From af9b4738574b46025de7ccbe75c7b24fd8914379 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 3 Jun 2010 00:43:44 +0000 Subject: [PATCH] syncookies: avoid unneeded tcp header flag double check caller: if (!th->rst && !th->syn && th->ack) callee: if (!th->ack) make the caller only check for !syn (common for 3whs), and move the !rst / ack test to the callee. Signed-off-by: Florian Westphal Signed-off-by: David S. Miller --- net/ipv4/syncookies.c | 2 +- net/ipv4/tcp_ipv4.c | 2 +- net/ipv6/syncookies.c | 2 +- net/ipv6/tcp_ipv6.c | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-) diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index 5c24db4..c9dac86 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -266,7 +266,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb, struct rtable *rt; __u8 rcv_wscale; - if (!sysctl_tcp_syncookies || !th->ack) + if (!sysctl_tcp_syncookies || !th->ack || th->rst) goto out; if (tcp_synq_no_recent_overflow(sk) || diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index a13f881..6558dfd 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1506,7 +1506,7 @@ static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb) } #ifdef CONFIG_SYN_COOKIES - if (!th->rst && !th->syn && th->ack) + if (!th->syn) sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt)); #endif return sk; diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c index 1238370..9fcb3ec 100644 --- a/net/ipv6/syncookies.c +++ b/net/ipv6/syncookies.c @@ -174,7 +174,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) struct dst_entry *dst; __u8 rcv_wscale; - if (!sysctl_tcp_syncookies || !th->ack) + if (!sysctl_tcp_syncookies || !th->ack || th->rst) goto out; if (tcp_synq_no_recent_overflow(sk) || diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index e487080..5887141 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -1157,7 +1157,7 @@ static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb) } #ifdef CONFIG_SYN_COOKIES - if (!th->rst && !th->syn && th->ack) + if (!th->syn) sk = cookie_v6_check(sk, skb); #endif return sk; -- 2.7.4