sbin/mount_dirfs/mount_dirfs.c

   1 /*
   2  * Copyright (c) 2013 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Antonio Huete Jimenez <tuxillo@quantumachine.net>
   6  * by Matthew Dillon <dillon@dragonflybsd.org>
   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  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in
  16  *    the documentation and/or other materials provided with the
  17  *    distribution.
  18  * 3. Neither the name of The DragonFly Project nor the names of its
  19  *    contributors may be used to endorse or promote products derived
  20  *    from this software without specific, prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <sys/param.h>
  37 #include <sys/diskslice.h>
  38 #include <sys/diskmbr.h>
  39 #include <sys/stat.h>
  40 #include <sys/mount.h>
  41 #include <sys/sysctl.h>
  42
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <stdarg.h>
  46 #include <stddef.h>
  47 #include <unistd.h>
  48 #include <string.h>
  49 #include <errno.h>
  50 #include <fcntl.h>
  51 #include <uuid.h>
  52 #include <err.h>
  53 #include <assert.h>
  54 #include <ctype.h>
  55 #include <mntopts.h>
  56
  57 #define MOPT_UPDATE         { "update",     0, MNT_UPDATE, 0 }
  58 #define PLATFORM_LEN    16
  59
  60 static struct mntopt mopts[] = { MOPT_STDOPTS, MOPT_UPDATE, MOPT_NULL };
  61
  62 static void usage(void);
  63
  64 int
  65 main(int ac, char **av)
  66 {
  67         struct vfsconf vfc;
  68         int mount_flags = 0;
  69         int error;
  70         int ch;
  71         int init_flags = 0;
  72         char *mountpt, *hostdir;
  73         size_t vsize;
  74         char platform[PLATFORM_LEN] = {0};
  75
  76         mount_flags = 0;
  77
  78         while ((ch = getopt(ac, av, "o:u")) != -1) {
  79                 switch(ch) {
  80                 case 'u':
  81                         init_flags |= MNT_UPDATE;
  82                         break;
  83
  84                 case 'o':
  85                         getmntopts(optarg, mopts, &mount_flags, NULL);
  86                         break;
  87                 default:
  88                         usage();
  89                         /* not reached */
  90                 }
  91         }
  92         ac -= optind;
  93         av += optind;
  94         mount_flags |= init_flags;
  95
  96         /*
  97          * Check we're in a vkernel or abort.
  98          */
  99         vsize = PLATFORM_LEN;
 100         error = sysctlbyname("hw.platform", &platform, &vsize, NULL,0);
 101         if (error)
 102                 errx(1, "Failed to get hw.platform sysctl");
 103
 104         if (strnstr(platform, "vkernel", PLATFORM_LEN) == NULL)
 105                 errx(1, "dirfs is only available for vkernels.");
 106
 107         /*
 108          * Only the mount point need be specified in update mode.
 109          */
 110         if (init_flags & MNT_UPDATE) {
 111                 if (ac != 1) {
 112                         usage();
 113                         /* not reached */
 114                 }
 115                 mountpt = av[0];
 116                 if (mount(vfc.vfc_name, mountpt, mount_flags, NULL))
 117                         err(1, "mountpoint %s", mountpt);
 118                 exit(0);
 119         }
 120
 121         if (ac < 2) {
 122                 usage();
 123                 /* not reached */
 124         }
 125
 126         hostdir = av[0];
 127         mountpt = av[1];
 128
 129         /*
 130          * Load the dirfs module if necessary (this bit stolen from
 131          * mount_null).
 132          */
 133         error = getvfsbyname("dirfs", &vfc);
 134         if (error && vfsisloadable("dirfs")) {
 135                 if (vfsload("dirfs") != 0)
 136                         err(1, "vfsload(dirfs)");
 137                 endvfsent();
 138                 error = getvfsbyname("dirfs", &vfc);
 139         }
 140         if (error)
 141                 errx(1, "dirfs filesystem is not available");
 142
 143         error = mount(vfc.vfc_name, mountpt, mount_flags, hostdir);
 144         if (error)
 145                 err(1, "failed to mount %s on %s", hostdir, mountpt);
 146
 147         exit (0);
 148 }
 149
 150 static
 151 void
 152 usage(void)
 153 {
 154         fprintf(stderr, "usage: mount_dirfs [-u] [-o options] "
 155                         "hostdir dir\n");
 156         exit(1);
 157 }