_Inside Windows Cabinet Files_
by Sven B. Schreiber


Listing One
// =================================================================
// CAB FILE LAYOUT
// =================================================================
/*
(1) CAB_HEADER structure
(2) Reserved area, if CAB_HEADER.flags & CAB_FLAG_RESERVE
(3) Previous cabinet name, if CAB_HEADER.flags & CAB_FLAG_HASPREV
(4) Previous disk name, if CAB_HEADER.flags & CAB_FLAG_HASPREV
(5) Next cabinet name, if CAB_HEADER.flags & CAB_FLAG_HASNEXT
(6) Next disk name, if CAB_HEADER.flags & CAB_FLAG_HASNEXT
(7) CAB_FOLDER structures (n = CAB_HEADER.cFolders)
(8) CAB_ENTRY structures / file names (n = CAB_HEADER.cFiles)
(9) File data (offset = CAB_FOLDER.coffCabStart)
*/

// =================================================================
// MACROS
// =================================================================
#define SWAPWORD(x)  ((WORD) (((x) << 8) | ((x) >> 8)))
#define SWAPDWORD(x) ((SWAPWORD ((WORD) (x)) << 16) | \
                      (SWAPWORD ((WORD) ((x) >> 16))))


// =================================================================
// CONSTANTS
// =================================================================
#define CAB_SIGNATURE        SWAPDWORD ('MSCF')
#define CAB_VERSION          0x0103

#define CAB_FLAG_HASPREV     0x0001
#define CAB_FLAG_HASNEXT     0x0002
#define CAB_FLAG_RESERVE     0x0004

#define CAB_ATTRIB_READONLY  0x0001
#define CAB_ATTRIB_HIDDEN    0x0002
#define CAB_ATTRIB_SYSTEM    0x0004
#define CAB_ATTRIB_VOLUME    0x0008
#define CAB_ATTRIB_DIRECTORY 0x0010
#define CAB_ATTRIB_ARCHIVE   0x0020

#define CAB_FILE_FIRST       0x0000
#define CAB_FILE_NEXT        0x0001
#define CAB_FILE_SPLIT       0xFFFE
#define CAB_FILE_CONTINUED   0xFFFD

#define CAB_NOTIFY_OK        1
#define CAB_NOTIFY_ERROR     0
#define CAB_NOTIFY_SKIP      0
#define CAB_NOTIFY_ABORT     (-1)

// =================================================================
// CABINET STRUCTURES
// =================================================================
typedef struct _CAB_HEADER
    {
    DWORD sig;              // file signature 'MSCF' (CAB_SIGNATURE)
    DWORD csumHeader;       // header checksum (0 if not used)
    DWORD cbCabinet;        // cabinet file size
    DWORD csumFolders;      // folders checksum (0 if not used)
    DWORD coffFiles;        // offset of first CAB_ENTRY
    DWORD csumFiles;        // files checksum (0 if not used)
    WORD  version;          // cabinet version (CAB_VERSION)
    WORD  cFolders;         // number of folders
    WORD  cFiles;           // number of files
    WORD  flags;            // cabinet flags (CAB_FLAG_*)
    WORD  setID;            // cabinet set id
    WORD  iCabinet;         // zero-based cabinet number
    }
    CAB_HEADER, *PCAB_HEADER;
#define CAB_HEADER_ sizeof (CAB_HEADER)

// -----------------------------------------------------------------
typedef struct _CAB_FOLDER
    {
    DWORD coffCabStart;     // offset of folder data
    WORD  cCFData;          // ???
    WORD  typeCompress;     // compression type (tcomp* in FDI.h)

    }
    CAB_FOLDER, *PCAB_FOLDER;
#define CAB_FOLDER_ sizeof (CAB_FOLDER)

// -----------------------------------------------------------------
typedef struct _CAB_ENTRY
    {
    DWORD cbFile;           // uncompressed file size
    DWORD uoffFolderStart;  // file offset after decompression
    WORD  iFolder;          // file control id (CAB_FILE_*)
    WORD  date;             // file date stamp, as used by DOS
    WORD  time;             // file time stamp, as used by DOS
    WORD  attribs;          // file attributes (CAB_ATTRIB_*)
    }
    CAB_ENTRY, *PCAB_ENTRY;
#define CAB_ENTRY_ sizeof (CAB_ENTRY)


Listing Two
// =================================================================
// FILE EXTRACTION CALLBACK
// =================================================================
int DIAMONDAPI FDIExtract (FDINOTIFICATIONTYPE fdint,
                           PFDINOTIFICATION    pfdin)
    {
    FILETIME ft, lft;
    BYTE     abFile [MAX_PATH];
    int      hf, iResult;

    switch (fdint)
        {
        case fdintCOPY_FILE:
            if (lstrcmpi (pfdin->psz1,
                          ((PEXTRACT_FILE) pfdin->pv)->pbEntry))
                {
                iResult = CAB_NOTIFY_SKIP;
                }
            else
                {
                hf = FDIOpen (((PEXTRACT_FILE) pfdin->pv)->pbFile,
                              _O_RDWR | _O_CREAT | _O_TRUNC,
                              _S_IREAD | _S_IWRITE);
                if (hf != -1)
                    {
                    iResult = hf;
                    }
                else
                    {
                    printfMessage
                        (((PEXTRACT_FILE) pfdin->pv)->hWnd,
                          MB_ICONERROR | MB_OK,
                          "CabLib Error",
                          "Unable to create file \"%s\"",
                          ((PEXTRACT_FILE) pfdin->pv)->pbFile);
                    iResult = CAB_NOTIFY_ABORT;

                    }
                }
            break;
        case fdintNEXT_CABINET:
            if (lstrlen (pfdin->psz3) + lstrlen (pfdin->psz1)
                < MAX_PATH)
                {
                lstrcpy (abFile, pfdin->psz3);
                lstrcat (abFile, pfdin->psz1);
                hf = FDIOpen (abFile, _O_RDONLY, 0);
                }
            else
                {
                hf = -1;
                }
            if (hf != -1)
                {
                FDIClose (hf);
                iResult = CAB_NOTIFY_OK;
                }
            else
                {
                printfMessage (((PEXTRACT_FILE) pfdin->pv)->hWnd,
                               MB_ICONERROR | MB_OK,
                               "CabLib Error",
                               "Unable to open file \"%s%s\"",
                               pfdin->psz3,
                               pfdin->psz1);
                iResult = CAB_NOTIFY_ABORT;
                }
            break;
        case fdintCLOSE_FILE_INFO:
            DosDateTimeToFileTime (pfdin->date, pfdin->time, &lft);
            LocalFileTimeToFileTime (&lft, &ft);
            SetFileTime ((HANDLE) pfdin->hf, &ft, &ft, &ft);

            if (FDIClose (pfdin->hf) == -1)
                {
                printfMessage (((PEXTRACT_FILE) pfdin->pv)->hWnd,
                               MB_ICONERROR | MB_OK,
                               "CabLib Error",
                               "Unable to close file \"%s\"",
                               ((PEXTRACT_FILE) pfdin->pv)->pbFile);
                }
            iResult = CAB_NOTIFY_OK;
            break;
        default:
            iResult = CAB_NOTIFY_OK;
            break;
        }
    return iResult;
    }


Example 1: 
HFDI FAR DIAMONDAPI FDICreate (PFNALLOC pfnalloc,
                               PFNFREE  pfnfree,
                               PFNOPEN  pfnopen,
                               PFNREAD  pfnread,
                               PFNWRITE pfnwrite,
                               PFNCLOSE pfnclose,
                               PFNSEEK  pfnseek,
                               int      cpuType,
                               PERF     perf);

Example 2:
BOOL FAR DIAMONDAPI FDICopy (HFDI          hfdi,
                             char FAR      *pszCabinet,
                             char FAR      *pszCabPath,
                             int           flags,
                             PFNFDINOTIFY  pfnfdin,
                             PFNFDIDECRYPT pfnfdid,
                             void FAR      *pvUser);



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