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 "../log.h"
  25 #include "init.h"
  26
  27 static void
  28 early_mounts(void)
  29 {
  30         mount("proc", "/proc", "proc", MS_NOATIME, 0);
  31         mount("sysfs", "/sys", "sysfs", MS_NOATIME, 0);
  32
  33         mount("tmpfs", "/tmp", "tmpfs", MS_NOSUID | MS_NODEV | MS_NOATIME, NULL);
  34         mkdir("/tmp/run", 0777);
  35         mkdir("/tmp/lock", 0777);
  36         mkdir("/tmp/state", 0777);
  37         symlink("/tmp", "/var");
  38
  39         mount("tmpfs", "/dev", "tmpfs", MS_NOATIME, "mode=0755,size=512K");
  40         mkdir("/dev/shm", 0755);
  41         mkdir("/dev/pts", 0755);
  42         mount("devpts", "/dev/pts", "devpts", MS_NOATIME, "mode=600");
  43 }
  44
  45 static void
  46 early_dev(void)
  47 {
  48         mkdev("*", 0600);
  49         mknod("/dev/null", 0666, makedev(1, 3));
  50 }
  51
  52 static void
  53 early_console(const char *dev)
  54 {
  55         struct stat s;
  56         int dd;
  57
  58         if (stat(dev, &s)) {
  59                 ERROR("Failed to stat %s\n", dev);
  60                 return;
  61         }
  62
  63         dd = open(dev, O_RDWR);
  64         if (dd < 0)
  65                 dd = open("/dev/null", O_RDWR);
  66
  67         dup2(dd, STDIN_FILENO);
  68         dup2(dd, STDOUT_FILENO);
  69         dup2(dd, STDERR_FILENO);
  70
  71         if (dd != STDIN_FILENO &&
  72             dd != STDOUT_FILENO &&
  73             dd != STDERR_FILENO)
  74                 close(dd);
  75 }
  76
  77 static void
  78 early_env(void)
  79 {
  80         setenv("PATH", "/bin:/sbin:/usr/bin:/usr/sbin", 1);
  81 }
  82
  83 void
  84 early(void)
  85 {
  86         if (getpid() != 1)
  87                 return;
  88
  89         early_mounts();
  90         early_dev();
  91         early_env();
  92         early_console("/dev/console");
  93
  94         LOG("Console is alive\n");
  95 }