Merge #16562: Refactor message transport packaging

16d6113f4faa901e248adb693d4768a9e5019a16 Refactor message transport packaging (Jonas Schnelli)

Pull request description:

  This PR factors out transport packaging logic from `CConnman::PushMessage()`.
  It's similar to #16202 (where we refactor deserialization).

  This allows implementing a new message transport protocol like BIP324.

ACKs for top commit:
  dongcarl:
    ACK 16d6113f4faa901e248adb693d4768a9e5019a16 FWIW
  ariard:
    Code review ACK 16d6113
  elichai:
    semiACK 16d6113f4faa901e248adb693d4768a9e5019a16 ran functional+unit tests.
  MarcoFalke:
    ACK 16d6113f4faa901e248adb693d4768a9e5019a16 🙎

Tree-SHA512: 8c2f8ab9f52e9b94327973ae15019a08109d5d9f9247492703a842827c5b5d634fc0411759e0bb316d824c586614b0220c2006410851933613bc143e58f7e6c1

1 files changed, 15 insertions, 0 deletions

diff --git a/src/net.h b/src/net.h
index 819947658a..7d3eaa2e0d 100644
--- a/src/net.h
+++ b/src/net.h
@@ -703,12 +703,27 @@ public:
     CNetMessage GetMessage(const CMessageHeader::MessageStartChars& message_start, int64_t time) override;
 };
 
+/** The TransportSerializer prepares messages for the network transport
+ */
+class TransportSerializer {
+public:
+    // prepare message for transport (header construction, error-correction computation, payload encryption, etc.)
+    virtual void prepareForTransport(CSerializedNetMsg& msg, std::vector<unsigned char>& header) = 0;
+    virtual ~TransportSerializer() {}
+};
+
+class V1TransportSerializer  : public TransportSerializer {
+public:
+    void prepareForTransport(CSerializedNetMsg& msg, std::vector<unsigned char>& header) override;
+};
+
 /** Information about a peer */
 class CNode
 {
     friend class CConnman;
 public:
     std::unique_ptr<TransportDeserializer> m_deserializer;
+    std::unique_ptr<TransportSerializer> m_serializer;
 
     // socket
     std::atomic<ServiceFlags> nServices{NODE_NONE};