merge: upstream/dev into observer-firmware-dev (v1.17.1)

Picks up upstream MeshCore 1.17.1.

Notable upstream content:
- 1.17.1 version/build-date bump in the example MyMesh headers.
- nRF52: combine radio entropy with CC310 RNG.
- Companion FEM prefs: load/save of fem_ properties commented out until they
  can be set from the client.
- Scoped reply routing: replies no longer dropped when flood.max.unscoped is
  low (RoutingPolicy + unit tests).
- nRF52 unused-pin sweep (T1, T-Echo Lite, MeshPocket).

No conflicts.

examples/simple_room_server/MyMesh.cpp

@@ -354,10 +354,9 @@ uint32_t MyMesh::getDirectRetransmitDelay(const mesh::Packet *packet) {
 
 bool MyMesh::allowPacketForward(const mesh::Packet *packet) {
   if (_prefs.disable_fwd) return false;
-  if (packet->isRouteFlood()) {
-    if (packet->getPathHashCount() >= _prefs.flood_max) return false;
-    if (packet->getRouteType() == ROUTE_TYPE_FLOOD && packet->getPathHashCount() >= _prefs.flood_max_unscoped) return false;
-    if (packet->getPayloadType() == PAYLOAD_TYPE_ADVERT && packet->getPathHashCount() >= _prefs.flood_max_advert) return false;
+  if (packet->isRouteFlood()
+      && mesh::isFloodHopLimitExceeded(packet, _prefs.flood_max, _prefs.flood_max_unscoped, _prefs.flood_max_advert)) {
+    return false;
   }
   return true;
 }
@@ -1055,15 +1054,23 @@ bool MyMesh::resolveAlertScope(TransportKey& dest) {
 }
 
 void MyMesh::sendFloodReply(mesh::Packet* packet, unsigned long delay_millis, uint8_t path_hash_size) {
-  if (recv_pkt_region && !recv_pkt_region->isWildcard()) {  // if _request_ packet scope is known, send reply with same scope
-    TransportKey scope;
-    if (region_map.getTransportKeysFor(*recv_pkt_region, &scope, 1) > 0) {
-      sendFloodScoped(scope, packet, delay_millis, path_hash_size);
-    } else {
+  TransportKey req_scope;
+  bool is_wildcard = recv_pkt_region != NULL && recv_pkt_region->isWildcard();
+  bool req_scope_known = recv_pkt_region != NULL && !is_wildcard
+                      && region_map.getTransportKeysFor(*recv_pkt_region, &req_scope, 1) > 0;
+
+  switch (mesh::chooseReplyScope(req_scope_known, is_wildcard, !default_scope.isNull())) {
+    case mesh::REPLY_SCOPE_REQUEST:
+      sendFloodScoped(req_scope, packet, delay_millis, path_hash_size);   // reply with same scope as request
+      break;
+    case mesh::REPLY_SCOPE_DEFAULT:
+      // requester's scope is unknown: DIRECT request (no transport codes), or code matched no Region.
+      // un-scoped would be dropped at hop 0 by repeaters running flood.max.unscoped=0
+      sendFloodScoped(default_scope, packet, delay_millis, path_hash_size);
+      break;
+    case mesh::REPLY_SCOPE_NONE:
       sendFlood(packet, delay_millis, path_hash_size);   // send un-scoped
-    }
-  } else {
-    sendFlood(packet, delay_millis, path_hash_size);   // send un-scoped
+      break;
   }
 }