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 <stdlib.h>
  20 #include <unistd.h>
  21
  22 #include "../procd.h"
  23 #include "../libc-compat.h"
  24
  25 #include "hotplug.h"
  26 #include "../container.h"
  27
  28 static struct uloop_process udevtrigger;
  29
  30 static void coldplug_complete(struct uloop_timeout *t)
  31 {
  32         DEBUG(4, "Coldplug complete\n");
  33         hotplug_last_event(NULL);
  34         procd_state_next();
  35 }
  36
  37 static void udevtrigger_complete(struct uloop_process *proc, int ret)
  38 {
  39         DEBUG(4, "Finished udevtrigger\n");
  40         hotplug_last_event(coldplug_complete);
  41 }
  42
  43 void procd_coldplug(void)
  44 {
  45         char *argv[] = { "udevtrigger", NULL };
  46         unsigned int oldumask = umask(0);
  47
  48         if (!is_container()) {
  49                 umount2("/dev/pts", MNT_DETACH);
  50                 umount2("/dev/", MNT_DETACH);
  51                 mount("tmpfs", "/dev", "tmpfs", MS_NOATIME | MS_NOEXEC | MS_NOSUID, "mode=0755,size=512K");
  52                 mkdir("/dev/pts", 0755);
  53                 mount("devpts", "/dev/pts", "devpts", MS_NOATIME | MS_NOEXEC | MS_NOSUID, 0);
  54         }
  55
  56         ignore(symlink("/tmp/shm", "/dev/shm"));
  57         umask(oldumask);
  58         udevtrigger.cb = udevtrigger_complete;
  59         udevtrigger.pid = fork();
  60         if (!udevtrigger.pid) {
  61                 execvp(argv[0], argv);
  62                 ERROR("Failed to start coldplug: %m\n");
  63                 exit(EXIT_FAILURE);
  64         }
  65
  66         if (udevtrigger.pid <= 0) {
  67                 ERROR("Failed to start new coldplug instance: %m\n");
  68                 return;
  69         }
  70
  71         uloop_process_add(&udevtrigger);
  72
  73         DEBUG(4, "Launched coldplug instance, pid=%d\n", (int) udevtrigger.pid);
  74 }