diff mbox series

[net,v2] net/smc: fix fallback failed while sendmsg with fastopen

Message ID 1678159426-72671-1-git-send-email-alibuda@linux.alibaba.com (mailing list archive)
State Not Applicable
Headers show
Series [net,v2] net/smc: fix fallback failed while sendmsg with fastopen | expand

Commit Message

D. Wythe March 7, 2023, 3:23 a.m. UTC 
From: "D. Wythe" <alibuda@linux.alibaba.com>

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@linux.alibaba.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>

v2 -> v1: Optimize code style

---
 net/smc/af_smc.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

Comments

Tony Lu March 8, 2023, 8:24 a.m. UTC | #1 
On Tue, Mar 07, 2023 at 11:23:46AM +0800, D. Wythe wrote:
> From: "D. Wythe" <alibuda@linux.alibaba.com>
> 
> 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@linux.alibaba.com>
> Signed-off-by: Simon Horman <simon.horman@corigine.com>

Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>

Thanks.

> v2 -> v1: Optimize code style
> 
> ---
>  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 b233c94..1c580ac 100644
> --- a/net/smc/af_smc.c
> +++ b/net/smc/af_smc.c
> @@ -2659,16 +2659,14 @@ 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)
> @@ -2677,6 +2675,11 @@ 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) {
> -- 
> 1.8.3.1
Wenjia Zhang March 9, 2023, 7:43 a.m. UTC | #2 
On 07.03.23 04:23, D. Wythe wrote:
> From: "D. Wythe" <alibuda@linux.alibaba.com>
> 
> 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@linux.alibaba.com>
> Signed-off-by: Simon Horman <simon.horman@corigine.com>
> 

Thanks for the fix!

Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>

> v2 -> v1: Optimize code style
> 
> ---
>   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 b233c94..1c580ac 100644
> --- a/net/smc/af_smc.c
> +++ b/net/smc/af_smc.c
> @@ -2659,16 +2659,14 @@ 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)
> @@ -2677,6 +2675,11 @@ 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) {
diff mbox series

Patch

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index b233c94..1c580ac 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -2659,16 +2659,14 @@  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)
@@ -2677,6 +2675,11 @@  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) {