dash/test/functional/feature_anchors.py

#!/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 block-relay-only anchors functionality"""

import os

from test_framework.p2p import P2PInterface
from test_framework.test_framework import BitcoinTestFramework
from test_framework.util import check_node_connections

INBOUND_CONNECTIONS = 5
BLOCK_RELAY_CONNECTIONS = 2


class AnchorsTest(BitcoinTestFramework):
    def set_test_params(self):
        self.num_nodes = 1

    def run_test(self):
        node_anchors_path = os.path.join(
            self.nodes[0].datadir, "regtest", "anchors.dat"
        )

        self.log.info("When node starts, check if anchors.dat doesn't exist")
        assert not os.path.exists(node_anchors_path)

        self.log.info(f"Add {BLOCK_RELAY_CONNECTIONS} block-relay-only connections to node")
        for i in range(BLOCK_RELAY_CONNECTIONS):
            self.log.debug(f"block-relay-only: {i}")
            self.nodes[0].add_outbound_p2p_connection(
                P2PInterface(), p2p_idx=i, connection_type="block-relay-only"
            )

        self.log.info(f"Add {INBOUND_CONNECTIONS} inbound connections to node")
        for i in range(INBOUND_CONNECTIONS):
            self.log.debug(f"inbound: {i}")
            self.nodes[0].add_p2p_connection(P2PInterface())

        self.log.info("Check node connections")
        check_node_connections(node=self.nodes[0], num_in=5, num_out=2)

        # 127.0.0.1
        ip = "7f000001"

        # Since the ip is always 127.0.0.1 for this case,
        # we store only the port to identify the peers
        block_relay_nodes_port = []
        inbound_nodes_port = []
        for p in self.nodes[0].getpeerinfo():
            addr_split = p["addr"].split(":")
            if p["connection_type"] == "block-relay-only":
                block_relay_nodes_port.append(hex(int(addr_split[1]))[2:])
            else:
                inbound_nodes_port.append(hex(int(addr_split[1]))[2:])

        self.log.info("Stop node 0")
        self.stop_node(0)

        # It should contain only the block-relay-only addresses
        self.log.info("Check the addresses in anchors.dat")

        with open(node_anchors_path, "rb") as file_handler:
            anchors = file_handler.read()

        anchors_hex = anchors.hex()
        for port in block_relay_nodes_port:
            ip_port = ip + port
            assert ip_port in anchors_hex
        for port in inbound_nodes_port:
            ip_port = ip + port
            assert ip_port not in anchors_hex

        self.log.info("Perturb anchors.dat to test it doesn't throw an error during initialization")
        with self.nodes[0].assert_debug_log(["0 block-relay-only anchors will be tried for connections."]):
            with open(node_anchors_path, "wb") as out_file_handler:
                tweaked_contents = bytearray(anchors)
                tweaked_contents[20:20] = b'1'
                out_file_handler.write(bytes(tweaked_contents))

            self.log.info("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)


if __name__ == "__main__":
    AnchorsTest().main()