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         struct stat s;
  33
  34         if (!stat("/tmp/sysupgrade", &s))
  35                 while (true)
  36                         sleep(1);
  37
  38         unsetenv("INITRAMFS");
  39         unsetenv("PREINIT");
  40         DEBUG(1, "Exec to real procd now\n");
  41         if (wdt_fd)
  42                 setenv("WDTFD", wdt_fd, 1);
  43         execvp(argv[0], argv);
  44 }
  45
  46 void procd_preinit(void)
  47 {
  48         char *argv[] = { "/bin/sh", "/etc/preinit", NULL };
  49
  50         LOG("- preinit -\n");
  51
  52         setenv("PREINIT", "1", 1);
  53         preinit.cb = spawn_procd;
  54         preinit.pid = fork();
  55         if (!preinit.pid) {
  56                 execvp(argv[0], argv);
  57                 ERROR("Failed to start preinit\n");
  58                 exit(-1);
  59         }
  60
  61         if (preinit.pid <= 0) {
  62                 ERROR("Failed to start new preinit instance\n");
  63                 return;
  64         }
  65
  66         uloop_process_add(&preinit);
  67         DEBUG(2, "Launched preinit instance, pid=%d\n", (int) preinit.pid);
  68 }