Merge bitcoin/bitcoin#27452: test: cover addrv2 anchors by adding TorV3 to CAddress in messages.py

ba8ab4fc545800c4fb283a5ff0b19138a0451aba test: cover addrv2 support in anchors.dat with a TorV3 address (Matthew Zipkin)
b4bee4bbf45785fbbb355194ccb23c70acd19d27 test: add keep_alive option to socks5 proxy in test_framework (Matthew Zipkin)
5aaf988ccca210228c5a41ea0a18b0c85a85cf71 test: cover TorV3 address in p2p_addrv2_relay (Matthew Zipkin)
80f64a3d40779d342b740fbc57474e170b102678 test: add support for all networks in CAddress in messages.py (brunoerg)

Pull request description:

  Closes https://github.com/bitcoin/bitcoin/issues/27140

  Adds test coverage for https://github.com/bitcoin/bitcoin/pull/20516 to ensure that https://github.com/bitcoin/bitcoin/issues/20511 is completed and may be closed.

  This PR adds a test case to `feature_anchors.py` where an onion v3 address is set as a blocks-only relay peer and then shutdown, ensuring that the address is saved to anchors.dat in addrv2 format. We then ensure that bitcoin attempts to reconnect to that anchor address on restart.

  To compute the addrv2 serialization of the onion v3 address, I added logic to `CAddress` in `messages.py`. This new logic is covered by extending `p2p_addrv2_relay.py` to include an onion v3 address. Future work will be adding coverage for ipv6, torv2 and cjdns in these modules and also `feature_proxy.py`

  Also includes de/serialization unit test for `CAddress` in test framework.

ACKs for top commit:
  jonatack:
    ACK ba8ab4fc545800c4fb283a5ff0b19138a0451aba
  brunoerg:
    crACK ba8ab4fc545800c4fb283a5ff0b19138a0451aba
  willcl-ark:
    ACK ba8ab4fc54

Tree-SHA512: 7220e30d7cb975903d9ac575a7215a08e8f784c24c5741561affcbde12fb92cbf8704cb42e66494b788ba6ed4bb255fb0cc327e4f2190fae50c0ed9f336c0ff0

5 files changed, 143 insertions, 17 deletions

diff --git a/test/functional/feature_anchors.py b/test/functional/feature_anchors.py
index 0961f21a40..3b75a06d9e 100755
--- a/test/functional/feature_anchors.py
+++ b/test/functional/feature_anchors.py
@@ -6,12 +6,15 @@
 
 import os
 
-from test_framework.p2p import P2PInterface
+from test_framework.p2p import P2PInterface, P2P_SERVICES
+from test_framework.socks5 import Socks5Configuration, Socks5Server
+from test_framework.messages import CAddress, hash256
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import check_node_connections
+from test_framework.util import check_node_connections, assert_equal, p2p_port
 
 INBOUND_CONNECTIONS = 5
 BLOCK_RELAY_CONNECTIONS = 2
+ONION_ADDR = "pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion:8333"
 
 
 class AnchorsTest(BitcoinTestFramework):
@@ -54,7 +57,7 @@ class AnchorsTest(BitcoinTestFramework):
             else:
                 inbound_nodes_port.append(hex(int(addr_split[1]))[2:])
 
-        self.log.info("Stop node 0")
+        self.log.debug("Stop node")
         self.stop_node(0)
 
         # It should contain only the block-relay-only addresses
@@ -78,12 +81,64 @@ class AnchorsTest(BitcoinTestFramework):
                 tweaked_contents[20:20] = b'1'
                 out_file_handler.write(bytes(tweaked_contents))
 
-            self.log.info("Start node")
+            self.log.debug("Start node")
             self.start_node(0)
 
         self.log.info("When node starts, check if anchors.dat doesn't exist anymore")
         assert not os.path.exists(node_anchors_path)
 
+        self.log.info("Ensure addrv2 support")
+        # Use proxies to catch outbound connections to networks with 256-bit addresses
+        onion_conf = Socks5Configuration()
+        onion_conf.auth = True
+        onion_conf.unauth = True
+        onion_conf.addr = ('127.0.0.1', p2p_port(self.num_nodes))
+        onion_conf.keep_alive = True
+        onion_proxy = Socks5Server(onion_conf)
+        onion_proxy.start()
+        self.restart_node(0, extra_args=[f"-onion={onion_conf.addr[0]}:{onion_conf.addr[1]}"])
+
+        self.log.info("Add 256-bit-address block-relay-only connections to node")
+        self.nodes[0].addconnection(ONION_ADDR, 'block-relay-only')
+
+        self.log.debug("Stop node")
+        with self.nodes[0].assert_debug_log([f"DumpAnchors: Flush 1 outbound block-relay-only peer addresses to anchors.dat"]):
+            self.stop_node(0)
+        # Manually close keep_alive proxy connection
+        onion_proxy.stop()
+
+        self.log.info("Check for addrv2 addresses in anchors.dat")
+        caddr = CAddress()
+        caddr.net = CAddress.NET_TORV3
+        caddr.ip, port_str = ONION_ADDR.split(":")
+        caddr.port = int(port_str)
+        # TorV3 addrv2 serialization:
+        # time(4) | services(1) | networkID(1) | address length(1) | address(32)
+        expected_pubkey = caddr.serialize_v2()[7:39].hex()
+
+        # position of services byte of first addr in anchors.dat
+        # network magic, vector length, version, nTime
+        services_index = 4 + 1 + 4 + 4
+        data = bytes()
+        with open(node_anchors_path, "rb") as file_handler:
+            data = file_handler.read()
+            assert_equal(data[services_index], 0x00)  # services == NONE
+            anchors2 = data.hex()
+            assert expected_pubkey in anchors2
+
+        with open(node_anchors_path, "wb") as file_handler:
+            # Modify service flags for this address even though we never connected to it.
+            # This is necessary because on restart we will not attempt an anchor connection
+            # to a host without our required services, even if its address is in the anchors.dat file
+            new_data = bytearray(data)[:-32]
+            new_data[services_index] = P2P_SERVICES
+            new_data_hash = hash256(new_data)
+            file_handler.write(new_data + new_data_hash)
+
+        self.log.info("Restarting node attempts to reconnect to anchors")
+        with self.nodes[0].assert_debug_log([f"Trying to make an anchor connection to {ONION_ADDR}"]):
+            self.start_node(0, extra_args=[f"-onion={onion_conf.addr[0]}:{onion_conf.addr[1]}"])
+
 
 if __name__ == "__main__":
     AnchorsTest().main()
diff --git a/test/functional/p2p_addrv2_relay.py b/test/functional/p2p_addrv2_relay.py
index 9ab190871f..f9a8c44be2 100755
--- a/test/functional/p2p_addrv2_relay.py
+++ b/test/functional/p2p_addrv2_relay.py
@@ -20,19 +20,24 @@ from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import assert_equal
 
 I2P_ADDR = "c4gfnttsuwqomiygupdqqqyy5y5emnk5c73hrfvatri67prd7vyq.b32.i2p"
+ONION_ADDR = "pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion"
 
 ADDRS = []
 for i in range(10):
     addr = CAddress()
     addr.time = int(time.time()) + i
+    addr.port = 8333 + i
     addr.nServices = P2P_SERVICES
-    # Add one I2P address at an arbitrary position.
+    # Add one I2P and one onion V3 address at an arbitrary position.
     if i == 5:
         addr.net = addr.NET_I2P
         addr.ip = I2P_ADDR
+        addr.port = 0
+    elif i == 8:
+        addr.net = addr.NET_TORV3
+        addr.ip = ONION_ADDR
     else:
         addr.ip = f"123.123.123.{i % 256}"
-    addr.port = 8333 + i
     ADDRS.append(addr)
 
 
@@ -52,6 +57,17 @@ class AddrReceiver(P2PInterface):
         self.wait_until(lambda: "addrv2" in self.last_message)
 
 
+def calc_addrv2_msg_size(addrs):
+    size = 1  # vector length byte
+    for addr in addrs:
+        size += 4  # time
+        size += 1  # services, COMPACTSIZE(P2P_SERVICES)
+        size += 1  # network id
+        size += 1  # address length byte
+        size += addr.ADDRV2_ADDRESS_LENGTH[addr.net]  # address
+        size += 2  # port
+    return size
+
 class AddrTest(BitcoinTestFramework):
     def set_test_params(self):
         self.setup_clean_chain = True
@@ -71,9 +87,10 @@ class AddrTest(BitcoinTestFramework):
         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
+        msg_size = calc_addrv2_msg_size(ADDRS)
         with self.nodes[0].assert_debug_log([
-                'received: addrv2 (159 bytes) peer=0',
-                'sending addrv2 (159 bytes) peer=1',
+                f'received: addrv2 ({msg_size} bytes) peer=0',
+                f'sending addrv2 ({msg_size} bytes) peer=1',
         ]):
             addr_source.send_and_ping(msg)
             self.nodes[0].setmocktime(int(time.time()) + 30 * 60)
diff --git a/test/functional/test_framework/messages.py b/test/functional/test_framework/messages.py
index a6764365c5..4d635556f4 100755
--- a/test/functional/test_framework/messages.py
+++ b/test/functional/test_framework/messages.py
@@ -27,6 +27,7 @@ import random
 import socket
 import struct
 import time
+import unittest
 
 from test_framework.siphash import siphash256
 from test_framework.util import assert_equal
@@ -77,6 +78,10 @@ def sha256(s):
     return hashlib.sha256(s).digest()
 
 
+def sha3(s):
+    return hashlib.sha3_256(s).digest()
+
+
 def hash256(s):
     return sha256(sha256(s))
 
@@ -229,16 +234,25 @@ class CAddress:
 
     # see https://github.com/bitcoin/bips/blob/master/bip-0155.mediawiki
     NET_IPV4 = 1
+    NET_IPV6 = 2
+    NET_TORV3 = 4
     NET_I2P = 5
+    NET_CJDNS = 6
 
     ADDRV2_NET_NAME = {
         NET_IPV4: "IPv4",
-        NET_I2P: "I2P"
+        NET_IPV6: "IPv6",
+        NET_TORV3: "TorV3",
+        NET_I2P: "I2P",
+        NET_CJDNS: "CJDNS"
     }
 
     ADDRV2_ADDRESS_LENGTH = {
         NET_IPV4: 4,
-        NET_I2P: 32
+        NET_IPV6: 16,
+        NET_TORV3: 32,
+        NET_I2P: 32,
+        NET_CJDNS: 16
     }
 
     I2P_PAD = "===="
@@ -285,7 +299,7 @@ class CAddress:
         self.nServices = deser_compact_size(f)
 
         self.net = struct.unpack("B", f.read(1))[0]
-        assert self.net in (self.NET_IPV4, self.NET_I2P)
+        assert self.net in self.ADDRV2_NET_NAME
 
         address_length = deser_compact_size(f)
         assert address_length == self.ADDRV2_ADDRESS_LENGTH[self.net]
@@ -293,14 +307,25 @@ class CAddress:
         addr_bytes = f.read(address_length)
         if self.net == self.NET_IPV4:
             self.ip = socket.inet_ntoa(addr_bytes)
-        else:
+        elif self.net == self.NET_IPV6:
+            self.ip = socket.inet_ntop(socket.AF_INET6, addr_bytes)
+        elif self.net == self.NET_TORV3:
+            prefix = b".onion checksum"
+            version = bytes([3])
+            checksum = sha3(prefix + addr_bytes + version)[:2]
+            self.ip = b32encode(addr_bytes + checksum + version).decode("ascii").lower() + ".onion"
+        elif self.net == self.NET_I2P:
             self.ip = b32encode(addr_bytes)[0:-len(self.I2P_PAD)].decode("ascii").lower() + ".b32.i2p"
+        elif self.net == self.NET_CJDNS:
+            self.ip = socket.inet_ntop(socket.AF_INET6, addr_bytes)
+        else:
+            raise Exception(f"Address type not supported")
 
         self.port = struct.unpack(">H", f.read(2))[0]
 
     def serialize_v2(self):
         """Serialize in addrv2 format (BIP155)"""
-        assert self.net in (self.NET_IPV4, self.NET_I2P)
+        assert self.net in self.ADDRV2_NET_NAME
         r = b""
         r += struct.pack("<I", self.time)
         r += ser_compact_size(self.nServices)
@@ -308,10 +333,20 @@ class CAddress:
         r += ser_compact_size(self.ADDRV2_ADDRESS_LENGTH[self.net])
         if self.net == self.NET_IPV4:
             r += socket.inet_aton(self.ip)
-        else:
+        elif self.net == self.NET_IPV6:
+            r += socket.inet_pton(socket.AF_INET6, self.ip)
+        elif self.net == self.NET_TORV3:
+            sfx = ".onion"
+            assert self.ip.endswith(sfx)
+            r += b32decode(self.ip[0:-len(sfx)], True)[0:32]
+        elif self.net == self.NET_I2P:
             sfx = ".b32.i2p"
             assert self.ip.endswith(sfx)
             r += b32decode(self.ip[0:-len(sfx)] + self.I2P_PAD, True)
+        elif self.net == self.NET_CJDNS:
+            r += socket.inet_pton(socket.AF_INET6, self.ip)
+        else:
+            raise Exception(f"Address type not supported")
         r += struct.pack(">H", self.port)
         return r
 
@@ -1852,3 +1887,19 @@ class msg_sendtxrcncl:
     def __repr__(self):
         return "msg_sendtxrcncl(version=%lu, salt=%lu)" %\
             (self.version, self.salt)
+
+class TestFrameworkScript(unittest.TestCase):
+    def test_addrv2_encode_decode(self):
+        def check_addrv2(ip, net):
+            addr = CAddress()
+            addr.net, addr.ip = net, ip
+            ser = addr.serialize_v2()
+            actual = CAddress()
+            actual.deserialize_v2(BytesIO(ser))
+            self.assertEqual(actual, addr)
+
+        check_addrv2("1.65.195.98", CAddress.NET_IPV4)
+        check_addrv2("2001:41f0::62:6974:636f:696e", CAddress.NET_IPV6)
+        check_addrv2("2bqghnldu6mcug4pikzprwhtjjnsyederctvci6klcwzepnjd46ikjyd.onion", CAddress.NET_TORV3)
+        check_addrv2("255fhcp6ajvftnyo7bwz3an3t4a4brhopm3bamyh2iu5r3gnr2rq.b32.i2p", CAddress.NET_I2P)
+        check_addrv2("fc32:17ea:e415:c3bf:9808:149d:b5a2:c9aa", CAddress.NET_CJDNS)
diff --git a/test/functional/test_framework/socks5.py b/test/functional/test_framework/socks5.py
index 799b1c74b8..0ca06a7396 100644
--- a/test/functional/test_framework/socks5.py
+++ b/test/functional/test_framework/socks5.py
@@ -40,6 +40,7 @@ class Socks5Configuration():
         self.af = socket.AF_INET # Bind address family
         self.unauth = False  # Support unauthenticated
         self.auth = False  # Support authentication
+        self.keep_alive = False  # Do not automatically close connections
 
 class Socks5Command():
     """Information about an incoming socks5 command."""
@@ -115,13 +116,14 @@ class Socks5Connection():
 
             cmdin = Socks5Command(cmd, atyp, addr, port, username, password)
             self.serv.queue.put(cmdin)
-            logger.info('Proxy: %s', cmdin)
+            logger.debug('Proxy: %s', cmdin)
             # Fall through to disconnect
         except Exception as e:
             logger.exception("socks5 request handling failed.")
             self.serv.queue.put(e)
         finally:
-            self.conn.close()
+            if not self.serv.keep_alive:
+                self.conn.close()
 
 class Socks5Server():
     def __init__(self, conf):
@@ -133,6 +135,7 @@ class Socks5Server():
         self.running = False
         self.thread = None
         self.queue = queue.Queue() # report connections and exceptions to client
+        self.keep_alive = conf.keep_alive
 
     def run(self):
         while self.running:
@@ -157,4 +160,3 @@ class Socks5Server():
         s.connect(self.conf.addr)
         s.close()
         self.thread.join()
-
diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
index e627a40e10..d93e6fd6da 100755
--- a/test/functional/test_runner.py
+++ b/test/functional/test_runner.py
@@ -76,6 +76,7 @@ TEST_FRAMEWORK_MODULES = [
     "blocktools",
     "ellswift",
     "key",
+    "messages",
     "muhash",
     "ripemd160",
     "script",