lib/libc/gen/fstab.c

   1 /*      $NetBSD: fstab.c,v 1.27 2005/12/24 21:11:16 perry 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 1.27 2005/12/24 21:11:16 perry 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 int fstabscan __P((void));
  67
  68 static char *nextfld(char **, const char *);
  69 static int fstabscan(void);
  70
  71
  72 static char *
  73 nextfld(char **str, const char *sep)
  74 {
  75         char *ret;
  76
  77         _DIAGASSERT(str != NULL);
  78         _DIAGASSERT(sep != NULL);
  79
  80         while ((ret = stresep(str, sep, '\\')) != NULL && *ret == '\0')
  81                 continue;
  82         return ret;
  83 }
  84
  85
  86 static int
  87 fstabscan(void)
  88 {
  89         char *cp, *lp, *sp;
  90 #define MAXLINELENGTH   1024
  91         static char line[MAXLINELENGTH];
  92         char subline[MAXLINELENGTH];
  93         static const char sep[] = ":\n";
  94         static const char ws[] = " \t\n";
  95         static const char *fstab_type[] = {
  96             FSTAB_RW, FSTAB_RQ, FSTAB_RO, FSTAB_SW, FSTAB_DP, FSTAB_XX, NULL
  97         };
  98
  99         (void)memset(&_fs_fstab, 0, sizeof(_fs_fstab));
 100         for (;;) {
 101                 if (!(lp = fgets(line, sizeof(line), _fs_fp)))
 102                         return 0;
 103                 _fs_lineno++;
 104 /* OLD_STYLE_FSTAB */
 105                 if (!strpbrk(lp, " \t")) {
 106                         _fs_fstab.fs_spec = nextfld(&lp, sep);
 107                         if (!_fs_fstab.fs_spec || *_fs_fstab.fs_spec == '#')
 108                                 continue;
 109                         _fs_fstab.fs_file = nextfld(&lp, sep);
 110                         _fs_fstab.fs_type = nextfld(&lp, sep);
 111                         if (_fs_fstab.fs_type) {
 112                                 if (!strcmp(_fs_fstab.fs_type, FSTAB_XX))
 113                                         continue;
 114                                 _fs_fstab.fs_mntops = _fs_fstab.fs_type;
 115                                 _fs_fstab.fs_vfstype =
 116                                     __UNCONST(
 117                                     strcmp(_fs_fstab.fs_type, FSTAB_SW) ?
 118                                     "ufs" : "swap");
 119                                 if ((cp = nextfld(&lp, sep)) != NULL) {
 120                                         _fs_fstab.fs_freq = atoi(cp);
 121                                         if ((cp = nextfld(&lp, sep)) != NULL) {
 122                                                 _fs_fstab.fs_passno = atoi(cp);
 123                                                 return 1;
 124                                         }
 125                                 }
 126                         }
 127                         goto bad;
 128                 }
 129 /* OLD_STYLE_FSTAB */
 130                 _fs_fstab.fs_spec = nextfld(&lp, ws);
 131                 if (!_fs_fstab.fs_spec || *_fs_fstab.fs_spec == '#')
 132                         continue;
 133                 _fs_fstab.fs_file = nextfld(&lp, ws);
 134                 _fs_fstab.fs_vfstype = nextfld(&lp, ws);
 135                 _fs_fstab.fs_mntops = nextfld(&lp, ws);
 136                 if (_fs_fstab.fs_mntops == NULL)
 137                         goto bad;
 138                 _fs_fstab.fs_freq = 0;
 139                 _fs_fstab.fs_passno = 0;
 140                 if ((cp = nextfld(&lp, ws)) != NULL) {
 141                         _fs_fstab.fs_freq = atoi(cp);
 142                         if ((cp = nextfld(&lp, ws)) != NULL)
 143                                 _fs_fstab.fs_passno = atoi(cp);
 144                 }
 145
 146                 /* subline truncated iff line truncated */
 147                 (void)strlcpy(subline, _fs_fstab.fs_mntops, sizeof(subline));
 148                 sp = subline;
 149
 150                 while ((cp = nextfld(&sp, ",")) != NULL) {
 151                         const char **tp;
 152
 153                         if (strlen(cp) != 2)
 154                                 continue;
 155
 156                         for (tp = fstab_type; *tp; tp++)
 157                                 if (strcmp(cp, *tp) == 0) {
 158                                         _fs_fstab.fs_type = __UNCONST(*tp);
 159                                         break;
 160                                 }
 161                         if (*tp)
 162                                 break;
 163                 }
 164                 if (_fs_fstab.fs_type == NULL)
 165                         goto bad;
 166                 if (strcmp(_fs_fstab.fs_type, FSTAB_XX) == 0)
 167                         continue;
 168                 if (cp != NULL)
 169                         return 1;
 170
 171 bad:
 172                 warnx("%s, %lu: Missing fields", _fs_file, (u_long)_fs_lineno);
 173         }
 174         /* NOTREACHED */
 175 }
 176
 177 struct fstab *
 178 getfsent(void)
 179 {
 180         if ((!_fs_fp && !setfsent()) || !fstabscan())
 181                 return NULL;
 182         return &_fs_fstab;
 183 }
 184
 185 struct fstab *
 186 getfsspec(const char *name)
 187 {
 188
 189         _DIAGASSERT(name != NULL);
 190
 191         if (setfsent())
 192                 while (fstabscan())
 193                         if (!strcmp(_fs_fstab.fs_spec, name))
 194                                 return &_fs_fstab;
 195         return NULL;
 196 }
 197
 198 struct fstab *
 199 getfsfile(const char *name)
 200 {
 201
 202         _DIAGASSERT(name != NULL);
 203
 204         if (setfsent())
 205                 while (fstabscan())
 206                         if (!strcmp(_fs_fstab.fs_file, name))
 207                                 return &_fs_fstab;
 208         return NULL;
 209 }
 210
 211 int
 212 setfsent(void)
 213 {
 214         _fs_lineno = 0;
 215         if (_fs_fp) {
 216                 rewind(_fs_fp);
 217                 return 1;
 218         }
 219         if ((_fs_fp = fopen(_PATH_FSTAB, "r")) == NULL) {
 220                 warn("Cannot open `%s'", _PATH_FSTAB);
 221                 return 0;
 222         }
 223         return 1;
 224 }
 225
 226 void
 227 endfsent(void)
 228 {
 229         if (_fs_fp) {
 230                 (void)fclose(_fs_fp);
 231                 _fs_fp = NULL;
 232         }
 233 }