protocol-native: improve security context properties

Remove the engine_name, use pipewire.sec.engine in the properties. Make
some constants for this.

Document some more properties.

src/modules/module-protocol-native/protocol-native.c

@@ -1890,7 +1890,7 @@ static int security_context_method_marshal_add_listener(void *object,
 	return 0;
 }
 
-static int security_context_marshal_create(void *object, const char *engine_name,
+static int security_context_marshal_create(void *object,
 		int listen_fd, int close_fd, const struct spa_dict *props)
 {
 	struct pw_proxy *proxy = object;
@@ -1901,7 +1901,6 @@ static int security_context_marshal_create(void *object, const char *engine_name
 
 	spa_pod_builder_push_struct(b, &f);
 	spa_pod_builder_add(b,
-			SPA_POD_String(engine_name),
 			SPA_POD_Fd(pw_protocol_native_add_proxy_fd(proxy, listen_fd)),
 			SPA_POD_Fd(pw_protocol_native_add_proxy_fd(proxy, close_fd)),
 			NULL);
@@ -1917,7 +1916,6 @@ static int security_context_demarshal_create(void *object, const struct pw_proto
 	struct spa_dict props = SPA_DICT_INIT(NULL, 0);
 	struct spa_pod_parser prs;
 	struct spa_pod_frame f[2];
-	char *engine_name;
 	int64_t listen_idx, close_idx;
 	int listen_fd, close_fd;
 
@@ -1925,7 +1923,6 @@ static int security_context_demarshal_create(void *object, const struct pw_proto
 	if (spa_pod_parser_push_struct(&prs, &f[0]) < 0)
 		return -EINVAL;
 	if (spa_pod_parser_get(&prs,
-				SPA_POD_String(&engine_name),
 				SPA_POD_Fd(&listen_idx),
 				SPA_POD_Fd(&close_idx),
 				NULL) < 0)
@@ -1936,7 +1933,7 @@ static int security_context_demarshal_create(void *object, const struct pw_proto
 	close_fd = pw_protocol_native_get_resource_fd(resource, close_idx);
 
 	return pw_resource_notify(resource, struct pw_security_context_methods, create, 0,
-			engine_name, listen_fd, close_fd, &props);
+			listen_fd, close_fd, &props);
 }
 
 

src/modules/module-protocol-native/security-context.c

@@ -28,7 +28,6 @@ struct resource_data {
 };
 
 static int security_context_create(void *object,
-			const char *engine_name,
 			int listen_fd,
 			int close_fd,
 			const struct spa_dict *props)
@@ -36,40 +35,25 @@ static int security_context_create(void *object,
 	struct resource_data *d = object;
 	struct impl *impl = d->impl;
 	struct pw_impl_client *client;
-	const struct pw_properties *cp;
+	const struct pw_properties *p;
-	struct pw_properties *p;
 	int res = 0;
 
-	if (engine_name == NULL)
-		goto invalid;
-
 	if ((client = impl->context->current_client) == NULL)
 		goto not_allowed;
 	if (client->protocol != impl->protocol)
 		goto not_allowed;
 
 	/* we can't make a nested security context */
-	cp = pw_impl_client_get_properties(client);
+	p = pw_impl_client_get_properties(client);
-	if (pw_properties_get(cp, PW_KEY_SEC_CONTEXT) != NULL)
+	if (pw_properties_get(p, PW_KEY_SEC_ENGINE) != NULL)
 		goto not_allowed;
 
-	p = props ? pw_properties_new_dict(props) : pw_properties_new(NULL, NULL);
-	if (p == NULL)
-		goto not_allowed;
-
-	pw_properties_set(p, PW_KEY_SEC_CONTEXT, engine_name);
-
 	if (pw_protocol_add_fd_server(impl->protocol, impl->context->core,
-			listen_fd, close_fd, &p->dict) == NULL)
+			listen_fd, close_fd, props) == NULL)
 		res = -errno;
 
-	pw_properties_free(p);
-
 	return res;
 
-invalid:
-	pw_log_warn("missing engine name");
-	return -EINVAL;
 not_allowed:
 	pw_log_warn("can't make security context");
 	return -EPERM;

src/pipewire/extensions/security-context.h

@@ -70,19 +70,25 @@ struct pw_security_context_methods {
 	 * After sending this request, closing listen_fd and close_fd remains the
 	 * only valid operation on them.
 	 *
-	 * \param engine_name a unique sandbox engine name.
 	 * \param listen_fd the fd to listen on for new connections
 	 * \param close_fd the fd used to stop listening
-	 * \param props extra (engine_name specific) properties. These will be
+	 * \param props extra properties. These will be copied on the client
-	 *       copied on the client that connects through this context.
+	 *     that connects through this context.
+	 *
+	 * Some properties to set:
+	 *
+	 *  - pipewire.sec.engine with the engine name.
+	 *  - pipewire.sec.app-id with the application id, this is an opaque,
+	 *      engine specific id for an application
+	 *  - pipewire.sec.instance-id with the instance id, this is an opaque,
+	 *      engine specific id for a running instance of an application.
 	 *
 	 * See https://gitlab.freedesktop.org/wayland/wayland-protocols/-/blob/main/staging/security-context/engines.md
-	 * For a list of engine_names and the properties to set.
+	 * For a list of engine names and the properties to set.
 	 *
 	 * This requires X and W permissions on the security_context.
 	 */
 	int (*create) (void *object,
-			const char *engine_name,
 			int listen_fd,
 			int close_fd,
 			const struct spa_dict *props);

src/pipewire/keys.h

@@ -39,7 +39,12 @@ extern "C" {
 #define PW_KEY_SEC_LABEL		"pipewire.sec.label"	/**< client security label, set by protocol*/
 
 #define PW_KEY_SEC_SOCKET		"pipewire.sec.socket"	/**< client socket name, set by protocol */
-#define PW_KEY_SEC_CONTEXT		"pipewire.sec.context"	/**< client secure context, set by protocol */
+
+#define PW_KEY_SEC_ENGINE		"pipewire.sec.engine"	/**< client secure context engine, set by protocol.
+								  *  This can also be set by a client when making a
+								  *  new security context. */
+#define PW_KEY_SEC_APP_ID		"pipewire.sec.app-id"	/**< client secure application id */
+#define PW_KEY_SEC_INSTANCE_ID		"pipewire.sec.instance-id"	/**< client secure instance id */
 
 #define PW_KEY_LIBRARY_NAME_SYSTEM	"library.name.system"	/**< name of the system library to use */
 #define PW_KEY_LIBRARY_NAME_LOOP	"library.name.loop"	/**< name of the loop library to use */

src/tests/test-security-context.c

@@ -137,10 +137,11 @@ static void test_create(void)
 
 	static const struct spa_dict_item items[] = {
 		{ "pipewire.foo.bar", "baz" },
-		{ "pipewire.access", "restricted" },
+		{ PW_KEY_SEC_ENGINE, "org.flatpak" },
+		{ PW_KEY_ACCESS, "restricted" },
 	};
 
-	pw_security_context_create(info.sec, "org.flatpak",
+	pw_security_context_create(info.sec,
 			listen_fd, close_fd[1],
 			&SPA_DICT_INIT_ARRAY(items));