SensorMesh: add the possibility to receive msgs from admin

examples/simple_sensor/SensorMesh.cpp

@@ -613,6 +613,23 @@ void SensorMesh::getPeerSharedSecret(uint8_t* dest_secret, int peer_idx) {
   }
 }
 
+void SensorMesh::sendAckTo(const ContactInfo& dest, uint32_t ack_hash) {
+  if (dest.out_path_len < 0) {
+    mesh::Packet* ack = createAck(ack_hash);
+    if (ack) sendFlood(ack, TXT_ACK_DELAY);
+  } else {
+    uint32_t d = TXT_ACK_DELAY;
+    if (getExtraAckTransmitCount() > 0) {
+      mesh::Packet* a1 = createMultiAck(ack_hash, 1);
+      if (a1) sendDirect(a1, dest.out_path, dest.out_path_len, d);
+      d += 300;
+    }
+
+    mesh::Packet* a2 = createAck(ack_hash);
+    if (a2) sendDirect(a2, dest.out_path, dest.out_path_len, d);
+  }
+}
+
 void SensorMesh::onPeerDataRecv(mesh::Packet* packet, uint8_t type, int sender_idx, const uint8_t* secret, uint8_t* data, size_t len) {
   int i = matching_peer_indexes[sender_idx];
   if (i < 0 || i >= num_contacts) {
@@ -656,9 +673,23 @@ void SensorMesh::onPeerDataRecv(mesh::Packet* packet, uint8_t type, int sender_i
     memcpy(&sender_timestamp, data, 4);  // timestamp (by sender's RTC clock - which could be wrong)
     uint flags = (data[4] >> 2);   // message attempt number, and other flags
 
-    if (!(flags == TXT_TYPE_CLI_DATA)) {
+    if (sender_timestamp > from.last_timestamp) {  // prevent replay attacks
-      MESH_DEBUG_PRINTLN("onPeerDataRecv: unsupported text type received: flags=%02x", (uint32_t)flags);
+      if (flags == TXT_TYPE_PLAIN) {
-    } else if (sender_timestamp > from.last_timestamp) {  // prevent replay attacks
+        bool handled = handleIncomingMsg(from, sender_timestamp, &data[5], flags, len - 5);
+        if (handled) { // if msg was handled then send an ack
+          uint32_t ack_hash;    // calc truncated hash of the message timestamp + text + sender pub_key, to prove to sender that we got it
+          mesh::Utils::sha256((uint8_t *) &ack_hash, 4, data, 5 + strlen((char *)&data[5]), from.id.pub_key, PUB_KEY_SIZE);
+
+          if (packet->isRouteFlood()) {
+            // let this sender know path TO here, so they can use sendDirect(), and ALSO encode the ACK
+            mesh::Packet* path = createPathReturn(from.id, secret, packet->path, packet->path_len,
+                                                    PAYLOAD_TYPE_ACK, (uint8_t *) &ack_hash, 4);
+            if (path) sendFlood(path, TXT_ACK_DELAY);
+          } else {
+            sendAckTo(from, ack_hash);
+          }          
+        }
+      } else if (flags == TXT_TYPE_CLI_DATA) {  
         from.last_timestamp = sender_timestamp;
         from.last_activity = getRTCClock()->getCurrentTime();
 
@@ -689,12 +720,24 @@ void SensorMesh::onPeerDataRecv(mesh::Packet* packet, uint8_t type, int sender_i
             }
           }
         }
+      } else {
+        MESH_DEBUG_PRINTLN("onPeerDataRecv: unsupported text type received: flags=%02x", (uint32_t)flags);
+      }
     } else {
       MESH_DEBUG_PRINTLN("onPeerDataRecv: possible replay attack detected");
     }
   }
 }
 
+bool SensorMesh::handleIncomingMsg(ContactInfo& from, uint32_t timestamp, uint8_t* data, uint flags, size_t len) {
+  MESH_DEBUG_PRINT("handleIncomingMsg: unhandled msg from ");
+  #ifdef MESH_DEBUG
+  mesh::Utils::printHex(Serial, from.id.pub_key, PUB_KEY_SIZE);
+  Serial.printf(": %s\n", data);
+  #endif
+  return false;
+}
+
 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 >= num_contacts) {

examples/simple_sensor/SensorMesh.h

@@ -140,7 +140,8 @@ protected:
   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 onAckRecv(mesh::Packet* packet, uint32_t ack_crc) override;
-
+  virtual bool handleIncomingMsg(ContactInfo& from, uint32_t timestamp, uint8_t* data, uint flags, size_t len);
+  void sendAckTo(const ContactInfo& dest, uint32_t ack_hash);
 private:
   FILESYSTEM* _fs;
   unsigned long next_local_advert, next_flood_advert;