3 files changed, 26 insertions, 14 deletions

diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index d850e291f87..6576eae9e77 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -78,12 +78,9 @@ static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hc)
 
 static int ccid2_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
 {
-	struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
-
-	if (hc->tx_pipe < hc->tx_cwnd)
-		return 0;
-
-	return 1; /* XXX CCID should dequeue when ready instead of polling */
+	if (ccid2_cwnd_network_limited(ccid2_hc_tx_sk(sk)))
+		return CCID_PACKET_WILL_DEQUEUE_LATER;
+	return CCID_PACKET_SEND_AT_ONCE;
 }
 
 static void ccid2_change_l_ack_ratio(struct sock *sk, u32 val)
@@ -115,6 +112,7 @@ static void ccid2_hc_tx_rto_expire(unsigned long data)
 {
 	struct sock *sk = (struct sock *)data;
 	struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
+	const bool sender_was_blocked = ccid2_cwnd_network_limited(hc);
 
 	bh_lock_sock(sk);
 	if (sock_owned_by_user(sk)) {
@@ -129,8 +127,6 @@ static void ccid2_hc_tx_rto_expire(unsigned long data)
 	if (hc->tx_rto > DCCP_RTO_MAX)
 		hc->tx_rto = DCCP_RTO_MAX;
 
-	sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto);
-
 	/* adjust pipe, cwnd etc */
 	hc->tx_ssthresh = hc->tx_cwnd / 2;
 	if (hc->tx_ssthresh < 2)
@@ -146,6 +142,12 @@ static void ccid2_hc_tx_rto_expire(unsigned long data)
 	hc->tx_rpseq    = 0;
 	hc->tx_rpdupack = -1;
 	ccid2_change_l_ack_ratio(sk, 1);
+
+	/* if we were blocked before, we may now send cwnd=1 packet */
+	if (sender_was_blocked)
+		tasklet_schedule(&dccp_sk(sk)->dccps_xmitlet);
+	/* restart backed-off timer */
+	sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto);
 out:
 	bh_unlock_sock(sk);
 	sock_put(sk);
@@ -434,6 +436,7 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 {
 	struct dccp_sock *dp = dccp_sk(sk);
 	struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk);
+	const bool sender_was_blocked = ccid2_cwnd_network_limited(hc);
 	u64 ackno, seqno;
 	struct ccid2_seq *seqp;
 	unsigned char *vector;
@@ -631,6 +634,10 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 		sk_stop_timer(sk, &hc->tx_rtotimer);
 	else
 		sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto);
+
+	/* check if incoming Acks allow pending packets to be sent */
+	if (sender_was_blocked && !ccid2_cwnd_network_limited(hc))
+		tasklet_schedule(&dccp_sk(sk)->dccps_xmitlet);
 }
 
 static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)
diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h
index 9731c2dc148..25cb6b216ed 100644
--- a/net/dccp/ccids/ccid2.h
+++ b/net/dccp/ccids/ccid2.h
@@ -81,6 +81,11 @@ struct ccid2_hc_tx_sock {
 	u64			tx_high_ack;
 };
 
+static inline bool ccid2_cwnd_network_limited(struct ccid2_hc_tx_sock *hc)
+{
+	return hc->tx_pipe >= hc->tx_cwnd;
+}
+
 struct ccid2_hc_rx_sock {
 	int	rx_data;
 };
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index 3060a60ed5a..3d604e1349c 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -268,11 +268,11 @@ out:
 	sock_put(sk);
 }
 
-/*
- * returns
- *   > 0: delay (in msecs) that should pass before actually sending
- *   = 0: can send immediately
- *   < 0: error condition; do not send packet
+/**
+ * ccid3_hc_tx_send_packet  -  Delay-based dequeueing of TX packets
+ * @skb: next packet candidate to send on @sk
+ * This function uses the convention of ccid_packet_dequeue_eval() and
+ * returns a millisecond-delay value between 0 and t_mbi = 64000 msec.
  */
 static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
 {
@@ -348,7 +348,7 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
 
 	/* set the nominal send time for the next following packet */
 	hc->tx_t_nom = ktime_add_us(hc->tx_t_nom, hc->tx_t_ipi);
-	return 0;
+	return CCID_PACKET_SEND_AT_ONCE;
 }
 
 static void ccid3_hc_tx_packet_sent(struct sock *sk, unsigned int len)