Commit 22a32557 authored by Jason Xing's avatar Jason Xing Committed by Jakub Kicinski
Browse files

tcp: rstreason: handle timewait cases in the receive path 



There are two possible cases where TCP layer can send an RST. Since they
happen in the same place, I think using one independent reason is enough
to identify this special situation.

Signed-off-by: default avatarJason Xing <kernelxing@tencent.com>
Link: https://lore.kernel.org/r/20240510122502.27850-5-kerneljasonxing@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent f6d5e2cc

include/net/rstreason.h

+5 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
	FN(TCP_FLAGS)			\

	FN(TCP_OLD_ACK)			\

	FN(TCP_ABORT_ON_DATA)		\

	FN(TCP_TIMEWAIT_SOCKET)		\

	FN(MPTCP_RST_EUNSPEC)		\

	FN(MPTCP_RST_EMPTCP)		\

	FN(MPTCP_RST_ERESOURCE)		\
@@ -72,6 +73,10 @@ enum sk_rst_reason { 
	 */

	SK_RST_REASON_TCP_ABORT_ON_DATA,



	/* Here start with the independent reasons */

	/** @SK_RST_REASON_TCP_TIMEWAIT_SOCKET: happen on the timewait socket */

	SK_RST_REASON_TCP_TIMEWAIT_SOCKET,



	/* Copy from include/uapi/linux/mptcp.h.

	 * These reset fields will not be changed since they adhere to

	 * RFC 8684. So do not touch them. I'm going to list each definition

net/ipv4/tcp_ipv4.c

+1 −1
Original line number Diff line number Diff line
@@ -2427,7 +2427,7 @@ int tcp_v4_rcv(struct sk_buff *skb) 
		tcp_v4_timewait_ack(sk, skb);

		break;

	case TCP_TW_RST:

		tcp_v4_send_reset(sk, skb, sk_rst_convert_drop_reason(drop_reason));

		tcp_v4_send_reset(sk, skb, SK_RST_REASON_TCP_TIMEWAIT_SOCKET);

		inet_twsk_deschedule_put(inet_twsk(sk));

		goto discard_it;

	case TCP_TW_SUCCESS:;

net/ipv6/tcp_ipv6.c

+1 −1
Original line number Diff line number Diff line
@@ -1999,7 +1999,7 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb) 
		tcp_v6_timewait_ack(sk, skb);

		break;

	case TCP_TW_RST:

		tcp_v6_send_reset(sk, skb, sk_rst_convert_drop_reason(drop_reason));

		tcp_v6_send_reset(sk, skb, SK_RST_REASON_TCP_TIMEWAIT_SOCKET);

		inet_twsk_deschedule_put(inet_twsk(sk));

		goto discard_it;

	case TCP_TW_SUCCESS: