refactor: Remove support for protocol version 2.1

src/test/overlay/ProtocolVersion_test.cpp

@@ -36,7 +36,6 @@ public:
         testcase("Convert protocol version to string");
         BEAST_EXPECT(to_string(makeProtocol(1, 3)) == "XRPL/1.3");
         BEAST_EXPECT(to_string(makeProtocol(2, 0)) == "XRPL/2.0");
-        BEAST_EXPECT(to_string(makeProtocol(2, 1)) == "XRPL/2.1");
         BEAST_EXPECT(to_string(makeProtocol(10, 10)) == "XRPL/10.10");
 
         {
@@ -59,11 +58,10 @@ public:
             testcase("Protocol version negotiation");
 
             BEAST_EXPECT(negotiateProtocolVersion("RTXP/1.2") == std::nullopt);
-            BEAST_EXPECT(
-                negotiateProtocolVersion("RTXP/1.2, XRPL/2.0, XRPL/2.1") == makeProtocol(2, 1));
+            BEAST_EXPECT(negotiateProtocolVersion("RTXP/1.2, XRPL/2.0, XRPL/2.1") == std::nullopt);
             BEAST_EXPECT(negotiateProtocolVersion("XRPL/2.2") == makeProtocol(2, 2));
             BEAST_EXPECT(
-                negotiateProtocolVersion("RTXP/1.2, XRPL/2.2, XRPL/2.3, XRPL/999.999") ==
+                negotiateProtocolVersion("RTXP/1.2, XRPL/2.1, XRPL/2.2, XRPL/2.3, XRPL/999.999") ==
                 makeProtocol(2, 2));
             BEAST_EXPECT(negotiateProtocolVersion("XRPL/999.999, WebSocket/1.0") == std::nullopt);
             BEAST_EXPECT(negotiateProtocolVersion("") == std::nullopt);

src/xrpld/app/misc/detail/ValidatorList.cpp

@@ -727,17 +727,8 @@ ValidatorList::sendValidatorList(
     HashRouter& hashRouter,
     beast::Journal j)
 {
-    std::size_t messageVersion = 0;
-    if (peer.supportsFeature(ProtocolFeature::ValidatorList2Propagation))
-    {
-        messageVersion = 2;
-    }
-    else if (peer.supportsFeature(ProtocolFeature::ValidatorListPropagation))
-    {
-        messageVersion = 1;
-    }
-    if (messageVersion == 0u)
-        return;
+    // v1 messages are no longer supported.
+    std::size_t const messageVersion = 2;
     auto const [newPeerSequence, numVLs] = buildValidatorListMessages(
         messageVersion, peerSequence, maxSequence, rawVersion, rawManifest, blobInfos, messages);
     if (newPeerSequence != 0u)
@@ -858,16 +849,9 @@ ValidatorList::broadcastBlobs(
 
     if (toSkip)
     {
-        // We don't know what messages or message versions we're sending
-        // until we examine our peer's properties. Build the message(s) on
-        // demand, but reuse them when possible.
-
-        // This will hold a v1 message with only the current VL if we have
-        // any peers that don't support v2
-        std::vector<ValidatorList::MessageWithHash> messages1;
-        // This will hold v2 messages indexed by the peer's
-        // `publisherListSequence`. For each `publisherListSequence`, we'll
-        // only send the VLs with higher sequences.
+        // Build v2 messages on demand and reuse them when possible. Messages
+        // are indexed by the peer's `publisherListSequence`; for each sequence,
+        // we only send VLs with higher sequences.
         std::map<std::size_t, std::vector<ValidatorList::MessageWithHash>> messages2;
         // If any peers are found that are worth considering, this list will
         // be built to hold info for all of the valid VLs.
@@ -887,8 +871,6 @@ ValidatorList::broadcastBlobs(
                 {
                     if (blobInfos.empty())
                         buildBlobInfos(blobInfos, lists);
-                    auto const v2 =
-                        peer->supportsFeature(ProtocolFeature::ValidatorList2Propagation);
                     sendValidatorList(
                         *peer,
                         peerSequence,
@@ -897,7 +879,7 @@ ValidatorList::broadcastBlobs(
                         lists.rawVersion,
                         lists.rawManifest,
                         blobInfos,
-                        v2 ? messages2[peerSequence] : messages1,
+                        messages2[peerSequence],
                         hashRouter,
                         j);
                     // Even if the peer doesn't support the messages,

src/xrpld/overlay/Peer.h

@@ -14,8 +14,7 @@ class Charge;
 }  // namespace Resource
 
 enum class ProtocolFeature {
-    ValidatorListPropagation,
-    ValidatorList2Propagation,
+    ValidatorList2Propagation,  // ValidatorListPropagation is no longer supported.
     LedgerReplay,
 };
 

src/xrpld/overlay/detail/PeerImp.cpp

@@ -545,8 +545,6 @@ PeerImp::supportsFeature(ProtocolFeature f) const
 {
     switch (f)
     {
-        case ProtocolFeature::ValidatorListPropagation:
-            return protocol_ >= makeProtocol(2, 1);
         case ProtocolFeature::ValidatorList2Propagation:
             return protocol_ >= makeProtocol(2, 2);
         case ProtocolFeature::LedgerReplay:
@@ -892,7 +890,7 @@ PeerImp::doProtocolStart()
     onReadMessage(error_code(), 0);
 
     // Send all the validator lists that have been loaded
-    if (inbound_ && supportsFeature(ProtocolFeature::ValidatorListPropagation))
+    if (inbound_)
     {
         app_.getValidators().forEachAvailable(
             [&](std::string const& manifest,
@@ -2275,14 +2273,6 @@ PeerImp::onMessage(std::shared_ptr<protocol::TMValidatorList> const& m)
 {
     try
     {
-        if (!supportsFeature(ProtocolFeature::ValidatorListPropagation))
-        {
-            JLOG(pJournal_.debug()) << "ValidatorList: received validator list from peer using "
-                                    << "protocol version " << to_string(protocol_)
-                                    << " which shouldn't support this feature.";
-            fee_.update(Resource::kFeeUselessData, "unsupported peer");
-            return;
-        }
         onValidatorListMessage(
             "ValidatorList", m->manifest(), m->version(), ValidatorList::parseBlobs(*m));
     }

src/xrpld/overlay/detail/ProtocolVersion.cpp

@@ -26,7 +26,6 @@ namespace xrpl {
 */
 
 constexpr ProtocolVersion const kSupportedProtocolList[]{
-    {2, 1},
     {2, 2},
 };