daemon/network: allow listening on part of interfaces

when whole interface is passed and some of the addresses are not bindable,
the daemon will print them, but will continue to bind to the rest of the
addresses

fixes #80

daemon/bindings.c

@@ -182,8 +182,7 @@ static int net_listen_iface(lua_State *L, int port)
 		int ret = network_listen(&engine->net, lua_tostring(L, -1),
 		                         port, NET_TCP|NET_UDP);
 		if (ret != 0) {
-			format_error(L, kr_strerror(ret));
-			lua_error(L);
+			kr_log_info("[system] bind to '%s#%d' %s\n", lua_tostring(L, -1), port, kr_strerror(ret));
 		}
 		lua_pop(L, 1);
 	}

daemon/io.c

@@ -80,6 +80,9 @@ static struct session *session_borrow(struct worker_ctx *worker)
 
 static void session_release(struct worker_ctx *worker, struct session *s)
 {
+	if (!s) {
+		return;
+	}
 	if (worker->pool_sessions.len < MP_FREELIST_SIZE) {
 		session_clear(s);
 		array_push(worker->pool_sessions, s);

daemon/network.c

@@ -135,6 +135,7 @@ static int open_endpoint(struct network *net, struct endpoint *ep, struct sockad
 		if (!ep->udp) {
 			return kr_error(ENOMEM);
 		}
+		memset(ep->udp, 0, sizeof(*ep->udp));
 		handle_init(udp, net->loop, ep->udp, sa->sa_family);
 		int ret = udp_bind(ep->udp, sa);
 		if (ret != 0) {
@@ -147,6 +148,7 @@ static int open_endpoint(struct network *net, struct endpoint *ep, struct sockad
 		if (!ep->tcp) {
 			return kr_error(ENOMEM);
 		}
+		memset(ep->tcp, 0, sizeof(*ep->tcp));
 		handle_init(tcp, net->loop, ep->tcp, sa->sa_family);
 		int ret = tcp_bind(ep->tcp, sa);
 		if (ret != 0) {