Merge pull request #6238 from SomberNight/202006_randomise_address_subscriptions

network: randomise the order of address subscriptions

electrum/lnwatcher.py

@@ -11,7 +11,7 @@ from typing import NamedTuple, Dict
 from . import util
 from .sql_db import SqlDB, sql
 from .wallet_db import WalletDB
-from .util import bh2u, bfh, log_exceptions, ignore_exceptions, TxMinedInfo
+from .util import bh2u, bfh, log_exceptions, ignore_exceptions, TxMinedInfo, random_shuffled_copy
 from .address_synchronizer import AddressSynchronizer, TX_HEIGHT_LOCAL, TX_HEIGHT_UNCONF_PARENT, TX_HEIGHT_UNCONFIRMED
 from .transaction import Transaction, TxOutpoint
 
@@ -278,8 +278,8 @@ class WatchTower(LNWatcher):
 
     async def start_watching(self):
         # I need to watch the addresses from sweepstore
-        l = await self.sweepstore.list_channels()
+        lst = await self.sweepstore.list_channels()
-        for outpoint, address in l:
+        for outpoint, address in random_shuffled_copy(lst):
             self.add_channel(outpoint, address)
 
     async def do_breach_remedy(self, funding_outpoint, closing_tx, spenders):

electrum/lnworker.py

@@ -35,7 +35,7 @@ from .crypto import sha256
 from .bip32 import BIP32Node
 from .util import bh2u, bfh, InvoiceError, resolve_dns_srv, is_ip_address, log_exceptions
 from .util import ignore_exceptions, make_aiohttp_session, SilentTaskGroup
-from .util import timestamp_to_datetime
+from .util import timestamp_to_datetime, random_shuffled_copy
 from .util import MyEncoder
 from .logging import Logger
 from .lntransport import LNTransport, LNResponderTransport
@@ -500,7 +500,7 @@ class LNWallet(LNWorker):
         # note: accessing channels (besides simple lookup) needs self.lock!
         self._channels = {}  # type: Dict[bytes, Channel]
         channels = self.db.get_dict("channels")
-        for channel_id, c in channels.items():
+        for channel_id, c in random_shuffled_copy(channels.items()):
             self._channels[bfh(channel_id)] = Channel(c, sweep_address=self.sweep_address, lnworker=self)
 
         self.pending_payments = defaultdict(asyncio.Future)  # type: Dict[bytes, asyncio.Future[BarePaymentAttemptLog]]
@@ -1413,7 +1413,7 @@ class LNBackups(Logger):
         self.wallet = wallet
         self.db = wallet.db
         self.channel_backups = {}
-        for channel_id, cb in self.db.get_dict("channel_backups").items():
+        for channel_id, cb in random_shuffled_copy(self.db.get_dict("channel_backups").items()):
             self.channel_backups[bfh(channel_id)] = ChannelBackup(cb, sweep_address=self.sweep_address, lnworker=self)
 
     @property

electrum/synchronizer.py

@@ -32,7 +32,7 @@ from aiorpcx import TaskGroup, run_in_thread, RPCError
 
 from . import util
 from .transaction import Transaction, PartialTransaction
-from .util import bh2u, make_aiohttp_session, NetworkJobOnDefaultServer
+from .util import bh2u, make_aiohttp_session, NetworkJobOnDefaultServer, random_shuffled_copy
 from .bitcoin import address_to_scripthash, is_address
 from .network import UntrustedServerReturnedError
 from .logging import Logger
@@ -240,7 +240,7 @@ class Synchronizer(SynchronizerBase):
             if history == ['*']: continue
             await self._request_missing_txs(history, allow_server_not_finding_tx=True)
         # add addresses to bootstrap
-        for addr in self.wallet.get_addresses():
+        for addr in random_shuffled_copy(self.wallet.get_addresses()):
             await self._add_address(addr)
         # main loop
         while True:

electrum/util.py

@@ -24,7 +24,7 @@ import binascii
 import os, sys, re, json
 from collections import defaultdict, OrderedDict
 from typing import (NamedTuple, Union, TYPE_CHECKING, Tuple, Optional, Callable, Any,
-                    Sequence, Dict, Generic, TypeVar)
+                    Sequence, Dict, Generic, TypeVar, List, Iterable)
 from datetime import datetime
 import decimal
 from decimal import Decimal
@@ -1398,3 +1398,12 @@ class JsonRPCClient:
         async def coro(*args):
             return await self.request(endpoint, *args)
         setattr(self, endpoint, coro)
+
+
+T = TypeVar('T')
+
+def random_shuffled_copy(x: Iterable[T]) -> List[T]:
+    """Returns a shuffled copy of the input."""
+    x_copy = list(x)  # copy
+    random.shuffle(x_copy)  # shuffle in-place
+    return x_copy