// Copyright 2018 yuzu emulator team
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <sstream>
#include "common/assert.h"
#include "common/hex_util.h"
#include "common/swap.h"
#include "core/file_sys/ips_layer.h"
#include "core/file_sys/vfs_vector.h"
namespace FileSys {
enum class IPSFileType {
IPS,
IPS32,
Error,
};
const std::map<const char*, const char*> ESCAPE_CHARACTER_MAP{
{"\\a", "\a"}, {"\\b", "\b"}, {"\\f", "\f"}, {"\\n", "\n"}, {"\\r", "\r"}, {"\\t", "\t"},
{"\\v", "\v"}, {"\\\\", "\\"}, {"\\\'", "\'"}, {"\\\"", "\""}, {"\\\?", "\?"},
};
static IPSFileType IdentifyMagic(const std::vector<u8>& magic) {
if (magic.size() != 5)
return IPSFileType::Error;
if (magic == std::vector<u8>{'P', 'A', 'T', 'C', 'H'})
return IPSFileType::IPS;
if (magic == std::vector<u8>{'I', 'P', 'S', '3', '2'})
return IPSFileType::IPS32;
return IPSFileType::Error;
}
VirtualFile PatchIPS(const VirtualFile& in, const VirtualFile& ips) {
if (in == nullptr || ips == nullptr)
return nullptr;
const auto type = IdentifyMagic(ips->ReadBytes(0x5));
if (type == IPSFileType::Error)
return nullptr;
auto in_data = in->ReadAllBytes();
std::vector<u8> temp(type == IPSFileType::IPS ? 3 : 4);
u64 offset = 5; // After header
while (ips->Read(temp.data(), temp.size(), offset) == temp.size()) {
offset += temp.size();
if (type == IPSFileType::IPS32 && temp == std::vector<u8>{'E', 'E', 'O', 'F'} ||
type == IPSFileType::IPS && temp == std::vector<u8>{'E', 'O', 'F'}) {
break;
}
u32 real_offset{};
if (type == IPSFileType::IPS32)
real_offset = (temp[0] << 24) | (temp[1] << 16) | (temp[2] << 8) | temp[3];
else
real_offset = (temp[0] << 16) | (temp[1] << 8) | temp[2];
u16 data_size{};
if (ips->ReadObject(&data_size, offset) != sizeof(u16))
return nullptr;
data_size = Common::swap16(data_size);
offset += sizeof(u16);
if (data_size == 0) { // RLE
u16 rle_size{};
if (ips->ReadObject(&rle_size, offset) != sizeof(u16))
return nullptr;
rle_size = Common::swap16(data_size);
offset += sizeof(u16);
const auto data = ips->ReadByte(offset++);
if (data == boost::none)
return nullptr;
if (real_offset + rle_size > in_data.size())
rle_size = in_data.size() - real_offset;
std::memset(in_data.data() + real_offset, data.get(), rle_size);
} else { // Standard Patch
auto read = data_size;
if (real_offset + read > in_data.size())
read = in_data.size() - real_offset;
if (ips->Read(in_data.data() + real_offset, read, offset) != data_size)
return nullptr;
offset += data_size;
}
}
if (temp != std::vector<u8>{'E', 'E', 'O', 'F'} && temp != std::vector<u8>{'E', 'O', 'F'})
return nullptr;
return std::make_shared<VectorVfsFile>(in_data, in->GetName(), in->GetContainingDirectory());
}
IPSwitchCompiler::IPSwitchCompiler(VirtualFile patch_text_)
: valid(false), patch_text(std::move(patch_text_)), nso_build_id{}, is_little_endian(false),
offset_shift(0), print_values(false), last_comment("") {
Parse();
}
std::array<u8, 32> IPSwitchCompiler::GetBuildID() const {
return nso_build_id;
}
bool IPSwitchCompiler::IsValid() const {
return valid;
}
static bool StartsWith(const std::string& base, const std::string& check) {
return base.size() >= check.size() && base.substr(0, check.size()) == check;
}
static std::string EscapeStringSequences(std::string in) {
for (const auto& seq : ESCAPE_CHARACTER_MAP) {
for (auto index = in.find(seq.first); index != std::string::npos;
index = in.find(seq.first, index)) {
in.replace(index, std::strlen(seq.first), seq.second);
index += std::strlen(seq.second);
}
}
return in;
}
void IPSwitchCompiler::Parse() {
const auto bytes = patch_text->ReadAllBytes();
std::stringstream s;
s.write(reinterpret_cast<const char*>(bytes.data()), bytes.size());
std::vector<std::string> lines;
std::string line;
while (std::getline(s, line)) {
// Remove a trailing \r
if (!line.empty() && line[line.size() - 1] == '\r')
line = line.substr(0, line.size() - 1);
lines.push_back(line);
}
for (std::size_t i = 0; i < lines.size(); ++i) {
auto line = lines[i];
// Remove midline comments
if (!StartsWith(line, "//") && line.find("//") != std::string::npos) {
last_comment = line.substr(line.find("//") + 2);
line = line.substr(0, line.find("//"));
}
if (StartsWith(line, "@stop")) {
// Force stop
break;
} else if (StartsWith(line, "@nsobid-")) {
// NSO Build ID Specifier
auto raw_build_id = line.substr(8);
if (raw_build_id.size() != 0x40)
raw_build_id.resize(0x40, '0');
nso_build_id = Common::HexStringToArray<0x20>(raw_build_id);
} else if (StartsWith(line, "@flag offset_shift ")) {
// Offset Shift Flag
offset_shift = std::stoll(line.substr(19), nullptr, 0);
} else if (StartsWith(line, "#")) {
// Mandatory Comment
LOG_INFO(Loader, "[IPSwitchCompiler ('{}')] Forced output comment: {}",
patch_text->GetName(), line.substr(1));
} else if (StartsWith(line, "//")) {
// Normal Comment
last_comment = line.substr(2);
if (last_comment.find_first_not_of(' ') == std::string::npos)
continue;
if (last_comment.find_first_not_of(' ') != 0)
last_comment = last_comment.substr(last_comment.find_first_not_of(' '));
} else if (StartsWith(line, "@little-endian")) {
// Set values to read as little endian
is_little_endian = true;
} else if (StartsWith(line, "@big-endian")) {
// Set values to read as big endian
is_little_endian = false;
} else if (StartsWith(line, "@flag print_values")) {
// Force printing of applied values
print_values = true;
} else if (StartsWith(line, "@enabled") || StartsWith(line, "@disabled")) {
// Start of patch
const auto enabled = StartsWith(line, "@enabled");
if (i == 0)
return;
LOG_INFO(Loader, "[IPSwitchCompiler ('{}')] Parsing patch '{}' ({})",
patch_text->GetName(), last_comment, line.substr(1));
IPSwitchPatch patch{last_comment, enabled, {}};
// Read rest of patch
while (true) {
if (i + 1 >= lines.size())
break;
line = lines[++i];
// 11 - 8 hex digit offset + space + minimum two digit overwrite val
if (line.length() < 11)
break;
auto offset = std::stoul(line.substr(0, 8), nullptr, 16);
offset += offset_shift;
std::vector<u8> replace;
// 9 - first char of replacement val
if (line[9] == '\"') {
// string replacement
const auto end_index = line.find('\"', 10);
if (end_index == std::string::npos || end_index < 10)
return;
auto value = line.substr(10, end_index - 10);
value = EscapeStringSequences(value);
replace.reserve(value.size());
std::copy(value.begin(), value.end(), std::back_inserter(replace));
} else {
// hex replacement
const auto value = line.substr(9);
replace.reserve(value.size() / 2);
replace = Common::HexStringToVector(value, is_little_endian);
}
if (print_values) {
LOG_INFO(Loader,
"[IPSwitchCompiler ('{}')] - Patching value at offset 0x{:08X} "
"with byte string '{}'",
patch_text->GetName(), offset, Common::HexVectorToString(replace));
}
patch.records.emplace(offset, replace);
}
patches.push_back(std::move(patch));
}
}
valid = true;
}
VirtualFile IPSwitchCompiler::Apply(const VirtualFile& in) const {
if (in == nullptr || !valid)
return nullptr;
auto in_data = in->ReadAllBytes();
for (const auto& patch : patches) {
if (!patch.enabled)
continue;
for (const auto& record : patch.records) {
if (record.first >= in_data.size())
continue;
auto replace_size = record.second.size();
if (record.first + replace_size > in_data.size())
replace_size = in_data.size() - record.first;
for (std::size_t i = 0; i < replace_size; ++i)
in_data[i + record.first] = record.second[i];
}
}
return std::make_shared<VectorVfsFile>(in_data, in->GetName(), in->GetContainingDirectory());
}
} // namespace FileSys
