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#include "main.hh"
using pointer_t = std::byte* const;
struct pointer {
const pointer_t address;
const std::byte* const deref;
std::shared_ptr<struct pointer> parent;
const size_t start_offset;
const size_t total_offset;
};
using pointers_t = std::vector<std::shared_ptr<struct pointer>>;
static pointers_t make_pointers(const memory::buffer_t& memory,
const pointers_t& targets,
const void* const start, const int tolerance,
const size_t total_offset) {
pointers_t ret{};
for (auto i = 0ul; i < std::size(memory) / sizeof(pointer_t); ++i) {
const auto byte_offset = i * sizeof(pointer_t);
const std::byte* const deref = [&]() {
std::byte* ret;
std::memcpy(&ret, &memory[byte_offset], sizeof(void*));
return ret;
}();
// -1 is 0xff...etc
if (deref == nullptr || deref > (pointer_t)(-1) - tolerance) {
continue;
}
const auto lower = std::lower_bound(
std::begin(targets), std::end(targets), deref,
[](const auto& target, const std::byte* const& deref) {
return target->address < deref;
});
const auto upper = std::upper_bound(
lower, std::end(targets), deref + tolerance,
[](const std::byte* const& deref, const auto& target) {
return deref < target->address;
});
std::for_each(lower, upper, [&](const auto& target) {
const auto address = (std::byte*)start + byte_offset;
if (address == target->address || deref == target->deref) {
return;
}
ret.emplace_back(std::make_shared<struct pointer>(
pointer{.address = address,
.deref = deref,
.parent = target,
.start_offset = byte_offset,
.total_offset = total_offset + byte_offset}));
});
}
return ret;
}
static pointers_t make_pointer_chain(const char* const binary_name,
const pointer_t target, const int depth,
const int tolerance) {
const memory::maps maps{binary_name};
const pid_t pid = std::stoi(maps.get_pid());
pointers_t ret{std::make_shared<struct pointer>(
pointer{.address = target, .parent = nullptr})};
for (int i = 0; i < depth; ++i) {
size_t total_offset = 0;
pointers_t pointers{};
for (const auto& map : maps) {
const auto size = static_cast<std::size_t>((std::byte*)map.end -
(std::byte*)map.start);
total_offset += size;
if (!map.is_read() || !map.is_write() || !map.is_protected()) {
continue;
}
const memory::buffer_t memory =
memory::read_buffer(size, pid, map.start);
std::ranges::move(make_pointers(memory, ret, map.start, tolerance,
total_offset - size),
std::back_inserter(pointers));
}
std::cout << "depth: " << i + 1 << " = " << std::size(pointers)
<< " chains...\n";
if (std::size(pointers) == 0) {
std::cout << "warning: only discovered chains of depth " << i
<< '\n';
break;
}
ret = std::move(pointers);
}
return ret;
}
static void do_pointer_scanner(const char* const binary_name,
const pointer_t target, const int depth,
const int tolerance) {
const auto pointer_chains =
make_pointer_chain(binary_name, target, depth, tolerance);
for (const auto& chain : pointer_chains) {
std::cout << std::hex << chain->total_offset << " = " << chain->address
<< std::dec;
const std::byte* prev = chain->deref;
for (const decltype(chain->parent)* p = &chain->parent; p != nullptr;
p = &(*p)->parent) {
if (*p == nullptr) {
break;
}
if ((*p)->address != nullptr) {
std::cout << " ] ";
}
if (prev != nullptr) {
std::cout << ((*p)->address - prev);
}
prev = (*p)->deref;
if ((*p)->address == nullptr) {
break;
}
}
std::cout << '\n';
}
}
int main(const int argc, const char* const argv[]) {
if (argc < 3 || argc > 5) {
std::cout << "usage: " << argv[0]
<< " BINARY_NAME 0xADDRESS DEPTH=10 "
"TOLERANCE=4096bytes\n";
return EXIT_SUCCESS;
}
std::cout.sync_with_stdio(false);
try {
const char* const binary_name = argv[1];
const pointer_t address = [&]() {
std::stringstream ss{argv[2]};
void* ptr;
ss >> std::hex >> ptr;
return static_cast<pointer_t>(ptr);
}();
const int depth = (argc >= 4 ? std::stoi(argv[3]) : 10);
const int tolerance = (argc >= 5 ? std::stoi(argv[4]) : 4096);
do_pointer_scanner(binary_name, address, depth, tolerance);
} catch (const std::exception& e) {
std::cerr << "unhandled exception!\n what(): " << e.what() << '\n';
} catch (...) {
std::cerr << "unhandled unknown exception!\n";
}
return EXIT_SUCCESS;
}
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