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, 15 insertions, 10 deletions

diff --git a/src/net.h b/src/net.h
index 5a8e57b68b..ca65c1dc19 100644
--- a/src/net.h
+++ b/src/net.h
@@ -10,12 +10,14 @@
 #include <addrman.h>
 #include <amount.h>
 #include <bloom.h>
+#include <chainparams.h>
 #include <compat.h>
 #include <crypto/siphash.h>
 #include <hash.h>
 #include <limitedmap.h>
-#include <netaddress.h>
 #include <net_permissions.h>
+#include <netaddress.h>
+#include <optional.h>
 #include <policy/feerate.h>
 #include <protocol.h>
 #include <random.h>
@@ -712,11 +714,8 @@ class CNetMessage {
 public:
     CDataStream m_recv;                  //!< received message data
     std::chrono::microseconds m_time{0}; //!< time of message receipt
-    bool m_valid_netmagic = false;
-    bool m_valid_header = false;
-    bool m_valid_checksum = false;
-    uint32_t m_message_size{0};     //!< size of the payload
-    uint32_t m_raw_message_size{0}; //!< used wire size of the message (including header/checksum)
+    uint32_t m_message_size{0};          //!< size of the payload
+    uint32_t m_raw_message_size{0};      //!< used wire size of the message (including header/checksum)
     std::string m_command;
 
     CNetMessage(CDataStream&& recv_in) : m_recv(std::move(recv_in)) {}
@@ -740,13 +739,15 @@ public:
     // read and deserialize data
     virtual int Read(const char *data, unsigned int bytes) = 0;
     // decomposes a message from the context
-    virtual CNetMessage GetMessage(const CMessageHeader::MessageStartChars& message_start, std::chrono::microseconds time) = 0;
+    virtual Optional<CNetMessage> GetMessage(std::chrono::microseconds time, uint32_t& out_err) = 0;
     virtual ~TransportDeserializer() {}
 };
 
 class V1TransportDeserializer final : public TransportDeserializer
 {
 private:
+    const CChainParams& m_chain_params;
+    const NodeId m_node_id; // Only for logging
     mutable CHash256 hasher;
     mutable uint256 data_hash;
     bool in_data;                   // parsing header (false) or data (true)
@@ -772,8 +773,12 @@ private:
     }
 
 public:
-
-    V1TransportDeserializer(const CMessageHeader::MessageStartChars& pchMessageStartIn, int nTypeIn, int nVersionIn) : hdrbuf(nTypeIn, nVersionIn), hdr(pchMessageStartIn), vRecv(nTypeIn, nVersionIn) {
+    V1TransportDeserializer(const CChainParams& chain_params, const NodeId node_id, int nTypeIn, int nVersionIn)
+        : m_chain_params(chain_params),
+          m_node_id(node_id),
+          hdrbuf(nTypeIn, nVersionIn),
+          vRecv(nTypeIn, nVersionIn)
+    {
         Reset();
     }
 
@@ -793,7 +798,7 @@ public:
         if (ret < 0) Reset();
         return ret;
     }
-    CNetMessage GetMessage(const CMessageHeader::MessageStartChars& message_start, std::chrono::microseconds time) override;
+    Optional<CNetMessage> GetMessage(std::chrono::microseconds time, uint32_t& out_err_raw_size) override;
 };
 
 /** The TransportSerializer prepares messages for the network transport