From: D. Wythe <alibuda@xxxxxxxxxxxxxxxxx>
[ 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 <alibuda@xxxxxxxxxxxxxxxxx>
Signed-off-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
v2 -> v1: Optimize code style
Reviewed-by: Tony Lu <tonylu@xxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 5d696b7fb47e1..b398d72a7bc39 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1542,16 +1542,14 @@ 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) {
smc_switch_to_fallback(smc);
smc->fallback_rsn = SMC_CLC_DECL_OPTUNSUPP;
@@ -1559,6 +1557,11 @@ 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)
--
2.39.2
