media-session: add flatpak module

Add a module that gives full access to flatpak apps. Later we should
do something more restrictive.

src/examples/media-session/access-flatpak.c

@@ -0,0 +1,182 @@
+/* PipeWire
+ *
+ * Copyright © 2020 Wim Taymans
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <math.h>
+#include <time.h>
+
+#include "config.h"
+
+#include "pipewire/pipewire.h"
+
+#include "media-session.h"
+
+#define NAME		"access-flatpak"
+#define SESSION_KEY	"access-flatpak"
+
+struct impl {
+	struct sm_media_session *session;
+	struct spa_hook listener;
+
+	struct pw_context *context;
+
+	struct spa_list client_list;
+	int seq;
+};
+
+struct client {
+	struct sm_client *obj;
+
+	uint32_t id;
+	struct impl *impl;
+
+	struct spa_list link;		/**< link in impl client_list */
+
+	struct spa_hook listener;
+	unsigned int active:1;
+};
+
+static void object_update(void *data)
+{
+	struct client *client = data;
+	struct impl *impl = client->impl;
+	const char *str;
+
+	pw_log_debug(NAME" %p: client %p %08x", impl, client, client->obj->obj.changed);
+
+	if (client->obj->obj.avail & SM_CLIENT_CHANGE_MASK_INFO &&
+	    !client->active) {
+		struct pw_permission permissions[1];
+
+		if (client->obj->info == NULL || client->obj->info->props == NULL ||
+		    (str = spa_dict_lookup(client->obj->info->props, "pipewire.access")) == NULL ||
+		    strcmp(str, "flatpak") != 0)
+			return;
+
+		/* full access for now */
+		permissions[0] = PW_PERMISSION_INIT(PW_ID_ANY, PW_PERM_RWX);
+		pw_client_update_permissions(client->obj->obj.proxy,
+				1, permissions);
+		client->active = true;
+	}
+}
+
+static const struct sm_object_events object_events = {
+	SM_VERSION_OBJECT_EVENTS,
+	.update = object_update
+};
+
+static int
+handle_client(struct impl *impl, struct sm_object *object)
+{
+	struct client *client;
+
+	pw_log_debug(NAME" %p: client", impl);
+
+	client = sm_object_add_data(object, SESSION_KEY, sizeof(struct client));
+	client->obj = (struct sm_client*)object;
+	client->id = object->id;
+	client->impl = impl;
+	spa_list_append(&impl->client_list, &client->link);
+
+	client->obj->obj.mask |= SM_CLIENT_CHANGE_MASK_INFO;
+	sm_object_add_listener(&client->obj->obj, &client->listener, &object_events, client);
+
+	return 1;
+}
+
+static void destroy_client(struct impl *impl, struct client *client)
+{
+	spa_list_remove(&client->link);
+	sm_object_remove_data((struct sm_object*)client->obj, SESSION_KEY);
+}
+
+static void session_create(void *data, struct sm_object *object)
+{
+	struct impl *impl = data;
+	int res;
+
+	pw_log_debug(NAME " %p: create global '%d'", impl, object->id);
+
+	if (strcmp(object->type, PW_TYPE_INTERFACE_Client) == 0)
+		res = handle_client(impl, object);
+	else
+		res = 0;
+
+	if (res < 0)
+		pw_log_warn(NAME" %p: can't handle global %d", impl, object->id);
+}
+
+static void session_remove(void *data, struct sm_object *object)
+{
+	struct impl *impl = data;
+	pw_log_debug(NAME " %p: remove global '%d'", impl, object->id);
+
+	if (strcmp(object->type, PW_TYPE_INTERFACE_Client) == 0) {
+		struct client *client;
+
+		if ((client = sm_object_get_data(object, SESSION_KEY)) != NULL)
+			destroy_client(impl, client);
+	}
+}
+
+static void session_destroy(void *data)
+{
+	struct impl *impl = data;
+	struct client *client;
+
+	spa_list_consume(client, &impl->client_list, link)
+		destroy_client(impl, client);
+
+	spa_hook_remove(&impl->listener);
+	free(impl);
+}
+
+static const struct sm_media_session_events session_events = {
+	SM_VERSION_MEDIA_SESSION_EVENTS,
+	.create = session_create,
+	.remove = session_remove,
+	.destroy = session_destroy,
+};
+
+int sm_access_flatpak_start(struct sm_media_session *session)
+{
+	struct impl *impl;
+
+	impl = calloc(1, sizeof(struct impl));
+	if (impl == NULL)
+		return -errno;
+
+	impl->session = session;
+	impl->context = session->context;
+
+	spa_list_init(&impl->client_list);
+
+	sm_media_session_add_listener(impl->session,
+			&impl->listener,
+			&session_events, impl);
+	return 0;
+}

src/examples/media-session/media-session.c

@@ -66,6 +66,7 @@
 #define sm_media_session_emit_rescan(s,seq)		sm_media_session_emit(s, rescan, 0, seq)
 #define sm_media_session_emit_destroy(s)		sm_media_session_emit(s, destroy, 0)
 
+int sm_access_flatpak_start(struct sm_media_session *sess);
 int sm_metadata_start(struct sm_media_session *sess);
 int sm_alsa_midi_start(struct sm_media_session *sess);
 int sm_v4l2_monitor_start(struct sm_media_session *sess);
@@ -1767,7 +1768,7 @@ static void do_quit(void *data, int signal_number)
 	pw_main_loop_quit(impl->loop);
 }
 
-#define DEFAULT_ENABLED		"alsa-pcm,alsa-seq,v4l2,bluez5,metadata,suspend-node,policy-node"
+#define DEFAULT_ENABLED		"flatpak,alsa-pcm,alsa-seq,v4l2,bluez5,metadata,suspend-node,policy-node"
 #define DEFAULT_DISABLED	""
 
 static const struct {
@@ -1777,6 +1778,7 @@ static const struct {
 	const char *props;
 
 } modules[] = {
+	{ "flatpak", "manage flatpak access", sm_access_flatpak_start, NULL },
 	{ "metadata", "export metadata API", sm_metadata_start, NULL },
 	{ "alsa-seq", "alsa seq midi support", sm_alsa_midi_start, NULL },
 	{ "alsa-pcm", "alsa pcm udev detection", sm_alsa_monitor_start, NULL },

src/examples/meson.build

@@ -67,6 +67,7 @@ executable('export-spa-device',
 
 if alsa_dep.found()
   executable('pipewire-media-session',
+    'media-session/access-flatpak.c',
     'media-session/alsa-midi.c',
     'media-session/alsa-monitor.c',
     'media-session/alsa-endpoint.c',