devilution/Source/mpqapi.cpp

/**
 * @file mpqapi.cpp
 *
 * Implementation of functions for creating and editing MPQ files.
 */
#include "all.h"
#include "../3rdParty/Storm/Source/storm.h"

DWORD sgdwMpqOffset;
char mpq_buf[4096];
_HASHENTRY *sgpHashTbl;
/** Has the savegame-file been modified in memory. */
BOOL save_archive_modified;
_BLOCKENTRY *sgpBlockTbl;
/** Is the savegame-file currently open. */
BOOLEAN save_archive_open;

//note: 32872 = 32768 + 104 (sizeof(_FILEHEADER))

/* data */

HANDLE sghArchive = INVALID_HANDLE_VALUE;

BOOL mpqapi_set_hidden(const char *pszArchive, BOOL hidden)
{
	DWORD dwFileAttributes;
	DWORD dwFileAttributesToSet;

	dwFileAttributes = GetFileAttributes(pszArchive);
	if (dwFileAttributes == INVALID_FILE_ATTRIBUTES)
		return GetLastError() == ERROR_FILE_NOT_FOUND;
	dwFileAttributesToSet = hidden ? FILE_ATTRIBUTE_SYSTEM | FILE_ATTRIBUTE_HIDDEN : 0;
	if (dwFileAttributes == dwFileAttributesToSet)
		return TRUE;
	else
		return SetFileAttributes(pszArchive, dwFileAttributesToSet);
}

void mpqapi_store_creation_time(const char *pszArchive, DWORD dwChar)
{
	HANDLE handle;
	struct _WIN32_FIND_DATAA FindFileData;
	char dst[160];

	if (gbMaxPlayers != 1) {
		mpqapi_reg_load_modification_time(dst, 160);
		handle = FindFirstFile(pszArchive, &FindFileData);
		if (handle != INVALID_HANDLE_VALUE) {
			FindClose(handle);
			*((FILETIME *)(dst) + dwChar * 2) = FindFileData.ftCreationTime;
			mpqapi_reg_store_modification_time(dst, 160);
		}
	}
}

BOOL mpqapi_reg_load_modification_time(char *dst, int size)
{
	char *pszDst;
	char *pbData;
	DWORD nbytes_read;

	pszDst = dst;
	memset(dst, 0, size);
#ifdef SPAWN
	if (!SRegLoadData("Diablo", "Audio Playback ", 0, (BYTE *)pszDst, size, &nbytes_read)) {
#else
	if (!SRegLoadData("Diablo", "Video Player ", 0, (BYTE *)pszDst, size, &nbytes_read)) {
#endif
		return FALSE;
	}

	if (nbytes_read != size)
		return FALSE;

	for (; size >= 8u; size -= 8) {
		pbData = pszDst;
		pszDst += 8;
		mpqapi_xor_buf(pbData);
	}

	return TRUE;
}

void mpqapi_xor_buf(char *pbData)
{
	DWORD mask;
	char *pbCurrentData;
	int i;

	mask = 0xF0761AB;
	pbCurrentData = pbData;

	for (i = 0; i < 8; i++) {
		*pbCurrentData ^= mask;
		pbCurrentData++;
		mask = _rotl(mask, 1);
	}
}

void mpqapi_store_default_time(DWORD dwChar)
{
	/*
	DWORD idx;
	char dst[160];

	if(gbMaxPlayers == 1) {
		return;
	}

	/// ASSERT: assert(dwChar < MAX_CHARACTERS);
	idx = 16 * dwChar;
	mpqapi_reg_load_modification_time(dst, sizeof(dst));
	*(DWORD *)&dst[idx + 4] = 0x78341348; // dwHighDateTime
	mpqapi_reg_store_modification_time(dst, sizeof(dst));
*/
}

BOOLEAN mpqapi_reg_store_modification_time(char *pbData, DWORD dwLen)
{
	char *pbCurrentData, *pbDataToXor;
	DWORD i;

	pbCurrentData = pbData;
	if (dwLen >= 8) {
		i = dwLen >> 3;
		do {
			pbDataToXor = pbCurrentData;
			pbCurrentData += 8;
			mpqapi_xor_buf(pbDataToXor);
			i--;
		} while (i);
	}

#ifdef SPAWN
	return SRegSaveData("Diablo", "Audio Playback ", 0, (BYTE *)pbData, dwLen);
#else
	return SRegSaveData("Diablo", "Video Player ", 0, (BYTE *)pbData, dwLen);
#endif
}

void mpqapi_remove_hash_entry(const char *pszName)
{
	_HASHENTRY *pHashTbl;
	_BLOCKENTRY *blockEntry;
	int hIdx, block_offset, block_size;

	hIdx = FetchHandle(pszName);
	if (hIdx != -1) {
		pHashTbl = &sgpHashTbl[hIdx];
		blockEntry = &sgpBlockTbl[pHashTbl->block];
		pHashTbl->block = -2;
		block_offset = blockEntry->offset;
		block_size = blockEntry->sizealloc;
		memset(blockEntry, 0, sizeof(*blockEntry));
		mpqapi_alloc_block(block_offset, block_size);
		save_archive_modified = TRUE;
	}
}

void mpqapi_alloc_block(int block_offset, int block_size)
{
	_BLOCKENTRY *block;
	int i;

	block = sgpBlockTbl;
	i = 2048;
	while (i-- != 0) {
		if (block->offset && !block->flags && !block->sizefile) {
			if (block->offset + block->sizealloc == block_offset) {
				block_offset = block->offset;
				block_size += block->sizealloc;
				memset(block, 0, sizeof(_BLOCKENTRY));
				mpqapi_alloc_block(block_offset, block_size);
				return;
			}
			if (block_offset + block_size == block->offset) {
				block_size += block->sizealloc;
				memset(block, 0, sizeof(_BLOCKENTRY));
				mpqapi_alloc_block(block_offset, block_size);
				return;
			}
		}
		block++;
	}
	if (block_offset + block_size > sgdwMpqOffset) {
		app_fatal("MPQ free list error");
	}
	if (block_offset + block_size == sgdwMpqOffset) {
		sgdwMpqOffset = block_offset;
	} else {
		block = mpqapi_new_block(NULL);
		block->offset = block_offset;
		block->sizealloc = block_size;
		block->sizefile = 0;
		block->flags = 0;
	}
}

_BLOCKENTRY *mpqapi_new_block(int *block_index)
{
	_BLOCKENTRY *blockEntry;
	DWORD i;

	blockEntry = sgpBlockTbl;

	i = 0;
	while (blockEntry->offset || blockEntry->sizealloc || blockEntry->flags || blockEntry->sizefile) {
		i++;
		blockEntry++;
		if (i >= 2048) {
			app_fatal("Out of free block entries");
			return NULL;
		}
	}
	if (block_index)
		*block_index = i;

	return blockEntry;
}

int FetchHandle(const char *pszName)
{
	return mpqapi_get_hash_index(Hash(pszName, 0), Hash(pszName, 1), Hash(pszName, 2), 0);
}

int mpqapi_get_hash_index(short index, int hash_a, int hash_b, int locale)
{
	int idx, i;

	i = 2048;
	for (idx = index & 0x7FF; sgpHashTbl[idx].block != -1; idx = (idx + 1) & 0x7FF) {
		if (!i--)
			break;
		if (sgpHashTbl[idx].hashcheck[0] == hash_a && sgpHashTbl[idx].hashcheck[1] == hash_b && sgpHashTbl[idx].lcid == locale && sgpHashTbl[idx].block != -2)
			return idx;
	}

	return -1;
}

void mpqapi_remove_hash_entries(BOOL(__stdcall *fnGetName)(DWORD, char *))
{
	DWORD dwIndex, i;
	char pszFileName[MAX_PATH];

	dwIndex = 1;
	for (i = fnGetName(0, pszFileName); i; i = fnGetName(dwIndex++, pszFileName)) {
		mpqapi_remove_hash_entry(pszFileName);
	}
}

BOOL mpqapi_write_file(const char *pszName, const BYTE *pbData, DWORD dwLen)
{
	_BLOCKENTRY *blockEntry;

	save_archive_modified = TRUE;
	mpqapi_remove_hash_entry(pszName);
	blockEntry = mpqapi_add_file(pszName, 0, 0);
	if (!mpqapi_write_file_contents(pszName, pbData, dwLen, blockEntry)) {
		mpqapi_remove_hash_entry(pszName);
		return FALSE;
	}
	return TRUE;
}

_BLOCKENTRY *mpqapi_add_file(const char *pszName, _BLOCKENTRY *pBlk, int block_index)
{
	DWORD h1, h2, h3;
	int i, hIdx;

	h1 = Hash(pszName, 0);
	h2 = Hash(pszName, 1);
	h3 = Hash(pszName, 2);
	if (mpqapi_get_hash_index(h1, h2, h3, 0) != -1)
		app_fatal("Hash collision between \"%s\" and existing file\n", pszName);
	hIdx = h1 & 0x7FF;
	i = 2048;
	while (i--) {
		if (sgpHashTbl[hIdx].block == -1 || sgpHashTbl[hIdx].block == -2)
			break;
		hIdx = (hIdx + 1) & 0x7FF;
	}
	if (i < 0)
		app_fatal("Out of hash space");
	if (!pBlk)
		pBlk = mpqapi_new_block(&block_index);

	sgpHashTbl[hIdx].hashcheck[0] = h2;
	sgpHashTbl[hIdx].hashcheck[1] = h3;
	sgpHashTbl[hIdx].lcid = 0;
	sgpHashTbl[hIdx].block = block_index;

	return pBlk;
}

BOOL mpqapi_write_file_contents(const char *pszName, const BYTE *pbData, DWORD dwLen, _BLOCKENTRY *pBlk)
{
	DWORD *sectoroffsettable;
	DWORD destsize, num_bytes, block_size, nNumberOfBytesToWrite;
	const BYTE *src;
	const char *tmp, *str_ptr;
	int i, j;

	str_ptr = pszName;
	src = pbData;
	while ((tmp = strchr(str_ptr, ':'))) {
		str_ptr = tmp + 1;
	}
	while ((tmp = strchr(str_ptr, '\\'))) {
		str_ptr = tmp + 1;
	}
	Hash(str_ptr, 3);
	num_bytes = (dwLen + 4095) >> 12;
	nNumberOfBytesToWrite = 4 * num_bytes + 4;
	pBlk->offset = mpqapi_find_free_block(dwLen + nNumberOfBytesToWrite, &pBlk->sizealloc);
	pBlk->sizefile = dwLen;
	pBlk->flags = 0x80000100;
	if (SetFilePointer(sghArchive, pBlk->offset, NULL, FILE_BEGIN) == (DWORD)-1)
		return FALSE;
	j = 0;
	destsize = 0;
	sectoroffsettable = NULL;
	while (dwLen != 0) {
		DWORD len;
		for (i = 0; i < 4096; i++)
			mpq_buf[i] -= 86;
		len = dwLen;
		if (dwLen >= 4096)
			len = 4096;
		memcpy(mpq_buf, src, len);
		src += len;
		len = PkwareCompress(mpq_buf, len);
		if (j == 0) {
			nNumberOfBytesToWrite = 4 * num_bytes + 4;
			sectoroffsettable = (DWORD *)DiabloAllocPtr(nNumberOfBytesToWrite);
			memset(sectoroffsettable, 0, nNumberOfBytesToWrite);
			if (!WriteFile(sghArchive, sectoroffsettable, nNumberOfBytesToWrite, &nNumberOfBytesToWrite, 0)) {
				goto on_error;
			}
			destsize += nNumberOfBytesToWrite;
		}
		sectoroffsettable[j] = destsize;
		if (!WriteFile(sghArchive, mpq_buf, len, &len, NULL)) {
			goto on_error;
		}
		j++;
		if (dwLen > 4096)
			dwLen -= 4096;
		else
			dwLen = 0;
		destsize += len;
	}

	sectoroffsettable[j] = destsize;
	if (SetFilePointer(sghArchive, -destsize, NULL, FILE_CURRENT) == (DWORD)-1) {
		goto on_error;
	}

	if (!WriteFile(sghArchive, sectoroffsettable, nNumberOfBytesToWrite, &nNumberOfBytesToWrite, 0)) {
		goto on_error;
	}

	if (SetFilePointer(sghArchive, destsize - nNumberOfBytesToWrite, NULL, FILE_CURRENT) == (DWORD)-1) {
		goto on_error;
	}

	mem_free_dbg(sectoroffsettable);
	if (destsize < pBlk->sizealloc) {
		block_size = pBlk->sizealloc - destsize;
		if (block_size >= 1024) {
			pBlk->sizealloc = destsize;
			mpqapi_alloc_block(pBlk->sizealloc + pBlk->offset, block_size);
		}
	}
	return TRUE;
on_error:
	if (sectoroffsettable)
		mem_free_dbg(sectoroffsettable);
	return FALSE;
}

int mpqapi_find_free_block(int size, int *block_size)
{
	_BLOCKENTRY *pBlockTbl;
	int i, result;

	pBlockTbl = sgpBlockTbl;
	i = 2048;
	while (1) {
		i--;
		if (pBlockTbl->offset && !pBlockTbl->flags && !pBlockTbl->sizefile && (DWORD)pBlockTbl->sizealloc >= size)
			break;
		pBlockTbl++;
		if (!i) {
			*block_size = size;
			result = sgdwMpqOffset;
			sgdwMpqOffset += size;
			return result;
		}
	}

	result = pBlockTbl->offset;
	*block_size = size;
	pBlockTbl->offset += size;
	pBlockTbl->sizealloc -= size;

	if (!pBlockTbl->sizealloc)
		memset(pBlockTbl, 0, sizeof(*pBlockTbl));

	return result;
}

void mpqapi_rename(char *pszOld, char *pszNew)
{
	int index, block;
	_HASHENTRY *hashEntry;
	_BLOCKENTRY *blockEntry;

	index = FetchHandle(pszOld);
	if (index != -1) {
		hashEntry = &sgpHashTbl[index];
		block = hashEntry->block;
		blockEntry = &sgpBlockTbl[block];
		hashEntry->block = -2;
		mpqapi_add_file(pszNew, blockEntry, block);
		save_archive_modified = TRUE;
	}
}

BOOL mpqapi_has_file(const char *pszName)
{
	return FetchHandle(pszName) != -1;
}

BOOL OpenMPQ(const char *pszArchive, BOOL hidden, DWORD dwChar)
{
	DWORD dwFlagsAndAttributes;
	DWORD key;
	DWORD dwTemp;
	_FILEHEADER fhdr;

	InitHash();
	if (!mpqapi_set_hidden(pszArchive, hidden)) {
		return FALSE;
	}
	dwFlagsAndAttributes = gbMaxPlayers > 1 ? FILE_FLAG_WRITE_THROUGH : 0;
	save_archive_open = FALSE;
	sghArchive = CreateFile(pszArchive, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, dwFlagsAndAttributes, NULL);
	if (sghArchive == INVALID_HANDLE_VALUE) {
		sghArchive = CreateFile(pszArchive, GENERIC_READ | GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, dwFlagsAndAttributes | (hidden ? FILE_ATTRIBUTE_SYSTEM | FILE_ATTRIBUTE_HIDDEN : 0), NULL);
		if (sghArchive == INVALID_HANDLE_VALUE)
			return FALSE;
		save_archive_open = TRUE;
		save_archive_modified = TRUE;
	}
	if (sgpBlockTbl == NULL || sgpHashTbl == NULL) {
		memset(&fhdr, 0, sizeof(fhdr));
		if (ParseMPQHeader(&fhdr, &sgdwMpqOffset) == FALSE) {
			goto on_error;
		}
		sgpBlockTbl = (_BLOCKENTRY *)DiabloAllocPtr(0x8000);
		memset(sgpBlockTbl, 0, 0x8000);
		if (fhdr.blockcount) {
			if (SetFilePointer(sghArchive, 104, NULL, FILE_BEGIN) == -1)
				goto on_error;
			if (!ReadFile(sghArchive, sgpBlockTbl, 0x8000, &dwTemp, NULL))
				goto on_error;
			key = Hash("(block table)", 3);
			Decrypt(sgpBlockTbl, 0x8000, key);
		}
		sgpHashTbl = (_HASHENTRY *)DiabloAllocPtr(0x8000);
		memset(sgpHashTbl, 255, 0x8000);
		if (fhdr.hashcount) {
			if (SetFilePointer(sghArchive, 32872, NULL, FILE_BEGIN) == -1)
				goto on_error;
			if (!ReadFile(sghArchive, sgpHashTbl, 0x8000, &dwTemp, NULL))
				goto on_error;
			key = Hash("(hash table)", 3);
			Decrypt(sgpHashTbl, 0x8000, key);
		}
		return TRUE;
	}
	return TRUE;
on_error:
	CloseMPQ(pszArchive, TRUE, dwChar);
	return FALSE;
}

BOOL ParseMPQHeader(_FILEHEADER *pHdr, DWORD *pdwNextFileStart)
{
	DWORD size;
	DWORD NumberOfBytesRead;

	size = GetFileSize(sghArchive, 0);
	*pdwNextFileStart = size;

	if (size == -1
	    || size < sizeof(*pHdr)
	    || !ReadFile(sghArchive, pHdr, sizeof(*pHdr), &NumberOfBytesRead, NULL)
	    || NumberOfBytesRead != 104
	    || pHdr->signature != '\x1AQPM'
	    || pHdr->headersize != 32
	    || pHdr->version > 0
	    || pHdr->sectorsizeid != 3
	    || pHdr->filesize != size
	    || pHdr->hashoffset != 32872
	    || pHdr->blockoffset != 104
	    || pHdr->hashcount != 2048
	    || pHdr->blockcount != 2048) {

		if (SetFilePointer(sghArchive, 0, NULL, FILE_BEGIN) == -1)
			return FALSE;
		if (!SetEndOfFile(sghArchive))
			return FALSE;

		memset(pHdr, 0, sizeof(*pHdr));
		pHdr->signature = '\x1AQPM';
		pHdr->headersize = 32;
		pHdr->sectorsizeid = 3;
		pHdr->version = 0;
		*pdwNextFileStart = 0x10068;
		save_archive_modified = TRUE;
		save_archive_open = TRUE;
	}

	return TRUE;
}

void CloseMPQ(const char *pszArchive, BOOL bFree, DWORD dwChar)
{
	if (bFree) {
		MemFreeDbg(sgpBlockTbl);
		MemFreeDbg(sgpHashTbl);
	}
	if (sghArchive != INVALID_HANDLE_VALUE) {
		CloseHandle(sghArchive);
		sghArchive = INVALID_HANDLE_VALUE;
	}
	if (save_archive_modified) {
		save_archive_modified = FALSE;
		mpqapi_store_modified_time(pszArchive, dwChar);
	}
	if (save_archive_open) {
		save_archive_open = FALSE;
		mpqapi_store_creation_time(pszArchive, dwChar);
	}
}

void mpqapi_store_modified_time(const char *pszArchive, DWORD dwChar)
{
	HANDLE handle;
	struct _WIN32_FIND_DATAA FindFileData;
	char dst[160];

	if (gbMaxPlayers != 1) {
		mpqapi_reg_load_modification_time(dst, 160);
		handle = FindFirstFile(pszArchive, &FindFileData);
		if (handle != INVALID_HANDLE_VALUE) {
			FindClose(handle);
			*((FILETIME *)(dst) + dwChar * 2 + 1) = FindFileData.ftLastWriteTime;
			mpqapi_reg_store_modification_time(dst, 160);
		}
	}
}

BOOL mpqapi_flush_and_close(const char *pszArchive, BOOL bFree, DWORD dwChar)
{
	BOOL ret = FALSE;
	if (sghArchive == INVALID_HANDLE_VALUE)
		ret = TRUE;
	else {
		ret = FALSE;
		if (!save_archive_modified)
			ret = TRUE;
		else if (mpqapi_can_seek() && WriteMPQHeader() && mpqapi_write_block_table()) {
			if (mpqapi_write_hash_table())
				ret = TRUE;
			else
				ret = FALSE;
		}
	}
	CloseMPQ(pszArchive, bFree, dwChar);
	return ret;
}

BOOL WriteMPQHeader()
{
	_FILEHEADER fhdr;
	DWORD NumberOfBytesWritten;

	memset(&fhdr, 0, sizeof(fhdr));
	fhdr.signature = '\x1AQPM';
	fhdr.headersize = 32;
	fhdr.filesize = GetFileSize(sghArchive, 0);
	fhdr.version = 0;
	fhdr.sectorsizeid = 3;
	fhdr.hashoffset = 32872;
	fhdr.blockoffset = 104;
	fhdr.hashcount = 2048;
	fhdr.blockcount = 2048;

	if (SetFilePointer(sghArchive, 0, NULL, FILE_BEGIN) == -1)
		return FALSE;
	if (!WriteFile(sghArchive, &fhdr, sizeof(fhdr), &NumberOfBytesWritten, 0))
		return FALSE;

	return NumberOfBytesWritten == 104;
}

BOOL mpqapi_write_block_table()
{
	BOOL success;
	DWORD NumberOfBytesWritten;

	if (SetFilePointer(sghArchive, 104, NULL, FILE_BEGIN) == -1)
		return FALSE;

	Encrypt(sgpBlockTbl, 0x8000, Hash("(block table)", 3));
	success = WriteFile(sghArchive, sgpBlockTbl, 0x8000, &NumberOfBytesWritten, 0);
	Decrypt(sgpBlockTbl, 0x8000, Hash("(block table)", 3));
	return success && NumberOfBytesWritten == 0x8000;
}

BOOL mpqapi_write_hash_table()
{
	BOOL success;
	DWORD NumberOfBytesWritten;

	if (SetFilePointer(sghArchive, 32872, NULL, FILE_BEGIN) == -1)
		return FALSE;

	Encrypt(sgpHashTbl, 0x8000, Hash("(hash table)", 3));
	success = WriteFile(sghArchive, sgpHashTbl, 0x8000, &NumberOfBytesWritten, 0);
	Decrypt(sgpHashTbl, 0x8000, Hash("(hash table)", 3));
	return success && NumberOfBytesWritten == 0x8000;
}

BOOL mpqapi_can_seek()
{
	if (SetFilePointer(sghArchive, sgdwMpqOffset, NULL, FILE_BEGIN) == -1)
		return FALSE;
	return SetEndOfFile(sghArchive);
}