Merge #19486: Remove unused constants CADDR_TIME_VERSION and GETHEADERS_VERSION

7bb6f9b [protocol] Remove unused GETHEADERS_VERSION (John Newbery)
37a934e [protocol] Remove unused CADDR_TIME_VERSION (John Newbery)

Pull request description:

  These constants are no longer required and can be removed.

  Additional code comments are added to explain CAddress serialization.

ACKs for top commit:
  MarcoFalke:
    ACK 7bb6f9b already an improvement, but maybe getting rid of INIT_PROTO_VERSION here would be an even stronger improvement (can be done later)
  jonatack:
    ACK 7bb6f9b
  vasild:
    ACK 7bb6f9b

Tree-SHA512: 5382562c60fd677c86583754eca11aad3719064efe2e5ef4f307d693b583422ca8d385926c2582aaab899f502b151f2eb87a7ac23363b15f4fceaa06296f98e3

Author: MarcoFalke

src/protocol.h

@@ -371,7 +371,13 @@ class CAddress : public CService
             READWRITE(nVersion);
         }
         if ((s.GetType() & SER_DISK) ||
-            (nVersion >= CADDR_TIME_VERSION && !(s.GetType() & SER_GETHASH))) {
+            (nVersion != INIT_PROTO_VERSION && !(s.GetType() & SER_GETHASH))) {
+            // The only time we serialize a CAddress object without nTime is in
+            // the initial VERSION messages which contain two CAddress records.
+            // At that point, the serialization version is INIT_PROTO_VERSION.
+            // After the version handshake, serialization version is >=
+            // MIN_PEER_PROTO_VERSION and all ADDR messages are serialized with
+            // nTime.
             READWRITE(obj.nTime);
         }
         READWRITE(Using<CustomUintFormatter<8>>(obj.nServices));

src/version.h

@@ -14,15 +14,8 @@ static const int PROTOCOL_VERSION = 70015;
 //! initial proto version, to be increased after version/verack negotiation
 static const int INIT_PROTO_VERSION = 209;
 
-//! In this version, 'getheaders' was introduced.
-static const int GETHEADERS_VERSION = 31800;
-
 //! disconnect from peers older than this proto version
-static const int MIN_PEER_PROTO_VERSION = GETHEADERS_VERSION;
-
-//! nTime field added to CAddress, starting with this version;
-//! if possible, avoid requesting addresses nodes older than this
-static const int CADDR_TIME_VERSION = 31402;
+static const int MIN_PEER_PROTO_VERSION = 31800;
 
 //! BIP 0031, pong message, is enabled for all versions AFTER this one
 static const int BIP0031_VERSION = 60000;

test/functional/test_framework/messages.py

@@ -207,17 +207,19 @@ def __init__(self):
         self.ip = "0.0.0.0"
         self.port = 0
 
-    def deserialize(self, f, with_time=True):
+    def deserialize(self, f, *, with_time=True):
         if with_time:
+            # VERSION messages serialize CAddress objects without time
             self.time = struct.unpack("<i", f.read(4))[0]
         self.nServices = struct.unpack("<Q", f.read(8))[0]
         self.pchReserved = f.read(12)
         self.ip = socket.inet_ntoa(f.read(4))
         self.port = struct.unpack(">H", f.read(2))[0]
 
-    def serialize(self, with_time=True):
+    def serialize(self, *, with_time=True):
         r = b""
         if with_time:
+            # VERSION messages serialize CAddress objects without time
             r += struct.pack("<i", self.time)
         r += struct.pack("<Q", self.nServices)
         r += self.pchReserved
@@ -973,10 +975,10 @@ def deserialize(self, f):
         self.nServices = struct.unpack("<Q", f.read(8))[0]
         self.nTime = struct.unpack("<q", f.read(8))[0]
         self.addrTo = CAddress()
-        self.addrTo.deserialize(f, False)
+        self.addrTo.deserialize(f, with_time=False)
 
         self.addrFrom = CAddress()
-        self.addrFrom.deserialize(f, False)
+        self.addrFrom.deserialize(f, with_time=False)
         self.nNonce = struct.unpack("<Q", f.read(8))[0]
         self.strSubVer = deser_string(f)
 
@@ -996,8 +998,8 @@ def serialize(self):
         r += struct.pack("<i", self.nVersion)
         r += struct.pack("<Q", self.nServices)
         r += struct.pack("<q", self.nTime)
-        r += self.addrTo.serialize(False)
-        r += self.addrFrom.serialize(False)
+        r += self.addrTo.serialize(with_time=False)
+        r += self.addrFrom.serialize(with_time=False)
         r += struct.pack("<Q", self.nNonce)
         r += ser_string(self.strSubVer)
         r += struct.pack("<i", self.nStartingHeight)