net_mn: cache MN quorum relay members + let them know that we are int…

…erested in plain LLMQ recovered signatures.

src/evo/mnauth.cpp

@@ -13,6 +13,7 @@
 #include "llmq/quorums_utils.h"
 #include "util/system.h" // for fMasternode and gArgs access
 #include "net_processing.h" // for cs_main
+#include "tiertwo/net_masternodes.h"
 #include "version.h" // for MNAUTH_NODE_VER_VERSION
 
 void CMNAuth::PushMNAUTH(CNode* pnode, CConnman& connman)
@@ -189,7 +190,15 @@ void CMNAuth::ProcessMessage(CNode* pnode, const std::string& strCommand, CDataS
             pnode->verifiedPubKeyHash = dmn->pdmnState->pubKeyOperator.GetHash();
         }
 
-        // todo: add iqr connection, send interest in plain LLMQ recovered signatures.
+        if (!pnode->m_masternode_iqr_connection && connman.GetTierTwoConnMan()->isMasternodeQuorumRelayMember(pnode->verifiedProRegTxHash)) {
+            // Tell our peer that we're interested in plain LLMQ recovered signatures.
+            // Otherwise, the peer would only announce/send messages resulting from QRECSIG,
+            // future e.g. tx locks or chainlocks. SPV and regular full nodes should not send
+            // this message as they are usually only interested in the higher level messages.
+            CNetMsgMaker msgMaker(pnode->GetSendVersion());
+            connman.PushMessage(pnode, msgMaker.Make(NetMsgType::QSENDRECSIGS, true));
+            pnode->m_masternode_iqr_connection = true;
+        }
 
         LogPrint(BCLog::NET_MN, "CMNAuth::%s -- Valid MNAUTH for %s, peer=%d\n", __func__, mnauth.proRegTxHash.ToString(), pnode->GetId());
     }

src/net.h

@@ -346,6 +346,8 @@ class CConnman
     unsigned int GetReceiveFloodSize() const;
 
     void SetAsmap(std::vector<bool> asmap) { addrman.m_asmap = std::move(asmap); }
+    /** Unique tier two connections manager */
+    TierTwoConnMan* GetTierTwoConnMan() { return m_tiertwo_conn_man.get(); };
 private:
     struct ListenSocket {
         SOCKET socket;
@@ -565,6 +567,8 @@ class CNodeStats
     bool m_masternode_connection{false};
     // If 'true' this node will be disconnected after MNAUTH
     bool m_masternode_probe_connection{false};
+    // If 'true', we identified it as an intra-quorum relay connection
+    bool m_masternode_iqr_connection{false};
     // In case this is a verified MN, this value is the proTx of the MN
     uint256 verifiedProRegTxHash;
     // In case this is a verified MN, this value is the hashed operator pubkey of the MN
@@ -661,7 +665,8 @@ class CNode
     bool fOneShot;
     bool fAddnode;
     bool m_masternode_connection{false}; // If true this node is only used for quorum related messages.
-    bool m_masternode_probe_connection{false}; // If true this will be disconnected right after the verack
+    bool m_masternode_probe_connection{false}; // If true this will be disconnected right after the verack.
+    bool m_masternode_iqr_connection{false}; // If 'true', we identified it as an intra-quorum relay connection.
     bool fClient;
     const bool fInbound;
     /**
@@ -917,8 +922,7 @@ class CNode
     //! Sets the addrName only if it was not previously set
     void MaybeSetAddrName(const std::string& addrNameIn);
 
-    // todo: add iqr connection
-    bool CanRelay() const { return !m_masternode_connection; }
+    bool CanRelay() const { return !m_masternode_connection || m_masternode_iqr_connection; }
 };
 
 class CExplicitNetCleanup

src/tiertwo/net_masternodes.cpp

@@ -10,6 +10,7 @@
 #include "scheduler.h"
 #include "tiertwo/masternode_meta_manager.h" // for g_mmetaman
 #include "masternode-sync.h" // for IsBlockchainSynced
+#include "netmessagemaker.h"
 
 TierTwoConnMan::TierTwoConnMan(CConnman* _connman) : connman(_connman) {}
 TierTwoConnMan::~TierTwoConnMan() { connman = nullptr; }
@@ -37,6 +38,30 @@ void TierTwoConnMan::removeQuorumNodes(Consensus::LLMQType llmqType, const uint2
     masternodeQuorumNodes.erase(std::make_pair(llmqType, quorumHash));
 }
 
+void TierTwoConnMan::setMasternodeQuorumRelayMembers(Consensus::LLMQType llmqType, const uint256& quorumHash, const std::set<uint256>& proTxHashes)
+{
+    {
+        LOCK(cs_vPendingMasternodes);
+        auto it = masternodeQuorumRelayMembers.emplace(std::make_pair(llmqType, quorumHash), proTxHashes);
+        if (!it.second) {
+            it.first->second = proTxHashes;
+        }
+    }
+
+    // Update existing connections
+    connman->ForEachNode([&](CNode* pnode) {
+        if (!pnode->verifiedProRegTxHash.IsNull() && !pnode->m_masternode_iqr_connection && isMasternodeQuorumRelayMember(pnode->verifiedProRegTxHash)) {
+            // Tell our peer that we're interested in plain LLMQ recovered signatures.
+            // Otherwise, the peer would only announce/send messages resulting from QRECSIG,
+            // future e.g. tx locks or chainlocks. SPV and regular full nodes should not send
+            // this message as they are usually only interested in the higher level messages.
+            CNetMsgMaker msgMaker(pnode->GetSendVersion());
+            connman->PushMessage(pnode, msgMaker.Make(NetMsgType::QSENDRECSIGS, true));
+            pnode->m_masternode_iqr_connection = true;
+        }
+    });
+}
+
 bool TierTwoConnMan::isMasternodeQuorumNode(const CNode* pnode)
 {
     // Let's see if this is an outgoing connection to an address that is known to be a masternode
@@ -67,6 +92,20 @@ bool TierTwoConnMan::isMasternodeQuorumNode(const CNode* pnode)
     return false;
 }
 
+bool TierTwoConnMan::isMasternodeQuorumRelayMember(const uint256& protxHash)
+{
+    if (protxHash.IsNull()) {
+        return false;
+    }
+    LOCK(cs_vPendingMasternodes);
+    for (const auto& p : masternodeQuorumRelayMembers) {
+        if (p.second.count(protxHash) > 0) {
+            return true;
+        }
+    }
+    return false;
+}
+
 bool TierTwoConnMan::addPendingMasternode(const uint256& proTxHash)
 {
     LOCK(cs_vPendingMasternodes);

src/tiertwo/net_masternodes.h

@@ -40,9 +40,15 @@ class TierTwoConnMan
     // Remove the registered quorum from the pending/protected MN connections
     void removeQuorumNodes(Consensus::LLMQType llmqType, const uint256& quorumHash);
 
+    // Add MNs to the active quorum relay members map and push QSENDRECSIGS to the verified connected peers that are part of this new quorum.
+    void setMasternodeQuorumRelayMembers(Consensus::LLMQType llmqType, const uint256& quorumHash, const std::set<uint256>& proTxHashes);
+
     // Returns true if the node has the same address as a MN.
     bool isMasternodeQuorumNode(const CNode* pnode);
 
+    // Whether protxHash an active quorum relay member
+    bool isMasternodeQuorumRelayMember(const uint256& protxHash);
+
     // Add DMN to the pending connection list
     bool addPendingMasternode(const uint256& proTxHash);
 
@@ -63,6 +69,7 @@ class TierTwoConnMan
     std::vector<uint256> vPendingMasternodes GUARDED_BY(cs_vPendingMasternodes);
     typedef std::pair<Consensus::LLMQType, uint256> QuorumTypeAndHash;
     std::map<QuorumTypeAndHash, std::set<uint256>> masternodeQuorumNodes GUARDED_BY(cs_vPendingMasternodes);
+    std::map<QuorumTypeAndHash, std::set<uint256>> masternodeQuorumRelayMembers GUARDED_BY(cs_vPendingMasternodes);
     std::set<uint256> masternodePendingProbes GUARDED_BY(cs_vPendingMasternodes);
 
     // parent connections manager