Merge #19954: Complete the BIP155 implementation and upgrade to TORv3

dcf0cb477699d11afd0ff37c8bfb2b1b4f7f1ee5 tor: make a TORv3 hidden service instead of TORv2 (Vasil Dimov)
353a3fdaad055eea42a0baf7326bdd591f541170 net: advertise support for ADDRv2 via new message (Vasil Dimov)
201a4596d92d640d5eb7e76cc8d959228fa09dbb net: CAddress & CAddrMan: (un)serialize as ADDRv2 (Vasil Dimov)
1d3ec2a1fda7446323786a52da1fd109c01aa6fb Support bypassing range check in ReadCompactSize (Pieter Wuille)

Pull request description:

  This PR contains the two remaining commits from #19031 to complete the [BIP155](https://github.com/bitcoin/bips/blob/master/bip-0155.mediawiki) implementation:

  `net: CAddress & CAddrMan: (un)serialize as ADDRv2`
  `net: advertise support for ADDRv2 via new message`

  plus one more commit:

  `tor: make a TORv3 hidden service instead of TORv2`

ACKs for top commit:
  jonatack:
    re-ACK dcf0cb477699d11afd0ff37c8bfb2b1b4f7f1ee5 per `git diff 9b56a68 dcf0cb4` only change since last review is an update to the release notes which partially picked up the suggested text. Running a node on this branch and addnode-ing to 6 other Tor v3 nodes, I see "addrv2" and "sendaddrv2" messages in getpeerinfo in both the "bytesrecv_per_msg" and "bytessent_per_msg" JSON objects.
  sipa:
    ACK dcf0cb477699d11afd0ff37c8bfb2b1b4f7f1ee5
  hebasto:
    re-ACK dcf0cb477699d11afd0ff37c8bfb2b1b4f7f1ee5, the node works flawlessly in all of the modes: Tor-only, clearnet-only, mixed.
  laanwj:
    Edit: I have to retract this ACK for now, I'm having some problems with this PR on a FreeBSD node. It drops all outgoing connections with this dcf0cb477699d11afd0ff37c8bfb2b1b4f7f1ee5 merged on master (12a1c3ad1a43634d2a98717e49e3f02c4acea2fe).
  ariard:
    Code Review ACK dcf0cb4

Tree-SHA512: 28d4d0d817b8664d2f4b18c0e0f31579b2f0f2d23310ed213f1f436a4242afea14dfbf99e07e15889bc5c5c71ad50056797e9307ff8a90e96704f588a6171308

1 files changed, 79 insertions, 0 deletions

diff --git a/test/functional/p2p_addrv2_relay.py b/test/functional/p2p_addrv2_relay.py
new file mode 100755
index 0000000000..23ce3e5d04
--- /dev/null
+++ b/test/functional/p2p_addrv2_relay.py
@@ -0,0 +1,79 @@
+#!/usr/bin/env python3
+# Copyright (c) 2020 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""
+Test addrv2 relay
+"""
+
+import time
+
+from test_framework.messages import (
+    CAddress,
+    msg_addrv2,
+    NODE_NETWORK,
+    NODE_WITNESS,
+)
+from test_framework.p2p import P2PInterface
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal
+
+ADDRS = []
+for i in range(10):
+    addr = CAddress()
+    addr.time = int(time.time()) + i
+    addr.nServices = NODE_NETWORK | NODE_WITNESS
+    addr.ip = "123.123.123.{}".format(i % 256)
+    addr.port = 8333 + i
+    ADDRS.append(addr)
+
+
+class AddrReceiver(P2PInterface):
+    addrv2_received_and_checked = False
+
+    def __init__(self):
+        super().__init__(support_addrv2 = True)
+
+    def on_addrv2(self, message):
+        for addr in message.addrs:
+            assert_equal(addr.nServices, 9)
+            assert addr.ip.startswith('123.123.123.')
+            assert (8333 <= addr.port < 8343)
+        self.addrv2_received_and_checked = True
+
+    def wait_for_addrv2(self):
+        self.wait_until(lambda: "addrv2" in self.last_message)
+
+
+class AddrTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.setup_clean_chain = True
+        self.num_nodes = 1
+
+    def run_test(self):
+        self.log.info('Create connection that sends addrv2 messages')
+        addr_source = self.nodes[0].add_p2p_connection(P2PInterface())
+        msg = msg_addrv2()
+
+        self.log.info('Send too-large addrv2 message')
+        msg.addrs = ADDRS * 101
+        with self.nodes[0].assert_debug_log(['addrv2 message size = 1010']):
+            addr_source.send_and_ping(msg)
+
+        self.log.info('Check that addrv2 message content is relayed and added to addrman')
+        addr_receiver = self.nodes[0].add_p2p_connection(AddrReceiver())
+        msg.addrs = ADDRS
+        with self.nodes[0].assert_debug_log([
+                'Added 10 addresses from 127.0.0.1: 0 tried',
+                'received: addrv2 (131 bytes) peer=0',
+                'sending addrv2 (131 bytes) peer=1',
+        ]):
+            addr_source.send_and_ping(msg)
+            self.nodes[0].setmocktime(int(time.time()) + 30 * 60)
+            addr_receiver.wait_for_addrv2()
+
+        assert addr_receiver.addrv2_received_and_checked
+
+
+if __name__ == '__main__':
+    AddrTest().main()