GUACAMOLE-1204: Add RDP support for multi-touch events via RDPEI channel.

src/protocols/rdp/Makefile.am

@@ -56,6 +56,7 @@ libguac_client_rdp_la_SOURCES =                  \
     channels/rdpdr/rdpdr-messages.c              \
     channels/rdpdr/rdpdr-printer.c               \
     channels/rdpdr/rdpdr.c                       \
+    channels/rdpei.c                             \
     channels/rdpsnd/rdpsnd-messages.c            \
     channels/rdpsnd/rdpsnd.c                     \
     client.c                                     \
@@ -101,6 +102,7 @@ noinst_HEADERS =                                 \
     channels/rdpdr/rdpdr-messages.h              \
     channels/rdpdr/rdpdr-printer.h               \
     channels/rdpdr/rdpdr.h                       \
+    channels/rdpei.h                             \
     channels/rdpsnd/rdpsnd-messages.h            \
     channels/rdpsnd/rdpsnd.h                     \
     client.h                                     \

src/protocols/rdp/channels/rdpei.c

@@ -0,0 +1,170 @@
+/*
+ * 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/rdpei.h"
+#include "common/surface.h"
+#include "plugins/channels.h"
+#include "rdp.h"
+#include "settings.h"
+
+#include <freerdp/client/rdpei.h>
+#include <freerdp/freerdp.h>
+#include <freerdp/event.h>
+#include <guacamole/client.h>
+#include <guacamole/timestamp.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+guac_rdp_rdpei* guac_rdp_rdpei_alloc() {
+
+    guac_rdp_rdpei* rdpei = malloc(sizeof(guac_rdp_rdpei));
+
+    /* Not yet connected */
+    rdpei->rdpei = NULL;
+
+    /* No active touches */
+    for (int i = 0; i < GUAC_RDP_RDPEI_MAX_TOUCHES; i++)
+        rdpei->touch[i].active = 0;
+
+    return rdpei;
+
+}
+
+void guac_rdp_rdpei_free(guac_rdp_rdpei* rdpei) {
+    free(rdpei);
+}
+
+/**
+ * Callback which associates handlers specific to Guacamole with the
+ * RdpeiClientContext instance allocated by FreeRDP to deal with received
+ * RDPEI (multi-touch input) 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 RDPEI channel. This specific callback is registered with the
+ * PubSub system of the relevant rdpContext when guac_rdp_rdpei_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_rdp_rdpei_channel_connected(rdpContext* context,
+        ChannelConnectedEventArgs* e) {
+
+    guac_client* client = ((rdp_freerdp_context*) context)->client;
+    guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
+    guac_rdp_rdpei* guac_rdpei = rdp_client->rdpei;
+
+    /* Ignore connection event if it's not for the RDPEI channel */
+    if (strcmp(e->name, RDPEI_DVC_CHANNEL_NAME) != 0)
+        return;
+
+    /* Store reference to the RDPEI plugin once it's connected */
+    RdpeiClientContext* rdpei = (RdpeiClientContext*) e->pInterface;
+    guac_rdpei->rdpei = rdpei;
+
+    /* Declare level of multi-touch support */
+    guac_common_surface_set_multitouch(rdp_client->display->default_surface,
+            GUAC_RDP_RDPEI_MAX_TOUCHES);
+
+    guac_client_log(client, GUAC_LOG_DEBUG, "RDPEI channel will be used for "
+            "multi-touch support.");
+
+}
+
+void guac_rdp_rdpei_load_plugin(rdpContext* context) {
+
+    /* Subscribe to and handle channel connected events */
+    PubSub_SubscribeChannelConnected(context->pubSub,
+        (pChannelConnectedEventHandler) guac_rdp_rdpei_channel_connected);
+
+    /* Add "rdpei" channel */
+    guac_freerdp_dynamic_channel_collection_add(context->settings, "rdpei", NULL);
+
+}
+
+int guac_rdp_rdpei_touch_update(guac_rdp_rdpei* rdpei, int id, int x, int y,
+        double force) {
+
+    int contact_id; /* Ignored */
+
+    /* Track touches only if channel is connected */
+    RdpeiClientContext* context = rdpei->rdpei;
+    if (context == NULL)
+        return 1;
+
+    /* Locate active touch having provided ID */
+    guac_rdp_rdpei_touch* touch = NULL;
+    for (int i = 0; i < GUAC_RDP_RDPEI_MAX_TOUCHES; i++) {
+        if (rdpei->touch[i].active && rdpei->touch[i].id == id) {
+            touch = &rdpei->touch[i];
+            break;
+        }
+    }
+
+    /* If no such touch exists, add it */
+    if (touch == NULL) {
+        for (int i = 0; i < GUAC_RDP_RDPEI_MAX_TOUCHES; i++) {
+            if (!rdpei->touch[i].active) {
+                touch = &rdpei->touch[i];
+                touch->id = id;
+                break;
+            }
+        }
+    }
+
+    /* If the touch couldn't be added, we're already at maximum touch capacity.
+     * Drop the event. */
+    if (touch == NULL)
+        return 1;
+
+    /* Signal the end of an established touch if touch force has become zero
+     * (this should be a safe comparison, as zero has an exact representation
+     * in floating point, and the client side will use an exact value to
+     * represent the absence of a touch) */
+    if (force == 0.0) {
+
+        /* Ignore release of touches that we aren't tracking */
+        if (!touch->active)
+            return 1;
+
+        context->TouchEnd(context, id, x, y, &contact_id);
+        touch->active = 0;
+
+    }
+
+    /* Signal the start of a touch if this is the first we've seen it */
+    else if (!touch->active) {
+        context->TouchBegin(context, id, x, y, &contact_id);
+        touch->active = 1;
+    }
+
+    /* Established touches need only be updated */
+    else
+        context->TouchUpdate(context, id, x, y, &contact_id);
+
+    return 0;
+
+}
+

src/protocols/rdp/channels/rdpei.h

@@ -0,0 +1,154 @@
+/*
+ * 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_RDPEI_H
+#define GUAC_RDP_CHANNELS_RDPEI_H
+
+#include "settings.h"
+
+#include <freerdp/client/rdpei.h>
+#include <freerdp/freerdp.h>
+#include <guacamole/client.h>
+#include <guacamole/timestamp.h>
+
+/**
+ * The maximum number of simultaneously-tracked touches.
+ */
+#define GUAC_RDP_RDPEI_MAX_TOUCHES 10
+
+/**
+ * A single, tracked touch contact.
+ */
+typedef struct guac_rdp_rdpei_touch {
+
+    /**
+     * Whether this touch is active (1) or inactive (0). An active touch is
+     * being tracked, while an inactive touch is simple an empty space awaiting
+     * use by some future touch event.
+     */
+    int active;
+
+    /**
+     * The unique ID representing this touch contact.
+     */
+    int id;
+
+    /**
+     * The X-coordinate of this touch, in pixels.
+     */
+    int x;
+
+    /**
+     * The Y-coordinate of this touch, in pixels.
+     */
+    int y;
+
+} guac_rdp_rdpei_touch;
+
+/**
+ * Multi-touch input module.
+ */
+typedef struct guac_rdp_rdpei {
+
+    /**
+     * RDPEI control interface.
+     */
+    RdpeiClientContext* rdpei;
+
+    /**
+     * All currently-tracked touches.
+     */
+    guac_rdp_rdpei_touch touch[GUAC_RDP_RDPEI_MAX_TOUCHES];
+
+} guac_rdp_rdpei;
+
+/**
+ * Allocates a new RDPEI module, which will ultimately control the RDPEI
+ * channel once connected. The RDPEI channel allows multi-touch input
+ * events to be sent to the RDP server.
+ *
+ * @return
+ *     A newly-allocated RDPEI module.
+ */
+guac_rdp_rdpei* guac_rdp_rdpei_alloc();
+
+/**
+ * Frees the resources associated with support for the RDPEI channel. Only
+ * resources specific to Guacamole are freed. Resources specific to FreeRDP's
+ * handling of the RDPEI channel will be freed by FreeRDP. If no resources are
+ * currently allocated for RDPEI, this function has no effect.
+ *
+ * @param rdpei
+ *     The RDPEI module to free.
+ */
+void guac_rdp_rdpei_free(guac_rdp_rdpei* rdpei);
+
+/**
+ * Adds FreeRDP's "rdpei" plugin to the list of dynamic virtual channel plugins
+ * to be loaded by FreeRDP's "drdynvc" plugin. The context of the plugin will
+ * automatically be assicated with the guac_rdp_rdpei instance pointed to by the
+ * current guac_rdp_client. The plugin will only be loaded once the "drdynvc"
+ * plugin is loaded. The "rdpei" plugin ultimately adds support for multi-touch
+ * input via the RDPEI channel.
+ *
+ * If failures occur, messages noting the specifics of those failures will be
+ * logged, and the RDP side of multi-touch support will not be functional.
+ *
+ * This MUST be called within the PreConnect callback of the freerdp instance
+ * for multi-touch support to be loaded.
+ *
+ * @param context
+ *     The rdpContext associated with the active RDP session.
+ */
+void guac_rdp_rdpei_load_plugin(rdpContext* context);
+
+/**
+ * Reports to the RDP server that the status of a single touch contact has
+ * changed. Depending on the amount of force associated with the touch and
+ * whether the touch has been encountered before, this will result a new touch
+ * contact, updates to an existing contact, or removal of an existing contact.
+ * If the RDPEI channel has not yet been connected, touches will be ignored and
+ * dropped until it is connected.
+ *
+ * @param rdpei
+ *     The RDPEI module associated with the RDP session.
+ *
+ * @param id
+ *     An arbitrary integer ID unique to the touch being updated.
+ *
+ * @param x
+ *     The X-coordinate of the touch, in pixels.
+ *
+ * @param y
+ *     The Y-coordinate of the touch, in pixels.
+ *
+ * @param force
+ *     The amount of force currently being exerted on the device by the touch
+ *     contact in question, where 1.0 is the maximum amount of force
+ *     representable and 0.0 indicates the contact has been lifted.
+ *
+ * @return
+ *     Zero if the touch event was successfully processed, non-zero if the
+ *     touch event had to be dropped.
+ */
+int guac_rdp_rdpei_touch_update(guac_rdp_rdpei* rdpei, int id, int x, int y,
+        double force);
+
+#endif
+

src/protocols/rdp/client.c

@@ -147,6 +147,9 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
     /* Init display update module */
     rdp_client->disp = guac_rdp_disp_alloc();
 
+    /* Init multi-touch support module (RDPEI) */
+    rdp_client->rdpei = guac_rdp_rdpei_alloc();
+
     /* Redirect FreeRDP log messages to guac_client_log() */
     guac_rdp_redirect_wlog(client);
 
@@ -187,6 +190,9 @@ int guac_rdp_client_free_handler(guac_client* client) {
     /* Free display update module */
     guac_rdp_disp_free(rdp_client->disp);
 
+    /* Free multi-touch support module (RDPEI) */
+    guac_rdp_rdpei_free(rdp_client->rdpei);
+
     /* Clean up filesystem, if allocated */
     if (rdp_client->filesystem != NULL)
         guac_rdp_fs_free(rdp_client->filesystem);

src/protocols/rdp/input.c

@@ -18,6 +18,7 @@
  */
 
 #include "channels/disp.h"
+#include "channels/rdpei.h"
 #include "common/cursor.h"
 #include "common/display.h"
 #include "common/recording.h"
@@ -122,6 +123,28 @@ complete:
     return 0;
 }
 
+int guac_rdp_user_touch_handler(guac_user* user, int id, int x, int y,
+        int x_radius, int y_radius, double angle, double force) {
+
+    guac_client* client = user->client;
+    guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
+
+    pthread_rwlock_rdlock(&(rdp_client->lock));
+
+    /* Skip if not yet connected */
+    freerdp* rdp_inst = rdp_client->rdp_inst;
+    if (rdp_inst == NULL)
+        goto complete;
+
+    /* Forward touch event along RDPEI channel */
+    guac_rdp_rdpei_touch_update(rdp_client->rdpei, id, x, y, force);
+
+complete:
+    pthread_rwlock_unlock(&(rdp_client->lock));
+
+    return 0;
+}
+
 int guac_rdp_user_key_handler(guac_user* user, int keysym, int pressed) {
 
     guac_client* client = user->client;

src/protocols/rdp/input.h

@@ -27,6 +27,11 @@
  */
 guac_user_mouse_handler guac_rdp_user_mouse_handler;
 
+/**
+ * Handler for Guacamole user touch events.
+ */
+guac_user_touch_handler guac_rdp_user_touch_handler;
+
 /**
  * Handler for Guacamole user key events.
  */

src/protocols/rdp/rdp.c

@@ -27,6 +27,7 @@
 #include "channels/pipe-svc.h"
 #include "channels/rail.h"
 #include "channels/rdpdr/rdpdr.h"
+#include "channels/rdpei.h"
 #include "channels/rdpsnd/rdpsnd.h"
 #include "client.h"
 #include "color.h"
@@ -100,6 +101,10 @@ BOOL rdp_freerdp_pre_connect(freerdp* instance) {
     if (settings->resize_method == GUAC_RESIZE_DISPLAY_UPDATE)
         guac_rdp_disp_load_plugin(context);
 
+    /* Load "rdpei" plugin for multi-touch support */
+    if (settings->enable_touch)
+        guac_rdp_rdpei_load_plugin(context);
+
     /* Load "AUDIO_INPUT" plugin for audio input*/
     if (settings->enable_audio_input) {
         rdp_client->audio_input = guac_rdp_audio_buffer_alloc();

src/protocols/rdp/rdp.h

@@ -23,6 +23,7 @@
 #include "channels/audio-input/audio-buffer.h"
 #include "channels/cliprdr.h"
 #include "channels/disp.h"
+#include "channels/rdpei.h"
 #include "common/clipboard.h"
 #include "common/display.h"
 #include "common/list.h"
@@ -148,6 +149,11 @@ typedef struct guac_rdp_client {
      */
     guac_rdp_disp* disp;
 
+    /**
+     * Multi-touch support module (RDPEI).
+     */
+    guac_rdp_rdpei* rdpei;
+
     /**
      * List of all available static virtual channels.
      */

src/protocols/rdp/settings.c

@@ -108,6 +108,7 @@ const char* GUAC_RDP_CLIENT_ARGS[] = {
     "create-recording-path",
     "resize-method",
     "enable-audio-input",
+    "enable-touch",
     "read-only",
 
     "gateway-hostname",
@@ -527,6 +528,12 @@ enum RDP_ARGS_IDX {
      */
     IDX_ENABLE_AUDIO_INPUT,
 
+    /**
+     * "true" if multi-touch support should be enabled for the RDP connection,
+     * "false" or blank otherwise.
+     */
+    IDX_ENABLE_TOUCH,
+
     /**
      * "true" if this connection should be read-only (user input should be
      * dropped), "false" or blank otherwise.
@@ -1070,6 +1077,11 @@ guac_rdp_settings* guac_rdp_parse_args(guac_user* user,
         settings->resize_method = GUAC_RESIZE_NONE;
     }
 
+    /* Multi-touch input enable/disable */
+    settings->enable_touch =
+        guac_user_parse_args_boolean(user, GUAC_RDP_CLIENT_ARGS, argv,
+                IDX_ENABLE_TOUCH, 0);
+
     /* Audio input enable/disable */
     settings->enable_audio_input =
         guac_user_parse_args_boolean(user, GUAC_RDP_CLIENT_ARGS, argv,

src/protocols/rdp/settings.h

@@ -525,6 +525,11 @@ typedef struct guac_rdp_settings {
      */
     int enable_audio_input;
 
+    /**
+     * Whether multi-touch support is enabled.
+     */
+    int enable_touch;
+
     /**
      * The hostname of the remote desktop gateway that should be used as an
      * intermediary for the remote desktop connection. If no gateway should

src/protocols/rdp/user.c

@@ -105,6 +105,10 @@ int guac_rdp_user_join_handler(guac_user* user, int argc, char** argv) {
         user->mouse_handler = guac_rdp_user_mouse_handler;
         user->key_handler = guac_rdp_user_key_handler;
 
+        /* Multi-touch events */
+        if (settings->enable_touch)
+            user->touch_handler = guac_rdp_user_touch_handler;
+
         /* Inbound (client to server) clipboard transfer */
         if (!settings->disable_paste)
             user->clipboard_handler = guac_rdp_clipboard_handler;