X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=dbus.c;h=6ed659a2393e870786035e71f22b05b193f85c36;hp=caafc975709024da5decb85f9cceff552204444a;hb=31cee6f634ce07aa2c3514a506f93830f91f14a5;hpb=0acb83e9e63206af9a2c6a35ca054453d235458a

diff --git a/dbus.c b/dbus.c
index caafc9757..6ed659a23 100644
--- a/dbus.c
+++ b/dbus.c
@@ -1,23 +1,64 @@
 /*-*- Mode: C; c-basic-offset: 8 -*-*/
 
-#include <dbus/dbus.h>
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
 
 #include <sys/epoll.h>
 #include <sys/timerfd.h>
 #include <errno.h>
 #include <unistd.h>
+#include <dbus/dbus.h>
 
 #include "dbus.h"
 #include "log.h"
 #include "strv.h"
+#include "cgroup.h"
+#include "dbus-unit.h"
+#include "dbus-job.h"
+#include "dbus-manager.h"
+
+static void api_bus_dispatch_status(DBusConnection *bus, DBusDispatchStatus status, void *data)  {
+        Manager *m = data;
+
+        assert(bus);
+        assert(m);
+
+        if (!m->api_bus)
+                return;
+
+        assert(m->api_bus == bus);
+
+        m->request_api_bus_dispatch = status != DBUS_DISPATCH_COMPLETE;
+}
 
-static void bus_dispatch_status(DBusConnection *bus, DBusDispatchStatus status, void *data)  {
+static void system_bus_dispatch_status(DBusConnection *bus, DBusDispatchStatus status, void *data)  {
         Manager *m = data;
 
         assert(bus);
         assert(m);
 
-        m->request_bus_dispatch = status != DBUS_DISPATCH_COMPLETE;
+        if (!m->system_bus)
+                return;
+
+        assert(m->system_bus == bus);
+
+        m->request_system_bus_dispatch = status != DBUS_DISPATCH_COMPLETE;
 }
 
 static uint32_t bus_flags_to_events(DBusWatch *bus_watch) {
@@ -62,7 +103,7 @@ void bus_watch_event(Manager *m, Watch *w, int events) {
         /* This is called by the event loop whenever there is
          * something happening on D-Bus' file handles. */
 
-        if (!(dbus_watch_get_enabled(w->data.bus_watch)))
+        if (!dbus_watch_get_enabled(w->data.bus_watch))
                 return;
 
         dbus_watch_handle(w->data.bus_watch, events_to_bus_flags(events));
@@ -257,101 +298,491 @@ static void bus_toggle_timeout(DBusTimeout *timeout, void *data) {
                 log_error("Failed to rearm timer: %s", strerror(-r));
 }
 
-void bus_dispatch(Manager *m) {
+static DBusHandlerResult api_bus_message_filter(DBusConnection  *connection, DBusMessage  *message, void *data) {
+        Manager *m = data;
+        DBusError error;
+
+        assert(connection);
+        assert(message);
+        assert(m);
+
+        dbus_error_init(&error);
+
+        /* 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_error("Warning! 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", error.message);
+                else  {
+                        if (set_remove(m->subscribed, (char*) name))
+                                log_debug("Subscription client vanished: %s (left: %u)", name, set_size(m->subscribed));
+
+                        if (old_owner[0] == 0)
+                                old_owner = NULL;
+
+                        if (new_owner[0] == 0)
+                                new_owner = NULL;
+
+                        manager_dispatch_bus_name_owner_changed(m, name, old_owner, new_owner);
+                }
+        }
+
+        dbus_error_free(&error);
+        return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+}
+
+static DBusHandlerResult system_bus_message_filter(DBusConnection  *connection, DBusMessage  *message, void *data) {
+        Manager *m = data;
+        DBusError error;
+
+        assert(connection);
+        assert(message);
+        assert(m);
+
+        dbus_error_init(&error);
+
+        /* 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_error("Warning! System D-Bus connection terminated.");
+                bus_done_system(m);
+
+        } if (dbus_message_is_signal(message, "org.freedesktop.systemd1.Agent", "Released")) {
+                const char *cgroup;
+
+                if (!dbus_message_get_args(message, &error,
+                                           DBUS_TYPE_STRING, &cgroup,
+                                           DBUS_TYPE_INVALID))
+                        log_error("Failed to parse Released message: %s", error.message);
+                else
+                        cgroup_notify_empty(m, cgroup);
+        }
+
+        dbus_error_free(&error);
+        return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+}
+
+unsigned bus_dispatch(Manager *m) {
         assert(m);
 
-        if (dbus_connection_dispatch(m->bus) == DBUS_DISPATCH_COMPLETE)
-                m->request_bus_dispatch = false;
+        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 (!dbus_connection_send(m->api_bus, m->queued_message, NULL))
+                        return 0;
+
+                dbus_message_unref(m->queued_message);
+                m->queued_message = NULL;
+        }
+
+        if (m->request_api_bus_dispatch) {
+                if (dbus_connection_dispatch(m->api_bus) == DBUS_DISPATCH_COMPLETE)
+                        m->request_api_bus_dispatch = false;
+
+                return 1;
+        }
+
+        if (m->request_system_bus_dispatch) {
+                if (dbus_connection_dispatch(m->system_bus) == DBUS_DISPATCH_COMPLETE)
+                        m->request_system_bus_dispatch = false;
+
+                return 1;
+        }
+
+        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));
+
+        switch (dbus_message_get_type(reply)) {
+
+        case DBUS_MESSAGE_TYPE_ERROR:
+
+                assert_se(dbus_set_error_from_message(&error, reply));
+                log_warning("RequestName() failed: %s", error.message);
+                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 RequestName() reply: %s", error.message);
+                        break;
+                }
+
+                if (r == 1)
+                        log_debug("Successfully acquired name.");
+                else
+                        log_error("Name already owned.");
+
+                break;
+        }
+
+        default:
+                assert_not_reached("Invalid reply message");
+        }
+
+        dbus_message_unref(reply);
+        dbus_error_free(&error);
 }
 
 static int request_name(Manager *m) {
-        DBusMessage *message;
         const char *name = "org.freedesktop.systemd1";
         uint32_t flags = 0;
+        DBusMessage *message = NULL;
+        DBusPendingCall *pending = NULL;
 
         if (!(message = dbus_message_new_method_call(
                               DBUS_SERVICE_DBUS,
                               DBUS_PATH_DBUS,
                               DBUS_INTERFACE_DBUS,
                               "RequestName")))
-                return -ENOMEM;
+                goto oom;
 
         if (!dbus_message_append_args(
                             message,
                             DBUS_TYPE_STRING, &name,
                             DBUS_TYPE_UINT32, &flags,
-                            DBUS_TYPE_INVALID)) {
+                            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;
+
+        dbus_message_unref(message);
+        dbus_pending_call_unref(pending);
+
+        /* We simple ask for the name and don't wait for it. Sooner or
+         * later we'll have it. */
+
+        return 0;
+
+oom:
+        if (pending) {
+                dbus_pending_call_cancel(pending);
+                dbus_pending_call_unref(pending);
+        }
+
+        if (message)
                 dbus_message_unref(message);
+
+        return -ENOMEM;
+}
+
+static int bus_setup_loop(Manager *m, DBusConnection *bus) {
+        assert(m);
+        assert(bus);
+
+        dbus_connection_set_exit_on_disconnect(bus, FALSE);
+
+        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 -ENOMEM;
+
+        return 0;
+}
+
+int bus_init_system(Manager *m) {
+        DBusError error;
+        char *id;
+        int r;
+
+        assert(m);
+
+        dbus_error_init(&error);
+
+        if (m->system_bus)
+                return 0;
+
+        if (m->running_as != MANAGER_SESSION && m->api_bus)
+                m->system_bus = m->api_bus;
+        else {
+                if (!(m->system_bus = dbus_bus_get_private(DBUS_BUS_SYSTEM, &error))) {
+                        log_debug("Failed to get system D-Bus connection, retrying later: %s", error.message);
+                        dbus_error_free(&error);
+                        return 0;
+                }
+
+                dbus_connection_set_dispatch_status_function(m->system_bus, system_bus_dispatch_status, m, NULL);
+                m->request_system_bus_dispatch = true;
+
+                if ((r = bus_setup_loop(m, m->system_bus)) < 0) {
+                        bus_done_system(m);
+                        return r;
+                }
         }
 
-        if (!dbus_connection_send(m->bus, message, NULL)) {
-                dbus_message_unref(message);
+        if (!dbus_connection_add_filter(m->system_bus, system_bus_message_filter, m, NULL)) {
+                bus_done_system(m);
                 return -ENOMEM;
         }
 
-        /* We simple ask for the name and don't wait for it. Sooner or
-         * later we'll have it, and we wouldn't know what to do on
-         * error anyway. */
+        dbus_bus_add_match(m->system_bus,
+                           "type='signal',"
+                           "interface='org.freedesktop.systemd1.Agent',"
+                           "path='/org/freedesktop/systemd1/agent'",
+                           &error);
 
-        dbus_message_unref(message);
+        if (dbus_error_is_set(&error)) {
+                log_error("Failed to register match: %s", error.message);
+                dbus_error_free(&error);
+                bus_done_system(m);
+                return -ENOMEM;
+        }
+
+        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);
 
         return 0;
 }
 
-int bus_init(Manager *m) {
+int bus_init_api(Manager *m) {
         DBusError error;
         char *id;
         int r;
 
         assert(m);
 
-        if (m->bus)
+        dbus_error_init(&error);
+
+        if (m->api_bus)
                 return 0;
 
-        dbus_connection_set_change_sigpipe(FALSE);
+        if (m->name_data_slot < 0)
+                if (!dbus_pending_call_allocate_data_slot(&m->name_data_slot))
+                        return -ENOMEM;
 
-        dbus_error_init(&error);
-        if (!(m->bus = dbus_bus_get_private(m->is_init ? DBUS_BUS_SYSTEM : DBUS_BUS_SESSION, &error))) {
-                log_error("Failed to get D-Bus connection: %s", error.message);
-                dbus_error_free(&error);
-                return -ECONNREFUSED;
+        if (m->running_as != MANAGER_SESSION && m->system_bus)
+                m->api_bus = m->system_bus;
+        else {
+                if (!(m->api_bus = dbus_bus_get_private(m->running_as == MANAGER_SESSION ? DBUS_BUS_SESSION : DBUS_BUS_SYSTEM, &error))) {
+                        log_debug("Failed to get API D-Bus connection, retrying later: %s", error.message);
+                        dbus_error_free(&error);
+                        return 0;
+                }
+
+                dbus_connection_set_dispatch_status_function(m->api_bus, api_bus_dispatch_status, m, NULL);
+                m->request_api_bus_dispatch = true;
+
+                if ((r = bus_setup_loop(m, m->api_bus)) < 0) {
+                        bus_done_api(m);
+                        return r;
+                }
         }
 
-        dbus_connection_set_exit_on_disconnect(m->bus, FALSE);
-        dbus_connection_set_dispatch_status_function(m->bus, bus_dispatch_status, m, NULL);
-        if (!dbus_connection_set_watch_functions(m->bus, bus_add_watch, bus_remove_watch, bus_toggle_watch, m, NULL) ||
-            !dbus_connection_set_timeout_functions(m->bus, bus_add_timeout, bus_remove_timeout, bus_toggle_timeout, m, NULL) ||
-            !dbus_connection_register_object_path(m->bus, "/org/freedesktop/systemd1", &bus_manager_vtable, m) ||
-            !dbus_connection_register_fallback(m->bus, "/org/freedesktop/systemd1/unit", &bus_unit_vtable, m) ||
-            !dbus_connection_register_fallback(m->bus, "/org/freedesktop/systemd1/job", &bus_job_vtable, m)) {
-                bus_done(m);
+        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)) {
+                bus_done_api(m);
+                return -ENOMEM;
+        }
+
+        dbus_bus_add_match(m->api_bus,
+                           "type='signal',"
+                           "sender='"DBUS_SERVICE_DBUS"',"
+                           "interface='"DBUS_INTERFACE_DBUS"',"
+                           "path='"DBUS_PATH_DBUS"'",
+                           &error);
+
+        if (dbus_error_is_set(&error)) {
+                log_error("Failed to register match: %s", error.message);
+                dbus_error_free(&error);
+                bus_done_api(m);
                 return -ENOMEM;
         }
 
         if ((r = request_name(m)) < 0) {
-                bus_done(m);
+                bus_done_api(m);
                 return r;
         }
 
-        log_debug("Successfully connected to D-Bus bus %s as %s",
-                  strnull((id = dbus_connection_get_server_id(m->bus))),
-                  strnull(dbus_bus_get_unique_name(m->bus)));
+        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);
 
-        m->request_bus_dispatch = true;
+        if (!m->subscribed)
+                if (!(m->subscribed = set_new(string_hash_func, string_compare_func)))
+                        return -ENOMEM;
 
         return 0;
 }
 
-void bus_done(Manager *m) {
+void bus_done_api(Manager *m) {
+        assert(m);
+
+        if (m->api_bus) {
+                if (m->system_bus == m->api_bus)
+                        m->system_bus = NULL;
+
+                dbus_connection_set_dispatch_status_function(m->api_bus, NULL, NULL, NULL);
+                dbus_connection_flush(m->api_bus);
+                dbus_connection_close(m->api_bus);
+                dbus_connection_unref(m->api_bus);
+                m->api_bus = NULL;
+        }
+
+        if (m->subscribed) {
+                char *c;
+
+                while ((c = set_steal_first(m->subscribed)))
+                        free(c);
+
+                set_free(m->subscribed);
+                m->subscribed = NULL;
+        }
+
+       if (m->name_data_slot >= 0)
+               dbus_pending_call_free_data_slot(&m->name_data_slot);
+
+       if (m->queued_message) {
+               dbus_message_unref(m->queued_message);
+               m->queued_message = NULL;
+       }
+}
+
+void bus_done_system(Manager *m) {
         assert(m);
 
-        if (m->bus) {
-                dbus_connection_close(m->bus);
-                dbus_connection_unref(m->bus);
-                m->bus = NULL;
+        if (m->system_bus == m->api_bus)
+                bus_done_api(m);
+
+        if (m->system_bus) {
+                dbus_connection_set_dispatch_status_function(m->system_bus, NULL, NULL, NULL);
+                dbus_connection_flush(m->system_bus);
+                dbus_connection_close(m->system_bus);
+                dbus_connection_unref(m->system_bus);
+                m->system_bus = NULL;
+        }
+}
+
+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 = dbus_pending_call_get_data(pending, m->name_data_slot));
+        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", error.message);
+                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", error.message);
+                        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;
+
+        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);
+
+        return 0;
+
+oom:
+        free(n);
+
+        if (pending) {
+                dbus_pending_call_cancel(pending);
+                dbus_pending_call_unref(pending);
+        }
+
+        if (message)
+                dbus_message_unref(message);
+
+        return -ENOMEM;
 }
 
 DBusHandlerResult bus_default_message_handler(Manager *m, DBusMessage *message, const char*introspection, const BusProperty *properties) {
@@ -399,7 +830,7 @@ DBusHandlerResult bus_default_message_handler(Manager *m, DBusMessage *message,
                         if (!dbus_message_iter_open_container(&iter, DBUS_TYPE_VARIANT, p->signature, &sub))
                                 goto oom;
 
-                        if ((r = p->append(m, &sub, property, p->data)) < 0) {
+                        if ((r = p->append(m, &sub, property, (void*) p->data)) < 0) {
 
                                 if (r == -ENOMEM)
                                         goto oom;
@@ -441,7 +872,7 @@ DBusHandlerResult bus_default_message_handler(Manager *m, DBusMessage *message,
                             !dbus_message_iter_open_container(&sub2, DBUS_TYPE_VARIANT, p->signature, &sub3))
                                 goto oom;
 
-                        if ((r = p->append(m, &sub3, p->property, p->data)) < 0) {
+                        if ((r = p->append(m, &sub3, p->property, (void*) p->data)) < 0) {
 
                                 if (r == -ENOMEM)
                                         goto oom;
@@ -462,7 +893,7 @@ DBusHandlerResult bus_default_message_handler(Manager *m, DBusMessage *message,
         }
 
         if (reply) {
-                if (!dbus_connection_send(m->bus, reply, NULL))
+                if (!dbus_connection_send(m->api_bus, reply, NULL))
                         goto oom;
 
                 dbus_message_unref(reply);
@@ -480,8 +911,6 @@ oom:
         return DBUS_HANDLER_RESULT_NEED_MEMORY;
 }
 
-
-
 static const char *error_to_dbus(int error) {
 
         switch(error) {
@@ -535,7 +964,7 @@ DBusHandlerResult bus_send_error_reply(Manager *m, DBusMessage *message, DBusErr
         if (!(reply = dbus_message_new_error(message, name, text)))
                 goto oom;
 
-        if (!dbus_connection_send(m->bus, reply, NULL))
+        if (!dbus_connection_send(m->api_bus, reply, NULL))
                 goto oom;
 
         dbus_message_unref(reply);
@@ -615,6 +1044,10 @@ int bus_property_append_uint64(Manager *m, DBusMessageIter *i, const char *prope
         assert(property);
         assert(data);
 
+        /* Let's ensure that pid_t is actually 64bit, and hence this
+         * function can be used for usec_t */
+        assert_cc(sizeof(uint64_t) == sizeof(usec_t));
+
         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_UINT64, data))
                 return -ENOMEM;
 
@@ -627,8 +1060,77 @@ int bus_property_append_uint32(Manager *m, DBusMessageIter *i, const char *prope
         assert(property);
         assert(data);
 
+        /* Let's ensure that pid_t and mode_t is actually 32bit, and
+         * hence this function can be used for pid_t/mode_t */
+        assert_cc(sizeof(uint32_t) == sizeof(pid_t));
+        assert_cc(sizeof(uint32_t) == sizeof(mode_t));
+        assert_cc(sizeof(uint32_t) == sizeof(unsigned));
+
         if (!dbus_message_iter_append_basic(i, DBUS_TYPE_UINT32, data))
                 return -ENOMEM;
 
         return 0;
 }
+
+int bus_property_append_int32(Manager *m, DBusMessageIter *i, const char *property, void *data) {
+        assert(m);
+        assert(i);
+        assert(property);
+        assert(data);
+
+        assert_cc(sizeof(int32_t) == sizeof(int));
+
+        if (!dbus_message_iter_append_basic(i, DBUS_TYPE_INT32, data))
+                return -ENOMEM;
+
+        return 0;
+}
+
+int bus_parse_strv(DBusMessage *m, char ***_l) {
+        DBusMessageIter iter, sub;
+        unsigned n = 0, i = 0;
+        char **l;
+
+        assert(m);
+        assert(_l);
+
+        if (!dbus_message_iter_init(m, &iter) ||
+            dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY ||
+            dbus_message_iter_get_element_type(&iter) != DBUS_TYPE_STRING)
+            return -EINVAL;
+
+        dbus_message_iter_recurse(&iter, &sub);
+
+        while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
+                n++;
+                dbus_message_iter_next(&sub);
+        }
+
+        if (!(l = new(char*, n+1)))
+                return -ENOMEM;
+
+        assert_se(dbus_message_iter_init(m, &iter));
+        dbus_message_iter_recurse(&iter, &sub);
+
+        while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
+                const char *s;
+
+                assert_se(dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_STRING);
+                dbus_message_iter_get_basic(&sub, &s);
+
+                if (!(l[i++] = strdup(s))) {
+                        strv_free(l);
+                        return -ENOMEM;
+                }
+
+                dbus_message_iter_next(&sub);
+        }
+
+        assert(i == n);
+        l[i] = NULL;
+
+        if (_l)
+                *_l = l;
+
+        return 0;
+}