Merge #16202: p2p: Refactor network message deserialization

ed2dc5e48abed1cde6ab98025dc8212917d47d21 Add override/final modifiers to V1TransportDeserializer (Pieter Wuille)
f342a5e61a73e1edf389b662d265d20cf26a1d51 Make resetting implicit in TransportDeserializer::Read() (Pieter Wuille)
6a91499496d76c2b3e84489e9723b60514fb08db Remove oversized message detection from log and interface (Pieter Wuille)
b0e10ff4df3d4c70fb172ea8c3128c82e6e368bb Force CNetMessage::m_recv to use std::move (Jonas Schnelli)
efecb74677222f6c70adf7f860c315f430d39ec4 Use adapter pattern for the network deserializer (Jonas Schnelli)
1a5c656c3169ba525f84145d19ce8c64f2cf1efb Remove transport protocol knowhow from CNetMessage / net processing (Jonas Schnelli)
6294ecdb8bb4eb7049a18c721ee8cb4a53d80a06 Refactor: split network transport deserializing from message container (Jonas Schnelli)

Pull request description:

  **This refactors the network message deserialization.**

  * It transforms the `CNetMessage` into a transport protocol agnostic message container.
  * A new class `TransportDeserializer` (unique pointer of `CNode`)  is introduced, handling the network buffer reading and the decomposing to a `CNetMessage`
  * **No behavioral changes** (in terms of disconnecting, punishing)
  * Moves the checksum finalizing into the `SocketHandler` thread (finalizing was in `ProcessMessages` before)

  The **optional last commit** makes the `TransportDeserializer` following an adapter pattern (polymorphic interface) to make it easier to later add a V2 transport protocol deserializer.

  Intentionally not touching the sending part.

  Pre-Requirement for BIP324 (v2 message transport protocol).
  Replacement for #14046 and inspired by a [comment](https://github.com/bitcoin/bitcoin/pull/14046#issuecomment-431528330) from sipa

ACKs for top commit:
  promag:
    Code review ACK ed2dc5e48abed1cde6ab98025dc8212917d47d21.
  marcinja:
    Code review ACK ed2dc5e48abed1cde6ab98025dc8212917d47d21
  ryanofsky:
    Code review ACK ed2dc5e48abed1cde6ab98025dc8212917d47d21. 4 cleanup commits added since last review. Unaddressed comments:
  ariard:
    Code review and tested ACK ed2dc5e.

Tree-SHA512: bab8d87464e2e8742529e488ddcdc8650f0c2025c9130913df00a0b17ecdb9a525061cbbbd0de0251b76bf75a8edb72e3ad0dbf5b79e26f2ad05d61b4e4ded6d

1 files changed, 14 insertions, 18 deletions

diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 4a3076e3c7..fd31c962c2 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -3272,41 +3272,37 @@ bool PeerLogicValidation::ProcessMessages(CNode* pfrom, std::atomic<bool>& inter
             return false;
         // Just take one message
         msgs.splice(msgs.begin(), pfrom->vProcessMsg, pfrom->vProcessMsg.begin());
-        pfrom->nProcessQueueSize -= msgs.front().vRecv.size() + CMessageHeader::HEADER_SIZE;
+        pfrom->nProcessQueueSize -= msgs.front().m_raw_message_size;
         pfrom->fPauseRecv = pfrom->nProcessQueueSize > connman->GetReceiveFloodSize();
         fMoreWork = !pfrom->vProcessMsg.empty();
     }
     CNetMessage& msg(msgs.front());
 
     msg.SetVersion(pfrom->GetRecvVersion());
-    // Scan for message start
-    if (memcmp(msg.hdr.pchMessageStart, chainparams.MessageStart(), CMessageHeader::MESSAGE_START_SIZE) != 0) {
-        LogPrint(BCLog::NET, "PROCESSMESSAGE: INVALID MESSAGESTART %s peer=%d\n", SanitizeString(msg.hdr.GetCommand()), pfrom->GetId());
+    // 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;
     }
 
-    // Read header
-    CMessageHeader& hdr = msg.hdr;
-    if (!hdr.IsValid(chainparams.MessageStart()))
+    // Check header
+    if (!msg.m_valid_header)
     {
-        LogPrint(BCLog::NET, "PROCESSMESSAGE: ERRORS IN HEADER %s peer=%d\n", SanitizeString(hdr.GetCommand()), pfrom->GetId());
+        LogPrint(BCLog::NET, "PROCESSMESSAGE: ERRORS IN HEADER %s peer=%d\n", SanitizeString(msg.m_command), pfrom->GetId());
         return fMoreWork;
     }
-    std::string strCommand = hdr.GetCommand();
+    const std::string& strCommand = msg.m_command;
 
     // Message size
-    unsigned int nMessageSize = hdr.nMessageSize;
+    unsigned int nMessageSize = msg.m_message_size;
 
     // Checksum
-    CDataStream& vRecv = msg.vRecv;
-    const uint256& hash = msg.GetMessageHash();
-    if (memcmp(hash.begin(), hdr.pchChecksum, CMessageHeader::CHECKSUM_SIZE) != 0)
+    CDataStream& vRecv = msg.m_recv;
+    if (!msg.m_valid_checksum)
     {
-        LogPrint(BCLog::NET, "%s(%s, %u bytes): CHECKSUM ERROR expected %s was %s\n", __func__,
-           SanitizeString(strCommand), nMessageSize,
-           HexStr(hash.begin(), hash.begin()+CMessageHeader::CHECKSUM_SIZE),
-           HexStr(hdr.pchChecksum, hdr.pchChecksum+CMessageHeader::CHECKSUM_SIZE));
+        LogPrint(BCLog::NET, "%s(%s, %u bytes): CHECKSUM ERROR peer=%d\n", __func__,
+           SanitizeString(strCommand), nMessageSize, pfrom->GetId());
         return fMoreWork;
     }
 
@@ -3314,7 +3310,7 @@ bool PeerLogicValidation::ProcessMessages(CNode* pfrom, std::atomic<bool>& inter
     bool fRet = false;
     try
     {
-        fRet = ProcessMessage(pfrom, strCommand, vRecv, msg.nTime, chainparams, connman, interruptMsgProc);
+        fRet = ProcessMessage(pfrom, strCommand, vRecv, msg.m_time, chainparams, connman, interruptMsgProc);
         if (interruptMsgProc)
             return false;
         if (!pfrom->vRecvGetData.empty())