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  1. /*
  2.  * Copyright (c) 2008 Jakub Jermar
  3.  * 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.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup fs
  30.  * @{
  31.  */
  32.  
  33. /**
  34.  * @file    fat_dentry.c
  35.  * @brief   Functions that work with FAT directory entries.
  36.  */
  37.  
  38. #include "fat_dentry.h"
  39. #include <ctype.h>
  40. #include <string.h>
  41.  
  42. static bool is_d_char(const char ch)
  43. {
  44.     if (isalnum(ch) || ch == '_')
  45.         return true;
  46.     else
  47.         return false;
  48. }
  49.  
  50. /** Compare path component with the name read from the dentry.
  51.  *
  52.  * This function compares the path component with the name read from the dentry.
  53.  * The comparison is case insensitive and tolerates a mismatch on the trailing
  54.  * dot character at the end of the name (i.e. when there is a dot, but no
  55.  * extension).
  56.  *
  57.  * @param name      Node name read from the dentry.
  58.  * @param component Path component.
  59.  *
  60.  * @return      Zero on match, non-zero otherwise.
  61.  */
  62. int fat_dentry_namecmp(char *name, const char *component)
  63. {
  64.     int rc;
  65.     if (!(rc = stricmp(name, component)))
  66.         return rc;
  67.     if (!strchr(name, '.')) {
  68.         /*
  69.          * There is no '.' in the name, so we know that there is enough
  70.          * space for appending an extra '.' to name.
  71.          */
  72.         name[strlen(name)] = '.';
  73.         name[strlen(name) + 1] = '\0';
  74.         rc = stricmp(name, component);
  75.     }
  76.     return rc;
  77. }
  78.  
  79. bool fat_dentry_name_verify(const char *name)
  80. {
  81.     unsigned i, dot;
  82.     bool dot_found = false;
  83.    
  84.  
  85.     for (i = 0; name[i]; i++) {
  86.         if (name[i] == '.') {
  87.             if (dot_found) {
  88.                 return false;
  89.             } else {
  90.                 dot_found = true;
  91.                 dot = i;
  92.             }
  93.         } else {
  94.             if (!is_d_char(name[i]))
  95.                 return false;
  96.         }
  97.     }
  98.  
  99.     if (dot_found) {
  100.         if (dot > FAT_NAME_LEN)
  101.             return false;
  102.         if (i - dot > FAT_EXT_LEN + 1)
  103.             return false;
  104.     } else {
  105.         if (i > FAT_NAME_LEN)
  106.             return false;
  107.     }
  108.  
  109.     return true;
  110. }
  111.  
  112. void fat_dentry_name_get(const fat_dentry_t *d, char *buf)
  113. {
  114.     int i;
  115.  
  116.     for (i = 0; i < FAT_NAME_LEN; i++) {
  117.         if (d->name[i] == FAT_PAD)
  118.             break;
  119.         if (d->name[i] == FAT_DENTRY_E5_ESC)
  120.             *buf++ = 0xe5;
  121.         else
  122.             *buf++ = d->name[i];
  123.     }
  124.     if (d->ext[0] != FAT_PAD)
  125.         *buf++ = '.';
  126.     for (i = 0; i < FAT_EXT_LEN; i++) {
  127.         if (d->ext[i] == FAT_PAD) {
  128.             *buf = '\0';
  129.             return;
  130.         }
  131.         if (d->ext[i] == FAT_DENTRY_E5_ESC)
  132.             *buf++ = 0xe5;
  133.         else
  134.             *buf++ = d->ext[i];
  135.     }
  136.     *buf = '\0';
  137. }
  138.  
  139. void fat_dentry_name_set(fat_dentry_t *d, const char *name)
  140. {
  141.     int i;
  142.     const char fake_ext[] = "   ";
  143.  
  144.  
  145.     for (i = 0; i < FAT_NAME_LEN; i++) {
  146.         switch ((uint8_t) *name) {
  147.         case 0xe5:
  148.             d->name[i] = FAT_DENTRY_E5_ESC;
  149.             name++;
  150.             break;
  151.         case '\0':
  152.         case '.':
  153.             d->name[i] = FAT_PAD;
  154.             break;
  155.         default:
  156.             d->name[i] = toupper(*name++);
  157.             break;
  158.         }
  159.     }
  160.     if (*name++ != '.')
  161.         name = fake_ext;
  162.     for (i = 0; i < FAT_EXT_LEN; i++) {
  163.         switch ((uint8_t) *name) {
  164.         case 0xe5:
  165.             d->ext[i] = FAT_DENTRY_E5_ESC;
  166.             name++;
  167.             break;
  168.         case '\0':
  169.             d->ext[i] = FAT_PAD;
  170.             break;
  171.         default:
  172.             d->ext[i] = toupper(*name++);
  173.             break;
  174.         }
  175.     }
  176. }
  177.  
  178. fat_dentry_clsf_t fat_classify_dentry(const fat_dentry_t *d)
  179. {
  180.     if (d->attr & FAT_ATTR_VOLLABEL) {
  181.         /* volume label entry */
  182.         return FAT_DENTRY_SKIP;
  183.     }
  184.     if (d->name[0] == FAT_DENTRY_ERASED) {
  185.         /* not-currently-used entry */
  186.         return FAT_DENTRY_FREE;
  187.     }
  188.     if (d->name[0] == FAT_DENTRY_UNUSED) {
  189.         /* never used entry */
  190.         return FAT_DENTRY_LAST;
  191.     }
  192.     if (d->name[0] == FAT_DENTRY_DOT) {
  193.         /*
  194.          * Most likely '.' or '..'.
  195.          * It cannot occur in a regular file name.
  196.          */
  197.         return FAT_DENTRY_SKIP;
  198.     }
  199.     return FAT_DENTRY_VALID;
  200. }
  201.  
  202. /**
  203.  * @}
  204.  */
  205.