+ LIST_FOREACH(callbacks, l, bus->filter_callbacks) {
+
+ if (bus->filter_callbacks_modified)
+ break;
+
+ /* Don't run this more than once per iteration */
+ if (l->last_iteration == bus->iteration_counter)
+ continue;
+
+ l->last_iteration = bus->iteration_counter;
+
+ r = sd_bus_message_rewind(m, true);
+ if (r < 0)
+ return r;
+
+ r = l->callback(bus, m, l->userdata);
+ if (r != 0)
+ return r;
+
+ }
+
+ } while (bus->filter_callbacks_modified);
+
+ return 0;
+}
+
+static int process_match(sd_bus *bus, sd_bus_message *m) {
+ int r;
+
+ assert(bus);
+ assert(m);
+
+ do {
+ bus->match_callbacks_modified = false;
+
+ r = bus_match_run(bus, &bus->match_callbacks, m);
+ if (r != 0)
+ return r;
+
+ } while (bus->match_callbacks_modified);
+
+ return 0;
+}
+
+static int process_builtin(sd_bus *bus, sd_bus_message *m) {
+ _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+ int r;
+
+ assert(bus);
+ assert(m);
+
+ if (m->header->type != SD_BUS_MESSAGE_METHOD_CALL)
+ return 0;
+
+ if (!streq_ptr(m->interface, "org.freedesktop.DBus.Peer"))
+ return 0;
+
+ if (m->header->flags & SD_BUS_MESSAGE_NO_REPLY_EXPECTED)
+ return 1;
+
+ if (streq_ptr(m->member, "Ping"))
+ r = sd_bus_message_new_method_return(bus, m, &reply);
+ else if (streq_ptr(m->member, "GetMachineId")) {
+ sd_id128_t id;
+ char sid[33];
+
+ r = sd_id128_get_machine(&id);
+ if (r < 0)
+ return r;
+
+ r = sd_bus_message_new_method_return(bus, m, &reply);
+ if (r < 0)
+ return r;
+
+ r = sd_bus_message_append(reply, "s", sd_id128_to_string(id, sid));
+ } else {
+ r = sd_bus_message_new_method_errorf(
+ bus, m, &reply,
+ SD_BUS_ERROR_UNKNOWN_METHOD,
+ "Unknown method '%s' on interface '%s'.", m->member, m->interface);
+ }
+
+ if (r < 0)
+ return r;
+
+ r = sd_bus_send(bus, reply, NULL);
+ if (r < 0)
+ return r;
+
+ return 1;
+}
+
+static int process_message(sd_bus *bus, sd_bus_message *m) {
+ int r;
+
+ assert(bus);
+ assert(m);
+
+ bus->current = m;
+ bus->iteration_counter++;
+
+ log_debug("Got message sender=%s object=%s interface=%s member=%s",
+ strna(sd_bus_message_get_sender(m)),
+ strna(sd_bus_message_get_path(m)),
+ strna(sd_bus_message_get_interface(m)),
+ strna(sd_bus_message_get_member(m)));
+
+ r = process_hello(bus, m);
+ if (r != 0)
+ goto finish;
+
+ r = process_reply(bus, m);
+ if (r != 0)
+ goto finish;
+
+ r = process_filter(bus, m);
+ if (r != 0)
+ goto finish;
+
+ r = process_match(bus, m);
+ if (r != 0)
+ goto finish;
+
+ r = process_builtin(bus, m);
+ if (r != 0)
+ goto finish;
+
+ r = bus_process_object(bus, m);
+
+finish:
+ bus->current = NULL;
+ return r;
+}
+
+static int process_running(sd_bus *bus, sd_bus_message **ret) {
+ _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
+ int r;
+
+ assert(bus);
+ assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO);
+
+ r = process_timeout(bus);
+ if (r != 0)
+ goto null_message;
+
+ r = dispatch_wqueue(bus);
+ if (r != 0)
+ goto null_message;
+
+ r = dispatch_rqueue(bus, &m);
+ if (r < 0)
+ return r;
+ if (!m)
+ goto null_message;
+
+ r = process_message(bus, m);
+ if (r != 0)
+ goto null_message;
+
+ if (ret) {
+ r = sd_bus_message_rewind(m, true);
+ if (r < 0)
+ return r;
+
+ *ret = m;
+ m = NULL;
+ return 1;
+ }
+
+ if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL) {
+
+ r = sd_bus_reply_method_errorf(
+ bus, m,
+ SD_BUS_ERROR_UNKNOWN_OBJECT,
+ "Unknown object '%s'.", m->path);
+ if (r < 0)
+ return r;
+ }
+
+ return 1;
+
+null_message:
+ if (r >= 0 && ret)
+ *ret = NULL;
+
+ return r;
+}
+
+_public_ int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
+ BUS_DONT_DESTROY(bus);
+ int r;
+
+ /* Returns 0 when we didn't do anything. This should cause the
+ * caller to invoke sd_bus_wait() before returning the next
+ * time. Returns > 0 when we did something, which possibly
+ * means *ret is filled in with an unprocessed message. */
+
+ assert_return(bus, -EINVAL);
+ assert_return(!bus_pid_changed(bus), -ECHILD);
+
+ /* We don't allow recursively invoking sd_bus_process(). */
+ assert_return(!bus->processing, -EBUSY);
+
+ switch (bus->state) {
+
+ case BUS_UNSET:
+ case BUS_CLOSED:
+ return -ENOTCONN;
+
+ case BUS_OPENING:
+ r = bus_socket_process_opening(bus);
+ if (r < 0)
+ return r;
+ if (ret)
+ *ret = NULL;
+ return r;
+
+ case BUS_AUTHENTICATING:
+
+ r = bus_socket_process_authenticating(bus);
+ if (r < 0)
+ return r;
+ if (ret)
+ *ret = NULL;
+ return r;
+
+ case BUS_RUNNING:
+ case BUS_HELLO:
+
+ bus->processing = true;
+ r = process_running(bus, ret);
+ bus->processing = false;
+
+ return r;
+ }
+
+ assert_not_reached("Unknown state");
+}
+
+static int bus_poll(sd_bus *bus, bool need_more, uint64_t timeout_usec) {
+ struct pollfd p[2] = {};
+ int r, e, n;
+ struct timespec ts;
+ usec_t m = (usec_t) -1;
+
+ assert(bus);
+ assert_return(BUS_IS_OPEN(bus->state), -ENOTCONN);
+
+ e = sd_bus_get_events(bus);
+ if (e < 0)
+ return e;
+
+ if (need_more)
+ /* The caller really needs some more data, he doesn't
+ * care about what's already read, or any timeouts
+ * except its own.*/
+ e |= POLLIN;
+ else {
+ usec_t until;
+ /* The caller wants to process if there's something to
+ * process, but doesn't care otherwise */
+
+ r = sd_bus_get_timeout(bus, &until);
+ if (r < 0)
+ return r;
+ if (r > 0) {
+ usec_t nw;
+ nw = now(CLOCK_MONOTONIC);
+ m = until > nw ? until - nw : 0;
+ }
+ }
+
+ if (timeout_usec != (uint64_t) -1 && (m == (uint64_t) -1 || timeout_usec < m))
+ m = timeout_usec;
+
+ p[0].fd = bus->input_fd;
+ if (bus->output_fd == bus->input_fd) {
+ p[0].events = e;
+ n = 1;
+ } else {
+ p[0].events = e & POLLIN;
+ p[1].fd = bus->output_fd;
+ p[1].events = e & POLLOUT;
+ n = 2;
+ }
+
+ r = ppoll(p, n, m == (uint64_t) -1 ? NULL : timespec_store(&ts, m), NULL);
+ if (r < 0)
+ return -errno;
+
+ return r > 0 ? 1 : 0;
+}
+
+_public_ int sd_bus_wait(sd_bus *bus, uint64_t timeout_usec) {
+
+ assert_return(bus, -EINVAL);
+ assert_return(BUS_IS_OPEN(bus->state), -ENOTCONN);
+ assert_return(!bus_pid_changed(bus), -ECHILD);
+
+ if (bus->rqueue_size > 0)
+ return 0;
+
+ return bus_poll(bus, false, timeout_usec);
+}
+
+_public_ int sd_bus_flush(sd_bus *bus) {
+ int r;
+
+ assert_return(bus, -EINVAL);
+ assert_return(BUS_IS_OPEN(bus->state), -ENOTCONN);
+ assert_return(!bus_pid_changed(bus), -ECHILD);
+
+ r = bus_ensure_running(bus);
+ if (r < 0)
+ return r;
+
+ if (bus->wqueue_size <= 0)
+ return 0;
+
+ for (;;) {
+ r = dispatch_wqueue(bus);
+ if (r < 0)