Merge pull request #2020 from fadams/improve-websocket-config-options

Provide compile time and run time options for WebSocket URL and subproto...

3 files changed, 51 insertions, 4 deletions

diff --git a/src/library.js b/src/library.js
index e711ee98..8aac2bb2 100644
--- a/src/library.js
+++ b/src/library.js
@@ -8176,7 +8176,9 @@ LibraryManager.library = {
   },
 
   setsockopt: function(d, level, optname, optval, optlen) {
+#if SOCKET_DEBUG
     console.log('ignoring setsockopt command');
+#endif
     return 0;
   },
 
@@ -8665,7 +8667,9 @@ LibraryManager.library = {
   },
 
   setsockopt: function(fd, level, optname, optval, optlen) {
+#if SOCKET_DEBUG
     console.log('ignoring setsockopt command');
+#endif
     return 0;
   },
 
diff --git a/src/library_sockfs.js b/src/library_sockfs.js
index 22fd8761..23641464 100644
--- a/src/library_sockfs.js
+++ b/src/library_sockfs.js
@@ -133,12 +133,42 @@ mergeInto(LibraryManager.library, {
         } else {
           // create the actual websocket object and connect
           try {
-            var url = 'ws://' + addr + ':' + port;
+            // runtimeConfig gets set to true if WebSocket runtime configuration is available.
+            var runtimeConfig = (Module['websocket'] && ('object' === typeof Module['websocket']));
+
+            // The default value is 'ws://' the replace is needed because the compiler replaces "//" comments with '#'
+            // comments without checking context, so we'd end up with ws:#, the replace swaps the "#" for "//" again.
+            var url = '{{{ WEBSOCKET_URL }}}'.replace('#', '//');
+
+            if (runtimeConfig) {
+              if ('string' === typeof Module['websocket']['url']) {
+                url = Module['websocket']['url']; // Fetch runtime WebSocket URL config.
+              }
+            }
+
+            if (url === 'ws://' || url === 'wss://') { // Is the supplied URL config just a prefix, if so complete it.
+              url = url + addr + ':' + port;
+            }
+
+            // Make the WebSocket subprotocol (Sec-WebSocket-Protocol) default to binary if no configuration is set.
+            var subProtocols = '{{{ WEBSOCKET_SUBPROTOCOL }}}'; // The default value is 'binary'
+
+            if (runtimeConfig) {
+              if ('string' === typeof Module['websocket']['subprotocol']) {
+                subProtocols = Module['websocket']['subprotocol']; // Fetch runtime WebSocket subprotocol config.
+              }
+            }
+
+            // The regex trims the string (removes spaces at the beginning and end, then splits the string by
+            // <any space>,<any space> into an Array. Whitespace removal is important for Websockify and ws.
+            subProtocols = subProtocols.replace(/^ +| +$/g,"").split(/ *, */);
+
+            // The node ws library API for specifying optional subprotocol is slightly different than the browser's.
+            var opts = ENVIRONMENT_IS_NODE ? {'protocol': subProtocols.toString()} : subProtocols;
+
 #if SOCKET_DEBUG
-            console.log('connect: ' + url);
+            Module.print('connect: ' + url + ', ' + subProtocols.toString());
 #endif
-            // the node ws library API is slightly different than the browser's
-            var opts = ENVIRONMENT_IS_NODE ? {headers: {'websocket-protocol': ['binary']}} : ['binary'];
             // If node we use the ws library.
             var WebSocket = ENVIRONMENT_IS_NODE ? require('ws') : window['WebSocket'];
             ws = new WebSocket(url, opts);
diff --git a/src/settings.js b/src/settings.js
index 1c41676d..6e644a54 100644
--- a/src/settings.js
+++ b/src/settings.js
@@ -225,6 +225,19 @@ var LIBRARY_DEBUG = 0; // Print out when we enter a library call (library*.js).
 var SOCKET_DEBUG = 0; // Log out socket/network data transfer.
 var SOCKET_WEBRTC = 0; // Select socket backend, either webrtc or websockets.
 
+// As well as being configurable at compile time via the "-s" option the WEBSOCKET_URL and WEBSOCKET_SUBPROTOCOL
+// settings may configured at run time via the Module object e.g.
+// Module['websocket'] = {subprotocol: 'base64, binary, text'};
+// Module['websocket'] = {url: 'wss://', subprotocol: 'base64'};
+// Run time configuration may be useful as it lets an application select multiple different services.
+var WEBSOCKET_URL = 'ws://'; // A string containing either a WebSocket URL prefix (ws:// or wss://) or a complete
+                             // RFC 6455 URL - "ws[s]:" "//" host [ ":" port ] path [ "?" query ].
+                             // In the (default) case of only a prefix being specified the URL will be constructed from
+                             // prefix + addr + ':' + port
+                             // where addr and port are derived from the socket connect/bind/accept calls.
+var WEBSOCKET_SUBPROTOCOL = 'binary'; // A string containing a comma separated list of WebSocket subprotocols
+                                      // as would be present in the Sec-WebSocket-Protocol header.
+
 var OPENAL_DEBUG = 0; // Print out debugging information from our OpenAL implementation.
 
 var GL_ASSERTIONS = 0; // Adds extra checks for error situations in the GL library. Can impact performance.