lnpeer: move htlc forwarding funcs to lnworker
forwarding happens independent of the peer that received the htlc to forward and fits better in lnworker.
This commit is contained in:
f321x
@@ -1926,57 +1926,6 @@ class Peer(Logger, EventListener):
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self.send_message("commitment_signed", channel_id=chan.channel_id, signature=sig_64, num_htlcs=len(htlc_sigs), htlc_signature=b"".join(htlc_sigs))
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return True
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def create_onion_for_route(
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self, *,
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route: 'LNPaymentRoute',
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amount_msat: int,
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total_msat: int,
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payment_hash: bytes,
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min_final_cltv_delta: int,
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payment_secret: bytes,
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trampoline_onion: Optional[OnionPacket] = None,
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):
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# add features learned during "init" for direct neighbour:
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route[0].node_features |= self.features
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local_height = self.network.get_local_height()
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final_cltv_abs = local_height + min_final_cltv_delta
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hops_data, amount_msat, cltv_abs = calc_hops_data_for_payment(
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route,
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amount_msat,
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final_cltv_abs=final_cltv_abs,
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total_msat=total_msat,
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payment_secret=payment_secret)
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num_hops = len(hops_data)
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self.logger.info(f"lnpeer.pay len(route)={len(route)}")
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for i in range(len(route)):
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self.logger.info(f" {i}: edge={route[i].short_channel_id} hop_data={hops_data[i]!r}")
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assert final_cltv_abs <= cltv_abs, (final_cltv_abs, cltv_abs)
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session_key = os.urandom(32) # session_key
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# if we are forwarding a trampoline payment, add trampoline onion
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if trampoline_onion:
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self.logger.info(f'adding trampoline onion to final payload')
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trampoline_payload = hops_data[-1].payload
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trampoline_payload["trampoline_onion_packet"] = {
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"version": trampoline_onion.version,
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"public_key": trampoline_onion.public_key,
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"hops_data": trampoline_onion.hops_data,
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"hmac": trampoline_onion.hmac
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}
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if t_hops_data := trampoline_onion._debug_hops_data: # None if trampoline-forwarding
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t_route = trampoline_onion._debug_route
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assert t_route is not None
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self.logger.info(f"lnpeer.pay len(t_route)={len(t_route)}")
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for i in range(len(t_route)):
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self.logger.info(f" {i}: t_node={t_route[i].end_node.hex()} hop_data={t_hops_data[i]!r}")
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# create onion packet
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payment_path_pubkeys = [x.node_id for x in route]
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onion = new_onion_packet(payment_path_pubkeys, session_key, hops_data, associated_data=payment_hash) # must use another sessionkey
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self.logger.info(f"starting payment. len(route)={len(hops_data)}.")
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# create htlc
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if cltv_abs > local_height + lnutil.NBLOCK_CLTV_DELTA_TOO_FAR_INTO_FUTURE:
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raise PaymentFailure(f"htlc expiry too far into future. (in {cltv_abs-local_height} blocks)")
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return onion, amount_msat, cltv_abs, session_key
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def send_htlc(
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self,
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*,
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@@ -2019,7 +1968,7 @@ class Peer(Logger, EventListener):
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assert len(route) > 0
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if not chan.can_send_update_add_htlc():
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raise PaymentFailure("Channel cannot send update_add_htlc")
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onion, amount_msat, cltv_abs, session_key = self.create_onion_for_route(
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onion, amount_msat, cltv_abs, session_key = self.lnworker.create_onion_for_route(
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route=route,
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amount_msat=amount_msat,
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total_msat=total_msat,
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@@ -2131,273 +2080,6 @@ class Peer(Logger, EventListener):
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chan.receive_htlc(htlc, onion_packet)
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util.trigger_callback('htlc_added', chan, htlc, RECEIVED)
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async def maybe_forward_htlc(
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self, *,
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incoming_chan: Channel,
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htlc: UpdateAddHtlc,
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processed_onion: ProcessedOnionPacket,
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) -> str:
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# Forward HTLC
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# FIXME: there are critical safety checks MISSING here
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# - for example; atm we forward first and then persist "forwarding_info",
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# so if we segfault in-between and restart, we might forward an HTLC twice...
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# (same for trampoline forwarding)
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# - we could check for the exposure to dust HTLCs, see:
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# https://github.com/ACINQ/eclair/pull/1985
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def log_fail_reason(reason: str):
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self.logger.debug(
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f"maybe_forward_htlc. will FAIL HTLC: inc_chan={incoming_chan.get_id_for_log()}. "
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f"{reason}. inc_htlc={str(htlc)}. onion_payload={processed_onion.hop_data.payload}")
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forwarding_enabled = self.network.config.EXPERIMENTAL_LN_FORWARD_PAYMENTS
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if not forwarding_enabled:
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log_fail_reason("forwarding is disabled")
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raise OnionRoutingFailure(code=OnionFailureCode.PERMANENT_CHANNEL_FAILURE, data=b'')
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chain = self.network.blockchain()
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if chain.is_tip_stale():
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raise OnionRoutingFailure(code=OnionFailureCode.TEMPORARY_NODE_FAILURE, data=b'')
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try:
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_next_chan_scid = processed_onion.hop_data.payload["short_channel_id"]["short_channel_id"] # type: bytes
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next_chan_scid = ShortChannelID(_next_chan_scid)
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except Exception:
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raise OnionRoutingFailure(code=OnionFailureCode.INVALID_ONION_PAYLOAD, data=b'\x00\x00\x00')
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try:
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next_amount_msat_htlc = processed_onion.hop_data.payload["amt_to_forward"]["amt_to_forward"]
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except Exception:
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raise OnionRoutingFailure(code=OnionFailureCode.INVALID_ONION_PAYLOAD, data=b'\x00\x00\x00')
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try:
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next_cltv_abs = processed_onion.hop_data.payload["outgoing_cltv_value"]["outgoing_cltv_value"]
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except Exception:
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raise OnionRoutingFailure(code=OnionFailureCode.INVALID_ONION_PAYLOAD, data=b'\x00\x00\x00')
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next_chan = self.lnworker.get_channel_by_short_id(next_chan_scid)
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if self.lnworker.features.supports(LnFeatures.OPTION_ZEROCONF_OPT):
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next_peer = self.lnworker.get_peer_by_static_jit_scid_alias(next_chan_scid)
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else:
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next_peer = None
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if not next_chan and next_peer and next_peer.accepts_zeroconf():
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# check if an already existing channel can be used.
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# todo: split the payment
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for next_chan in next_peer.channels.values():
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if next_chan.can_pay(next_amount_msat_htlc):
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break
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else:
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return await self.lnworker.open_channel_just_in_time(
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next_peer=next_peer,
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next_amount_msat_htlc=next_amount_msat_htlc,
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next_cltv_abs=next_cltv_abs,
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payment_hash=htlc.payment_hash,
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next_onion=processed_onion.next_packet)
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local_height = chain.height()
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if next_chan is None:
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log_fail_reason(f"cannot find next_chan {next_chan_scid}")
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raise OnionRoutingFailure(code=OnionFailureCode.UNKNOWN_NEXT_PEER, data=b'')
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outgoing_chan_upd = next_chan.get_outgoing_gossip_channel_update(scid=next_chan_scid)[2:]
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outgoing_chan_upd_len = len(outgoing_chan_upd).to_bytes(2, byteorder="big")
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outgoing_chan_upd_message = outgoing_chan_upd_len + outgoing_chan_upd
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if not next_chan.can_send_update_add_htlc():
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log_fail_reason(
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f"next_chan {next_chan.get_id_for_log()} cannot send ctx updates. "
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f"chan state {next_chan.get_state()!r}, peer state: {next_chan.peer_state!r}")
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raise OnionRoutingFailure(code=OnionFailureCode.TEMPORARY_CHANNEL_FAILURE, data=outgoing_chan_upd_message)
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if not next_chan.can_pay(next_amount_msat_htlc):
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log_fail_reason(f"transient error (likely due to insufficient funds): not next_chan.can_pay(amt)")
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raise OnionRoutingFailure(code=OnionFailureCode.TEMPORARY_CHANNEL_FAILURE, data=outgoing_chan_upd_message)
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if htlc.cltv_abs - next_cltv_abs < next_chan.forwarding_cltv_delta:
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log_fail_reason(
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f"INCORRECT_CLTV_EXPIRY. "
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f"{htlc.cltv_abs=} - {next_cltv_abs=} < {next_chan.forwarding_cltv_delta=}")
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data = htlc.cltv_abs.to_bytes(4, byteorder="big") + outgoing_chan_upd_message
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raise OnionRoutingFailure(code=OnionFailureCode.INCORRECT_CLTV_EXPIRY, data=data)
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if htlc.cltv_abs - lnutil.MIN_FINAL_CLTV_DELTA_ACCEPTED <= local_height \
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or next_cltv_abs <= local_height:
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raise OnionRoutingFailure(code=OnionFailureCode.EXPIRY_TOO_SOON, data=outgoing_chan_upd_message)
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if max(htlc.cltv_abs, next_cltv_abs) > local_height + lnutil.NBLOCK_CLTV_DELTA_TOO_FAR_INTO_FUTURE:
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raise OnionRoutingFailure(code=OnionFailureCode.EXPIRY_TOO_FAR, data=b'')
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forwarding_fees = fee_for_edge_msat(
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forwarded_amount_msat=next_amount_msat_htlc,
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fee_base_msat=next_chan.forwarding_fee_base_msat,
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fee_proportional_millionths=next_chan.forwarding_fee_proportional_millionths)
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if htlc.amount_msat - next_amount_msat_htlc < forwarding_fees:
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data = next_amount_msat_htlc.to_bytes(8, byteorder="big") + outgoing_chan_upd_message
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raise OnionRoutingFailure(code=OnionFailureCode.FEE_INSUFFICIENT, data=data)
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if self._maybe_refuse_to_forward_htlc_that_corresponds_to_payreq_we_created(htlc.payment_hash):
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log_fail_reason(f"RHASH corresponds to payreq we created")
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raise OnionRoutingFailure(code=OnionFailureCode.TEMPORARY_NODE_FAILURE, data=b'')
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self.logger.info(
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f"maybe_forward_htlc. will forward HTLC: inc_chan={incoming_chan.short_channel_id}. inc_htlc={str(htlc)}. "
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f"next_chan={next_chan.get_id_for_log()}.")
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next_peer = self.lnworker.peers.get(next_chan.node_id)
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if next_peer is None:
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log_fail_reason(f"next_peer offline ({next_chan.node_id.hex()})")
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raise OnionRoutingFailure(code=OnionFailureCode.TEMPORARY_CHANNEL_FAILURE, data=outgoing_chan_upd_message)
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try:
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next_htlc = next_peer.send_htlc(
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chan=next_chan,
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payment_hash=htlc.payment_hash,
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amount_msat=next_amount_msat_htlc,
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cltv_abs=next_cltv_abs,
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onion=processed_onion.next_packet,
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)
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except BaseException as e:
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log_fail_reason(f"error sending message to next_peer={next_chan.node_id.hex()}")
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raise OnionRoutingFailure(code=OnionFailureCode.TEMPORARY_CHANNEL_FAILURE, data=outgoing_chan_upd_message)
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htlc_key = serialize_htlc_key(next_chan.get_scid_or_local_alias(), next_htlc.htlc_id)
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return htlc_key
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@log_exceptions
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async def maybe_forward_trampoline(
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self, *,
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payment_hash: bytes,
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inc_cltv_abs: int,
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outer_onion: ProcessedOnionPacket,
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trampoline_onion: ProcessedOnionPacket,
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fw_payment_key: str,
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) -> None:
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forwarding_enabled = self.network.config.EXPERIMENTAL_LN_FORWARD_PAYMENTS
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forwarding_trampoline_enabled = self.network.config.EXPERIMENTAL_LN_FORWARD_TRAMPOLINE_PAYMENTS
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if not (forwarding_enabled and forwarding_trampoline_enabled):
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self.logger.info(f"trampoline forwarding is disabled. failing htlc.")
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raise OnionRoutingFailure(code=OnionFailureCode.PERMANENT_CHANNEL_FAILURE, data=b'')
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payload = trampoline_onion.hop_data.payload
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payment_data = payload.get('payment_data')
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try:
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payment_secret = payment_data['payment_secret'] if payment_data else os.urandom(32)
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outgoing_node_id = payload["outgoing_node_id"]["outgoing_node_id"]
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amt_to_forward = payload["amt_to_forward"]["amt_to_forward"]
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out_cltv_abs = payload["outgoing_cltv_value"]["outgoing_cltv_value"]
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if "invoice_features" in payload:
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self.logger.info('forward_trampoline: legacy')
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next_trampoline_onion = None
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invoice_features = payload["invoice_features"]["invoice_features"]
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invoice_routing_info = payload["invoice_routing_info"]["invoice_routing_info"]
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r_tags = decode_routing_info(invoice_routing_info)
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self.logger.info(f'r_tags {r_tags}')
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# TODO legacy mpp payment, use total_msat from trampoline onion
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else:
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self.logger.info('forward_trampoline: end-to-end')
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invoice_features = LnFeatures.BASIC_MPP_OPT
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next_trampoline_onion = trampoline_onion.next_packet
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r_tags = []
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except Exception as e:
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self.logger.exception('')
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raise OnionRoutingFailure(code=OnionFailureCode.INVALID_ONION_PAYLOAD, data=b'\x00\x00\x00')
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if self._maybe_refuse_to_forward_htlc_that_corresponds_to_payreq_we_created(payment_hash):
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self.logger.debug(
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f"maybe_forward_trampoline. will FAIL HTLC(s). "
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f"RHASH corresponds to payreq we created. {payment_hash.hex()=}")
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raise OnionRoutingFailure(code=OnionFailureCode.TEMPORARY_NODE_FAILURE, data=b'')
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# these are the fee/cltv paid by the sender
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# pay_to_node will raise if they are not sufficient
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total_msat = outer_onion.hop_data.payload["payment_data"]["total_msat"]
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budget = PaymentFeeBudget(
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fee_msat=total_msat - amt_to_forward,
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cltv=inc_cltv_abs - out_cltv_abs,
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)
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self.logger.info(f'trampoline forwarding. budget={budget}')
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self.logger.info(f'trampoline forwarding. {inc_cltv_abs=}, {out_cltv_abs=}')
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# To convert abs vs rel cltvs, we need to guess blockheight used by original sender as "current blockheight".
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# Blocks might have been mined since.
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# - if we skew towards the past, we decrease our own cltv_budget accordingly (which is ok)
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# - if we skew towards the future, we decrease the cltv_budget for the subsequent nodes in the path,
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# which can result in them failing the payment.
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# So we skew towards the past and guess that there has been 1 new block mined since the payment began:
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local_height_of_onion_creator = self.network.get_local_height() - 1
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cltv_budget_for_rest_of_route = out_cltv_abs - local_height_of_onion_creator
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if budget.fee_msat < 1000:
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raise OnionRoutingFailure(code=OnionFailureCode.TRAMPOLINE_FEE_INSUFFICIENT, data=b'')
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if budget.cltv < 576:
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raise OnionRoutingFailure(code=OnionFailureCode.TRAMPOLINE_EXPIRY_TOO_SOON, data=b'')
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# do we have a connection to the node?
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next_peer = self.lnworker.peers.get(outgoing_node_id)
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if next_peer and next_peer.accepts_zeroconf():
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self.logger.info(f'JIT: found next_peer')
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for next_chan in next_peer.channels.values():
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if next_chan.can_pay(amt_to_forward):
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# todo: detect if we can do mpp
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self.logger.info(f'jit: next_chan can pay')
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break
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else:
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scid_alias = self.lnworker._scid_alias_of_node(next_peer.pubkey)
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route = [RouteEdge(
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start_node=next_peer.pubkey,
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end_node=outgoing_node_id,
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short_channel_id=scid_alias,
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fee_base_msat=0,
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fee_proportional_millionths=0,
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cltv_delta=144,
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node_features=0
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)]
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next_onion, amount_msat, cltv_abs, session_key = self.create_onion_for_route(
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route=route,
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amount_msat=amt_to_forward,
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total_msat=amt_to_forward,
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payment_hash=payment_hash,
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min_final_cltv_delta=cltv_budget_for_rest_of_route,
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payment_secret=payment_secret,
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trampoline_onion=next_trampoline_onion,
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)
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await self.lnworker.open_channel_just_in_time(
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next_peer=next_peer,
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next_amount_msat_htlc=amt_to_forward,
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next_cltv_abs=cltv_abs,
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payment_hash=payment_hash,
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next_onion=next_onion)
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return
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try:
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await self.lnworker.pay_to_node(
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node_pubkey=outgoing_node_id,
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payment_hash=payment_hash,
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payment_secret=payment_secret,
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amount_to_pay=amt_to_forward,
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min_final_cltv_delta=cltv_budget_for_rest_of_route,
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r_tags=r_tags,
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invoice_features=invoice_features,
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fwd_trampoline_onion=next_trampoline_onion,
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budget=budget,
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attempts=100,
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fw_payment_key=fw_payment_key,
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)
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except OnionRoutingFailure as e:
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raise
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except FeeBudgetExceeded:
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raise OnionRoutingFailure(code=OnionFailureCode.TRAMPOLINE_FEE_INSUFFICIENT, data=b'')
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except PaymentFailure as e:
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self.logger.debug(
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f"maybe_forward_trampoline. PaymentFailure for {payment_hash.hex()=}, {payment_secret.hex()=}: {e!r}")
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raise OnionRoutingFailure(code=OnionFailureCode.UNKNOWN_NEXT_PEER, data=b'')
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def _maybe_refuse_to_forward_htlc_that_corresponds_to_payreq_we_created(self, payment_hash: bytes) -> bool:
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"""Returns True if the HTLC should be failed.
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We must not forward HTLCs with a matching payment_hash to a payment request we created.
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Example attack:
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- Bob creates payment request with HASH1, for 1 BTC; and gives the payreq to Alice
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- Alice sends htlc A->B->C, for 1 sat, with HASH1
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- Bob must not release the preimage of HASH1
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"""
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payment_info = self.lnworker.get_payment_info(payment_hash)
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is_our_payreq = payment_info and payment_info.direction == RECEIVED
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# note: If we don't have the preimage for a payment request, then it must be a hold invoice.
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# Hold invoices are created by other parties (e.g. a counterparty initiating a submarine swap),
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# and it is the other party choosing the payment_hash. If we failed HTLCs with payment_hashes colliding
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# with hold invoices, then a party that can make us save a hold invoice for an arbitrary hash could
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# also make us fail arbitrary HTLCs.
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return bool(is_our_payreq and self.lnworker.get_preimage(payment_hash))
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def check_accepted_htlc(
|
||||
self, *,
|
||||
chan: Channel,
|
||||
@@ -2502,7 +2184,7 @@ class Peer(Logger, EventListener):
|
||||
return None, None
|
||||
# use the htlc key if we are forwarding
|
||||
payment_key = serialize_htlc_key(chan.get_scid_or_local_alias(), htlc.htlc_id)
|
||||
callback = lambda: self.maybe_forward_htlc(
|
||||
callback = lambda: self.lnworker.maybe_forward_htlc(
|
||||
incoming_chan=chan,
|
||||
htlc=htlc,
|
||||
processed_onion=processed_onion)
|
||||
@@ -2572,7 +2254,7 @@ class Peer(Logger, EventListener):
|
||||
already_forwarded=already_forwarded,
|
||||
)
|
||||
else:
|
||||
callback = lambda: self.maybe_forward_trampoline(
|
||||
callback = lambda: self.lnworker.maybe_forward_trampoline(
|
||||
payment_hash=payment_hash,
|
||||
inc_cltv_abs=htlc.cltv_abs, # TODO: use max or enforce same value across mpp parts
|
||||
outer_onion=processed_onion,
|
||||
|
||||
@@ -32,7 +32,7 @@ from .i18n import _
|
||||
from .json_db import stored_in
|
||||
from .channel_db import UpdateStatus, ChannelDBNotLoaded, get_mychannel_info, get_mychannel_policy
|
||||
|
||||
from . import constants, util
|
||||
from . import constants, util, lnutil
|
||||
from .util import (
|
||||
profiler, OldTaskGroup, ESocksProxy, NetworkRetryManager, JsonRPCClient, NotEnoughFunds, EventListener,
|
||||
event_listener, bfh, InvoiceError, resolve_dns_srv, is_ip_address, log_exceptions, ignore_exceptions,
|
||||
@@ -71,17 +71,21 @@ from .lnutil import (
|
||||
NBLOCK_CLTV_DELTA_TOO_FAR_INTO_FUTURE, GossipForwardingMessage, MIN_FUNDING_SAT,
|
||||
RecvMPPResolution, ReceivedMPPStatus,
|
||||
)
|
||||
from .lnonion import decode_onion_error, OnionFailureCode, OnionRoutingFailure, OnionPacket
|
||||
from .lnonion import (
|
||||
decode_onion_error, OnionFailureCode, OnionRoutingFailure, OnionPacket,
|
||||
ProcessedOnionPacket, calc_hops_data_for_payment, new_onion_packet,
|
||||
)
|
||||
from .lnmsg import decode_msg
|
||||
from .lnrouter import (
|
||||
RouteEdge, LNPaymentRoute, LNPaymentPath, is_route_within_budget, NoChannelPolicy, LNPathInconsistent
|
||||
RouteEdge, LNPaymentRoute, LNPaymentPath, is_route_within_budget, NoChannelPolicy,
|
||||
LNPathInconsistent, fee_for_edge_msat,
|
||||
)
|
||||
from .lnwatcher import LNWatcher
|
||||
from .submarine_swaps import SwapManager
|
||||
from .mpp_split import suggest_splits, SplitConfigRating
|
||||
from .trampoline import (
|
||||
create_trampoline_route_and_onion, is_legacy_relay, trampolines_by_id, hardcoded_trampoline_nodes,
|
||||
is_hardcoded_trampoline
|
||||
is_hardcoded_trampoline, decode_routing_info
|
||||
)
|
||||
|
||||
if TYPE_CHECKING:
|
||||
@@ -3349,6 +3353,323 @@ class LNWallet(LNWorker):
|
||||
util.trigger_callback('channels_updated', self.wallet)
|
||||
self.lnwatcher.add_channel(cb)
|
||||
|
||||
async def maybe_forward_htlc(
|
||||
self, *,
|
||||
incoming_chan: Channel,
|
||||
htlc: UpdateAddHtlc,
|
||||
processed_onion: ProcessedOnionPacket,
|
||||
) -> str:
|
||||
|
||||
# Forward HTLC
|
||||
# FIXME: there are critical safety checks MISSING here
|
||||
# - for example; atm we forward first and then persist "forwarding_info",
|
||||
# so if we segfault in-between and restart, we might forward an HTLC twice...
|
||||
# (same for trampoline forwarding)
|
||||
# - we could check for the exposure to dust HTLCs, see:
|
||||
# https://github.com/ACINQ/eclair/pull/1985
|
||||
|
||||
def log_fail_reason(reason: str):
|
||||
self.logger.debug(
|
||||
f"_maybe_forward_htlc. will FAIL HTLC: inc_chan={incoming_chan.get_id_for_log()}. "
|
||||
f"{reason}. inc_htlc={str(htlc)}. onion_payload={processed_onion.hop_data.payload}")
|
||||
|
||||
forwarding_enabled = self.network.config.EXPERIMENTAL_LN_FORWARD_PAYMENTS
|
||||
if not forwarding_enabled:
|
||||
log_fail_reason("forwarding is disabled")
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.PERMANENT_CHANNEL_FAILURE, data=b'')
|
||||
chain = self.network.blockchain()
|
||||
if chain.is_tip_stale():
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.TEMPORARY_NODE_FAILURE, data=b'')
|
||||
try:
|
||||
_next_chan_scid = processed_onion.hop_data.payload["short_channel_id"]["short_channel_id"] # type: bytes
|
||||
next_chan_scid = ShortChannelID(_next_chan_scid)
|
||||
except Exception:
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.INVALID_ONION_PAYLOAD, data=b'\x00\x00\x00')
|
||||
try:
|
||||
next_amount_msat_htlc = processed_onion.hop_data.payload["amt_to_forward"]["amt_to_forward"]
|
||||
except Exception:
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.INVALID_ONION_PAYLOAD, data=b'\x00\x00\x00')
|
||||
try:
|
||||
next_cltv_abs = processed_onion.hop_data.payload["outgoing_cltv_value"]["outgoing_cltv_value"]
|
||||
except Exception:
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.INVALID_ONION_PAYLOAD, data=b'\x00\x00\x00')
|
||||
|
||||
next_chan = self.get_channel_by_short_id(next_chan_scid)
|
||||
|
||||
if self.features.supports(LnFeatures.OPTION_ZEROCONF_OPT):
|
||||
next_peer = self.get_peer_by_static_jit_scid_alias(next_chan_scid)
|
||||
else:
|
||||
next_peer = None
|
||||
|
||||
if not next_chan and next_peer and next_peer.accepts_zeroconf():
|
||||
# check if an already existing channel can be used.
|
||||
# todo: split the payment
|
||||
for next_chan in next_peer.channels.values():
|
||||
if next_chan.can_pay(next_amount_msat_htlc):
|
||||
break
|
||||
else:
|
||||
return await self.open_channel_just_in_time(
|
||||
next_peer=next_peer,
|
||||
next_amount_msat_htlc=next_amount_msat_htlc,
|
||||
next_cltv_abs=next_cltv_abs,
|
||||
payment_hash=htlc.payment_hash,
|
||||
next_onion=processed_onion.next_packet)
|
||||
|
||||
local_height = chain.height()
|
||||
if next_chan is None:
|
||||
log_fail_reason(f"cannot find next_chan {next_chan_scid}")
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.UNKNOWN_NEXT_PEER, data=b'')
|
||||
outgoing_chan_upd = next_chan.get_outgoing_gossip_channel_update(scid=next_chan_scid)[2:]
|
||||
outgoing_chan_upd_len = len(outgoing_chan_upd).to_bytes(2, byteorder="big")
|
||||
outgoing_chan_upd_message = outgoing_chan_upd_len + outgoing_chan_upd
|
||||
if not next_chan.can_send_update_add_htlc():
|
||||
log_fail_reason(
|
||||
f"next_chan {next_chan.get_id_for_log()} cannot send ctx updates. "
|
||||
f"chan state {next_chan.get_state()!r}, peer state: {next_chan.peer_state!r}")
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.TEMPORARY_CHANNEL_FAILURE, data=outgoing_chan_upd_message)
|
||||
if not next_chan.can_pay(next_amount_msat_htlc):
|
||||
log_fail_reason(f"transient error (likely due to insufficient funds): not next_chan.can_pay(amt)")
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.TEMPORARY_CHANNEL_FAILURE, data=outgoing_chan_upd_message)
|
||||
if htlc.cltv_abs - next_cltv_abs < next_chan.forwarding_cltv_delta:
|
||||
log_fail_reason(
|
||||
f"INCORRECT_CLTV_EXPIRY. "
|
||||
f"{htlc.cltv_abs=} - {next_cltv_abs=} < {next_chan.forwarding_cltv_delta=}")
|
||||
data = htlc.cltv_abs.to_bytes(4, byteorder="big") + outgoing_chan_upd_message
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.INCORRECT_CLTV_EXPIRY, data=data)
|
||||
if htlc.cltv_abs - lnutil.MIN_FINAL_CLTV_DELTA_ACCEPTED <= local_height \
|
||||
or next_cltv_abs <= local_height:
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.EXPIRY_TOO_SOON, data=outgoing_chan_upd_message)
|
||||
if max(htlc.cltv_abs, next_cltv_abs) > local_height + lnutil.NBLOCK_CLTV_DELTA_TOO_FAR_INTO_FUTURE:
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.EXPIRY_TOO_FAR, data=b'')
|
||||
forwarding_fees = fee_for_edge_msat(
|
||||
forwarded_amount_msat=next_amount_msat_htlc,
|
||||
fee_base_msat=next_chan.forwarding_fee_base_msat,
|
||||
fee_proportional_millionths=next_chan.forwarding_fee_proportional_millionths)
|
||||
if htlc.amount_msat - next_amount_msat_htlc < forwarding_fees:
|
||||
data = next_amount_msat_htlc.to_bytes(8, byteorder="big") + outgoing_chan_upd_message
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.FEE_INSUFFICIENT, data=data)
|
||||
if self._maybe_refuse_to_forward_htlc_that_corresponds_to_payreq_we_created(htlc.payment_hash):
|
||||
log_fail_reason(f"RHASH corresponds to payreq we created")
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.TEMPORARY_NODE_FAILURE, data=b'')
|
||||
self.logger.info(
|
||||
f"maybe_forward_htlc. will forward HTLC: inc_chan={incoming_chan.short_channel_id}. inc_htlc={str(htlc)}. "
|
||||
f"next_chan={next_chan.get_id_for_log()}.")
|
||||
|
||||
next_peer = self.peers.get(next_chan.node_id)
|
||||
if next_peer is None:
|
||||
log_fail_reason(f"next_peer offline ({next_chan.node_id.hex()})")
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.TEMPORARY_CHANNEL_FAILURE, data=outgoing_chan_upd_message)
|
||||
try:
|
||||
next_htlc = next_peer.send_htlc(
|
||||
chan=next_chan,
|
||||
payment_hash=htlc.payment_hash,
|
||||
amount_msat=next_amount_msat_htlc,
|
||||
cltv_abs=next_cltv_abs,
|
||||
onion=processed_onion.next_packet,
|
||||
)
|
||||
except BaseException as e:
|
||||
log_fail_reason(f"error sending message to next_peer={next_chan.node_id.hex()}")
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.TEMPORARY_CHANNEL_FAILURE, data=outgoing_chan_upd_message)
|
||||
|
||||
htlc_key = serialize_htlc_key(next_chan.get_scid_or_local_alias(), next_htlc.htlc_id)
|
||||
return htlc_key
|
||||
|
||||
@log_exceptions
|
||||
async def maybe_forward_trampoline(
|
||||
self, *,
|
||||
payment_hash: bytes,
|
||||
inc_cltv_abs: int,
|
||||
outer_onion: ProcessedOnionPacket,
|
||||
trampoline_onion: ProcessedOnionPacket,
|
||||
fw_payment_key: str,
|
||||
) -> None:
|
||||
|
||||
forwarding_enabled = self.network.config.EXPERIMENTAL_LN_FORWARD_PAYMENTS
|
||||
forwarding_trampoline_enabled = self.network.config.EXPERIMENTAL_LN_FORWARD_TRAMPOLINE_PAYMENTS
|
||||
if not (forwarding_enabled and forwarding_trampoline_enabled):
|
||||
self.logger.info(f"trampoline forwarding is disabled. failing htlc.")
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.PERMANENT_CHANNEL_FAILURE, data=b'')
|
||||
payload = trampoline_onion.hop_data.payload
|
||||
payment_data = payload.get('payment_data')
|
||||
try:
|
||||
payment_secret = payment_data['payment_secret'] if payment_data else os.urandom(32)
|
||||
outgoing_node_id = payload["outgoing_node_id"]["outgoing_node_id"]
|
||||
amt_to_forward = payload["amt_to_forward"]["amt_to_forward"]
|
||||
out_cltv_abs = payload["outgoing_cltv_value"]["outgoing_cltv_value"]
|
||||
if "invoice_features" in payload:
|
||||
self.logger.info('forward_trampoline: legacy')
|
||||
next_trampoline_onion = None
|
||||
invoice_features = payload["invoice_features"]["invoice_features"]
|
||||
invoice_routing_info = payload["invoice_routing_info"]["invoice_routing_info"]
|
||||
r_tags = decode_routing_info(invoice_routing_info)
|
||||
self.logger.info(f'r_tags {r_tags}')
|
||||
# TODO legacy mpp payment, use total_msat from trampoline onion
|
||||
else:
|
||||
self.logger.info('forward_trampoline: end-to-end')
|
||||
invoice_features = LnFeatures.BASIC_MPP_OPT
|
||||
next_trampoline_onion = trampoline_onion.next_packet
|
||||
r_tags = []
|
||||
except Exception as e:
|
||||
self.logger.exception('')
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.INVALID_ONION_PAYLOAD, data=b'\x00\x00\x00')
|
||||
|
||||
if self._maybe_refuse_to_forward_htlc_that_corresponds_to_payreq_we_created(payment_hash):
|
||||
self.logger.debug(
|
||||
f"maybe_forward_trampoline. will FAIL HTLC(s). "
|
||||
f"RHASH corresponds to payreq we created. {payment_hash.hex()=}")
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.TEMPORARY_NODE_FAILURE, data=b'')
|
||||
|
||||
# these are the fee/cltv paid by the sender
|
||||
# pay_to_node will raise if they are not sufficient
|
||||
total_msat = outer_onion.hop_data.payload["payment_data"]["total_msat"]
|
||||
budget = PaymentFeeBudget(
|
||||
fee_msat=total_msat - amt_to_forward,
|
||||
cltv=inc_cltv_abs - out_cltv_abs,
|
||||
)
|
||||
self.logger.info(f'trampoline forwarding. budget={budget}')
|
||||
self.logger.info(f'trampoline forwarding. {inc_cltv_abs=}, {out_cltv_abs=}')
|
||||
# To convert abs vs rel cltvs, we need to guess blockheight used by original sender as "current blockheight".
|
||||
# Blocks might have been mined since.
|
||||
# - if we skew towards the past, we decrease our own cltv_budget accordingly (which is ok)
|
||||
# - if we skew towards the future, we decrease the cltv_budget for the subsequent nodes in the path,
|
||||
# which can result in them failing the payment.
|
||||
# So we skew towards the past and guess that there has been 1 new block mined since the payment began:
|
||||
local_height_of_onion_creator = self.network.get_local_height() - 1
|
||||
cltv_budget_for_rest_of_route = out_cltv_abs - local_height_of_onion_creator
|
||||
|
||||
if budget.fee_msat < 1000:
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.TRAMPOLINE_FEE_INSUFFICIENT, data=b'')
|
||||
if budget.cltv < 576:
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.TRAMPOLINE_EXPIRY_TOO_SOON, data=b'')
|
||||
|
||||
# do we have a connection to the node?
|
||||
next_peer = self.peers.get(outgoing_node_id)
|
||||
if next_peer and next_peer.accepts_zeroconf():
|
||||
self.logger.info(f'JIT: found next_peer')
|
||||
for next_chan in next_peer.channels.values():
|
||||
if next_chan.can_pay(amt_to_forward):
|
||||
# todo: detect if we can do mpp
|
||||
self.logger.info(f'jit: next_chan can pay')
|
||||
break
|
||||
else:
|
||||
scid_alias = self._scid_alias_of_node(next_peer.pubkey)
|
||||
route = [RouteEdge(
|
||||
start_node=next_peer.pubkey,
|
||||
end_node=outgoing_node_id,
|
||||
short_channel_id=scid_alias,
|
||||
fee_base_msat=0,
|
||||
fee_proportional_millionths=0,
|
||||
cltv_delta=144,
|
||||
node_features=0
|
||||
)]
|
||||
next_onion, amount_msat, cltv_abs, session_key = self.create_onion_for_route(
|
||||
route=route,
|
||||
amount_msat=amt_to_forward,
|
||||
total_msat=amt_to_forward,
|
||||
payment_hash=payment_hash,
|
||||
min_final_cltv_delta=cltv_budget_for_rest_of_route,
|
||||
payment_secret=payment_secret,
|
||||
trampoline_onion=next_trampoline_onion,
|
||||
)
|
||||
await self.open_channel_just_in_time(
|
||||
next_peer=next_peer,
|
||||
next_amount_msat_htlc=amt_to_forward,
|
||||
next_cltv_abs=cltv_abs,
|
||||
payment_hash=payment_hash,
|
||||
next_onion=next_onion)
|
||||
return
|
||||
|
||||
try:
|
||||
await self.pay_to_node(
|
||||
node_pubkey=outgoing_node_id,
|
||||
payment_hash=payment_hash,
|
||||
payment_secret=payment_secret,
|
||||
amount_to_pay=amt_to_forward,
|
||||
min_final_cltv_delta=cltv_budget_for_rest_of_route,
|
||||
r_tags=r_tags,
|
||||
invoice_features=invoice_features,
|
||||
fwd_trampoline_onion=next_trampoline_onion,
|
||||
budget=budget,
|
||||
attempts=100,
|
||||
fw_payment_key=fw_payment_key,
|
||||
)
|
||||
except OnionRoutingFailure as e:
|
||||
raise
|
||||
except FeeBudgetExceeded:
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.TRAMPOLINE_FEE_INSUFFICIENT, data=b'')
|
||||
except PaymentFailure as e:
|
||||
self.logger.debug(
|
||||
f"maybe_forward_trampoline. PaymentFailure for {payment_hash.hex()=}, {payment_secret.hex()=}: {e!r}")
|
||||
raise OnionRoutingFailure(code=OnionFailureCode.UNKNOWN_NEXT_PEER, data=b'')
|
||||
|
||||
def _maybe_refuse_to_forward_htlc_that_corresponds_to_payreq_we_created(self, payment_hash: bytes) -> bool:
|
||||
"""Returns True if the HTLC should be failed.
|
||||
We must not forward HTLCs with a matching payment_hash to a payment request we created.
|
||||
Example attack:
|
||||
- Bob creates payment request with HASH1, for 1 BTC; and gives the payreq to Alice
|
||||
- Alice sends htlc A->B->C, for 1 sat, with HASH1
|
||||
- Bob must not release the preimage of HASH1
|
||||
"""
|
||||
payment_info = self.get_payment_info(payment_hash)
|
||||
is_our_payreq = payment_info and payment_info.direction == RECEIVED
|
||||
# note: If we don't have the preimage for a payment request, then it must be a hold invoice.
|
||||
# Hold invoices are created by other parties (e.g. a counterparty initiating a submarine swap),
|
||||
# and it is the other party choosing the payment_hash. If we failed HTLCs with payment_hashes colliding
|
||||
# with hold invoices, then a party that can make us save a hold invoice for an arbitrary hash could
|
||||
# also make us fail arbitrary HTLCs.
|
||||
return bool(is_our_payreq and self.get_preimage(payment_hash))
|
||||
|
||||
def create_onion_for_route(
|
||||
self, *,
|
||||
route: 'LNPaymentRoute',
|
||||
amount_msat: int,
|
||||
total_msat: int,
|
||||
payment_hash: bytes,
|
||||
min_final_cltv_delta: int,
|
||||
payment_secret: bytes,
|
||||
trampoline_onion: Optional[OnionPacket] = None,
|
||||
):
|
||||
# add features learned during "init" for direct neighbour:
|
||||
route[0].node_features |= self.features
|
||||
local_height = self.network.get_local_height()
|
||||
final_cltv_abs = local_height + min_final_cltv_delta
|
||||
hops_data, amount_msat, cltv_abs = calc_hops_data_for_payment(
|
||||
route,
|
||||
amount_msat,
|
||||
final_cltv_abs=final_cltv_abs,
|
||||
total_msat=total_msat,
|
||||
payment_secret=payment_secret)
|
||||
num_hops = len(hops_data)
|
||||
self.logger.info(f"pay len(route)={len(route)}")
|
||||
for i in range(len(route)):
|
||||
self.logger.info(f" {i}: edge={route[i].short_channel_id} hop_data={hops_data[i]!r}")
|
||||
assert final_cltv_abs <= cltv_abs, (final_cltv_abs, cltv_abs)
|
||||
session_key = os.urandom(32) # session_key
|
||||
# if we are forwarding a trampoline payment, add trampoline onion
|
||||
if trampoline_onion:
|
||||
self.logger.info(f'adding trampoline onion to final payload')
|
||||
trampoline_payload = hops_data[-1].payload
|
||||
trampoline_payload["trampoline_onion_packet"] = {
|
||||
"version": trampoline_onion.version,
|
||||
"public_key": trampoline_onion.public_key,
|
||||
"hops_data": trampoline_onion.hops_data,
|
||||
"hmac": trampoline_onion.hmac
|
||||
}
|
||||
if t_hops_data := trampoline_onion._debug_hops_data: # None if trampoline-forwarding
|
||||
t_route = trampoline_onion._debug_route
|
||||
assert t_route is not None
|
||||
self.logger.info(f"lnpeer.pay len(t_route)={len(t_route)}")
|
||||
for i in range(len(t_route)):
|
||||
self.logger.info(f" {i}: t_node={t_route[i].end_node.hex()} hop_data={t_hops_data[i]!r}")
|
||||
# create onion packet
|
||||
payment_path_pubkeys = [x.node_id for x in route]
|
||||
onion = new_onion_packet(payment_path_pubkeys, session_key, hops_data, associated_data=payment_hash) # must use another sessionkey
|
||||
self.logger.info(f"starting payment. len(route)={len(hops_data)}.")
|
||||
# create htlc
|
||||
if cltv_abs > local_height + lnutil.NBLOCK_CLTV_DELTA_TOO_FAR_INTO_FUTURE:
|
||||
raise PaymentFailure(f"htlc expiry too far into future. (in {cltv_abs-local_height} blocks)")
|
||||
return onion, amount_msat, cltv_abs, session_key
|
||||
|
||||
def save_forwarding_failure(
|
||||
self,
|
||||
payment_key: str,
|
||||
|
||||
@@ -347,6 +347,10 @@ class MockLNWallet(Logger, EventListener, NetworkRetryManager[LNPeerAddr]):
|
||||
current_target_feerate_per_kw = LNWallet.current_target_feerate_per_kw
|
||||
current_low_feerate_per_kw_srk_channel = LNWallet.current_low_feerate_per_kw_srk_channel
|
||||
maybe_cleanup_mpp = LNWallet.maybe_cleanup_mpp
|
||||
create_onion_for_route = LNWallet.create_onion_for_route
|
||||
maybe_forward_htlc = LNWallet.maybe_forward_htlc
|
||||
maybe_forward_trampoline = LNWallet.maybe_forward_trampoline
|
||||
_maybe_refuse_to_forward_htlc_that_corresponds_to_payreq_we_created = LNWallet._maybe_refuse_to_forward_htlc_that_corresponds_to_payreq_we_created
|
||||
|
||||
|
||||
class MockTransport:
|
||||
|
||||
Reference in New Issue
Block a user