lib/libc/gen/fstab.c

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