diff options
-rw-r--r-- | net/ipv4/tcp_input.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index bf79a5aae24e..25988229f68f 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5214,8 +5214,11 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb, * an acknowledgment should be sent in reply (unless the RST * bit is set, if so drop the segment and return)". */ - if (!th->rst) + if (!th->rst) { + if (th->syn) + goto syn_challenge; tcp_send_dupack(sk, skb); + } goto discard; } @@ -5245,6 +5248,7 @@ static bool tcp_validate_incoming(struct sock *sk, struct sk_buff *skb, * RFC 5691 4.2 : Send a challenge ack */ if (th->syn) { +syn_challenge: if (syn_inerr) TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS); NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSYNCHALLENGE); |