From edefba66d929eb2d023df93a0a8175a4ffe82684 Mon Sep 17 00:00:00 2001 From: Jason Xing Date: Fri, 2 Aug 2024 18:21:09 +0800 Subject: [PATCH] tcp: rstreason: introduce SK_RST_REASON_TCP_STATE for active reset Introducing a new type TCP_STATE to handle some reset conditions appearing in RFC 793 due to its socket state. Actually, we can look into RFC 9293 which has no discrepancy about this part. Signed-off-by: Jason Xing Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/rstreason.h | 6 ++++++ net/ipv4/tcp.c | 10 ++++++---- net/ipv4/tcp_timer.c | 2 +- 3 files changed, 13 insertions(+), 5 deletions(-) diff --git a/include/net/rstreason.h b/include/net/rstreason.h index eef658da8952..bbf20d0bbde7 100644 --- a/include/net/rstreason.h +++ b/include/net/rstreason.h @@ -20,6 +20,7 @@ FN(TCP_ABORT_ON_CLOSE) \ FN(TCP_ABORT_ON_LINGER) \ FN(TCP_ABORT_ON_MEMORY) \ + FN(TCP_STATE) \ FN(MPTCP_RST_EUNSPEC) \ FN(MPTCP_RST_EMPTCP) \ FN(MPTCP_RST_ERESOURCE) \ @@ -102,6 +103,11 @@ enum sk_rst_reason { * corresponding to LINUX_MIB_TCPABORTONMEMORY */ SK_RST_REASON_TCP_ABORT_ON_MEMORY, + /** + * @SK_RST_REASON_TCP_STATE: abort on tcp state + * Please see RFC 9293 for all possible reset conditions + */ + SK_RST_REASON_TCP_STATE, /* Copy from include/uapi/linux/mptcp.h. * These reset fields will not be changed since they adhere to diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index fd928c447ce8..24777e48bcc8 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3025,9 +3025,11 @@ int tcp_disconnect(struct sock *sk, int flags) inet_csk_listen_stop(sk); } else if (unlikely(tp->repair)) { WRITE_ONCE(sk->sk_err, ECONNABORTED); - } else if (tcp_need_reset(old_state) || - (tp->snd_nxt != tp->write_seq && - (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) { + } else if (tcp_need_reset(old_state)) { + tcp_send_active_reset(sk, gfp_any(), SK_RST_REASON_TCP_STATE); + WRITE_ONCE(sk->sk_err, ECONNRESET); + } else if (tp->snd_nxt != tp->write_seq && + (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK)) { /* The last check adjusts for discrepancy of Linux wrt. RFC * states */ @@ -4649,7 +4651,7 @@ int tcp_abort(struct sock *sk, int err) if (!sock_flag(sk, SOCK_DEAD)) { if (tcp_need_reset(sk->sk_state)) tcp_send_active_reset(sk, GFP_ATOMIC, - SK_RST_REASON_NOT_SPECIFIED); + SK_RST_REASON_TCP_STATE); tcp_done_with_error(sk, err); } diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 0fba4a4fb988..3910f6d8614e 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -779,7 +779,7 @@ static void tcp_keepalive_timer (struct timer_list *t) goto out; } } - tcp_send_active_reset(sk, GFP_ATOMIC, SK_RST_REASON_NOT_SPECIFIED); + tcp_send_active_reset(sk, GFP_ATOMIC, SK_RST_REASON_TCP_STATE); goto death; }