Merge pull request #5036 from leoetlino/bps

file_sys: Add support for BPS patching
This commit is contained in:
James Rowe 2020-01-15 12:04:54 -07:00 committed by GitHub
commit cd86c9b043
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6 changed files with 318 additions and 63 deletions

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@ -74,6 +74,8 @@ add_library(core STATIC
file_sys/ivfc_archive.h
file_sys/ncch_container.cpp
file_sys/ncch_container.h
file_sys/patch.cpp
file_sys/patch.h
file_sys/path_parser.cpp
file_sys/path_parser.h
file_sys/romfs_reader.cpp

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@ -12,6 +12,7 @@
#include "common/logging/log.h"
#include "core/core.h"
#include "core/file_sys/ncch_container.h"
#include "core/file_sys/patch.h"
#include "core/file_sys/seed_db.h"
#include "core/hw/aes/key.h"
#include "core/loader/loader.h"
@ -24,53 +25,6 @@ namespace FileSys {
static const int kMaxSections = 8; ///< Maximum number of sections (files) in an ExeFs
static const int kBlockSize = 0x200; ///< Size of ExeFS blocks (in bytes)
/**
* Attempts to patch a buffer using an IPS
* @param ips Vector of the patches to apply
* @param buffer Vector to patch data into
*/
static void ApplyIPS(std::vector<u8>& ips, std::vector<u8>& buffer) {
u32 cursor = 5;
u32 patch_length = ips.size() - 3;
std::string ips_header(ips.begin(), ips.begin() + 5);
if (ips_header != "PATCH") {
LOG_INFO(Service_FS, "Attempted to load invalid IPS");
return;
}
while (cursor < patch_length) {
std::string eof_check(ips.begin() + cursor, ips.begin() + cursor + 3);
if (eof_check == "EOF")
return;
u32 offset = ips[cursor] << 16 | ips[cursor + 1] << 8 | ips[cursor + 2];
std::size_t length = ips[cursor + 3] << 8 | ips[cursor + 4];
// check for an rle record
if (length == 0) {
length = ips[cursor + 5] << 8 | ips[cursor + 6];
if (buffer.size() < offset + length)
return;
for (u32 i = 0; i < length; ++i)
buffer[offset + i] = ips[cursor + 7];
cursor += 8;
continue;
}
if (buffer.size() < offset + length)
return;
std::memcpy(&buffer[offset], &ips[cursor + 5], length);
cursor += length + 5;
}
}
/**
* Get the decompressed size of an LZSS compressed ExeFS file
* @param buffer Buffer of compressed file
@ -553,20 +507,32 @@ Loader::ResultStatus NCCHContainer::LoadSectionExeFS(const char* name, std::vect
return Loader::ResultStatus::ErrorNotUsed;
}
bool NCCHContainer::ApplyIPSPatch(std::vector<u8>& code) const {
const std::string override_ips = filepath + ".exefsdir/code.ips";
Loader::ResultStatus NCCHContainer::ApplyCodePatch(std::vector<u8>& code) const {
struct PatchLocation {
std::string path;
bool (*patch_fn)(const std::vector<u8>& patch, std::vector<u8>& code);
};
const std::array<PatchLocation, 2> patch_paths{{
{filepath + ".exefsdir/code.ips", Patch::ApplyIpsPatch},
{filepath + ".exefsdir/code.bps", Patch::ApplyBpsPatch},
}};
FileUtil::IOFile ips_file{override_ips, "rb"};
if (!ips_file)
return false;
for (const PatchLocation& info : patch_paths) {
FileUtil::IOFile file{info.path, "rb"};
if (!file)
continue;
std::vector<u8> ips(ips_file.GetSize());
if (ips_file.ReadBytes(ips.data(), ips.size()) != ips.size())
return false;
std::vector<u8> patch(file.GetSize());
if (file.ReadBytes(patch.data(), patch.size()) != patch.size())
return Loader::ResultStatus::Error;
LOG_INFO(Service_FS, "File {} patching code.bin", override_ips);
ApplyIPS(ips, code);
return true;
LOG_INFO(Service_FS, "File {} patching code.bin", info.path);
if (!info.patch_fn(patch, code))
return Loader::ResultStatus::Error;
return Loader::ResultStatus::Success;
}
return Loader::ResultStatus::ErrorNotUsed;
}
Loader::ResultStatus NCCHContainer::LoadOverrideExeFSSection(const char* name,

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@ -272,11 +272,11 @@ public:
Loader::ResultStatus ReadExtdataId(u64& extdata_id);
/**
* Apply an IPS patch for .code (if it exists).
* Apply a patch for .code (if it exists).
* This should only be called after allocating .bss.
* @return bool true if a patch was applied, false otherwise
* @return ResultStatus success if a patch was applied, ErrorNotUsed if no patch was found
*/
bool ApplyIPSPatch(std::vector<u8>& code) const;
Loader::ResultStatus ApplyCodePatch(std::vector<u8>& code) const;
/**
* Checks whether the NCCH container contains an ExeFS

268
src/core/file_sys/patch.cpp Normal file
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@ -0,0 +1,268 @@
// Copyright 2019 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <array>
#include <cstring>
#include <optional>
#include <string>
#include <string_view>
#include <type_traits>
#include <boost/crc.hpp>
#include "common/logging/log.h"
#include "core/file_sys/patch.h"
namespace FileSys::Patch {
bool ApplyIpsPatch(const std::vector<u8>& ips, std::vector<u8>& buffer) {
u32 cursor = 5;
u32 patch_length = ips.size() - 3;
std::string ips_header(ips.begin(), ips.begin() + 5);
if (ips_header != "PATCH") {
LOG_INFO(Service_FS, "Attempted to load invalid IPS");
return false;
}
while (cursor < patch_length) {
std::string eof_check(ips.begin() + cursor, ips.begin() + cursor + 3);
if (eof_check == "EOF")
return false;
u32 offset = ips[cursor] << 16 | ips[cursor + 1] << 8 | ips[cursor + 2];
std::size_t length = ips[cursor + 3] << 8 | ips[cursor + 4];
// check for an rle record
if (length == 0) {
length = ips[cursor + 5] << 8 | ips[cursor + 6];
if (buffer.size() < offset + length)
return false;
for (u32 i = 0; i < length; ++i)
buffer[offset + i] = ips[cursor + 7];
cursor += 8;
continue;
}
if (buffer.size() < offset + length)
return false;
std::memcpy(&buffer[offset], &ips[cursor + 5], length);
cursor += length + 5;
}
return true;
}
namespace Bps {
// The BPS format uses variable length encoding for all integers.
// Realistically uint32s are more than enough for code patching.
using Number = u32;
constexpr std::size_t FooterSize = 12;
// The BPS format uses CRC32 checksums.
static u32 crc32(const u8* data, std::size_t size) {
boost::crc_32_type result;
result.process_bytes(data, size);
return result.checksum();
}
// Utility class to make keeping track of offsets and bound checks less error prone.
template <typename T>
class Stream {
public:
Stream(T* ptr, std::size_t size) : m_ptr{ptr}, m_size{size} {}
bool Read(void* buffer, std::size_t length) {
if (m_offset + length > m_size)
return false;
std::memcpy(buffer, m_ptr + m_offset, length);
m_offset += length;
return true;
}
template <typename OtherType>
bool CopyFrom(Stream<OtherType>& other, std::size_t length) {
if (m_offset + length > m_size)
return false;
if (!other.Read(m_ptr + m_offset, length))
return false;
m_offset += length;
return true;
}
template <typename ValueType>
std::optional<ValueType> Read() {
static_assert(std::is_pod_v<ValueType>);
ValueType val{};
if (!Read(&val, sizeof(val)))
return std::nullopt;
return val;
}
Number ReadNumber() {
Number data = 0, shift = 1;
std::optional<u8> x;
while ((x = Read<u8>())) {
data += (*x & 0x7f) * shift;
if (*x & 0x80)
break;
shift <<= 7;
data += shift;
}
return data;
}
auto data() const {
return m_ptr;
}
std::size_t size() const {
return m_size;
}
std::size_t Tell() const {
return m_offset;
}
bool Seek(size_t offset) {
if (offset > m_size)
return false;
m_offset = offset;
return true;
}
private:
T* m_ptr = nullptr;
std::size_t m_size = 0;
std::size_t m_offset = 0;
};
class PatchApplier {
public:
PatchApplier(Stream<const u8> source, Stream<u8> target, Stream<const u8> patch)
: m_source{source}, m_target{target}, m_patch{patch} {}
bool Apply() {
const auto magic = *m_patch.Read<std::array<char, 4>>();
if (std::string_view(magic.data(), magic.size()) != "BPS1") {
LOG_ERROR(Service_FS, "Invalid BPS magic");
return false;
}
const Bps::Number source_size = m_patch.ReadNumber();
const Bps::Number target_size = m_patch.ReadNumber();
const Bps::Number metadata_size = m_patch.ReadNumber();
if (source_size > m_source.size() || target_size > m_target.size() || metadata_size != 0) {
LOG_ERROR(Service_FS, "Invalid sizes");
return false;
}
const std::size_t command_start_offset = m_patch.Tell();
const std::size_t command_end_offset = m_patch.size() - FooterSize;
m_patch.Seek(command_end_offset);
const u32 source_crc32 = *m_patch.Read<u32>();
const u32 target_crc32 = *m_patch.Read<u32>();
m_patch.Seek(command_start_offset);
if (crc32(m_source.data(), source_size) != source_crc32) {
LOG_ERROR(Service_FS, "Unexpected source hash");
return false;
}
// Process all patch commands.
std::memset(m_target.data(), 0, m_target.size());
while (m_patch.Tell() < command_end_offset) {
if (!HandleCommand())
return false;
}
if (crc32(m_target.data(), target_size) != target_crc32) {
LOG_ERROR(Service_FS, "Unexpected target hash");
return false;
}
return true;
}
private:
bool HandleCommand() {
const std::size_t offset = m_patch.Tell();
const Number data = m_patch.ReadNumber();
const Number command = data & 3;
const Number length = (data >> 2) + 1;
const bool ok = [&] {
switch (command) {
case 0:
return SourceRead(length);
case 1:
return TargetRead(length);
case 2:
return SourceCopy(length);
case 3:
return TargetCopy(length);
default:
return false;
}
}();
if (!ok)
LOG_ERROR(Service_FS, "Failed to process command {} at 0x{:x}", command, offset);
return ok;
}
bool SourceRead(Number length) {
return m_source.Seek(m_target.Tell()) && m_target.CopyFrom(m_source, length);
}
bool TargetRead(Number length) {
return m_target.CopyFrom(m_patch, length);
}
bool SourceCopy(Number length) {
const Number data = m_patch.ReadNumber();
m_source_relative_offset += (data & 1 ? -1 : +1) * int(data >> 1);
if (!m_source.Seek(m_source_relative_offset) || !m_target.CopyFrom(m_source, length))
return false;
m_source_relative_offset += length;
return true;
}
bool TargetCopy(Number length) {
const Number data = m_patch.ReadNumber();
m_target_relative_offset += (data & 1 ? -1 : +1) * int(data >> 1);
if (m_target.Tell() + length > m_target.size())
return false;
if (m_target_relative_offset + length > m_target.size())
return false;
// Byte by byte copy.
for (size_t i = 0; i < length; ++i)
m_target.data()[m_target.Tell() + i] = m_target.data()[m_target_relative_offset++];
m_target.Seek(m_target.Tell() + length);
return true;
}
std::size_t m_source_relative_offset = 0;
std::size_t m_target_relative_offset = 0;
Stream<const u8> m_source;
Stream<u8> m_target;
Stream<const u8> m_patch;
};
} // namespace Bps
bool ApplyBpsPatch(const std::vector<u8>& patch, std::vector<u8>& buffer) {
const std::vector<u8> source = buffer;
Bps::Stream source_stream{source.data(), source.size()};
Bps::Stream target_stream{buffer.data(), buffer.size()};
Bps::Stream patch_stream{patch.data(), patch.size()};
Bps::PatchApplier applier{source_stream, target_stream, patch_stream};
return applier.Apply();
}
} // namespace FileSys::Patch

17
src/core/file_sys/patch.h Normal file
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@ -0,0 +1,17 @@
// Copyright 2019 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <vector>
#include "common/common_types.h"
namespace FileSys::Patch {
bool ApplyIpsPatch(const std::vector<u8>& patch, std::vector<u8>& buffer);
bool ApplyBpsPatch(const std::vector<u8>& patch, std::vector<u8>& buffer);
} // namespace FileSys::Patch

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@ -100,8 +100,10 @@ ResultStatus AppLoader_NCCH::LoadExec(std::shared_ptr<Kernel::Process>& process)
overlay_ncch->exheader_header.codeset_info.data.num_max_pages * Memory::PAGE_SIZE +
bss_page_size;
// Apply any IPS patch now that the entire codeset (including .bss) has been allocated
overlay_ncch->ApplyIPSPatch(code);
// Apply patches now that the entire codeset (including .bss) has been allocated
const ResultStatus patch_result = overlay_ncch->ApplyCodePatch(code);
if (patch_result != ResultStatus::Success && patch_result != ResultStatus::ErrorNotUsed)
return patch_result;
codeset->entrypoint = codeset->CodeSegment().addr;
codeset->memory = std::move(code);