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  * 3. 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 char *_fs_spec;          /* allocated via getdevpath() */
  50 static struct fstab _fs_fstab;
  51 static int LineNo = 0;
  52 static char *path_fstab;
  53 static char fstab_path[PATH_MAX];
  54 static int fsp_set = 0;
  55
  56 static void error(int);
  57 static void fixfsfile(void);
  58 static int fstabscan(void);
  59 static char *gdplookup(char *spec);
  60
  61 void
  62 setfstab(const char *file)
  63 {
  64
  65         if (file == NULL) {
  66                 path_fstab = _PATH_FSTAB;
  67         } else {
  68                 strncpy(fstab_path, file, PATH_MAX);
  69                 fstab_path[PATH_MAX - 1] = '\0';
  70                 path_fstab = fstab_path;
  71         }
  72         fsp_set = 1;
  73 }
  74
  75 const char *
  76 getfstab(void)
  77 {
  78
  79         if (fsp_set)
  80                 return (path_fstab);
  81         else
  82                 return (_PATH_FSTAB);
  83 }
  84
  85 static void
  86 fixfsfile(void)
  87 {
  88         static char buf[sizeof(_PATH_DEV) + MNAMELEN];
  89         struct stat sb;
  90         struct statfs sf;
  91
  92         if (strcmp(_fs_fstab.fs_file, "/") != 0)
  93                 return;
  94         if (statfs("/", &sf) != 0)
  95                 return;
  96         if (sf.f_mntfromname[0] == '/')
  97                 buf[0] = '\0';
  98         else
  99                 strcpy(buf, _PATH_DEV);
 100         strcat(buf, sf.f_mntfromname);
 101         if (stat(buf, &sb) != 0 ||
 102             (!S_ISBLK(sb.st_mode) && !S_ISCHR(sb.st_mode)))
 103                 return;
 104         _fs_fstab.fs_spec = buf;
 105 }
 106
 107 static int
 108 fstabscan(void)
 109 {
 110         char *cp, *p;
 111 #define MAXLINELENGTH   1024
 112         static char line[MAXLINELENGTH];
 113         char subline[MAXLINELENGTH];
 114         int typexx;
 115
 116         for (;;) {
 117
 118                 if (!(p = fgets(line, sizeof(line), _fs_fp)))
 119                         return(0);
 120 /* OLD_STYLE_FSTAB */
 121                 ++LineNo;
 122                 if (*line == '#' || *line == '\n')
 123                         continue;
 124                 if (!strpbrk(p, " \t")) {
 125                         _fs_fstab.fs_spec = gdplookup(strsep(&p, ":\n"));
 126                         _fs_fstab.fs_file = strsep(&p, ":\n");
 127                         fixfsfile();
 128                         _fs_fstab.fs_type = strsep(&p, ":\n");
 129                         if (_fs_fstab.fs_type) {
 130                                 if (!strcmp(_fs_fstab.fs_type, FSTAB_XX))
 131                                         continue;
 132                                 _fs_fstab.fs_mntops = _fs_fstab.fs_type;
 133                                 _fs_fstab.fs_vfstype =
 134                                     strcmp(_fs_fstab.fs_type, FSTAB_SW) ?
 135                                     "ufs" : "swap";
 136                                 if ((cp = strsep(&p, ":\n")) != NULL) {
 137                                         _fs_fstab.fs_freq = atoi(cp);
 138                                         if ((cp = strsep(&p, ":\n")) != NULL) {
 139                                                 _fs_fstab.fs_passno = atoi(cp);
 140                                                 return(1);
 141                                         }
 142                                 }
 143                         }
 144                         goto bad;
 145                 }
 146 /* OLD_STYLE_FSTAB */
 147                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 148                         ;
 149                 _fs_fstab.fs_spec = cp;
 150                 if (!_fs_fstab.fs_spec || *_fs_fstab.fs_spec == '#')
 151                         continue;
 152                 _fs_fstab.fs_spec = gdplookup(_fs_fstab.fs_spec);
 153                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 154                         ;
 155                 _fs_fstab.fs_file = cp;
 156                 fixfsfile();
 157                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 158                         ;
 159                 _fs_fstab.fs_vfstype = cp;
 160                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 161                         ;
 162                 _fs_fstab.fs_mntops = cp;
 163                 if (_fs_fstab.fs_mntops == NULL)
 164                         goto bad;
 165                 _fs_fstab.fs_freq = 0;
 166                 _fs_fstab.fs_passno = 0;
 167                 while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 168                         ;
 169                 if (cp != NULL) {
 170                         _fs_fstab.fs_freq = atoi(cp);
 171                         while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
 172                                 ;
 173                         if (cp != NULL)
 174                                 _fs_fstab.fs_passno = atoi(cp);
 175                 }
 176                 strcpy(subline, _fs_fstab.fs_mntops);
 177                 p = subline;
 178                 for (typexx = 0, cp = strsep(&p, ","); cp;
 179                      cp = strsep(&p, ",")) {
 180                         if (strlen(cp) != 2)
 181                                 continue;
 182                         if (!strcmp(cp, FSTAB_RW)) {
 183                                 _fs_fstab.fs_type = FSTAB_RW;
 184                                 break;
 185                         }
 186                         if (!strcmp(cp, FSTAB_RQ)) {
 187                                 _fs_fstab.fs_type = FSTAB_RQ;
 188                                 break;
 189                         }
 190                         if (!strcmp(cp, FSTAB_RO)) {
 191                                 _fs_fstab.fs_type = FSTAB_RO;
 192                                 break;
 193                         }
 194                         if (!strcmp(cp, FSTAB_SW)) {
 195                                 _fs_fstab.fs_type = FSTAB_SW;
 196                                 break;
 197                         }
 198                         if (!strcmp(cp, FSTAB_XX)) {
 199                                 _fs_fstab.fs_type = FSTAB_XX;
 200                                 typexx++;
 201                                 break;
 202                         }
 203                 }
 204                 if (typexx)
 205                         continue;
 206                 if (cp != NULL)
 207                         return(1);
 208
 209 bad:            /* no way to distinguish between EOF and syntax error */
 210                 error(EFTYPE);
 211         }
 212         /* NOTREACHED */
 213 }
 214
 215 struct fstab *
 216 getfsent(void)
 217 {
 218         if ((!_fs_fp && !setfsent()) || !fstabscan())
 219                 return(NULL);
 220         return(&_fs_fstab);
 221 }
 222
 223 struct fstab *
 224 getfsspec(const char *name)
 225 {
 226         if (setfsent())
 227                 while (fstabscan())
 228                         if (!strcmp(_fs_fstab.fs_spec, name))
 229                                 return(&_fs_fstab);
 230         return(NULL);
 231 }
 232
 233 struct fstab *
 234 getfsfile(const char *name)
 235 {
 236         if (setfsent())
 237                 while (fstabscan())
 238                         if (!strcmp(_fs_fstab.fs_file, name))
 239                                 return(&_fs_fstab);
 240         return(NULL);
 241 }
 242
 243 int
 244 setfsent(void)
 245 {
 246         if (_fs_fp) {
 247                 rewind(_fs_fp);
 248                 LineNo = 0;
 249                 return(1);
 250         }
 251         if (fsp_set == 0) {
 252                 if (issetugid())
 253                         setfstab(NULL);
 254                 else
 255                         setfstab(getenv("PATH_FSTAB"));
 256         }
 257         if ((_fs_fp = fopen(path_fstab, "r")) != NULL) {
 258                 LineNo = 0;
 259                 return(1);
 260         }
 261         error(errno);
 262         return(0);
 263 }
 264
 265 void
 266 endfsent(void)
 267 {
 268         if (_fs_fp) {
 269                 fclose(_fs_fp);
 270                 _fs_fp = NULL;
 271         }
 272
 273         fsp_set = 0;
 274 }
 275
 276 static char *
 277 gdplookup(char *spec)
 278 {
 279         if (_fs_spec)
 280                 free(_fs_spec);
 281         _fs_spec = getdevpath(spec, 0);
 282         if (strcmp(_fs_spec, spec) != 0)
 283                 spec = _fs_spec;
 284         return(spec);
 285 }
 286
 287 static void
 288 error(int err)
 289 {
 290         char *p;
 291         char num[30];
 292
 293         _write(STDERR_FILENO, "fstab: ", 7);
 294         _write(STDERR_FILENO, path_fstab, strlen(path_fstab));
 295         _write(STDERR_FILENO, ":", 1);
 296         sprintf(num, "%d: ", LineNo);
 297         _write(STDERR_FILENO, num, strlen(num));
 298         p = strerror(err);
 299         _write(STDERR_FILENO, p, strlen(p));
 300         _write(STDERR_FILENO, "\n", 1);
 301 }