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/types.h>
  37 #include <sys/diskslice.h>
  38 #include <sys/diskmbr.h>
  39 #include <sys/stat.h>
  40 #include <sys/time.h>
  41 #include <sys/syslimits.h>
  42 #include <sys/mount.h>
  43 #include <sys/sysctl.h>
  44
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include <stdarg.h>
  48 #include <stddef.h>
  49 #include <unistd.h>
  50 #include <string.h>
  51 #include <errno.h>
  52 #include <fcntl.h>
  53 #include <uuid.h>
  54 #include <err.h>
  55 #include <assert.h>
  56 #include <ctype.h>
  57 #include <mntopts.h>
  58
  59 #define MOPT_UPDATE         { "update",     0, MNT_UPDATE, 0 }
  60 #define PLATFORM_LEN    16
  61
  62 static struct mntopt mopts[] = { MOPT_STDOPTS, MOPT_UPDATE, MOPT_NULL };
  63
  64 static void usage(void);
  65
  66 int
  67 main(int ac, char **av)
  68 {
  69         struct vfsconf vfc;
  70         int mount_flags = 0;
  71         int error;
  72         int ch;
  73         int init_flags = 0;
  74         char *mountpt, *hostdir;
  75         size_t vsize;
  76         char platform[PLATFORM_LEN] = {0};
  77
  78         mount_flags = 0;
  79
  80         while ((ch = getopt(ac, av, "o:u")) != -1) {
  81                 switch(ch) {
  82                 case 'u':
  83                         init_flags |= MNT_UPDATE;
  84                         break;
  85
  86                 case 'o':
  87                         getmntopts(optarg, mopts, &mount_flags, NULL);
  88                         break;
  89                 default:
  90                         usage();
  91                         /* not reached */
  92                 }
  93         }
  94         ac -= optind;
  95         av += optind;
  96         mount_flags |= init_flags;
  97
  98         /*
  99          * Check we're in a vkernel or abort.
 100          */
 101         vsize = PLATFORM_LEN;
 102         error = sysctlbyname("hw.platform", &platform, &vsize, NULL,0);
 103         if (error)
 104                 errx(1, "Failed to get hw.platform sysctl");
 105
 106         if (strnstr(platform, "vkernel", PLATFORM_LEN) == NULL)
 107                 errx(1, "dirfs is only available for vkernels.");
 108
 109         /*
 110          * Only the mount point need be specified in update mode.
 111          */
 112         if (init_flags & MNT_UPDATE) {
 113                 if (ac != 1) {
 114                         usage();
 115                         /* not reached */
 116                 }
 117                 mountpt = av[0];
 118                 if (mount(vfc.vfc_name, mountpt, mount_flags, NULL))
 119                         err(1, "mountpoint %s", mountpt);
 120                 exit(0);
 121         }
 122
 123         if (ac < 2) {
 124                 usage();
 125                 /* not reached */
 126         }
 127
 128         hostdir = av[0];
 129         mountpt = av[1];
 130
 131         /*
 132          * Load the dirfs module if necessary (this bit stolen from
 133          * mount_null).
 134          */
 135         error = getvfsbyname("dirfs", &vfc);
 136         if (error && vfsisloadable("dirfs")) {
 137                 if (vfsload("dirfs") != 0)
 138                         err(1, "vfsload(dirfs)");
 139                 endvfsent();
 140                 error = getvfsbyname("dirfs", &vfc);
 141         }
 142         if (error)
 143                 errx(1, "dirfs filesystem is not available");
 144
 145         error = mount(vfc.vfc_name, mountpt, mount_flags, hostdir);
 146         if (error)
 147                 err(1, "failed to mount %s on %s", hostdir, mountpt);
 148
 149         exit (0);
 150 }
 151
 152 static
 153 void
 154 usage(void)
 155 {
 156         fprintf(stderr, "usage: mount_dirfs [-u] [-o options] "
 157                         "hostdir dir\n");
 158         exit(1);
 159 }