global: emit permissions_changed event

Add a permissions_changed event when the permissions change for a
global for a client.
Recheck if a link is still allowed when node permissions changed
and destroy the link if not.

src/pipewire/client.c

@@ -395,6 +395,7 @@ static int do_permissions(void *data, struct pw_global *global)
 	struct impl *impl = SPA_CONTAINER_OF(client, struct impl, this);
 	struct permission *p;
 	size_t len, i;
+	uint32_t old;
 
 	len = pw_array_get_len(&impl->permissions, struct permission);
 	if (len <= global->id) {
@@ -410,12 +411,16 @@ static int do_permissions(void *data, struct pw_global *global)
 
 	p = pw_array_get_unchecked(&impl->permissions, global->id, struct permission);
 	if (p->permissions == -1)
-		p->permissions = impl->permissions_default;
+		old = p->permissions = impl->permissions_default;
 	else if (update->only_new)
 		return 0;
 
+	old = p->permissions;
 	p->permissions &= update->permissions;
-	pw_log_debug("client %p: set global %d permissions to %08x", client, global->id, p->permissions);
+	pw_log_debug("client %p: change global %d permissions %08x -> %08x",
+			client, global->id, old, p->permissions);
+
+	pw_global_events_permissions_changed(global, client, old, p->permissions);
 
 	return 0;
 }

src/pipewire/global.h

@@ -57,7 +57,7 @@ struct pw_global;
 
 /** Global events, use \ref pw_global_add_listener */
 struct pw_global_events {
-#define PW_VERSION_GLOBAL_EVENTS 0
+#define PW_VERSION_GLOBAL_EVENTS 1
 	uint32_t version;
 
 	/** The global is destroyed */
@@ -72,6 +72,12 @@ struct pw_global_events {
 		      uint32_t permissions,	/**< permissions for the bind */
 		      uint32_t version,		/**< client interface version */
 		      uint32_t id		/**< client proxy id */);
+
+	/* permissions for the global changed, Since version 1 */
+	void (*permissions_changed) (void *data,
+			struct pw_client *client,
+			uint32_t old_permissions,
+			uint32_t new_permissions);
 };
 
 /** Create a new global object */

src/pipewire/link.c

@@ -51,8 +51,10 @@ struct impl {
 
 	struct spa_hook input_port_listener;
 	struct spa_hook input_node_listener;
+	struct spa_hook input_global_listener;
 	struct spa_hook output_port_listener;
 	struct spa_hook output_node_listener;
+	struct spa_hook output_global_listener;
 };
 
 struct resource_data {
@@ -868,6 +870,7 @@ static void input_remove(struct pw_link *this, struct pw_port *port)
 	pw_log_debug("link %p: remove input port %p", this, port);
 	spa_hook_remove(&impl->input_port_listener);
 	spa_hook_remove(&impl->input_node_listener);
+	spa_hook_remove(&impl->input_global_listener);
 
 	pw_loop_invoke(port->node->data_loop,
 		       do_remove_input, 1, NULL, 0, true, this);
@@ -897,6 +900,7 @@ static void output_remove(struct pw_link *this, struct pw_port *port)
 	pw_log_debug("link %p: remove output port %p", this, port);
 	spa_hook_remove(&impl->output_port_listener);
 	spa_hook_remove(&impl->output_node_listener);
+	spa_hook_remove(&impl->output_global_listener);
 
 	pw_loop_invoke(port->node->data_loop,
 		       do_remove_output, 1, NULL, 0, true, this);
@@ -1105,9 +1109,25 @@ check_permission(struct pw_core *core,
 	if ((client = input_node->global->owner) != NULL &&
 	    !PW_PERM_IS_R(pw_global_get_permissions(output_node->global, client)))
 		return -EPERM;
+
 	return 0;
 }
 
+static void global_permissions_changed(void *data,
+		struct pw_client *client, uint32_t old, uint32_t new)
+{
+	struct pw_link *this = data;
+
+	if (check_permission(this->core, this->output, this->input, this->properties) < 0)
+		pw_link_destroy(this);
+}
+
+
+static const struct pw_global_events global_node_events = {
+	PW_VERSION_GLOBAL_EVENTS,
+	.permissions_changed = global_permissions_changed,
+};
+
 SPA_EXPORT
 struct pw_link *pw_link_new(struct pw_core *core,
 			    struct pw_port *output,
@@ -1166,8 +1186,10 @@ struct pw_link *pw_link_new(struct pw_core *core,
 
 	pw_port_add_listener(input, &impl->input_port_listener, &input_port_events, impl);
 	pw_node_add_listener(input_node, &impl->input_node_listener, &input_node_events, impl);
+	pw_global_add_listener(input_node->global, &impl->input_global_listener, &global_node_events, impl);
 	pw_port_add_listener(output, &impl->output_port_listener, &output_port_events, impl);
 	pw_node_add_listener(output_node, &impl->output_node_listener, &output_node_events, impl);
+	pw_global_add_listener(output_node->global, &impl->output_global_listener, &global_node_events, impl);
 
 	input_node->live = output_node->live;
 	if (output_node->clock)

src/pipewire/private.h

@@ -124,6 +124,8 @@ struct pw_client {
 #define pw_global_events_destroy(g)	pw_global_events_emit(g, destroy, 0)
 #define pw_global_events_free(g)	pw_global_events_emit(g, free, 0)
 #define pw_global_events_bind(g,...)	pw_global_events_emit(g, bind, 0, __VA_ARGS__)
+#define pw_global_events_permissions_changed(g,...) \
+					pw_global_events_emit(g, permissions_changed, 1, __VA_ARGS__)
 
 struct pw_global {
 	struct pw_core *core;		/**< the core */