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authorYuchung Cheng2013-01-31 20:16:46 +0100
committerDavid S. Miller2013-01-31 20:20:07 +0100
commit66555e92fb7a619188c02cceae4bbc414f15f96d (patch)
treec64ca59aef09b3d659223e71f9282631a9289787 /net/ipv4
parentl2tp: correctly handle ancillary data in the ip6 recv path (diff)
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tcp: detect SYN/data drop when F-RTO is disabled
On receiving the SYN-ACK, Fast Open checks icsk_retransmit for SYN retransmission to detect SYN/data drops. But if F-RTO is disabled, icsk_retransmit is reset at step D of tcp_fastretrans_alert() ( under tcp_ack()) before tcp_rcv_fastopen_synack(). The fix is to use total_retrans instead which accounts for SYN retransmission regardless the use of F-RTO. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/tcp_input.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 18f97ca76b00..8aca4ee95ff9 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5649,8 +5649,7 @@ static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack,
* the remote receives only the retransmitted (regular) SYNs: either
* the original SYN-data or the corresponding SYN-ACK is lost.
*/
- syn_drop = (cookie->len <= 0 && data &&
- inet_csk(sk)->icsk_retransmits);
+ syn_drop = (cookie->len <= 0 && data && tp->total_retrans);
tcp_fastopen_cache_set(sk, mss, cookie, syn_drop);