Hey everyone,
[I'm not subscribed, so please CC me on any replies]
I've attached a patch that changes the order of the ACK and RST checking
in the LISTEN state in tcp_rcv_state_process() in tcp_input.c
Before: If an ACK/RST packet is received, then tcp_rcv_state_process()
would return 1 because of the ACK. Then (following the function calls
in tcp_ipv4.c and tcp_minisocks.c), tcp_v4_send_reset() is called--but
since there is a RST in the packet it just returns. After this, the
kfree_skb() is called. The same goes in tcp_ipv6.c as well.
But if the order of the ACK and RST checking is reversed, __kfree_skb()
is called in tcp_rcv_state_process() because of the RST and the function
returns 0, which skips that other useless stuff.
This is the order specified on page 65 of RFC 793 anyway.
Signed-off-by: Kris Katterjohn <[EMAIL PROTECTED]>
Thanks,
Kris Katterjohn
--- net/ipv4/tcp_input.c 2008-02-13 00:05:59.000000000 -0600
+++ net/ipv4/tcp_input.c 2008-02-13 00:10:40.000000000 -0600
@@ -4962,12 +4962,12 @@ int tcp_rcv_state_process(struct sock *s
goto discard;
case TCP_LISTEN:
- if (th->ack)
- return 1;
-
if (th->rst)
goto discard;
+ if (th->ack)
+ return 1;
+
if (th->syn) {
if (icsk->icsk_af_ops->conn_request(sk, skb) < 0)
return 1;
