share/initrd/mini_init/oinit.c

   1 /*-
   2  * Copyright (c) 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Donn Seeley at Berkeley Software Design, Inc.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * @(#) Copyright (c) 1991, 1993 The Regents of the University of California.  All rights reserved.
  33  * @(#)init.c   8.1 (Berkeley) 7/15/93
  34  * $FreeBSD: src/sbin/init/init.c,v 1.38.2.8 2001/10/22 11:27:32 des Exp $
  35  */
  36
  37 #include <sys/param.h>
  38 #include <sys/ioctl.h>
  39 #include <sys/mount.h>
  40 #include <sys/sysctl.h>
  41 #include <sys/wait.h>
  42 #include <sys/stat.h>
  43
  44 #include <db.h>
  45 #include <errno.h>
  46 #include <fcntl.h>
  47 #include <libutil.h>
  48 #include <paths.h>
  49 #include <signal.h>
  50 #include <stdio.h>
  51 #include <stdlib.h>
  52 #include <string.h>
  53 #include <syslog.h>
  54 #include <time.h>
  55 #include <ttyent.h>
  56 #include <unistd.h>
  57 #include <sys/reboot.h>
  58 #include <err.h>
  59
  60 #include <stdarg.h>
  61
  62 #include "pathnames.h"
  63
  64 static int      setctty(const char *);
  65 static void     runcom(char **);
  66
  67 /*
  68  * The mother of all processes.
  69  */
  70 int
  71 main(int argc __unused, char **argv)
  72 {
  73         /* Dispose of random users. */
  74         if (getuid() != 0)
  75                 errx(1, "%s", strerror(EPERM));
  76
  77         /* Init is not allowed to die, it would make the kernel panic */
  78         signal(SIGTERM, SIG_IGN);
  79
  80         runcom(argv);
  81         return 1;
  82 }
  83
  84 static int
  85 setctty(const char *name)
  86 {
  87         int fd;
  88
  89         revoke(name);
  90         if ((fd = open(name, O_RDWR)) == -1) {
  91                 exit(1);
  92         }
  93
  94         if (login_tty(fd) == -1) {
  95                 exit(1);
  96         }
  97
  98         return fd;
  99 }
 100
 101
 102 static void
 103 runcom(char **argv_orig)
 104 {
 105         pid_t pid, wpid;
 106         int status, fd, error;
 107         const char *argv[4];
 108         struct sigaction sa;
 109
 110         fd = -1;
 111
 112         if ((pid = fork()) == 0) {
 113                 sigemptyset(&sa.sa_mask);
 114                 sa.sa_flags = 0;
 115                 sa.sa_handler = SIG_IGN;
 116                 sigaction(SIGTSTP, &sa, NULL);
 117                 sigaction(SIGHUP, &sa, NULL);
 118
 119                 setctty(_PATH_CONSOLE);
 120
 121                 argv[0] = "sh";
 122                 argv[1] = _PATH_RUNCOM;
 123                 argv[2] = "autoboot" ;
 124                 argv[3] = NULL;
 125
 126                 sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL);
 127
 128                 execv(_PATH_BSHELL, __DECONST(char **, argv));
 129                 exit(1);        /* force single user mode */
 130         }
 131
 132         do {
 133                 wpid = waitpid(-1, &status, WUNTRACED);
 134         } while (wpid != pid);
 135
 136         error = chdir("/new_root");
 137         if (error)
 138                 goto chroot_failed;
 139
 140         error = chroot_kernel("/new_root");
 141         if (error)
 142                 goto chroot_failed;
 143
 144         error = chroot("/new_root");
 145         if (error)
 146                 goto chroot_failed;
 147
 148         execv("/sbin/init", __DECONST(char **, argv_orig));
 149
 150         /* We failed to exec /sbin/init in the chroot, sleep forever */
 151 chroot_failed:
 152         while(1) {
 153                 sleep(3);
 154         };
 155 }
 156