rdp: add virtual channel support

RDP exposes certain features (audio, clipboard, RAIL) through a facility
called "virtual channels". Set up the communications framework for using
these.

Co-authored-by: Steve Pronovost <spronovo@microsoft.com>
Co-authored-by: Brenton DeGeer <brdegeer@microsoft.com>
Signed-off-by: Hideyuki Nagase <hideyukn@microsoft.com>
Signed-off-by: Steve Pronovost <spronovo@microsoft.com>
Signed-off-by: Brenton DeGeer <brdegeer@microsoft.com>

libweston/backend-rdp/meson.build

@@ -13,6 +13,11 @@ if not dep_frdp.found()
 	error('RDP-backend requires freerdp >= 2.2.0 which was not found. Or, you can use \'-Dbackend-rdp=false\'.')
 endif
 
+dep_frdp_server = dependency('freerdp-server2', version: '>= 2.2.0', required: false)
+if not dep_frdp_server.found()
+	error('RDP-backend requires freerdp-server2 >= 2.2.0 which was not found. Or, you can use \'-Dbackend-rdp=false\'.')
+endif
+
 dep_wpr = dependency('winpr2', version: '>= 2.2.0', required: false)
 if not dep_wpr.found()
 	error('RDP-backend requires winpr >= 2.2.0 which was not found. Or, you can use \'-Dbackend-rdp=false\'.')
@@ -21,6 +26,7 @@ endif
 deps_rdp = [
 	dep_libweston_private,
 	dep_frdp,
+	dep_frdp_server,
 	dep_wpr,
 ]
 srcs_rdp = [

libweston/backend-rdp/rdp.c

@@ -51,6 +51,8 @@
 #define KBD_HEBREW_STANDARD 0x2040D
 #endif
 
+extern PWtsApiFunctionTable FreeRDP_InitWtsApi(void);
+
 static void
 rdp_peer_refresh_rfx(pixman_region32_t *damage, pixman_image_t *image, freerdp_peer *peer)
 {
@@ -656,16 +658,20 @@ out_error_stream:
 static void
 rdp_peer_context_free(freerdp_peer* client, RdpPeerContext* context)
 {
-	int i;
+	unsigned i;
 	if (!context)
 		return;
 
 	wl_list_remove(&context->item.link);
-	for (i = 0; i < MAX_FREERDP_FDS; i++) {
+
+	for (i = 0; i < ARRAY_LENGTH(context->events); i++) {
 		if (context->events[i])
 			wl_event_source_remove(context->events[i]);
 	}
 
+	if (context->vcm)
+		WTSCloseServer(context->vcm);
+
 	rdp_destroy_dispatch_task_event_source(context);
 
 	if (context->item.flags & RDP_PEER_ACTIVATED) {
@@ -686,11 +692,21 @@ static int
 rdp_client_activity(int fd, uint32_t mask, void *data)
 {
 	freerdp_peer* client = (freerdp_peer *)data;
+	RdpPeerContext *peerCtx = (RdpPeerContext *)client->context;
 
 	if (!client->CheckFileDescriptor(client)) {
 		weston_log("unable to checkDescriptor for %p\n", client);
 		goto out_clean;
 	}
+
+	if (peerCtx && peerCtx->vcm)
+	{
+		if (!WTSVirtualChannelManagerCheckFileDescriptor(peerCtx->vcm)) {
+			weston_log("failed to check FreeRDP WTS VC file descriptor for %p\n", client);
+			goto out_clean;
+		}
+	}
+
 	return 0;
 
 out_clean:
@@ -1394,7 +1410,7 @@ static int
 rdp_peer_init(freerdp_peer *client, struct rdp_backend *b)
 {
 	int rcount = 0;
-	void *rfds[MAX_FREERDP_FDS];
+	void *rfds[MAX_FREERDP_FDS + 1]; /* +1 for WTSVirtualChannelManagerGetFileDescriptor. */
 	int i, fd;
 	struct wl_event_loop *loop;
 	rdpSettings	*settings;
@@ -1455,6 +1471,15 @@ rdp_peer_init(freerdp_peer *client, struct rdp_backend *b)
 		goto error_initialize;
 	}
 
+	PWtsApiFunctionTable fn = FreeRDP_InitWtsApi();
+	WTSRegisterWtsApiFunctionTable(fn);
+	peerCtx->vcm = WTSOpenServerA((LPSTR)peerCtx);
+	if (peerCtx->vcm) {
+		WTSVirtualChannelManagerGetFileDescriptor(peerCtx->vcm, rfds, &rcount);
+	} else {
+		weston_log("WTSOpenServer is failed! continue without virtual channel.\n");
+	}
+
 	loop = wl_display_get_event_loop(b->compositor->wl_display);
 	for (i = 0; i < rcount; i++) {
 		fd = (int)(long)(rfds[i]);
@@ -1462,16 +1487,28 @@ rdp_peer_init(freerdp_peer *client, struct rdp_backend *b)
 		peerCtx->events[i] = wl_event_loop_add_fd(loop, fd, WL_EVENT_READABLE,
 				rdp_client_activity, client);
 	}
-	for ( ; i < MAX_FREERDP_FDS; i++)
+	for ( ; i < (int)ARRAY_LENGTH(peerCtx->events); i++)
 		peerCtx->events[i] = 0;
 
 	wl_list_insert(&b->output->peers, &peerCtx->item.link);
 
 	if (!rdp_initialize_dispatch_task_event_source(peerCtx))
-		goto error_initialize;
+		goto error_dispatch_initialize;
 
 	return 0;
 
+error_dispatch_initialize:
+	for (i = 0; i < (int)ARRAY_LENGTH(peerCtx->events); i++) {
+		if (peerCtx->events[i]) {
+			wl_event_source_remove(peerCtx->events[i]);
+			peerCtx->events[i] = NULL;
+		}
+	}
+	if (peerCtx->vcm) {
+		WTSCloseServer(peerCtx->vcm);
+		peerCtx->vcm = NULL;
+	}
+
 error_initialize:
 	client->Close(client);
 	return -1;

libweston/backend-rdp/rdp.h

@@ -37,6 +37,7 @@
 #include <freerdp/codec/rfx.h>
 #include <freerdp/codec/nsc.h>
 #include <freerdp/locale/keyboard.h>
+#include <freerdp/channels/wtsvc.h>
 
 #include <libweston/libweston.h>
 #include <libweston/backend-rdp.h>
@@ -118,7 +119,7 @@ struct rdp_peer_context {
 	rdpContext _p;
 
 	struct rdp_backend *rdpBackend;
-	struct wl_event_source *events[MAX_FREERDP_FDS];
+	struct wl_event_source *events[MAX_FREERDP_FDS + 1]; /* +1 for WTSVirtualChannelManagerGetFileDescriptor */
 	RFX_CONTEXT *rfx_context;
 	wStream *encode_stream;
 	RFX_RECT *rfx_rects;
@@ -133,6 +134,8 @@ struct rdp_peer_context {
 	int horizontalAccumWheelRotationPrecise;
 	int horizontalAccumWheelRotationDiscrete;
 
+	HANDLE vcm;
+
 	/* list of outstanding event_source sent from FreeRDP thread to display loop.*/
 	int loop_task_event_source_fd;
 	struct wl_event_source *loop_task_event_source;