contrib/bind-9.5.2/lib/isc/unix/dir.c

   1 /*
   2  * Copyright (C) 2004, 2005, 2007, 2009  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 1999-2001  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and/or distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  * PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* $Id: dir.c,v 1.25.128.3 2009/02/16 23:46:44 tbox Exp $ */
  19
  20 /*! \file
  21  * \author  Principal Authors: DCL */
  22
  23 #include <config.h>
  24
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27
  28 #include <ctype.h>
  29 #include <errno.h>
  30 #include <unistd.h>
  31
  32 #include <isc/dir.h>
  33 #include <isc/magic.h>
  34 #include <isc/string.h>
  35 #include <isc/util.h>
  36
  37 #include "errno2result.h"
  38
  39 #define ISC_DIR_MAGIC           ISC_MAGIC('D', 'I', 'R', '*')
  40 #define VALID_DIR(dir)          ISC_MAGIC_VALID(dir, ISC_DIR_MAGIC)
  41
  42 void
  43 isc_dir_init(isc_dir_t *dir) {
  44         REQUIRE(dir != NULL);
  45
  46         dir->entry.name[0] = '\0';
  47         dir->entry.length = 0;
  48
  49         dir->handle = NULL;
  50
  51         dir->magic = ISC_DIR_MAGIC;
  52 }
  53
  54 /*!
  55  * \brief Allocate workspace and open directory stream. If either one fails,
  56  * NULL will be returned.
  57  */
  58 isc_result_t
  59 isc_dir_open(isc_dir_t *dir, const char *dirname) {
  60         char *p;
  61         isc_result_t result = ISC_R_SUCCESS;
  62
  63         REQUIRE(VALID_DIR(dir));
  64         REQUIRE(dirname != NULL);
  65
  66         /*
  67          * Copy directory name.  Need to have enough space for the name,
  68          * a possible path separator, the wildcard, and the final NUL.
  69          */
  70         if (strlen(dirname) + 3 > sizeof(dir->dirname))
  71                 /* XXXDCL ? */
  72                 return (ISC_R_NOSPACE);
  73         strcpy(dir->dirname, dirname);
  74
  75         /*
  76          * Append path separator, if needed, and "*".
  77          */
  78         p = dir->dirname + strlen(dir->dirname);
  79         if (dir->dirname < p && *(p - 1) != '/')
  80                 *p++ = '/';
  81         *p++ = '*';
  82         *p++ = '\0';
  83
  84         /*
  85          * Open stream.
  86          */
  87         dir->handle = opendir(dirname);
  88
  89         if (dir->handle == NULL)
  90                 return isc__errno2result(errno);
  91
  92         return (result);
  93 }
  94
  95 /*!
  96  * \brief Return previously retrieved file or get next one.
  97
  98  * Unix's dirent has
  99  * separate open and read functions, but the Win32 and DOS interfaces open
 100  * the dir stream and reads the first file in one operation.
 101  */
 102 isc_result_t
 103 isc_dir_read(isc_dir_t *dir) {
 104         struct dirent *entry;
 105
 106         REQUIRE(VALID_DIR(dir) && dir->handle != NULL);
 107
 108         /*
 109          * Fetch next file in directory.
 110          */
 111         entry = readdir(dir->handle);
 112
 113         if (entry == NULL)
 114                 return (ISC_R_NOMORE);
 115
 116         /*
 117          * Make sure that the space for the name is long enough.
 118          */
 119         if (sizeof(dir->entry.name) <= strlen(entry->d_name))
 120             return (ISC_R_UNEXPECTED);
 121
 122         strcpy(dir->entry.name, entry->d_name);
 123
 124         /*
 125          * Some dirents have d_namlen, but it is not portable.
 126          */
 127         dir->entry.length = strlen(entry->d_name);
 128
 129         return (ISC_R_SUCCESS);
 130 }
 131
 132 /*!
 133  * \brief Close directory stream.
 134  */
 135 void
 136 isc_dir_close(isc_dir_t *dir) {
 137        REQUIRE(VALID_DIR(dir) && dir->handle != NULL);
 138
 139        (void)closedir(dir->handle);
 140        dir->handle = NULL;
 141 }
 142
 143 /*!
 144  * \brief Reposition directory stream at start.
 145  */
 146 isc_result_t
 147 isc_dir_reset(isc_dir_t *dir) {
 148         REQUIRE(VALID_DIR(dir) && dir->handle != NULL);
 149
 150         rewinddir(dir->handle);
 151
 152         return (ISC_R_SUCCESS);
 153 }
 154
 155 isc_result_t
 156 isc_dir_chdir(const char *dirname) {
 157         /*!
 158          * \brief Change the current directory to 'dirname'.
 159          */
 160
 161         REQUIRE(dirname != NULL);
 162
 163         if (chdir(dirname) < 0)
 164                 return (isc__errno2result(errno));
 165
 166         return (ISC_R_SUCCESS);
 167 }
 168
 169 isc_result_t
 170 isc_dir_chroot(const char *dirname) {
 171
 172         REQUIRE(dirname != NULL);
 173
 174 #ifdef HAVE_CHROOT
 175         if (chroot(dirname) < 0 || chdir("/") < 0)
 176                 return (isc__errno2result(errno));
 177
 178         return (ISC_R_SUCCESS);
 179 #else
 180         return (ISC_R_NOTIMPLEMENTED);
 181 #endif
 182 }
 183
 184 isc_result_t
 185 isc_dir_createunique(char *templet) {
 186         isc_result_t result;
 187         char *x;
 188         char *p;
 189         int i;
 190         int pid;
 191
 192         REQUIRE(templet != NULL);
 193
 194         /*!
 195          * \brief mkdtemp is not portable, so this emulates it.
 196          */
 197
 198         pid = getpid();
 199
 200         /*
 201          * Replace trailing Xs with the process-id, zero-filled.
 202          */
 203         for (x = templet + strlen(templet) - 1; *x == 'X' && x >= templet;
 204              x--, pid /= 10)
 205                 *x = pid % 10 + '0';
 206
 207         x++;                    /* Set x to start of ex-Xs. */
 208
 209         do {
 210                 i = mkdir(templet, 0700);
 211                 if (i == 0 || errno != EEXIST)
 212                         break;
 213
 214                 /*
 215                  * The BSD algorithm.
 216                  */
 217                 p = x;
 218                 while (*p != '\0') {
 219                         if (isdigit(*p & 0xff))
 220                                 *p = 'a';
 221                         else if (*p != 'z')
 222                                 ++*p;
 223                         else {
 224                                 /*
 225                                  * Reset character and move to next.
 226                                  */
 227                                 *p++ = 'a';
 228                                 continue;
 229                         }
 230
 231                         break;
 232                 }
 233
 234                 if (*p == '\0') {
 235                         /*
 236                          * Tried all combinations.  errno should already
 237                          * be EEXIST, but ensure it is anyway for
 238                          * isc__errno2result().
 239                          */
 240                         errno = EEXIST;
 241                         break;
 242                 }
 243         } while (1);
 244
 245         if (i == -1)
 246                 result = isc__errno2result(errno);
 247         else
 248                 result = ISC_R_SUCCESS;
 249
 250         return (result);
 251 }