conf, tcp, udp: Exit if we fail to bind sockets for all given ports

passt supports ranges of forwarded ports as well as 'all' for TCP and
UDP, so it might be convenient to proceed if we fail to bind only
some of the desired ports.

But if we fail to bind even a single port for a given specification,
we're clearly, unexpectedly, conflicting with another network
service. In that case, report failure and exit.

Reported-by: Yalan Zhang <yalzhang@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 18 insertions, 7 deletions

diff --git a/tcp.c b/tcp.c
index f028e01..32ce1e9 100644
--- a/tcp.c
+++ b/tcp.c
@@ -2916,20 +2916,31 @@ static int tcp_sock_init_af(const struct ctx *c, int af, in_port_t port,
  * @addr:	Pointer to address for binding, NULL if not configured
  * @ifname:	Name of interface to bind to, NULL if not configured
  * @port:	Port, host order
+ *
+ * Return: 0 on (partial) success, -1 on (complete) failure
  */
-void tcp_sock_init(const struct ctx *c, sa_family_t af, const void *addr,
-		   const char *ifname, in_port_t port)
+int tcp_sock_init(const struct ctx *c, sa_family_t af, const void *addr,
+		  const char *ifname, in_port_t port)
 {
+	int ret = 0;
+
 	if (af == AF_UNSPEC && c->ifi4 && c->ifi6)
 		/* Attempt to get a dual stack socket */
 		if (tcp_sock_init_af(c, AF_UNSPEC, port, addr, ifname) >= 0)
-			return;
+			return 0;
 
 	/* Otherwise create a socket per IP version */
-	if ((af == AF_INET  || af == AF_UNSPEC) && c->ifi4)
-		tcp_sock_init_af(c, AF_INET, port, addr, ifname);
-	if ((af == AF_INET6 || af == AF_UNSPEC) && c->ifi6)
-		tcp_sock_init_af(c, AF_INET6, port, addr, ifname);
+	if ((af == AF_INET  || af == AF_UNSPEC) && c->ifi4) {
+		if (tcp_sock_init_af(c, AF_INET, port, addr, ifname) < 0)
+			ret = -1;
+	}
+
+	if ((af == AF_INET6 || af == AF_UNSPEC) && c->ifi6) {
+		if (tcp_sock_init_af(c, AF_INET6, port, addr, ifname) < 0)
+			ret = -1;
+	}
+
+	return ret;
 }
 
 /**