(websocket server) Handle programmer error when the server callback is not registered properly (fix #227)

docs/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 All changes to this project will be documented in this file.
 
+## [10.1.6] - 2020-08-06
+
+(websocket server) Handle programmer error when the server callback is not registered properly (fix #227)
+
 ## [10.1.5] - 2020-08-02
 
 (ws) Add a new ws sub-command, push_server. This command runs a server which sends many messages in a loop to a websocket client. We can receive above 200,000 messages per second (cf #235).

ixwebsocket/IXWebSocket.cpp

@@ -405,6 +405,11 @@ namespace ix
         _onMessageCallback = callback;
     }
 
+    bool WebSocket::isOnMessageCallbackRegistered() const
+    {
+        return _onMessageCallback != nullptr;
+    }
+
     void WebSocket::setTrafficTrackerCallback(const OnTrafficTrackerCallback& callback)
     {
         _onTrafficTrackerCallback = callback;

ixwebsocket/IXWebSocket.h

@@ -84,6 +84,7 @@ namespace ix
                    const std::string& reason = WebSocketCloseConstants::kNormalClosureMessage);
 
         void setOnMessageCallback(const OnMessageCallback& callback);
+        bool isOnMessageCallbackRegistered() const;
         static void setTrafficTrackerCallback(const OnTrafficTrackerCallback& callback);
         static void resetTrafficTrackerCallback();
 

ixwebsocket/IXWebSocketServer.cpp

@@ -86,6 +86,15 @@ namespace ix
         if (_onConnectionCallback)
         {
             _onConnectionCallback(webSocket, connectionState, std::move(connectionInfo));
+
+            if (!webSocket->isOnMessageCallbackRegistered())
+            {
+                logError("WebSocketServer Application developer error: Server callback improperly "
+                         "registerered.");
+                logError("Missing call to setOnMessageCallback inside setOnConnectionCallback.");
+                connectionState->setTerminated();
+                return;
+            }
         }
         else if (_onClientMessageCallback)
         {

test/compatibility/cpp/libwebsockets/devnull_client.cpp

@@ -36,68 +36,55 @@
  *
  */
 
-#include <libwebsockets.h>
-#include <string.h>
-#include <signal.h>
-
 #include <atomic>
-#include <thread>
 #include <iostream>
+#include <libwebsockets.h>
+#include <signal.h>
+#include <string.h>
+#include <thread>
 
 static int interrupted;
-static struct lws *client_wsi;
+static struct lws* client_wsi;
 
 std::atomic<uint64_t> receivedCount(0);
 
-static int
+static int callback_dumb_increment(
-callback_dumb_increment(struct lws *wsi, enum lws_callback_reasons reason,
+    struct lws* wsi, enum lws_callback_reasons reason, void* user, void* in, size_t len)
-              void *user, void *in, size_t len)
 {
-        switch (reason) {
+    switch (reason)
-
+    {
         /* because we are protocols[0] ... */
         case LWS_CALLBACK_CLIENT_CONNECTION_ERROR:
-                lwsl_err("CLIENT_CONNECTION_ERROR: %s\n",
+            lwsl_err("CLIENT_CONNECTION_ERROR: %s\n", in ? (char*) in : "(null)");
-                         in ? (char *)in : "(null)");
             client_wsi = NULL;
             break;
 
-        case LWS_CALLBACK_CLIENT_ESTABLISHED:
+        case LWS_CALLBACK_CLIENT_ESTABLISHED: lwsl_user("%s: established\n", __func__); break;
-                lwsl_user("%s: established\n", __func__);
-                break;
 
-        case LWS_CALLBACK_CLIENT_RECEIVE:
+        case LWS_CALLBACK_CLIENT_RECEIVE: receivedCount++; break;
-                receivedCount++;
-                break;
 
-        case LWS_CALLBACK_CLIENT_CLOSED:
+        case LWS_CALLBACK_CLIENT_CLOSED: client_wsi = NULL; break;
-                client_wsi = NULL;
-                break;
 
-        default:
+        default: break;
-                break;
     }
 
     return lws_callback_http_dummy(wsi, reason, user, in, len);
 }
 
-static const struct lws_protocols protocols[] = {
+static const struct lws_protocols protocols[] = {{
-        {
                                                      "dumb-increment-protocol",
                                                      callback_dumb_increment,
                                                      0,
                                                      0,
                                                  },
-        { NULL, NULL, 0, 0 }
+                                                 {NULL, NULL, 0, 0}};
-};
 
-static void
+static void sigint_handler(int sig)
-sigint_handler(int sig)
 {
     interrupted = 1;
 }
 
-int main(int argc, const char **argv)
+int main(int argc, const char** argv)
 {
     uint64_t receivedCountTotal(0);
     uint64_t receivedCountPerSecs(0);
@@ -105,12 +92,8 @@ int main(int argc, const char **argv)
     auto timer = [&receivedCountTotal, &receivedCountPerSecs] {
         while (!interrupted)
         {
-                std::cerr << "messages received: "
+            std::cerr << "messages received: " << receivedCountPerSecs << " per second "
-                          << receivedCountPerSecs
+                      << receivedCountTotal << " total" << std::endl;
-                          << " per second "
-                          << receivedCountTotal 
-                          << " total"
-                          << std::endl;
 
             receivedCountPerSecs = receivedCount - receivedCountTotal;
             receivedCountTotal += receivedCountPerSecs;
@@ -124,8 +107,8 @@ int main(int argc, const char **argv)
 
     struct lws_context_creation_info info;
     struct lws_client_connect_info i;
-        struct lws_context *context;
+    struct lws_context* context;
-        const char *p;
+    const char* p;
     int n = 0, logs = LLL_USER | LLL_ERR | LLL_WARN | LLL_NOTICE
         /* for LLL_ verbosity above NOTICE to be built into lws, lws
          * must have been configured with -DCMAKE_BUILD_TYPE=DEBUG
@@ -135,8 +118,7 @@ int main(int argc, const char **argv)
         /* | LLL_DEBUG */;
 
     signal(SIGINT, sigint_handler);
-        if ((p = lws_cmdline_option(argc, argv, "-d")))
+    if ((p = lws_cmdline_option(argc, argv, "-d"))) logs = atoi(p);
-                logs = atoi(p);
 
     lws_set_log_level(logs, NULL);
     lwsl_user("LWS minimal ws client rx [-d <logs>] [--h2]\n");
@@ -156,7 +138,8 @@ int main(int argc, const char **argv)
     info.fd_limit_per_thread = 1 + 1 + 1;
 
     context = lws_create_context(&info);
-        if (!context) {
+    if (!context)
+    {
         lwsl_err("lws init failed\n");
         return 1;
     }
@@ -171,8 +154,7 @@ int main(int argc, const char **argv)
     i.protocol = protocols[0].name; /* "dumb-increment-protocol" */
     i.pwsi = &client_wsi;
 
-        if (lws_cmdline_option(argc, argv, "--h2"))
+    if (lws_cmdline_option(argc, argv, "--h2")) i.alpn = "h2";
-                i.alpn = "h2";
 
     lws_client_connect_via_info(&i);