From c0f5aec28edf98906d28f08daace6522adf9ee7a Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Tue, 16 Jan 2024 18:18:47 +0100 Subject: [PATCH] mptcp: relax check on MPC passive fallback While testing the blamed commit below, I was able to miss (!) packetdrill failures in the fastopen test-cases. On passive fastopen the child socket is created by incoming TCP MPC syn, allow for both MPC_SYN and MPC_ACK header. Fixes: 724b00c12957 ("mptcp: refine opt_mp_capable determination") Reviewed-by: Matthieu Baerts Signed-off-by: Paolo Abeni Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller --- net/mptcp/subflow.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 1117d1e84274..0dcb721c89d1 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -783,7 +783,8 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, * options. */ mptcp_get_options(skb, &mp_opt); - if (!(mp_opt.suboptions & OPTION_MPTCP_MPC_ACK)) + if (!(mp_opt.suboptions & + (OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_ACK))) fallback = true; } else if (subflow_req->mp_join) {