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  * @(#)fstab.c  8.1 (Berkeley) 6/4/93
  30  * $FreeBSD: src/lib/libc/gen/fstab.c,v 1.15 2007/01/09 00:27:53 imp Exp $
  31  * $DragonFly: src/lib/libc/gen/fstab.c,v 1.6 2005/11/13 00:07:42 swildner Exp $
  32  */
  33
  34 #include "namespace.h"
  35 #include <sys/param.h>
  36 #include <sys/mount.h>
  37 #include <sys/stat.h>
  38
  39 #include <errno.h>
  40 #include <fstab.h>
  41 #include <paths.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45 #include <unistd.h>
  46 #include "un-namespace.h"
  47
  48 static FILE *_fs_fp;
  49 static struct fstab _fs_fstab;
  50 static int LineNo = 0;
  51 static char *path_fstab;
  52 static char fstab_path[PATH_MAX];
  53 static int fsp_set = 0;
  54
  55 static void error(int);
  56 static void fixfsfile(void);
  57 static int fstabscan(void);
  58
  59 void
  60 setfstab(const char *file)
  61 {
  62
  63         if (file == NULL) {
  64                 path_fstab = _PATH_FSTAB;
  65         } else {
  66                 strncpy(fstab_path, file, PATH_MAX);
  67                 fstab_path[PATH_MAX - 1] = '\0';
  68                 path_fstab = fstab_path;
  69         }
  70         fsp_set = 1;
  71 }
  72
  73 const char *
  74 getfstab(void)
  75 {
  76
  77         if (fsp_set)
  78                 return (path_fstab);
  79         else
  80                 return (_PATH_FSTAB);
  81 }
  82
  83 static void
  84 fixfsfile(void)
  85 {
  86         static char buf[sizeof(_PATH_DEV) + MNAMELEN];
  87         struct stat sb;
  88         struct statfs sf;
  89
  90         if (strcmp(_fs_fstab.fs_file, "/") != 0)
  91                 return;
  92         if (statfs("/", &sf) != 0)
  93                 return;
  94         if (sf.f_mntfromname[0] == '/')
  95                 buf[0] = '\0';
  96         else
  97                 strcpy(buf, _PATH_DEV);
  98         strcat(buf, sf.f_mntfromname);
  99         if (stat(buf, &sb) != 0 ||
 100             (!S_ISBLK(sb.st_mode) && !S_ISCHR(sb.st_mode)))
 101                 return;
 102         _fs_fstab.fs_spec = buf;
 103 }
 104
 105 static int
 106 fstabscan(void)
 107 {
 108         char *cp, *p;
 109 #define MAXLINELENGTH   1024
 110         static char line[MAXLINELENGTH];
 111         char subline[MAXLINELENGTH];
 112         int typexx;
 113
 114         for (;;) {
 115
 116                 if (!(p = fgets(line, sizeof(line), _fs_fp)))
 117                         return(0);
 118 /* OLD_STYLE_FSTAB */
 119                 ++LineNo;
 120                 if (*line == '#' || *line == '\n')
 121                         continue;
 122                 if (!strpbrk(p, " \t")) {
 123                         _fs_fstab.fs_spec = strsep(&p, ":\n");
 124                         _fs_fstab.fs_file = strsep(&p, ":\n");
 125                         fixfsfile();
 126                         _fs_fstab.fs_type = strsep(&p, ":\n");
 127                         if (_fs_fstab.fs_type) {
 128                                 if (!strcmp(_fs_fstab.fs_type, FSTAB_XX))
 129                                         continue;
 130                                 _fs_fstab.fs_mntops = _fs_fstab.fs_type;
 131                                 _fs_fstab.fs_vfstype =
 132                                     strcmp(_fs_fstab.fs_type, FSTAB_SW) ?
 133                                     "ufs" : "swap";
 134                                 if ((cp = strsep(&p, ":\n")) != NULL) {
 135                                         _fs_fstab.fs_freq = atoi(cp);
 136                                         if ((cp = strsep(&p, ":\n")) != NULL) {
 137                                                 _fs_fstab.fs_passno = atoi(cp);
 138                                                 return(1);
 139                                         }
 140                                 }
 141                         }
 142                         goto bad;
 143                 }
 144 /* OLD_STYLE_FSTAB */
 145                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 146                         ;
 147                 _fs_fstab.fs_spec = cp;
 148                 if (!_fs_fstab.fs_spec || *_fs_fstab.fs_spec == '#')
 149                         continue;
 150                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 151                         ;
 152                 _fs_fstab.fs_file = cp;
 153                 fixfsfile();
 154                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 155                         ;
 156                 _fs_fstab.fs_vfstype = cp;
 157                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 158                         ;
 159                 _fs_fstab.fs_mntops = cp;
 160                 if (_fs_fstab.fs_mntops == NULL)
 161                         goto bad;
 162                 _fs_fstab.fs_freq = 0;
 163                 _fs_fstab.fs_passno = 0;
 164                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 165                         ;
 166                 if (cp != NULL) {
 167                         _fs_fstab.fs_freq = atoi(cp);
 168                         while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 169                                 ;
 170                         if (cp != NULL)
 171                                 _fs_fstab.fs_passno = atoi(cp);
 172                 }
 173                 strcpy(subline, _fs_fstab.fs_mntops);
 174                 p = subline;
 175                 for (typexx = 0, cp = strsep(&p, ","); cp;
 176                      cp = strsep(&p, ",")) {
 177                         if (strlen(cp) != 2)
 178                                 continue;
 179                         if (!strcmp(cp, FSTAB_RW)) {
 180                                 _fs_fstab.fs_type = FSTAB_RW;
 181                                 break;
 182                         }
 183                         if (!strcmp(cp, FSTAB_RQ)) {
 184                                 _fs_fstab.fs_type = FSTAB_RQ;
 185                                 break;
 186                         }
 187                         if (!strcmp(cp, FSTAB_RO)) {
 188                                 _fs_fstab.fs_type = FSTAB_RO;
 189                                 break;
 190                         }
 191                         if (!strcmp(cp, FSTAB_SW)) {
 192                                 _fs_fstab.fs_type = FSTAB_SW;
 193                                 break;
 194                         }
 195                         if (!strcmp(cp, FSTAB_XX)) {
 196                                 _fs_fstab.fs_type = FSTAB_XX;
 197                                 typexx++;
 198                                 break;
 199                         }
 200                 }
 201                 if (typexx)
 202                         continue;
 203                 if (cp != NULL)
 204                         return(1);
 205
 206 bad:            /* no way to distinguish between EOF and syntax error */
 207                 error(EFTYPE);
 208         }
 209         /* NOTREACHED */
 210 }
 211
 212 struct fstab *
 213 getfsent(void)
 214 {
 215         if ((!_fs_fp && !setfsent()) || !fstabscan())
 216                 return(NULL);
 217         return(&_fs_fstab);
 218 }
 219
 220 struct fstab *
 221 getfsspec(const char *name)
 222 {
 223         if (setfsent())
 224                 while (fstabscan())
 225                         if (!strcmp(_fs_fstab.fs_spec, name))
 226                                 return(&_fs_fstab);
 227         return(NULL);
 228 }
 229
 230 struct fstab *
 231 getfsfile(const char *name)
 232 {
 233         if (setfsent())
 234                 while (fstabscan())
 235                         if (!strcmp(_fs_fstab.fs_file, name))
 236                                 return(&_fs_fstab);
 237         return(NULL);
 238 }
 239
 240 int
 241 setfsent(void)
 242 {
 243         if (_fs_fp) {
 244                 rewind(_fs_fp);
 245                 LineNo = 0;
 246                 return(1);
 247         }
 248         if (fsp_set == 0) {
 249                 if (issetugid())
 250                         setfstab(NULL);
 251                 else
 252                         setfstab(getenv("PATH_FSTAB"));
 253         }
 254         if ((_fs_fp = fopen(path_fstab, "r")) != NULL) {
 255                 LineNo = 0;
 256                 return(1);
 257         }
 258         error(errno);
 259         return(0);
 260 }
 261
 262 void
 263 endfsent(void)
 264 {
 265         if (_fs_fp) {
 266                 fclose(_fs_fp);
 267                 _fs_fp = NULL;
 268         }
 269
 270         fsp_set = 0;
 271 }
 272
 273 static void
 274 error(int err)
 275 {
 276         char *p;
 277         char num[30];
 278
 279         _write(STDERR_FILENO, "fstab: ", 7);
 280         _write(STDERR_FILENO, path_fstab, strlen(path_fstab));
 281         _write(STDERR_FILENO, ":", 1);
 282         sprintf(num, "%d: ", LineNo);
 283         _write(STDERR_FILENO, num, strlen(num));
 284         p = strerror(err);
 285         _write(STDERR_FILENO, p, strlen(p));
 286         _write(STDERR_FILENO, "\n", 1);
 287 }