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net/smc: fix fallback failed while sendmsg with fastopen

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[ Upstream commit ce7ca79471 ]

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: ee9dfbef02 ("net/smc: handle sockopts forcing fallback")
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>

v2 -> v1: Optimize code style
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
D. Wythe 2023-03-07 11:23:46 +08:00 committed by Greg Kroah-Hartman
parent 1bd9219177
commit 4de04f8f63
1 changed files with 8 additions and 5 deletions
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13
net/smc/af_smc.c
View file

@ -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) {