Merge #19107: p2p: Move all header verification into the network layer, extend logging

deb52711a17236d0fca302701b5af585341ab42a Remove header checks out of net_processing (Troy Giorshev)
52d4ae46ab822d0f54e246a6f2364415cda149bd Give V1TransportDeserializer CChainParams& member (Troy Giorshev)
5bceef6b12fa16d20287693be377dace3dfec3e5 Change CMessageHeader Constructor (Troy Giorshev)
1ca20c1af8f08f07c407c3183c37b467ddf0f413 Add doxygen comment for ReceiveMsgBytes (Troy Giorshev)
890b1d7c2b8312d41d048d2db124586c5dbc8a49 Move checksum check from net_processing to net (Troy Giorshev)
2716647ebf60cea05fc9edce6a18dcce4e7727ad Give V1TransportDeserializer an m_node_id member (Troy Giorshev)

Pull request description:

  Inspired by #15206 and #15197, this PR moves all message header verification from the message processing layer and into the network/transport layer.

  In the previous PRs there is a change in behavior, where we would disconnect from peers upon a single failed checksum check.  In various discussions there was concern over whether this was the right choice, and some expressed a desire to see how this would look if it was made to be a pure refactor.

  For more context, see https://bitcoincore.reviews/15206.html#l-81.

  This PR improves the separation between the p2p layers, helping improvements like [BIP324](https://github.com/bitcoin/bitcoin/pull/18242) and #18989.

ACKs for top commit:
  ryanofsky:
    Code review ACK deb52711a17236d0fca302701b5af585341ab42a just rebase due to conflict on adjacent line
  jnewbery:
    Code review ACK deb52711a17236d0fca302701b5af585341ab42a.

Tree-SHA512: 1a3b7ae883b020cfee1bef968813e04df651ffdad9dd961a826bd80654f2c98676ce7f4721038a1b78d8790e4cebe8060419e3d8affc97ce2b9b4e4b72e6fa9f

1 files changed, 1 insertions, 31 deletions

diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index d2a76550ea..f784a9b754 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -3815,14 +3815,6 @@ bool PeerManager::MaybeDiscourageAndDisconnect(CNode& pnode)
 
 bool PeerManager::ProcessMessages(CNode* pfrom, std::atomic<bool>& interruptMsgProc)
 {
-    //
-    // Message format
-    //  (4) message start
-    //  (12) command
-    //  (4) size
-    //  (4) checksum
-    //  (x) data
-    //
     bool fMoreWork = false;
 
     if (!pfrom->vRecvGetData.empty())
@@ -3863,35 +3855,13 @@ bool PeerManager::ProcessMessages(CNode* pfrom, std::atomic<bool>& interruptMsgP
     CNetMessage& msg(msgs.front());
 
     msg.SetVersion(pfrom->GetCommonVersion());
-    // Check network magic
-    if (!msg.m_valid_netmagic) {
-        LogPrint(BCLog::NET, "PROCESSMESSAGE: INVALID MESSAGESTART %s peer=%d\n", SanitizeString(msg.m_command), pfrom->GetId());
-        pfrom->fDisconnect = true;
-        return false;
-    }
-
-    // Check header
-    if (!msg.m_valid_header)
-    {
-        LogPrint(BCLog::NET, "PROCESSMESSAGE: ERRORS IN HEADER %s peer=%d\n", SanitizeString(msg.m_command), pfrom->GetId());
-        return fMoreWork;
-    }
     const std::string& msg_type = msg.m_command;
 
     // Message size
     unsigned int nMessageSize = msg.m_message_size;
 
-    // Checksum
-    CDataStream& vRecv = msg.m_recv;
-    if (!msg.m_valid_checksum)
-    {
-        LogPrint(BCLog::NET, "%s(%s, %u bytes): CHECKSUM ERROR peer=%d\n", __func__,
-           SanitizeString(msg_type), nMessageSize, pfrom->GetId());
-        return fMoreWork;
-    }
-
     try {
-        ProcessMessage(*pfrom, msg_type, vRecv, msg.m_time, interruptMsgProc);
+        ProcessMessage(*pfrom, msg_type, msg.m_recv, msg.m_time, interruptMsgProc);
         if (interruptMsgProc)
             return false;
         if (!pfrom->vRecvGetData.empty())