spicetools/acio2emu/packet.h

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2024-08-28 15:10:34 +00:00
#pragma once
#include <vector>
#include <queue>
#include <random> // std::linear_congruential_engine
#include <cstdint>
#include "acio2emu/internal/lz.h"
namespace acio2emu {
struct Packet {
uint8_t node;
uint8_t tag;
std::vector<uint8_t> payload;
};
class PacketDecoder {
private:
Packet packet_ = {};
// order matters, don't change this enum!
enum payloadEncoding {
byteStuffing,
raw,
unknown,
replace,
lz,
} encoding_;
uint32_t payload_size_ = 0, payload_size_count_ = 0;
// payloadEncoding::replace state
uint8_t substitute_;
// payloadEncoding::lz state
detail::InflateTransformer inflate_;
// deobfuscation state
bool obfuscated_;
std::linear_congruential_engine<uint32_t, 1103515245, 12345, 0> lcg_;
enum class readStep {
idle,
readNode,
readTag,
readPayloadSize,
readPayloadFlags,
readReplacementByte,
readPayload,
readEscaped,
} step_ = readStep::idle;
void set_step_(readStep s);
void reset_(readStep s);
int update_payload_size_(uint8_t b);
uint8_t deobfuscate_(uint8_t b);
public:
bool update(uint8_t b);
const Packet &packet();
};
bool encode_packet(std::queue<uint8_t> &out, uint8_t node, uint8_t tag, const std::vector<uint8_t> &payload);
}