From f6627c69a303754d79b132e797a19b605c68044f Mon Sep 17 00:00:00 2001 From: "Matthieu Baerts (NGI0)" Date: Wed, 28 Aug 2024 08:14:28 +0200 Subject: [PATCH] mptcp: pm: skip connecting to already established sf commit bc19ff57637ff563d2bdf2b385b48c41e6509e0d upstream. The lookup_subflow_by_daddr() helper checks if there is already a subflow connected to this address. But there could be a subflow that is closing, but taking time due to some reasons: latency, losses, data to process, etc. If an ADD_ADDR is received while the endpoint is being closed, it is better to try connecting to it, instead of rejecting it: the peer which has sent the ADD_ADDR will not be notified that the ADD_ADDR has been rejected for this reason, and the expected subflow will not be created at the end. This helper should then only look for subflows that are established, or going to be, but not the ones being closed. Fixes: d84ad04941c3 ("mptcp: skip connecting the connected address") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman --- net/mptcp/pm_netlink.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 2bce3a32bd88..d15d0d5b5a4c 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -134,12 +134,15 @@ static bool lookup_subflow_by_daddr(const struct list_head *list, { struct mptcp_subflow_context *subflow; struct mptcp_addr_info cur; - struct sock_common *skc; list_for_each_entry(subflow, list, node) { - skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow); + struct sock *ssk = mptcp_subflow_tcp_sock(subflow); - remote_address(skc, &cur); + if (!((1 << inet_sk_state_load(ssk)) & + (TCPF_ESTABLISHED | TCPF_SYN_SENT | TCPF_SYN_RECV))) + continue; + + remote_address((struct sock_common *)ssk, &cur); if (mptcp_addresses_equal(&cur, daddr, daddr->port)) return true; }