commit c02cc9bb3baa1215b7e73b84dec26161ba6fb1d3
parent bc06ded4b929641214299bbae7eb404b307ccdca
Author: SomberNight <somber.night@protonmail.com>
Date: Fri, 27 Jul 2018 20:59:04 +0200
persist recent peers. implement dns seed bootstrapping.
dns seeds are currently disabled though, as they always seem to return mainnet nodes.
Diffstat:
7 files changed, 194 insertions(+), 34 deletions(-)
diff --git a/electrum/constants.py b/electrum/constants.py
@@ -84,6 +84,11 @@ class BitcoinMainnet(AbstractNet):
}
XPUB_HEADERS_INV = inv_dict(XPUB_HEADERS)
BIP44_COIN_TYPE = 0
+ LN_REALM_BYTE = 0
+ LN_DNS_SEEDS = [
+ 'nodes.lightning.directory.',
+ 'lseed.bitcoinstats.com.',
+ ]
class BitcoinTestnet(AbstractNet):
@@ -115,6 +120,11 @@ class BitcoinTestnet(AbstractNet):
}
XPUB_HEADERS_INV = inv_dict(XPUB_HEADERS)
BIP44_COIN_TYPE = 1
+ LN_REALM_BYTE = 1
+ LN_DNS_SEEDS = [
+ 'test.nodes.lightning.directory.',
+ 'lseed.bitcoinstats.com.',
+ ]
class BitcoinRegtest(BitcoinTestnet):
@@ -123,6 +133,7 @@ class BitcoinRegtest(BitcoinTestnet):
GENESIS = "0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206"
DEFAULT_SERVERS = read_json('servers_regtest.json', {})
CHECKPOINTS = []
+ LN_DNS_SEEDS = []
class BitcoinSimnet(BitcoinTestnet):
@@ -134,6 +145,7 @@ class BitcoinSimnet(BitcoinTestnet):
GENESIS = "683e86bd5c6d110d91b94b97137ba6bfe02dbbdb8e3dff722a669b5d69d77af6"
DEFAULT_SERVERS = read_json('servers_regtest.json', {})
CHECKPOINTS = []
+ LN_DNS_SEEDS = []
# don't import net directly, import the module instead (so that net is singleton)
diff --git a/electrum/lnbase.py b/electrum/lnbase.py
@@ -7,7 +7,7 @@
from collections import namedtuple, defaultdict, OrderedDict, defaultdict
from .lnutil import Outpoint, ChannelConfig, LocalState, RemoteState, Keypair, OnlyPubkeyKeypair, ChannelConstraints, RevocationStore
from .lnutil import sign_and_get_sig_string, funding_output_script, get_ecdh, get_per_commitment_secret_from_seed
-from .lnutil import secret_to_pubkey
+from .lnutil import secret_to_pubkey, LNPeerAddr
from .bitcoin import COIN
from ecdsa.util import sigdecode_der, sigencode_string_canonize, sigdecode_string
@@ -439,7 +439,6 @@ class Peer(PrintError):
def on_channel_announcement(self, payload):
self.channel_db.on_channel_announcement(payload)
- self.network.trigger_callback('ln_status')
def on_announcement_signatures(self, payload):
channel_id = payload['channel_id']
@@ -462,6 +461,7 @@ class Peer(PrintError):
@aiosafe
async def main_loop(self):
await asyncio.wait_for(self.initialize(), 5)
+ self.channel_db.add_recent_peer(LNPeerAddr(self.host, self.port, self.pubkey))
# loop
while True:
self.ping_if_required()
diff --git a/electrum/lnrouter.py b/electrum/lnrouter.py
@@ -38,7 +38,7 @@ from .storage import JsonDB
from .lnchanannverifier import LNChanAnnVerifier, verify_sig_for_channel_update
from .crypto import Hash
from . import ecc
-from .lnutil import LN_GLOBAL_FEATURE_BITS
+from .lnutil import LN_GLOBAL_FEATURE_BITS, LNPeerAddr
class UnknownEvenFeatureBits(Exception): pass
@@ -256,16 +256,19 @@ class NodeInfo(PrintError):
class ChannelDB(JsonDB):
+ NUM_MAX_RECENT_PEERS = 20
+
def __init__(self, network):
self.network = network
path = os.path.join(get_headers_dir(network.config), 'channel_db')
JsonDB.__init__(self, path)
- self.lock = threading.Lock()
+ self.lock = threading.RLock()
self._id_to_channel_info = {}
self._channels_for_node = defaultdict(set) # node -> set(short_channel_id)
self.nodes = {} # node_id -> NodeInfo
+ self._recent_peers = []
self.ca_verifier = LNChanAnnVerifier(network, self)
self.network.add_jobs([self.ca_verifier])
@@ -289,6 +292,11 @@ class ChannelDB(JsonDB):
node_info = NodeInfo.from_json(node_info_d)
node_id = bfh(node_id)
self.nodes[node_id] = node_info
+ # recent peers
+ recent_peers = self.get('recent_peers', {})
+ for host, port, pubkey in recent_peers:
+ peer = LNPeerAddr(str(host), int(port), bfh(pubkey))
+ self._recent_peers.append(peer)
def save_data(self):
with self.lock:
@@ -302,6 +310,12 @@ class ChannelDB(JsonDB):
for node_id, node_info in self.nodes.items():
node_infos[bh2u(node_id)] = node_info
self.put('node_infos', node_infos)
+ # recent peers
+ recent_peers = []
+ for peer in self._recent_peers:
+ recent_peers.append(
+ [str(peer.host), int(peer.port), bh2u(peer.pubkey)])
+ self.put('recent_peers', recent_peers)
self.write()
def __len__(self):
@@ -320,12 +334,26 @@ class ChannelDB(JsonDB):
self._id_to_channel_info[short_channel_id] = channel_info
self._channels_for_node[channel_info.node_id_1].add(short_channel_id)
self._channels_for_node[channel_info.node_id_2].add(short_channel_id)
+ self.network.trigger_callback('ln_status')
+
+ def get_recent_peers(self):
+ with self.lock:
+ return list(self._recent_peers)
+
+ def add_recent_peer(self, peer: LNPeerAddr):
+ with self.lock:
+ # list is ordered
+ if peer in self._recent_peers:
+ self._recent_peers.remove(peer)
+ self._recent_peers.insert(0, peer)
+ self._recent_peers = self._recent_peers[:self.NUM_MAX_RECENT_PEERS]
def on_channel_announcement(self, msg_payload, trusted=False):
short_channel_id = msg_payload['short_channel_id']
if short_channel_id in self._id_to_channel_info:
return
if constants.net.rev_genesis_bytes() != msg_payload['chain_hash']:
+ #self.print_error("ChanAnn has unexpected chain_hash {}".format(bh2u(msg_payload['chain_hash'])))
return
try:
channel_info = ChannelInfo(msg_payload)
@@ -365,6 +393,10 @@ class ChannelDB(JsonDB):
new_node_info = NodeInfo(msg_payload)
except UnknownEvenFeatureBits:
return
+ # TODO if this message is for a new node, and if we have no associated
+ # channels for this node, we should ignore the message and return here,
+ # to mitigate DOS. but race condition: the channels we have for this
+ # node, might be under verification in self.ca_verifier, what then?
if old_node_info and old_node_info.timestamp >= new_node_info.timestamp:
return # ignore
self.nodes[pubkey] = new_node_info
diff --git a/electrum/lnutil.py b/electrum/lnutil.py
@@ -7,6 +7,7 @@ from .ecc import CURVE_ORDER, sig_string_from_der_sig, ECPubkey, string_to_numbe
from . import ecc, bitcoin, crypto, transaction
from .transaction import opcodes
from .bitcoin import push_script
+from . import segwit_addr
HTLC_TIMEOUT_WEIGHT = 663
HTLC_SUCCESS_WEIGHT = 703
@@ -396,3 +397,20 @@ LN_LOCAL_FEATURE_BITS_INV = inv_dict(LN_LOCAL_FEATURE_BITS)
LN_GLOBAL_FEATURE_BITS = {}
LN_GLOBAL_FEATURE_BITS_INV = inv_dict(LN_GLOBAL_FEATURE_BITS)
+
+class LNPeerAddr(namedtuple('LNPeerAddr', ['host', 'port', 'pubkey'])):
+ __slots__ = ()
+
+ def __str__(self):
+ return '{}@{}:{}'.format(bh2u(self.pubkey), self.host, self.port)
+
+
+def get_compressed_pubkey_from_bech32(bech32_pubkey: str) -> bytes:
+ hrp, data_5bits = segwit_addr.bech32_decode(bech32_pubkey)
+ if hrp != 'ln':
+ raise Exception('unexpected hrp: {}'.format(hrp))
+ data_8bits = segwit_addr.convertbits(data_5bits, 5, 8, False)
+ # pad with zeroes
+ COMPRESSED_PUBKEY_LENGTH = 33
+ data_8bits = data_8bits + ((COMPRESSED_PUBKEY_LENGTH - len(data_8bits)) * [0])
+ return bytes(data_8bits)
diff --git a/electrum/lnworker.py b/electrum/lnworker.py
@@ -1,35 +1,39 @@
-import json
-import binascii
import asyncio
import os
from decimal import Decimal
-import threading
-from collections import defaultdict
import random
+import time
+from typing import Optional, Sequence
+
+import dns.resolver
+import dns.exception
from . import constants
from .bitcoin import sha256, COIN
-from .util import bh2u, bfh, PrintError, InvoiceError
-from .constants import set_testnet, set_simnet
+from .util import bh2u, bfh, PrintError, InvoiceError, resolve_dns_srv
from .lnbase import Peer, privkey_to_pubkey, aiosafe
from .lnaddr import lnencode, LnAddr, lndecode
from .ecc import der_sig_from_sig_string
-from .transaction import Transaction
from .lnhtlc import HTLCStateMachine
-from .lnutil import Outpoint, calc_short_channel_id
+from .lnutil import Outpoint, calc_short_channel_id, LNPeerAddr, get_compressed_pubkey_from_bech32
from .lnwatcher import LNChanCloseHandler
from .i18n import _
-# hardcoded nodes
-node_list = [
- ('ecdsa.net', '9735', '038370f0e7a03eded3e1d41dc081084a87f0afa1c5b22090b4f3abb391eb15d8ff'),
-]
+
+NUM_PEERS_TARGET = 4
+PEER_RETRY_INTERVAL = 600 # seconds
+
+FALLBACK_NODE_LIST = (
+ LNPeerAddr('ecdsa.net', 9735, bfh('038370f0e7a03eded3e1d41dc081084a87f0afa1c5b22090b4f3abb391eb15d8ff')),
+)
+
class LNWorker(PrintError):
def __init__(self, wallet, network):
self.wallet = wallet
self.network = network
+ self.channel_db = self.network.channel_db
pk = wallet.storage.get('lightning_privkey')
if pk is None:
pk = bh2u(os.urandom(32))
@@ -43,17 +47,21 @@ class LNWorker(PrintError):
self.invoices = wallet.storage.get('lightning_invoices', {})
for chan_id, chan in self.channels.items():
self.network.lnwatcher.watch_channel(chan, self.on_channel_utxos)
+ self._last_tried_peer = {} # LNPeerAddr -> unix timestamp
# TODO peers that we have channels with should also be added now
# but we don't store their IP/port yet.. also what if it changes?
# need to listen for node_announcements and save the new IP/port
- peer_list = self.config.get('lightning_peers', node_list)
- for host, port, pubkey in peer_list:
- self.add_peer(host, int(port), bfh(pubkey))
+ self._add_peers_from_config()
# wait until we see confirmations
self.network.register_callback(self.on_network_update, ['updated', 'verified', 'fee_histogram']) # thread safe
self.on_network_update('updated') # shortcut (don't block) if funding tx locked and verified
self.network.futures.append(asyncio.run_coroutine_threadsafe(self.main_loop(), asyncio.get_event_loop()))
+ def _add_peers_from_config(self):
+ peer_list = self.config.get('lightning_peers', [])
+ for host, port, pubkey in peer_list:
+ self.add_peer(host, int(port), bfh(pubkey))
+
def suggest_peer(self):
for node_id, peer in self.peers.items():
if len(peer.channels) > 0:
@@ -67,7 +75,8 @@ class LNWorker(PrintError):
return {x: y for (x, y) in self.channels.items() if y.node_id == node_id}
def add_peer(self, host, port, node_id):
- peer = Peer(self, host, int(port), node_id, request_initial_sync=self.config.get("request_initial_sync", True))
+ port = int(port)
+ peer = Peer(self, host, port, node_id, request_initial_sync=self.config.get("request_initial_sync", True))
self.network.futures.append(asyncio.run_coroutine_threadsafe(peer.main_loop(), asyncio.get_event_loop()))
self.peers[node_id] = peer
self.network.trigger_callback('ln_status')
@@ -218,6 +227,80 @@ class LNWorker(PrintError):
assert tx.is_complete()
return self.network.broadcast_transaction(tx)
+ def _get_next_peers_to_try(self) -> Sequence[LNPeerAddr]:
+ now = time.time()
+ recent_peers = self.channel_db.get_recent_peers()
+ # maintenance for last tried times
+ for peer in list(self._last_tried_peer):
+ if now >= self._last_tried_peer[peer] + PEER_RETRY_INTERVAL:
+ del self._last_tried_peer[peer]
+ # first try from recent peers
+ for peer in recent_peers:
+ if peer in self.peers:
+ continue
+ if peer in self._last_tried_peer:
+ # due to maintenance above, this means we tried recently
+ continue
+ return [peer]
+ # try random peer from graph
+ all_nodes = self.channel_db.nodes
+ if all_nodes:
+ self.print_error('trying to get ln peers from channel db')
+ node_ids = list(all_nodes)
+ max_tries = min(200, len(all_nodes))
+ for i in range(max_tries):
+ node_id = random.choice(node_ids)
+ node = all_nodes.get(node_id)
+ if node is None: continue
+ addresses = node.addresses
+ if not addresses: continue
+ host, port = addresses[0]
+ peer = LNPeerAddr(host, port, node_id)
+ if peer in self._last_tried_peer:
+ continue
+ self.print_error('taking random ln peer from our channel db')
+ return [peer]
+
+ # TODO remove this. For some reason the dns seeds seem to ignore the realm byte
+ # and only return mainnet nodes. so for the time being dns seeding is disabled:
+ if constants.net in (constants.BitcoinTestnet, ):
+ return [random.choice(FALLBACK_NODE_LIST)]
+ else:
+ return []
+
+ # try peers from dns seed.
+ # return several peers to reduce the number of dns queries.
+ if not constants.net.LN_DNS_SEEDS:
+ return []
+ dns_seed = random.choice(constants.net.LN_DNS_SEEDS)
+ self.print_error('asking dns seed "{}" for ln peers'.format(dns_seed))
+ try:
+ # note: this might block for several seconds
+ # this will include bech32-encoded-pubkeys and ports
+ srv_answers = resolve_dns_srv('r{}.{}'.format(
+ constants.net.LN_REALM_BYTE, dns_seed))
+ except dns.exception.DNSException as e:
+ return []
+ random.shuffle(srv_answers)
+ num_peers = 2 * NUM_PEERS_TARGET
+ srv_answers = srv_answers[:num_peers]
+ # we now have pubkeys and ports but host is still needed
+ peers = []
+ for srv_ans in srv_answers:
+ try:
+ # note: this might block for several seconds
+ answers = dns.resolver.query(srv_ans['host'])
+ except dns.exception.DNSException:
+ continue
+ else:
+ ln_host = str(answers[0])
+ port = int(srv_ans['port'])
+ bech32_pubkey = srv_ans['host'].split('.')[0]
+ pubkey = get_compressed_pubkey_from_bech32(bech32_pubkey)
+ peers.append(LNPeerAddr(ln_host, port, pubkey))
+ self.print_error('got {} ln peers from dns seed'.format(len(peers)))
+ return peers
+
@aiosafe
async def main_loop(self):
while True:
@@ -226,15 +309,10 @@ class LNWorker(PrintError):
if peer.exception:
self.print_error("removing peer", peer.host)
self.peers.pop(k)
- if len(self.peers) > 3:
+ if len(self.peers) >= NUM_PEERS_TARGET:
continue
- if not self.network.channel_db.nodes:
- continue
- all_nodes = self.network.channel_db.nodes
- node_id = random.choice(list(all_nodes))
- node = all_nodes.get(node_id)
- addresses = node.addresses
- if addresses:
- host, port = addresses[0]
- self.print_error("trying node", bh2u(node_id))
- self.add_peer(host, port, node_id)
+ peers = self._get_next_peers_to_try()
+ for peer in peers:
+ self._last_tried_peer[peer] = time.time()
+ self.print_error("trying node", peer)
+ self.add_peer(peer.host, peer.port, peer.pubkey)
diff --git a/electrum/tests/test_lnutil.py b/electrum/tests/test_lnutil.py
@@ -2,9 +2,10 @@ import unittest
import json
from electrum import bitcoin
from electrum.lnutil import (RevocationStore, get_per_commitment_secret_from_seed, make_offered_htlc,
- make_received_htlc, make_commitment, make_htlc_tx_witness, make_htlc_tx_output,
- make_htlc_tx_inputs, secret_to_pubkey, derive_blinded_pubkey, derive_privkey,
- derive_pubkey, make_htlc_tx, extract_ctn_from_tx, UnableToDeriveSecret)
+ make_received_htlc, make_commitment, make_htlc_tx_witness, make_htlc_tx_output,
+ make_htlc_tx_inputs, secret_to_pubkey, derive_blinded_pubkey, derive_privkey,
+ derive_pubkey, make_htlc_tx, extract_ctn_from_tx, UnableToDeriveSecret,
+ get_compressed_pubkey_from_bech32)
from electrum.util import bh2u, bfh
from electrum.transaction import Transaction
@@ -675,3 +676,7 @@ class TestLNUtil(unittest.TestCase):
index_of_pubkey = pubkeys.index(bh2u(remote_pubkey))
tx._inputs[0]["signatures"][index_of_pubkey] = remote_signature + "01"
tx.raw = None
+
+ def test_get_compressed_pubkey_from_bech32(self):
+ self.assertEqual(b'\x03\x84\xef\x87\xd9d\xa2\xaaa7=\xff\xb8\xfe=t8[}>;\n\x13\xa8e\x8eo:\xf5Mi\xb5H',
+ get_compressed_pubkey_from_bech32('ln1qwzwlp7evj325cfh8hlm3l3awsu9klf78v9p82r93ehn4a2ddx65s66awg5'))
diff --git a/electrum/util.py b/electrum/util.py
@@ -46,6 +46,7 @@ import aiohttp
from aiohttp_socks import SocksConnector, SocksVer
from aiorpcx import TaskGroup
import certifi
+import dns.resolver
from .i18n import _
from .logging import get_logger, Logger
@@ -1174,3 +1175,17 @@ def list_enabled_bits(x: int) -> Sequence[int]:
binary = bin(x)[2:]
rev_bin = reversed(binary)
return tuple(i for i, b in enumerate(rev_bin) if b == '1')
+
+
+def resolve_dns_srv(host: str):
+ srv_records = dns.resolver.query(host, 'SRV')
+ # priority: prefer lower
+ # weight: tie breaker; prefer higher
+ srv_records = sorted(srv_records, key=lambda x: (x.priority, -x.weight))
+
+ def dict_from_srv_record(srv):
+ return {
+ 'host': str(srv.target),
+ 'port': srv.port,
+ }
+ return [dict_from_srv_record(srv) for srv in srv_records]
