2hctx_seqbuf[hctx->ccid2hctx_seqbufc] = seqp; + hctx->ccid2hctx_seqbufc++; return 0; } static int ccid2_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) { - if (ccid2_cwnd_network_limited(ccid2_hc_tx_sk(sk))) - return CCID_PACKET_WILL_DEQUEUE_LATER; - return CCID_PACKET_SEND_AT_ONCE; + struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); + + if (hctx->ccid2hctx_pipe < hctx->ccid2hctx_cwnd) + return 0; + + return 1; /* XXX CCID should dequeue when ready instead of polling */ } static void ccid2_change_l_ack_ratio(struct sock *sk, u32 val) { struct dccp_sock *dp = dccp_sk(sk); - u32 max_ratio = DIV_ROUND_UP(ccid2_hc_tx_sk(sk)->cwnd, 2); + u32 max_ratio = DIV_ROUND_UP(ccid2_hc_tx_sk(sk)->ccid2hctx_cwnd, 2); /* * Ensure that Ack Ratio does not exceed ceil(cwnd/2), which is (2) from @@ -100,8 +147,8 @@ static void ccid2_change_l_ack_ratio(struct sock *sk, u32 val) DCCP_WARN("Limiting Ack Ratio (%u) to %u\n", val, max_ratio); val = max_ratio; } - if (val > DCCPF_ACK_RATIO_MAX) - val = DCCPF_ACK_RATIO_MAX; + if (val > 0xFFFF) /* RFC 4340, 11.3 */ + val = 0xFFFF; if (val == dp->dccps_l_ack_ratio) return; @@ -110,77 +157,99 @@ static void ccid2_change_l_ack_ratio(struct sock *sk, u32 val) dp->dccps_l_ack_ratio = val; } +static void ccid2_change_srtt(struct ccid2_hc_tx_sock *hctx, long val) +{ + ccid2_pr_debug("change SRTT to %ld\n", val); + hctx->ccid2hctx_srtt = val; +} + +static void ccid2_start_rto_timer(struct sock *sk); + static void ccid2_hc_tx_rto_expire(unsigned long data) { struct sock *sk = (struct sock *)data; struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); - const bool sender_was_blocked = ccid2_cwnd_network_limited(hctx); + long s; bh_lock_sock(sk); if (sock_owned_by_user(sk)) { - sk_reset_timer(sk, &hctx->rtotimer, jiffies + HZ / 5); + sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer, + jiffies + HZ / 5); goto out; } ccid2_pr_debug("RTO_EXPIRE\n"); + ccid2_hc_tx_check_sanity(hctx); + /* back-off timer */ - hctx->rto <<= 1; - if (hctx->rto > DCCP_RTO_MAX) - hctx->rto = DCCP_RTO_MAX; + hctx->ccid2hctx_rto <<= 1; + + s = hctx->ccid2hctx_rto / HZ; + if (s > 60) + hctx->ccid2hctx_rto = 60 * HZ; + + ccid2_start_rto_timer(sk); /* adjust pipe, cwnd etc */ - hctx->ssthresh = hctx->cwnd / 2; - if (hctx->ssthresh < 2) - hctx->ssthresh = 2; - hctx->cwnd = 1; - hctx->pipe = 0; + hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd / 2; + if (hctx->ccid2hctx_ssthresh < 2) + hctx->ccid2hctx_ssthresh = 2; + hctx->ccid2hctx_cwnd = 1; + hctx->ccid2hctx_pipe = 0; /* clear state about stuff we sent */ - hctx->seqt = hctx->seqh; - hctx->packets_acked = 0; + hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqh; + hctx->ccid2hctx_packets_acked = 0; /* clear ack ratio state. */ - hctx->rpseq = 0; - hctx->rpdupack = -1; + hctx->ccid2hctx_rpseq = 0; + hctx->ccid2hctx_rpdupack = -1; ccid2_change_l_ack_ratio(sk, 1); - - /* if we were blocked before, we may now send cwnd=1 packet */ - if (sender_was_blocked) - tasklet_schedule(&dccp_sk(sk)->dccps_xmitlet); - /* restart backed-off timer */ - sk_reset_timer(sk, &hctx->rtotimer, jiffies + hctx->rto); + ccid2_hc_tx_check_sanity(hctx); out: bh_unlock_sock(sk); sock_put(sk); } -static void ccid2_hc_tx_packet_sent(struct sock *sk, unsigned int len) +static void ccid2_start_rto_timer(struct sock *sk) +{ + struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); + + ccid2_pr_debug("setting RTO timeout=%ld\n", hctx->ccid2hctx_rto); + + BUG_ON(timer_pending(&hctx->ccid2hctx_rtotimer)); + sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer, + jiffies + hctx->ccid2hctx_rto); +} + +static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len) { struct dccp_sock *dp = dccp_sk(sk); struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); struct ccid2_seq *next; - hctx->pipe++; + hctx->ccid2hctx_pipe++; - hctx->seqh->ccid2s_seq = dp->dccps_gss; - hctx->seqh->ccid2s_acked = 0; - hctx->seqh->ccid2s_sent = jiffies; + hctx->ccid2hctx_seqh->ccid2s_seq = dp->dccps_gss; + hctx->ccid2hctx_seqh->ccid2s_acked = 0; + hctx->ccid2hctx_seqh->ccid2s_sent = jiffies; - next = hctx->seqh->ccid2s_next; + next = hctx->ccid2hctx_seqh->ccid2s_next; /* check if we need to alloc more space */ - if (next == hctx->seqt) { + if (next == hctx->ccid2hctx_seqt) { if (ccid2_hc_tx_alloc_seq(hctx)) { DCCP_CRIT("packet history - out of memory!"); /* FIXME: find a more graceful way to bail out */ return; } - next = hctx->seqh->ccid2s_next; - BUG_ON(next == hctx->seqt); + next = hctx->ccid2hctx_seqh->ccid2s_next; + BUG_ON(next == hctx->ccid2hctx_seqt); } - hctx->seqh = next; + hctx->ccid2hctx_seqh = next; - ccid2_pr_debug("cwnd=%d pipe=%d\n", hctx->cwnd, hctx->pipe); + ccid2_pr_debug("cwnd=%d pipe=%d\n", hctx->ccid2hctx_cwnd, + hctx->ccid2hctx_pipe); /* * FIXME: The code below is broken and the variables have been removed @@ -203,12 +272,12 @@ static void ccid2_hc_tx_packet_sent(struct sock *sk, unsigned int len) */ #if 0 /* Ack Ratio. Need to maintain a concept of how many windows we sent */ - hctx->arsent++; + hctx->ccid2hctx_arsent++; /* We had an ack loss in this window... */ - if (hctx->ackloss) { - if (hctx->arsent >= hctx->cwnd) { - hctx->arsent = 0; - hctx->ackloss = 0; + if (hctx->ccid2hctx_ackloss) { + if (hctx->ccid2hctx_arsent >= hctx->ccid2hctx_cwnd) { + hctx->ccid2hctx_arsent = 0; + hctx->ccid2hctx_ackloss = 0; } } else { /* No acks lost up to now... */ @@ -218,28 +287,28 @@ static void ccid2_hc_tx_packet_sent(struct sock *sk, unsigned int len) int denom = dp->dccps_l_ack_ratio * dp->dccps_l_ack_ratio - dp->dccps_l_ack_ratio; - denom = hctx->cwnd * hctx->cwnd / denom; + denom = hctx->ccid2hctx_cwnd * hctx->ccid2hctx_cwnd / denom; - if (hctx->arsent >= denom) { + if (hctx->ccid2hctx_arsent >= denom) { ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio - 1); - hctx->arsent = 0; + hctx->ccid2hctx_arsent = 0; } } else { /* we can't increase ack ratio further [1] */ - hctx->arsent = 0; /* or maybe set it to cwnd*/ + hctx->ccid2hctx_arsent = 0; /* or maybe set it to cwnd*/ } } #endif /* setup RTO timer */ - if (!timer_pending(&hctx->rtotimer)) - sk_reset_timer(sk, &hctx->rtotimer, jiffies + hctx->rto); + if (!timer_pending(&hctx->ccid2hctx_rtotimer)) + ccid2_start_rto_timer(sk); #ifdef CONFIG_IP_DCCP_CCID2_DEBUG do { - struct ccid2_seq *seqp = hctx->seqt; + struct ccid2_seq *seqp = hctx->ccid2hctx_seqt; - while (seqp != hctx->seqh) { + while (seqp != hctx->ccid2hctx_seqh) { ccid2_pr_debug("out seq=%llu acked=%d time=%lu\n", (unsigned long long)seqp->ccid2s_seq, seqp->ccid2s_acked, seqp->ccid2s_sent); @@ -247,158 +316,205 @@ static void ccid2_hc_tx_packet_sent(struct sock *sk, unsigned int len) } } while (0); ccid2_pr_debug("=========\n"); + ccid2_hc_tx_check_sanity(hctx); #endif } -/** - * ccid2_rtt_estimator - Sample RTT and compute RTO using RFC2988 algorithm - * This code is almost identical with TCP's tcp_rtt_estimator(), since - * - it has a higher sampling frequency (recommended by RFC 1323), - * - the RTO does not collapse into RTT due to RTTVAR going towards zero, - * - it is simple (cf. more complex proposals such as Eifel timer or research - * which suggests that the gain should be set according to window size), - * - in tests it was found to work well with CCID2 [gerrit]. +/* XXX Lame code duplication! + * returns -1 if none was found. + * else returns the next offset to use in the function call. */ -static void ccid2_rtt_estimator(struct sock *sk, const long mrtt) +static int ccid2_ackvector(struct sock *sk, struct sk_buff *skb, int offset, + unsigned char **vec, unsigned char *veclen) { - struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); - long m = mrtt ? : 1; - - if (hctx->srtt == 0) { - /* First measurement m */ - hctx->srtt = m << 3; - hctx->mdev = m << 1; - - hctx->mdev_max = max(TCP_RTO_MIN, hctx->mdev); - hctx->rttvar = hctx->mdev_max; - hctx->rtt_seq = dccp_sk(sk)->dccps_gss; - } else { - /* Update scaled SRTT as SRTT += 1/8 * (m - SRTT) */ - m -= (hctx->srtt >> 3); - hctx->srtt += m; - - /* Similarly, update scaled mdev with regard to |m| */ - if (m < 0) { - m = -m; - m -= (hctx->mdev >> 2); + const struct dccp_hdr *dh = dccp_hdr(skb); + unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); + unsigned char *opt_ptr; + const unsigned char *opt_end = (unsigned char *)dh + + (dh->dccph_doff * 4); + unsigned char opt, len; + unsigned char *value; + + BUG_ON(offset < 0); + options += offset; + opt_ptr = options; + if (opt_ptr >= opt_end) + return -1; + + while (opt_ptr != opt_end) { + opt = *opt_ptr++; + len = 0; + value = NULL; + + /* Check if this isn't a single byte option */ + if (opt > DCCPO_MAX_RESERVED) { + if (opt_ptr == opt_end) + goto out_invalid_option; + + len = *opt_ptr++; + if (len < 3) + goto out_invalid_option; /* - * This neutralises RTO increase when RTT < SRTT - mdev - * (see P. Sarolahti, A. Kuznetsov,"Congestion Control - * in Linux TCP", USENIX 2002, pp. 49-62). + * Remove the type and len fields, leaving + * just the value size */ - if (m > 0) - m >>= 3; - } else { - m -= (hctx->mdev >> 2); - } - hctx->mdev += m; + len -= 2; + value = opt_ptr; + opt_ptr += len; - if (hctx->mdev > hctx->mdev_max) { - hctx->mdev_max = hctx->mdev; - if (hctx->mdev_max > hctx->rttvar) - hctx->rttvar = hctx->mdev_max; + if (opt_ptr > opt_end) + goto out_invalid_option; } - /* - * Decay RTTVAR at most once per flight, exploiting that - * 1) pipe <= cwnd <= Sequence_Window = W (RFC 4340, 7.5.2) - * 2) AWL = GSS-W+1 <= GAR <= GSS (RFC 4340, 7.5.1) - * GAR is a useful bound for FlightSize = pipe, AWL is probably - * too low as it over-estimates pipe. - */ - if (after48(dccp_sk(sk)->dccps_gar, hctx->rtt_seq)) { - if (hctx->mdev_max < hctx->rttvar) - hctx->rttvar -= (hctx->rttvar - - hctx->mdev_max) >> 2; - hctx->rtt_seq = dccp_sk(sk)->dccps_gss; - hctx->mdev_max = TCP_RTO_MIN; + switch (opt) { + case DCCPO_ACK_VECTOR_0: + case DCCPO_ACK_VECTOR_1: + *vec = value; + *veclen = len; + return offset + (opt_ptr - options); } } - /* - * Set RTO from SRTT and RTTVAR - * Clock granularity is ignored since the minimum error for RTTVAR is - * clamped to 50msec (corresponding to HZ=20). This leads to a minimum - * RTO of 200msec. This agrees with TCP and RFC 4341, 5.: "Because DCCP - * does not retransmit data, DCCP does not require TCP's recommended - * minimum timeout of one second". - */ - hctx->rto = (hctx->srtt >> 3) + hctx->rttvar; + return -1; - if (hctx->rto > DCCP_RTO_MAX) - hctx->rto = DCCP_RTO_MAX; +out_invalid_option: + DCCP_BUG("Invalid option - this should not happen (previous parsing)!"); + return -1; } -static void ccid2_new_ack(struct sock *sk, struct ccid2_seq *seqp, - unsigned int *maxincr) +static void ccid2_hc_tx_kill_rto_timer(struct sock *sk) { struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); - if (hctx->cwnd < hctx->ssthresh) { - if (*maxincr > 0 && ++hctx->packets_acked == 2) { - hctx->cwnd += 1; - *maxincr -= 1; - hctx->packets_acked = 0; - } - } else if (++hctx->packets_acked >= hctx->cwnd) { - hctx->cwnd += 1; - hctx->packets_acked = 0; - } - /* - * FIXME: RTT is sampled several times per acknowledgment (for each - * entry in the Ack Vector), instead of once per Ack (as in TCP SACK). - * This causes the RTT to be over-estimated, since the older entries - * in the Ack Vector have earlier sending times. - * The cleanest solution is to not use the ccid2s_sent field at all - * and instead use DCCP timestamps - need to be resolved at some time. - */ - ccid2_rtt_estimator(sk, jiffies - seqp->ccid2s_sent); + sk_stop_timer(sk, &hctx->ccid2hctx_rtotimer); + ccid2_pr_debug("deleted RTO timer\n"); } -static void ccid2_congestion_event(struct sock *sk, struct ccid2_seq *seqp) +static inline void ccid2_new_ack(struct sock *sk, + struct ccid2_seq *seqp, + unsigned int *maxincr) { struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); - if (time_before(seqp->ccid2s_sent, hctx->last_cong)) { - ccid2_pr_debug("Multiple losses in an RTT---treating as one\n"); - return; + if (hctx->ccid2hctx_cwnd < hctx->ccid2hctx_ssthresh) { + if (*maxincr > 0 && ++hctx->ccid2hctx_packets_acked == 2) { + hctx->ccid2hctx_cwnd += 1; + *maxincr -= 1; + hctx->ccid2hctx_packets_acked = 0; + } + } else if (++hctx->ccid2hctx_packets_acked >= hctx->ccid2hctx_cwnd) { + hctx->ccid2hctx_cwnd += 1; + hctx->ccid2hctx_packets_acked = 0; } - hctx->last_cong = jiffies; + /* update RTO */ + if (hctx->ccid2hctx_srtt == -1 || + time_after(jiffies, hctx->ccid2hctx_lastrtt + hctx->ccid2hctx_srtt)) { + unsigned long r = (long)jiffies - (long)seqp->ccid2s_sent; + int s; + + /* first measurement */ + if (hctx->ccid2hctx_srtt == -1) { + ccid2_pr_debug("R: %lu Time=%lu seq=%llu\n", + r, jiffies, + (unsigned long long)seqp->ccid2s_seq); + ccid2_change_srtt(hctx, r); + hctx->ccid2hctx_rttvar = r >> 1; + } else { + /* RTTVAR */ + long tmp = hctx->ccid2hctx_srtt - r; + long srtt; + + if (tmp < 0) + tmp *= -1; + + tmp >>= 2; + hctx->ccid2hctx_rttvar *= 3; + hctx->ccid2hctx_rttvar >>= 2; + hctx->ccid2hctx_rttvar += tmp; + + /* SRTT */ + srtt = hctx->ccid2hctx_srtt; + srtt *= 7; + srtt >>= 3; + tmp = r >> 3; + srtt += tmp; + ccid2_change_srtt(hctx, srtt); + } + s = hctx->ccid2hctx_rttvar << 2; + /* clock granularity is 1 when based on jiffies */ + if (!s) + s = 1; + hctx->ccid2hctx_rto = hctx->ccid2hctx_srtt + s; + + /* must be at least a second */ + s = hctx->ccid2hctx_rto / HZ; + /* DCCP doesn't require this [but I like it cuz my code sux] */ +#if 1 + if (s < 1) + hctx->ccid2hctx_rto = HZ; +#endif + /* max 60 seconds */ + if (s > 60) + hctx->ccid2hctx_rto = HZ * 60; - hctx->cwnd = hctx->cwnd / 2 ? : 1U; - hctx->ssthresh = max(hctx->cwnd, 2U); + hctx->ccid2hctx_lastrtt = jiffies; - /* Avoid spurious timeouts resulting from Ack Ratio > cwnd */ - if (dccp_sk(sk)->dccps_l_ack_ratio > hctx->cwnd) - ccid2_change_l_ack_ratio(sk, hctx->cwnd); + ccid2_pr_debug("srtt: %ld rttvar: %ld rto: %ld (HZ=%d) R=%lu\n", + hctx->ccid2hctx_srtt, hctx->ccid2hctx_rttvar, + hctx->ccid2hctx_rto, HZ, r); + } + + /* we got a new ack, so re-start RTO timer */ + ccid2_hc_tx_kill_rto_timer(sk); + ccid2_start_rto_timer(sk); } -static int ccid2_hc_tx_parse_options(struct sock *sk, u8 packet_type, - u8 option, u8 *optval, u8 optlen) +static void ccid2_hc_tx_dec_pipe(struct sock *sk) { struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); - switch (option) { - case DCCPO_ACK_VECTOR_0: - case DCCPO_ACK_VECTOR_1: - return dccp_ackvec_parsed_add(&hctx->av_chunks, optval, optlen, - option - DCCPO_ACK_VECTOR_0); + if (hctx->ccid2hctx_pipe == 0) + DCCP_BUG("pipe == 0"); + else + hctx->ccid2hctx_pipe--; + + if (hctx->ccid2hctx_pipe == 0) + ccid2_hc_tx_kill_rto_timer(sk); +} + +static void ccid2_congestion_event(struct sock *sk, struct ccid2_seq *seqp) +{ + struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); + + if (time_before(seqp->ccid2s_sent, hctx->ccid2hctx_last_cong)) { + ccid2_pr_debug("Multiple losses in an RTT---treating as one\n"); + return; } - return 0; + + hctx->ccid2hctx_last_cong = jiffies; + + hctx->ccid2hctx_cwnd = hctx->ccid2hctx_cwnd / 2 ? : 1U; + hctx->ccid2hctx_ssthresh = max(hctx->ccid2hctx_cwnd, 2U); + + /* Avoid spurious timeouts resulting from Ack Ratio > cwnd */ + if (dccp_sk(sk)->dccps_l_ack_ratio > hctx->ccid2hctx_cwnd) + ccid2_change_l_ack_ratio(sk, hctx->ccid2hctx_cwnd); } static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) { struct dccp_sock *dp = dccp_sk(sk); struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); - const bool sender_was_blocked = ccid2_cwnd_network_limited(hctx); - struct dccp_ackvec_parsed *avp; u64 ackno, seqno; struct ccid2_seq *seqp; + unsigned char *vector; + unsigned char veclen; + int offset = 0; int done = 0; unsigned int maxincr = 0; + ccid2_hc_tx_check_sanity(hctx); /* check reverse path congestion */ seqno = DCCP_SKB_CB(skb)->dccpd_seq; @@ -407,21 +523,21 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) * -sorbo. */ /* need to bootstrap */ - if (hctx->rpdupack == -1) { - hctx->rpdupack = 0; - hctx->rpseq = seqno; + if (hctx->ccid2hctx_rpdupack == -1) { + hctx->ccid2hctx_rpdupack = 0; + hctx->ccid2hctx_rpseq = seqno; } else { /* check if packet is consecutive */ - if (dccp_delta_seqno(hctx->rpseq, seqno) == 1) - hctx->rpseq = seqno; + if (dccp_delta_seqno(hctx->ccid2hctx_rpseq, seqno) == 1) + hctx->ccid2hctx_rpseq = seqno; /* it's a later packet */ - else if (after48(seqno, hctx->rpseq)) { - hctx->rpdupack++; + else if (after48(seqno, hctx->ccid2hctx_rpseq)) { + hctx->ccid2hctx_rpdupack++; /* check if we got enough dupacks */ - if (hctx->rpdupack >= NUMDUPACK) { - hctx->rpdupack = -1; /* XXX lame */ - hctx->rpseq = 0; + if (hctx->ccid2hctx_rpdupack >= NUMDUPACK) { + hctx->ccid2hctx_rpdupack = -1; /* XXX lame */ + hctx->ccid2hctx_rpseq = 0; ccid2_change_l_ack_ratio(sk, 2 * dp->dccps_l_ack_ratio); } @@ -429,22 +545,27 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) } /* check forward path congestion */ - if (dccp_packet_without_ack(skb)) + /* still didn't send out new data packets */ + if (hctx->ccid2hctx_seqh == hctx->ccid2hctx_seqt) return; - /* still didn't send out new data packets */ - if (hctx->seqh == hctx->seqt) - goto done; + switch (DCCP_SKB_CB(skb)->dccpd_type) { + case DCCP_PKT_ACK: + case DCCP_PKT_DATAACK: + break; + default: + return; + } ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; - if (after48(ackno, hctx->high_ack)) - hctx->high_ack = ackno; + if (after48(ackno, hctx->ccid2hctx_high_ack)) + hctx->ccid2hctx_high_ack = ackno; - seqp = hctx->seqt; + seqp = hctx->ccid2hctx_seqt; while (before48(seqp->ccid2s_seq, ackno)) { seqp = seqp->ccid2s_next; - if (seqp == hctx->seqh) { - seqp = hctx->seqh->ccid2s_prev; + if (seqp == hctx->ccid2hctx_seqh) { + seqp = hctx->ccid2hctx_seqh->ccid2s_prev; break; } } @@ -454,26 +575,26 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) * packets per acknowledgement. Rounding up avoids that cwnd is not * advanced when Ack Ratio is 1 and gives a slight edge otherwise. */ - if (hctx->cwnd < hctx->ssthresh) + if (hctx->ccid2hctx_cwnd < hctx->ccid2hctx_ssthresh) maxincr = DIV_ROUND_UP(dp->dccps_l_ack_ratio, 2); /* go through all ack vectors */ - list_for_each_entry(avp, &hctx->av_chunks, node) { + while ((offset = ccid2_ackvector(sk, skb, offset, + &vector, &veclen)) != -1) { /* go through this ack vector */ - for (; avp->len--; avp->vec++) { - u64 ackno_end_rl = SUB48(ackno, - dccp_ackvec_runlen(avp->vec)); + while (veclen--) { + const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK; + u64 ackno_end_rl = SUB48(ackno, rl); - ccid2_pr_debug("ackvec %llu |%u,%u|\n", + ccid2_pr_debug("ackvec start:%llu end:%llu\n", (unsigned long long)ackno, - dccp_ackvec_state(avp->vec) >> 6, - dccp_ackvec_runlen(avp->vec)); + (unsigned long long)ackno_end_rl); /* if the seqno we are analyzing is larger than the * current ackno, then move towards the tail of our * seqnos. */ while (after48(seqp->ccid2s_seq, ackno)) { - if (seqp == hctx->seqt) { + if (seqp == hctx->ccid2hctx_seqt) { done = 1; break; } @@ -486,24 +607,26 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) * run length */ while (between48(seqp->ccid2s_seq,ackno_end_rl,ackno)) { - const u8 state = dccp_ackvec_state(avp->vec); + const u8 state = *vector & + DCCP_ACKVEC_STATE_MASK; /* new packet received or marked */ - if (state != DCCPAV_NOT_RECEIVED && + if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED && !seqp->ccid2s_acked) { - if (state == DCCPAV_ECN_MARKED) + if (state == + DCCP_ACKVEC_STATE_ECN_MARKED) { ccid2_congestion_event(sk, seqp); - else + } else ccid2_new_ack(sk, seqp, &maxincr); seqp->ccid2s_acked = 1; ccid2_pr_debug("Got ack for %llu\n", (unsigned long long)seqp->ccid2s_seq); - hctx->pipe--; + ccid2_hc_tx_dec_pipe(sk); } - if (seqp == hctx->seqt) { + if (seqp == hctx->ccid2hctx_seqt) { done = 1; break; } @@ -513,6 +636,7 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) break; ackno = SUB48(ackno_end_rl, 1); + vector++; } if (done) break; @@ -521,11 +645,11 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) /* The state about what is acked should be correct now * Check for NUMDUPACK */ - seqp = hctx->seqt; - while (before48(seqp->ccid2s_seq, hctx->high_ack)) { + seqp = hctx->ccid2hctx_seqt; + while (before48(seqp->ccid2s_seq, hctx->ccid2hctx_high_ack)) { seqp = seqp->ccid2s_next; - if (seqp == hctx->seqh) { - seqp = hctx->seqh->ccid2s_prev; + if (seqp == hctx->ccid2hctx_seqh) { + seqp = hctx->ccid2hctx_seqh->ccid2s_prev; break; } } @@ -536,7 +660,7 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) if (done == NUMDUPACK) break; } - if (seqp == hctx->seqt) + if (seqp == hctx->ccid2hctx_seqt) break; seqp = seqp->ccid2s_prev; } @@ -557,34 +681,25 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) * one ack vector. */ ccid2_congestion_event(sk, seqp); - hctx->pipe--; + ccid2_hc_tx_dec_pipe(sk); } - if (seqp == hctx->seqt) + if (seqp == hctx->ccid2hctx_seqt) break; seqp = seqp->ccid2s_prev; } - hctx->seqt = last_acked; + hctx->ccid2hctx_seqt = last_acked; } /* trim acked packets in tail */ - while (hctx->seqt != hctx->seqh) { - if (!hctx->seqt->ccid2s_acked) + while (hctx->ccid2hctx_seqt != hctx->ccid2hctx_seqh) { + if (!hctx->ccid2hctx_seqt->ccid2s_acked) break; - hctx->seqt = hctx->seqt->ccid2s_next; + hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqt->ccid2s_next; } - /* restart RTO timer if not all outstanding data has been acked */ - if (hctx->pipe == 0) - sk_stop_timer(sk, &hctx->rtotimer); - else - sk_reset_timer(sk, &hctx->rtotimer, jiffies + hctx->rto); -done: - /* check if incoming Acks allow pending packets to be sent */ - if (sender_was_blocked && !ccid2_cwnd_network_limited(hctx)) - tasklet_schedule(&dccp_sk(sk)->dccps_xmitlet); - dccp_ackvec_parsed_cleanup(&hctx->av_chunks); + ccid2_hc_tx_check_sanity(hctx); } static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) @@ -594,13 +709,17 @@ static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) u32 max_ratio; /* RFC 4341, 5: initialise ssthresh to arbitrarily high (max) value */ - hctx->ssthresh = ~0U; + hctx->ccid2hctx_ssthresh = ~0U; - /* Use larger initial windows (RFC 3390, rfc2581bis) */ - hctx->cwnd = rfc3390_bytes_to_packets(dp->dccps_mss_cache); + /* + * RFC 4341, 5: "The cwnd parameter is initialized to at most four + * packets for new connections, following the rules from [RFC3390]". + * We need to convert the bytes of RFC3390 into the packets of RFC 4341. + */ + hctx->ccid2hctx_cwnd = clamp(4380U / dp->dccps_mss_cache, 2U, 4U); /* Make sure that Ack Ratio is enabled and within bounds. */ - max_ratio = DIV_ROUND_UP(hctx->cwnd, 2); + max_ratio = DIV_ROUND_UP(hctx->ccid2hctx_cwnd, 2); if (dp->dccps_l_ack_ratio == 0 || dp->dccps_l_ack_ratio > max_ratio) dp->dccps_l_ack_ratio = max_ratio; @@ -608,11 +727,15 @@ static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) if (ccid2_hc_tx_alloc_seq(hctx)) return -ENOMEM; - hctx->rto = DCCP_TIMEOUT_INIT; - hctx->rpdupack = -1; - hctx->last_cong = jiffies; - setup_timer(&hctx->rtotimer, ccid2_hc_tx_rto_expire, (unsigned long)sk); - INIT_LIST_HEAD(&hctx->av_chunks); + hctx->ccid2hctx_rto = 3 * HZ; + ccid2_change_srtt(hctx, -1); + hctx->ccid2hctx_rttvar = -1; + hctx->ccid2hctx_rpdupack = -1; + hctx->ccid2hctx_last_cong = jiffies; + setup_timer(&hctx->ccid2hctx_rtotimer, ccid2_hc_tx_rto_expire, + (unsigned long)sk); + + ccid2_hc_tx_check_sanity(hctx); return 0; } @@ -621,11 +744,11 @@ static void ccid2_hc_tx_exit(struct sock *sk) struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); int i; - sk_stop_timer(sk, &hctx->rtotimer); + ccid2_hc_tx_kill_rto_timer(sk); - for (i = 0; i < hctx->seqbufc; i++) - kfree(hctx->seqbuf[i]); - hctx->seqbufc = 0; + for (i = 0; i < hctx->ccid2hctx_seqbufc; i++) + kfree(hctx->ccid2hctx_seqbuf[i]); + hctx->ccid2hctx_seqbufc = 0; } static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) @@ -636,28 +759,27 @@ static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) switch (DCCP_SKB_CB(skb)->dccpd_type) { case DCCP_PKT_DATA: case DCCP_PKT_DATAACK: - hcrx->data++; - if (hcrx->data >= dp->dccps_r_ack_ratio) { + hcrx->ccid2hcrx_data++; + if (hcrx->ccid2hcrx_data >= dp->dccps_r_ack_ratio) { dccp_send_ack(sk); - hcrx->data = 0; + hcrx->ccid2hcrx_data = 0; } break; } } static struct ccid_operations ccid2 = { - .ccid_id = DCCPC_CCID2, - .ccid_name = "TCP-like", - .ccid_owner = THIS_MODULE, - .ccid_hc_tx_obj_size = sizeof(struct ccid2_hc_tx_sock), - .ccid_hc_tx_init = ccid2_hc_tx_init, - .ccid_hc_tx_exit = ccid2_hc_tx_exit, - .ccid_hc_tx_send_packet = ccid2_hc_tx_send_packet, - .ccid_hc_tx_packet_sent = ccid2_hc_tx_packet_sent, - .ccid_hc_tx_parse_options = ccid2_hc_tx_parse_options, - .ccid_hc_tx_packet_recv = ccid2_hc_tx_packet_recv, - .ccid_hc_rx_obj_size = sizeof(struct ccid2_hc_rx_sock), - .ccid_hc_rx_packet_recv = ccid2_hc_rx_packet_recv, + .ccid_id = DCCPC_CCID2, + .ccid_name = "TCP-like", + .ccid_owner = THIS_MODULE, + .ccid_hc_tx_obj_size = sizeof(struct ccid2_hc_tx_sock), + .ccid_hc_tx_init = ccid2_hc_tx_init, + .ccid_hc_tx_exit = ccid2_hc_tx_exit, + .ccid_hc_tx_send_packet = ccid2_hc_tx_send_packet, + .ccid_hc_tx_packet_sent = ccid2_hc_tx_packet_sent, + .ccid_hc_tx_packet_recv = ccid2_hc_tx_packet_recv, + .ccid_hc_rx_obj_size = sizeof(struct ccid2_hc_rx_sock), + .ccid_hc_rx_packet_recv = ccid2_hc_rx_packet_recv, }; #ifdef CONFIG_IP_DCCP_CCID2_DEBUG diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h index 8b7a2dee2f6..2c94ca02901 100644 --- a/net/dccp/ccids/ccid2.h +++ b/net/dccp/ccids/ccid2.h @@ -42,49 +42,34 @@ struct ccid2_seq { /** struct ccid2_hc_tx_sock - CCID2 TX half connection * - * @{cwnd,ssthresh,pipe}: as per RFC 4341, section 5 - * @packets_acked: Ack counter for deriving cwnd growth (RFC 3465) - * @srtt: smoothed RTT estimate, scaled by 2^3 - * @mdev: smoothed RTT variation, scaled by 2^2 - * @mdev_max: maximum of @mdev during one flight - * @rttvar: moving average/maximum of @mdev_max - * @rto: RTO value deriving from SRTT and RTTVAR (RFC 2988) - * @rtt_seq: to decay RTTVAR at most once per flight - * @rpseq: last consecutive seqno - * @rpdupack: dupacks since rpseq - * @av_chunks: list of Ack Vectors received on current skb - */ + * @ccid2hctx_{cwnd,ssthresh,pipe}: as per RFC 4341, section 5 + * @ccid2hctx_packets_acked - Ack counter for deriving cwnd growth (RFC 3465) + * @ccid2hctx_lastrtt -time RTT was last measured + * @ccid2hctx_rpseq - last consecutive seqno + * @ccid2hctx_rpdupack - dupacks since rpseq +*/ struct ccid2_hc_tx_sock { - u32 cwnd; - u32 ssthresh; - u32 pipe; - u32 packets_acked; - struct ccid2_seq *seqbuf[CCID2_SEQBUF_MAX]; - int seqbufc; - struct ccid2_seq *seqh; - struct ccid2_seq *seqt; - /* RTT measurement: variables/principles are the same as in TCP */ - u32 srtt, - mdev, - mdev_max, - rttvar, - rto; - u64 rtt_seq:48; - struct timer_list rtotimer; - u64 rpseq; - int rpdupack; - unsigned long last_cong; - u64 high_ack; - struct list_head av_chunks; + u32 ccid2hctx_cwnd; + u32 ccid2hctx_ssthresh; + u32 ccid2hctx_pipe; + u32 ccid2hctx_packets_acked; + struct ccid2_seq *ccid2hctx_seqbuf[CCID2_SEQBUF_MAX]; + int ccid2hctx_seqbufc; + struct ccid2_seq *ccid2hctx_seqh; + struct ccid2_seq *ccid2hctx_seqt; + long ccid2hctx_rto; + long ccid2hctx_srtt; + long ccid2hctx_rttvar; + unsigned long ccid2hctx_lastrtt; + struct timer_list ccid2hctx_rtotimer; + u64 ccid2hctx_rpseq; + int ccid2hctx_rpdupack; + unsigned long ccid2hctx_last_cong; + u64 ccid2hctx_high_ack; }; -static inline bool ccid2_cwnd_network_limited(struct ccid2_hc_tx_sock *hctx) -{ - return (hctx->pipe >= hctx->cwnd); -} - struct ccid2_hc_rx_sock { - int data; + int ccid2hcrx_data; }; static inline struct ccid2_hc_tx_sock *ccid2_hc_tx_sk(const struct sock *sk) diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index 06cfdad84a6..3b8bd7ca676 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -49,41 +49,75 @@ static int ccid3_debug; /* * Transmitter Half-Connection Routines */ -/* Oscillation Prevention/Reduction: recommended by rfc3448bis, on by default */ -static int do_osc_prev = true; +#ifdef CONFIG_IP_DCCP_CCID3_DEBUG +static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state) +{ + static char *ccid3_state_names[] = { + [TFRC_SSTATE_NO_SENT] = "NO_SENT", + [TFRC_SSTATE_NO_FBACK] = "NO_FBACK", + [TFRC_SSTATE_FBACK] = "FBACK", + [TFRC_SSTATE_TERM] = "TERM", + }; + + return ccid3_state_names[state]; +} +#endif + +static void ccid3_hc_tx_set_state(struct sock *sk, + enum ccid3_hc_tx_states state) +{ + struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); + enum ccid3_hc_tx_states oldstate = hctx->ccid3hctx_state; + + ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", + dccp_role(sk), sk, ccid3_tx_state_name(oldstate), + ccid3_tx_state_name(state)); + WARN_ON(state == oldstate); + hctx->ccid3hctx_state = state; +} /* * Compute the initial sending rate X_init in the manner of RFC 3390: * - * X_init = min(4 * MPS, max(2 * MPS, 4380 bytes)) / RTT + * X_init = min(4 * s, max(2 * s, 4380 bytes)) / RTT * + * Note that RFC 3390 uses MSS, RFC 4342 refers to RFC 3390, and rfc3448bis + * (rev-02) clarifies the use of RFC 3390 with regard to the above formula. * For consistency with other parts of the code, X_init is scaled by 2^6. */ static inline u64 rfc3390_initial_rate(struct sock *sk) { - const u32 mps = dccp_sk(sk)->dccps_mss_cache, - w_init = clamp(4380U, 2 * mps, 4 * mps); + const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); + const __u32 w_init = clamp_t(__u32, 4380U, + 2 * hctx->ccid3hctx_s, 4 * hctx->ccid3hctx_s); - return scaled_div(w_init << 6, ccid3_hc_tx_sk(sk)->rtt); + return scaled_div(w_init << 6, hctx->ccid3hctx_rtt); } -/** - * ccid3_update_send_interval - Calculate new t_ipi = s / X - * This respects the granularity of X (64 * bytes/second) and enforces the - * scaled minimum of s * 64 / t_mbi = `s' bytes/second as per RFC 3448/4342. +/* + * Recalculate t_ipi and delta (should be called whenever X changes) */ static void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hctx) { - if (unlikely(hctx->x <= hctx->s)) - hctx->x = hctx->s; - hctx->t_ipi = scaled_div32(((u64)hctx->s) << 6, hctx->x); + /* Calculate new t_ipi = s / X_inst (X_inst is in 64 * bytes/second) */ + hctx->ccid3hctx_t_ipi = scaled_div32(((u64)hctx->ccid3hctx_s) << 6, + hctx->ccid3hctx_x); + + /* Calculate new delta by delta = min(t_ipi / 2, t_gran / 2) */ + hctx->ccid3hctx_delta = min_t(u32, hctx->ccid3hctx_t_ipi / 2, + TFRC_OPSYS_HALF_TIME_GRAN); + + ccid3_pr_debug("t_ipi=%u, delta=%u, s=%u, X=%u\n", + hctx->ccid3hctx_t_ipi, hctx->ccid3hctx_delta, + hctx->ccid3hctx_s, (unsigned)(hctx->ccid3hctx_x >> 6)); + } static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hctx, ktime_t now) { - u32 delta = ktime_us_delta(now, hctx->t_last_win_count); + u32 delta = ktime_us_delta(now, hctx->ccid3hctx_t_last_win_count); - return delta / hctx->rtt; + return delta / hctx->ccid3hctx_rtt; } /** @@ -99,8 +133,8 @@ static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hctx, ktime_t now) static void ccid3_hc_tx_update_x(struct sock *sk, ktime_t *stamp) { struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - u64 min_rate = 2 * hctx->x_recv; - const u64 old_x = hctx->x; + __u64 min_rate = 2 * hctx->ccid3hctx_x_recv; + const __u64 old_x = hctx->ccid3hctx_x; ktime_t now = stamp ? *stamp : ktime_get_real(); /* @@ -111,44 +145,50 @@ static void ccid3_hc_tx_update_x(struct sock *sk, ktime_t *stamp) */ if (ccid3_hc_tx_idle_rtt(hctx, now) >= 2) { min_rate = rfc3390_initial_rate(sk); - min_rate = max(min_rate, 2 * hctx->x_recv); + min_rate = max(min_rate, 2 * hctx->ccid3hctx_x_recv); } - if (hctx->p > 0) { + if (hctx->ccid3hctx_p > 0) { - hctx->x = min(((u64)hctx->x_calc) << 6, min_rate); + hctx->ccid3hctx_x = min(((__u64)hctx->ccid3hctx_x_calc) << 6, + min_rate); + hctx->ccid3hctx_x = max(hctx->ccid3hctx_x, + (((__u64)hctx->ccid3hctx_s) << 6) / + TFRC_T_MBI); - } else if (ktime_us_delta(now, hctx->t_ld) - (s64)hctx->rtt >= 0) { + } else if (ktime_us_delta(now, hctx->ccid3hctx_t_ld) + - (s64)hctx->ccid3hctx_rtt >= 0) { - hctx->x = min(2 * hctx->x, min_rate); - hctx->x = max(hctx->x, - scaled_div(((u64)hctx->s) << 6, hctx->rtt)); - hctx->t_ld = now; + hctx->ccid3hctx_x = min(2 * hctx->ccid3hctx_x, min_rate); + hctx->ccid3hctx_x = max(hctx->ccid3hctx_x, + scaled_div(((__u64)hctx->ccid3hctx_s) << 6, + hctx->ccid3hctx_rtt)); + hctx->ccid3hctx_t_ld = now; } - if (hctx->x != old_x) { + if (hctx->ccid3hctx_x != old_x) { ccid3_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, " "X_recv=%u\n", (unsigned)(old_x >> 6), - (unsigned)(hctx->x >> 6), hctx->x_calc, - (unsigned)(hctx->x_recv >> 6)); + (unsigned)(hctx->ccid3hctx_x >> 6), + hctx->ccid3hctx_x_calc, + (unsigned)(hctx->ccid3hctx_x_recv >> 6)); ccid3_update_send_interval(hctx); } } /* - * ccid3_hc_tx_measure_packet_size - Measuring the packet size `s' (sec 4.1) - * @new_len: DCCP payload size in bytes (not used by all methods) + * Track the mean packet size `s' (cf. RFC 4342, 5.3 and RFC 3448, 4.1) + * @len: DCCP packet payload size in bytes */ -static u32 ccid3_hc_tx_measure_packet_size(struct sock *sk, const u16 new_len) +static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hctx, int len) { -#if defined(CONFIG_IP_DCCP_CCID3_MEASURE_S_AS_AVG) - return tfrc_ewma(ccid3_hc_tx_sk(sk)->s, new_len, 9); -#elif defined(CONFIG_IP_DCCP_CCID3_MEASURE_S_AS_MAX) - return max(ccid3_hc_tx_sk(sk)->s, new_len); -#else /* CONFIG_IP_DCCP_CCID3_MEASURE_S_AS_MPS */ - return dccp_sk(sk)->dccps_mss_cache; -#endif + const u16 old_s = hctx->ccid3hctx_s; + + hctx->ccid3hctx_s = tfrc_ewma(hctx->ccid3hctx_s, len, 9); + + if (hctx->ccid3hctx_s != old_s) + ccid3_update_send_interval(hctx); } /* @@ -158,13 +198,13 @@ static u32 ccid3_hc_tx_measure_packet_size(struct sock *sk, const u16 new_len) static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hctx, ktime_t now) { - u32 delta = ktime_us_delta(now, hctx->t_last_win_count), - quarter_rtts = (4 * delta) / hctx->rtt; + u32 delta = ktime_us_delta(now, hctx->ccid3hctx_t_last_win_count), + quarter_rtts = (4 * delta) / hctx->ccid3hctx_rtt; if (quarter_rtts > 0) { - hctx->t_last_win_count = now; - hctx->last_win_count += min(quarter_rtts, 5U); - hctx->last_win_count &= 0xF; /* mod 16 */ + hctx->ccid3hctx_t_last_win_count = now; + hctx->ccid3hctx_last_win_count += min(quarter_rtts, 5U); + hctx->ccid3hctx_last_win_count &= 0xF; /* mod 16 */ } } @@ -181,26 +221,25 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data) goto restart_timer; } - ccid3_pr_debug("%s(%p) entry with%s feedback\n", dccp_role(sk), sk, - hctx->feedback ? "" : "out"); + ccid3_pr_debug("%s(%p, state=%s) - entry \n", dccp_role(sk), sk, + ccid3_tx_state_name(hctx->ccid3hctx_state)); - /* Ignore and do not restart after leaving the established state */ - if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN)) + if (hctx->ccid3hctx_state == TFRC_SSTATE_FBACK) + ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); + else if (hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK) goto out; - /* Reset feedback state to "no feedback received" */ - hctx->feedback = false; - /* * Determine new allowed sending rate X as per draft rfc3448bis-00, 4.4 - * RTO is 0 if and only if no feedback has been received yet. */ - if (hctx->t_rto == 0 || hctx->p == 0) { + if (hctx->ccid3hctx_t_rto == 0 || /* no feedback received yet */ + hctx->ccid3hctx_p == 0) { /* halve send rate directly */ - hctx->x /= 2; + hctx->ccid3hctx_x = max(hctx->ccid3hctx_x / 2, + (((__u64)hctx->ccid3hctx_s) << 6) / + TFRC_T_MBI); ccid3_update_send_interval(hctx); - } else { /* * Modify the cached value of X_recv @@ -212,41 +251,44 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data) * * Note that X_recv is scaled by 2^6 while X_calc is not */ - BUG_ON(hctx->p && !hctx->x_calc); + BUG_ON(hctx->ccid3hctx_p && !hctx->ccid3hctx_x_calc); - if (hctx->x_calc > (hctx->x_recv >> 5)) - hctx->x_recv /= 2; + if (hctx->ccid3hctx_x_calc > (hctx->ccid3hctx_x_recv >> 5)) + hctx->ccid3hctx_x_recv = + max(hctx->ccid3hctx_x_recv / 2, + (((__u64)hctx->ccid3hctx_s) << 6) / + (2 * TFRC_T_MBI)); else { - hctx->x_recv = hctx->x_calc; - hctx->x_recv <<= 4; + hctx->ccid3hctx_x_recv = hctx->ccid3hctx_x_calc; + hctx->ccid3hctx_x_recv <<= 4; } ccid3_hc_tx_update_x(sk, NULL); } ccid3_pr_debug("Reduced X to %llu/64 bytes/sec\n", - (unsigned long long)hctx->x); + (unsigned long long)hctx->ccid3hctx_x); /* * Set new timeout for the nofeedback timer. * See comments in packet_recv() regarding the value of t_RTO. */ - if (unlikely(hctx->t_rto == 0)) /* no feedback received yet */ + if (unlikely(hctx->ccid3hctx_t_rto == 0)) /* no feedback yet */ t_nfb = TFRC_INITIAL_TIMEOUT; else - t_nfb = max(hctx->t_rto, 2 * hctx->t_ipi); + t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi); restart_timer: - sk_reset_timer(sk, &hctx->no_feedback_timer, + sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, jiffies + usecs_to_jiffies(t_nfb)); out: bh_unlock_sock(sk); sock_put(sk); } -/** - * ccid3_hc_tx_send_packet - Delay-based dequeueing of TX packets - * @skb: next packet candidate to send on @sk - * This function uses the convention of ccid_packet_dequeue_eval() and - * returns a millisecond-delay value between 0 and t_mbi = 64000 msec. +/* + * returns + * > 0: delay (in msecs) that should pass before actually sending + * = 0: can send immediately + * < 0: error condition; do not send packet */ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) { @@ -263,14 +305,18 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) if (unlikely(skb->len == 0)) return -EBADMSG; - if (hctx->s == 0) { - sk_reset_timer(sk, &hctx->no_feedback_timer, (jiffies + + switch (hctx->ccid3hctx_state) { + case TFRC_SSTATE_NO_SENT: + sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, + (jiffies + usecs_to_jiffies(TFRC_INITIAL_TIMEOUT))); - hctx->last_win_count = 0; - hctx->t_last_win_count = now; + hctx->ccid3hctx_last_win_count = 0; + hctx->ccid3hctx_t_last_win_count = now; /* Set t_0 for initial packet */ - hctx->t_nom = now; + hctx->ccid3hctx_t_nom = now; + + hctx->ccid3hctx_s = skb->len; /* * Use initial RTT sample when available: recommended by erratum @@ -279,9 +325,9 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) */ if (dp->dccps_syn_rtt) { ccid3_pr_debug("SYN RTT = %uus\n", dp->dccps_syn_rtt); - hctx->rtt = dp->dccps_syn_rtt; - hctx->x = rfc3390_initial_rate(sk); - hctx->t_ld = now; + hctx->ccid3hctx_rtt = dp->dccps_syn_rtt; + hctx->ccid3hctx_x = rfc3390_initial_rate(sk); + hctx->ccid3hctx_t_ld = now; } else { /* * Sender does not have RTT sample: @@ -289,20 +335,17 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) * is needed in several parts (e.g. window counter); * - set sending rate X_pps = 1pps as per RFC 3448, 4.2. */ - hctx->rtt = DCCP_FALLBACK_RTT; - hctx->x = dp->dccps_mss_cache; - hctx->x <<= 6; + hctx->ccid3hctx_rtt = DCCP_FALLBACK_RTT; + hctx->ccid3hctx_x = hctx->ccid3hctx_s; + hctx->ccid3hctx_x <<= 6; } - - /* Compute t_ipi = s / X */ - hctx->s = ccid3_hc_tx_measure_packet_size(sk, skb->len); ccid3_update_send_interval(hctx); - /* Seed value for Oscillation Prevention (sec. 4.5) */ - hctx->r_sqmean = tfrc_scaled_sqrt(hctx->rtt); - - } else { - delay = ktime_us_delta(hctx->t_nom, now); + ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); + break; + case TFRC_SSTATE_NO_FBACK: + case TFRC_SSTATE_FBACK: + delay = ktime_us_delta(hctx->ccid3hctx_t_nom, now); ccid3_pr_debug("delay=%ld\n", (long)delay); /* * Scheduling of packet transmissions [RFC 3448, 4.6] @@ -312,80 +355,99 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) * else * // send the packet in (t_nom - t_now) milliseconds. */ - if (delay >= TFRC_T_DELTA) - return (u32)delay / USEC_PER_MSEC; + if (delay - (s64)hctx->ccid3hctx_delta >= 1000) + return (u32)delay / 1000L; ccid3_hc_tx_update_win_count(hctx, now); + break; + case TFRC_SSTATE_TERM: + DCCP_BUG("%s(%p) - Illegal state TERM", dccp_role(sk), sk); + return -EINVAL; } /* prepare to send now (add options etc.) */ dp->dccps_hc_tx_insert_options = 1; - DCCP_SKB_CB(skb)->dccpd_ccval = hctx->last_win_count; + DCCP_SKB_CB(skb)->dccpd_ccval = hctx->ccid3hctx_last_win_count; /* set the nominal send time for the next following packet */ - hctx->t_nom = ktime_add_us(hctx->t_nom, hctx->t_ipi); - return CCID_PACKET_SEND_AT_ONCE; + hctx->ccid3hctx_t_nom = ktime_add_us(hctx->ccid3hctx_t_nom, + hctx->ccid3hctx_t_ipi); + return 0; } -static void ccid3_hc_tx_packet_sent(struct sock *sk, unsigned int len) +static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, + unsigned int len) { struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - /* Changes to s will become effective the next time X is computed */ - hctx->s = ccid3_hc_tx_measure_packet_size(sk, len); + ccid3_hc_tx_update_s(hctx, len); - if (tfrc_tx_hist_add(&hctx->hist, dccp_sk(sk)->dccps_gss)) + if (tfrc_tx_hist_add(&hctx->ccid3hctx_hist, dccp_sk(sk)->dccps_gss)) DCCP_CRIT("packet history - out of memory!"); } static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) { struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - struct tfrc_tx_hist_entry *acked; + struct ccid3_options_received *opt_recv; ktime_t now; unsigned long t_nfb; - u32 r_sample; + u32 pinv, r_sample; /* we are only interested in ACKs */ if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK || DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK)) return; - /* - * Locate the acknowledged packet in the TX history. - * - * Returning "entry not found" here can for instance happen when - * - the host has not sent out anything (e.g. a passive server), - * - the Ack is outdated (packet with higher Ack number was received), - * - it is a bogus Ack (for a packet not sent on this connection). - */ - acked = tfrc_tx_hist_find_entry(hctx->hist, dccp_hdr_ack_seq(skb)); - if (acked == NULL) + /* ... and only in the established state */ + if (hctx->ccid3hctx_state != TFRC_SSTATE_FBACK && + hctx->ccid3hctx_state != TFRC_SSTATE_NO_FBACK) + return; + + opt_recv = &hctx->ccid3hctx_options_received; + now = ktime_get_real(); + + /* Estimate RTT from history if ACK number is valid */ + r_sample = tfrc_tx_hist_rtt(hctx->ccid3hctx_hist, + DCCP_SKB_CB(skb)->dccpd_ack_seq, now); + if (r_sample == 0) { + DCCP_WARN("%s(%p): %s with bogus ACK-%llu\n", dccp_role(sk), sk, + dccp_packet_name(DCCP_SKB_CB(skb)->dccpd_type), + (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq); return; - /* For the sake of RTT sampling, ignore/remove all older entries */ - tfrc_tx_hist_purge(&acked->next); + } - /* Update the moving average for the RTT estimate (RFC 3448, 4.3) */ - now = ktime_get_real(); - r_sample = dccp_sample_rtt(sk, ktime_us_delta(now, acked->stamp)); - hctx->rtt = tfrc_ewma(hctx->rtt, r_sample, 9); + /* Update receive rate in units of 64 * bytes/second */ + hctx->ccid3hctx_x_recv = opt_recv->ccid3or_receive_rate; + hctx->ccid3hctx_x_recv <<= 6; + /* Update loss event rate (which is scaled by 1e6) */ + pinv = opt_recv->ccid3or_loss_event_rate; + if (pinv == ~0U || pinv == 0) /* see RFC 4342, 8.5 */ + hctx->ccid3hctx_p = 0; + else /* can not exceed 100% */ + hctx->ccid3hctx_p = scaled_div(1, pinv); + /* + * Validate new RTT sample and update moving average + */ + r_sample = dccp_sample_rtt(sk, r_sample); + hctx->ccid3hctx_rtt = tfrc_ewma(hctx->ccid3hctx_rtt, r_sample, 9); /* * Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3 */ - if (!hctx->feedback) { - hctx->feedback = true; + if (hctx->ccid3hctx_state == TFRC_SSTATE_NO_FBACK) { + ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); - if (hctx->t_rto == 0) { + if (hctx->ccid3hctx_t_rto == 0) { /* * Initial feedback packet: Larger Initial Windows (4.2) */ - hctx->x = rfc3390_initial_rate(sk); - hctx->t_ld = now; + hctx->ccid3hctx_x = rfc3390_initial_rate(sk); + hctx->ccid3hctx_t_ld = now; ccid3_update_send_interval(hctx); goto done_computing_x; - } else if (hctx->p == 0) { + } else if (hctx->ccid3hctx_p == 0) { /* * First feedback after nofeedback timer expiry (4.3) */ @@ -394,52 +456,25 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) } /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ - if (hctx->p > 0) - hctx->x_calc = tfrc_calc_x(hctx->s, hctx->rtt, hctx->p); + if (hctx->ccid3hctx_p > 0) + hctx->ccid3hctx_x_calc = + tfrc_calc_x(hctx->ccid3hctx_s, + hctx->ccid3hctx_rtt, + hctx->ccid3hctx_p); ccid3_hc_tx_update_x(sk, &now); done_computing_x: ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, " "p=%u, X_calc=%u, X_recv=%u, X=%u\n", - dccp_role(sk), sk, hctx->rtt, r_sample, - hctx->s, hctx->p, hctx->x_calc, - (unsigned)(hctx->x_recv >> 6), - (unsigned)(hctx->x >> 6)); - /* - * Oscillation Reduction (RFC 3448, 4.5) - modifying t_ipi according to - * RTT changes, multiplying by X/X_inst = sqrt(R_sample)/R_sqmean. This - * can be useful if few connections share a link, avoiding that buffer - * fill levels (RTT) oscillate as a result of frequent adjustments to X. - * A useful presentation with background information is in - * Joerg Widmer, "Equation-Based Congestion Control", - * MSc Thesis, University of Mannheim, Germany, 2000 - * (sec. 3.6.4), who calls this ISM ("Inter-packet Space Modulation"). - */ - if (do_osc_prev) { - r_sample = tfrc_scaled_sqrt(r_sample); - /* - * The modulation can work in both ways: increase/decrease t_ipi - * according to long-term increases/decreases of the RTT. The - * former is a useful measure, since it works against queue - * build-up. The latter temporarily increases the sending rate, - * so that buffers fill up more quickly. This in turn causes - * the RTT to increase, so that either later reduction becomes - * necessary or the RTT stays at a very high level. Decreasing - * t_ipi is therefore not supported. - * Furthermore, during the initial slow-start phase the RTT - * naturally increases, where using the algorithm would cause - * delays. Hence it is disabled during the initial slow-start. - */ - if (r_sample > hctx->r_sqmean && hctx->p > 0) - hctx->t_ipi = div_u64((u64)hctx->t_ipi * (u64)r_sample, - hctx->r_sqmean); - hctx->t_ipi = min_t(u32, hctx->t_ipi, TFRC_T_MBI); - /* update R_sqmean _after_ computing the modulation factor */ - hctx->r_sqmean = tfrc_ewma(hctx->r_sqmean, r_sample, 9); - } + dccp_role(sk), + sk, hctx->ccid3hctx_rtt, r_sample, + hctx->ccid3hctx_s, hctx->ccid3hctx_p, + hctx->ccid3hctx_x_calc, + (unsigned)(hctx->ccid3hctx_x_recv >> 6), + (unsigned)(hctx->ccid3hctx_x >> 6)); /* unschedule no feedback timer */ - sk_stop_timer(sk, &hctx->no_feedback_timer); + sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); /* * As we have calculated new ipi, delta, t_nom it is possible @@ -453,66 +488,95 @@ done_computing_x: * This can help avoid triggering the nofeedback timer too * often ('spinning') on LANs with small RTTs. */ - hctx->t_rto = max_t(u32, 4 * hctx->rtt, (CONFIG_IP_DCCP_CCID3_RTO * - (USEC_PER_SEC / 1000))); + hctx->ccid3hctx_t_rto = max_t(u32, 4 * hctx->ccid3hctx_rtt, + (CONFIG_IP_DCCP_CCID3_RTO * + (USEC_PER_SEC / 1000))); /* * Schedule no feedback timer to expire in * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) */ - t_nfb = max(hctx->t_rto, 2 * hctx->t_ipi); + t_nfb = max(hctx->ccid3hctx_t_rto, 2 * hctx->ccid3hctx_t_ipi); ccid3_pr_debug("%s(%p), Scheduled no feedback timer to " "expire in %lu jiffies (%luus)\n", - dccp_role(sk), sk, usecs_to_jiffies(t_nfb), t_nfb); + dccp_role(sk), + sk, usecs_to_jiffies(t_nfb), t_nfb); - sk_reset_timer(sk, &hctx->no_feedback_timer, + sk_reset_timer(sk, &hctx->ccid3hctx_no_feedback_timer, jiffies + usecs_to_jiffies(t_nfb)); } -static int ccid3_hc_tx_parse_options(struct sock *sk, u8 packet_type, - u8 option, u8 *optval, u8 optlen) +static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option, + unsigned char len, u16 idx, + unsigned char *value) { + int rc = 0; + const struct dccp_sock *dp = dccp_sk(sk); struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); + struct ccid3_options_received *opt_recv; __be32 opt_val; - switch (option) { - case TFRC_OPT_RECEIVE_RATE: - case TFRC_OPT_LOSS_EVENT_RATE: - /* Must be ignored on Data packets, cf. RFC 4342 8.3 and 8.5 */ - if (packet_type == DCCP_PKT_DATA) - break; - if (unlikely(optlen != 4)) { - DCCP_WARN("%s(%p), invalid len %d for %u\n", - dccp_role(sk), sk, optlen, option); - return -EINVAL; - } - opt_val = ntohl(get_unaligned((__be32 *)optval)); + opt_recv = &hctx->ccid3hctx_options_received; - if (option == TFRC_OPT_RECEIVE_RATE) { - /* Receive Rate is kept in units of 64 bytes/second */ - hctx->x_recv = opt_val; - hctx->x_recv <<= 6; + if (opt_recv->ccid3or_seqno != dp->dccps_gsr) { + opt_recv->ccid3or_seqno = dp->dccps_gsr; + opt_recv->ccid3or_loss_event_rate = ~0; + opt_recv->ccid3or_loss_intervals_idx = 0; + opt_recv->ccid3or_loss_intervals_len = 0; + opt_recv->ccid3or_receive_rate = 0; + } - ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n", - dccp_role(sk), sk, opt_val); + switch (option) { + case TFRC_OPT_LOSS_EVENT_RATE: + if (unlikely(len != 4)) { + DCCP_WARN("%s(%p), invalid len %d " + "for TFRC_OPT_LOSS_EVENT_RATE\n", + dccp_role(sk), sk, len); + rc = -EINVAL; } else { - /* Update the fixpoint Loss Event Rate fraction */ - hctx->p = tfrc_invert_loss_event_rate(opt_val); - + opt_val = get_unaligned((__be32 *)value); + opt_recv->ccid3or_loss_event_rate = ntohl(opt_val); ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n", - dccp_role(sk), sk, opt_val); + dccp_role(sk), sk, + opt_recv->ccid3or_loss_event_rate); } + break; + case TFRC_OPT_LOSS_INTERVALS: + opt_recv->ccid3or_loss_intervals_idx = idx; + opt_recv->ccid3or_loss_intervals_len = len; + ccid3_pr_debug("%s(%p), LOSS_INTERVALS=(%u, %u)\n", + dccp_role(sk), sk, + opt_recv->ccid3or_loss_intervals_idx, + opt_recv->ccid3or_loss_intervals_len); + break; + case TFRC_OPT_RECEIVE_RATE: + if (unlikely(len != 4)) { + DCCP_WARN("%s(%p), invalid len %d " + "for TFRC_OPT_RECEIVE_RATE\n", + dccp_role(sk), sk, len); + rc = -EINVAL; + } else { + opt_val = get_unaligned((__be32 *)value); + opt_recv->ccid3or_receive_rate = ntohl(opt_val); + ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n", + dccp_role(sk), sk, + opt_recv->ccid3or_receive_rate); + } + break; } - return 0; + + return rc; } static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk) { struct ccid3_hc_tx_sock *hctx = ccid_priv(ccid); - hctx->hist = NULL; - setup_timer(&hctx->no_feedback_timer, - ccid3_hc_tx_no_feedback_timer, (unsigned long)sk); + hctx->ccid3hctx_state = TFRC_SSTATE_NO_SENT; + hctx->ccid3hctx_hist = NULL; + setup_timer(&hctx->ccid3hctx_no_feedback_timer, + ccid3_hc_tx_no_feedback_timer, (unsigned long)sk); + return 0; } @@ -520,36 +584,42 @@ static void ccid3_hc_tx_exit(struct sock *sk) { struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - sk_stop_timer(sk, &hctx->no_feedback_timer); - tfrc_tx_hist_purge(&hctx->hist); + ccid3_hc_tx_set_state(sk, TFRC_SSTATE_TERM); + sk_stop_timer(sk, &hctx->ccid3hctx_no_feedback_timer); + + tfrc_tx_hist_purge(&hctx->ccid3hctx_hist); } static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info) { - info->tcpi_rto = ccid3_hc_tx_sk(sk)->t_rto; - info->tcpi_rtt = ccid3_hc_tx_sk(sk)->rtt; + struct ccid3_hc_tx_sock *hctx; + + /* Listen socks doesn't have a private CCID block */ + if (sk->sk_state == DCCP_LISTEN) + return; + + hctx = ccid3_hc_tx_sk(sk); + info->tcpi_rto = hctx->ccid3hctx_t_rto; + info->tcpi_rtt = hctx->ccid3hctx_rtt; } static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len, u32 __user *optval, int __user *optlen) { - const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk); - struct tfrc_tx_info tfrc; + const struct ccid3_hc_tx_sock *hctx; const void *val; + /* Listen socks doesn't have a private CCID block */ + if (sk->sk_state == DCCP_LISTEN) + return -EINVAL; + + hctx = ccid3_hc_tx_sk(sk); switch (optname) { case DCCP_SOCKOPT_CCID_TX_INFO: - if (len < sizeof(tfrc)) + if (len < sizeof(hctx->ccid3hctx_tfrc)) return -EINVAL; - tfrc.tfrctx_x = hctx->x; - tfrc.tfrctx_x_recv = hctx->x_recv; - tfrc.tfrctx_x_calc = hctx->x_calc; - tfrc.tfrctx_rtt = hctx->rtt; - tfrc.tfrctx_p = hctx->p; - tfrc.tfrctx_rto = hctx->t_rto; - tfrc.tfrctx_ipi = hctx->t_ipi; - len = sizeof(tfrc); - val = &tfrc; + len = sizeof(hctx->ccid3hctx_tfrc); + val = &hctx->ccid3hctx_tfrc; break; default: return -ENOPROTOOPT; @@ -564,82 +634,112 @@ static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len, /* * Receiver Half-Connection Routines */ + +/* CCID3 feedback types */ +enum ccid3_fback_type { + CCID3_FBACK_NONE = 0, + CCID3_FBACK_INITIAL, + CCID3_FBACK_PERIODIC, + CCID3_FBACK_PARAM_CHANGE +}; + +#ifdef CONFIG_IP_DCCP_CCID3_DEBUG +static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state) +{ + static char *ccid3_rx_state_names[] = { + [TFRC_RSTATE_NO_DATA] = "NO_DATA", + [TFRC_RSTATE_DATA] = "DATA", + [TFRC_RSTATE_TERM] = "TERM", + }; + + return ccid3_rx_state_names[state]; +} +#endif + +static void ccid3_hc_rx_set_state(struct sock *sk, + enum ccid3_hc_rx_states state) +{ + struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); + enum ccid3_hc_rx_states oldstate = hcrx->ccid3hcrx_state; + + ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", + dccp_role(sk), sk, ccid3_rx_state_name(oldstate), + ccid3_rx_state_name(state)); + WARN_ON(state == oldstate); + hcrx->ccid3hcrx_state = state; +} + static void ccid3_hc_rx_send_feedback(struct sock *sk, const struct sk_buff *skb, enum ccid3_fback_type fbtype) { struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); + struct dccp_sock *dp = dccp_sk(sk); + ktime_t now; + s64 delta = 0; + + if (unlikely(hcrx->ccid3hcrx_state == TFRC_RSTATE_TERM)) + return; + + now = ktime_get_real(); switch (fbtype) { case CCID3_FBACK_INITIAL: - hcrx->x_recv = 0; - hcrx->p_inverse = ~0U; /* see RFC 4342, 8.5 */ + hcrx->ccid3hcrx_x_recv = 0; + hcrx->ccid3hcrx_pinv = ~0U; /* see RFC 4342, 8.5 */ break; case CCID3_FBACK_PARAM_CHANGE: - if (unlikely(hcrx->feedback == CCID3_FBACK_NONE)) { - /* - * rfc3448bis-06, 6.3.1: First packet(s) lost or marked - * FIXME: in rfc3448bis the receiver returns X_recv=0 - * here as it normally would in the first feedback packet. - * However this is not possible yet, since the code still - * uses RFC 3448, i.e. - * If (p > 0) - * Calculate X_calc using the TCP throughput equation. - * X = max(min(X_calc, 2*X_recv), s/t_mbi); - * would bring X down to s/t_mbi. That is why we return - * X_recv according to rfc3448bis-06 for the moment. - */ - u32 s = tfrc_rx_hist_packet_size(&hcrx->hist), - rtt = tfrc_rx_hist_rtt(&hcrx->hist); - - hcrx->x_recv = scaled_div32(s, 2 * rtt); - break; - } /* * When parameters change (new loss or p > p_prev), we do not * have a reliable estimate for R_m of [RFC 3448, 6.2] and so - * always check whether at least RTT time units were covered. + * need to reuse the previous value of X_recv. However, when + * X_recv was 0 (due to early loss), this would kill X down to + * s/t_mbi (i.e. one packet in 64 seconds). + * To avoid such drastic reduction, we approximate X_recv as + * the number of bytes since last feedback. + * This is a safe fallback, since X is bounded above by X_calc. */ - hcrx->x_recv = tfrc_rx_hist_x_recv(&hcrx->hist, hcrx->x_recv); - break; + if (hcrx->ccid3hcrx_x_recv > 0) + break; + /* fall through */ case CCID3_FBACK_PERIODIC: - /* - * Step (2) of rfc3448bis-06, 6.2: - * - if no data packets have been received, just restart timer - * - if data packets have been received, re-compute X_recv - */ - if (hcrx->hist.bytes_recvd == 0) - goto prepare_for_next_time; - hcrx->x_recv = tfrc_rx_hist_x_recv(&hcrx->hist, hcrx->x_recv); + delta = ktime_us_delta(now, hcrx->ccid3hcrx_tstamp_last_feedback); + if (delta <= 0) + DCCP_BUG("delta (%ld) <= 0", (long)delta); + else + hcrx->ccid3hcrx_x_recv = + scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta); break; default: return; } - ccid3_pr_debug("X_recv=%u, 1/p=%u\n", hcrx->x_recv, hcrx->p_inverse); + ccid3_pr_debug("Interval %ldusec, X_recv=%u, 1/p=%u\n", (long)delta, + hcrx->ccid3hcrx_x_recv, hcrx->ccid3hcrx_pinv); - dccp_sk(sk)->dccps_hc_rx_insert_options = 1; - dccp_send_ack(sk); + hcrx->ccid3hcrx_tstamp_last_feedback = now; + hcrx->ccid3hcrx_last_counter = dccp_hdr(skb)->dccph_ccval; + hcrx->ccid3hcrx_bytes_recv = 0; -prepare_for_next_time: - tfrc_rx_hist_restart_byte_counter(&hcrx->hist); - hcrx->last_counter = dccp_hdr(skb)->dccph_ccval; - hcrx->feedback = fbtype; + dp->dccps_hc_rx_insert_options = 1; + dccp_send_ack(sk); } static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb) { - const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); + const struct ccid3_hc_rx_sock *hcrx; __be32 x_recv, pinv; if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)) return 0; + hcrx = ccid3_hc_rx_sk(sk); + if (dccp_packet_without_ack(skb)) return 0; - x_recv = htonl(hcrx->x_recv); - pinv = htonl(hcrx->p_inverse); + x_recv = htonl(hcrx->ccid3hcrx_x_recv); + pinv = htonl(hcrx->ccid3hcrx_pinv); if (dccp_insert_option(sk, skb, TFRC_OPT_LOSS_EVENT_RATE, &pinv, sizeof(pinv)) || @@ -662,95 +762,171 @@ static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb) static u32 ccid3_first_li(struct sock *sk) { struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); - u32 s = tfrc_rx_hist_packet_size(&hcrx->hist), - rtt = tfrc_rx_hist_rtt(&hcrx->hist), x_recv, p; + u32 x_recv, p, delta; u64 fval; - /* - * rfc3448bis-06, 6.3.1: First data packet(s) are marked or lost. Set p - * to give the equivalent of X_target = s/(2*R). Thus fval = 2 and so p - * is about 20.64%. This yields an interval length of 4.84 (rounded up). - */ - if (unlikely(hcrx->feedback == CCID3_FBACK_NONE)) - return 5; + if (hcrx->ccid3hcrx_rtt == 0) { + DCCP_WARN("No RTT estimate available, using fallback RTT\n"); + hcrx->ccid3hcrx_rtt = DCCP_FALLBACK_RTT; + } - x_recv = tfrc_rx_hist_x_recv(&hcrx->hist, hcrx->x_recv); - if (x_recv == 0) - goto failed; + delta = ktime_to_us(net_timedelta(hcrx->ccid3hcrx_tstamp_last_feedback)); + x_recv = scaled_div32(hcrx->ccid3hcrx_bytes_recv, delta); + if (x_recv == 0) { /* would also trigger divide-by-zero */ + DCCP_WARN("X_recv==0\n"); + if ((x_recv = hcrx->ccid3hcrx_x_recv) == 0) { + DCCP_BUG("stored value of X_recv is zero"); + return ~0U; + } + } - fval = scaled_div32(scaled_div(s, rtt), x_recv); + fval = scaled_div(hcrx->ccid3hcrx_s, hcrx->ccid3hcrx_rtt); + fval = scaled_div32(fval, x_recv); p = tfrc_calc_x_reverse_lookup(fval); ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied " "loss rate=%u\n", dccp_role(sk), sk, x_recv, p); - if (p > 0) - return scaled_div(1, p); -failed: - return UINT_MAX; + return p == 0 ? ~0U : scaled_div(1, p); } static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) { struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); + enum ccid3_fback_type do_feedback = CCID3_FBACK_NONE; const u64 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp; const bool is_data_packet = dccp_data_packet(skb); + if (unlikely(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)) { + if (is_data_packet) { + const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; + do_feedback = CCID3_FBACK_INITIAL; + ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA); + hcrx->ccid3hcrx_s = payload; + /* + * Not necessary to update ccid3hcrx_bytes_recv here, + * since X_recv = 0 for the first feedback packet (cf. + * RFC 3448, 6.3) -- gerrit + */ + } + goto update_records; + } + + if (tfrc_rx_hist_duplicate(&hcrx->ccid3hcrx_hist, skb)) + return; /* done receiving */ + + if (is_data_packet) { + const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; + /* + * Update moving-average of s and the sum of received payload bytes + */ + hcrx->ccid3hcrx_s = tfrc_ewma(hcrx->ccid3hcrx_s, payload, 9); + hcrx->ccid3hcrx_bytes_recv += payload; + } + /* * Perform loss detection and handle pending losses */ - if (tfrc_rx_congestion_event(&hcrx->hist, &hcrx->li_hist, - skb, ndp, ccid3_first_li, sk)) - ccid3_hc_rx_send_feedback(sk, skb, CCID3_FBACK_PARAM_CHANGE); + if (tfrc_rx_handle_loss(&hcrx->ccid3hcrx_hist, &hcrx->ccid3hcrx_li_hist, + skb, ndp, ccid3_first_li, sk)) { + do_feedback = CCID3_FBACK_PARAM_CHANGE; + goto done_receiving; + } + + if (tfrc_rx_hist_loss_pending(&hcrx->ccid3hcrx_hist)) + return; /* done receiving */ + /* - * Feedback for first non-empty data packet (RFC 3448, 6.3) + * Handle data packets: RTT sampling and monitoring p */ - else if (unlikely(hcrx->feedback == CCID3_FBACK_NONE && is_data_packet)) - ccid3_hc_rx_send_feedback(sk, skb, CCID3_FBACK_INITIAL); + if (unlikely(!is_data_packet)) + goto update_records; + + if (!tfrc_lh_is_initialised(&hcrx->ccid3hcrx_li_hist)) { + const u32 sample = tfrc_rx_hist_sample_rtt(&hcrx->ccid3hcrx_hist, skb); + /* + * Empty loss history: no loss so far, hence p stays 0. + * Sample RTT values, since an RTT estimate is required for the + * computation of p when the first loss occurs; RFC 3448, 6.3.1. + */ + if (sample != 0) + hcrx->ccid3hcrx_rtt = tfrc_ewma(hcrx->ccid3hcrx_rtt, sample, 9); + + } else if (tfrc_lh_update_i_mean(&hcrx->ccid3hcrx_li_hist, skb)) { + /* + * Step (3) of [RFC 3448, 6.1]: Recompute I_mean and, if I_mean + * has decreased (resp. p has increased), send feedback now. + */ + do_feedback = CCID3_FBACK_PARAM_CHANGE; + } + /* * Check if the periodic once-per-RTT feedback is due; RFC 4342, 10.3 */ - else if (!tfrc_rx_hist_loss_pending(&hcrx->hist) && is_data_packet && - SUB16(dccp_hdr(skb)->dccph_ccval, hcrx->last_counter) > 3) - ccid3_hc_rx_send_feedback(sk, skb, CCID3_FBACK_PERIODIC); + if (SUB16(dccp_hdr(skb)->dccph_ccval, hcrx->ccid3hcrx_last_counter) > 3) + do_feedback = CCID3_FBACK_PERIODIC; + +update_records: + tfrc_rx_hist_add_packet(&hcrx->ccid3hcrx_hist, skb, ndp); + +done_receiving: + if (do_feedback) + ccid3_hc_rx_send_feedback(sk, skb, do_feedback); } static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk) { struct ccid3_hc_rx_sock *hcrx = ccid_priv(ccid); - tfrc_lh_init(&hcrx->li_hist); - return tfrc_rx_hist_init(&hcrx->hist, sk); + hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA; + tfrc_lh_init(&hcrx->ccid3hcrx_li_hist); + return tfrc_rx_hist_alloc(&hcrx->ccid3hcrx_hist); } static void ccid3_hc_rx_exit(struct sock *sk) { struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); - tfrc_rx_hist_purge(&hcrx->hist); - tfrc_lh_cleanup(&hcrx->li_hist); + ccid3_hc_rx_set_state(sk, TFRC_RSTATE_TERM); + + tfrc_rx_hist_purge(&hcrx->ccid3hcrx_hist); + tfrc_lh_cleanup(&hcrx->ccid3hcrx_li_hist); } static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info) { + const struct ccid3_hc_rx_sock *hcrx; + + /* Listen socks doesn't have a private CCID block */ + if (sk->sk_state == DCCP_LISTEN) + return; + + hcrx = ccid3_hc_rx_sk(sk); + info->tcpi_ca_state = hcrx->ccid3hcrx_state; info->tcpi_options |= TCPI_OPT_TIMESTAMPS; - info->tcpi_rcv_rtt = tfrc_rx_hist_rtt(&ccid3_hc_rx_sk(sk)->hist); + info->tcpi_rcv_rtt = hcrx->ccid3hcrx_rtt; } static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len, u32 __user *optval, int __user *optlen) { - const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); + const struct ccid3_hc_rx_sock *hcrx; struct tfrc_rx_info rx_info; const void *val; + /* Listen socks doesn't have a private CCID block */ + if (sk->sk_state == DCCP_LISTEN) + return -EINVAL; + + hcrx = ccid3_hc_rx_sk(sk); switch (optname) { case DCCP_SOCKOPT_CCID_RX_INFO: if (len < sizeof(rx_info)) return -EINVAL; - rx_info.tfrcrx_x_recv = hcrx->x_recv; - rx_info.tfrcrx_rtt = tfrc_rx_hist_rtt(&hcrx->hist); - rx_info.tfrcrx_p = tfrc_invert_loss_event_rate(hcrx->p_inverse); + rx_info.tfrcrx_x_recv = hcrx->ccid3hcrx_x_recv; + rx_info.tfrcrx_rtt = hcrx->ccid3hcrx_rtt; + rx_info.tfrcrx_p = hcrx->ccid3hcrx_pinv == 0 ? ~0U : + scaled_div(1, hcrx->ccid3hcrx_pinv); len = sizeof(rx_info); val = &rx_info; break; @@ -786,9 +962,6 @@ static struct ccid_operations ccid3 = { .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt, }; -module_param(do_osc_prev, bool, 0644); -MODULE_PARM_DESC(do_osc_prev, "Use Oscillation Prevention (RFC 3448, 4.5)"); - #ifdef CONFIG_IP_DCCP_CCID3_DEBUG module_param(ccid3_debug, bool, 0644); MODULE_PARM_DESC(ccid3_debug, "Enable debug messages"); @@ -796,19 +969,6 @@ MODULE_PARM_DESC(ccid3_debug, "Enable debug messages"); static __init int ccid3_module_init(void) { - struct timespec tp; - - /* - * Without a fine-grained clock resolution, RTTs/X_recv are not sampled - * correctly and feedback is sent either too early or too late. - */ - hrtimer_get_res(CLOCK_MONOTONIC, &tp); - if (tp.tv_sec || tp.tv_nsec > DCCP_TIME_RESOLUTION * NSEC_PER_USEC) { - printk(KERN_ERR "%s: Timer too coarse (%ld usec), need %u-usec" - " resolution - check your clocksource.\n", __func__, - tp.tv_nsec/NSEC_PER_USEC, DCCP_TIME_RESOLUTION); - return -ESOCKTNOSUPPORT; - } return ccid_register(&ccid3); } module_init(ccid3_module_init); diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h index af6e1bf937d..49ca32bd7e7 100644 --- a/net/dccp/ccids/ccid3.h +++ b/net/dccp/ccids/ccid3.h @@ -47,22 +47,11 @@ /* Two seconds as per RFC 3448 4.2 */ #define TFRC_INITIAL_TIMEOUT (2 * USEC_PER_SEC) -/* Maximum backoff interval t_mbi (RFC 3448, 4.3) */ -#define TFRC_T_MBI (64 * USEC_PER_SEC) +/* In usecs - half the scheduling granularity as per RFC3448 4.6 */ +#define TFRC_OPSYS_HALF_TIME_GRAN (USEC_PER_SEC / (2 * HZ)) -/* - * The t_delta parameter (RFC 3448, 4.6): delays of less than %USEC_PER_MSEC are - * rounded down to 0, since sk_reset_timer() here uses millisecond granularity. - * Hence we can use a constant t_delta = %USEC_PER_MSEC when HZ >= 500. A coarse - * resolution of HZ < 500 means that the error is below one timer tick (t_gran) - * when using the constant t_delta = t_gran / 2 = %USEC_PER_SEC / (2 * HZ). - */ -#if (HZ >= 500) -# define TFRC_T_DELTA USEC_PER_MSEC -#else -# define TFRC_T_DELTA (USEC_PER_SEC / (2 * HZ)) -#warning Coarse CONFIG_HZ resolution -- higher value recommended for TFRC. -#endif +/* Parameter t_mbi from [RFC 3448, 4.3]: backoff interval in seconds */ +#define TFRC_T_MBI 64 enum ccid3_options { TFRC_OPT_LOSS_EVENT_RATE = 192, @@ -70,43 +59,62 @@ enum ccid3_options { TFRC_OPT_RECEIVE_RATE = 194, }; +struct ccid3_options_received { + u64 ccid3or_seqno:48, + ccid3or_loss_intervals_idx:16; + u16 ccid3or_loss_intervals_len; + u32 ccid3or_loss_event_rate; + u32 ccid3or_receive_rate; +}; + +/* TFRC sender states */ +enum ccid3_hc_tx_states { + TFRC_SSTATE_NO_SENT = 1, + TFRC_SSTATE_NO_FBACK, + TFRC_SSTATE_FBACK, + TFRC_SSTATE_TERM, +}; + /** struct ccid3_hc_tx_sock - CCID3 sender half-connection socket * - * @x - Current sending rate in 64 * bytes per second - * @x_recv - Receive rate in 64 * bytes per second - * @x_calc - Calculated rate in bytes per second - * @rtt - Estimate of current round trip time in usecs - * @r_sqmean - Estimate of long-term RTT (RFC 3448, 4.5) - * @p - Current loss event rate (0-1) scaled by 1000000 - * @s - Packet size in bytes - * @t_rto - Nofeedback Timer setting in usecs - * @t_ipi - Interpacket (send) interval (RFC 3448, 4.6) in usecs - * @feedback - Whether feedback has been received or not - * @last_win_count - Last window counter sent - * @t_last_win_count - Timestamp of earliest packet with - * last_win_count value sent - * @no_feedback_timer - Handle to no feedback timer - * @t_ld - Time last doubled during slow start - * @t_nom - Nominal send time of next packet - * @hist - Packet history + * @ccid3hctx_x - Current sending rate in 64 * bytes per second + * @ccid3hctx_x_recv - Receive rate in 64 * bytes per second + * @ccid3hctx_x_calc - Calculated rate in bytes per second + * @ccid3hctx_rtt - Estimate of current round trip time in usecs + * @ccid3hctx_p - Current loss event rate (0-1) scaled by 1000000 + * @ccid3hctx_s - Packet size in bytes + * @ccid3hctx_t_rto - Nofeedback Timer setting in usecs + * @ccid3hctx_t_ipi - Interpacket (send) interval (RFC 3448, 4.6) in usecs + * @ccid3hctx_state - Sender state, one of %ccid3_hc_tx_states + * @ccid3hctx_last_win_count - Last window counter sent + * @ccid3hctx_t_last_win_count - Timestamp of earliest packet + * with last_win_count value sent + * @ccid3hctx_no_feedback_timer - Handle to no feedback timer + * @ccid3hctx_t_ld - Time last doubled during slow start + * @ccid3hctx_t_nom - Nominal send time of next packet + * @ccid3hctx_delta - Send timer delta (RFC 3448, 4.6) in usecs + * @ccid3hctx_hist - Packet history + * @ccid3hctx_options_received - Parsed set of retrieved options */ struct ccid3_hc_tx_sock { - u64 x; - u64 x_recv; - u32 x_calc; - u32 rtt; - u16 r_sqmean; - u32 p; - u32 t_rto; - u32 t_ipi; - u16 s; - bool feedback:1; - u8 last_win_count; - ktime_t t_last_win_count; - struct timer_list no_feedback_timer; - ktime_t t_ld; - ktime_t t_nom; - struct tfrc_tx_hist_entry *hist; + struct tfrc_tx_info ccid3hctx_tfrc; +#define ccid3hctx_x ccid3hctx_tfrc.tfrctx_x +#define ccid3hctx_x_recv ccid3hctx_tfrc.tfrctx_x_recv +#define ccid3hctx_x_calc ccid3hctx_tfrc.tfrctx_x_calc +#define ccid3hctx_rtt ccid3hctx_tfrc.tfrctx_rtt +#define ccid3hctx_p ccid3hctx_tfrc.tfrctx_p +#define ccid3hctx_t_rto ccid3hctx_tfrc.tfrctx_rto +#define ccid3hctx_t_ipi ccid3hctx_tfrc.tfrctx_ipi + u16 ccid3hctx_s; + enum ccid3_hc_tx_states ccid3hctx_state:8; + u8 ccid3hctx_last_win_count; + ktime_t ccid3hctx_t_last_win_count; + struct timer_list ccid3hctx_no_feedback_timer; + ktime_t ccid3hctx_t_ld; + ktime_t ccid3hctx_t_nom; + u32 ccid3hctx_delta; + struct tfrc_tx_hist_entry *ccid3hctx_hist; + struct ccid3_options_received ccid3hctx_options_received; }; static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk) @@ -116,32 +124,41 @@ static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk) return hctx; } - -enum ccid3_fback_type { - CCID3_FBACK_NONE = 0, - CCID3_FBACK_INITIAL, - CCID3_FBACK_PERIODIC, - CCID3_FBACK_PARAM_CHANGE +/* TFRC receiver states */ +enum ccid3_hc_rx_states { + TFRC_RSTATE_NO_DATA = 1, + TFRC_RSTATE_DATA, + TFRC_RSTATE_TERM = 127, }; /** struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket * - * @last_counter - Tracks window counter (RFC 4342, 8.1) - * @feedback - The type of the feedback last sent - * @x_recv - Receiver estimate of send rate (RFC 3448, sec. 4.3) - * @tstamp_last_feedback - Time at which last feedback was sent - * @hist - Packet history (loss detection + RTT sampling) - * @li_hist - Loss Interval database - * @p_inverse - Inverse of Loss Event Rate (RFC 4342, sec. 8.5) + * @ccid3hcrx_x_recv - Receiver estimate of send rate (RFC 3448 4.3) + * @ccid3hcrx_rtt - Receiver estimate of rtt (non-standard) + * @ccid3hcrx_p - Current loss event rate (RFC 3448 5.4) + * @ccid3hcrx_last_counter - Tracks window counter (RFC 4342, 8.1) + * @ccid3hcrx_state - Receiver state, one of %ccid3_hc_rx_states + * @ccid3hcrx_bytes_recv - Total sum of DCCP payload bytes + * @ccid3hcrx_x_recv - Receiver estimate of send rate (RFC 3448, sec. 4.3) + * @ccid3hcrx_rtt - Receiver estimate of RTT + * @ccid3hcrx_tstamp_last_feedback - Time at which last feedback was sent + * @ccid3hcrx_tstamp_last_ack - Time at which last feedback was sent + * @ccid3hcrx_hist - Packet history (loss detection + RTT sampling) + * @ccid3hcrx_li_hist - Loss Interval database + * @ccid3hcrx_s - Received packet size in bytes + * @ccid3hcrx_pinv - Inverse of Loss Event Rate (RFC 4342, sec. 8.5) */ struct ccid3_hc_rx_sock { - u8 last_counter:4; - enum ccid3_fback_type feedback:4; - u32 x_recv; - ktime_t tstamp_last_feedback; - struct tfrc_rx_hist hist; - struct tfrc_loss_hist li_hist; -#define p_inverse li_hist.i_mean + u8 ccid3hcrx_last_counter:4; + enum ccid3_hc_rx_states ccid3hcrx_state:8; + u32 ccid3hcrx_bytes_recv; + u32 ccid3hcrx_x_recv; + u32 ccid3hcrx_rtt; + ktime_t ccid3hcrx_tstamp_last_feedback; + struct tfrc_rx_hist ccid3hcrx_hist; + struct tfrc_loss_hist ccid3hcrx_li_hist; + u16 ccid3hcrx_s; +#define ccid3hcrx_pinv ccid3hcrx_li_hist.i_mean }; static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk) diff --git a/net/dccp/ccids/lib/loss_interval.c b/net/dccp/ccids/lib/loss_interval.c index b1ae8f8259e..5b3ce0688c5 100644 --- a/net/dccp/ccids/lib/loss_interval.c +++ b/net/dccp/ccids/lib/loss_interval.c @@ -86,26 +86,21 @@ static void tfrc_lh_calc_i_mean(struct tfrc_loss_hist *lh) /** * tfrc_lh_update_i_mean - Update the `open' loss interval I_0 - * This updates I_mean as the sequence numbers increase. As a consequence, the - * open loss interval I_0 increases, hence p = W_tot/max(I_tot0, I_tot1) - * decreases, and thus there is no need to send renewed feedback. + * For recomputing p: returns `true' if p > p_prev <=> 1/p < 1/p_prev */ -void tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *skb) +u8 tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *skb) { struct tfrc_loss_interval *cur = tfrc_lh_peek(lh); + u32 old_i_mean = lh->i_mean; s64 len; if (cur == NULL) /* not initialised */ - return; - - /* FIXME: should probably also count non-data packets (RFC 4342, 6.1) */ - if (!dccp_data_packet(skb)) - return; + return 0; len = dccp_delta_seqno(cur->li_seqno, DCCP_SKB_CB(skb)->dccpd_seq) + 1; if (len - (s64)cur->li_length <= 0) /* duplicate or reordered */ - return; + return 0; if (SUB16(dccp_hdr(skb)->dccph_ccval, cur->li_ccval) > 4) /* @@ -119,11 +114,14 @@ void tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *skb) cur->li_is_closed = 1; if (tfrc_lh_length(lh) == 1) /* due to RFC 3448, 6.3.1 */ - return; + return 0; cur->li_length = len; tfrc_lh_calc_i_mean(lh); + + return (lh->i_mean < old_i_mean); } +EXPORT_SYMBOL_GPL(tfrc_lh_update_i_mean); /* Determine if `new_loss' does begin a new loss interval [RFC 4342, 10.2] */ static inline u8 tfrc_lh_is_new_loss(struct tfrc_loss_interval *cur, @@ -140,18 +138,18 @@ static inline u8 tfrc_lh_is_new_loss(struct tfrc_loss_interval *cur, * @sk: Used by @calc_first_li in caller-specific way (subtyping) * Updates I_mean and returns 1 if a new interval has in fact been added to @lh. */ -bool tfrc_lh_interval_add(struct tfrc_loss_hist *lh, struct tfrc_rx_hist *rh, - u32 (*calc_first_li)(struct sock *), struct sock *sk) +int tfrc_lh_interval_add(struct tfrc_loss_hist *lh, struct tfrc_rx_hist *rh, + u32 (*calc_first_li)(struct sock *), struct sock *sk) { struct tfrc_loss_interval *cur = tfrc_lh_peek(lh), *new; if (cur != NULL && !tfrc_lh_is_new_loss(cur, tfrc_rx_hist_loss_prev(rh))) - return false; + return 0; new = tfrc_lh_demand_next(lh); if (unlikely(new == NULL)) { DCCP_CRIT("Cannot allocate/add loss record."); - return false; + return 0; } new->li_seqno = tfrc_rx_hist_loss_prev(rh)->tfrchrx_seqno; @@ -169,7 +167,7 @@ bool tfrc_lh_interval_add(struct tfrc_loss_hist *lh, struct tfrc_rx_hist *rh, tfrc_lh_calc_i_mean(lh); } - return true; + return 1; } EXPORT_SYMBOL_GPL(tfrc_lh_interval_add); diff --git a/net/dccp/ccids/lib/loss_interval.h b/net/dccp/ccids/lib/loss_interval.h index d08a226db43..246018a3b26 100644 --- a/net/dccp/ccids/lib/loss_interval.h +++ b/net/dccp/ccids/lib/loss_interval.h @@ -67,9 +67,9 @@ static inline u8 tfrc_lh_length(struct tfrc_loss_hist *lh) struct tfrc_rx_hist; -extern bool tfrc_lh_interval_add(struct tfrc_loss_hist *, struct tfrc_rx_hist *, +extern int tfrc_lh_interval_add(struct tfrc_loss_hist *, struct tfrc_rx_hist *, u32 (*first_li)(struct sock *), struct sock *); -extern void tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *); +extern u8 tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *); extern void tfrc_lh_cleanup(struct tfrc_loss_hist *lh); #endif /* _DCCP_LI_HIST_ */ diff --git a/net/dccp/ccids/lib/packet_history.c b/net/dccp/ccids/lib/packet_history.c index cce9f03bda3..6cc108afdc3 100644 --- a/net/dccp/ccids/lib/packet_history.c +++ b/net/dccp/ccids/lib/packet_history.c @@ -40,6 +40,18 @@ #include "packet_history.h" #include "../../dccp.h" +/** + * tfrc_tx_hist_entry - Simple singly-linked TX history list + * @next: next oldest entry (LIFO order) + * @seqno: sequence number of this entry + * @stamp: send time of packet with sequence number @seqno + */ +struct tfrc_tx_hist_entry { + struct tfrc_tx_hist_entry *next; + u64 seqno; + ktime_t stamp; +}; + /* * Transmitter History Routines */ @@ -61,6 +73,15 @@ void tfrc_tx_packet_history_exit(void) } } +static struct tfrc_tx_hist_entry * + tfrc_tx_hist_find_entry(struct tfrc_tx_hist_entry *head, u64 seqno) +{ + while (head != NULL && head->seqno != seqno) + head = head->next; + + return head; +} + int tfrc_tx_hist_add(struct tfrc_tx_hist_entry **headp, u64 seqno) { struct tfrc_tx_hist_entry *entry = kmem_cache_alloc(tfrc_tx_hist_slab, gfp_any()); @@ -90,6 +111,25 @@ void tfrc_tx_hist_purge(struct tfrc_tx_hist_entry **headp) } EXPORT_SYMBOL_GPL(tfrc_tx_hist_purge); +u32 tfrc_tx_hist_rtt(struct tfrc_tx_hist_entry *head, const u64 seqno, + const ktime_t now) +{ + u32 rtt = 0; + struct tfrc_tx_hist_entry *packet = tfrc_tx_hist_find_entry(head, seqno); + + if (packet != NULL) { + rtt = ktime_us_delta(now, packet->stamp); + /* + * Garbage-collect older (irrelevant) entries: + */ + tfrc_tx_hist_purge(&packet->next); + } + + return rtt; +} +EXPORT_SYMBOL_GPL(tfrc_tx_hist_rtt); + + /* * Receiver History Routines */ @@ -151,31 +191,14 @@ int tfrc_rx_hist_duplicate(struct tfrc_rx_hist *h, struct sk_buff *skb) } EXPORT_SYMBOL_GPL(tfrc_rx_hist_duplicate); - -static void __tfrc_rx_hist_swap(struct tfrc_rx_hist *h, const u8 a, const u8 b) -{ - struct tfrc_rx_hist_entry *tmp = h->ring[a]; - - h->ring[a] = h->ring[b]; - h->ring[b] = tmp; -} - static void tfrc_rx_hist_swap(struct tfrc_rx_hist *h, const u8 a, const u8 b) { - __tfrc_rx_hist_swap(h, tfrc_rx_hist_index(h, a), - tfrc_rx_hist_index(h, b)); -} + const u8 idx_a = tfrc_rx_hist_index(h, a), + idx_b = tfrc_rx_hist_index(h, b); + struct tfrc_rx_hist_entry *tmp = h->ring[idx_a]; -/** - * tfrc_rx_hist_resume_rtt_sampling - Prepare RX history for RTT sampling - * This is called after loss detection has finished, when the history entry - * with the index of `loss_count' holds the highest-received sequence number. - * RTT sampling requires this information at ring[0] (tfrc_rx_hist_sample_rtt). - */ -static inline void tfrc_rx_hist_resume_rtt_sampling(struct tfrc_rx_hist *h) -{ - __tfrc_rx_hist_swap(h, 0, tfrc_rx_hist_index(h, h->loss_count)); - h->loss_count = h->loss_start = 0; + h->ring[idx_a] = h->ring[idx_b]; + h->ring[idx_b] = tmp; } /* @@ -192,8 +215,10 @@ static void __do_track_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u64 n1) u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, s1 = DCCP_SKB_CB(skb)->dccpd_seq; - if (!dccp_loss_free(s0, s1, n1)) /* gap between S0 and S1 */ + if (!dccp_loss_free(s0, s1, n1)) { /* gap between S0 and S1 */ h->loss_count = 1; + tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n1); + } } static void __one_after_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u32 n2) @@ -215,7 +240,8 @@ static void __one_after_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u32 n2 if (dccp_loss_free(s2, s1, n1)) { /* hole is filled: S0, S2, and S1 are consecutive */ - tfrc_rx_hist_resume_rtt_sampling(h); + h->loss_count = 0; + h->loss_start = tfrc_rx_hist_index(h, 1); } else /* gap between S2 and S1: just update loss_prev */ tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_loss_prev(h), skb, n2); @@ -268,7 +294,8 @@ static int __two_after_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u32 n3) if (dccp_loss_free(s1, s2, n2)) { /* entire hole filled by S0, S3, S1, S2 */ - tfrc_rx_hist_resume_rtt_sampling(h); + h->loss_start = tfrc_rx_hist_index(h, 2); + h->loss_count = 0; } else { /* gap remains between S1 and S2 */ h->loss_start = tfrc_rx_hist_index(h, 1); @@ -312,7 +339,8 @@ static void __three_after_loss(struct tfrc_rx_hist *h) if (dccp_loss_free(s2, s3, n3)) { /* no gap between S2 and S3: entire hole is filled */ - tfrc_rx_hist_resume_rtt_sampling(h); + h->loss_start = tfrc_rx_hist_index(h, 3); + h->loss_count = 0; } else { /* gap between S2 and S3 */ h->loss_start = tfrc_rx_hist_index(h, 2); @@ -326,13 +354,13 @@ static void __three_after_loss(struct tfrc_rx_hist *h) } /** - * tfrc_rx_congestion_event - Loss detection and further processing - * @h: The non-empty RX history object - * @lh: Loss Intervals database to update - * @skb: Currently received packet - * @ndp: The NDP count belonging to @skb - * @first_li: Caller-dependent computation of first loss interval in @lh - * @sk: Used by @calc_first_li (see tfrc_lh_interval_add) + * tfrc_rx_handle_loss - Loss detection and further processing + * @h: The non-empty RX history object + * @lh: Loss Intervals database to update + * @skb: Currently received packet + * @ndp: The NDP count belonging to @skb + * @calc_first_li: Caller-dependent computation of first loss interval in @lh + * @sk: Used by @calc_first_li (see tfrc_lh_interval_add) * Chooses action according to pending loss, updates LI database when a new * loss was detected, and does required post-processing. Returns 1 when caller * should send feedback, 0 otherwise. @@ -340,20 +368,15 @@ static void __three_after_loss(struct tfrc_rx_hist *h) * records accordingly, the caller should not perform any more RX history * operations when loss_count is greater than 0 after calling this function. */ -bool tfrc_rx_congestion_event(struct tfrc_rx_hist *h, - struct tfrc_loss_hist *lh, - struct sk_buff *skb, const u64 ndp, - u32 (*first_li)(struct sock *), struct sock *sk) +int tfrc_rx_handle_loss(struct tfrc_rx_hist *h, + struct tfrc_loss_hist *lh, + struct sk_buff *skb, const u64 ndp, + u32 (*calc_first_li)(struct sock *), struct sock *sk) { - bool new_event = false; - - if (tfrc_rx_hist_duplicate(h, skb)) - return 0; + int is_new_loss = 0; if (h->loss_count == 0) { __do_track_loss(h, skb, ndp); - tfrc_rx_hist_sample_rtt(h, skb); - tfrc_rx_hist_add_packet(h, skb, ndp); } else if (h->loss_count == 1) { __one_after_loss(h, skb, ndp); } else if (h->loss_count != 2) { @@ -362,57 +385,34 @@ bool tfrc_rx_congestion_event(struct tfrc_rx_hist *h, /* * Update Loss Interval database and recycle RX records */ - new_event = tfrc_lh_interval_add(lh, h, first_li, sk); + is_new_loss = tfrc_lh_interval_add(lh, h, calc_first_li, sk); __three_after_loss(h); } - - /* - * Update moving-average of `s' and the sum of received payload bytes. - */ - if (dccp_data_packet(skb)) { - const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; - - h->packet_size = tfrc_ewma(h->packet_size, payload, 9); - h->bytes_recvd += payload; - } - - /* RFC 3448, 6.1: update I_0, whose growth implies p <= p_prev */ - if (!new_event) - tfrc_lh_update_i_mean(lh, skb); - - return new_event; + return is_new_loss; } -EXPORT_SYMBOL_GPL(tfrc_rx_congestion_event); +EXPORT_SYMBOL_GPL(tfrc_rx_handle_loss); -/* Compute the sending rate X_recv measured between feedback intervals */ -u32 tfrc_rx_hist_x_recv(struct tfrc_rx_hist *h, const u32 last_x_recv) +int tfrc_rx_hist_alloc(struct tfrc_rx_hist *h) { - u64 bytes = h->bytes_recvd, last_rtt = h->rtt_estimate; - s64 delta = ktime_to_us(net_timedelta(h->bytes_start)); - - WARN_ON(delta <= 0); - /* - * Ensure that the sampling interval for X_recv is at least one RTT, - * by extending the sampling interval backwards in time, over the last - * R_(m-1) seconds, as per rfc3448bis-06, 6.2. - * To reduce noise (e.g. when the RTT changes often), this is only - * done when delta is smaller than RTT/2. - */ - if (last_x_recv > 0 && delta < last_rtt/2) { - tfrc_pr_debug("delta < RTT ==> %ld us < %u us\n", - (long)delta, (unsigned)last_rtt); + int i; - delta = (bytes ? delta : 0) + last_rtt; - bytes += div_u64((u64)last_x_recv * last_rtt, USEC_PER_SEC); + for (i = 0; i <= TFRC_NDUPACK; i++) { + h->ring[i] = kmem_cache_alloc(tfrc_rx_hist_slab, GFP_ATOMIC); + if (h->ring[i] == NULL) + goto out_free; } - if (unlikely(bytes == 0)) { - DCCP_WARN("X_recv == 0, using old value of %u\n", last_x_recv); - return last_x_recv; + h->loss_count = h->loss_start = 0; + return 0; + +out_free: + while (i-- != 0) { + kmem_cache_free(tfrc_rx_hist_slab, h->ring[i]); + h->ring[i] = NULL; } - return scaled_div32(bytes, delta); + return -ENOBUFS; } -EXPORT_SYMBOL_GPL(tfrc_rx_hist_x_recv); +EXPORT_SYMBOL_GPL(tfrc_rx_hist_alloc); void tfrc_rx_hist_purge(struct tfrc_rx_hist *h) { @@ -426,81 +426,73 @@ void tfrc_rx_hist_purge(struct tfrc_rx_hist *h) } EXPORT_SYMBOL_GPL(tfrc_rx_hist_purge); -static int tfrc_rx_hist_alloc(struct tfrc_rx_hist *h) +/** + * tfrc_rx_hist_rtt_last_s - reference entry to compute RTT samples against + */ +static inline struct tfrc_rx_hist_entry * + tfrc_rx_hist_rtt_last_s(const struct tfrc_rx_hist *h) { - int i; - - memset(h, 0, sizeof(*h)); - - for (i = 0; i <= TFRC_NDUPACK; i++) { - h->ring[i] = kmem_cache_alloc(tfrc_rx_hist_slab, GFP_ATOMIC); - if (h->ring[i] == NULL) { - tfrc_rx_hist_purge(h); - return -ENOBUFS; - } - } - return 0; + return h->ring[0]; } -int tfrc_rx_hist_init(struct tfrc_rx_hist *h, struct sock *sk) +/** + * tfrc_rx_hist_rtt_prev_s: previously suitable (wrt rtt_last_s) RTT-sampling entry + */ +static inline struct tfrc_rx_hist_entry * + tfrc_rx_hist_rtt_prev_s(const struct tfrc_rx_hist *h) { - if (tfrc_rx_hist_alloc(h)) - return -ENOBUFS; - /* - * Initialise first entry with GSR to start loss detection as early as - * possible. Code using this must not use any other fields. The entry - * will be overwritten once the CCID updates its received packets. - */ - tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno = dccp_sk(sk)->dccps_gsr; - return 0; + return h->ring[h->rtt_sample_prev]; } -EXPORT_SYMBOL_GPL(tfrc_rx_hist_init); /** * tfrc_rx_hist_sample_rtt - Sample RTT from timestamp / CCVal - * Based on ideas presented in RFC 4342, 8.1. This function expects that no loss - * is pending and uses the following history entries (via rtt_sample_prev): - * - h->ring[0] contains the most recent history entry prior to @skb; - * - h->ring[1] is an unused `dummy' entry when the current difference is 0; + * Based on ideas presented in RFC 4342, 8.1. Returns 0 if it was not able + * to compute a sample with given data - calling function should check this. */ -void tfrc_rx_hist_sample_rtt(struct tfrc_rx_hist *h, const struct sk_buff *skb) +u32 tfrc_rx_hist_sample_rtt(struct tfrc_rx_hist *h, const struct sk_buff *skb) { - struct tfrc_rx_hist_entry *last = h->ring[0]; - u32 sample, delta_v; - - /* - * When not to sample: - * - on non-data packets - * (RFC 4342, 8.1: CCVal only fully defined for data packets); - * - when no data packets have been received yet - * (FIXME: using sampled packet size as indicator here); - * - as long as there are gaps in the sequence space (pending loss). - */ - if (!dccp_data_packet(skb) || h->packet_size == 0 || - tfrc_rx_hist_loss_pending(h)) - return; + u32 sample = 0, + delta_v = SUB16(dccp_hdr(skb)->dccph_ccval, + tfrc_rx_hist_rtt_last_s(h)->tfrchrx_ccval); + + if (delta_v < 1 || delta_v > 4) { /* unsuitable CCVal delta */ + if (h->rtt_sample_prev == 2) { /* previous candidate stored */ + sample = SUB16(tfrc_rx_hist_rtt_prev_s(h)->tfrchrx_ccval, + tfrc_rx_hist_rtt_last_s(h)->tfrchrx_ccval); + if (sample) + sample = 4 / sample * + ktime_us_delta(tfrc_rx_hist_rtt_prev_s(h)->tfrchrx_tstamp, + tfrc_rx_hist_rtt_last_s(h)->tfrchrx_tstamp); + else /* + * FIXME: This condition is in principle not + * possible but occurs when CCID is used for + * two-way data traffic. I have tried to trace + * it, but the cause does not seem to be here. + */ + DCCP_BUG("please report to dccp@vger.kernel.org" + " => prev = %u, last = %u", + tfrc_rx_hist_rtt_prev_s(h)->tfrchrx_ccval, + tfrc_rx_hist_rtt_last_s(h)->tfrchrx_ccval); + } else if (delta_v < 1) { + h->rtt_sample_prev = 1; + goto keep_ref_for_next_time; + } - h->rtt_sample_prev = 0; /* reset previous candidate */ + } else if (delta_v == 4) /* optimal match */ + sample = ktime_to_us(net_timedelta(tfrc_rx_hist_rtt_last_s(h)->tfrchrx_tstamp)); + else { /* suboptimal match */ + h->rtt_sample_prev = 2; + goto keep_ref_for_next_time; + } - delta_v = SUB16(dccp_hdr(skb)->dccph_ccval, last->tfrchrx_ccval); - if (delta_v == 0) { /* less than RTT/4 difference */ - h->rtt_sample_prev = 1; - return; + if (unlikely(sample > DCCP_SANE_RTT_MAX)) { + DCCP_WARN("RTT sample %u too large, using max\n", sample); + sample = DCCP_SANE_RTT_MAX; } - sample = dccp_sane_rtt(ktime_to_us(net_timedelta(last->tfrchrx_tstamp))); - if (delta_v <= 4) /* between RTT/4 and RTT */ - sample *= 4 / delta_v; - else if (!(sample < h->rtt_estimate && sample > h->rtt_estimate/2)) - /* - * Optimisation: CCVal difference is greater than 1 RTT, yet the - * sample is less than the local RTT estimate; which means that - * the RTT estimate is too high. - * To avoid noise, it is not done if the sample is below RTT/2. - */ - return; + h->rtt_sample_prev = 0; /* use current entry as next reference */ +keep_ref_for_next_time: - /* Use a lower weight than usual to increase responsiveness */ - h->rtt_estimate = tfrc_ewma(h->rtt_estimate, sample, 5); + return sample; } EXPORT_SYMBOL_GPL(tfrc_rx_hist_sample_rtt); diff --git a/net/dccp/ccids/lib/packet_history.h b/net/dccp/ccids/lib/packet_history.h index 555e65cd73a..461cc91cce8 100644 --- a/net/dccp/ccids/lib/packet_history.h +++ b/net/dccp/ccids/lib/packet_history.h @@ -40,28 +40,12 @@ #include <linux/slab.h> #include "tfrc.h" -/** - * tfrc_tx_hist_entry - Simple singly-linked TX history list - * @next: next oldest entry (LIFO order) - * @seqno: sequence number of this entry - * @stamp: send time of packet with sequence number @seqno - */ -struct tfrc_tx_hist_entry { - struct tfrc_tx_hist_entry *next; - u64 seqno; - ktime_t stamp; -}; - -static inline struct tfrc_tx_hist_entry * - tfrc_tx_hist_find_entry(struct tfrc_tx_hist_entry *head, u64 seqno) -{ - while (head != NULL && head->seqno != seqno) - head = head->next; - return head; -} +struct tfrc_tx_hist_entry; extern int tfrc_tx_hist_add(struct tfrc_tx_hist_entry **headp, u64 seqno); extern void tfrc_tx_hist_purge(struct tfrc_tx_hist_entry **headp); +extern u32 tfrc_tx_hist_rtt(struct tfrc_tx_hist_entry *head, + const u64 seqno, const ktime_t now); /* Subtraction a-b modulo-16, respects circular wrap-around */ #define SUB16(a, b) (((a) + 16 - (b)) & 0xF) @@ -91,22 +75,12 @@ struct tfrc_rx_hist_entry { * @loss_count: Number of entries in circular history * @loss_start: Movable index (for loss detection) * @rtt_sample_prev: Used during RTT sampling, points to candidate entry - * @rtt_estimate: Receiver RTT estimate - * @packet_size: Packet size in bytes (as per RFC 3448, 3.1) - * @bytes_recvd: Number of bytes received since @bytes_start - * @bytes_start: Start time for counting @bytes_recvd */ struct tfrc_rx_hist { struct tfrc_rx_hist_entry *ring[TFRC_NDUPACK + 1]; u8 loss_count:2, loss_start:2; - /* Receiver RTT sampling */ #define rtt_sample_prev loss_start - u32 rtt_estimate; - /* Receiver sampling of application payload lengths */ - u32 packet_size, - bytes_recvd; - ktime_t bytes_start; }; /** @@ -150,50 +124,20 @@ static inline bool tfrc_rx_hist_loss_pending(const struct tfrc_rx_hist *h) return h->loss_count > 0; } -/* - * Accessor functions to retrieve parameters sampled by the RX history - */ -static inline u32 tfrc_rx_hist_packet_size(const struct tfrc_rx_hist *h) -{ - if (h->packet_size == 0) { - DCCP_WARN("No sample for s, using fallback\n"); - return TCP_MIN_RCVMSS; - } - return h->packet_size; - -} -static inline u32 tfrc_rx_hist_rtt(const struct tfrc_rx_hist *h) -{ - if (h->rtt_estimate == 0) { - DCCP_WARN("No RTT estimate available, using fallback RTT\n"); - return DCCP_FALLBACK_RTT; - } - return h->rtt_estimate; -} - -static inline void tfrc_rx_hist_restart_byte_counter(struct tfrc_rx_hist *h) -{ - h->bytes_recvd = 0; - h->bytes_start = ktime_get_real(); -} - -extern u32 tfrc_rx_hist_x_recv(struct tfrc_rx_hist *h, const u32 last_x_recv); - - extern void tfrc_rx_hist_add_packet(struct tfrc_rx_hist *h, const struct sk_buff *skb, const u64 ndp); extern int tfrc_rx_hist_duplicate(struct tfrc_rx_hist *h, struct sk_buff *skb); struct tfrc_loss_hist; -extern bool tfrc_rx_congestion_event(struct tfrc_rx_hist *h, - struct tfrc_loss_hist *lh, - struct sk_buff *skb, const u64 ndp, - u32 (*first_li)(struct sock *sk), - struct sock *sk); -extern void tfrc_rx_hist_sample_rtt(struct tfrc_rx_hist *h, - const struct sk_buff *skb); -extern int tfrc_rx_hist_init(struct tfrc_rx_hist *h, struct sock *sk); +extern int tfrc_rx_handle_loss(struct tfrc_rx_hist *h, + struct tfrc_loss_hist *lh, + struct sk_buff *skb, const u64 ndp, + u32 (*first_li)(struct sock *sk), + struct sock *sk); +extern u32 tfrc_rx_hist_sample_rtt(struct tfrc_rx_hist *h, + const struct sk_buff *skb); +extern int tfrc_rx_hist_alloc(struct tfrc_rx_hist *h); extern void tfrc_rx_hist_purge(struct tfrc_rx_hist *h); #endif /* _DCCP_PKT_HIST_ */ diff --git a/net/dccp/ccids/lib/tfrc.h b/net/dccp/ccids/lib/tfrc.h index ede12f53de5..ed9857527ac 100644 --- a/net/dccp/ccids/lib/tfrc.h +++ b/net/dccp/ccids/lib/tfrc.h @@ -48,21 +48,6 @@ static inline u32 scaled_div32(u64 a, u64 b) } /** - * tfrc_scaled_sqrt - Compute scaled integer sqrt(x) for 0 < x < 2^22-1 - * Uses scaling to improve accuracy of the integer approximation of sqrt(). The - * scaling factor of 2^10 limits the maximum @sample to 4e6; this is okay for - * clamped RTT samples (dccp_sample_rtt). - * Should best be used for expressions of type sqrt(x)/sqrt(y), since then the - * scaling factor is neutralised. For this purpose, it avoids returning zero. - */ -static inline u16 tfrc_scaled_sqrt(const u32 sample) -{ - const unsigned long non_zero_sample = sample ? : 1; - - return int_sqrt(non_zero_sample << 10); -} - -/** * tfrc_ewma - Exponentially weighted moving average * @weight: Weight to be used as damping factor, in units of 1/10 */ @@ -73,7 +58,6 @@ static inline u32 tfrc_ewma(const u32 avg, const u32 newval, const u8 weight) extern u32 tfrc_calc_x(u16 s, u32 R, u32 p); extern u32 tfrc_calc_x_reverse_lookup(u32 fvalue); -extern u32 tfrc_invert_loss_event_rate(u32 loss_event_rate); extern int tfrc_tx_packet_history_init(void); extern void tfrc_tx_packet_history_exit(void); diff --git a/net/dccp/ccids/lib/tfrc_equation.c b/net/dccp/ccids/lib/tfrc_equation.c index 38239c4d5e1..2f20a29cffe 100644 --- a/net/dccp/ccids/lib/tfrc_equation.c +++ b/net/dccp/ccids/lib/tfrc_equation.c @@ -632,16 +632,8 @@ u32 tfrc_calc_x(u16 s, u32 R, u32 p) if (p <= TFRC_CALC_X_SPLIT) { /* 0.0000 < p <= 0.05 */ if (p < TFRC_SMALLEST_P) { /* 0.0000 < p < 0.0001 */ - /* - * In the congestion-avoidance phase p decays towards 0 - * when there are no further losses, so this case is - * natural. Truncating to p_min = 0.01% means that the - * maximum achievable throughput is limited to about - * X_calc_max = 122.4 * s/RTT (see RFC 3448, 3.1); e.g. - * with s=1500 bytes, RTT=0.01 s: X_calc_max = 147 Mbps. - */ - tfrc_pr_debug("Value of p (%d) below resolution. " - "Substituting %d\n", p, TFRC_SMALLEST_P); + DCCP_WARN("Value of p (%d) below resolution. " + "Substituting %d\n", p, TFRC_SMALLEST_P); index = 0; } else /* 0.0001 <= p <= 0.05 */ index = p/TFRC_SMALLEST_P - 1; @@ -666,6 +658,7 @@ u32 tfrc_calc_x(u16 s, u32 R, u32 p) result = scaled_div(s, R); return scaled_div32(result, f); } + EXPORT_SYMBOL_GPL(tfrc_calc_x); /** @@ -700,19 +693,5 @@ u32 tfrc_calc_x_reverse_lookup(u32 fvalue) index = tfrc_binsearch(fvalue, 0); return (index + 1) * 1000000 / TFRC_CALC_X_ARRSIZE; } -EXPORT_SYMBOL_GPL(tfrc_calc_x_reverse_lookup); -/** - * tfrc_invert_loss_event_rate - Compute p so that 10^6 corresponds to 100% - * When @loss_event_rate is large, there is a chance that p is truncated to 0. - * To avoid re-entering slow-start in that case, we set p = TFRC_SMALLEST_P > 0. - */ -u32 tfrc_invert_loss_event_rate(u32 loss_event_rate) -{ - if (loss_event_rate == UINT_MAX) /* see RFC 4342, 8.5 */ - return 0; - if (unlikely(loss_event_rate == 0)) /* map 1/0 into 100% */ - return 1000000; - return max_t(u32, scaled_div(1, loss_event_rate), TFRC_SMALLEST_P); -} -EXPORT_SYMBOL_GPL(tfrc_invert_loss_event_rate); +EXPORT_SYMBOL_GPL(tfrc_calc_x_reverse_lookup); diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h index 5281190aa19..b4bc6e095a0 100644 --- a/net/dccp/dccp.h +++ b/net/dccp/dccp.h @@ -42,11 +42,9 @@ extern int dccp_debug; #define dccp_pr_debug(format, a...) DCCP_PR_DEBUG(dccp_debug, format, ##a) #define dccp_pr_debug_cat(format, a...) DCCP_PRINTK(dccp_debug, format, ##a) -#define dccp_debug(fmt, a...) dccp_pr_debug_cat(KERN_DEBUG fmt, ##a) #else #define dccp_pr_debug(format, a...) #define dccp_pr_debug_cat(format, a...) -#define dccp_debug(format, a...) #endif extern struct inet_hashinfo dccp_hashinfo; @@ -63,14 +61,11 @@ extern void dccp_time_wait(struct sock *sk, int state, int timeo); * - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields * Hence a safe upper bound for the maximum option length is 1020-28 = 992 */ -#define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(uint32_t)) +#define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(int)) #define DCCP_MAX_PACKET_HDR 28 #define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR) #define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER) -/* Upper bound for initial feature-negotiation overhead (padded to 32 bits) */ -#define DCCP_FEATNEG_OVERHEAD (32 * sizeof(uint32_t)) - #define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT * state, about 60 seconds */ @@ -86,13 +81,10 @@ extern void dccp_time_wait(struct sock *sk, int state, int timeo); */ #define DCCP_RTO_MAX ((unsigned)(64 * HZ)) -/* DCCP base time resolution - 10 microseconds (RFC 4340, 13.1 ... 13.3) */ -#define DCCP_TIME_RESOLUTION 10 - /* * RTT sampling: sanity bounds and fallback RTT value from RFC 4340, section 3.4 */ -#define DCCP_SANE_RTT_MIN (10 * DCCP_TIME_RESOLUTION) +#define DCCP_SANE_RTT_MIN 100 #define DCCP_FALLBACK_RTT (USEC_PER_SEC / 5) #define DCCP_SANE_RTT_MAX (3 * USEC_PER_SEC) @@ -103,6 +95,12 @@ extern void dccp_time_wait(struct sock *sk, int state, int timeo); extern int sysctl_dccp_request_retries; extern int sysctl_dccp_retries1; extern int sysctl_dccp_retries2; +extern int sysctl_dccp_feat_sequence_window; +extern int sysctl_dccp_feat_rx_ccid; +extern int sysctl_dccp_feat_tx_ccid; +extern int sysctl_dccp_feat_ack_ratio; +extern int sysctl_dccp_feat_send_ack_vector; +extern int sysctl_dccp_feat_send_ndp_count; extern int sysctl_dccp_tx_qlen; extern int sysctl_dccp_sync_ratelimit; @@ -237,22 +235,8 @@ extern void dccp_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, extern void dccp_send_sync(struct sock *sk, const u64 seq, const enum dccp_pkt_type pkt_type); -/* - * TX Packet Dequeueing Interface - */ -extern void dccp_qpolicy_push(struct sock *sk, struct sk_buff *skb); -extern bool dccp_qpolicy_full(struct sock *sk); -extern void dccp_qpolicy_drop(struct sock *sk, struct sk_buff *skb); -extern struct sk_buff *dccp_qpolicy_top(struct sock *sk); -extern struct sk_buff *dccp_qpolicy_pop(struct sock *sk); -extern bool dccp_qpolicy_param_ok(struct sock *sk, __be32 param); - -/* - * TX Packet Output and TX Timers - */ -extern void dccp_write_xmit(struct sock *sk); +extern void dccp_write_xmit(struct sock *sk, int block); extern void dccp_write_space(struct sock *sk); -extern void dccp_flush_write_queue(struct sock *sk, long *time_budget); extern void dccp_init_xmit_timers(struct sock *sk); static inline void dccp_clear_xmit_timers(struct sock *sk) @@ -268,8 +252,7 @@ extern const char *dccp_state_name(const int state); extern void dccp_set_state(struct sock *sk, const int state); extern void dccp_done(struct sock *sk); -extern int dccp_reqsk_init(struct request_sock *rq, struct dccp_sock const *dp, - struct sk_buff const *skb); +extern void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb); extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb); @@ -334,14 +317,7 @@ extern struct sk_buff *dccp_ctl_make_reset(struct sock *sk, extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code); extern void dccp_send_close(struct sock *sk, const int active); extern int dccp_invalid_packet(struct sk_buff *skb); - -static inline u32 dccp_sane_rtt(long usec_sample) -{ - if (unlikely(usec_sample <= 0 || usec_sample > DCCP_SANE_RTT_MAX)) - DCCP_WARN("RTT sample %ld out of bounds!\n", usec_sample); - return clamp_val(usec_sample, DCCP_SANE_RTT_MIN, DCCP_SANE_RTT_MAX); -} -extern u32 dccp_sample_rtt(struct sock *sk, long delta); +extern u32 dccp_sample_rtt(struct sock *sk, long delta); static inline int dccp_bad_service_code(const struct sock *sk, const __be32 service) @@ -435,62 +411,36 @@ static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack, static inline void dccp_update_gsr(struct sock *sk, u64 seq) { struct dccp_sock *dp = dccp_sk(sk); + const struct dccp_minisock *dmsk = dccp_msk(sk); dp->dccps_gsr = seq; - /* Sequence validity window depends on remote Sequence Window (7.5.1) */ - dp->dccps_swl = SUB48(ADD48(dp->dccps_gsr, 1), dp->dccps_r_seq_win / 4); - /* - * Adjust SWL so that it is not below ISR. In contrast to RFC 4340, - * 7.5.1 we perform this check beyond the initial handshake: W/W' are - * always > 32, so for the first W/W' packets in the lifetime of a - * connection we always have to adjust SWL. - * A second reason why we are doing this is that the window depends on - * the feature-remote value of Sequence Window: nothing stops the peer - * from updating this value while we are busy adjusting SWL for the - * first W packets (we would have to count from scratch again then). - * Therefore it is safer to always make sure that the Sequence Window - * is not artificially extended by a peer who grows SWL downwards by - * continually updating the feature-remote Sequence-Window. - * If sequence numbers wrap it is bad luck. But that will take a while - * (48 bit), and this measure prevents Sequence-number attacks. - */ - if (before48(dp->dccps_swl, dp->dccps_isr)) - dp->dccps_swl = dp->dccps_isr; - dp->dccps_swh = ADD48(dp->dccps_gsr, (3 * dp->dccps_r_seq_win) / 4); + dccp_set_seqno(&dp->dccps_swl, + dp->dccps_gsr + 1 - (dmsk->dccpms_sequence_window / 4)); + dccp_set_seqno(&dp->dccps_swh, + dp->dccps_gsr + (3 * dmsk->dccpms_sequence_window) / 4); } static inline void dccp_update_gss(struct sock *sk, u64 seq) { struct dccp_sock *dp = dccp_sk(sk); - dp->dccps_gss = seq; - /* Ack validity window depends on local Sequence Window value (7.5.1) */ - dp->dccps_awl = SUB48(ADD48(dp->dccps_gss, 1), dp->dccps_l_seq_win); - /* Adjust AWL so that it is not below ISS - see comment above for SWL */ - if (before48(dp->dccps_awl, dp->dccps_iss)) - dp->dccps_awl = dp->dccps_iss; - dp->dccps_awh = dp->dccps_gss; -} - -static inline int dccp_ackvec_pending(const struct sock *sk) -{ - return dccp_sk(sk)->dccps_hc_rx_ackvec != NULL && - !dccp_ackvec_is_empty(dccp_sk(sk)->dccps_hc_rx_ackvec); + dp->dccps_awh = dp->dccps_gss = seq; + dccp_set_seqno(&dp->dccps_awl, + (dp->dccps_gss - + dccp_msk(sk)->dccpms_sequence_window + 1)); } static inline int dccp_ack_pending(const struct sock *sk) { - return dccp_ackvec_pending(sk) || inet_csk_ack_scheduled(sk); + const struct dccp_sock *dp = dccp_sk(sk); + return dp->dccps_timestamp_echo != 0 || +#ifdef CONFIG_IP_DCCP_ACKVEC + (dccp_msk(sk)->dccpms_send_ack_vector && + dccp_ackvec_pending(dp->dccps_hc_rx_ackvec)) || +#endif + inet_csk_ack_scheduled(sk); } -extern int dccp_feat_signal_nn_change(struct sock *sk, u8 feat, u64 nn_val); -extern int dccp_feat_finalise_settings(struct dccp_sock *dp); -extern int dccp_feat_server_ccid_dependencies(struct dccp_request_sock *dreq); -extern int dccp_feat_insert_opts(struct dccp_sock*, struct dccp_request_sock*, - struct sk_buff *skb); -extern int dccp_feat_activate_values(struct sock *sk, struct list_head *fn); -extern void dccp_feat_list_purge(struct list_head *fn_list); - extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb); extern int dccp_insert_options_rsk(struct dccp_request_sock*, struct sk_buff*); extern int dccp_insert_option_elapsed_time(struct sock *sk, diff --git a/net/dccp/diag.c b/net/dccp/diag.c index 93aae7c9555..d8a3509b26f 100644 --- a/net/dccp/diag.c +++ b/net/dccp/diag.c @@ -29,7 +29,7 @@ static void dccp_get_info(struct sock *sk, struct tcp_info *info) info->tcpi_backoff = icsk->icsk_backoff; info->tcpi_pmtu = icsk->icsk_pmtu_cookie; - if (dp->dccps_hc_rx_ackvec != NULL) + if (dccp_msk(sk)->dccpms_send_ack_vector) info->tcpi_options |= TCPI_OPT_SACK; ccid_hc_rx_get_info(dp->dccps_hc_rx_ccid, sk, info); diff --git a/net/dccp/feat.c b/net/dccp/feat.c index f94c7c9d1a7..933a0ecf8d4 100644 --- a/net/dccp/feat.c +++ b/net/dccp/feat.c @@ -1,19 +1,11 @@ /* * net/dccp/feat.c * - * Feature negotiation for the DCCP protocol (RFC 4340, section 6) - * - * Copyright (c) 2008 The University of Aberdeen, Scotland, UK - * Copyright (c) 2008 Gerrit Renker <gerrit@erg.abdn.ac.uk> - * Rewrote from scratch, some bits from earlier code by - * Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk> - * + * An implementation of the DCCP protocol + * Andrea Bittau <a.bittau@cs.ucl.ac.uk> * * ASSUMPTIONS * ----------- - * o Feature negotiation is coordinated with connection setup (as in TCP), wild - * changes of parameters of an established connection are not supported. - * o Changing NN values (Ack Ratio only) is supported in state OPEN/PARTOPEN. * o All currently known SP features have 1-byte quantities. If in the future * extensions of RFCs 4340..42 define features with item lengths larger than * one byte, a feature-specific extension of the code will be required. @@ -23,1510 +15,635 @@ * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ + #include <linux/module.h> + #include "ccid.h" #include "feat.h" -/* feature-specific sysctls - initialised to the defaults from RFC 4340, 6.4 */ -unsigned long sysctl_dccp_sequence_window __read_mostly = 100; -int sysctl_dccp_rx_ccid __read_mostly = 2, - sysctl_dccp_tx_ccid __read_mostly = 2; +#define DCCP_FEAT_SP_NOAGREE (-123) -/* - * Feature activation handlers. - * - * These all use an u64 argument, to provide enough room for NN/SP features. At - * this stage the negotiated values have been checked to be within their range. - */ -static int dccp_hdlr_ccid(struct sock *sk, u64 ccid, bool rx) +int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature, + u8 *val, u8 len, gfp_t gfp) { - struct dccp_sock *dp = dccp_sk(sk); - struct ccid *new_ccid = ccid_new(ccid, sk, rx, gfp_any()); + struct dccp_opt_pend *opt; - if (new_ccid == NULL) - return -ENOMEM; + dccp_feat_debug(type, feature, *val); - if (rx) { - ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); - dp->dccps_hc_rx_ccid = new_ccid; - } else { - ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk); - dp->dccps_hc_tx_ccid = new_ccid; + if (len > 3) { + DCCP_WARN("invalid length %d\n", len); + return -EINVAL; + } + /* XXX add further sanity checks */ + + /* check if that feature is already being negotiated */ + list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) { + /* ok we found a negotiation for this option already */ + if (opt->dccpop_feat == feature && opt->dccpop_type == type) { + dccp_pr_debug("Replacing old\n"); + /* replace */ + BUG_ON(opt->dccpop_val == NULL); + kfree(opt->dccpop_val); + opt->dccpop_val = val; + opt->dccpop_len = len; + opt->dccpop_conf = 0; + return 0; + } } - return 0; -} -static int dccp_hdlr_seq_win(struct sock *sk, u64 seq_win, bool rx) -{ - struct dccp_sock *dp = dccp_sk(sk); + /* negotiation for a new feature */ + opt = kmalloc(sizeof(*opt), gfp); + if (opt == NULL) + return -ENOMEM; - if (rx) { - dp->dccps_r_seq_win = seq_win; - /* propagate changes to update SWL/SWH */ - dccp_update_gsr(sk, dp->dccps_gsr); - } else { - dp->dccps_l_seq_win = seq_win; - /* propagate changes to update AWL */ - dccp_update_gss(sk, dp->dccps_gss); - } - return 0; -} + opt->dccpop_type = type; + opt->dccpop_feat = feature; + opt->dccpop_len = len; + opt->dccpop_val = val; + opt->dccpop_conf = 0; + opt->dccpop_sc = NULL; -static int dccp_hdlr_ack_ratio(struct sock *sk, u64 ratio, bool rx) -{ -#ifndef __CCID2_COPES_GRACEFULLY_WITH_DYNAMIC_ACK_RATIO_UPDATES__ - /* - * FIXME: This is required until several problems in the CCID-2 code are - * resolved. The CCID-2 code currently does not cope well; using dynamic - * Ack Ratios greater than 1 caused instabilities. These were manifest - * in hangups and long RTO timeouts (1...3 seconds). Until this has been - * stabilised, it is safer not to activate dynamic Ack Ratio changes. - */ - dccp_pr_debug("Not changing %s Ack Ratio from 1 to %u\n", - rx ? "RX" : "TX", (u16)ratio); - ratio = 1; -#endif - if (rx) - dccp_sk(sk)->dccps_r_ack_ratio = ratio; - else - dccp_sk(sk)->dccps_l_ack_ratio = ratio; + BUG_ON(opt->dccpop_val == NULL); + + list_add_tail(&opt->dccpop_node, &dmsk->dccpms_pending); return 0; } -static int dccp_hdlr_ackvec(struct sock *sk, u64 enable, bool rx) +EXPORT_SYMBOL_GPL(dccp_feat_change); + +static int dccp_feat_update_ccid(struct sock *sk, u8 type, u8 new_ccid_nr) { struct dccp_sock *dp = dccp_sk(sk); + struct dccp_minisock *dmsk = dccp_msk(sk); + /* figure out if we are changing our CCID or the peer's */ + const int rx = type == DCCPO_CHANGE_R; + const u8 ccid_nr = rx ? dmsk->dccpms_rx_ccid : dmsk->dccpms_tx_ccid; + struct ccid *new_ccid; + + /* Check if nothing is being changed. */ + if (ccid_nr == new_ccid_nr) + return 0; + + new_ccid = ccid_new(new_ccid_nr, sk, rx, GFP_ATOMIC); + if (new_ccid == NULL) + return -ENOMEM; if (rx) { - if (enable && dp->dccps_hc_rx_ackvec == NULL) { - dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(gfp_any()); - if (dp->dccps_hc_rx_ackvec == NULL) - return -ENOMEM; - } else if (!enable) { - dccp_ackvec_free(dp->dccps_hc_rx_ackvec); - dp->dccps_hc_rx_ackvec = NULL; - } + ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); + dp->dccps_hc_rx_ccid = new_ccid; + dmsk->dccpms_rx_ccid = new_ccid_nr; + } else { + ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk); + dp->dccps_hc_tx_ccid = new_ccid; + dmsk->dccpms_tx_ccid = new_ccid_nr; } - return 0; -} -static int dccp_hdlr_ndp(struct sock *sk, u64 enable, bool rx) -{ - if (!rx) - dccp_sk(sk)->dccps_send_ndp_count = (enable > 0); return 0; } -/* - * Minimum Checksum Coverage is located at the RX side (9.2.1). This means that - * `rx' holds when the sending peer informs about his partial coverage via a - * ChangeR() option. In the other case, we are the sender and the receiver - * announces its coverage via ChangeL() options. The policy here is to honour - * such communication by enabling the corresponding partial coverage - but only - * if it has not been set manually before; the warning here means that all - * packets will be dropped. - */ -static int dccp_hdlr_min_cscov(struct sock *sk, u64 cscov, bool rx) +static int dccp_feat_update(struct sock *sk, u8 type, u8 feat, u8 val) { - struct dccp_sock *dp = dccp_sk(sk); + dccp_feat_debug(type, feat, val); - if (rx) - dp->dccps_pcrlen = cscov; - else { - if (dp->dccps_pcslen == 0) - dp->dccps_pcslen = cscov; - else if (cscov > dp->dccps_pcslen) - DCCP_WARN("CsCov %u too small, peer requires >= %u\n", - dp->dccps_pcslen, (u8)cscov); + switch (feat) { + case DCCPF_CCID: + return dccp_feat_update_ccid(sk, type, val); + default: + dccp_pr_debug("UNIMPLEMENTED: %s(%d, ...)\n", + dccp_feat_typename(type), feat); + break; } return 0; } -static const struct { - u8 feat_num; /* DCCPF_xxx */ - enum dccp_feat_type rxtx; /* RX or TX */ - enum dccp_feat_type reconciliation; /* SP or NN */ - u8 default_value; /* as in 6.4 */ - int (*activation_hdlr)(struct sock *sk, u64 val, bool rx); -/* - * Lookup table for location and type of features (from RFC 4340/4342) - * +--------------------------+----+-----+----+----+---------+-----------+ - * | Feature | Location | Reconc. | Initial | Section | - * | | RX | TX | SP | NN | Value | Reference | - * +--------------------------+----+-----+----+----+---------+-----------+ - * | DCCPF_CCID | | X | X | | 2 | 10 | - * | DCCPF_SHORT_SEQNOS | | X | X | | 0 | 7.6.1 | - * | DCCPF_SEQUENCE_WINDOW | | X | | X | 100 | 7.5.2 | - * | DCCPF_ECN_INCAPABLE | X | | X | | 0 | 12.1 | - * | DCCPF_ACK_RATIO | | X | | X | 2 | 11.3 | - * | DCCPF_SEND_ACK_VECTOR | X | | X | | 0 | 11.5 | - * | DCCPF_SEND_NDP_COUNT | | X | X | | 0 | 7.7.2 | - * | DCCPF_MIN_CSUM_COVER | X | | X | | 0 | 9.2.1 | - * | DCCPF_DATA_CHECKSUM | X | | X | | 0 | 9.3.1 | - * | DCCPF_SEND_LEV_RATE | X | | X | | 0 | 4342/8.4 | - * +--------------------------+----+-----+----+----+---------+-----------+ - */ -} dccp_feat_table[] = { - { DCCPF_CCID, FEAT_AT_TX, FEAT_SP, 2, dccp_hdlr_ccid }, - { DCCPF_SHORT_SEQNOS, FEAT_AT_TX, FEAT_SP, 0, NULL }, - { DCCPF_SEQUENCE_WINDOW, FEAT_AT_TX, FEAT_NN, 100, dccp_hdlr_seq_win }, - { DCCPF_ECN_INCAPABLE, FEAT_AT_RX, FEAT_SP, 0, NULL }, - { DCCPF_ACK_RATIO, FEAT_AT_TX, FEAT_NN, 2, dccp_hdlr_ack_ratio}, - { DCCPF_SEND_ACK_VECTOR, FEAT_AT_RX, FEAT_SP, 0, dccp_hdlr_ackvec }, - { DCCPF_SEND_NDP_COUNT, FEAT_AT_TX, FEAT_SP, 0, dccp_hdlr_ndp }, - { DCCPF_MIN_CSUM_COVER, FEAT_AT_RX, FEAT_SP, 0, dccp_hdlr_min_cscov}, - { DCCPF_DATA_CHECKSUM, FEAT_AT_RX, FEAT_SP, 0, NULL }, - { DCCPF_SEND_LEV_RATE, FEAT_AT_RX, FEAT_SP, 0, NULL }, -}; -#define DCCP_FEAT_SUPPORTED_MAX ARRAY_SIZE(dccp_feat_table) - -/** - * dccp_feat_index - Hash function to map feature number into array position - * Returns consecutive array index or -1 if the feature is not understood. - */ -static int dccp_feat_index(u8 feat_num) +static int dccp_feat_reconcile(struct sock *sk, struct dccp_opt_pend *opt, + u8 *rpref, u8 rlen) { - /* The first 9 entries are occupied by the types from RFC 4340, 6.4 */ - if (feat_num > DCCPF_RESERVED && feat_num <= DCCPF_DATA_CHECKSUM) - return feat_num - 1; + struct dccp_sock *dp = dccp_sk(sk); + u8 *spref, slen, *res = NULL; + int i, j, rc, agree = 1; + BUG_ON(rpref == NULL); + + /* check if we are the black sheep */ + if (dp->dccps_role == DCCP_ROLE_CLIENT) { + spref = rpref; + slen = rlen; + rpref = opt->dccpop_val; + rlen = opt->dccpop_len; + } else { + spref = opt->dccpop_val; + slen = opt->dccpop_len; + } /* - * Other features: add cases for new feature types here after adding - * them to the above table. + * Now we have server preference list in spref and client preference in + * rpref */ - switch (feat_num) { - case DCCPF_SEND_LEV_RATE: - return DCCP_FEAT_SUPPORTED_MAX - 1; - } - return -1; -} - -static u8 dccp_feat_type(u8 feat_num) -{ - int idx = dccp_feat_index(feat_num); - - if (idx < 0) - return FEAT_UNKNOWN; - return dccp_feat_table[idx].reconciliation; -} + BUG_ON(spref == NULL); + BUG_ON(rpref == NULL); -static int dccp_feat_default_value(u8 feat_num) -{ - int idx = dccp_feat_index(feat_num); + /* FIXME sanity check vals */ - return idx < 0 ? : dccp_feat_table[idx].default_value; -} - -/* - * Debugging and verbose-printing section - */ -static const char *dccp_feat_fname(const u8 feat) -{ - static const char *feature_names[] = { - [DCCPF_RESERVED] = "Reserved", - [DCCPF_CCID] = "CCID", - [DCCPF_SHORT_SEQNOS] = "Allow Short Seqnos", - [DCCPF_SEQUENCE_WINDOW] = "Sequence Window", - [DCCPF_ECN_INCAPABLE] = "ECN Incapable", - [DCCPF_ACK_RATIO] = "Ack Ratio", - [DCCPF_SEND_ACK_VECTOR] = "Send ACK Vector", - [DCCPF_SEND_NDP_COUNT] = "Send NDP Count", - [DCCPF_MIN_CSUM_COVER] = "Min. Csum Coverage", - [DCCPF_DATA_CHECKSUM] = "Send Data Checksum", - }; - if (feat > DCCPF_DATA_CHECKSUM && feat < DCCPF_MIN_CCID_SPECIFIC) - return feature_names[DCCPF_RESERVED]; - - if (feat == DCCPF_SEND_LEV_RATE) - return "Send Loss Event Rate"; - if (feat >= DCCPF_MIN_CCID_SPECIFIC) - return "CCID-specific"; - - return feature_names[feat]; -} - -static const char *dccp_feat_sname[] = { "DEFAULT", "INITIALISING", "CHANGING", - "UNSTABLE", "STABLE" }; - -#ifdef CONFIG_IP_DCCP_DEBUG -static const char *dccp_feat_oname(const u8 opt) -{ - switch (opt) { - case DCCPO_CHANGE_L: return "Change_L"; - case DCCPO_CONFIRM_L: return "Confirm_L"; - case DCCPO_CHANGE_R: return "Change_R"; - case DCCPO_CONFIRM_R: return "Confirm_R"; + /* Are values in any order? XXX Lame "algorithm" here */ + for (i = 0; i < slen; i++) { + for (j = 0; j < rlen; j++) { + if (spref[i] == rpref[j]) { + res = &spref[i]; + break; + } + } + if (res) + break; } - return NULL; -} -static void dccp_feat_printval(u8 feat_num, dccp_feat_val const *val) -{ - u8 i, type = dccp_feat_type(feat_num); - - if (val == NULL || (type == FEAT_SP && val->sp.vec == NULL)) - dccp_pr_debug_cat("(NULL)"); - else if (type == FEAT_SP) - for (i = 0; i < val->sp.len; i++) - dccp_pr_debug_cat("%s%u", i ? " " : "", val->sp.vec[i]); - else if (type == FEAT_NN) - dccp_pr_debug_cat("%llu", (unsigned long long)val->nn); - else - dccp_pr_debug_cat("unknown type %u", type); -} - -static void dccp_feat_printvals(u8 feat_num, u8 *list, u8 len) -{ - u8 type = dccp_feat_type(feat_num); - dccp_feat_val fval = { .sp.vec = list, .sp.len = len }; - - if (type == FEAT_NN) - fval.nn = dccp_decode_value_var(list, len); - dccp_feat_printval(feat_num, &fval); -} + /* we didn't agree on anything */ + if (res == NULL) { + /* confirm previous value */ + switch (opt->dccpop_feat) { + case DCCPF_CCID: + /* XXX did i get this right? =P */ + if (opt->dccpop_type == DCCPO_CHANGE_L) + res = &dccp_msk(sk)->dccpms_tx_ccid; + else + res = &dccp_msk(sk)->dccpms_rx_ccid; + break; -static void dccp_feat_print_entry(struct dccp_feat_entry const *entry) -{ - dccp_debug(" * %s %s = ", entry->is_local ? "local" : "remote", - dccp_feat_fname(entry->feat_num)); - dccp_feat_printval(entry->feat_num, &entry->val); - dccp_pr_debug_cat(", state=%s %s\n", dccp_feat_sname[entry->state], - entry->needs_confirm ? "(Confirm pending)" : ""); -} + default: + DCCP_BUG("Fell through, feat=%d", opt->dccpop_feat); + /* XXX implement res */ + return -EFAULT; + } -#define dccp_feat_print_opt(opt, feat, val, len, mandatory) do { \ - dccp_pr_debug("%s(%s, ", dccp_feat_oname(opt), dccp_feat_fname(feat));\ - dccp_feat_printvals(feat, val, len); \ - dccp_pr_debug_cat(") %s\n", mandatory ? "!" : ""); } while (0) - -#define dccp_feat_print_fnlist(fn_list) { \ - const struct dccp_feat_entry *___entry; \ - \ - dccp_pr_debug("List Dump:\n"); \ - list_for_each_entry(___entry, fn_list, node) \ - dccp_feat_print_entry(___entry); \ -} -#else /* ! CONFIG_IP_DCCP_DEBUG */ -#define dccp_feat_print_opt(opt, feat, val, len, mandatory) -#define dccp_feat_print_fnlist(fn_list) -#endif + dccp_pr_debug("Don't agree... reconfirming %d\n", *res); + agree = 0; /* this is used for mandatory options... */ + } -static int __dccp_feat_activate(struct sock *sk, const int idx, - const bool is_local, dccp_feat_val const *fval) -{ - bool rx; - u64 val; + /* need to put result and our preference list */ + rlen = 1 + opt->dccpop_len; + rpref = kmalloc(rlen, GFP_ATOMIC); + if (rpref == NULL) + return -ENOMEM; - if (idx < 0 || idx >= DCCP_FEAT_SUPPORTED_MAX) - return -1; - if (dccp_feat_table[idx].activation_hdlr == NULL) - return 0; + *rpref = *res; + memcpy(&rpref[1], opt->dccpop_val, opt->dccpop_len); - if (fval == NULL) { - val = dccp_feat_table[idx].default_value; - } else if (dccp_feat_table[idx].reconciliation == FEAT_SP) { - if (fval->sp.vec == NULL) { - /* - * This can happen when an empty Confirm is sent - * for an SP (i.e. known) feature. In this case - * we would be using the default anyway. - */ - DCCP_CRIT("Feature #%d undefined: using default", idx); - val = dccp_feat_table[idx].default_value; - } else { - val = fval->sp.vec[0]; + /* put it in the "confirm queue" */ + if (opt->dccpop_sc == NULL) { + opt->dccpop_sc = kmalloc(sizeof(*opt->dccpop_sc), GFP_ATOMIC); + if (opt->dccpop_sc == NULL) { + kfree(rpref); + return -ENOMEM; } } else { - val = fval->nn; + /* recycle the confirm slot */ + BUG_ON(opt->dccpop_sc->dccpoc_val == NULL); + kfree(opt->dccpop_sc->dccpoc_val); + dccp_pr_debug("recycling confirm slot\n"); + } + memset(opt->dccpop_sc, 0, sizeof(*opt->dccpop_sc)); + + opt->dccpop_sc->dccpoc_val = rpref; + opt->dccpop_sc->dccpoc_len = rlen; + + /* update the option on our side [we are about to send the confirm] */ + rc = dccp_feat_update(sk, opt->dccpop_type, opt->dccpop_feat, *res); + if (rc) { + kfree(opt->dccpop_sc->dccpoc_val); + kfree(opt->dccpop_sc); + opt->dccpop_sc = NULL; + return rc; } - /* Location is RX if this is a local-RX or remote-TX feature */ - rx = (is_local == (dccp_feat_table[idx].rxtx == FEAT_AT_RX)); - - dccp_debug(" -> activating %s %s, %sval=%llu\n", rx ? "RX" : "TX", - dccp_feat_fname(dccp_feat_table[idx].feat_num), - fval ? "" : "default ", (unsigned long long)val); - - return dccp_feat_table[idx].activation_hdlr(sk, val, rx); -} - -/** - * dccp_feat_activate - Activate feature value on socket - * @sk: fully connected DCCP socket (after handshake is complete) - * @feat_num: feature to activate, one of %dccp_feature_numbers - * @local: whether local (1) or remote (0) @feat_num is meant - * @fval: the value (SP or NN) to activate, or NULL to use the default value - * For general use this function is preferable over __dccp_feat_activate(). - */ -static int dccp_feat_activate(struct sock *sk, u8 feat_num, bool local, - dccp_feat_val const *fval) -{ - return __dccp_feat_activate(sk, dccp_feat_index(feat_num), local, fval); -} - -/* Test for "Req'd" feature (RFC 4340, 6.4) */ -static inline int dccp_feat_must_be_understood(u8 feat_num) -{ - return feat_num == DCCPF_CCID || feat_num == DCCPF_SHORT_SEQNOS || - feat_num == DCCPF_SEQUENCE_WINDOW; -} + dccp_pr_debug("Will confirm %d\n", *rpref); -/* copy constructor, fval must not already contain allocated memory */ -static int dccp_feat_clone_sp_val(dccp_feat_val *fval, u8 const *val, u8 len) -{ - fval->sp.len = len; - if (fval->sp.len > 0) { - fval->sp.vec = kmemdup(val, len, gfp_any()); - if (fval->sp.vec == NULL) { - fval->sp.len = 0; - return -ENOBUFS; - } + /* say we want to change to X but we just got a confirm X, suppress our + * change + */ + if (!opt->dccpop_conf) { + if (*opt->dccpop_val == *res) + opt->dccpop_conf = 1; + dccp_pr_debug("won't ask for change of same feature\n"); } - return 0; -} -static void dccp_feat_val_destructor(u8 feat_num, dccp_feat_val *val) -{ - if (unlikely(val == NULL)) - return; - if (dccp_feat_type(feat_num) == FEAT_SP) - kfree(val->sp.vec); - memset(val, 0, sizeof(*val)); + return agree ? 0 : DCCP_FEAT_SP_NOAGREE; /* used for mandatory opts */ } -static struct dccp_feat_entry * - dccp_feat_clone_entry(struct dccp_feat_entry const *original) +static int dccp_feat_sp(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len) { - struct dccp_feat_entry *new; - u8 type = dccp_feat_type(original->feat_num); - - if (type == FEAT_UNKNOWN) - return NULL; + struct dccp_minisock *dmsk = dccp_msk(sk); + struct dccp_opt_pend *opt; + int rc = 1; + u8 t; - new = kmemdup(original, sizeof(struct dccp_feat_entry), gfp_any()); - if (new == NULL) - return NULL; + /* + * We received a CHANGE. We gotta match it against our own preference + * list. If we got a CHANGE_R it means it's a change for us, so we need + * to compare our CHANGE_L list. + */ + if (type == DCCPO_CHANGE_L) + t = DCCPO_CHANGE_R; + else + t = DCCPO_CHANGE_L; - if (type == FEAT_SP && dccp_feat_clone_sp_val(&new->val, - original->val.sp.vec, - original->val.sp.len)) { - kfree(new); - return NULL; - } - return new; -} + /* find our preference list for this feature */ + list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) { + if (opt->dccpop_type != t || opt->dccpop_feat != feature) + continue; -static void dccp_feat_entry_destructor(struct dccp_feat_entry *entry) -{ - if (entry != NULL) { - dccp_feat_val_destructor(entry->feat_num, &entry->val); - kfree(entry); + /* find the winner from the two preference lists */ + rc = dccp_feat_reconcile(sk, opt, val, len); + break; } -} -/* - * List management functions - * - * Feature negotiation lists rely on and maintain the following invariants: - * - each feat_num in the list is known, i.e. we know its type and default value - * - each feat_num/is_local combination is unique (old entries are overwritten) - * - SP values are always freshly allocated - * - list is sorted in increasing order of feature number (faster lookup) - */ -static struct dccp_feat_entry *dccp_feat_list_lookup(struct list_head *fn_list, - u8 feat_num, bool is_local) -{ - struct dccp_feat_entry *entry; + /* We didn't deal with the change. This can happen if we have no + * preference list for the feature. In fact, it just shouldn't + * happen---if we understand a feature, we should have a preference list + * with at least the default value. + */ + BUG_ON(rc == 1); - list_for_each_entry(entry, fn_list, node) - if (entry->feat_num == feat_num && entry->is_local == is_local) - return entry; - else if (entry->feat_num > feat_num) - break; - return NULL; + return rc; } -/** - * dccp_feat_entry_new - Central list update routine (called by all others) - * @head: list to add to - * @feat: feature number - * @local: whether the local (1) or remote feature with number @feat is meant - * This is the only constructor and serves to ensure the above invariants. - */ -static struct dccp_feat_entry * - dccp_feat_entry_new(struct list_head *head, u8 feat, bool local) +static int dccp_feat_nn(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len) { - struct dccp_feat_entry *entry; - - list_for_each_entry(entry, head, node) - if (entry->feat_num == feat && entry->is_local == local) { - dccp_feat_val_destructor(entry->feat_num, &entry->val); - return entry; - } else if (entry->feat_num > feat) { - head = &entry->node; - break; - } + struct dccp_opt_pend *opt; + struct dccp_minisock *dmsk = dccp_msk(sk); + u8 *copy; + int rc; - entry = kmalloc(sizeof(*entry), gfp_any()); - if (entry != NULL) { - entry->feat_num = feat; - entry->is_local = local; - list_add_tail(&entry->node, head); + /* NN features must be Change L (sec. 6.3.2) */ + if (type != DCCPO_CHANGE_L) { + dccp_pr_debug("received %s for NN feature %d\n", + dccp_feat_typename(type), feature); + return -EFAULT; } - return entry; -} -/** - * dccp_feat_push_change - Add/overwrite a Change option in the list - * @fn_list: feature-negotiation list to update - * @feat: one of %dccp_feature_numbers - * @local: whether local (1) or remote (0) @feat_num is meant - * @needs_mandatory: whether to use Mandatory feature negotiation options - * @fval: pointer to NN/SP value to be inserted (will be copied) - */ -static int dccp_feat_push_change(struct list_head *fn_list, u8 feat, u8 local, - u8 mandatory, dccp_feat_val *fval) -{ - struct dccp_feat_entry *new = dccp_feat_entry_new(fn_list, feat, local); + /* XXX sanity check opt val */ - if (new == NULL) + /* copy option so we can confirm it */ + opt = kzalloc(sizeof(*opt), GFP_ATOMIC); + if (opt == NULL) return -ENOMEM; - new->feat_num = feat; - new->is_local = local; - new->state = FEAT_INITIALISING; - new->needs_confirm = 0; - new->empty_confirm = 0; - new->val = *fval; - new->needs_mandatory = mandatory; + copy = kmemdup(val, len, GFP_ATOMIC); + if (copy == NULL) { + kfree(opt); + return -ENOMEM; + } - return 0; -} + opt->dccpop_type = DCCPO_CONFIRM_R; /* NN can only confirm R */ + opt->dccpop_feat = feature; + opt->dccpop_val = copy; + opt->dccpop_len = len; -/** - * dccp_feat_push_confirm - Add a Confirm entry to the FN list - * @fn_list: feature-negotiation list to add to - * @feat: one of %dccp_feature_numbers - * @local: whether local (1) or remote (0) @feat_num is being confirmed - * @fval: pointer to NN/SP value to be inserted or NULL - * Returns 0 on success, a Reset code for further processing otherwise. - */ -static int dccp_feat_push_confirm(struct list_head *fn_list, u8 feat, u8 local, - dccp_feat_val *fval) -{ - struct dccp_feat_entry *new = dccp_feat_entry_new(fn_list, feat, local); + /* change feature */ + rc = dccp_feat_update(sk, type, feature, *val); + if (rc) { + kfree(opt->dccpop_val); + kfree(opt); + return rc; + } - if (new == NULL) - return DCCP_RESET_CODE_TOO_BUSY; + dccp_feat_debug(type, feature, *copy); - new->feat_num = feat; - new->is_local = local; - new->state = FEAT_STABLE; /* transition in 6.6.2 */ - new->needs_confirm = 1; - new->empty_confirm = (fval == NULL); - new->val.nn = 0; /* zeroes the whole structure */ - if (!new->empty_confirm) - new->val = *fval; - new->needs_mandatory = 0; + list_add_tail(&opt->dccpop_node, &dmsk->dccpms_conf); return 0; } -static int dccp_push_empty_confirm(struct list_head *fn_list, u8 feat, u8 local) +static void dccp_feat_empty_confirm(struct dccp_minisock *dmsk, + u8 type, u8 feature) { - return dccp_feat_push_confirm(fn_list, feat, local, NULL); -} + /* XXX check if other confirms for that are queued and recycle slot */ + struct dccp_opt_pend *opt = kzalloc(sizeof(*opt), GFP_ATOMIC); -static inline void dccp_feat_list_pop(struct dccp_feat_entry *entry) -{ - list_del(&entry->node); - dccp_feat_entry_destructor(entry); -} - -void dccp_feat_list_purge(struct list_head *fn_list) -{ - struct dccp_feat_entry *entry, *next; - - list_for_each_entry_safe(entry, next, fn_list, node) - dccp_feat_entry_destructor(entry); - INIT_LIST_HEAD(fn_list); -} -EXPORT_SYMBOL_GPL(dccp_feat_list_purge); - -/* generate @to as full clone of @from - @to must not contain any nodes */ -int dccp_feat_clone_list(struct list_head const *from, struct list_head *to) -{ - struct dccp_feat_entry *entry, *new; - - INIT_LIST_HEAD(to); - list_for_each_entry(entry, from, node) { - new = dccp_feat_clone_entry(entry); - if (new == NULL) - goto cloning_failed; - list_add_tail(&new->node, to); + if (opt == NULL) { + /* XXX what do we do? Ignoring should be fine. It's a change + * after all =P + */ + return; } - return 0; -cloning_failed: - dccp_feat_list_purge(to); - return -ENOMEM; -} + switch (type) { + case DCCPO_CHANGE_L: + opt->dccpop_type = DCCPO_CONFIRM_R; + break; + case DCCPO_CHANGE_R: + opt->dccpop_type = DCCPO_CONFIRM_L; + break; + default: + DCCP_WARN("invalid type %d\n", type); + kfree(opt); + return; + } + opt->dccpop_feat = feature; + opt->dccpop_val = NULL; + opt->dccpop_len = 0; -/** - * dccp_feat_valid_nn_length - Enforce length constraints on NN options - * Length is between 0 and %DCCP_OPTVAL_MAXLEN. Used for outgoing packets only, - * incoming options are accepted as long as their values are valid. - */ -static u8 dccp_feat_valid_nn_length(u8 feat_num) -{ - if (feat_num == DCCPF_ACK_RATIO) /* RFC 4340, 11.3 and 6.6.8 */ - return 2; - if (feat_num == DCCPF_SEQUENCE_WINDOW) /* RFC 4340, 7.5.2 and 6.5 */ - return 6; - return 0; -} + /* change feature */ + dccp_pr_debug("Empty %s(%d)\n", dccp_feat_typename(type), feature); -static u8 dccp_feat_is_valid_nn_val(u8 feat_num, u64 val) -{ - switch (feat_num) { - case DCCPF_ACK_RATIO: - return val <= DCCPF_ACK_RATIO_MAX; - case DCCPF_SEQUENCE_WINDOW: - return val >= DCCPF_SEQ_WMIN && val <= DCCPF_SEQ_WMAX; - } - return 0; /* feature unknown - so we can't tell */ + list_add_tail(&opt->dccpop_node, &dmsk->dccpms_conf); } -/* check that SP values are within the ranges defined in RFC 4340 */ -static u8 dccp_feat_is_valid_sp_val(u8 feat_num, u8 val) +static void dccp_feat_flush_confirm(struct sock *sk) { - switch (feat_num) { - case DCCPF_CCID: - return val == DCCPC_CCID2 || val == DCCPC_CCID3; - /* Type-check Boolean feature values: */ - case DCCPF_SHORT_SEQNOS: - case DCCPF_ECN_INCAPABLE: - case DCCPF_SEND_ACK_VECTOR: - case DCCPF_SEND_NDP_COUNT: - case DCCPF_DATA_CHECKSUM: - case DCCPF_SEND_LEV_RATE: - return val < 2; - case DCCPF_MIN_CSUM_COVER: - return val < 16; - } - return 0; /* feature unknown */ -} + struct dccp_minisock *dmsk = dccp_msk(sk); + /* Check if there is anything to confirm in the first place */ + int yes = !list_empty(&dmsk->dccpms_conf); -static u8 dccp_feat_sp_list_ok(u8 feat_num, u8 const *sp_list, u8 sp_len) -{ - if (sp_list == NULL || sp_len < 1) - return 0; - while (sp_len--) - if (!dccp_feat_is_valid_sp_val(feat_num, *sp_list++)) - return 0; - return 1; -} + if (!yes) { + struct dccp_opt_pend *opt; -/** - * dccp_feat_insert_opts - Generate FN options from current list state - * @skb: next sk_buff to be sent to the peer - * @dp: for client during handshake and general negotiation - * @dreq: used by the server only (all Changes/Confirms in LISTEN/RESPOND) - */ -int dccp_feat_insert_opts(struct dccp_sock *dp, struct dccp_request_sock *dreq, - struct sk_buff *skb) -{ - struct list_head *fn = dreq ? &dreq->dreq_featneg : &dp->dccps_featneg; - struct dccp_feat_entry *pos, *next; - u8 opt, type, len, *ptr, nn_in_nbo[DCCP_OPTVAL_MAXLEN]; - bool rpt; - - /* put entries into @skb in the order they appear in the list */ - list_for_each_entry_safe_reverse(pos, next, fn, node) { - opt = dccp_feat_genopt(pos); - type = dccp_feat_type(pos->feat_num); - rpt = false; - - if (pos->empty_confirm) { - len = 0; - ptr = NULL; - } else { - if (type == FEAT_SP) { - len = pos->val.sp.len; - ptr = pos->val.sp.vec; - rpt = pos->needs_confirm; - } else if (type == FEAT_NN) { - len = dccp_feat_valid_nn_length(pos->feat_num); - ptr = nn_in_nbo; - dccp_encode_value_var(pos->val.nn, ptr, len); - } else { - DCCP_BUG("unknown feature %u", pos->feat_num); - return -1; + list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) { + if (opt->dccpop_conf) { + yes = 1; + break; } } - dccp_feat_print_opt(opt, pos->feat_num, ptr, len, 0); - - if (dccp_insert_fn_opt(skb, opt, pos->feat_num, ptr, len, rpt)) - return -1; - if (pos->needs_mandatory && dccp_insert_option_mandatory(skb)) - return -1; - /* - * Enter CHANGING after transmitting the Change option (6.6.2). - */ - if (pos->state == FEAT_INITIALISING) - pos->state = FEAT_CHANGING; } - return 0; -} - -/** - * __feat_register_nn - Register new NN value on socket - * @fn: feature-negotiation list to register with - * @feat: an NN feature from %dccp_feature_numbers - * @mandatory: use Mandatory option if 1 - * @nn_val: value to register (restricted to 4 bytes) - * Note that NN features are local by definition (RFC 4340, 6.3.2). - */ -static int __feat_register_nn(struct list_head *fn, u8 feat, - u8 mandatory, u64 nn_val) -{ - dccp_feat_val fval = { .nn = nn_val }; - - if (dccp_feat_type(feat) != FEAT_NN || - !dccp_feat_is_valid_nn_val(feat, nn_val)) - return -EINVAL; - - /* Don't bother with default values, they will be activated anyway. */ - if (nn_val - (u64)dccp_feat_default_value(feat) == 0) - return 0; - - return dccp_feat_push_change(fn, feat, 1, mandatory, &fval); -} - -/** - * __feat_register_sp - Register new SP value/list on socket - * @fn: feature-negotiation list to register with - * @feat: an SP feature from %dccp_feature_numbers - * @is_local: whether the local (1) or the remote (0) @feat is meant - * @mandatory: use Mandatory option if 1 - * @sp_val: SP value followed by optional preference list - * @sp_len: length of @sp_val in bytes - */ -static int __feat_register_sp(struct list_head *fn, u8 feat, u8 is_local, - u8 mandatory, u8 const *sp_val, u8 sp_len) -{ - dccp_feat_val fval; - if (dccp_feat_type(feat) != FEAT_SP || - !dccp_feat_sp_list_ok(feat, sp_val, sp_len)) - return -EINVAL; - - /* Avoid negotiating alien CCIDs by only advertising supported ones */ - if (feat == DCCPF_CCID && !ccid_support_check(sp_val, sp_len)) - return -EOPNOTSUPP; - - if (dccp_feat_clone_sp_val(&fval, sp_val, sp_len)) - return -ENOMEM; + if (!yes) + return; - return dccp_feat_push_change(fn, feat, is_local, mandatory, &fval); + /* OK there is something to confirm... */ + /* XXX check if packet is in flight? Send delayed ack?? */ + if (sk->sk_state == DCCP_OPEN) + dccp_send_ack(sk); } -/** - * dccp_feat_register_sp - Register requests to change SP feature values - * @sk: client or listening socket - * @feat: one of %dccp_feature_numbers - * @is_local: whether the local (1) or remote (0) @feat is meant - * @list: array of preferred values, in descending order of preference - * @len: length of @list in bytes - */ -int dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local, - u8 const *list, u8 len) -{ /* any changes must be registered before establishing the connection */ - if (sk->sk_state != DCCP_CLOSED) - return -EISCONN; - if (dccp_feat_type(feat) != FEAT_SP) - return -EINVAL; - return __feat_register_sp(&dccp_sk(sk)->dccps_featneg, feat, is_local, - 0, list, len); -} - -/* Analogous to dccp_feat_register_sp(), but for non-negotiable values */ -int dccp_feat_register_nn(struct sock *sk, u8 feat, u64 val) +int dccp_feat_change_recv(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len) { - /* any changes must be registered before establishing the connection */ - if (sk->sk_state != DCCP_CLOSED) - return -EISCONN; - if (dccp_feat_type(feat) != FEAT_NN) - return -EINVAL; - return __feat_register_nn(&dccp_sk(sk)->dccps_featneg, feat, 0, val); -} + int rc; -/** - * dccp_feat_signal_nn_change - Update NN values for an established connection - * @sk: DCCP socket of an established connection - * @feat: NN feature number from %dccp_feature_numbers - * @nn_val: the new value to use - * This function is used to communicate NN updates out-of-band. The difference - * to feature negotiation during connection setup is that values are activated - * immediately after validation, i.e. we don't wait for the Confirm: either the - * value is accepted by the peer (and then the waiting is futile), or it is not - * (Reset or empty Confirm). We don't accept empty Confirms - transmitted values - * are validated, and the peer "MUST accept any valid value" (RFC 4340, 6.3.2). - */ -int dccp_feat_signal_nn_change(struct sock *sk, u8 feat, u64 nn_val) -{ - struct list_head *fn = &dccp_sk(sk)->dccps_featneg; - dccp_feat_val fval = { .nn = nn_val }; - struct dccp_feat_entry *entry; + dccp_feat_debug(type, feature, *val); - if (sk->sk_state != DCCP_OPEN && sk->sk_state != DCCP_PARTOPEN) - return 0; + /* figure out if it's SP or NN feature */ + switch (feature) { + /* deal with SP features */ + case DCCPF_CCID: + rc = dccp_feat_sp(sk, type, feature, val, len); + break; - if (dccp_feat_type(feat) != FEAT_NN || - !dccp_feat_is_valid_nn_val(feat, nn_val)) - return -EINVAL; + /* deal with NN features */ + case DCCPF_ACK_RATIO: + rc = dccp_feat_nn(sk, type, feature, val, len); + break; - entry = dccp_feat_list_lookup(fn, feat, 1); - if (entry != NULL) { - dccp_pr_debug("Ignoring %llu, entry %llu exists in state %s\n", - (unsigned long long)nn_val, - (unsigned long long)entry->val.nn, - dccp_feat_sname[entry->state]); - return 0; + /* XXX implement other features */ + default: + dccp_pr_debug("UNIMPLEMENTED: not handling %s(%d, ...)\n", + dccp_feat_typename(type), feature); + rc = -EFAULT; + break; } - if (dccp_feat_activate(sk, feat, 1, &fval)) - return -EADV; - - inet_csk_schedule_ack(sk); - return dccp_feat_push_change(fn, feat, 1, 0, &fval); -} -EXPORT_SYMBOL_GPL(dccp_feat_signal_nn_change); - -/* - * Tracking features whose value depend on the choice of CCID - * - * This is designed with an extension in mind so that a list walk could be done - * before activating any features. However, the existing framework was found to - * work satisfactorily up until now, the automatic verification is left open. - * When adding new CCIDs, add a corresponding dependency table here. - */ -static const struct ccid_dependency *dccp_feat_ccid_deps(u8 ccid, bool is_local) -{ - static const struct ccid_dependency ccid2_dependencies[2][2] = { - /* - * CCID2 mandates Ack Vectors (RFC 4341, 4.): as CCID is a TX - * feature and Send Ack Vector is an RX feature, `is_local' - * needs to be reversed. + /* check if there were problems changing features */ + if (rc) { + /* If we don't agree on SP, we sent a confirm for old value. + * However we propagate rc to caller in case option was + * mandatory */ - { /* Dependencies of the receiver-side (remote) CCID2 */ - { - .dependent_feat = DCCPF_SEND_ACK_VECTOR, - .is_local = true, - .is_mandatory = true, - .val = 1 - }, - { 0, 0, 0, 0 } - }, - { /* Dependencies of the sender-side (local) CCID2 */ - { - .dependent_feat = DCCPF_SEND_ACK_VECTOR, - .is_local = false, - .is_mandatory = true, - .val = 1 - }, - { 0, 0, 0, 0 } - } - }; - static const struct ccid_dependency ccid3_dependencies[2][5] = { - { /* - * Dependencies of the receiver-side CCID3 - */ - { /* locally disable Ack Vectors */ - .dependent_feat = DCCPF_SEND_ACK_VECTOR, - .is_local = true, - .is_mandatory = false, - .val = 0 - }, - { /* see below why Send Loss Event Rate is on */ - .dependent_feat = DCCPF_SEND_LEV_RATE, - .is_local = true, - .is_mandatory = true, - .val = 1 - }, - { /* NDP Count is needed as per RFC 4342, 6.1.1 */ - .dependent_feat = DCCPF_SEND_NDP_COUNT, - .is_local = false, - .is_mandatory = true, - .val = 1 - }, - { 0, 0, 0, 0 }, - }, - { /* - * CCID3 at the TX side: we request that the HC-receiver - * will not send Ack Vectors (they will be ignored, so - * Mandatory is not set); we enable Send Loss Event Rate - * (Mandatory since the implementation does not support - * the Loss Intervals option of RFC 4342, 8.6). - * The last two options are for peer's information only. - */ - { - .dependent_feat = DCCPF_SEND_ACK_VECTOR, - .is_local = false, - .is_mandatory = false, - .val = 0 - }, - { - .dependent_feat = DCCPF_SEND_LEV_RATE, - .is_local = false, - .is_mandatory = true, - .val = 1 - }, - { /* this CCID does not support Ack Ratio */ - .dependent_feat = DCCPF_ACK_RATIO, - .is_local = true, - .is_mandatory = false, - .val = 0 - }, - { /* tell receiver we are sending NDP counts */ - .dependent_feat = DCCPF_SEND_NDP_COUNT, - .is_local = true, - .is_mandatory = false, - .val = 1 - }, - { 0, 0, 0, 0 } - } - }; - switch (ccid) { - case DCCPC_CCID2: - return ccid2_dependencies[is_local]; - case DCCPC_CCID3: - return ccid3_dependencies[is_local]; - default: - return NULL; + if (rc != DCCP_FEAT_SP_NOAGREE) + dccp_feat_empty_confirm(dccp_msk(sk), type, feature); } -} -/** - * dccp_feat_propagate_ccid - Resolve dependencies of features on choice of CCID - * @fn: feature-negotiation list to update - * @id: CCID number to track - * @is_local: whether TX CCID (1) or RX CCID (0) is meant - * This function needs to be called after registering all other features. - */ -static int dccp_feat_propagate_ccid(struct list_head *fn, u8 id, bool is_local) -{ - const struct ccid_dependency *table = dccp_feat_ccid_deps(id, is_local); - int i, rc = (table == NULL); - - for (i = 0; rc == 0 && table[i].dependent_feat != DCCPF_RESERVED; i++) - if (dccp_feat_type(table[i].dependent_feat) == FEAT_SP) - rc = __feat_register_sp(fn, table[i].dependent_feat, - table[i].is_local, - table[i].is_mandatory, - &table[i].val, 1); - else - rc = __feat_register_nn(fn, table[i].dependent_feat, - table[i].is_mandatory, - table[i].val); - return rc; -} - -/** - * dccp_feat_finalise_settings - Finalise settings before starting negotiation - * @dp: client or listening socket (settings will be inherited) - * This is called after all registrations (socket initialisation, sysctls, and - * sockopt calls), and before sending the first packet containing Change options - * (ie. client-Request or server-Response), to ensure internal consistency. - */ -int dccp_feat_finalise_settings(struct dccp_sock *dp) -{ - struct list_head *fn = &dp->dccps_featneg; - struct dccp_feat_entry *entry; - int i = 2, ccids[2] = { -1, -1 }; + /* generate the confirm [if required] */ + dccp_feat_flush_confirm(sk); - /* - * Propagating CCIDs: - * 1) not useful to propagate CCID settings if this host advertises more - * than one CCID: the choice of CCID may still change - if this is - * the client, or if this is the server and the client sends - * singleton CCID values. - * 2) since is that propagate_ccid changes the list, we defer changing - * the sorted list until after the traversal. - */ - list_for_each_entry(entry, fn, node) - if (entry->feat_num == DCCPF_CCID && entry->val.sp.len == 1) - ccids[entry->is_local] = entry->val.sp.vec[0]; - while (i--) - if (ccids[i] > 0 && dccp_feat_propagate_ccid(fn, ccids[i], i)) - return -1; - dccp_feat_print_fnlist(fn); - return 0; + return rc; } -/** - * dccp_feat_server_ccid_dependencies - Resolve CCID-dependent features - * It is the server which resolves the dependencies once the CCID has been - * fully negotiated. If no CCID has been negotiated, it uses the default CCID. - */ -int dccp_feat_server_ccid_dependencies(struct dccp_request_sock *dreq) -{ - struct list_head *fn = &dreq->dreq_featneg; - struct dccp_feat_entry *entry; - u8 is_local, ccid; - - for (is_local = 0; is_local <= 1; is_local++) { - entry = dccp_feat_list_lookup(fn, DCCPF_CCID, is_local); - - if (entry != NULL && !entry->empty_confirm) - ccid = entry->val.sp.vec[0]; - else - ccid = dccp_feat_default_value(DCCPF_CCID); - - if (dccp_feat_propagate_ccid(fn, ccid, is_local)) - return -1; - } - return 0; -} +EXPORT_SYMBOL_GPL(dccp_feat_change_recv); -/* Select the first entry in @servlist that also occurs in @clilist (6.3.1) */ -static int dccp_feat_preflist_match(u8 *servlist, u8 slen, u8 *clilist, u8 clen) +int dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature, + u8 *val, u8 len) { - u8 c, s; + u8 t; + struct dccp_opt_pend *opt; + struct dccp_minisock *dmsk = dccp_msk(sk); + int found = 0; + int all_confirmed = 1; - for (s = 0; s < slen; s++) - for (c = 0; c < clen; c++) - if (servlist[s] == clilist[c]) - return servlist[s]; - return -1; -} + dccp_feat_debug(type, feature, *val); -/** - * dccp_feat_prefer - Move preferred entry to the start of array - * Reorder the @array_len elements in @array so that @preferred_value comes - * first. Returns >0 to indicate that @preferred_value does occur in @array. - */ -static u8 dccp_feat_prefer(u8 preferred_value, u8 *array, u8 array_len) -{ - u8 i, does_occur = 0; + /* locate our change request */ + switch (type) { + case DCCPO_CONFIRM_L: t = DCCPO_CHANGE_R; break; + case DCCPO_CONFIRM_R: t = DCCPO_CHANGE_L; break; + default: DCCP_WARN("invalid type %d\n", type); + return 1; - if (array != NULL) { - for (i = 0; i < array_len; i++) - if (array[i] == preferred_value) { - array[i] = array[0]; - does_occur++; - } - if (does_occur) - array[0] = preferred_value; } - return does_occur; -} + /* XXX sanity check feature value */ -/** - * dccp_feat_reconcile - Reconcile SP preference lists - * @fval: SP list to reconcile into - * @arr: received SP preference list - * @len: length of @arr in bytes - * @is_server: whether this side is the server (and @fv is the server's list) - * @reorder: whether to reorder the list in @fv after reconciling with @arr - * When successful, > 0 is returned and the reconciled list is in @fval. - * A value of 0 means that negotiation failed (no shared entry). - */ -static int dccp_feat_reconcile(dccp_feat_val *fv, u8 *arr, u8 len, - bool is_server, bool reorder) -{ - int rc; + list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) { + if (!opt->dccpop_conf && opt->dccpop_type == t && + opt->dccpop_feat == feature) { + found = 1; + dccp_pr_debug("feature %d found\n", opt->dccpop_feat); - if (!fv->sp.vec || !arr) { - DCCP_CRIT("NULL feature value or array"); - return 0; - } + /* XXX do sanity check */ - if (is_server) - rc = dccp_feat_preflist_match(fv->sp.vec, fv->sp.len, arr, len); - else - rc = dccp_feat_preflist_match(arr, len, fv->sp.vec, fv->sp.len); - - if (!reorder) - return rc; - if (rc < 0) - return 0; + opt->dccpop_conf = 1; - /* - * Reorder list: used for activating features and in dccp_insert_fn_opt. - */ - return dccp_feat_prefer(rc, fv->sp.vec, fv->sp.len); -} + /* We got a confirmation---change the option */ + dccp_feat_update(sk, opt->dccpop_type, + opt->dccpop_feat, *val); -/** - * dccp_feat_change_recv - Process incoming ChangeL/R options - * @fn: feature-negotiation list to update - * @is_mandatory: whether the Change was preceded by a Mandatory option - * @opt: %DCCPO_CHANGE_L or %DCCPO_CHANGE_R - * @feat: one of %dccp_feature_numbers - * @val: NN value or SP value/preference list - * @len: length of @val in bytes - * @server: whether this node is the server (1) or the client (0) - */ -static u8 dccp_feat_change_recv(struct list_head *fn, u8 is_mandatory, u8 opt, - u8 feat, u8 *val, u8 len, const bool server) -{ - u8 defval, type = dccp_feat_type(feat); - const bool local = (opt == DCCPO_CHANGE_R); - struct dccp_feat_entry *entry; - dccp_feat_val fval; - - if (len == 0 || type == FEAT_UNKNOWN) /* 6.1 and 6.6.8 */ - goto unknown_feature_or_value; - - dccp_feat_print_opt(opt, feat, val, len, is_mandatory); - - /* - * Negotiation of NN features: Change R is invalid, so there is no - * simultaneous negotiation; hence we do not look up in the list. - */ - if (type == FEAT_NN) { - if (local || len > sizeof(fval.nn)) - goto unknown_feature_or_value; - - /* 6.3.2: "The feature remote MUST accept any valid value..." */ - fval.nn = dccp_decode_value_var(val, len); - if (!dccp_feat_is_valid_nn_val(feat, fval.nn)) - goto unknown_feature_or_value; + /* XXX check the return value of dccp_feat_update */ + break; + } - return dccp_feat_push_confirm(fn, feat, local, &fval); + if (!opt->dccpop_conf) + all_confirmed = 0; } - /* - * Unidirectional/simultaneous negotiation of SP features (6.3.1) + /* fix re-transmit timer */ + /* XXX gotta make sure that no option negotiation occurs during + * connection shutdown. Consider that the CLOSEREQ is sent and timer is + * on. if all options are confirmed it might kill timer which should + * remain alive until close is received. */ - entry = dccp_feat_list_lookup(fn, feat, local); - if (entry == NULL) { - /* - * No particular preferences have been registered. We deal with - * this situation by assuming that all valid values are equally - * acceptable, and apply the following checks: - * - if the peer's list is a singleton, we accept a valid value; - * - if we are the server, we first try to see if the peer (the - * client) advertises the default value. If yes, we use it, - * otherwise we accept the preferred value; - * - else if we are the client, we use the first list element. - */ - if (dccp_feat_clone_sp_val(&fval, val, 1)) - return DCCP_RESET_CODE_TOO_BUSY; - - if (len > 1 && server) { - defval = dccp_feat_default_value(feat); - if (dccp_feat_preflist_match(&defval, 1, val, len) > -1) - fval.sp.vec[0] = defval; - } else if (!dccp_feat_is_valid_sp_val(feat, fval.sp.vec[0])) { - kfree(fval.sp.vec); - goto unknown_feature_or_value; - } - - /* Treat unsupported CCIDs like invalid values */ - if (feat == DCCPF_CCID && !ccid_support_check(fval.sp.vec, 1)) { - kfree(fval.sp.vec); - goto not_valid_or_not_known; - } - - return dccp_feat_push_confirm(fn, feat, local, &fval); - - } else if (entry->state == FEAT_UNSTABLE) { /* 6.6.2 */ - return 0; + if (all_confirmed) { + dccp_pr_debug("clear feat negotiation timer %p\n", sk); + inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS); } - if (dccp_feat_reconcile(&entry->val, val, len, server, true)) { - entry->empty_confirm = 0; - } else if (is_mandatory) { - return DCCP_RESET_CODE_MANDATORY_ERROR; - } else if (entry->state == FEAT_INITIALISING) { - /* - * Failed simultaneous negotiation (server only): try to `save' - * the connection by checking whether entry contains the default - * value for @feat. If yes, send an empty Confirm to signal that - * the received Change was not understood - which implies using - * the default value. - * If this also fails, we use Reset as the last resort. - */ - WARN_ON(!server); - defval = dccp_feat_default_value(feat); - if (!dccp_feat_reconcile(&entry->val, &defval, 1, server, true)) - return DCCP_RESET_CODE_OPTION_ERROR; - entry->empty_confirm = 1; - } - entry->needs_confirm = 1; - entry->needs_mandatory = 0; - entry->state = FEAT_STABLE; + if (!found) + dccp_pr_debug("%s(%d, ...) never requested\n", + dccp_feat_typename(type), feature); return 0; - -unknown_feature_or_value: - if (!is_mandatory) - return dccp_push_empty_confirm(fn, feat, local); - -not_valid_or_not_known: - return is_mandatory ? DCCP_RESET_CODE_MANDATORY_ERROR - : DCCP_RESET_CODE_OPTION_ERROR; } -/** - * dccp_feat_confirm_recv - Process received Confirm options - * @fn: feature-negotiation list to update - * @is_mandatory: whether @opt was preceded by a Mandatory option - * @opt: %DCCPO_CONFIRM_L or %DCCPO_CONFIRM_R - * @feat: one of %dccp_feature_numbers - * @val: NN value or SP value/preference list - * @len: length of @val in bytes - * @server: whether this node is server (1) or client (0) - */ -static u8 dccp_feat_confirm_recv(struct list_head *fn, u8 is_mandatory, u8 opt, - u8 feat, u8 *val, u8 len, const bool server) -{ - u8 *plist, plen, type = dccp_feat_type(feat); - const bool local = (opt == DCCPO_CONFIRM_R); - struct dccp_feat_entry *entry = dccp_feat_list_lookup(fn, feat, local); - - dccp_feat_print_opt(opt, feat, val, len, is_mandatory); - - if (entry == NULL) { /* nothing queued: ignore or handle error */ - if (is_mandatory && type == FEAT_UNKNOWN) - return DCCP_RESET_CODE_MANDATORY_ERROR; - - if (!local && type == FEAT_NN) /* 6.3.2 */ - goto confirmation_failed; - return 0; - } - - if (entry->state != FEAT_CHANGING) /* 6.6.2 */ - return 0; - - if (len == 0) { - if (dccp_feat_must_be_understood(feat)) /* 6.6.7 */ - goto confirmation_failed; - /* - * Empty Confirm during connection setup: this means reverting - * to the `old' value, which in this case is the default. Since - * we handle default values automatically when no other values - * have been set, we revert to the old value by removing this - * entry from the list. - */ - dccp_feat_list_pop(entry); - return 0; - } +EXPORT_SYMBOL_GPL(dccp_feat_confirm_recv); - if (type == FEAT_NN) { - if (len > sizeof(entry->val.nn)) - goto confirmation_failed; +void dccp_feat_clean(struct dccp_minisock *dmsk) +{ + struct dccp_opt_pend *opt, *next; - if (entry->val.nn == dccp_decode_value_var(val, len)) - goto confirmation_succeeded; + list_for_each_entry_safe(opt, next, &dmsk->dccpms_pending, + dccpop_node) { + BUG_ON(opt->dccpop_val == NULL); + kfree(opt->dccpop_val); - DCCP_WARN("Bogus Confirm for non-existing value\n"); - goto confirmation_failed; - } + if (opt->dccpop_sc != NULL) { + BUG_ON(opt->dccpop_sc->dccpoc_val == NULL); + kfree(opt->dccpop_sc->dccpoc_val); + kfree(opt->dccpop_sc); + } - /* - * Parsing SP Confirms: the first element of @val is the preferred - * SP value which the peer confirms, the remainder depends on @len. - * Note that only the confirmed value need to be a valid SP value. - */ - if (!dccp_feat_is_valid_sp_val(feat, *val)) - goto confirmation_failed; - - if (len == 1) { /* peer didn't supply a preference list */ - plist = val; - plen = len; - } else { /* preferred value + preference list */ - plist = val + 1; - plen = len - 1; + kfree(opt); } + INIT_LIST_HEAD(&dmsk->dccpms_pending); - /* Check whether the peer got the reconciliation right (6.6.8) */ - if (dccp_feat_reconcile(&entry->val, plist, plen, server, 0) != *val) { - DCCP_WARN("Confirm selected the wrong value %u\n", *val); - return DCCP_RESET_CODE_OPTION_ERROR; + list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) { + BUG_ON(opt == NULL); + if (opt->dccpop_val != NULL) + kfree(opt->dccpop_val); + kfree(opt); } - entry->val.sp.vec[0] = *val; - -confirmation_succeeded: - entry->state = FEAT_STABLE; - return 0; - -confirmation_failed: - DCCP_WARN("Confirmation failed\n"); - return is_mandatory ? DCCP_RESET_CODE_MANDATORY_ERROR - : DCCP_RESET_CODE_OPTION_ERROR; + INIT_LIST_HEAD(&dmsk->dccpms_conf); } -/** - * dccp_feat_handle_nn_established - Fast-path reception of NN options - * @sk: socket of an established DCCP connection - * @mandatory: whether @opt was preceded by a Mandatory option - * @opt: %DCCPO_CHANGE_L | %DCCPO_CONFIRM_R (NN only) - * @feat: NN number, one of %dccp_feature_numbers - * @val: NN value - * @len: length of @val in bytes - * This function combines the functionality of change_recv/confirm_recv, with - * the following differences (reset codes are the same): - * - cleanup after receiving the Confirm; - * - values are directly activated after successful parsing; - * - deliberately restricted to NN features. - * The restriction to NN features is essential since SP features can have non- - * predictable outcomes (depending on the remote configuration), and are inter- - * dependent (CCIDs for instance cause further dependencies). +EXPORT_SYMBOL_GPL(dccp_feat_clean); + +/* this is to be called only when a listening sock creates its child. It is + * assumed by the function---the confirm is not duplicated, but rather it is + * "passed on". */ -static u8 dccp_feat_handle_nn_established(struct sock *sk, u8 mandatory, u8 opt, - u8 feat, u8 *val, u8 len) +int dccp_feat_clone(struct sock *oldsk, struct sock *newsk) { - struct list_head *fn = &dccp_sk(sk)->dccps_featneg; - const bool local = (opt == DCCPO_CONFIRM_R); - struct dccp_feat_entry *entry; - u8 type = dccp_feat_type(feat); - dccp_feat_val fval; + struct dccp_minisock *olddmsk = dccp_msk(oldsk); + struct dccp_minisock *newdmsk = dccp_msk(newsk); + struct dccp_opt_pend *opt; + int rc = 0; - dccp_feat_print_opt(opt, feat, val, len, mandatory); + INIT_LIST_HEAD(&newdmsk->dccpms_pending); + INIT_LIST_HEAD(&newdmsk->dccpms_conf); - /* Ignore non-mandatory unknown and non-NN features */ - if (type == FEAT_UNKNOWN) { - if (local && !mandatory) - return 0; - goto fast_path_unknown; - } else if (type != FEAT_NN) { - return 0; - } - - /* - * We don't accept empty Confirms, since in fast-path feature - * negotiation the values are enabled immediately after sending - * the Change option. - * Empty Changes on the other hand are invalid (RFC 4340, 6.1). - */ - if (len == 0 || len > sizeof(fval.nn)) - goto fast_path_unknown; - - if (opt == DCCPO_CHANGE_L) { - fval.nn = dccp_decode_value_var(val, len); - if (!dccp_feat_is_valid_nn_val(feat, fval.nn)) - goto fast_path_unknown; + list_for_each_entry(opt, &olddmsk->dccpms_pending, dccpop_node) { + struct dccp_opt_pend *newopt; + /* copy the value of the option */ + u8 *val = kmemdup(opt->dccpop_val, opt->dccpop_len, GFP_ATOMIC); - if (dccp_feat_push_confirm(fn, feat, local, &fval) || - dccp_feat_activate(sk, feat, local, &fval)) - return DCCP_RESET_CODE_TOO_BUSY; + if (val == NULL) + goto out_clean; - /* set the `Ack Pending' flag to piggyback a Confirm */ - inet_csk_schedule_ack(sk); - - } else if (opt == DCCPO_CONFIRM_R) { - entry = dccp_feat_list_lookup(fn, feat, local); - if (entry == NULL || entry->state != FEAT_CHANGING) - return 0; - - fval.nn = dccp_decode_value_var(val, len); - if (fval.nn != entry->val.nn) { - DCCP_WARN("Bogus Confirm for non-existing value\n"); - goto fast_path_failed; + newopt = kmemdup(opt, sizeof(*newopt), GFP_ATOMIC); + if (newopt == NULL) { + kfree(val); + goto out_clean; } - /* It has been confirmed - so remove the entry */ - dccp_feat_list_pop(entry); + /* insert the option */ + newopt->dccpop_val = val; + list_add_tail(&newopt->dccpop_node, &newdmsk->dccpms_pending); - } else { - DCCP_WARN("Received illegal option %u\n", opt); - goto fast_path_failed; + /* XXX what happens with backlogs and multiple connections at + * once... + */ + /* the master socket no longer needs to worry about confirms */ + opt->dccpop_sc = NULL; /* it's not a memleak---new socket has it */ + + /* reset state for a new socket */ + opt->dccpop_conf = 0; } - return 0; -fast_path_unknown: - if (!mandatory) - return dccp_push_empty_confirm(fn, feat, local); + /* XXX not doing anything about the conf queue */ + +out: + return rc; -fast_path_failed: - return mandatory ? DCCP_RESET_CODE_MANDATORY_ERROR - : DCCP_RESET_CODE_OPTION_ERROR; +out_clean: + dccp_feat_clean(newdmsk); + rc = -ENOMEM; + goto out; } -/** - * dccp_feat_parse_options - Process Feature-Negotiation Options - * @sk: for general use and used by the client during connection setup - * @dreq: used by the server during connection setup - * @mandatory: whether @opt was preceded by a Mandatory option - * @opt: %DCCPO_CHANGE_L | %DCCPO_CHANGE_R | %DCCPO_CONFIRM_L | %DCCPO_CONFIRM_R - * @feat: one of %dccp_feature_numbers - * @val: value contents of @opt - * @len: length of @val in bytes - * Returns 0 on success, a Reset code for ending the connection otherwise. - */ -int dccp_feat_parse_options(struct sock *sk, struct dccp_request_sock *dreq, - u8 mandatory, u8 opt, u8 feat, u8 *val, u8 len) +EXPORT_SYMBOL_GPL(dccp_feat_clone); + +static int __dccp_feat_init(struct dccp_minisock *dmsk, u8 type, u8 feat, + u8 *val, u8 len) { - struct dccp_sock *dp = dccp_sk(sk); - struct list_head *fn = dreq ? &dreq->dreq_featneg : &dp->dccps_featneg; - bool server = false; + int rc = -ENOMEM; + u8 *copy = kmemdup(val, len, GFP_KERNEL); - switch (sk->sk_state) { - /* - * Negotiation during connection setup - */ - case DCCP_LISTEN: - server = true; /* fall through */ - case DCCP_REQUESTING: - switch (opt) { - case DCCPO_CHANGE_L: - case DCCPO_CHANGE_R: - return dccp_feat_change_recv(fn, mandatory, opt, feat, - val, len, server); - case DCCPO_CONFIRM_R: - case DCCPO_CONFIRM_L: - return dccp_feat_confirm_recv(fn, mandatory, opt, feat, - val, len, server); - } - break; - /* - * Support for exchanging NN options on an established connection - * This is currently restricted to Ack Ratio (RFC 4341, 6.1.2) - */ - case DCCP_OPEN: - case DCCP_PARTOPEN: - return dccp_feat_handle_nn_established(sk, mandatory, opt, feat, - val, len); + if (copy != NULL) { + rc = dccp_feat_change(dmsk, type, feat, copy, len, GFP_KERNEL); + if (rc) + kfree(copy); } - return 0; /* ignore FN options in all other states */ + return rc; } -/** - * dccp_feat_init - Seed feature negotiation with host-specific defaults - * This initialises global defaults, depending on the value of the sysctls. - * These can later be overridden by registering changes via setsockopt calls. - * The last link in the chain is finalise_settings, to make sure that between - * here and the start of actual feature negotiation no inconsistencies enter. - * - * All features not appearing below use either defaults or are otherwise - * later adjusted through dccp_feat_finalise_settings(). - */ -int dccp_feat_init(struct sock *sk) +int dccp_feat_init(struct dccp_minisock *dmsk) { - struct list_head *fn = &dccp_sk(sk)->dccps_featneg; - u8 on = 1, off = 0; int rc; - struct { - u8 *val; - u8 len; - } tx, rx; - - /* Non-negotiable (NN) features */ - rc = __feat_register_nn(fn, DCCPF_SEQUENCE_WINDOW, 0, - sysctl_dccp_sequence_window); - if (rc) - return rc; - /* Server-priority (SP) features */ - - /* Advertise that short seqnos are not supported (7.6.1) */ - rc = __feat_register_sp(fn, DCCPF_SHORT_SEQNOS, true, true, &off, 1); - if (rc) - return rc; + INIT_LIST_HEAD(&dmsk->dccpms_pending); + INIT_LIST_HEAD(&dmsk->dccpms_conf); - /* RFC 4340 12.1: "If a DCCP is not ECN capable, ..." */ - rc = __feat_register_sp(fn, DCCPF_ECN_INCAPABLE, true, true, &on, 1); + /* CCID L */ + rc = __dccp_feat_init(dmsk, DCCPO_CHANGE_L, DCCPF_CCID, + &dmsk->dccpms_tx_ccid, 1); if (rc) - return rc; - - /* - * We advertise the available list of CCIDs and reorder according to - * preferences, to avoid failure resulting from negotiating different - * singleton values (which always leads to failure). - * These settings can still (later) be overridden via sockopts. - */ - if (ccid_get_builtin_ccids(&tx.val, &tx.len) || - ccid_get_builtin_ccids(&rx.val, &rx.len)) - return -ENOBUFS; - - /* Pre-load all CCID modules that are going to be advertised */ - rc = -EUNATCH; - if (ccid_request_modules(tx.val, tx.len)) - goto free_ccid_lists; - - if (!dccp_feat_prefer(sysctl_dccp_tx_ccid, tx.val, tx.len) || - !dccp_feat_prefer(sysctl_dccp_rx_ccid, rx.val, rx.len)) - goto free_ccid_lists; + goto out; - rc = __feat_register_sp(fn, DCCPF_CCID, true, false, tx.val, tx.len); + /* CCID R */ + rc = __dccp_feat_init(dmsk, DCCPO_CHANGE_R, DCCPF_CCID, + &dmsk->dccpms_rx_ccid, 1); if (rc) - goto free_ccid_lists; + goto out; - rc = __feat_register_sp(fn, DCCPF_CCID, false, false, rx.val, rx.len); - -free_ccid_lists: - kfree(tx.val); - kfree(rx.val); + /* Ack ratio */ + rc = __dccp_feat_init(dmsk, DCCPO_CHANGE_L, DCCPF_ACK_RATIO, + &dmsk->dccpms_ack_ratio, 1); +out: return rc; } -int dccp_feat_activate_values(struct sock *sk, struct list_head *fn_list) -{ - struct dccp_sock *dp = dccp_sk(sk); - struct dccp_feat_entry *cur, *next; - int idx; - dccp_feat_val *fvals[DCCP_FEAT_SUPPORTED_MAX][2] = { - [0 ... DCCP_FEAT_SUPPORTED_MAX-1] = { NULL, NULL } - }; - - list_for_each_entry(cur, fn_list, node) { - /* - * An empty Confirm means that either an unknown feature type - * or an invalid value was present. In the first case there is - * nothing to activate, in the other the default value is used. - */ - if (cur->empty_confirm) - continue; +EXPORT_SYMBOL_GPL(dccp_feat_init); - idx = dccp_feat_index(cur->feat_num); - if (idx < 0) { - DCCP_BUG("Unknown feature %u", cur->feat_num); - goto activation_failed; - } - if (cur->state != FEAT_STABLE) { - DCCP_CRIT("Negotiation of %s %s failed in state %s", - cur->is_local ? "local" : "remote", - dccp_feat_fname(cur->feat_num), - dccp_feat_sname[cur->state]); - goto activation_failed; - } - fvals[idx][cur->is_local] = &cur->val; +#ifdef CONFIG_IP_DCCP_DEBUG +const char *dccp_feat_typename(const u8 type) +{ + switch(type) { + case DCCPO_CHANGE_L: return("ChangeL"); + case DCCPO_CONFIRM_L: return("ConfirmL"); + case DCCPO_CHANGE_R: return("ChangeR"); + case DCCPO_CONFIRM_R: return("ConfirmR"); + /* the following case must not appear in feature negotation */ + default: dccp_pr_debug("unknown type %d [BUG!]\n", type); } + return NULL; +} - /* - * Activate in decreasing order of index, so that the CCIDs are always - * activated as the last feature. This avoids the case where a CCID - * relies on the initialisation of one or more features that it depends - * on (e.g. Send NDP Count, Send Ack Vector, and Ack Ratio features). - */ - for (idx = DCCP_FEAT_SUPPORTED_MAX; --idx >= 0;) - if (__dccp_feat_activate(sk, idx, 0, fvals[idx][0]) || - __dccp_feat_activate(sk, idx, 1, fvals[idx][1])) { - DCCP_CRIT("Could not activate %d", idx); - goto activation_failed; - } +EXPORT_SYMBOL_GPL(dccp_feat_typename); - /* Clean up Change options which have been confirmed already */ - list_for_each_entry_safe(cur, next, fn_list, node) - if (!cur->needs_confirm) - dccp_feat_list_pop(cur); +const char *dccp_feat_name(const u8 feat) +{ + static const char *feature_names[] = { + [DCCPF_RESERVED] = "Reserved", + [DCCPF_CCID] = "CCID", + [DCCPF_SHORT_SEQNOS] = "Allow Short Seqnos", + [DCCPF_SEQUENCE_WINDOW] = "Sequence Window", + [DCCPF_ECN_INCAPABLE] = "ECN Incapable", + [DCCPF_ACK_RATIO] = "Ack Ratio", + [DCCPF_SEND_ACK_VECTOR] = "Send ACK Vector", + [DCCPF_SEND_NDP_COUNT] = "Send NDP Count", + [DCCPF_MIN_CSUM_COVER] = "Min. Csum Coverage", + [DCCPF_DATA_CHECKSUM] = "Send Data Checksum", + }; + if (feat > DCCPF_DATA_CHECKSUM && feat < DCCPF_MIN_CCID_SPECIFIC) + return feature_names[DCCPF_RESERVED]; - dccp_pr_debug("Activation OK\n"); - return 0; + if (feat >= DCCPF_MIN_CCID_SPECIFIC) + return "CCID-specific"; -activation_failed: - /* - * We clean up everything that may have been allocated, since - * it is difficult to track at which stage negotiation failed. - * This is ok, since all allocation functions below are robust - * against NULL arguments. - */ - ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); - ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk); - dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL; - dccp_ackvec_free(dp->dccps_hc_rx_ackvec); - dp->dccps_hc_rx_ackvec = NULL; - return -1; + return feature_names[feat]; } + +EXPORT_SYMBOL_GPL(dccp_feat_name); +#endif /* CONFIG_IP_DCCP_DEBUG */ diff --git a/net/dccp/feat.h b/net/dccp/feat.h index 2217066e22d..e272222c7ac 100644 --- a/net/dccp/feat.h +++ b/net/dccp/feat.h @@ -3,134 +3,38 @@ /* * net/dccp/feat.h * - * Feature negotiation for the DCCP protocol (RFC 4340, section 6) - * Copyright (c) 2008 Gerrit Renker <gerrit@erg.abdn.ac.uk> + * An implementation of the DCCP protocol * Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk> * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. */ + #include <linux/types.h> #include "dccp.h" -/* - * Known limit values - */ -/* Ack Ratio takes 2-byte integer values (11.3) */ -#define DCCPF_ACK_RATIO_MAX 0xFFFF -/* Wmin=32 and Wmax=2^46-1 from 7.5.2 */ -#define DCCPF_SEQ_WMIN 32 -#define DCCPF_SEQ_WMAX 0x3FFFFFFFFFFFull -/* Maximum number of SP values that fit in a single (Confirm) option */ -#define DCCP_FEAT_MAX_SP_VALS (DCCP_SINGLE_OPT_MAXLEN - 2) - -enum dccp_feat_type { - FEAT_AT_RX = 1, /* located at RX side of half-connection */ - FEAT_AT_TX = 2, /* located at TX side of half-connection */ - FEAT_SP = 4, /* server-priority reconciliation (6.3.1) */ - FEAT_NN = 8, /* non-negotiable reconciliation (6.3.2) */ - FEAT_UNKNOWN = 0xFF /* not understood or invalid feature */ -}; - -enum dccp_feat_state { - FEAT_DEFAULT = 0, /* using default values from 6.4 */ - FEAT_INITIALISING, /* feature is being initialised */ - FEAT_CHANGING, /* Change sent but not confirmed yet */ - FEAT_UNSTABLE, /* local modification in state CHANGING */ - FEAT_STABLE /* both ends (think they) agree */ -}; +#ifdef CONFIG_IP_DCCP_DEBUG +extern const char *dccp_feat_typename(const u8 type); +extern const char *dccp_feat_name(const u8 feat); -/** - * dccp_feat_val - Container for SP or NN feature values - * @nn: single NN value - * @sp.vec: single SP value plus optional preference list - * @sp.len: length of @sp.vec in bytes - */ -typedef union { - u64 nn; - struct { - u8 *vec; - u8 len; - } sp; -} dccp_feat_val; - -/** - * struct feat_entry - Data structure to perform feature negotiation - * @feat_num: one of %dccp_feature_numbers - * @val: feature's current value (SP features may have preference list) - * @state: feature's current state - * @needs_mandatory: whether Mandatory options should be sent - * @needs_confirm: whether to send a Confirm instead of a Change - * @empty_confirm: whether to send an empty Confirm (depends on @needs_confirm) - * @is_local: feature location (1) or feature-remote (0) - * @node: list pointers, entries arranged in FIFO order - */ -struct dccp_feat_entry { - u8 feat_num; - dccp_feat_val val; - enum dccp_feat_state state:8; - bool needs_mandatory:1, - needs_confirm:1, - empty_confirm:1, - is_local:1; - - struct list_head node; -}; - -static inline u8 dccp_feat_genopt(struct dccp_feat_entry *entry) +static inline void dccp_feat_debug(const u8 type, const u8 feat, const u8 val) { - if (entry->needs_confirm) - return entry->is_local ? DCCPO_CONFIRM_L : DCCPO_CONFIRM_R; - return entry->is_local ? DCCPO_CHANGE_L : DCCPO_CHANGE_R; + dccp_pr_debug("%s(%s (%d), %d)\n", dccp_feat_typename(type), + dccp_feat_name(feat), feat, val); } +#else +#define dccp_feat_debug(type, feat, val) +#endif /* CONFIG_IP_DCCP_DEBUG */ + +extern int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature, + u8 *val, u8 len, gfp_t gfp); +extern int dccp_feat_change_recv(struct sock *sk, u8 type, u8 feature, + u8 *val, u8 len); +extern int dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature, + u8 *val, u8 len); +extern void dccp_feat_clean(struct dccp_minisock *dmsk); +extern int dccp_feat_clone(struct sock *oldsk, struct sock *newsk); +extern int dccp_feat_init(struct dccp_minisock *dmsk); -/** - * struct ccid_dependency - Track changes resulting from choosing a CCID - * @dependent_feat: one of %dccp_feature_numbers - * @is_local: local (1) or remote (0) @dependent_feat - * @is_mandatory: whether presence of @dependent_feat is mission-critical or not - * @val: corresponding default value for @dependent_feat (u8 is sufficient here) - */ -struct ccid_dependency { - u8 dependent_feat; - bool is_local:1, - is_mandatory:1; - u8 val; -}; - -/* - * Sysctls to seed defaults for feature negotiation - */ -extern unsigned long sysctl_dccp_sequence_window; -extern int sysctl_dccp_rx_ccid; -extern int sysctl_dccp_tx_ccid; - -extern int dccp_feat_init(struct sock *sk); -extern void dccp_feat_initialise_sysctls(void); -extern int dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local, - u8 const *list, u8 len); -extern int dccp_feat_register_nn(struct sock *sk, u8 feat, u64 val); -extern int dccp_feat_parse_options(struct sock *, struct dccp_request_sock *, - u8 mand, u8 opt, u8 feat, u8 *val, u8 len); -extern int dccp_feat_clone_list(struct list_head const *, struct list_head *); - -/* - * Encoding variable-length options and their maximum length. - * - * This affects NN options (SP options are all u8) and other variable-length - * options (see table 3 in RFC 4340). The limit is currently given the Sequence - * Window NN value (sec. 7.5.2) and the NDP count (sec. 7.7) option, all other - * options consume less than 6 bytes (timestamps are 4 bytes). - * When updating this constant (e.g. due to new internet drafts / RFCs), make - * sure that you also update all code which refers to it. - */ -#define DCCP_OPTVAL_MAXLEN 6 - -extern void dccp_encode_value_var(const u64 value, u8 *to, const u8 len); -extern u64 dccp_decode_value_var(const u8 *bf, const u8 len); - -extern int dccp_insert_option_mandatory(struct sk_buff *skb); -extern int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat, - u8 *val, u8 len, bool repeat_first); #endif /* _DCCP_FEAT_H */ diff --git a/net/dccp/input.c b/net/dccp/input.c index df0e6714aa1..779d0ed9ae9 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -159,15 +159,13 @@ static void dccp_rcv_reset(struct sock *sk, struct sk_buff *skb) dccp_time_wait(sk, DCCP_TIME_WAIT, 0); } -static void dccp_handle_ackvec_processing(struct sock *sk, struct sk_buff *skb) +static void dccp_event_ack_recv(struct sock *sk, struct sk_buff *skb) { - struct dccp_ackvec *av = dccp_sk(sk)->dccps_hc_rx_ackvec; + struct dccp_sock *dp = dccp_sk(sk); - if (av == NULL) - return; - if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) - dccp_ackvec_clear_state(av, DCCP_SKB_CB(skb)->dccpd_ack_seq); - dccp_ackvec_input(av, skb); + if (dccp_msk(sk)->dccpms_send_ack_vector) + dccp_ackvec_check_rcv_ackno(dp->dccps_hc_rx_ackvec, sk, + DCCP_SKB_CB(skb)->dccpd_ack_seq); } static void dccp_deliver_input_to_ccids(struct sock *sk, struct sk_buff *skb) @@ -366,13 +364,22 @@ discard: int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, const struct dccp_hdr *dh, const unsigned len) { + struct dccp_sock *dp = dccp_sk(sk); + if (dccp_check_seqno(sk, skb)) goto discard; if (dccp_parse_options(sk, NULL, skb)) return 1; - dccp_handle_ackvec_processing(sk, skb); + if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) + dccp_event_ack_recv(sk, skb); + + if (dccp_msk(sk)->dccpms_send_ack_vector && + dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, + DCCP_SKB_CB(skb)->dccpd_seq, + DCCP_ACKVEC_STATE_RECEIVED)) + goto discard; dccp_deliver_input_to_ccids(sk, skb); return __dccp_rcv_established(sk, skb, dh, len); @@ -414,33 +421,40 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk, goto out_invalid_packet; } - /* - * If option processing (Step 8) failed, return 1 here so that - * dccp_v4_do_rcv() sends a Reset. The Reset code depends on - * the option type and is set in dccp_parse_options(). - */ if (dccp_parse_options(sk, NULL, skb)) - return 1; + goto out_invalid_packet; /* Obtain usec RTT sample from SYN exchange (used by CCID 3) */ if (likely(dp->dccps_options_received.dccpor_timestamp_echo)) dp->dccps_syn_rtt = dccp_sample_rtt(sk, 10 * (tstamp - dp->dccps_options_received.dccpor_timestamp_echo)); + if (dccp_msk(sk)->dccpms_send_ack_vector && + dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, + DCCP_SKB_CB(skb)->dccpd_seq, + DCCP_ACKVEC_STATE_RECEIVED)) + goto out_invalid_packet; /* FIXME: change error code */ + /* Stop the REQUEST timer */ inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS); WARN_ON(sk->sk_send_head == NULL); kfree_skb(sk->sk_send_head); sk->sk_send_head = NULL; + dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq; + dccp_update_gsr(sk, dp->dccps_isr); /* - * Set ISR, GSR from packet. ISS was set in dccp_v{4,6}_connect - * and GSS in dccp_transmit_skb(). Setting AWL/AWH and SWL/SWH - * is done as part of activating the feature values below, since - * these settings depend on the local/remote Sequence Window - * features, which were undefined or not confirmed until now. + * SWL and AWL are initially adjusted so that they are not less than + * the initial Sequence Numbers received and sent, respectively: + * SWL := max(GSR + 1 - floor(W/4), ISR), + * AWL := max(GSS - W' + 1, ISS). + * These adjustments MUST be applied only at the beginning of the + * connection. + * + * AWL was adjusted in dccp_v4_connect -acme */ - dp->dccps_gsr = dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq; + dccp_set_seqno(&dp->dccps_swl, + max48(dp->dccps_swl, dp->dccps_isr)); dccp_sync_mss(sk, icsk->icsk_pmtu_cookie); @@ -461,15 +475,6 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk, */ dccp_set_state(sk, DCCP_PARTOPEN); - /* - * If feature negotiation was successful, activate features now; - * an activation failure means that this host could not activate - * one ore more features (e.g. insufficient memory), which would - * leave at least one feature in an undefined state. - */ - if (dccp_feat_activate_values(sk, &dp->dccps_featneg)) - goto unable_to_proceed; - /* Make sure socket is routed, for correct metrics. */ icsk->icsk_af_ops->rebuild_header(sk); @@ -504,16 +509,6 @@ out_invalid_packet: /* dccp_v4_do_rcv will send a reset */ DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR; return 1; - -unable_to_proceed: - DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_ABORTED; - /* - * We mark this socket as no longer usable, so that the loop in - * dccp_sendmsg() terminates and the application gets notified. - */ - dccp_set_state(sk, DCCP_CLOSED); - sk->sk_err = ECOMM; - return 1; } static int dccp_rcv_respond_partopen_state_process(struct sock *sk, @@ -595,6 +590,8 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, if (inet_csk(sk)->icsk_af_ops->conn_request(sk, skb) < 0) return 1; + + /* FIXME: do congestion control initialization */ goto discard; } if (dh->dccph_type == DCCP_PKT_RESET) @@ -603,35 +600,29 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, /* Caller (dccp_v4_do_rcv) will send Reset */ dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; return 1; - } else if (sk->sk_state == DCCP_CLOSED) { - dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; - return 1; } - /* Step 6: Check sequence numbers (omitted in LISTEN/REQUEST state) */ - if (sk->sk_state != DCCP_REQUESTING && dccp_check_seqno(sk, skb)) - goto discard; + if (sk->sk_state != DCCP_REQUESTING) { + if (dccp_check_seqno(sk, skb)) + goto discard; - /* - * Step 7: Check for unexpected packet types - * If (S.is_server and P.type == Response) - * or (S.is_client and P.type == Request) - * or (S.state == RESPOND and P.type == Data), - * Send Sync packet acknowledging P.seqno - * Drop packet and return - */ - if ((dp->dccps_role != DCCP_ROLE_CLIENT && - dh->dccph_type == DCCP_PKT_RESPONSE) || - (dp->dccps_role == DCCP_ROLE_CLIENT && - dh->dccph_type == DCCP_PKT_REQUEST) || - (sk->sk_state == DCCP_RESPOND && dh->dccph_type == DCCP_PKT_DATA)) { - dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNC); - goto discard; - } + /* + * Step 8: Process options and mark acknowledgeable + */ + if (dccp_parse_options(sk, NULL, skb)) + return 1; - /* Step 8: Process options */ - if (dccp_parse_options(sk, NULL, skb)) - return 1; + if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) + dccp_event_ack_recv(sk, skb); + + if (dccp_msk(sk)->dccpms_send_ack_vector && + dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, + DCCP_SKB_CB(skb)->dccpd_seq, + DCCP_ACKVEC_STATE_RECEIVED)) + goto discard; + + dccp_deliver_input_to_ccids(sk, skb); + } /* * Step 9: Process Reset @@ -640,22 +631,44 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, * S.state := TIMEWAIT * Set TIMEWAIT timer * Drop packet and return - */ + */ if (dh->dccph_type == DCCP_PKT_RESET) { dccp_rcv_reset(sk, skb); return 0; - } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { /* Step 13 */ + /* + * Step 7: Check for unexpected packet types + * If (S.is_server and P.type == Response) + * or (S.is_client and P.type == Request) + * or (S.state == RESPOND and P.type == Data), + * Send Sync packet acknowledging P.seqno + * Drop packet and return + */ + } else if ((dp->dccps_role != DCCP_ROLE_CLIENT && + dh->dccph_type == DCCP_PKT_RESPONSE) || + (dp->dccps_role == DCCP_ROLE_CLIENT && + dh->dccph_type == DCCP_PKT_REQUEST) || + (sk->sk_state == DCCP_RESPOND && + dh->dccph_type == DCCP_PKT_DATA)) { + dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNC); + goto discard; + } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { if (dccp_rcv_closereq(sk, skb)) return 0; goto discard; - } else if (dh->dccph_type == DCCP_PKT_CLOSE) { /* Step 14 */ + } else if (dh->dccph_type == DCCP_PKT_CLOSE) { if (dccp_rcv_close(sk, skb)) return 0; goto discard; } switch (sk->sk_state) { + case DCCP_CLOSED: + dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; + return 1; + case DCCP_REQUESTING: + /* FIXME: do congestion control initialization */ + queued = dccp_rcv_request_sent_state_process(sk, skb, dh, len); if (queued >= 0) return queued; @@ -663,12 +676,8 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, __kfree_skb(skb); return 0; - case DCCP_PARTOPEN: - /* Step 8: if using Ack Vectors, mark packet acknowledgeable */ - dccp_handle_ackvec_processing(sk, skb); - dccp_deliver_input_to_ccids(sk, skb); - /* fall through */ case DCCP_RESPOND: + case DCCP_PARTOPEN: queued = dccp_rcv_respond_partopen_state_process(sk, skb, dh, len); break; @@ -707,7 +716,16 @@ u32 dccp_sample_rtt(struct sock *sk, long delta) /* dccpor_elapsed_time is either zeroed out or set and > 0 */ delta -= dccp_sk(sk)->dccps_options_received.dccpor_elapsed_time * 10; - return dccp_sane_rtt(delta); + if (unlikely(delta <= 0)) { + DCCP_WARN("unusable RTT sample %ld, using min\n", delta); + return DCCP_SANE_RTT_MIN; + } + if (unlikely(delta > DCCP_SANE_RTT_MAX)) { + DCCP_WARN("RTT sample %ld too large, using max\n", delta); + return DCCP_SANE_RTT_MAX; + } + + return delta; } EXPORT_SYMBOL_GPL(dccp_sample_rtt); diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c index b623f6b2548..882c5c4de69 100644 --- a/net/dccp/ipv4.c +++ b/net/dccp/ipv4.c @@ -545,7 +545,6 @@ out: static void dccp_v4_reqsk_destructor(struct request_sock *req) { - dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg); kfree(inet_rsk(req)->opt); } @@ -596,8 +595,7 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb) if (req == NULL) goto drop; - if (dccp_reqsk_init(req, dccp_sk(sk), skb)) - goto drop_and_free; + dccp_reqsk_init(req, skb); dreq = dccp_rsk(req); if (dccp_parse_options(sk, dreq, skb)) diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c index ad6212e0043..5e1ee0da2c4 100644 --- a/net/dccp/ipv6.c +++ b/net/dccp/ipv6.c @@ -302,7 +302,6 @@ done: static void dccp_v6_reqsk_destructor(struct request_sock *req) { - dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg); if (inet6_rsk(req)->pktopts != NULL) kfree_skb(inet6_rsk(req)->pktopts); } @@ -425,8 +424,7 @@ static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb) if (req == NULL) goto drop; - if (dccp_reqsk_init(req, dccp_sk(sk), skb)) - goto drop_and_free; + dccp_reqsk_init(req, skb); dreq = dccp_rsk(req); if (dccp_parse_options(sk, dreq, skb)) diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c index f4d9c8f60ed..b2804e2d1b8 100644 --- a/net/dccp/minisocks.c +++ b/net/dccp/minisocks.c @@ -42,6 +42,16 @@ struct inet_timewait_death_row dccp_death_row = { EXPORT_SYMBOL_GPL(dccp_death_row); +void dccp_minisock_init(struct dccp_minisock *dmsk) +{ + dmsk->dccpms_sequence_window = sysctl_dccp_feat_sequence_window; + dmsk->dccpms_rx_ccid = sysctl_dccp_feat_rx_ccid; + dmsk->dccpms_tx_ccid = sysctl_dccp_feat_tx_ccid; + dmsk->dccpms_ack_ratio = sysctl_dccp_feat_ack_ratio; + dmsk->dccpms_send_ack_vector = sysctl_dccp_feat_send_ack_vector; + dmsk->dccpms_send_ndp_count = sysctl_dccp_feat_send_ndp_count; +} + void dccp_time_wait(struct sock *sk, int state, int timeo) { struct inet_timewait_sock *tw = NULL; @@ -102,9 +112,10 @@ struct sock *dccp_create_openreq_child(struct sock *sk, struct sock *newsk = inet_csk_clone(sk, req, GFP_ATOMIC); if (newsk != NULL) { - struct dccp_request_sock *dreq = dccp_rsk(req); + const struct dccp_request_sock *dreq = dccp_rsk(req); struct inet_connection_sock *newicsk = inet_csk(newsk); struct dccp_sock *newdp = dccp_sk(newsk); + struct dccp_minisock *newdmsk = dccp_msk(newsk); newdp->dccps_role = DCCP_ROLE_SERVER; newdp->dccps_hc_rx_ackvec = NULL; @@ -114,32 +125,65 @@ struct sock *dccp_create_openreq_child(struct sock *sk, newdp->dccps_timestamp_time = dreq->dreq_timestamp_time; newicsk->icsk_rto = DCCP_TIMEOUT_INIT; - INIT_LIST_HEAD(&newdp->dccps_featneg); + if (dccp_feat_clone(sk, newsk)) + goto out_free; + + if (newdmsk->dccpms_send_ack_vector) { + newdp->dccps_hc_rx_ackvec = + dccp_ackvec_alloc(GFP_ATOMIC); + if (unlikely(newdp->dccps_hc_rx_ackvec == NULL)) + goto out_free; + } + + newdp->dccps_hc_rx_ccid = + ccid_hc_rx_new(newdmsk->dccpms_rx_ccid, + newsk, GFP_ATOMIC); + newdp->dccps_hc_tx_ccid = + ccid_hc_tx_new(newdmsk->dccpms_tx_ccid, + newsk, GFP_ATOMIC); + if (unlikely(newdp->dccps_hc_rx_ccid == NULL || + newdp->dccps_hc_tx_ccid == NULL)) { + dccp_ackvec_free(newdp->dccps_hc_rx_ackvec); + ccid_hc_rx_delete(newdp->dccps_hc_rx_ccid, newsk); + ccid_hc_tx_delete(newdp->dccps_hc_tx_ccid, newsk); +out_free: + /* It is still raw copy of parent, so invalidate + * destructor and make plain sk_free() */ + newsk->sk_destruct = NULL; + sk_free(newsk); + return NULL; + } + /* * Step 3: Process LISTEN state * * Choose S.ISS (initial seqno) or set from Init Cookies * Initialize S.GAR := S.ISS - * Set S.ISR, S.GSR from packet (or Init Cookies) - * - * Setting AWL/AWH and SWL/SWH happens as part of the feature - * activation below, as these windows all depend on the local - * and remote Sequence Window feature values (7.5.2). + * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies */ - newdp->dccps_gss = newdp->dccps_iss = dreq->dreq_iss; - newdp->dccps_gar = newdp->dccps_iss; - newdp->dccps_gsr = newdp->dccps_isr = dreq->dreq_isr; + + /* See dccp_v4_conn_request */ + newdmsk->dccpms_sequence_window = req->rcv_wnd; + + newdp->dccps_gar = newdp->dccps_iss = dreq->dreq_iss; + dccp_update_gss(newsk, dreq->dreq_iss); + + newdp->dccps_isr = dreq->dreq_isr; + dccp_update_gsr(newsk, dreq->dreq_isr); /* - * Activate features: initialise CCIDs, sequence windows etc. + * SWL and AWL are initially adjusted so that they are not less than + * the initial Sequence Numbers received and sent, respectively: + * SWL := max(GSR + 1 - floor(W/4), ISR), + * AWL := max(GSS - W' + 1, ISS). + * These adjustments MUST be applied only at the beginning of the + * connection. */ - if (dccp_feat_activate_values(newsk, &dreq->dreq_featneg)) { - /* It is still raw copy of parent, so invalidate - * destructor and make plain sk_free() */ - newsk->sk_destruct = NULL; - sk_free(newsk); - return NULL; - } + dccp_set_seqno(&newdp->dccps_swl, + max48(newdp->dccps_swl, newdp->dccps_isr)); + dccp_set_seqno(&newdp->dccps_awl, + max48(newdp->dccps_awl, newdp->dccps_iss)); + dccp_init_xmit_timers(newsk); DCCP_INC_STATS_BH(DCCP_MIB_PASSIVEOPENS); @@ -260,17 +304,14 @@ void dccp_reqsk_send_ack(struct sock *sk, struct sk_buff *skb, EXPORT_SYMBOL_GPL(dccp_reqsk_send_ack); -int dccp_reqsk_init(struct request_sock *req, - struct dccp_sock const *dp, struct sk_buff const *skb) +void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb) { struct dccp_request_sock *dreq = dccp_rsk(req); inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport; inet_rsk(req)->acked = 0; + req->rcv_wnd = sysctl_dccp_feat_sequence_window; dreq->dreq_timestamp_echo = 0; - - /* inherit feature negotiation options from listening socket */ - return dccp_feat_clone_list(&dp->dccps_featneg, &dreq->dreq_featneg); } EXPORT_SYMBOL_GPL(dccp_reqsk_init); diff --git a/net/dccp/options.c b/net/dccp/options.c index e5a32979d7d..0809b63cb05 100644 --- a/net/dccp/options.c +++ b/net/dccp/options.c @@ -23,20 +23,23 @@ #include "dccp.h" #include "feat.h" -u64 dccp_decode_value_var(const u8 *bf, const u8 len) +int sysctl_dccp_feat_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW; +int sysctl_dccp_feat_rx_ccid = DCCPF_INITIAL_CCID; +int sysctl_dccp_feat_tx_ccid = DCCPF_INITIAL_CCID; +int sysctl_dccp_feat_ack_ratio = DCCPF_INITIAL_ACK_RATIO; +int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR; +int sysctl_dccp_feat_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT; + +static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len) { - u64 value = 0; + u32 value = 0; - if (len >= DCCP_OPTVAL_MAXLEN) - value += ((u64)*bf++) << 40; - if (len > 4) - value += ((u64)*bf++) << 32; if (len > 3) - value += ((u64)*bf++) << 24; + value += *bf++ << 24; if (len > 2) - value += ((u64)*bf++) << 16; + value += *bf++ << 16; if (len > 1) - value += ((u64)*bf++) << 8; + value += *bf++ << 8; if (len > 0) value += *bf; @@ -54,6 +57,7 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, struct dccp_sock *dp = dccp_sk(sk); const struct dccp_hdr *dh = dccp_hdr(skb); const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type; + u64 ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); unsigned char *opt_ptr = options; const unsigned char *opt_end = (unsigned char *)dh + @@ -95,11 +99,18 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, } /* + * CCID-Specific Options (from RFC 4340, sec. 10.3): + * + * Option numbers 128 through 191 are for options sent from the + * HC-Sender to the HC-Receiver; option numbers 192 through 255 + * are for options sent from the HC-Receiver to the HC-Sender. + * * CCID-specific options are ignored during connection setup, as * negotiation may still be in progress (see RFC 4340, 10.3). * The same applies to Ack Vectors, as these depend on the CCID. + * */ - if (dreq != NULL && (opt >= DCCPO_MIN_RX_CCID_SPECIFIC || + if (dreq != NULL && (opt >= 128 || opt == DCCPO_ACK_VECTOR_0 || opt == DCCPO_ACK_VECTOR_1)) goto ignore_option; @@ -120,13 +131,43 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk), (unsigned long long)opt_recv->dccpor_ndp); break; - case DCCPO_CHANGE_L ... DCCPO_CONFIRM_R: - if (pkt_type == DCCP_PKT_DATA) /* RFC 4340, 6 */ + case DCCPO_CHANGE_L: + /* fall through */ + case DCCPO_CHANGE_R: + if (pkt_type == DCCP_PKT_DATA) break; - rc = dccp_feat_parse_options(sk, dreq, mandatory, opt, - *value, value + 1, len - 1); - if (rc) - goto out_featneg_failed; + if (len < 2) + goto out_invalid_option; + rc = dccp_feat_change_recv(sk, opt, *value, value + 1, + len - 1); + /* + * When there is a change error, change_recv is + * responsible for dealing with it. i.e. reply with an + * empty confirm. + * If the change was mandatory, then we need to die. + */ + if (rc && mandatory) + goto out_invalid_option; + break; + case DCCPO_CONFIRM_L: + /* fall through */ + case DCCPO_CONFIRM_R: + if (pkt_type == DCCP_PKT_DATA) + break; + if (len < 2) /* FIXME this disallows empty confirm */ + goto out_invalid_option; + if (dccp_feat_confirm_recv(sk, opt, *value, + value + 1, len - 1)) + goto out_invalid_option; + break; + case DCCPO_ACK_VECTOR_0: + case DCCPO_ACK_VECTOR_1: + if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */ + break; + + if (dccp_msk(sk)->dccpms_send_ack_vector && + dccp_ackvec_parse(sk, skb, &ackno, opt, value, len)) + goto out_invalid_option; break; case DCCPO_TIMESTAMP: if (len != 4) @@ -154,8 +195,6 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, dccp_role(sk), ntohl(opt_val), (unsigned long long) DCCP_SKB_CB(skb)->dccpd_ack_seq); - /* schedule an Ack in case this sender is quiescent */ - inet_csk_schedule_ack(sk); break; case DCCPO_TIMESTAMP_ECHO: if (len != 4 && len != 6 && len != 8) @@ -212,25 +251,23 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n", dccp_role(sk), elapsed_time); break; - case DCCPO_MIN_RX_CCID_SPECIFIC ... DCCPO_MAX_RX_CCID_SPECIFIC: + case 128 ... 191: { + const u16 idx = value - options; + if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk, - pkt_type, opt, value, len)) + opt, len, idx, + value) != 0) goto out_invalid_option; + } break; - case DCCPO_ACK_VECTOR_0: - case DCCPO_ACK_VECTOR_1: - if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */ - break; - /* - * Ack vectors are processed by the TX CCID if it is - * interested. The RX CCID need not parse Ack Vectors, - * since it is only interested in clearing old state. - * Fall through. - */ - case DCCPO_MIN_TX_CCID_SPECIFIC ... DCCPO_MAX_TX_CCID_SPECIFIC: + case 192 ... 255: { + const u16 idx = value - options; + if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk, - pkt_type, opt, value, len)) + opt, len, idx, + value) != 0) goto out_invalid_option; + } break; default: DCCP_CRIT("DCCP(%p): option %d(len=%d) not " @@ -252,10 +289,8 @@ out_nonsensical_length: out_invalid_option: DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT); - rc = DCCP_RESET_CODE_OPTION_ERROR; -out_featneg_failed: - DCCP_WARN("DCCP(%p): Option %d (len=%d) error=%u\n", sk, opt, len, rc); - DCCP_SKB_CB(skb)->dccpd_reset_code = rc; + DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR; + DCCP_WARN("DCCP(%p): invalid option %d, len=%d", sk, opt, len); DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt; DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0; DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0; @@ -264,12 +299,9 @@ out_featneg_failed: EXPORT_SYMBOL_GPL(dccp_parse_options); -void dccp_encode_value_var(const u64 value, u8 *to, const u8 len) +static void dccp_encode_value_var(const u32 value, unsigned char *to, + const unsigned int len) { - if (len >= DCCP_OPTVAL_MAXLEN) - *to++ = (value & 0xFF0000000000ull) >> 40; - if (len > 4) - *to++ = (value & 0xFF00000000ull) >> 32; if (len > 3) *to++ = (value & 0xFF000000) >> 24; if (len > 2) @@ -429,140 +461,92 @@ static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp, return 0; } -static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) +static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat, + u8 *val, u8 len) { - struct dccp_sock *dp = dccp_sk(sk); - struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec; - struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); - const u16 buflen = dccp_ackvec_buflen(av); - /* Figure out how many options do we need to represent the ackvec */ - const u8 nr_opts = DIV_ROUND_UP(buflen, DCCP_SINGLE_OPT_MAXLEN); - u16 len = buflen + 2 * nr_opts; - u8 i, nonce = 0; - const unsigned char *tail, *from; - unsigned char *to; + u8 *to; - if (dcb->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) { - DCCP_WARN("Lacking space for %u bytes on %s packet\n", len, - dccp_packet_name(dcb->dccpd_type)); + if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) { + DCCP_WARN("packet too small for feature %d option!\n", feat); return -1; } - /* - * Since Ack Vectors are variable-length, we can not always predict - * their size. To catch exception cases where the space is running out - * on the skb, a separate Sync is scheduled to carry the Ack Vector. - */ - if (len > DCCPAV_MIN_OPTLEN && - len + dcb->dccpd_opt_len + skb->len > dp->dccps_mss_cache) { - DCCP_WARN("No space left for Ack Vector (%u) on skb (%u+%u), " - "MPS=%u ==> reduce payload size?\n", len, skb->len, - dcb->dccpd_opt_len, dp->dccps_mss_cache); - dp->dccps_sync_scheduled = 1; - return 0; - } - dcb->dccpd_opt_len += len; - to = skb_push(skb, len); - len = buflen; - from = av->av_buf + av->av_buf_head; - tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN; + DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3; - for (i = 0; i < nr_opts; ++i) { - int copylen = len; - - if (len > DCCP_SINGLE_OPT_MAXLEN) - copylen = DCCP_SINGLE_OPT_MAXLEN; - - /* - * RFC 4340, 12.2: Encode the Nonce Echo for this Ack Vector via - * its type; ack_nonce is the sum of all individual buf_nonce's. - */ - nonce ^= av->av_buf_nonce[i]; - - *to++ = DCCPO_ACK_VECTOR_0 + av->av_buf_nonce[i]; - *to++ = copylen + 2; - - /* Check if buf_head wraps */ - if (from + copylen > tail) { - const u16 tailsize = tail - from; - - memcpy(to, from, tailsize); - to += tailsize; - len -= tailsize; - copylen -= tailsize; - from = av->av_buf; - } - - memcpy(to, from, copylen); - from += copylen; - to += copylen; - len -= copylen; - } - /* - * Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340. - */ - if (dccp_ackvec_update_records(av, dcb->dccpd_seq, nonce)) - return -ENOBUFS; - return 0; -} + to = skb_push(skb, len + 3); + *to++ = type; + *to++ = len + 3; + *to++ = feat; -/** - * dccp_insert_option_mandatory - Mandatory option (5.8.2) - * Note that since we are using skb_push, this function needs to be called - * _after_ inserting the option it is supposed to influence (stack order). - */ -int dccp_insert_option_mandatory(struct sk_buff *skb) -{ - if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN) - return -1; + if (len) + memcpy(to, val, len); - DCCP_SKB_CB(skb)->dccpd_opt_len++; - *skb_push(skb, 1) = DCCPO_MANDATORY; + dccp_pr_debug("%s(%s (%d), ...), length %d\n", + dccp_feat_typename(type), + dccp_feat_name(feat), feat, len); return 0; } -/** - * dccp_insert_fn_opt - Insert single Feature-Negotiation option into @skb - * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R - * @feat: one out of %dccp_feature_numbers - * @val: NN value or SP array (preferred element first) to copy - * @len: true length of @val in bytes (excluding first element repetition) - * @repeat_first: whether to copy the first element of @val twice - * The last argument is used to construct Confirm options, where the preferred - * value and the preference list appear separately (RFC 4340, 6.3.1). Preference - * lists are kept such that the preferred entry is always first, so we only need - * to copy twice, and avoid the overhead of cloning into a bigger array. - */ -int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat, - u8 *val, u8 len, bool repeat_first) +static int dccp_insert_options_feat(struct sock *sk, struct sk_buff *skb) { - u8 tot_len, *to; + struct dccp_sock *dp = dccp_sk(sk); + struct dccp_minisock *dmsk = dccp_msk(sk); + struct dccp_opt_pend *opt, *next; + int change = 0; + + /* confirm any options [NN opts] */ + list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) { + dccp_insert_feat_opt(skb, opt->dccpop_type, + opt->dccpop_feat, opt->dccpop_val, + opt->dccpop_len); + /* fear empty confirms */ + if (opt->dccpop_val) + kfree(opt->dccpop_val); + kfree(opt); + } + INIT_LIST_HEAD(&dmsk->dccpms_conf); + + /* see which features we need to send */ + list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) { + /* see if we need to send any confirm */ + if (opt->dccpop_sc) { + dccp_insert_feat_opt(skb, opt->dccpop_type + 1, + opt->dccpop_feat, + opt->dccpop_sc->dccpoc_val, + opt->dccpop_sc->dccpoc_len); + + BUG_ON(!opt->dccpop_sc->dccpoc_val); + kfree(opt->dccpop_sc->dccpoc_val); + kfree(opt->dccpop_sc); + opt->dccpop_sc = NULL; + } - /* take the `Feature' field and possible repetition into account */ - if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) { - DCCP_WARN("length %u for feature %u too large\n", len, feat); - return -1; + /* any option not confirmed, re-send it */ + if (!opt->dccpop_conf) { + dccp_insert_feat_opt(skb, opt->dccpop_type, + opt->dccpop_feat, opt->dccpop_val, + opt->dccpop_len); + change++; + } } - if (unlikely(val == NULL || len == 0)) - len = repeat_first = 0; - tot_len = 3 + repeat_first + len; + /* Retransmit timer. + * If this is the master listening sock, we don't set a timer on it. It + * should be fine because if the dude doesn't receive our RESPONSE + * [which will contain the CHANGE] he will send another REQUEST which + * will "retrnasmit" the change. + */ + if (change && dp->dccps_role != DCCP_ROLE_LISTEN) { + dccp_pr_debug("reset feat negotiation timer %p\n", sk); - if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) { - DCCP_WARN("packet too small for feature %d option!\n", feat); - return -1; + /* XXX don't reset the timer on re-transmissions. I.e. reset it + * only when sending new stuff i guess. Currently the timer + * never backs off because on re-transmission it just resets it! + */ + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, + inet_csk(sk)->icsk_rto, DCCP_RTO_MAX); } - DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len; - - to = skb_push(skb, tot_len); - *to++ = type; - *to++ = tot_len; - *to++ = feat; - if (repeat_first) - *to++ = *val; - if (len) - memcpy(to, val, len); return 0; } @@ -581,30 +565,19 @@ static void dccp_insert_option_padding(struct sk_buff *skb) int dccp_insert_options(struct sock *sk, struct sk_buff *skb) { struct dccp_sock *dp = dccp_sk(sk); + struct dccp_minisock *dmsk = dccp_msk(sk); DCCP_SKB_CB(skb)->dccpd_opt_len = 0; - if (dp->dccps_send_ndp_count && dccp_insert_option_ndp(sk, skb)) + if (dmsk->dccpms_send_ndp_count && + dccp_insert_option_ndp(sk, skb)) return -1; - if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) { - - /* Feature Negotiation */ - if (dccp_feat_insert_opts(dp, NULL, skb)) + if (!dccp_packet_without_ack(skb)) { + if (dmsk->dccpms_send_ack_vector && + dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) && + dccp_insert_option_ackvec(sk, skb)) return -1; - - if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) { - /* - * Obtain RTT sample from Request/Response exchange. - * This is currently used in CCID 3 initialisation. - */ - if (dccp_insert_option_timestamp(sk, skb)) - return -1; - - } else if (dccp_ackvec_pending(sk) && - dccp_insert_option_ackvec(sk, skb)) { - return -1; - } } if (dp->dccps_hc_rx_insert_options) { @@ -613,6 +586,21 @@ int dccp_insert_options(struct sock *sk, struct sk_buff *skb) dp->dccps_hc_rx_insert_options = 0; } + /* Feature negotiation */ + /* Data packets can't do feat negotiation */ + if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA && + DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATAACK && + dccp_insert_options_feat(sk, skb)) + return -1; + + /* + * Obtain RTT sample from Request/Response exchange. + * This is currently used in CCID 3 initialisation. + */ + if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST && + dccp_insert_option_timestamp(sk, skb)) + return -1; + if (dp->dccps_timestamp_echo != 0 && dccp_insert_option_timestamp_echo(dp, NULL, skb)) return -1; @@ -625,9 +613,6 @@ int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb) { DCCP_SKB_CB(skb)->dccpd_opt_len = 0; - if (dccp_feat_insert_opts(NULL, dreq, skb)) - return -1; - if (dreq->dreq_timestamp_echo != 0 && dccp_insert_option_timestamp_echo(NULL, dreq, skb)) return -1; diff --git a/net/dccp/output.c b/net/dccp/output.c index 2532797a800..d06945c7d3d 100644 --- a/net/dccp/output.c +++ b/net/dccp/output.c @@ -26,13 +26,11 @@ static inline void dccp_event_ack_sent(struct sock *sk) inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); } -/* enqueue @skb on sk_send_head for retransmission, return clone to send now */ -static struct sk_buff *dccp_skb_entail(struct sock *sk, struct sk_buff *skb) +static void dccp_skb_entail(struct sock *sk, struct sk_buff *skb) { skb_set_owner_w(skb, sk); WARN_ON(sk->sk_send_head); sk->sk_send_head = skb; - return skb_clone(sk->sk_send_head, gfp_any()); } /* @@ -163,27 +161,21 @@ unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu) struct inet_connection_sock *icsk = inet_csk(sk); struct dccp_sock *dp = dccp_sk(sk); u32 ccmps = dccp_determine_ccmps(dp); - u32 cur_mps = ccmps ? min(pmtu, ccmps) : pmtu; + int cur_mps = ccmps ? min(pmtu, ccmps) : pmtu; /* Account for header lengths and IPv4/v6 option overhead */ cur_mps -= (icsk->icsk_af_ops->net_header_len + icsk->icsk_ext_hdr_len + sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext)); /* - * Leave enough headroom for common DCCP header options. - * This only considers options which may appear on DCCP-Data packets, as - * per table 3 in RFC 4340, 5.8. When running out of space for other - * options (eg. Ack Vector which can take up to 255 bytes), it is better - * to schedule a separate Ack. Thus we leave headroom for the following: - * - 1 byte for Slow Receiver (11.6) - * - 6 bytes for Timestamp (13.1) - * - 10 bytes for Timestamp Echo (13.3) - * - 8 bytes for NDP count (7.7, when activated) - * - 6 bytes for Data Checksum (9.3) - * - %DCCPAV_MIN_OPTLEN bytes for Ack Vector size (11.4, when enabled) + * FIXME: this should come from the CCID infrastructure, where, say, + * TFRC will say it wants TIMESTAMPS, ELAPSED time, etc, for now lets + * put a rough estimate for NDP + TIMESTAMP + TIMESTAMP_ECHO + ELAPSED + * TIME + TFRC_OPT_LOSS_EVENT_RATE + TFRC_OPT_RECEIVE_RATE + padding to + * make it a multiple of 4 */ - cur_mps -= roundup(1 + 6 + 10 + dp->dccps_send_ndp_count * 8 + 6 + - (dp->dccps_hc_rx_ackvec ? DCCPAV_MIN_OPTLEN : 0), 4); + + cur_mps -= ((5 + 6 + 10 + 6 + 6 + 6 + 3) / 4) * 4; /* And store cached results */ icsk->icsk_pmtu_cookie = pmtu; @@ -208,158 +200,95 @@ void dccp_write_space(struct sock *sk) } /** - * dccp_wait_for_ccid - Await CCID send permission + * dccp_wait_for_ccid - Wait for ccid to tell us we can send a packet * @sk: socket to wait for - * @delay: timeout in jiffies - * This is used by CCIDs which need to delay the send time in process context. + * @skb: current skb to pass on for waiting + * @delay: sleep timeout in milliseconds (> 0) + * This function is called by default when the socket is closed, and + * when a non-zero linger time is set on the socket. For consistency */ -static int dccp_wait_for_ccid(struct sock *sk, unsigned long delay) +static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb, int delay) { + struct dccp_sock *dp = dccp_sk(sk); DEFINE_WAIT(wait); - long remaining; - - prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); - sk->sk_write_pending++; - release_sock(sk); + unsigned long jiffdelay; + int rc; - remaining = schedule_timeout(delay); - - lock_sock(sk); - sk->sk_write_pending--; - finish_wait(sk->sk_sleep, &wait); + do { + dccp_pr_debug("delayed send by %d msec\n", delay); + jiffdelay = msecs_to_jiffies(delay); - if (signal_pending(current) || sk->sk_err) - return -1; - return remaining; -} - -/** - * dccp_xmit_packet - Send data packet under control of CCID - * Transmits next-queued payload and informs CCID to account for the packet. - */ -static void dccp_xmit_packet(struct sock *sk) -{ - int err, len; - struct dccp_sock *dp = dccp_sk(sk); - struct sk_buff *skb = dccp_qpolicy_pop(sk); + prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); - if (unlikely(skb == NULL)) - return; - len = skb->len; + sk->sk_write_pending++; + release_sock(sk); + schedule_timeout(jiffdelay); + lock_sock(sk); + sk->sk_write_pending--; - if (sk->sk_state == DCCP_PARTOPEN) { - const u32 cur_mps = dp->dccps_mss_cache - DCCP_FEATNEG_OVERHEAD; - /* - * See 8.1.5 - Handshake Completion. - * - * For robustness we resend Confirm options until the client has - * entered OPEN. During the initial feature negotiation, the MPS - * is smaller than usual, reduced by the Change/Confirm options. - */ - if (!list_empty(&dp->dccps_featneg) && len > cur_mps) { - DCCP_WARN("Payload too large (%d) for featneg.\n", len); - dccp_send_ack(sk); - dccp_feat_list_purge(&dp->dccps_featneg); - } + if (sk->sk_err) + goto do_error; + if (signal_pending(current)) + goto do_interrupted; - inet_csk_schedule_ack(sk); - inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, - inet_csk(sk)->icsk_rto, - DCCP_RTO_MAX); - DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATAACK; - } else if (dccp_ack_pending(sk)) { - DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATAACK; - } else { - DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATA; - } - - err = dccp_transmit_skb(sk, skb); - if (err) - dccp_pr_debug("transmit_skb() returned err=%d\n", err); - /* - * Register this one as sent even if an error occurred. To the remote - * end a local packet drop is indistinguishable from network loss, i.e. - * any local drop will eventually be reported via receiver feedback. - */ - ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, len); - - /* - * If the CCID needs to transfer additional header options out-of-band - * (e.g. Ack Vectors or feature-negotiation options), it activates this - * flag to schedule a Sync. The Sync will automatically incorporate all - * currently pending header options, thus clearing the backlog. - */ - if (dp->dccps_sync_scheduled) - dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC); + rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); + } while ((delay = rc) > 0); +out: + finish_wait(sk->sk_sleep, &wait); + return rc; + +do_error: + rc = -EPIPE; + goto out; +do_interrupted: + rc = -EINTR; + goto out; } -/** - * dccp_flush_write_queue - Drain queue at end of connection - * Since dccp_sendmsg queues packets without waiting for them to be sent, it may - * happen that the TX queue is not empty at the end of a connection. We give the - * HC-sender CCID a grace period of up to @time_budget jiffies. If this function - * returns with a non-empty write queue, it will be purged later. - */ -void dccp_flush_write_queue(struct sock *sk, long *time_budget) +void dccp_write_xmit(struct sock *sk, int block) { struct dccp_sock *dp = dccp_sk(sk); struct sk_buff *skb; - long delay, rc; - - while (*time_budget > 0 && (skb = skb_peek(&sk->sk_write_queue))) { - rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); - switch (ccid_packet_dequeue_eval(rc)) { - case CCID_PACKET_WILL_DEQUEUE_LATER: - /* - * If the CCID determines when to send, the next sending - * time is unknown or the CCID may not even send again - * (e.g. remote host crashes or lost Ack packets). - */ - DCCP_WARN("CCID did not manage to send all packets\n"); - return; - case CCID_PACKET_DELAY: - delay = msecs_to_jiffies(rc); - if (delay > *time_budget) - return; - rc = dccp_wait_for_ccid(sk, delay); - if (rc < 0) - return; - *time_budget -= (delay - rc); - /* check again if we can send now */ - break; - case CCID_PACKET_SEND_AT_ONCE: - dccp_xmit_packet(sk); - break; - case CCID_PACKET_ERR: - skb_dequeue(&sk->sk_write_queue); - kfree_skb(skb); - dccp_pr_debug("packet discarded due to err=%ld\n", rc); + while ((skb = skb_peek(&sk->sk_write_queue))) { + int err = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); + + if (err > 0) { + if (!block) { + sk_reset_timer(sk, &dp->dccps_xmit_timer, + msecs_to_jiffies(err)+jiffies); + break; + } else + err = dccp_wait_for_ccid(sk, skb, err); + if (err && err != -EINTR) + DCCP_BUG("err=%d after dccp_wait_for_ccid", err); } - } -} -void dccp_write_xmit(struct sock *sk) -{ - struct dccp_sock *dp = dccp_sk(sk); - struct sk_buff *skb; + skb_dequeue(&sk->sk_write_queue); + if (err == 0) { + struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); + const int len = skb->len; - while ((skb = dccp_qpolicy_top(sk))) { - int rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); - - switch (ccid_packet_dequeue_eval(rc)) { - case CCID_PACKET_WILL_DEQUEUE_LATER: - return; - case CCID_PACKET_DELAY: - sk_reset_timer(sk, &dp->dccps_xmit_timer, - jiffies + msecs_to_jiffies(rc)); - return; - case CCID_PACKET_SEND_AT_ONCE: - dccp_xmit_packet(sk); - break; - case CCID_PACKET_ERR: - dccp_qpolicy_drop(sk, skb); - dccp_pr_debug("packet discarded due to err=%d\n", rc); + if (sk->sk_state == DCCP_PARTOPEN) { + /* See 8.1.5. Handshake Completion */ + inet_csk_schedule_ack(sk); + inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, + inet_csk(sk)->icsk_rto, + DCCP_RTO_MAX); + dcb->dccpd_type = DCCP_PKT_DATAACK; + } else if (dccp_ack_pending(sk)) + dcb->dccpd_type = DCCP_PKT_DATAACK; + else + dcb->dccpd_type = DCCP_PKT_DATA; + + err = dccp_transmit_skb(sk, skb); + ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len); + if (err) + DCCP_BUG("err=%d after ccid_hc_tx_packet_sent", + err); + } else { + dccp_pr_debug("packet discarded due to err=%d\n", err); + kfree_skb(skb); } } } @@ -410,12 +339,10 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst, DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss; - /* Resolve feature dependencies resulting from choice of CCID */ - if (dccp_feat_server_ccid_dependencies(dreq)) - goto response_failed; - - if (dccp_insert_options_rsk(dreq, skb)) - goto response_failed; + if (dccp_insert_options_rsk(dreq, skb)) { + kfree_skb(skb); + return NULL; + } /* Build and checksum header */ dh = dccp_zeroed_hdr(skb, dccp_header_size); @@ -436,9 +363,6 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst, inet_rsk(req)->acked = 1; DCCP_INC_STATS(DCCP_MIB_OUTSEGS); return skb; -response_failed: - kfree_skb(skb); - return NULL; } EXPORT_SYMBOL_GPL(dccp_make_response); @@ -523,9 +447,8 @@ int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code) /* * Do all connect socket setups that can be done AF independent. */ -int dccp_connect(struct sock *sk) +static inline void dccp_connect_init(struct sock *sk) { - struct sk_buff *skb; struct dccp_sock *dp = dccp_sk(sk); struct dst_entry *dst = __sk_dst_get(sk); struct inet_connection_sock *icsk = inet_csk(sk); @@ -535,13 +458,19 @@ int dccp_connect(struct sock *sk) dccp_sync_mss(sk, dst_mtu(dst)); - /* do not connect if feature negotiation setup fails */ - if (dccp_feat_finalise_settings(dccp_sk(sk))) - return -EPROTO; - /* Initialise GAR as per 8.5; AWL/AWH are set in dccp_transmit_skb() */ dp->dccps_gar = dp->dccps_iss; + icsk->icsk_retransmits = 0; +} + +int dccp_connect(struct sock *sk) +{ + struct sk_buff *skb; + struct inet_connection_sock *icsk = inet_csk(sk); + + dccp_connect_init(sk); + skb = alloc_skb(sk->sk_prot->max_header, sk->sk_allocation); if (unlikely(skb == NULL)) return -ENOBUFS; @@ -551,11 +480,11 @@ int dccp_connect(struct sock *sk) DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST; - dccp_transmit_skb(sk, dccp_skb_entail(sk, skb)); + dccp_skb_entail(sk, skb); + dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL)); DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS); /* Timer for repeating the REQUEST until an answer. */ - icsk->icsk_retransmits = 0; inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, icsk->icsk_rto, DCCP_RTO_MAX); return 0; @@ -642,12 +571,6 @@ void dccp_send_sync(struct sock *sk, const u64 ackno, DCCP_SKB_CB(skb)->dccpd_type = pkt_type; DCCP_SKB_CB(skb)->dccpd_ack_seq = ackno; - /* - * Clear the flag in case the Sync was scheduled for out-of-band data, - * such as carrying a long Ack Vector. - */ - dccp_sk(sk)->dccps_sync_scheduled = 0; - dccp_transmit_skb(sk, skb); } @@ -676,7 +599,9 @@ void dccp_send_close(struct sock *sk, const int active) DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSE; if (active) { - skb = dccp_skb_entail(sk, skb); + dccp_write_xmit(sk, 1); + dccp_skb_entail(sk, skb); + dccp_transmit_skb(sk, skb_clone(skb, prio)); /* * Retransmission timer for active-close: RFC 4340, 8.3 requires * to retransmit the Close/CloseReq until the CLOSING/CLOSEREQ @@ -689,6 +614,6 @@ void dccp_send_close(struct sock *sk, const int active) */ inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, DCCP_TIMEOUT_INIT, DCCP_RTO_MAX); - } - dccp_transmit_skb(sk, skb); + } else + dccp_transmit_skb(sk, skb); } diff --git a/net/dccp/probe.c b/net/dccp/probe.c index eaa59d82ab0..81368a7f537 100644 --- a/net/dccp/probe.c +++ b/net/dccp/probe.c @@ -46,54 +46,75 @@ static struct { struct kfifo *fifo; spinlock_t lock; wait_queue_head_t wait; - ktime_t start; + struct timespec tstart; } dccpw; -static void jdccp_write_xmit(struct sock *sk) +static void printl(const char *fmt, ...) { - const struct inet_sock *inet = inet_sk(sk); - struct ccid3_hc_tx_sock *hctx = NULL; - struct timespec tv; - char buf[256]; - int len, ccid = ccid_get_current_tx_ccid(dccp_sk(sk)); + va_list args; + int len; + struct timespec now; + char tbuf[256]; - if (ccid == DCCPC_CCID3) - hctx = ccid3_hc_tx_sk(sk); + va_start(args, fmt); + getnstimeofday(&now); - if (!port || ntohs(inet->dport) == port || ntohs(inet->sport) == port) { + now = timespec_sub(now, dccpw.tstart); - tv = ktime_to_timespec(ktime_sub(ktime_get(), dccpw.start)); - len = sprintf(buf, "%lu.%09lu %d.%d.%d.%d:%u %d.%d.%d.%d:%u %d", - (unsigned long)tv.tv_sec, - (unsigned long)tv.tv_nsec, - NIPQUAD(inet->saddr), ntohs(inet->sport), - NIPQUAD(inet->daddr), ntohs(inet->dport), ccid); + len = sprintf(tbuf, "%lu.%06lu ", + (unsigned long) now.tv_sec, + (unsigned long) now.tv_nsec / NSEC_PER_USEC); + len += vscnprintf(tbuf+len, sizeof(tbuf)-len, fmt, args); + va_end(args); + kfifo_put(dccpw.fifo, tbuf, len); + wake_up(&dccpw.wait); +} + +static int jdccp_sendmsg(struct kiocb *iocb, struct sock *sk, + struct msghdr *msg, size_t size) +{ + const struct dccp_minisock *dmsk = dccp_msk(sk); + const struct inet_sock *inet = inet_sk(sk); + const struct ccid3_hc_tx_sock *hctx; + + if (dmsk->dccpms_tx_ccid == DCCPC_CCID3) + hctx = ccid3_hc_tx_sk(sk); + else + hctx = NULL; + + if (port == 0 || ntohs(inet->dport) == port || + ntohs(inet->sport) == port) { if (hctx) - len += sprintf(buf + len, " %d %d %d %u %u %u %d", - hctx->s, hctx->rtt, hctx->p, hctx->x_calc, - (unsigned)(hctx->x_recv >> 6), - (unsigned)(hctx->x >> 6), hctx->t_ipi); - - len += sprintf(buf + len, "\n"); - kfifo_put(dccpw.fifo, buf, len); - wake_up(&dccpw.wait); + printl("%d.%d.%d.%d:%u %d.%d.%d.%d:%u %d %d %d %d %u " + "%llu %llu %d\n", + NIPQUAD(inet->saddr), ntohs(inet->sport), + NIPQUAD(inet->daddr), ntohs(inet->dport), size, + hctx->ccid3hctx_s, hctx->ccid3hctx_rtt, + hctx->ccid3hctx_p, hctx->ccid3hctx_x_calc, + hctx->ccid3hctx_x_recv >> 6, + hctx->ccid3hctx_x >> 6, hctx->ccid3hctx_t_ipi); + else + printl("%d.%d.%d.%d:%u %d.%d.%d.%d:%u %d\n", + NIPQUAD(inet->saddr), ntohs(inet->sport), + NIPQUAD(inet->daddr), ntohs(inet->dport), size); } jprobe_return(); + return 0; } static struct jprobe dccp_send_probe = { .kp = { - .symbol_name = "dccp_write_xmit", + .symbol_name = "dccp_sendmsg", }, - .entry = jdccp_write_xmit, + .entry = jdccp_sendmsg, }; static int dccpprobe_open(struct inode *inode, struct file *file) { kfifo_reset(dccpw.fifo); - dccpw.start = ktime_get(); + getnstimeofday(&dccpw.tstart); return 0; } diff --git a/net/dccp/proto.c b/net/dccp/proto.c index ecf3be961e1..d0bd3481976 100644 --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -67,9 +67,6 @@ void dccp_set_state(struct sock *sk, const int state) case DCCP_OPEN: if (oldstate != DCCP_OPEN) DCCP_INC_STATS(DCCP_MIB_CURRESTAB); - /* Client retransmits all Confirm options until entering OPEN */ - if (oldstate == DCCP_PARTOPEN) - dccp_feat_list_purge(&dccp_sk(sk)->dccps_featneg); break; case DCCP_CLOSED: @@ -178,25 +175,63 @@ EXPORT_SYMBOL_GPL(dccp_state_name); int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized) { struct dccp_sock *dp = dccp_sk(sk); + struct dccp_minisock *dmsk = dccp_msk(sk); struct inet_connection_sock *icsk = inet_csk(sk); + dccp_minisock_init(&dp->dccps_minisock); + icsk->icsk_rto = DCCP_TIMEOUT_INIT; icsk->icsk_syn_retries = sysctl_dccp_request_retries; sk->sk_state = DCCP_CLOSED; sk->sk_write_space = dccp_write_space; icsk->icsk_sync_mss = dccp_sync_mss; - dp->dccps_mss_cache = TCP_MIN_RCVMSS; + dp->dccps_mss_cache = 536; dp->dccps_rate_last = jiffies; dp->dccps_role = DCCP_ROLE_UNDEFINED; dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT; - dp->dccps_tx_qlen = sysctl_dccp_tx_qlen; + dp->dccps_l_ack_ratio = dp->dccps_r_ack_ratio = 1; dccp_init_xmit_timers(sk); - INIT_LIST_HEAD(&dp->dccps_featneg); - /* control socket doesn't need feat nego */ - if (likely(ctl_sock_initialized)) - return dccp_feat_init(sk); + /* + * FIXME: We're hardcoding the CCID, and doing this at this point makes + * the listening (master) sock get CCID control blocks, which is not + * necessary, but for now, to not mess with the test userspace apps, + * lets leave it here, later the real solution is to do this in a + * setsockopt(CCIDs-I-want/accept). -acme + */ + if (likely(ctl_sock_initialized)) { + int rc = dccp_feat_init(dmsk); + + if (rc) + return rc; + + if (dmsk->dccpms_send_ack_vector) { + dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(GFP_KERNEL); + if (dp->dccps_hc_rx_ackvec == NULL) + return -ENOMEM; + } + dp->dccps_hc_rx_ccid = ccid_hc_rx_new(dmsk->dccpms_rx_ccid, + sk, GFP_KERNEL); + dp->dccps_hc_tx_ccid = ccid_hc_tx_new(dmsk->dccpms_tx_ccid, + sk, GFP_KERNEL); + if (unlikely(dp->dccps_hc_rx_ccid == NULL || + dp->dccps_hc_tx_ccid == NULL)) { + ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); + ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk); + if (dmsk->dccpms_send_ack_vector) { + dccp_ackvec_free(dp->dccps_hc_rx_ackvec); + dp->dccps_hc_rx_ackvec = NULL; + } + dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL; + return -ENOMEM; + } + } else { + /* control socket doesn't need feat nego */ + INIT_LIST_HEAD(&dmsk->dccpms_pending); + INIT_LIST_HEAD(&dmsk->dccpms_conf); + } + return 0; } @@ -205,6 +240,7 @@ EXPORT_SYMBOL_GPL(dccp_init_sock); void dccp_destroy_sock(struct sock *sk) { struct dccp_sock *dp = dccp_sk(sk); + struct dccp_minisock *dmsk = dccp_msk(sk); /* * DCCP doesn't use sk_write_queue, just sk_send_head @@ -222,7 +258,7 @@ void dccp_destroy_sock(struct sock *sk) kfree(dp->dccps_service_list); dp->dccps_service_list = NULL; - if (dp->dccps_hc_rx_ackvec != NULL) { + if (dmsk->dccpms_send_ack_vector) { dccp_ackvec_free(dp->dccps_hc_rx_ackvec); dp->dccps_hc_rx_ackvec = NULL; } @@ -231,7 +267,7 @@ void dccp_destroy_sock(struct sock *sk) dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL; /* clean up feature negotiation state */ - dccp_feat_list_purge(&dp->dccps_featneg); + dccp_feat_clean(dmsk); } EXPORT_SYMBOL_GPL(dccp_destroy_sock); @@ -241,9 +277,6 @@ static inline int dccp_listen_start(struct sock *sk, int backlog) struct dccp_sock *dp = dccp_sk(sk); dp->dccps_role = DCCP_ROLE_LISTEN; - /* do not start to listen if feature negotiation setup fails */ - if (dccp_feat_finalise_settings(dp)) - return -EPROTO; return inet_csk_listen_start(sk, backlog); } @@ -433,70 +466,42 @@ static int dccp_setsockopt_service(struct sock *sk, const __be32 service, return 0; } -static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx) +/* byte 1 is feature. the rest is the preference list */ +static int dccp_setsockopt_change(struct sock *sk, int type, + struct dccp_so_feat __user *optval) { - u8 *list, len; - int i, rc; + struct dccp_so_feat opt; + u8 *val; + int rc; - if (cscov < 0 || cscov > 15) - return -EINVAL; + if (copy_from_user(&opt, optval, sizeof(opt))) + return -EFAULT; /* - * Populate a list of permissible values, in the range cscov...15. This - * is necessary since feature negotiation of single values only works if - * both sides incidentally choose the same value. Since the list starts - * lowest-value first, negotiation will pick the smallest shared value. + * rfc4340: 6.1. Change Options */ - if (cscov == 0) - return 0; - len = 16 - cscov; - - list = kmalloc(len, GFP_KERNEL); - if (list == NULL) - return -ENOBUFS; - - for (i = 0; i < len; i++) - list[i] = cscov++; - - rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len); - - if (rc == 0) { - if (rx) - dccp_sk(sk)->dccps_pcrlen = cscov; - else - dccp_sk(sk)->dccps_pcslen = cscov; - } - kfree(list); - return rc; -} - -static int dccp_setsockopt_ccid(struct sock *sk, int type, - char __user *optval, int optlen) -{ - u8 *val; - int rc = 0; - - if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS) + if (opt.dccpsf_len < 1) return -EINVAL; - val = kmalloc(optlen, GFP_KERNEL); - if (val == NULL) + val = kmalloc(opt.dccpsf_len, GFP_KERNEL); + if (!val) return -ENOMEM; - if (copy_from_user(val, optval, optlen)) { - kfree(val); - return -EFAULT; + if (copy_from_user(val, opt.dccpsf_val, opt.dccpsf_len)) { + rc = -EFAULT; + goto out_free_val; } - lock_sock(sk); - if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID) - rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen); + rc = dccp_feat_change(dccp_msk(sk), type, opt.dccpsf_feat, + val, opt.dccpsf_len, GFP_KERNEL); + if (rc) + goto out_free_val; - if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID)) - rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen); - release_sock(sk); +out: + return rc; +out_free_val: kfree(val); - return rc; + goto out; } static int do_dccp_setsockopt(struct sock *sk, int level, int optname, @@ -505,21 +510,7 @@ static int do_dccp_setsockopt(struct sock *sk, int level, int optname, struct dccp_sock *dp = dccp_sk(sk); int val, err = 0; - switch (optname) { - case DCCP_SOCKOPT_PACKET_SIZE: - DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); - return 0; - case DCCP_SOCKOPT_CHANGE_L: - case DCCP_SOCKOPT_CHANGE_R: - DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n"); - return 0; - case DCCP_SOCKOPT_CCID: - case DCCP_SOCKOPT_RX_CCID: - case DCCP_SOCKOPT_TX_CCID: - return dccp_setsockopt_ccid(sk, optname, optval, optlen); - } - - if (optlen < (int)sizeof(int)) + if (optlen < sizeof(int)) return -EINVAL; if (get_user(val, (int __user *)optval)) @@ -530,38 +521,53 @@ static int do_dccp_setsockopt(struct sock *sk, int level, int optname, lock_sock(sk); switch (optname) { + case DCCP_SOCKOPT_PACKET_SIZE: + DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); + err = 0; + break; + case DCCP_SOCKOPT_CHANGE_L: + if (optlen != sizeof(struct dccp_so_feat)) + err = -EINVAL; + else + err = dccp_setsockopt_change(sk, DCCPO_CHANGE_L, + (struct dccp_so_feat __user *) + optval); + break; + case DCCP_SOCKOPT_CHANGE_R: + if (optlen != sizeof(struct dccp_so_feat)) + err = -EINVAL; + else + err = dccp_setsockopt_change(sk, DCCPO_CHANGE_R, + (struct dccp_so_feat __user *) + optval); + break; case DCCP_SOCKOPT_SERVER_TIMEWAIT: if (dp->dccps_role != DCCP_ROLE_SERVER) err = -EOPNOTSUPP; else dp->dccps_server_timewait = (val != 0); break; - case DCCP_SOCKOPT_SEND_CSCOV: - err = dccp_setsockopt_cscov(sk, val, false); - break; - case DCCP_SOCKOPT_RECV_CSCOV: - err = dccp_setsockopt_cscov(sk, val, true); - break; - case DCCP_SOCKOPT_QPOLICY_ID: - if (sk->sk_state != DCCP_CLOSED) - err = -EISCONN; - else if (val < 0 || val >= DCCPQ_POLICY_MAX) + case DCCP_SOCKOPT_SEND_CSCOV: /* sender side, RFC 4340, sec. 9.2 */ + if (val < 0 || val > 15) err = -EINVAL; else - dp->dccps_qpolicy = val; + dp->dccps_pcslen = val; break; - case DCCP_SOCKOPT_QPOLICY_TXQLEN: - if (val < 0) + case DCCP_SOCKOPT_RECV_CSCOV: /* receiver side, RFC 4340 sec. 9.2.1 */ + if (val < 0 || val > 15) err = -EINVAL; - else - dp->dccps_tx_qlen = val; + else { + dp->dccps_pcrlen = val; + /* FIXME: add feature negotiation, + * ChangeL(MinimumChecksumCoverage, val) */ + } break; default: err = -ENOPROTOOPT; break; } - release_sock(sk); + release_sock(sk); return err; } @@ -642,18 +648,6 @@ static int do_dccp_getsockopt(struct sock *sk, int level, int optname, case DCCP_SOCKOPT_GET_CUR_MPS: val = dp->dccps_mss_cache; break; - case DCCP_SOCKOPT_AVAILABLE_CCIDS: - return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen); - case DCCP_SOCKOPT_TX_CCID: - val = ccid_get_current_tx_ccid(dp); - if (val < 0) - return -ENOPROTOOPT; - break; - case DCCP_SOCKOPT_RX_CCID: - val = ccid_get_current_rx_ccid(dp); - if (val < 0) - return -ENOPROTOOPT; - break; case DCCP_SOCKOPT_SERVER_TIMEWAIT: val = dp->dccps_server_timewait; break; @@ -663,12 +657,6 @@ static int do_dccp_getsockopt(struct sock *sk, int level, int optname, case DCCP_SOCKOPT_RECV_CSCOV: val = dp->dccps_pcrlen; break; - case DCCP_SOCKOPT_QPOLICY_ID: - val = dp->dccps_qpolicy; - break; - case DCCP_SOCKOPT_QPOLICY_TXQLEN: - val = dp->dccps_tx_qlen; - break; case 128 ... 191: return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname, len, (u32 __user *)optval, optlen); @@ -711,47 +699,6 @@ int compat_dccp_getsockopt(struct sock *sk, int level, int optname, EXPORT_SYMBOL_GPL(compat_dccp_getsockopt); #endif -static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb) -{ - struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg); - - /* - * Assign an (opaque) qpolicy priority value to skb->priority. - * - * We are overloading this skb field for use with the qpolicy subystem. - * The skb->priority is normally used for the SO_PRIORITY option, which - * is initialised from sk_priority. Since the assignment of sk_priority - * to skb->priority happens later (on layer 3), we overload this field - * for use with queueing priorities as long as the skb is on layer 4. - * The default priority value (if nothing is set) is 0. - */ - skb->priority = 0; - - for (; cmsg != NULL; cmsg = CMSG_NXTHDR(msg, cmsg)) { - - if (!CMSG_OK(msg, cmsg)) - return -EINVAL; - - if (cmsg->cmsg_level != SOL_DCCP) - continue; - - if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX && - !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type)) - return -EINVAL; - - switch (cmsg->cmsg_type) { - case DCCP_SCM_PRIORITY: - if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32))) - return -EINVAL; - skb->priority = *(__u32 *)CMSG_DATA(cmsg); - break; - default: - return -EINVAL; - } - } - return 0; -} - int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t len) { @@ -767,7 +714,8 @@ int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, lock_sock(sk); - if (dccp_qpolicy_full(sk)) { + if (sysctl_dccp_tx_qlen && + (sk->sk_write_queue.qlen >= sysctl_dccp_tx_qlen)) { rc = -EAGAIN; goto out_release; } @@ -795,12 +743,8 @@ int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, if (rc != 0) goto out_discard; - rc = dccp_msghdr_parse(msg, skb); - if (rc != 0) - goto out_discard; - - dccp_qpolicy_push(sk, skb); - dccp_write_xmit(sk); + skb_queue_tail(&sk->sk_write_queue, skb); + dccp_write_xmit(sk,0); out_release: release_sock(sk); return rc ? : len; @@ -1023,22 +967,9 @@ void dccp_close(struct sock *sk, long timeout) /* Check zero linger _after_ checking for unread data. */ sk->sk_prot->disconnect(sk, 0); } else if (sk->sk_state != DCCP_CLOSED) { - /* - * Normal connection termination. May need to wait if there are - * still packets in the TX queue that are delayed by the CCID. - */ - dccp_flush_write_queue(sk, &timeout); dccp_terminate_connection(sk); } - /* - * Flush write queue. This may be necessary in several cases: - * - we have been closed by the peer but still have application data; - * - abortive termination (unread data or zero linger time), - * - normal termination but queue could not be flushed within time limit - */ - __skb_queue_purge(&sk->sk_write_queue); - sk_stream_wait_close(sk, timeout); adjudge_to_death: diff --git a/net/dccp/qpolicy.c b/net/dccp/qpolicy.c deleted file mode 100644 index 27383f88c75..00000000000 --- a/net/dccp/qpolicy.c +++ /dev/null @@ -1,137 +0,0 @@ -/* - * net/dccp/qpolicy.c - * - * Policy-based packet dequeueing interface for DCCP. - * - * Copyright (c) 2008 Tomasz Grobelny <tomasz@grobelny.oswiecenia.net> - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License v2 - * as published by the Free Software Foundation. - */ -#include "dccp.h" - -/* - * Simple Dequeueing Policy: - * If tx_qlen is different from 0, enqueue up to tx_qlen elements. - */ -static void qpolicy_simple_push(struct sock *sk, struct sk_buff *skb) -{ - skb_queue_tail(&sk->sk_write_queue, skb); -} - -static bool qpolicy_simple_full(struct sock *sk) -{ - return dccp_sk(sk)->dccps_tx_qlen && - sk->sk_write_queue.qlen >= dccp_sk(sk)->dccps_tx_qlen; -} - -static struct sk_buff *qpolicy_simple_top(struct sock *sk) -{ - return skb_peek(&sk->sk_write_queue); -} - -/* - * Priority-based Dequeueing Policy: - * If tx_qlen is different from 0 and the queue has reached its upper bound - * of tx_qlen elements, replace older packets lowest-priority-first. - */ -static struct sk_buff *qpolicy_prio_best_skb(struct sock *sk) -{ - struct sk_buff *skb, *best = NULL; - - skb_queue_walk(&sk->sk_write_queue, skb) - if (best == NULL || skb->priority > best->priority) - best = skb; - return best; -} - -static struct sk_buff *qpolicy_prio_worst_skb(struct sock *sk) -{ - struct sk_buff *skb, *worst = NULL; - - skb_queue_walk(&sk->sk_write_queue, skb) - if (worst == NULL || skb->priority < worst->priority) - worst = skb; - return worst; -} - -static bool qpolicy_prio_full(struct sock *sk) -{ - if (qpolicy_simple_full(sk)) - dccp_qpolicy_drop(sk, qpolicy_prio_worst_skb(sk)); - return false; -} - -/** - * struct dccp_qpolicy_operations - TX Packet Dequeueing Interface - * @push: add a new @skb to the write queue - * @full: indicates that no more packets will be admitted - * @top: peeks at whatever the queueing policy defines as its `top' - */ -static struct dccp_qpolicy_operations { - void (*push) (struct sock *sk, struct sk_buff *skb); - bool (*full) (struct sock *sk); - struct sk_buff* (*top) (struct sock *sk); - __be32 params; - -} qpol_table[DCCPQ_POLICY_MAX] = { - [DCCPQ_POLICY_SIMPLE] = { - .push = qpolicy_simple_push, - .full = qpolicy_simple_full, - .top = qpolicy_simple_top, - .params = 0, - }, - [DCCPQ_POLICY_PRIO] = { - .push = qpolicy_simple_push, - .full = qpolicy_prio_full, - .top = qpolicy_prio_best_skb, - .params = DCCP_SCM_PRIORITY, - }, -}; - -/* - * Externally visible interface - */ -void dccp_qpolicy_push(struct sock *sk, struct sk_buff *skb) -{ - qpol_table[dccp_sk(sk)->dccps_qpolicy].push(sk, skb); -} - -bool dccp_qpolicy_full(struct sock *sk) -{ - return qpol_table[dccp_sk(sk)->dccps_qpolicy].full(sk); -} - -void dccp_qpolicy_drop(struct sock *sk, struct sk_buff *skb) -{ - if (skb != NULL) { - skb_unlink(skb, &sk->sk_write_queue); - kfree_skb(skb); - } -} - -struct sk_buff *dccp_qpolicy_top(struct sock *sk) -{ - return qpol_table[dccp_sk(sk)->dccps_qpolicy].top(sk); -} - -struct sk_buff *dccp_qpolicy_pop(struct sock *sk) -{ - struct sk_buff *skb = dccp_qpolicy_top(sk); - - /* Clear any skb fields that we used internally */ - skb->priority = 0; - - if (skb) - skb_unlink(skb, &sk->sk_write_queue); - return skb; -} - -bool dccp_qpolicy_param_ok(struct sock *sk, __be32 param) -{ - /* check if exactly one bit is set */ - if (!param || (param & (param - 1))) - return false; - return (qpol_table[dccp_sk(sk)->dccps_qpolicy].params & param) == param; -} diff --git a/net/dccp/sysctl.c b/net/dccp/sysctl.c index a5a1856234e..21295993fdb 100644 --- a/net/dccp/sysctl.c +++ b/net/dccp/sysctl.c @@ -18,72 +18,76 @@ #error This file should not be compiled without CONFIG_SYSCTL defined #endif -/* Boundary values */ -static int zero = 0, - u8_max = 0xFF; -static unsigned long seqw_min = 32; - static struct ctl_table dccp_default_table[] = { { .procname = "seq_window", - .data = &sysctl_dccp_sequence_window, - .maxlen = sizeof(sysctl_dccp_sequence_window), + .data = &sysctl_dccp_feat_sequence_window, + .maxlen = sizeof(sysctl_dccp_feat_sequence_window), .mode = 0644, - .proc_handler = proc_doulongvec_minmax, - .extra1 = &seqw_min, /* RFC 4340, 7.5.2 */ + .proc_handler = proc_dointvec, }, { .procname = "rx_ccid", - .data = &sysctl_dccp_rx_ccid, - .maxlen = sizeof(sysctl_dccp_rx_ccid), + .data = &sysctl_dccp_feat_rx_ccid, + .maxlen = sizeof(sysctl_dccp_feat_rx_ccid), .mode = 0644, - .proc_handler = proc_dointvec_minmax, - .extra1 = &zero, - .extra2 = &u8_max, /* RFC 4340, 10. */ + .proc_handler = proc_dointvec, }, { .procname = "tx_ccid", - .data = &sysctl_dccp_tx_ccid, - .maxlen = sizeof(sysctl_dccp_tx_ccid), + .data = &sysctl_dccp_feat_tx_ccid, + .maxlen = sizeof(sysctl_dccp_feat_tx_ccid), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "ack_ratio", + .data = &sysctl_dccp_feat_ack_ratio, + .maxlen = sizeof(sysctl_dccp_feat_ack_ratio), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "send_ackvec", + .data = &sysctl_dccp_feat_send_ack_vector, + .maxlen = sizeof(sysctl_dccp_feat_send_ack_vector), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "send_ndp", + .data = &sysctl_dccp_feat_send_ndp_count, + .maxlen = sizeof(sysctl_dccp_feat_send_ndp_count), .mode = 0644, - .proc_handler = proc_dointvec_minmax, - .extra1 = &zero, - .extra2 = &u8_max, /* RFC 4340, 10. */ + .proc_handler = proc_dointvec, }, { .procname = "request_retries", .data = &sysctl_dccp_request_retries, .maxlen = sizeof(sysctl_dccp_request_retries), .mode = 0644, - .proc_handler = proc_dointvec_minmax, - .extra1 = &zero, - .extra2 = &u8_max, + .proc_handler = proc_dointvec, }, { .procname = "retries1", .data = &sysctl_dccp_retries1, .maxlen = sizeof(sysctl_dccp_retries1), .mode = 0644, - .proc_handler = proc_dointvec_minmax, - .extra1 = &zero, - .extra2 = &u8_max, + .proc_handler = proc_dointvec, }, { .procname = "retries2", .data = &sysctl_dccp_retries2, .maxlen = sizeof(sysctl_dccp_retries2), .mode = 0644, - .proc_handler = proc_dointvec_minmax, - .extra1 = &zero, - .extra2 = &u8_max, + .proc_handler = proc_dointvec, }, { .procname = "tx_qlen", .data = &sysctl_dccp_tx_qlen, .maxlen = sizeof(sysctl_dccp_tx_qlen), .mode = 0644, - .proc_handler = proc_dointvec_minmax, - .extra1 = &zero, + .proc_handler = proc_dointvec, }, { .procname = "sync_ratelimit", diff --git a/net/dccp/timer.c b/net/dccp/timer.c index 16359e29e7f..54b3c7e9e01 100644 --- a/net/dccp/timer.c +++ b/net/dccp/timer.c @@ -87,6 +87,17 @@ static void dccp_retransmit_timer(struct sock *sk) { struct inet_connection_sock *icsk = inet_csk(sk); + /* retransmit timer is used for feature negotiation throughout + * connection. In this case, no packet is re-transmitted, but rather an + * ack is generated and pending changes are placed into its options. + */ + if (sk->sk_send_head == NULL) { + dccp_pr_debug("feat negotiation retransmit timeout %p\n", sk); + if (sk->sk_state == DCCP_OPEN) + dccp_send_ack(sk); + goto backoff; + } + /* * More than than 4MSL (8 minutes) has passed, a RESET(aborted) was * sent, no need to retransmit, this sock is dead. @@ -115,6 +126,7 @@ static void dccp_retransmit_timer(struct sock *sk) return; } +backoff: icsk->icsk_backoff++; icsk->icsk_rto = min(icsk->icsk_rto << 1, DCCP_RTO_MAX); @@ -237,35 +249,32 @@ out: sock_put(sk); } -/** - * dccp_write_xmitlet - Workhorse for CCID packet dequeueing interface - * See the comments above %ccid_dequeueing_decision for supported modes. - */ -static void dccp_write_xmitlet(unsigned long data) +/* Transmit-delay timer: used by the CCIDs to delay actual send time */ +static void dccp_write_xmit_timer(unsigned long data) { struct sock *sk = (struct sock *)data; + struct dccp_sock *dp = dccp_sk(sk); bh_lock_sock(sk); if (sock_owned_by_user(sk)) - sk_reset_timer(sk, &dccp_sk(sk)->dccps_xmit_timer, jiffies + 1); + sk_reset_timer(sk, &dp->dccps_xmit_timer, jiffies+1); else - dccp_write_xmit(sk); + dccp_write_xmit(sk, 0); bh_unlock_sock(sk); + sock_put(sk); } -static void dccp_write_xmit_timer(unsigned long data) +static void dccp_init_write_xmit_timer(struct sock *sk) { - dccp_write_xmitlet(data); - sock_put((struct sock *)data); + struct dccp_sock *dp = dccp_sk(sk); + + setup_timer(&dp->dccps_xmit_timer, dccp_write_xmit_timer, + (unsigned long)sk); } void dccp_init_xmit_timers(struct sock *sk) { - struct dccp_sock *dp = dccp_sk(sk); - - tasklet_init(&dp->dccps_xmitlet, dccp_write_xmitlet, (unsigned long)sk); - setup_timer(&dp->dccps_xmit_timer, dccp_write_xmit_timer, - (unsigned long)sk); + dccp_init_write_xmit_timer(sk); inet_csk_init_xmit_timers(sk, &dccp_write_timer, &dccp_delack_timer, &dccp_keepalive_timer); } @@ -281,7 +290,8 @@ u32 dccp_timestamp(void) { s64 delta = ktime_us_delta(ktime_get_real(), dccp_timestamp_seed); - return div_u64(delta, DCCP_TIME_RESOLUTION); + do_div(delta, 10); + return delta; } EXPORT_SYMBOL_GPL(dccp_timestamp); diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 9da9f19ece8..f79a5160729 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -811,12 +811,25 @@ void tcp_update_metrics(struct sock *sk) } } +/* Numbers are taken from RFC3390. + * + * John Heffner states: + * + * The RFC specifies a window of no more than 4380 bytes + * unless 2*MSS > 4380. Reading the pseudocode in the RFC + * is a bit misleading because they use a clamp at 4380 bytes + * rather than use a multiplier in the relevant range. + */ __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst) { __u32 cwnd = (dst ? dst_metric(dst, RTAX_INITCWND) : 0); - if (!cwnd) - cwnd = rfc3390_bytes_to_packets(tp->mss_cache); + if (!cwnd) { + if (tp->mss_cache > 1460) + cwnd = 2; + else + cwnd = (tp->mss_cache > 1095) ? 3 : 4; + } return min_t(__u32, cwnd, tp->snd_cwnd_clamp); } |