From 13246598b8b84af2ade8b3d0368655fc64f5cca0 Mon Sep 17 00:00:00 2001
From: Evan Duffield <evan@darkcoin.io>
Date: Mon, 2 Feb 2015 04:42:41 -0700
Subject: [PATCH] Added dstx support for free transactions

---
 src/main.cpp | 75 +++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 68 insertions(+), 7 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index f9894a5d53..d5e545db59 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -26,6 +26,7 @@
 #include <boost/algorithm/string/replace.hpp>
 #include <boost/filesystem.hpp>
 #include <boost/filesystem/fstream.hpp>
+#include <boost/lexical_cast.hpp>
 
 using namespace std;
 using namespace boost;
@@ -4002,13 +4003,27 @@ void static ProcessGetData(CNode* pfrom)
                     }
                 }
                 if (!pushed && inv.type == MSG_TX) {
-                    CTransaction tx;
-                    if (mempool.lookup(inv.hash, tx)) {
+
+                    if(mapDarksendBroadcastTxes.count(inv.hash)){
                         CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
                         ss.reserve(1000);
-                        ss << tx;
-                        pfrom->PushMessage("tx", ss);
+                        ss <<
+                            mapDarksendBroadcastTxes[inv.hash].tx <<
+                            mapDarksendBroadcastTxes[inv.hash].vin <<
+                            mapDarksendBroadcastTxes[inv.hash].vchSig <<
+                            mapDarksendBroadcastTxes[inv.hash].sigTime;
+
+                        pfrom->PushMessage("dstx", ss);
                         pushed = true;
+                    } else {
+                        CTransaction tx;
+                        if (mempool.lookup(inv.hash, tx)) {
+                            CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
+                            ss.reserve(1000);
+                            ss << tx;
+                            pfrom->PushMessage("tx", ss);
+                            pushed = true;
+                        }
                     }
                 }
                 if (!pushed) {
@@ -4381,12 +4396,58 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
     }
 
 
-    else if (strCommand == "tx")
+    else if (strCommand == "tx"|| strCommand == "dstx")
     {
         vector<uint256> vWorkQueue;
         vector<uint256> vEraseQueue;
         CTransaction tx;
-        vRecv >> tx;
+
+        //masternode signed transaction
+        bool allowFree = false;
+        CTxIn vin;
+        vector<unsigned char> vchSig;
+        int64_t sigTime;
+
+        if(strCommand == "tx") {
+            vRecv >> tx;
+        } else if (strCommand == "dstx") {
+            //these allow masternodes to publish a limited amount of free transactions
+            vRecv >> tx >> vin >> vchSig >> sigTime;
+
+            BOOST_FOREACH(CMasterNode& mn, vecMasternodes) {
+                if(mn.vin == vin) {
+                    if(!mn.allowFreeTx){
+                        //multiple peers can send us a valid masternode transaction
+                        if(fDebug) LogPrintf("dstx: Masternode sending too many transactions %s\n", tx.GetHash().ToString().c_str());
+                        return true;
+                    }
+
+                    std::string strMessage = tx.GetHash().ToString() + boost::lexical_cast<std::string>(sigTime);
+
+                    std::string errorMessage = "";
+                    if(!darkSendSigner.VerifyMessage(mn.pubkey2, vchSig, strMessage, errorMessage)){
+                        LogPrintf("dstx: Got bad masternode address signature %s \n", vin.ToString().c_str());
+                        //pfrom->Misbehaving(20);
+                        return false;
+                    }
+
+                    LogPrintf("dstx: Got Masternode transaction %s\n", tx.GetHash().ToString().c_str());
+
+                    allowFree = true;
+                    mn.allowFreeTx = false;
+
+                    if(!mapDarksendBroadcastTxes.count(tx.GetHash())){
+                        CDarksendBroadcastTx dstx;
+                        dstx.tx = tx;
+                        dstx.vin = vin;
+                        dstx.vchSig = vchSig;
+                        dstx.sigTime = sigTime;
+
+                        mapDarksendBroadcastTxes.insert(make_pair(tx.GetHash(), dstx));
+                    }
+                }
+            }
+        }
 
         CInv inv(MSG_TX, tx.GetHash());
         pfrom->AddInventoryKnown(inv);
@@ -4395,7 +4456,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
 
         bool fMissingInputs = false;
         CValidationState state;
-        if (AcceptToMemoryPool(mempool, state, tx, true, &fMissingInputs))
+        if (AcceptToMemoryPool(mempool, state, tx, true, &fMissingInputs, allowFree))
         {
             mempool.check(pcoinsTip);
             RelayTransaction(tx, inv.hash);