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Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
-rw-r--r--net/ipv4/tcp_ipv4.c24
1 files changed, 13 insertions, 11 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 202cf09c4cd..a13f881e503 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -793,19 +793,20 @@ static void tcp_v4_reqsk_destructor(struct request_sock *req)
kfree(inet_rsk(req)->opt);
}
-#ifdef CONFIG_SYN_COOKIES
-static void syn_flood_warning(struct sk_buff *skb)
+static void syn_flood_warning(const struct sk_buff *skb)
{
- static unsigned long warntime;
+ const char *msg;
- if (time_after(jiffies, (warntime + HZ * 60))) {
- warntime = jiffies;
- printk(KERN_INFO
- "possible SYN flooding on port %d. Sending cookies.\n",
- ntohs(tcp_hdr(skb)->dest));
- }
-}
+#ifdef CONFIG_SYN_COOKIES
+ if (sysctl_tcp_syncookies)
+ msg = "Sending cookies";
+ else
#endif
+ msg = "Dropping request";
+
+ pr_info("TCP: Possible SYN flooding on port %d. %s.\n",
+ ntohs(tcp_hdr(skb)->dest), msg);
+}
/*
* Save and compile IPv4 options into the request_sock if needed.
@@ -1243,6 +1244,8 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
* evidently real one.
*/
if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
+ if (net_ratelimit())
+ syn_flood_warning(skb);
#ifdef CONFIG_SYN_COOKIES
if (sysctl_tcp_syncookies) {
want_cookie = 1;
@@ -1328,7 +1331,6 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
if (want_cookie) {
#ifdef CONFIG_SYN_COOKIES
- syn_flood_warning(skb);
req->cookie_ts = tmp_opt.tstamp_ok;
#endif
isn = cookie_v4_init_sequence(sk, skb, &req->mss);