[dpdk-dev] [PATCH] rte_vhost: do not treat empty socket message as error

[dpdk-dev] [PATCH] rte_vhost: do not treat empty socket message as error

[Vitaliy Mysak]

According to recvmsg() specification, 0 is a valid
return code when client is disconnecting.
Therefore, it should not be reported as error, unless there
are other dependencies that require message to not be empty.
But there are none, since the next immediate caller of recvmsg()
reports "vhost peer closed" info (not error) when message is empty.

This patch changes return code check for recvmsg() so that
misleading error message is not printed when the code is 0.

Signed-off-by: Vitaliy Mysak <vitaliy.mysak@intel.com>
---
 lib/librte_vhost/socket.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
index 9740fb340..0cac3ce8e 100644
--- a/lib/librte_vhost/socket.c
+++ b/lib/librte_vhost/socket.c
@@ -127,7 +127,8 @@ read_fd_message(int sockfd, char *buf, int buflen, int *fds, int max_fds,
 
 	ret = recvmsg(sockfd, &msgh, 0);
 	if (ret <= 0) {
-		VHOST_LOG_CONFIG(ERR, "recvmsg failed\n");
+		if (ret)
+			VHOST_LOG_CONFIG(ERR, "recvmsg failed\n");
 		return ret;
 	}
 
-- 
2.17.1

Re: [dpdk-dev] [PATCH] rte_vhost: do not treat empty socket message as error

[Tiwei Bie]

[PATCH] rte_vhost: do not treat empty socket message as error

s/rte_vhost:/vhost:/

On Thu, Jan 30, 2020 at 09:05:39AM +0100, Vitaliy Mysak wrote:
> According to recvmsg() specification, 0 is a valid
> return code when client is disconnecting.
> Therefore, it should not be reported as error, unless there
> are other dependencies that require message to not be empty.
> But there are none, since the next immediate caller of recvmsg()
> reports "vhost peer closed" info (not error) when message is empty.
> 
> This patch changes return code check for recvmsg() so that
> misleading error message is not printed when the code is 0.

Fixes: 8f972312b8f4 ("vhost: support vhost-user")
Cc: stable@dpdk.org

> 
> Signed-off-by: Vitaliy Mysak <vitaliy.mysak@intel.com>
> ---
>  lib/librte_vhost/socket.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>

Thanks,
Tiwei

Re: [dpdk-dev] [PATCH] rte_vhost: do not treat empty socket message as error

[Maxime Coquelin]

On 1/30/20 9:05 AM, Vitaliy Mysak wrote:
> According to recvmsg() specification, 0 is a valid
> return code when client is disconnecting.
> Therefore, it should not be reported as error, unless there
> are other dependencies that require message to not be empty.
> But there are none, since the next immediate caller of recvmsg()
> reports "vhost peer closed" info (not error) when message is empty.
> 
> This patch changes return code check for recvmsg() so that
> misleading error message is not printed when the code is 0.
> 
> Signed-off-by: Vitaliy Mysak <vitaliy.mysak@intel.com>
> ---
>  lib/librte_vhost/socket.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Applied to dpdk-next-virtio tree.

Thanks,
Maxime

[dpdk-dev] [PATCH] rte_vhost: do not treat empty socket message as error

[Vitaliy Mysak]

According to recvmsg() specification, 0 is a valid
return code when client is disconnecting.
Therefore, it should not be reported as error, unless there
are other dependencies that require message to not be empty.
But there are none, since the next immediate caller of recvmsg()
reports "vhost peer closed" info (not error) when message is empty.

This patch changes return code check for recvmsg() so that
misleading error message is not printed when the code is 0.

Signed-off-by: Vitaliy Mysak <vitaliy.mysak@intel.com>
---
 lib/librte_vhost/socket.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
index 9740fb340..0cac3ce8e 100644
--- a/lib/librte_vhost/socket.c
+++ b/lib/librte_vhost/socket.c
@@ -127,7 +127,8 @@ read_fd_message(int sockfd, char *buf, int buflen, int *fds, int max_fds,
 
 	ret = recvmsg(sockfd, &msgh, 0);
 	if (ret <= 0) {
-		VHOST_LOG_CONFIG(ERR, "recvmsg failed\n");
+		if (ret)
+			VHOST_LOG_CONFIG(ERR, "recvmsg failed\n");
 		return ret;
 	}
 
-- 
2.17.1

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