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 <manojbm@xxxxxxxxxxxxxx>
Signed-off-by: Sauvik Saha <ssaha@xxxxxxxxxxxxxx>
---
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);
--
2.29.0
