tcp: detect SYN/data drop when F-RTO is disabled
authorYuchung Cheng <ycheng@google.com>
Thu, 31 Jan 2013 19:16:46 +0000 (11:16 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 14 Feb 2013 18:48:34 +0000 (10:48 -0800)
commit3005cf62aac8c1b68c0201ead876b30a6c0f9ddd
tree449560481ad3af88b979eacc354d59092f5888d0
parent3cea56174bd3d79f8bb9ec500dfc95c4660a6ca9
tcp: detect SYN/data drop when F-RTO is disabled

[ Upstream commit 66555e92fb7a619188c02cceae4bbc414f15f96d ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/ipv4/tcp_input.c