core: convert PID 1 to libsystemd-bus

This patch converts PID 1 to libsystemd-bus and thus drops the
dependency on libdbus. The only remaining code using libdbus is a test
case that validates our bus marshalling against libdbus' marshalling,
and this dependency can be turned off.

This patch also adds a couple of things to libsystem-bus, that are
necessary to make the port work:

- Synthesizing of "Disconnected" messages when bus connections are
  severed.

- Support for attaching multiple vtables for the same interface on the
  same path.

This patch also fixes the SetDefaultTarget() and GetDefaultTarget() bus
calls which used an inappropriate signature.

As a side effect we will now generate PropertiesChanged messages which
carry property contents, rather than just invalidation information.

1 files changed, 696 insertions, 1200 deletions

diff --git a/src/core/dbus.c b/src/core/dbus.c
index b0ae3e1ae7..35d185a601 100644
--- a/src/core/dbus.c
+++ b/src/core/dbus.c
@@ -23,9 +23,8 @@
 #include <sys/timerfd.h>
 #include <errno.h>
 #include <unistd.h>
-#include <dbus/dbus.h>
 
-#include "dbus.h"
+#include "sd-bus.h"
 #include "log.h"
 #include "strv.h"
 #include "mkdir.h"
@@ -33,1034 +32,851 @@
 #include "dbus-unit.h"
 #include "dbus-job.h"
 #include "dbus-manager.h"
-#include "dbus-service.h"
-#include "dbus-socket.h"
-#include "dbus-target.h"
-#include "dbus-device.h"
-#include "dbus-mount.h"
-#include "dbus-automount.h"
-#include "dbus-snapshot.h"
-#include "dbus-swap.h"
-#include "dbus-timer.h"
-#include "dbus-path.h"
-#include "bus-errors.h"
+#include "dbus-execute.h"
+#include "dbus-kill.h"
+#include "dbus-cgroup.h"
 #include "special.h"
-#include "dbus-common.h"
+#include "dbus.h"
+#include "bus-util.h"
+#include "bus-error.h"
+#include "bus-errors.h"
+#include "strxcpyx.h"
+#include "dbus-client-track.h"
 
 #define CONNECTIONS_MAX 512
 
-/* Well-known address (http://dbus.freedesktop.org/doc/dbus-specification.html#message-bus-types) */
-#define DBUS_SYSTEM_BUS_DEFAULT_ADDRESS "unix:path=/var/run/dbus/system_bus_socket"
-/* Only used as a fallback */
-#define DBUS_SESSION_BUS_DEFAULT_ADDRESS "autolaunch:"
-
-static const char bus_properties_interface[] = BUS_PROPERTIES_INTERFACE;
-static const char bus_introspectable_interface[] = BUS_INTROSPECTABLE_INTERFACE;
-
-const char *const bus_interface_table[] = {
-        "org.freedesktop.DBus.Properties",     bus_properties_interface,
-        "org.freedesktop.DBus.Introspectable", bus_introspectable_interface,
-        "org.freedesktop.systemd1.Manager",    bus_manager_interface,
-        "org.freedesktop.systemd1.Job",        bus_job_interface,
-        "org.freedesktop.systemd1.Unit",       bus_unit_interface,
-        "org.freedesktop.systemd1.Service",    bus_service_interface,
-        "org.freedesktop.systemd1.Socket",     bus_socket_interface,
-        "org.freedesktop.systemd1.Target",     bus_target_interface,
-        "org.freedesktop.systemd1.Device",     bus_device_interface,
-        "org.freedesktop.systemd1.Mount",      bus_mount_interface,
-        "org.freedesktop.systemd1.Automount",  bus_automount_interface,
-        "org.freedesktop.systemd1.Snapshot",   bus_snapshot_interface,
-        "org.freedesktop.systemd1.Swap",       bus_swap_interface,
-        "org.freedesktop.systemd1.Timer",      bus_timer_interface,
-        "org.freedesktop.systemd1.Path",       bus_path_interface,
-        NULL
-};
-
-static void bus_done_api(Manager *m);
-static void bus_done_system(Manager *m);
-static void bus_done_private(Manager *m);
-static void shutdown_connection(Manager *m, DBusConnection *c);
-
-static void bus_dispatch_status(DBusConnection *bus, DBusDispatchStatus status, void *data)  {
-        Manager *m = data;
+static void destroy_bus(Manager *m, sd_bus **bus);
+
+int bus_send_queued_message(Manager *m) {
+        int r;
 
-        assert(bus);
         assert(m);
 
-        /* We maintain two sets, one for those connections where we
-         * requested a dispatch, and another where we didn't. And then,
-         * we move the connections between the two sets. */
+        if (!m->queued_message)
+                return 0;
 
-        if (status == DBUS_DISPATCH_COMPLETE)
-                set_move_one(m->bus_connections, m->bus_connections_for_dispatch, bus);
-        else
-                set_move_one(m->bus_connections_for_dispatch, m->bus_connections, bus);
-}
+        assert(m->queued_message_bus);
 
-void bus_watch_event(Manager *m, Watch *w, int events) {
-        assert(m);
-        assert(w);
+        /* If we cannot get rid of this message we won't dispatch any
+         * D-Bus messages, so that we won't end up wanting to queue
+         * another message. */
 
-        /* This is called by the event loop whenever there is
-         * something happening on D-Bus' file handles. */
+        r = sd_bus_send(m->queued_message_bus, m->queued_message, NULL);
+        if (r < 0)
+                log_warning("Failed to send queued message: %s", strerror(-r));
 
-        if (!dbus_watch_get_enabled(w->data.bus_watch))
-                return;
+        m->queued_message = sd_bus_message_unref(m->queued_message);
+        m->queued_message_bus = sd_bus_unref(m->queued_message_bus);
 
-        dbus_watch_handle(w->data.bus_watch, bus_events_to_flags(events));
+        return 0;
 }
 
-static dbus_bool_t bus_add_watch(DBusWatch *bus_watch, void *data) {
-        Manager *m = data;
-        Watch *w;
-        struct epoll_event ev;
+static int signal_agent_released(sd_bus *bus, sd_bus_message *message, void *userdata) {
+        Manager *m = userdata;
+        const char *cgroup;
+        int r;
 
-        assert(bus_watch);
+        assert(bus);
+        assert(message);
         assert(m);
 
-        if (!(w = new0(Watch, 1)))
-                return FALSE;
-
-        w->fd = dbus_watch_get_unix_fd(bus_watch);
-        w->type = WATCH_DBUS_WATCH;
-        w->data.bus_watch = bus_watch;
+        r = sd_bus_message_read(message, "s", &cgroup);
+        if (r < 0) {
+                bus_log_parse_error(r);
+                return 0;
+        }
 
-        zero(ev);
-        ev.events = bus_flags_to_events(bus_watch);
-        ev.data.ptr = w;
+        manager_notify_cgroup_empty(m, cgroup);
 
-        if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, w->fd, &ev) < 0) {
+        if (m->running_as == SYSTEMD_SYSTEM && m->system_bus) {
+                /* If we are running as system manager, forward the
+                 * message to the system bus */
 
-                if (errno != EEXIST) {
-                        free(w);
-                        return FALSE;
-                }
+                r = sd_bus_send(m->system_bus, message, NULL);
+                if (r < 0)
+                        log_warning("Failed to forward Released message: %s", strerror(-r));
+        }
 
-                /* Hmm, bloody D-Bus creates multiple watches on the
-                 * same fd. epoll() does not like that. As a dirty
-                 * hack we simply dup() the fd and hence get a second
-                 * one we can safely add to the epoll(). */
+        return 0;
+}
 
-                if ((w->fd = dup(w->fd)) < 0) {
-                        free(w);
-                        return FALSE;
-                }
+static int signal_disconnected(sd_bus *bus, sd_bus_message *message, void *userdata) {
+        Manager *m = userdata;
 
-                if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, w->fd, &ev) < 0) {
-                        close_nointr_nofail(w->fd);
-                        free(w);
-                        return FALSE;
-                }
+        assert(bus);
+        assert(message);
+        assert(m);
 
-                w->fd_is_dupped = true;
+        if (bus == m->api_bus)
+                destroy_bus(m, &m->api_bus);
+        if (bus == m->system_bus)
+                destroy_bus(m, &m->system_bus);
+        if (set_remove(m->private_buses, bus)) {
+                log_debug("Got disconnect on private connection.");
+                destroy_bus(m, &bus);
         }
 
-        dbus_watch_set_data(bus_watch, w, NULL);
-
-        return TRUE;
+        return 0;
 }
 
-static void bus_remove_watch(DBusWatch *bus_watch, void *data) {
-        Manager *m = data;
-        Watch *w;
+static int signal_name_owner_changed(sd_bus *bus, sd_bus_message *message, void *userdata) {
+        const char *name, *old_owner, *new_owner;
+        Manager *m = userdata;
+        int r;
 
-        assert(bus_watch);
+        assert(bus);
+        assert(message);
         assert(m);
 
-        w = dbus_watch_get_data(bus_watch);
-        if (!w)
-                return;
-
-        assert(w->type == WATCH_DBUS_WATCH);
-        assert_se(epoll_ctl(m->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
+        r = sd_bus_message_read(message, "sss", &name, &old_owner, &new_owner);
+        if (r < 0) {
+                bus_log_parse_error(r);
+                return 0;
+        }
 
-        if (w->fd_is_dupped)
-                close_nointr_nofail(w->fd);
+        manager_dispatch_bus_name_owner_changed(
+                        m, name,
+                        isempty(old_owner) ? NULL : old_owner,
+                        isempty(new_owner) ? NULL : new_owner);
 
-        free(w);
+        return 0;
 }
 
-static void bus_toggle_watch(DBusWatch *bus_watch, void *data) {
-        Manager *m = data;
-        Watch *w;
-        struct epoll_event ev;
+static int signal_activation_request(sd_bus *bus, sd_bus_message *message, void *userdata) {
+        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        Manager *m = userdata;
+        const char *name;
+        Unit *u;
+        int r;
 
-        assert(bus_watch);
+        assert(bus);
+        assert(message);
         assert(m);
 
-        w = dbus_watch_get_data(bus_watch);
-        if (!w)
-                return;
-
-        assert(w->type == WATCH_DBUS_WATCH);
-
-        zero(ev);
-        ev.events = bus_flags_to_events(bus_watch);
-        ev.data.ptr = w;
-
-        assert_se(epoll_ctl(m->epoll_fd, EPOLL_CTL_MOD, w->fd, &ev) == 0);
-}
+        r = sd_bus_message_read(message, "s", &name);
+        if (r < 0) {
+                bus_log_parse_error(r);
+                return 0;
+        }
 
-static int bus_timeout_arm(Manager *m, Watch *w) {
-        struct itimerspec its = {};
+        if (manager_unit_inactive_or_pending(m, SPECIAL_DBUS_SERVICE) ||
+            manager_unit_inactive_or_pending(m, SPECIAL_DBUS_SOCKET)) {
+                r = sd_bus_error_setf(&error, BUS_ERROR_SHUTTING_DOWN, "Refusing activation, D-Bus is shutting down.");
+                goto failed;
+        }
 
-        assert(m);
-        assert(w);
+        r = manager_load_unit(m, name, NULL, &error, &u);
+        if (r < 0)
+                goto failed;
 
-        if (dbus_timeout_get_enabled(w->data.bus_timeout)) {
-                timespec_store(&its.it_value, dbus_timeout_get_interval(w->data.bus_timeout) * USEC_PER_MSEC);
-                its.it_interval = its.it_value;
+        if (u->refuse_manual_start) {
+                r = sd_bus_error_setf(&error, BUS_ERROR_ONLY_BY_DEPENDENCY, "Operation refused, %u may be requested by dependency only.", u->id);
+                goto failed;
         }
 
-        if (timerfd_settime(w->fd, 0, &its, NULL) < 0)
-                return -errno;
+        r = manager_add_job(m, JOB_START, u, JOB_REPLACE, true, &error, NULL);
+        if (r < 0)
+                goto failed;
 
+        /* Successfully queued, that's it for us */
         return 0;
-}
 
-void bus_timeout_event(Manager *m, Watch *w, int events) {
-        assert(m);
-        assert(w);
+failed:
+        if (!sd_bus_error_is_set(&error))
+                sd_bus_error_set_errno(&error, r);
 
-        /* This is called by the event loop whenever there is
-         * something happening on D-Bus' file handles. */
+        log_debug("D-Bus activation failed for %s: %s", name, bus_error_message(&error, r));
 
-        if (!(dbus_timeout_get_enabled(w->data.bus_timeout)))
-                return;
+        r = sd_bus_message_new_signal(bus, "/org/freedesktop/systemd1", "org.freedesktop.systemd1.Activator", "ActivationFailure", &reply);
+        if (r < 0) {
+                bus_log_create_error(r);
+                return 0;
+        }
 
-        dbus_timeout_handle(w->data.bus_timeout);
+        r = sd_bus_message_append(reply, "sss", error.name, error.message);
+        if (r < 0) {
+                bus_log_create_error(r);
+                return 0;
+        }
+
+        r = sd_bus_send_to(bus, reply, "org.freedesktop.DBus", NULL);
+        if (r < 0) {
+                log_error("Failed to respond with to bus activation request: %s", strerror(-r));
+                return r;
+        }
+
+        return 0;
 }
 
-static dbus_bool_t bus_add_timeout(DBusTimeout *timeout, void *data) {
-        Manager *m = data;
-        Watch *w;
-        struct epoll_event ev;
+static int bus_job_find(sd_bus *bus, const char *path, const char *interface, void **found, void *userdata) {
+        Manager *m = userdata;
+        Job *j;
+        int r;
 
-        assert(timeout);
+        assert(bus);
+        assert(path);
+        assert(interface);
+        assert(found);
         assert(m);
 
-        if (!(w = new0(Watch, 1)))
-                return FALSE;
-
-        if ((w->fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0)
-                goto fail;
+        r = manager_get_job_from_dbus_path(m, path, &j);
+        if (r < 0)
+                return 0;
 
-        w->type = WATCH_DBUS_TIMEOUT;
-        w->data.bus_timeout = timeout;
+        *found = j;
+        return 1;
+}
 
-        if (bus_timeout_arm(m, w) < 0)
-                goto fail;
+static Unit *find_unit(Manager *m, sd_bus *bus, const char *path) {
+        Unit *u;
+        int r;
 
-        zero(ev);
-        ev.events = EPOLLIN;
-        ev.data.ptr = w;
+        assert(m);
+        assert(bus);
+        assert(path);
 
-        if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, w->fd, &ev) < 0)
-                goto fail;
+        if (streq_ptr(path, "/org/freedesktop/systemd1/unit/self")) {
+                sd_bus_message *message;
+                pid_t pid;
 
-        dbus_timeout_set_data(timeout, w, NULL);
+                message = sd_bus_get_current(bus);
+                if (!message)
+                        return NULL;
 
-        return TRUE;
+                r = sd_bus_get_owner_pid(bus, sd_bus_message_get_sender(message), &pid);
+                if (r < 0)
+                        return NULL;
 
-fail:
-        if (w->fd >= 0)
-                close_nointr_nofail(w->fd);
+                u = manager_get_unit_by_pid(m, pid);
+        } else {
+                r = manager_load_unit_from_dbus_path(m, path, NULL, &u);
+                if (r < 0)
+                        return NULL;
+        }
 
-        free(w);
-        return FALSE;
+        return u;
 }
 
-static void bus_remove_timeout(DBusTimeout *timeout, void *data) {
-        Manager *m = data;
-        Watch *w;
+static int bus_unit_find(sd_bus *bus, const char *path, const char *interface, void **found, void *userdata) {
+        Manager *m = userdata;
+        Unit *u;
 
-        assert(timeout);
+        assert(bus);
+        assert(path);
+        assert(interface);
+        assert(found);
         assert(m);
 
-        w = dbus_timeout_get_data(timeout);
-        if (!w)
-                return;
-
-        assert(w->type == WATCH_DBUS_TIMEOUT);
+        u = find_unit(m, bus, path);
+        if (!u)
+                return 0;
 
-        assert_se(epoll_ctl(m->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0);
-        close_nointr_nofail(w->fd);
-        free(w);
+        *found = u;
+        return 1;
 }
 
-static void bus_toggle_timeout(DBusTimeout *timeout, void *data) {
-        Manager *m = data;
-        Watch *w;
-        int r;
+static int bus_unit_interface_find(sd_bus *bus, const char *path, const char *interface, void **found, void *userdata) {
+        Manager *m = userdata;
+        Unit *u;
 
-        assert(timeout);
+        assert(bus);
+        assert(path);
+        assert(interface);
+        assert(found);
         assert(m);
 
-        w = dbus_timeout_get_data(timeout);
-        if (!w)
-                return;
+        u = find_unit(m, bus, path);
+        if (!u)
+                return 0;
 
-        assert(w->type == WATCH_DBUS_TIMEOUT);
+        if (!streq_ptr(interface, UNIT_VTABLE(u)->bus_interface))
+                return 0;
 
-        if ((r = bus_timeout_arm(m, w)) < 0)
-                log_error("Failed to rearm timer: %s", strerror(-r));
+        *found = u;
+        return 1;
 }
 
-static DBusHandlerResult api_bus_message_filter(DBusConnection *connection, DBusMessage *message, void *data) {
-        Manager *m = data;
-        DBusError error;
-        DBusMessage *reply = NULL;
+static int bus_unit_cgroup_find(sd_bus *bus, const char *path, const char *interface, void **found, void *userdata) {
+        Manager *m = userdata;
+        Unit *u;
 
-        assert(connection);
-        assert(message);
+        assert(bus);
+        assert(path);
+        assert(interface);
+        assert(found);
         assert(m);
 
-        dbus_error_init(&error);
-
-        if (dbus_message_get_type(message) == DBUS_MESSAGE_TYPE_METHOD_CALL ||
-            dbus_message_get_type(message) == DBUS_MESSAGE_TYPE_SIGNAL)
-                log_debug("Got D-Bus request: %s.%s() on %s",
-                          dbus_message_get_interface(message),
-                          dbus_message_get_member(message),
-                          dbus_message_get_path(message));
-
-        if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) {
-                log_debug("API D-Bus connection terminated.");
-                bus_done_api(m);
-
-        } else if (dbus_message_is_signal(message, DBUS_INTERFACE_DBUS, "NameOwnerChanged")) {
-                const char *name, *old_owner, *new_owner;
-
-                if (!dbus_message_get_args(message, &error,
-                                           DBUS_TYPE_STRING, &name,
-                                           DBUS_TYPE_STRING, &old_owner,
-                                           DBUS_TYPE_STRING, &new_owner,
-                                           DBUS_TYPE_INVALID))
-                        log_error("Failed to parse NameOwnerChanged message: %s", bus_error_message(&error));
-                else  {
-                        if (set_remove(BUS_CONNECTION_SUBSCRIBED(m, connection), (char*) name))
-                                log_debug("Subscription client vanished: %s (left: %u)", name, set_size(BUS_CONNECTION_SUBSCRIBED(m, connection)));
-
-                        if (old_owner[0] == 0)
-                                old_owner = NULL;
+        u = find_unit(m, bus, path);
+        if (!u)
+                return 0;
 
-                        if (new_owner[0] == 0)
-                                new_owner = NULL;
+        if (!streq_ptr(interface, UNIT_VTABLE(u)->bus_interface))
+                return 0;
 
-                        manager_dispatch_bus_name_owner_changed(m, name, old_owner, new_owner);
-                }
-        } else if (dbus_message_is_signal(message, "org.freedesktop.systemd1.Activator", "ActivationRequest")) {
-                const char *name;
-
-                if (!dbus_message_get_args(message, &error,
-                                           DBUS_TYPE_STRING, &name,
-                                           DBUS_TYPE_INVALID))
-                        log_error("Failed to parse ActivationRequest message: %s", bus_error_message(&error));
-                else  {
-                        int r;
-                        Unit *u;
-
-                        log_debug("Got D-Bus activation request for %s", name);
-
-                        if (manager_unit_inactive_or_pending(m, SPECIAL_DBUS_SERVICE) ||
-                            manager_unit_inactive_or_pending(m, SPECIAL_DBUS_SOCKET)) {
-                                r = -EADDRNOTAVAIL;
-                                dbus_set_error(&error, BUS_ERROR_SHUTTING_DOWN, "Refusing activation, D-Bus is shutting down.");
-                        } else {
-                                r = manager_load_unit(m, name, NULL, &error, &u);
-
-                                if (r >= 0 && u->refuse_manual_start)
-                                        r = -EPERM;
-
-                                if (r >= 0)
-                                        r = manager_add_job(m, JOB_START, u, JOB_REPLACE, true, &error, NULL);
-                        }
+        if (!unit_get_cgroup_context(u))
+                return 0;
 
-                        if (r < 0) {
-                                const char *id, *text;
+        *found = u;
+        return 1;
+}
 
-                                log_debug("D-Bus activation failed for %s: %s", name, strerror(-r));
+static int bus_cgroup_context_find(sd_bus *bus, const char *path, const char *interface, void **found, void *userdata) {
+        Manager *m = userdata;
+        CGroupContext *c;
+        Unit *u;
 
-                                if (!(reply = dbus_message_new_signal("/org/freedesktop/systemd1", "org.freedesktop.systemd1.Activator", "ActivationFailure")))
-                                        goto oom;
+        assert(bus);
+        assert(path);
+        assert(interface);
+        assert(found);
+        assert(m);
 
-                                id = error.name ? error.name : bus_errno_to_dbus(r);
-                                text = bus_error(&error, r);
+        u = find_unit(m, bus, path);
+        if (!u)
+                return 0;
 
-                                if (!dbus_message_set_destination(reply, DBUS_SERVICE_DBUS) ||
-                                    !dbus_message_append_args(reply,
-                                                              DBUS_TYPE_STRING, &name,
-                                                              DBUS_TYPE_STRING, &id,
-                                                              DBUS_TYPE_STRING, &text,
-                                                              DBUS_TYPE_INVALID))
-                                        goto oom;
-                        }
+        if (!streq_ptr(interface, UNIT_VTABLE(u)->bus_interface))
+                return 0;
 
-                        /* On success we don't do anything, the service will be spawned now */
-                }
-        }
+        c = unit_get_cgroup_context(u);
+        if (!c)
+                return 0;
 
-        dbus_error_free(&error);
+        *found = c;
+        return 1;
+}
 
-        if (reply) {
-                if (!bus_maybe_send_reply(connection, message, reply))
-                        goto oom;
+static int bus_exec_context_find(sd_bus *bus, const char *path, const char *interface, void **found, void *userdata) {
+        Manager *m = userdata;
+        ExecContext *c;
+        Unit *u;
 
-                dbus_message_unref(reply);
-        }
+        assert(bus);
+        assert(path);
+        assert(interface);
+        assert(found);
+        assert(m);
 
-        return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+        u = find_unit(m, bus, path);
+        if (!u)
+                return 0;
 
-oom:
-        if (reply)
-                dbus_message_unref(reply);
+        if (!streq_ptr(interface, UNIT_VTABLE(u)->bus_interface))
+                return 0;
 
-        dbus_error_free(&error);
+        c = unit_get_exec_context(u);
+        if (!c)
+                return 0;
 
-        return DBUS_HANDLER_RESULT_NEED_MEMORY;
+        *found = c;
+        return 1;
 }
 
-static DBusHandlerResult system_bus_message_filter(DBusConnection *connection, DBusMessage *message, void *data) {
-        Manager *m = data;
-        DBusError error;
+static int bus_kill_context_find(sd_bus *bus, const char *path, const char *interface, void **found, void *userdata) {
+        Manager *m = userdata;
+        KillContext *c;
+        Unit *u;
 
-        assert(connection);
-        assert(message);
+        assert(bus);
+        assert(path);
+        assert(interface);
+        assert(found);
         assert(m);
 
-        dbus_error_init(&error);
-
-        if (m->api_bus != m->system_bus &&
-            (dbus_message_get_type(message) == DBUS_MESSAGE_TYPE_METHOD_CALL ||
-             dbus_message_get_type(message) == DBUS_MESSAGE_TYPE_SIGNAL))
-                log_debug("Got D-Bus request on system bus: %s.%s() on %s",
-                          dbus_message_get_interface(message),
-                          dbus_message_get_member(message),
-                          dbus_message_get_path(message));
+        u = find_unit(m, bus, path);
+        if (!u)
+                return 0;
 
-        if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) {
-                log_debug("System D-Bus connection terminated.");
-                bus_done_system(m);
+        if (!streq_ptr(interface, UNIT_VTABLE(u)->bus_interface))
+                return 0;
 
-        } else if (m->running_as != SYSTEMD_SYSTEM &&
-                   dbus_message_is_signal(message, "org.freedesktop.systemd1.Agent", "Released")) {
+        c = unit_get_kill_context(u);
+        if (!c)
+                return 0;
 
-                const char *cgroup;
+        *found = c;
+        return 1;
+}
 
-                if (!dbus_message_get_args(message, &error,
-                                           DBUS_TYPE_STRING, &cgroup,
-                                           DBUS_TYPE_INVALID))
-                        log_error("Failed to parse Released message: %s", bus_error_message(&error));
-                else
-                        manager_notify_cgroup_empty(m, cgroup);
-        }
+static int bus_job_enumerate(sd_bus *bus, const char *path, char ***nodes, void *userdata) {
+        _cleanup_free_ char **l = NULL;
+        Manager *m = userdata;
+        unsigned k = 0;
+        Iterator i;
+        Job *j;
 
-        dbus_error_free(&error);
-        return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
-}
+        l = new0(char*, hashmap_size(m->jobs)+1);
+        if (!l)
+                return -ENOMEM;
 
-static DBusHandlerResult private_bus_message_filter(DBusConnection *connection, DBusMessage *message, void *data) {
-        Manager *m = data;
-        DBusError error;
+        HASHMAP_FOREACH(j, m->jobs, i) {
+                l[k] = job_dbus_path(j);
+                if (!l[k])
+                        return -ENOMEM;
 
-        assert(connection);
-        assert(message);
-        assert(m);
+                k++;
+        }
 
-        dbus_error_init(&error);
+        assert(hashmap_size(m->jobs) == k);
 
-        if (dbus_message_get_type(message) == DBUS_MESSAGE_TYPE_METHOD_CALL ||
-            dbus_message_get_type(message) == DBUS_MESSAGE_TYPE_SIGNAL)
-                log_debug("Got D-Bus request: %s.%s() on %s",
-                          dbus_message_get_interface(message),
-                          dbus_message_get_member(message),
-                          dbus_message_get_path(message));
+        *nodes = l;
+        l = NULL;
 
-        if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected"))
-                shutdown_connection(m, connection);
-        else if (m->running_as == SYSTEMD_SYSTEM &&
-                 dbus_message_is_signal(message, "org.freedesktop.systemd1.Agent", "Released")) {
+        return k;
+}
 
-                const char *cgroup;
+static int bus_unit_enumerate(sd_bus *bus, const char *path, char ***nodes, void *userdata) {
+        _cleanup_free_ char **l = NULL;
+        Manager *m = userdata;
+        unsigned k = 0;
+        Iterator i;
+        Unit *u;
 
-                if (!dbus_message_get_args(message, &error,
-                                           DBUS_TYPE_STRING, &cgroup,
-                                           DBUS_TYPE_INVALID))
-                        log_error("Failed to parse Released message: %s", bus_error_message(&error));
-                else
-                        manager_notify_cgroup_empty(m, cgroup);
+        l = new0(char*, hashmap_size(m->units)+1);
+        if (!l)
+                return -ENOMEM;
 
-                /* Forward the message to the system bus, so that user
-                 * instances are notified as well */
+        HASHMAP_FOREACH(u, m->units, i) {
+                l[k] = unit_dbus_path(u);
+                if (!l[k])
+                        return -ENOMEM;
 
-                if (m->system_bus)
-                        dbus_connection_send(m->system_bus, message, NULL);
+                k++;
         }
 
-        dbus_error_free(&error);
+        *nodes = l;
+        l = NULL;
 
-        return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+        return k;
 }
 
-unsigned bus_dispatch(Manager *m) {
-        DBusConnection *c;
+static int bus_setup_api_vtables(Manager *m, sd_bus *bus) {
+        UnitType t;
+        int r;
 
         assert(m);
+        assert(bus);
 
-        if (m->queued_message) {
-                /* If we cannot get rid of this message we won't
-                 * dispatch any D-Bus messages, so that we won't end
-                 * up wanting to queue another message. */
-
-                if (m->queued_message_connection)
-                        if (!dbus_connection_send(m->queued_message_connection, m->queued_message, NULL))
-                                return 0;
-
-                dbus_message_unref(m->queued_message);
-                m->queued_message = NULL;
-                m->queued_message_connection = NULL;
+        r = sd_bus_add_object_vtable(bus, "/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", bus_manager_vtable, m);
+        if (r < 0) {
+                log_error("Failed to register Manager vtable: %s", strerror(-r));
+                return r;
         }
 
-        if ((c = set_first(m->bus_connections_for_dispatch))) {
-                if (dbus_connection_dispatch(c) == DBUS_DISPATCH_COMPLETE)
-                        set_move_one(m->bus_connections, m->bus_connections_for_dispatch, c);
-
-                return 1;
+        r = sd_bus_add_fallback_vtable(bus, "/org/freedesktop/systemd1/job", "org.freedesktop.systemd1.Job", bus_job_vtable, bus_job_find, m);
+        if (r < 0) {
+                log_error("Failed to register Job vtable: %s", strerror(-r));
+                return r;
         }
 
-        return 0;
-}
-
-static void request_name_pending_cb(DBusPendingCall *pending, void *userdata) {
-        DBusMessage *reply;
-        DBusError error;
-
-        dbus_error_init(&error);
-
-        assert_se(reply = dbus_pending_call_steal_reply(pending));
+        r = sd_bus_add_node_enumerator(bus, "/org/freedesktop/systemd1/job", bus_job_enumerate, m);
+        if (r < 0) {
+                log_error("Failed to add job enumerator: %s", strerror(-r));
+                return r;
+        }
 
-        switch (dbus_message_get_type(reply)) {
+        r = sd_bus_add_fallback_vtable(bus, "/org/freedesktop/systemd1/unit", "org.freedesktop.systemd1.Unit", bus_unit_vtable, bus_unit_find, m);
+        if (r < 0) {
+                log_error("Failed to register Unit vtable: %s", strerror(-r));
+                return r;
+        }
 
-        case DBUS_MESSAGE_TYPE_ERROR:
+        r = sd_bus_add_node_enumerator(bus, "/org/freedesktop/systemd1/unit", bus_unit_enumerate, m);
+        if (r < 0) {
+                log_error("Failed to add job enumerator: %s", strerror(-r));
+                return r;
+        }
 
-                assert_se(dbus_set_error_from_message(&error, reply));
-                log_warning("RequestName() failed: %s", bus_error_message(&error));
-                break;
+        for (t = 0; t < _UNIT_TYPE_MAX; t++) {
+                r = sd_bus_add_fallback_vtable(bus, "/org/freedesktop/systemd1/unit", unit_vtable[t]->bus_interface, unit_vtable[t]->bus_vtable, bus_unit_interface_find, m);
+                if (r < 0)  {
+                        log_error("Failed to register type specific vtable for %s: %s", unit_vtable[t]->bus_interface, strerror(-r));
+                        return r;
+                }
 
-        case DBUS_MESSAGE_TYPE_METHOD_RETURN: {
-                uint32_t r;
+                if (unit_vtable[t]->cgroup_context_offset > 0) {
+                        r = sd_bus_add_fallback_vtable(bus, "/org/freedesktop/systemd1/unit", unit_vtable[t]->bus_interface, bus_unit_cgroup_vtable, bus_unit_cgroup_find, m);
+                        if (r < 0) {
+                                log_error("Failed to register control group unit vtable for %s: %s", unit_vtable[t]->bus_interface, strerror(-r));
+                                return r;
+                        }
 
-                if (!dbus_message_get_args(reply,
-                                           &error,
-                                           DBUS_TYPE_UINT32, &r,
-                                           DBUS_TYPE_INVALID)) {
-                        log_error("Failed to parse RequestName() reply: %s", bus_error_message(&error));
-                        break;
+                        r = sd_bus_add_fallback_vtable(bus, "/org/freedesktop/systemd1/unit", unit_vtable[t]->bus_interface, bus_cgroup_vtable, bus_cgroup_context_find, m);
+                        if (r < 0) {
+                                log_error("Failed to register control group vtable for %s: %s", unit_vtable[t]->bus_interface, strerror(-r));
+                                return r;
+                        }
                 }
 
-                if (r == 1)
-                        log_debug("Successfully acquired name.");
-                else
-                        log_error("Name already owned.");
-
-                break;
-        }
+                if (unit_vtable[t]->exec_context_offset > 0) {
+                        r = sd_bus_add_fallback_vtable(bus, "/org/freedesktop/systemd1/unit", unit_vtable[t]->bus_interface, bus_exec_vtable, bus_exec_context_find, m);
+                        if (r < 0) {
+                                log_error("Failed to register execute vtable for %s: %s", unit_vtable[t]->bus_interface, strerror(-r));
+                                return r;
+                        }
+                }
 
-        default:
-                assert_not_reached("Invalid reply message");
+                if (unit_vtable[t]->kill_context_offset > 0) {
+                        r = sd_bus_add_fallback_vtable(bus, "/org/freedesktop/systemd1/unit", unit_vtable[t]->bus_interface, bus_kill_vtable, bus_kill_context_find, m);
+                        if (r < 0) {
+                                log_error("Failed to register kill vtable for %s: %s", unit_vtable[t]->bus_interface, strerror(-r));
+                                return r;
+                        }
+                }
         }
 
-        dbus_message_unref(reply);
-        dbus_error_free(&error);
+        return 0;
 }
 
-static int request_name(Manager *m) {
-        const char *name = "org.freedesktop.systemd1";
-        /* Allow replacing of our name, to ease implementation of
-         * reexecution, where we keep the old connection open until
-         * after the new connection is set up and the name installed
-         * to allow clients to synchronously wait for reexecution to
-         * finish */
-        uint32_t flags = DBUS_NAME_FLAG_ALLOW_REPLACEMENT|DBUS_NAME_FLAG_REPLACE_EXISTING;
-        DBusMessage *message = NULL;
-        DBusPendingCall *pending = NULL;
-
-        if (!(message = dbus_message_new_method_call(
-                              DBUS_SERVICE_DBUS,
-                              DBUS_PATH_DBUS,
-                              DBUS_INTERFACE_DBUS,
-                              "RequestName")))
-                goto oom;
-
-        if (!dbus_message_append_args(
-                            message,
-                            DBUS_TYPE_STRING, &name,
-                            DBUS_TYPE_UINT32, &flags,
-                            DBUS_TYPE_INVALID))
-                goto oom;
-
-        if (!dbus_connection_send_with_reply(m->api_bus, message, &pending, -1))
-                goto oom;
-
-        if (!dbus_pending_call_set_notify(pending, request_name_pending_cb, m, NULL))
-                goto oom;
+static int bus_setup_disconnected_match(Manager *m, sd_bus *bus) {
+        int r;
 
-        dbus_message_unref(message);
-        dbus_pending_call_unref(pending);
+        assert(m);
+        assert(bus);
 
-        /* We simple ask for the name and don't wait for it. Sooner or
-         * later we'll have it. */
+        r = sd_bus_add_match(
+                        bus,
+                        "type='signal',"
+                        "path='/org/freedesktop/DBus/Local',"
+                        "interface='org.freedesktop.DBus.Local',"
+                        "member='Disconnected'",
+                        signal_disconnected, m);
 
-        return 0;
-
-oom:
-        if (pending) {
-                dbus_pending_call_cancel(pending);
-                dbus_pending_call_unref(pending);
+        if (r < 0) {
+                log_error("Failed to register match for Disconnected message: %s", strerror(-r));
+                return r;
         }
 
-        if (message)
-                dbus_message_unref(message);
-
-        return -ENOMEM;
+        return 0;
 }
 
-static void query_name_list_pending_cb(DBusPendingCall *pending, void *userdata) {
-        DBusMessage *reply;
-        DBusError error;
+static int bus_on_connection(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        _cleanup_bus_unref_ sd_bus *bus = NULL;
+        _cleanup_close_ int nfd = -1;
         Manager *m = userdata;
+        sd_id128_t id;
+        int r;
 
+        assert(s);
         assert(m);
 
-        dbus_error_init(&error);
-
-        assert_se(reply = dbus_pending_call_steal_reply(pending));
-
-        switch (dbus_message_get_type(reply)) {
-
-        case DBUS_MESSAGE_TYPE_ERROR:
-
-                assert_se(dbus_set_error_from_message(&error, reply));
-                log_warning("ListNames() failed: %s", bus_error_message(&error));
-                break;
-
-        case DBUS_MESSAGE_TYPE_METHOD_RETURN: {
-                int r;
-                char **l;
-
-                if ((r = bus_parse_strv(reply, &l)) < 0)
-                        log_warning("Failed to parse ListNames() reply: %s", strerror(-r));
-                else {
-                        char **t;
-
-                        STRV_FOREACH(t, l)
-                                /* This is a bit hacky, we say the
-                                 * owner of the name is the name
-                                 * itself, because we don't want the
-                                 * extra traffic to figure out the
-                                 * real owner. */
-                                manager_dispatch_bus_name_owner_changed(m, *t, NULL, *t);
-
-                        strv_free(l);
-                }
-
-                break;
+        nfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
+        if (nfd < 0) {
+                log_warning("Failed to accept private connection, ignoring: %m");
+                return 0;
         }
 
-        default:
-                assert_not_reached("Invalid reply message");
+        if (set_size(m->private_buses) >= CONNECTIONS_MAX) {
+                log_warning("Too many concurrent connections, refusing");
+                return 0;
         }
 
-        dbus_message_unref(reply);
-        dbus_error_free(&error);
-}
-
-static int query_name_list(Manager *m) {
-        DBusMessage *message = NULL;
-        DBusPendingCall *pending = NULL;
+        r = set_ensure_allocated(&m->private_buses, trivial_hash_func, trivial_compare_func);
+        if (r < 0) {
+                log_oom();
+                return 0;
+        }
 
-        /* Asks for the currently installed bus names */
+        r = sd_bus_new(&bus);
+        if (r < 0) {
+                log_warning("Failed to allocate new private connection bus: %s", strerror(-r));
+                return 0;
+        }
 
-        if (!(message = dbus_message_new_method_call(
-                              DBUS_SERVICE_DBUS,
-                              DBUS_PATH_DBUS,
-                              DBUS_INTERFACE_DBUS,
-                              "ListNames")))
-                goto oom;
+        r = sd_bus_set_fd(bus, nfd, nfd);
+        if (r < 0) {
+                log_warning("Failed to set fd on new connection bus: %s", strerror(-r));
+                return 0;
+        }
 
-        if (!dbus_connection_send_with_reply(m->api_bus, message, &pending, -1))
-                goto oom;
+        nfd = -1;
 
-        if (!dbus_pending_call_set_notify(pending, query_name_list_pending_cb, m, NULL))
-                goto oom;
+        r = bus_check_peercred(bus);
+        if (r < 0) {
+                log_warning("Incoming private connection from unprivileged client, refusing: %s", strerror(-r));
+                return 0;
+        }
 
-        dbus_message_unref(message);
-        dbus_pending_call_unref(pending);
+        assert_se(sd_id128_randomize(&id) >= 0);
 
-        /* We simple ask for the list and don't wait for it. Sooner or
-         * later we'll get it. */
+        r = sd_bus_set_server(bus, 1, id);
+        if (r < 0) {
+                log_warning("Failed to enable server support for new connection bus: %s", strerror(-r));
+                return 0;
+        }
 
-        return 0;
+        r = sd_bus_start(bus);
+        if (r < 0) {
+                log_warning("Failed to start new connection bus: %s", strerror(-r));
+                return 0;
+        }
 
-oom:
-        if (pending) {
-                dbus_pending_call_cancel(pending);
-                dbus_pending_call_unref(pending);
+        r = sd_bus_attach_event(bus, m->event, SD_EVENT_PRIORITY_NORMAL);
+        if (r < 0) {
+                log_warning("Failed to attach new connection bus to event loop: %s", strerror(-r));
+                return 0;
         }
 
-        if (message)
-                dbus_message_unref(message);
+        if (m->running_as == SYSTEMD_SYSTEM) {
+                /* When we run as system instance we get the Released
+                 * signal via a direct connection */
+
+                r = sd_bus_add_match(
+                                bus,
+                                "type='signal',"
+                                "interface='org.freedesktop.systemd1.Agent',"
+                                "member='Released',"
+                                "path='/org/freedesktop/systemd1/agent'",
+                                signal_agent_released, m);
+
+                if (r < 0) {
+                        log_warning("Failed to register Released match on new connection bus: %s", strerror(-r));
+                        return 0;
+                }
+        }
 
-        return -ENOMEM;
-}
+        r = bus_setup_disconnected_match(m, bus);
+        if (r < 0)
+                return 0;
 
-static int bus_setup_loop(Manager *m, DBusConnection *bus) {
-        assert(m);
-        assert(bus);
+        r = bus_setup_api_vtables(m, bus);
+        if (r < 0) {
+                log_warning("Failed to set up API vtables on new connection bus: %s", strerror(-r));
+                return 0;
+        }
 
-        dbus_connection_set_exit_on_disconnect(bus, FALSE);
+        r = set_put(m->private_buses, bus);
+        if (r < 0) {
+                log_warning("Failed to add new conenction bus to set: %s", strerror(-r));
+                return 0;
+        }
 
-        if (!dbus_connection_set_watch_functions(bus, bus_add_watch, bus_remove_watch, bus_toggle_watch, m, NULL) ||
-            !dbus_connection_set_timeout_functions(bus, bus_add_timeout, bus_remove_timeout, bus_toggle_timeout, m, NULL))
-                return log_oom();
+        bus = NULL;
 
-        if (set_put(m->bus_connections_for_dispatch, bus) < 0)
-                return log_oom();
+        log_debug("Accepted new private connection.");
 
-        dbus_connection_set_dispatch_status_function(bus, bus_dispatch_status, m, NULL);
         return 0;
 }
 
-static dbus_bool_t allow_only_same_user(DBusConnection *connection, unsigned long uid, void *data) {
-        return uid == 0 || uid == geteuid();
-}
-
-static void bus_new_connection(
-                DBusServer *server,
-                DBusConnection *new_connection,
-                void *data) {
-
-        Manager *m = data;
+static int bus_list_names(Manager *m, sd_bus *bus) {
+        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        const char *name;
+        int r;
 
         assert(m);
+        assert(bus);
 
-        if (set_size(m->bus_connections) >= CONNECTIONS_MAX) {
-                log_error("Too many concurrent connections.");
-                return;
+        r = sd_bus_call_method(
+                        bus,
+                        "org.freedesktop.DBus",
+                        "/org/freedesktop/DBus",
+                        "org.freedesktop.DBus",
+                        "ListNames",
+                        &error, &reply,
+                        NULL);
+        if (r < 0) {
+                log_error("Failed to get initial list of names: %s", bus_error_message(&error, r));
+                return r;
         }
 
-        dbus_connection_set_unix_user_function(new_connection, allow_only_same_user, NULL, NULL);
-
-        if (bus_setup_loop(m, new_connection) < 0)
-                return;
+        r = sd_bus_message_enter_container(reply, 'a', "s");
+        if (r < 0)
+                return bus_log_parse_error(r);
 
-        if (!dbus_connection_register_object_path(new_connection, "/org/freedesktop/systemd1", &bus_manager_vtable, m) ||
-            !dbus_connection_register_fallback(new_connection, "/org/freedesktop/systemd1/unit", &bus_unit_vtable, m) ||
-            !dbus_connection_register_fallback(new_connection, "/org/freedesktop/systemd1/job", &bus_job_vtable, m) ||
-            !dbus_connection_add_filter(new_connection, private_bus_message_filter, m, NULL)) {
-                log_oom();
-                return;
-        }
+        /* This is a bit hacky, we say the owner of the name is the
+         * name itself, because we don't want the extra traffic to
+         * figure out the real owner. */
+        while ((r = sd_bus_message_read(reply, "s", &name)) > 0)
+                manager_dispatch_bus_name_owner_changed(m, name, NULL, name);
+        if (r < 0)
+                return bus_log_parse_error(r);
 
-        log_debug("Accepted connection on private bus.");
+        r = sd_bus_message_exit_container(reply);
+        if (r < 0)
+                return bus_log_parse_error(r);
 
-        dbus_connection_ref(new_connection);
+        return 0;
 }
 
-static int init_registered_system_bus(Manager *m) {
-        char *id = NULL;
+static int bus_setup_api(Manager *m, sd_bus *bus) {
+        int r;
 
-        if (!dbus_connection_add_filter(m->system_bus, system_bus_message_filter, m, NULL))
-                return log_oom();
+        assert(m);
+        assert(bus);
 
-        if (m->running_as != SYSTEMD_SYSTEM) {
-                DBusError error;
+        r = bus_setup_api_vtables(m, bus);
+        if (r < 0)
+                return r;
 
-                dbus_error_init(&error);
+        r = sd_bus_add_match(
+                        bus,
+                        "type='signal',"
+                        "sender='org.freedesktop.DBus',"
+                        "path='/org/freedesktop/DBus',"
+                        "interface='org.freedesktop.DBus',"
+                        "member='NameOwnerChanged'",
+                        signal_name_owner_changed, m);
+        if (r < 0)
+                log_warning("Failed to subscribe to NameOwnerChanged signal: %s", strerror(-r));
+
+        r = sd_bus_add_match(
+                        bus,
+                        "type='signal',"
+                        "sender='org.freedesktop.DBus',"
+                        "path='/org/freedesktop/DBus',"
+                        "interface='org.freedesktop.systemd1.Activator',"
+                        "member='ActivationRequest'",
+                        signal_activation_request, m);
+        if (r < 0)
+                log_warning("Failed to subscribe to activation signal: %s", strerror(-r));
 
-                dbus_bus_add_match(m->system_bus,
-                                   "type='signal',"
-                                   "interface='org.freedesktop.systemd1.Agent',"
-                                   "member='Released',"
-                                   "path='/org/freedesktop/systemd1/agent'",
-                                   &error);
+        /* Allow replacing of our name, to ease implementation of
+         * reexecution, where we keep the old connection open until
+         * after the new connection is set up and the name installed
+         * to allow clients to synchronously wait for reexecution to
+         * finish */
+        r = sd_bus_request_name(bus,"org.freedesktop.systemd1", SD_BUS_NAME_ALLOW_REPLACEMENT|SD_BUS_NAME_REPLACE_EXISTING);
+        if (r < 0) {
+                log_error("Failed to register name: %s", strerror(-r));
+                return r;
+        }
 
-                if (dbus_error_is_set(&error)) {
-                        log_error("Failed to register match: %s", bus_error_message(&error));
-                        dbus_error_free(&error);
-                        return -1;
-                }
+        if (r != SD_BUS_NAME_PRIMARY_OWNER) {
+                log_error("Failed to acquire name.");
+                return -EEXIST;
         }
 
-        log_debug("Successfully connected to system D-Bus bus %s as %s",
-                 strnull((id = dbus_connection_get_server_id(m->system_bus))),
-                 strnull(dbus_bus_get_unique_name(m->system_bus)));
-        dbus_free(id);
+        bus_list_names(m, bus);
 
+        log_debug("Successfully connected to API bus.");
         return 0;
 }
 
-static int init_registered_api_bus(Manager *m) {
+static int bus_init_api(Manager *m) {
+        _cleanup_bus_unref_ sd_bus *bus = NULL;
         int r;
 
-        if (!dbus_connection_register_object_path(m->api_bus, "/org/freedesktop/systemd1", &bus_manager_vtable, m) ||
-            !dbus_connection_register_fallback(m->api_bus, "/org/freedesktop/systemd1/unit", &bus_unit_vtable, m) ||
-            !dbus_connection_register_fallback(m->api_bus, "/org/freedesktop/systemd1/job", &bus_job_vtable, m) ||
-            !dbus_connection_add_filter(m->api_bus, api_bus_message_filter, m, NULL))
-                return log_oom();
-
-        /* Get NameOwnerChange messages */
-        dbus_bus_add_match(m->api_bus,
-                           "type='signal',"
-                           "sender='"DBUS_SERVICE_DBUS"',"
-                           "interface='"DBUS_INTERFACE_DBUS"',"
-                           "member='NameOwnerChanged',"
-                           "path='"DBUS_PATH_DBUS"'",
-                           NULL);
-
-        /* Get activation requests */
-        dbus_bus_add_match(m->api_bus,
-                           "type='signal',"
-                           "sender='"DBUS_SERVICE_DBUS"',"
-                           "interface='org.freedesktop.systemd1.Activator',"
-                           "member='ActivationRequest',"
-                           "path='"DBUS_PATH_DBUS"'",
-                           NULL);
-
-        r = request_name(m);
-        if (r < 0)
-                return r;
-
-        r = query_name_list(m);
-        if (r < 0)
-                return r;
-
-        if (m->running_as == SYSTEMD_USER) {
-                char *id = NULL;
-
-                log_debug("Successfully connected to API D-Bus bus %s as %s",
-                         strnull((id = dbus_connection_get_server_id(m->api_bus))),
-                         strnull(dbus_bus_get_unique_name(m->api_bus)));
-                dbus_free(id);
-        } else
-                log_debug("Successfully initialized API on the system bus");
+        if (m->api_bus)
+                return 0;
 
-        return 0;
-}
+        /* The API and system bus is the same if we are running in system mode */
+        if (m->running_as == SYSTEMD_SYSTEM && m->system_bus)
+                bus = sd_bus_ref(m->system_bus);
+        else {
+                if (m->running_as == SYSTEMD_SYSTEM)
+                        r = sd_bus_open_system(&bus);
+                else
+                        r = sd_bus_open_user(&bus);
 
-static void bus_register_cb(DBusPendingCall *pending, void *userdata) {
-        Manager *m = userdata;
-        DBusConnection **conn;
-        DBusMessage *reply;
-        DBusError error;
-        const char *name;
-        int r = 0;
-
-        dbus_error_init(&error);
-
-        conn = dbus_pending_call_get_data(pending, m->conn_data_slot);
-        assert(conn == &m->system_bus || conn == &m->api_bus);
-
-        reply = dbus_pending_call_steal_reply(pending);
-
-        switch (dbus_message_get_type(reply)) {
-        case DBUS_MESSAGE_TYPE_ERROR:
-                assert_se(dbus_set_error_from_message(&error, reply));
-                log_warning("Failed to register to bus: %s", bus_error_message(&error));
-                r = -1;
-                break;
-        case DBUS_MESSAGE_TYPE_METHOD_RETURN:
-                if (!dbus_message_get_args(reply, &error,
-                                           DBUS_TYPE_STRING, &name,
-                                           DBUS_TYPE_INVALID)) {
-                        log_error("Failed to parse Hello reply: %s", bus_error_message(&error));
-                        r = -1;
-                        break;
+                if (r < 0) {
+                        log_debug("Failed to connect to API bus, retrying later...");
+                        return 0;
                 }
 
-                log_debug("Received name %s in reply to Hello", name);
-                if (!dbus_bus_set_unique_name(*conn, name)) {
-                        log_error("Failed to set unique name");
-                        r = -1;
-                        break;
+                r = sd_bus_attach_event(bus, m->event, SD_EVENT_PRIORITY_NORMAL);
+                if (r < 0) {
+                        log_error("Failed to attach API bus to event loop: %s", strerror(-r));
+                        return 0;
                 }
 
-                if (conn == &m->system_bus) {
-                        r = init_registered_system_bus(m);
-                        if (r == 0 && m->running_as == SYSTEMD_SYSTEM)
-                                r = init_registered_api_bus(m);
-                } else
-                        r = init_registered_api_bus(m);
-
-                break;
-        default:
-                assert_not_reached("Invalid reply message");
+                r = bus_setup_disconnected_match(m, bus);
+                if (r < 0)
+                        return 0;
         }
 
-        dbus_message_unref(reply);
-        dbus_error_free(&error);
-
+        r = bus_setup_api(m, bus);
         if (r < 0) {
-                if (conn == &m->system_bus) {
-                        log_debug("Failed setting up the system bus");
-                        bus_done_system(m);
-                } else {
-                        log_debug("Failed setting up the API bus");
-                        bus_done_api(m);
-                }
+                log_error("Failed to set up API bus: %s", strerror(-r));
+                return 0;
         }
-}
-
-static int manager_bus_async_register(Manager *m, DBusConnection **conn) {
-        DBusMessage *message = NULL;
-        DBusPendingCall *pending = NULL;
-
-        message = dbus_message_new_method_call(DBUS_SERVICE_DBUS,
-                                               DBUS_PATH_DBUS,
-                                               DBUS_INTERFACE_DBUS,
-                                               "Hello");
-        if (!message)
-                goto oom;
 
-        if (!dbus_connection_send_with_reply(*conn, message, &pending, -1))
-                goto oom;
-
-        if (!dbus_pending_call_set_data(pending, m->conn_data_slot, conn, NULL))
-                goto oom;
-
-        if (!dbus_pending_call_set_notify(pending, bus_register_cb, m, NULL))
-                goto oom;
-
-        dbus_message_unref(message);
-        dbus_pending_call_unref(pending);
+        m->api_bus = bus;
+        bus = NULL;
 
         return 0;
-oom:
-        if (pending) {
-                dbus_pending_call_cancel(pending);
-                dbus_pending_call_unref(pending);
-        }
-
-        if (message)
-                dbus_message_unref(message);
-
-        return -ENOMEM;
 }
 
-static DBusConnection* manager_bus_connect_private(Manager *m, DBusBusType type) {
-        const char *address;
-        DBusConnection *connection;
-        DBusError error;
-
-        switch (type) {
-        case DBUS_BUS_SYSTEM:
-                address = secure_getenv("DBUS_SYSTEM_BUS_ADDRESS");
-                if (!address || !address[0])
-                        address = DBUS_SYSTEM_BUS_DEFAULT_ADDRESS;
-                break;
-        case DBUS_BUS_SESSION:
-                address = secure_getenv("DBUS_SESSION_BUS_ADDRESS");
-                if (!address || !address[0])
-                        address = DBUS_SESSION_BUS_DEFAULT_ADDRESS;
-                break;
-        default:
-                assert_not_reached("Invalid bus type");
-        }
+static int bus_setup_system(Manager *m, sd_bus *bus) {
+        int r;
 
-        dbus_error_init(&error);
+        assert(m);
+        assert(bus);
 
-        connection = dbus_connection_open_private(address, &error);
-        if (!connection) {
-                log_warning("Failed to open private bus connection: %s", bus_error_message(&error));
-                goto fail;
-        }
+        if (m->running_as == SYSTEMD_SYSTEM)
+                return 0;
+
+        /* If we are a user instance we get the Released message via
+         * the system bus */
+        r = sd_bus_add_match(
+                        bus,
+                        "type='signal',"
+                        "interface='org.freedesktop.systemd1.Agent',"
+                        "member='Released',"
+                        "path='/org/freedesktop/systemd1/agent'",
+                        signal_agent_released, m);
 
-        return connection;
+        if (r < 0)
+                log_warning("Failed to register Released match on system bus: %s", strerror(-r));
 
-fail:
-        dbus_error_free(&error);
-        return NULL;
+        log_debug("Successfully connected to system bus.");
+        return 0;
 }
 
 static int bus_init_system(Manager *m) {
+        _cleanup_bus_unref_ sd_bus *bus = NULL;
         int r;
 
         if (m->system_bus)
                 return 0;
 
-        m->system_bus = manager_bus_connect_private(m, DBUS_BUS_SYSTEM);
-        if (!m->system_bus) {
-                log_debug("Failed to connect to system D-Bus, retrying later");
-                r = 0;
-                goto fail;
+        /* The API and system bus is the same if we are running in system mode */
+        if (m->running_as == SYSTEMD_SYSTEM && m->api_bus) {
+                m->system_bus = sd_bus_ref(m->api_bus);
+                return 0;
         }
 
-        r = bus_setup_loop(m, m->system_bus);
-        if (r < 0)
-                goto fail;
+        r = sd_bus_open_system(&bus);
+        if (r < 0) {
+                log_debug("Failed to connect to system bus, retrying later...");
+                return 0;
+        }
 
-        r = manager_bus_async_register(m, &m->system_bus);
+        r = bus_setup_disconnected_match(m, bus);
         if (r < 0)
-                goto fail;
-
-        return 0;
-fail:
-        bus_done_system(m);
-
-        return r;
-}
-
-static int bus_init_api(Manager *m) {
-        int r;
-
-        if (m->api_bus)
                 return 0;
 
-        if (m->running_as == SYSTEMD_SYSTEM) {
-                m->api_bus = m->system_bus;
-                /* In this mode there is no distinct connection to the API bus,
-                 * the API is published on the system bus.
-                 * bus_register_cb() is aware of that and will init the API
-                 * when the system bus gets registered.
-                 * No need to setup anything here. */
+        r = sd_bus_attach_event(bus, m->event, SD_EVENT_PRIORITY_NORMAL);
+        if (r < 0) {
+                log_error("Failed to attach system bus to event loop: %s", strerror(-r));
                 return 0;
         }
 
-        m->api_bus = manager_bus_connect_private(m, DBUS_BUS_SESSION);
-        if (!m->api_bus) {
-                log_debug("Failed to connect to API D-Bus, retrying later");
-                r = 0;
-                goto fail;
+        r = bus_setup_system(m, bus);
+        if (r < 0) {
+                log_error("Fauiled to set up system bus: %s", strerror(-r));
+                return 0;
         }
 
-        r = bus_setup_loop(m, m->api_bus);
-        if (r < 0)
-                goto fail;
-
-        r = manager_bus_async_register(m, &m->api_bus);
-        if (r < 0)
-                goto fail;
+        m->system_bus = bus;
+        bus = NULL;
 
         return 0;
-fail:
-        bus_done_api(m);
-
-        return r;
 }
 
 static int bus_init_private(Manager *m) {
-        DBusError error;
-        int r;
-        static const char *const external_only[] = {
-                "EXTERNAL",
-                NULL
+        _cleanup_close_ int fd = -1;
+        union sockaddr_union sa = {
+                .un.sun_family = AF_UNIX
         };
+        sd_event_source *s;
+        socklen_t salen;
+        int r;
 
         assert(m);
 
-        dbus_error_init(&error);
-
-        if (m->private_bus)
+        if (m->private_listen_fd >= 0)
                 return 0;
 
         if (m->running_as == SYSTEMD_SYSTEM) {
@@ -1069,90 +885,72 @@ static int bus_init_private(Manager *m) {
                 if (getpid() != 1)
                         return 0;
 
-                unlink("/run/systemd/private");
-                m->private_bus = dbus_server_listen("unix:path=/run/systemd/private", &error);
+                strcpy(sa.un.sun_path, "/run/systemd/private");
+                salen = offsetof(union sockaddr_union, un.sun_path) + sizeof("/run/systemd/private") - 1;
         } else {
+                size_t left = sizeof(sa.un.sun_path);
+                char *p = sa.un.sun_path;
                 const char *e;
-                char *p;
-                char *escaped;
 
                 e = secure_getenv("XDG_RUNTIME_DIR");
-                if (!e)
-                        return 0;
-
-                if (asprintf(&p, "%s/systemd/private", e) < 0) {
-                        r = log_oom();
-                        goto fail;
+                if (!e) {
+                        log_error("Failed to determine XDG_RUNTIME_DIR");
+                        return -EHOSTDOWN;
                 }
 
-                mkdir_parents_label(p, 0755);
-                unlink(p);
-                free(p);
+                left = strpcpy(&p, left, e);
+                left = strpcpy(&p, left, "/systemd/private");
 
-                escaped = dbus_address_escape_value(e);
-                if (!escaped) {
-                        r = log_oom();
-                        goto fail;
-                }
-                if (asprintf(&p, "unix:path=%s/systemd/private", escaped) < 0) {
-                        dbus_free(escaped);
-                        r = log_oom();
-                        goto fail;
-                }
-                dbus_free(escaped);
+                salen = sizeof(sa.un) - left;
+
+                mkdir_parents_label(sa.un.sun_path, 0755);
+        }
+
+        unlink(sa.un.sun_path);
 
-                m->private_bus = dbus_server_listen(p, &error);
-                free(p);
+        fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+        if (fd < 0) {
+                log_error("Failed to allocate private socket: %m");
+                return -errno;
         }
 
-        if (!m->private_bus) {
-                log_error("Failed to create private D-Bus server: %s", bus_error_message(&error));
-                r = -EIO;
-                goto fail;
+        r = bind(fd, &sa.sa, salen);
+        if (r < 0) {
+                log_error("Failed to bind private socket: %m");
+                return -errno;
         }
 
-        if (!dbus_server_set_auth_mechanisms(m->private_bus, (const char**) external_only) ||
-            !dbus_server_set_watch_functions(m->private_bus, bus_add_watch, bus_remove_watch, bus_toggle_watch, m, NULL) ||
-            !dbus_server_set_timeout_functions(m->private_bus, bus_add_timeout, bus_remove_timeout, bus_toggle_timeout, m, NULL)) {
-                r = log_oom();
-                goto fail;
+        r = listen(fd, SOMAXCONN);
+        if (r < 0) {
+                log_error("Failed to make private socket listening: %m");
+                return -errno;
         }
 
-        dbus_server_set_new_connection_function(m->private_bus, bus_new_connection, m, NULL);
+        r = sd_event_add_io(m->event, fd, EPOLLIN, bus_on_connection, m, &s);
+        if (r < 0) {
+                log_error("Failed to allocate event source: %s", strerror(-r));
+                return r;
+        }
+
+        m->private_listen_fd = fd;
+        m->private_listen_event_source = s;
+        fd = -1;
 
         log_debug("Successfully created private D-Bus server.");
 
         return 0;
-
-fail:
-        bus_done_private(m);
-        dbus_error_free(&error);
-
-        return r;
 }
 
 int bus_init(Manager *m, bool try_bus_connect) {
         int r;
 
-        if (set_ensure_allocated(&m->bus_connections, trivial_hash_func, trivial_compare_func) < 0 ||
-            set_ensure_allocated(&m->bus_connections_for_dispatch, trivial_hash_func, trivial_compare_func) < 0)
-                return log_oom();
-
-        if (m->name_data_slot < 0)
-                if (!dbus_pending_call_allocate_data_slot(&m->name_data_slot))
-                        return log_oom();
-
-        if (m->conn_data_slot < 0)
-                if (!dbus_pending_call_allocate_data_slot(&m->conn_data_slot))
-                        return log_oom();
-
-        if (m->subscribed_data_slot < 0)
-                if (!dbus_connection_allocate_data_slot(&m->subscribed_data_slot))
-                        return log_oom();
-
         if (try_bus_connect) {
-                if ((r = bus_init_system(m)) < 0 ||
-                    (r = bus_init_api(m)) < 0)
+                r = bus_init_system(m);
+                if (r < 0)
+                        return r;
+
+                r = bus_init_api(m);
+                if (r < 0)
                         return r;
         }
 
@@ -1163,415 +961,113 @@ int bus_init(Manager *m, bool try_bus_connect) {
         return 0;
 }
 
-static void shutdown_connection(Manager *m, DBusConnection *c) {
-        Job *j;
+static void destroy_bus(Manager *m, sd_bus **bus) {
         Iterator i;
+        Job *j;
 
-        HASHMAP_FOREACH(j, m->jobs, i) {
-                JobBusClient *cl, *nextcl;
-                LIST_FOREACH_SAFE(client, cl, nextcl, j->bus_client_list) {
-                        if (cl->bus == c) {
-                                LIST_REMOVE(client, j->bus_client_list, cl);
-                                free(cl);
-                        }
-                }
-        }
-
-        set_remove(m->bus_connections, c);
-        set_remove(m->bus_connections_for_dispatch, c);
-        set_free_free(BUS_CONNECTION_SUBSCRIBED(m, c));
-
-        if (m->queued_message_connection == c) {
-                m->queued_message_connection = NULL;
-
-                if (m->queued_message) {
-                        dbus_message_unref(m->queued_message);
-                        m->queued_message = NULL;
-                }
-        }
-
-        dbus_connection_set_dispatch_status_function(c, NULL, NULL, NULL);
-        /* system manager cannot afford to block on DBus */
-        if (m->running_as != SYSTEMD_SYSTEM)
-                dbus_connection_flush(c);
-        dbus_connection_close(c);
-        dbus_connection_unref(c);
-}
+        assert(m);
+        assert(bus);
 
-static void bus_done_api(Manager *m) {
-        if (!m->api_bus)
+        if (!*bus)
                 return;
 
-        if (m->running_as == SYSTEMD_USER)
-                shutdown_connection(m, m->api_bus);
+        /* Get rid of tracked clients on this bus */
+        bus_client_untrack_bus(m->subscribed, *bus);
+        HASHMAP_FOREACH(j, m->jobs, i)
+                bus_client_untrack_bus(j->subscribed, *bus);
 
-        m->api_bus = NULL;
+        /* Get rid of queued message on this bus */
+        if (m->queued_message_bus == *bus) {
+                m->queued_message_bus = sd_bus_unref(m->queued_message_bus);
 
-        if (m->queued_message) {
-                dbus_message_unref(m->queued_message);
-                m->queued_message = NULL;
+                if (m->queued_message)
+                        m->queued_message = sd_bus_message_unref(m->queued_message);
         }
-}
 
-static void bus_done_system(Manager *m) {
-        if (!m->system_bus)
-                return;
-
-        if (m->running_as == SYSTEMD_SYSTEM)
-                bus_done_api(m);
-
-        shutdown_connection(m, m->system_bus);
-        m->system_bus = NULL;
-}
-
-static void bus_done_private(Manager *m) {
-        if (!m->private_bus)
-                return;
+        /* Possibly flush unwritten data, but only if we are
+         * unprivileged, since we don't want to sync here */
+        if (m->running_as != SYSTEMD_SYSTEM)
+                sd_bus_flush(*bus);
 
-        dbus_server_disconnect(m->private_bus);
-        dbus_server_unref(m->private_bus);
-        m->private_bus = NULL;
+        /* And destroy the object */
+        sd_bus_close(*bus);
+        *bus = sd_bus_unref(*bus);
 }
 
 void bus_done(Manager *m) {
-        DBusConnection *c;
-
-        bus_done_api(m);
-        bus_done_system(m);
-        bus_done_private(m);
-
-        while ((c = set_steal_first(m->bus_connections)))
-                shutdown_connection(m, c);
-
-        while ((c = set_steal_first(m->bus_connections_for_dispatch)))
-                shutdown_connection(m, c);
-
-        set_free(m->bus_connections);
-        set_free(m->bus_connections_for_dispatch);
-
-        if (m->name_data_slot >= 0)
-                dbus_pending_call_free_data_slot(&m->name_data_slot);
-
-        if (m->conn_data_slot >= 0)
-                dbus_pending_call_free_data_slot(&m->conn_data_slot);
-
-        if (m->subscribed_data_slot >= 0)
-                dbus_connection_free_data_slot(&m->subscribed_data_slot);
-}
-
-static void query_pid_pending_cb(DBusPendingCall *pending, void *userdata) {
-        Manager *m = userdata;
-        DBusMessage *reply;
-        DBusError error;
-        const char *name;
-
-        dbus_error_init(&error);
-
-        assert_se(name = BUS_PENDING_CALL_NAME(m, pending));
-        assert_se(reply = dbus_pending_call_steal_reply(pending));
-
-        switch (dbus_message_get_type(reply)) {
-
-        case DBUS_MESSAGE_TYPE_ERROR:
-
-                assert_se(dbus_set_error_from_message(&error, reply));
-                log_warning("GetConnectionUnixProcessID() failed: %s", bus_error_message(&error));
-                break;
-
-        case DBUS_MESSAGE_TYPE_METHOD_RETURN: {
-                uint32_t r;
-
-                if (!dbus_message_get_args(reply,
-                                           &error,
-                                           DBUS_TYPE_UINT32, &r,
-                                           DBUS_TYPE_INVALID)) {
-                        log_error("Failed to parse GetConnectionUnixProcessID() reply: %s", bus_error_message(&error));
-                        break;
-                }
-
-                manager_dispatch_bus_query_pid_done(m, name, (pid_t) r);
-                break;
-        }
-
-        default:
-                assert_not_reached("Invalid reply message");
-        }
-
-        dbus_message_unref(reply);
-        dbus_error_free(&error);
-}
-
-int bus_query_pid(Manager *m, const char *name) {
-        DBusMessage *message = NULL;
-        DBusPendingCall *pending = NULL;
-        char *n = NULL;
+        sd_bus *b;
 
         assert(m);
-        assert(name);
-
-        if (!(message = dbus_message_new_method_call(
-                              DBUS_SERVICE_DBUS,
-                              DBUS_PATH_DBUS,
-                              DBUS_INTERFACE_DBUS,
-                              "GetConnectionUnixProcessID")))
-                goto oom;
-
-        if (!(dbus_message_append_args(
-                              message,
-                              DBUS_TYPE_STRING, &name,
-                              DBUS_TYPE_INVALID)))
-                goto oom;
-
-        if (!dbus_connection_send_with_reply(m->api_bus, message, &pending, -1))
-                goto oom;
-
-        if (!(n = strdup(name)))
-                goto oom;
-
-        if (!dbus_pending_call_set_data(pending, m->name_data_slot, n, free))
-                goto oom;
-
-        n = NULL;
-
-        if (!dbus_pending_call_set_notify(pending, query_pid_pending_cb, m, NULL))
-                goto oom;
 
-        dbus_message_unref(message);
-        dbus_pending_call_unref(pending);
+        if (m->api_bus)
+                destroy_bus(m, &m->api_bus);
+        if (m->system_bus)
+                destroy_bus(m, &m->system_bus);
+        while ((b = set_steal_first(m->private_buses)))
+                destroy_bus(m, &b);
 
-        return 0;
+        set_free(m->private_buses);
+        set_free(m->subscribed);
 
-oom:
-        free(n);
+        if (m->private_listen_event_source)
+                m->private_listen_event_source = sd_event_source_unref(m->private_listen_event_source);
 
-        if (pending) {
-                dbus_pending_call_cancel(pending);
-                dbus_pending_call_unref(pending);
+        if (m->private_listen_fd >= 0) {
+                close_nointr_nofail(m->private_listen_fd);
+                m->private_listen_fd = -1;
         }
-
-        if (message)
-                dbus_message_unref(message);
-
-        return -ENOMEM;
-}
-
-int bus_broadcast(Manager *m, DBusMessage *message) {
-        bool oom = false;
-        Iterator i;
-        DBusConnection *c;
-
-        assert(m);
-        assert(message);
-
-        SET_FOREACH(c, m->bus_connections_for_dispatch, i)
-                if (c != m->system_bus || m->running_as == SYSTEMD_SYSTEM)
-                        oom = !dbus_connection_send(c, message, NULL);
-
-        SET_FOREACH(c, m->bus_connections, i)
-                if (c != m->system_bus || m->running_as == SYSTEMD_SYSTEM)
-                        oom = !dbus_connection_send(c, message, NULL);
-
-        return oom ? -ENOMEM : 0;
-}
-
-bool bus_has_subscriber(Manager *m) {
-        Iterator i;
-        DBusConnection *c;
-
-        assert(m);
-
-        /* If we are reloading then we might not have deserialized the
-           subscribers yet, hence let's assume that there are some */
-
-        if (m->n_reloading > 0)
-                return true;
-
-        SET_FOREACH(c, m->bus_connections_for_dispatch, i)
-                if (bus_connection_has_subscriber(m, c))
-                        return true;
-
-        SET_FOREACH(c, m->bus_connections, i)
-                if (bus_connection_has_subscriber(m, c))
-                        return true;
-
-        return false;
-}
-
-bool bus_connection_has_subscriber(Manager *m, DBusConnection *c) {
-        assert(m);
-        assert(c);
-
-        return !set_isempty(BUS_CONNECTION_SUBSCRIBED(m, c));
 }
 
 int bus_fdset_add_all(Manager *m, FDSet *fds) {
         Iterator i;
-        DBusConnection *c;
+        sd_bus *b;
+        int fd;
 
         assert(m);
         assert(fds);
 
         /* When we are about to reexecute we add all D-Bus fds to the
          * set to pass over to the newly executed systemd. They won't
-         * be used there however, except that they are closed at the
+         * be used there however, except thatt they are closed at the
          * very end of deserialization, those making it possible for
          * clients to synchronously wait for systemd to reexec by
          * simply waiting for disconnection */
 
-        SET_FOREACH(c, m->bus_connections_for_dispatch, i) {
-                int fd;
-
-                if (dbus_connection_get_unix_fd(c, &fd)) {
+        if (m->api_bus) {
+                fd = sd_bus_get_fd(m->api_bus);
+                if (fd >= 0) {
                         fd = fdset_put_dup(fds, fd);
-
                         if (fd < 0)
                                 return fd;
                 }
         }
 
-        SET_FOREACH(c, m->bus_connections, i) {
-                int fd;
-
-                if (dbus_connection_get_unix_fd(c, &fd)) {
+        SET_FOREACH(b, m->private_buses, i) {
+                fd = sd_bus_get_fd(b);
+                if (fd >= 0) {
                         fd = fdset_put_dup(fds, fd);
-
                         if (fd < 0)
                                 return fd;
                 }
         }
 
-        return 0;
-}
-
-void bus_broadcast_finished(
-                Manager *m,
-                usec_t firmware_usec,
-                usec_t loader_usec,
-                usec_t kernel_usec,
-                usec_t initrd_usec,
-                usec_t userspace_usec,
-                usec_t total_usec) {
-
-        _cleanup_dbus_message_unref_ DBusMessage *message = NULL;
-
-        assert(m);
-
-        message = dbus_message_new_signal("/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", "StartupFinished");
-        if (!message) {
-                log_oom();
-                return;
-        }
-
-        assert_cc(sizeof(usec_t) == sizeof(uint64_t));
-        if (!dbus_message_append_args(message,
-                                      DBUS_TYPE_UINT64, &firmware_usec,
-                                      DBUS_TYPE_UINT64, &loader_usec,
-                                      DBUS_TYPE_UINT64, &kernel_usec,
-                                      DBUS_TYPE_UINT64, &initrd_usec,
-                                      DBUS_TYPE_UINT64, &userspace_usec,
-                                      DBUS_TYPE_UINT64, &total_usec,
-                                      DBUS_TYPE_INVALID)) {
-                log_oom();
-                return;
-        }
-
-
-        if (bus_broadcast(m, message) < 0) {
-                log_oom();
-                return;
-        }
-}
-
-void bus_broadcast_reloading(Manager *m, bool active) {
-
-        _cleanup_dbus_message_unref_ DBusMessage *message = NULL;
-        dbus_bool_t b = active;
-
-        assert(m);
-
-        message = dbus_message_new_signal("/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", "Reloading");
-        if (!message) {
-                log_oom();
-                return;
-        }
-
-        assert_cc(sizeof(usec_t) == sizeof(uint64_t));
-        if (!dbus_message_append_args(message,
-                                      DBUS_TYPE_BOOLEAN, &b,
-                                      DBUS_TYPE_INVALID)) {
-                log_oom();
-                return;
-        }
-
-
-        if (bus_broadcast(m, message) < 0) {
-                log_oom();
-                return;
-        }
-}
-
-Set *bus_acquire_subscribed(Manager *m, DBusConnection *c) {
-        Set *s;
-
-        assert(m);
-        assert(c);
-
-        s = BUS_CONNECTION_SUBSCRIBED(m, c);
-        if (s)
-                return s;
-
-        s = set_new(string_hash_func, string_compare_func);
-        if (!s)
-                return NULL;
-
-        if (!dbus_connection_set_data(c, m->subscribed_data_slot, s, NULL)) {
-                set_free(s);
-                return NULL;
-        }
+        /* We don't offer any APIs on the system bus (well, unless it
+         * is the same as the API bus) hence we don't bother with it
+         * here */
 
-        return s;
+        return 0;
 }
 
 void bus_serialize(Manager *m, FILE *f) {
-        char *client;
-        Iterator i;
-        Set *s;
-
         assert(m);
         assert(f);
 
-        if (!m->api_bus)
-                return;
-
-        s = BUS_CONNECTION_SUBSCRIBED(m, m->api_bus);
-        SET_FOREACH(client, s, i)
-                fprintf(f, "subscribed=%s\n", client);
+        bus_client_track_serialize(m, f, m->subscribed);
 }
 
 int bus_deserialize_item(Manager *m, const char *line) {
-        const char *e;
-        char *b;
-        Set *s;
-
         assert(m);
         assert(line);
 
-        if (!m->api_bus)
-                return 0;
-
-        e = startswith(line, "subscribed=");
-        if (!e)
-                return 0;
-
-        s = bus_acquire_subscribed(m, m->api_bus);
-        if (!s)
-                return -ENOMEM;
-
-        b = strdup(e);
-        if (!b)
-                return -ENOMEM;
-
-        set_consume(s, b);
-
-        return 1;
+        return bus_client_track_deserialize_item(m, &m->subscribed, line);
 }