lib/nl: preserve s_local if nl_connect() fails

s_local.nl_pid is used to track the generated port unless NL_OWN_PORT is set.
Ensure that getsockname() doesn't overwrite the value and possibly reset
the local port manually to release the generated port.

Signed-off-by: Thomas Haller <thaller@redhat.com>

diff --git a/lib/nl.c b/lib/nl.c
index bb11d2c7872dd34f4cd3cbb54ad480e6f644cf7d..8e4c4552cf4e59e1765119cf25993ec1aef20208 100644 (file)
--- a/lib/nl.c
+++ b/lib/nl.c
@@ -98,6 +98,7 @@ int nl_connect(struct nl_sock *sk, int protocol)
        int err, flags = 0;
        int errsv;
        socklen_t addrlen;
+       struct sockaddr_nl local = { 0 };
        char buf[64];
 
 #ifdef SOCK_CLOEXEC
@@ -163,8 +164,8 @@ int nl_connect(struct nl_sock *sk, int protocol)
                }
        }
 
-       addrlen = sizeof(sk->s_local);
-       err = getsockname(sk->s_fd, (struct sockaddr *) &sk->s_local,
+       addrlen = sizeof(local);
+       err = getsockname(sk->s_fd, (struct sockaddr *) &local,
                          &addrlen);
        if (err < 0) {
                NL_DBG(4, "nl_connect(%p): getsockname() failed with %d (%s)\n",
@@ -173,24 +174,31 @@ int nl_connect(struct nl_sock *sk, int protocol)
                goto errout;
        }
 
-       if (addrlen != sizeof(sk->s_local)) {
+       if (addrlen != sizeof(local)) {
                err = -NLE_NOADDR;
                goto errout;
        }
 
-       if (sk->s_local.nl_family != AF_NETLINK) {
+       if (local.nl_family != AF_NETLINK) {
                err = -NLE_AF_NOSUPPORT;
                goto errout;
        }
 
+       if (sk->s_local.nl_pid != local.nl_pid) {
+               /* strange, the port id is not as expected. Set the local
+                * port id to release a possibly generated port and un-own
+                * it. */
+               nl_socket_set_local_port (sk, local.nl_pid);
+       }
+       sk->s_local = local;
        sk->s_proto = protocol;
 
        return 0;
 errout:
-        if (sk->s_fd != -1) {
-               close(sk->s_fd);
-               sk->s_fd = -1;
-        }
+       if (sk->s_fd != -1) {
+               close(sk->s_fd);
+               sk->s_fd = -1;
+       }
 
        return err;
 }