MeshCore/src/helpers/bridges/ESPNowBridge.cpp
2025-09-24 16:30:00 +01:00

237 lines
7.1 KiB
C++

#include "ESPNowBridge.h"
#include <WiFi.h>
#include <esp_wifi.h>
#ifdef WITH_ESPNOW_BRIDGE
// Static member to handle callbacks
ESPNowBridge *ESPNowBridge::_instance = nullptr;
// Static callback wrappers
void ESPNowBridge::recv_cb(const uint8_t *mac, const uint8_t *data, int32_t len) {
if (_instance) {
_instance->onDataRecv(mac, data, len);
}
}
void ESPNowBridge::send_cb(const uint8_t *mac, esp_now_send_status_t status) {
if (_instance) {
_instance->onDataSent(mac, status);
}
}
ESPNowBridge::ESPNowBridge(mesh::PacketManager *mgr, mesh::RTCClock *rtc)
: BridgeBase(mgr, rtc), _rx_buffer_pos(0) {
_instance = this;
}
void ESPNowBridge::begin() {
Serial.printf("%s: ESPNOW BRIDGE: Initializing...\n", getLogDateTime());
// Initialize WiFi in station mode
WiFi.mode(WIFI_STA);
// Set wifi channel
if (esp_wifi_set_channel(_channel, WIFI_SECOND_CHAN_NONE) != ESP_OK) {
Serial.printf("%s: ESPNOW BRIDGE: Error setting WIFI channel to %d\n", getLogDateTime(), _channel);
return;
}
// Initialize ESP-NOW
if (esp_now_init() != ESP_OK) {
Serial.printf("%s: ESPNOW BRIDGE: Error initializing ESP-NOW\n", getLogDateTime());
return;
}
// Register callbacks
esp_now_register_recv_cb(recv_cb);
esp_now_register_send_cb(send_cb);
// Add broadcast peer
esp_now_peer_info_t peerInfo = {};
memset(&peerInfo, 0, sizeof(peerInfo));
memset(peerInfo.peer_addr, 0xFF, ESP_NOW_ETH_ALEN); // Broadcast address
peerInfo.channel = _channel;
peerInfo.encrypt = false;
if (esp_now_add_peer(&peerInfo) != ESP_OK) {
Serial.printf("%s: ESPNOW BRIDGE: Failed to add broadcast peer\n", getLogDateTime());
return;
}
// Update bridge state
_initialized = true;
}
void ESPNowBridge::end() {
Serial.printf("%s: ESPNOW BRIDGE: Stopping...\n", getLogDateTime());
// Remove broadcast peer
uint8_t broadcastAddress[] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
if (esp_now_del_peer(broadcastAddress) != ESP_OK) {
Serial.printf("%s: ESPNOW BRIDGE: Error removing broadcast peer\n", getLogDateTime());
}
// Unregister callbacks
esp_now_register_recv_cb(nullptr);
esp_now_register_send_cb(nullptr);
// Deinitialize ESP-NOW
if (esp_now_deinit() != ESP_OK) {
Serial.printf("%s: ESPNOW BRIDGE: Error deinitializing ESP-NOW\n", getLogDateTime());
}
// Turn off WiFi
WiFi.mode(WIFI_OFF);
// Update bridge state
_initialized = false;
}
void ESPNowBridge::loop() {
// Nothing to do here - ESP-NOW is callback based
}
void ESPNowBridge::xorCrypt(uint8_t *data, size_t len) {
size_t keyLen = strlen(_secret);
for (size_t i = 0; i < len; i++) {
data[i] ^= _secret[i % keyLen];
}
}
void ESPNowBridge::onDataRecv(const uint8_t *mac, const uint8_t *data, int32_t len) {
// Ignore packets that are too small to contain header + checksum
if (len < (BRIDGE_MAGIC_SIZE + BRIDGE_CHECKSUM_SIZE)) {
#if MESH_PACKET_LOGGING
Serial.printf("%s: ESPNOW BRIDGE: RX packet too small, len=%d\n", getLogDateTime(), len);
#endif
return;
}
// Validate total packet size
if (len > MAX_ESPNOW_PACKET_SIZE) {
#if MESH_PACKET_LOGGING
Serial.printf("%s: ESPNOW BRIDGE: RX packet too large, len=%d\n", getLogDateTime(), len);
#endif
return;
}
// Check packet header magic
uint16_t received_magic = (data[0] << 8) | data[1];
if (received_magic != BRIDGE_PACKET_MAGIC) {
#if MESH_PACKET_LOGGING
Serial.printf("%s: ESPNOW BRIDGE: RX invalid magic 0x%04X\n", getLogDateTime(), received_magic);
#endif
return;
}
// Make a copy we can decrypt
uint8_t decrypted[MAX_ESPNOW_PACKET_SIZE];
const size_t encryptedDataLen = len - BRIDGE_MAGIC_SIZE;
memcpy(decrypted, data + BRIDGE_MAGIC_SIZE, encryptedDataLen);
// Try to decrypt (checksum + payload)
xorCrypt(decrypted, encryptedDataLen);
// Validate checksum
uint16_t received_checksum = (decrypted[0] << 8) | decrypted[1];
const size_t payloadLen = encryptedDataLen - BRIDGE_CHECKSUM_SIZE;
if (!validateChecksum(decrypted + BRIDGE_CHECKSUM_SIZE, payloadLen, received_checksum)) {
// Failed to decrypt - likely from a different network
#if MESH_PACKET_LOGGING
Serial.printf("%s: ESPNOW BRIDGE: RX checksum mismatch, rcv=0x%04X\n", getLogDateTime(),
received_checksum);
#endif
return;
}
#if MESH_PACKET_LOGGING
Serial.printf("%s: ESPNOW BRIDGE: RX, payload_len=%d\n", getLogDateTime(), payloadLen);
#endif
// Create mesh packet
mesh::Packet *pkt = _instance->_mgr->allocNew();
if (!pkt) return;
if (pkt->readFrom(decrypted + BRIDGE_CHECKSUM_SIZE, payloadLen)) {
_instance->onPacketReceived(pkt);
} else {
_instance->_mgr->free(pkt);
}
}
void ESPNowBridge::onDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) {
// Could add transmission error handling here if needed
}
void ESPNowBridge::onPacketTransmitted(mesh::Packet *packet) {
// Guard against uninitialized state
if (_initialized == false) {
Serial.printf("%s: ESPNOW BRIDGE: TX packet attempted before initialization\n", getLogDateTime());
return;
}
// First validate the packet pointer
if (!packet) {
#if MESH_PACKET_LOGGING
Serial.printf("%s: ESPNOW BRIDGE: TX invalid packet pointer\n", getLogDateTime());
#endif
return;
}
if (!_seen_packets.hasSeen(packet)) {
// Create a temporary buffer just for size calculation and reuse for actual writing
uint8_t sizingBuffer[MAX_PAYLOAD_SIZE];
uint16_t meshPacketLen = packet->writeTo(sizingBuffer);
// Check if packet fits within our maximum payload size
if (meshPacketLen > MAX_PAYLOAD_SIZE) {
#if MESH_PACKET_LOGGING
Serial.printf("%s: ESPNOW BRIDGE: TX packet too large (payload=%d, max=%d)\n", getLogDateTime(),
meshPacketLen, MAX_PAYLOAD_SIZE);
#endif
return;
}
uint8_t buffer[MAX_ESPNOW_PACKET_SIZE];
// Write magic header (2 bytes)
buffer[0] = (BRIDGE_PACKET_MAGIC >> 8) & 0xFF;
buffer[1] = BRIDGE_PACKET_MAGIC & 0xFF;
// Write packet payload starting after magic header and checksum
const size_t packetOffset = BRIDGE_MAGIC_SIZE + BRIDGE_CHECKSUM_SIZE;
memcpy(buffer + packetOffset, sizingBuffer, meshPacketLen);
// Calculate and add checksum (only of the payload)
uint16_t checksum = fletcher16(buffer + packetOffset, meshPacketLen);
buffer[2] = (checksum >> 8) & 0xFF; // High byte
buffer[3] = checksum & 0xFF; // Low byte
// Encrypt payload and checksum (not including magic header)
xorCrypt(buffer + BRIDGE_MAGIC_SIZE, meshPacketLen + BRIDGE_CHECKSUM_SIZE);
// Total packet size: magic header + checksum + payload
const size_t totalPacketSize = BRIDGE_MAGIC_SIZE + BRIDGE_CHECKSUM_SIZE + meshPacketLen;
// Broadcast using ESP-NOW
uint8_t broadcastAddress[] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
esp_err_t result = esp_now_send(broadcastAddress, buffer, totalPacketSize);
#if MESH_PACKET_LOGGING
if (result == ESP_OK) {
Serial.printf("%s: ESPNOW BRIDGE: TX, len=%d\n", getLogDateTime(), meshPacketLen);
} else {
Serial.printf("%s: ESPNOW BRIDGE: TX FAILED!\n", getLogDateTime());
}
#endif
}
}
void ESPNowBridge::onPacketReceived(mesh::Packet *packet) {
handleReceivedPacket(packet);
}
#endif