systemctl: rework how we connect to busses

Sometimes we have to connect to the system manager directly (early boot,
initrd, late boot, ...), sometimes through the system bus (unprivileged,
remote, logind, ...). Instead of guessing in advance, which kind of
connection we require (and sometimes guessing incorrectly), let's make
sure each time we need  bus connection we request the right bus
explicitly.

This way, we set up exactly the bus connections require, never guess
incorrectly, and do so only immediately when necessary.

As effect this reworks avoid_bus() into install_client_side(), since
that's all it determines now: whether to install unit files client-side
or server-side (i.e. in PID 1).

1 files changed, 394 insertions, 233 deletions

diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c
index 2208081c44..7dcdf32a9b 100644
--- a/src/systemctl/systemctl.c
+++ b/src/systemctl/systemctl.c
@@ -140,12 +140,56 @@ static bool arg_plain = false;
 static bool arg_firmware_setup = false;
 static bool arg_now = false;
 
-static bool original_stdout_is_tty;
-
-static int daemon_reload(sd_bus *bus, char **args);
+static int daemon_reload(char **args);
 static int halt_now(enum action a);
 static int check_one_unit(sd_bus *bus, const char *name, const char *good_states, bool quiet);
 
+static bool original_stdout_is_tty;
+
+typedef enum BusFocus {
+        BUS_FULL,      /* The full bus indicated via --system or --user */
+        BUS_MANAGER,   /* The manager itself, possibly directly, possibly via the bus */
+        _BUS_FOCUS_MAX
+} BusFocus;
+
+static sd_bus *busses[_BUS_FOCUS_MAX] = {};
+
+static int acquire_bus(BusFocus focus, sd_bus **ret) {
+        int r;
+
+        assert(focus < _BUS_FOCUS_MAX);
+        assert(ret);
+
+        /* We only go directly to the manager, if we are using a local transport */
+        if (arg_transport != BUS_TRANSPORT_LOCAL)
+                focus = BUS_FULL;
+
+        if (!busses[focus]) {
+                bool user;
+
+                user = arg_scope != UNIT_FILE_SYSTEM;
+
+                if (focus == BUS_MANAGER)
+                        r = bus_connect_transport_systemd(arg_transport, arg_host, user, &busses[focus]);
+                else
+                        r = bus_connect_transport(arg_transport, arg_host, user, &busses[focus]);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to connect to bus: %m");
+
+                (void) sd_bus_set_allow_interactive_authorization(busses[focus], arg_ask_password);
+        }
+
+        *ret = busses[focus];
+        return 0;
+}
+
+static void release_busses(void) {
+        BusFocus w;
+
+        for (w = 0; w < _BUS_FOCUS_MAX; w++)
+                busses[w] = sd_bus_flush_close_unref(busses[w]);
+}
+
 static void pager_open_if_enabled(void) {
 
         if (arg_no_pager)
@@ -223,12 +267,10 @@ static int translate_bus_error_to_exit_status(int r, const sd_bus_error *error)
         return EXIT_FAILURE;
 }
 
-static bool avoid_bus(void) {
+static bool install_client_side(void) {
 
-        /* /sbin/runlevel doesn't need to communicate via D-Bus, so
-         * let's shortcut this */
-        if (arg_action == ACTION_RUNLEVEL)
-                return true;
+        /* Decides when to execute enable/disable/... operations
+         * client-side rather than server-side. */
 
         if (running_in_chroot() > 0)
                 return true;
@@ -615,14 +657,19 @@ static int get_unit_list_recursive(
         return c;
 }
 
-static int list_units(sd_bus *bus, char **args) {
+static int list_units(char **args) {
         _cleanup_free_ UnitInfo *unit_infos = NULL;
         _cleanup_(message_set_freep) Set *replies = NULL;
         _cleanup_strv_free_ char **machines = NULL;
+        sd_bus *bus;
         int r;
 
         pager_open_if_enabled();
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         r = get_unit_list_recursive(bus, strv_skip(args, 1), &unit_infos, &replies, &machines);
         if (r < 0)
                 return r;
@@ -639,6 +686,10 @@ static int get_triggered_units(
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         int r;
 
+        assert(bus);
+        assert(path);
+        assert(ret);
+
         r = sd_bus_get_property_strv(
                         bus,
                         "org.freedesktop.systemd1",
@@ -816,7 +867,7 @@ static int output_sockets_list(struct socket_info *socket_infos, unsigned cs) {
         return 0;
 }
 
-static int list_sockets(sd_bus *bus, char **args) {
+static int list_sockets(char **args) {
         _cleanup_(message_set_freep) Set *replies = NULL;
         _cleanup_strv_free_ char **machines = NULL;
         _cleanup_free_ UnitInfo *unit_infos = NULL;
@@ -826,9 +877,14 @@ static int list_sockets(sd_bus *bus, char **args) {
         unsigned cs = 0;
         size_t size = 0;
         int r = 0, n;
+        sd_bus *bus;
 
         pager_open_if_enabled();
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         n = get_unit_list_recursive(bus, strv_skip(args, 1), &unit_infos, &replies, &machines);
         if (n < 0)
                 return n;
@@ -1123,7 +1179,7 @@ static usec_t calc_next_elapse(dual_timestamp *nw, dual_timestamp *next) {
         return next_elapse;
 }
 
-static int list_timers(sd_bus *bus, char **args) {
+static int list_timers(char **args) {
         _cleanup_(message_set_freep) Set *replies = NULL;
         _cleanup_strv_free_ char **machines = NULL;
         _cleanup_free_ struct timer_info *timer_infos = NULL;
@@ -1133,10 +1189,15 @@ static int list_timers(sd_bus *bus, char **args) {
         size_t size = 0;
         int n, c = 0;
         dual_timestamp nw;
+        sd_bus *bus;
         int r = 0;
 
         pager_open_if_enabled();
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         n = get_unit_list_recursive(bus, strv_skip(args, 1), &unit_infos, &replies, &machines);
         if (n < 0)
                 return n;
@@ -1289,7 +1350,7 @@ static void output_unit_file_list(const UnitFileList *units, unsigned c) {
                 printf("\n%u unit files listed.\n", c);
 }
 
-static int list_unit_files(sd_bus *bus, char **args) {
+static int list_unit_files(char **args) {
         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
         _cleanup_free_ UnitFileList *units = NULL;
         UnitFileList *unit;
@@ -1301,7 +1362,7 @@ static int list_unit_files(sd_bus *bus, char **args) {
 
         pager_open_if_enabled();
 
-        if (avoid_bus()) {
+        if (install_client_side()) {
                 Hashmap *h;
                 UnitFileList *u;
                 Iterator i;
@@ -1338,6 +1399,11 @@ static int list_unit_files(sd_bus *bus, char **args) {
                 hashmap_free(h);
         } else {
                 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+                sd_bus *bus;
+
+                r = acquire_bus(BUS_MANAGER, &bus);
+                if (r < 0)
+                        return r;
 
                 r = sd_bus_call_method(
                                 bus,
@@ -1382,7 +1448,7 @@ static int list_unit_files(sd_bus *bus, char **args) {
         qsort_safe(units, c, sizeof(UnitFileList), compare_unit_file_list);
         output_unit_file_list(units, c);
 
-        if (avoid_bus()) {
+        if (install_client_side()) {
                 for (unit = units; unit < units + c; unit++)
                         free(unit->path);
         }
@@ -1601,14 +1667,13 @@ static int list_dependencies_one(
         return 0;
 }
 
-static int list_dependencies(sd_bus *bus, char **args) {
+static int list_dependencies(char **args) {
         _cleanup_strv_free_ char **units = NULL;
         _cleanup_free_ char *unit = NULL;
         const char *u;
+        sd_bus *bus;
         int r;
 
-        assert(bus);
-
         if (args[1]) {
                 r = unit_name_mangle(args[1], UNIT_NAME_NOGLOB, &unit);
                 if (r < 0)
@@ -1620,6 +1685,10 @@ static int list_dependencies(sd_bus *bus, char **args) {
 
         pager_open_if_enabled();
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         puts(u);
 
         return list_dependencies_one(bus, u, 0, &units, 0);
@@ -1835,12 +1904,11 @@ static void output_machines_list(struct machine_info *machine_infos, unsigned n)
                 printf("\n%u machines listed.\n", n);
 }
 
-static int list_machines(sd_bus *bus, char **args) {
+static int list_machines(char **args) {
         struct machine_info *machine_infos = NULL;
+        sd_bus *bus;
         int r;
 
-        assert(bus);
-
         if (geteuid() != 0) {
                 log_error("Must be root.");
                 return -EPERM;
@@ -1848,6 +1916,10 @@ static int list_machines(sd_bus *bus, char **args) {
 
         pager_open_if_enabled();
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         r = get_machine_list(bus, &machine_infos, strv_skip(args, 1));
         if (r < 0)
                 return r;
@@ -1859,13 +1931,13 @@ static int list_machines(sd_bus *bus, char **args) {
         return 0;
 }
 
-static int get_default(sd_bus *bus, char **args) {
+static int get_default(char **args) {
         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
         _cleanup_free_ char *_path = NULL;
         const char *path;
         int r;
 
-        if (!bus || avoid_bus()) {
+        if (install_client_side()) {
                 r = unit_file_get_default(arg_scope, arg_root, &_path);
                 if (r < 0)
                         return log_error_errno(r, "Failed to get default target: %m");
@@ -1873,6 +1945,11 @@ static int get_default(sd_bus *bus, char **args) {
 
         } else {
                 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+                sd_bus *bus;
+
+                r = acquire_bus(BUS_MANAGER, &bus);
+                if (r < 0)
+                        return r;
 
                 r = sd_bus_call_method(
                                 bus,
@@ -1912,17 +1989,18 @@ static void dump_unit_file_changes(const UnitFileChange *changes, unsigned n_cha
         }
 }
 
-static int set_default(sd_bus *bus, char **args) {
+static int set_default(char **args) {
         _cleanup_free_ char *unit = NULL;
-        UnitFileChange *changes = NULL;
-        unsigned n_changes = 0;
         int r;
 
         r = unit_name_mangle_with_suffix(args[1], UNIT_NAME_NOGLOB, ".target", &unit);
         if (r < 0)
                 return log_error_errno(r, "Failed to mangle unit name: %m");
 
-        if (!bus || avoid_bus()) {
+        if (install_client_side()) {
+                UnitFileChange *changes = NULL;
+                unsigned n_changes = 0;
+
                 r = unit_file_set_default(arg_scope, arg_root, unit, true, &changes, &n_changes);
                 if (r < 0)
                         return log_error_errno(r, "Failed to set default target: %m");
@@ -1930,13 +2008,19 @@ static int set_default(sd_bus *bus, char **args) {
                 if (!arg_quiet)
                         dump_unit_file_changes(changes, n_changes);
 
+                unit_file_changes_free(changes, n_changes);
                 r = 0;
         } else {
                 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
                 _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+                sd_bus *bus;
 
                 polkit_agent_open_if_enabled();
 
+                r = acquire_bus(BUS_MANAGER, &bus);
+                if (r < 0)
+                        return r;
+
                 r = sd_bus_call_method(
                                 bus,
                                 "org.freedesktop.systemd1",
@@ -1957,13 +2041,11 @@ static int set_default(sd_bus *bus, char **args) {
 
                 /* Try to reload if enabled */
                 if (!arg_no_reload)
-                        r = daemon_reload(bus, args);
+                        r = daemon_reload(args);
                 else
                         r = 0;
         }
 
-        unit_file_changes_free(changes, n_changes);
-
         return r;
 }
 
@@ -2048,17 +2130,24 @@ static bool output_show_job(struct job_info *job, char **patterns) {
         return strv_fnmatch_or_empty(patterns, job->name, FNM_NOESCAPE);
 }
 
-static int list_jobs(sd_bus *bus, char **args) {
+static int list_jobs(char **args) {
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
         const char *name, *type, *state, *job_path, *unit_path;
         _cleanup_free_ struct job_info *jobs = NULL;
         size_t size = 0;
         unsigned c = 0;
+        sd_bus *bus;
         uint32_t id;
         int r;
         bool skipped = false;
 
+        pager_open_if_enabled();
+
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         r = sd_bus_call_method(
                         bus,
                         "org.freedesktop.systemd1",
@@ -2101,17 +2190,22 @@ static int list_jobs(sd_bus *bus, char **args) {
         return r;
 }
 
-static int cancel_job(sd_bus *bus, char **args) {
+static int cancel_job(char **args) {
+        sd_bus *bus;
         char **name;
         int r = 0;
 
         assert(args);
 
         if (strv_length(args) <= 1)
-                return daemon_reload(bus, args);
+                return daemon_reload(args);
 
         polkit_agent_open_if_enabled();
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         STRV_FOREACH(name, args+1) {
                 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
                 uint32_t id;
@@ -2216,7 +2310,6 @@ static int unit_file_find_path(LookupPaths *lp, const char *unit_name, char **un
 static int unit_find_paths(
                 sd_bus *bus,
                 const char *unit_name,
-                bool avoid_bus_cache,
                 LookupPaths *lp,
                 char **fragment_path,
                 char ***dropin_paths) {
@@ -2237,7 +2330,7 @@ static int unit_find_paths(
         assert(fragment_path);
         assert(lp);
 
-        if (!avoid_bus_cache && !unit_name_is_valid(unit_name, UNIT_NAME_TEMPLATE)) {
+        if (!install_client_side() && !unit_name_is_valid(unit_name, UNIT_NAME_TEMPLATE)) {
                 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
                 _cleanup_bus_message_unref_ sd_bus_message *unit_load_error = NULL;
                 _cleanup_free_ char *unit = NULL;
@@ -2571,11 +2664,13 @@ static int start_unit_one(
 }
 
 static int expand_names(sd_bus *bus, char **names, const char* suffix, char ***ret) {
-
         _cleanup_strv_free_ char **mangled = NULL, **globs = NULL;
         char **name;
         int r, i;
 
+        assert(bus);
+        assert(ret);
+
         STRV_FOREACH(name, names) {
                 char *t;
 
@@ -2600,9 +2695,6 @@ static int expand_names(sd_bus *bus, char **names, const char* suffix, char ***r
                 _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
                 _cleanup_free_ UnitInfo *unit_infos = NULL;
 
-                if (!bus)
-                        return log_error_errno(EOPNOTSUPP, "Unit name globbing without bus is not implemented.");
-
                 r = get_unit_list(bus, NULL, globs, &unit_infos, 0, &reply);
                 if (r < 0)
                         return r;
@@ -2650,18 +2742,21 @@ static enum action verb_to_action(const char *verb) {
         return _ACTION_INVALID;
 }
 
-static int start_unit(sd_bus *bus, char **args) {
+static int start_unit(char **args) {
         _cleanup_(bus_wait_for_jobs_freep) BusWaitForJobs *w = NULL;
         const char *method, *mode, *one_name, *suffix = NULL;
         _cleanup_strv_free_ char **names = NULL;
+        sd_bus *bus;
         char **name;
         int r = 0;
 
-        assert(bus);
-
         ask_password_agent_open_if_enabled();
         polkit_agent_open_if_enabled();
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         if (arg_action == ACTION_SYSTEMCTL) {
                 enum action action;
                 method = verb_to_method(args[0]);
@@ -2687,7 +2782,7 @@ static int start_unit(sd_bus *bus, char **args) {
         if (one_name)
                 names = strv_new(one_name, NULL);
         else {
-                r = expand_names(bus, args + 1, suffix, &names);
+                r = expand_names(bus, strv_skip(args, 1), suffix, &names);
                 if (r < 0)
                         log_error_errno(r, "Failed to expand names: %m");
         }
@@ -2724,13 +2819,16 @@ static int start_unit(sd_bus *bus, char **args) {
         return r;
 }
 
-static int logind_set_wall_message(sd_bus *bus) {
+static int logind_set_wall_message(void) {
 #ifdef HAVE_LOGIND
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+        sd_bus *bus;
         _cleanup_free_ char *m = NULL;
         int r;
 
-        assert(bus);
+        r = acquire_bus(BUS_FULL, &bus);
+        if (r < 0)
+                return r;
 
         m = strv_join(arg_wall, " ");
         if (!m)
@@ -2757,18 +2855,19 @@ static int logind_set_wall_message(sd_bus *bus) {
 
 /* Ask systemd-logind, which might grant access to unprivileged users
  * through PolicyKit */
-static int logind_reboot(sd_bus *bus, enum action a) {
+static int logind_reboot(enum action a) {
 #ifdef HAVE_LOGIND
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         const char *method, *description;
+        sd_bus *bus;
         int r;
 
-        if (!bus)
-                return -EIO;
-
         polkit_agent_open_if_enabled();
+        (void) logind_set_wall_message();
 
-        (void) logind_set_wall_message(bus);
+        r = acquire_bus(BUS_FULL, &bus);
+        if (r < 0)
+                return r;
 
         switch (a) {
 
@@ -2819,19 +2918,17 @@ static int logind_reboot(sd_bus *bus, enum action a) {
 #endif
 }
 
-static int logind_check_inhibitors(sd_bus *bus, enum action a) {
+static int logind_check_inhibitors(enum action a) {
 #ifdef HAVE_LOGIND
         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
         _cleanup_strv_free_ char **sessions = NULL;
         const char *what, *who, *why, *mode;
         uint32_t uid, pid;
+        sd_bus *bus;
         unsigned c = 0;
         char **s;
         int r;
 
-        if (!bus)
-                return 0;
-
         if (arg_ignore_inhibitors || arg_force > 0)
                 return 0;
 
@@ -2844,6 +2941,10 @@ static int logind_check_inhibitors(sd_bus *bus, enum action a) {
         if (!on_tty())
                 return 0;
 
+        r = acquire_bus(BUS_FULL, &bus);
+        if (r < 0)
+                return r;
+
         r = sd_bus_call_method(
                         bus,
                         "org.freedesktop.login1",
@@ -2933,25 +3034,16 @@ static int logind_check_inhibitors(sd_bus *bus, enum action a) {
 #endif
 }
 
-static int prepare_firmware_setup(sd_bus *bus) {
+static int logind_prepare_firmware_setup(void) {
 #ifdef HAVE_LOGIND
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
-#endif
+        sd_bus *bus;
         int r;
 
-        if (!arg_firmware_setup)
-                return 0;
-
-        if (arg_transport == BUS_TRANSPORT_LOCAL) {
-
-                r = efi_set_reboot_to_firmware(true);
-                if (r < 0)
-                        log_debug_errno(r, "Cannot indicate to EFI to boot into setup mode, will retry via logind: %m");
-                else
-                        return r;
-        }
+        r = acquire_bus(BUS_FULL, &bus);
+        if (r < 0)
+                return r;
 
-#ifdef HAVE_LOGIND
         r = sd_bus_call_method(
                         bus,
                         "org.freedesktop.login1",
@@ -2961,20 +3053,35 @@ static int prepare_firmware_setup(sd_bus *bus) {
                         &error,
                         NULL,
                         "b", true);
-        if (r < 0) {
-                log_error("Cannot indicate to EFI to boot into setup mode: %s", bus_error_message(&error, r));
-                return r;
-        }
+        if (r < 0)
+                return log_error_errno(r, "Cannot indicate to EFI to boot into setup mode: %s", bus_error_message(&error, r));
 
         return 0;
 #else
         log_error("Cannot remotely indicate to EFI to boot into setup mode.");
-        return -EINVAL;
+        return -ENOSYS;
 #endif
 }
 
-static int start_special(sd_bus *bus, char **args) {
-        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+static int prepare_firmware_setup(void) {
+        int r;
+
+        if (!arg_firmware_setup)
+                return 0;
+
+        if (arg_transport == BUS_TRANSPORT_LOCAL) {
+
+                r = efi_set_reboot_to_firmware(true);
+                if (r < 0)
+                        log_debug_errno(r, "Cannot indicate to EFI to boot into setup mode, will retry via logind: %m");
+                else
+                        return r;
+        }
+
+        return logind_prepare_firmware_setup();
+}
+
+static int start_special(char **args) {
         enum action a;
         int r;
 
@@ -2982,7 +3089,7 @@ static int start_special(sd_bus *bus, char **args) {
 
         a = verb_to_action(args[0]);
 
-        r = logind_check_inhibitors(bus, a);
+        r = logind_check_inhibitors(a);
         if (r < 0)
                 return r;
 
@@ -2991,7 +3098,7 @@ static int start_special(sd_bus *bus, char **args) {
                 return -EPERM;
         }
 
-        r = prepare_firmware_setup(bus);
+        r = prepare_firmware_setup();
         if (r < 0)
                 return r;
 
@@ -3000,10 +3107,12 @@ static int start_special(sd_bus *bus, char **args) {
                 if (r < 0)
                         return r;
         } else if (a == ACTION_EXIT && strv_length(args) > 1) {
+                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
                 /* If the exit code is not given on the command line, don't
                  * reset it to zero: just keep it as it might have been set
                  * previously. */
                 uint8_t code = 0;
+                sd_bus *bus;
 
                 r = safe_atou8(args[1], &code);
                 if (r < 0) {
@@ -3011,6 +3120,10 @@ static int start_special(sd_bus *bus, char **args) {
                         return -EINVAL;
                 }
 
+                r = acquire_bus(BUS_MANAGER, &bus);
+                if (r < 0)
+                        return r;
+
                 r = sd_bus_call_method(
                                 bus,
                                 "org.freedesktop.systemd1",
@@ -3040,7 +3153,7 @@ static int start_special(sd_bus *bus, char **args) {
                    ACTION_REBOOT,
                    ACTION_KEXEC,
                    ACTION_EXIT))
-                return daemon_reload(bus, args);
+                return daemon_reload(args);
 
         /* first try logind, to allow authentication with polkit */
         if (geteuid() != 0 &&
@@ -3050,7 +3163,7 @@ static int start_special(sd_bus *bus, char **args) {
                    ACTION_SUSPEND,
                    ACTION_HIBERNATE,
                    ACTION_HYBRID_SLEEP)) {
-                r = logind_reboot(bus, a);
+                r = logind_reboot(a);
                 if (r >= 0)
                         return r;
                 if (IN_SET(r, -EOPNOTSUPP, -EINPROGRESS))
@@ -3059,17 +3172,21 @@ static int start_special(sd_bus *bus, char **args) {
                 /* on all other errors, try low-level operation */
         }
 
-        return start_unit(bus, args);
+        return start_unit(args);
 }
 
-static int check_unit_generic(sd_bus *bus, int code, const char *good_states, char **args) {
+static int check_unit_generic(int code, const char *good_states, char **args) {
         _cleanup_strv_free_ char **names = NULL;
+        sd_bus *bus;
         char **name;
         int r;
 
-        assert(bus);
         assert(args);
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         r = expand_names(bus, args, NULL, &names);
         if (r < 0)
                 return log_error_errno(r, "Failed to expand names: %m");
@@ -3087,25 +3204,29 @@ static int check_unit_generic(sd_bus *bus, int code, const char *good_states, ch
         return r;
 }
 
-static int check_unit_active(sd_bus *bus, char **args) {
+static int check_unit_active(char **args) {
         /* According to LSB: 3, "program is not running" */
-        return check_unit_generic(bus, 3, "active\0reloading\0", args + 1);
+        return check_unit_generic(3, "active\0reloading\0", strv_skip(args, 1));
 }
 
-static int check_unit_failed(sd_bus *bus, char **args) {
-        return check_unit_generic(bus, 1, "failed\0", args + 1);
+static int check_unit_failed(char **args) {
+        return check_unit_generic(1, "failed\0", strv_skip(args, 1));
 }
 
-static int kill_unit(sd_bus *bus, char **args) {
+static int kill_unit(char **args) {
         _cleanup_strv_free_ char **names = NULL;
         char *kill_who = NULL, **name;
+        sd_bus *bus;
         int r, q;
 
-        assert(bus);
         assert(args);
 
         polkit_agent_open_if_enabled();
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         if (!arg_kill_who)
                 arg_kill_who = "all";
 
@@ -4516,12 +4637,12 @@ static int show_system_status(sd_bus *bus) {
         return 0;
 }
 
-static int show(sd_bus *bus, char **args) {
+static int show(char **args) {
         bool show_properties, show_status, new_line = false;
         bool ellipsized = false;
         int r, ret = 0;
+        sd_bus *bus;
 
-        assert(bus);
         assert(args);
 
         show_properties = streq(args[0], "show");
@@ -4536,8 +4657,11 @@ static int show(sd_bus *bus, char **args) {
                  * be split up into many files. */
                 setrlimit_closest(RLIMIT_NOFILE, &RLIMIT_MAKE_CONST(16384));
 
-        /* If no argument is specified inspect the manager itself */
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
 
+        /* If no argument is specified inspect the manager itself */
         if (show_properties && strv_length(args) <= 1)
                 return show_one(args[0], bus, "/org/freedesktop/systemd1", show_properties, &new_line, &ellipsized);
 
@@ -4659,19 +4783,20 @@ static int cat_file(const char *filename, bool newline) {
         return copy_bytes(fd, STDOUT_FILENO, (uint64_t) -1, false);
 }
 
-static int cat(sd_bus *bus, char **args) {
+static int cat(char **args) {
         _cleanup_free_ char *user_home = NULL;
         _cleanup_free_ char *user_runtime = NULL;
         _cleanup_lookup_paths_free_ LookupPaths lp = {};
         _cleanup_strv_free_ char **names = NULL;
         char **name;
-        bool first = true, avoid_bus_cache;
+        sd_bus *bus;
+        bool first = true;
         int r;
 
         assert(args);
 
         if (arg_transport != BUS_TRANSPORT_LOCAL) {
-                log_error("Cannot remotely cat units");
+                log_error("Cannot remotely cat units.");
                 return -EINVAL;
         }
 
@@ -4679,11 +4804,13 @@ static int cat(sd_bus *bus, char **args) {
         if (r < 0)
                 return r;
 
-        r = expand_names(bus, args + 1, NULL, &names);
+        r = acquire_bus(BUS_MANAGER, &bus);
         if (r < 0)
-                return log_error_errno(r, "Failed to expand names: %m");
+                return r;
 
-        avoid_bus_cache = !bus || avoid_bus();
+        r = expand_names(bus, strv_skip(args, 1), NULL, &names);
+        if (r < 0)
+                return log_error_errno(r, "Failed to expand names: %m");
 
         pager_open_if_enabled();
 
@@ -4692,7 +4819,7 @@ static int cat(sd_bus *bus, char **args) {
                 _cleanup_strv_free_ char **dropin_paths = NULL;
                 char **path;
 
-                r = unit_find_paths(bus, *name, avoid_bus_cache, &lp, &fragment_path, &dropin_paths);
+                r = unit_find_paths(bus, *name, &lp, &fragment_path, &dropin_paths);
                 if (r < 0)
                         return r;
                 else if (r == 0)
@@ -4719,15 +4846,20 @@ static int cat(sd_bus *bus, char **args) {
         return 0;
 }
 
-static int set_property(sd_bus *bus, char **args) {
+static int set_property(char **args) {
         _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_free_ char *n = NULL;
+        sd_bus *bus;
         char **i;
         int r;
 
         polkit_agent_open_if_enabled();
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         r = sd_bus_message_new_method_call(
                         bus,
                         &m,
@@ -4777,11 +4909,12 @@ static int set_property(sd_bus *bus, char **args) {
         return 0;
 }
 
-static int snapshot(sd_bus *bus, char **args) {
+static int snapshot(char **args) {
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
         _cleanup_free_ char *n = NULL, *id = NULL;
         const char *path;
+        sd_bus *bus;
         int r;
 
         polkit_agent_open_if_enabled();
@@ -4796,6 +4929,10 @@ static int snapshot(sd_bus *bus, char **args) {
                         return log_oom();
         }
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         r = sd_bus_call_method(
                         bus,
                         "org.freedesktop.systemd1",
@@ -4833,8 +4970,9 @@ static int snapshot(sd_bus *bus, char **args) {
         return 0;
 }
 
-static int delete_snapshot(sd_bus *bus, char **args) {
+static int delete_snapshot(char **args) {
         _cleanup_strv_free_ char **names = NULL;
+        sd_bus *bus;
         char **name;
         int r;
 
@@ -4842,9 +4980,13 @@ static int delete_snapshot(sd_bus *bus, char **args) {
 
         polkit_agent_open_if_enabled();
 
-        r = expand_names(bus, args + 1, ".snapshot", &names);
+        r = acquire_bus(BUS_MANAGER, &bus);
         if (r < 0)
-                log_error_errno(r, "Failed to expand names: %m");
+                return r;
+
+        r = expand_names(bus, strv_skip(args, 1), ".snapshot", &names);
+        if (r < 0)
+                return log_error_errno(r, "Failed to expand names: %m");
 
         STRV_FOREACH(name, names) {
                 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
@@ -4869,13 +5011,18 @@ static int delete_snapshot(sd_bus *bus, char **args) {
         return r;
 }
 
-static int daemon_reload(sd_bus *bus, char **args) {
+static int daemon_reload(char **args) {
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         const char *method;
+        sd_bus *bus;
         int r;
 
         polkit_agent_open_if_enabled();
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         if (arg_action == ACTION_RELOAD)
                 method = "Reload";
         else if (arg_action == ACTION_REEXEC)
@@ -4919,17 +5066,22 @@ static int daemon_reload(sd_bus *bus, char **args) {
         return r < 0 ? r : 0;
 }
 
-static int reset_failed(sd_bus *bus, char **args) {
+static int reset_failed(char **args) {
         _cleanup_strv_free_ char **names = NULL;
+        sd_bus *bus;
         char **name;
         int r, q;
 
         if (strv_length(args) <= 1)
-                return daemon_reload(bus, args);
+                return daemon_reload(args);
 
         polkit_agent_open_if_enabled();
 
-        r = expand_names(bus, args + 1, NULL, &names);
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
+        r = expand_names(bus, strv_skip(args, 1), NULL, &names);
         if (r < 0)
                 log_error_errno(r, "Failed to expand names: %m");
 
@@ -4955,14 +5107,19 @@ static int reset_failed(sd_bus *bus, char **args) {
         return r;
 }
 
-static int show_environment(sd_bus *bus, char **args) {
+static int show_environment(char **args) {
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
         const char *text;
+        sd_bus *bus;
         int r;
 
         pager_open_if_enabled();
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         r = sd_bus_get_property(
                         bus,
                         "org.freedesktop.systemd1",
@@ -4993,13 +5150,19 @@ static int show_environment(sd_bus *bus, char **args) {
         return 0;
 }
 
-static int switch_root(sd_bus *bus, char **args) {
+static int switch_root(char **args) {
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_free_ char *cmdline_init = NULL;
         const char *root, *init;
+        sd_bus *bus;
         unsigned l;
         int r;
 
+        if (arg_transport != BUS_TRANSPORT_LOCAL) {
+                log_error("Cannot switch root remotely.");
+                return -EINVAL;
+        }
+
         l = strv_length(args);
         if (l < 2 || l > 3) {
                 log_error("Wrong number of arguments.");
@@ -5035,6 +5198,10 @@ static int switch_root(sd_bus *bus, char **args) {
                         init = NULL;
         }
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         log_debug("Switching root - root: %s; init: %s", root, strna(init));
 
         r = sd_bus_call_method(
@@ -5054,17 +5221,21 @@ static int switch_root(sd_bus *bus, char **args) {
         return 0;
 }
 
-static int set_environment(sd_bus *bus, char **args) {
+static int set_environment(char **args) {
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
         const char *method;
+        sd_bus *bus;
         int r;
 
-        assert(bus);
         assert(args);
 
         polkit_agent_open_if_enabled();
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         method = streq(args[0], "set-environment")
                 ? "SetEnvironment"
                 : "UnsetEnvironment";
@@ -5092,16 +5263,20 @@ static int set_environment(sd_bus *bus, char **args) {
         return 0;
 }
 
-static int import_environment(sd_bus *bus, char **args) {
+static int import_environment(char **args) {
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
+        sd_bus *bus;
         int r;
 
-        assert(bus);
         assert(args);
 
         polkit_agent_open_if_enabled();
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         r = sd_bus_message_new_method_call(
                         bus,
                         &m,
@@ -5331,7 +5506,7 @@ static int mangle_names(char **original_names, char ***mangled_names) {
         return 0;
 }
 
-static int enable_unit(sd_bus *bus, char **args) {
+static int enable_unit(char **args) {
         _cleanup_strv_free_ char **names = NULL;
         const char *verb = args[0];
         UnitFileChange *changes = NULL;
@@ -5355,7 +5530,7 @@ static int enable_unit(sd_bus *bus, char **args) {
         if (strv_isempty(names))
                 return 0;
 
-        if (!bus || avoid_bus()) {
+        if (install_client_side()) {
                 if (streq(verb, "enable")) {
                         r = unit_file_enable(arg_scope, arg_runtime, arg_root, names, arg_force, &changes, &n_changes);
                         carries_install_info = r;
@@ -5391,9 +5566,14 @@ static int enable_unit(sd_bus *bus, char **args) {
                 int expect_carries_install_info = false;
                 bool send_force = true, send_preset_mode = false;
                 const char *method;
+                sd_bus *bus;
 
                 polkit_agent_open_if_enabled();
 
+                r = acquire_bus(BUS_MANAGER, &bus);
+                if (r < 0)
+                        return r;
+
                 if (streq(verb, "enable")) {
                         method = "EnableUnitFiles";
                         expect_carries_install_info = true;
@@ -5470,7 +5650,7 @@ static int enable_unit(sd_bus *bus, char **args) {
 
                 /* Try to reload if enabled */
                 if (!arg_no_reload)
-                        r = daemon_reload(bus, args);
+                        r = daemon_reload(args);
                 else
                         r = 0;
         }
@@ -5488,14 +5668,19 @@ static int enable_unit(sd_bus *bus, char **args) {
 
         if (arg_now && n_changes > 0 && STR_IN_SET(args[0], "enable", "disable", "mask")) {
                 char *new_args[n_changes + 2];
+                sd_bus *bus;
                 unsigned i;
 
-                new_args[0] = streq(args[0], "enable") ? (char *)"start" : (char *)"stop";
+                r = acquire_bus(BUS_MANAGER, &bus);
+                if (r < 0)
+                        return r;
+
+                new_args[0] = (char*) (streq(args[0], "enable") ? "start" : "stop");
                 for (i = 0; i < n_changes; i++)
                         new_args[i + 1] = basename(changes[i].path);
                 new_args[i + 1] = NULL;
 
-                r = start_unit(bus, new_args);
+                r = start_unit(new_args);
         }
 
 finish:
@@ -5504,7 +5689,7 @@ finish:
         return r;
 }
 
-static int add_dependency(sd_bus *bus, char **args) {
+static int add_dependency(char **args) {
         _cleanup_strv_free_ char **names = NULL;
         _cleanup_free_ char *target = NULL;
         const char *verb = args[0];
@@ -5529,7 +5714,7 @@ static int add_dependency(sd_bus *bus, char **args) {
         else
                 assert_not_reached("Unknown verb");
 
-        if (!bus || avoid_bus()) {
+        if (install_client_side()) {
                 UnitFileChange *changes = NULL;
                 unsigned n_changes = 0;
 
@@ -5546,9 +5731,14 @@ static int add_dependency(sd_bus *bus, char **args) {
         } else {
                 _cleanup_bus_message_unref_ sd_bus_message *reply = NULL, *m = NULL;
                 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+                sd_bus *bus;
 
                 polkit_agent_open_if_enabled();
 
+                r = acquire_bus(BUS_MANAGER, &bus);
+                if (r < 0)
+                        return r;
+
                 r = sd_bus_message_new_method_call(
                                 bus,
                                 &m,
@@ -5578,7 +5768,7 @@ static int add_dependency(sd_bus *bus, char **args) {
                         return r;
 
                 if (!arg_no_reload)
-                        r = daemon_reload(bus, args);
+                        r = daemon_reload(args);
                 else
                         r = 0;
         }
@@ -5586,12 +5776,12 @@ static int add_dependency(sd_bus *bus, char **args) {
         return r;
 }
 
-static int preset_all(sd_bus *bus, char **args) {
+static int preset_all(char **args) {
         UnitFileChange *changes = NULL;
         unsigned n_changes = 0;
         int r;
 
-        if (!bus || avoid_bus()) {
+        if (install_client_side()) {
 
                 r = unit_file_preset_all(arg_scope, arg_runtime, arg_root, arg_preset_mode, arg_force, &changes, &n_changes);
                 if (r < 0) {
@@ -5607,9 +5797,14 @@ static int preset_all(sd_bus *bus, char **args) {
         } else {
                 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
                 _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+                sd_bus *bus;
 
                 polkit_agent_open_if_enabled();
 
+                r = acquire_bus(BUS_MANAGER, &bus);
+                if (r < 0)
+                        return r;
+
                 r = sd_bus_call_method(
                                 bus,
                                 "org.freedesktop.systemd1",
@@ -5632,7 +5827,7 @@ static int preset_all(sd_bus *bus, char **args) {
                         return r;
 
                 if (!arg_no_reload)
-                        r = daemon_reload(bus, args);
+                        r = daemon_reload(args);
                 else
                         r = 0;
         }
@@ -5643,9 +5838,8 @@ finish:
         return r;
 }
 
-static int unit_is_enabled(sd_bus *bus, char **args) {
+static int unit_is_enabled(char **args) {
 
-        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_strv_free_ char **names = NULL;
         bool enabled;
         char **name;
@@ -5661,7 +5855,7 @@ static int unit_is_enabled(sd_bus *bus, char **args) {
 
         enabled = r > 0;
 
-        if (!bus || avoid_bus()) {
+        if (install_client_side()) {
 
                 STRV_FOREACH(name, names) {
                         UnitFileState state;
@@ -5682,6 +5876,13 @@ static int unit_is_enabled(sd_bus *bus, char **args) {
                 }
 
         } else {
+                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+                sd_bus *bus;
+
+                r = acquire_bus(BUS_MANAGER, &bus);
+                if (r < 0)
+                        return r;
+
                 STRV_FOREACH(name, names) {
                         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
                         const char *s;
@@ -5715,8 +5916,9 @@ static int unit_is_enabled(sd_bus *bus, char **args) {
         return !enabled;
 }
 
-static int is_system_running(sd_bus *bus, char **args) {
+static int is_system_running(char **args) {
         _cleanup_free_ char *state = NULL;
+        sd_bus *bus;
         int r;
 
         if (arg_transport == BUS_TRANSPORT_LOCAL && !sd_booted()) {
@@ -5725,6 +5927,10 @@ static int is_system_running(sd_bus *bus, char **args) {
                 return EXIT_FAILURE;
         }
 
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
         r = sd_bus_get_property_string(
                         bus,
                         "org.freedesktop.systemd1",
@@ -5995,7 +6201,6 @@ static int find_paths_to_edit(sd_bus *bus, char **names, char ***paths) {
         _cleanup_free_ char *user_home = NULL;
         _cleanup_free_ char *user_runtime = NULL;
         _cleanup_lookup_paths_free_ LookupPaths lp = {};
-        bool avoid_bus_cache;
         char **name;
         int r;
 
@@ -6006,13 +6211,11 @@ static int find_paths_to_edit(sd_bus *bus, char **names, char ***paths) {
         if (r < 0)
                 return r;
 
-        avoid_bus_cache = !bus || avoid_bus();
-
         STRV_FOREACH(name, names) {
                 _cleanup_free_ char *path = NULL;
                 char *new_path, *tmp_path;
 
-                r = unit_find_paths(bus, *name, avoid_bus_cache, &lp, &path, NULL);
+                r = unit_find_paths(bus, *name, &lp, &path, NULL);
                 if (r < 0)
                         return r;
                 else if (r == 0)
@@ -6038,25 +6241,30 @@ static int find_paths_to_edit(sd_bus *bus, char **names, char ***paths) {
         return 0;
 }
 
-static int edit(sd_bus *bus, char **args) {
+static int edit(char **args) {
         _cleanup_strv_free_ char **names = NULL;
         _cleanup_strv_free_ char **paths = NULL;
         char **original, **tmp;
+        sd_bus *bus;
         int r;
 
         assert(args);
 
         if (!on_tty()) {
-                log_error("Cannot edit units if not on a tty");
+                log_error("Cannot edit units if not on a tty.");
                 return -EINVAL;
         }
 
         if (arg_transport != BUS_TRANSPORT_LOCAL) {
-                log_error("Cannot remotely edit units");
+                log_error("Cannot edit units remotely.");
                 return -EINVAL;
         }
 
-        r = expand_names(bus, args + 1, NULL, &names);
+        r = acquire_bus(BUS_MANAGER, &bus);
+        if (r < 0)
+                return r;
+
+        r = expand_names(bus, strv_skip(args, 1), NULL, &names);
         if (r < 0)
                 return log_error_errno(r, "Failed to expand names: %m");
 
@@ -6086,8 +6294,8 @@ static int edit(sd_bus *bus, char **args) {
                 }
         }
 
-        if (!arg_no_reload && bus && !avoid_bus())
-                r = daemon_reload(bus, args);
+        if (!arg_no_reload && bus && !install_client_side())
+                r = daemon_reload(args);
 
 end:
         STRV_FOREACH_PAIR(original, tmp, paths)
@@ -7153,7 +7361,7 @@ static int talk_initctl(void) {
 #endif
 }
 
-static int systemctl_main(sd_bus *bus, int argc, char *argv[], int bus_error) {
+static int systemctl_main(int argc, char *argv[], int bus_error) {
 
         static const struct {
                 const char* verb;
@@ -7163,14 +7371,10 @@ static int systemctl_main(sd_bus *bus, int argc, char *argv[], int bus_error) {
                         EQUAL
                 } argc_cmp;
                 const int argc;
-                int (* const dispatch)(sd_bus *bus, char **args);
-                const enum {
-                        NOBUS = 1,
-                        FORCE,
-                } bus;
+                int (* const dispatch)(char **args);
         } verbs[] = {
                 { "list-units",            MORE,  0, list_units        },
-                { "list-unit-files",       MORE,  1, list_unit_files,  NOBUS },
+                { "list-unit-files",       MORE,  1, list_unit_files   },
                 { "list-sockets",          MORE,  1, list_sockets      },
                 { "list-timers",           MORE,  1, list_timers       },
                 { "list-jobs",             MORE,  1, list_jobs         },
@@ -7194,7 +7398,7 @@ static int systemctl_main(sd_bus *bus, int argc, char *argv[], int bus_error) {
                 { "check",                 MORE,  2, check_unit_active },
                 { "is-failed",             MORE,  2, check_unit_failed },
                 { "show",                  MORE,  1, show              },
-                { "cat",                   MORE,  2, cat,              NOBUS },
+                { "cat",                   MORE,  2, cat,              },
                 { "status",                MORE,  1, show              },
                 { "help",                  MORE,  2, show              },
                 { "snapshot",              LESS,  2, snapshot          },
@@ -7205,9 +7409,9 @@ static int systemctl_main(sd_bus *bus, int argc, char *argv[], int bus_error) {
                 { "set-environment",       MORE,  2, set_environment   },
                 { "unset-environment",     MORE,  2, set_environment   },
                 { "import-environment",    MORE,  1, import_environment},
-                { "halt",                  EQUAL, 1, start_special,    FORCE },
-                { "poweroff",              EQUAL, 1, start_special,    FORCE },
-                { "reboot",                MORE,  1, start_special,    FORCE },
+                { "halt",                  EQUAL, 1, start_special,    },
+                { "poweroff",              EQUAL, 1, start_special,    },
+                { "reboot",                MORE,  1, start_special,    },
                 { "kexec",                 EQUAL, 1, start_special     },
                 { "suspend",               EQUAL, 1, start_special     },
                 { "hibernate",             EQUAL, 1, start_special     },
@@ -7217,24 +7421,24 @@ static int systemctl_main(sd_bus *bus, int argc, char *argv[], int bus_error) {
                 { "emergency",             EQUAL, 1, start_special     },
                 { "exit",                  LESS,  2, start_special     },
                 { "reset-failed",          MORE,  1, reset_failed      },
-                { "enable",                MORE,  2, enable_unit,      NOBUS },
-                { "disable",               MORE,  2, enable_unit,      NOBUS },
-                { "is-enabled",            MORE,  2, unit_is_enabled,  NOBUS },
-                { "reenable",              MORE,  2, enable_unit,      NOBUS },
-                { "preset",                MORE,  2, enable_unit,      NOBUS },
-                { "preset-all",            EQUAL, 1, preset_all,       NOBUS },
-                { "mask",                  MORE,  2, enable_unit,      NOBUS },
-                { "unmask",                MORE,  2, enable_unit,      NOBUS },
-                { "link",                  MORE,  2, enable_unit,      NOBUS },
+                { "enable",                MORE,  2, enable_unit,      },
+                { "disable",               MORE,  2, enable_unit,      },
+                { "is-enabled",            MORE,  2, unit_is_enabled,  },
+                { "reenable",              MORE,  2, enable_unit,      },
+                { "preset",                MORE,  2, enable_unit,      },
+                { "preset-all",            EQUAL, 1, preset_all,       },
+                { "mask",                  MORE,  2, enable_unit,      },
+                { "unmask",                MORE,  2, enable_unit,      },
+                { "link",                  MORE,  2, enable_unit,      },
                 { "switch-root",           MORE,  2, switch_root       },
                 { "list-dependencies",     LESS,  2, list_dependencies },
-                { "set-default",           EQUAL, 2, set_default,      NOBUS },
-                { "get-default",           EQUAL, 1, get_default,      NOBUS },
+                { "set-default",           EQUAL, 2, set_default,      },
+                { "get-default",           EQUAL, 1, get_default,      },
                 { "set-property",          MORE,  3, set_property      },
                 { "is-system-running",     EQUAL, 1, is_system_running },
-                { "add-wants",             MORE,  3, add_dependency,   NOBUS },
-                { "add-requires",          MORE,  3, add_dependency,   NOBUS },
-                { "edit",                  MORE,  2, edit,             NOBUS },
+                { "add-wants",             MORE,  3, add_dependency,   },
+                { "add-requires",          MORE,  3, add_dependency,   },
+                { "edit",                  MORE,  2, edit,             },
                 {}
         }, *verb = verbs;
 
@@ -7292,36 +7496,14 @@ found:
                 assert_not_reached("Unknown comparison operator.");
         }
 
-        /* Require a bus connection for all operations but
-         * enable/disable */
-        if (verb->bus == NOBUS) {
-                if (!bus && !avoid_bus()) {
-                        log_error_errno(bus_error, "Failed to get D-Bus connection: %m");
-                        return -EIO;
-                }
-
-        } else {
-                if (running_in_chroot() > 0) {
-                        log_info("Running in chroot, ignoring request.");
-                        return 0;
-                }
-
-                if ((verb->bus != FORCE || arg_force <= 0) && !bus) {
-                        log_error_errno(bus_error, "Failed to get D-Bus connection: %m");
-                        return -EIO;
-                }
-        }
-
-        return verb->dispatch(bus, argv + optind);
+        return verb->dispatch(argv + optind);
 }
 
-static int reload_with_fallback(sd_bus *bus) {
+static int reload_with_fallback(void) {
 
-        if (bus) {
-                /* First, try systemd via D-Bus. */
-                if (daemon_reload(bus, NULL) >= 0)
-                        return 0;
-        }
+        /* First, try systemd via D-Bus. */
+        if (daemon_reload(NULL) >= 0)
+                return 0;
 
         /* Nothing else worked, so let's try signals */
         assert(arg_action == ACTION_RELOAD || arg_action == ACTION_REEXEC);
@@ -7332,13 +7514,11 @@ static int reload_with_fallback(sd_bus *bus) {
         return 0;
 }
 
-static int start_with_fallback(sd_bus *bus) {
+static int start_with_fallback(void) {
 
-        if (bus) {
-                /* First, try systemd via D-Bus. */
-                if (start_unit(bus, NULL) >= 0)
-                        return 0;
-        }
+        /* First, try systemd via D-Bus. */
+        if (start_unit(NULL) >= 0)
+                return 0;
 
         /* Nothing else worked, so let's try
          * /dev/initctl */
@@ -7396,23 +7576,16 @@ static int logind_schedule_shutdown(void) {
 
 #ifdef HAVE_LOGIND
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
-        _cleanup_bus_flush_close_unref_ sd_bus *b = NULL;
         char date[FORMAT_TIMESTAMP_MAX];
         const char *action;
+        sd_bus *bus;
         int r;
 
-        assert(geteuid() == 0);
-
-        if (avoid_bus()) {
-                log_error("Unable to perform operation without bus connection.");
-                return -ENOSYS;
-        }
+        (void) logind_set_wall_message();
 
-        r = sd_bus_open_system(&b);
+        r = acquire_bus(BUS_FULL, &bus);
         if (r < 0)
-                return log_error_errno(r, "Unable to open system bus: %m");
-
-        (void) logind_set_wall_message(b);
+                return r;
 
         switch (arg_action) {
         case ACTION_HALT:
@@ -7433,7 +7606,7 @@ static int logind_schedule_shutdown(void) {
                 action = strjoina("dry-", action);
 
         r = sd_bus_call_method(
-                        b,
+                        bus,
                         "org.freedesktop.login1",
                         "/org/freedesktop/login1",
                         "org.freedesktop.login1.Manager",
@@ -7454,10 +7627,10 @@ static int logind_schedule_shutdown(void) {
 #endif
 }
 
-static int halt_main(sd_bus *bus) {
+static int halt_main(void) {
         int r;
 
-        r = logind_check_inhibitors(bus, arg_action);
+        r = logind_check_inhibitors(arg_action);
         if (r < 0)
                 return r;
 
@@ -7475,7 +7648,7 @@ static int halt_main(sd_bus *bus) {
                 if (IN_SET(arg_action,
                            ACTION_POWEROFF,
                            ACTION_REBOOT)) {
-                        r = logind_reboot(bus, arg_action);
+                        r = logind_reboot(arg_action);
                         if (r >= 0)
                                 return r;
                         if (IN_SET(r, -EOPNOTSUPP, -EINPROGRESS))
@@ -7492,7 +7665,7 @@ static int halt_main(sd_bus *bus) {
         }
 
         if (!arg_dry && !arg_force)
-                return start_with_fallback(bus);
+                return start_with_fallback();
 
         assert(geteuid() == 0);
 
@@ -7534,22 +7707,17 @@ static int runlevel_main(void) {
 static int logind_cancel_shutdown(void) {
 #ifdef HAVE_LOGIND
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
-        _cleanup_bus_flush_close_unref_ sd_bus *b = NULL;
+        sd_bus *bus;
         int r;
 
-        if (avoid_bus()) {
-                log_error("Unable to perform operation without bus connection.");
-                return -ENOSYS;
-        }
-
-        r = sd_bus_open_system(&b);
+        r = acquire_bus(BUS_FULL, &bus);
         if (r < 0)
-                return log_error_errno(r, "Unable to open system bus: %m");
+                return r;
 
-        (void) logind_set_wall_message(b);
+        (void) logind_set_wall_message();
 
         r = sd_bus_call_method(
-                        b,
+                        bus,
                         "org.freedesktop.login1",
                         "/org/freedesktop/login1",
                         "org.freedesktop.login1.Manager",
@@ -7567,7 +7735,6 @@ static int logind_cancel_shutdown(void) {
 }
 
 int main(int argc, char*argv[]) {
-        _cleanup_bus_flush_close_unref_ sd_bus *bus = NULL;
         int r;
 
         setlocale(LC_ALL, "");
@@ -7589,26 +7756,20 @@ int main(int argc, char*argv[]) {
                 goto finish;
         }
 
-        if (!avoid_bus())
-                r = bus_connect_transport_systemd(arg_transport, arg_host, arg_scope != UNIT_FILE_SYSTEM, &bus);
-
-        if (bus)
-                sd_bus_set_allow_interactive_authorization(bus, arg_ask_password);
-
         /* systemctl_main() will print an error message for the bus
          * connection, but only if it needs to */
 
         switch (arg_action) {
 
         case ACTION_SYSTEMCTL:
-                r = systemctl_main(bus, argc, argv, r);
+                r = systemctl_main(argc, argv, r);
                 break;
 
         case ACTION_HALT:
         case ACTION_POWEROFF:
         case ACTION_REBOOT:
         case ACTION_KEXEC:
-                r = halt_main(bus);
+                r = halt_main();
                 break;
 
         case ACTION_RUNLEVEL2:
@@ -7618,12 +7779,12 @@ int main(int argc, char*argv[]) {
         case ACTION_RESCUE:
         case ACTION_EMERGENCY:
         case ACTION_DEFAULT:
-                r = start_with_fallback(bus);
+                r = start_with_fallback();
                 break;
 
         case ACTION_RELOAD:
         case ACTION_REEXEC:
-                r = reload_with_fallback(bus);
+                r = reload_with_fallback();
                 break;
 
         case ACTION_CANCEL_SHUTDOWN:
@@ -7650,7 +7811,7 @@ finish:
 
         strv_free(arg_wall);
 
-        sd_bus_default_flush_close();
+        release_busses();
 
         return r < 0 ? EXIT_FAILURE : r;
 }