tree a4b9d5c0a863eb7e7dd2cd63421841d6349b8baf
parent b6fe83e9525a03b3141e5857eb7d8af219db94e5
author Eric Dumazet <edumazet@google.com> 1342528170 +0000
committer David S. Miller <davem@davemloft.net> 1342629085 -0700

tcp: refine SYN handling in tcp_validate_incoming

Followup of commit 0c24604b68fc (tcp: implement RFC 5961 4.2)

As reported by Vijay Subramanian, we should send a challenge ACK
instead of a dup ack if a SYN flag is set on a packet received out of
window.

This permits the ratelimiting to work as intended, and to increase
correct SNMP counters.

Suggested-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Cc: Kiran Kumar Kella <kkiran@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>