initd/early.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/mount.h>
  16 #include <sys/types.h>
  17 #include <sys/stat.h>
  18
  19 #include <stdio.h>
  20 #include <fcntl.h>
  21 #include <unistd.h>
  22 #include <stdlib.h>
  23
  24 #include "init.h"
  25 #include "../libc-compat.h"
  26
  27 static void
  28 early_dev(void)
  29 {
  30         mkdev("*", 0600);
  31         mknod("/dev/null", 0666, makedev(1, 3));
  32 }
  33
  34 static void
  35 early_console(const char *dev)
  36 {
  37         struct stat s;
  38         int dd;
  39
  40         if (stat(dev, &s)) {
  41                 ERROR("Failed to stat %s\n", dev);
  42                 return;
  43         }
  44
  45         dd = open(dev, O_RDWR);
  46         if (dd < 0)
  47                 dd = open("/dev/null", O_RDWR);
  48
  49         dup2(dd, STDIN_FILENO);
  50         dup2(dd, STDOUT_FILENO);
  51         dup2(dd, STDERR_FILENO);
  52
  53         if (dd != STDIN_FILENO &&
  54             dd != STDOUT_FILENO &&
  55             dd != STDERR_FILENO)
  56                 close(dd);
  57
  58         fcntl(STDERR_FILENO, F_SETFL, fcntl(STDERR_FILENO, F_GETFL) | O_NONBLOCK);
  59 }
  60
  61 static void
  62 early_mounts(void)
  63 {
  64         unsigned int oldumask = umask(0);
  65
  66         mount("proc", "/proc", "proc", MS_NOATIME | MS_NODEV | MS_NOEXEC | MS_NOSUID, 0);
  67         mount("sysfs", "/sys", "sysfs", MS_NOATIME | MS_NODEV | MS_NOEXEC | MS_NOSUID, 0);
  68         mount("cgroup", "/sys/fs/cgroup", "cgroup",  MS_NODEV | MS_NOEXEC | MS_NOSUID, 0);
  69         mount("tmpfs", "/dev", "tmpfs", MS_NOATIME | MS_NOSUID, "mode=0755,size=512K");
  70         ignore(symlink("/tmp/shm", "/dev/shm"));
  71         mkdir("/dev/pts", 0755);
  72         mount("devpts", "/dev/pts", "devpts", MS_NOATIME | MS_NOEXEC | MS_NOSUID, "mode=600");
  73         early_dev();
  74
  75         early_console("/dev/console");
  76         if (mount_zram_on_tmp()) {
  77                 mount("tmpfs", "/tmp", "tmpfs", MS_NOSUID | MS_NODEV | MS_NOATIME, 0);
  78                 mkdir("/tmp/shm", 01777);
  79         } else {
  80                 mkdir("/tmp/shm", 01777);
  81                 mount("tmpfs", "/tmp/shm", "tmpfs", MS_NOSUID | MS_NODEV | MS_NOATIME,
  82                                 "mode=01777");
  83         }
  84         mkdir("/tmp/run", 0777);
  85         mkdir("/tmp/lock", 0777);
  86         mkdir("/tmp/state", 0777);
  87         umask(oldumask);
  88 }
  89
  90 static void
  91 early_env(void)
  92 {
  93         setenv("PATH", "/usr/sbin:/usr/bin:/sbin:/bin", 1);
  94 }
  95
  96 void
  97 early(void)
  98 {
  99         if (getpid() != 1)
 100                 return;
 101
 102         early_mounts();
 103         early_env();
 104
 105         LOG("Console is alive\n");
 106 }