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 /* ファイルオープン */
  17 HANDLE FatVol_Open(C_DRVOBJ *pDrvObj, const char *pszPath, int iMode)
  18 {
  19         C_FATVOL                        *self;
  20         HANDLE                          hFile;
  21         FATVOL_UINT                     uiDirStartCluster;
  22         FATVOL_UINT                     uiDirCluster;
  23         FATVOL_UINT                     uiDirEntryPos;
  24         char                            szName[8+3];
  25         int                             iNameLen;
  26         FATVOL_UINT                     uiFileCluster;
  27         unsigned char           ubFileAttr;
  28         FILE_POS                        FileSize;
  29         T_FATVOL_CLUSTERBUF *pClusterBuf;
  30         unsigned char           *pubBuf;
  31         int                                     iEntryHit;
  32         int                             i, j;
  33
  34
  35         /* upper cast */
  36         self = (C_FATVOL *)pDrvObj;
  37
  38
  39         /* クリティカルセクションに入る */
  40         SysMtx_Lock(self->hMtx);
  41
  42
  43         /* ルートディレクトリを設定 */
  44         uiDirStartCluster = FATVOL_CLUSTER_ENDMARKER;
  45         uiDirCluster      = FATVOL_CLUSTER_ENDMARKER;
  46         uiDirEntryPos     = 0;
  47         uiFileCluster     = self->RootDirCluster;
  48         ubFileAttr        = 0x10;
  49         FileSize          = 0;
  50
  51         /* パス探索 */
  52         for ( ; ; )
  53         {
  54                 /* 区切りを読み飛ばす */
  55                 while ( pszPath[0] == '/' )
  56                 {
  57                         pszPath++;
  58                 }
  59
  60                 /* 名前の部分を探索 */
  61                 for ( i = 0; pszPath[i] != '\0'; i++ )
  62                 {
  63                         /* パス区切りなら抜ける */
  64                         if ( pszPath[i] == '/' )
  65                         {
  66                                 break;
  67                         }
  68                 }
  69                 iNameLen = i;
  70
  71                 /* ディレクトリ自身を指す場合 */
  72                 if ( iNameLen == 0 )
  73                 {
  74                         iEntryHit = 1;
  75                         break;
  76                 }
  77
  78                 /* ディレクトリエントリ名を作成 */
  79                 for ( i = 0, j = 0; i < iNameLen && j < 8; i++, j++ )
  80                 {
  81                         if ( pszPath[i] == '.' )
  82                         {
  83                                 break;
  84                         }
  85                         szName[j] = pszPath[i];
  86                 }
  87                 for ( ; j < 8; j++ )
  88                 {
  89                         szName[j] = 0x20;
  90                 }
  91                 if ( pszPath[i] != '.' && i < iNameLen )        /* ファイル名長すぎ */
  92                 {
  93                         SysMtx_Unlock(self->hMtx);
  94                         return HANDLE_NULL;
  95                 }
  96
  97                 /* 拡張子 */
  98                 if ( pszPath[i] == '.' )
  99                 {
 100                         i++;
 101                 }
 102                 for ( j = 0; i < iNameLen && j < 3; i++, j++ )
 103                 {
 104                         szName[8+j] = pszPath[i];
 105                 }
 106                 for ( ; j < 3; j++ )
 107                 {
 108                         szName[8+j] = 0x20;
 109                 }
 110                 if ( i < iNameLen )             /* 拡張子長すぎ */
 111                 {
 112                         SysMtx_Unlock(self->hMtx);
 113                         return HANDLE_NULL;
 114                 }
 115
 116
 117                 /* ポインタを進める */
 118                 pszPath += iNameLen;
 119
 120
 121                 /* 文字変換 */
 122                 for ( i = 0; i < 8+3; i++ )
 123                 {
 124                         /* 大文字化 */
 125                         if ( szName[i] >= 'a' && szName[i] <= 'z')
 126                         {
 127                                 szName[i] -= ('a' - 'A');
 128                         }
 129                 }
 130                 if ( szName[0] == 0xe5 )
 131                 {
 132                         szName[0] = 0x05;
 133                 }
 134
 135
 136
 137                 /* ディレクトリを開く */
 138                 uiDirStartCluster = uiFileCluster;
 139                 uiDirCluster      = uiDirStartCluster;
 140                 uiDirEntryPos     = 0;
 141                 if ( (pClusterBuf = FatVol_GetClusterBuf(self, uiDirCluster, 1)) == NULL )
 142                 {
 143                         SysMtx_Unlock(self->hMtx);
 144                         return HANDLE_NULL;
 145                 }
 146
 147                 /* ディレクトリエントリを検索 */
 148                 iEntryHit = 0;
 149                 for ( ; ; )
 150                 {
 151                         /* ディレクトリエントリ位置 */
 152                         pubBuf = &pClusterBuf->pubBuf[uiDirEntryPos];
 153
 154                         /* 0なら打ち切り */
 155                         if ( pubBuf[0] == 0x00 )
 156                         {
 157                                 break;
 158                         }
 159
 160                         /* 名前比較 */
 161                         if ( memcmp(pubBuf, szName, 8+3) == 0 )
 162                         {
 163                                 /* 開始クラスタ取得 */
 164                                 uiFileCluster = pubBuf[26] + (pubBuf[27] << 8);
 165                                 if ( self->iFatType == FATVOL_TYPE_FAT32 )
 166                                 {
 167                                         uiFileCluster += (pubBuf[20] << 16) + (pubBuf[21] << 24);
 168                                 }
 169
 170                                 /* 属性取得 */
 171                                 ubFileAttr = pubBuf[11];
 172
 173                                 /* サイズ取得 */
 174                                 FileSize = pubBuf[28] + (pubBuf[29] << 8) + (pubBuf[30] << 16) + (pubBuf[31] << 24);
 175
 176                                 iEntryHit = 1;
 177                                 break;
 178                         }
 179
 180                         /* シーク */
 181                         uiDirEntryPos += 32;
 182                         if ( uiDirEntryPos >= self->BytesPerCluster )
 183                         {
 184                                 FatVol_RelClusterBuf(self, pClusterBuf, 0);
 185                                 uiDirCluster = FatVol_GetNextCluster(self, uiDirCluster);
 186                                 if ( uiDirCluster == FATVOL_CLUSTER_ENDMARKER
 187                                         || (pClusterBuf = FatVol_GetClusterBuf(self, uiDirCluster, 1)) == NULL )
 188                                 {
 189                                         SysMtx_Unlock(self->hMtx);
 190                                         return HANDLE_NULL;
 191                                 }
 192                                 uiDirEntryPos = 0;
 193                         }
 194                 }
 195
 196                 /* ディレクトリを閉じる */
 197                 FatVol_RelClusterBuf(self, pClusterBuf, 0);
 198
 199
 200                 /* これ以上開くサブディレクトリがなければ抜ける */
 201                 if ( !(iEntryHit && (ubFileAttr & 0x10)) )
 202                 {
 203                         break;
 204                 }
 205         }
 206
 207
 208         /* パスをすべて探索できていなければNG */
 209         if ( *pszPath != '\0' )
 210         {
 211                 SysMtx_Unlock(self->hMtx);
 212                 return HANDLE_NULL;
 213         }
 214
 215
 216         /* ディレクトリに存在しない場合 */
 217         if ( !iEntryHit )
 218         {
 219                 /* 新規作成禁止ならばエラー */
 220                 if ( iMode & FILE_OPEN_EXIST )
 221                 {
 222                         SysMtx_Unlock(self->hMtx);
 223                         return HANDLE_NULL;
 224                 }
 225
 226                 /* ディレクトリを開く */
 227                 uiDirCluster  = uiDirStartCluster;
 228                 uiDirEntryPos = 0;
 229                 if ( (pClusterBuf = FatVol_GetClusterBuf(self, uiDirCluster, 1)) == NULL )
 230                 {
 231                         SysMtx_Unlock(self->hMtx);
 232                         return HANDLE_NULL;
 233                 }
 234
 235                 /* 空き探索 */
 236                 for ( ; ; )
 237                 {
 238                         /* ディレクトリエントリ位置 */
 239                         pubBuf = &pClusterBuf->pubBuf[uiDirEntryPos];
 240
 241                         /* 空き発見 */
 242                         if ( pubBuf[0] == 0xe5 || pubBuf[0] == 0x00 )
 243                         {
 244                                 break;
 245                         }
 246
 247                         /* シーク */
 248                         uiDirEntryPos += 32;
 249                         if ( uiDirEntryPos >= self->BytesPerCluster )   /* クラスタ越えなら */
 250                         {
 251                                 FatVol_RelClusterBuf(self, pClusterBuf, 0);
 252                                 uiDirCluster = FatVol_GetNextCluster(self, uiDirCluster);
 253                                 if ( uiDirCluster == FATVOL_CLUSTER_ENDMARKER )
 254                                 {
 255                                         /* FAT32以外のルートディレクトリなら拡張不能 */
 256                                         if ( self->iFatType != FATVOL_TYPE_FAT32 && uiDirCluster >= 0x0f000000 )
 257                                         {
 258                                                 SysMtx_Unlock(self->hMtx);
 259                                                 return HANDLE_NULL;
 260                                         }
 261                                         if ( (uiFileCluster = FatVol_AllocCluster(self)) == FATVOL_CLUSTER_ENDMARKER )
 262                                         {
 263                                                 SysMtx_Unlock(self->hMtx);
 264                                                 return HANDLE_NULL;
 265                                         }
 266                                         FatVol_SetNextCluster(self, uiDirCluster, uiFileCluster);
 267                                         uiDirCluster = uiFileCluster;
 268                                 }
 269                                 if ( (pClusterBuf = FatVol_GetClusterBuf(self, uiDirCluster, 1)) == NULL )
 270                                 {
 271                                         SysMtx_Unlock(self->hMtx);
 272                                         return HANDLE_NULL;
 273                                 }
 274                                 uiDirEntryPos = 0;
 275                         }
 276                 }
 277
 278                 /* 新規クラスタ作成 */
 279                 if ( (uiFileCluster = FatVol_AllocCluster(self)) == FATVOL_CLUSTER_ENDMARKER )
 280                 {
 281                         FatVol_RelClusterBuf(self, pClusterBuf, 0);
 282                         SysMtx_Unlock(self->hMtx);
 283                         return HANDLE_NULL;
 284                 }
 285                 FatVol_SetNextCluster(self, uiFileCluster, FATVOL_CLUSTER_ENDMARKER);
 286
 287                 MemUtil_MemSetB(&pubBuf[0], 0, 32);                                             /* 初期化 */
 288                 MemUtil_MemCopyB(&pubBuf[0], szName, 8+3);                              /* ファイル名 */
 289                 pubBuf[11] = (iMode & FILE_OPEN_DIR) ? 0x10 : 0x20;             /* 属性 */
 290                 pubBuf[26] = ((uiFileCluster >>  0) & 0xff);                    /* 開始クラスタ */
 291                 pubBuf[27] = ((uiFileCluster >>  8) & 0xff);
 292                 pubBuf[20] = ((uiFileCluster >> 16) & 0xff);
 293                 pubBuf[21] = ((uiFileCluster >> 24) & 0xff);
 294                 FileSize   = 0;
 295                 ubFileAttr = pubBuf[11];
 296
 297                 /* ディレクトリを閉じる */
 298                 FatVol_RelClusterBuf(self, pClusterBuf, 1);
 299         }
 300         else
 301         {
 302                 /* 存在した場合 */
 303                 if ( iMode & FILE_OPEN_CREATE )
 304                 {
 305                         FatVol_FreeCluster(self, uiFileCluster);
 306                         FatVol_SetNextCluster(self, uiFileCluster, FATVOL_CLUSTER_ENDMARKER);
 307                         FileSize = 0;
 308                 }
 309         }
 310
 311         /* モードチェック */
 312         if ( ((ubFileAttr & 0x10) && !(iMode & FILE_OPEN_DIR))
 313                 || (!(ubFileAttr & 0x10) && (iMode & FILE_OPEN_DIR)) )
 314         {
 315                 SysMtx_Unlock(self->hMtx);
 316                 return HANDLE_NULL;
 317         }
 318
 319         /* ファイルディスクリプタを作成 */
 320         hFile = FatFile_Create(self, uiFileCluster, uiDirCluster, uiDirEntryPos, FileSize, iMode);
 321         if ( hFile != HANDLE_NULL )
 322         {
 323                 self->iOpenCount++;
 324         }
 325
 326         /* クリティカルセクションを出る */
 327         SysMtx_Unlock(self->hMtx);
 328
 329         return hFile;
 330 }
 331
 332
 333 /* end of file */