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
  26 static void
  27 early_dev(void)
  28 {
  29         mkdev("*", 0600);
  30         mknod("/dev/null", 0666, makedev(1, 3));
  31 }
  32
  33 static void
  34 early_console(const char *dev)
  35 {
  36         struct stat s;
  37         int dd;
  38
  39         if (stat(dev, &s)) {
  40                 ERROR("Failed to stat %s\n", dev);
  41                 return;
  42         }
  43
  44         dd = open(dev, O_RDWR);
  45         if (dd < 0)
  46                 dd = open("/dev/null", O_RDWR);
  47
  48         dup2(dd, STDIN_FILENO);
  49         dup2(dd, STDOUT_FILENO);
  50         dup2(dd, STDERR_FILENO);
  51
  52         if (dd != STDIN_FILENO &&
  53             dd != STDOUT_FILENO &&
  54             dd != STDERR_FILENO)
  55                 close(dd);
  56
  57         fcntl(STDERR_FILENO, F_SETFL, fcntl(STDERR_FILENO, F_GETFL) | O_NONBLOCK);
  58 }
  59
  60 static void
  61 early_mounts(void)
  62 {
  63         unsigned int oldumask = umask(0);
  64
  65         mount("proc", "/proc", "proc", MS_NOATIME, 0);
  66         mount("sysfs", "/sys", "sysfs", MS_NOATIME, 0);
  67         mount("none", "/sys/fs/cgroup", "cgroup", 0, 0);
  68         mount("tmpfs", "/dev", "tmpfs", MS_NOATIME, "mode=0755,size=512K");
  69         symlink("/tmp/shm", "/dev/shm");
  70         mkdir("/dev/pts", 0755);
  71         mount("devpts", "/dev/pts", "devpts", MS_NOATIME, "mode=600");
  72         early_dev();
  73
  74         early_console("/dev/console");
  75         if (mount_zram_on_tmp()) {
  76                 mount("tmpfs", "/tmp", "tmpfs", MS_NOSUID | MS_NODEV | MS_NOATIME, NULL);
  77                 mkdir("/tmp/shm", 01777);
  78         } else {
  79                 mkdir("/tmp/shm", 01777);
  80                 mount("tmpfs", "/tmp/shm", "tmpfs", MS_NOSUID | MS_NODEV | MS_NOATIME,
  81                                 "mode=01777");
  82         }
  83         mkdir("/tmp/run", 0777);
  84         mkdir("/tmp/lock", 0777);
  85         mkdir("/tmp/state", 0777);
  86         umask(oldumask);
  87 }
  88
  89 static void
  90 early_env(void)
  91 {
  92         setenv("PATH", "/bin:/sbin:/usr/bin:/usr/sbin", 1);
  93 }
  94
  95 void
  96 early(void)
  97 {
  98         if (getpid() != 1)
  99                 return;
 100
 101         early_mounts();
 102         early_env();
 103
 104         LOG("Console is alive\n");
 105 }