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Diffstat (limited to 'net/sctp/outqueue.c')
| -rw-r--r-- | net/sctp/outqueue.c | 1734 |
1 files changed, 1734 insertions, 0 deletions
diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c new file mode 100644 index 00000000000..1b2d4adc4dd --- /dev/null +++ b/net/sctp/outqueue.c @@ -0,0 +1,1734 @@ +/* SCTP kernel reference Implementation + * (C) Copyright IBM Corp. 2001, 2004 + * Copyright (c) 1999-2000 Cisco, Inc. + * Copyright (c) 1999-2001 Motorola, Inc. + * Copyright (c) 2001-2003 Intel Corp. + * + * This file is part of the SCTP kernel reference Implementation + * + * These functions implement the sctp_outq class. The outqueue handles + * bundling and queueing of outgoing SCTP chunks. + * + * The SCTP reference implementation 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; either version 2, or (at your option) + * any later version. + * + * The SCTP reference implementation is distributed in the hope that it + * will be useful, but WITHOUT ANY WARRANTY; without even the implied + * ************************ + * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + * See the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GNU CC; see the file COPYING. If not, write to + * the Free Software Foundation, 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + * + * Please send any bug reports or fixes you make to the + * email address(es): + * lksctp developers <lksctp-developers@lists.sourceforge.net> + * + * Or submit a bug report through the following website: + * http://www.sf.net/projects/lksctp + * + * Written or modified by: + * La Monte H.P. Yarroll <piggy@acm.org> + * Karl Knutson <karl@athena.chicago.il.us> + * Perry Melange <pmelange@null.cc.uic.edu> + * Xingang Guo <xingang.guo@intel.com> + * Hui Huang <hui.huang@nokia.com> + * Sridhar Samudrala <sri@us.ibm.com> + * Jon Grimm <jgrimm@us.ibm.com> + * + * Any bugs reported given to us we will try to fix... any fixes shared will + * be incorporated into the next SCTP release. + */ + +#include <linux/types.h> +#include <linux/list.h> /* For struct list_head */ +#include <linux/socket.h> +#include <linux/ip.h> +#include <net/sock.h> /* For skb_set_owner_w */ + +#include <net/sctp/sctp.h> +#include <net/sctp/sm.h> + +/* Declare internal functions here. */ +static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn); +static void sctp_check_transmitted(struct sctp_outq *q, + struct list_head *transmitted_queue, + struct sctp_transport *transport, + struct sctp_sackhdr *sack, + __u32 highest_new_tsn); + +static void sctp_mark_missing(struct sctp_outq *q, + struct list_head *transmitted_queue, + struct sctp_transport *transport, + __u32 highest_new_tsn, + int count_of_newacks); + +static void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn); + +/* Add data to the front of the queue. */ +static inline void sctp_outq_head_data(struct sctp_outq *q, + struct sctp_chunk *ch) +{ + __skb_queue_head(&q->out, (struct sk_buff *)ch); + q->out_qlen += ch->skb->len; + return; +} + +/* Take data from the front of the queue. */ +static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q) +{ + struct sctp_chunk *ch; + ch = (struct sctp_chunk *)__skb_dequeue(&q->out); + if (ch) + q->out_qlen -= ch->skb->len; + return ch; +} +/* Add data chunk to the end of the queue. */ +static inline void sctp_outq_tail_data(struct sctp_outq *q, + struct sctp_chunk *ch) +{ + __skb_queue_tail(&q->out, (struct sk_buff *)ch); + q->out_qlen += ch->skb->len; + return; +} + +/* + * SFR-CACC algorithm: + * D) If count_of_newacks is greater than or equal to 2 + * and t was not sent to the current primary then the + * sender MUST NOT increment missing report count for t. + */ +static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary, + struct sctp_transport *transport, + int count_of_newacks) +{ + if (count_of_newacks >=2 && transport != primary) + return 1; + return 0; +} + +/* + * SFR-CACC algorithm: + * F) If count_of_newacks is less than 2, let d be the + * destination to which t was sent. If cacc_saw_newack + * is 0 for destination d, then the sender MUST NOT + * increment missing report count for t. + */ +static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport, + int count_of_newacks) +{ + if (count_of_newacks < 2 && !transport->cacc.cacc_saw_newack) + return 1; + return 0; +} + +/* + * SFR-CACC algorithm: + * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD + * execute steps C, D, F. + * + * C has been implemented in sctp_outq_sack + */ +static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary, + struct sctp_transport *transport, + int count_of_newacks) +{ + if (!primary->cacc.cycling_changeover) { + if (sctp_cacc_skip_3_1_d(primary, transport, count_of_newacks)) + return 1; + if (sctp_cacc_skip_3_1_f(transport, count_of_newacks)) + return 1; + return 0; + } + return 0; +} + +/* + * SFR-CACC algorithm: + * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less + * than next_tsn_at_change of the current primary, then + * the sender MUST NOT increment missing report count + * for t. + */ +static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn) +{ + if (primary->cacc.cycling_changeover && + TSN_lt(tsn, primary->cacc.next_tsn_at_change)) + return 1; + return 0; +} + +/* + * SFR-CACC algorithm: + * 3) If the missing report count for TSN t is to be + * incremented according to [RFC2960] and + * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set, + * then the sender MUST futher execute steps 3.1 and + * 3.2 to determine if the missing report count for + * TSN t SHOULD NOT be incremented. + * + * 3.3) If 3.1 and 3.2 do not dictate that the missing + * report count for t should not be incremented, then + * the sender SOULD increment missing report count for + * t (according to [RFC2960] and [SCTP_STEWART_2002]). + */ +static inline int sctp_cacc_skip(struct sctp_transport *primary, + struct sctp_transport *transport, + int count_of_newacks, + __u32 tsn) +{ + if (primary->cacc.changeover_active && + (sctp_cacc_skip_3_1(primary, transport, count_of_newacks) + || sctp_cacc_skip_3_2(primary, tsn))) + return 1; + return 0; +} + +/* Initialize an existing sctp_outq. This does the boring stuff. + * You still need to define handlers if you really want to DO + * something with this structure... + */ +void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q) +{ + q->asoc = asoc; + skb_queue_head_init(&q->out); + skb_queue_head_init(&q->control); + INIT_LIST_HEAD(&q->retransmit); + INIT_LIST_HEAD(&q->sacked); + INIT_LIST_HEAD(&q->abandoned); + + q->outstanding_bytes = 0; + q->empty = 1; + q->cork = 0; + + q->malloced = 0; + q->out_qlen = 0; +} + +/* Free the outqueue structure and any related pending chunks. + */ +void sctp_outq_teardown(struct sctp_outq *q) +{ + struct sctp_transport *transport; + struct list_head *lchunk, *pos, *temp; + struct sctp_chunk *chunk; + + /* Throw away unacknowledged chunks. */ + list_for_each(pos, &q->asoc->peer.transport_addr_list) { + transport = list_entry(pos, struct sctp_transport, transports); + while ((lchunk = sctp_list_dequeue(&transport->transmitted)) != NULL) { + chunk = list_entry(lchunk, struct sctp_chunk, + transmitted_list); + /* Mark as part of a failed message. */ + sctp_chunk_fail(chunk, q->error); + sctp_chunk_free(chunk); + } + } + + /* Throw away chunks that have been gap ACKed. */ + list_for_each_safe(lchunk, temp, &q->sacked) { + list_del_init(lchunk); + chunk = list_entry(lchunk, struct sctp_chunk, + transmitted_list); + sctp_chunk_fail(chunk, q->error); + sctp_chunk_free(chunk); + } + + /* Throw away any chunks in the retransmit queue. */ + list_for_each_safe(lchunk, temp, &q->retransmit) { + list_del_init(lchunk); + chunk = list_entry(lchunk, struct sctp_chunk, + transmitted_list); + sctp_chunk_fail(chunk, q->error); + sctp_chunk_free(chunk); + } + + /* Throw away any chunks that are in the abandoned queue. */ + list_for_each_safe(lchunk, temp, &q->abandoned) { + list_del_init(lchunk); + chunk = list_entry(lchunk, struct sctp_chunk, + transmitted_list); + sctp_chunk_fail(chunk, q->error); + sctp_chunk_free(chunk); + } + + /* Throw away any leftover data chunks. */ + while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { + + /* Mark as send failure. */ + sctp_chunk_fail(chunk, q->error); + sctp_chunk_free(chunk); + } + + q->error = 0; + + /* Throw away any leftover control chunks. */ + while ((chunk = (struct sctp_chunk *) skb_dequeue(&q->control)) != NULL) + sctp_chunk_free(chunk); +} + +/* Free the outqueue structure and any related pending chunks. */ +void sctp_outq_free(struct sctp_outq *q) +{ + /* Throw away leftover chunks. */ + sctp_outq_teardown(q); + + /* If we were kmalloc()'d, free the memory. */ + if (q->malloced) + kfree(q); +} + +/* Put a new chunk in an sctp_outq. */ +int sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk) +{ + int error = 0; + + SCTP_DEBUG_PRINTK("sctp_outq_tail(%p, %p[%s])\n", + q, chunk, chunk && chunk->chunk_hdr ? + sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) + : "Illegal Chunk"); + + /* If it is data, queue it up, otherwise, send it + * immediately. + */ + if (SCTP_CID_DATA == chunk->chunk_hdr->type) { + /* Is it OK to queue data chunks? */ + /* From 9. Termination of Association + * + * When either endpoint performs a shutdown, the + * association on each peer will stop accepting new + * data from its user and only deliver data in queue + * at the time of sending or receiving the SHUTDOWN + * chunk. + */ + switch (q->asoc->state) { + case SCTP_STATE_EMPTY: + case SCTP_STATE_CLOSED: + case SCTP_STATE_SHUTDOWN_PENDING: + case SCTP_STATE_SHUTDOWN_SENT: + case SCTP_STATE_SHUTDOWN_RECEIVED: + case SCTP_STATE_SHUTDOWN_ACK_SENT: + /* Cannot send after transport endpoint shutdown */ + error = -ESHUTDOWN; + break; + + default: + SCTP_DEBUG_PRINTK("outqueueing (%p, %p[%s])\n", + q, chunk, chunk && chunk->chunk_hdr ? + sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)) + : "Illegal Chunk"); + + sctp_outq_tail_data(q, chunk); + if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) + SCTP_INC_STATS(SCTP_MIB_OUTUNORDERCHUNKS); + else + SCTP_INC_STATS(SCTP_MIB_OUTORDERCHUNKS); + q->empty = 0; + break; + }; + } else { + __skb_queue_tail(&q->control, (struct sk_buff *) chunk); + SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); + } + + if (error < 0) + return error; + + if (!q->cork) + error = sctp_outq_flush(q, 0); + + return error; +} + +/* Insert a chunk into the sorted list based on the TSNs. The retransmit list + * and the abandoned list are in ascending order. + */ +static void sctp_insert_list(struct list_head *head, struct list_head *new) +{ + struct list_head *pos; + struct sctp_chunk *nchunk, *lchunk; + __u32 ntsn, ltsn; + int done = 0; + + nchunk = list_entry(new, struct sctp_chunk, transmitted_list); + ntsn = ntohl(nchunk->subh.data_hdr->tsn); + + list_for_each(pos, head) { + lchunk = list_entry(pos, struct sctp_chunk, transmitted_list); + ltsn = ntohl(lchunk->subh.data_hdr->tsn); + if (TSN_lt(ntsn, ltsn)) { + list_add(new, pos->prev); + done = 1; + break; + } + } + if (!done) + list_add_tail(new, head); +} + +/* Mark all the eligible packets on a transport for retransmission. */ +void sctp_retransmit_mark(struct sctp_outq *q, + struct sctp_transport *transport, + __u8 fast_retransmit) +{ + struct list_head *lchunk, *ltemp; + struct sctp_chunk *chunk; + + /* Walk through the specified transmitted queue. */ + list_for_each_safe(lchunk, ltemp, &transport->transmitted) { + chunk = list_entry(lchunk, struct sctp_chunk, + transmitted_list); + + /* If the chunk is abandoned, move it to abandoned list. */ + if (sctp_chunk_abandoned(chunk)) { + list_del_init(lchunk); + sctp_insert_list(&q->abandoned, lchunk); + continue; + } + + /* If we are doing retransmission due to a fast retransmit, + * only the chunk's that are marked for fast retransmit + * should be added to the retransmit queue. If we are doing + * retransmission due to a timeout or pmtu discovery, only the + * chunks that are not yet acked should be added to the + * retransmit queue. + */ + if ((fast_retransmit && chunk->fast_retransmit) || + (!fast_retransmit && !chunk->tsn_gap_acked)) { + /* RFC 2960 6.2.1 Processing a Received SACK + * + * C) Any time a DATA chunk is marked for + * retransmission (via either T3-rtx timer expiration + * (Section 6.3.3) or via fast retransmit + * (Section 7.2.4)), add the data size of those + * chunks to the rwnd. + */ + q->asoc->peer.rwnd += sctp_data_size(chunk); + q->outstanding_bytes -= sctp_data_size(chunk); + transport->flight_size -= sctp_data_size(chunk); + + /* sctpimpguide-05 Section 2.8.2 + * M5) If a T3-rtx timer expires, the + * 'TSN.Missing.Report' of all affected TSNs is set + * to 0. + */ + chunk->tsn_missing_report = 0; + + /* If a chunk that is being used for RTT measurement + * has to be retransmitted, we cannot use this chunk + * anymore for RTT measurements. Reset rto_pending so + * that a new RTT measurement is started when a new + * data chunk is sent. + */ + if (chunk->rtt_in_progress) { + chunk->rtt_in_progress = 0; + transport->rto_pending = 0; + } + + /* Move the chunk to the retransmit queue. The chunks + * on the retransmit queue are always kept in order. + */ + list_del_init(lchunk); + sctp_insert_list(&q->retransmit, lchunk); + } + } + + SCTP_DEBUG_PRINTK("%s: transport: %p, fast_retransmit: %d, " + "cwnd: %d, ssthresh: %d, flight_size: %d, " + "pba: %d\n", __FUNCTION__, + transport, fast_retransmit, + transport->cwnd, transport->ssthresh, + transport->flight_size, + transport->partial_bytes_acked); + +} + +/* Mark all the eligible packets on a transport for retransmission and force + * one packet out. + */ +void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, + sctp_retransmit_reason_t reason) +{ + int error = 0; + __u8 fast_retransmit = 0; + + switch(reason) { + case SCTP_RTXR_T3_RTX: + sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX); + /* Update the retran path if the T3-rtx timer has expired for + * the current retran path. + */ + if (transport == transport->asoc->peer.retran_path) + sctp_assoc_update_retran_path(transport->asoc); + break; + case SCTP_RTXR_FAST_RTX: + sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX); + fast_retransmit = 1; + break; + case SCTP_RTXR_PMTUD: + default: + break; + } + + sctp_retransmit_mark(q, transport, fast_retransmit); + + /* PR-SCTP A5) Any time the T3-rtx timer expires, on any destination, + * the sender SHOULD try to advance the "Advanced.Peer.Ack.Point" by + * following the procedures outlined in C1 - C5. + */ + sctp_generate_fwdtsn(q, q->asoc->ctsn_ack_point); + + error = sctp_outq_flush(q, /* rtx_timeout */ 1); + + if (error) + q->asoc->base.sk->sk_err = -error; +} + +/* + * Transmit DATA chunks on the retransmit queue. Upon return from + * sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which + * need to be transmitted by the caller. + * We assume that pkt->transport has already been set. + * + * The return value is a normal kernel error return value. + */ +static int sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, + int rtx_timeout, int *start_timer) +{ + struct list_head *lqueue; + struct list_head *lchunk, *lchunk1; + struct sctp_transport *transport = pkt->transport; + sctp_xmit_t status; + struct sctp_chunk *chunk, *chunk1; + struct sctp_association *asoc; + int error = 0; + + asoc = q->asoc; + lqueue = &q->retransmit; + + /* RFC 2960 6.3.3 Handle T3-rtx Expiration + * + * E3) Determine how many of the earliest (i.e., lowest TSN) + * outstanding DATA chunks for the address for which the + * T3-rtx has expired will fit into a single packet, subject + * to the MTU constraint for the path corresponding to the + * destination transport address to which the retransmission + * is being sent (this may be different from the address for + * which the timer expires [see Section 6.4]). Call this value + * K. Bundle and retransmit those K DATA chunks in a single + * packet to the destination endpoint. + * + * [Just to be painfully clear, if we are retransmitting + * because a timeout just happened, we should send only ONE + * packet of retransmitted data.] + */ + lchunk = sctp_list_dequeue(lqueue); + + while (lchunk) { + chunk = list_entry(lchunk, struct sctp_chunk, + transmitted_list); + + /* Make sure that Gap Acked TSNs are not retransmitted. A + * simple approach is just to move such TSNs out of the + * way and into a 'transmitted' queue and skip to the + * next chunk. + */ + if (chunk->tsn_gap_acked) { + list_add_tail(lchunk, &transport->transmitted); + lchunk = sctp_list_dequeue(lqueue); + continue; + } + + /* Attempt to append this chunk to the packet. */ + status = sctp_packet_append_chunk(pkt, chunk); + + switch (status) { + case SCTP_XMIT_PMTU_FULL: + /* Send this packet. */ + if ((error = sctp_packet_transmit(pkt)) == 0) + *start_timer = 1; + + /* If we are retransmitting, we should only + * send a single packet. + */ + if (rtx_timeout) { + list_add(lchunk, lqueue); + lchunk = NULL; + } + + /* Bundle lchunk in the next round. */ + break; + + case SCTP_XMIT_RWND_FULL: + /* Send this packet. */ + if ((error = sctp_packet_transmit(pkt)) == 0) + *start_timer = 1; + + /* Stop sending DATA as there is no more room + * at the receiver. + */ + list_add(lchunk, lqueue); + lchunk = NULL; + break; + + case SCTP_XMIT_NAGLE_DELAY: + /* Send this packet. */ + if ((error = sctp_packet_transmit(pkt)) == 0) + *start_timer = 1; + + /* Stop sending DATA because of nagle delay. */ + list_add(lchunk, lqueue); + lchunk = NULL; + break; + + default: + /* The append was successful, so add this chunk to + * the transmitted list. + */ + list_add_tail(lchunk, &transport->transmitted); + + /* Mark the chunk as ineligible for fast retransmit + * after it is retransmitted. + */ + chunk->fast_retransmit = 0; + + *start_timer = 1; + q->empty = 0; + + /* Retrieve a new chunk to bundle. */ + lchunk = sctp_list_dequeue(lqueue); + break; + }; + + /* If we are here due to a retransmit timeout or a fast + * retransmit and if there are any chunks left in the retransmit + * queue that could not fit in the PMTU sized packet, they need * to be marked as ineligible for a subsequent fast retransmit. + */ + if (rtx_timeout && !lchunk) { + list_for_each(lchunk1, lqueue) { + chunk1 = list_entry(lchunk1, struct sctp_chunk, + transmitted_list); + chunk1->fast_retransmit = 0; + } + } + } + + return error; +} + +/* Cork the outqueue so queued chunks are really queued. */ +int sctp_outq_uncork(struct sctp_outq *q) +{ + int error = 0; + if (q->cork) { + q->cork = 0; + error = sctp_outq_flush(q, 0); + } + return error; +} + +/* + * Try to flush an outqueue. + * + * Description: Send everything in q which we legally can, subject to + * congestion limitations. + * * Note: This function can be called from multiple contexts so appropriate + * locking concerns must be made. Today we use the sock lock to protect + * this function. + */ +int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout) +{ + struct sctp_packet *packet; + struct sctp_packet singleton; + struct sctp_association *asoc = q->asoc; + __u16 sport = asoc->base.bind_addr.port; + __u16 dport = asoc->peer.port; + __u32 vtag = asoc->peer.i.init_tag; + struct sk_buff_head *queue; + struct sctp_transport *transport = NULL; + struct sctp_transport *new_transport; + struct sctp_chunk *chunk; + sctp_xmit_t status; + int error = 0; + int start_timer = 0; + + /* These transports have chunks to send. */ + struct list_head transport_list; + struct list_head *ltransport; + + INIT_LIST_HEAD(&transport_list); + packet = NULL; + + /* + * 6.10 Bundling + * ... + * When bundling control chunks with DATA chunks, an + * endpoint MUST place control chunks first in the outbound + * SCTP packet. The transmitter MUST transmit DATA chunks + * within a SCTP packet in increasing order of TSN. + * ... + */ + + queue = &q->control; + while ((chunk = (struct sctp_chunk *)skb_dequeue(queue)) != NULL) { + /* Pick the right transport to use. */ + new_transport = chunk->transport; + + if (!new_transport) { + new_transport = asoc->peer.active_path; + } else if (!new_transport->active) { + /* If the chunk is Heartbeat or Heartbeat Ack, + * send it to chunk->transport, even if it's + * inactive. + * + * 3.3.6 Heartbeat Acknowledgement: + * ... + * A HEARTBEAT ACK is always sent to the source IP + * address of the IP datagram containing the + * HEARTBEAT chunk to which this ack is responding. + * ... + */ + if (chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT && + chunk->chunk_hdr->type != SCTP_CID_HEARTBEAT_ACK) + new_transport = asoc->peer.active_path; + } + + /* Are we switching transports? + * Take care of transport locks. + */ + if (new_transport != transport) { + transport = new_transport; + if (list_empty(&transport->send_ready)) { + list_add_tail(&transport->send_ready, + &transport_list); + } + packet = &transport->packet; + sctp_packet_config(packet, vtag, + asoc->peer.ecn_capable); + } + + switch (chunk->chunk_hdr->type) { + /* + * 6.10 Bundling + * ... + * An endpoint MUST NOT bundle INIT, INIT ACK or SHUTDOWN + * COMPLETE with any other chunks. [Send them immediately.] + */ + case SCTP_CID_INIT: + case SCTP_CID_INIT_ACK: + case SCTP_CID_SHUTDOWN_COMPLETE: + sctp_packet_init(&singleton, transport, sport, dport); + sctp_packet_config(&singleton, vtag, 0); + sctp_packet_append_chunk(&singleton, chunk); + error = sctp_packet_transmit(&singleton); + if (error < 0) + return error; + break; + + case SCTP_CID_ABORT: + case SCTP_CID_SACK: + case SCTP_CID_HEARTBEAT: + case SCTP_CID_HEARTBEAT_ACK: + case SCTP_CID_SHUTDOWN: + case SCTP_CID_SHUTDOWN_ACK: + case SCTP_CID_ERROR: + case SCTP_CID_COOKIE_ECHO: + case SCTP_CID_COOKIE_ACK: + case SCTP_CID_ECN_ECNE: + case SCTP_CID_ECN_CWR: + case SCTP_CID_ASCONF: + case SCTP_CID_ASCONF_ACK: + case SCTP_CID_FWD_TSN: + sctp_packet_transmit_chunk(packet, chunk); + break; + + default: + /* We built a chunk with an illegal type! */ + BUG(); + }; + } + + /* Is it OK to send data chunks? */ + switch (asoc->state) { + case SCTP_STATE_COOKIE_ECHOED: + /* Only allow bundling when this packet has a COOKIE-ECHO + * chunk. + */ + if (!packet || !packet->has_cookie_echo) + break; + + /* fallthru */ + case SCTP_STATE_ESTABLISHED: + case SCTP_STATE_SHUTDOWN_PENDING: + case SCTP_STATE_SHUTDOWN_RECEIVED: + /* + * RFC 2960 6.1 Transmission of DATA Chunks + * + * C) When the time comes for the sender to transmit, + * before sending new DATA chunks, the sender MUST + * first transmit any outstanding DATA chunks which + * are marked for retransmission (limited by the + * current cwnd). + */ + if (!list_empty(&q->retransmit)) { + if (transport == asoc->peer.retran_path) + goto retran; + + /* Switch transports & prepare the packet. */ + + transport = asoc->peer.retran_path; + + if (list_empty(&transport->send_ready)) { + list_add_tail(&transport->send_ready, + &transport_list); + } + + packet = &transport->packet; + sctp_packet_config(packet, vtag, + asoc->peer.ecn_capable); + retran: + error = sctp_outq_flush_rtx(q, packet, + rtx_timeout, &start_timer); + + if (start_timer) + sctp_transport_reset_timers(transport); + + /* This can happen on COOKIE-ECHO resend. Only + * one chunk can get bundled with a COOKIE-ECHO. + */ + if (packet->has_cookie_echo) + goto sctp_flush_out; + + /* Don't send new data if there is still data + * waiting to retransmit. + */ + if (!list_empty(&q->retransmit)) + goto sctp_flush_out; + } + + /* Finally, transmit new packets. */ + start_timer = 0; + queue = &q->out; + + while ((chunk = sctp_outq_dequeue_data(q)) != NULL) { + /* RFC 2960 6.5 Every DATA chunk MUST carry a valid + * stream identifier. + */ + if (chunk->sinfo.sinfo_stream >= + asoc->c.sinit_num_ostreams) { + + /* Mark as failed send. */ + sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM); + sctp_chunk_free(chunk); + continue; + } + + /* Has this chunk expired? */ + if (sctp_chunk_abandoned(chunk)) { + sctp_chunk_fail(chunk, 0); + sctp_chunk_free(chunk); + continue; + } + + /* If there is a specified transport, use it. + * Otherwise, we want to use the active path. + */ + new_transport = chunk->transport; + if (!new_transport || !new_transport->active) + new_transport = asoc->peer.active_path; + + /* Change packets if necessary. */ + if (new_transport != transport) { + transport = new_transport; + + /* Schedule to have this transport's + * packet flushed. + */ + if (list_empty(&transport->send_ready)) { + list_add_tail(&transport->send_ready, + &transport_list); + } + + packet = &transport->packet; + sctp_packet_config(packet, vtag, + asoc->peer.ecn_capable); + } + + SCTP_DEBUG_PRINTK("sctp_outq_flush(%p, %p[%s]), ", + q, chunk, + chunk && chunk->chunk_hdr ? + sctp_cname(SCTP_ST_CHUNK( + chunk->chunk_hdr->type)) + : "Illegal Chunk"); + + SCTP_DEBUG_PRINTK("TX TSN 0x%x skb->head " + "%p skb->users %d.\n", + ntohl(chunk->subh.data_hdr->tsn), + chunk->skb ?chunk->skb->head : NULL, + chunk->skb ? + atomic_read(&chunk->skb->users) : -1); + + /* Add the chunk to the packet. */ + status = sctp_packet_transmit_chunk(packet, chunk); + + switch (status) { + case SCTP_XMIT_PMTU_FULL: + case SCTP_XMIT_RWND_FULL: + case SCTP_XMIT_NAGLE_DELAY: + /* We could not append this chunk, so put + * the chunk back on the output queue. + */ + SCTP_DEBUG_PRINTK("sctp_outq_flush: could " + "not transmit TSN: 0x%x, status: %d\n", + ntohl(chunk->subh.data_hdr->tsn), + status); + sctp_outq_head_data(q, chunk); + goto sctp_flush_out; + break; + + case SCTP_XMIT_OK: + break; + + default: + BUG(); + } + + /* BUG: We assume that the sctp_packet_transmit() + * call below will succeed all the time and add the + * chunk to the transmitted list and restart the + * timers. + * It is possible that the call can fail under OOM + * conditions. + * + * Is this really a problem? Won't this behave + * like a lost TSN? + */ + list_add_tail(&chunk->transmitted_list, + &transport->transmitted); + + sctp_transport_reset_timers(transport); + + q->empty = 0; + + /* Only let one DATA chunk get bundled with a + * COOKIE-ECHO chunk. + */ + if (packet->has_cookie_echo) + goto sctp_flush_out; + } + break; + + default: + /* Do nothing. */ + break; + } + +sctp_flush_out: + + /* Before returning, examine all the transports touched in + * this call. Right now, we bluntly force clear all the + * transports. Things might change after we implement Nagle. + * But such an examination is still required. + * + * --xguo + */ + while ((ltransport = sctp_list_dequeue(&transport_list)) != NULL ) { + struct sctp_transport *t = list_entry(ltransport, + struct sctp_transport, + send_ready); + packet = &t->packet; + if (!sctp_packet_empty(packet)) + error = sctp_packet_transmit(packet); + } + + return error; +} + +/* Update unack_data based on the incoming SACK chunk */ +static void sctp_sack_update_unack_data(struct sctp_association *assoc, + struct sctp_sackhdr *sack) +{ + sctp_sack_variable_t *frags; + __u16 unack_data; + int i; + + unack_data = assoc->next_tsn - assoc->ctsn_ack_point - 1; + + frags = sack->variable; + for (i = 0; i < ntohs(sack->num_gap_ack_blocks); i++) { + unack_data -= ((ntohs(frags[i].gab.end) - + ntohs(frags[i].gab.start) + 1)); + } + + assoc->unack_data = unack_data; +} + +/* Return the highest new tsn that is acknowledged by the given SACK chunk. */ +static __u32 sctp_highest_new_tsn(struct sctp_sackhdr *sack, + struct sctp_association *asoc) +{ + struct list_head *ltransport, *lchunk; + struct sctp_transport *transport; + struct sctp_chunk *chunk; + __u32 highest_new_tsn, tsn; + struct list_head *transport_list = &asoc->peer.transport_addr_list; + + highest_new_tsn = ntohl(sack->cum_tsn_ack); + + list_for_each(ltransport, transport_list) { + transport = list_entry(ltransport, struct sctp_transport, + transports); + list_for_each(lchunk, &transport->transmitted) { + chunk = list_entry(lchunk, struct sctp_chunk, + transmitted_list); + tsn = ntohl(chunk->subh.data_hdr->tsn); + + if (!chunk->tsn_gap_acked && + TSN_lt(highest_new_tsn, tsn) && + sctp_acked(sack, tsn)) + highest_new_tsn = tsn; + } + } + + return highest_new_tsn; +} + +/* This is where we REALLY process a SACK. + * + * Process the SACK against the outqueue. Mostly, this just frees + * things off the transmitted queue. + */ +int sctp_outq_sack(struct sctp_outq *q, struct sctp_sackhdr *sack) +{ + struct sctp_association *asoc = q->asoc; + struct sctp_transport *transport; + struct sctp_chunk *tchunk = NULL; + struct list_head *lchunk, *transport_list, *pos, *temp; + sctp_sack_variable_t *frags = sack->variable; + __u32 sack_ctsn, ctsn, tsn; + __u32 highest_tsn, highest_new_tsn; + __u32 sack_a_rwnd; + unsigned outstanding; + struct sctp_transport *primary = asoc->peer.primary_path; + int count_of_newacks = 0; + + /* Grab the association's destination address list. */ + transport_list = &asoc->peer.transport_addr_list; + + sack_ctsn = ntohl(sack->cum_tsn_ack); + + /* + * SFR-CACC algorithm: + * On receipt of a SACK the sender SHOULD execute the + * following statements. + * + * 1) If the cumulative ack in the SACK passes next tsn_at_change + * on the current primary, the CHANGEOVER_ACTIVE flag SHOULD be + * cleared. The CYCLING_CHANGEOVER flag SHOULD also be cleared for + * all destinations. + */ + if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) { + primary->cacc.changeover_active = 0; + list_for_each(pos, transport_list) { + transport = list_entry(pos, struct sctp_transport, + transports); + transport->cacc.cycling_changeover = 0; + } + } + + /* + * SFR-CACC algorithm: + * 2) If the SACK contains gap acks and the flag CHANGEOVER_ACTIVE + * is set the receiver of the SACK MUST take the following actions: + * + * A) Initialize the cacc_saw_newack to 0 for all destination + * addresses. + */ + if (sack->num_gap_ack_blocks > 0 && + primary->cacc.changeover_active) { + list_for_each(pos, transport_list) { + transport = list_entry(pos, struct sctp_transport, + transports); + transport->cacc.cacc_saw_newack = 0; + } + } + + /* Get the highest TSN in the sack. */ + highest_tsn = sack_ctsn; + if (sack->num_gap_ack_blocks) + highest_tsn += + ntohs(frags[ntohs(sack->num_gap_ack_blocks) - 1].gab.end); + + if (TSN_lt(asoc->highest_sacked, highest_tsn)) { + highest_new_tsn = highest_tsn; + asoc->highest_sacked = highest_tsn; + } else { + highest_new_tsn = sctp_highest_new_tsn(sack, asoc); + } + + /* Run through the retransmit queue. Credit bytes received + * and free those chunks that we can. + */ + sctp_check_transmitted(q, &q->retransmit, NULL, sack, highest_new_tsn); + sctp_mark_missing(q, &q->retransmit, NULL, highest_new_tsn, 0); + + /* Run through the transmitted queue. + * Credit bytes received and free those chunks which we can. + * + * This is a MASSIVE candidate for optimization. + */ + list_for_each(pos, transport_list) { + transport = list_entry(pos, struct sctp_transport, + transports); + sctp_check_transmitted(q, &transport->transmitted, + transport, sack, highest_new_tsn); + /* + * SFR-CACC algorithm: + * C) Let count_of_newacks be the number of + * destinations for which cacc_saw_newack is set. + */ + if (transport->cacc.cacc_saw_newack) + count_of_newacks ++; + } + + list_for_each(pos, transport_list) { + transport = list_entry(pos, struct sctp_transport, + transports); + sctp_mark_missing(q, &transport->transmitted, transport, + highest_new_tsn, count_of_newacks); + } + + /* Move the Cumulative TSN Ack Point if appropriate. */ + if (TSN_lt(asoc->ctsn_ack_point, sack_ctsn)) + asoc->ctsn_ack_point = sack_ctsn; + + /* Update unack_data field in the assoc. */ + sctp_sack_update_unack_data(asoc, sack); + + ctsn = asoc->ctsn_ack_point; + + /* Throw away stuff rotting on the sack queue. */ + list_for_each_safe(lchunk, temp, &q->sacked) { + tchunk = list_entry(lchunk, struct sctp_chunk, + transmitted_list); + tsn = ntohl(tchunk->subh.data_hdr->tsn); + if (TSN_lte(tsn, ctsn)) + sctp_chunk_free(tchunk); + } + + /* ii) Set rwnd equal to the newly received a_rwnd minus the + * number of bytes still outstanding after processing the + * Cumulative TSN Ack and the Gap Ack Blocks. + */ + + sack_a_rwnd = ntohl(sack->a_rwnd); + outstanding = q->outstanding_bytes; + + if (outstanding < sack_a_rwnd) + sack_a_rwnd -= outstanding; + else + sack_a_rwnd = 0; + + asoc->peer.rwnd = sack_a_rwnd; + + sctp_generate_fwdtsn(q, sack_ctsn); + + SCTP_D |