context: move registry generation checks to context methods

Add registry generation checks to pw_context methods that find globals,
(pw_context_find_global, pw_context_for_each_global), so that they are
made everywhere where a client acquires globals.

In addition to previously covered registry bind/destroy, this also
covers link creation (port/node ids) and metadata (subject ids).

src/pipewire/context.c

@@ -553,6 +553,19 @@ static bool global_can_read(struct pw_context *context, struct pw_global *global
 	return true;
 }
 
+static bool global_is_stale(struct pw_context *context, struct pw_global *global)
+{
+	struct pw_impl_client *client = context->current_client;
+
+	if (!client)
+		return false;
+
+	if (client->recv_generation != 0 && global->generation > client->recv_generation)
+		return true;
+
+	return false;
+}
+
 SPA_EXPORT
 int pw_context_for_each_global(struct pw_context *context,
 			    int (*callback) (void *data, struct pw_global *global),
@@ -562,7 +575,7 @@ int pw_context_for_each_global(struct pw_context *context,
 	int res;
 
 	spa_list_for_each_safe(g, t, &context->global_list, link) {
-		if (!global_can_read(context, g))
+		if (!global_can_read(context, g) || global_is_stale(context, g))
 			continue;
 		if ((res = callback(data, g)) != 0)
 			return res;
@@ -581,6 +594,11 @@ struct pw_global *pw_context_find_global(struct pw_context *context, uint32_t id
 		return NULL;
 	}
 
+	if (global_is_stale(context, global)) {
+		errno = global_can_read(context, global) ? ESTALE : ENOENT;
+		return NULL;
+	}
+
 	if (!global_can_read(context, global)) {
 		errno = EACCES;
 		return NULL;

src/pipewire/impl-client.c

@@ -117,15 +117,16 @@ static int client_error(void *object, uint32_t id, int res, const char *error)
 	struct pw_impl_client *sender = resource->client;
 	struct pw_impl_client *client = data->client;
 	struct error_data d = { id, res, error };
-	struct pw_global *global;
 
 	/* Check the global id provided by sender refers to a registered global
 	 * known to the sender.
 	 */
-	if ((global = pw_context_find_global(resource->context, id)) == NULL)
+	if (pw_context_find_global(resource->context, id) == NULL) {
-		goto error_no_id;
+		if (errno == ESTALE)
-	if (sender->recv_generation != 0 && global->generation > sender->recv_generation)
+			goto error_stale_id;
-		goto error_stale_id;
+		else
+			goto error_no_id;
+	}
 
 	pw_log_debug("%p: sender %p: error for global %u", client, sender, id);
 	pw_map_for_each(&client->objects, error_resource, &d);
@@ -136,8 +137,8 @@ error_no_id:
 	pw_resource_errorf(resource, -ENOENT, "no global %u", id);
 	return -ENOENT;
 error_stale_id:
-	pw_log_debug("%p: sender %p: error for stale global %u generation:%"PRIu64" recv-generation:%"PRIu64,
+	pw_log_debug("%p: sender %p: error for stale global %u recv-generation:%"PRIu64,
-			client, sender, id, global->generation, sender->recv_generation);
+			client, sender, id, sender->recv_generation);
 	pw_resource_errorf(resource, -ESTALE, "no global %u any more", id);
 	return -ESTALE;
 }
@@ -804,10 +805,7 @@ int pw_impl_client_check_permissions(struct pw_impl_client *client,
 	uint32_t perms;
 
 	if ((global = pw_context_find_global(context, global_id)) == NULL)
-		return -ENOENT;
+		return (errno == ESTALE) ? -ESTALE : -ENOENT;
-
-	if (client->recv_generation != 0 && global->generation > client->recv_generation)
-		return -ESTALE;
 
 	perms = pw_global_get_permissions(global, client);
 	if ((perms & permissions) != permissions)

src/pipewire/impl-core.c

@@ -33,17 +33,18 @@ static void * registry_bind(void *object, uint32_t id,
 	struct pw_global *global;
 	uint32_t permissions, new_id = user_data_size;
 
-	if ((global = pw_context_find_global(context, id)) == NULL)
+	if ((global = pw_context_find_global(context, id)) == NULL) {
-		goto error_no_id;
+		if (errno == ESTALE)
+			goto error_stale_id;
+		else
+			goto error_no_id;
+	}
 
 	permissions = pw_global_get_permissions(global, client);
 
 	if (!PW_PERM_IS_R(permissions))
 		goto error_no_id;
 
-	if (resource->client->recv_generation != 0 && global->generation > resource->client->recv_generation)
-		goto error_stale_id;
-
 	if (!spa_streq(global->type, type))
 		goto error_wrong_interface;
 
@@ -57,8 +58,8 @@ static void * registry_bind(void *object, uint32_t id,
 
 error_stale_id:
 	pw_log_debug("registry %p: not binding stale global "
-			"id %u to %u, generation:%"PRIu64" recv-generation:%"PRIu64,
+			"id %u to %u recv-generation:%"PRIu64,
-			resource, id, new_id, global->generation, resource->client->recv_generation);
+			resource, id, new_id, resource->client->recv_generation);
 	pw_resource_errorf_id(resource, new_id, -ESTALE, "no global %u any more", id);
 	goto error_exit_clean;
 error_no_id:
@@ -88,17 +89,18 @@ static int registry_destroy(void *object, uint32_t id)
 	uint32_t permissions;
 	int res;
 
-	if ((global = pw_context_find_global(context, id)) == NULL)
+	if ((global = pw_context_find_global(context, id)) == NULL) {
-		goto error_no_id;
+		if (errno == ESTALE)
+			goto error_stale_id;
+		else
+			goto error_no_id;
+	}
 
 	permissions = pw_global_get_permissions(global, client);
 
 	if (!PW_PERM_IS_R(permissions))
 		goto error_no_id;
 
-	if (resource->client->recv_generation != 0 && global->generation > resource->client->recv_generation)
-		goto error_stale_id;
-
 	if (id == PW_ID_CORE || !PW_PERM_IS_X(permissions))
 		goto error_not_allowed;
 
@@ -109,8 +111,8 @@ static int registry_destroy(void *object, uint32_t id)
 
 error_stale_id:
 	pw_log_debug("registry %p: not destroying stale global "
-			"id %u, generation:%"PRIu64" recv-generation:%"PRIu64,
+			"id %u, recv-generation:%"PRIu64,
-			resource, id, global->generation, resource->client->recv_generation);
+			resource, id, resource->client->recv_generation);
 	pw_resource_errorf(resource, -ESTALE, "no global %u any more", id);
 	res = -ESTALE;
 	goto error_exit;