electrum

Electrum Bitcoin wallet
git clone https://git.parazyd.org/electrum
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commit ae3971259de76dda850ffdf949f786a1677d8c24
parent aafbe74a28a48a50369ab81133b341941f1077d1
Author: Janus <ysangkok@gmail.com>
Date:   Tue, 29 May 2018 18:12:48 +0200

ln: restore channels correctly after restart

* save funding_locked_received: if a node already sent us
funding_locked, save it to avoid superfluous messages

* use Queues instead of Futures: this ensure that we don't error if we
receive two messages of the same type, and in avoids having to delete
futures in finally blocks. A queue monitor could be added to detect
queue elements that are not popped.

* request initial routing sync: since we don't store the graph yet, it
is better to request the graph from the Peer so that we can route

* channel_state cleanup: now each channel should have a state, which is
initialized to OPENING and only marked OPEN once we have verified that
the funding_tx has been mined

Diffstat:
Mlib/lnbase.py | 116+++++++++++++++++++++----------------------------------------------------------
Mlib/lnworker.py | 68++++++++++++++++++++++++++++++++++++++++++--------------------------
2 files changed, 73 insertions(+), 111 deletions(-)

diff --git a/lib/lnbase.py b/lib/lnbase.py @@ -273,7 +273,7 @@ ChannelConfig = namedtuple("ChannelConfig", [ "to_self_delay", "dust_limit_sat", "max_htlc_value_in_flight_msat", "max_accepted_htlcs"]) OnlyPubkeyKeypair = namedtuple("OnlyPubkeyKeypair", ["pubkey"]) RemoteState = namedtuple("RemoteState", ["ctn", "next_per_commitment_point", "amount_msat", "revocation_store", "last_per_commitment_point", "next_htlc_id"]) -LocalState = namedtuple("LocalState", ["ctn", "per_commitment_secret_seed", "amount_msat", "next_htlc_id"]) +LocalState = namedtuple("LocalState", ["ctn", "per_commitment_secret_seed", "amount_msat", "next_htlc_id", "funding_locked_received"]) ChannelConstraints = namedtuple("ChannelConstraints", ["feerate", "capacity", "is_initiator", "funding_txn_minimum_depth"]) OpenChannel = namedtuple("OpenChannel", ["channel_id", "short_channel_id", "funding_outpoint", "local_config", "remote_config", "remote_state", "local_state", "constraints", "node_id"]) @@ -580,22 +580,12 @@ class Peer(PrintError): self.path_finder = path_finder self.read_buffer = b'' self.ping_time = 0 - self.futures = ["channel_accepted", - "funding_signed", - "local_funding_locked", - "remote_funding_locked", - "revoke_and_ack", - "channel_reestablish", - "update_fulfill_htlc", - "commitment_signed"] - self.channel_accepted = defaultdict(asyncio.Future) - self.funding_signed = defaultdict(asyncio.Future) - self.local_funding_locked = defaultdict(asyncio.Future) - self.remote_funding_locked = defaultdict(asyncio.Future) - self.revoke_and_ack = defaultdict(asyncio.Future) - self.update_fulfill_htlc = defaultdict(asyncio.Future) - self.commitment_signed = defaultdict(asyncio.Future) - self.initialized = asyncio.Future() + self.channel_accepted = defaultdict(asyncio.Queue) + self.funding_signed = defaultdict(asyncio.Queue) + self.remote_funding_locked = defaultdict(asyncio.Queue) + self.revoke_and_ack = defaultdict(asyncio.Queue) + self.update_fulfill_htlc = defaultdict(asyncio.Queue) + self.commitment_signed = defaultdict(asyncio.Queue) self.localfeatures = (0x08 if request_initial_sync else 0) self.unfulfilled_htlcs = [] self.channel_state = channel_state @@ -703,11 +693,7 @@ class Peer(PrintError): f(payload) def on_error(self, payload): - for i in self.futures: - if payload["channel_id"] in getattr(self, i): - getattr(self, i)[payload["channel_id"]].set_exception(LightningError(payload["data"])) - return - self.print_error("no future found to resolve", payload) + self.print_error("error", payload) def on_ping(self, payload): l = int.from_bytes(payload['num_pong_bytes'], 'big') @@ -716,17 +702,17 @@ class Peer(PrintError): def on_accept_channel(self, payload): temp_chan_id = payload["temporary_channel_id"] if temp_chan_id not in self.channel_accepted: raise Exception("Got unknown accept_channel") - self.channel_accepted[temp_chan_id].set_result(payload) + self.channel_accepted[temp_chan_id].put_nowait(payload) def on_funding_signed(self, payload): channel_id = int.from_bytes(payload['channel_id'], 'big') if channel_id not in self.funding_signed: raise Exception("Got unknown funding_signed") - self.funding_signed[channel_id].set_result(payload) + self.funding_signed[channel_id].put_nowait(payload) def on_funding_locked(self, payload): channel_id = int.from_bytes(payload['channel_id'], 'big') if channel_id not in self.funding_signed: print("Got unknown funding_locked", payload) - self.remote_funding_locked[channel_id].set_result(payload) + self.remote_funding_locked[channel_id].put_nowait(payload) def on_node_announcement(self, payload): pubkey = payload['node_id'] @@ -785,8 +771,6 @@ class Peer(PrintError): # read init msg = await self.read_message() self.process_message(msg) - # initialized - self.initialized.set_result(msg) # reestablish channels [await self.reestablish_channel(c) for c in self.channels] # loop @@ -799,7 +783,6 @@ class Peer(PrintError): self.writer.close() async def channel_establishment_flow(self, wallet, config, password, funding_sat, push_msat, temp_channel_id): - await self.initialized # see lnd/keychain/derivation.go keyfamilymultisig = 0 keyfamilyrevocationbase = 1 @@ -849,10 +832,7 @@ class Peer(PrintError): channel_reserve_satoshis=10 ) self.send_message(msg) - try: - payload = await self.channel_accepted[temp_channel_id] - finally: - del self.channel_accepted[temp_channel_id] + payload = await self.channel_accepted[temp_channel_id].get() remote_per_commitment_point = payload['first_per_commitment_point'] remote_config=ChannelConfig( payment_basepoint=OnlyPubkeyKeypair(payload['payment_basepoint']), @@ -903,16 +883,12 @@ class Peer(PrintError): sig_64 = sign_and_get_sig_string(remote_ctx, local_config, remote_config) funding_txid_bytes = bytes.fromhex(funding_txid)[::-1] channel_id = int.from_bytes(funding_txid_bytes, 'big') ^ funding_index - self.channel_state[channel_id] = "OPENING" self.send_message(gen_msg("funding_created", temporary_channel_id=temp_channel_id, funding_txid=funding_txid_bytes, funding_output_index=funding_index, signature=sig_64)) - try: - payload = await self.funding_signed[channel_id] - finally: - del self.funding_signed[channel_id] + payload = await self.funding_signed[channel_id].get() self.print_error('received funding_signed') remote_sig = payload['signature'] # verify remote signature @@ -949,14 +925,14 @@ class Peer(PrintError): ctn = 0, per_commitment_secret_seed=per_commitment_secret_seed, amount_msat=local_amount, - next_htlc_id = 0 + next_htlc_id = 0, + funding_locked_received = False ), constraints=ChannelConstraints(capacity=funding_sat, feerate=local_feerate, is_initiator=True, funding_txn_minimum_depth=funding_txn_minimum_depth) ) return chan async def reestablish_channel(self, chan): - assert chan.channel_id not in self.channel_state self.send_message(gen_msg("channel_reestablish", channel_id=chan.channel_id, next_local_commitment_number=chan.local_state.ctn+1, @@ -980,27 +956,21 @@ class Peer(PrintError): raise Exception("expected local ctn {}, got {}".format(chan.local_state.ctn, local_ctn)) if channel_reestablish_msg["my_current_per_commitment_point"] != chan.remote_state.last_per_commitment_point: raise Exception("Remote PCP mismatch") - self.channel_state[chan.channel_id] = "OPEN" async def funding_locked(self, chan): channel_id = chan.channel_id - try: - short_channel_id = await self.local_funding_locked[channel_id] - finally: - del self.local_funding_locked[channel_id] + short_channel_id = chan.short_channel_id per_commitment_secret_index = 2**48 - 2 per_commitment_point_second = secret_to_pubkey(int.from_bytes( get_per_commitment_secret_from_seed(chan.local_state.per_commitment_secret_seed, per_commitment_secret_index), 'big')) self.send_message(gen_msg("funding_locked", channel_id=channel_id, next_per_commitment_point=per_commitment_point_second)) # wait until we receive funding_locked - try: - remote_funding_locked_msg = await self.remote_funding_locked[channel_id] - finally: - del self.remote_funding_locked[channel_id] + remote_funding_locked_msg = await self.remote_funding_locked[channel_id].get() self.print_error('Done waiting for remote_funding_locked', remote_funding_locked_msg) - self.channel_state[chan.channel_id] = "OPEN" - return chan._replace(short_channel_id=short_channel_id, remote_state=chan.remote_state._replace(next_per_commitment_point=remote_funding_locked_msg["next_per_commitment_point"])) + new_remote_state = chan.remote_state._replace(next_per_commitment_point=remote_funding_locked_msg["next_per_commitment_point"]) + new_local_state = chan.local_state._replace(funding_locked_received = True) + return chan._replace(short_channel_id=short_channel_id, remote_state=new_remote_state, local_state=new_local_state) def on_update_fail_htlc(self, payload): print("UPDATE_FAIL_HTLC", decode_onion_error(payload["reason"], self.node_keys, self.secret_key)) @@ -1097,10 +1067,7 @@ class Peer(PrintError): self.send_message(gen_msg("commitment_signed", channel_id=chan.channel_id, signature=sig_64, num_htlcs=1, htlc_signature=htlc_sig)) - try: - revoke_and_ack_msg = await self.revoke_and_ack[chan.channel_id] - finally: - del self.revoke_and_ack[chan.channel_id] + revoke_and_ack_msg = await self.revoke_and_ack[chan.channel_id].get() # TODO check revoke_and_ack results last_secret, _, next_point = derive_and_incr() @@ -1112,16 +1079,10 @@ class Peer(PrintError): print("waiting for update_fulfill") - try: - update_fulfill_htlc_msg = await self.update_fulfill_htlc[chan.channel_id] - finally: - del self.update_fulfill_htlc[chan.channel_id] + update_fulfill_htlc_msg = await self.update_fulfill_htlc[chan.channel_id].get() print("waiting for commitment_signed") - try: - commitment_signed_msg = await self.commitment_signed[chan.channel_id] - finally: - del self.commitment_signed[chan.channel_id] + commitment_signed_msg = await self.commitment_signed[chan.channel_id].get() last_secret, _, next_point = derive_and_incr() their_revstore.add_next_entry(last_secret) @@ -1139,10 +1100,7 @@ class Peer(PrintError): self.send_message(gen_msg("commitment_signed", channel_id=chan.channel_id, signature=sig_64, num_htlcs=0)) - try: - revoke_and_ack_msg = await self.revoke_and_ack[chan.channel_id] - finally: - del self.revoke_and_ack[chan.channel_id] + revoke_and_ack_msg = await self.revoke_and_ack[chan.channel_id].get() # TODO check revoke_and_ack results return chan._replace( @@ -1182,10 +1140,7 @@ class Peer(PrintError): their_revstore = chan.remote_state.revocation_store channel_id = chan.channel_id - try: - commitment_signed_msg = await self.commitment_signed[channel_id] - finally: - del self.commitment_signed[channel_id] + commitment_signed_msg = await self.commitment_signed[channel_id].get() if int.from_bytes(commitment_signed_msg["num_htlcs"], "big") < 1: while len(self.unfulfilled_htlcs) < 1: @@ -1267,10 +1222,7 @@ class Peer(PrintError): self.send_message(gen_msg("commitment_signed", channel_id=channel_id, signature=sig_64, num_htlcs=1, htlc_signature=htlc_sig)) - try: - revoke_and_ack_msg = await self.revoke_and_ack[channel_id] - finally: - del self.revoke_and_ack[channel_id] + revoke_and_ack_msg = await self.revoke_and_ack[channel_id].get() # TODO check revoke_and_ack_msg contents @@ -1285,17 +1237,11 @@ class Peer(PrintError): sig_64 = sign_and_get_sig_string(bare_ctx, chan.local_config, chan.remote_config) self.send_message(gen_msg("commitment_signed", channel_id=channel_id, signature=sig_64, num_htlcs=0)) - try: - revoke_and_ack_msg = await self.revoke_and_ack[channel_id] - finally: - del self.revoke_and_ack[channel_id] + revoke_and_ack_msg = await self.revoke_and_ack[channel_id].get() # TODO check revoke_and_ack results - try: - commitment_signed_msg = await self.commitment_signed[channel_id] - finally: - del self.commitment_signed[channel_id] + commitment_signed_msg = await self.commitment_signed[channel_id].get() # TODO check commitment_signed results @@ -1325,11 +1271,11 @@ class Peer(PrintError): def on_commitment_signed(self, payload): self.print_error("commitment_signed", payload) channel_id = int.from_bytes(payload['channel_id'], 'big') - self.commitment_signed[channel_id].set_result(payload) + self.commitment_signed[channel_id].put_nowait(payload) def on_update_fulfill_htlc(self, payload): channel_id = int.from_bytes(payload["channel_id"], 'big') - self.update_fulfill_htlc[channel_id].set_result(payload) + self.update_fulfill_htlc[channel_id].put_nowait(payload) def on_update_fail_malformed_htlc(self, payload): self.on_error(payload) @@ -1343,7 +1289,7 @@ class Peer(PrintError): def on_revoke_and_ack(self, payload): channel_id = int.from_bytes(payload["channel_id"], 'big') - self.revoke_and_ack[channel_id].set_result(payload) + self.revoke_and_ack[channel_id].put_nowait(payload) def count_trailing_zeros(index): diff --git a/lib/lnworker.py b/lib/lnworker.py @@ -12,7 +12,7 @@ import asyncio from . import constants from .bitcoin import sha256, COIN -from .util import bh2u, bfh +from .util import bh2u, bfh, PrintError from .constants import set_testnet, set_simnet from .simple_config import SimpleConfig from .network import Network @@ -86,7 +86,7 @@ node_list = [ -class LNWorker: +class LNWorker(PrintError): def __init__(self, wallet, network): self.wallet = wallet @@ -100,7 +100,7 @@ class LNWorker: self.path_finder = lnrouter.LNPathFinder(self.channel_db) self.channels = [reconstruct_namedtuples(x) for x in wallet.storage.get("channels", {})] peer_list = network.config.get('lightning_peers', node_list) - self.channel_state = {} + self.channel_state = {chan.channel_id: "OPENING" for chan in self.channels} for host, port, pubkey in peer_list: self.add_peer(host, int(port), pubkey) # wait until we see confirmations @@ -110,49 +110,65 @@ class LNWorker: def add_peer(self, host, port, pubkey): node_id = bfh(pubkey) channels = list(filter(lambda x: x.node_id == node_id, self.channels)) - peer = Peer(host, int(port), node_id, self.privkey, self.network, self.channel_db, self.path_finder, self.channel_state, channels) + peer = Peer(host, int(port), node_id, self.privkey, self.network, self.channel_db, self.path_finder, self.channel_state, channels, request_initial_sync=True) self.network.futures.append(asyncio.run_coroutine_threadsafe(peer.main_loop(), asyncio.get_event_loop())) self.peers[node_id] = peer def save_channel(self, openchannel): + if openchannel.channel_id not in self.channel_state: + self.channel_state[openchannel.channel_id] = "OPENING" self.channels = [openchannel] # TODO multiple channels dumped = serialize_channels(self.channels) self.wallet.storage.put("channels", dumped) self.wallet.storage.write() + def save_short_chan_id(self, chan): + """ + Checks if the Funding TX has been mined. If it has save the short channel ID to disk and return the new OpenChannel. + + If the Funding TX has not been mined, return None + """ + assert self.channel_state[chan.channel_id] == "OPENING" + peer = self.peers[chan.node_id] + conf = self.wallet.get_tx_height(chan.funding_outpoint.txid)[1] + if conf >= chan.constraints.funding_txn_minimum_depth: + block_height, tx_pos = self.wallet.get_txpos(chan.funding_outpoint.txid) + if tx_pos == -1: + self.print_error('funding tx is not yet SPV verified.. but there are ' + 'already enough confirmations (currently {})'.format(conf)) + return None + chan = chan._replace(short_channel_id = calc_short_channel_id(block_height, tx_pos, chan.funding_outpoint.output_index)) + self.save_channel(chan) + return chan + return None + def on_network_update(self, event, *args): for chan in self.channels: + if self.channel_state[chan.channel_id] == "OPEN": + continue + chan = self.save_short_chan_id(chan) + if not chan: + self.print_error("network update but funding tx is still not at sufficient depth") + continue peer = self.peers[chan.node_id] - conf = self.wallet.get_tx_height(chan.funding_outpoint.txid)[1] - if conf >= chan.constraints.funding_txn_minimum_depth: - block_height, tx_pos = self.wallet.get_txpos(chan.funding_outpoint.txid) - if tx_pos == -1: - self.print_error('funding tx is not yet SPV verified.. but there are ' - 'already enough confirmations (currently {})'.format(conf)) - return - if chan.channel_id not in self.channel_state or self.channel_state[chan.channel_id] != "OPENING": - return - asyncio.run_coroutine_threadsafe(self.set_local_funding_locked_result(peer, chan, block_height, tx_pos), asyncio.get_event_loop()) + asyncio.run_coroutine_threadsafe(self.wait_funding_locked_and_mark_open(peer, chan), asyncio.get_event_loop()) # aiosafe because we don't wait for result @aiosafe - async def set_local_funding_locked_result(self, peer, chan, block_height, tx_pos): - channel_id = chan.channel_id - short_channel_id = calc_short_channel_id(block_height, tx_pos, chan.funding_outpoint.output_index) - try: - peer.local_funding_locked[channel_id].set_result(short_channel_id) - except (asyncio.InvalidStateError, KeyError) as e: - # FIXME race condition if updates come in quickly, set_result might be called multiple times - # or self.local_funding_locked[channel_id] might be deleted already - self.print_error('local_funding_locked.set_result error for channel {}: {}'.format(channel_id, e)) - openchannel = await peer.funding_locked(chan) - self.save_channel(openchannel) - print("CHANNEL OPENING COMPLETED") + async def wait_funding_locked_and_mark_open(self, peer, chan): + if self.channel_state[chan.channel_id] == "OPEN": + return + if not chan.local_state.funding_locked_received: + chan = await peer.funding_locked(chan) + self.save_channel(chan) + self.print_error("CHANNEL OPENING COMPLETED") + self.channel_state[chan.channel_id] = "OPEN" # not aiosafe because we call .result() which will propagate an exception async def _open_channel_coroutine(self, node_id, amount, push_msat, password): peer = self.peers[bfh(node_id)] openingchannel = await peer.channel_establishment_flow(self.wallet, self.config, password, amount, push_msat, temp_channel_id=os.urandom(32)) + self.print_error("SAVING OPENING CHANNEL") self.save_channel(openingchannel) def open_channel(self, node_id, local_amt, push_amt, pw):