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
  21         HANDLE                          hFile;
  22
  23
  24         FATVOL_UINT                     uiDirStartCluster;
  25         FATVOL_UINT                     uiDirCluster;
  26         FATVOL_UINT                     uiDirEntryPos;
  27
  28         char                            szName[8+3];
  29         int                             iNameLen;
  30
  31         FATVOL_UINT                     uiFileCluster;
  32         unsigned char           ubFileAttr;
  33         FILE_POS                        FileSize;
  34         T_FATVOL_CLUSTERBUF *pClusterBuf;
  35         unsigned char           *pubBuf;
  36         int                                     iEntryHit;
  37         int                             i, j;
  38
  39
  40         /* upper cast */
  41         self = (C_FATVOL *)pDrvObj;
  42
  43
  44         /* クリティカルセクションに入る */
  45         SysMtx_Lock(self->hMtx);
  46
  47
  48         /* ルートディレクトリを設定 */
  49         uiDirStartCluster = FATVOL_CLUSTER_ENDMARKER;
  50         uiDirCluster      = FATVOL_CLUSTER_ENDMARKER;
  51         uiDirEntryPos     = 0;
  52         uiFileCluster     = self->RootDirCluster;
  53         ubFileAttr        = 0x10;
  54         FileSize          = 0;
  55
  56         /* パス探索 */
  57         for ( ; ; )
  58         {
  59                 /* 区切りを読み飛ばす */
  60                 while ( pszPath[0] == '/' )
  61                 {
  62                         pszPath++;
  63                 }
  64
  65                 /* 名前の部分を探索 */
  66                 for ( i = 0; pszPath[i] != '\0'; i++ )
  67                 {
  68                         /* パス区切りなら抜ける */
  69                         if ( pszPath[i] == '/' )
  70                         {
  71                                 break;
  72                         }
  73                 }
  74                 iNameLen = i;
  75
  76                 /* ディレクトリ自身を指す場合 */
  77                 if ( iNameLen == 0 )
  78                 {
  79                         iEntryHit = 1;
  80                         break;
  81                 }
  82
  83                 /* ディレクトリエントリ名を作成 */
  84                 for ( i = 0, j = 0; i < iNameLen && j < 8; i++, j++ )
  85                 {
  86                         if ( pszPath[i] == '.' )
  87                         {
  88                                 break;
  89                         }
  90                         szName[j] = pszPath[i];
  91                 }
  92                 for ( ; j < 8; j++ )
  93                 {
  94                         szName[j] = 0x20;
  95                 }
  96                 if ( pszPath[i] != '.' && i < iNameLen )        /* ファイル名長すぎ */
  97                 {
  98                         SysMtx_Unlock(self->hMtx);
  99                         return HANDLE_NULL;
 100                 }
 101
 102                 /* 拡張子 */
 103                 if ( pszPath[i] == '.' )
 104                 {
 105                         i++;
 106                 }
 107                 for ( j = 0; i < iNameLen && j < 3; i++, j++ )
 108                 {
 109                         szName[8+j] = pszPath[i];
 110                 }
 111                 for ( ; j < 3; j++ )
 112                 {
 113                         szName[8+j] = 0x20;
 114                 }
 115                 if ( i < iNameLen )             /* 拡張子長すぎ */
 116                 {
 117                         SysMtx_Unlock(self->hMtx);
 118                         return HANDLE_NULL;
 119                 }
 120
 121
 122                 /* ポインタを進める */
 123                 pszPath += iNameLen;
 124
 125
 126                 /* 文字変換 */
 127                 for ( i = 0; i < 8+3; i++ )
 128                 {
 129                         /* 大文字化 */
 130                         if ( szName[i] >= 'a' && szName[i] <= 'z')
 131                         {
 132                                 szName[i] -= ('a' - 'A');
 133                         }
 134                 }
 135                 if ( szName[0] == 0xe5 )
 136                 {
 137                         szName[0] = 0x05;
 138                 }
 139
 140
 141
 142                 /* ディレクトリを開く */
 143                 uiDirStartCluster = uiFileCluster;
 144                 uiDirCluster      = uiDirStartCluster;
 145                 uiDirEntryPos     = 0;
 146                 if ( (pClusterBuf = FatVol_GetClusterBuf(self, uiDirCluster, 1)) == NULL )
 147                 {
 148                         SysMtx_Unlock(self->hMtx);
 149                         return HANDLE_NULL;
 150                 }
 151
 152                 /* ディレクトリエントリを検索 */
 153                 iEntryHit = 0;
 154                 for ( ; ; )
 155                 {
 156                         /* ディレクトリエントリ位置 */
 157                         pubBuf = &pClusterBuf->pubBuf[uiDirEntryPos];
 158
 159                         /* 0なら打ち切り */
 160                         if ( pubBuf[0] == 0x00 )
 161                         {
 162                                 break;
 163                         }
 164
 165                         /* 名前比較 */
 166                         if ( memcmp(pubBuf, szName, 8+3) == 0 )
 167                         {
 168                                 /* 開始クラスタ取得 */
 169                                 uiFileCluster = pubBuf[26] + (pubBuf[27] << 8);
 170                                 if ( self->iFatType == FATVOL_TYPE_FAT32 )
 171                                 {
 172                                         uiFileCluster += (pubBuf[20] << 16) + (pubBuf[21] << 24);
 173                                 }
 174
 175                                 /* 属性取得 */
 176                                 ubFileAttr = pubBuf[11];
 177
 178                                 /* サイズ取得 */
 179                                 FileSize = pubBuf[28] + (pubBuf[29] << 8) + (pubBuf[30] << 16) + (pubBuf[31] << 24);
 180
 181                                 iEntryHit = 1;
 182                                 break;
 183                         }
 184
 185                         /* シーク */
 186                         uiDirEntryPos += 32;
 187                         if ( uiDirEntryPos >= self->BytesPerCluster )
 188                         {
 189                                 FatVol_RelClusterBuf(self, pClusterBuf, 0);
 190                                 uiDirCluster = FatVol_GetNextCluster(self, uiDirCluster);
 191                                 if ( uiDirCluster == FATVOL_CLUSTER_ENDMARKER
 192                                         || (pClusterBuf = FatVol_GetClusterBuf(self, uiDirCluster, 1)) == NULL )
 193                                 {
 194                                         SysMtx_Unlock(self->hMtx);
 195                                         return HANDLE_NULL;
 196                                 }
 197                                 uiDirEntryPos = 0;
 198                         }
 199                 }
 200
 201                 /* ディレクトリを閉じる */
 202                 FatVol_RelClusterBuf(self, pClusterBuf, 0);
 203
 204
 205                 /* これ以上開くサブディレクトリがなければ抜ける */
 206                 if ( !(iEntryHit && (ubFileAttr & 0x10)) )
 207                 {
 208                         break;
 209                 }
 210         }
 211
 212
 213         /* パスをすべて探索できていなければNG */
 214         if ( *pszPath != '\0' )
 215         {
 216                 SysMtx_Unlock(self->hMtx);
 217                 return HANDLE_NULL;
 218         }
 219
 220
 221         /* ディレクトリに存在しない場合 */
 222         if ( !iEntryHit )
 223         {
 224                 /* 新規作成でなければエラー */
 225                 if ( !(iMode & FILE_OPEN_CREATE) )
 226                 {
 227                         SysMtx_Unlock(self->hMtx);
 228                         return HANDLE_NULL;
 229                 }
 230
 231
 232                 /* ディレクトリを開く */
 233                 uiDirCluster  = uiDirStartCluster;
 234                 uiDirEntryPos = 0;
 235                 if ( (pClusterBuf = FatVol_GetClusterBuf(self, uiDirCluster, 1)) == NULL )
 236                 {
 237                         SysMtx_Unlock(self->hMtx);
 238                         return HANDLE_NULL;
 239                 }
 240
 241                 /* 空き探索 */
 242                 for ( ; ; )
 243                 {
 244                         /* ディレクトリエントリ位置 */
 245                         pubBuf = &pClusterBuf->pubBuf[uiDirEntryPos];
 246
 247                         /* 空き発見 */
 248                         if ( pubBuf[0] == 0xe5 || pubBuf[0] == 0x00 )
 249                         {
 250                                 break;
 251                         }
 252
 253                         /* シーク */
 254                         uiDirEntryPos += 32;
 255                         if ( uiDirEntryPos >= self->BytesPerCluster )   /* クラスタ越えなら */
 256                         {
 257                                 FatVol_RelClusterBuf(self, pClusterBuf, 0);
 258                                 uiDirCluster = FatVol_GetNextCluster(self, uiDirCluster);
 259                                 if ( uiDirCluster == FATVOL_CLUSTER_ENDMARKER )
 260                                 {
 261                                         /* FAT32以外のルートディレクトリなら拡張不能 */
 262                                         if ( self->iFatType != FATVOL_TYPE_FAT32 && uiDirCluster >= 0xf0000000 )
 263                                         {
 264                                                 SysMtx_Unlock(self->hMtx);
 265                                                 return HANDLE_NULL;
 266                                         }
 267                                         if ( (uiFileCluster = FatVol_GetNewCluster(self)) == FATVOL_CLUSTER_ENDMARKER )
 268                                         {
 269                                                 SysMtx_Unlock(self->hMtx);
 270                                                 return HANDLE_NULL;
 271                                         }
 272                                         FatVol_SetNextCluster(self, uiDirCluster, uiFileCluster);
 273                                         uiDirCluster = uiFileCluster;
 274                                 }
 275                                 if ( (pClusterBuf = FatVol_GetClusterBuf(self, uiDirCluster, 1)) == NULL )
 276                                 {
 277                                         SysMtx_Unlock(self->hMtx);
 278                                         return HANDLE_NULL;
 279                                 }
 280                                 uiDirEntryPos = 0;
 281                         }
 282                 }
 283
 284                 /* 新規クラスタ作成 */
 285                 if ( (uiFileCluster = FatVol_GetNewCluster(self)) == FATVOL_CLUSTER_ENDMARKER )
 286                 {
 287                         FatVol_RelClusterBuf(self, pClusterBuf, 0);
 288                         SysMtx_Unlock(self->hMtx);
 289                         return HANDLE_NULL;
 290                 }
 291                 FatVol_SetNextCluster(self, uiFileCluster, FATVOL_CLUSTER_ENDMARKER);
 292
 293                 memset(&pubBuf[0], 0, 32);                                                              /* 初期化 */
 294                 memcpy(&pubBuf[0], szName, 8+3);                                                /* ファイル名 */
 295                 pubBuf[11] = (iMode & FILE_OPEN_DIR) ? 0x10 : 0x20;             /* 属性 */
 296                 pubBuf[26] = ((uiFileCluster >>  0) & 0xff);                                    /* 開始クラスタ */
 297                 pubBuf[27] = ((uiFileCluster >>  8) & 0xff);
 298                 pubBuf[20] = ((uiFileCluster >> 16) & 0xff);
 299                 pubBuf[21] = ((uiFileCluster >> 24) & 0xff);
 300                 FileSize   = 0;
 301                 ubFileAttr = pubBuf[11];
 302
 303                 /* ディレクトリを閉じる */
 304                 FatVol_RelClusterBuf(self, pClusterBuf, 1);
 305         }
 306
 307         /* モードチェック */
 308         if ( ((ubFileAttr & 0x10) && !(iMode & FILE_OPEN_DIR))
 309                 || (!(ubFileAttr & 0x10) && (iMode & FILE_OPEN_DIR)) )
 310         {
 311                 SysMtx_Unlock(self->hMtx);
 312                 return HANDLE_NULL;
 313         }
 314
 315         /* ファイルディスクリプタを作成 */
 316         hFile = FatVol_FileCreate(self, uiFileCluster, uiDirCluster, uiDirEntryPos, FileSize, iMode);
 317         if ( hFile != HANDLE_NULL )
 318         {
 319                 self->iOpenCount++;
 320         }
 321
 322         /* クリティカルセクションを出る */
 323         SysMtx_Unlock(self->hMtx);
 324
 325         return hFile;
 326 }
 327
 328