[PATCH v2] Add an option to disable client initiated resizes

[Hardening]

This patch adds an option to the RDP compositor to disable
desktop resizes initiated by RDP peer. The current behaviour
is that if an incoming RDP peer suggests a resolution that is
not the current one, a mode_switch() is done and the desktop is
resized to that new resolution. This new flag allows to disable
that behaviour, and in that case the RDP peer will be instructed
to resize to the size of the desktop.
---
 src/compositor-rdp.c | 44 ++++++++++++++++++++++++++++++++------------
 src/compositor.c     |  1 +
 2 files changed, 33 insertions(+), 12 deletions(-)

diff --git a/src/compositor-rdp.c b/src/compositor-rdp.c
index 909e225..4c5ae36 100644
--- a/src/compositor-rdp.c
+++ b/src/compositor-rdp.c
@@ -60,6 +60,7 @@ struct rdp_compositor_config {
 	char *server_cert;
 	char *server_key;
 	int env_socket;
+	int no_clients_resize;
 };
 
 struct rdp_output;
@@ -75,6 +76,7 @@ struct rdp_compositor {
 	char *server_key;
 	char *rdp_key;
 	int tls_enabled;
+	int no_clients_resize;
 };
 
 enum peer_item_flags {
@@ -122,6 +124,7 @@ rdp_compositor_config_init(struct rdp_compositor_config *config) {
 	config->server_cert = NULL;
 	config->server_key = NULL;
 	config->env_socket = 0;
+	config->no_clients_resize = 0;
 }
 
 static void
@@ -412,7 +415,8 @@ rdp_switch_mode(struct weston_output *output, struct weston_mode *target_mode) {
 
 	wl_list_for_each(rdpPeer, &rdpOutput->peers, link) {
 		settings = rdpPeer->peer->settings;
-		if (settings->DesktopWidth == target_mode->width && settings->DesktopHeight == target_mode->height)
+		if (settings->DesktopWidth == (UINT32)target_mode->width &&
+				settings->DesktopHeight == (UINT32)target_mode->height)
 			continue;
 
 		if (!settings->DesktopResize) {
@@ -672,18 +676,32 @@ xf_peer_post_connect(freerdp_peer* client)
 	if (output->base.width != (int)settings->DesktopWidth ||
 			output->base.height != (int)settings->DesktopHeight)
 	{
-		struct weston_mode new_mode;
-		struct weston_mode *target_mode;
-		new_mode.width = (int)settings->DesktopWidth;
-		new_mode.height = (int)settings->DesktopHeight;
-		target_mode = ensure_matching_mode(&output->base, &new_mode);
-		if (!target_mode) {
-			weston_log("client mode not found\n");
-			return FALSE;
+		if (c->no_clients_resize) {
+			/* RDP peers don't dictate their resolution to weston */
+			if (!settings->DesktopResize) {
+				/* peer does not support desktop resize */
+				weston_log("%s: client doesn't support resizing, closing connection\n", __FUNCTION__);
+				return FALSE;
+			} else {
+				settings->DesktopWidth = output->base.width;
+				settings->DesktopHeight = output->base.height;
+				client->update->DesktopResize(client->context);
+			}
+		} else {
+			/* ask weston to adjust size */
+			struct weston_mode new_mode;
+			struct weston_mode *target_mode;
+			new_mode.width = (int)settings->DesktopWidth;
+			new_mode.height = (int)settings->DesktopHeight;
+			target_mode = ensure_matching_mode(&output->base, &new_mode);
+			if (!target_mode) {
+				weston_log("client mode not found\n");
+				return FALSE;
+			}
+			weston_output_switch_mode(&output->base, target_mode, 1, WESTON_MODE_SWITCH_SET_NATIVE);
+			output->base.width = new_mode.width;
+			output->base.height = new_mode.height;
 		}
-		weston_output_switch_mode(&output->base, target_mode, 1, WESTON_MODE_SWITCH_SET_NATIVE);
-		output->base.width = new_mode.width;
-		output->base.height = new_mode.height;
 	}
 
 	weston_log("kbd_layout:%x kbd_type:%x kbd_subType:%x kbd_functionKeys:%x\n",
@@ -988,6 +1006,7 @@ rdp_compositor_create(struct wl_display *display,
 	c->base.destroy = rdp_destroy;
 	c->base.restore = rdp_restore;
 	c->rdp_key = config->rdp_key ? strdup(config->rdp_key) : NULL;
+	c->no_clients_resize = config->no_clients_resize;
 
 	/* activate TLS only if certificate/key are available */
 	if (config->server_cert && config->server_key) {
@@ -1067,6 +1086,7 @@ backend_init(struct wl_display *display, int *argc, char *argv[],
 		{ WESTON_OPTION_INTEGER, "height", 0, &config.height },
 		{ WESTON_OPTION_STRING,  "address", 0, &config.bind_address },
 		{ WESTON_OPTION_INTEGER, "port", 0, &config.port },
+		{ WESTON_OPTION_BOOLEAN, "no-clients-resize", 0, &config.no_clients_resize },
 		{ WESTON_OPTION_STRING,  "rdp4-key", 0, &config.rdp_key },
 		{ WESTON_OPTION_STRING,  "rdp-tls-cert", 0, &config.server_cert },
 		{ WESTON_OPTION_STRING,  "rdp-tls-key", 0, &config.server_key }
diff --git a/src/compositor.c b/src/compositor.c
index 016f514..2ef07b2 100644
--- a/src/compositor.c
+++ b/src/compositor.c
@@ -4059,6 +4059,7 @@ usage(int error_code)
        "  --env-socket=SOCKET\tUse that socket as peer connection\n"
        "  --address=ADDR\tThe address to bind\n"
        "  --port=PORT\tThe port to listen on\n"
+       "  --no-clients-resize\tThe RDP peers will be forced to the size of the desktop\n"
        "  --rdp4-key=FILE\tThe file containing the key for RDP4 encryption\n"
        "  --rdp-tls-cert=FILE\tThe file containing the certificate for TLS encryption\n"
        "  --rdp-tls-key=FILE\tThe file containing the private key for TLS encryption\n"
-- 
1.8.1.2