[WIP]: Add support for links channel.

src/libguac/client.c

@@ -717,3 +717,62 @@ int guac_client_supports_webp(guac_client* client) {
 
 }
 
+/**
+ * A callback that it is invokved by the call to guac_client_owner_send_uri
+ * which sends the 'uri" instruction and parameter to the specified user, who
+ * is the owner of the connection.
+ *
+ * @param user
+ *     The user to send the "uri" instruction and parameter to, who owns the
+ *     connection.
+ *
+ * @param data
+ *     The URI to send to the owner, cast as a void*.
+ *
+ * @return
+ *     Zero if the operation succeeds or non-zero on failure.
+ */
+static void* guac_client_owner_send_uri_callback(guac_user* user, void* data) {
+    
+    const char* uri = (const char *) data;
+    
+    /* Send uri parameter to owner. */
+    if (user != NULL)
+        return (void*) ((intptr_t) guac_protocol_send_uri(user->socket, uri));
+    
+    return (void*) ((intptr_t) -1);
+}
+
+int guac_client_owner_send_uri(guac_client* client, const char* uri) {
+
+    /* Don't send the uri instruction if the client does not support it. */
+    if (!guac_client_owner_supports_uri(client))
+        return -1;
+
+    return (int) ((intptr_t) guac_client_for_owner(client, guac_client_owner_send_uri_callback, (void *) uri));
+
+}
+
+/**
+ * Callback function that is invoked by guac_client_owner_supports_uri to
+ * determine if the owner of a connection supports the "uri" instruction,
+ * so that Guacamole can pass URIs to the client browser.
+ *
+ * @param user
+ *     The user that is being checked for URI support, which should be the
+ *     owner of the connection.
+ *
+ * @param data
+ *     Additional data - this will always be null.
+ *
+ * @return
+ *     A non-zero integer if the user supports the "uri" instruction, otherwise
+ *     zero to indicate a lack of URI support.
+ */
+static void* guac_owner_supports_uri_callback(guac_user* user, void* data) {
+    return (void*) ((intptr_t) guac_user_supports_uri(user));
+}
+
+int guac_client_owner_supports_uri(guac_client* client) {
+    return (int) ((intptr_t) guac_client_for_owner(client, guac_owner_supports_uri_callback, NULL));
+}

src/libguac/guacamole/client.h

@@ -565,6 +565,22 @@ int guac_client_get_processing_lag(guac_client* client);
  */
 int guac_client_owner_send_required(guac_client* client, const char** required);
 
+/**
+ * Sends the "uri" instruction to the given guac_client so that the remote
+ * client can process the URI, if the client supports it and has a handler
+ * configured for the URI.
+ *
+ * @param client
+ *     The client to which to send the URI instruction.
+ * 
+ * @param uri
+ *     The URI to send to the remote client.
+ *
+ * @return
+ *     Zero on success, non-zero on failure.
+ */
+int guac_client_owner_send_uri(guac_client* client, const char* uri);
+
 /**
  * Streams the given connection parameter value over an argument value stream
  * ("argv" instruction), exposing the current value of the named connection
@@ -736,6 +752,8 @@ int guac_client_owner_supports_required(guac_client* client);
  */
 int guac_client_supports_webp(guac_client* client);
 
+int guac_client_owner_supports_uri(guac_client* client);
+
 /**
  * The default Guacamole client layer, layer 0.
  */

src/libguac/guacamole/protocol-constants.h

@@ -38,7 +38,7 @@
  * This version is passed by the __guac_protocol_send_args() function from the
  * server to the client during the client/server handshake.
  */
-#define GUACAMOLE_PROTOCOL_VERSION "VERSION_1_3_0"
+#define GUACAMOLE_PROTOCOL_VERSION "VERSION_1_6_0"
 
 /**
  * The maximum number of bytes that should be sent in any one blob instruction

src/libguac/guacamole/protocol-types.h

@@ -306,7 +306,13 @@ typedef enum guac_protocol_version {
      * allowing connections in guacd to request information from the client and
      * await a response.
      */
-    GUAC_PROTOCOL_VERSION_1_3_0 = 0x010300
+    GUAC_PROTOCOL_VERSION_1_3_0 = 0x010300,
+
+    /**
+     * Protocol version 1.6.0, which supports the "uri" instruction, allowing
+     * remote systems to send 
+     */
+    GUAC_PROTOCOL_VERSION_1_6_0 = 0x010600
 
 } guac_protocol_version;
 

src/libguac/guacamole/protocol.h

@@ -1037,6 +1037,21 @@ int guac_protocol_send_shade(guac_socket* socket, const guac_layer* layer,
 int guac_protocol_send_size(guac_socket* socket, const guac_layer* layer,
         int w, int h);
 
+/**
+ * Send the uri instruction over the given guac_socket connection,
+ * providing a URI that the client should then process locally.
+ * 
+ * @param socket
+ *     The guac_socket connection to which to send the uri instruction.
+ *
+ * @param uri
+ *     The URI that should be sent to the client.
+ *
+ * @return
+ *     Zero on success, non-zero on error.
+ */
+int guac_protocol_send_uri(guac_socket* socket, const char* uri);
+
 /* TEXT INSTRUCTIONS */
 
 /**

src/libguac/guacamole/user.h

@@ -861,6 +861,17 @@ void guac_user_stream_webp(guac_user* user, guac_socket* socket,
  */
 int guac_user_supports_required(guac_user* user);
 
+/**
+ * Returns non-zero if the user supports the "uri" instruction.
+ *
+ * @param user
+ *     The Guacamole user to check for support of the "uri" instruction.
+ *
+ * @return
+ *     Non-zero if the user supports the "uri" instruction, otherwise zero.
+ */
+int guac_user_supports_uri(guac_user* user);
+
 /**
  * Returns whether the given user supports WebP. If the user does not
  * support WebP, or the server cannot encode WebP images, zero is returned.

src/libguac/protocol.c

@@ -65,6 +65,7 @@ guac_protocol_version_mapping guac_protocol_version_table[] = {
     { GUAC_PROTOCOL_VERSION_1_0_0,   "VERSION_1_0_0" },
     { GUAC_PROTOCOL_VERSION_1_1_0,   "VERSION_1_1_0" },
     { GUAC_PROTOCOL_VERSION_1_3_0,   "VERSION_1_3_0" },
+    { GUAC_PROTOCOL_VERSION_1_6_0,   "VERSION_1_6_0" },
     { GUAC_PROTOCOL_VERSION_UNKNOWN, NULL }
 };
 
@@ -1274,6 +1275,21 @@ int guac_protocol_send_undefine(guac_socket* socket,
 
 }
 
+int guac_protocol_send_uri(guac_socket* socket, const char* uri) {
+
+    int ret_val;
+    
+    guac_socket_instruction_begin(socket);
+    ret_val =
+           guac_socket_write_string(socket, "3.uri,")
+        || __guac_socket_write_length_string(socket, uri)
+        || guac_socket_write_string(socket, ";");
+
+    guac_socket_instruction_end(socket);
+    return ret_val;
+
+}
+
 int guac_protocol_send_video(guac_socket* socket, const guac_stream* stream,
         const guac_layer* layer, const char* mimetype) {
 

src/libguac/user.c

@@ -325,6 +325,14 @@ int guac_user_supports_required(guac_user* user) {
     
 }
 
+int guac_user_supports_uri(guac_user* user) {
+    
+    if (user == NULL)
+        return 0;
+
+    return (user->info.protocol_version >= GUAC_PROTOCOL_VERSION_1_6_0);
+}
+
 int guac_user_supports_webp(guac_user* user) {
 
 #ifdef ENABLE_WEBP

src/protocols/rdp/Makefile.am

@@ -59,6 +59,7 @@ libguac_client_rdp_la_SOURCES =                  \
     channels/rdpei.c                             \
     channels/rdpsnd/rdpsnd-messages.c            \
     channels/rdpsnd/rdpsnd.c                     \
+    channels/rdpuri.c                            \
     client.c                                     \
     color.c                                      \
     decompose.c                                  \
@@ -105,6 +106,7 @@ noinst_HEADERS =                                 \
     channels/rdpei.h                             \
     channels/rdpsnd/rdpsnd-messages.h            \
     channels/rdpsnd/rdpsnd.h                     \
+    channels/rdpuri.h                            \
     client.h                                     \
     color.h                                      \
     decompose.h                                  \

src/protocols/rdp/channels/rdpuri.c

@@ -0,0 +1,133 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include "channels/rdpuri.h"
+#include "client.h"
+#include "config.h"
+#include "plugins/channels.h"
+#include "rdp.h"
+#include "unicode.h"
+
+#include <freerdp/client/cliprdr.h>
+#include <freerdp/event.h>
+#include <freerdp/freerdp.h>
+#include <guacamole/client.h>
+#include <guacamole/stream.h>
+#include <guacamole/user.h>
+#include <winpr/wtsapi.h>
+#include <winpr/wtypes.h>
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+/**
+ * Callback which associates handlers specific to Guacamole with the
+ * CliprdrClientContext instance allocated by FreeRDP to deal with received
+ * CLIPRDR (clipboard redirection) messages.
+ *
+ * This function is called whenever a channel connects via the PubSub event
+ * system within FreeRDP, but only has any effect if the connected channel is
+ * the CLIPRDR channel. This specific callback is registered with the PubSub
+ * system of the relevant rdpContext when guac_rdp_clipboard_load_plugin() is
+ * called.
+ *
+ * @param context
+ *     The rdpContext associated with the active RDP session.
+ *
+ * @param e
+ *     Event-specific arguments, mainly the name of the channel, and a
+ *     reference to the associated plugin loaded for that channel by FreeRDP.
+ */
+static void guac_rdpuri_channel_connected(guac_rdp_common_svc* svc) {
+
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "RDPURI (URI redirection) "
+            "channel connected.");
+
+}
+
+/**
+ * Callback which disassociates Guacamole from the CliprdrClientContext
+ * instance that was originally allocated by FreeRDP and is about to be
+ * deallocated.
+ *
+ * This function is called whenever a channel disconnects via the PubSub event
+ * system within FreeRDP, but only has any effect if the disconnected channel
+ * is the CLIPRDR channel. This specific callback is registered with the PubSub
+ * system of the relevant rdpContext when guac_rdp_clipboard_load_plugin() is
+ * called.
+ *
+ * @param context
+ *     The rdpContext associated with the active RDP session.
+ *
+ * @param e
+ *     Event-specific arguments, mainly the name of the channel, and a
+ *     reference to the associated plugin loaded for that channel by FreeRDP.
+ */
+static void guac_rdpuri_channel_disconnected(guac_rdp_common_svc* svc) {
+
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "RDPURI (URI redirection) "
+            "channel disconnected.");
+
+}
+
+static void guac_rdpuri_channel_receive(guac_rdp_common_svc* svc, wStream* input_stream) {
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "RDPURI (URI redirection) "
+            "channel received data.");
+
+    // int len = Stream_Length(input_stream);
+    int len = Stream_Length(input_stream);
+
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "Received URI %d in length.", len);
+
+    if (len < 1) {
+        guac_client_log(svc->client, GUAC_LOG_WARNING, "Received URI data is too "
+            "small.");
+        return;
+    }
+
+    /* Convert input stream to UTF8 and send it to the client. */
+    char uri[len/2];
+    guac_rdp_utf16_to_utf8(Stream_Pointer(input_stream), len/2 - 1, uri, sizeof(uri));
+    guac_client_log(svc->client, GUAC_LOG_DEBUG, "Received URI from server: %s", uri);
+    guac_client_owner_send_uri(svc->client, uri);
+
+}
+
+void guac_rdpuri_load_plugin(rdpContext* context) {
+
+    guac_client* client = ((rdp_freerdp_context*) context)->client;
+
+    /* Attempt to load FreeRDP support for the CLIPRDR channel */
+    if (guac_rdp_common_svc_load_plugin(context, "rdpuri", 0, 
+                guac_rdpuri_channel_connected, guac_rdpuri_channel_receive,
+                guac_rdpuri_channel_disconnected)) {
+        guac_client_log(client, GUAC_LOG_WARNING,
+                "Support for the RDPURI channel (URI redirection) "
+                "could not be loaded. This support normally takes the form of "
+                "a plugin which is built into FreeRDP. Lacking this support, "
+                "URI redirection will not work.");
+        return;
+    }
+
+    guac_client_log(client, GUAC_LOG_DEBUG, "Support for RDPURI "
+            "(URI redirection) registered. Awaiting channel "
+            "connection.");
+
+}

src/protocols/rdp/channels/rdpuri.h

@@ -0,0 +1,45 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#ifndef GUAC_RDP_CHANNELS_RDPURI_H
+#define GUAC_RDP_CHANNELS_RDPURI_H
+
+#include "channels/common-svc.h"
+
+#include <freerdp/freerdp.h>
+#include <guacamole/client.h>
+#include <guacamole/user.h>
+#include <winpr/stream.h>
+#include <winpr/wtypes.h>
+
+/**
+ * Initializes clipboard support for RDP and handling of the RDPURI channel.
+ * If failures occur, messages noting the specifics of those failures will be
+ * logged, and the RDP side of URI redirection will not be functional.
+ *
+ * This MUST be called within the PreConnect callback of the freerdp instance
+ * for RDPURI support to be loaded.
+ *
+ * @param context
+ *     The rdpContext associated with the FreeRDP side of the RDP connection.
+ */
+void guac_rdpuri_load_plugin(rdpContext* context);
+
+#endif
+

src/protocols/rdp/rdp.c

@@ -29,6 +29,7 @@
 #include "channels/rdpdr/rdpdr.h"
 #include "channels/rdpei.h"
 #include "channels/rdpsnd/rdpsnd.h"
+#include "channels/rdpuri.h"
 #include "client.h"
 #include "color.h"
 #include "common/cursor.h"
@@ -123,6 +124,9 @@ BOOL rdp_freerdp_pre_connect(freerdp* instance) {
         guac_rdpsnd_load_plugin(context);
     }
 
+    /* Load rdpuri service */
+    guac_rdpuri_load_plugin(context);
+
     /* Load RAIL plugin if RemoteApp in use */
     if (settings->remote_app != NULL)
         guac_rdp_rail_load_plugin(context);