net/virtio: improve vhost-user error logging

This patch improves error logging in vhost_user_read,
especially printing errno when recv() fails.

Suggested-by: Adrian Moreno <amorenoz@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>

diff --git a/drivers/net/virtio/virtio_user/vhost_user.c b/drivers/net/virtio/virtio_user/vhost_user.c
index 088aae3..ec2c53c 100644 (file)
--- a/drivers/net/virtio/virtio_user/vhost_user.c
+++ b/drivers/net/virtio/virtio_user/vhost_user.c
@@ -148,38 +148,43 @@ vhost_user_read(int fd, struct vhost_user_msg *msg)
        int ret, sz_hdr = VHOST_USER_HDR_SIZE, sz_payload;
 
        ret = recv(fd, (void *)msg, sz_hdr, 0);
-       if (ret < sz_hdr) {
+       if (ret < 0) {
+               PMD_DRV_LOG(ERR, "Failed to recv msg header: %s", strerror(errno));
+               return -1;
+       } else if (ret < sz_hdr) {
                PMD_DRV_LOG(ERR, "Failed to recv msg hdr: %d instead of %d.",
                            ret, sz_hdr);
-               goto fail;
+               return -1;
        }
 
        /* validate msg flags */
        if (msg->flags != (valid_flags)) {
-               PMD_DRV_LOG(ERR, "Failed to recv msg: flags %x instead of %x.",
+               PMD_DRV_LOG(ERR, "Failed to recv msg: flags 0x%x instead of 0x%x.",
                            msg->flags, valid_flags);
-               goto fail;
+               return -1;
        }
 
        sz_payload = msg->size;
 
-       if ((size_t)sz_payload > sizeof(msg->payload))
-               goto fail;
+       if ((size_t)sz_payload > sizeof(msg->payload)) {
+               PMD_DRV_LOG(ERR, "Payload size overflow, header says %d but max %zu\n",
+                               sz_payload, sizeof(msg->payload));
+               return -1;
+       }
 
        if (sz_payload) {
                ret = recv(fd, (void *)((char *)msg + sz_hdr), sz_payload, 0);
-               if (ret < sz_payload) {
-                       PMD_DRV_LOG(ERR,
-                               "Failed to recv msg payload: %d instead of %d.",
+               if (ret < 0) {
+                       PMD_DRV_LOG(ERR, "Failed to recv msg payload: %s", strerror(errno));
+                       return -1;
+               } else if (ret < sz_payload) {
+                       PMD_DRV_LOG(ERR, "Failed to recv msg payload: %d instead of %u.",
                                ret, msg->size);
-                       goto fail;
+                       return -1;
                }
        }
 
        return 0;
-
-fail:
-       return -1;
 }
 
 static int