sensor: copy control data code from repeater

examples/simple_sensor/SensorMesh.cpp

@@ -617,6 +617,38 @@ bool SensorMesh::handleIncomingMsg(ClientInfo& from, uint32_t timestamp, uint8_t
   return false;
 }
 
+#define CTL_TYPE_NODE_DISCOVER_REQ   0x80
+#define CTL_TYPE_NODE_DISCOVER_RESP  0x90
+
+void SensorMesh::onControlDataRecv(mesh::Packet* packet) {
+  uint8_t type = packet->payload[0] & 0xF0;    // just test upper 4 bits
+  if (type == CTL_TYPE_NODE_DISCOVER_REQ && packet->payload_len >= 6) {
+    // TODO: apply rate limiting to these!
+    int i = 1;
+    uint8_t  filter = packet->payload[i++];
+    uint32_t tag;
+    memcpy(&tag, &packet->payload[i], 4); i += 4;
+    uint32_t since;
+    if (packet->payload_len >= i+4) {   // optional since field
+      memcpy(&since, &packet->payload[i], 4); i += 4;
+    } else {
+      since = 0;
+    }
+
+    if ((filter & (1 << ADV_TYPE_SENSOR)) != 0 && _prefs.discovery_mod_timestamp >= since) {
+      uint8_t data[6 + PUB_KEY_SIZE];
+      data[0] = CTL_TYPE_NODE_DISCOVER_RESP | ADV_TYPE_SENSOR;   // low 4-bits for node type
+      data[1] = packet->_snr;   // let sender know the inbound SNR ( x 4)
+      memcpy(&data[2], &tag, 4);     // include tag from request, for client to match to
+      memcpy(&data[6], self_id.pub_key, PUB_KEY_SIZE);
+      auto resp = createControlData(data, sizeof(data));
+      if (resp) {
+        sendZeroHop(resp, getRetransmitDelay(resp));  // apply random delay, as multiple nodes can respond to this
+      }
+    }
+  }
+}
+
 bool SensorMesh::onPeerPathRecv(mesh::Packet* packet, int sender_idx, const uint8_t* secret, uint8_t* path, uint8_t path_len, uint8_t extra_type, uint8_t* extra, uint8_t extra_len) {
   int i = matching_peer_indexes[sender_idx];
   if (i < 0 || i >= acl.getNumClients()) {

examples/simple_sensor/SensorMesh.h

@@ -125,6 +125,7 @@ protected:
   void getPeerSharedSecret(uint8_t* dest_secret, int peer_idx) override;
   void onPeerDataRecv(mesh::Packet* packet, uint8_t type, int sender_idx, const uint8_t* secret, uint8_t* data, size_t len) override;
   bool onPeerPathRecv(mesh::Packet* packet, int sender_idx, const uint8_t* secret, uint8_t* path, uint8_t path_len, uint8_t extra_type, uint8_t* extra, uint8_t extra_len) override;
+  void onControlDataRecv(mesh::Packet* packet) override;
   void onAckRecv(mesh::Packet* packet, uint32_t ack_crc) override;
   virtual bool handleIncomingMsg(ClientInfo& from, uint32_t timestamp, uint8_t* data, uint flags, size_t len);
   void sendAckTo(const ClientInfo& dest, uint32_t ack_hash);