src/core/busname.c

	busname.c revision a9c8343e83ec09f80a76930573b2592f97ae4283
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering/***
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  This file is part of systemd.
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  Copyright 2013 Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  systemd is free software; you can redistribute it and/or modify it
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  under the terms of the GNU Lesser General Public License as published by
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  the Free Software Foundation; either version 2.1 of the License, or
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  (at your option) any later version.
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  systemd is distributed in the hope that it will be useful, but
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  WITHOUT ANY WARRANTY; without even the implied warranty of
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  Lesser General Public License for more details.
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  You should have received a copy of the GNU Lesser General Public License
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering  along with systemd; If not, see <http://www.gnu.org/licenses/>.
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering***/
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering#include <sys/mman.h>
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
3c0cf502796be355431d4a64d738e75f543aa51dLennart Poettering#include "special.h"
3c0cf502796be355431d4a64d738e75f543aa51dLennart Poettering#include "bus-kernel.h"
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering#include "bus-internal.h"
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering#include "bus-util.h"
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering#include "service.h"
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering#include "kdbus.h"
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering#include "bus-policy.h"
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering#include "dbus-busname.h"
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering#include "busname.h"
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poetteringstatic const UnitActiveState state_translation_table[_BUSNAME_STATE_MAX] = {
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering        [BUSNAME_DEAD] = UNIT_INACTIVE,
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering        [BUSNAME_MAKING] = UNIT_ACTIVATING,
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering        [BUSNAME_REGISTERED] = UNIT_ACTIVE,
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering        [BUSNAME_LISTENING] = UNIT_ACTIVE,
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        [BUSNAME_RUNNING] = UNIT_ACTIVE,
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        [BUSNAME_SIGTERM] = UNIT_DEACTIVATING,
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        [BUSNAME_SIGKILL] = UNIT_DEACTIVATING,
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering        [BUSNAME_FAILED] = UNIT_FAILED
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering};
3c0cf502796be355431d4a64d738e75f543aa51dLennart Poettering
3c0cf502796be355431d4a64d738e75f543aa51dLennart Poetteringstatic int busname_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata);
0dd25fb9f005d8ab7ac4bc10a609d00569f8c56aLennart Poetteringstatic int busname_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata);
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poetteringstatic void busname_init(Unit *u) {
3c0cf502796be355431d4a64d738e75f543aa51dLennart Poettering        BusName *n = BUSNAME(u);
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        assert(u);
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        assert(u->load_state == UNIT_STUB);
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        n->starter_fd = -1;
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        n->accept_fd = true;
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        n->activating = true;
4e945a6f7971fd7d1f6b2c62ee3afdaff3c95ce4Lennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        n->timeout_usec = u->manager->default_timeout_start_usec;
0dd25fb9f005d8ab7ac4bc10a609d00569f8c56aLennart Poettering}
3c0cf502796be355431d4a64d738e75f543aa51dLennart Poettering
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poetteringstatic void busname_unwatch_control_pid(BusName *n) {
74b2466e14a1961bf3ac0e8a60cfaceec705bd59Lennart Poettering        assert(n);

        if (n->control_pid <= 0)
                return;

        unit_unwatch_pid(UNIT(n), n->control_pid);
        n->control_pid = 0;
}

static void busname_free_policy(BusName *n) {
        BusNamePolicy *p;

        assert(n);

        while ((p = n->policy)) {
                LIST_REMOVE(policy, n->policy, p);

                free(p->name);
                free(p);
        }
}

static void busname_close_fd(BusName *n) {
        assert(n);

        n->starter_event_source = sd_event_source_unref(n->starter_event_source);
        n->starter_fd = safe_close(n->starter_fd);
}

static void busname_done(Unit *u) {
        BusName *n = BUSNAME(u);

        assert(n);

        free(n->name);
        n->name = NULL;

        busname_free_policy(n);
        busname_unwatch_control_pid(n);
        busname_close_fd(n);

        unit_ref_unset(&n->service);

        n->timer_event_source = sd_event_source_unref(n->timer_event_source);
}

static int busname_arm_timer(BusName *n) {
        int r;

        assert(n);

        if (n->timeout_usec <= 0) {
                n->timer_event_source = sd_event_source_unref(n->timer_event_source);
                return 0;
        }

        if (n->timer_event_source) {
                r = sd_event_source_set_time(n->timer_event_source, now(CLOCK_MONOTONIC) + n->timeout_usec);
                if (r < 0)
                        return r;

                return sd_event_source_set_enabled(n->timer_event_source, SD_EVENT_ONESHOT);
        }

        return sd_event_add_time(
                        UNIT(n)->manager->event,
                        &n->timer_event_source,
                        CLOCK_MONOTONIC,
                        now(CLOCK_MONOTONIC) + n->timeout_usec, 0,
                        busname_dispatch_timer, n);
}

static int busname_add_default_default_dependencies(BusName *n) {
        int r;

        assert(n);

        r = unit_add_dependency_by_name(UNIT(n), UNIT_BEFORE, SPECIAL_BUSNAMES_TARGET, NULL, true);
        if (r < 0)
                return r;

        if (UNIT(n)->manager->running_as == SYSTEMD_SYSTEM) {
                r = unit_add_two_dependencies_by_name(UNIT(n), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true);
                if (r < 0)
                        return r;
        }

        return unit_add_two_dependencies_by_name(UNIT(n), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true);
}

static int busname_add_extras(BusName *n) {
        Unit *u = UNIT(n);
        int r;

        assert(n);

        if (!n->name) {
                n->name = unit_name_to_prefix(u->id);
                if (!n->name)
                        return -ENOMEM;
        }

        if (!u->description) {
                r = unit_set_description(u, n->name);
                if (r < 0)
                        return r;
        }

        if (n->activating) {
                if (!UNIT_DEREF(n->service)) {
                        Unit *x;

                        r = unit_load_related_unit(u, ".service", &x);
                        if (r < 0)
                                return r;

                        unit_ref_set(&n->service, x);
                }

                r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, UNIT_DEREF(n->service), true);
                if (r < 0)
                        return r;
        }

        if (u->default_dependencies) {
                r = busname_add_default_default_dependencies(n);
                if (r < 0)
                        return r;
        }

        return 0;
}

static int busname_verify(BusName *n) {
        char *e;

        assert(n);

        if (UNIT(n)->load_state != UNIT_LOADED)
                return 0;

        if (!service_name_is_valid(n->name)) {
                log_unit_error(UNIT(n)->id, "%s's Name= setting is not a valid service name Refusing.", UNIT(n)->id);
                return -EINVAL;
        }

        e = strappenda(n->name, ".busname");
        if (!unit_has_name(UNIT(n), e)) {
                log_unit_error(UNIT(n)->id, "%s's Name= setting doesn't match unit name. Refusing.", UNIT(n)->id);
                return -EINVAL;
        }

        return 0;
}

static int busname_load(Unit *u) {
        BusName *n = BUSNAME(u);
        int r;

        assert(u);
        assert(u->load_state == UNIT_STUB);

        r = unit_load_fragment_and_dropin(u);
        if (r < 0)
                return r;

        if (u->load_state == UNIT_LOADED) {
                /* This is a new unit? Then let's add in some extras */
                r = busname_add_extras(n);
                if (r < 0)
                        return r;
        }

        return busname_verify(n);
}

static void busname_dump(Unit *u, FILE *f, const char *prefix) {
        BusName *n = BUSNAME(u);

        assert(n);
        assert(f);

        fprintf(f,
                "%sBus Name State: %s\n"
                "%sResult: %s\n"
                "%sName: %s\n"
                "%sActivating: %s\n"
                "%sAccept FD: %s\n",
                prefix, busname_state_to_string(n->state),
                prefix, busname_result_to_string(n->result),
                prefix, n->name,
                prefix, yes_no(n->activating),
                prefix, yes_no(n->accept_fd));

        if (n->control_pid > 0)
                fprintf(f,
                        "%sControl PID: "PID_FMT"\n",
                        prefix, n->control_pid);
}

static void busname_unwatch_fd(BusName *n) {
        int r;

        assert(n);

        if (!n->starter_event_source)
                return;

        r = sd_event_source_set_enabled(n->starter_event_source, SD_EVENT_OFF);
        if (r < 0)
                log_unit_debug(UNIT(n)->id, "Failed to disable event source.");
}

static int busname_watch_fd(BusName *n) {
        int r;

        assert(n);

        if (n->starter_fd < 0)
                return 0;

        if (n->starter_event_source)
                r = sd_event_source_set_enabled(n->starter_event_source, SD_EVENT_ON);
        else
                r = sd_event_add_io(UNIT(n)->manager->event, &n->starter_event_source, n->starter_fd, EPOLLIN, busname_dispatch_io, n);
        if (r < 0) {
                log_unit_warning_errno(UNIT(n)->id, r, "Failed to watch starter fd: %m");
                busname_unwatch_fd(n);
                return r;
        }

        return 0;
}

static int busname_open_fd(BusName *n) {
        _cleanup_free_ char *path = NULL;
        const char *mode;

        assert(n);

        if (n->starter_fd >= 0)
                return 0;

        mode = UNIT(n)->manager->running_as == SYSTEMD_SYSTEM ? "system" : "user";
        n->starter_fd = bus_kernel_open_bus_fd(mode, &path);
        if (n->starter_fd < 0)
                return log_unit_warning_errno(UNIT(n)->id, n->starter_fd, "Failed to open %s: %m", path ?: "kdbus");

        return 0;
}

static void busname_set_state(BusName *n, BusNameState state) {
        BusNameState old_state;
        assert(n);

        old_state = n->state;
        n->state = state;

        if (!IN_SET(state, BUSNAME_MAKING, BUSNAME_SIGTERM, BUSNAME_SIGKILL)) {
                n->timer_event_source = sd_event_source_unref(n->timer_event_source);
                busname_unwatch_control_pid(n);
        }

        if (state != BUSNAME_LISTENING)
                busname_unwatch_fd(n);

        if (!IN_SET(state, BUSNAME_LISTENING, BUSNAME_MAKING, BUSNAME_REGISTERED, BUSNAME_RUNNING))
                busname_close_fd(n);

        if (state != old_state)
                log_unit_debug(UNIT(n)->id, "%s changed %s -> %s",
                               UNIT(n)->id, busname_state_to_string(old_state), busname_state_to_string(state));

        unit_notify(UNIT(n), state_translation_table[old_state], state_translation_table[state], true);
}

static int busname_coldplug(Unit *u) {
        BusName *n = BUSNAME(u);
        int r;

        assert(n);
        assert(n->state == BUSNAME_DEAD);

        if (n->deserialized_state == n->state)
                return 0;

        if (IN_SET(n->deserialized_state, BUSNAME_MAKING, BUSNAME_SIGTERM, BUSNAME_SIGKILL)) {

                if (n->control_pid <= 0)
                        return -EBADMSG;

                r = unit_watch_pid(UNIT(n), n->control_pid);
                if (r < 0)
                        return r;

                r = busname_arm_timer(n);
                if (r < 0)
                        return r;
        }

        if (IN_SET(n->deserialized_state, BUSNAME_MAKING, BUSNAME_LISTENING, BUSNAME_REGISTERED, BUSNAME_RUNNING)) {
                r = busname_open_fd(n);
                if (r < 0)
                        return r;
        }

        if (n->deserialized_state == BUSNAME_LISTENING) {
                r = busname_watch_fd(n);
                if (r < 0)
                        return r;
        }

        busname_set_state(n, n->deserialized_state);
        return 0;
}

static int busname_make_starter(BusName *n, pid_t *_pid) {
        pid_t pid;
        int r;

        r = busname_arm_timer(n);
        if (r < 0)
                goto fail;

        /* We have to resolve the user/group names out-of-process,
         * hence let's fork here. It's messy, but well, what can we
         * do? */

        pid = fork();
        if (pid < 0)
                return -errno;

        if (pid == 0) {
                int ret;

                default_signals(SIGNALS_CRASH_HANDLER, SIGNALS_IGNORE, -1);
                ignore_signals(SIGPIPE, -1);
                log_forget_fds();

                r = bus_kernel_make_starter(n->starter_fd, n->name, n->activating, n->accept_fd, n->policy, n->policy_world);
                if (r < 0) {
                        ret = EXIT_MAKE_STARTER;
                        goto fail_child;
                }

                _exit(0);

        fail_child:
                log_open();
                log_error_errno(r, "Failed to create starter connection at step %s: %m", exit_status_to_string(ret, EXIT_STATUS_SYSTEMD));

                _exit(ret);
        }

        r = unit_watch_pid(UNIT(n), pid);
        if (r < 0)
                goto fail;

        *_pid = pid;
        return 0;

fail:
        n->timer_event_source = sd_event_source_unref(n->timer_event_source);
        return r;
}

static void busname_enter_dead(BusName *n, BusNameResult f) {
        assert(n);

        if (f != BUSNAME_SUCCESS)
                n->result = f;

        busname_set_state(n, n->result != BUSNAME_SUCCESS ? BUSNAME_FAILED : BUSNAME_DEAD);
}

static void busname_enter_signal(BusName *n, BusNameState state, BusNameResult f) {
        KillContext kill_context = {};
        int r;

        assert(n);

        if (f != BUSNAME_SUCCESS)
                n->result = f;

        kill_context_init(&kill_context);

        r = unit_kill_context(UNIT(n),
                              &kill_context,
                              state != BUSNAME_SIGTERM ? KILL_KILL : KILL_TERMINATE,
                              -1,
                              n->control_pid,
                              false);
        if (r < 0) {
                log_unit_warning_errno(UNIT(n)->id, r, "%s failed to kill control process: %m", UNIT(n)->id);
                goto fail;
        }

        if (r > 0) {
                r = busname_arm_timer(n);
                if (r < 0) {
                        log_unit_warning_errno(UNIT(n)->id, r, "%s failed to arm timer: %m", UNIT(n)->id);
                        goto fail;
                }

                busname_set_state(n, state);
        } else if (state == BUSNAME_SIGTERM)
                busname_enter_signal(n, BUSNAME_SIGKILL, BUSNAME_SUCCESS);
        else
                busname_enter_dead(n, BUSNAME_SUCCESS);

        return;

fail:
        busname_enter_dead(n, BUSNAME_FAILURE_RESOURCES);
}

static void busname_enter_listening(BusName *n) {
        int r;

        assert(n);

        if (n->activating) {
                r = busname_watch_fd(n);
                if (r < 0) {
                        log_unit_warning_errno(UNIT(n)->id, r, "%s failed to watch names: %m", UNIT(n)->id);
                        goto fail;
                }

                busname_set_state(n, BUSNAME_LISTENING);
        } else
                busname_set_state(n, BUSNAME_REGISTERED);

        return;

fail:
        busname_enter_signal(n, BUSNAME_SIGTERM, BUSNAME_FAILURE_RESOURCES);
}

static void busname_enter_making(BusName *n) {
        int r;

        assert(n);

        r = busname_open_fd(n);
        if (r < 0)
                goto fail;

        if (n->policy) {
                /* If there is a policy, we need to resolve user/group
                 * names, which we can't do from PID1, hence let's
                 * fork. */
                busname_unwatch_control_pid(n);

                r = busname_make_starter(n, &n->control_pid);
                if (r < 0) {
                        log_unit_warning_errno(UNIT(n)->id, r, "%s failed to fork 'making' task: %m", UNIT(n)->id);
                        goto fail;
                }

                busname_set_state(n, BUSNAME_MAKING);
        } else {
                /* If there is no policy, we can do everything
                 * directly from PID 1, hence do so. */

                r = bus_kernel_make_starter(n->starter_fd, n->name, n->activating, n->accept_fd, NULL, n->policy_world);
                if (r < 0) {
                        log_unit_warning_errno(UNIT(n)->id, r, "%s failed to make starter: %m", UNIT(n)->id);
                        goto fail;
                }

                busname_enter_listening(n);
        }

        return;

fail:
        busname_enter_dead(n, BUSNAME_FAILURE_RESOURCES);
}

static void busname_enter_running(BusName *n) {
        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
        bool pending = false;
        Unit *other;
        Iterator i;
        int r;

        assert(n);

        if (!n->activating)
                return;

        /* We don't take conenctions anymore if we are supposed to
         * shut down anyway */

        if (unit_stop_pending(UNIT(n))) {
                log_unit_debug(UNIT(n)->id, "Suppressing activation request on %s since unit stop is scheduled.", UNIT(n)->id);

                /* Flush all queued activation reqeuest by closing and reopening the connection */
                bus_kernel_drop_one(n->starter_fd);

                busname_enter_listening(n);
                return;
        }

        /* If there's already a start pending don't bother to do
         * anything */
        SET_FOREACH(other, UNIT(n)->dependencies[UNIT_TRIGGERS], i)
                if (unit_active_or_pending(other)) {
                        pending = true;
                        break;
                }

        if (!pending) {
                r = manager_add_job(UNIT(n)->manager, JOB_START, UNIT_DEREF(n->service), JOB_REPLACE, true, &error, NULL);
                if (r < 0)
                        goto fail;
        }

        busname_set_state(n, BUSNAME_RUNNING);
        return;

fail:
        log_unit_warning(UNIT(n)->id, "%s failed to queue service startup job: %s", UNIT(n)->id, bus_error_message(&error, r));
        busname_enter_dead(n, BUSNAME_FAILURE_RESOURCES);
}

static int busname_start(Unit *u) {
        BusName *n = BUSNAME(u);

        assert(n);

        /* We cannot fulfill this request right now, try again later
         * please! */
        if (IN_SET(n->state, BUSNAME_SIGTERM, BUSNAME_SIGKILL))
                return -EAGAIN;

        /* Already on it! */
        if (n->state == BUSNAME_MAKING)
                return 0;

        if (n->activating && UNIT_ISSET(n->service)) {
                Service *service;

                service = SERVICE(UNIT_DEREF(n->service));

                if (UNIT(service)->load_state != UNIT_LOADED) {
                        log_unit_error(u->id, "Bus service %s not loaded, refusing.", UNIT(service)->id);
                        return -ENOENT;
                }
        }

        assert(IN_SET(n->state, BUSNAME_DEAD, BUSNAME_FAILED));

        n->result = BUSNAME_SUCCESS;
        busname_enter_making(n);

        return 0;
}

static int busname_stop(Unit *u) {
        BusName *n = BUSNAME(u);

        assert(n);

        /* Already on it */
        if (IN_SET(n->state, BUSNAME_SIGTERM, BUSNAME_SIGKILL))
                return 0;

        /* If there's already something running, we go directly into
         * kill mode. */

        if (n->state == BUSNAME_MAKING) {
                busname_enter_signal(n, BUSNAME_SIGTERM, BUSNAME_SUCCESS);
                return -EAGAIN;
        }

        assert(IN_SET(n->state, BUSNAME_REGISTERED, BUSNAME_LISTENING, BUSNAME_RUNNING));

        busname_enter_dead(n, BUSNAME_SUCCESS);
        return 0;
}

static int busname_serialize(Unit *u, FILE *f, FDSet *fds) {
        BusName *n = BUSNAME(u);

        assert(n);
        assert(f);
        assert(fds);

        unit_serialize_item(u, f, "state", busname_state_to_string(n->state));
        unit_serialize_item(u, f, "result", busname_result_to_string(n->result));

        if (n->control_pid > 0)
                unit_serialize_item_format(u, f, "control-pid", PID_FMT, n->control_pid);

        if (n->starter_fd >= 0) {
                int copy;

                copy = fdset_put_dup(fds, n->starter_fd);
                if (copy < 0)
                        return copy;

                unit_serialize_item_format(u, f, "starter-fd", "%i", copy);
        }

        return 0;
}

static int busname_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
        BusName *n = BUSNAME(u);

        assert(n);
        assert(key);
        assert(value);

        if (streq(key, "state")) {
                BusNameState state;

                state = busname_state_from_string(value);
                if (state < 0)
                        log_unit_debug(u->id, "Failed to parse state value %s", value);
                else
                        n->deserialized_state = state;

        } else if (streq(key, "result")) {
                BusNameResult f;

                f = busname_result_from_string(value);
                if (f < 0)
                        log_unit_debug(u->id, "Failed to parse result value %s", value);
                else if (f != BUSNAME_SUCCESS)
                        n->result = f;

        } else if (streq(key, "control-pid")) {
                pid_t pid;

                if (parse_pid(value, &pid) < 0)
                        log_unit_debug(u->id, "Failed to parse control-pid value %s", value);
                else
                        n->control_pid = pid;
        } else if (streq(key, "starter-fd")) {
                int fd;

                if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd))
                        log_unit_debug(u->id, "Failed to parse starter fd value %s", value);
                else {
                        safe_close(n->starter_fd);
                        n->starter_fd = fdset_remove(fds, fd);
                }
        } else
                log_unit_debug(u->id, "Unknown serialization key '%s'", key);

        return 0;
}

_pure_ static UnitActiveState busname_active_state(Unit *u) {
        assert(u);

        return state_translation_table[BUSNAME(u)->state];
}

_pure_ static const char *busname_sub_state_to_string(Unit *u) {
        assert(u);

        return busname_state_to_string(BUSNAME(u)->state);
}

static int busname_peek_message(BusName *n) {
        struct kdbus_cmd_recv cmd_recv = {
                .size = sizeof(cmd_recv),
                .flags = KDBUS_RECV_PEEK,
        };
        struct kdbus_cmd_free cmd_free = {
                .size = sizeof(cmd_free),
        };
        const char *comm = NULL;
        struct kdbus_item *d;
        struct kdbus_msg *k;
        size_t start, ps, sz, delta;
        void *p = NULL;
        pid_t pid = 0;
        int r;

        /* Generate a friendly debug log message about which process
         * caused triggering of this bus name. This simply peeks the
         * metadata of the first queued message and logs it. */

        assert(n);

        /* Let's shortcut things a bit, if debug logging is turned off
         * anyway. */

        if (log_get_max_level() < LOG_DEBUG)
                return 0;

        r = ioctl(n->starter_fd, KDBUS_CMD_RECV, &cmd_recv);
        if (r < 0) {
                if (errno == EINTR || errno == EAGAIN)
                        return 0;

                log_unit_error(UNIT(n)->id, "%s: Failed to query activation message: %m", UNIT(n)->id);
                return -errno;
        }

        /* We map as late as possible, and unmap imemdiately after
         * use. On 32bit address space is scarce and we want to be
         * able to handle a lot of activator connections at the same
         * time, and hence shouldn't keep the mmap()s around for
         * longer than necessary. */

        ps = page_size();
        start = (cmd_recv.msg.offset / ps) * ps;
        delta = cmd_recv.msg.offset - start;
        sz = PAGE_ALIGN(delta + cmd_recv.msg.msg_size);

        p = mmap(NULL, sz, PROT_READ, MAP_SHARED, n->starter_fd, start);
        if (p == MAP_FAILED) {
                log_unit_error(UNIT(n)->id, "%s: Failed to map activation message: %m", UNIT(n)->id);
                r = -errno;
                goto finish;
        }

        k = (struct kdbus_msg *) ((uint8_t *) p + delta);
        KDBUS_ITEM_FOREACH(d, k, items) {
                switch (d->type) {

                case KDBUS_ITEM_PIDS:
                        pid = d->pids.pid;
                        break;

                case KDBUS_ITEM_PID_COMM:
                        comm = d->str;
                        break;
                }
        }

        if (pid > 0)
                log_unit_debug(UNIT(n)->id, "%s: Activation triggered by process " PID_FMT " (%s)", UNIT(n)->id, pid, strna(comm));

        r = 0;

finish:
        if (p)
                (void) munmap(p, sz);

        cmd_free.offset = cmd_recv.msg.offset;
        if (ioctl(n->starter_fd, KDBUS_CMD_FREE, &cmd_free) < 0)
                log_unit_warning(UNIT(n)->id, "Failed to free peeked message, ignoring: %m");

        return r;
}

static int busname_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
        BusName *n = userdata;

        assert(n);
        assert(fd >= 0);

        if (n->state != BUSNAME_LISTENING)
                return 0;

        log_unit_debug(UNIT(n)->id, "Activation request on %s", UNIT(n)->id);

        if (revents != EPOLLIN) {
                log_unit_error(UNIT(n)->id, "%s: Got unexpected poll event (0x%x) on starter fd.",
                               UNIT(n)->id, revents);
                goto fail;
        }

        busname_peek_message(n);
        busname_enter_running(n);
        return 0;
fail:

        busname_enter_dead(n, BUSNAME_FAILURE_RESOURCES);
        return 0;
}

static void busname_sigchld_event(Unit *u, pid_t pid, int code, int status) {
        BusName *n = BUSNAME(u);
        BusNameResult f;

        assert(n);
        assert(pid >= 0);

        if (pid != n->control_pid)
                return;

        n->control_pid = 0;

        if (is_clean_exit(code, status, NULL))
                f = BUSNAME_SUCCESS;
        else if (code == CLD_EXITED)
                f = BUSNAME_FAILURE_EXIT_CODE;
        else if (code == CLD_KILLED)
                f = BUSNAME_FAILURE_SIGNAL;
        else if (code == CLD_DUMPED)
                f = BUSNAME_FAILURE_CORE_DUMP;
        else
                assert_not_reached("Unknown sigchld code");

        log_unit_full(u->id,
                      f == BUSNAME_SUCCESS ? LOG_DEBUG : LOG_NOTICE,
                      "%s control process exited, code=%s status=%i",
                      u->id, sigchld_code_to_string(code), status);

        if (f != BUSNAME_SUCCESS)
                n->result = f;

        switch (n->state) {

        case BUSNAME_MAKING:
                if (f == BUSNAME_SUCCESS)
                        busname_enter_listening(n);
                else
                        busname_enter_signal(n, BUSNAME_SIGTERM, f);
                break;

        case BUSNAME_SIGTERM:
        case BUSNAME_SIGKILL:
                busname_enter_dead(n, f);
                break;

        default:
                assert_not_reached("Uh, control process died at wrong time.");
        }

        /* Notify clients about changed exit status */
        unit_add_to_dbus_queue(u);
}

static int busname_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata) {
        BusName *n = BUSNAME(userdata);

        assert(n);
        assert(n->timer_event_source == source);

        switch (n->state) {

        case BUSNAME_MAKING:
                log_unit_warning(UNIT(n)->id, "%s making timed out. Terminating.", UNIT(n)->id);
                busname_enter_signal(n, BUSNAME_SIGTERM, BUSNAME_FAILURE_TIMEOUT);
                break;

        case BUSNAME_SIGTERM:
                log_unit_warning(UNIT(n)->id, "%s stopping timed out. Killing.", UNIT(n)->id);
                busname_enter_signal(n, BUSNAME_SIGKILL, BUSNAME_FAILURE_TIMEOUT);
                break;

        case BUSNAME_SIGKILL:
                log_unit_warning(UNIT(n)->id, "%s still around after SIGKILL. Ignoring.", UNIT(n)->id);
                busname_enter_dead(n, BUSNAME_FAILURE_TIMEOUT);
                break;

        default:
                assert_not_reached("Timeout at wrong time.");
        }

        return 0;
}

static void busname_reset_failed(Unit *u) {
        BusName *n = BUSNAME(u);

        assert(n);

        if (n->state == BUSNAME_FAILED)
                busname_set_state(n, BUSNAME_DEAD);

        n->result = BUSNAME_SUCCESS;
}

static void busname_trigger_notify(Unit *u, Unit *other) {
        BusName *n = BUSNAME(u);
        Service *s;

        assert(n);
        assert(other);

        if (!IN_SET(n->state, BUSNAME_RUNNING, BUSNAME_LISTENING))
                return;

        if (other->load_state != UNIT_LOADED || other->type != UNIT_SERVICE)
                return;

        s = SERVICE(other);

        if (s->state == SERVICE_FAILED && s->result == SERVICE_FAILURE_START_LIMIT)
                busname_enter_dead(n, BUSNAME_FAILURE_SERVICE_FAILED_PERMANENT);
        else if (IN_SET(s->state,
                        SERVICE_DEAD, SERVICE_FAILED,
                        SERVICE_STOP, SERVICE_STOP_SIGTERM, SERVICE_STOP_SIGKILL,
                        SERVICE_STOP_POST, SERVICE_FINAL_SIGTERM, SERVICE_FINAL_SIGKILL,
                        SERVICE_AUTO_RESTART))
                busname_enter_listening(n);
}

static int busname_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) {
        return unit_kill_common(u, who, signo, -1, BUSNAME(u)->control_pid, error);
}

static int busname_get_timeout(Unit *u, uint64_t *timeout) {
        BusName *n = BUSNAME(u);
        int r;

        if (!n->timer_event_source)
                return 0;

        r = sd_event_source_get_time(n->timer_event_source, timeout);
        if (r < 0)
                return r;

        return 1;
}

static bool busname_supported(Manager *m) {
        int supported = -1;
        assert(m);

        if (supported < 0)
                supported = access("/sys/fs/kdbus", F_OK) >= 0;

        return supported;
}

static const char* const busname_state_table[_BUSNAME_STATE_MAX] = {
        [BUSNAME_DEAD] = "dead",
        [BUSNAME_MAKING] = "making",
        [BUSNAME_REGISTERED] = "registered",
        [BUSNAME_LISTENING] = "listening",
        [BUSNAME_RUNNING] = "running",
        [BUSNAME_SIGTERM] = "sigterm",
        [BUSNAME_SIGKILL] = "sigkill",
        [BUSNAME_FAILED] = "failed",
};

DEFINE_STRING_TABLE_LOOKUP(busname_state, BusNameState);

static const char* const busname_result_table[_BUSNAME_RESULT_MAX] = {
        [BUSNAME_SUCCESS] = "success",
        [BUSNAME_FAILURE_RESOURCES] = "resources",
        [BUSNAME_FAILURE_TIMEOUT] = "timeout",
        [BUSNAME_FAILURE_EXIT_CODE] = "exit-code",
        [BUSNAME_FAILURE_SIGNAL] = "signal",
        [BUSNAME_FAILURE_CORE_DUMP] = "core-dump",
        [BUSNAME_FAILURE_SERVICE_FAILED_PERMANENT] = "service-failed-permanent",
};

DEFINE_STRING_TABLE_LOOKUP(busname_result, BusNameResult);

const UnitVTable busname_vtable = {
        .object_size = sizeof(BusName),

        .sections =
                "Unit\0"
                "BusName\0"
                "Install\0",
        .private_section = "BusName",

        .init = busname_init,
        .done = busname_done,
        .load = busname_load,

        .coldplug = busname_coldplug,

        .dump = busname_dump,

        .start = busname_start,
        .stop = busname_stop,

        .kill = busname_kill,

        .get_timeout = busname_get_timeout,

        .serialize = busname_serialize,
        .deserialize_item = busname_deserialize_item,

        .active_state = busname_active_state,
        .sub_state_to_string = busname_sub_state_to_string,

        .sigchld_event = busname_sigchld_event,

        .trigger_notify = busname_trigger_notify,

        .reset_failed = busname_reset_failed,

        .supported = busname_supported,

        .bus_interface = "org.freedesktop.systemd1.BusName",
        .bus_vtable = bus_busname_vtable,

        .status_message_formats = {
                .finished_start_job = {
                        [JOB_DONE]       = "Listening on %s.",
                        [JOB_FAILED]     = "Failed to listen on %s.",
                        [JOB_DEPENDENCY] = "Dependency failed for %s.",
                        [JOB_TIMEOUT]    = "Timed out starting %s.",
                },
                .finished_stop_job = {
                        [JOB_DONE]       = "Closed %s.",
                        [JOB_FAILED]     = "Failed stopping %s.",
                        [JOB_TIMEOUT]    = "Timed out stopping %s.",
                },
        },
};