X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;ds=sidebyside;f=src%2Flibsystemd-bus%2Fsd-bus.c;h=0be5a29f367fbe4e53bd2ef6a849feb55a8a1169;hb=aea93debfa1281a7d5f1523225b043955c1c2472;hp=f42d5d0ee133fde80b7a6ba27f78795198c21e1f;hpb=a7893c6b28772edbc7e1fea3c209caa54d465648;p=elogind.git

diff --git a/src/libsystemd-bus/sd-bus.c b/src/libsystemd-bus/sd-bus.c
index f42d5d0ee..0be5a29f3 100644
--- a/src/libsystemd-bus/sd-bus.c
+++ b/src/libsystemd-bus/sd-bus.c
@@ -159,7 +159,7 @@ static void bus_free(sd_bus *b) {
         free(b);
 }
 
-int sd_bus_new(sd_bus **ret) {
+_public_ int sd_bus_new(sd_bus **ret) {
         sd_bus *r;
 
         assert_return(ret, -EINVAL);
@@ -188,7 +188,7 @@ int sd_bus_new(sd_bus **ret) {
         return 0;
 }
 
-int sd_bus_set_address(sd_bus *bus, const char *address) {
+_public_ int sd_bus_set_address(sd_bus *bus, const char *address) {
         char *a;
 
         assert_return(bus, -EINVAL);
@@ -206,7 +206,7 @@ int sd_bus_set_address(sd_bus *bus, const char *address) {
         return 0;
 }
 
-int sd_bus_set_fd(sd_bus *bus, int input_fd, int output_fd) {
+_public_ int sd_bus_set_fd(sd_bus *bus, int input_fd, int output_fd) {
         assert_return(bus, -EINVAL);
         assert_return(bus->state == BUS_UNSET, -EPERM);
         assert_return(input_fd >= 0, -EINVAL);
@@ -218,7 +218,7 @@ int sd_bus_set_fd(sd_bus *bus, int input_fd, int output_fd) {
         return 0;
 }
 
-int sd_bus_set_exec(sd_bus *bus, const char *path, char *const argv[]) {
+_public_ int sd_bus_set_exec(sd_bus *bus, const char *path, char *const argv[]) {
         char *p, **a;
 
         assert_return(bus, -EINVAL);
@@ -246,7 +246,7 @@ int sd_bus_set_exec(sd_bus *bus, const char *path, char *const argv[]) {
         return 0;
 }
 
-int sd_bus_set_bus_client(sd_bus *bus, int b) {
+_public_ int sd_bus_set_bus_client(sd_bus *bus, int b) {
         assert_return(bus, -EINVAL);
         assert_return(bus->state == BUS_UNSET, -EPERM);
         assert_return(!bus_pid_changed(bus), -ECHILD);
@@ -255,7 +255,7 @@ int sd_bus_set_bus_client(sd_bus *bus, int b) {
         return 0;
 }
 
-int sd_bus_negotiate_fds(sd_bus *bus, int b) {
+_public_ int sd_bus_negotiate_fds(sd_bus *bus, int b) {
         assert_return(bus, -EINVAL);
         assert_return(bus->state == BUS_UNSET, -EPERM);
         assert_return(!bus_pid_changed(bus), -ECHILD);
@@ -264,7 +264,25 @@ int sd_bus_negotiate_fds(sd_bus *bus, int b) {
         return 0;
 }
 
-int sd_bus_negotiate_attach_comm(sd_bus *bus, int b) {
+_public_ int sd_bus_negotiate_attach_timestamp(sd_bus *bus, int b) {
+        assert_return(bus, -EINVAL);
+        assert_return(bus->state == BUS_UNSET, -EPERM);
+        assert_return(!bus_pid_changed(bus), -ECHILD);
+
+        SET_FLAG(bus->hello_flags, KDBUS_HELLO_ATTACH_TIMESTAMP, b);
+        return 0;
+}
+
+_public_ int sd_bus_negotiate_attach_creds(sd_bus *bus, int b) {
+        assert_return(bus, -EINVAL);
+        assert_return(bus->state == BUS_UNSET, -EPERM);
+        assert_return(!bus_pid_changed(bus), -ECHILD);
+
+        SET_FLAG(bus->hello_flags, KDBUS_HELLO_ATTACH_CREDS, b);
+        return 0;
+}
+
+_public_ int sd_bus_negotiate_attach_comm(sd_bus *bus, int b) {
         assert_return(bus, -EINVAL);
         assert_return(bus->state == BUS_UNSET, -EPERM);
         assert_return(!bus_pid_changed(bus), -ECHILD);
@@ -273,7 +291,7 @@ int sd_bus_negotiate_attach_comm(sd_bus *bus, int b) {
         return 0;
 }
 
-int sd_bus_negotiate_attach_exe(sd_bus *bus, int b) {
+_public_ int sd_bus_negotiate_attach_exe(sd_bus *bus, int b) {
         assert_return(bus, -EINVAL);
         assert_return(bus->state == BUS_UNSET, -EPERM);
         assert_return(!bus_pid_changed(bus), -ECHILD);
@@ -282,7 +300,7 @@ int sd_bus_negotiate_attach_exe(sd_bus *bus, int b) {
         return 0;
 }
 
-int sd_bus_negotiate_attach_cmdline(sd_bus *bus, int b) {
+_public_ int sd_bus_negotiate_attach_cmdline(sd_bus *bus, int b) {
         assert_return(bus, -EINVAL);
         assert_return(bus->state == BUS_UNSET, -EPERM);
         assert_return(!bus_pid_changed(bus), -ECHILD);
@@ -291,7 +309,7 @@ int sd_bus_negotiate_attach_cmdline(sd_bus *bus, int b) {
         return 0;
 }
 
-int sd_bus_negotiate_attach_cgroup(sd_bus *bus, int b) {
+_public_ int sd_bus_negotiate_attach_cgroup(sd_bus *bus, int b) {
         assert_return(bus, -EINVAL);
         assert_return(bus->state == BUS_UNSET, -EPERM);
         assert_return(!bus_pid_changed(bus), -ECHILD);
@@ -300,7 +318,7 @@ int sd_bus_negotiate_attach_cgroup(sd_bus *bus, int b) {
         return 0;
 }
 
-int sd_bus_negotiate_attach_caps(sd_bus *bus, int b) {
+_public_ int sd_bus_negotiate_attach_caps(sd_bus *bus, int b) {
         assert_return(bus, -EINVAL);
         assert_return(bus->state == BUS_UNSET, -EPERM);
         assert_return(!bus_pid_changed(bus), -ECHILD);
@@ -309,7 +327,7 @@ int sd_bus_negotiate_attach_caps(sd_bus *bus, int b) {
         return 0;
 }
 
-int sd_bus_negotiate_attach_selinux_context(sd_bus *bus, int b) {
+_public_ int sd_bus_negotiate_attach_selinux_context(sd_bus *bus, int b) {
         assert_return(bus, -EINVAL);
         assert_return(bus->state == BUS_UNSET, -EPERM);
         assert_return(!bus_pid_changed(bus), -ECHILD);
@@ -318,7 +336,7 @@ int sd_bus_negotiate_attach_selinux_context(sd_bus *bus, int b) {
         return 0;
 }
 
-int sd_bus_negotiate_attach_audit(sd_bus *bus, int b) {
+_public_ int sd_bus_negotiate_attach_audit(sd_bus *bus, int b) {
         assert_return(bus, -EINVAL);
         assert_return(bus->state == BUS_UNSET, -EPERM);
         assert_return(!bus_pid_changed(bus), -ECHILD);
@@ -327,7 +345,7 @@ int sd_bus_negotiate_attach_audit(sd_bus *bus, int b) {
         return 0;
 }
 
-int sd_bus_set_server(sd_bus *bus, int b, sd_id128_t server_id) {
+_public_ int sd_bus_set_server(sd_bus *bus, int b, sd_id128_t server_id) {
         assert_return(bus, -EINVAL);
         assert_return(b || sd_id128_equal(server_id, SD_ID128_NULL), -EINVAL);
         assert_return(bus->state == BUS_UNSET, -EPERM);
@@ -338,7 +356,7 @@ int sd_bus_set_server(sd_bus *bus, int b, sd_id128_t server_id) {
         return 0;
 }
 
-int sd_bus_set_anonymous(sd_bus *bus, int b) {
+_public_ int sd_bus_set_anonymous(sd_bus *bus, int b) {
         assert_return(bus, -EINVAL);
         assert_return(bus->state == BUS_UNSET, -EPERM);
         assert_return(!bus_pid_changed(bus), -ECHILD);
@@ -396,7 +414,7 @@ static int bus_send_hello(sd_bus *bus) {
         if (r < 0)
                 return r;
 
-        return sd_bus_send_with_reply(bus, m, hello_callback, NULL, 0, &bus->hello_serial);
+        return sd_bus_call_async(bus, m, hello_callback, NULL, 0, &bus->hello_serial);
 }
 
 int bus_start_running(sd_bus *bus) {
@@ -982,7 +1000,7 @@ static int bus_start_fd(sd_bus *b) {
                 return bus_socket_take_fd(b);
 }
 
-int sd_bus_start(sd_bus *bus) {
+_public_ int sd_bus_start(sd_bus *bus) {
         int r;
 
         assert_return(bus, -EINVAL);
@@ -1007,7 +1025,7 @@ int sd_bus_start(sd_bus *bus) {
         return bus_send_hello(bus);
 }
 
-int sd_bus_open_system(sd_bus **ret) {
+_public_ int sd_bus_open_system(sd_bus **ret) {
         const char *e;
         sd_bus *b;
         int r;
@@ -1043,7 +1061,7 @@ fail:
         return r;
 }
 
-int sd_bus_open_user(sd_bus **ret) {
+_public_ int sd_bus_open_user(sd_bus **ret) {
         const char *e;
         sd_bus *b;
         size_t l;
@@ -1092,7 +1110,7 @@ fail:
         return r;
 }
 
-int sd_bus_open_system_remote(const char *host, sd_bus **ret) {
+_public_ int sd_bus_open_system_remote(const char *host, sd_bus **ret) {
         _cleanup_free_ char *e = NULL;
         char *p = NULL;
         sd_bus *bus;
@@ -1128,7 +1146,7 @@ int sd_bus_open_system_remote(const char *host, sd_bus **ret) {
         return 0;
 }
 
-int sd_bus_open_system_container(const char *machine, sd_bus **ret) {
+_public_ int sd_bus_open_system_container(const char *machine, sd_bus **ret) {
         _cleanup_free_ char *e = NULL;
         sd_bus *bus;
         char *p;
@@ -1164,7 +1182,7 @@ int sd_bus_open_system_container(const char *machine, sd_bus **ret) {
         return 0;
 }
 
-void sd_bus_close(sd_bus *bus) {
+_public_ void sd_bus_close(sd_bus *bus) {
         if (!bus)
                 return;
         if (bus->state == BUS_CLOSED)
@@ -1186,18 +1204,16 @@ void sd_bus_close(sd_bus *bus) {
          * freed. */
 }
 
-sd_bus *sd_bus_ref(sd_bus *bus) {
-        if (!bus)
-                return NULL;
+_public_ sd_bus *sd_bus_ref(sd_bus *bus) {
+        assert_return(bus, NULL);
 
         assert_se(REFCNT_INC(bus->n_ref) >= 2);
 
         return bus;
 }
 
-sd_bus *sd_bus_unref(sd_bus *bus) {
-        if (!bus)
-                return NULL;
+_public_ sd_bus *sd_bus_unref(sd_bus *bus) {
+        assert_return(bus, NULL);
 
         if (REFCNT_DEC(bus->n_ref) <= 0)
                 bus_free(bus);
@@ -1205,7 +1221,7 @@ sd_bus *sd_bus_unref(sd_bus *bus) {
         return NULL;
 }
 
-int sd_bus_is_open(sd_bus *bus) {
+_public_ int sd_bus_is_open(sd_bus *bus) {
 
         assert_return(bus, -EINVAL);
         assert_return(!bus_pid_changed(bus), -ECHILD);
@@ -1213,7 +1229,7 @@ int sd_bus_is_open(sd_bus *bus) {
         return BUS_IS_OPEN(bus->state);
 }
 
-int sd_bus_can_send(sd_bus *bus, char type) {
+_public_ int sd_bus_can_send(sd_bus *bus, char type) {
         int r;
 
         assert_return(bus, -EINVAL);
@@ -1234,7 +1250,7 @@ int sd_bus_can_send(sd_bus *bus, char type) {
         return bus_type_is_valid(type);
 }
 
-int sd_bus_get_server_id(sd_bus *bus, sd_id128_t *server_id) {
+_public_ int sd_bus_get_server_id(sd_bus *bus, sd_id128_t *server_id) {
         int r;
 
         assert_return(bus, -EINVAL);
@@ -1255,8 +1271,13 @@ static int bus_seal_message(sd_bus *b, sd_bus_message *m) {
         if (m->header->version > b->message_version)
                 return -EPERM;
 
-        if (m->sealed)
+        if (m->sealed) {
+                /* If we copy the same message to multiple
+                 * destinations, avoid using the same serial
+                 * numbers. */
+                b->serial = MAX(b->serial, BUS_MESSAGE_SERIAL(m));
                 return 0;
+        }
 
         return bus_message_seal(m, ++b->serial);
 }
@@ -1341,7 +1362,7 @@ static int dispatch_rqueue(sd_bus *bus, sd_bus_message **m) {
         return ret;
 }
 
-int sd_bus_send(sd_bus *bus, sd_bus_message *m, uint64_t *serial) {
+_public_ int sd_bus_send(sd_bus *bus, sd_bus_message *m, uint64_t *serial) {
         int r;
 
         assert_return(bus, -EINVAL);
@@ -1442,7 +1463,7 @@ static int timeout_compare(const void *a, const void *b) {
         return 0;
 }
 
-int sd_bus_send_with_reply(
+_public_ int sd_bus_call_async(
                 sd_bus *bus,
                 sd_bus_message *m,
                 sd_bus_message_handler_t callback,
@@ -1494,21 +1515,21 @@ int sd_bus_send_with_reply(
                 r = prioq_put(bus->reply_callbacks_prioq, c, &c->prioq_idx);
                 if (r < 0) {
                         c->timeout = 0;
-                        sd_bus_send_with_reply_cancel(bus, c->serial);
+                        sd_bus_call_async_cancel(bus, c->serial);
                         return r;
                 }
         }
 
         r = sd_bus_send(bus, m, serial);
         if (r < 0) {
-                sd_bus_send_with_reply_cancel(bus, c->serial);
+                sd_bus_call_async_cancel(bus, c->serial);
                 return r;
         }
 
         return r;
 }
 
-int sd_bus_send_with_reply_cancel(sd_bus *bus, uint64_t serial) {
+_public_ int sd_bus_call_async_cancel(sd_bus *bus, uint64_t serial) {
         struct reply_callback *c;
 
         assert_return(bus, -EINVAL);
@@ -1551,7 +1572,7 @@ int bus_ensure_running(sd_bus *bus) {
         }
 }
 
-int sd_bus_send_with_reply_and_block(
+_public_ int sd_bus_call(
                 sd_bus *bus,
                 sd_bus_message *m,
                 uint64_t usec,
@@ -1639,6 +1660,19 @@ int sd_bus_send_with_reply_and_block(
 
                                 sd_bus_message_unref(incoming);
                                 return -EIO;
+
+                        } else if (incoming->header->serial == serial &&
+                                   bus->unique_name &&
+                                   incoming->sender &&
+                                   streq(bus->unique_name, incoming->sender)) {
+
+                                /* Our own message? Somebody is trying
+                                 * to send its own client a message,
+                                 * let's not dead-lock, let's fail
+                                 * immediately. */
+
+                                sd_bus_message_unref(incoming);
+                                return -ELOOP;
                         }
 
                         /* There's already guaranteed to be room for
@@ -1673,7 +1707,7 @@ int sd_bus_send_with_reply_and_block(
         }
 }
 
-int sd_bus_get_fd(sd_bus *bus) {
+_public_ int sd_bus_get_fd(sd_bus *bus) {
 
         assert_return(bus, -EINVAL);
         assert_return(BUS_IS_OPEN(bus->state), -ENOTCONN);
@@ -1683,7 +1717,7 @@ int sd_bus_get_fd(sd_bus *bus) {
         return bus->input_fd;
 }
 
-int sd_bus_get_events(sd_bus *bus) {
+_public_ int sd_bus_get_events(sd_bus *bus) {
         int flags = 0;
 
         assert_return(bus, -EINVAL);
@@ -1709,7 +1743,7 @@ int sd_bus_get_events(sd_bus *bus) {
         return flags;
 }
 
-int sd_bus_get_timeout(sd_bus *bus, uint64_t *timeout_usec) {
+_public_ int sd_bus_get_timeout(sd_bus *bus, uint64_t *timeout_usec) {
         struct reply_callback *c;
 
         assert_return(bus, -EINVAL);
@@ -1933,6 +1967,7 @@ static int process_message(sd_bus *bus, sd_bus_message *m) {
         assert(bus);
         assert(m);
 
+        bus->current = m;
         bus->iteration_counter++;
 
         log_debug("Got message sender=%s object=%s interface=%s member=%s",
@@ -1943,25 +1978,29 @@ static int process_message(sd_bus *bus, sd_bus_message *m) {
 
         r = process_hello(bus, m);
         if (r != 0)
-                return r;
+                goto finish;
 
         r = process_reply(bus, m);
         if (r != 0)
-                return r;
+                goto finish;
 
         r = process_filter(bus, m);
         if (r != 0)
-                return r;
+                goto finish;
 
         r = process_match(bus, m);
         if (r != 0)
-                return r;
+                goto finish;
 
         r = process_builtin(bus, m);
         if (r != 0)
-                return r;
+                goto finish;
 
-        return bus_process_object(bus, m);
+        r = bus_process_object(bus, m);
+
+finish:
+        bus->current = NULL;
+        return r;
 }
 
 static int process_running(sd_bus *bus, sd_bus_message **ret) {
@@ -2018,7 +2057,7 @@ null_message:
         return r;
 }
 
-int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
+_public_ int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
         BUS_DONT_DESTROY(bus);
         int r;
 
@@ -2123,7 +2162,7 @@ static int bus_poll(sd_bus *bus, bool need_more, uint64_t timeout_usec) {
         return r > 0 ? 1 : 0;
 }
 
-int sd_bus_wait(sd_bus *bus, uint64_t timeout_usec) {
+_public_ int sd_bus_wait(sd_bus *bus, uint64_t timeout_usec) {
 
         assert_return(bus, -EINVAL);
         assert_return(BUS_IS_OPEN(bus->state), -ENOTCONN);
@@ -2135,7 +2174,7 @@ int sd_bus_wait(sd_bus *bus, uint64_t timeout_usec) {
         return bus_poll(bus, false, timeout_usec);
 }
 
-int sd_bus_flush(sd_bus *bus) {
+_public_ int sd_bus_flush(sd_bus *bus) {
         int r;
 
         assert_return(bus, -EINVAL);
@@ -2163,7 +2202,10 @@ int sd_bus_flush(sd_bus *bus) {
         }
 }
 
-int sd_bus_add_filter(sd_bus *bus, sd_bus_message_handler_t callback, void *userdata) {
+_public_ int sd_bus_add_filter(sd_bus *bus,
+                               sd_bus_message_handler_t callback,
+                               void *userdata) {
+
         struct filter_callback *f;
 
         assert_return(bus, -EINVAL);
@@ -2181,7 +2223,10 @@ int sd_bus_add_filter(sd_bus *bus, sd_bus_message_handler_t callback, void *user
         return 0;
 }
 
-int sd_bus_remove_filter(sd_bus *bus, sd_bus_message_handler_t callback, void *userdata) {
+_public_ int sd_bus_remove_filter(sd_bus *bus,
+                                  sd_bus_message_handler_t callback,
+                                  void *userdata) {
+
         struct filter_callback *f;
 
         assert_return(bus, -EINVAL);
@@ -2200,7 +2245,11 @@ int sd_bus_remove_filter(sd_bus *bus, sd_bus_message_handler_t callback, void *u
         return 0;
 }
 
-int sd_bus_add_match(sd_bus *bus, const char *match, sd_bus_message_handler_t callback, void *userdata) {
+_public_ int sd_bus_add_match(sd_bus *bus,
+                              const char *match,
+                              sd_bus_message_handler_t callback,
+                              void *userdata) {
+
         struct bus_match_component *components = NULL;
         unsigned n_components = 0;
         uint64_t cookie = 0;
@@ -2234,7 +2283,11 @@ finish:
         return r;
 }
 
-int sd_bus_remove_match(sd_bus *bus, const char *match, sd_bus_message_handler_t callback, void *userdata) {
+_public_ int sd_bus_remove_match(sd_bus *bus,
+                                 const char *match,
+                                 sd_bus_message_handler_t callback,
+                                 void *userdata) {
+
         struct bus_match_component *components = NULL;
         unsigned n_components = 0;
         int r = 0, q = 0;
@@ -2269,7 +2322,7 @@ bool bus_pid_changed(sd_bus *bus) {
 }
 
 static int io_callback(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
-        void *bus = userdata;
+        sd_bus *bus = userdata;
         int r;
 
         assert(bus);
@@ -2282,7 +2335,7 @@ static int io_callback(sd_event_source *s, int fd, uint32_t revents, void *userd
 }
 
 static int time_callback(sd_event_source *s, uint64_t usec, void *userdata) {
-        void *bus = userdata;
+        sd_bus *bus = userdata;
         int r;
 
         assert(bus);
@@ -2349,20 +2402,25 @@ static int quit_callback(sd_event_source *event, void *userdata) {
         return 1;
 }
 
-int sd_bus_attach_event(sd_bus *bus, sd_event *event, int priority) {
+_public_ int sd_bus_attach_event(sd_bus *bus, sd_event *event, int priority) {
         int r;
 
         assert_return(bus, -EINVAL);
-        assert_return(event, -EINVAL);
         assert_return(!bus->event, -EBUSY);
 
         assert(!bus->input_io_event_source);
         assert(!bus->output_io_event_source);
         assert(!bus->time_event_source);
 
-        bus->event = sd_event_ref(event);
+        if (event)
+                bus->event = sd_event_ref(event);
+        else  {
+                r = sd_event_default(&bus->event);
+                if (r < 0)
+                        return r;
+        }
 
-        r = sd_event_add_io(event, bus->input_fd, 0, io_callback, bus, &bus->input_io_event_source);
+        r = sd_event_add_io(bus->event, bus->input_fd, 0, io_callback, bus, &bus->input_io_event_source);
         if (r < 0)
                 goto fail;
 
@@ -2371,7 +2429,7 @@ int sd_bus_attach_event(sd_bus *bus, sd_event *event, int priority) {
                 goto fail;
 
         if (bus->output_fd != bus->input_fd) {
-                r = sd_event_add_io(event, bus->output_fd, 0, io_callback, bus, &bus->output_io_event_source);
+                r = sd_event_add_io(bus->event, bus->output_fd, 0, io_callback, bus, &bus->output_io_event_source);
                 if (r < 0)
                         goto fail;
 
@@ -2384,7 +2442,7 @@ int sd_bus_attach_event(sd_bus *bus, sd_event *event, int priority) {
         if (r < 0)
                 goto fail;
 
-        r = sd_event_add_monotonic(event, 0, 0, time_callback, bus, &bus->time_event_source);
+        r = sd_event_add_monotonic(bus->event, 0, 0, time_callback, bus, &bus->time_event_source);
         if (r < 0)
                 goto fail;
 
@@ -2392,7 +2450,7 @@ int sd_bus_attach_event(sd_bus *bus, sd_event *event, int priority) {
         if (r < 0)
                 goto fail;
 
-        r = sd_event_add_quit(event, quit_callback, bus, &bus->quit_event_source);
+        r = sd_event_add_quit(bus->event, quit_callback, bus, &bus->quit_event_source);
         if (r < 0)
                 goto fail;
 
@@ -2403,7 +2461,7 @@ fail:
         return r;
 }
 
-int sd_bus_detach_event(sd_bus *bus) {
+_public_ int sd_bus_detach_event(sd_bus *bus) {
         assert_return(bus, -EINVAL);
         assert_return(bus->event, -ENXIO);
 
@@ -2424,3 +2482,64 @@ int sd_bus_detach_event(sd_bus *bus) {
 
         return 0;
 }
+
+_public_ sd_bus_message* sd_bus_get_current(sd_bus *bus) {
+        assert_return(bus, NULL);
+
+        return bus->current;
+}
+
+static int bus_default(int (*bus_open)(sd_bus **), sd_bus **default_bus, sd_bus **ret) {
+        sd_bus *b = NULL;
+        int r;
+
+        assert(bus_open);
+        assert(default_bus);
+
+        if (!ret)
+                return !!*default_bus;
+
+        if (*default_bus) {
+                *ret = sd_bus_ref(*default_bus);
+                return 0;
+        }
+
+        r = bus_open(&b);
+        if (r < 0)
+                return r;
+
+        b->default_bus_ptr = default_bus;
+        b->tid = gettid();
+        *default_bus = b;
+
+        *ret = b;
+        return 1;
+}
+
+_public_ int sd_bus_default_system(sd_bus **ret) {
+        static __thread sd_bus *default_system_bus = NULL;
+
+        return bus_default(sd_bus_open_system, &default_system_bus, ret);
+}
+
+_public_ int sd_bus_default_user(sd_bus **ret) {
+        static __thread sd_bus *default_user_bus = NULL;
+
+        return bus_default(sd_bus_open_user, &default_user_bus, ret);
+}
+
+_public_ int sd_bus_get_tid(sd_bus *b, pid_t *tid) {
+        assert_return(b, -EINVAL);
+        assert_return(tid, -EINVAL);
+        assert_return(!bus_pid_changed(b), -ECHILD);
+
+        if (b->tid != 0) {
+                *tid = b->tid;
+                return 0;
+        }
+
+        if (b->event)
+                return sd_event_get_tid(b->event, tid);
+
+        return -ENXIO;
+}