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         mount("proc", "/proc", "proc", MS_NOATIME, 0);
  64         mount("sysfs", "/sys", "sysfs", MS_NOATIME, 0);
  65         mount("none", "/sys/fs/cgroup", "cgroup", 0, 0);
  66         mount("tmpfs", "/dev", "tmpfs", MS_NOATIME, "mode=0755,size=512K");
  67         mkdir("/dev/shm", 0755);
  68         mkdir("/dev/pts", 0755);
  69         mount("devpts", "/dev/pts", "devpts", MS_NOATIME, "mode=600");
  70         early_dev();
  71
  72         early_console("/dev/console");
  73         if (mount_zram_on_tmp())
  74                 mount("tmpfs", "/tmp", "tmpfs", MS_NOSUID | MS_NODEV | MS_NOATIME, NULL);
  75         else
  76                 mkdev("*", 0600);
  77         mkdir("/tmp/run", 0777);
  78         mkdir("/tmp/lock", 0777);
  79         mkdir("/tmp/state", 0777);
  80 }
  81
  82 static void
  83 early_env(void)
  84 {
  85         setenv("PATH", "/bin:/sbin:/usr/bin:/usr/sbin", 1);
  86 }
  87
  88 void
  89 early(void)
  90 {
  91         if (getpid() != 1)
  92                 return;
  93
  94         early_mounts();
  95         early_env();
  96
  97         LOG("Console is alive\n");
  98 }