aboutsummaryrefslogtreecommitdiff
path: root/net/dccp/output.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/dccp/output.c')
-rw-r--r--net/dccp/output.c306
1 files changed, 188 insertions, 118 deletions
diff --git a/net/dccp/output.c b/net/dccp/output.c
index 22a618af489..0248e8a3460 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -13,6 +13,7 @@
#include <linux/dccp.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
+#include <linux/slab.h>
#include <net/inet_sock.h>
#include <net/sock.h>
@@ -26,11 +27,13 @@ static inline void dccp_event_ack_sent(struct sock *sk)
inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
}
-static void dccp_skb_entail(struct sock *sk, struct sk_buff *skb)
+/* 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)
{
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());
}
/*
@@ -42,7 +45,7 @@ static void dccp_skb_entail(struct sock *sk, struct sk_buff *skb)
static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
{
if (likely(skb != NULL)) {
- const struct inet_sock *inet = inet_sk(sk);
+ struct inet_sock *inet = inet_sk(sk);
const struct inet_connection_sock *icsk = inet_csk(sk);
struct dccp_sock *dp = dccp_sk(sk);
struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
@@ -99,8 +102,8 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
/* Build DCCP header and checksum it. */
dh = dccp_zeroed_hdr(skb, dccp_header_size);
dh->dccph_type = dcb->dccpd_type;
- dh->dccph_sport = inet->sport;
- dh->dccph_dport = inet->dport;
+ dh->dccph_sport = inet->inet_sport;
+ dh->dccph_dport = inet->inet_dport;
dh->dccph_doff = (dccp_header_size + dcb->dccpd_opt_len) / 4;
dh->dccph_ccval = dcb->dccpd_ccval;
dh->dccph_cscov = dp->dccps_pcslen;
@@ -128,21 +131,21 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
break;
}
- icsk->icsk_af_ops->send_check(sk, 0, skb);
+ icsk->icsk_af_ops->send_check(sk, skb);
if (set_ack)
dccp_event_ack_sent(sk);
DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
- err = icsk->icsk_af_ops->queue_xmit(skb, 0);
+ err = icsk->icsk_af_ops->queue_xmit(sk, skb, &inet->cork.fl);
return net_xmit_eval(err);
}
return -ENOBUFS;
}
/**
- * dccp_determine_ccmps - Find out about CCID-specfic packet-size limits
+ * dccp_determine_ccmps - Find out about CCID-specific packet-size limits
* We only consider the HC-sender CCID for setting the CCMPS (RFC 4340, 14.),
* since the RX CCID is restricted to feedback packets (Acks), which are small
* in comparison with the data traffic. A value of 0 means "no current CCMPS".
@@ -161,21 +164,27 @@ 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);
- int cur_mps = ccmps ? min(pmtu, ccmps) : pmtu;
+ u32 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));
/*
- * 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
+ * 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)
*/
-
- cur_mps -= roundup(5 + 6 + 10 + 6 + 6 + 6, 4);
+ cur_mps -= roundup(1 + 6 + 10 + dp->dccps_send_ndp_count * 8 + 6 +
+ (dp->dccps_hc_rx_ackvec ? DCCPAV_MIN_OPTLEN : 0), 4);
/* And store cached results */
icsk->icsk_pmtu_cookie = pmtu;
@@ -188,107 +197,173 @@ EXPORT_SYMBOL_GPL(dccp_sync_mss);
void dccp_write_space(struct sock *sk)
{
- read_lock(&sk->sk_callback_lock);
+ struct socket_wq *wq;
- if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
- wake_up_interruptible(sk->sk_sleep);
+ rcu_read_lock();
+ wq = rcu_dereference(sk->sk_wq);
+ if (wq_has_sleeper(wq))
+ wake_up_interruptible(&wq->wait);
/* Should agree with poll, otherwise some programs break */
if (sock_writeable(sk))
sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
- read_unlock(&sk->sk_callback_lock);
+ rcu_read_unlock();
}
/**
- * dccp_wait_for_ccid - Wait for ccid to tell us we can send a packet
+ * dccp_wait_for_ccid - Await CCID send permission
* @sk: socket to wait for
- * @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
+ * @delay: timeout in jiffies
+ *
+ * This is used by CCIDs which need to delay the send time in process context.
*/
-static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb, int delay)
+static int dccp_wait_for_ccid(struct sock *sk, unsigned long delay)
{
- struct dccp_sock *dp = dccp_sk(sk);
DEFINE_WAIT(wait);
- unsigned long jiffdelay;
- int rc;
+ long remaining;
- do {
- dccp_pr_debug("delayed send by %d msec\n", delay);
- jiffdelay = msecs_to_jiffies(delay);
+ prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+ sk->sk_write_pending++;
+ release_sock(sk);
- prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
+ remaining = schedule_timeout(delay);
- sk->sk_write_pending++;
- release_sock(sk);
- schedule_timeout(jiffdelay);
- lock_sock(sk);
- sk->sk_write_pending--;
+ lock_sock(sk);
+ sk->sk_write_pending--;
+ finish_wait(sk_sleep(sk), &wait);
- if (sk->sk_err)
- goto do_error;
- if (signal_pending(current))
- goto do_interrupted;
+ if (signal_pending(current) || sk->sk_err)
+ return -1;
+ return remaining;
+}
- 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_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);
+
+ if (unlikely(skb == NULL))
+ return;
+ len = skb->len;
+
+ 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);
+ }
+
+ 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);
}
-void dccp_write_xmit(struct sock *sk, int block)
+/**
+ * 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)
{
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);
- 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);
+ 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);
}
+ }
+}
- skb_dequeue(&sk->sk_write_queue);
- if (err == 0) {
- struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
- const int len = skb->len;
+void dccp_write_xmit(struct sock *sk)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct sk_buff *skb;
- 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);
+ 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);
}
}
}
@@ -331,13 +406,13 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
/* Reserve space for headers. */
skb_reserve(skb, sk->sk_prot->max_header);
- skb->dst = dst_clone(dst);
+ skb_dst_set(skb, dst_clone(dst));
dreq = dccp_rsk(req);
- if (inet_rsk(req)->acked) /* increase ISS upon retransmission */
- dccp_inc_seqno(&dreq->dreq_iss);
+ if (inet_rsk(req)->acked) /* increase GSS upon retransmission */
+ dccp_inc_seqno(&dreq->dreq_gss);
DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE;
- DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss;
+ DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_gss;
/* Resolve feature dependencies resulting from choice of CCID */
if (dccp_feat_server_ccid_dependencies(dreq))
@@ -349,14 +424,14 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
/* Build and checksum header */
dh = dccp_zeroed_hdr(skb, dccp_header_size);
- dh->dccph_sport = inet_rsk(req)->loc_port;
- dh->dccph_dport = inet_rsk(req)->rmt_port;
+ dh->dccph_sport = htons(inet_rsk(req)->ir_num);
+ dh->dccph_dport = inet_rsk(req)->ir_rmt_port;
dh->dccph_doff = (dccp_header_size +
DCCP_SKB_CB(skb)->dccpd_opt_len) / 4;
dh->dccph_type = DCCP_PKT_RESPONSE;
dh->dccph_x = 1;
- dccp_hdr_set_seq(dh, dreq->dreq_iss);
- dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr);
+ dccp_hdr_set_seq(dh, dreq->dreq_gss);
+ dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_gsr);
dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service;
dccp_csum_outgoing(skb);
@@ -452,8 +527,9 @@ int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code)
/*
* Do all connect socket setups that can be done AF independent.
*/
-static inline void dccp_connect_init(struct sock *sk)
+int dccp_connect(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);
@@ -463,22 +539,12 @@ static inline void dccp_connect_init(struct sock *sk)
dccp_sync_mss(sk, dst_mtu(dst));
- /* 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);
-
/* do not connect if feature negotiation setup fails */
if (dccp_feat_finalise_settings(dccp_sk(sk)))
return -EPROTO;
- dccp_connect_init(sk);
+ /* Initialise GAR as per 8.5; AWL/AWH are set in dccp_transmit_skb() */
+ dp->dccps_gar = dp->dccps_iss;
skb = alloc_skb(sk->sk_prot->max_header, sk->sk_allocation);
if (unlikely(skb == NULL))
@@ -489,11 +555,11 @@ int dccp_connect(struct sock *sk)
DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST;
- dccp_skb_entail(sk, skb);
- dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL));
+ dccp_transmit_skb(sk, dccp_skb_entail(sk, skb));
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;
@@ -580,6 +646,12 @@ 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);
}
@@ -608,9 +680,7 @@ void dccp_send_close(struct sock *sk, const int active)
DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSE;
if (active) {
- dccp_write_xmit(sk, 1);
- dccp_skb_entail(sk, skb);
- dccp_transmit_skb(sk, skb_clone(skb, prio));
+ skb = dccp_skb_entail(sk, skb);
/*
* Retransmission timer for active-close: RFC 4340, 8.3 requires
* to retransmit the Close/CloseReq until the CLOSING/CLOSEREQ
@@ -623,6 +693,6 @@ 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);
- } else
- dccp_transmit_skb(sk, skb);
+ }
+ dccp_transmit_skb(sk, skb);
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-06 15:12:09 +0000