lib/libc/gen/fstab.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 1980, 1988, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #if defined(LIBC_SCCS) && !defined(lint)
  33 static char sccsid[] = "@(#)fstab.c     8.1 (Berkeley) 6/4/93";
  34 #endif /* LIBC_SCCS and not lint */
  35 #include <sys/cdefs.h>
  36 __FBSDID("$FreeBSD$");
  37
  38 #include "namespace.h"
  39 #include <sys/param.h>
  40 #include <sys/mount.h>
  41 #include <sys/stat.h>
  42
  43 #include <errno.h>
  44 #include <fstab.h>
  45 #include <paths.h>
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <unistd.h>
  50 #include <vis.h>
  51 #include "un-namespace.h"
  52
  53 static FILE *_fs_fp;
  54 static struct fstab _fs_fstab;
  55 static int LineNo = 0;
  56 static char *path_fstab;
  57 static char fstab_path[PATH_MAX];
  58 static int fsp_set = 0;
  59
  60 static void error(int);
  61 static void fixfsfile(void);
  62 static int fstabscan(void);
  63
  64 void
  65 setfstab(const char *file)
  66 {
  67
  68         if (file == NULL) {
  69                 path_fstab = _PATH_FSTAB;
  70         } else {
  71                 strncpy(fstab_path, file, PATH_MAX);
  72                 fstab_path[PATH_MAX - 1] = '\0';
  73                 path_fstab = fstab_path;
  74         }
  75         fsp_set = 1;
  76
  77         return;
  78 }
  79
  80 const char *
  81 getfstab(void)
  82 {
  83
  84         if (fsp_set)
  85                 return (path_fstab);
  86         else
  87                 return (_PATH_FSTAB);
  88 }
  89
  90 static void
  91 fixfsfile(void)
  92 {
  93         static char buf[sizeof(_PATH_DEV) + MNAMELEN];
  94         struct stat sb;
  95         struct statfs sf;
  96
  97         if (_fs_fstab.fs_file != NULL && strcmp(_fs_fstab.fs_file, "/") != 0)
  98                 return;
  99         if (statfs("/", &sf) != 0)
 100                 return;
 101         if (sf.f_mntfromname[0] == '/')
 102                 buf[0] = '\0';
 103         else
 104                 strcpy(buf, _PATH_DEV);
 105         strcat(buf, sf.f_mntfromname);
 106         if (stat(buf, &sb) != 0 ||
 107             (!S_ISBLK(sb.st_mode) && !S_ISCHR(sb.st_mode)))
 108                 return;
 109         _fs_fstab.fs_spec = buf;
 110 }
 111
 112 static int
 113 fstabscan(void)
 114 {
 115         char *cp, *p;
 116 #define MAXLINELENGTH   1024
 117         static char line[MAXLINELENGTH];
 118         char subline[MAXLINELENGTH];
 119         int typexx;
 120
 121         for (;;) {
 122
 123                 if (!(p = fgets(line, sizeof(line), _fs_fp)))
 124                         return (0);
 125 /* OLD_STYLE_FSTAB */
 126                 ++LineNo;
 127                 if (*line == '#' || *line == '\n')
 128                         continue;
 129                 if (!strpbrk(p, " \t")) {
 130                         _fs_fstab.fs_spec = strsep(&p, ":\n");
 131                         _fs_fstab.fs_file = strsep(&p, ":\n");
 132                         fixfsfile();
 133                         _fs_fstab.fs_type = strsep(&p, ":\n");
 134                         if (_fs_fstab.fs_type) {
 135                                 if (!strcmp(_fs_fstab.fs_type, FSTAB_XX))
 136                                         continue;
 137                                 _fs_fstab.fs_mntops = _fs_fstab.fs_type;
 138                                 _fs_fstab.fs_vfstype =
 139                                     strcmp(_fs_fstab.fs_type, FSTAB_SW) ?
 140                                     "ufs" : "swap";
 141                                 if ((cp = strsep(&p, ":\n")) != NULL) {
 142                                         _fs_fstab.fs_freq = atoi(cp);
 143                                         if ((cp = strsep(&p, ":\n")) != NULL) {
 144                                                 _fs_fstab.fs_passno = atoi(cp);
 145                                                 return (1);
 146                                         }
 147                                 }
 148                         }
 149                         goto bad;
 150                 }
 151 /* OLD_STYLE_FSTAB */
 152                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 153                         ;
 154                 _fs_fstab.fs_spec = cp;
 155                 if (_fs_fstab.fs_spec == NULL || *_fs_fstab.fs_spec == '#')
 156                         continue;
 157                 if (strunvis(_fs_fstab.fs_spec, _fs_fstab.fs_spec) < 0)
 158                         goto bad;
 159                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 160                         ;
 161                 _fs_fstab.fs_file = cp;
 162                 if (_fs_fstab.fs_file == NULL)
 163                         goto bad;
 164                 if (strunvis(_fs_fstab.fs_file, _fs_fstab.fs_file) < 0)
 165                         goto bad;
 166                 fixfsfile();
 167                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 168                         ;
 169                 _fs_fstab.fs_vfstype = cp;
 170                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 171                         ;
 172                 _fs_fstab.fs_mntops = cp;
 173                 if (_fs_fstab.fs_mntops == NULL)
 174                         goto bad;
 175                 _fs_fstab.fs_freq = 0;
 176                 _fs_fstab.fs_passno = 0;
 177                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 178                         ;
 179                 if (cp != NULL) {
 180                         _fs_fstab.fs_freq = atoi(cp);
 181                         while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 182                                 ;
 183                         if (cp != NULL)
 184                                 _fs_fstab.fs_passno = atoi(cp);
 185                 }
 186                 (void)strlcpy(subline, _fs_fstab.fs_mntops, sizeof(subline));
 187                 p = subline;
 188                 for (typexx = 0, cp = strsep(&p, ","); cp;
 189                      cp = strsep(&p, ",")) {
 190                         if (strlen(cp) != 2)
 191                                 continue;
 192                         if (!strcmp(cp, FSTAB_RW)) {
 193                                 _fs_fstab.fs_type = FSTAB_RW;
 194                                 break;
 195                         }
 196                         if (!strcmp(cp, FSTAB_RQ)) {
 197                                 _fs_fstab.fs_type = FSTAB_RQ;
 198                                 break;
 199                         }
 200                         if (!strcmp(cp, FSTAB_RO)) {
 201                                 _fs_fstab.fs_type = FSTAB_RO;
 202                                 break;
 203                         }
 204                         if (!strcmp(cp, FSTAB_SW)) {
 205                                 _fs_fstab.fs_type = FSTAB_SW;
 206                                 break;
 207                         }
 208                         if (!strcmp(cp, FSTAB_XX)) {
 209                                 _fs_fstab.fs_type = FSTAB_XX;
 210                                 typexx++;
 211                                 break;
 212                         }
 213                 }
 214                 if (typexx)
 215                         continue;
 216                 if (cp != NULL)
 217                         return (1);
 218
 219 bad:            /* no way to distinguish between EOF and syntax error */
 220                 error(EFTYPE);
 221         }
 222         /* NOTREACHED */
 223 }
 224
 225 struct fstab *
 226 getfsent(void)
 227 {
 228
 229         if ((!_fs_fp && !setfsent()) || !fstabscan())
 230                 return (NULL);
 231         return (&_fs_fstab);
 232 }
 233
 234 struct fstab *
 235 getfsspec(const char *name)
 236 {
 237
 238         if (setfsent())
 239                 while (fstabscan())
 240                         if (!strcmp(_fs_fstab.fs_spec, name))
 241                                 return (&_fs_fstab);
 242         return (NULL);
 243 }
 244
 245 struct fstab *
 246 getfsfile(const char *name)
 247 {
 248
 249         if (setfsent())
 250                 while (fstabscan())
 251                         if (!strcmp(_fs_fstab.fs_file, name))
 252                                 return (&_fs_fstab);
 253         return (NULL);
 254 }
 255
 256 int
 257 setfsent(void)
 258 {
 259         if (_fs_fp) {
 260                 rewind(_fs_fp);
 261                 LineNo = 0;
 262                 return (1);
 263         }
 264         if (fsp_set == 0) {
 265                 if (issetugid())
 266                         setfstab(NULL);
 267                 else
 268                         setfstab(getenv("PATH_FSTAB"));
 269         }
 270         if ((_fs_fp = fopen(path_fstab, "re")) != NULL) {
 271                 LineNo = 0;
 272                 return (1);
 273         }
 274         error(errno);
 275         return (0);
 276 }
 277
 278 void
 279 endfsent(void)
 280 {
 281
 282         if (_fs_fp) {
 283                 (void)fclose(_fs_fp);
 284                 _fs_fp = NULL;
 285         }
 286
 287         fsp_set = 0;
 288 }
 289
 290 static void
 291 error(int err)
 292 {
 293         char *p;
 294         char num[30];
 295
 296         (void)_write(STDERR_FILENO, "fstab: ", 7);
 297         (void)_write(STDERR_FILENO, path_fstab, strlen(path_fstab));
 298         (void)_write(STDERR_FILENO, ":", 1);
 299         sprintf(num, "%d: ", LineNo);
 300         (void)_write(STDERR_FILENO, num, strlen(num));
 301         p = strerror(err);
 302         (void)_write(STDERR_FILENO, p, strlen(p));
 303         (void)_write(STDERR_FILENO, "\n", 1);
 304 }