Merge #18877: Serve cfcheckpt requests

23083856a551ca13e8b142791c296ecb25cc4e7f [test] Add test for cfcheckpt (Jim Posen)
f9e00bb25ac4039056808affeb5ffa86a2c317fe [net processing] Message handling for getcfcheckpt. (Jim Posen)
9ccaaba11e94571fe984857494042ac292c17156 [init] Add -peerblockfilters option (Jim Posen)

Pull request description:

  Serve cfcheckpt messages if basic block filter index is enabled and `-peercfilters` is set.

  `NODE_COMPACT_FILTERS` is not signaled to peers, but functionality can be used for testing and serving pre-configured clients.

ACKs for top commit:
  jonatack:
    Code review re-ACK 23083856a551ca13e8b142791c296ecb25cc4e7f the only change since my review @ 967e2b1 is an update required for #16224 that was merged yesterday.
  fjahr:
    re-ACK 23083856a551ca13e8b142791c296ecb25cc4e7f
  jkczyz:
    re-ACK 23083856a551ca13e8b142791c296ecb25cc4e7f
  ariard:
    re-Code Review ACK 2308385
  clarkmoody:
    Tested ACK 23083856a
  MarcoFalke:
    re-ACK 23083856a5 🌳
  theStack:
    ACK https://github.com/bitcoin/bitcoin/commit/23083856a551ca13e8b142791c296ecb25cc4e7f

Tree-SHA512: 8c751bbd7d1c31a413096462ae025c3d2f3163c7016cbec472a5f5ec267f8dd19a2dfc4d749876d7409c1db546e6fdd16461c6863effcfa0d3e993edcfa92a08

2 files changed, 52 insertions, 0 deletions

diff --git a/test/functional/test_framework/messages.py b/test/functional/test_framework/messages.py
index 4855f62a8f..ef5ef49eaf 100755
--- a/test/functional/test_framework/messages.py
+++ b/test/functional/test_framework/messages.py
@@ -57,6 +57,8 @@ MSG_FILTERED_BLOCK = 3
 MSG_WITNESS_FLAG = 1 << 30
 MSG_TYPE_MASK = 0xffffffff >> 2
 
+FILTER_TYPE_BASIC = 0
+
 # Serialization/deserialization tools
 def sha256(s):
     return hashlib.new('sha256', s).digest()
@@ -1512,3 +1514,50 @@ class msg_no_witness_blocktxn(msg_blocktxn):
 
     def serialize(self):
         return self.block_transactions.serialize(with_witness=False)
+
+class msg_getcfcheckpt:
+    __slots__ = ("filter_type", "stop_hash")
+    msgtype =  b"getcfcheckpt"
+
+    def __init__(self, filter_type, stop_hash):
+        self.filter_type = filter_type
+        self.stop_hash = stop_hash
+
+    def deserialize(self, f):
+        self.filter_type = struct.unpack("<B", f.read(1))[0]
+        self.stop_hash = deser_uint256(f)
+
+    def serialize(self):
+        r = b""
+        r += struct.pack("<B", self.filter_type)
+        r += ser_uint256(self.stop_hash)
+        return r
+
+    def __repr__(self):
+        return "msg_getcfcheckpt(filter_type={:#x}, stop_hash={:x})".format(
+            self.filter_type, self.stop_hash)
+
+class msg_cfcheckpt:
+    __slots__ = ("filter_type", "stop_hash", "headers")
+    msgtype =  b"cfcheckpt"
+
+    def __init__(self, filter_type=None, stop_hash=None, headers=None):
+        self.filter_type = filter_type
+        self.stop_hash = stop_hash
+        self.headers = headers
+
+    def deserialize(self, f):
+        self.filter_type = struct.unpack("<B", f.read(1))[0]
+        self.stop_hash = deser_uint256(f)
+        self.headers = deser_uint256_vector(f)
+
+    def serialize(self):
+        r = b""
+        r += struct.pack("<B", self.filter_type)
+        r += ser_uint256(self.stop_hash)
+        r += ser_uint256_vector(self.headers)
+        return r
+
+    def __repr__(self):
+        return "msg_cfcheckpt(filter_type={:#x}, stop_hash={:x})".format(
+            self.filter_type, self.stop_hash)
diff --git a/test/functional/test_framework/mininode.py b/test/functional/test_framework/mininode.py
index 31cec66ee7..ba0391625e 100755
--- a/test/functional/test_framework/mininode.py
+++ b/test/functional/test_framework/mininode.py
@@ -31,6 +31,7 @@ from test_framework.messages import (
     msg_block,
     MSG_BLOCK,
     msg_blocktxn,
+    msg_cfcheckpt,
     msg_cmpctblock,
     msg_feefilter,
     msg_filteradd,
@@ -67,6 +68,7 @@ MESSAGEMAP = {
     b"addr": msg_addr,
     b"block": msg_block,
     b"blocktxn": msg_blocktxn,
+    b"cfcheckpt": msg_cfcheckpt,
     b"cmpctblock": msg_cmpctblock,
     b"feefilter": msg_feefilter,
     b"filteradd": msg_filteradd,
@@ -328,6 +330,7 @@ class P2PInterface(P2PConnection):
     def on_addr(self, message): pass
     def on_block(self, message): pass
     def on_blocktxn(self, message): pass
+    def on_cfcheckpt(self, message): pass
     def on_cmpctblock(self, message): pass
     def on_feefilter(self, message): pass
     def on_filteradd(self, message): pass