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 <vis.h>
  50 #include "un-namespace.h"
  51
  52 static FILE *_fs_fp;
  53 static struct fstab _fs_fstab;
  54 static int LineNo = 0;
  55 static char *path_fstab;
  56 static char fstab_path[PATH_MAX];
  57 static int fsp_set = 0;
  58
  59 static void error(int);
  60 static void fixfsfile(void);
  61 static int fstabscan(void);
  62
  63 void
  64 setfstab(const char *file)
  65 {
  66
  67         if (file == NULL) {
  68                 path_fstab = _PATH_FSTAB;
  69         } else {
  70                 strncpy(fstab_path, file, PATH_MAX);
  71                 fstab_path[PATH_MAX - 1] = '\0';
  72                 path_fstab = fstab_path;
  73         }
  74         fsp_set = 1;
  75
  76         return;
  77 }
  78
  79 const char *
  80 getfstab (void)
  81 {
  82
  83         if (fsp_set)
  84                 return (path_fstab);
  85         else
  86                 return (_PATH_FSTAB);
  87 }
  88
  89 static void
  90 fixfsfile()
  91 {
  92         static char buf[sizeof(_PATH_DEV) + MNAMELEN];
  93         struct stat sb;
  94         struct statfs sf;
  95
  96         if (_fs_fstab.fs_file != NULL && strcmp(_fs_fstab.fs_file, "/") != 0)
  97                 return;
  98         if (statfs("/", &sf) != 0)
  99                 return;
 100         if (sf.f_mntfromname[0] == '/')
 101                 buf[0] = '\0';
 102         else
 103                 strcpy(buf, _PATH_DEV);
 104         strcat(buf, sf.f_mntfromname);
 105         if (stat(buf, &sb) != 0 ||
 106             (!S_ISBLK(sb.st_mode) && !S_ISCHR(sb.st_mode)))
 107                 return;
 108         _fs_fstab.fs_spec = buf;
 109 }
 110
 111 static int
 112 fstabscan()
 113 {
 114         char *cp, *p;
 115 #define MAXLINELENGTH   1024
 116         static char line[MAXLINELENGTH];
 117         char subline[MAXLINELENGTH];
 118         int typexx;
 119
 120         for (;;) {
 121
 122                 if (!(p = fgets(line, sizeof(line), _fs_fp)))
 123                         return(0);
 124 /* OLD_STYLE_FSTAB */
 125                 ++LineNo;
 126                 if (*line == '#' || *line == '\n')
 127                         continue;
 128                 if (!strpbrk(p, " \t")) {
 129                         _fs_fstab.fs_spec = strsep(&p, ":\n");
 130                         _fs_fstab.fs_file = strsep(&p, ":\n");
 131                         fixfsfile();
 132                         _fs_fstab.fs_type = strsep(&p, ":\n");
 133                         if (_fs_fstab.fs_type) {
 134                                 if (!strcmp(_fs_fstab.fs_type, FSTAB_XX))
 135                                         continue;
 136                                 _fs_fstab.fs_mntops = _fs_fstab.fs_type;
 137                                 _fs_fstab.fs_vfstype =
 138                                     strcmp(_fs_fstab.fs_type, FSTAB_SW) ?
 139                                     "ufs" : "swap";
 140                                 if ((cp = strsep(&p, ":\n")) != NULL) {
 141                                         _fs_fstab.fs_freq = atoi(cp);
 142                                         if ((cp = strsep(&p, ":\n")) != NULL) {
 143                                                 _fs_fstab.fs_passno = atoi(cp);
 144                                                 return(1);
 145                                         }
 146                                 }
 147                         }
 148                         goto bad;
 149                 }
 150 /* OLD_STYLE_FSTAB */
 151                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 152                         ;
 153                 _fs_fstab.fs_spec = cp;
 154                 if (_fs_fstab.fs_spec == NULL || *_fs_fstab.fs_spec == '#')
 155                         continue;
 156                 if (strunvis(_fs_fstab.fs_spec, _fs_fstab.fs_spec) < 0)
 157                         goto bad;
 158                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 159                         ;
 160                 _fs_fstab.fs_file = cp;
 161                 if (_fs_fstab.fs_file == NULL)
 162                         goto bad;
 163                 if (strunvis(_fs_fstab.fs_file, _fs_fstab.fs_file) < 0)
 164                         goto bad;
 165                 fixfsfile();
 166                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 167                         ;
 168                 _fs_fstab.fs_vfstype = cp;
 169                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 170                         ;
 171                 _fs_fstab.fs_mntops = cp;
 172                 if (_fs_fstab.fs_mntops == NULL)
 173                         goto bad;
 174                 _fs_fstab.fs_freq = 0;
 175                 _fs_fstab.fs_passno = 0;
 176                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 177                         ;
 178                 if (cp != NULL) {
 179                         _fs_fstab.fs_freq = atoi(cp);
 180                         while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 181                                 ;
 182                         if (cp != NULL)
 183                                 _fs_fstab.fs_passno = atoi(cp);
 184                 }
 185                 strcpy(subline, _fs_fstab.fs_mntops);
 186                 p = subline;
 187                 for (typexx = 0, cp = strsep(&p, ","); cp;
 188                      cp = strsep(&p, ",")) {
 189                         if (strlen(cp) != 2)
 190                                 continue;
 191                         if (!strcmp(cp, FSTAB_RW)) {
 192                                 _fs_fstab.fs_type = FSTAB_RW;
 193                                 break;
 194                         }
 195                         if (!strcmp(cp, FSTAB_RQ)) {
 196                                 _fs_fstab.fs_type = FSTAB_RQ;
 197                                 break;
 198                         }
 199                         if (!strcmp(cp, FSTAB_RO)) {
 200                                 _fs_fstab.fs_type = FSTAB_RO;
 201                                 break;
 202                         }
 203                         if (!strcmp(cp, FSTAB_SW)) {
 204                                 _fs_fstab.fs_type = FSTAB_SW;
 205                                 break;
 206                         }
 207                         if (!strcmp(cp, FSTAB_XX)) {
 208                                 _fs_fstab.fs_type = FSTAB_XX;
 209                                 typexx++;
 210                                 break;
 211                         }
 212                 }
 213                 if (typexx)
 214                         continue;
 215                 if (cp != NULL)
 216                         return(1);
 217
 218 bad:            /* no way to distinguish between EOF and syntax error */
 219                 error(EFTYPE);
 220         }
 221         /* NOTREACHED */
 222 }
 223
 224 struct fstab *
 225 getfsent()
 226 {
 227         if ((!_fs_fp && !setfsent()) || !fstabscan())
 228                 return((struct fstab *)NULL);
 229         return(&_fs_fstab);
 230 }
 231
 232 struct fstab *
 233 getfsspec(name)
 234         const char *name;
 235 {
 236         if (setfsent())
 237                 while (fstabscan())
 238                         if (!strcmp(_fs_fstab.fs_spec, name))
 239                                 return(&_fs_fstab);
 240         return((struct fstab *)NULL);
 241 }
 242
 243 struct fstab *
 244 getfsfile(name)
 245         const char *name;
 246 {
 247         if (setfsent())
 248                 while (fstabscan())
 249                         if (!strcmp(_fs_fstab.fs_file, name))
 250                                 return(&_fs_fstab);
 251         return((struct fstab *)NULL);
 252 }
 253
 254 int
 255 setfsent()
 256 {
 257         int fd;
 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         fd = _open(path_fstab, O_RDONLY | O_CLOEXEC);
 271         if (fd == -1) {
 272                 error(errno);
 273                 return (0);
 274         }
 275         _fs_fp = fdopen(fd, "r");
 276         if (_fs_fp  != NULL) {
 277                 LineNo = 0;
 278                 return(1);
 279         }
 280         error(errno);
 281         _close(fd);
 282         return(0);
 283 }
 284
 285 void
 286 endfsent()
 287 {
 288         if (_fs_fp) {
 289                 (void)fclose(_fs_fp);
 290                 _fs_fp = NULL;
 291         }
 292
 293         fsp_set = 0;
 294 }
 295
 296 static void
 297 error(err)
 298         int err;
 299 {
 300         char *p;
 301         char num[30];
 302
 303         (void)_write(STDERR_FILENO, "fstab: ", 7);
 304         (void)_write(STDERR_FILENO, path_fstab, strlen(path_fstab));
 305         (void)_write(STDERR_FILENO, ":", 1);
 306         sprintf(num, "%d: ", LineNo);
 307         (void)_write(STDERR_FILENO, num, strlen(num));
 308         p = strerror(err);
 309         (void)_write(STDERR_FILENO, p, strlen(p));
 310         (void)_write(STDERR_FILENO, "\n", 1);
 311 }