ips_layer: Add IPSwitchCompiler to process IPSwitch format

This commit is contained in:
Zach Hilman 2018-09-30 18:13:22 -04:00
parent f62227aa95
commit 306739c2c4
2 changed files with 168 additions and 0 deletions

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@ -2,7 +2,9 @@
// Licensed under GPLv2 or any later version // Licensed under GPLv2 or any later version
// Refer to the license.txt file included. // Refer to the license.txt file included.
#include <sstream>
#include "common/assert.h" #include "common/assert.h"
#include "common/hex_util.h"
#include "common/swap.h" #include "common/swap.h"
#include "core/file_sys/ips_layer.h" #include "core/file_sys/ips_layer.h"
#include "core/file_sys/vfs_vector.h" #include "core/file_sys/vfs_vector.h"
@ -85,4 +87,144 @@ VirtualFile PatchIPS(const VirtualFile& in, const VirtualFile& ips) {
return std::make_shared<VectorVfsFile>(in_data, in->GetName(), in->GetContainingDirectory()); 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) {
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;
}
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];
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::stoull(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, "@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;
const auto name = lines[i - 1].substr(3);
LOG_INFO(Loader, "[IPSwitchCompiler ('{}')] Parsing patch '{}' ({})",
patch_text->GetName(), name, line.substr(1));
IPSwitchPatch patch{name, 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_last_of('\"');
if (end_index == std::string::npos || end_index < 10)
return;
const auto value = line.substr(10, end_index - 10);
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 } // namespace FileSys

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@ -12,4 +12,30 @@ namespace FileSys {
VirtualFile PatchIPS(const VirtualFile& in, const VirtualFile& ips); VirtualFile PatchIPS(const VirtualFile& in, const VirtualFile& ips);
class IPSwitchCompiler {
public:
explicit IPSwitchCompiler(VirtualFile patch_text);
std::array<u8, 0x20> GetBuildID() const;
bool IsValid() const;
VirtualFile Apply(const VirtualFile& in) const;
private:
void Parse();
bool valid;
struct IPSwitchPatch {
std::string name;
bool enabled;
std::map<u32, std::vector<u8>> records;
};
VirtualFile patch_text;
std::vector<IPSwitchPatch> patches;
std::array<u8, 0x20> nso_build_id;
bool is_little_endian;
u64 offset_shift;
bool print_values;
};
} // namespace FileSys } // namespace FileSys