lib/libc/gen/fstab.c

   1 /*      $NetBSD: fstab.c,v 1.31 2012/03/13 21:13:34 christos Exp $      */
   2
   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 #include <sys/cdefs.h>
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 #if 0
  35 static char sccsid[] = "@(#)fstab.c     8.1 (Berkeley) 6/4/93";
  36 #else
  37 __RCSID("$NetBSD: fstab.c,v 1.31 2012/03/13 21:13:34 christos Exp $");
  38 #endif
  39 #endif /* LIBC_SCCS and not lint */
  40
  41 #include "namespace.h"
  42 #include <sys/types.h>
  43
  44 #include <assert.h>
  45 #include <err.h>
  46 #include <errno.h>
  47 #include <fstab.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <unistd.h>
  52
  53 #ifdef __weak_alias
  54 __weak_alias(endfsent,_endfsent)
  55 __weak_alias(getfsent,_getfsent)
  56 __weak_alias(getfsfile,_getfsfile)
  57 __weak_alias(getfsspec,_getfsspec)
  58 __weak_alias(setfsent,_setfsent)
  59 #endif
  60
  61 static FILE *_fs_fp;
  62 static size_t _fs_lineno = 0;
  63 static const char *_fs_file = _PATH_FSTAB;
  64 static struct fstab _fs_fstab;
  65
  66 static char *nextfld(char **, const char *);
  67 static int fstabscan(void);
  68
  69
  70 static char *
  71 nextfld(char **str, const char *sep)
  72 {
  73         char *ret;
  74
  75         _DIAGASSERT(str != NULL);
  76         _DIAGASSERT(sep != NULL);
  77
  78         while ((ret = stresep(str, sep, '\\')) != NULL && *ret == '\0')
  79                 continue;
  80         return ret;
  81 }
  82
  83
  84 static int
  85 fstabscan(void)
  86 {
  87         char *cp, *lp, *sp;
  88 #define MAXLINELENGTH   1024
  89         static char line[MAXLINELENGTH];
  90         char subline[MAXLINELENGTH];
  91         static const char sep[] = ":\n";
  92         static const char ws[] = " \t\n";
  93         static const char *fstab_type[] = {
  94             FSTAB_RW, FSTAB_RQ, FSTAB_RO, FSTAB_SW, FSTAB_DP, FSTAB_XX, NULL
  95         };
  96
  97         (void)memset(&_fs_fstab, 0, sizeof(_fs_fstab));
  98         for (;;) {
  99                 if (!(lp = fgets(line, (int)sizeof(line), _fs_fp)))
 100                         return 0;
 101                 _fs_lineno++;
 102 /* OLD_STYLE_FSTAB */
 103                 if (!strpbrk(lp, " \t")) {
 104                         _fs_fstab.fs_spec = nextfld(&lp, sep);
 105                         if (!_fs_fstab.fs_spec || *_fs_fstab.fs_spec == '#')
 106                                 continue;
 107                         _fs_fstab.fs_file = nextfld(&lp, sep);
 108                         _fs_fstab.fs_type = nextfld(&lp, sep);
 109                         if (_fs_fstab.fs_type) {
 110                                 if (!strcmp(_fs_fstab.fs_type, FSTAB_XX))
 111                                         continue;
 112                                 _fs_fstab.fs_mntops = _fs_fstab.fs_type;
 113                                 _fs_fstab.fs_vfstype =
 114                                     __UNCONST(
 115                                     strcmp(_fs_fstab.fs_type, FSTAB_SW) ?
 116                                     "ufs" : "swap");
 117                                 if ((cp = nextfld(&lp, sep)) != NULL) {
 118                                         _fs_fstab.fs_freq = atoi(cp);
 119                                         if ((cp = nextfld(&lp, sep)) != NULL) {
 120                                                 _fs_fstab.fs_passno = atoi(cp);
 121                                                 return 1;
 122                                         }
 123                                 }
 124                         }
 125                         goto bad;
 126                 }
 127 /* OLD_STYLE_FSTAB */
 128                 _fs_fstab.fs_spec = nextfld(&lp, ws);
 129                 if (!_fs_fstab.fs_spec || *_fs_fstab.fs_spec == '#')
 130                         continue;
 131                 _fs_fstab.fs_file = nextfld(&lp, ws);
 132                 _fs_fstab.fs_vfstype = nextfld(&lp, ws);
 133                 _fs_fstab.fs_mntops = nextfld(&lp, ws);
 134                 if (_fs_fstab.fs_mntops == NULL)
 135                         goto bad;
 136                 _fs_fstab.fs_freq = 0;
 137                 _fs_fstab.fs_passno = 0;
 138                 if ((cp = nextfld(&lp, ws)) != NULL) {
 139                         _fs_fstab.fs_freq = atoi(cp);
 140                         if ((cp = nextfld(&lp, ws)) != NULL)
 141                                 _fs_fstab.fs_passno = atoi(cp);
 142                 }
 143
 144                 /* subline truncated iff line truncated */
 145                 (void)strlcpy(subline, _fs_fstab.fs_mntops, sizeof(subline));
 146                 sp = subline;
 147
 148                 while ((cp = nextfld(&sp, ",")) != NULL) {
 149                         const char **tp;
 150
 151                         if (strlen(cp) != 2)
 152                                 continue;
 153
 154                         for (tp = fstab_type; *tp; tp++)
 155                                 if (strcmp(cp, *tp) == 0) {
 156                                         _fs_fstab.fs_type = __UNCONST(*tp);
 157                                         break;
 158                                 }
 159                         if (*tp)
 160                                 break;
 161                 }
 162                 if (_fs_fstab.fs_type == NULL)
 163                         goto bad;
 164                 if (strcmp(_fs_fstab.fs_type, FSTAB_XX) == 0)
 165                         continue;
 166                 if (cp != NULL)
 167                         return 1;
 168
 169 bad:
 170                 warnx("%s, %lu: Missing fields", _fs_file, (u_long)_fs_lineno);
 171         }
 172         /* NOTREACHED */
 173 }
 174
 175 struct fstab *
 176 getfsent(void)
 177 {
 178         if ((!_fs_fp && !setfsent()) || !fstabscan())
 179                 return NULL;
 180         return &_fs_fstab;
 181 }
 182
 183 struct fstab *
 184 getfsspec(const char *name)
 185 {
 186
 187         _DIAGASSERT(name != NULL);
 188
 189         if (setfsent())
 190                 while (fstabscan())
 191                         if (!strcmp(_fs_fstab.fs_spec, name))
 192                                 return &_fs_fstab;
 193         return NULL;
 194 }
 195
 196 struct fstab *
 197 getfsfile(const char *name)
 198 {
 199
 200         _DIAGASSERT(name != NULL);
 201
 202         if (setfsent())
 203                 while (fstabscan())
 204                         if (!strcmp(_fs_fstab.fs_file, name))
 205                                 return &_fs_fstab;
 206         return NULL;
 207 }
 208
 209 int
 210 setfsent(void)
 211 {
 212         _fs_lineno = 0;
 213         if (_fs_fp) {
 214                 rewind(_fs_fp);
 215                 return 1;
 216         }
 217         if ((_fs_fp = fopen(_PATH_FSTAB, "re")) == NULL) {
 218                 warn("Cannot open `%s'", _PATH_FSTAB);
 219                 return 0;
 220         }
 221         return 1;
 222 }
 223
 224 void
 225 endfsent(void)
 226 {
 227         if (_fs_fp) {
 228                 (void)fclose(_fs_fp);
 229                 _fs_fp = NULL;
 230         }
 231 }