RetroArch/patch.c
twinaphex 8487cd0204 Start using C89-style for loop initial declarations for
reusable code module parts that we reuse in other projects. It's
a huge maintenance burden having to change this stuff around everytime
when compiling in non-C99 mode
2013-10-19 19:39:38 +02:00

402 lines
11 KiB
C

/* RetroArch - A frontend for libretro.
* Copyright (C) 2010-2013 - Hans-Kristian Arntzen
*
* RetroArch 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 Found-
* ation, either version 3 of the License, or (at your option) any later version.
*
* RetroArch 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 RetroArch.
* If not, see <http://www.gnu.org/licenses/>.
*/
// BPS/UPS/IPS implementation from bSNES (nall::).
// Modified for RetroArch.
#include "patch.h"
#include "hash.h"
#include "boolean.h"
#include "msvc/msvc_compat.h"
#include <stdint.h>
#include <string.h>
enum bps_mode
{
SOURCE_READ = 0,
TARGET_READ,
SOURCE_COPY,
TARGET_COPY
};
struct bps_data
{
const uint8_t *modify_data, *source_data;
uint8_t *target_data;
size_t modify_length, source_length, target_length;
size_t modify_offset, source_offset, target_offset;
uint32_t modify_checksum, source_checksum, target_checksum;
size_t source_relative_offset, target_relative_offset, output_offset;
};
static uint8_t bps_read(struct bps_data *bps)
{
uint8_t data = bps->modify_data[bps->modify_offset++];
bps->modify_checksum = crc32_adjust(bps->modify_checksum, data);
return data;
}
static uint64_t bps_decode(struct bps_data *bps)
{
uint64_t data = 0, shift = 1;
for (;;)
{
uint8_t x = bps_read(bps);
data += (x & 0x7f) * shift;
if (x & 0x80)
break;
shift <<= 7;
data += shift;
}
return data;
}
static void bps_write(struct bps_data *bps, uint8_t data)
{
bps->target_data[bps->output_offset++] = data;
bps->target_checksum = crc32_adjust(bps->target_checksum, data);
}
patch_error_t bps_apply_patch(
const uint8_t *modify_data, size_t modify_length,
const uint8_t *source_data, size_t source_length,
uint8_t *target_data, size_t *target_length)
{
size_t i;
if (modify_length < 19)
return PATCH_PATCH_TOO_SMALL;
struct bps_data bps = {0};
bps.modify_data = modify_data;
bps.modify_length = modify_length;
bps.target_data = target_data;
bps.target_length = *target_length;
bps.source_data = source_data;
bps.source_length = source_length;
bps.modify_checksum = ~0;
bps.target_checksum = ~0;
if ((bps_read(&bps) != 'B') || (bps_read(&bps) != 'P') || (bps_read(&bps) != 'S') || (bps_read(&bps) != '1'))
return PATCH_PATCH_INVALID_HEADER;
size_t modify_source_size = bps_decode(&bps);
size_t modify_target_size = bps_decode(&bps);
size_t modify_markup_size = bps_decode(&bps);
for (i = 0; i < modify_markup_size; i++)
bps_read(&bps);
if (modify_source_size > bps.source_length)
return PATCH_SOURCE_TOO_SMALL;
if (modify_target_size > bps.target_length)
return PATCH_TARGET_TOO_SMALL;
while (bps.modify_offset < bps.modify_length - 12)
{
size_t length = bps_decode(&bps);
unsigned mode = length & 3;
length = (length >> 2) + 1;
switch (mode)
{
case SOURCE_READ:
while (length--)
bps_write(&bps, bps.source_data[bps.output_offset]);
break;
case TARGET_READ:
while (length--)
bps_write(&bps, bps_read(&bps));
break;
case SOURCE_COPY:
case TARGET_COPY:
{
int offset = bps_decode(&bps);
bool negative = offset & 1;
offset >>= 1;
if (negative)
offset = -offset;
if (mode == SOURCE_COPY)
{
bps.source_offset += offset;
while (length--)
bps_write(&bps, bps.source_data[bps.source_offset++]);
}
else
{
bps.target_offset += offset;
while (length--)
bps_write(&bps, bps.target_data[bps.target_offset++]);
break;
}
break;
}
}
}
uint32_t modify_source_checksum = 0, modify_target_checksum = 0, modify_modify_checksum = 0;
for (i = 0; i < 32; i += 8)
modify_source_checksum |= bps_read(&bps) << i;
for (i = 0; i < 32; i += 8)
modify_target_checksum |= bps_read(&bps) << i;
uint32_t checksum = ~bps.modify_checksum;
for (i = 0; i < 32; i += 8)
modify_modify_checksum |= bps_read(&bps) << i;
bps.source_checksum = crc32_calculate(bps.source_data, bps.source_length);
bps.target_checksum = ~bps.target_checksum;
if (bps.source_checksum != modify_source_checksum)
return PATCH_SOURCE_CHECKSUM_INVALID;
if (bps.target_checksum != modify_target_checksum)
return PATCH_TARGET_CHECKSUM_INVALID;
if (checksum != modify_modify_checksum)
return PATCH_PATCH_CHECKSUM_INVALID;
*target_length = modify_target_size;
return PATCH_SUCCESS;
}
struct ups_data
{
const uint8_t *patch_data, *source_data;
uint8_t *target_data;
unsigned patch_length, source_length, target_length;
unsigned patch_offset, source_offset, target_offset;
unsigned patch_checksum, source_checksum, target_checksum;
};
static uint8_t ups_patch_read(struct ups_data *data)
{
if (data->patch_offset < data->patch_length)
{
uint8_t n = data->patch_data[data->patch_offset++];
data->patch_checksum = crc32_adjust(data->patch_checksum, n);
return n;
}
return 0x00;
}
static uint8_t ups_source_read(struct ups_data *data)
{
if (data->source_offset < data->source_length)
{
uint8_t n = data->source_data[data->source_offset++];
data->source_checksum = crc32_adjust(data->source_checksum, n);
return n;
}
return 0x00;
}
static void ups_target_write(struct ups_data *data, uint8_t n)
{
if (data->target_offset < data->target_length)
{
data->target_data[data->target_offset] = n;
data->target_checksum = crc32_adjust(data->target_checksum, n);
}
data->target_offset++;
}
static uint64_t ups_decode(struct ups_data *data)
{
uint64_t offset = 0, shift = 1;
while (true)
{
uint8_t x = ups_patch_read(data);
offset += (x & 0x7f) * shift;
if (x & 0x80)
break;
shift <<= 7;
offset += shift;
}
return offset;
}
patch_error_t ups_apply_patch(
const uint8_t *patchdata, size_t patchlength,
const uint8_t *sourcedata, size_t sourcelength,
uint8_t *targetdata, size_t *targetlength)
{
size_t i;
struct ups_data data = {0};
data.patch_data = patchdata;
data.source_data = sourcedata;
data.target_data = targetdata;
data.patch_length = patchlength;
data.source_length = sourcelength;
data.target_length = *targetlength;
data.patch_checksum = ~0;
data.source_checksum = ~0;
data.target_checksum = ~0;
if (data.patch_length < 18)
return PATCH_PATCH_INVALID;
if (ups_patch_read(&data) != 'U')
return PATCH_PATCH_INVALID;
if (ups_patch_read(&data) != 'P')
return PATCH_PATCH_INVALID;
if (ups_patch_read(&data) != 'S')
return PATCH_PATCH_INVALID;
if (ups_patch_read(&data) != '1')
return PATCH_PATCH_INVALID;
unsigned source_read_length = ups_decode(&data);
unsigned target_read_length = ups_decode(&data);
if (data.source_length != source_read_length && data.source_length != target_read_length)
return PATCH_SOURCE_INVALID;
*targetlength = (data.source_length == source_read_length ? target_read_length : source_read_length);
if (data.target_length < *targetlength)
return PATCH_TARGET_TOO_SMALL;
data.target_length = *targetlength;
while (data.patch_offset < data.patch_length - 12)
{
unsigned length = ups_decode(&data);
while (length--)
ups_target_write(&data, ups_source_read(&data));
while (true)
{
uint8_t patch_xor = ups_patch_read(&data);
ups_target_write(&data, patch_xor ^ ups_source_read(&data));
if (patch_xor == 0) break;
}
}
while (data.source_offset < data.source_length)
ups_target_write(&data, ups_source_read(&data));
while (data.target_offset < data.target_length)
ups_target_write(&data, ups_source_read(&data));
uint32_t patch_read_checksum = 0, source_read_checksum = 0, target_read_checksum = 0;
for (i = 0; i < 4; i++)
source_read_checksum |= ups_patch_read(&data) << (i * 8);
for (i = 0; i < 4; i++)
target_read_checksum |= ups_patch_read(&data) << (i * 8);
uint32_t patch_result_checksum = ~data.patch_checksum;
data.source_checksum = ~data.source_checksum;
data.target_checksum = ~data.target_checksum;
for (i = 0; i < 4; i++)
patch_read_checksum |= ups_patch_read(&data) << (i * 8);
if (patch_result_checksum != patch_read_checksum)
return PATCH_PATCH_INVALID;
if (data.source_checksum == source_read_checksum && data.source_length == source_read_length)
{
if (data.target_checksum == target_read_checksum && data.target_length == target_read_length)
return PATCH_SUCCESS;
return PATCH_TARGET_INVALID;
}
else if (data.source_checksum == target_read_checksum && data.source_length == target_read_length)
{
if (data.target_checksum == source_read_checksum && data.target_length == source_read_length)
return PATCH_SUCCESS;
return PATCH_TARGET_INVALID;
}
else
return PATCH_SOURCE_INVALID;
}
patch_error_t ips_apply_patch(
const uint8_t *patchdata, size_t patchlen,
const uint8_t *sourcedata, size_t sourcelength,
uint8_t *targetdata, size_t *targetlength)
{
if (patchlen < 8 ||
patchdata[0] != 'P' ||
patchdata[1] != 'A' ||
patchdata[2] != 'T' ||
patchdata[3] != 'C' ||
patchdata[4] != 'H')
return PATCH_PATCH_INVALID;
memcpy(targetdata, sourcedata, sourcelength);
uint32_t offset = 5;
*targetlength = sourcelength;
for (;;)
{
if (offset > patchlen - 3)
break;
uint32_t address = patchdata[offset++] << 16;
address |= patchdata[offset++] << 8;
address |= patchdata[offset++] << 0;
if (address == 0x454f46) // EOF
{
if (offset == patchlen)
return PATCH_SUCCESS;
else if (offset == patchlen - 3)
{
uint32_t size = patchdata[offset++] << 16;
size |= patchdata[offset++] << 8;
size |= patchdata[offset++] << 0;
*targetlength = size;
return PATCH_SUCCESS;
}
}
if (offset > patchlen - 2)
break;
unsigned length = patchdata[offset++] << 8;
length |= patchdata[offset++] << 0;
if (length) // Copy
{
if (offset > patchlen - length)
break;
while (length--)
targetdata[address++] = patchdata[offset++];
}
else // RLE
{
if (offset > patchlen - 3)
break;
length = patchdata[offset++] << 8;
length |= patchdata[offset++] << 0;
if (length == 0) // Illegal
break;
while (length--)
targetdata[address++] = patchdata[offset];
offset++;
}
if (address > *targetlength)
*targetlength = address;
}
return PATCH_PATCH_INVALID;
}