/* $Id: kLdrRdrFile.c 2860 2006-11-08 04:10:14Z bird $ */
/** @file
 *
 * kLdr - The Dynamic Loader, file abstraction.
 *
 * Copyright (c) 2006 knut st. osmundsen <bird-kbuild-src@anduin.net>
 *
 *
 * This file is part of kLdr.
 *
 * kLdr is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * kLdr is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with kLdr; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */


/*******************************************************************************
*   Header Files                                                               *
*******************************************************************************/
#ifdef __OS2__
# define INCL_ERRORS
# define INCL_BASE
# include <os2.h>

#elif defined(__WIN32__) || defined(__WIN64__) || defined(__WIN__)
# include <Windows.h>
# ifndef __WIN__
#  define __WIN__
# endif

#else
# error "port me"
#endif

#include <kLdr.h>
#include "kLdrHlp.h"


/*******************************************************************************
*   Structures and Typedefs                                                    *
*******************************************************************************/
/**
 * Prepared stuff.
 */
typedef struct KLDRRDRFILEPREP
{
    /** The address of the prepared region. */
    void           *pv;
    /** The size of the prepared region. */
    size_t          cb;
#if defined(__WIN__) || defined(__NT__)
    /** Handle to the section created to map the file. */
    HANDLE          hSection;
#endif
} KLDRRDRFILEPREP, *PKLDRRDRFILEPREP;

/**
 * The file provier instance for native files.
 */
typedef struct KLDRRDRFILE
{
    /** The file reader vtable. */
    KLDRRDR             Core;
    /** The file handle. */
#ifdef __OS2__
    HFILE               File;
#elif defined(__WIN__) || defined(__NT__)
    HANDLE              File;
#else
# error "Port me!"
#endif
    /** The current file offset. */
    off_t               off;
    /** The file size. */
    off_t               cb;
    /** Array where we stuff the mapping area data. */
    KLDRRDRFILEPREP     aPreps[4];
    /** The number of current preps. */
    uint32_t            cPreps;
    /** Number of mapping references. */
    int32_t             cMappings;
    /** The memory mapping. */
    void               *pvMapping;
    /** The filename. */
    char                szFilename[1];
} KLDRRDRFILE, *PKLDRRDRFILE;


/*******************************************************************************
*   Internal Functions                                                         *
*******************************************************************************/
static void     kldrRdrFileDone(PKLDRRDR pRdr);
static int      kldrRdrFileUnprepare(PKLDRRDR pRdr, void *pv, size_t cb);
static int      kldrRdrFileUnmap(PKLDRRDR pRdr, void *pv, size_t cb);
static int      kldrRdrFileProtect(PKLDRRDR pRdr, void *pv, size_t cb, KLDRPROT enmProt);
static int      kldrRdrFileRefreshMap(PKLDRRDR pRdr, void *pv, size_t cb, KLDRPROT enmProt, off_t offFile, size_t cbFile);
static int      kldrRdrFileMap(PKLDRRDR pRdr, void *pv, size_t cb, KLDRPROT enmProt, off_t offFile, size_t cbFile);
static int      kldrRdrFilePrepare(PKLDRRDR pRdr, void **ppv, size_t cb, unsigned fFixed);
static size_t   kldrRdrFilePageSize(PKLDRRDR pRdr);
static const char *kldrRdrFileName(PKLDRRDR pRdr);
static off_t    kldrRdrFileTell(PKLDRRDR pRdr);
static off_t    kldrRdrFileSize(PKLDRRDR pRdr);
static int      kldrRdrFileAllUnmap(PKLDRRDR pRdr, const void *pvBits);
static int      kldrRdrFileAllMap(PKLDRRDR pRdr, const void **ppvBits);
static int      kldrRdrFileRead(PKLDRRDR pRdr, void *pvBuf, size_t cb, off_t off);
static int      kldrRdrFileDestroy(PKLDRRDR pRdr);
static int      kldrRdrFileCreate(PPKLDRRDR ppRdr, const char *pszFilename);


/*******************************************************************************
*   Global Variables                                                           *
*******************************************************************************/
/** Native file provider operations. */
const KLDRRDROPS g_kLdrRdrFileOps =
{
    "native file",
    NULL,
    kldrRdrFileCreate,
    kldrRdrFileDestroy,
    kldrRdrFileRead,
    kldrRdrFileAllMap,
    kldrRdrFileAllUnmap,
    kldrRdrFileSize,
    kldrRdrFileTell,
    kldrRdrFileName,
    kldrRdrFilePageSize,
    kldrRdrFilePrepare,
    kldrRdrFileMap,
    kldrRdrFileRefreshMap,
    kldrRdrFileProtect,
    kldrRdrFileUnmap,
    kldrRdrFileUnprepare,
    kldrRdrFileDone,
    42
};


/** @copydoc KLDRRDR::pfnDone */
static void     kldrRdrFileDone(PKLDRRDR pRdr)
{
}


/**
 * Finds a prepared mapping region.
 *
 * @returns Pointer to the aPrep entry.
 * @param   pFile   The instance data.
 * @param   pv      The base of the region.
 * @param   cb      The size of the region.
 */
static PKLDRRDRFILEPREP kldrRdrFileFindPrepExact(PKLDRRDRFILE pFile, void *pv, size_t cb)
{
    int32_t i = pFile->cPreps;
    while (i-- > 0)
        if (    pFile->aPreps[i].pv == pv
            ||  pFile->aPreps[i].cb == cb)
            return &pFile->aPreps[i];
    return NULL;
}


/**
 * Finds a prepared mapping region containing the specified region.
 *
 * @returns Pointer to the aPrep entry.
 * @param   pFile   The instance data.
 * @param   pv      The base of the sub region.
 * @param   cb      The size of the sub region.
 */
static PKLDRRDRFILEPREP kldrRdrFileFindPrepWithin(PKLDRRDRFILE pFile, void *pv, size_t cb)
{
    int32_t i = pFile->cPreps;
    while (i-- > 0)
        if ((uintptr_t)pv - (uintptr_t)pFile->aPreps[i].pv < pFile->aPreps[i].cb)
        {
            if ((uintptr_t)pv - (uintptr_t)pFile->aPreps[i].pv + cb <= pFile->aPreps[i].cb)
                return &pFile->aPreps[i];
            return NULL;
        }
    return NULL;
}


/** @copydoc KLDRRDR::pfnUnprepare */
static int      kldrRdrFileUnprepare(PKLDRRDR pRdr, void *pv, size_t cb)
{
    PKLDRRDRFILE        pRdrFile = (PKLDRRDRFILE)pRdr;
    PKLDRRDRFILEPREP    pPrep = kldrRdrFileFindPrepExact(pRdrFile, pv, cb);
    if (!pPrep)
        return KLDR_ERR_INVALID_PARAMETER;

    return -1;
}


/** @copydoc KLDRRDR::pfnUnmap */
static int      kldrRdrFileUnmap(PKLDRRDR pRdr, void *pv, size_t cb)
{
    PKLDRRDRFILE        pRdrFile = (PKLDRRDRFILE)pRdr;
    PKLDRRDRFILEPREP    pPrep = kldrRdrFileFindPrepExact(pRdrFile, pv, cb);
    if (!pPrep)
        return KLDR_ERR_INVALID_PARAMETER;

    return -1;
}


/** @copydoc KLDRRDR::pfnProtect */
static int      kldrRdrFileProtect(PKLDRRDR pRdr, void *pv, size_t cb, KLDRPROT enmProt)
{
    PKLDRRDRFILE        pRdrFile = (PKLDRRDRFILE)pRdr;
    PKLDRRDRFILEPREP    pPrep = kldrRdrFileFindPrepExact(pRdrFile, pv, cb);
    if (!pPrep)
        return KLDR_ERR_INVALID_PARAMETER;

    return -1;
}


/** @copydoc KLDRRDR::pfnRefreshMap */
static int      kldrRdrFileRefreshMap(PKLDRRDR pRdr, void *pv, size_t cb, KLDRPROT enmProt, off_t offFile, size_t cbFile)
{
    PKLDRRDRFILE        pRdrFile = (PKLDRRDRFILE)pRdr;
    PKLDRRDRFILEPREP    pPrep = kldrRdrFileFindPrepExact(pRdrFile, pv, cb);
    if (!pPrep)
        return KLDR_ERR_INVALID_PARAMETER;

    return -1;
}


/** @copydoc KLDRRDR::pfnMap */
static int      kldrRdrFileMap(PKLDRRDR pRdr, void *pv, size_t cb, KLDRPROT enmProt, off_t offFile, size_t cbFile)
{
    PKLDRRDRFILE        pRdrFile = (PKLDRRDRFILE)pRdr;
    PKLDRRDRFILEPREP    pPrep = kldrRdrFileFindPrepExact(pRdrFile, pv, cb);
    if (!pPrep)
        return KLDR_ERR_INVALID_PARAMETER;

    return -1;
}


/** @copydoc KLDRRDR:pfnPrepare */
static int      kldrRdrFilePrepare(PKLDRRDR pRdr, void **ppv, size_t cb, unsigned fFixed)
{
#ifdef __OS2__


#elif defined(__WIN__)

#else
# error "port me."
#endif
    return -1;
}


/** @copydoc KLDRRDR::pfnPageSize */
static size_t   kldrRdrFilePageSize(PKLDRRDR pRdr)
{
#ifdef __OS2__
    /* The page size on OS/2 wont change anytime soon. :-) */
    return 0x1000;

#elif defined(__WIN__)
    SYSTEM_INFO SysInfo;
    GetSystemInfo(&SysInfo);
    return SysInfo.dwPageSize;
    /*return SysInfo.dwAllocationGranularity;*/
#else
# error "port me"
#endif
}


/** @copydoc KLDRRDR::pfnName */
static const char *kldrRdrFileName(PKLDRRDR pRdr)
{
    PKLDRRDRFILE pRdrFile = (PKLDRRDRFILE)pRdr;
    return &pRdrFile->szFilename[0];
}


/** @copydoc KLDRRDR::pfnTell */
static off_t kldrRdrFileTell(PKLDRRDR pRdr)
{
    PKLDRRDRFILE pRdrFile = (PKLDRRDRFILE)pRdr;

    /*
     * If the offset is undefined, try figure out what it is.
     */
    if (pRdrFile->off == -1)
    {
#ifdef __OS2__
        ULONG ulNew;
        APIRET rc = DosSetFilePtr(pRdrFile->File, 0, FILE_CURRENT, &ulNew);
        if (rc)
            return -1;
        pRdrFile->off = ulNew;

#elif defined(__WIN__)
        LONG offHigh = 0;
        LONG offLow;
        int rc;

        SetLastError(0);
        offLow = SetFilePointer(pRdrFile->File, 0, &offHigh, FILE_CURRENT);
        rc = GetLastError();
        if (rc)
            return -1;
        pRdrFile->off = ((off_t)offHigh << 32) | offLow;

#else
# error "port me."
#endif
    }
    return pRdrFile->off;
}


/** @copydoc KLDRRDR::pfnSize */
static off_t kldrRdrFileSize(PKLDRRDR pRdr)
{
    PKLDRRDRFILE pRdrFile = (PKLDRRDRFILE)pRdr;
    return pRdrFile->cb;
}


/** @copydoc KLDRRDR::pfnAllUnmap */
static int kldrRdrFileAllUnmap(PKLDRRDR pRdr, const void *pvBits)
{
    PKLDRRDRFILE pRdrFile = (PKLDRRDRFILE)pRdr;

    /* check for underflow */
    if (pRdrFile->cMappings <= 0)
#if defined(__OS2__) || defined(__WIN__)
        return ERROR_INVALID_PARAMETER;
#else
# error "port me"
#endif

    /* decrement usage counter, free mapping if no longer in use. */
    if (!--pRdrFile->cMappings)
    {
        kldrHlpFree(pRdrFile->pvMapping);
        pRdrFile->pvMapping = NULL;
    }

    return 0;
}


/** @copydoc KLDRRDR::pfnAllMap */
static int kldrRdrFileAllMap(PKLDRRDR pRdr, const void **ppvBits)
{
    PKLDRRDRFILE pRdrFile = (PKLDRRDRFILE)pRdr;

    /*
     * Do we need to map it?
     */
    if (!pRdrFile->pvMapping)
    {
        int rc;
        off_t cb = pRdrFile->Core.pOps->pfnSize(pRdr);

        pRdrFile->pvMapping = kldrHlpAlloc(cb);
        if (!pRdrFile->pvMapping)
#if defined(__OS2__) || defined(__WIN__)
            return ERROR_NOT_ENOUGH_MEMORY;
#else
# error "port me"
#endif
        rc = pRdrFile->Core.pOps->pfnRead(pRdr, pRdrFile->pvMapping, cb, 0);
        if (rc)
        {
            kldrHlpFree(pRdrFile->pvMapping);
            pRdrFile->pvMapping = NULL;
            return rc;
        }
        pRdrFile->cMappings = 0;
    }

    pRdrFile->cMappings++;
    return 0;
}


/** @copydoc KLDRRDR::pfnRead */
static int kldrRdrFileRead(PKLDRRDR pRdr, void *pvBuf, size_t cb, off_t off)
{
    PKLDRRDRFILE pRdrFile = (PKLDRRDRFILE)pRdr;

    /*
     * Do a seek if needed.
     */
    if (pRdrFile->off != off)
    {
#ifdef __OS2__
        ULONG ulNew;
        APIRET rc;

        rc = DosSetFilePtr(pRdrFile->File, off, FILE_BEGIN, &ulNew);
        if (rc)
        {
            pRdrFile->off = -1;
            return rc;
        }

#elif defined(__WIN__)
        LONG offHigh;
        LONG offLow;

        offHigh = sizeof(off_t) == 4 ? 0 : (off >> 32);
        offLow = SetFilePointer(pRdrFile->File, (LONG)off, &offHigh, FILE_BEGIN);
        if (    offLow != (LONG)off
            ||  offHigh != (LONG)(sizeof(off_t) == 4 ? 0 : (off >> 32)))
        {
            int rc = GetLastError();
            if (!rc)
                rc = ERROR_GEN_FAILURE;
            pRdrFile->off = -1;
            return rc;
        }

#else
# error "port me."
#endif
    }

    /*
     * Do the read.
     */
#ifdef __OS2__
    {
    ULONG cbRead = 0;
    APIRET rc = DosRead(pRdrFile->File, pvBuf, cb, &cbRead);
    if (rc)
    {
        pRdrFile->off = -1;
        return rc;
    }
    if (cbRead != cb)
    {
        pRdrFile->off = -1;
        return ERROR_GEN_FAILURE;
    }
    }

#elif defined(__WIN__)
    {
    DWORD cbRead = 0;
    if (!ReadFile(pRdrFile->File, pvBuf, cb, &cbRead, NULL))
    {
        int rc = GetLastError();
        if (!rc)
            rc = ERROR_GEN_FAILURE;
        pRdrFile->off = -1;
        return rc;
    }
    if (cbRead != cb)
    {
        pRdrFile->off = -1;
        return ERROR_GEN_FAILURE;
    }
    }

#else
# error "port me."
#endif

    pRdrFile->off = off + cb;
    return 0;
}


/** @copydoc KLDRRDR::pfnDestroy */
static int kldrRdrFileDestroy(PKLDRRDR pRdr)
{
    PKLDRRDRFILE    pRdrFile = (PKLDRRDRFILE)pRdr;
    int             rc;
#ifdef __OS2__
    rc = DosClose(pRdrFile->File);

#elif defined(__WIN__)
    rc = 0;
    if (!CloseHandle(pRdrFile->File))
        rc = GetLastError();

#else
# error "port me"
#endif

    if (pRdrFile->pvMapping)
    {
        kldrHlpFree(pRdrFile->pvMapping);
        pRdrFile->pvMapping = NULL;
    }

    kldrHlpFree(pRdr);
    return rc;
}


/** @copydoc KLDRRDROPS::pfnCreate */
static int kldrRdrFileCreate(PPKLDRRDR ppRdr, const char *pszFilename)
{
    size_t          cchFilename;
    PKLDRRDRFILE    pRdrFile;

    /*
     * Open the file and determin its size.
     */
#ifdef __OS2__
    ULONG           ulAction = 0;
    FILESTATUS3     Info;
    APIRET          rc;
    HFILE           File = 0;
    off_t           cb;
    char            szFilename[CCHMAXPATH];

    if ((uintptr_t)pszFilename >= 0x20000000)
    {
        char *psz = (char *)kLdrHlpAllocA(cchFilename + 1);
        kLdrHlpMemCopy(psz, pszFilename, cchFilename + 1);
        pszFilename = psz;
    }
    rc = DosOpen((PCSZ)pszFilename, &File, &ulAction, 0, FILE_NORMAL,
                 OPEN_ACTION_OPEN_IF_EXISTS | OPEN_ACTION_FAIL_IF_NEW,
                 OPEN_FLAGS_NOINHERIT | OPEN_SHARE_DENYWRITE | OPEN_ACCESS_READONLY | OPEN_FLAGS_RANDOMSEQUENTIAL,
                 NULL);
    if (rc)
        return rc;

    rc = DosQueryPathInfo(pszFilename, FIL_QUERYFULLNAME, szFilename, sizeof(szFilename));
    if (rc)
    {
        DosClose(File);
        return rc;
    }

    rc = DosQueryFileInfo(File, FIL_STANDARD, &Info, sizeof(Info));
    if (rc)
    {
        DosClose(File);
        return rc;
    }
    cb = Info.cbFile;

#elif defined(__WIN__)
    SECURITY_ATTRIBUTES SecAttr;
    DWORD               High;
    DWORD               Low;
    int                 rc;
    HANDLE              File;
    off_t               cb;
    char                szFilename[MAX_PATH];

    SecAttr.bInheritHandle = FALSE;
    SecAttr.lpSecurityDescriptor = NULL;
    SecAttr.nLength = 0;
    File = CreateFile(pszFilename, GENERIC_READ, FILE_SHARE_READ, &SecAttr, OPEN_ALWAYS, 0, NULL);
    if (File == INVALID_HANDLE_VALUE)
        return GetLastError();

    if (!GetFullPathName(pszFilename, sizeof(szFilename), szFilename, NULL))
    {
        rc = GetLastError();
        CloseHandle(File);
        return rc;
    }

    SetLastError(0);
    Low = GetFileSize(File, &High);
    rc = GetLastError();
    if (rc)
    {
        CloseHandle(File);
        return rc;
    }
    if (sizeof(off_t) == 4)
        cb = High ? 0x7fffffff : Low;
    else
        cb = ((off_t)High << 32) | Low;

#else
# error "port me"
#endif


    /*
     * Allocate the reader instance.
     */
    cchFilename = kLdrHlpStrLen(szFilename);
    pRdrFile = (PKLDRRDRFILE)kldrHlpAlloc(sizeof(*pRdrFile) + cchFilename);
    if (!pRdrFile)
#if defined(__OS2__)
    {
        DosClose(File);
        return ERROR_NOT_ENOUGH_MEMORY;
    }
#elif defined(__WIN__)
    {
        CloseHandle(File);
        return ERROR_NOT_ENOUGH_MEMORY;
    }
#else
# error "port me"
#endif

    /*
     * Initialize it and return successfully.
     */
    pRdrFile->Core.u32Magic = KLDRRDR_MAGIC;
    pRdrFile->Core.pOps = &g_kLdrRdrFileOps;
    pRdrFile->File = File;
    pRdrFile->cb = cb;
    pRdrFile->off = 0;
    pRdrFile->cMappings = 0;
    pRdrFile->cPreps = 0;
    kLdrHlpMemCopy(&pRdrFile->szFilename[0], szFilename, cchFilename + 1);

    *ppRdr = &pRdrFile->Core;
    return 0;
}