electrum/electrum/channel_db.py

# -*- coding: utf-8 -*-
#
# Electrum - lightweight Bitcoin client
# Copyright (C) 2018 The Electrum developers
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation files
# (the "Software"), to deal in the Software without restriction,
# including without limitation the rights to use, copy, modify, merge,
# publish, distribute, sublicense, and/or sell copies of the Software,
# and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

from datetime import datetime
import time
import random
import queue
import os
import json
import threading
import concurrent
from collections import defaultdict
from typing import Sequence, List, Tuple, Optional, Dict, NamedTuple, TYPE_CHECKING, Set
import binascii
import base64


from .sql_db import SqlDB, sql
from . import constants
from .util import bh2u, profiler, get_headers_dir, bfh, is_ip_address, list_enabled_bits, print_msg, chunks
from .logging import Logger
from .storage import JsonDB
from .lnverifier import LNChannelVerifier, verify_sig_for_channel_update
from .crypto import sha256d
from . import ecc
from .lnutil import (LN_GLOBAL_FEATURES_KNOWN_SET, LNPeerAddr, NUM_MAX_EDGES_IN_PAYMENT_PATH,
                     NotFoundChanAnnouncementForUpdate)
from .lnverifier import verify_sig_for_channel_update
from .lnmsg import encode_msg

if TYPE_CHECKING:
    from .lnchannel import Channel
    from .network import Network

class UnknownEvenFeatureBits(Exception): pass

def validate_features(features : int):
    enabled_features = list_enabled_bits(features)
    for fbit in enabled_features:
        if (1 << fbit) not in LN_GLOBAL_FEATURES_KNOWN_SET and fbit % 2 == 0:
            raise UnknownEvenFeatureBits()


FLAG_DISABLE   = 1 << 1
FLAG_DIRECTION = 1 << 0

class ChannelInfo(NamedTuple):
    short_channel_id: bytes
    node1_id: bytes
    node2_id: bytes
    capacity_sat: int

    @staticmethod
    def from_msg(payload):
        features = int.from_bytes(payload['features'], 'big')
        validate_features(features)
        channel_id = payload['short_channel_id']
        node_id_1 = payload['node_id_1']
        node_id_2 = payload['node_id_2']
        assert list(sorted([node_id_1, node_id_2])) == [node_id_1, node_id_2]
        capacity_sat = None
        return ChannelInfo(
            short_channel_id = channel_id,
            node1_id = node_id_1,
            node2_id = node_id_2,
            capacity_sat = capacity_sat)


class Policy(NamedTuple):
    key: bytes
    cltv_expiry_delta: int
    htlc_minimum_msat: int
    htlc_maximum_msat: int
    fee_base_msat: int
    fee_proportional_millionths: int
    channel_flags: int
    timestamp: int

    @staticmethod
    def from_msg(payload):
        return Policy(
            key                         = payload['short_channel_id'] + payload['start_node'],
            cltv_expiry_delta           = int.from_bytes(payload['cltv_expiry_delta'], "big"),
            htlc_minimum_msat           = int.from_bytes(payload['htlc_minimum_msat'], "big"),
            htlc_maximum_msat           = int.from_bytes(payload['htlc_maximum_msat'], "big") if 'htlc_maximum_msat' in payload else None,
            fee_base_msat               = int.from_bytes(payload['fee_base_msat'], "big"),
            fee_proportional_millionths = int.from_bytes(payload['fee_proportional_millionths'], "big"),
            channel_flags               = int.from_bytes(payload['channel_flags'], "big"),
            timestamp                   = int.from_bytes(payload['timestamp'], "big")
        )

    def is_disabled(self):
        return self.channel_flags & FLAG_DISABLE

    @property
    def short_channel_id(self):
        return self.key[0:8]

    @property
    def start_node(self):
        return self.key[8:]



class NodeInfo(NamedTuple):
    node_id: bytes
    features: int
    timestamp: int
    alias: str

    @staticmethod
    def from_msg(payload):
        node_id = payload['node_id']
        features = int.from_bytes(payload['features'], "big")
        validate_features(features)
        addresses = NodeInfo.parse_addresses_field(payload['addresses'])
        alias = payload['alias'].rstrip(b'\x00')
        timestamp = int.from_bytes(payload['timestamp'], "big")
        return NodeInfo(node_id=node_id, features=features, timestamp=timestamp, alias=alias), [
            Address(host=host, port=port, node_id=node_id, last_connected_date=None) for host, port in addresses]

    @staticmethod
    def parse_addresses_field(addresses_field):
        buf = addresses_field
        def read(n):
            nonlocal buf
            data, buf = buf[0:n], buf[n:]
            return data
        addresses = []
        while buf:
            atype = ord(read(1))
            if atype == 0:
                pass
            elif atype == 1:  # IPv4
                ipv4_addr = '.'.join(map(lambda x: '%d' % x, read(4)))
                port = int.from_bytes(read(2), 'big')
                if is_ip_address(ipv4_addr) and port != 0:
                    addresses.append((ipv4_addr, port))
            elif atype == 2:  # IPv6
                ipv6_addr = b':'.join([binascii.hexlify(read(2)) for i in range(8)])
                ipv6_addr = ipv6_addr.decode('ascii')
                port = int.from_bytes(read(2), 'big')
                if is_ip_address(ipv6_addr) and port != 0:
                    addresses.append((ipv6_addr, port))
            elif atype == 3:  # onion v2
                host = base64.b32encode(read(10)) + b'.onion'
                host = host.decode('ascii').lower()
                port = int.from_bytes(read(2), 'big')
                addresses.append((host, port))
            elif atype == 4:  # onion v3
                host = base64.b32encode(read(35)) + b'.onion'
                host = host.decode('ascii').lower()
                port = int.from_bytes(read(2), 'big')
                addresses.append((host, port))
            else:
                # unknown address type
                # we don't know how long it is -> have to escape
                # if there are other addresses we could have parsed later, they are lost.
                break
        return addresses


class Address(NamedTuple):
    node_id: bytes
    host: str
    port: int
    last_connected_date: int

create_channel_info = """
CREATE TABLE IF NOT EXISTS channel_info (
short_channel_id VARCHAR(64),
node1_id VARCHAR(66),
node2_id VARCHAR(66),
capacity_sat INTEGER,
PRIMARY KEY(short_channel_id)
)"""

create_policy = """
CREATE TABLE IF NOT EXISTS policy (
key VARCHAR(66),
cltv_expiry_delta INTEGER NOT NULL,
htlc_minimum_msat INTEGER NOT NULL,
htlc_maximum_msat INTEGER,
fee_base_msat INTEGER NOT NULL,
fee_proportional_millionths INTEGER NOT NULL,
channel_flags INTEGER NOT NULL,
timestamp INTEGER NOT NULL,
PRIMARY KEY(key)
)"""

create_address = """
CREATE TABLE IF NOT EXISTS address (
node_id VARCHAR(66),
host STRING(256),
port INTEGER NOT NULL,
timestamp INTEGER,
PRIMARY KEY(node_id, host, port)
)"""

create_node_info = """
CREATE TABLE IF NOT EXISTS node_info (
node_id VARCHAR(66),
features INTEGER NOT NULL,
timestamp INTEGER NOT NULL,
alias STRING(64),
PRIMARY KEY(node_id)
)"""


class ChannelDB(SqlDB):

    NUM_MAX_RECENT_PEERS = 20

    def __init__(self, network: 'Network'):
        path = os.path.join(get_headers_dir(network.config), 'channel_db')
        super().__init__(network, path, commit_interval=100)
        self.num_nodes = 0
        self.num_channels = 0
        self._channel_updates_for_private_channels = {}  # type: Dict[Tuple[bytes, bytes], dict]
        self.ca_verifier = LNChannelVerifier(network, self)
        # initialized in load_data
        self._channels = {}
        self._policies = {}
        self._nodes = {}
        self._addresses = defaultdict(set)
        self._channels_for_node = defaultdict(set)

    def update_counts(self):
        self.num_channels = len(self._channels)
        self.num_policies = len(self._policies)
        self.num_nodes = len(self._nodes)

    def get_channel_ids(self):
        return set(self._channels.keys())

    def add_recent_peer(self, peer: LNPeerAddr):
        now = int(time.time())
        node_id = peer.pubkey
        self._addresses[node_id].add((peer.host, peer.port, now))
        self.save_node_address(node_id, peer, now)

    def get_200_randomly_sorted_nodes_not_in(self, node_ids):
        unshuffled = set(self._nodes.keys()) - node_ids
        return random.sample(unshuffled, min(200, len(unshuffled)))

    def get_last_good_address(self, node_id) -> Optional[LNPeerAddr]:
        r = self._addresses.get(node_id)
        if not r:
            return None
        addr = sorted(list(r), key=lambda x: x[2])[0]
        host, port, timestamp = addr
        return LNPeerAddr(host, port, node_id)

    def get_recent_peers(self):
        r = [self.get_last_good_address(x) for x in self._addresses.keys()]
        r = r[-self.NUM_MAX_RECENT_PEERS:]
        return r

    def add_channel_announcement(self, msg_payloads, trusted=True):
        if type(msg_payloads) is dict:
            msg_payloads = [msg_payloads]
        added = 0
        for msg in msg_payloads:
            short_channel_id = msg['short_channel_id']
            if short_channel_id in self._channels:
                continue
            if constants.net.rev_genesis_bytes() != msg['chain_hash']:
                self.logger.info("ChanAnn has unexpected chain_hash {}".format(bh2u(msg['chain_hash'])))
                continue
            try:
                channel_info = ChannelInfo.from_msg(msg)
            except UnknownEvenFeatureBits:
                self.logger.info("unknown feature bits")
                continue
            added += 1
            self._channels[short_channel_id] = channel_info
            self._channels_for_node[channel_info.node1_id].add(channel_info.short_channel_id)
            self._channels_for_node[channel_info.node2_id].add(channel_info.short_channel_id)
            self.save_channel(channel_info)
            if not trusted:
                self.ca_verifier.add_new_channel_info(channel_info.short_channel_id, msg)

        self.update_counts()
        self.logger.debug('add_channel_announcement: %d/%d'%(added, len(msg_payloads)))

    def print_change(self, old_policy, new_policy):
        # print what changed between policies
        if old_policy.cltv_expiry_delta != new_policy.cltv_expiry_delta:
            self.logger.info(f'cltv_expiry_delta: {old_policy.cltv_expiry_delta} -> {new_policy.cltv_expiry_delta}')
        if old_policy.htlc_minimum_msat != new_policy.htlc_minimum_msat:
            self.logger.info(f'htlc_minimum_msat: {old_policy.htlc_minimum_msat} -> {new_policy.htlc_minimum_msat}')
        if old_policy.htlc_maximum_msat != new_policy.htlc_maximum_msat:
            self.logger.info(f'htlc_maximum_msat: {old_policy.htlc_maximum_msat} -> {new_policy.htlc_maximum_msat}')
        if old_policy.fee_base_msat != new_policy.fee_base_msat:
            self.logger.info(f'fee_base_msat: {old_policy.fee_base_msat} -> {new_policy.fee_base_msat}')
        if old_policy.fee_proportional_millionths != new_policy.fee_proportional_millionths:
            self.logger.info(f'fee_proportional_millionths: {old_policy.fee_proportional_millionths} -> {new_policy.fee_proportional_millionths}')
        if old_policy.channel_flags != new_policy.channel_flags:
            self.logger.info(f'channel_flags: {old_policy.channel_flags} -> {new_policy.channel_flags}')

    def add_channel_updates(self, payloads, max_age=None, verify=True):
        orphaned = []      # no channel announcement for channel update
        expired = []       # update older than two weeks
        deprecated = []    # update older than database entry
        good = []          # good updates
        to_delete = []     # database entries to delete
        # filter orphaned and expired first
        known = []
        now = int(time.time())
        for payload in payloads:
            short_channel_id = payload['short_channel_id']
            timestamp = int.from_bytes(payload['timestamp'], "big")
            if max_age and now - timestamp > max_age:
                expired.append(short_channel_id)
                continue
            channel_info = self._channels.get(short_channel_id)
            if not channel_info:
                orphaned.append(short_channel_id)
                continue
            flags = int.from_bytes(payload['channel_flags'], 'big')
            direction = flags & FLAG_DIRECTION
            start_node = channel_info.node1_id if direction == 0 else channel_info.node2_id
            payload['start_node'] = start_node
            known.append(payload)
        # compare updates to existing database entries
        for payload in known:
            timestamp = int.from_bytes(payload['timestamp'], "big")
            start_node = payload['start_node']
            short_channel_id = payload['short_channel_id']
            key = (start_node, short_channel_id)
            old_policy = self._policies.get(key)
            if old_policy and timestamp <= old_policy.timestamp:
                deprecated.append(short_channel_id)
                continue
            good.append(payload)
            if verify:
                self.verify_channel_update(payload)
            policy = Policy.from_msg(payload)
            self._policies[key] = policy
            self.save_policy(policy)
        #
        self.update_counts()
        return orphaned, expired, deprecated, good, to_delete

    def add_channel_update(self, payload):
        orphaned, expired, deprecated, good, to_delete = self.add_channel_updates([payload], verify=False)
        assert len(good) == 1

    def create_database(self):
        c = self.conn.cursor()
        c.execute(create_node_info)
        c.execute(create_address)
        c.execute(create_policy)
        c.execute(create_channel_info)
        self.conn.commit()

    @sql
    def save_policy(self, policy):
        c = self.conn.cursor()
        c.execute("""REPLACE INTO policy (key, cltv_expiry_delta, htlc_minimum_msat, htlc_maximum_msat, fee_base_msat, fee_proportional_millionths, channel_flags, timestamp) VALUES (?,?,?,?,?,?, ?, ?)""", list(policy))

    @sql
    def delete_policy(self, node_id, short_channel_id):
        key = short_channel_id + node_id
        c = self.conn.cursor()
        c.execute("""DELETE FROM policy WHERE key=?""", (key,))

    @sql
    def save_channel(self, channel_info):
        c = self.conn.cursor()
        c.execute("REPLACE INTO channel_info (short_channel_id, node1_id, node2_id, capacity_sat) VALUES (?,?,?,?)", list(channel_info))

    @sql
    def delete_channel(self, short_channel_id):
        c = self.conn.cursor()
        c.execute("""DELETE FROM channel_info WHERE short_channel_id=?""", (short_channel_id,))

    @sql
    def save_node(self, node_info):
        c = self.conn.cursor()
        c.execute("REPLACE INTO node_info (node_id, features, timestamp, alias) VALUES (?,?,?,?)", list(node_info))

    @sql
    def save_node_address(self, node_id, peer, now):
        c = self.conn.cursor()
        c.execute("REPLACE INTO address (node_id, host, port, timestamp) VALUES (?,?,?,?)", (node_id, peer.host, peer.port, now))

    @sql
    def save_node_addresses(self, node_id, node_addresses):
        c = self.conn.cursor()
        for addr in node_addresses:
            c.execute("SELECT * FROM address WHERE node_id=? AND host=? AND port=?", (addr.node_id, addr.host, addr.port))
            r = c.fetchall()
            if r == []:
                c.execute("INSERT INTO address (node_id, host, port, timestamp) VALUES (?,?,?,?)", (addr.node_id, addr.host, addr.port, 0))

    def verify_channel_update(self, payload):
        short_channel_id = payload['short_channel_id']
        if constants.net.rev_genesis_bytes() != payload['chain_hash']:
            raise Exception('wrong chain hash')
        if not verify_sig_for_channel_update(payload, payload['start_node']):
            raise BaseException('verify error')

    def add_node_announcement(self, msg_payloads):
        if type(msg_payloads) is dict:
            msg_payloads = [msg_payloads]
        old_addr = None
        new_nodes = {}
        for msg_payload in msg_payloads:
            try:
                node_info, node_addresses = NodeInfo.from_msg(msg_payload)
            except UnknownEvenFeatureBits:
                continue
            node_id = node_info.node_id
            # Ignore node if it has no associated channel (DoS protection)
            if node_id not in self._channels_for_node:
                #self.logger.info('ignoring orphan node_announcement')
                continue
            node = self._nodes.get(node_id)
            if node and node.timestamp >= node_info.timestamp:
                continue
            node = new_nodes.get(node_id)
            if node and node.timestamp >= node_info.timestamp:
                continue
            # save
            self._nodes[node_id] = node_info
            self.save_node(node_info)
            for addr in node_addresses:
                self._addresses[node_id].add((addr.host, addr.port, 0))
            self.save_node_addresses(node_id, node_addresses)

        self.logger.debug("on_node_announcement: %d/%d"%(len(new_nodes), len(msg_payloads)))
        self.update_counts()

    def get_routing_policy_for_channel(self, start_node_id: bytes,
                                       short_channel_id: bytes) -> Optional[bytes]:
        if not start_node_id or not short_channel_id: return None
        channel_info = self.get_channel_info(short_channel_id)
        if channel_info is not None:
            return self.get_policy_for_node(short_channel_id, start_node_id)
        msg = self._channel_updates_for_private_channels.get((start_node_id, short_channel_id))
        if not msg:
            return None
        return Policy.from_msg(msg) # won't actually be written to DB

    def get_old_policies(self, delta):
        now = int(time.time())
        return list(k for k, v in list(self._policies.items()) if v.timestamp <= now - delta)

    def prune_old_policies(self, delta):
        l = self.get_old_policies(delta)
        for k in l:
            self._policies.pop(k)
            self.delete_policy(*k)
        if l:
            self.logger.info(f'Deleting {len(l)} old policies')

    def get_orphaned_channels(self):
        ids = set(x[1] for x in self._policies.keys())
        return list(x for x in self._channels.keys() if x not in ids)

    def prune_orphaned_channels(self):
        l = self.get_orphaned_channels()
        for short_channel_id in l:
            self.remove_channel(short_channel_id)
            self.delete_channel(short_channel_id)
        self.update_counts()
        if l:
            self.logger.info(f'Deleting {len(l)} orphaned channels')

    def add_channel_update_for_private_channel(self, msg_payload: dict, start_node_id: bytes):
        if not verify_sig_for_channel_update(msg_payload, start_node_id):
            return  # ignore
        short_channel_id = msg_payload['short_channel_id']
        msg_payload['start_node'] = start_node_id
        self._channel_updates_for_private_channels[(start_node_id, short_channel_id)] = msg_payload

    def remove_channel(self, short_channel_id):
        channel_info = self._channels.pop(short_channel_id, None)
        if channel_info:
            self._channels_for_node[channel_info.node1_id].remove(channel_info.short_channel_id)
            self._channels_for_node[channel_info.node2_id].remove(channel_info.short_channel_id)

    def get_node_addresses(self, node_id):
        return self._addresses.get(node_id)

    @sql
    @profiler
    def load_data(self):
        c = self.conn.cursor()
        c.execute("""SELECT * FROM address""")
        for x in c:
            node_id, host, port, timestamp = x
            self._addresses[node_id].add((str(host), int(port), int(timestamp or 0)))
        c.execute("""SELECT * FROM channel_info""")
        for x in c:
            ci = ChannelInfo(*x)
            self._channels[ci.short_channel_id] = ci
        c.execute("""SELECT * FROM policy""")
        for x in c:
            p = Policy(*x)
            self._policies[(p.start_node, p.short_channel_id)] = p
        for channel_info in self._channels.values():
            self._channels_for_node[channel_info.node1_id].add(channel_info.short_channel_id)
            self._channels_for_node[channel_info.node2_id].add(channel_info.short_channel_id)
        self.logger.info(f'load data {len(self._channels)} {len(self._policies)} {len(self._channels_for_node)}')
        self.update_counts()

    def get_policy_for_node(self, short_channel_id: bytes, node_id: bytes) -> Optional['Policy']:
        return self._policies.get((node_id, short_channel_id))

    def get_channel_info(self, channel_id: bytes):
        return self._channels.get(channel_id)

    def get_channels_for_node(self, node_id) -> Set[bytes]:
        """Returns the set of channels that have node_id as one of the endpoints."""
        return self._channels_for_node.get(node_id) or set()