Merge #15437: p2p: Remove BIP61 reject messages

fa25f43ac5 p2p: Remove BIP61 reject messages (MarcoFalke)

Pull request description:

  Reject messages (BIP 61) appear in the following settings:

  * Parsing of reject messages (in case `-debug=net` is set, off by default). This has only been used for a single `LogPrint` call for several releases now. Such logging is completely meaningless to us and should thus be removed.

  * The sending of reject messages (in case `-enablebip61` is set, off by default). This can be used to debug a node that is under our control. Instead of hacking this debugging into the p2p protocol, it could be more easily achieved by parsing the debug log. (Use `-printtoconsole` to have it as stream, or read from the `debug.log` file like our python function `assert_debug_log` in the test framework does)

  Having to maintain all of this logic and code to accommodate debugging, which can be achieved by other means a lot easier, is a burden. It makes review on net processing changes a lot harder, since the reject message logic has to be carried around without introducing any errors or DOS vectors.

ACKs for top commit:
  jnewbery:
    utACK fa25f43ac5
  laanwj:
    I'm still not 100% convinced that I like getting rid of BIP61 conceptually, but apparently everyone wants it, code review ACK fa25f43ac5.
  ryanofsky:
    Code review ACK fa25f43ac5

Tree-SHA512: daf55254202925e56be3d6cfb3c1c804e7a82cecb1dd1e5bd7b472bae989fd68ac4f21ec53fc46751353056fd645f7f877bebcb0b40920257991423a3d99e0be

test/functional/feature_cltv.py

@@ -22,9 +22,6 @@ from io import BytesIO
 
 CLTV_HEIGHT = 1351
 
-# Reject codes that we might receive in this test
-REJECT_INVALID = 16
-REJECT_NONSTANDARD = 64
 
 def cltv_invalidate(tx):
     '''Modify the signature in vin 0 of the tx to fail CLTV

test/functional/feature_dersig.py

@@ -9,19 +9,15 @@ Test that the DERSIG soft-fork activates at (regtest) height 1251.
 
 from test_framework.blocktools import create_coinbase, create_block, create_transaction
 from test_framework.messages import msg_block
-from test_framework.mininode import mininode_lock, P2PInterface
+from test_framework.mininode import P2PInterface
 from test_framework.script import CScript
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_equal,
-    wait_until,
 )
 
 DERSIG_HEIGHT = 1251
 
-# Reject codes that we might receive in this test
-REJECT_INVALID = 16
-REJECT_NONSTANDARD = 64
 
 # A canonical signature consists of:
 # <30> <total len> <02> <len R> <R> <02> <len S> <S> <hashtype>
@@ -44,7 +40,7 @@ def unDERify(tx):
 class BIP66Test(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 1
-        self.extra_args = [['-whitelist=127.0.0.1', '-par=1', '-enablebip61']]  # Use only one script thread to get the exact reject reason for testing
+        self.extra_args = [['-whitelist=127.0.0.1', '-par=1']]  # Use only one script thread to get the exact log msg for testing
         self.setup_clean_chain = True
         self.rpc_timeout = 120
 
@@ -129,12 +125,6 @@ class BIP66Test(BitcoinTestFramework):
             assert_equal(int(self.nodes[0].getbestblockhash(), 16), tip)
             self.nodes[0].p2p.sync_with_ping()
 
-        wait_until(lambda: "reject" in self.nodes[0].p2p.last_message.keys(), lock=mininode_lock)
-        with mininode_lock:
-            assert self.nodes[0].p2p.last_message["reject"].code in [REJECT_INVALID, REJECT_NONSTANDARD]
-            assert_equal(self.nodes[0].p2p.last_message["reject"].data, block.sha256)
-            assert b'Non-canonical DER signature' in self.nodes[0].p2p.last_message["reject"].reason
-
         self.log.info("Test that a version 3 block with a DERSIG-compliant transaction is accepted")
         block.vtx[1] = create_transaction(self.nodes[0], self.coinbase_txids[1], self.nodeaddress, amount=1.0)
         block.hashMerkleRoot = block.calc_merkle_root()

test/functional/test_framework/messages.py

@@ -1317,38 +1317,6 @@ class msg_headers:
         return "msg_headers(headers=%s)" % repr(self.headers)
 
 
-class msg_reject:
-    __slots__ = ("code", "data", "message", "reason")
-    command = b"reject"
-    REJECT_MALFORMED = 1
-
-    def __init__(self):
-        self.message = b""
-        self.code = 0
-        self.reason = b""
-        self.data = 0
-
-    def deserialize(self, f):
-        self.message = deser_string(f)
-        self.code = struct.unpack("<B", f.read(1))[0]
-        self.reason = deser_string(f)
-        if (self.code != self.REJECT_MALFORMED and
-                (self.message == b"block" or self.message == b"tx")):
-            self.data = deser_uint256(f)
-
-    def serialize(self):
-        r = ser_string(self.message)
-        r += struct.pack("<B", self.code)
-        r += ser_string(self.reason)
-        if (self.code != self.REJECT_MALFORMED and
-                (self.message == b"block" or self.message == b"tx")):
-            r += ser_uint256(self.data)
-        return r
-
-    def __repr__(self):
-        return "msg_reject: %s %d %s [%064x]" \
-            % (self.message, self.code, self.reason, self.data)
-
 
 class msg_feefilter:
     __slots__ = ("feerate",)

test/functional/test_framework/mininode.py

@@ -41,7 +41,6 @@ from test_framework.messages import (
     msg_notfound,
     msg_ping,
     msg_pong,
-    msg_reject,
     msg_sendcmpct,
     msg_sendheaders,
     msg_tx,
@@ -74,7 +73,6 @@ MESSAGEMAP = {
     b"notfound": msg_notfound,
     b"ping": msg_ping,
     b"pong": msg_pong,
-    b"reject": msg_reject,
     b"sendcmpct": msg_sendcmpct,
     b"sendheaders": msg_sendheaders,
     b"tx": msg_tx,