From 5ad37d5deee1ff7150a2d0602370101de158ad86 Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Fri, 26 Jul 2013 17:43:23 +0200 Subject: tcp: add tcp_syncookies mode to allow unconditionally generation of syncookies | If you want to test which effects syncookies have to your | network connections you can set this knob to 2 to enable | unconditionally generation of syncookies. Original idea and first implementation by Eric Dumazet. Cc: Florian Westphal Cc: David Miller Signed-off-by: Eric Dumazet Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- net/ipv6/tcp_ipv6.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'net/ipv6') diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index b792e870686b..38c196ca6011 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -963,7 +963,8 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb) if (!ipv6_unicast_destination(skb)) goto drop; - if (inet_csk_reqsk_queue_is_full(sk) && !isn) { + if ((sysctl_tcp_syncookies == 2 || + inet_csk_reqsk_queue_is_full(sk)) && !isn) { want_cookie = tcp_syn_flood_action(sk, skb, "TCPv6"); if (!want_cookie) goto drop; -- cgit v1.2.3