Refine #2162

src/server.c

@@ -2050,6 +2050,7 @@ main(int argc, char **argv)
     }
 
     if (mode != TCP_ONLY) {
+        int num_listen_ctx = 0;
         for (int i = 0; i < server_num; i++) {
             const char *host = server_host[i];
             const char *port = server_port;
@@ -2061,7 +2062,13 @@ main(int argc, char **argv)
             else
                 LOGI("udp server listening at %s:%s", host ? host : "0.0.0.0", port);
             // Setup UDP
-            init_udprelay(host, port, mtu, crypto, atoi(timeout), iface);
+            int err = init_udprelay(host, port, mtu, crypto, atoi(timeout), iface);
+            if (err == -1) continue;
+            num_listen_ctx++;
+        }
+
+        if (num_listen_ctx == 0) {
+            FATAL("failed to listen on any address");
         }
     }
 

src/udprelay.c

@@ -1355,20 +1355,20 @@ init_udprelay(const char *server_host, const char *server_port,
         buf_size    = packet_size * 2;
     }
 
-    // Initialize cache
-    struct cache *conn_cache;
-    cache_create(&conn_cache, MAX_UDP_CONN_NUM, free_cb);
-
     // ////////////////////////////////////////////////
     // Setup server context
 
     // Bind to port
     int serverfd = create_server_socket(server_host, server_port);
     if (serverfd < 0) {
-        FATAL("[udp] bind() error");
+        return -1;
     }
     setnonblocking(serverfd);
 
+    // Initialize cache
+    struct cache *conn_cache;
+    cache_create(&conn_cache, MAX_UDP_CONN_NUM, free_cb);
+
     server_ctx_t *server_ctx = new_server_ctx(serverfd);
 #ifdef MODULE_REMOTE
     server_ctx->loop = loop;