From 2046617b5e06ddb7f960b28219c155995542f029 Mon Sep 17 00:00:00 2001
From: Cory Fields <cory-nospam-@coryfields.com>
Date: Wed, 18 Jan 2017 18:15:00 -0500
Subject: net: deserialize the entire version message locally

This avoids having some vars set if the version negotiation fails.

Also copy it all into CNode at the same site. nVersion and
fSuccessfullyConnected are set last, as they are the gates for the other vars.
Make them atomic for that reason.
---
 src/net_processing.cpp | 61 ++++++++++++++++++++++++++++----------------------
 1 file changed, 34 insertions(+), 27 deletions(-)

(limited to 'src/net_processing.cpp')

diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 6dcb907bcf..d1e6b1ae04 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -1199,16 +1199,23 @@ bool static ProcessMessage(CNode* pfrom, std::string strCommand, CDataStream& vR
         CAddress addrFrom;
         uint64_t nNonce = 1;
         uint64_t nServiceInt;
+        ServiceFlags nServices;
         int nVersion;
+        int nSendVersion;
+        std::string strSubVer;
+        int nStartingHeight = -1;
+        bool fRelay = true;
+
         vRecv >> nVersion >> nServiceInt >> nTime >> addrMe;
-        pfrom->nServices = ServiceFlags(nServiceInt);
+        nSendVersion = std::min(nVersion, PROTOCOL_VERSION);
+        nServices = ServiceFlags(nServiceInt);
         if (!pfrom->fInbound)
         {
-            connman.SetServices(pfrom->addr, pfrom->nServices);
+            connman.SetServices(pfrom->addr, nServices);
         }
-        if (pfrom->nServicesExpected & ~pfrom->nServices)
+        if (pfrom->nServicesExpected & ~nServices)
         {
-            LogPrint("net", "peer=%d does not offer the expected services (%08x offered, %08x expected); disconnecting\n", pfrom->id, pfrom->nServices, pfrom->nServicesExpected);
+            LogPrint("net", "peer=%d does not offer the expected services (%08x offered, %08x expected); disconnecting\n", pfrom->id, nServices, pfrom->nServicesExpected);
             connman.PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_NONSTANDARD,
                                strprintf("Expected to offer services %08x", pfrom->nServicesExpected)));
             pfrom->fDisconnect = true;
@@ -1230,20 +1237,13 @@ bool static ProcessMessage(CNode* pfrom, std::string strCommand, CDataStream& vR
         if (!vRecv.empty())
             vRecv >> addrFrom >> nNonce;
         if (!vRecv.empty()) {
-            vRecv >> LIMITED_STRING(pfrom->strSubVer, MAX_SUBVERSION_LENGTH);
-            pfrom->cleanSubVer = SanitizeString(pfrom->strSubVer);
+            vRecv >> LIMITED_STRING(strSubVer, MAX_SUBVERSION_LENGTH);
         }
         if (!vRecv.empty()) {
-            vRecv >> pfrom->nStartingHeight;
+            vRecv >> nStartingHeight;
         }
-        {
-            LOCK(pfrom->cs_filter);
-            if (!vRecv.empty())
-                vRecv >> pfrom->fRelayTxes; // set to true after we get the first filter* message
-            else
-                pfrom->fRelayTxes = true;
-        }
-
+        if (!vRecv.empty())
+            vRecv >> fRelay;
         // Disconnect if we connected to ourself
         if (pfrom->fInbound && !connman.CheckIncomingNonce(nNonce))
         {
@@ -1252,7 +1252,6 @@ bool static ProcessMessage(CNode* pfrom, std::string strCommand, CDataStream& vR
             return true;
         }
 
-        pfrom->addrLocal = addrMe;
         if (pfrom->fInbound && addrMe.IsRoutable())
         {
             SeenLocal(addrMe);
@@ -1262,9 +1261,25 @@ bool static ProcessMessage(CNode* pfrom, std::string strCommand, CDataStream& vR
         if (pfrom->fInbound)
             PushNodeVersion(pfrom, connman, GetAdjustedTime());
 
-        pfrom->fClient = !(pfrom->nServices & NODE_NETWORK);
+        connman.PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::VERACK));
+
+        pfrom->nServices = nServices;
+        pfrom->addrLocal = addrMe;
+        pfrom->strSubVer = strSubVer;
+        pfrom->cleanSubVer = SanitizeString(strSubVer);
+        pfrom->nStartingHeight = nStartingHeight;
+        pfrom->fClient = !(nServices & NODE_NETWORK);
+        {
+            LOCK(pfrom->cs_filter);
+            pfrom->fRelayTxes = fRelay; // set to true after we get the first filter* message
+        }
+
+        // Change version
+        pfrom->SetSendVersion(nSendVersion);
+        pfrom->nVersion = nVersion;
+        pfrom->fSuccessfullyConnected = true;
 
-        if((pfrom->nServices & NODE_WITNESS))
+        if((nServices & NODE_WITNESS))
         {
             LOCK(cs_main);
             State(pfrom->GetId())->fHaveWitness = true;
@@ -1276,12 +1291,6 @@ bool static ProcessMessage(CNode* pfrom, std::string strCommand, CDataStream& vR
         UpdatePreferredDownload(pfrom, State(pfrom->GetId()));
         }
 
-        // Change version
-        connman.PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::VERACK));
-        int nSendVersion = std::min(nVersion, PROTOCOL_VERSION);
-        pfrom->nVersion = nVersion;
-        pfrom->SetSendVersion(nSendVersion);
-
         if (!pfrom->fInbound)
         {
             // Advertise our address
@@ -1309,8 +1318,6 @@ bool static ProcessMessage(CNode* pfrom, std::string strCommand, CDataStream& vR
             connman.MarkAddressGood(pfrom->addr);
         }
 
-        pfrom->fSuccessfullyConnected = true;
-
         std::string remoteAddr;
         if (fLogIPs)
             remoteAddr = ", peeraddr=" + pfrom->addr.ToString();
@@ -1352,7 +1359,7 @@ bool static ProcessMessage(CNode* pfrom, std::string strCommand, CDataStream& vR
 
     if (strCommand == NetMsgType::VERACK)
     {
-        pfrom->SetRecvVersion(std::min(pfrom->nVersion, PROTOCOL_VERSION));
+        pfrom->SetRecvVersion(std::min(pfrom->nVersion.load(), PROTOCOL_VERSION));
 
         if (!pfrom->fInbound) {
             // Mark this node as currently connected, so we update its timestamp later.
-- 
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