release/src/router/busybox/libbb/systemd_support.c

   1 /*
   2  * Copyright (C) 2011 Davide Cavalca <davide@geexbox.org>
   3  *
   4  * Based on http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.c
   5  * Copyright 2010 Lennart Poettering
   6  *
   7  * Permission is hereby granted, free of charge, to any person
   8  * obtaining a copy of this software and associated documentation files
   9  * (the "Software"), to deal in the Software without restriction,
  10  * including without limitation the rights to use, copy, modify, merge,
  11  * publish, distribute, sublicense, and/or sell copies of the Software,
  12  * and to permit persons to whom the Software is furnished to do so,
  13  * subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be
  16  * included in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  21  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  22  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  23  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  24  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  25  * SOFTWARE.
  26  */
  27 #include "libbb.h"
  28
  29 //config:config FEATURE_SYSTEMD
  30 //config:       bool "Enable systemd support"
  31 //config:       default y
  32 //config:       help
  33 //config:         If you plan to use busybox daemons on a system where daemons
  34 //config:         are controlled by systemd, enable this option.
  35 //config:         If you don't use systemd, it is still safe to enable it,
  36 //config:         but the downside is increased code size.
  37
  38 //kbuild:lib-$(CONFIG_FEATURE_SYSTEMD) += systemd_support.o
  39
  40 int sd_listen_fds(void)
  41 {
  42         const char *e;
  43         int n;
  44         int fd;
  45
  46         e = getenv("LISTEN_PID");
  47         if (!e)
  48                 return 0;
  49         n = xatoi_positive(e);
  50         /* Is this for us? */
  51         if (getpid() != (pid_t) n)
  52                 return 0;
  53
  54         e = getenv("LISTEN_FDS");
  55         if (!e)
  56                 return 0;
  57         n = xatoi_positive(e);
  58         for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd++)
  59                 close_on_exec_on(fd);
  60
  61         return n;
  62 }