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 <fcntl.h>
  43 #include <fstab.h>
  44 #include <paths.h>
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include <unistd.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()
  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()
 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 || *_fs_fstab.fs_spec == '#')
 154                         continue;
 155                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 156                         ;
 157                 _fs_fstab.fs_file = cp;
 158                 fixfsfile();
 159                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 160                         ;
 161                 _fs_fstab.fs_vfstype = cp;
 162                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 163                         ;
 164                 _fs_fstab.fs_mntops = cp;
 165                 if (_fs_fstab.fs_mntops == NULL)
 166                         goto bad;
 167                 _fs_fstab.fs_freq = 0;
 168                 _fs_fstab.fs_passno = 0;
 169                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 170                         ;
 171                 if (cp != NULL) {
 172                         _fs_fstab.fs_freq = atoi(cp);
 173                         while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 174                                 ;
 175                         if (cp != NULL)
 176                                 _fs_fstab.fs_passno = atoi(cp);
 177                 }
 178                 strcpy(subline, _fs_fstab.fs_mntops);
 179                 p = subline;
 180                 for (typexx = 0, cp = strsep(&p, ","); cp;
 181                      cp = strsep(&p, ",")) {
 182                         if (strlen(cp) != 2)
 183                                 continue;
 184                         if (!strcmp(cp, FSTAB_RW)) {
 185                                 _fs_fstab.fs_type = FSTAB_RW;
 186                                 break;
 187                         }
 188                         if (!strcmp(cp, FSTAB_RQ)) {
 189                                 _fs_fstab.fs_type = FSTAB_RQ;
 190                                 break;
 191                         }
 192                         if (!strcmp(cp, FSTAB_RO)) {
 193                                 _fs_fstab.fs_type = FSTAB_RO;
 194                                 break;
 195                         }
 196                         if (!strcmp(cp, FSTAB_SW)) {
 197                                 _fs_fstab.fs_type = FSTAB_SW;
 198                                 break;
 199                         }
 200                         if (!strcmp(cp, FSTAB_XX)) {
 201                                 _fs_fstab.fs_type = FSTAB_XX;
 202                                 typexx++;
 203                                 break;
 204                         }
 205                 }
 206                 if (typexx)
 207                         continue;
 208                 if (cp != NULL)
 209                         return(1);
 210
 211 bad:            /* no way to distinguish between EOF and syntax error */
 212                 error(EFTYPE);
 213         }
 214         /* NOTREACHED */
 215 }
 216
 217 struct fstab *
 218 getfsent()
 219 {
 220         if ((!_fs_fp && !setfsent()) || !fstabscan())
 221                 return((struct fstab *)NULL);
 222         return(&_fs_fstab);
 223 }
 224
 225 struct fstab *
 226 getfsspec(name)
 227         const char *name;
 228 {
 229         if (setfsent())
 230                 while (fstabscan())
 231                         if (!strcmp(_fs_fstab.fs_spec, name))
 232                                 return(&_fs_fstab);
 233         return((struct fstab *)NULL);
 234 }
 235
 236 struct fstab *
 237 getfsfile(name)
 238         const char *name;
 239 {
 240         if (setfsent())
 241                 while (fstabscan())
 242                         if (!strcmp(_fs_fstab.fs_file, name))
 243                                 return(&_fs_fstab);
 244         return((struct fstab *)NULL);
 245 }
 246
 247 int
 248 setfsent()
 249 {
 250         int fd;
 251
 252         if (_fs_fp) {
 253                 rewind(_fs_fp);
 254                 LineNo = 0;
 255                 return(1);
 256         }
 257         if (fsp_set == 0) {
 258                 if (issetugid())
 259                         setfstab(NULL);
 260                 else
 261                         setfstab(getenv("PATH_FSTAB"));
 262         }
 263         fd = _open(path_fstab, O_RDONLY | O_CLOEXEC);
 264         if (fd == -1) {
 265                 error(errno);
 266                 return (0);
 267         }
 268         _fs_fp = fdopen(fd, "r");
 269         if (_fs_fp  != NULL) {
 270                 LineNo = 0;
 271                 return(1);
 272         }
 273         error(errno);
 274         _close(fd);
 275         return(0);
 276 }
 277
 278 void
 279 endfsent()
 280 {
 281         if (_fs_fp) {
 282                 (void)fclose(_fs_fp);
 283                 _fs_fp = NULL;
 284         }
 285
 286         fsp_set = 0;
 287 }
 288
 289 static void
 290 error(err)
 291         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 }