contrib/vhost-user-blk: fix bind() using the right size of the address

On macOS passing `-s /tmp/vhost.socket` parameter to the vhost-user-blk
application, the bind was done on `/tmp/vhost.socke` pathname,
missing the last character.

This sounds like one of the portability problems described in the
unix(7) manpage:

   Pathname sockets
       When  binding  a socket to a pathname, a few rules should
       be observed for maximum portability and ease of coding:

       •  The pathname in sun_path should be null-terminated.

       •  The length of the pathname, including the  terminating
          null byte, should not exceed the size of sun_path.

       •  The  addrlen  argument  that  describes  the enclosing
          sockaddr_un structure should have a value of at least:

              offsetof(struct sockaddr_un, sun_path) +
              strlen(addr.sun_path)+1

          or,  more  simply,  addrlen  can   be   specified   as
          sizeof(struct sockaddr_un).

So let's follow the last advice and simplify the code as well.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20240618100440.145664-1-sgarzare@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Stefano Garzarella 2024-06-18 12:04:39 +02:00 committed by Michael S. Tsirkin
parent 4c58843e5d
commit 03582094da

View File

@ -469,7 +469,6 @@ static int unix_sock_new(char *unix_fn)
{
int sock;
struct sockaddr_un un;
size_t len;
assert(unix_fn);
@ -481,10 +480,9 @@ static int unix_sock_new(char *unix_fn)
un.sun_family = AF_UNIX;
(void)snprintf(un.sun_path, sizeof(un.sun_path), "%s", unix_fn);
len = sizeof(un.sun_family) + strlen(un.sun_path);
(void)unlink(unix_fn);
if (bind(sock, (struct sockaddr *)&un, len) < 0) {
if (bind(sock, (struct sockaddr *)&un, sizeof(un)) < 0) {
perror("bind");
goto fail;
}