src/cgroups-agent/cgroups-agent.c

/*-*- 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 Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 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
  Lesser General Public License for more details.

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

#include <dbus/dbus.h>

#include <stdlib.h>

#include "log.h"
#include "dbus-common.h"

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

        dbus_error_init(&error);

        if (argc != 2) {
                log_error("Incorrect number of arguments.");
                goto finish;
        }

        log_set_target(LOG_TARGET_AUTO);
        log_parse_environment();
        log_open();

        /* We send this event to the private D-Bus socket and then the
         * system instance will forward this to the system bus. We do
         * this to avoid an activation loop when we start dbus when we
         * are called when the dbus service is shut down. */

        if (!(bus = dbus_connection_open_private("unix:path=/run/systemd/private", &error))) {
#ifndef LEGACY
                dbus_error_free(&error);

                /* Retry with the pre v21 socket name, to ease upgrades */
                if (!(bus = dbus_connection_open_private("unix:abstract=/org/freedesktop/systemd1/private", &error))) {
#endif
                        log_error("Failed to get D-Bus connection: %s", bus_error_message(&error));
                        goto finish;
                }
#ifndef LEGACY
        }
#endif

        if (bus_check_peercred(bus) < 0) {
                log_error("Bus owner not root.");
                goto finish;
        }

        if (!(m = dbus_message_new_signal("/org/freedesktop/systemd1/agent", "org.freedesktop.systemd1.Agent", "Released"))) {
                log_error("Could not allocate signal message.");
                goto finish;
        }

        if (!dbus_message_append_args(m,
                                      DBUS_TYPE_STRING, &argv[1],
                                      DBUS_TYPE_INVALID)) {
                log_error("Could not attach group information to signal message.");
                goto finish;
        }

        if (!dbus_connection_send(bus, m, NULL)) {
                log_error("Failed to send signal message on private connection.");
                goto finish;
        }

        r = EXIT_SUCCESS;

finish:
        if (bus) {
                dbus_connection_flush(bus);
                dbus_connection_close(bus);
                dbus_connection_unref(bus);
        }

        if (m)
                dbus_message_unref(m);

        dbus_error_free(&error);
        return r;
}