+_public_ int sd_bus_get_owner(
+ sd_bus *bus,
+ const char *name,
+ uint64_t mask,
+ sd_bus_creds **creds) {
+
+ assert_return(bus, -EINVAL);
+ assert_return(name, -EINVAL);
+ assert_return(mask <= _SD_BUS_CREDS_ALL, -ENOTSUP);
+ assert_return(mask == 0 || creds, -EINVAL);
+ assert_return(BUS_IS_OPEN(bus->state), -ENOTCONN);
+ assert_return(!bus_pid_changed(bus), -ECHILD);
+ assert_return(service_name_is_valid(name), -EINVAL);
+ assert_return(bus->bus_client, -ENODATA);
+
+ if (bus->is_kernel)
+ return bus_get_owner_kdbus(bus, name, mask, creds);
+ else
+ return bus_get_owner_dbus1(bus, name, mask, creds);
+}
+
+static int add_name_change_match(sd_bus *bus,
+ uint64_t cookie,
+ const char *name,
+ const char *old_owner,
+ const char *new_owner) {
+
+ uint64_t name_id = KDBUS_MATCH_ID_ANY, old_owner_id = 0, new_owner_id = 0;
+ int is_name_id = -1, r;
+ struct kdbus_item *item;
+
+ assert(bus);
+
+ /* If we encounter a match that could match against
+ * NameOwnerChanged messages, then we need to create
+ * KDBUS_ITEM_NAME_{ADD,REMOVE,CHANGE} and
+ * KDBUS_ITEM_ID_{ADD,REMOVE} matches for it, possibly
+ * multiple if the match is underspecified.
+ *
+ * The NameOwnerChanged signals take three parameters with
+ * unique or well-known names, but only some forms actually
+ * exist:
+ *
+ * WELLKNOWN, "", UNIQUE → KDBUS_ITEM_NAME_ADD
+ * WELLKNOWN, UNIQUE, "" → KDBUS_ITEM_NAME_REMOVE
+ * WELLKNOWN, UNIQUE, UNIQUE → KDBUS_ITEM_NAME_CHANGE
+ * UNIQUE, "", UNIQUE → KDBUS_ITEM_ID_ADD
+ * UNIQUE, UNIQUE, "" → KDBUS_ITEM_ID_REMOVE
+ *
+ * For the latter two the two unique names must be identical.
+ *
+ * */
+
+ if (name) {
+ is_name_id = bus_kernel_parse_unique_name(name, &name_id);
+ if (is_name_id < 0)
+ return 0;
+ }
+
+ if (!isempty(old_owner)) {
+ r = bus_kernel_parse_unique_name(old_owner, &old_owner_id);
+ if (r < 0)
+ return 0;
+ if (r == 0)
+ return 0;
+ if (is_name_id > 0 && old_owner_id != name_id)
+ return 0;
+ } else
+ old_owner_id = KDBUS_MATCH_ID_ANY;
+
+ if (!isempty(new_owner)) {
+ r = bus_kernel_parse_unique_name(new_owner, &new_owner_id);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ return 0;
+ if (is_name_id > 0 && new_owner_id != name_id)
+ return 0;
+ } else
+ new_owner_id = KDBUS_MATCH_ID_ANY;
+
+ if (is_name_id <= 0) {
+ struct kdbus_cmd_match *m;
+ size_t sz, l;
+
+ /* If the name argument is missing or is a well-known
+ * name, then add KDBUS_ITEM_NAME_{ADD,REMOVE,CHANGE}
+ * matches for it */
+
+ l = name ? strlen(name) + 1 : 0;
+
+ sz = ALIGN8(offsetof(struct kdbus_cmd_match, items) +
+ offsetof(struct kdbus_item, name_change) +
+ offsetof(struct kdbus_notify_name_change, name) +
+ l);
+
+ m = alloca0(sz);
+ m->size = sz;
+ m->cookie = cookie;
+
+ item = m->items;
+ item->size =
+ offsetof(struct kdbus_item, name_change) +
+ offsetof(struct kdbus_notify_name_change, name) +
+ l;
+
+ item->name_change.old.id = old_owner_id;
+ item->name_change.new.id = new_owner_id;
+
+ if (name)
+ memcpy(item->name_change.name, name, l);
+
+ /* If the old name is unset or empty, then
+ * this can match against added names */
+ if (!old_owner || old_owner[0] == 0) {
+ item->type = KDBUS_ITEM_NAME_ADD;
+
+ r = ioctl(bus->input_fd, KDBUS_CMD_MATCH_ADD, m);
+ if (r < 0)
+ return -errno;
+ }
+
+ /* If the new name is unset or empty, then
+ * this can match against removed names */
+ if (!new_owner || new_owner[0] == 0) {
+ item->type = KDBUS_ITEM_NAME_REMOVE;
+
+ r = ioctl(bus->input_fd, KDBUS_CMD_MATCH_ADD, m);
+ if (r < 0)
+ return -errno;
+ }
+
+ /* The CHANGE match we need in either case, because
+ * what is reported as a name change by the kernel
+ * might just be an owner change between starter and
+ * normal clients. For userspace such a change should
+ * be considered a removal/addition, hence let's
+ * subscribe to this unconditionally. */
+ item->type = KDBUS_ITEM_NAME_CHANGE;
+ r = ioctl(bus->input_fd, KDBUS_CMD_MATCH_ADD, m);
+ if (r < 0)
+ return -errno;
+ }
+
+ if (is_name_id != 0) {
+ struct kdbus_cmd_match *m;
+ uint64_t sz;
+
+ /* If the name argument is missing or is a unique
+ * name, then add KDBUS_ITEM_ID_{ADD,REMOVE} matches
+ * for it */
+
+ sz = ALIGN8(offsetof(struct kdbus_cmd_match, items) +
+ offsetof(struct kdbus_item, id_change) +
+ sizeof(struct kdbus_notify_id_change));
+
+ m = alloca0(sz);
+ m->size = sz;
+ m->cookie = cookie;
+
+ item = m->items;
+ item->size =
+ offsetof(struct kdbus_item, id_change) +
+ sizeof(struct kdbus_notify_id_change);
+ item->id_change.id = name_id;
+
+ /* If the old name is unset or empty, then this can
+ * match against added ids */
+ if (!old_owner || old_owner[0] == 0) {
+ item->type = KDBUS_ITEM_ID_ADD;
+
+ r = ioctl(bus->input_fd, KDBUS_CMD_MATCH_ADD, m);
+ if (r < 0)
+ return -errno;
+ }
+
+ /* If thew new name is unset or empty, then this can
+ * match against removed ids */
+ if (!new_owner || new_owner[0] == 0) {
+ item->type = KDBUS_ITEM_ID_REMOVE;
+
+ r = ioctl(bus->input_fd, KDBUS_CMD_MATCH_ADD, m);
+ if (r < 0)
+ return -errno;
+ }
+ }
+
+ return 0;
+}
+
+int bus_add_match_internal_kernel(
+ sd_bus *bus,
+ uint64_t id,
+ struct bus_match_component *components,
+ unsigned n_components,
+ uint64_t cookie) {
+
+ struct kdbus_cmd_match *m;
+ struct kdbus_item *item;
+ uint64_t bloom[BLOOM_SIZE/8];
+ size_t sz;
+ const char *sender = NULL;
+ size_t sender_length = 0;
+ uint64_t src_id = KDBUS_MATCH_ID_ANY;
+ bool using_bloom = false;
+ unsigned i;
+ bool matches_name_change = true;
+ const char *name_change_arg[3] = {};