tcp: constify tcp_syn_flood_action() socket argument

tcp_syn_flood_action() will soon be called with unlocked socket.
In order to avoid SYN flood warning being emitted multiple times,
use xchg().
Extend max_qlen_log and synflood_warned fields in struct listen_sock
to u32

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2015-09-29 07:42:51 -07:00
committed by David S. Miller
parent f964629e33
commit 2985aaac01
2 changed files with 7 additions and 7 deletions
+5 -4
View File
@@ -6064,7 +6064,7 @@ EXPORT_SYMBOL(inet_reqsk_alloc);
/*
* Return true if a syncookie should be sent
*/
static bool tcp_syn_flood_action(struct sock *sk,
static bool tcp_syn_flood_action(const struct sock *sk,
const struct sk_buff *skb,
const char *proto)
{
@@ -6082,11 +6082,12 @@ static bool tcp_syn_flood_action(struct sock *sk,
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPREQQFULLDROP);
lopt = inet_csk(sk)->icsk_accept_queue.listen_opt;
if (!lopt->synflood_warned && sysctl_tcp_syncookies != 2) {
lopt->synflood_warned = 1;
if (!lopt->synflood_warned &&
sysctl_tcp_syncookies != 2 &&
xchg(&lopt->synflood_warned, 1) == 0)
pr_info("%s: Possible SYN flooding on port %d. %s. Check SNMP counters.\n",
proto, ntohs(tcp_hdr(skb)->dest), msg);
}
return want_cookie;
}