diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index 3eb264b608239c74c16d27625cc4b3b5199a3ef8..a8ed459508b294feb774c1597e788fa38313e995 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 11418a9a389d3564654d3b5a971dafe481f14969..45b91853f5aee3d452d5795da832b9e1f04651ed 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 7e5fc04eb6d1989986b7c7241f0e5cb2106ce4d8..ef343d53fcea22edf7d7bb2be677f349ec63f547 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 916f9d1dab36e2f3616a9c6bea95b3fb37092671..7587870b7040d0d997a54efd4d2c0786a1bb8a7d 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);
}