usr.sbin/fstyp/fstyp.c

   1 /*-
   2  * Copyright (c) 2014 The FreeBSD Foundation
   3  * All rights reserved.
   4  *
   5  * This software was developed by Edward Tomasz Napierala under sponsorship
   6  * from the FreeBSD Foundation.
   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  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  */
  30
  31 #include <sys/cdefs.h>
  32 __FBSDID("$FreeBSD$");
  33
  34 #include <sys/capsicum.h>
  35 #include <sys/disk.h>
  36 #include <sys/ioctl.h>
  37 #include <sys/stat.h>
  38 #include <err.h>
  39 #include <errno.h>
  40 #include <stdbool.h>
  41 #include <stddef.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45 #include <unistd.h>
  46 #include <vis.h>
  47
  48 #include "fstyp.h"
  49
  50 #define LABEL_LEN       256
  51
  52 typedef int (*fstyp_function)(FILE *, char *, size_t);
  53
  54 static struct {
  55         const char      *name;
  56         fstyp_function  function;
  57         bool            unmountable;
  58 } fstypes[] = {
  59         { "cd9660", &fstyp_cd9660, false },
  60         { "ext2fs", &fstyp_ext2fs, false },
  61         { "geli", &fstyp_geli, true },
  62         { "msdosfs", &fstyp_msdosfs, false },
  63         { "ntfs", &fstyp_ntfs, false },
  64         { "ufs", &fstyp_ufs, false },
  65 #ifdef HAVE_ZFS
  66         { "zfs", &fstyp_zfs, true },
  67 #endif
  68         { NULL, NULL, NULL }
  69 };
  70
  71 void *
  72 read_buf(FILE *fp, off_t off, size_t len)
  73 {
  74         int error;
  75         size_t nread;
  76         void *buf;
  77
  78         error = fseek(fp, off, SEEK_SET);
  79         if (error != 0) {
  80                 warn("cannot seek to %jd", (uintmax_t)off);
  81                 return (NULL);
  82         }
  83
  84         buf = malloc(len);
  85         if (buf == NULL) {
  86                 warn("cannot malloc %zd bytes of memory", len);
  87                 return (NULL);
  88         }
  89
  90         nread = fread(buf, len, 1, fp);
  91         if (nread != 1) {
  92                 free(buf);
  93                 if (feof(fp) == 0)
  94                         warn("fread");
  95                 return (NULL);
  96         }
  97
  98         return (buf);
  99 }
 100
 101 char *
 102 checked_strdup(const char *s)
 103 {
 104         char *c;
 105
 106         c = strdup(s);
 107         if (c == NULL)
 108                 err(1, "strdup");
 109         return (c);
 110 }
 111
 112 void
 113 rtrim(char *label, size_t size)
 114 {
 115         ptrdiff_t i;
 116
 117         for (i = size - 1; i >= 0; i--) {
 118                 if (label[i] == '\0')
 119                         continue;
 120                 else if (label[i] == ' ')
 121                         label[i] = '\0';
 122                 else
 123                         break;
 124         }
 125 }
 126
 127 static void
 128 usage(void)
 129 {
 130
 131         fprintf(stderr, "usage: fstyp [-l] [-s] [-u] special\n");
 132         exit(1);
 133 }
 134
 135 static void
 136 type_check(const char *path, FILE *fp)
 137 {
 138         int error, fd;
 139         off_t mediasize;
 140         struct stat sb;
 141
 142         fd = fileno(fp);
 143
 144         error = fstat(fd, &sb);
 145         if (error != 0)
 146                 err(1, "%s: fstat", path);
 147
 148         if (S_ISREG(sb.st_mode))
 149                 return;
 150
 151         error = ioctl(fd, DIOCGMEDIASIZE, &mediasize);
 152         if (error != 0)
 153                 errx(1, "%s: not a disk", path);
 154 }
 155
 156 int
 157 main(int argc, char **argv)
 158 {
 159         int ch, error, i, nbytes;
 160         bool ignore_type = false, show_label = false, show_unmountable = false;
 161         char label[LABEL_LEN + 1], strvised[LABEL_LEN * 4 + 1];
 162         char *path;
 163         FILE *fp;
 164         fstyp_function fstyp_f;
 165
 166         while ((ch = getopt(argc, argv, "lsu")) != -1) {
 167                 switch (ch) {
 168                 case 'l':
 169                         show_label = true;
 170                         break;
 171                 case 's':
 172                         ignore_type = true;
 173                         break;
 174                 case 'u':
 175                         show_unmountable = true;
 176                         break;
 177                 default:
 178                         usage();
 179                 }
 180         }
 181
 182         argc -= optind;
 183         argv += optind;
 184         if (argc != 1)
 185                 usage();
 186
 187         path = argv[0];
 188
 189         fp = fopen(path, "r");
 190         if (fp == NULL)
 191                 err(1, "%s", path);
 192
 193         error = cap_enter();
 194         if (error != 0 && errno != ENOSYS)
 195                 err(1, "cap_enter");
 196
 197         if (ignore_type == false)
 198                 type_check(path, fp);
 199
 200         memset(label, '\0', sizeof(label));
 201
 202         for (i = 0;; i++) {
 203                 if (show_unmountable == false && fstypes[i].unmountable == true)
 204                         continue;
 205                 fstyp_f = fstypes[i].function;
 206                 if (fstyp_f == NULL)
 207                         break;
 208
 209                 error = fstyp_f(fp, label, sizeof(label));
 210                 if (error == 0)
 211                         break;
 212         }
 213
 214         if (fstypes[i].name == NULL) {
 215                 warnx("%s: filesystem not recognized", path);
 216                 return (1);
 217         }
 218
 219         if (show_label && label[0] != '\0') {
 220                 /*
 221                  * XXX: I'd prefer VIS_HTTPSTYLE, but it unconditionally
 222                  *      encodes spaces.
 223                  */
 224                 nbytes = strsnvis(strvised, sizeof(strvised), label,
 225                     VIS_GLOB | VIS_NL, "\"'$");
 226                 if (nbytes == -1)
 227                         err(1, "strsnvis");
 228
 229                 printf("%s %s\n", fstypes[i].name, strvised);
 230         } else {
 231                 printf("%s\n", fstypes[i].name);
 232         }
 233
 234         return (0);
 235 }