aplfw/driver/volume/fat/fatvol_open.c

   1 /**
   2  *  Hyper Operating System  Application Framework
   3  *
   4  * @file  fatvol.c
   5  * @brief %jp{FATボリューム用デバイスドライバ}
   6  *
   7  * Copyright (C) 2006-2007 by Project HOS
   8  * http://sourceforge.jp/projects/hos/
   9  */
  10
  11
  12 #include <string.h>
  13 #include "fatvol_local.h"
  14
  15
  16 HANDLE FatVol_Open(C_DRVOBJ *pDrvObj, const char *pszPath, int iMode)
  17 {
  18         C_FATVOL                        *self;
  19         FATVOL_UINT                     uiCluster;
  20         HANDLE                          hFile;
  21         char                            szEntryName[8+1+3+1];
  22         int                             iEntryNameLen;
  23         char                            szName[8+1+3+1];
  24         int                             iNameLen;
  25         unsigned char           ubAttr;
  26         FILE_POS                        FileSize;
  27         T_FATVOL_CLUSTERBUF *pClusterBuf;
  28         unsigned char           *pubBuf;
  29         FATVOL_UINT                     uiDirCluster;
  30         FATVOL_UINT                     uiDirEntryPos;
  31         int                                     iEntryHit;
  32         int                             i;
  33
  34         /* upper cast */
  35         self = (C_FATVOL *)pDrvObj;
  36
  37
  38         /* クリティカルセクションに入る */
  39         SysMtx_Lock(self->hMtx);
  40
  41         /* ルートディレクトリを設定 */
  42         uiDirCluster  = self->RootDirCluster;
  43         uiDirEntryPos = 0;
  44         if ( (pClusterBuf = FatVol_GetClusterBuf(self, uiDirCluster, 1)) == NULL )
  45         {
  46                 SysMtx_Unlock(self->hMtx);
  47                 return HANDLE_NULL;
  48         }
  49
  50         /* パス探索 */
  51         for ( ; ; )
  52         {
  53                 /* 名前の部分を切り出し */
  54                 for ( iNameLen = 0; iNameLen < sizeof(szName) && *pszPath != '\0'; pszPath++, iNameLen++ )
  55                 {
  56                         /* パス区切りなら抜ける */
  57                         if ( *pszPath == '/' )
  58                         {
  59                                 pszPath++;
  60                                 break;
  61                         }
  62                         szName[iNameLen] = *pszPath;
  63
  64                         /* 大文字に変換 */
  65                         if ( szName[iNameLen] >= 'a' && szName[iNameLen] <= 'z' )
  66                         {
  67                                 szName[iNameLen] -= ('a' - 'A');
  68                         }
  69                 }
  70                 szName[iNameLen] = '\0';
  71
  72
  73                 /* ディレクトリ自身を指す場合 */
  74                 if ( iNameLen == 0 )
  75                 {
  76                         /* ディレクトリを閉じる */
  77                         FatVol_RelClusterBuf(self, pClusterBuf, 0);
  78
  79                         /* ディレクトリ指定があれば開く */
  80                         if ( iMode & FILE_OPEN_DIR )
  81                         {
  82                                 if ( (hFile = FatVol_FileCreate(self, uiDirCluster, FATVOL_CLUSTER_ENDMARKER, 0, 0, iMode)) != HANDLE_NULL )
  83                                 {
  84                                         self->iOpenCount++;
  85                                         SysMtx_Unlock(self->hMtx);
  86                                         return hFile;
  87                                 }
  88                         }
  89
  90                         /* エラー終了 */
  91                         SysMtx_Unlock(self->hMtx);
  92                         return HANDLE_NULL;
  93                 }
  94
  95
  96                 /* ディレクトリエントリを検索 */
  97                 iEntryHit = 0;
  98                 for ( ; ; )
  99                 {
 100                         /* ディレクトリエントリ位置 */
 101                         pubBuf = &pClusterBuf->pubBuf[uiDirEntryPos];
 102
 103                         /* 0なら打ち切り */
 104                         if ( pubBuf[0] == 0x00 )
 105                         {
 106                                 break;
 107                         }
 108
 109                         /* 名前部分取り出し */
 110                         iEntryNameLen = 0;
 111                         for ( i = 0; i < 8; i++ )
 112                         {
 113                                 if ( pubBuf[0+i] == ' ' || pubBuf[0+i] == '\0' )
 114                                 {
 115                                         break;
 116                                 }
 117                                 szEntryName[iEntryNameLen++] = (char)pubBuf[0+i];
 118                         }
 119                         szEntryName[iEntryNameLen++] = '.';
 120                         for ( i = 0; i < 3; i++ )
 121                         {
 122                                 if ( pubBuf[8+i] == ' ' || pubBuf[8+i] == '\0' )
 123                                 {
 124                                         break;
 125                                 }
 126                                 szEntryName[iEntryNameLen++] = (char)pubBuf[8+i];
 127                         }
 128                         szEntryName[iEntryNameLen] = '\0';
 129                         if ( iEntryNameLen > 2 && szEntryName[iEntryNameLen-1] == '.' )
 130                         {
 131                                 szEntryName[--iEntryNameLen] = '\0';
 132                         }
 133
 134                         /* 名前比較 */
 135                         if ( strcmp(szEntryName, szName) == 0 )
 136                         {
 137                                 iEntryHit = 1;
 138                                 break;
 139                         }
 140
 141                         /* シーク */
 142                         uiDirEntryPos += 32;
 143                         if ( uiDirEntryPos >= self->BytesPerCluster )
 144                         {
 145                                 FatVol_RelClusterBuf(self, pClusterBuf, 0);
 146                                 uiDirCluster = FatVol_GetNextCluster(self, uiDirCluster);
 147                                 if ( uiDirCluster == FATVOL_CLUSTER_ENDMARKER
 148                                         || (pClusterBuf = FatVol_GetClusterBuf(self, uiDirCluster, 1)) == NULL )
 149                                 {
 150                                         SysMtx_Unlock(self->hMtx);
 151                                         return HANDLE_NULL;
 152                                 }
 153                                 uiDirEntryPos = 0;
 154                         }
 155                 }
 156
 157                 /* 見つからなければエラー */
 158                 if ( !iEntryHit )
 159                 {
 160                         FatVol_RelClusterBuf(self, pClusterBuf, 0);
 161                         SysMtx_Unlock(self->hMtx);
 162                         return HANDLE_NULL;
 163                 }
 164
 165                 /* 開始クラスタ取得 */
 166                 uiCluster = pubBuf[26] + (pubBuf[27] << 8);
 167                 if ( self->iFatType == FATVOL_TYPE_FAT32 )
 168                 {
 169                         uiCluster += (pubBuf[20] << 16) + (pubBuf[21] << 24);
 170                 }
 171
 172                 /* 属性取得 */
 173                 ubAttr = pubBuf[11];
 174
 175                 /* サイズ取得 */
 176                 FileSize = pubBuf[28] + (pubBuf[29] << 8) + (pubBuf[30] << 16) + (pubBuf[31] << 24);
 177
 178                 /* 親ディレクトリを閉じる */
 179                 FatVol_RelClusterBuf(self, pClusterBuf, 0);
 180
 181
 182                 /* パス部分の解析が終わっていればここで抜ける */
 183                 if ( *pszPath == '\0' )
 184                 {
 185                         break;
 186                 }
 187
 188                 /* サブディレクトリでなければエラー */
 189                 if ( !(ubAttr & 0x10) )
 190                 {
 191                         SysMtx_Unlock(self->hMtx);
 192                         return HANDLE_NULL;
 193                 }
 194
 195                 /* サブディレクトリを開く */
 196                 uiDirCluster = uiCluster;
 197                 uiDirEntryPos = 0;
 198                 if ( (pClusterBuf = FatVol_GetClusterBuf(self, uiDirCluster, 1)) == NULL )
 199                 {
 200                         SysMtx_Unlock(self->hMtx);
 201                         return HANDLE_NULL;
 202                 }
 203         }
 204
 205         /* モードチェック */
 206         if ( iMode & FILE_OPEN_DIR )
 207         {
 208                 SysMtx_Unlock(self->hMtx);
 209                 return HANDLE_NULL;
 210         }
 211
 212         /* ファイルディスクリプタを作成 */
 213         hFile = FatVol_FileCreate(self, uiCluster, uiDirCluster, uiDirEntryPos, FileSize, iMode);
 214         if ( hFile != HANDLE_NULL )
 215         {
 216                 self->iOpenCount++;
 217         }
 218
 219         /* クリティカルセクションを出る */
 220         SysMtx_Unlock(self->hMtx);
 221
 222         return hFile;
 223 }
 224
 225