improved file scanners

This commit is contained in:
2026-06-10 04:29:52 +03:00
parent ce589b4f17
commit 00287c7a58
9 changed files with 660 additions and 78 deletions
+93 -9
View File
@@ -304,8 +304,8 @@ namespace
elf_headers);
}
template<class FileHeader, class SectionHeader>
std::optional<std::uintptr_t> scan_in_module_impl(const std::byte* base, const std::string_view pattern,
template<class FileHeader, class SectionHeader, class ScanPattern>
std::optional<std::uintptr_t> scan_in_module_impl(const std::byte* base, const ScanPattern scan_pattern,
const std::string_view target_section_name)
{
const auto* file_header = reinterpret_cast<const FileHeader*>(base);
@@ -336,13 +336,14 @@ namespace
continue;
const auto* section_begin = base + static_cast<std::size_t>(section->sh_addr);
const auto* section_end = section_begin + static_cast<std::size_t>(section->sh_size);
const auto scan_range =
std::span<const std::byte>{section_begin, static_cast<std::size_t>(section->sh_size)};
const auto scan_result = omath::PatternScanner::scan_for_pattern(section_begin, section_end, pattern);
if (scan_result == section_end)
const auto target_offset = scan_pattern(scan_range);
if (!target_offset.has_value())
return std::nullopt;
return reinterpret_cast<std::uintptr_t>(scan_result);
return reinterpret_cast<std::uintptr_t>(section_begin + target_offset.value());
}
return std::nullopt;
@@ -374,15 +375,58 @@ namespace omath
if (!arch.has_value()) [[unlikely]]
return std::nullopt;
const auto scan_pattern =
[&pattern](const std::span<const std::byte> section_data) -> std::optional<std::ptrdiff_t>
{
const auto scan_result =
PatternScanner::scan_for_pattern(section_data.begin(), section_data.end(), pattern);
if (scan_result == section_data.end())
return std::nullopt;
return scan_result - section_data.begin();
};
if (arch == FileArch::x64)
return scan_in_module_impl<Elf64Ehdr, Elf64Shdr>(static_cast<const std::byte*>(module_base_address),
pattern, target_section_name);
scan_pattern, target_section_name);
if (arch == FileArch::x32)
return scan_in_module_impl<Elf32Ehdr, Elf32Shdr>(static_cast<const std::byte*>(module_base_address),
pattern, target_section_name);
scan_pattern, target_section_name);
std::unreachable();
}
std::optional<std::uintptr_t>
ElfPatternScanner::scan_for_pattern_in_loaded_module(const void* module_base_address,
const std::string_view& target_section_name,
const SectionScanFunction scan_pattern)
{
if (module_base_address == nullptr) [[unlikely]]
return std::nullopt;
const auto* base = static_cast<const std::byte*>(module_base_address);
constexpr std::string_view valid_elf_signature = "\x7F"
"ELF";
if (std::string_view{reinterpret_cast<const char*>(base), valid_elf_signature.size()} != valid_elf_signature)
return std::nullopt;
const auto ei_class_value = static_cast<uint8_t>(base[ei_class]);
const auto arch = ei_class_value == elfclass64 ? FileArch::x64
: ei_class_value == elfclass32 ? FileArch::x32
: std::optional<FileArch>{};
if (!arch.has_value()) [[unlikely]]
return std::nullopt;
if (arch == FileArch::x64)
return scan_in_module_impl<Elf64Ehdr, Elf64Shdr>(base, scan_pattern, target_section_name);
if (arch == FileArch::x32)
return scan_in_module_impl<Elf32Ehdr, Elf32Shdr>(base, scan_pattern, target_section_name);
std::unreachable();
}
std::optional<SectionScanResult>
ElfPatternScanner::scan_for_pattern_in_file(const std::filesystem::path& path_to_file,
const std::string_view& pattern,
@@ -405,6 +449,26 @@ namespace omath
.target_offset = offset};
}
std::optional<SectionScanResult>
ElfPatternScanner::scan_for_pattern_in_file(const std::filesystem::path& path_to_file,
const std::string_view& target_section_name,
const SectionScanFunction scan_pattern)
{
const auto section = get_elf_section_by_name(path_to_file, target_section_name);
if (!section.has_value()) [[unlikely]]
return std::nullopt;
const auto target_offset = scan_pattern(std::span<const std::byte>{section->data.data(), section->data.size()});
if (!target_offset.has_value())
return std::nullopt;
return SectionScanResult{.virtual_base_addr = section->virtual_base_addr,
.raw_base_addr = section->raw_base_addr,
.target_offset = target_offset.value()};
}
std::optional<SectionScanResult>
ElfPatternScanner::scan_for_pattern_in_memory_file(const std::span<const std::byte> file_data,
const std::string_view& pattern,
@@ -427,4 +491,24 @@ namespace omath
.raw_base_addr = section->raw_base_addr,
.target_offset = offset};
}
} // namespace omath
std::optional<SectionScanResult>
ElfPatternScanner::scan_for_pattern_in_memory_file(const std::span<const std::byte> file_data,
const std::string_view& target_section_name,
const SectionScanFunction scan_pattern)
{
const auto section = get_elf_section_by_name_from_memory(file_data, target_section_name);
if (!section.has_value()) [[unlikely]]
return std::nullopt;
const auto target_offset = scan_pattern(std::span<const std::byte>{section->data.data(), section->data.size()});
if (!target_offset.has_value())
return std::nullopt;
return SectionScanResult{.virtual_base_addr = section->virtual_base_addr,
.raw_base_addr = section->raw_base_addr,
.target_offset = target_offset.value()};
}
} // namespace omath