diff --git a/electrum/gui/qt/channels_list.py b/electrum/gui/qt/channels_list.py index 1a85045cb..257256cf1 100644 --- a/electrum/gui/qt/channels_list.py +++ b/electrum/gui/qt/channels_list.py @@ -119,9 +119,6 @@ class ChannelsList(MyTreeView): def on_channel_closed(self, txid): self.main_window.show_error('Channel closed' + '\n' + txid) - def on_request_sent(self, b): - self.main_window.show_message(_('Request sent')) - def on_failure(self, exc_info): type_, e, tb = exc_info traceback.print_tb(tb) @@ -137,7 +134,7 @@ class ChannelsList(MyTreeView): on_success = self.on_channel_closed def task(): return self.network.run_from_another_thread(coro) - WaitingDialog(self, 'please wait..', task, on_success, self.on_failure) + WaitingDialog(self, _('Please wait...'), task, on_success, self.on_failure) def force_close(self, channel_id): self.save_backup = True @@ -161,7 +158,7 @@ class ChannelsList(MyTreeView): def task(): coro = self.lnworker.force_close_channel(channel_id) return self.network.run_from_another_thread(coro) - WaitingDialog(self, 'please wait..', task, self.on_channel_closed, self.on_failure) + WaitingDialog(self, _('Please wait...'), task, self.on_channel_closed, self.on_failure) def remove_channel(self, channel_id): if self.main_window.question(_('Are you sure you want to delete this channel? This will purge associated transactions from your wallet history.')): @@ -191,7 +188,9 @@ class ChannelsList(MyTreeView): def task(): coro = self.lnworker.request_force_close(channel_id) return self.network.run_from_another_thread(coro) - WaitingDialog(self, 'please wait..', task, self.on_request_sent, self.on_failure) + def on_done(b): + self.main_window.show_message(_('Request scheduled')) + WaitingDialog(self, _('Please wait...'), task, on_done, self.on_failure) def set_frozen(self, chan, *, for_sending, value): if not self.lnworker.uses_trampoline() or self.lnworker.is_trampoline_peer(chan.node_id): diff --git a/electrum/lnchannel.py b/electrum/lnchannel.py index 3827b22e7..973e1c0f3 100644 --- a/electrum/lnchannel.py +++ b/electrum/lnchannel.py @@ -140,6 +140,7 @@ state_transitions = [ (cs.OPEN, cs.WE_ARE_TOXIC), (cs.SHUTDOWN, cs.WE_ARE_TOXIC), (cs.REQUESTED_FCLOSE, cs.WE_ARE_TOXIC), + (cs.WE_ARE_TOXIC, cs.WE_ARE_TOXIC), # (cs.FORCE_CLOSING, cs.FORCE_CLOSING), # allow multiple attempts (cs.FORCE_CLOSING, cs.CLOSED), @@ -1015,6 +1016,8 @@ class Channel(AbstractChannel): def should_try_to_reestablish_peer(self) -> bool: if self.peer_state != PeerState.DISCONNECTED: return False + if self.should_request_force_close: + return True return ChannelState.PREOPENING < self._state < ChannelState.CLOSING def get_funding_address(self): @@ -1629,6 +1632,8 @@ class Channel(AbstractChannel): if not self.has_unsettled_htlcs(): ret.append(ChanCloseOption.COOP_CLOSE) ret.append(ChanCloseOption.REQUEST_REMOTE_FCLOSE) + if self.get_state() == ChannelState.WE_ARE_TOXIC: + ret.append(ChanCloseOption.REQUEST_REMOTE_FCLOSE) if not self.is_closed() or self.get_state() == ChannelState.REQUESTED_FCLOSE: ret.append(ChanCloseOption.LOCAL_FCLOSE) assert not (self.get_state() == ChannelState.WE_ARE_TOXIC and ChanCloseOption.LOCAL_FCLOSE in ret), "local force-close unsafe if we are toxic" diff --git a/electrum/lnpeer.py b/electrum/lnpeer.py index 37b67579e..537eb292c 100644 --- a/electrum/lnpeer.py +++ b/electrum/lnpeer.py @@ -1113,6 +1113,7 @@ class Peer(Logger): async def request_force_close(self, channel_id: bytes): """Try to trigger the remote peer to force-close.""" await self.initialized + self.logger.info(f"trying to get remote peer to force-close chan {channel_id.hex()}") # First, we intentionally send a "channel_reestablish" msg with an old state. # Many nodes (but not all) automatically force-close when seeing this. latest_point = secret_to_pubkey(42) # we need a valid point (BOLT2) @@ -1146,7 +1147,11 @@ class Peer(Logger): self.logger.info(f"tried to force-close channel {chan.get_id_for_log()} " f"but close option is not allowed. {chan.get_state()=!r}") - def on_channel_reestablish(self, chan, msg): + def on_channel_reestablish(self, chan: Channel, msg): + # Note: it is critical for this message handler to block processing of further messages, + # until this msg is processed. If we are behind (lost state), and send chan_reest to the remote, + # when the remote realizes we are behind, they might send an "error" message - but the spec mandates + # they send chan_reest first. If we processed the error first, we might force-close and lose money! their_next_local_ctn = msg["next_commitment_number"] their_oldest_unrevoked_remote_ctn = msg["next_revocation_number"] their_local_pcp = msg.get("my_current_per_commitment_point") @@ -1230,40 +1235,23 @@ class Peer(Logger): self.lnworker.save_channel(chan) chan.peer_state = PeerState.BAD # raise after we send channel_reestablish, so the remote can realize they are ahead - fut.set_exception(RemoteMisbehaving("remote ahead of us")) + # FIXME what if we have multiple chans with peer? timing... + fut.set_exception(GracefulDisconnect("remote ahead of us")) elif we_are_ahead: self.logger.warning(f"channel_reestablish ({chan.get_id_for_log()}): we are ahead of remote! trying to force-close.") self.schedule_force_closing(chan.channel_id) - fut.set_exception(RemoteMisbehaving("we are ahead of remote")) + # FIXME what if we have multiple chans with peer? timing... + fut.set_exception(GracefulDisconnect("we are ahead of remote")) else: # all good fut.set_result((we_must_resend_revoke_and_ack, their_next_local_ctn)) - async def reestablish_channel(self, chan: Channel): - await self.initialized + def _send_channel_reestablish(self, chan: Channel): + assert self.is_initialized() chan_id = chan.channel_id - if chan.should_request_force_close: - chan.set_state(ChannelState.REQUESTED_FCLOSE) - await self.request_force_close(chan_id) - chan.should_request_force_close = False - return - assert ChannelState.PREOPENING < chan.get_state() < ChannelState.FORCE_CLOSING - if chan.peer_state != PeerState.DISCONNECTED: - self.logger.info( - f'reestablish_channel was called but channel {chan.get_id_for_log()} ' - f'already in peer_state {chan.peer_state!r}') - return - chan.peer_state = PeerState.REESTABLISHING - util.trigger_callback('channel', self.lnworker.wallet, chan) # ctns - oldest_unrevoked_local_ctn = chan.get_oldest_unrevoked_ctn(LOCAL) - latest_local_ctn = chan.get_latest_ctn(LOCAL) next_local_ctn = chan.get_next_ctn(LOCAL) oldest_unrevoked_remote_ctn = chan.get_oldest_unrevoked_ctn(REMOTE) - latest_remote_ctn = chan.get_latest_ctn(REMOTE) - next_remote_ctn = chan.get_next_ctn(REMOTE) - # BOLT-02: "A node [...] upon disconnection [...] MUST reverse any uncommitted updates sent by the other side" - chan.hm.discard_unsigned_remote_updates() # send message assert chan.is_static_remotekey_enabled() latest_secret, latest_point = chan.get_secret_and_point(LOCAL, 0) @@ -1284,6 +1272,46 @@ class Peer(Logger): f'(next_local_ctn={next_local_ctn}, ' f'oldest_unrevoked_remote_ctn={oldest_unrevoked_remote_ctn})') + async def reestablish_channel(self, chan: Channel): + await self.initialized + chan_id = chan.channel_id + if chan.should_request_force_close: + if chan.get_state() != ChannelState.WE_ARE_TOXIC: + chan.set_state(ChannelState.REQUESTED_FCLOSE) + await self.request_force_close(chan_id) + chan.should_request_force_close = False + return + if chan.get_state() == ChannelState.WE_ARE_TOXIC: + # Depending on timing, the remote might not know we are behind. + # We should let them know, so that they force-close. + # We do "request force-close" with ctn=0, instead of leaking our actual ctns, + # to decrease the remote's confidence of actual data loss on our part. + await self.request_force_close(chan_id) + return + if chan.get_state() == ChannelState.FORCE_CLOSING: + # We likely got here because we found out that we are ahead (i.e. remote lost state). + # Depending on timing, the remote might not know they are behind. + # We should let them know: + self._send_channel_reestablish(chan) + return + # if we get here, we will try to do a proper reestablish + if not (ChannelState.PREOPENING < chan.get_state() < ChannelState.FORCE_CLOSING): + raise Exception(f"unexpected {chan.get_state()=} for reestablish") + if chan.peer_state != PeerState.DISCONNECTED: + self.logger.info( + f'reestablish_channel was called but channel {chan.get_id_for_log()} ' + f'already in peer_state {chan.peer_state!r}') + return + chan.peer_state = PeerState.REESTABLISHING + util.trigger_callback('channel', self.lnworker.wallet, chan) + # ctns + oldest_unrevoked_local_ctn = chan.get_oldest_unrevoked_ctn(LOCAL) + next_local_ctn = chan.get_next_ctn(LOCAL) + oldest_unrevoked_remote_ctn = chan.get_oldest_unrevoked_ctn(REMOTE) + # BOLT-02: "A node [...] upon disconnection [...] MUST reverse any uncommitted updates sent by the other side" + chan.hm.discard_unsigned_remote_updates() + # send message + self._send_channel_reestablish(chan) # wait until we receive their channel_reestablish fut = self.channel_reestablish_msg[chan_id] await fut diff --git a/electrum/lnworker.py b/electrum/lnworker.py index 17d9ccd6b..d0b034808 100644 --- a/electrum/lnworker.py +++ b/electrum/lnworker.py @@ -2904,9 +2904,8 @@ class LNWallet(LNWorker): if self._can_retry_addr(peer, urgent=True): await self._add_peer(peer.host, peer.port, peer.pubkey) for chan in self.channels.values(): - if chan.is_closed(): - continue # reestablish + # note: we delegate filtering out uninteresting chans to this: if not chan.should_try_to_reestablish_peer(): continue peer = self._peers.get(chan.node_id, None) @@ -2961,10 +2960,9 @@ class LNWallet(LNWorker): if channel_id in self.channels: chan = self.channels[channel_id] peer = self._peers.get(chan.node_id) - if not peer: - raise Exception('Peer not found') chan.should_request_force_close = True - peer.close_and_cleanup() + if peer: + peer.close_and_cleanup() # to force a reconnect elif connect_str: peer = await self.add_peer(connect_str) await peer.request_force_close(channel_id) diff --git a/electrum/tests/test_lnpeer.py b/electrum/tests/test_lnpeer.py index fc25a8bb0..8d04474a1 100644 --- a/electrum/tests/test_lnpeer.py +++ b/electrum/tests/test_lnpeer.py @@ -566,30 +566,50 @@ class TestPeerDirect(TestPeer): await gath async def test_reestablish_with_old_state(self): - random_seed = os.urandom(32) - alice_channel, bob_channel = create_test_channels(random_seed=random_seed) - alice_channel_0, bob_channel_0 = create_test_channels(random_seed=random_seed) # these are identical - p1, p2, w1, w2, _q1, _q2 = self.prepare_peers(alice_channel, bob_channel) - lnaddr, pay_req = self.prepare_invoice(w2) - async def pay(): - result, log = await w1.pay_invoice(pay_req) - self.assertEqual(result, True) - gath.cancel() - gath = asyncio.gather(pay(), p1._message_loop(), p2._message_loop(), p1.htlc_switch(), p2.htlc_switch()) - with self.assertRaises(asyncio.CancelledError): - await gath - p1, p2, w1, w2, _q1, _q2 = self.prepare_peers(alice_channel_0, bob_channel) - for chan in (alice_channel_0, bob_channel): - chan.peer_state = PeerState.DISCONNECTED - async def reestablish(): - await asyncio.gather( - p1.reestablish_channel(alice_channel_0), - p2.reestablish_channel(bob_channel)) - gath = asyncio.gather(reestablish(), p1._message_loop(), p2._message_loop(), p1.htlc_switch(), p2.htlc_switch()) - with self.assertRaises(lnutil.RemoteMisbehaving): - await gath - self.assertEqual(alice_channel_0.peer_state, PeerState.BAD) - self.assertEqual(bob_channel._state, ChannelState.FORCE_CLOSING) + async def f(alice_slow: bool, bob_slow: bool): + random_seed = os.urandom(32) + alice_channel, bob_channel = create_test_channels(random_seed=random_seed) + alice_channel_0, bob_channel_0 = create_test_channels(random_seed=random_seed) # these are identical + p1, p2, w1, w2, _q1, _q2 = self.prepare_peers(alice_channel, bob_channel) + lnaddr, pay_req = self.prepare_invoice(w2) + async def pay(): + result, log = await w1.pay_invoice(pay_req) + self.assertEqual(result, True) + gath.cancel() + gath = asyncio.gather(pay(), p1._message_loop(), p2._message_loop(), p1.htlc_switch(), p2.htlc_switch()) + with self.assertRaises(asyncio.CancelledError): + await gath + p1, p2, w1, w2, _q1, _q2 = self.prepare_peers(alice_channel_0, bob_channel) + for chan in (alice_channel_0, bob_channel): + chan.peer_state = PeerState.DISCONNECTED + + async def alice_sends_reest(): + if alice_slow: await asyncio.sleep(0.05) + await p1.reestablish_channel(alice_channel_0) + async def bob_sends_reest(): + if bob_slow: await asyncio.sleep(0.05) + await p2.reestablish_channel(bob_channel) + + with self.assertRaises(GracefulDisconnect): + async with OldTaskGroup() as group: + await group.spawn(p1._message_loop()) + await group.spawn(p1.htlc_switch()) + await group.spawn(p2._message_loop()) + await group.spawn(p2.htlc_switch()) + await group.spawn(alice_sends_reest) + await group.spawn(bob_sends_reest) + self.assertEqual(alice_channel_0.peer_state, PeerState.BAD) + self.assertEqual(alice_channel_0._state, ChannelState.WE_ARE_TOXIC) + self.assertEqual(bob_channel._state, ChannelState.FORCE_CLOSING) + + with self.subTest(msg="both fast"): + # FIXME: we want to test the case where both Alice and Bob sends channel-reestablish before + # receiving what the other sent. This is not a reliable way to do that... + await f(alice_slow=False, bob_slow=False) + with self.subTest(msg="alice is slow"): + await f(alice_slow=True, bob_slow=False) + with self.subTest(msg="bob is slow"): + await f(alice_slow=False, bob_slow=True) @staticmethod def _send_fake_htlc(peer: Peer, chan: Channel) -> UpdateAddHtlc: