commit af9b4738574b46025de7ccbe75c7b24fd8914379
author Florian Westphal <fw@strlen.de> Thu Jun 03 00:43:44 2010 +0000
committer David S. Miller <davem@davemloft.net> Sat Jun 05 02:23:14 2010 -0700
tree 6d05b82261ce76e6ecf00131c667292b62d16adf
parent 2a1d4bd46047efff513600d7ff422bc344f540a6

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 <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/syncookies.c

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 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) ||

net/ipv4/tcp_ipv4.c

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 @@
 	}
 
 #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;

net/ipv6/syncookies.c

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 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) ||

net/ipv6/tcp_ipv6.c

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 @@
 	}
 
 #ifdef CONFIG_SYN_COOKIES
-	if (!th->rst && !th->syn && th->ack)
+	if (!th->syn)
 		sk = cookie_v6_check(sk, skb);
 #endif
 	return sk;