AaronFiore/electrum
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Trampoline forwarding:

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- fix regression in create_routes:
   fwd_trampoline_onion was not added to the tuple
 - fix onion structure for e2e
 - maybe_fulfill_htlc:
   check the mpp_status of the outer onion,
   return trampoline_onion to be forwarded
This commit is contained in:
ThomasV
2021-03-03 20:36:48 +01:00
parent ba4d6bc8b3
commit 738411e32b
3 changed files with 70 additions and 59 deletions
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82
electrum/lnpeer.py
View File

@@ -1328,11 +1328,10 @@ class Peer(Logger):
util.trigger_callback('htlc_added', chan, htlc, RECEIVED)
def maybe_forward_htlc(
self,
*,
self, *,
htlc: UpdateAddHtlc,
processed_onion: ProcessedOnionPacket,
) -> Tuple[bytes, int]:
processed_onion: ProcessedOnionPacket) -> Tuple[bytes, int]:
# Forward HTLC
# FIXME: there are critical safety checks MISSING here
forwarding_enabled = self.network.config.get('lightning_forward_payments', False)
@@ -1414,9 +1413,9 @@ class Peer(Logger):
payload = trampoline_onion.hop_data.payload
payment_hash = htlc.payment_hash
payment_secret = os.urandom(32)
try:
outgoing_node_id = payload["outgoing_node_id"]["outgoing_node_id"]
payment_secret = payload["payment_data"]["payment_secret"]
amt_to_forward = payload["amt_to_forward"]["amt_to_forward"]
cltv_from_onion = payload["outgoing_cltv_value"]["outgoing_cltv_value"]
if "invoice_features" in payload:
@@ -1426,12 +1425,14 @@ class Peer(Logger):
invoice_routing_info = payload["invoice_routing_info"]["invoice_routing_info"]
else:
self.logger.info('forward_trampoline: end-to-end')
invoice_features = 0
invoice_features = LnFeatures.BASIC_MPP_OPT
next_trampoline_onion = trampoline_onion.next_packet
except Exception as e:
self.logger.exception('')
raise OnionRoutingFailure(code=OnionFailureCode.INVALID_ONION_PAYLOAD, data=b'\x00\x00\x00')
# these are the fee/cltv paid by the sender
# pay_to_node will raise if they are not sufficient
trampoline_cltv_delta = htlc.cltv_expiry - cltv_from_onion
trampoline_fee = htlc.amount_msat - amt_to_forward
@@ -1447,7 +1448,7 @@ class Peer(Logger):
r_tags=[],
t_tags=[],
invoice_features=invoice_features,
trampoline_onion=next_trampoline_onion,
fwd_trampoline_onion=next_trampoline_onion,
trampoline_fee=trampoline_fee,
trampoline_cltv_delta=trampoline_cltv_delta,
attempts=1)
@@ -1466,10 +1467,10 @@ class Peer(Logger):
chan: Channel,
htlc: UpdateAddHtlc,
processed_onion: ProcessedOnionPacket,
is_trampoline: bool = False) -> Optional[bytes]:
is_trampoline: bool = False) -> Tuple[Optional[bytes], Optional[bytes]]:
"""As a final recipient of an HTLC, decide if we should fulfill it.
Returns the preimage if yes, or None.
Return (preimage, trampoline_onion_packet) with at most a single element not None
"""
def log_fail_reason(reason: str):
self.logger.info(f"maybe_fulfill_htlc. will FAIL HTLC: chan {chan.short_channel_id}. "
@@ -1518,15 +1519,6 @@ class Peer(Logger):
code=OnionFailureCode.FINAL_INCORRECT_HTLC_AMOUNT,
data=htlc.amount_msat.to_bytes(8, byteorder="big"))
# if there is a trampoline_onion, perform the above checks on it
if processed_onion.trampoline_onion_packet:
return
info = self.lnworker.get_payment_info(htlc.payment_hash)
if info is None:
log_fail_reason(f"no payment_info found for RHASH {htlc.payment_hash.hex()}")
raise exc_incorrect_or_unknown_pd
preimage = self.lnworker.get_preimage(htlc.payment_hash)
try:
payment_secret_from_onion = processed_onion.hop_data.payload["payment_data"]["payment_secret"]
except:
@@ -1535,7 +1527,26 @@ class Peer(Logger):
log_fail_reason(f"'payment_secret' missing from onion")
raise exc_incorrect_or_unknown_pd
# TODO fail here if invoice has set PAYMENT_SECRET_REQ
else:
payment_secret_from_onion = None
mpp_status = self.lnworker.add_received_htlc(chan.short_channel_id, htlc, total_msat)
if mpp_status is None:
return None, None
if mpp_status is False:
log_fail_reason(f"MPP_TIMEOUT")
raise OnionRoutingFailure(code=OnionFailureCode.MPP_TIMEOUT, data=b'')
assert mpp_status is True
# if there is a trampoline_onion, maybe_fulfill_htlc will be called again
if processed_onion.trampoline_onion_packet:
return None, processed_onion.trampoline_onion_packet
info = self.lnworker.get_payment_info(htlc.payment_hash)
if info is None:
log_fail_reason(f"no payment_info found for RHASH {htlc.payment_hash.hex()}")
raise exc_incorrect_or_unknown_pd
preimage = self.lnworker.get_preimage(htlc.payment_hash)
if payment_secret_from_onion:
if payment_secret_from_onion != derive_payment_secret_from_payment_preimage(preimage):
log_fail_reason(f'incorrect payment secret {payment_secret_from_onion.hex()} != {derive_payment_secret_from_payment_preimage(preimage).hex()}')
raise exc_incorrect_or_unknown_pd
@@ -1543,15 +1554,7 @@ class Peer(Logger):
if not (invoice_msat is None or invoice_msat <= total_msat <= 2 * invoice_msat):
log_fail_reason(f"total_msat={total_msat} too different from invoice_msat={invoice_msat}")
raise exc_incorrect_or_unknown_pd
mpp_status = self.lnworker.add_received_htlc(chan.short_channel_id, htlc, total_msat)
if mpp_status is True:
self.logger.info(f"maybe_fulfill_htlc. will FULFILL HTLC: chan {chan.short_channel_id}. htlc={str(htlc)}")
return preimage
elif mpp_status is False:
log_fail_reason(f"MPP_TIMEOUT")
raise OnionRoutingFailure(code=OnionFailureCode.MPP_TIMEOUT, data=b'')
else:
return None
return preimage, None
def fulfill_htlc(self, chan: Channel, htlc_id: int, preimage: bytes):
self.logger.info(f"_fulfill_htlc. chan {chan.short_channel_id}. htlc_id {htlc_id}")
@@ -1835,16 +1838,14 @@ class Peer(Logger):
unfulfilled.pop(htlc_id)
def process_unfulfilled_htlc(
self,
*,
self, *,
chan: Channel,
htlc: UpdateAddHtlc,
forwarding_info: Tuple[str, int],
onion_packet_bytes: bytes,
onion_packet: OnionPacket,
) -> Tuple[Optional[bytes], Union[bool, None, Tuple[str, int]], Optional[bytes]]:
onion_packet: OnionPacket) -> Tuple[Optional[bytes], Union[bool, None, Tuple[str, int]], Optional[bytes]]:
"""
returns either preimage or fw_info or error_bytes or (None, None, None)
return (preimage, fw_info, error_bytes) with at most a single element that is not None
raise an OnionRoutingFailure if we need to fail the htlc
"""
payment_hash = htlc.payment_hash
@@ -1853,20 +1854,20 @@ class Peer(Logger):
payment_hash=payment_hash,
onion_packet_bytes=onion_packet_bytes)
if processed_onion.are_we_final:
preimage = self.maybe_fulfill_htlc(
preimage, trampoline_onion_packet = self.maybe_fulfill_htlc(
chan=chan,
htlc=htlc,
processed_onion=processed_onion)
# trampoline forwarding
if not preimage and processed_onion.trampoline_onion_packet:
if trampoline_onion_packet:
if not forwarding_info:
trampoline_onion = self.process_onion_packet(
processed_onion.trampoline_onion_packet,
trampoline_onion_packet,
payment_hash=htlc.payment_hash,
onion_packet_bytes=onion_packet_bytes,
is_trampoline=True)
if trampoline_onion.are_we_final:
preimage = self.maybe_fulfill_htlc(
preimage, _ = self.maybe_fulfill_htlc(
chan=chan,
htlc=htlc,
processed_onion=trampoline_onion,
@@ -1907,12 +1908,11 @@ class Peer(Logger):
def process_onion_packet(
self,
onion_packet: OnionPacket,
*,
onion_packet: OnionPacket, *,
payment_hash: bytes,
onion_packet_bytes: bytes,
is_trampoline: bool = False,
) -> ProcessedOnionPacket:
is_trampoline: bool = False) -> ProcessedOnionPacket:
failure_data = sha256(onion_packet_bytes)
try:
processed_onion = process_onion_packet(

12
electrum/lnworker.py
View File

@@ -1059,11 +1059,11 @@ class LNWallet(LNWorker):
invoice_features: int,
attempts: int = 1,
full_path: LNPaymentPath = None,
trampoline_onion=None,
fwd_trampoline_onion=None,
trampoline_fee=None,
trampoline_cltv_delta=None) -> None:
if trampoline_onion:
if fwd_trampoline_onion:
# todo: compare to the fee of the actual route we found
if trampoline_fee < 1000:
raise OnionRoutingFailure(code=OnionFailureCode.TRAMPOLINE_FEE_INSUFFICIENT, data=b'')
@@ -1089,7 +1089,8 @@ class LNWallet(LNWorker):
invoice_features=invoice_features,
full_path=full_path,
payment_hash=payment_hash,
payment_secret=payment_secret))
payment_secret=payment_secret,
fwd_trampoline_onion=fwd_trampoline_onion))
# 2. send htlcs
for route, amount_msat, total_msat, cltv_delta, bucket_payment_secret, trampoline_onion in routes:
await self.pay_to_route(
@@ -1301,6 +1302,7 @@ class LNWallet(LNWorker):
invoice_features: int,
payment_hash,
payment_secret,
fwd_trampoline_onion=None,
full_path: LNPaymentPath = None) -> Sequence[Tuple[LNPaymentRoute, int]]:
"""Creates multiple routes for splitting a payment over the available
@@ -1364,7 +1366,7 @@ class LNWallet(LNWorker):
r_tags=r_tags, t_tags=t_tags,
invoice_features=invoice_features,
outgoing_channel=None, full_path=full_path)
routes = [(route, amount_msat, final_total_msat, min_cltv_expiry, payment_secret, None)]
routes = [(route, amount_msat, final_total_msat, min_cltv_expiry, payment_secret, fwd_trampoline_onion)]
except NoPathFound:
if not invoice_features.supports(LnFeatures.BASIC_MPP_OPT):
raise
@@ -1438,7 +1440,7 @@ class LNWallet(LNWorker):
r_tags=r_tags, t_tags=t_tags,
invoice_features=invoice_features,
outgoing_channel=channel, full_path=None)
routes.append((route, part_amount_msat, final_total_msat, min_cltv_expiry, payment_secret, None))
routes.append((route, part_amount_msat, final_total_msat, min_cltv_expiry, payment_secret, fwd_trampoline_onion))
self.logger.info(f"found acceptable split configuration: {list(s[0].values())} rating: {s[1]}")
break
except NoPathFound:

35
electrum/trampoline.py
View File

@@ -127,6 +127,7 @@ def create_trampoline_route(
invoice_routing_info = encode_routing_info(r_tags)
route[-1].invoice_routing_info = invoice_routing_info
route[-1].invoice_features = invoice_features
route[-1].outgoing_node_id = invoice_pubkey
else:
if t_tag:
pubkey, feebase, feerate, cltv = t_tag
@@ -139,7 +140,7 @@ def create_trampoline_route(
fee_proportional_millionths=feerate,
cltv_expiry_delta=cltv,
node_features=trampoline_features))
# Fake edge (not part of actual route, needed by calc_hops_data)
# Final edge (not part of the route if payment is legacy, but eclair requires an encrypted blob)
route.append(
TrampolineEdge(
start_node=route[-1].end_node,
@@ -171,22 +172,30 @@ def create_trampoline_onion(*, route, amount_msat, final_cltv, total_msat, payme
# detect trampoline hops.
payment_path_pubkeys = [x.node_id for x in route]
num_hops = len(payment_path_pubkeys)
for i in range(num_hops-1):
for i in range(num_hops):
route_edge = route[i]
next_edge = route[i+1]
assert route_edge.is_trampoline()
assert next_edge.is_trampoline()
hops_data[i].payload["outgoing_node_id"] = {"outgoing_node_id":next_edge.node_id}
if route_edge.invoice_features:
hops_data[i].payload["invoice_features"] = {"invoice_features":route_edge.invoice_features}
if route_edge.invoice_routing_info:
hops_data[i].payload["invoice_routing_info"] = {"invoice_routing_info":route_edge.invoice_routing_info}
# only for final, legacy
if i == num_hops - 2:
hops_data[i].payload["payment_data"] = {
payload = hops_data[i].payload
if i < num_hops - 1:
payload.pop('short_channel_id')
next_edge = route[i+1]
assert next_edge.is_trampoline()
hops_data[i].payload["outgoing_node_id"] = {"outgoing_node_id":next_edge.node_id}
# only for final
if i == num_hops - 1:
payload["payment_data"] = {
"payment_secret":payment_secret,
"total_msat": total_msat,
"total_msat": total_msat
}
# legacy
if i == num_hops - 2 and route_edge.invoice_features:
payload["invoice_features"] = {"invoice_features":route_edge.invoice_features}
payload["invoice_routing_info"] = {"invoice_routing_info":route_edge.invoice_routing_info}
payload["payment_data"] = {
"payment_secret":payment_secret,
"total_msat": total_msat
}
_logger.info(f'payload {i} {payload}')
trampoline_session_key = os.urandom(32)
trampoline_onion = new_onion_packet(payment_path_pubkeys, trampoline_session_key, hops_data, associated_data=payment_hash, trampoline=True)
return trampoline_onion, amount_msat, cltv