diff options
| -rw-r--r-- | net/dccp/dccp.h | 5 | ||||
| -rw-r--r-- | net/dccp/output.c | 115 | ||||
| -rw-r--r-- | net/dccp/proto.c | 21 | ||||
| -rw-r--r-- | net/dccp/timer.c | 2 |
4 files changed, 89 insertions, 54 deletions
diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h index 3eb264b60823..a8ed459508b2 100644 --- a/net/dccp/dccp.h +++ b/net/dccp/dccp.h @@ -243,8 +243,9 @@ 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); -extern void dccp_write_xmit(struct sock *sk, int block); -extern void dccp_write_space(struct sock *sk); +extern void dccp_write_xmit(struct sock *sk); +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) diff --git a/net/dccp/output.c b/net/dccp/output.c index 11418a9a389d..45b91853f5ae 100644 --- a/net/dccp/output.c +++ b/net/dccp/output.c @@ -209,49 +209,29 @@ void dccp_write_space(struct sock *sk) } /** - * 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; - - 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); + long remaining; - sk->sk_write_pending++; - release_sock(sk); - schedule_timeout(jiffdelay); - lock_sock(sk); - sk->sk_write_pending--; + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + sk->sk_write_pending++; + release_sock(sk); - if (sk->sk_err) - goto do_error; - if (signal_pending(current)) - goto do_interrupted; + remaining = schedule_timeout(delay); - rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); - } while ((delay = rc) > 0); -out: + lock_sock(sk); + sk->sk_write_pending--; finish_wait(sk_sleep(sk), &wait); - return rc; - -do_error: - rc = -EPIPE; - goto out; -do_interrupted: - rc = -EINTR; - goto out; + + if (signal_pending(current) || sk->sk_err) + return -1; + return remaining; } /** @@ -305,7 +285,53 @@ static void dccp_xmit_packet(struct sock *sk) ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, len); } -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); + + 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); + } + } +} + +void dccp_write_xmit(struct sock *sk) { struct dccp_sock *dp = dccp_sk(sk); struct sk_buff *skb; @@ -317,19 +343,9 @@ void dccp_write_xmit(struct sock *sk, int block) case CCID_PACKET_WILL_DEQUEUE_LATER: return; case CCID_PACKET_DELAY: - if (!block) { - sk_reset_timer(sk, &dp->dccps_xmit_timer, - msecs_to_jiffies(rc)+jiffies); - return; - } - rc = dccp_wait_for_ccid(sk, skb, rc); - if (rc && rc != -EINTR) { - DCCP_BUG("err=%d after dccp_wait_for_ccid", rc); - skb_dequeue(&sk->sk_write_queue); - kfree_skb(skb); - break; - } - /* fall through */ + 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; @@ -648,7 +664,6 @@ 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)); /* diff --git a/net/dccp/proto.c b/net/dccp/proto.c index 7e5fc04eb6d1..ef343d53fcea 100644 --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -726,7 +726,13 @@ int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, goto out_discard; skb_queue_tail(&sk->sk_write_queue, skb); - dccp_write_xmit(sk,0); + /* + * The xmit_timer is set if the TX CCID is rate-based and will expire + * when congestion control permits to release further packets into the + * network. Window-based CCIDs do not use this timer. + */ + if (!timer_pending(&dp->dccps_xmit_timer)) + dccp_write_xmit(sk); out_release: release_sock(sk); return rc ? : len; @@ -951,9 +957,22 @@ 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/timer.c b/net/dccp/timer.c index 916f9d1dab36..7587870b7040 100644 --- a/net/dccp/timer.c +++ b/net/dccp/timer.c @@ -249,7 +249,7 @@ static void dccp_write_xmitlet(unsigned long data) if (sock_owned_by_user(sk)) sk_reset_timer(sk, &dccp_sk(sk)->dccps_xmit_timer, jiffies + 1); else - dccp_write_xmit(sk, 0); + dccp_write_xmit(sk); bh_unlock_sock(sk); } |