---

yaml
---
r: 220943
b: refs/heads/master
c: b1fcf55
h: refs/heads/master
i:
  220941: 998f924
  220939: 6cf6fd2
  220935: de793e2
  220927: 97e2b04
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: dc841e30eaea9f9f83c9ab1ee0b3ef9e5c95ce8a
+refs/heads/master: b1fcf55eea541af9efa5d39f5a0d1aec8ceca55d

trunk/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)

trunk/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));
 		/*

trunk/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:

trunk/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);
 }