From e880f8b3a24a73704731a7227ed5fee14bd90192 Mon Sep 17 00:00:00 2001 From: Manoj Basapathi Date: Mon, 5 Apr 2021 22:32:42 +0530 Subject: tcp: Reset tcp connections in SYN-SENT state Userspace sends tcp connection (sock) destroy on network switch i.e switching the default network of the device between multiple networks(Cellular/Wifi/Ethernet). Kernel though doesn't send reset for the connections in SYN-SENT state and these connections continue to remain. Even as per RFC 793, there is no hard rule to not send RST on ABORT in this state. Modify tcp_abort and tcp_disconnect behavior to send RST for connections in syn-sent state to avoid lingering connections on network switch. Signed-off-by: Manoj Basapathi Signed-off-by: Sauvik Saha Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index e14fd0c50c10..627a472161fb 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2888,7 +2888,7 @@ static inline bool tcp_need_reset(int state) { return (1 << state) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 | - TCPF_FIN_WAIT2 | TCPF_SYN_RECV); + TCPF_FIN_WAIT2 | TCPF_SYN_RECV | TCPF_SYN_SENT); } static void tcp_rtx_queue_purge(struct sock *sk) @@ -2954,8 +2954,7 @@ int tcp_disconnect(struct sock *sk, int flags) */ tcp_send_active_reset(sk, gfp_any()); sk->sk_err = ECONNRESET; - } else if (old_state == TCP_SYN_SENT) - sk->sk_err = ECONNRESET; + } tcp_clear_xmit_timers(sk); __skb_queue_purge(&sk->sk_receive_queue); -- cgit v1.2.3