syncookies: remove last_synq_overflow from struct tcp_sock

last_synq_overflow eats 4 or 8 bytes in struct tcp_sock, even
though it is only used when a listening sockets syn queue
is full.

We can (ab)use rx_opt.ts_recent_stamp to store the same information;
it is not used otherwise as long as a socket is in listen state.

Move linger2 around to avoid splitting struct mtu_probe
across cacheline boundary on 32 bit arches.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Florian Westphal
2009-04-19 09:43:48 +00:00
committed by David S. Miller
parent 7eebb0b28f
commit a0f82f64e2
4 changed files with 18 additions and 8 deletions

View File

@ -131,7 +131,7 @@ __u32 cookie_v6_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mssp)
int mssind;
const __u16 mss = *mssp;
tcp_sk(sk)->last_synq_overflow = jiffies;
tcp_synq_overflow(sk);
for (mssind = 0; mss > msstab[mssind + 1]; mssind++)
;
@ -175,7 +175,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
if (!sysctl_tcp_syncookies || !th->ack)
goto out;
if (time_after(jiffies, tp->last_synq_overflow + TCP_TIMEOUT_INIT) ||
if (tcp_synq_no_recent_overflow(sk) ||
(mss = cookie_check(skb, cookie)) == 0) {
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_SYNCOOKIESFAILED);
goto out;