Enable passive squelching (#5358)

This change updates the squelching logic to accept squelch messages for untrusted validators. As a result, servers will also squelch untrusted validator messages reducing duplicate traffic they generate.

In particular:
* Updates squelch message handling logic to squelch messages for all validators, not only trusted ones.
* Updates the logic to send squelch messages to peers that don't squelch themselves
* Increases the threshold for the number of messages that a peer has to deliver to consider it as a candidate for validator messages.

src/xrpld/overlay/ReduceRelayCommon.h

@@ -45,8 +45,8 @@ static constexpr auto IDLED = std::chrono::seconds{8};
 // of messages from the validator. We add peers who reach
 // MIN_MESSAGE_THRESHOLD to considered pool once MAX_SELECTED_PEERS
 // reach MAX_MESSAGE_THRESHOLD.
-static constexpr uint16_t MIN_MESSAGE_THRESHOLD = 9;
-static constexpr uint16_t MAX_MESSAGE_THRESHOLD = 10;
+static constexpr uint16_t MIN_MESSAGE_THRESHOLD = 19;
+static constexpr uint16_t MAX_MESSAGE_THRESHOLD = 20;
 // Max selected peers to choose as the source of messages from validator
 static constexpr uint16_t MAX_SELECTED_PEERS = 5;
 // Wait before reduce-relay feature is enabled on boot up to let

src/xrpld/overlay/detail/PeerImp.cpp

@@ -112,10 +112,7 @@ PeerImp::PeerImp(
           headers_,
           FEATURE_TXRR,
           app_.config().TX_REDUCE_RELAY_ENABLE))
-    , vpReduceRelayEnabled_(peerFeatureEnabled(
-          headers_,
-          FEATURE_VPRR,
-          app_.config().VP_REDUCE_RELAY_ENABLE))
+    , vpReduceRelayEnabled_(app_.config().VP_REDUCE_RELAY_ENABLE)
     , ledgerReplayEnabled_(peerFeatureEnabled(
           headers_,
           FEATURE_LEDGER_REPLAY,
@@ -2705,16 +2702,6 @@ PeerImp::onMessage(std::shared_ptr<protocol::TMSquelch> const& m)
     }
     PublicKey key(slice);
 
-    // Ignore non-validator squelch
-    if (!app_.validators().listed(key))
-    {
-        fee_.update(Resource::feeInvalidData, "squelch non-validator");
-        JLOG(p_journal_.debug())
-            << "onMessage: TMSquelch discarding non-validator squelch "
-            << slice;
-        return;
-    }
-
     // Ignore the squelch for validator's own messages.
     if (key == app_.getValidationPublicKey())
     {

src/xrpld/overlay/detail/PeerImp.h

@@ -705,10 +705,7 @@ PeerImp::PeerImp(
           headers_,
           FEATURE_TXRR,
           app_.config().TX_REDUCE_RELAY_ENABLE))
-    , vpReduceRelayEnabled_(peerFeatureEnabled(
-          headers_,
-          FEATURE_VPRR,
-          app_.config().VP_REDUCE_RELAY_ENABLE))
+    , vpReduceRelayEnabled_(app_.config().VP_REDUCE_RELAY_ENABLE)
     , ledgerReplayEnabled_(peerFeatureEnabled(
           headers_,
           FEATURE_LEDGER_REPLAY,