[PATCH 3/3] vhost: remove use of strncpy

[Bruce Richardson]

The strlcpy is preferred over use of strncpy, which removes the need to
try and explicitly null-terminate some string buffers. We can also
simplify some name length handling as a result of this, as we no longer
need to use strnlen to clamp the length before calling the set_ifname
function.

Fixes: a277c7159876 ("vhost: refactor code structure")
Fixes: 0adb8eccc6a6 ("vhost: add VDUSE device creation and destruction")
Fixes: c171a2d5ff17 ("vhost: use strlcpy instead of strncpy")
Cc: stable at dpdk.org

Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
---
 lib/vhost/socket.c |  4 +---
 lib/vhost/vduse.c  |  2 +-
 lib/vhost/vhost.c  | 12 +++---------
 lib/vhost/vhost.h  |  2 +-
 4 files changed, 6 insertions(+), 14 deletions(-)

diff --git a/lib/vhost/socket.c b/lib/vhost/socket.c
index 70e582a18d..0943b3e9bb 100644
--- a/lib/vhost/socket.c
+++ b/lib/vhost/socket.c
@@ -207,7 +207,6 @@ static void
 vhost_user_add_connection(int fd, struct vhost_user_socket *vsocket)
 {
 	int vid;
-	size_t size;
 	struct vhost_user_connection *conn;
 	int ret;
 	struct virtio_net *dev;
@@ -226,8 +225,7 @@ vhost_user_add_connection(int fd, struct vhost_user_socket *vsocket)
 		goto err;
 	}
 
-	size = strnlen(vsocket->path, PATH_MAX);
-	vhost_set_ifname(vid, vsocket->path, size);
+	vhost_set_ifname(vid, vsocket->path);
 
 	vhost_setup_virtio_net(vid, vsocket->use_builtin_virtio_net,
 		vsocket->net_compliant_ol_flags, vsocket->stats_enabled,
diff --git a/lib/vhost/vduse.c b/lib/vhost/vduse.c
index 0b5d158fee..f8a4a8edcb 100644
--- a/lib/vhost/vduse.c
+++ b/lib/vhost/vduse.c
@@ -796,7 +796,7 @@ vduse_device_create(const char *path, bool compliant_ol_flags, bool extbuf, bool
 		goto out_dev_destroy;
 	}
 
-	strncpy(dev->ifname, path, IF_NAME_SZ - 1);
+	strlcpy(dev->ifname, path, sizeof(dev->ifname));
 	dev->vduse_ctrl_fd = control_fd;
 	dev->vduse_dev_fd = dev_fd;
 
diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
index 7e68b2c3be..fde8acb00c 100644
--- a/lib/vhost/vhost.c
+++ b/lib/vhost/vhost.c
@@ -776,20 +776,15 @@ vhost_attach_vdpa_device(int vid, struct rte_vdpa_device *vdpa_dev)
 }
 
 void
-vhost_set_ifname(int vid, const char *if_name, unsigned int if_len)
+vhost_set_ifname(int vid, const char *if_name)
 {
 	struct virtio_net *dev;
-	unsigned int len;
 
 	dev = get_device(vid);
 	if (dev == NULL)
 		return;
 
-	len = if_len > sizeof(dev->ifname) ?
-		sizeof(dev->ifname) : if_len;
-
-	strncpy(dev->ifname, if_name, len);
-	dev->ifname[sizeof(dev->ifname) - 1] = '\0';
+	strlcpy(dev->ifname, if_name, sizeof(dev->ifname));
 }
 
 void
@@ -915,8 +910,7 @@ rte_vhost_get_ifname(int vid, char *buf, size_t len)
 
 	len = RTE_MIN(len, sizeof(dev->ifname));
 
-	strncpy(buf, dev->ifname, len);
-	buf[len - 1] = '\0';
+	strlcpy(buf, dev->ifname, len);
 
 	return 0;
 }
diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
index ee61f7415e..1c957d2929 100644
--- a/lib/vhost/vhost.h
+++ b/lib/vhost/vhost.h
@@ -877,7 +877,7 @@ int alloc_vring_queue(struct virtio_net *dev, uint32_t vring_idx);
 
 void vhost_attach_vdpa_device(int vid, struct rte_vdpa_device *dev);
 
-void vhost_set_ifname(int, const char *if_name, unsigned int if_len);
+void vhost_set_ifname(int, const char *if_name);
 void vhost_setup_virtio_net(int vid, bool enable, bool legacy_ol_flags, bool stats_enabled,
 	bool support_iommu);
 void vhost_enable_extbuf(int vid);
-- 
2.53.0