connman is in charge of pushing messages

The changes here are dense and subtle, but hopefully all is more explicit
than before.

- CConnman is now in charge of sending data rather than the nodes themselves.
  This is necessary because many decisions need to be made with all nodes in
  mind, and a model that requires the nodes calling up to their manager quickly
  turns to spaghetti.

- The per-node-serializer (ssSend) has been replaced with a (quasi-)const
  send-version. Since the send version for serialization can only change once
  per connection, we now explicitly tag messages with INIT_PROTO_VERSION if
  they are sent before the handshake. With this done, there's no need to lock
  for access to nSendVersion.

  Also, a new stream is used for each message, so there's no need to lock
  during the serialization process.

- This takes care of accounting for optimistic sends, so the
  nOptimisticBytesWritten hack can be removed.

- -dropmessagestest and -fuzzmessagestest have not been preserved, as I suspect
  they haven't been used in years.

1 files changed, 7 insertions, 7 deletions

diff --git a/src/main.cpp b/src/main.cpp
index 3f706b1503..62fbf9e455 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -5047,7 +5047,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
         // Each connection can only send one version message
         if (pfrom->nVersion != 0)
         {
-            pfrom->PushMessage(NetMsgType::REJECT, strCommand, REJECT_DUPLICATE, string("Duplicate version message"));
+            connman.PushMessageWithVersion(pfrom, INIT_PROTO_VERSION, NetMsgType::REJECT, strCommand, REJECT_DUPLICATE, string("Duplicate version message"));
             LOCK(cs_main);
             Misbehaving(pfrom->GetId(), 1);
             return false;
@@ -5067,7 +5067,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
         if (pfrom->nServicesExpected & ~pfrom->nServices)
         {
             LogPrint("net", "peer=%d does not offer the expected services (%08x offered, %08x expected); disconnecting\n", pfrom->id, pfrom->nServices, pfrom->nServicesExpected);
-            pfrom->PushMessage(NetMsgType::REJECT, strCommand, REJECT_NONSTANDARD,
+            connman.PushMessageWithVersion(pfrom, INIT_PROTO_VERSION, NetMsgType::REJECT, strCommand, REJECT_NONSTANDARD,
                                strprintf("Expected to offer services %08x", pfrom->nServicesExpected));
             pfrom->fDisconnect = true;
             return false;
@@ -5077,7 +5077,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
         {
             // disconnect from peers older than this proto version
             LogPrintf("peer=%d using obsolete version %i; disconnecting\n", pfrom->id, pfrom->nVersion);
-            pfrom->PushMessage(NetMsgType::REJECT, strCommand, REJECT_OBSOLETE,
+            connman.PushMessageWithVersion(pfrom, INIT_PROTO_VERSION, NetMsgType::REJECT, strCommand, REJECT_OBSOLETE,
                                strprintf("Version must be %d or greater", MIN_PEER_PROTO_VERSION));
             pfrom->fDisconnect = true;
             return false;
@@ -5118,7 +5118,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
 
         // Be shy and don't send version until we hear
         if (pfrom->fInbound)
-            pfrom->PushVersion();
+            connman.PushVersion(pfrom, GetAdjustedTime());
 
         pfrom->fClient = !(pfrom->nServices & NODE_NETWORK);
 
@@ -5135,8 +5135,8 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv,
         }
 
         // Change version
-        pfrom->PushMessage(NetMsgType::VERACK);
-        pfrom->ssSend.SetVersion(min(pfrom->nVersion, PROTOCOL_VERSION));
+        connman.PushMessageWithVersion(pfrom, INIT_PROTO_VERSION, NetMsgType::VERACK);
+        pfrom->SetSendVersion(min(pfrom->nVersion, PROTOCOL_VERSION));
 
         if (!pfrom->fInbound)
         {
@@ -6391,7 +6391,7 @@ bool ProcessMessages(CNode* pfrom, CConnman& connman)
         }
         catch (const std::ios_base::failure& e)
         {
-            pfrom->PushMessage(NetMsgType::REJECT, strCommand, REJECT_MALFORMED, string("error parsing message"));
+            connman.PushMessageWithVersion(pfrom, INIT_PROTO_VERSION, NetMsgType::REJECT, strCommand, REJECT_MALFORMED, string("error parsing message"));
             if (strstr(e.what(), "end of data"))
             {
                 // Allow exceptions from under-length message on vRecv