From 0530020a7c8f2204e784f0dbdc882bbd961fdbde Mon Sep 17 00:00:00 2001 From: Geliang Tang Date: Fri, 22 Apr 2022 14:55:38 -0700 Subject: mptcp: track and update contiguous data status This patch adds a new member allow_infinite_fallback in mptcp_sock, which is initialized to 'true' when the connection begins and is set to 'false' on any retransmit or successful MP_JOIN. Only do infinite mapping fallback if there is a single subflow AND there have been no retransmissions AND there have never been any MP_JOINs. Suggested-by: Paolo Abeni Signed-off-by: Geliang Tang Signed-off-by: Mat Martineau Signed-off-by: David S. Miller --- net/mptcp/subflow.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'net/mptcp/subflow.c') diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 7f26a5b04ad3..31dcb550316f 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -1206,7 +1206,8 @@ fallback: if (!__mptcp_check_fallback(msk)) { /* RFC 8684 section 3.7. */ if (subflow->send_mp_fail) { - if (mptcp_has_another_subflow(ssk)) { + if (mptcp_has_another_subflow(ssk) || + !READ_ONCE(msk->allow_infinite_fallback)) { ssk->sk_err = EBADMSG; tcp_set_state(ssk, TCP_CLOSE); subflow->reset_transient = 0; @@ -1486,6 +1487,7 @@ int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc, /* discard the subflow socket */ mptcp_sock_graft(ssk, sk->sk_socket); iput(SOCK_INODE(sf)); + WRITE_ONCE(msk->allow_infinite_fallback, false); return err; failed_unlink: -- cgit v1.2.3