plug/coldplug.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
  21 #include "../procd.h"
  22
  23 #include "hotplug.h"
  24
  25 static struct uloop_process udevtrigger;
  26
  27 static void coldplug_complete(struct uloop_timeout *t)
  28 {
  29         DEBUG(4, "Coldplug complete\n");
  30         hotplug_last_event(NULL);
  31         procd_state_next();
  32 }
  33
  34 static void udevtrigger_complete(struct uloop_process *proc, int ret)
  35 {
  36         DEBUG(4, "Finished udevtrigger\n");
  37         hotplug_last_event(coldplug_complete);
  38 }
  39
  40 void procd_coldplug(void)
  41 {
  42         char *argv[] = { "udevtrigger", NULL };
  43         unsigned int oldumask = umask(0);
  44
  45         umount2("/dev/pts", MNT_DETACH);
  46         umount2("/dev/", MNT_DETACH);
  47         mount("tmpfs", "/dev", "tmpfs", MS_NOSUID, "mode=0755,size=512K");
  48         symlink("/tmp/shm", "/dev/shm");
  49         mkdir("/dev/pts", 0755);
  50         umask(oldumask);
  51         mount("devpts", "/dev/pts", "devpts", MS_NOEXEC | MS_NOSUID, 0);
  52         udevtrigger.cb = udevtrigger_complete;
  53         udevtrigger.pid = fork();
  54         if (!udevtrigger.pid) {
  55                 execvp(argv[0], argv);
  56                 ERROR("Failed to start coldplug\n");
  57                 exit(-1);
  58         }
  59
  60         if (udevtrigger.pid <= 0) {
  61                 ERROR("Failed to start new coldplug instance\n");
  62                 return;
  63         }
  64
  65         uloop_process_add(&udevtrigger);
  66
  67         DEBUG(4, "Launched coldplug instance, pid=%d\n", (int) udevtrigger.pid);
  68 }