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Add LoRaWan MAC response

This commit is contained in:
Theo Arends 2024-04-09 14:06:38 +02:00
parent 56fcd0e634
commit 54e4aba750
1 changed files with 53 additions and 0 deletions
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53
tasmota/tasmota_xdrv_driver/xdrv_73_8_lorawan_bridge.ino
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@ -237,6 +237,36 @@ void LoraWanSendLinkADRReq(uint32_t node) {
LoraWanSendResponse(data, sizeof(data), TAS_LORAWAN_RECEIVE_DELAY1);
}
void LoraWanSendMacResponse(uint32_t node, uint8_t* FOpts, uint32_t FCtrl) {
if (FCtrl > 15) { return; } // FOpts = 0..15
uint32_t DevAddr = Lora->device_address +node;
uint16_t FCnt = Lora->settings.end_node[node].FCntDown++;
uint8_t NwkSKey[TAS_LORAWAN_AES128_KEY_SIZE];
LoraWanDeriveLegacyNwkSKey(node, NwkSKey);
uint32_t data_size = 12 + FCtrl;
uint8_t data[data_size];
data[0] = TAS_LORAWAN_MTYPE_UNCONFIRMED_DATA_DOWNLINK << 5;
data[1] = DevAddr;
data[2] = DevAddr >> 8;
data[3] = DevAddr >> 16;
data[4] = DevAddr >> 24;
data[5] = 0x20 + FCtrl; // FCtrl ACK + FOpts
data[6] = FCnt;
data[7] = FCnt >> 8;
for (uint32_t i = 0; i < FCtrl; i++) {
data[8 +i] = FOpts[i];
}
uint32_t MIC = LoraWanComputeLegacyDownlinkMIC(NwkSKey, DevAddr, FCnt, data, data_size -4);
data[data_size -4] = MIC;
data[data_size -3] = MIC >> 8;
data[data_size -2] = MIC >> 16;
data[data_size -1] = MIC >> 24;
LoraWanSendResponse(data, data_size, TAS_LORAWAN_RECEIVE_DELAY1);
}
bool LoraWanInput(uint8_t* data, uint32_t packet_size) {
bool result = false;
uint32_t MType = data[0] >> 5; // Upper three bits (used to be called FType)
@ -400,11 +430,20 @@ bool LoraWanInput(uint8_t* data, uint32_t packet_size) {
Lora->settings.end_node[node].FCntUp = FCnt;
if (FOptsLen) {
uint8_t mac_data[16];
uint32_t mac_data_idx = 0;
uint32_t i = 0;
while (i < FOptsLen) {
if (TAS_LORAWAN_CID_LINK_CHECK_REQ == FOpts[i]) {
// Used by end-device to validate it's connectivity to a network
// Need to send Margin/GWCnt
if (mac_data_idx < 13) {
mac_data[mac_data_idx++] = TAS_LORAWAN_CID_LINK_CHECK_ANS;
int snr = Lora->snr;
if (snr < 0) { snr = 0; }
mac_data[mac_data_idx++] = snr; // Margin - Demodulation margin
mac_data[mac_data_idx++] = 1; // GwCnt - Gateway count
}
}
else if (TAS_LORAWAN_CID_LINK_ADR_ANS == FOpts[i]) {
i++;
@ -435,12 +474,26 @@ bool LoraWanInput(uint8_t* data, uint32_t packet_size) {
else if (TAS_LORAWAN_CID_DEVICE_TIME_REQ == FOpts[i]) {
// Used by the end-device to request the current GPS time
// Need to send epoch/fractional second
if (mac_data_idx < 10) {
mac_data[mac_data_idx++] = TAS_LORAWAN_CID_DEVICE_TIME_ANS;
// ToDo - need to find a way how to calculate the leap seconds
uint32_t gps_time = UtcTime() -315964800 +18 +1; // Time at RX1
mac_data[mac_data_idx++] = gps_time;
mac_data[mac_data_idx++] = gps_time >> 8;
mac_data[mac_data_idx++] = gps_time >> 16;
mac_data[mac_data_idx++] = gps_time >> 24;
// uint32_t frac_time = RtcMillis();
mac_data[mac_data_idx++] = 0x00; // Fractional-second 1/256 sec
}
}
else {
// RFU
}
i++;
}
if (mac_data_idx > 0) {
LoraWanSendMacResponse(node, mac_data, mac_data_idx);
}
}
if (payload_len) {