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Split code in reestablish_channel: 

Messages are sent in reestablish_channel (async)
  Message checks and force_close are performed in on_channel_reestablish (not async).
  That task should not be cancelled if the connection is closed.
  Revert 57583c05cf
patch-4
ThomasV 3 years ago
parent
7a47eb9906
commit
b2f84187bc
3 changed files with 123 additions and 121 deletions
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  1. 226
      electrum/lnpeer.py
  2. 8
      electrum/lnworker.py
  3. 10
      electrum/tests/test_lnpeer.py

226
electrum/lnpeer.py
View File

@ -65,7 +65,7 @@ class Peer(Logger):
LOGGING_SHORTCUT = 'P'
ORDERED_MESSAGES = (
'accept_channel', 'funding_signed', 'funding_created', 'accept_channel', 'channel_reestablish', 'closing_signed')
'accept_channel', 'funding_signed', 'funding_created', 'accept_channel', 'closing_signed')
SPAMMY_MESSAGES = (
'ping', 'pong', 'channel_announcement', 'node_announcement', 'channel_update',)
@ -103,6 +103,7 @@ class Peer(Logger):
self.funding_signed_sent = set() # for channels in PREOPENING
self.shutdown_received = {} # chan_id -> asyncio.Future()
self.announcement_signatures = defaultdict(asyncio.Queue)
self.channel_reestablish_msg = defaultdict(asyncio.Queue)
self.orphan_channel_updates = OrderedDict() # type: OrderedDict[ShortChannelID, dict]
Logger.__init__(self)
self.taskgroup = OldTaskGroup()
@ -907,103 +908,40 @@ class Peer(Logger):
your_last_per_commitment_secret=0,
my_current_per_commitment_point=latest_point)
async def reestablish_channel(self, chan: Channel):
await self.initialized
chan_id = chan.channel_id
if chan.should_request_force_close:
await self.trigger_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)
# BOLT-02: "A node [...] upon disconnection [...] MUST reverse any uncommitted updates sent by the other side"
chan.hm.discard_unsigned_remote_updates()
# 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)
assert self.features.supports(LnFeatures.OPTION_DATA_LOSS_PROTECT_OPT)
# send message
if chan.is_static_remotekey_enabled():
latest_secret, latest_point = chan.get_secret_and_point(LOCAL, 0)
else:
latest_secret, latest_point = chan.get_secret_and_point(LOCAL, latest_local_ctn)
if oldest_unrevoked_remote_ctn == 0:
last_rev_secret = 0
else:
last_rev_index = oldest_unrevoked_remote_ctn - 1
last_rev_secret = chan.revocation_store.retrieve_secret(RevocationStore.START_INDEX - last_rev_index)
self.send_message(
"channel_reestablish",
channel_id=chan_id,
next_commitment_number=next_local_ctn,
next_revocation_number=oldest_unrevoked_remote_ctn,
your_last_per_commitment_secret=last_rev_secret,
my_current_per_commitment_point=latest_point)
self.logger.info(f'channel_reestablish ({chan.get_id_for_log()}): sent channel_reestablish with '
f'(next_local_ctn={next_local_ctn}, '
f'oldest_unrevoked_remote_ctn={oldest_unrevoked_remote_ctn})')
while True:
try:
msg = await self.wait_for_message('channel_reestablish', chan_id)
break
except asyncio.TimeoutError:
self.logger.info('waiting to receive channel_reestablish...')
continue
except Exception as e:
# do not kill connection, because we might have other channels with that peer
self.logger.info(f'channel_reestablish failed, {e}')
return
def on_channel_reestablish(self, chan, msg):
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")
their_claim_of_our_last_per_commitment_secret = msg.get("your_last_per_commitment_secret")
self.logger.info(f'channel_reestablish ({chan.get_id_for_log()}): received channel_reestablish with '
f'(their_next_local_ctn={their_next_local_ctn}, '
f'their_oldest_unrevoked_remote_ctn={their_oldest_unrevoked_remote_ctn})')
self.logger.info(
f'channel_reestablish ({chan.get_id_for_log()}): received channel_reestablish with '
f'(their_next_local_ctn={their_next_local_ctn}, '
f'their_oldest_unrevoked_remote_ctn={their_oldest_unrevoked_remote_ctn})')
# sanity checks of received values
if their_next_local_ctn < 0:
raise RemoteMisbehaving(f"channel reestablish: their_next_local_ctn < 0")
if their_oldest_unrevoked_remote_ctn < 0:
raise RemoteMisbehaving(f"channel reestablish: their_oldest_unrevoked_remote_ctn < 0")
# Replay un-acked local updates (including commitment_signed) byte-for-byte.
# If we have sent them a commitment signature that they "lost" (due to disconnect),
# we need to make sure we replay the same local updates, as otherwise they could
# end up with two (or more) signed valid commitment transactions at the same ctn.
# Multiple valid ctxs at the same ctn is a major headache for pre-signing spending txns,
# e.g. for watchtowers, hence we must ensure these ctxs coincide.
# We replay the local updates even if they were not yet committed.
unacked = chan.hm.get_unacked_local_updates()
n_replayed_msgs = 0
for ctn, messages in unacked.items():
if ctn < their_next_local_ctn:
# They claim to have received these messages and the corresponding
# commitment_signed, hence we must not replay them.
continue
for raw_upd_msg in messages:
self.transport.send_bytes(raw_upd_msg)
n_replayed_msgs += 1
self.logger.info(f'channel_reestablish ({chan.get_id_for_log()}): replayed {n_replayed_msgs} unacked messages')
# 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)
# compare remote ctns
we_are_ahead = False
they_are_ahead = False
# compare remote ctns
we_must_resend_revoke_and_ack = False
if next_remote_ctn != their_next_local_ctn:
if their_next_local_ctn == latest_remote_ctn and chan.hm.is_revack_pending(REMOTE):
# We replayed the local updates (see above), which should have contained a commitment_signed
# (due to is_revack_pending being true), and this should have remedied this situation.
# We will replay the local updates (see reestablish_channel), which should contain a commitment_signed
# (due to is_revack_pending being true), and this should remedy this situation.
pass
else:
self.logger.warning(f"channel_reestablish ({chan.get_id_for_log()}): "
f"expected remote ctn {next_remote_ctn}, got {their_next_local_ctn}")
self.logger.warning(
f"channel_reestablish ({chan.get_id_for_log()}): "
f"expected remote ctn {next_remote_ctn}, got {their_next_local_ctn}")
if their_next_local_ctn < next_remote_ctn:
we_are_ahead = True
else:
@ -1011,25 +949,17 @@ class Peer(Logger):
# compare local ctns
if oldest_unrevoked_local_ctn != their_oldest_unrevoked_remote_ctn:
if oldest_unrevoked_local_ctn - 1 == their_oldest_unrevoked_remote_ctn:
# A node:
# if next_revocation_number is equal to the commitment number of the last revoke_and_ack
# the receiving node sent, AND the receiving node hasn't already received a closing_signed:
# MUST re-send the revoke_and_ack.
last_secret, last_point = chan.get_secret_and_point(LOCAL, oldest_unrevoked_local_ctn - 1)
next_secret, next_point = chan.get_secret_and_point(LOCAL, oldest_unrevoked_local_ctn + 1)
self.send_message(
"revoke_and_ack",
channel_id=chan.channel_id,
per_commitment_secret=last_secret,
next_per_commitment_point=next_point)
we_must_resend_revoke_and_ack = True
else:
self.logger.warning(f"channel_reestablish ({chan.get_id_for_log()}): "
f"expected local ctn {oldest_unrevoked_local_ctn}, got {their_oldest_unrevoked_remote_ctn}")
self.logger.warning(
f"channel_reestablish ({chan.get_id_for_log()}): "
f"expected local ctn {oldest_unrevoked_local_ctn}, got {their_oldest_unrevoked_remote_ctn}")
if their_oldest_unrevoked_remote_ctn < oldest_unrevoked_local_ctn:
we_are_ahead = True
else:
they_are_ahead = True
# option_data_loss_protect
assert self.features.supports(LnFeatures.OPTION_DATA_LOSS_PROTECT_OPT)
def are_datalossprotect_fields_valid() -> bool:
if their_local_pcp is None or their_claim_of_our_last_per_commitment_secret is None:
return False
@ -1039,8 +969,9 @@ class Peer(Logger):
assert their_oldest_unrevoked_remote_ctn == 0
our_pcs = bytes(32)
if our_pcs != their_claim_of_our_last_per_commitment_secret:
self.logger.error(f"channel_reestablish ({chan.get_id_for_log()}): "
f"(DLP) local PCS mismatch: {bh2u(our_pcs)} != {bh2u(their_claim_of_our_last_per_commitment_secret)}")
self.logger.error(
f"channel_reestablish ({chan.get_id_for_log()}): "
f"(DLP) local PCS mismatch: {bh2u(our_pcs)} != {bh2u(their_claim_of_our_last_per_commitment_secret)}")
return False
if chan.is_static_remotekey_enabled():
return True
@ -1050,27 +981,108 @@ class Peer(Logger):
pass
else:
if our_remote_pcp != their_local_pcp:
self.logger.error(f"channel_reestablish ({chan.get_id_for_log()}): "
f"(DLP) remote PCP mismatch: {bh2u(our_remote_pcp)} != {bh2u(their_local_pcp)}")
self.logger.error(
f"channel_reestablish ({chan.get_id_for_log()}): "
f"(DLP) remote PCP mismatch: {bh2u(our_remote_pcp)} != {bh2u(their_local_pcp)}")
return False
return True
if not are_datalossprotect_fields_valid():
raise RemoteMisbehaving("channel_reestablish: data loss protect fields invalid")
if they_are_ahead:
self.logger.warning(f"channel_reestablish ({chan.get_id_for_log()}): "
f"remote is ahead of us! They should force-close. Remote PCP: {bh2u(their_local_pcp)}")
self.logger.warning(
f"channel_reestablish ({chan.get_id_for_log()}): "
f"remote is ahead of us! They should force-close. Remote PCP: {bh2u(their_local_pcp)}")
# data_loss_protect_remote_pcp is used in lnsweep
chan.set_data_loss_protect_remote_pcp(their_next_local_ctn - 1, their_local_pcp)
self.lnworker.save_channel(chan)
chan.peer_state = PeerState.BAD
return
elif we_are_ahead:
raise RemoteMisbehaving("remote ahead of us")
if we_are_ahead:
self.logger.warning(f"channel_reestablish ({chan.get_id_for_log()}): we are ahead of remote! trying to force-close.")
await self.lnworker.try_force_closing(chan_id)
asyncio.ensure_future(self.lnworker.try_force_closing(chan.channel_id))
raise RemoteMisbehaving("we are ahead of remote")
# all good
self.channel_reestablish_msg[chan.channel_id].put_nowait((we_must_resend_revoke_and_ack, their_next_local_ctn))
async def reestablish_channel(self, chan: Channel):
await self.initialized
chan_id = chan.channel_id
if chan.should_request_force_close:
await self.trigger_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
if chan.is_static_remotekey_enabled():
latest_secret, latest_point = chan.get_secret_and_point(LOCAL, 0)
else:
latest_secret, latest_point = chan.get_secret_and_point(LOCAL, latest_local_ctn)
if oldest_unrevoked_remote_ctn == 0:
last_rev_secret = 0
else:
last_rev_index = oldest_unrevoked_remote_ctn - 1
last_rev_secret = chan.revocation_store.retrieve_secret(RevocationStore.START_INDEX - last_rev_index)
self.send_message(
"channel_reestablish",
channel_id=chan_id,
next_commitment_number=next_local_ctn,
next_revocation_number=oldest_unrevoked_remote_ctn,
your_last_per_commitment_secret=last_rev_secret,
my_current_per_commitment_point=latest_point)
self.logger.info(
f'channel_reestablish ({chan.get_id_for_log()}): sent channel_reestablish with '
f'(next_local_ctn={next_local_ctn}, '
f'oldest_unrevoked_remote_ctn={oldest_unrevoked_remote_ctn})')
# wait until we receive their channel_reestablish
we_must_resend_revoke_and_ack, their_next_local_ctn = await self.channel_reestablish_msg[chan_id].get()
# Replay un-acked local updates (including commitment_signed) byte-for-byte.
# If we have sent them a commitment signature that they "lost" (due to disconnect),
# we need to make sure we replay the same local updates, as otherwise they could
# end up with two (or more) signed valid commitment transactions at the same ctn.
# Multiple valid ctxs at the same ctn is a major headache for pre-signing spending txns,
# e.g. for watchtowers, hence we must ensure these ctxs coincide.
# We replay the local updates even if they were not yet committed.
unacked = chan.hm.get_unacked_local_updates()
n_replayed_msgs = 0
for ctn, messages in unacked.items():
if ctn < their_next_local_ctn:
# They claim to have received these messages and the corresponding
# commitment_signed, hence we must not replay them.
continue
for raw_upd_msg in messages:
self.transport.send_bytes(raw_upd_msg)
n_replayed_msgs += 1
self.logger.info(f'channel_reestablish ({chan.get_id_for_log()}): replayed {n_replayed_msgs} unacked messages')
# A node:
# if next_revocation_number is equal to the commitment number of the last revoke_and_ack
# the receiving node sent, AND the receiving node hasn't already received a closing_signed:
# MUST re-send the revoke_and_ack.
if we_must_resend_revoke_and_ack:
last_secret, last_point = chan.get_secret_and_point(LOCAL, oldest_unrevoked_local_ctn - 1)
next_secret, next_point = chan.get_secret_and_point(LOCAL, oldest_unrevoked_local_ctn + 1)
self.send_message(
"revoke_and_ack",
channel_id=chan.channel_id,
per_commitment_secret=last_secret,
next_per_commitment_point=next_point)
chan.peer_state = PeerState.GOOD
if chan.is_funded() and their_next_local_ctn == next_local_ctn == 1:
self.send_funding_locked(chan)

8
electrum/lnworker.py
View File

@ -2283,16 +2283,10 @@ class LNWallet(LNWorker):
peer_addr = LNPeerAddr(host, port, node_id)
transport = LNTransport(privkey, peer_addr, proxy=self.network.proxy)
peer = Peer(self, node_id, transport, is_channel_backup=True)
async def trigger_force_close_and_wait():
# wait before closing the transport, so that
# remote has time to process the message.
await peer.trigger_force_close(channel_id)
await asyncio.sleep(1)
peer.transport.close()
try:
async with OldTaskGroup(wait=any) as group:
await group.spawn(peer._message_loop())
await group.spawn(trigger_force_close_and_wait())
await group.spawn(peer.trigger_force_close(channel_id))
return
except Exception as e:
self.logger.info(f'failed to connect {host} {e}')

10
electrum/tests/test_lnpeer.py
View File

@ -540,7 +540,6 @@ class TestPeer(TestCaseForTestnet):
await gath
with self.assertRaises(concurrent.futures.CancelledError):
run(f())
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
@ -548,16 +547,13 @@ class TestPeer(TestCaseForTestnet):
await asyncio.gather(
p1.reestablish_channel(alice_channel_0),
p2.reestablish_channel(bob_channel))
self.assertEqual(alice_channel_0.peer_state, PeerState.BAD)
self.assertEqual(bob_channel._state, ChannelState.FORCE_CLOSING)
# wait so that pending messages are processed
#await asyncio.sleep(1)
gath.cancel()
gath = asyncio.gather(reestablish(), p1._message_loop(), p2._message_loop(), p1.htlc_switch(), p2.htlc_switch())
async def f():
await gath
with self.assertRaises(concurrent.futures.CancelledError):
with self.assertRaises(electrum.lnutil.RemoteMisbehaving):
run(f())
self.assertEqual(alice_channel_0.peer_state, PeerState.BAD)
self.assertEqual(bob_channel._state, ChannelState.FORCE_CLOSING)
@needs_test_with_all_chacha20_implementations
def test_payment(self):

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