mirror of
https://github.com/meshcore-dev/MeshCore.git
synced 2026-03-29 08:39:56 +00:00
363 lines
8.6 KiB
C++
363 lines
8.6 KiB
C++
#include "KissModem.h"
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KissModem::KissModem(Stream& serial, mesh::LocalIdentity& identity, mesh::RNG& rng)
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: _serial(serial), _identity(identity), _rng(rng) {
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_rx_len = 0;
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_rx_escaped = false;
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_rx_active = false;
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_has_pending_tx = false;
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_pending_tx_len = 0;
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_setRadioCallback = nullptr;
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_setTxPowerCallback = nullptr;
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_setSyncWordCallback = nullptr;
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_config = {0, 0, 0, 0, 0, 0x12};
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}
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void KissModem::begin() {
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_rx_len = 0;
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_rx_escaped = false;
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_rx_active = false;
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_has_pending_tx = false;
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}
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void KissModem::writeByte(uint8_t b) {
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if (b == KISS_FEND) {
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_serial.write(KISS_FESC);
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_serial.write(KISS_TFEND);
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} else if (b == KISS_FESC) {
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_serial.write(KISS_FESC);
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_serial.write(KISS_TFESC);
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} else {
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_serial.write(b);
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}
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}
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void KissModem::writeFrame(uint8_t cmd, const uint8_t* data, uint16_t len) {
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_serial.write(KISS_FEND);
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writeByte(cmd);
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for (uint16_t i = 0; i < len; i++) {
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writeByte(data[i]);
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}
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_serial.write(KISS_FEND);
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}
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void KissModem::writeErrorFrame(uint8_t error_code) {
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writeFrame(RESP_ERROR, &error_code, 1);
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}
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void KissModem::loop() {
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while (_serial.available()) {
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uint8_t b = _serial.read();
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if (b == KISS_FEND) {
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if (_rx_active && _rx_len > 0) {
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processFrame();
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}
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_rx_len = 0;
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_rx_escaped = false;
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_rx_active = true;
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continue;
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}
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if (!_rx_active) continue;
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if (b == KISS_FESC) {
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_rx_escaped = true;
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continue;
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}
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if (_rx_escaped) {
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_rx_escaped = false;
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if (b == KISS_TFEND) b = KISS_FEND;
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else if (b == KISS_TFESC) b = KISS_FESC;
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}
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if (_rx_len < KISS_MAX_FRAME_SIZE) {
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_rx_buf[_rx_len++] = b;
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}
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}
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}
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void KissModem::processFrame() {
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if (_rx_len < 1) return;
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uint8_t cmd = _rx_buf[0];
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const uint8_t* data = &_rx_buf[1];
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uint16_t data_len = _rx_len - 1;
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switch (cmd) {
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case CMD_DATA:
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if (data_len < 2) {
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writeErrorFrame(ERR_INVALID_LENGTH);
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} else if (data_len > KISS_MAX_PACKET_SIZE) {
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writeErrorFrame(ERR_INVALID_LENGTH);
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} else {
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memcpy(_pending_tx, data, data_len);
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_pending_tx_len = data_len;
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_has_pending_tx = true;
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}
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break;
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case CMD_GET_IDENTITY:
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handleGetIdentity();
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break;
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case CMD_GET_RANDOM:
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handleGetRandom(data, data_len);
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break;
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case CMD_VERIFY_SIGNATURE:
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handleVerifySignature(data, data_len);
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break;
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case CMD_SIGN_DATA:
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handleSignData(data, data_len);
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break;
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case CMD_ENCRYPT_DATA:
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handleEncryptData(data, data_len);
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break;
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case CMD_DECRYPT_DATA:
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handleDecryptData(data, data_len);
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break;
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case CMD_KEY_EXCHANGE:
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handleKeyExchange(data, data_len);
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break;
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case CMD_HASH:
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handleHash(data, data_len);
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break;
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case CMD_SET_RADIO:
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handleSetRadio(data, data_len);
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break;
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case CMD_SET_TX_POWER:
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handleSetTxPower(data, data_len);
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break;
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case CMD_SET_SYNC_WORD:
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handleSetSyncWord(data, data_len);
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break;
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case CMD_GET_RADIO:
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handleGetRadio();
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break;
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case CMD_GET_TX_POWER:
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handleGetTxPower();
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break;
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case CMD_GET_SYNC_WORD:
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handleGetSyncWord();
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break;
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case CMD_GET_VERSION:
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handleGetVersion();
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break;
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default:
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writeErrorFrame(ERR_UNKNOWN_CMD);
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break;
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}
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}
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void KissModem::handleGetIdentity() {
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writeFrame(RESP_IDENTITY, _identity.pub_key, PUB_KEY_SIZE);
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}
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void KissModem::handleGetRandom(const uint8_t* data, uint16_t len) {
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if (len < 1) {
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writeErrorFrame(ERR_INVALID_LENGTH);
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return;
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}
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uint8_t requested = data[0];
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if (requested < 1 || requested > 64) {
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writeErrorFrame(ERR_INVALID_PARAM);
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return;
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}
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uint8_t buf[64];
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_rng.random(buf, requested);
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writeFrame(RESP_RANDOM, buf, requested);
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}
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void KissModem::handleVerifySignature(const uint8_t* data, uint16_t len) {
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if (len < PUB_KEY_SIZE + SIGNATURE_SIZE + 1) {
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writeErrorFrame(ERR_INVALID_LENGTH);
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return;
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}
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mesh::Identity signer(data);
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const uint8_t* signature = data + PUB_KEY_SIZE;
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const uint8_t* msg = data + PUB_KEY_SIZE + SIGNATURE_SIZE;
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uint16_t msg_len = len - PUB_KEY_SIZE - SIGNATURE_SIZE;
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uint8_t result = signer.verify(signature, msg, msg_len) ? 0x01 : 0x00;
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writeFrame(RESP_VERIFY, &result, 1);
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}
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void KissModem::handleSignData(const uint8_t* data, uint16_t len) {
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if (len < 1) {
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writeErrorFrame(ERR_INVALID_LENGTH);
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return;
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}
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uint8_t signature[SIGNATURE_SIZE];
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_identity.sign(signature, data, len);
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writeFrame(RESP_SIGNATURE, signature, SIGNATURE_SIZE);
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}
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void KissModem::handleEncryptData(const uint8_t* data, uint16_t len) {
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if (len < PUB_KEY_SIZE + 1) {
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writeErrorFrame(ERR_INVALID_LENGTH);
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return;
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}
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const uint8_t* key = data;
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const uint8_t* plaintext = data + PUB_KEY_SIZE;
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uint16_t plaintext_len = len - PUB_KEY_SIZE;
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uint8_t buf[KISS_MAX_FRAME_SIZE];
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int encrypted_len = mesh::Utils::encryptThenMAC(key, buf, plaintext, plaintext_len);
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if (encrypted_len > 0) {
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writeFrame(RESP_ENCRYPTED, buf, encrypted_len);
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} else {
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writeErrorFrame(ERR_ENCRYPT_FAILED);
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}
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}
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void KissModem::handleDecryptData(const uint8_t* data, uint16_t len) {
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if (len < PUB_KEY_SIZE + CIPHER_MAC_SIZE + 1) {
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writeErrorFrame(ERR_INVALID_LENGTH);
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return;
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}
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const uint8_t* key = data;
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const uint8_t* ciphertext = data + PUB_KEY_SIZE;
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uint16_t ciphertext_len = len - PUB_KEY_SIZE;
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uint8_t buf[KISS_MAX_FRAME_SIZE];
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int decrypted_len = mesh::Utils::MACThenDecrypt(key, buf, ciphertext, ciphertext_len);
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if (decrypted_len > 0) {
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writeFrame(RESP_DECRYPTED, buf, decrypted_len);
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} else {
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writeErrorFrame(ERR_MAC_FAILED);
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}
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}
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void KissModem::handleKeyExchange(const uint8_t* data, uint16_t len) {
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if (len < PUB_KEY_SIZE) {
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writeErrorFrame(ERR_INVALID_LENGTH);
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return;
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}
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uint8_t shared_secret[PUB_KEY_SIZE];
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_identity.calcSharedSecret(shared_secret, data);
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writeFrame(RESP_SHARED_SECRET, shared_secret, PUB_KEY_SIZE);
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}
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void KissModem::handleHash(const uint8_t* data, uint16_t len) {
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if (len < 1) {
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writeErrorFrame(ERR_INVALID_LENGTH);
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return;
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}
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uint8_t hash[32];
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mesh::Utils::sha256(hash, 32, data, len);
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writeFrame(RESP_HASH, hash, 32);
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}
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bool KissModem::getPacketToSend(uint8_t* packet, uint16_t* len) {
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if (!_has_pending_tx) return false;
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memcpy(packet, _pending_tx, _pending_tx_len);
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*len = _pending_tx_len;
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_has_pending_tx = false;
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return true;
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}
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void KissModem::onPacketReceived(int8_t snr, int8_t rssi, const uint8_t* packet, uint16_t len) {
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uint8_t buf[2 + KISS_MAX_PACKET_SIZE];
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buf[0] = (uint8_t)snr;
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buf[1] = (uint8_t)rssi;
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memcpy(&buf[2], packet, len);
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writeFrame(CMD_DATA, buf, 2 + len);
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}
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void KissModem::handleSetRadio(const uint8_t* data, uint16_t len) {
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if (len < 10) {
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writeErrorFrame(ERR_INVALID_LENGTH);
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return;
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}
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if (!_setRadioCallback) {
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writeErrorFrame(ERR_NO_CALLBACK);
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return;
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}
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uint32_t freq_hz, bw_hz;
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memcpy(&freq_hz, data, 4);
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memcpy(&bw_hz, data + 4, 4);
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uint8_t sf = data[8];
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uint8_t cr = data[9];
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_config.freq_hz = freq_hz;
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_config.bw_hz = bw_hz;
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_config.sf = sf;
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_config.cr = cr;
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float freq = freq_hz / 1000000.0f;
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float bw = bw_hz / 1000.0f;
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_setRadioCallback(freq, bw, sf, cr);
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writeFrame(RESP_OK, nullptr, 0);
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}
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void KissModem::handleSetTxPower(const uint8_t* data, uint16_t len) {
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if (len < 1) {
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writeErrorFrame(ERR_INVALID_LENGTH);
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return;
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}
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if (!_setTxPowerCallback) {
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writeErrorFrame(ERR_NO_CALLBACK);
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return;
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}
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_config.tx_power = data[0];
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_setTxPowerCallback(data[0]);
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writeFrame(RESP_OK, nullptr, 0);
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}
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void KissModem::handleSetSyncWord(const uint8_t* data, uint16_t len) {
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if (len < 1) {
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writeErrorFrame(ERR_INVALID_LENGTH);
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return;
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}
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if (!_setSyncWordCallback) {
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writeErrorFrame(ERR_NO_CALLBACK);
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return;
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}
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_config.sync_word = data[0];
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_setSyncWordCallback(data[0]);
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writeFrame(RESP_OK, nullptr, 0);
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}
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void KissModem::handleGetRadio() {
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uint8_t buf[10];
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memcpy(buf, &_config.freq_hz, 4);
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memcpy(buf + 4, &_config.bw_hz, 4);
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buf[8] = _config.sf;
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buf[9] = _config.cr;
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writeFrame(RESP_RADIO, buf, 10);
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}
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void KissModem::handleGetTxPower() {
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writeFrame(RESP_TX_POWER, &_config.tx_power, 1);
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}
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void KissModem::handleGetSyncWord() {
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writeFrame(RESP_SYNC_WORD, &_config.sync_word, 1);
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}
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void KissModem::handleGetVersion() {
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uint8_t buf[2];
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buf[0] = KISS_FIRMWARE_VERSION;
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buf[1] = 0;
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writeFrame(RESP_VERSION, buf, 2);
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}
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void KissModem::onTxComplete(bool success) {
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uint8_t result = success ? 0x01 : 0x00;
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writeFrame(RESP_TX_DONE, &result, 1);
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}
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