GUACAMOLE-25: Add stub callbacks for AUDIO_INPUT data handling.

src/protocols/rdp/guac_ai/ai_service.c

@@ -37,6 +37,208 @@
 #include "compat/winpr-stream.h"
 #endif
 
+/**
+ * Handles the given data received along the AUDIO_INPUT channel of the RDP
+ * connection associated with the given guac_client. This handler is
+ * API-independent and is invoked by API-dependent guac_rdp_ai_data callback
+ * specific to the version of FreeRDP installed.
+ *
+ * @param client
+ *     The guac_client associated with RDP connection having the AUDIO_INPUT
+ *     connection along which the given data was received.
+ *
+ * @param stream
+ *     The data received along the AUDIO_INPUT channel.
+ */
+static void guac_rdp_ai_handle_data(guac_client* client, wStream* stream) {
+
+    /* Read message ID from received PDU */
+    BYTE message_id;
+    Stream_Read_UINT8(stream, message_id);
+
+    /* STUB */
+    guac_client_log(client, GUAC_LOG_DEBUG, "AUDIO_INPUT data received: 0x%x",
+            message_id);
+
+}
+
+/**
+ * Callback which is invoked when data is received along a connection to the
+ * AUDIO_INPUT plugin. This callback is specific to FreeRDP 1.1 and older.
+ *
+ * @param channel_callback
+ *     The IWTSVirtualChannelCallback structure to which this callback was
+ *     originally assigned.
+ *
+ * @param size
+ *     The number of bytes received.
+ *
+ * @param buffer
+ *     A buffer containing all bytes received.
+ *
+ * @return
+ *     Always zero.
+ */
+static int guac_rdp_ai_data(IWTSVirtualChannelCallback* channel_callback,
+        UINT32 size, BYTE* buffer) {
+
+    guac_rdp_ai_channel_callback* ai_channel_callback =
+        (guac_rdp_ai_channel_callback*) channel_callback;
+
+    /* Invoke generalized (API-independent) data handler */
+    wStream* stream = Stream_New(buffer, size);
+    guac_rdp_ai_handle_data(ai_channel_callback->client, stream);
+    Stream_Free(stream, FALSE);
+
+    return 0;
+
+}
+
+/**
+ * Callback which is invoked when a connection to the AUDIO_INPUT plugin is
+ * closed.
+ *
+ * @param channel_callback
+ *     The IWTSVirtualChannelCallback structure to which this callback was
+ *     originally assigned.
+ *
+ * @return
+ *     Always zero.
+ */
+static int guac_rdp_ai_close(IWTSVirtualChannelCallback* channel_callback) {
+
+    guac_rdp_ai_channel_callback* ai_channel_callback =
+        (guac_rdp_ai_channel_callback*) channel_callback;
+
+    /* Log closure of AUDIO_INPUT channel */
+    guac_client_log(ai_channel_callback->client, GUAC_LOG_DEBUG,
+            "AUDIO_INPUT channel connection closed");
+
+    free(ai_channel_callback);
+    return 0;
+
+}
+
+/**
+ * Callback which is invoked when a new connection is received by the
+ * AUDIO_INPUT plugin. Additional callbacks required to handle received data
+ * and closure of the connection must be installed at this point.
+ *
+ * @param listener_callback
+ *     The IWTSListenerCallback structure associated with the AUDIO_INPUT
+ *     plugin receiving the new connection.
+ *
+ * @param channel
+ *     A reference to the IWTSVirtualChannel instance along which data related
+ *     to the AUDIO_INPUT channel should be sent.
+ *
+ * @param data
+ *     Absolutely no idea. According to Microsoft's documentation for the
+ *     function prototype on which FreeRDP's API appears to be based: "This
+ *     parameter is not implemented and is reserved for future use."
+ *
+ * @param accept
+ *     Pointer to a flag which should be set to TRUE if the connection should
+ *     be accepted or FALSE otherwise. In the case of FreeRDP, this value
+ *     defaults to TRUE, and TRUE absolutely MUST be identically 1 or it will
+ *     be interpreted as FALSE.
+ *
+ * @param channel_callback
+ *     A pointer to the location that the new IWTSVirtualChannelCallback
+ *     structure containing the required callbacks should be assigned.
+ *
+ * @return
+ *     Always zero.
+ */
+static int guac_rdp_ai_new_connection(
+        IWTSListenerCallback* listener_callback, IWTSVirtualChannel* channel,
+        BYTE* data, int* accept,
+        IWTSVirtualChannelCallback** channel_callback) {
+
+    guac_rdp_ai_listener_callback* ai_listener_callback =
+        (guac_rdp_ai_listener_callback*) listener_callback;
+
+    /* Log new AUDIO_INPUT connection */
+    guac_client_log(ai_listener_callback->client, GUAC_LOG_DEBUG,
+            "New AUDIO_INPUT channel connection");
+
+    /* Allocate new channel callback */
+    guac_rdp_ai_channel_callback* ai_channel_callback =
+        calloc(1, sizeof(guac_rdp_ai_channel_callback));
+
+    /* Init listener callback with data from plugin */
+    ai_channel_callback->client = ai_listener_callback->client;
+    ai_channel_callback->parent.OnDataReceived = guac_rdp_ai_data;
+    ai_channel_callback->parent.OnClose = guac_rdp_ai_close;
+
+    /* Return callback through pointer */
+    *channel_callback = (IWTSVirtualChannelCallback*) ai_channel_callback;
+    return 0;
+
+}
+
+/**
+ * Callback which is invoked when the AUDIO_INPUT plugin has been loaded and
+ * needs to be initialized with other callbacks and data.
+ *
+ * @param plugin
+ *     The AUDIO_INPUT plugin that needs to be initialied.
+ *
+ * @param manager
+ *     The IWTSVirtualChannelManager instance with which the AUDIO_INPUT plugin
+ *     must be registered.
+ *
+ * @return
+ *     Always zero.
+ */
+static int guac_rdp_ai_initialize(IWTSPlugin* plugin,
+        IWTSVirtualChannelManager* manager) {
+
+    /* Allocate new listener callback */
+    guac_rdp_ai_listener_callback* ai_listener_callback =
+        calloc(1, sizeof(guac_rdp_ai_listener_callback));
+
+    /* Ensure listener callback is freed when plugin is terminated */
+    guac_rdp_ai_plugin* ai_plugin = (guac_rdp_ai_plugin*) plugin;
+    ai_plugin->listener_callback = ai_listener_callback;
+
+    /* Init listener callback with data from plugin */
+    ai_listener_callback->client = ai_plugin->client;
+    ai_listener_callback->parent.OnNewChannelConnection =
+        guac_rdp_ai_new_connection;
+
+    /* Register listener for "AUDIO_INPUT" channel */
+    manager->CreateListener(manager, "AUDIO_INPUT", 0,
+            (IWTSListenerCallback*) ai_listener_callback, NULL);
+
+    return 0;
+
+}
+
+/**
+ * Callback which is invoked when all connections to the AUDIO_INPUT plugin
+ * have closed and the plugin is being unloaded.
+ *
+ * @param plugin
+ *     The AUDIO_INPUT plugin being unloaded.
+ *
+ * @return
+ *     Always zero.
+ */
+static int guac_rdp_ai_terminated(IWTSPlugin* plugin) {
+
+    guac_rdp_ai_plugin* ai_plugin = (guac_rdp_ai_plugin*) plugin;
+    guac_client* client = ai_plugin->client;
+
+    /* Free all non-FreeRDP data */
+    free(ai_plugin->listener_callback);
+    free(ai_plugin);
+
+    guac_client_log(client, GUAC_LOG_DEBUG, "AUDIO_INPUT plugin unloaded.");
+    return 0;
+
+}
+
 /**
  * Entry point for AUDIO_INPUT dynamic virtual channel.
  */
@@ -45,9 +247,25 @@ int DVCPluginEntry(IDRDYNVC_ENTRY_POINTS* pEntryPoints) {
     ADDIN_ARGV* args = pEntryPoints->GetPluginData(pEntryPoints);
     guac_client* client = (guac_client*) guac_rdp_string_to_ptr(args->argv[1]);
 
-    /* STUB */
+    /* Pull previously-allocated plugin */
-    guac_client_log(client, GUAC_LOG_DEBUG,
+    guac_rdp_ai_plugin* ai_plugin = (guac_rdp_ai_plugin*)
-            "STUB: AUDIO_INPUT DVC (entry point)");
+        pEntryPoints->GetPlugin(pEntryPoints, "guacai");
+
+    /* If no such plugin allocated, allocate and register it now */
+    if (ai_plugin == NULL) {
+
+        /* Init plugin callbacks and data */
+        ai_plugin = calloc(1, sizeof(guac_rdp_ai_plugin));
+        ai_plugin->parent.Initialize = guac_rdp_ai_initialize;
+        ai_plugin->parent.Terminated = guac_rdp_ai_terminated;
+        ai_plugin->client = client;
+
+        /* Register plugin as "guacai" for later retrieval */
+        pEntryPoints->RegisterPlugin(pEntryPoints, "guacai",
+                (IWTSPlugin*) ai_plugin);
+
+        guac_client_log(client, GUAC_LOG_DEBUG, "AUDIO_INPUT plugin loaded.");
+    }
 
     return 1;
 

src/protocols/rdp/guac_ai/ai_service.h

@@ -17,13 +17,86 @@
  * under the License.
  */
 
-
 #ifndef GUAC_RDP_AI_SERVICE_H
 #define GUAC_RDP_AI_SERVICE_H
 
 #include "config.h"
 
-/* STUB */
+#include <freerdp/freerdp.h>
+#include <freerdp/constants.h>
+#include <freerdp/dvc.h>
+#include <guacamole/client.h>
+
+/**
+ * Extended version of the IWTSListenerCallback structure, providing additional
+ * access to Guacamole-specific data. The IWTSListenerCallback provides access
+ * to callbacks related to the receipt of new connections to the AUDIO_INPUT
+ * channel.
+ */
+typedef struct guac_rdp_ai_listener_callback {
+
+    /**
+     * The parent IWTSListenerCallback structure that this structure extends.
+     * THIS MEMBER MUST BE FIRST!
+     */
+    IWTSListenerCallback parent;
+
+    /**
+     * The guac_client instance associated with the RDP connection using the
+     * AUDIO_INPUT plugin.
+     */
+    guac_client* client;
+
+} guac_rdp_ai_listener_callback;
+
+/**
+ * Extended version of the IWTSVirtualChannelCallback structure, providing
+ * additional access to Guacamole-specific data. The IWTSVirtualChannelCallback
+ * provides access to callbacks related to an active connection to the
+ * AUDIO_INPUT channel, including receipt of data. 
+ */
+typedef struct guac_rdp_ai_channel_callback {
+
+    /**
+     * The parent IWTSVirtualChannelCallback structure that this structure
+     * extends. THIS MEMBER MUST BE FIRST!
+     */
+    IWTSVirtualChannelCallback parent;
+
+    /**
+     * The guac_client instance associated with the RDP connection using the
+     * AUDIO_INPUT plugin.
+     */
+    guac_client* client;
+
+} guac_rdp_ai_channel_callback;
+
+/**
+ * All data associated with Guacamole's AUDIO_INPUT plugin for FreeRDP.
+ */
+typedef struct guac_rdp_ai_plugin {
+
+    /**
+     * The parent IWTSPlugin structure that this structure extends. THIS
+     * MEMBER MUST BE FIRST!
+     */
+    IWTSPlugin parent;
+
+    /**
+     * The listener callback structure allocated when the AUDIO_INPUT plugin
+     * was loaded, if any. If the plugin did not fully load, this will be NULL.
+     * If non-NULL, this callback structure must be freed when the plugin is
+     * terminated.
+     */
+    guac_rdp_ai_listener_callback* listener_callback;
+
+    /**
+     * The guac_client instance associated with the RDP connection using the
+     * AUDIO_INPUT plugin.
+     */
+    guac_client* client;
+
+} guac_rdp_ai_plugin;
 
 #endif