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
  23 #include "procd.h"
  24
  25 static void early_mounts(void)
  26 {
  27         mount("proc", "/proc", "proc", MS_NOATIME, 0);
  28         mount("sysfs", "/sys", "sysfs", MS_NOATIME, 0);
  29
  30         mount("tmpfs", "/tmp", "tmpfs", MS_NOSUID | MS_NODEV | MS_NOATIME, NULL);
  31         mkdir("/tmp/run", 0777);
  32         mkdir("/tmp/lock", 0777);
  33         mkdir("/tmp/state", 0777);
  34         symlink("/tmp", "/var");
  35
  36         mount("tmpfs", "/dev", "tmpfs", MS_NOATIME, "mode=0755,size=512K");
  37         mkdir("/dev/shm", 0755);
  38         mkdir("/dev/pts", 0755);
  39         mount("devpts", "/dev/pts", "devpts", MS_NOATIME, "mode=600");
  40 }
  41
  42 static void early_dev(void)
  43 {
  44         mkdev("*", 0600);
  45 }
  46
  47 static void early_console(const char *dev)
  48 {
  49         struct stat s;
  50         int dd;
  51
  52         if (stat(dev, &s)) {
  53                 ERROR("Failed to stat %s\n", dev);
  54                 return;
  55         }
  56
  57         dd = open(dev, O_RDWR);
  58         if (dd < 0) {
  59                 ERROR("Failed to open %s\n", dev);
  60                 return;
  61         }
  62
  63         dup2(dd, STDIN_FILENO);
  64         dup2(dd, STDOUT_FILENO);
  65         dup2(dd, STDERR_FILENO);
  66
  67         if (dd != STDIN_FILENO &&
  68             dd != STDOUT_FILENO &&
  69             dd != STDERR_FILENO)
  70                 close(dd);
  71 }
  72
  73 static void early_env(void)
  74 {
  75         setenv("PATH", "/bin:/sbin:/usr/bin:/usr/sbin", 1);
  76 }
  77
  78 void procd_early(void)
  79 {
  80         if (getpid() != 1)
  81                 return;
  82
  83         early_mounts();
  84         early_dev();
  85         early_env();
  86         early_console("/dev/console");
  87
  88         LOG("Console is alive\n");
  89 }