/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

/***
  This file is part of systemd.

  Copyright 2010 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <sys/reboot.h>
#include <stdio.h>
#include <getopt.h>
#include <stdbool.h>
#include <string.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <termios.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/stat.h>

#include <dbus/dbus.h>

#include "log.h"
#include "util.h"
#include "macro.h"
#include "set.h"
#include "utmp-wtmp.h"
#include "special.h"
#include "initreq.h"
#include "strv.h"
#include "dbus-common.h"
#include "cgroup-show.h"
#include "cgroup-util.h"
#include "list.h"
#include "path-lookup.h"
#include "conf-parser.h"
#include "sd-daemon.h"
#include "shutdownd.h"
#include "exit-status.h"

static const char *arg_type = NULL;
static char **arg_property = NULL;
static bool arg_all = false;
static bool arg_fail = false;
static bool arg_session = false;
static bool arg_global = false;
static bool arg_immediate = false;
static bool arg_no_block = false;
static bool arg_no_wtmp = false;
static bool arg_no_sync = false;
static bool arg_no_wall = false;
static bool arg_no_reload = false;
static bool arg_dry = false;
static bool arg_quiet = false;
static bool arg_full = false;
static bool arg_force = false;
static bool arg_defaults = false;
static bool arg_sysv_compat = false; /* this is undocumented, and
                                      * exists simply to make
                                      * implementation of SysV
                                      * compatible shell glue
                                      * easier */
static char **arg_wall = NULL;
static usec_t arg_when = 0;
static enum action {
        ACTION_INVALID,
        ACTION_SYSTEMCTL,
        ACTION_HALT,
        ACTION_POWEROFF,
        ACTION_REBOOT,
        ACTION_RUNLEVEL2,
        ACTION_RUNLEVEL3,
        ACTION_RUNLEVEL4,
        ACTION_RUNLEVEL5,
        ACTION_RESCUE,
        ACTION_EMERGENCY,
        ACTION_DEFAULT,
        ACTION_RELOAD,
        ACTION_REEXEC,
        ACTION_RUNLEVEL,
        ACTION_CANCEL_SHUTDOWN,
        _ACTION_MAX
} arg_action = ACTION_SYSTEMCTL;
static enum dot {
        DOT_ALL,
        DOT_ORDER,
        DOT_REQUIRE
} arg_dot = DOT_ALL;

static bool private_bus = false;

static int daemon_reload(DBusConnection *bus, char **args, unsigned n);

static bool on_tty(void) {
        static int t = -1;

        if (_unlikely_(t < 0))
                t = isatty(STDOUT_FILENO) > 0;

        return t;
}

static const char *ansi_highlight(bool b) {

        if (!on_tty())
                return "";

        return b ? ANSI_HIGHLIGHT_ON : ANSI_HIGHLIGHT_OFF;
}

static const char *ansi_highlight_green(bool b) {

        if (!on_tty())
                return "";

        return b ? ANSI_HIGHLIGHT_GREEN_ON : ANSI_HIGHLIGHT_OFF;
}

static bool error_is_no_service(DBusError *error) {

        assert(error);

        if (!dbus_error_is_set(error))
                return false;

        if (dbus_error_has_name(error, DBUS_ERROR_NAME_HAS_NO_OWNER))
                return true;

        if (dbus_error_has_name(error, DBUS_ERROR_SERVICE_UNKNOWN))
                return true;

        return startswith(error->name, "org.freedesktop.DBus.Error.Spawn.");
}

static int bus_iter_get_basic_and_next(DBusMessageIter *iter, int type, void *data, bool next) {

        assert(iter);
        assert(data);

        if (dbus_message_iter_get_arg_type(iter) != type)
                return -EIO;

        dbus_message_iter_get_basic(iter, data);

        if (!dbus_message_iter_next(iter) != !next)
                return -EIO;

        return 0;
}

static void warn_wall(enum action action) {
        static const char *table[_ACTION_MAX] = {
                [ACTION_HALT]      = "The system is going down for system halt NOW!",
                [ACTION_REBOOT]    = "The system is going down for reboot NOW!",
                [ACTION_POWEROFF]  = "The system is going down for power-off NOW!",
                [ACTION_RESCUE]    = "The system is going down to rescue mode NOW!",
                [ACTION_EMERGENCY] = "The system is going down to emergency mode NOW!"
        };

        if (arg_no_wall)
                return;

        if (arg_wall) {
                char *p;

                if (!(p = strv_join(arg_wall, " "))) {
                        log_error("Failed to join strings.");
                        return;
                }

                if (*p) {
                        utmp_wall(p);
                        free(p);
                        return;
                }

                free(p);
        }

        if (!table[action])
                return;

        utmp_wall(table[action]);
}

struct unit_info {
        const char *id;
        const char *description;
        const char *load_state;
        const char *active_state;
        const char *sub_state;
        const char *following;
        const char *unit_path;
        uint32_t job_id;
        const char *job_type;
        const char *job_path;
};

static int compare_unit_info(const void *a, const void *b) {
        const char *d1, *d2;
        const struct unit_info *u = a, *v = b;

        d1 = strrchr(u->id, '.');
        d2 = strrchr(v->id, '.');

        if (d1 && d2) {
                int r;

                if ((r = strcasecmp(d1, d2)) != 0)
                        return r;
        }

        return strcasecmp(u->id, v->id);
}

static int list_units(DBusConnection *bus, char **args, unsigned n) {
        DBusMessage *m = NULL, *reply = NULL;
        DBusError error;
        int r;
        DBusMessageIter iter, sub, sub2;
        unsigned c = 0, k, n_units = 0;
        struct unit_info *unit_infos = NULL;

        dbus_error_init(&error);

        assert(bus);

        if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              "/org/freedesktop/systemd1",
                              "org.freedesktop.systemd1.Manager",
                              "ListUnits"))) {
                log_error("Could not allocate message.");
                return -ENOMEM;
        }

        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                log_error("Failed to issue method call: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        if (!dbus_message_iter_init(reply, &iter) ||
            dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY ||
            dbus_message_iter_get_element_type(&iter) != DBUS_TYPE_STRUCT)  {
                log_error("Failed to parse reply.");
                r = -EIO;
                goto finish;
        }

        dbus_message_iter_recurse(&iter, &sub);

        while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
                struct unit_info *u;

                if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_STRUCT) {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                if (c >= n_units) {
                        struct unit_info *w;

                        n_units = MAX(2*c, 16);
                        w = realloc(unit_infos, sizeof(struct unit_info) * n_units);

                        if (!w) {
                                log_error("Failed to allocate unit array.");
                                r = -ENOMEM;
                                goto finish;
                        }

                        unit_infos = w;
                }

                u = unit_infos+c;

                dbus_message_iter_recurse(&sub, &sub2);

                if (bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &u->id, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &u->description, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &u->load_state, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &u->active_state, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &u->sub_state, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &u->following, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_OBJECT_PATH, &u->unit_path, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_UINT32, &u->job_id, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &u->job_type, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_OBJECT_PATH, &u->job_path, false) < 0) {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                dbus_message_iter_next(&sub);
                c++;
        }

        qsort(unit_infos, c, sizeof(struct unit_info), compare_unit_info);

        if (isatty(STDOUT_FILENO))
                printf("%-45s %-6s %-12s %-12s %-15s %s\n", "UNIT", "LOAD", "ACTIVE", "SUB", "JOB", "DESCRIPTION");

        for (k = 0; k < c; k++) {
                const char *dot;
                struct unit_info *u = unit_infos+k;

                if ((!arg_type || ((dot = strrchr(u->id, '.')) &&
                                   streq(dot+1, arg_type))) &&
                    (arg_all || !(streq(u->active_state, "inactive") || u->following[0]) || u->job_id > 0)) {
                        char *e;
                        int a = 0, b = 0;
                        const char *on, *off;

                        if (streq(u->active_state, "failed")) {
                                on = ansi_highlight(true);
                                off = ansi_highlight(false);
                        } else
                                on = off = "";

                        e = arg_full ? NULL : ellipsize(u->id, 45, 33);
                        printf("%-45s %-6s %s%-12s %-12s%s%n", e ? e : u->id, u->load_state, on, u->active_state, u->sub_state, off, &a);
                        free(e);

                        a -= strlen(on) + strlen(off);

                        if (u->job_id != 0)
                                printf(" => %-12s%n", u->job_type, &b);
                        else
                                b = 1 + 15;

                        if (a + b + 2 < columns()) {
                                if (u->job_id == 0)
                                        printf("                ");

                                printf(" %.*s", columns() - a - b - 2, u->description);
                        }

                        fputs("\n", stdout);
                }
        }

        if (isatty(STDOUT_FILENO)) {

                printf("\nLOAD   = Reflects whether the unit definition was properly loaded.\n"
                       "ACTIVE = The high-level unit activation state, i.e. generalization of SUB.\n"
                       "SUB    = The low-level unit activation state, values depend on unit type.\n"
                       "JOB    = Pending job for the unit.\n");

                if (arg_all)
                        printf("\n%u units listed.\n", c);
                else
                        printf("\n%u units listed. Pass --all to see inactive units, too.\n", c);
        }

        r = 0;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        free(unit_infos);

        dbus_error_free(&error);

        return r;
}

static int dot_one_property(const char *name, const char *prop, DBusMessageIter *iter) {
        static const char * const colors[] = {
                "Requires",              "[color=\"black\"]",
                "RequiresOverridable",   "[color=\"black\"]",
                "Requisite",             "[color=\"darkblue\"]",
                "RequisiteOverridable",  "[color=\"darkblue\"]",
                "Wants",                 "[color=\"darkgrey\"]",
                "Conflicts",             "[color=\"red\"]",
                "ConflictedBy",          "[color=\"red\"]",
                "After",                 "[color=\"green\"]"
        };

        const char *c = NULL;
        unsigned i;

        assert(name);
        assert(prop);
        assert(iter);

        for (i = 0; i < ELEMENTSOF(colors); i += 2)
                if (streq(colors[i], prop)) {
                        c = colors[i+1];
                        break;
                }

        if (!c)
                return 0;

        if (arg_dot != DOT_ALL)
                if ((arg_dot == DOT_ORDER) != streq(prop, "After"))
                        return 0;

        switch (dbus_message_iter_get_arg_type(iter)) {

        case DBUS_TYPE_ARRAY:

                if (dbus_message_iter_get_element_type(iter) == DBUS_TYPE_STRING) {
                        DBusMessageIter sub;

                        dbus_message_iter_recurse(iter, &sub);

                        while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
                                const char *s;

                                assert(dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_STRING);
                                dbus_message_iter_get_basic(&sub, &s);
                                printf("\t\"%s\"->\"%s\" %s;\n", name, s, c);

                                dbus_message_iter_next(&sub);
                        }

                        return 0;
                }
        }

        return 0;
}

static int dot_one(DBusConnection *bus, const char *name, const char *path) {
        DBusMessage *m = NULL, *reply = NULL;
        const char *interface = "org.freedesktop.systemd1.Unit";
        int r;
        DBusError error;
        DBusMessageIter iter, sub, sub2, sub3;

        assert(bus);
        assert(path);

        dbus_error_init(&error);

        if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              path,
                              "org.freedesktop.DBus.Properties",
                              "GetAll"))) {
                log_error("Could not allocate message.");
                r = -ENOMEM;
                goto finish;
        }

        if (!dbus_message_append_args(m,
                                      DBUS_TYPE_STRING, &interface,
                                      DBUS_TYPE_INVALID)) {
                log_error("Could not append arguments to message.");
                r = -ENOMEM;
                goto finish;
        }

        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                log_error("Failed to issue method call: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        if (!dbus_message_iter_init(reply, &iter) ||
            dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY ||
            dbus_message_iter_get_element_type(&iter) != DBUS_TYPE_DICT_ENTRY)  {
                log_error("Failed to parse reply.");
                r = -EIO;
                goto finish;
        }

        dbus_message_iter_recurse(&iter, &sub);

        while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
                const char *prop;

                if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_DICT_ENTRY) {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                dbus_message_iter_recurse(&sub, &sub2);

                if (bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &prop, true) < 0) {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                if (dbus_message_iter_get_arg_type(&sub2) != DBUS_TYPE_VARIANT)  {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                dbus_message_iter_recurse(&sub2, &sub3);

                if (dot_one_property(name, prop, &sub3)) {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                dbus_message_iter_next(&sub);
        }

        r = 0;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

static int dot(DBusConnection *bus, char **args, unsigned n) {
        DBusMessage *m = NULL, *reply = NULL;
        DBusError error;
        int r;
        DBusMessageIter iter, sub, sub2;

        dbus_error_init(&error);

        assert(bus);

        if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              "/org/freedesktop/systemd1",
                              "org.freedesktop.systemd1.Manager",
                              "ListUnits"))) {
                log_error("Could not allocate message.");
                return -ENOMEM;
        }

        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                log_error("Failed to issue method call: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        if (!dbus_message_iter_init(reply, &iter) ||
            dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY ||
            dbus_message_iter_get_element_type(&iter) != DBUS_TYPE_STRUCT)  {
                log_error("Failed to parse reply.");
                r = -EIO;
                goto finish;
        }

        printf("digraph systemd {\n");

        dbus_message_iter_recurse(&iter, &sub);
        while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
                const char *id, *description, *load_state, *active_state, *sub_state, *following, *unit_path;

                if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_STRUCT) {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                dbus_message_iter_recurse(&sub, &sub2);

                if (bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &id, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &description, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &load_state, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &active_state, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &sub_state, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &following, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_OBJECT_PATH, &unit_path, true) < 0) {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                if ((r = dot_one(bus, id, unit_path)) < 0)
                        goto finish;

                /* printf("\t\"%s\";\n", id); */
                dbus_message_iter_next(&sub);
        }

        printf("}\n");

        log_info("   Color legend: black     = Requires\n"
                 "                 dark blue = Requisite\n"
                 "                 dark grey = Wants\n"
                 "                 red       = Conflicts\n"
                 "                 green     = After\n");

        if (isatty(fileno(stdout)))
                log_notice("-- You probably want to process this output with graphviz' dot tool.\n"
                           "-- Try a shell pipeline like 'systemctl dot | dot -Tsvg > systemd.svg'!\n");

        r = 0;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

static int list_jobs(DBusConnection *bus, char **args, unsigned n) {
        DBusMessage *m = NULL, *reply = NULL;
        DBusError error;
        int r;
        DBusMessageIter iter, sub, sub2;
        unsigned k = 0;

        dbus_error_init(&error);

        assert(bus);

        if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              "/org/freedesktop/systemd1",
                              "org.freedesktop.systemd1.Manager",
                              "ListJobs"))) {
                log_error("Could not allocate message.");
                return -ENOMEM;
        }

        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                log_error("Failed to issue method call: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        if (!dbus_message_iter_init(reply, &iter) ||
            dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY ||
            dbus_message_iter_get_element_type(&iter) != DBUS_TYPE_STRUCT)  {
                log_error("Failed to parse reply.");
                r = -EIO;
                goto finish;
        }

        dbus_message_iter_recurse(&iter, &sub);

        printf("%4s %-45s %-17s %-7s\n", "JOB", "UNIT", "TYPE", "STATE");

        while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
                const char *name, *type, *state, *job_path, *unit_path;
                uint32_t id;
                char *e;

                if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_STRUCT) {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                dbus_message_iter_recurse(&sub, &sub2);

                if (bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_UINT32, &id, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &name, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &type, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &state, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_OBJECT_PATH, &job_path, true) < 0 ||
                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_OBJECT_PATH, &unit_path, false) < 0) {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                e = arg_full ? NULL : ellipsize(name, 45, 33);
                printf("%4u %-45s %-17s %-7s\n", id, e ? e : name, type, state);
                free(e);

                k++;

                dbus_message_iter_next(&sub);
        }

        printf("\n%u jobs listed.\n", k);
        r = 0;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

static int load_unit(DBusConnection *bus, char **args, unsigned n) {
        DBusMessage *m = NULL, *reply = NULL;
        DBusError error;
        int r;
        unsigned i;

        dbus_error_init(&error);

        assert(bus);
        assert(args);

        for (i = 1; i < n; i++) {

                if (!(m = dbus_message_new_method_call(
                                      "org.freedesktop.systemd1",
                                      "/org/freedesktop/systemd1",
                                      "org.freedesktop.systemd1.Manager",
                                      "LoadUnit"))) {
                        log_error("Could not allocate message.");
                        r = -ENOMEM;
                        goto finish;
                }

                if (!dbus_message_append_args(m,
                                              DBUS_TYPE_STRING, &args[i],
                                              DBUS_TYPE_INVALID)) {
                        log_error("Could not append arguments to message.");
                        r = -ENOMEM;
                        goto finish;
                }

                if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                        log_error("Failed to issue method call: %s", bus_error_message(&error));
                        r = -EIO;
                        goto finish;
                }

                dbus_message_unref(m);
                dbus_message_unref(reply);

                m = reply = NULL;
        }

        r = 0;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

static int cancel_job(DBusConnection *bus, char **args, unsigned n) {
        DBusMessage *m = NULL, *reply = NULL;
        DBusError error;
        int r;
        unsigned i;

        dbus_error_init(&error);

        assert(bus);
        assert(args);

        if (n <= 1)
                return daemon_reload(bus, args, n);

        for (i = 1; i < n; i++) {
                unsigned id;
                const char *path;

                if (!(m = dbus_message_new_method_call(
                                      "org.freedesktop.systemd1",
                                      "/org/freedesktop/systemd1",
                                      "org.freedesktop.systemd1.Manager",
                                      "GetJob"))) {
                        log_error("Could not allocate message.");
                        r = -ENOMEM;
                        goto finish;
                }

                if ((r = safe_atou(args[i], &id)) < 0) {
                        log_error("Failed to parse job id: %s", strerror(-r));
                        goto finish;
                }

                assert_cc(sizeof(uint32_t) == sizeof(id));
                if (!dbus_message_append_args(m,
                                              DBUS_TYPE_UINT32, &id,
                                              DBUS_TYPE_INVALID)) {
                        log_error("Could not append arguments to message.");
                        r = -ENOMEM;
                        goto finish;
                }

                if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                        log_error("Failed to issue method call: %s", bus_error_message(&error));
                        r = -EIO;
                        goto finish;
                }

                if (!dbus_message_get_args(reply, &error,
                                           DBUS_TYPE_OBJECT_PATH, &path,
                                           DBUS_TYPE_INVALID)) {
                        log_error("Failed to parse reply: %s", bus_error_message(&error));
                        r = -EIO;
                        goto finish;
                }

                dbus_message_unref(m);
                if (!(m = dbus_message_new_method_call(
                                      "org.freedesktop.systemd1",
                                      path,
                                      "org.freedesktop.systemd1.Job",
                                      "Cancel"))) {
                        log_error("Could not allocate message.");
                        r = -ENOMEM;
                        goto finish;
                }

                dbus_message_unref(reply);
                if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                        log_error("Failed to issue method call: %s", bus_error_message(&error));
                        r = -EIO;
                        goto finish;
                }

                dbus_message_unref(m);
                dbus_message_unref(reply);
                m = reply = NULL;
        }

        r = 0;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

static bool need_daemon_reload(DBusConnection *bus, const char *unit) {
        DBusMessage *m = NULL, *reply = NULL;
        dbus_bool_t b = FALSE;
        DBusMessageIter iter, sub;
        const char
                *interface = "org.freedesktop.systemd1.Unit",
                *property = "NeedDaemonReload",
                *path;

        /* We ignore all errors here, since this is used to show a warning only */

        if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              "/org/freedesktop/systemd1",
                              "org.freedesktop.systemd1.Manager",
                              "GetUnit")))
                goto finish;

        if (!dbus_message_append_args(m,
                                      DBUS_TYPE_STRING, &unit,
                                      DBUS_TYPE_INVALID))
                goto finish;

        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, NULL)))
                goto finish;

        if (!dbus_message_get_args(reply, NULL,
                                   DBUS_TYPE_OBJECT_PATH, &path,
                                   DBUS_TYPE_INVALID))
                goto finish;

        dbus_message_unref(m);
        if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              path,
                              "org.freedesktop.DBus.Properties",
                              "Get")))
                goto finish;

        if (!dbus_message_append_args(m,
                                      DBUS_TYPE_STRING, &interface,
                                      DBUS_TYPE_STRING, &property,
                                      DBUS_TYPE_INVALID)) {
                goto finish;
        }

        dbus_message_unref(reply);
        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, NULL)))
                goto finish;

        if (!dbus_message_iter_init(reply, &iter) ||
            dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_VARIANT)
                goto finish;

        dbus_message_iter_recurse(&iter, &sub);

        if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_BOOLEAN)
                goto finish;

        dbus_message_iter_get_basic(&sub, &b);

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        return b;
}

typedef struct WaitData {
        Set *set;
        bool failed;
} WaitData;

static DBusHandlerResult wait_filter(DBusConnection *connection, DBusMessage *message, void *data) {
        DBusError error;
        WaitData *d = data;

        assert(connection);
        assert(message);
        assert(d);

        dbus_error_init(&error);

        log_debug("Got D-Bus request: %s.%s() on %s",
                  dbus_message_get_interface(message),
                  dbus_message_get_member(message),
                  dbus_message_get_path(message));

        if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) {
                log_error("Warning! D-Bus connection terminated.");
                dbus_connection_close(connection);

        } else if (dbus_message_is_signal(message, "org.freedesktop.systemd1.Manager", "JobRemoved")) {
                uint32_t id;
                const char *path;
                dbus_bool_t success = true;

                if (!dbus_message_get_args(message, &error,
                                           DBUS_TYPE_UINT32, &id,
                                           DBUS_TYPE_OBJECT_PATH, &path,
                                           DBUS_TYPE_BOOLEAN, &success,
                                           DBUS_TYPE_INVALID))
                        log_error("Failed to parse message: %s", bus_error_message(&error));
                else {
                        char *p;

                        if ((p = set_remove(d->set, (char*) path)))
                                free(p);

                        if (!success)
                                d->failed = true;
                }
        }

        dbus_error_free(&error);
        return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}

static int enable_wait_for_jobs(DBusConnection *bus) {
        DBusError error;

        assert(bus);

        if (private_bus)
                return 0;

        dbus_error_init(&error);
        dbus_bus_add_match(bus,
                           "type='signal',"
                           "sender='org.freedesktop.systemd1',"
                           "interface='org.freedesktop.systemd1.Manager',"
                           "member='JobRemoved',"
                           "path='/org/freedesktop/systemd1'",
                           &error);

        if (dbus_error_is_set(&error)) {
                log_error("Failed to add match: %s", bus_error_message(&error));
                dbus_error_free(&error);
                return -EIO;
        }

        /* This is slightly dirty, since we don't undo the match registrations. */
        return 0;
}

static int wait_for_jobs(DBusConnection *bus, Set *s) {
        int r;
        WaitData d;

        assert(bus);
        assert(s);

        zero(d);
        d.set = s;
        d.failed = false;

        if (!dbus_connection_add_filter(bus, wait_filter, &d, NULL)) {
                log_error("Failed to add filter.");
                r = -ENOMEM;
                goto finish;
        }

        while (!set_isempty(s) &&
               dbus_connection_read_write_dispatch(bus, -1))
                ;

        if (!arg_quiet && d.failed)
                log_error("Job failed, see logs for details.");

        r = d.failed ? -EIO : 0;

finish:
        /* This is slightly dirty, since we don't undo the filter registration. */

        return r;
}

static int start_unit_one(
                DBusConnection *bus,
                const char *method,
                const char *name,
                const char *mode,
                Set *s) {

        DBusMessage *m = NULL, *reply = NULL;
        DBusError error;
        const char *path;
        int r;

        assert(bus);
        assert(method);
        assert(name);
        assert(mode);
        assert(arg_no_block || s);

        dbus_error_init(&error);

        if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              "/org/freedesktop/systemd1",
                              "org.freedesktop.systemd1.Manager",
                              method))) {
                log_error("Could not allocate message.");
                r = -ENOMEM;
                goto finish;
        }

        if (!dbus_message_append_args(m,
                                      DBUS_TYPE_STRING, &name,
                                      DBUS_TYPE_STRING, &mode,
                                      DBUS_TYPE_INVALID)) {
                log_error("Could not append arguments to message.");
                r = -ENOMEM;
                goto finish;
        }

        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {

                if (arg_action != ACTION_SYSTEMCTL && error_is_no_service(&error)) {
                        /* There's always a fallback possible for
                         * legacy actions. */
                        r = 0;
                        goto finish;
                }

                log_error("Failed to issue method call: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        if (!dbus_message_get_args(reply, &error,
                                   DBUS_TYPE_OBJECT_PATH, &path,
                                   DBUS_TYPE_INVALID)) {
                log_error("Failed to parse reply: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        if (need_daemon_reload(bus, name))
                log_warning("Unit file of created job changed on disk, 'systemctl %s daemon-reload' recommended.",
                            arg_session ? "--session" : "--system");

        if (!arg_no_block) {
                char *p;

                if (!(p = strdup(path))) {
                        log_error("Failed to duplicate path.");
                        r = -ENOMEM;
                        goto finish;
                }

                if ((r = set_put(s, p)) < 0) {
                        free(p);
                        log_error("Failed to add path to set.");
                        goto finish;
                }
        }

        r = 1;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

static enum action verb_to_action(const char *verb) {
        if (streq(verb, "halt"))
                return ACTION_HALT;
        else if (streq(verb, "poweroff"))
                return ACTION_POWEROFF;
        else if (streq(verb, "reboot"))
                return ACTION_REBOOT;
        else if (streq(verb, "rescue"))
                return ACTION_RESCUE;
        else if (streq(verb, "emergency"))
                return ACTION_EMERGENCY;
        else if (streq(verb, "default"))
                return ACTION_DEFAULT;
        else
                return ACTION_INVALID;
}

static int start_unit(DBusConnection *bus, char **args, unsigned n) {

        static const char * const table[_ACTION_MAX] = {
                [ACTION_HALT] = SPECIAL_HALT_TARGET,
                [ACTION_POWEROFF] = SPECIAL_POWEROFF_TARGET,
                [ACTION_REBOOT] = SPECIAL_REBOOT_TARGET,
                [ACTION_RUNLEVEL2] = SPECIAL_RUNLEVEL2_TARGET,
                [ACTION_RUNLEVEL3] = SPECIAL_RUNLEVEL3_TARGET,
                [ACTION_RUNLEVEL4] = SPECIAL_RUNLEVEL4_TARGET,
                [ACTION_RUNLEVEL5] = SPECIAL_RUNLEVEL5_TARGET,
                [ACTION_RESCUE] = SPECIAL_RESCUE_TARGET,
                [ACTION_EMERGENCY] = SPECIAL_EMERGENCY_TARGET,
                [ACTION_DEFAULT] = SPECIAL_DEFAULT_TARGET
        };

        int r;
        unsigned i;
        const char *method, *mode, *one_name;
        Set *s = NULL;

        assert(bus);

        if (arg_action == ACTION_SYSTEMCTL) {
                method =
                        streq(args[0], "stop")                  ? "StopUnit" :
                        streq(args[0], "reload")                ? "ReloadUnit" :
                        streq(args[0], "restart")               ? "RestartUnit" :
                        streq(args[0], "try-restart")           ? "TryRestartUnit" :
                        streq(args[0], "reload-or-restart")     ? "ReloadOrRestartUnit" :
                        streq(args[0], "reload-or-try-restart") ||
                        streq(args[0], "force-reload")          ||
                        streq(args[0], "condrestart")           ? "ReloadOrTryRestartUnit" :
                                                                  "StartUnit";

                mode =
                        (streq(args[0], "isolate") ||
                         streq(args[0], "rescue")  ||
                         streq(args[0], "emergency")) ? "isolate" :
                                             arg_fail ? "fail" :
                                                        "replace";

                one_name = table[verb_to_action(args[0])];

        } else {
                assert(arg_action < ELEMENTSOF(table));
                assert(table[arg_action]);

                method = "StartUnit";

                mode = (arg_action == ACTION_EMERGENCY ||
                        arg_action == ACTION_RESCUE) ? "isolate" : "replace";

                one_name = table[arg_action];
        }

        if (!arg_no_block) {
                if ((r = enable_wait_for_jobs(bus)) < 0) {
                        log_error("Could not watch jobs: %s", strerror(-r));
                        goto finish;
                }

                if (!(s = set_new(string_hash_func, string_compare_func))) {
                        log_error("Failed to allocate set.");
                        r = -ENOMEM;
                        goto finish;
                }
        }

        r = 0;

        if (one_name) {
                if ((r = start_unit_one(bus, method, one_name, mode, s)) <= 0)
                        goto finish;
        } else {
                for (i = 1; i < n; i++)
                        if ((r = start_unit_one(bus, method, args[i], mode, s)) < 0)
                                goto finish;
        }

        if (!arg_no_block)
                if ((r = wait_for_jobs(bus, s)) < 0)
                        goto finish;

        r = 1;

finish:
        if (s)
                set_free_free(s);

        return r;
}

static int start_special(DBusConnection *bus, char **args, unsigned n) {
        int r;

        assert(bus);
        assert(args);

        r = start_unit(bus, args, n);

        if (r >= 0)
                warn_wall(verb_to_action(args[0]));

        return r;
}

static int check_unit(DBusConnection *bus, char **args, unsigned n) {
        DBusMessage *m = NULL, *reply = NULL;
        const char
                *interface = "org.freedesktop.systemd1.Unit",
                *property = "ActiveState";
        int r = -EADDRNOTAVAIL;
        DBusError error;
        unsigned i;

        assert(bus);
        assert(args);

        dbus_error_init(&error);

        for (i = 1; i < n; i++) {
                const char *path = NULL;
                const char *state;
                DBusMessageIter iter, sub;

                if (!(m = dbus_message_new_method_call(
                                      "org.freedesktop.systemd1",
                                      "/org/freedesktop/systemd1",
                                      "org.freedesktop.systemd1.Manager",
                                      "GetUnit"))) {
                        log_error("Could not allocate message.");
                        r = -ENOMEM;
                        goto finish;
                }

                if (!dbus_message_append_args(m,
                                              DBUS_TYPE_STRING, &args[i],
                                              DBUS_TYPE_INVALID)) {
                        log_error("Could not append arguments to message.");
                        r = -ENOMEM;
                        goto finish;
                }

                if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {

                        /* Hmm, cannot figure out anything about this unit... */
                        if (!arg_quiet)
                                puts("unknown");

                        dbus_error_free(&error);
                        continue;
                }

                if (!dbus_message_get_args(reply, &error,
                                           DBUS_TYPE_OBJECT_PATH, &path,
                                           DBUS_TYPE_INVALID)) {
                        log_error("Failed to parse reply: %s", bus_error_message(&error));
                        r = -EIO;
                        goto finish;
                }

                dbus_message_unref(m);
                if (!(m = dbus_message_new_method_call(
                                      "org.freedesktop.systemd1",
                                      path,
                                      "org.freedesktop.DBus.Properties",
                                      "Get"))) {
                        log_error("Could not allocate message.");
                        r = -ENOMEM;
                        goto finish;
                }

                if (!dbus_message_append_args(m,
                                              DBUS_TYPE_STRING, &interface,
                                              DBUS_TYPE_STRING, &property,
                                              DBUS_TYPE_INVALID)) {
                        log_error("Could not append arguments to message.");
                        r = -ENOMEM;
                        goto finish;
                }

                dbus_message_unref(reply);
                if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                        log_error("Failed to issue method call: %s", bus_error_message(&error));
                        r = -EIO;
                        goto finish;
                }

                if (!dbus_message_iter_init(reply, &iter) ||
                    dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_VARIANT)  {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                dbus_message_iter_recurse(&iter, &sub);

                if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_STRING)  {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                dbus_message_iter_get_basic(&sub, &state);

                if (!arg_quiet)
                        puts(state);

                if (streq(state, "active") || streq(state, "reloading"))
                        r = 0;

                dbus_message_unref(m);
                dbus_message_unref(reply);
                m = reply = NULL;
        }

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

typedef struct ExecStatusInfo {
        char *path;
        char **argv;

        bool ignore;

        usec_t start_timestamp;
        usec_t exit_timestamp;
        pid_t pid;
        int code;
        int status;

        LIST_FIELDS(struct ExecStatusInfo, exec);
} ExecStatusInfo;

static void exec_status_info_free(ExecStatusInfo *i) {
        assert(i);

        free(i->path);
        strv_free(i->argv);
        free(i);
}

static int exec_status_info_deserialize(DBusMessageIter *sub, ExecStatusInfo *i) {
        uint64_t start_timestamp, exit_timestamp;
        DBusMessageIter sub2, sub3;
        const char*path;
        unsigned n;
        uint32_t pid;
        int32_t code, status;
        dbus_bool_t ignore;

        assert(i);
        assert(i);

        if (dbus_message_iter_get_arg_type(sub) != DBUS_TYPE_STRUCT)
                return -EIO;

        dbus_message_iter_recurse(sub, &sub2);

        if (bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &path, true) < 0)
                return -EIO;

        if (!(i->path = strdup(path)))
                return -ENOMEM;

        if (dbus_message_iter_get_arg_type(&sub2) != DBUS_TYPE_ARRAY ||
            dbus_message_iter_get_element_type(&sub2) != DBUS_TYPE_STRING)
                return -EIO;

        n = 0;
        dbus_message_iter_recurse(&sub2, &sub3);
        while (dbus_message_iter_get_arg_type(&sub3) != DBUS_TYPE_INVALID) {
                assert(dbus_message_iter_get_arg_type(&sub3) == DBUS_TYPE_STRING);
                dbus_message_iter_next(&sub3);
                n++;
        }


        if (!(i->argv = new0(char*, n+1)))
                return -ENOMEM;

        n = 0;
        dbus_message_iter_recurse(&sub2, &sub3);
        while (dbus_message_iter_get_arg_type(&sub3) != DBUS_TYPE_INVALID) {
                const char *s;

                assert(dbus_message_iter_get_arg_type(&sub3) == DBUS_TYPE_STRING);
                dbus_message_iter_get_basic(&sub3, &s);
                dbus_message_iter_next(&sub3);

                if (!(i->argv[n++] = strdup(s)))
                        return -ENOMEM;
        }

        if (!dbus_message_iter_next(&sub2) ||
            bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_BOOLEAN, &ignore, true) < 0 ||
            bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_UINT64, &start_timestamp, true) < 0 ||
            bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_UINT64, &exit_timestamp, true) < 0 ||
            bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_UINT32, &pid, true) < 0 ||
            bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_INT32, &code, true) < 0 ||
            bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_INT32, &status, false) < 0)
                return -EIO;

        i->ignore = ignore;
        i->start_timestamp = (usec_t) start_timestamp;
        i->exit_timestamp = (usec_t) exit_timestamp;
        i->pid = (pid_t) pid;
        i->code = code;
        i->status = status;

        return 0;
}

typedef struct UnitStatusInfo {
        const char *id;
        const char *load_state;
        const char *active_state;
        const char *sub_state;

        const char *description;

        const char *path;
        const char *default_control_group;

        usec_t inactive_exit_timestamp;
        usec_t active_enter_timestamp;
        usec_t active_exit_timestamp;
        usec_t inactive_enter_timestamp;

        bool need_daemon_reload;

        /* Service */
        pid_t main_pid;
        pid_t control_pid;
        const char *status_text;
        bool running:1;
        bool is_sysv:1;

        usec_t start_timestamp;
        usec_t exit_timestamp;

        int exit_code, exit_status;

        /* Socket */
        unsigned n_accepted;
        unsigned n_connections;
        bool accept;

        /* Device */
        const char *sysfs_path;

        /* Mount, Automount */
        const char *where;

        /* Swap */
        const char *what;

        LIST_HEAD(ExecStatusInfo, exec);
} UnitStatusInfo;

static void print_status_info(UnitStatusInfo *i) {
        ExecStatusInfo *p;
        const char *on, *off, *ss;
        usec_t timestamp;
        char since1[FORMAT_TIMESTAMP_PRETTY_MAX], *s1;
        char since2[FORMAT_TIMESTAMP_MAX], *s2;

        assert(i);

        /* This shows pretty information about a unit. See
         * print_property() for a low-level property printer */

        printf("%s", strna(i->id));

        if (i->description && !streq_ptr(i->id, i->description))
                printf(" - %s", i->description);

        printf("\n");

        if (streq_ptr(i->load_state, "failed")) {
                on = ansi_highlight(true);
                off = ansi_highlight(false);
        } else
                on = off = "";

        if (i->path)
                printf("\t  Loaded: %s%s%s (%s)\n", on, strna(i->load_state), off, i->path);
        else
                printf("\t  Loaded: %s%s%s\n", on, strna(i->load_state), off);

        ss = streq_ptr(i->active_state, i->sub_state) ? NULL : i->sub_state;

        if (streq_ptr(i->active_state, "failed")) {
                on = ansi_highlight(true);
                off = ansi_highlight(false);
        } else if (streq_ptr(i->active_state, "active") || streq_ptr(i->active_state, "reloading")) {
                on = ansi_highlight_green(true);
                off = ansi_highlight_green(false);
        } else
                on = off = "";

        if (ss)
                printf("\t  Active: %s%s (%s)%s",
                       on,
                       strna(i->active_state),
                       ss,
                       off);
        else
                printf("\t  Active: %s%s%s",
                       on,
                       strna(i->active_state),
                       off);

        timestamp = (streq_ptr(i->active_state, "active")      ||
                     streq_ptr(i->active_state, "reloading"))   ? i->active_enter_timestamp :
                    (streq_ptr(i->active_state, "inactive")    ||
                     streq_ptr(i->active_state, "failed"))      ? i->inactive_enter_timestamp :
                    streq_ptr(i->active_state, "activating")    ? i->inactive_exit_timestamp :
                                                                  i->active_exit_timestamp;

        s1 = format_timestamp_pretty(since1, sizeof(since1), timestamp);
        s2 = format_timestamp(since2, sizeof(since2), timestamp);

        if (s1)
                printf(" since [%s; %s]\n", s2, s1);
        else if (s2)
                printf(" since [%s]\n", s2);
        else
                printf("\n");

        if (i->sysfs_path)
                printf("\t  Device: %s\n", i->sysfs_path);
        else if (i->where)
                printf("\t   Where: %s\n", i->where);
        else if (i->what)
                printf("\t    What: %s\n", i->what);

        if (i->accept)
                printf("\tAccepted: %u; Connected: %u\n", i->n_accepted, i->n_connections);

        LIST_FOREACH(exec, p, i->exec) {
                char *t;

                /* Only show exited processes here */
                if (p->code == 0)
                        continue;

                t = strv_join(p->argv, " ");
                printf("\t Process: %u (%s, code=%s, ", p->pid, strna(t), sigchld_code_to_string(p->code));
                free(t);

                if (p->code == CLD_EXITED) {
                        const char *c;

                        printf("status=%i", p->status);

                        if ((c = exit_status_to_string(p->status, i->is_sysv ? EXIT_STATUS_LSB : EXIT_STATUS_SYSTEMD)))
                                printf("/%s", c);

                } else
                        printf("signal=%s", signal_to_string(p->status));
                printf(")\n");

                if (i->main_pid == p->pid &&
                    i->start_timestamp == p->start_timestamp &&
                    i->exit_timestamp == p->start_timestamp)
                        /* Let's not show this twice */
                        i->main_pid = 0;

                if (p->pid == i->control_pid)
                        i->control_pid = 0;
        }

        if (i->main_pid > 0 || i->control_pid > 0) {
                printf("\t");

                if (i->main_pid > 0) {
                        printf("Main PID: %u", (unsigned) i->main_pid);

                        if (i->running) {
                                char *t = NULL;
                                get_process_name(i->main_pid, &t);
                                if (t) {
                                        printf(" (%s)", t);
                                        free(t);
                                }
                        } else if (i->exit_code > 0) {
                                printf(" (code=%s, ", sigchld_code_to_string(i->exit_code));

                                if (i->exit_code == CLD_EXITED) {
                                        const char *c;

                                        printf("status=%i", i->exit_status);

                                        if ((c = exit_status_to_string(i->exit_status, i->is_sysv ? EXIT_STATUS_LSB : EXIT_STATUS_SYSTEMD)))
                                                printf("/%s", c);

                                } else
                                        printf("signal=%s", signal_to_string(i->exit_status));
                                printf(")");
                        }
                }

                if (i->main_pid > 0 && i->control_pid > 0)
                        printf(";");

                if (i->control_pid > 0) {
                        char *t = NULL;

                        printf(" Control: %u", (unsigned) i->control_pid);

                        get_process_name(i->control_pid, &t);
                        if (t) {
                                printf(" (%s)", t);
                                free(t);
                        }
                }

                printf("\n");
        }

        if (i->status_text)
                printf("\t  Status: \"%s\"\n", i->status_text);

        if (i->default_control_group) {
                unsigned c;

                printf("\t  CGroup: %s\n", i->default_control_group);

                if ((c = columns()) > 18)
                        c -= 18;
                else
                        c = 0;

                show_cgroup_by_path(i->default_control_group, "\t\t  ", c);
        }

        if (i->need_daemon_reload)
                printf("\n%sWarning:%s Unit file changed on disk, 'systemctl %s daemon-reload' recommended.\n",
                       ansi_highlight(true),
                       ansi_highlight(false),
                       arg_session ? "--session" : "--system");
}

static int status_property(const char *name, DBusMessageIter *iter, UnitStatusInfo *i) {

        switch (dbus_message_iter_get_arg_type(iter)) {

        case DBUS_TYPE_STRING: {
                const char *s;

                dbus_message_iter_get_basic(iter, &s);

                if (s[0]) {
                        if (streq(name, "Id"))
                                i->id = s;
                        else if (streq(name, "LoadState"))
                                i->load_state = s;
                        else if (streq(name, "ActiveState"))
                                i->active_state = s;
                        else if (streq(name, "SubState"))
                                i->sub_state = s;
                        else if (streq(name, "Description"))
                                i->description = s;
                        else if (streq(name, "FragmentPath"))
                                i->path = s;
                        else if (streq(name, "SysVPath")) {
                                i->is_sysv = true;
                                i->path = s;
                        } else if (streq(name, "DefaultControlGroup"))
                                i->default_control_group = s;
                        else if (streq(name, "StatusText"))
                                i->status_text = s;
                        else if (streq(name, "SysFSPath"))
                                i->sysfs_path = s;
                        else if (streq(name, "Where"))
                                i->where = s;
                        else if (streq(name, "What"))
                                i->what = s;
                }

                break;
        }

        case DBUS_TYPE_BOOLEAN: {
                dbus_bool_t b;

                dbus_message_iter_get_basic(iter, &b);

                if (streq(name, "Accept"))
                        i->accept = b;
                else if (streq(name, "NeedDaemonReload"))
                        i->need_daemon_reload = b;

                break;
        }

        case DBUS_TYPE_UINT32: {
                uint32_t u;

                dbus_message_iter_get_basic(iter, &u);

                if (streq(name, "MainPID")) {
                        if (u > 0) {
                                i->main_pid = (pid_t) u;
                                i->running = true;
                        }
                } else if (streq(name, "ControlPID"))
                        i->control_pid = (pid_t) u;
                else if (streq(name, "ExecMainPID")) {
                        if (u > 0)
                                i->main_pid = (pid_t) u;
                } else if (streq(name, "NAccepted"))
                        i->n_accepted = u;
                else if (streq(name, "NConnections"))
                        i->n_connections = u;

                break;
        }

        case DBUS_TYPE_INT32: {
                int32_t j;

                dbus_message_iter_get_basic(iter, &j);

                if (streq(name, "ExecMainCode"))
                        i->exit_code = (int) j;
                else if (streq(name, "ExecMainStatus"))
                        i->exit_status = (int) j;

                break;
        }

        case DBUS_TYPE_UINT64: {
                uint64_t u;

                dbus_message_iter_get_basic(iter, &u);

                if (streq(name, "ExecMainStartTimestamp"))
                        i->start_timestamp = (usec_t) u;
                else if (streq(name, "ExecMainExitTimestamp"))
                        i->exit_timestamp = (usec_t) u;
                else if (streq(name, "ActiveEnterTimestamp"))
                        i->active_enter_timestamp = (usec_t) u;
                else if (streq(name, "InactiveEnterTimestamp"))
                        i->inactive_enter_timestamp = (usec_t) u;
                else if (streq(name, "InactiveExitTimestamp"))
                        i->inactive_exit_timestamp = (usec_t) u;
                else if (streq(name, "ActiveExitTimestamp"))
                        i->active_exit_timestamp = (usec_t) u;

                break;
        }

        case DBUS_TYPE_ARRAY: {

                if (dbus_message_iter_get_element_type(iter) == DBUS_TYPE_STRUCT &&
                    startswith(name, "Exec")) {
                        DBusMessageIter sub;

                        dbus_message_iter_recurse(iter, &sub);
                        while (dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_STRUCT) {
                                ExecStatusInfo *info;
                                int r;

                                if (!(info = new0(ExecStatusInfo, 1)))
                                        return -ENOMEM;

                                if ((r = exec_status_info_deserialize(&sub, info)) < 0) {
                                        free(info);
                                        return r;
                                }

                                LIST_PREPEND(ExecStatusInfo, exec, i->exec, info);

                                dbus_message_iter_next(&sub);
                        }
                }

                break;
        }
        }

        return 0;
}

static int print_property(const char *name, DBusMessageIter *iter) {
        assert(name);
        assert(iter);

        /* This is a low-level property printer, see
         * print_status_info() for the nicer output */

        if (arg_property && !strv_find(arg_property, name))
                return 0;

        switch (dbus_message_iter_get_arg_type(iter)) {

        case DBUS_TYPE_STRING: {
                const char *s;
                dbus_message_iter_get_basic(iter, &s);

                if (arg_all || s[0])
                        printf("%s=%s\n", name, s);

                return 0;
        }

        case DBUS_TYPE_BOOLEAN: {
                dbus_bool_t b;
                dbus_message_iter_get_basic(iter, &b);
                printf("%s=%s\n", name, yes_no(b));

                return 0;
        }

        case DBUS_TYPE_UINT64: {
                uint64_t u;
                dbus_message_iter_get_basic(iter, &u);

                /* Yes, heuristics! But we can change this check
                 * should it turn out to not be sufficient */

                if (strstr(name, "Timestamp")) {
                        char timestamp[FORMAT_TIMESTAMP_MAX], *t;

                        if ((t = format_timestamp(timestamp, sizeof(timestamp), u)) || arg_all)
                                printf("%s=%s\n", name, strempty(t));
                } else if (strstr(name, "USec")) {
                        char timespan[FORMAT_TIMESPAN_MAX];

                        printf("%s=%s\n", name, format_timespan(timespan, sizeof(timespan), u));
                } else
                        printf("%s=%llu\n", name, (unsigned long long) u);

                return 0;
        }

        case DBUS_TYPE_UINT32: {
                uint32_t u;
                dbus_message_iter_get_basic(iter, &u);

                if (strstr(name, "UMask") || strstr(name, "Mode"))
                        printf("%s=%04o\n", name, u);
                else
                        printf("%s=%u\n", name, (unsigned) u);

                return 0;
        }

        case DBUS_TYPE_INT32: {
                int32_t i;
                dbus_message_iter_get_basic(iter, &i);

                printf("%s=%i\n", name, (int) i);
                return 0;
        }

        case DBUS_TYPE_STRUCT: {
                DBusMessageIter sub;
                dbus_message_iter_recurse(iter, &sub);

                if (dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_UINT32 && streq(name, "Job")) {
                        uint32_t u;

                        dbus_message_iter_get_basic(&sub, &u);

                        if (u)
                                printf("%s=%u\n", name, (unsigned) u);
                        else if (arg_all)
                                printf("%s=\n", name);

                        return 0;
                } else if (dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_STRING && streq(name, "Unit")) {
                        const char *s;

                        dbus_message_iter_get_basic(&sub, &s);

                        if (arg_all || s[0])
                                printf("%s=%s\n", name, s);

                        return 0;
                }

                break;
        }

        case DBUS_TYPE_ARRAY:

                if (dbus_message_iter_get_element_type(iter) == DBUS_TYPE_STRING) {
                        DBusMessageIter sub;
                        bool space = false;

                        dbus_message_iter_recurse(iter, &sub);
                        if (arg_all ||
                            dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
                                printf("%s=", name);

                                while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
                                        const char *s;

                                        assert(dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_STRING);
                                        dbus_message_iter_get_basic(&sub, &s);
                                        printf("%s%s", space ? " " : "", s);

                                        space = true;
                                        dbus_message_iter_next(&sub);
                                }

                                puts("");
                        }

                        return 0;

                } else if (dbus_message_iter_get_element_type(iter) == DBUS_TYPE_BYTE) {
                        DBusMessageIter sub;

                        dbus_message_iter_recurse(iter, &sub);
                        if (arg_all ||
                            dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
                                printf("%s=", name);

                                while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
                                        uint8_t u;

                                        assert(dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_BYTE);
                                        dbus_message_iter_get_basic(&sub, &u);
                                        printf("%02x", u);

                                        dbus_message_iter_next(&sub);
                                }

                                puts("");
                        }

                        return 0;

                } else if (dbus_message_iter_get_element_type(iter) == DBUS_TYPE_STRUCT && streq(name, "Paths")) {
                        DBusMessageIter sub, sub2;

                        dbus_message_iter_recurse(iter, &sub);
                        while (dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_STRUCT) {
                                const char *type, *path;

                                dbus_message_iter_recurse(&sub, &sub2);

                                if (bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &type, true) >= 0 &&
                                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &path, false) >= 0)
                                        printf("%s=%s\n", type, path);

                                dbus_message_iter_next(&sub);
                        }

                        return 0;

                } else if (dbus_message_iter_get_element_type(iter) == DBUS_TYPE_STRUCT && streq(name, "Timers")) {
                        DBusMessageIter sub, sub2;

                        dbus_message_iter_recurse(iter, &sub);
                        while (dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_STRUCT) {
                                const char *base;
                                uint64_t value, next_elapse;

                                dbus_message_iter_recurse(&sub, &sub2);

                                if (bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &base, true) >= 0 &&
                                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_UINT64, &value, true) >= 0 &&
                                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_UINT64, &next_elapse, false) >= 0) {
                                        char timespan1[FORMAT_TIMESPAN_MAX], timespan2[FORMAT_TIMESPAN_MAX];

                                        printf("%s={ value=%s ; next_elapse=%s }\n",
                                               base,
                                               format_timespan(timespan1, sizeof(timespan1), value),
                                               format_timespan(timespan2, sizeof(timespan2), next_elapse));
                                }

                                dbus_message_iter_next(&sub);
                        }

                        return 0;

                } else if (dbus_message_iter_get_element_type(iter) == DBUS_TYPE_STRUCT && startswith(name, "Exec")) {
                        DBusMessageIter sub;

                        dbus_message_iter_recurse(iter, &sub);
                        while (dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_STRUCT) {
                                ExecStatusInfo info;

                                zero(info);
                                if (exec_status_info_deserialize(&sub, &info) >= 0) {
                                        char timestamp1[FORMAT_TIMESTAMP_MAX], timestamp2[FORMAT_TIMESTAMP_MAX];
                                        char *t;

                                        t = strv_join(info.argv, " ");

                                        printf("%s={ path=%s ; argv[]=%s ; ignore=%s ; start_time=[%s] ; stop_time=[%s] ; pid=%u ; code=%s ; status=%i%s%s }\n",
                                               name,
                                               strna(info.path),
                                               strna(t),
                                               yes_no(info.ignore),
                                               strna(format_timestamp(timestamp1, sizeof(timestamp1), info.start_timestamp)),
                                               strna(format_timestamp(timestamp2, sizeof(timestamp2), info.exit_timestamp)),
                                               (unsigned) info. pid,
                                               sigchld_code_to_string(info.code),
                                               info.status,
                                               info.code == CLD_EXITED ? "" : "/",
                                               strempty(info.code == CLD_EXITED ? NULL : signal_to_string(info.status)));

                                        free(t);
                                }

                                free(info.path);
                                strv_free(info.argv);

                                dbus_message_iter_next(&sub);
                        }

                        return 0;
                }

                break;
        }

        if (arg_all)
                printf("%s=[unprintable]\n", name);

        return 0;
}

static int show_one(DBusConnection *bus, const char *path, bool show_properties, bool *new_line) {
        DBusMessage *m = NULL, *reply = NULL;
        const char *interface = "";
        int r;
        DBusError error;
        DBusMessageIter iter, sub, sub2, sub3;
        UnitStatusInfo info;
        ExecStatusInfo *p;

        assert(bus);
        assert(path);
        assert(new_line);

        zero(info);
        dbus_error_init(&error);

        if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              path,
                              "org.freedesktop.DBus.Properties",
                              "GetAll"))) {
                log_error("Could not allocate message.");
                r = -ENOMEM;
                goto finish;
        }

        if (!dbus_message_append_args(m,
                                      DBUS_TYPE_STRING, &interface,
                                      DBUS_TYPE_INVALID)) {
                log_error("Could not append arguments to message.");
                r = -ENOMEM;
                goto finish;
        }

        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                log_error("Failed to issue method call: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        if (!dbus_message_iter_init(reply, &iter) ||
            dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY ||
            dbus_message_iter_get_element_type(&iter) != DBUS_TYPE_DICT_ENTRY)  {
                log_error("Failed to parse reply.");
                r = -EIO;
                goto finish;
        }

        dbus_message_iter_recurse(&iter, &sub);

        if (*new_line)
                printf("\n");

        *new_line = true;

        while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
                const char *name;

                if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_DICT_ENTRY) {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                dbus_message_iter_recurse(&sub, &sub2);

                if (bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &name, true) < 0) {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                if (dbus_message_iter_get_arg_type(&sub2) != DBUS_TYPE_VARIANT)  {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                dbus_message_iter_recurse(&sub2, &sub3);

                if (show_properties)
                        r = print_property(name, &sub3);
                else
                        r = status_property(name, &sub3, &info);

                if (r < 0) {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                dbus_message_iter_next(&sub);
        }

        r = 0;

        if (!show_properties) {
                if (arg_sysv_compat &&
                    !streq_ptr(info.active_state, "active") &&
                    !streq_ptr(info.active_state, "reloading")) {

                        /* If the SysV compatibility mode is on, we
                         * will refuse to run "status" on units that
                         * aren't active */
                        log_error("Unit not active.");
                        r = -EADDRNOTAVAIL;
                } else
                        print_status_info(&info);
        }

        while ((p = info.exec)) {
                LIST_REMOVE(ExecStatusInfo, exec, info.exec, p);
                exec_status_info_free(p);
        }

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

static int show(DBusConnection *bus, char **args, unsigned n) {
        DBusMessage *m = NULL, *reply = NULL;
        int r;
        DBusError error;
        unsigned i;
        bool show_properties, new_line = false;

        assert(bus);
        assert(args);

        dbus_error_init(&error);

        show_properties = !streq(args[0], "status");

        if (show_properties && n <= 1) {
                /* If not argument is specified inspect the manager
                 * itself */

                r = show_one(bus, "/org/freedesktop/systemd1", show_properties, &new_line);
                goto finish;
        }

        for (i = 1; i < n; i++) {
                const char *path = NULL;
                uint32_t id;

                if (safe_atou32(args[i], &id) < 0) {

                        /* Interpret as unit name */

                        if (!(m = dbus_message_new_method_call(
                                              "org.freedesktop.systemd1",
                                              "/org/freedesktop/systemd1",
                                              "org.freedesktop.systemd1.Manager",
                                              "LoadUnit"))) {
                                log_error("Could not allocate message.");
                                r = -ENOMEM;
                                goto finish;
                        }

                        if (!dbus_message_append_args(m,
                                                      DBUS_TYPE_STRING, &args[i],
                                                      DBUS_TYPE_INVALID)) {
                                log_error("Could not append arguments to message.");
                                r = -ENOMEM;
                                goto finish;
                        }

                        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {

                                if (!dbus_error_has_name(&error, DBUS_ERROR_ACCESS_DENIED)) {
                                        log_error("Failed to issue method call: %s", bus_error_message(&error));
                                        r = -EIO;
                                        goto finish;
                                }

                                dbus_error_free(&error);

                                dbus_message_unref(m);
                                if (!(m = dbus_message_new_method_call(
                                                      "org.freedesktop.systemd1",
                                                      "/org/freedesktop/systemd1",
                                                      "org.freedesktop.systemd1.Manager",
                                                      "GetUnit"))) {
                                        log_error("Could not allocate message.");
                                        r = -ENOMEM;
                                        goto finish;
                                }

                                if (!dbus_message_append_args(m,
                                                              DBUS_TYPE_STRING, &args[i],
                                                              DBUS_TYPE_INVALID)) {
                                        log_error("Could not append arguments to message.");
                                        r = -ENOMEM;
                                        goto finish;
                                }

                                if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                                        log_error("Failed to issue method call: %s", bus_error_message(&error));
                                        r = -EIO;
                                        goto finish;
                                }
                        }

                } else if (show_properties) {

                        /* Interpret as job id */

                        if (!(m = dbus_message_new_method_call(
                                              "org.freedesktop.systemd1",
                                              "/org/freedesktop/systemd1",
                                              "org.freedesktop.systemd1.Manager",
                                              "GetJob"))) {
                                log_error("Could not allocate message.");
                                r = -ENOMEM;
                                goto finish;
                        }

                        if (!dbus_message_append_args(m,
                                                      DBUS_TYPE_UINT32, &id,
                                                      DBUS_TYPE_INVALID)) {
                                log_error("Could not append arguments to message.");
                                r = -ENOMEM;
                                goto finish;
                        }

                        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                                log_error("Failed to issue method call: %s", bus_error_message(&error));
                                r = -EIO;
                                goto finish;
                        }
                } else {

                        /* Interpret as PID */

                        if (!(m = dbus_message_new_method_call(
                                              "org.freedesktop.systemd1",
                                              "/org/freedesktop/systemd1",
                                              "org.freedesktop.systemd1.Manager",
                                              "GetUnitByPID"))) {
                                log_error("Could not allocate message.");
                                r = -ENOMEM;
                                goto finish;
                        }

                        if (!dbus_message_append_args(m,
                                                      DBUS_TYPE_UINT32, &id,
                                                      DBUS_TYPE_INVALID)) {
                                log_error("Could not append arguments to message.");
                                r = -ENOMEM;
                                goto finish;
                        }

                        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                                log_error("Failed to issue method call: %s", bus_error_message(&error));
                                r = -EIO;
                                goto finish;
                        }
                }

                if (!dbus_message_get_args(reply, &error,
                                           DBUS_TYPE_OBJECT_PATH, &path,
                                           DBUS_TYPE_INVALID)) {
                        log_error("Failed to parse reply: %s", bus_error_message(&error));
                        r = -EIO;
                        goto finish;
                }

                if ((r = show_one(bus, path, show_properties, &new_line)) < 0)
                        goto finish;

                dbus_message_unref(m);
                dbus_message_unref(reply);
                m = reply = NULL;
        }

        r = 0;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

static DBusHandlerResult monitor_filter(DBusConnection *connection, DBusMessage *message, void *data) {
        DBusError error;
        DBusMessage *m = NULL, *reply = NULL;

        assert(connection);
        assert(message);

        dbus_error_init(&error);

        log_debug("Got D-Bus request: %s.%s() on %s",
                  dbus_message_get_interface(message),
                  dbus_message_get_member(message),
                  dbus_message_get_path(message));

        if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) {
                log_error("Warning! D-Bus connection terminated.");
                dbus_connection_close(connection);

        } else if (dbus_message_is_signal(message, "org.freedesktop.systemd1.Manager", "UnitNew") ||
                   dbus_message_is_signal(message, "org.freedesktop.systemd1.Manager", "UnitRemoved")) {
                const char *id, *path;

                if (!dbus_message_get_args(message, &error,
                                           DBUS_TYPE_STRING, &id,
                                           DBUS_TYPE_OBJECT_PATH, &path,
                                           DBUS_TYPE_INVALID))
                        log_error("Failed to parse message: %s", bus_error_message(&error));
                else if (streq(dbus_message_get_member(message), "UnitNew"))
                        printf("Unit %s added.\n", id);
                else
                        printf("Unit %s removed.\n", id);

        } else if (dbus_message_is_signal(message, "org.freedesktop.systemd1.Manager", "JobNew") ||
                   dbus_message_is_signal(message, "org.freedesktop.systemd1.Manager", "JobRemoved")) {
                uint32_t id;
                const char *path;

                if (!dbus_message_get_args(message, &error,
                                           DBUS_TYPE_UINT32, &id,
                                           DBUS_TYPE_OBJECT_PATH, &path,
                                           DBUS_TYPE_INVALID))
                        log_error("Failed to parse message: %s", bus_error_message(&error));
                else if (streq(dbus_message_get_member(message), "JobNew"))
                        printf("Job %u added.\n", id);
                else
                        printf("Job %u removed.\n", id);


        } else if (dbus_message_is_signal(message, "org.freedesktop.DBus.Properties", "PropertiesChanged")) {

                const char *path, *interface, *property = "Id";
                DBusMessageIter iter, sub;

                path = dbus_message_get_path(message);

                if (!dbus_message_get_args(message, &error,
                                          DBUS_TYPE_STRING, &interface,
                                          DBUS_TYPE_INVALID)) {
                        log_error("Failed to parse message: %s", bus_error_message(&error));
                        goto finish;
                }

                if (!streq(interface, "org.freedesktop.systemd1.Job") &&
                    !streq(interface, "org.freedesktop.systemd1.Unit"))
                        goto finish;

                if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              path,
                              "org.freedesktop.DBus.Properties",
                              "Get"))) {
                        log_error("Could not allocate message.");
                        goto oom;
                }

                if (!dbus_message_append_args(m,
                                              DBUS_TYPE_STRING, &interface,
                                              DBUS_TYPE_STRING, &property,
                                              DBUS_TYPE_INVALID)) {
                        log_error("Could not append arguments to message.");
                        goto finish;
                }

                if (!(reply = dbus_connection_send_with_reply_and_block(connection, m, -1, &error))) {
                        log_error("Failed to issue method call: %s", bus_error_message(&error));
                        goto finish;
                }

                if (!dbus_message_iter_init(reply, &iter) ||
                    dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_VARIANT)  {
                        log_error("Failed to parse reply.");
                        goto finish;
                }

                dbus_message_iter_recurse(&iter, &sub);

                if (streq(interface, "org.freedesktop.systemd1.Unit")) {
                        const char *id;

                        if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_STRING)  {
                                log_error("Failed to parse reply.");
                                goto finish;
                        }

                        dbus_message_iter_get_basic(&sub, &id);
                        printf("Unit %s changed.\n", id);
                } else {
                        uint32_t id;

                        if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_UINT32)  {
                                log_error("Failed to parse reply.");
                                goto finish;
                        }

                        dbus_message_iter_get_basic(&sub, &id);
                        printf("Job %u changed.\n", id);
                }
        }

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);
        return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;

oom:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);
        return DBUS_HANDLER_RESULT_NEED_MEMORY;
}

static int monitor(DBusConnection *bus, char **args, unsigned n) {
        DBusMessage *m = NULL, *reply = NULL;
        DBusError error;
        int r;

        dbus_error_init(&error);

        if (!private_bus) {
                dbus_bus_add_match(bus,
                                   "type='signal',"
                                   "sender='org.freedesktop.systemd1',"
                                   "interface='org.freedesktop.systemd1.Manager',"
                                   "path='/org/freedesktop/systemd1'",
                                   &error);

                if (dbus_error_is_set(&error)) {
                        log_error("Failed to add match: %s", bus_error_message(&error));
                        r = -EIO;
                        goto finish;
                }

                dbus_bus_add_match(bus,
                                   "type='signal',"
                                   "sender='org.freedesktop.systemd1',"
                                   "interface='org.freedesktop.DBus.Properties',"
                                   "member='PropertiesChanged'",
                                   &error);

                if (dbus_error_is_set(&error)) {
                        log_error("Failed to add match: %s", bus_error_message(&error));
                        r = -EIO;
                        goto finish;
                }
        }

        if (!dbus_connection_add_filter(bus, monitor_filter, NULL, NULL)) {
                log_error("Failed to add filter.");
                r = -ENOMEM;
                goto finish;
        }

        if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              "/org/freedesktop/systemd1",
                              "org.freedesktop.systemd1.Manager",
                              "Subscribe"))) {
                log_error("Could not allocate message.");
                r = -ENOMEM;
                goto finish;
        }

        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                log_error("Failed to issue method call: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        while (dbus_connection_read_write_dispatch(bus, -1))
                ;

        r = 0;

finish:

        /* This is slightly dirty, since we don't undo the filter or the matches. */

        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

static int dump(DBusConnection *bus, char **args, unsigned n) {
        DBusMessage *m = NULL, *reply = NULL;
        DBusError error;
        int r;
        const char *text;

        dbus_error_init(&error);

        if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              "/org/freedesktop/systemd1",
                              "org.freedesktop.systemd1.Manager",
                              "Dump"))) {
                log_error("Could not allocate message.");
                return -ENOMEM;
        }

        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                log_error("Failed to issue method call: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        if (!dbus_message_get_args(reply, &error,
                                   DBUS_TYPE_STRING, &text,
                                   DBUS_TYPE_INVALID)) {
                log_error("Failed to parse reply: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        fputs(text, stdout);

        r = 0;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

static int snapshot(DBusConnection *bus, char **args, unsigned n) {
        DBusMessage *m = NULL, *reply = NULL;
        DBusError error;
        int r;
        const char *name = "", *path, *id;
        dbus_bool_t cleanup = FALSE;
        DBusMessageIter iter, sub;
        const char
                *interface = "org.freedesktop.systemd1.Unit",
                *property = "Id";

        dbus_error_init(&error);

        if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              "/org/freedesktop/systemd1",
                              "org.freedesktop.systemd1.Manager",
                              "CreateSnapshot"))) {
                log_error("Could not allocate message.");
                return -ENOMEM;
        }

        if (n > 1)
                name = args[1];

        if (!dbus_message_append_args(m,
                                      DBUS_TYPE_STRING, &name,
                                      DBUS_TYPE_BOOLEAN, &cleanup,
                                      DBUS_TYPE_INVALID)) {
                log_error("Could not append arguments to message.");
                r = -ENOMEM;
                goto finish;
        }

        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                log_error("Failed to issue method call: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        if (!dbus_message_get_args(reply, &error,
                                   DBUS_TYPE_OBJECT_PATH, &path,
                                   DBUS_TYPE_INVALID)) {
                log_error("Failed to parse reply: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        dbus_message_unref(m);
        if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              path,
                              "org.freedesktop.DBus.Properties",
                              "Get"))) {
                log_error("Could not allocate message.");
                return -ENOMEM;
        }

        if (!dbus_message_append_args(m,
                                      DBUS_TYPE_STRING, &interface,
                                      DBUS_TYPE_STRING, &property,
                                      DBUS_TYPE_INVALID)) {
                log_error("Could not append arguments to message.");
                r = -ENOMEM;
                goto finish;
        }

        dbus_message_unref(reply);
        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                log_error("Failed to issue method call: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        if (!dbus_message_iter_init(reply, &iter) ||
            dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_VARIANT)  {
                log_error("Failed to parse reply.");
                r = -EIO;
                goto finish;
        }

        dbus_message_iter_recurse(&iter, &sub);

        if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_STRING)  {
                log_error("Failed to parse reply.");
                r = -EIO;
                goto finish;
        }

        dbus_message_iter_get_basic(&sub, &id);

        if (!arg_quiet)
                puts(id);
        r = 0;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

static int delete_snapshot(DBusConnection *bus, char **args, unsigned n) {
        DBusMessage *m = NULL, *reply = NULL;
        int r;
        DBusError error;
        unsigned i;

        assert(bus);
        assert(args);

        dbus_error_init(&error);

        for (i = 1; i < n; i++) {
                const char *path = NULL;

                if (!(m = dbus_message_new_method_call(
                                      "org.freedesktop.systemd1",
                                      "/org/freedesktop/systemd1",
                                      "org.freedesktop.systemd1.Manager",
                                      "GetUnit"))) {
                        log_error("Could not allocate message.");
                        r = -ENOMEM;
                        goto finish;
                }

                if (!dbus_message_append_args(m,
                                              DBUS_TYPE_STRING, &args[i],
                                              DBUS_TYPE_INVALID)) {
                        log_error("Could not append arguments to message.");
                        r = -ENOMEM;
                        goto finish;
                }

                if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                        log_error("Failed to issue method call: %s", bus_error_message(&error));
                        r = -EIO;
                        goto finish;
                }

                if (!dbus_message_get_args(reply, &error,
                                           DBUS_TYPE_OBJECT_PATH, &path,
                                           DBUS_TYPE_INVALID)) {
                        log_error("Failed to parse reply: %s", bus_error_message(&error));
                        r = -EIO;
                        goto finish;
                }

                dbus_message_unref(m);
                if (!(m = dbus_message_new_method_call(
                                      "org.freedesktop.systemd1",
                                      path,
                                      "org.freedesktop.systemd1.Snapshot",
                                      "Remove"))) {
                        log_error("Could not allocate message.");
                        r = -ENOMEM;
                        goto finish;
                }

                dbus_message_unref(reply);
                if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                        log_error("Failed to issue method call: %s", bus_error_message(&error));
                        r = -EIO;
                        goto finish;
                }

                dbus_message_unref(m);
                dbus_message_unref(reply);
                m = reply = NULL;
        }

        r = 0;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

static int daemon_reload(DBusConnection *bus, char **args, unsigned n) {
        DBusMessage *m = NULL, *reply = NULL;
        DBusError error;
        int r;
        const char *method;

        dbus_error_init(&error);

        if (arg_action == ACTION_RELOAD)
                method = "Reload";
        else if (arg_action == ACTION_REEXEC)
                method = "Reexecute";
        else {
                assert(arg_action == ACTION_SYSTEMCTL);

                method =
                        streq(args[0], "clear-jobs")        ||
                        streq(args[0], "cancel")            ? "ClearJobs" :
                        streq(args[0], "daemon-reexec")     ? "Reexecute" :
                        streq(args[0], "reset-failed")      ? "ResetFailed" :
                        streq(args[0], "daemon-exit")       ? "Exit" :
                                                              "Reload";
        }

        if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              "/org/freedesktop/systemd1",
                              "org.freedesktop.systemd1.Manager",
                              method))) {
                log_error("Could not allocate message.");
                return -ENOMEM;
        }

        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {

                if (arg_action != ACTION_SYSTEMCTL && error_is_no_service(&error)) {
                        /* There's always a fallback possible for
                         * legacy actions. */
                        r = 0;
                        goto finish;
                }

                log_error("Failed to issue method call: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        r = 1;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

static int reset_failed(DBusConnection *bus, char **args, unsigned n) {
        DBusMessage *m = NULL, *reply = NULL;
        unsigned i;
        int r;
        DBusError error;

        assert(bus);
        dbus_error_init(&error);

        if (n <= 1)
                return daemon_reload(bus, args, n);

        for (i = 1; i < n; i++) {

                if (!(m = dbus_message_new_method_call(
                                      "org.freedesktop.systemd1",
                                      "/org/freedesktop/systemd1",
                                      "org.freedesktop.systemd1.Manager",
                                      "ResetFailedUnit"))) {
                        log_error("Could not allocate message.");
                        r = -ENOMEM;
                        goto finish;
                }

                if (!dbus_message_append_args(m,
                                              DBUS_TYPE_STRING, args + i,
                                              DBUS_TYPE_INVALID)) {
                        log_error("Could not append arguments to message.");
                        r = -ENOMEM;
                        goto finish;
                }

                if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                        log_error("Failed to issue method call: %s", bus_error_message(&error));
                        r = -EIO;
                        goto finish;
                }

                dbus_message_unref(m);
                dbus_message_unref(reply);
                m = reply = NULL;
        }

        r = 0;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

static int show_enviroment(DBusConnection *bus, char **args, unsigned n) {
        DBusMessage *m = NULL, *reply = NULL;
        DBusError error;
        DBusMessageIter iter, sub, sub2;
        int r;
        const char
                *interface = "org.freedesktop.systemd1.Manager",
                *property = "Environment";

        dbus_error_init(&error);

        if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              "/org/freedesktop/systemd1",
                              "org.freedesktop.DBus.Properties",
                              "Get"))) {
                log_error("Could not allocate message.");
                return -ENOMEM;
        }

        if (!dbus_message_append_args(m,
                                      DBUS_TYPE_STRING, &interface,
                                      DBUS_TYPE_STRING, &property,
                                      DBUS_TYPE_INVALID)) {
                log_error("Could not append arguments to message.");
                r = -ENOMEM;
                goto finish;
        }

        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                log_error("Failed to issue method call: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        if (!dbus_message_iter_init(reply, &iter) ||
            dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_VARIANT)  {
                log_error("Failed to parse reply.");
                r = -EIO;
                goto finish;
        }

        dbus_message_iter_recurse(&iter, &sub);

        if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_ARRAY ||
            dbus_message_iter_get_element_type(&sub) != DBUS_TYPE_STRING)  {
                log_error("Failed to parse reply.");
                r = -EIO;
                goto finish;
        }

        dbus_message_iter_recurse(&sub, &sub2);

        while (dbus_message_iter_get_arg_type(&sub2) != DBUS_TYPE_INVALID) {
                const char *text;

                if (dbus_message_iter_get_arg_type(&sub2) != DBUS_TYPE_STRING) {
                        log_error("Failed to parse reply.");
                        r = -EIO;
                        goto finish;
                }

                dbus_message_iter_get_basic(&sub2, &text);
                printf("%s\n", text);

                dbus_message_iter_next(&sub2);
        }

        r = 0;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

static int set_environment(DBusConnection *bus, char **args, unsigned n) {
        DBusMessage *m = NULL, *reply = NULL;
        DBusError error;
        int r;
        const char *method;
        DBusMessageIter iter, sub;
        unsigned i;

        dbus_error_init(&error);

        method = streq(args[0], "set-environment")
                ? "SetEnvironment"
                : "UnsetEnvironment";

        if (!(m = dbus_message_new_method_call(
                              "org.freedesktop.systemd1",
                              "/org/freedesktop/systemd1",
                              "org.freedesktop.systemd1.Manager",
                              method))) {

                log_error("Could not allocate message.");
                return -ENOMEM;
        }

        dbus_message_iter_init_append(m, &iter);

        if (!dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY, "s", &sub)) {
                log_error("Could not append arguments to message.");
                r = -ENOMEM;
                goto finish;
        }

        for (i = 1; i < n; i++)
                if (!dbus_message_iter_append_basic(&sub, DBUS_TYPE_STRING, &args[i])) {
                        log_error("Could not append arguments to message.");
                        r = -ENOMEM;
                        goto finish;
                }

        if (!dbus_message_iter_close_container(&iter, &sub)) {
                log_error("Could not append arguments to message.");
                r = -ENOMEM;
                goto finish;
        }

        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {
                log_error("Failed to issue method call: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        r = 0;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        dbus_error_free(&error);

        return r;
}

typedef struct {
        char *name;
        char *path;

        char **aliases;
        char **wanted_by;
} InstallInfo;

static Hashmap *will_install = NULL, *have_installed = NULL;
static Set *remove_symlinks_to = NULL;

static void install_info_free(InstallInfo *i) {
        assert(i);

        free(i->name);
        free(i->path);
        strv_free(i->aliases);
        strv_free(i->wanted_by);
        free(i);
}

static void install_info_hashmap_free(Hashmap *m) {
        InstallInfo *i;

        while ((i = hashmap_steal_first(m)))
                install_info_free(i);

        hashmap_free(m);
}

static bool unit_name_valid(const char *name) {

        /* This is a minimal version of unit_name_valid() from
         * unit-name.c */

        if (!*name)
                return false;

        if (ignore_file(name))
                return false;

        return true;
}

static int install_info_add(const char *name) {
        InstallInfo *i;
        int r;

        assert(will_install);

        if (!unit_name_valid(name))
                return -EINVAL;

        if (hashmap_get(have_installed, name) ||
            hashmap_get(will_install, name))
                return 0;

        if (!(i = new0(InstallInfo, 1))) {
                r = -ENOMEM;
                goto fail;
        }

        if (!(i->name = strdup(name))) {
                r = -ENOMEM;
                goto fail;
        }

        if ((r = hashmap_put(will_install, i->name, i)) < 0)
                goto fail;

        return 0;

fail:
        if (i)
                install_info_free(i);

        return r;
}

static int config_parse_also(
                const char *filename,
                unsigned line,
                const char *section,
                const char *lvalue,
                const char *rvalue,
                void *data,
                void *userdata) {

        char *w;
        size_t l;
        char *state;

        assert(filename);
        assert(lvalue);
        assert(rvalue);

        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
                char *n;
                int r;

                if (!(n = strndup(w, l)))
                        return -ENOMEM;

                r = install_info_add(n);
                free(n);

                if (r < 0)
                        return r;
        }

        return 0;
}

static int mark_symlink_for_removal(const char *p) {
        char *n;
        int r;

        assert(p);
        assert(path_is_absolute(p));

        if (!remove_symlinks_to)
                return 0;

        if (!(n = strdup(p)))
                return -ENOMEM;

        path_kill_slashes(n);

        if ((r = set_put(remove_symlinks_to, n)) < 0) {
                free(n);
                return r == -EEXIST ? 0 : r;
        }

        return 0;
}

static int remove_marked_symlinks_fd(int fd, const char *config_path, const char *root, bool *deleted) {
        int r = 0;
        DIR *d;
        struct dirent *de;

        assert(fd >= 0);
        assert(root);
        assert(deleted);

        if (!(d = fdopendir(fd))) {
                close_nointr_nofail(fd);
                return -errno;
        }

        rewinddir(d);

        while ((de = readdir(d))) {
                bool is_dir = false, is_link = false;

                if (ignore_file(de->d_name))
                        continue;

                if (de->d_type == DT_LNK)
                        is_link = true;
                else if (de->d_type == DT_DIR)
                        is_dir = true;
                else if (de->d_type == DT_UNKNOWN) {
                        struct stat st;

                        if (fstatat(fd, de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {
                                log_error("Failed to stat %s/%s: %m", root, de->d_name);

                                if (r == 0)
                                        r = -errno;
                                continue;
                        }

                        is_link = S_ISLNK(st.st_mode);
                        is_dir = S_ISDIR(st.st_mode);
                } else
                        continue;

                if (is_dir) {
                        int nfd, q;
                        char *p;

                        if ((nfd = openat(fd, de->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW)) < 0) {
                                log_error("Failed to open %s/%s: %m", root, de->d_name);

                                if (r == 0)
                                        r = -errno;
                                continue;
                        }

                        if (asprintf(&p, "%s/%s", root, de->d_name) < 0) {
                                log_error("Failed to allocate directory string.");
                                close_nointr_nofail(nfd);
                                r = -ENOMEM;
                                break;
                        }

                        /* This will close nfd, regardless whether it succeeds or not */
                        q = remove_marked_symlinks_fd(nfd, config_path, p, deleted);
                        free(p);

                        if (r == 0)
                                r = q;

                } else if (is_link) {
                        char *p, *dest, *c;
                        int q;

                        if (asprintf(&p, "%s/%s", root, de->d_name) < 0) {
                                log_error("Failed to allocate symlink string.");
                                r = -ENOMEM;
                                break;
                        }

                        if ((q = readlink_and_make_absolute(p, &dest)) < 0) {
                                log_error("Cannot read symlink %s: %s", p, strerror(-q));
                                free(p);

                                if (r == 0)
                                        r = q;
                                continue;
                        }

                        if ((c = canonicalize_file_name(dest))) {
                                /* This might fail if the destination
                                 * is already removed */

                                free(dest);
                                dest = c;
                        }

                        path_kill_slashes(dest);
                        if (set_get(remove_symlinks_to, dest)) {

                                if (!arg_quiet)
                                        log_info("rm '%s'", p);

                                if (unlink(p) < 0) {
                                        log_error("Cannot unlink symlink %s: %m", p);

                                        if (r == 0)
                                                r = -errno;
                                } else {
                                        rmdir_parents(p, config_path);
                                        path_kill_slashes(p);

                                        if (!set_get(remove_symlinks_to, p)) {

                                                if ((r = mark_symlink_for_removal(p)) < 0) {
                                                        if (r == 0)
                                                                r = q;
                                                } else
                                                        *deleted = true;
                                        }
                                }
                        }

                        free(p);
                        free(dest);
                }
        }

        closedir(d);

        return r;
}

static int remove_marked_symlinks(const char *config_path) {
        int fd, r = 0;
        bool deleted;

        assert(config_path);

        if (set_size(remove_symlinks_to) <= 0)
                return 0;

        if ((fd = open(config_path, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW)) < 0)
                return -errno;

        do {
                int q, cfd;
                deleted = false;

                if ((cfd = dup(fd)) < 0) {
                        r = -errno;
                        break;
                }

                /* This takes possession of cfd and closes it */
                if ((q = remove_marked_symlinks_fd(cfd, config_path, config_path, &deleted)) < 0) {
                        if (r == 0)
                                r = q;
                }
        } while (deleted);

        close_nointr_nofail(fd);

        return r;
}

static int create_symlink(const char *verb, const char *old_path, const char *new_path) {
        int r;

        assert(old_path);
        assert(new_path);
        assert(verb);

        if (streq(verb, "enable")) {
                char *dest;

                mkdir_parents(new_path, 0755);

                if (symlink(old_path, new_path) >= 0) {

                        if (!arg_quiet)
                                log_info("ln -s '%s' '%s'", old_path, new_path);

                        return 0;
                }

                if (errno != EEXIST) {
                        log_error("Cannot link %s to %s: %m", old_path, new_path);
                        return -errno;
                }

                if ((r = readlink_and_make_absolute(new_path, &dest)) < 0) {

                        if (errno == EINVAL) {
                                log_error("Cannot link %s to %s, file exists already and is not a symlink.", old_path, new_path);
                                return -EEXIST;
                        }

                        log_error("readlink() failed: %s", strerror(-r));
                        return r;
                }

                if (streq(dest, old_path)) {
                        free(dest);
                        return 0;
                }

                if (!arg_force) {
                        log_error("Cannot link %s to %s, symlink exists already and points to %s.", old_path, new_path, dest);
                        free(dest);
                        return -EEXIST;
                }

                free(dest);
                unlink(new_path);

                if (!arg_quiet)
                        log_info("ln -s '%s' '%s'", old_path, new_path);

                if (symlink(old_path, new_path) >= 0)
                        return 0;

                log_error("Cannot link %s to %s: %m", old_path, new_path);
                return -errno;

        } else if (streq(verb, "disable")) {
                char *dest;

                if ((r = mark_symlink_for_removal(old_path)) < 0)
                        return r;

                if ((r = readlink_and_make_absolute(new_path, &dest)) < 0) {
                        if (errno == ENOENT)
                                return 0;

                        if (errno == EINVAL) {
                                log_warning("File %s not a symlink, ignoring.", old_path);
                                return 0;
                        }

                        log_error("readlink() failed: %s", strerror(-r));
                        return r;
                }

                if (!streq(dest, old_path)) {
                        log_warning("File %s not a symlink to %s but points to %s, ignoring.", new_path, old_path, dest);
                        free(dest);
                        return 0;
                }

                free(dest);

                if ((r = mark_symlink_for_removal(new_path)) < 0)
                        return r;

                if (!arg_quiet)
                        log_info("rm '%s'", new_path);

                if (unlink(new_path) >= 0)
                        return 0;

                log_error("Cannot unlink %s: %m", new_path);
                return -errno;

        } else if (streq(verb, "is-enabled")) {
                char *dest;

                if ((r = readlink_and_make_absolute(new_path, &dest)) < 0) {

                        if (errno == ENOENT || errno == EINVAL)
                                return 0;

                        log_error("readlink() failed: %s", strerror(-r));
                        return r;
                }

                if (streq(dest, old_path)) {
                        free(dest);
                        return 1;
                }

                return 0;
        }

        assert_not_reached("Unknown action.");
}

static int install_info_symlink_alias(const char *verb, InstallInfo *i, const char *config_path) {
        char **s;
        char *alias_path = NULL;
        int r;

        assert(verb);
        assert(i);
        assert(config_path);

        STRV_FOREACH(s, i->aliases) {

                if (!unit_name_valid(*s)) {
                        log_error("Invalid name %s.", *s);
                        r = -EINVAL;
                        goto finish;
                }

                free(alias_path);
                if (!(alias_path = path_make_absolute(*s, config_path))) {
                        log_error("Out of memory");
                        r = -ENOMEM;
                        goto finish;
                }

                if ((r = create_symlink(verb, i->path, alias_path)) != 0)
                        goto finish;

                if (streq(verb, "disable"))
                        rmdir_parents(alias_path, config_path);
        }

        r = 0;

finish:
        free(alias_path);

        return r;
}

static int install_info_symlink_wants(const char *verb, InstallInfo *i, const char *config_path) {
        char **s;
        char *alias_path = NULL;
        int r;

        assert(verb);
        assert(i);
        assert(config_path);

        STRV_FOREACH(s, i->wanted_by) {
                if (!unit_name_valid(*s)) {
                        log_error("Invalid name %s.", *s);
                        r = -EINVAL;
                        goto finish;
                }

                free(alias_path);
                alias_path = NULL;

                if (asprintf(&alias_path, "%s/%s.wants/%s", config_path, *s, i->name) < 0) {
                        log_error("Out of memory");
                        r = -ENOMEM;
                        goto finish;
                }

                if ((r = create_symlink(verb, i->path, alias_path)) != 0)
                        goto finish;

                if (streq(verb, "disable"))
                        rmdir_parents(alias_path, config_path);
        }

        r = 0;

finish:
        free(alias_path);

        return r;
}

static int install_info_apply(const char *verb, LookupPaths *paths, InstallInfo *i, const char *config_path) {

        const ConfigItem items[] = {
                { "Alias",    config_parse_strv, &i->aliases,   "Install" },
                { "WantedBy", config_parse_strv, &i->wanted_by, "Install" },
                { "Also",     config_parse_also, NULL,          "Install" },

                { NULL, NULL, NULL, NULL }
        };

        char **p;
        char *filename = NULL;
        FILE *f = NULL;
        int r;

        assert(paths);
        assert(i);

        STRV_FOREACH(p, paths->unit_path) {
                int fd;

                if (!(filename = path_make_absolute(i->name, *p))) {
                        log_error("Out of memory");
                        return -ENOMEM;
                }

                /* Ensure that we don't follow symlinks */
                if ((fd = open(filename, O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NOCTTY)) >= 0)
                        if ((f = fdopen(fd, "re")))
                                break;

                if (errno == ELOOP) {
                        log_error("Refusing to operate on symlinks, please pass unit names or absolute paths to unit files.");
                        free(filename);
                        return -errno;
                }

                if (errno != ENOENT) {
                        log_error("Failed to open %s: %m", filename);
                        free(filename);
                        return -errno;
                }

                free(filename);
                filename = NULL;
        }

        if (!f) {
                log_error("Couldn't find %s.", i->name);
                return -ENOENT;
        }

        i->path = filename;

        if ((r = config_parse(filename, f, NULL, items, true, i)) < 0) {
                fclose(f);
                return r;
        }

        fclose(f);

        if ((r = install_info_symlink_alias(verb, i, config_path)) != 0)
                return r;

        if ((r = install_info_symlink_wants(verb, i, config_path)) != 0)
                return r;

        if ((r = mark_symlink_for_removal(filename)) < 0)
                return r;

        if ((r = remove_marked_symlinks(config_path)) < 0)
                return r;

        return 0;
}

static char *get_config_path(void) {

        if (arg_session && arg_global)
                return strdup(SESSION_CONFIG_UNIT_PATH);

        if (arg_session) {
                char *p;

                if (session_config_home(&p) < 0)
                        return NULL;

                return p;
        }

        return strdup(SYSTEM_CONFIG_UNIT_PATH);
}

static int enable_unit(DBusConnection *bus, char **args, unsigned n) {
        DBusError error;
        int r;
        LookupPaths paths;
        char *config_path = NULL;
        unsigned j;
        InstallInfo *i;
        const char *verb = args[0];

        dbus_error_init(&error);

        zero(paths);
        if ((r = lookup_paths_init(&paths, arg_session ? MANAGER_SESSION : MANAGER_SYSTEM)) < 0) {
                log_error("Failed to determine lookup paths: %s", strerror(-r));
                goto finish;
        }

        if (!(config_path = get_config_path())) {
                log_error("Failed to determine config path");
                r = -ENOMEM;
                goto finish;
        }

        will_install = hashmap_new(string_hash_func, string_compare_func);
        have_installed = hashmap_new(string_hash_func, string_compare_func);

        if (!will_install || !have_installed) {
                log_error("Failed to allocate unit sets.");
                r = -ENOMEM;
                goto finish;
        }

        if (!arg_defaults && streq(verb, "disable"))
                if (!(remove_symlinks_to = set_new(string_hash_func, string_compare_func))) {
                        log_error("Failed to allocate symlink sets.");
                        r = -ENOMEM;
                        goto finish;
                }

        for (j = 1; j < n; j++)
                if ((r = install_info_add(args[j])) < 0)
                        goto finish;

        while ((i = hashmap_first(will_install))) {
                int q;

                assert_se(hashmap_move_one(have_installed, will_install, i->name) == 0);

                if ((q = install_info_apply(verb, &paths, i, config_path)) != 0) {

                        if (q < 0) {
                                if (r == 0)
                                        r = q;
                                goto finish;
                        }

                        /* In test mode and found something */
                        r = 1;
                        break;
                }
        }

        if (streq(verb, "is-enabled"))
                r = r > 0 ? 0 : -ENOENT;
        else if (bus &&
                 /* Don't try to reload anything if the user asked us to not do this */
                 !arg_no_reload &&
                 /* Don't try to reload anything when updating a unit globally */
                 !arg_global &&
                 /* Don't try to reload anything if we are called for system changes but the system wasn't booted with systemd */
                 (arg_session || sd_booted() > 0) &&
                 /* Don't try to reload anything if we are running in a chroot environment */
                 (arg_session || running_in_chroot() <= 0) ) {
                int q;

                if ((q = daemon_reload(bus, args, n)) < 0)
                        r = q;
        }

finish:
        install_info_hashmap_free(will_install);
        install_info_hashmap_free(have_installed);

        set_free_free(remove_symlinks_to);

        lookup_paths_free(&paths);

        free(config_path);

        return r;
}

static int systemctl_help(void) {

        printf("%s [OPTIONS...] {COMMAND} ...\n\n"
               "Send control commands to or query the systemd manager.\n\n"
               "  -h --help          Show this help\n"
               "  -t --type=TYPE     List only units of a particular type\n"
               "  -p --property=NAME Show only properties by this name\n"
               "  -a --all           Show all units/properties, including dead/empty ones\n"
               "     --full          Don't ellipsize unit names on output\n"
               "     --fail          When queueing a new job, fail if conflicting jobs are\n"
               "                     pending\n"
               "  -q --quiet         Suppress output\n"
               "     --no-block      Do not wait until operation finished\n"
               "     --system        Connect to system bus\n"
               "     --session       Connect to session bus\n"
               "     --order         When generating graph for dot, show only order\n"
               "     --require       When generating graph for dot, show only requirement\n"
               "     --no-wall       Don't send wall message before halt/power-off/reboot\n"
               "     --global        Enable/disable unit files globally\n"
               "     --no-reload     When enabling/disabling unit files, don't reload daemon\n"
               "                     configuration\n"
               "     --force         When enabling unit files, override existing symlinks\n"
               "     --defaults      When disabling unit files, remove default symlinks only\n\n"
               "Commands:\n"
               "  list-units                      List units\n"
               "  start [NAME...]                 Start (activate) one or more units\n"
               "  stop [NAME...]                  Stop (deactivate) one or more units\n"
               "  reload [NAME...]                Reload one or more units\n"
               "  restart [NAME...]               Start or restart one or more units\n"
               "  try-restart [NAME...]           Restart one or more units if active\n"
               "  reload-or-restart [NAME...]     Reload one or more units is possible,\n"
               "                                  otherwise start or restart\n"
               "  reload-or-try-restart [NAME...] Reload one or more units is possible,\n"
               "                                  otherwise restart if active\n"
               "  isolate [NAME]                  Start one unit and stop all others\n"
               "  is-active [NAME...]             Check whether units are active\n"
               "  status [NAME...|PID...]         Show runtime status of one or more units\n"
               "  show [NAME...|JOB...]           Show properties of one or more\n"
               "                                  units/jobs or the manager\n"
               "  reset-failed [NAME...]          Reset failed state for all, one, or more\n"
               "                                  units\n"
               "  enable [NAME...]                Enable one or more unit files\n"
               "  disable [NAME...]               Disable one or more unit files\n"
               "  is-enabled [NAME...]            Check whether unit files are enabled\n"
               "  load [NAME...]                  Load one or more units\n"
               "  list-jobs                       List jobs\n"
               "  cancel [JOB...]                 Cancel all, one, or more jobs\n"
               "  monitor                         Monitor unit/job changes\n"
               "  dump                            Dump server status\n"
               "  dot                             Dump dependency graph for dot(1)\n"
               "  snapshot [NAME]                 Create a snapshot\n"
               "  delete [NAME...]                Remove one or more snapshots\n"
               "  daemon-reload                   Reload systemd manager configuration\n"
               "  daemon-reexec                   Reexecute systemd manager\n"
               "  daemon-exit                     Ask the systemd manager to quit\n"
               "  show-environment                Dump environment\n"
               "  set-environment [NAME=VALUE...] Set one or more environment variables\n"
               "  unset-environment [NAME...]     Unset one or more environment variables\n"
               "  halt                            Shut down and halt the system\n"
               "  poweroff                        Shut down and power-off the system\n"
               "  reboot                          Shut down and reboot the system\n"
               "  rescue                          Enter system rescue mode\n"
               "  emergency                       Enter system emergency mode\n"
               "  default                         Enter system default mode\n",
               program_invocation_short_name);

        return 0;
}

static int halt_help(void) {

        printf("%s [OPTIONS...]\n\n"
               "%s the system.\n\n"
               "     --help      Show this help\n"
               "     --halt      Halt the machine\n"
               "  -p --poweroff  Switch off the machine\n"
               "     --reboot    Reboot the machine\n"
               "  -f --force     Force immediate halt/power-off/reboot\n"
               "  -w --wtmp-only Don't halt/power-off/reboot, just write wtmp record\n"
               "  -d --no-wtmp   Don't write wtmp record\n"
               "  -n --no-sync   Don't sync before halt/power-off/reboot\n"
               "     --no-wall   Don't send wall message before halt/power-off/reboot\n",
               program_invocation_short_name,
               arg_action == ACTION_REBOOT   ? "Reboot" :
               arg_action == ACTION_POWEROFF ? "Power off" :
                                               "Halt");

        return 0;
}

static int shutdown_help(void) {

        printf("%s [OPTIONS...] [TIME] [WALL...]\n\n"
               "Shut down the system.\n\n"
               "     --help      Show this help\n"
               "  -H --halt      Halt the machine\n"
               "  -P --poweroff  Power-off the machine\n"
               "  -r --reboot    Reboot the machine\n"
               "  -h             Equivalent to --poweroff, overriden by --halt\n"
               "  -k             Don't halt/power-off/reboot, just send warnings\n"
               "     --no-wall   Don't send wall message before halt/power-off/reboot\n"
               "  -c             Cancel a pending shutdown\n",
               program_invocation_short_name);

        return 0;
}

static int telinit_help(void) {

        printf("%s [OPTIONS...] {COMMAND}\n\n"
               "Send control commands to the init daemon.\n\n"
               "     --help      Show this help\n"
               "     --no-wall   Don't send wall message before halt/power-off/reboot\n\n"
               "Commands:\n"
               "  0              Power-off the machine\n"
               "  6              Reboot the machine\n"
               "  2, 3, 4, 5     Start runlevelX.target unit\n"
               "  1, s, S        Enter rescue mode\n"
               "  q, Q           Reload init daemon configuration\n"
               "  u, U           Reexecute init daemon\n",
               program_invocation_short_name);

        return 0;
}

static int runlevel_help(void) {

        printf("%s [OPTIONS...]\n\n"
               "Prints the previous and current runlevel of the init system.\n\n"
               "     --help      Show this help\n",
               program_invocation_short_name);

        return 0;
}

static int systemctl_parse_argv(int argc, char *argv[]) {

        enum {
                ARG_FAIL = 0x100,
                ARG_SESSION,
                ARG_SYSTEM,
                ARG_GLOBAL,
                ARG_NO_BLOCK,
                ARG_NO_WALL,
                ARG_ORDER,
                ARG_REQUIRE,
                ARG_FULL,
                ARG_FORCE,
                ARG_NO_RELOAD,
                ARG_DEFAULTS,
                ARG_SYSV_COMPAT
        };

        static const struct option options[] = {
                { "help",      no_argument,       NULL, 'h'           },
                { "type",      required_argument, NULL, 't'           },
                { "property",  required_argument, NULL, 'p'           },
                { "all",       no_argument,       NULL, 'a'           },
                { "full",      no_argument,       NULL, ARG_FULL      },
                { "fail",      no_argument,       NULL, ARG_FAIL      },
                { "session",   no_argument,       NULL, ARG_SESSION   },
                { "system",    no_argument,       NULL, ARG_SYSTEM    },
                { "global",    no_argument,       NULL, ARG_GLOBAL    },
                { "no-block",  no_argument,       NULL, ARG_NO_BLOCK  },
                { "no-wall",   no_argument,       NULL, ARG_NO_WALL   },
                { "quiet",     no_argument,       NULL, 'q'           },
                { "order",     no_argument,       NULL, ARG_ORDER     },
                { "require",   no_argument,       NULL, ARG_REQUIRE   },
                { "force",     no_argument,       NULL, ARG_FORCE     },
                { "no-reload", no_argument,       NULL, ARG_NO_RELOAD },
                { "defaults",  no_argument,       NULL, ARG_DEFAULTS  },
                { "sysv-compat", no_argument,     NULL, ARG_SYSV_COMPAT },
                { NULL,        0,                 NULL, 0             }
        };

        int c;

        assert(argc >= 0);
        assert(argv);

        while ((c = getopt_long(argc, argv, "ht:p:aq", options, NULL)) >= 0) {

                switch (c) {

                case 'h':
                        systemctl_help();
                        return 0;

                case 't':
                        arg_type = optarg;
                        break;

                case 'p': {
                        char **l;

                        if (!(l = strv_append(arg_property, optarg)))
                                return -ENOMEM;

                        strv_free(arg_property);
                        arg_property = l;

                        /* If the user asked for a particular
                         * property, show it to him, even if it is
                         * empty. */
                        arg_all = true;
                        break;
                }

                case 'a':
                        arg_all = true;
                        break;

                case ARG_FAIL:
                        arg_fail = true;
                        break;

                case ARG_SESSION:
                        arg_session = true;
                        break;

                case ARG_SYSTEM:
                        arg_session = false;
                        break;

                case ARG_NO_BLOCK:
                        arg_no_block = true;
                        break;

                case ARG_NO_WALL:
                        arg_no_wall = true;
                        break;

                case ARG_ORDER:
                        arg_dot = DOT_ORDER;
                        break;

                case ARG_REQUIRE:
                        arg_dot = DOT_REQUIRE;
                        break;

                case ARG_FULL:
                        arg_full = true;
                        break;

                case 'q':
                        arg_quiet = true;
                        break;

                case ARG_FORCE:
                        arg_force = true;
                        break;

                case ARG_NO_RELOAD:
                        arg_no_reload = true;
                        break;

                case ARG_GLOBAL:
                        arg_global = true;
                        arg_session = true;
                        break;

                case ARG_DEFAULTS:
                        arg_defaults = true;
                        break;

                case ARG_SYSV_COMPAT:
                        arg_sysv_compat = true;
                        break;

                case '?':
                        return -EINVAL;

                default:
                        log_error("Unknown option code %c", c);
                        return -EINVAL;
                }
        }

        return 1;
}

static int halt_parse_argv(int argc, char *argv[]) {

        enum {
                ARG_HELP = 0x100,
                ARG_HALT,
                ARG_REBOOT,
                ARG_NO_WALL
        };

        static const struct option options[] = {
                { "help",      no_argument,       NULL, ARG_HELP    },
                { "halt",      no_argument,       NULL, ARG_HALT    },
                { "poweroff",  no_argument,       NULL, 'p'         },
                { "reboot",    no_argument,       NULL, ARG_REBOOT  },
                { "force",     no_argument,       NULL, 'f'         },
                { "wtmp-only", no_argument,       NULL, 'w'         },
                { "no-wtmp",   no_argument,       NULL, 'd'         },
                { "no-sync",   no_argument,       NULL, 'n'         },
                { "no-wall",   no_argument,       NULL, ARG_NO_WALL },
                { NULL,        0,                 NULL, 0           }
        };

        int c, runlevel;

        assert(argc >= 0);
        assert(argv);

        if (utmp_get_runlevel(&runlevel, NULL) >= 0)
                if (runlevel == '0' || runlevel == '6')
                        arg_immediate = true;

        while ((c = getopt_long(argc, argv, "pfwdnih", options, NULL)) >= 0) {
                switch (c) {

                case ARG_HELP:
                        halt_help();
                        return 0;

                case ARG_HALT:
                        arg_action = ACTION_HALT;
                        break;

                case 'p':
                        if (arg_action != ACTION_REBOOT)
                                arg_action = ACTION_POWEROFF;
                        break;

                case ARG_REBOOT:
                        arg_action = ACTION_REBOOT;
                        break;

                case 'f':
                        arg_immediate = true;
                        break;

                case 'w':
                        arg_dry = true;
                        break;

                case 'd':
                        arg_no_wtmp = true;
                        break;

                case 'n':
                        arg_no_sync = true;
                        break;

                case ARG_NO_WALL:
                        arg_no_wall = true;
                        break;

                case 'i':
                case 'h':
                        /* Compatibility nops */
                        break;

                case '?':
                        return -EINVAL;

                default:
                        log_error("Unknown option code %c", c);
                        return -EINVAL;
                }
        }

        if (optind < argc) {
                log_error("Too many arguments.");
                return -EINVAL;
        }

        return 1;
}

static int parse_time_spec(const char *t, usec_t *_u) {
        assert(t);
        assert(_u);

        if (streq(t, "now"))
                *_u = 0;
        else if (t[0] == '+') {
                uint64_t u;

                if (safe_atou64(t + 1, &u) < 0)
                        return -EINVAL;

                *_u = now(CLOCK_REALTIME) + USEC_PER_MINUTE * u;
        } else {
                char *e = NULL;
                long hour, minute;
                struct tm tm;
                time_t s;
                usec_t n;

                errno = 0;
                hour = strtol(t, &e, 10);
                if (errno != 0 || *e != ':' || hour < 0 || hour > 23)
                        return -EINVAL;

                minute = strtol(e+1, &e, 10);
                if (errno != 0 || *e != 0 || minute < 0 || minute > 59)
                        return -EINVAL;

                n = now(CLOCK_REALTIME);
                s = (time_t) (n / USEC_PER_SEC);

                zero(tm);
                assert_se(localtime_r(&s, &tm));

                tm.tm_hour = (int) hour;
                tm.tm_min = (int) minute;
                tm.tm_sec = 0;

                assert_se(s = mktime(&tm));

                *_u = (usec_t) s * USEC_PER_SEC;

                while (*_u <= n)
                        *_u += USEC_PER_DAY;
        }

        return 0;
}

static int shutdown_parse_argv(int argc, char *argv[]) {

        enum {
                ARG_HELP = 0x100,
                ARG_NO_WALL
        };

        static const struct option options[] = {
                { "help",      no_argument,       NULL, ARG_HELP    },
                { "halt",      no_argument,       NULL, 'H'         },
                { "poweroff",  no_argument,       NULL, 'P'         },
                { "reboot",    no_argument,       NULL, 'r'         },
                { "no-wall",   no_argument,       NULL, ARG_NO_WALL },
                { NULL,        0,                 NULL, 0           }
        };

        int c, r;

        assert(argc >= 0);
        assert(argv);

        while ((c = getopt_long(argc, argv, "HPrhkt:afFc", options, NULL)) >= 0) {
                switch (c) {

                case ARG_HELP:
                        shutdown_help();
                        return 0;

                case 'H':
                        arg_action = ACTION_HALT;
                        break;

                case 'P':
                        arg_action = ACTION_POWEROFF;
                        break;

                case 'r':
                        arg_action = ACTION_REBOOT;
                        break;

                case 'h':
                        if (arg_action != ACTION_HALT)
                                arg_action = ACTION_POWEROFF;
                        break;

                case 'k':
                        arg_dry = true;
                        break;

                case ARG_NO_WALL:
                        arg_no_wall = true;
                        break;

                case 't':
                case 'a':
                        /* Compatibility nops */
                        break;

                case 'c':
                        arg_action = ACTION_CANCEL_SHUTDOWN;
                        break;

                case '?':
                        return -EINVAL;

                default:
                        log_error("Unknown option code %c", c);
                        return -EINVAL;
                }
        }

        if (argc > optind) {
                if ((r = parse_time_spec(argv[optind], &arg_when)) < 0) {
                        log_error("Failed to parse time specification: %s", argv[optind]);
                        return r;
                }
        } else
                arg_when = now(CLOCK_REALTIME) + USEC_PER_MINUTE;

        /* We skip the time argument */
        if (argc > optind + 1)
                arg_wall = argv + optind + 1;

        optind = argc;

        return 1;
}

static int telinit_parse_argv(int argc, char *argv[]) {

        enum {
                ARG_HELP = 0x100,
                ARG_NO_WALL
        };

        static const struct option options[] = {
                { "help",      no_argument,       NULL, ARG_HELP    },
                { "no-wall",   no_argument,       NULL, ARG_NO_WALL },
                { NULL,        0,                 NULL, 0           }
        };

        static const struct {
                char from;
                enum action to;
        } table[] = {
                { '0', ACTION_POWEROFF },
                { '6', ACTION_REBOOT },
                { '1', ACTION_RESCUE },
                { '2', ACTION_RUNLEVEL2 },
                { '3', ACTION_RUNLEVEL3 },
                { '4', ACTION_RUNLEVEL4 },
                { '5', ACTION_RUNLEVEL5 },
                { 's', ACTION_RESCUE },
                { 'S', ACTION_RESCUE },
                { 'q', ACTION_RELOAD },
                { 'Q', ACTION_RELOAD },
                { 'u', ACTION_REEXEC },
                { 'U', ACTION_REEXEC }
        };

        unsigned i;
        int c;

        assert(argc >= 0);
        assert(argv);

        while ((c = getopt_long(argc, argv, "", options, NULL)) >= 0) {
                switch (c) {

                case ARG_HELP:
                        telinit_help();
                        return 0;

                case ARG_NO_WALL:
                        arg_no_wall = true;
                        break;

                case '?':
                        return -EINVAL;

                default:
                        log_error("Unknown option code %c", c);
                        return -EINVAL;
                }
        }

        if (optind >= argc) {
                telinit_help();
                return -EINVAL;
        }

        if (optind + 1 < argc) {
                log_error("Too many arguments.");
                return -EINVAL;
        }

        if (strlen(argv[optind]) != 1) {
                log_error("Expected single character argument.");
                return -EINVAL;
        }

        for (i = 0; i < ELEMENTSOF(table); i++)
                if (table[i].from == argv[optind][0])
                        break;

        if (i >= ELEMENTSOF(table)) {
                log_error("Unknown command %s.", argv[optind]);
                return -EINVAL;
        }

        arg_action = table[i].to;

        optind ++;

        return 1;
}

static int runlevel_parse_argv(int argc, char *argv[]) {

        enum {
                ARG_HELP = 0x100,
        };

        static const struct option options[] = {
                { "help",      no_argument,       NULL, ARG_HELP    },
                { NULL,        0,                 NULL, 0           }
        };

        int c;

        assert(argc >= 0);
        assert(argv);

        while ((c = getopt_long(argc, argv, "", options, NULL)) >= 0) {
                switch (c) {

                case ARG_HELP:
                        runlevel_help();
                        return 0;

                case '?':
                        return -EINVAL;

                default:
                        log_error("Unknown option code %c", c);
                        return -EINVAL;
                }
        }

        if (optind < argc) {
                log_error("Too many arguments.");
                return -EINVAL;
        }

        return 1;
}

static int parse_argv(int argc, char *argv[]) {
        assert(argc >= 0);
        assert(argv);

        if (program_invocation_short_name) {

                if (strstr(program_invocation_short_name, "halt")) {
                        arg_action = ACTION_HALT;
                        return halt_parse_argv(argc, argv);
                } else if (strstr(program_invocation_short_name, "poweroff")) {
                        arg_action = ACTION_POWEROFF;
                        return halt_parse_argv(argc, argv);
                } else if (strstr(program_invocation_short_name, "reboot")) {
                        arg_action = ACTION_REBOOT;
                        return halt_parse_argv(argc, argv);
                } else if (strstr(program_invocation_short_name, "shutdown")) {
                        arg_action = ACTION_POWEROFF;
                        return shutdown_parse_argv(argc, argv);
                } else if (strstr(program_invocation_short_name, "init")) {

                        if (sd_booted() > 0) {
                                arg_action = ACTION_INVALID;
                                return telinit_parse_argv(argc, argv);
                        } else {
                                /* Hmm, so some other init system is
                                 * running, we need to forward this
                                 * request to it. For now we simply
                                 * guess that it is Upstart. */

                                execv("/lib/upstart/telinit", argv);

                                log_error("Couldn't find an alternative telinit implementation to spawn.");
                                return -EIO;
                        }

                } else if (strstr(program_invocation_short_name, "runlevel")) {
                        arg_action = ACTION_RUNLEVEL;
                        return runlevel_parse_argv(argc, argv);
                }
        }

        arg_action = ACTION_SYSTEMCTL;
        return systemctl_parse_argv(argc, argv);
}

static int action_to_runlevel(void) {

        static const char table[_ACTION_MAX] = {
                [ACTION_HALT] =      '0',
                [ACTION_POWEROFF] =  '0',
                [ACTION_REBOOT] =    '6',
                [ACTION_RUNLEVEL2] = '2',
                [ACTION_RUNLEVEL3] = '3',
                [ACTION_RUNLEVEL4] = '4',
                [ACTION_RUNLEVEL5] = '5',
                [ACTION_RESCUE] =    '1'
        };

        assert(arg_action < _ACTION_MAX);

        return table[arg_action];
}

static int talk_upstart(void) {
        DBusMessage *m = NULL, *reply = NULL;
        DBusError error;
        int previous, rl, r;
        char
                env1_buf[] = "RUNLEVEL=X",
                env2_buf[] = "PREVLEVEL=X";
        char *env1 = env1_buf, *env2 = env2_buf;
        const char *emit = "runlevel";
        dbus_bool_t b_false = FALSE;
        DBusMessageIter iter, sub;
        DBusConnection *bus;

        dbus_error_init(&error);

        if (!(rl = action_to_runlevel()))
                return 0;

        if (utmp_get_runlevel(&previous, NULL) < 0)
                previous = 'N';

        if (!(bus = dbus_connection_open_private("unix:abstract=/com/ubuntu/upstart", &error))) {
                if (dbus_error_has_name(&error, DBUS_ERROR_NO_SERVER)) {
                        r = 0;
                        goto finish;
                }

                log_error("Failed to connect to Upstart bus: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        if ((r = bus_check_peercred(bus)) < 0) {
                log_error("Failed to verify owner of bus.");
                goto finish;
        }

        if (!(m = dbus_message_new_method_call(
                              "com.ubuntu.Upstart",
                              "/com/ubuntu/Upstart",
                              "com.ubuntu.Upstart0_6",
                              "EmitEvent"))) {

                log_error("Could not allocate message.");
                r = -ENOMEM;
                goto finish;
        }

        dbus_message_iter_init_append(m, &iter);

        env1_buf[sizeof(env1_buf)-2] = rl;
        env2_buf[sizeof(env2_buf)-2] = previous;

        if (!dbus_message_iter_append_basic(&iter, DBUS_TYPE_STRING, &emit) ||
            !dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY, "s", &sub) ||
            !dbus_message_iter_append_basic(&sub, DBUS_TYPE_STRING, &env1) ||
            !dbus_message_iter_append_basic(&sub, DBUS_TYPE_STRING, &env2) ||
            !dbus_message_iter_close_container(&iter, &sub) ||
            !dbus_message_iter_append_basic(&iter, DBUS_TYPE_BOOLEAN, &b_false)) {
                log_error("Could not append arguments to message.");
                r = -ENOMEM;
                goto finish;
        }

        if (!(reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error))) {

                if (error_is_no_service(&error)) {
                        r = 0;
                        goto finish;
                }

                log_error("Failed to issue method call: %s", bus_error_message(&error));
                r = -EIO;
                goto finish;
        }

        r = 1;

finish:
        if (m)
                dbus_message_unref(m);

        if (reply)
                dbus_message_unref(reply);

        if (bus) {
                dbus_connection_close(bus);
                dbus_connection_unref(bus);
        }

        dbus_error_free(&error);

        return r;
}

static int talk_initctl(void) {
        struct init_request request;
        int r, fd;
        char rl;

        if (!(rl = action_to_runlevel()))
                return 0;

        zero(request);
        request.magic = INIT_MAGIC;
        request.sleeptime = 0;
        request.cmd = INIT_CMD_RUNLVL;
        request.runlevel = rl;

        if ((fd = open(INIT_FIFO, O_WRONLY|O_NDELAY|O_CLOEXEC|O_NOCTTY)) < 0) {

                if (errno == ENOENT)
                        return 0;

                log_error("Failed to open "INIT_FIFO": %m");
                return -errno;
        }

        errno = 0;
        r = loop_write(fd, &request, sizeof(request), false) != sizeof(request);
        close_nointr_nofail(fd);

        if (r < 0) {
                log_error("Failed to write to "INIT_FIFO": %m");
                return errno ? -errno : -EIO;
        }

        return 1;
}

static int systemctl_main(DBusConnection *bus, int argc, char *argv[], DBusError *error) {

        static const struct {
                const char* verb;
                const enum {
                        MORE,
                        LESS,
                        EQUAL
                } argc_cmp;
                const int argc;
                int (* const dispatch)(DBusConnection *bus, char **args, unsigned n);
        } verbs[] = {
                { "list-units",            LESS,  1, list_units        },
                { "list-jobs",             EQUAL, 1, list_jobs         },
                { "clear-jobs",            EQUAL, 1, daemon_reload     },
                { "load",                  MORE,  2, load_unit         },
                { "cancel",                MORE,  2, cancel_job        },
                { "start",                 MORE,  2, start_unit        },
                { "stop",                  MORE,  2, start_unit        },
                { "reload",                MORE,  2, start_unit        },
                { "restart",               MORE,  2, start_unit        },
                { "try-restart",           MORE,  2, start_unit        },
                { "reload-or-restart",     MORE,  2, start_unit        },
                { "reload-or-try-restart", MORE,  2, start_unit        },
                { "force-reload",          MORE,  2, start_unit        }, /* For compatibility with SysV */
                { "condrestart",           MORE,  2, start_unit        }, /* For compatibility with RH */
                { "isolate",               EQUAL, 2, start_unit        },
                { "is-active",             MORE,  2, check_unit        },
                { "check",                 MORE,  2, check_unit        },
                { "show",                  MORE,  1, show              },
                { "status",                MORE,  2, show              },
                { "monitor",               EQUAL, 1, monitor           },
                { "dump",                  EQUAL, 1, dump              },
                { "dot",                   EQUAL, 1, dot               },
                { "snapshot",              LESS,  2, snapshot          },
                { "delete",                MORE,  2, delete_snapshot   },
                { "daemon-reload",         EQUAL, 1, daemon_reload     },
                { "daemon-reexec",         EQUAL, 1, daemon_reload     },
                { "daemon-exit",           EQUAL, 1, daemon_reload     },
                { "show-environment",      EQUAL, 1, show_enviroment   },
                { "set-environment",       MORE,  2, set_environment   },
                { "unset-environment",     MORE,  2, set_environment   },
                { "halt",                  EQUAL, 1, start_special     },
                { "poweroff",              EQUAL, 1, start_special     },
                { "reboot",                EQUAL, 1, start_special     },
                { "default",               EQUAL, 1, start_special     },
                { "rescue",                EQUAL, 1, start_special     },
                { "emergency",             EQUAL, 1, start_special     },
                { "reset-failed",          MORE,  1, reset_failed      },
                { "enable",                MORE,  2, enable_unit       },
                { "disable",               MORE,  2, enable_unit       },
                { "is-enabled",            MORE,  2, enable_unit       }
        };

        int left;
        unsigned i;

        assert(argc >= 0);
        assert(argv);
        assert(error);

        left = argc - optind;

        if (left <= 0)
                /* Special rule: no arguments means "list-units" */
                i = 0;
        else {
                if (streq(argv[optind], "help")) {
                        systemctl_help();
                        return 0;
                }

                for (i = 0; i < ELEMENTSOF(verbs); i++)
                        if (streq(argv[optind], verbs[i].verb))
                                break;

                if (i >= ELEMENTSOF(verbs)) {
                        log_error("Unknown operation %s", argv[optind]);
                        return -EINVAL;
                }
        }

        switch (verbs[i].argc_cmp) {

        case EQUAL:
                if (left != verbs[i].argc) {
                        log_error("Invalid number of arguments.");
                        return -EINVAL;
                }

                break;

        case MORE:
                if (left < verbs[i].argc) {
                        log_error("Too few arguments.");
                        return -EINVAL;
                }

                break;

        case LESS:
                if (left > verbs[i].argc) {
                        log_error("Too many arguments.");
                        return -EINVAL;
                }

                break;

        default:
                assert_not_reached("Unknown comparison operator.");
        }

        /* Require a bus connection for all operations but
         * enable/disable */
        if (!streq(verbs[i].verb, "enable") &&
            !streq(verbs[i].verb, "disable") &&
            !bus) {
                log_error("Failed to get D-Bus connection: %s", error->message);
                return -EIO;
        }

        return verbs[i].dispatch(bus, argv + optind, left);
}

static int send_shutdownd(usec_t t, char mode, bool warn, const char *message) {
        int fd = -1;
        struct msghdr msghdr;
        struct iovec iovec;
        union sockaddr_union sockaddr;
        struct ucred *ucred;
        union {
                struct cmsghdr cmsghdr;
                uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
        } control;
        struct shutdownd_command c;

        zero(c);
        c.elapse = t;
        c.mode = mode;
        c.warn_wall = warn;

        if (message)
                strncpy(c.wall_message, message, sizeof(c.wall_message));

        if ((fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0)) < 0)
                return -errno;

        zero(sockaddr);
        sockaddr.sa.sa_family = AF_UNIX;
        sockaddr.un.sun_path[0] = 0;
        strncpy(sockaddr.un.sun_path+1, "/org/freedesktop/systemd1/shutdownd", sizeof(sockaddr.un.sun_path)-1);

        zero(iovec);
        iovec.iov_base = (char*) &c;
        iovec.iov_len = sizeof(c);

        zero(control);
        control.cmsghdr.cmsg_level = SOL_SOCKET;
        control.cmsghdr.cmsg_type = SCM_CREDENTIALS;
        control.cmsghdr.cmsg_len = CMSG_LEN(sizeof(struct ucred));

        ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
        ucred->pid = getpid();
        ucred->uid = getuid();
        ucred->gid = getgid();

        zero(msghdr);
        msghdr.msg_name = &sockaddr;
        msghdr.msg_namelen = sizeof(sa_family_t) + 1 + sizeof("/org/freedesktop/systemd1/shutdownd") - 1;

        msghdr.msg_iov = &iovec;
        msghdr.msg_iovlen = 1;
        msghdr.msg_control = &control;
        msghdr.msg_controllen = control.cmsghdr.cmsg_len;

        if (sendmsg(fd, &msghdr, MSG_NOSIGNAL) < 0) {
                close_nointr_nofail(fd);
                return -errno;
        }

        close_nointr_nofail(fd);
        return 0;
}

static int reload_with_fallback(DBusConnection *bus) {

        if (bus) {
                /* First, try systemd via D-Bus. */
                if (daemon_reload(bus, NULL, 0) > 0)
                        return 0;
        }

        /* Nothing else worked, so let's try signals */
        assert(arg_action == ACTION_RELOAD || arg_action == ACTION_REEXEC);

        if (kill(1, arg_action == ACTION_RELOAD ? SIGHUP : SIGTERM) < 0) {
                log_error("kill() failed: %m");
                return -errno;
        }

        return 0;
}

static int start_with_fallback(DBusConnection *bus) {

        if (bus) {
                /* First, try systemd via D-Bus. */
                if (start_unit(bus, NULL, 0) > 0)
                        goto done;
        }

        /* Hmm, talking to systemd via D-Bus didn't work. Then
         * let's try to talk to Upstart via D-Bus. */
        if (talk_upstart() > 0)
                goto done;

        /* Nothing else worked, so let's try
         * /dev/initctl */
        if (talk_initctl() > 0)
                goto done;

        log_error("Failed to talk to init daemon.");
        return -EIO;

done:
        warn_wall(arg_action);
        return 0;
}

static int halt_main(DBusConnection *bus) {
        int r;

        if (geteuid() != 0) {
                log_error("Must be root.");
                return -EPERM;
        }

        if (arg_when > 0) {
                char *m;
                char date[FORMAT_TIMESTAMP_MAX];

                m = strv_join(arg_wall, " ");
                r = send_shutdownd(arg_when,
                                   arg_action == ACTION_HALT     ? 'H' :
                                   arg_action == ACTION_POWEROFF ? 'P' :
                                                                   'r',
                                   !arg_no_wall,
                                   m);
                free(m);

                if (r < 0)
                        log_warning("Failed to talk to shutdownd, proceeding with immediate shutdown: %s", strerror(-r));
                else {
                        log_info("Shutdown scheduled for %s, use 'shutdown -c' to cancel.",
                                 format_timestamp(date, sizeof(date), arg_when));
                        return 0;
                }
        }

        if (!arg_dry && !arg_immediate)
                return start_with_fallback(bus);

        if (!arg_no_wtmp) {
                if (sd_booted() > 0)
                        log_debug("Not writing utmp record, assuming that systemd-update-utmp is used.");
                else if ((r = utmp_put_shutdown(0)) < 0)
                        log_warning("Failed to write utmp record: %s", strerror(-r));
        }

        if (!arg_no_sync)
                sync();

        if (arg_dry)
                return 0;

        /* Make sure C-A-D is handled by the kernel from this
         * point on... */
        reboot(RB_ENABLE_CAD);

        switch (arg_action) {

        case ACTION_HALT:
                log_info("Halting.");
                reboot(RB_HALT_SYSTEM);
                break;

        case ACTION_POWEROFF:
                log_info("Powering off.");
                reboot(RB_POWER_OFF);
                break;

        case ACTION_REBOOT:
                log_info("Rebooting.");
                reboot(RB_AUTOBOOT);
                break;

        default:
                assert_not_reached("Unknown halt action.");
        }

        /* We should never reach this. */
        return -ENOSYS;
}

static int runlevel_main(void) {
        int r, runlevel, previous;

        if ((r = utmp_get_runlevel(&runlevel, &previous)) < 0) {
                printf("unknown\n");
                return r;
        }

        printf("%c %c\n",
               previous <= 0 ? 'N' : previous,
               runlevel <= 0 ? 'N' : runlevel);

        return 0;
}

int main(int argc, char*argv[]) {
        int r, retval = 1;
        DBusConnection *bus = NULL;
        DBusError error;

        dbus_error_init(&error);

        log_parse_environment();
        log_open();

        if ((r = parse_argv(argc, argv)) < 0)
                goto finish;
        else if (r == 0) {
                retval = 0;
                goto finish;
        }

        /* /sbin/runlevel doesn't need to communicate via D-Bus, so
         * let's shortcut this */
        if (arg_action == ACTION_RUNLEVEL) {
                retval = runlevel_main() < 0;
                goto finish;
        }

        bus_connect(arg_session ? DBUS_BUS_SESSION : DBUS_BUS_SYSTEM, &bus, &private_bus, &error);

        switch (arg_action) {

        case ACTION_SYSTEMCTL: {
                retval = systemctl_main(bus, argc, argv, &error) < 0;
                break;
        }

        case ACTION_HALT:
        case ACTION_POWEROFF:
        case ACTION_REBOOT:
                retval = halt_main(bus) < 0;
                break;

        case ACTION_RUNLEVEL2:
        case ACTION_RUNLEVEL3:
        case ACTION_RUNLEVEL4:
        case ACTION_RUNLEVEL5:
        case ACTION_RESCUE:
        case ACTION_EMERGENCY:
        case ACTION_DEFAULT:
                retval = start_with_fallback(bus) < 0;
                break;

        case ACTION_RELOAD:
        case ACTION_REEXEC:
                retval = reload_with_fallback(bus) < 0;
                break;

        case ACTION_CANCEL_SHUTDOWN:
                retval = send_shutdownd(0, 0, false, NULL) < 0;
                break;

        case ACTION_INVALID:
        case ACTION_RUNLEVEL:
        default:
                assert_not_reached("Unknown action");
        }

finish:

        if (bus) {
                dbus_connection_close(bus);
                dbus_connection_unref(bus);
        }

        dbus_error_free(&error);

        dbus_shutdown();

        strv_free(arg_property);

        return retval;
}