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Diffstat (limited to 'net/ipv4/tcp_input.c')
-rw-r--r--net/ipv4/tcp_input.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 12fda8f27b08..f3a0eb139b76 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -261,7 +261,8 @@ static void tcp_ecn_accept_cwr(struct sock *sk, const struct sk_buff *skb)
* cwnd may be very low (even just 1 packet), so we should ACK
* immediately.
*/
- inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_NOW;
+ if (TCP_SKB_CB(skb)->seq != TCP_SKB_CB(skb)->end_seq)
+ inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_NOW;
}
}
@@ -3665,6 +3666,15 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
tcp_in_ack_event(sk, ack_ev_flags);
}
+ /* This is a deviation from RFC3168 since it states that:
+ * "When the TCP data sender is ready to set the CWR bit after reducing
+ * the congestion window, it SHOULD set the CWR bit only on the first
+ * new data packet that it transmits."
+ * We accept CWR on pure ACKs to be more robust
+ * with widely-deployed TCP implementations that do this.
+ */
+ tcp_ecn_accept_cwr(sk, skb);
+
/* We passed data and got it acked, remove any soft error
* log. Something worked...
*/
@@ -4800,8 +4810,6 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
skb_dst_drop(skb);
__skb_pull(skb, tcp_hdr(skb)->doff * 4);
- tcp_ecn_accept_cwr(sk, skb);
-
tp->rx_opt.dsack = 0;
/* Queue data for delivery to the user.