fix broadcast compution

src/lxc/confile.c

@@ -423,9 +423,8 @@ static int config_network_ipv4(const char *key, char *value,
 	 * prefix and address
 	 */
 	if (!bcast) {
-		inetdev->bcast.s_addr =
-			htonl(INADDR_BROADCAST << (32 - inetdev->prefix));
-		inetdev->bcast.s_addr &= inetdev->addr.s_addr;
+		int mask = htonl(INADDR_BROADCAST << (32 - inetdev->prefix));
+		inetdev->bcast.s_addr = (inetdev->addr.s_addr & mask) | ~mask;
 	}
 
 	lxc_list_add(&netdev->ipv4, list);

src/lxc/network.c

@@ -742,7 +742,7 @@ static int ip_addr_add(int family, int ifindex,
 	if (nla_put_buffer(nlmsg, IFA_ADDRESS, addr, addrlen))
 		goto out;
 
-	if (bcast && nla_put_buffer(nlmsg, IFA_BROADCAST, bcast, addrlen))
+	if (nla_put_buffer(nlmsg, IFA_BROADCAST, bcast, addrlen))
 		goto out;
 
 	/* TODO : multicast, anycast with ipv6 */