From ed8dbecba5e347dded7103e7717241cf4a248422 Mon Sep 17 00:00:00 2001 From: "D. Wythe" Date: Tue, 7 Mar 2023 11:23:46 +0800 Subject: [PATCH] net/smc: fix fallback failed while sendmsg with fastopen [ Upstream commit ce7ca794712f186da99719e8b4e97bd5ddbb04c3 ] Before determining whether the msg has unsupported options, it has been prematurely terminated by the wrong status check. For the application, the general usages of MSG_FASTOPEN likes fd = socket(...) /* rather than connect */ sendto(fd, data, len, MSG_FASTOPEN) Hence, We need to check the flag before state check, because the sock state here is always SMC_INIT when applications tries MSG_FASTOPEN. Once we found unsupported options, fallback it to TCP. Fixes: ee9dfbef02d1 ("net/smc: handle sockopts forcing fallback") Signed-off-by: D. Wythe Signed-off-by: Simon Horman v2 -> v1: Optimize code style Reviewed-by: Tony Lu Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/smc/af_smc.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index d9413d43b104..e8018b0fb767 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -2644,16 +2644,14 @@ static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) { struct sock *sk = sock->sk; struct smc_sock *smc; - int rc = -EPIPE; + int rc; smc = smc_sk(sk); lock_sock(sk); - if ((sk->sk_state != SMC_ACTIVE) && - (sk->sk_state != SMC_APPCLOSEWAIT1) && - (sk->sk_state != SMC_INIT)) - goto out; + /* SMC does not support connect with fastopen */ if (msg->msg_flags & MSG_FASTOPEN) { + /* not connected yet, fallback */ if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) { rc = smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP); if (rc) @@ -2662,6 +2660,11 @@ static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) rc = -EINVAL; goto out; } + } else if ((sk->sk_state != SMC_ACTIVE) && + (sk->sk_state != SMC_APPCLOSEWAIT1) && + (sk->sk_state != SMC_INIT)) { + rc = -EPIPE; + goto out; } if (smc->use_fallback) {