preinit.c

   1 /*
   2  * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   3  * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License version 2.1
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <sys/stat.h>
  16 #include <sys/types.h>
  17 #include <sys/mount.h>
  18
  19 #include <unistd.h>
  20 #include <unistd.h>
  21
  22 #include "procd.h"
  23 #include "hotplug.h"
  24 #include "watchdog.h"
  25
  26 static struct uloop_process preinit;
  27
  28 static void spawn_procd(struct uloop_process *proc, int ret)
  29 {
  30         char *wdt_fd = watchdog_fd();
  31         char *argv[] = { "/sbin/procd", NULL };
  32
  33         unsetenv("INITRAMFS");
  34         unsetenv("PREINIT");
  35         DEBUG(1, "Exec to real procd now\n");
  36         if (wdt_fd)
  37                 setenv("WDTFD", wdt_fd, 1);
  38         execvp(argv[0], argv);
  39 }
  40
  41 void procd_preinit(void)
  42 {
  43         char *argv[] = { "/bin/sh", "/etc/preinit", NULL };
  44
  45         LOG("- preinit -\n");
  46
  47         setenv("PREINIT", "1", 1);
  48         preinit.cb = spawn_procd;
  49         preinit.pid = fork();
  50         if (!preinit.pid) {
  51                 execvp(argv[0], argv);
  52                 ERROR("Failed to start preinit\n");
  53                 exit(-1);
  54         }
  55
  56         if (preinit.pid <= 0) {
  57                 ERROR("Failed to start new preinit instance\n");
  58                 return;
  59         }
  60
  61         uloop_process_add(&preinit);
  62         DEBUG(2, "Launched preinit instance, pid=%d\n", (int) preinit.pid);
  63 }