From f985c65c908f6b26c30019a83dc5ea295f5fcf62 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 14 Oct 2015 06:16:49 -0700 Subject: [PATCH] tcp: avoid spurious SYN flood detection at listen() time At listen() time, there is a small window where listener is visible with a zero backlog, triggering a spurious "Possible SYN flooding on port" message. Nothing prevents us from setting the correct backlog. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/inet_connection_sock.h | 2 +- net/ipv4/inet_connection_sock.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h index 3208a65d1c28..fd645c49e71e 100644 --- a/include/net/inet_connection_sock.h +++ b/include/net/inet_connection_sock.h @@ -312,7 +312,7 @@ static inline unsigned int inet_csk_listen_poll(const struct sock *sk) (POLLIN | POLLRDNORM) : 0; } -int inet_csk_listen_start(struct sock *sk, const int nr_table_entries); +int inet_csk_listen_start(struct sock *sk, int backlog); void inet_csk_listen_stop(struct sock *sk); void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr); diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 514b9e910bd4..ba9ec9a0d0ce 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -727,14 +727,14 @@ void inet_csk_prepare_forced_close(struct sock *sk) } EXPORT_SYMBOL(inet_csk_prepare_forced_close); -int inet_csk_listen_start(struct sock *sk, const int nr_table_entries) +int inet_csk_listen_start(struct sock *sk, int backlog) { struct inet_connection_sock *icsk = inet_csk(sk); struct inet_sock *inet = inet_sk(sk); reqsk_queue_alloc(&icsk->icsk_accept_queue); - sk->sk_max_ack_backlog = 0; + sk->sk_max_ack_backlog = backlog; sk->sk_ack_backlog = 0; inet_csk_delack_init(sk);