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#pragma once
namespace pe {
struct import_t {
std::string name;
uint32_t rva;
};
struct section_t {
std::string name;
size_t size;
uint32_t rva;
uint32_t va;
};
template <bool x64 = false>
class image {
win::image_t<x64> *m_image;
std::vector<char> m_buffer;
std::string m_name;
std::unordered_map<std::string, std::vector<import_t>> m_imports;
std::vector<section_t> m_sections;
std::vector<std::pair<uint32_t, win::reloc_entry_t>> m_relocs;
public:
image() = default;
image(const std::string_view name) : m_image{nullptr}, m_name{name} {
if (!io::read_file(name, m_buffer)) {
io::logger->error("failed to load image {}.", name);
return;
}
m_image = reinterpret_cast<win::image_t<x64> *>(m_buffer.data());
load();
}
void load() {
parse_sections();
parse_relocs();
parse_imports();
}
void reload() {
io::read_file(m_name, m_buffer);
if (m_buffer.empty()) {
io::logger->error("failed to reload image {}.", m_name);
return;
}
m_image = reinterpret_cast<win::image_t<x64> *>(m_buffer.data());
load();
io::logger->info("reloaded {}.", m_name);
}
void parse_sections() {
const auto nt = m_image->get_nt_headers();
const size_t n = nt->file_header.num_sections;
for (size_t i = 0; i < n; i++) {
auto section = nt->get_section(i);
m_sections.emplace_back(section_t{section->name, section->size_raw_data,
section->ptr_raw_data,
section->virtual_address});
}
};
void parse_relocs() {
const auto reloc_dir =
m_image->get_directory(win::directory_id::directory_entry_basereloc);
if (!reloc_dir) return;
const auto ptr = m_image->rva_to_ptr(reloc_dir->rva);
auto block = reinterpret_cast<win::reloc_block_t *>(ptr);
while (block->base_rva) {
for (size_t i = 0; i < block->num_entries(); ++i) {
auto entry = block->entries[i];
m_relocs.emplace_back(std::make_pair(block->base_rva, entry));
}
block = block->get_next();
}
}
void parse_imports() {
const auto import_dir =
m_image->get_directory(win::directory_id::directory_entry_import);
if (!import_dir) return;
const auto ptr = m_image->rva_to_ptr(import_dir->rva);
auto table = reinterpret_cast<win::import_directory_t *>(ptr);
for (uint32_t previous_name = 0; previous_name < table->rva_name;
previous_name = table->rva_name, ++table) {
auto name_ptr = m_image->rva_to_ptr(table->rva_name);
auto mod_name = std::string(reinterpret_cast<char *>(name_ptr));
auto thunk = reinterpret_cast<win::image_thunk_data_t<x64> *>(
m_image->rva_to_ptr(table->rva_original_first_thunk));
auto step = x64 ? sizeof(uint64_t) : sizeof(uint32_t);
for (uint32_t index = 0; thunk->address; index += step, ++thunk) {
auto named_import = reinterpret_cast<win::image_named_import_t *>(
m_image->rva_to_ptr(thunk->address));
if (thunk->is_ordinal) {
io::logger->error("found import by ordinal in module {}, {}.",
mod_name, m_name);
continue;
}
import_t data;
data.name = reinterpret_cast<const char *>(named_import->name);
data.rva = table->rva_first_thunk + index;
std::transform(mod_name.begin(), mod_name.end(), mod_name.begin(),
::tolower);
m_imports[mod_name].emplace_back(std::move(data));
}
}
}
void copy(std::vector<char> &out) {
const auto nt = m_image->get_nt_headers();
const auto n = nt->file_header.num_sections;
out.resize(nt->optional_header.size_image);
for (auto &sec : m_sections) {
if(sec.name == ".reloc" || sec.name == ".rsrc" || sec.name == ".idata") {
continue;
}
std::memcpy(&out[sec.va], &m_buffer[sec.rva], sec.size);
}
}
void relocate(std::vector<char> &image, uintptr_t base) {
const auto delta =
base - m_image->get_nt_headers()->optional_header.image_base;
if (delta > 0) {
for (auto &[base_rva, entry] : m_relocs) {
if (x64) {
if (entry.type == win::rel_based_high_low ||
entry.type == win::rel_based_dir64) {
*reinterpret_cast<uint64_t *>(image.data() + base_rva +
entry.offset) += delta;
}
continue;
}
if (entry.type == win::rel_based_high_low) {
*reinterpret_cast<uint32_t *>(image.data() + base_rva +
entry.offset) += delta;
}
}
}
}
void fix_imports(std::vector<char> &image, const std::string_view imports) {
if (!nlohmann::json::accept(imports.data())) {
io::logger->error("imports arent valid json!!");
return;
}
auto j = nlohmann::json::parse(imports.data());
for (auto &[mod, funcs] : m_imports) {
for (auto &func : funcs) {
if (!j.contains(func.name)) {
io::logger->warn("missing {} import address.", func.name);
continue;
}
auto addr = j[func.name];
if (x64) {
*reinterpret_cast<uint64_t *>(image.data() + func.rva) = addr;
continue;
}
*reinterpret_cast<uint32_t *>(image.data() + func.rva) = addr;
}
}
}
const auto operator->() { return m_image; }
operator bool() const { return m_image != nullptr; }
auto &imports() const { return m_imports; }
auto &relocs() const { return m_relocs; }
auto §ions() const { return m_sections; }
std::string get_json_imports() {
nlohmann::json json;
for (auto &[mod, imports] : m_imports) {
for (auto &i : imports) {
json[mod].emplace_back(i.name);
}
}
return json.dump();
}
};
}; // namespace pe
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