commit 259dacd56f8d272738682875f7a88b037981fecd
parent 2da90add8f3df5f4302631abcecc46100d0cc53f
Author: ThomasV <thomasv@electrum.org>
Date: Sat, 27 Feb 2021 09:45:19 +0100
Trampoline MPP aggregation:
- trampoline node is the final recipient of MPP
- each trampoline receives a bucket of HTLCs
- if a HTLC from a bucket fails, wait for the entire bucket to fail
- move trampoline route and onion code into trampoline module
Diffstat:
4 files changed, 406 insertions(+), 282 deletions(-)
diff --git a/electrum/lnpeer.py b/electrum/lnpeer.py
@@ -1195,9 +1195,16 @@ class Peer(Logger):
sig_64, htlc_sigs = chan.sign_next_commitment()
self.send_message("commitment_signed", channel_id=chan.channel_id, signature=sig_64, num_htlcs=len(htlc_sigs), htlc_signature=b"".join(htlc_sigs))
- def pay(self, *, route: 'LNPaymentRoute', chan: Channel, amount_msat: int,
- total_msat: int, payment_hash: bytes, min_final_cltv_expiry: int,
- payment_secret: bytes = None, fwd_trampoline_onion=None) -> UpdateAddHtlc:
+ def pay(self, *,
+ route: 'LNPaymentRoute',
+ chan: Channel,
+ amount_msat: int,
+ total_msat: int,
+ payment_hash: bytes,
+ min_final_cltv_expiry: int,
+ payment_secret: bytes = None,
+ trampoline_onion=None) -> UpdateAddHtlc:
+
assert amount_msat > 0, "amount_msat is not greater zero"
assert len(route) > 0
if not chan.can_send_update_add_htlc():
@@ -1211,78 +1218,26 @@ class Peer(Logger):
amount_msat,
final_cltv,
total_msat=total_msat,
- payment_secret=payment_secret
- )
+ payment_secret=payment_secret)
+ num_hops = len(hops_data)
self.logger.info(f"lnpeer.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 <= cltv, (final_cltv, cltv)
session_key = os.urandom(32) # session_key
- # 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):
- route_edge = route[i]
- next_edge = route[i+1]
- if route_edge.is_trampoline():
- assert next_edge.is_trampoline()
- self.logger.info(f'trampoline hop at position {i}')
- 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:
- self.logger.info(f'adding payment secret for legacy trampoline')
- hops_data[i].payload["payment_data"] = {
- "payment_secret":payment_secret,
- "total_msat": amount_msat,
- }
-
# if we are forwarding a trampoline payment, add trampoline onion
- if fwd_trampoline_onion:
+ if trampoline_onion:
self.logger.info(f'adding trampoline onion to final payload')
trampoline_payload = hops_data[num_hops-2].payload
trampoline_payload["trampoline_onion_packet"] = {
- "version": fwd_trampoline_onion.version,
- "public_key": fwd_trampoline_onion.public_key,
- "hops_data": fwd_trampoline_onion.hops_data,
- "hmac": fwd_trampoline_onion.hmac
+ "version": trampoline_onion.version,
+ "public_key": trampoline_onion.public_key,
+ "hops_data": trampoline_onion.hops_data,
+ "hmac": trampoline_onion.hmac
}
-
- # create trampoline onion
- for i in range(num_hops):
- route_edge = route[i]
- if route_edge.is_trampoline():
- self.logger.info(f'first trampoline hop at position {i}')
- self.logger.info(f'inner onion: {hops_data[i:]}')
- trampoline_session_key = os.urandom(32)
- trampoline_onion = new_onion_packet(payment_path_pubkeys[i:], trampoline_session_key, hops_data[i:], associated_data=payment_hash, trampoline=True)
- # drop hop_data
- payment_path_pubkeys = payment_path_pubkeys[:i]
- hops_data = hops_data[:i]
- # we must generate a different secret for the outer onion
- outer_payment_secret = os.urandom(32)
- # trampoline_payload is a final payload
- trampoline_payload = hops_data[i-1].payload
- p = trampoline_payload.pop('short_channel_id')
- amt_to_forward = trampoline_payload["amt_to_forward"]["amt_to_forward"]
- trampoline_payload["payment_data"] = {
- "payment_secret":outer_payment_secret,
- "total_msat": amt_to_forward
- }
- 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
- }
- break
# 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 > local_height + lnutil.NBLOCK_CLTV_EXPIRY_TOO_FAR_INTO_FUTURE:
diff --git a/electrum/lnworker.py b/electrum/lnworker.py
@@ -78,6 +78,7 @@ from .channel_db import get_mychannel_info, get_mychannel_policy
from .submarine_swaps import SwapManager
from .channel_db import ChannelInfo, Policy
from .mpp_split import suggest_splits
+from .trampoline import create_trampoline_route_and_onion
if TYPE_CHECKING:
from .network import Network
@@ -163,45 +164,6 @@ def trampolines_by_id():
is_hardcoded_trampoline = lambda node_id: node_id in trampolines_by_id().keys()
-# trampoline nodes are supposed to advertise their fee and cltv in node_update message
-TRAMPOLINE_FEES = [
- {
- 'fee_base_msat': 0,
- 'fee_proportional_millionths': 0,
- 'cltv_expiry_delta': 576,
- },
- {
- 'fee_base_msat': 1000,
- 'fee_proportional_millionths': 100,
- 'cltv_expiry_delta': 576,
- },
- {
- 'fee_base_msat': 3000,
- 'fee_proportional_millionths': 100,
- 'cltv_expiry_delta': 576,
- },
- {
- 'fee_base_msat': 5000,
- 'fee_proportional_millionths': 500,
- 'cltv_expiry_delta': 576,
- },
- {
- 'fee_base_msat': 7000,
- 'fee_proportional_millionths': 1000,
- 'cltv_expiry_delta': 576,
- },
- {
- 'fee_base_msat': 12000,
- 'fee_proportional_millionths': 3000,
- 'cltv_expiry_delta': 576,
- },
- {
- 'fee_base_msat': 100000,
- 'fee_proportional_millionths': 3000,
- 'cltv_expiry_delta': 576,
- },
-]
-
class PaymentInfo(NamedTuple):
payment_hash: bytes
@@ -658,7 +620,8 @@ class LNWallet(LNWorker):
self._channels[bfh(channel_id)] = Channel(c, sweep_address=self.sweep_address, lnworker=self)
self.sent_htlcs = defaultdict(asyncio.Queue) # type: Dict[bytes, asyncio.Queue[HtlcLog]]
- self.sent_htlcs_routes = dict() # (RHASH, scid, htlc_id) -> route, amount_for_receiver
+ self.sent_htlcs_routes = dict() # (RHASH, scid, htlc_id) -> route, payment_secret, amount_msat, bucket_msat
+ self.sent_buckets = defaultdict(set)
self.received_htlcs = dict() # RHASH -> mpp_status, htlc_set
self.swap_manager = SwapManager(wallet=self.wallet, lnworker=self)
@@ -1019,6 +982,8 @@ class LNWallet(LNWorker):
r_tags=decoded_invoice.get_routing_info('r'),
t_tags=decoded_invoice.get_routing_info('t'),
invoice_features=decoded_invoice.get_tag('9') or 0,
+ payment_hash=decoded_invoice.paymenthash,
+ payment_secret=decoded_invoice.payment_secret,
full_path=full_path)
@log_exceptions
@@ -1113,17 +1078,25 @@ class LNWallet(LNWorker):
# note: path-finding runs in a separate thread so that we don't block the asyncio loop
# graph updates might occur during the computation
routes = await run_in_thread(partial(
- self.create_routes_for_payment, amount_to_send, node_pubkey,
- min_cltv_expiry, r_tags, t_tags, invoice_features, full_path=full_path))
+ self.create_routes_for_payment,
+ amount_msat=amount_to_send,
+ invoice_pubkey=node_pubkey,
+ min_cltv_expiry=min_cltv_expiry,
+ r_tags=r_tags,
+ t_tags=t_tags,
+ invoice_features=invoice_features,
+ full_path=full_path,
+ payment_hash=payment_hash,
+ payment_secret=payment_secret))
# 2. send htlcs
- for route, amount_msat in routes:
+ for route, amount_msat, total_msat, cltv_delta, bucket_payment_secret, trampoline_onion in routes:
await self.pay_to_route(
route=route,
amount_msat=amount_msat,
- total_msat=amount_to_pay,
+ total_msat=total_msat,
payment_hash=payment_hash,
- payment_secret=payment_secret,
- min_cltv_expiry=min_cltv_expiry,
+ payment_secret=bucket_payment_secret,
+ min_cltv_expiry=cltv_delta,
trampoline_onion=trampoline_onion)
amount_inflight += amount_msat
util.trigger_callback('invoice_status', self.wallet, payment_hash.hex())
@@ -1165,8 +1138,11 @@ class LNWallet(LNWorker):
payment_hash=payment_hash,
min_final_cltv_expiry=min_cltv_expiry,
payment_secret=payment_secret,
- fwd_trampoline_onion=trampoline_onion)
- self.sent_htlcs_routes[(payment_hash, short_channel_id, htlc.htlc_id)] = route, amount_msat
+ trampoline_onion=trampoline_onion)
+
+ key = (payment_hash, short_channel_id, htlc.htlc_id)
+ self.sent_htlcs_routes[key] = route, payment_secret, amount_msat, total_msat
+ self.sent_buckets[payment_secret] = total_msat
util.trigger_callback('htlc_added', chan, htlc, SENT)
def handle_error_code_from_failed_htlc(self, htlc_log):
@@ -1293,16 +1269,6 @@ class LNWallet(LNWorker):
f"min_final_cltv_expiry: {addr.get_min_final_cltv_expiry()}"))
return addr
- def encode_routing_info(self, r_tags):
- import bitstring
- result = bitstring.BitArray()
- for route in r_tags:
- result.append(bitstring.pack('uint:8', len(route)))
- for step in route:
- pubkey, channel, feebase, feerate, cltv = step
- result.append(bitstring.BitArray(pubkey) + bitstring.BitArray(channel) + bitstring.pack('intbe:32', feebase) + bitstring.pack('intbe:32', feerate) + bitstring.pack('intbe:16', cltv))
- return result.tobytes()
-
def is_trampoline_peer(self, node_id: bytes) -> bool:
# until trampoline is advertised in lnfeatures, check against hardcoded list
if is_hardcoded_trampoline(node_id):
@@ -1318,178 +1284,150 @@ class LNWallet(LNWorker):
else:
return random.choice(list(hardcoded_trampoline_nodes().values())).pubkey
- def create_trampoline_route(
- self, amount_msat:int,
- min_cltv_expiry:int,
- invoice_pubkey:bytes,
- invoice_features:int,
- channels: List[Channel],
- r_tags, t_tags) -> LNPaymentRoute:
- """ return the route that leads to trampoline, and the trampoline fake edge"""
-
- invoice_features = LnFeatures(invoice_features)
-
- # We do not set trampoline_routing_opt in our invoices, because the spec is not ready
- # Do not use t_tags if the flag is set, because we the format is not decided yet
- if invoice_features.supports(LnFeatures.OPTION_TRAMPOLINE_ROUTING_OPT):
- is_legacy = False
- if len(r_tags) > 0 and len(r_tags[0]) == 1:
- pubkey, scid, feebase, feerate, cltv = r_tags[0][0]
- t_tag = pubkey, feebase, feerate, cltv
- else:
- t_tag = None
- elif len(t_tags) > 0:
- is_legacy = False
- t_tag = t_tags[0]
- else:
- is_legacy = True
-
- # fee level. the same fee is used for all trampolines
- if self.trampoline_fee_level < len(TRAMPOLINE_FEES):
- params = TRAMPOLINE_FEES[self.trampoline_fee_level]
- else:
- raise NoPathFound()
- # Find a trampoline. We assume we have a direct channel to trampoline
- for chan in channels:
- if not self.is_trampoline_peer(chan.node_id):
- continue
- trampoline_short_channel_id = chan.short_channel_id
- trampoline_node_id = chan.node_id
- # use attempt number to decide fee and second trampoline
- # we need a state with the list of nodes we have not tried
- # add optional second trampoline
- trampoline2 = None
- if is_legacy:
- for node_id in self.trampoline2_list:
- if node_id != trampoline_node_id:
- trampoline2 = node_id
- break
- # node_features is only used to determine is_tlv
- trampoline_features = LnFeatures.VAR_ONION_OPT
- # hop to trampoline
- route = [
- RouteEdge(
- node_id=trampoline_node_id,
- short_channel_id=trampoline_short_channel_id,
- fee_base_msat=0,
- fee_proportional_millionths=0,
- cltv_expiry_delta=0,
- node_features=trampoline_features)
- ]
- # trampoline hop
- route.append(
- TrampolineEdge(
- node_id=trampoline_node_id,
- fee_base_msat=params['fee_base_msat'],
- fee_proportional_millionths=params['fee_proportional_millionths'],
- cltv_expiry_delta=params['cltv_expiry_delta'],
- node_features=trampoline_features))
- if trampoline2:
- route.append(
- TrampolineEdge(
- node_id=trampoline2,
- fee_base_msat=params['fee_base_msat'],
- fee_proportional_millionths=params['fee_proportional_millionths'],
- cltv_expiry_delta=params['cltv_expiry_delta'],
- node_features=trampoline_features))
- # add routing info
- if is_legacy:
- invoice_routing_info = self.encode_routing_info(r_tags)
- route[-1].invoice_routing_info = invoice_routing_info
- route[-1].invoice_features = invoice_features
- else:
- if t_tag:
- pubkey, feebase, feerate, cltv = t_tag
- if route[-1].node_id != pubkey:
- route.append(
- TrampolineEdge(
- node_id=pubkey,
- fee_base_msat=feebase,
- fee_proportional_millionths=feerate,
- cltv_expiry_delta=cltv,
- node_features=trampoline_features))
- # Fake edge (not part of actual route, needed by calc_hops_data)
- route.append(
- TrampolineEdge(
- node_id=invoice_pubkey,
- fee_base_msat=0,
- fee_proportional_millionths=0,
- cltv_expiry_delta=0,
- node_features=trampoline_features))
- # check that we can pay amount and fees
- for edge in route[::-1]:
- amount_msat += edge.fee_for_edge(amount_msat)
- if not chan.can_pay(amount_msat, check_frozen=True):
- continue
- if not is_route_sane_to_use(route, amount_msat, min_cltv_expiry):
- continue
- break
- else:
- raise NoPathFound()
- self.logger.info(f'created route with trampoline: fee_level={self.trampoline_fee_level}, is legacy: {is_legacy}')
- self.logger.info(f'first trampoline: {trampoline_node_id.hex()}')
- self.logger.info(f'second trampoline: {trampoline2.hex() if trampoline2 else None}')
- self.logger.info(f'params: {params}')
- return route
-
@profiler
def create_routes_for_payment(
- self,
+ self, *,
amount_msat: int,
invoice_pubkey,
min_cltv_expiry,
r_tags, t_tags,
invoice_features: int,
- *,
- full_path: LNPaymentPath = None,
- ) -> Sequence[Tuple[LNPaymentRoute, int]]:
+ payment_hash,
+ payment_secret,
+ full_path: LNPaymentPath = None) -> Sequence[Tuple[LNPaymentRoute, int]]:
+
"""Creates multiple routes for splitting a payment over the available
private channels.
We first try to conduct the payment over a single channel. If that fails
and mpp is supported by the receiver, we will split the payment."""
+ # It could happen that the pathfinding uses a channel
+ # in the graph multiple times, meaning we could exhaust
+ # its capacity. This could be dealt with by temporarily
+ # iteratively blacklisting channels for this mpp attempt.
invoice_features = LnFeatures(invoice_features)
- # try to send over a single channel
+ trampoline_features = LnFeatures.VAR_ONION_OPT
+ local_height = self.network.get_local_height()
try:
- routes = [self.create_route_for_payment(
- amount_msat=amount_msat,
- invoice_pubkey=invoice_pubkey,
- min_cltv_expiry=min_cltv_expiry,
- r_tags=r_tags,
- t_tags=t_tags,
- invoice_features=invoice_features,
- outgoing_channel=None,
- full_path=full_path,
- )]
+ # try to send over a single channel
+ if not self.channel_db:
+ for chan in self.channels.values():
+ if not self.is_trampoline_peer(chan.node_id):
+ continue
+ if chan.is_frozen_for_sending():
+ continue
+ trampoline_onion, trampoline_fee, amount_with_fees, cltv_delta = create_trampoline_route_and_onion(
+ amount_msat=amount_msat,
+ bucket_amount_msat=amount_msat,
+ min_cltv_expiry=min_cltv_expiry,
+ invoice_pubkey=invoice_pubkey,
+ invoice_features=invoice_features,
+ node_id=chan.node_id,
+ r_tags=r_tags,
+ t_tags=t_tags,
+ payment_hash=payment_hash,
+ payment_secret=payment_secret,
+ local_height=local_height,
+ trampoline_fee_level=self.trampoline_fee_level,
+ trampoline2_list=self.trampoline2_list)
+ trampoline_payment_secret = os.urandom(32)
+ amount_to_send = amount_with_fees + trampoline_fee
+ if chan.available_to_spend(LOCAL, strict=True) < amount_to_send:
+ continue
+ route = [
+ RouteEdge(
+ node_id=chan.node_id,
+ short_channel_id=chan.short_channel_id,
+ fee_base_msat=0,
+ fee_proportional_millionths=0,
+ cltv_expiry_delta=0,
+ node_features=trampoline_features)
+ ]
+ routes = [(route, amount_to_send, amount_to_send, cltv_delta, trampoline_payment_secret, trampoline_onion)]
+ break
+ else:
+ raise NoPathFound()
+ else:
+ route = self.create_route_for_payment(
+ amount_msat=amount_msat,
+ invoice_pubkey=invoice_pubkey,
+ min_cltv_expiry=min_cltv_expiry,
+ r_tags=r_tags, t_tags=t_tags,
+ invoice_features=invoice_features,
+ outgoing_channel=None, full_path=full_path)
+ routes = [(route, amount_msat, amount_msat, min_cltv_expiry, payment_secret, None)]
except NoPathFound:
if not invoice_features.supports(LnFeatures.BASIC_MPP_OPT):
raise
channels_with_funds = dict([
(cid, int(chan.available_to_spend(HTLCOwner.LOCAL)))
- for cid, chan in self._channels.items()])
+ for cid, chan in self._channels.items() if not chan.is_frozen_for_sending()])
+ self.logger.info(f"channels_with_funds: {channels_with_funds}")
# Create split configurations that are rated according to our
# preference -funds = (low rating=high preference).
split_configurations = suggest_splits(amount_msat, channels_with_funds)
+ self.logger.info(f'suggest_split {amount_msat} returned {len(split_configurations)} configurations')
for s in split_configurations:
+ self.logger.info(f"trying split configuration: {s[0].values()} rating: {s[1]}")
routes = []
try:
- for chanid, part_amount_msat in s[0].items():
+ buckets = defaultdict(list)
+ for chan_id, part_amount_msat in s[0].items():
+ chan = self.channels[chan_id]
if part_amount_msat:
- channel = self.channels[chanid]
- # It could happen that the pathfinding uses a channel
- # in the graph multiple times, meaning we could exhaust
- # its capacity. This could be dealt with by temporarily
- # iteratively blacklisting channels for this mpp attempt.
- route, amt = self.create_route_for_payment(
- amount_msat=part_amount_msat,
- invoice_pubkey=invoice_pubkey,
+ buckets[chan.node_id].append((chan_id, part_amount_msat))
+ for node_id, bucket in buckets.items():
+ bucket_amount_msat = sum([x[1] for x in bucket])
+ if not self.channel_db:
+ trampoline_onion, trampoline_fee, bucket_amount_with_fees, bucket_cltv_delta = create_trampoline_route_and_onion(
+ amount_msat=amount_msat,
+ bucket_amount_msat=bucket_amount_msat,
min_cltv_expiry=min_cltv_expiry,
+ invoice_pubkey=invoice_pubkey,
+ invoice_features=invoice_features,
+ node_id=node_id,
r_tags=r_tags,
t_tags=t_tags,
- invoice_features=invoice_features,
- outgoing_channel=channel,
- full_path=None)
- routes.append((route, amt))
+ payment_hash=payment_hash,
+ payment_secret=payment_secret,
+ local_height=local_height,
+ trampoline_fee_level=self.trampoline_fee_level,
+ trampoline2_list=self.trampoline2_list)
+ self.logger.info(f'trampoline fee {trampoline_fee}')
+ # node_features is only used to determine is_tlv
+ bucket_payment_secret = os.urandom(32)
+ for chan_id, part_amount_msat in bucket:
+ chan = self.channels[chan_id]
+ margin = chan.available_to_spend(LOCAL, strict=True) - part_amount_msat
+ delta_fee = min(trampoline_fee, margin)
+ part_amount_msat_with_fees = part_amount_msat + delta_fee
+ trampoline_fee -= delta_fee
+ route = [
+ RouteEdge(
+ node_id=node_id,
+ short_channel_id=chan.short_channel_id,
+ fee_base_msat=0,
+ fee_proportional_millionths=0,
+ cltv_expiry_delta=0,
+ node_features=trampoline_features)
+ ]
+ self.logger.info(f'adding route {part_amount_msat} {delta_fee} {margin}')
+ routes.append((route, part_amount_msat_with_fees, bucket_amount_with_fees, bucket_cltv_delta, bucket_payment_secret, trampoline_onion))
+ if trampoline_fee > 0:
+ self.logger.info('not enough marging to pay trampoline fee')
+ raise NoPathFound()
+ else:
+ # then we need bucket_amount_msat that includes the trampoline fees.. then create small routes here
+ for chan_id, part_amount_msat in bucket:
+ channel = self.channels[chan_id]
+ route = self.create_route_for_payment(
+ amount_msat=part_amount_msat,
+ invoice_pubkey=invoice_pubkey,
+ min_cltv_expiry=min_cltv_expiry,
+ r_tags=r_tags, t_tags=t_tags,
+ invoice_features=invoice_features,
+ outgoing_channel=channel, full_path=None)
+ routes.append((route, part_amount_msat, bucket_amount_msat, bucket_payment_secret))
self.logger.info(f"found acceptable split configuration: {list(s[0].values())} rating: {s[1]}")
break
except NoPathFound:
@@ -1499,24 +1437,16 @@ class LNWallet(LNWorker):
return routes
def create_route_for_payment(
- self,
- *,
+ self, *,
amount_msat: int,
invoice_pubkey: bytes,
min_cltv_expiry: int,
- r_tags,
- t_tags,
+ r_tags, t_tags,
invoice_features: int,
outgoing_channel: Channel = None,
- full_path: Optional[LNPaymentPath],
- ) -> Tuple[LNPaymentRoute, int]:
+ full_path: Optional[LNPaymentPath]) -> Tuple[LNPaymentRoute, int]:
channels = [outgoing_channel] if outgoing_channel else list(self.channels.values())
- if not self.channel_db:
- route = self.create_trampoline_route(
- amount_msat, min_cltv_expiry, invoice_pubkey, invoice_features, channels, r_tags, t_tags)
- return route, amount_msat
-
route = None
scid_to_my_channels = {
chan.short_channel_id: chan for chan in channels
@@ -1591,7 +1521,7 @@ class LNWallet(LNWorker):
raise LNPathInconsistent("last node_id != invoice pubkey")
# add features from invoice
route[-1].node_features |= invoice_features
- return route, amount_msat
+ return route
def add_request(self, amount_sat, message, expiry) -> str:
coro = self._add_request_coro(amount_sat, message, expiry)
@@ -1743,7 +1673,7 @@ class LNWallet(LNWorker):
util.trigger_callback('htlc_fulfilled', payment_hash, chan.channel_id)
q = self.sent_htlcs.get(payment_hash)
if q:
- route, amount_msat = self.sent_htlcs_routes[(payment_hash, chan.short_channel_id, htlc_id)]
+ route, payment_secret, amount_msat, bucket_msat = self.sent_htlcs_routes[(payment_hash, chan.short_channel_id, htlc_id)]
htlc_log = HtlcLog(
success=True,
route=route,
@@ -1765,7 +1695,10 @@ class LNWallet(LNWorker):
util.trigger_callback('htlc_failed', payment_hash, chan.channel_id)
q = self.sent_htlcs.get(payment_hash)
if q:
- route, amount_msat = self.sent_htlcs_routes[(payment_hash, chan.short_channel_id, htlc_id)]
+ # detect if it is part of a bucket
+ # if yes, wait until the bucket completely failed
+ key = (payment_hash, chan.short_channel_id, htlc_id)
+ route, payment_secret, amount_msat, bucket_msat = self.sent_htlcs_routes[key]
if error_bytes:
# TODO "decode_onion_error" might raise, catch and maybe blacklist/penalise someone?
try:
@@ -1778,6 +1711,13 @@ class LNWallet(LNWorker):
assert failure_message is not None
sender_idx = None
self.logger.info(f"htlc_failed {failure_message}")
+
+ if payment_secret in self.sent_buckets:
+ self.sent_buckets[payment_secret] -= amount_msat
+ if self.sent_buckets[payment_secret] > 0:
+ return
+ else:
+ amount_msat = bucket_msat
htlc_log = HtlcLog(
success=False,
route=route,
diff --git a/electrum/tests/test_lnpeer.py b/electrum/tests/test_lnpeer.py
@@ -135,6 +135,7 @@ class MockLNWallet(Logger, NetworkRetryManager[LNPeerAddr]):
self.received_htlcs = dict()
self.sent_htlcs = defaultdict(asyncio.Queue)
self.sent_htlcs_routes = dict()
+ self.sent_buckets = defaultdict(set)
def get_invoice_status(self, key):
pass
@@ -497,7 +498,7 @@ class TestPeer(ElectrumTestCase):
q2 = w2.sent_htlcs[lnaddr1.paymenthash]
# alice sends htlc BUT NOT COMMITMENT_SIGNED
p1.maybe_send_commitment = lambda x: None
- route1, amount_msat1 = w1.create_routes_from_invoice(lnaddr2.get_amount_msat(), decoded_invoice=lnaddr2)[0]
+ route1, amount_msat1 = w1.create_routes_from_invoice(lnaddr2.get_amount_msat(), decoded_invoice=lnaddr2)[0][0:2]
await w1.pay_to_route(
route=route1,
amount_msat=lnaddr2.get_amount_msat(),
@@ -509,7 +510,7 @@ class TestPeer(ElectrumTestCase):
p1.maybe_send_commitment = _maybe_send_commitment1
# bob sends htlc BUT NOT COMMITMENT_SIGNED
p2.maybe_send_commitment = lambda x: None
- route2, amount_msat2 = w2.create_routes_from_invoice(lnaddr1.get_amount_msat(), decoded_invoice=lnaddr1)[0]
+ route2, amount_msat2 = w2.create_routes_from_invoice(lnaddr1.get_amount_msat(), decoded_invoice=lnaddr1)[0][0:2]
await w2.pay_to_route(
route=route2,
amount_msat=lnaddr1.get_amount_msat(),
@@ -664,7 +665,7 @@ class TestPeer(ElectrumTestCase):
await asyncio.wait_for(p1.initialized, 1)
await asyncio.wait_for(p2.initialized, 1)
# alice sends htlc
- route, amount_msat = w1.create_routes_from_invoice(lnaddr.get_amount_msat(), decoded_invoice=lnaddr)[0]
+ route, amount_msat = w1.create_routes_from_invoice(lnaddr.get_amount_msat(), decoded_invoice=lnaddr)[0][0:2]
htlc = p1.pay(route=route,
chan=alice_channel,
amount_msat=lnaddr.get_amount_msat(),
@@ -760,7 +761,7 @@ class TestPeer(ElectrumTestCase):
pay_req = run(self.prepare_invoice(w2))
lnaddr = w1._check_invoice(pay_req)
- route, amount_msat = w1.create_routes_from_invoice(lnaddr.get_amount_msat(), decoded_invoice=lnaddr)[0]
+ route, amount_msat = w1.create_routes_from_invoice(lnaddr.get_amount_msat(), decoded_invoice=lnaddr)[0][0:2]
assert amount_msat == lnaddr.get_amount_msat()
run(w1.force_close_channel(alice_channel.channel_id))
diff --git a/electrum/trampoline.py b/electrum/trampoline.py
@@ -0,0 +1,228 @@
+import os
+import bitstring
+
+from .lnutil import LnFeatures
+from .lnonion import calc_hops_data_for_payment, new_onion_packet
+from .lnrouter import RouteEdge, TrampolineEdge, LNPaymentRoute, is_route_sane_to_use
+from .lnutil import NoPathFound
+
+from .logging import get_logger, Logger
+
+_logger = get_logger(__name__)
+
+# trampoline nodes are supposed to advertise their fee and cltv in node_update message
+TRAMPOLINE_FEES = [
+ {
+ 'fee_base_msat': 0,
+ 'fee_proportional_millionths': 0,
+ 'cltv_expiry_delta': 576,
+ },
+ {
+ 'fee_base_msat': 1000,
+ 'fee_proportional_millionths': 100,
+ 'cltv_expiry_delta': 576,
+ },
+ {
+ 'fee_base_msat': 3000,
+ 'fee_proportional_millionths': 100,
+ 'cltv_expiry_delta': 576,
+ },
+ {
+ 'fee_base_msat': 5000,
+ 'fee_proportional_millionths': 500,
+ 'cltv_expiry_delta': 576,
+ },
+ {
+ 'fee_base_msat': 7000,
+ 'fee_proportional_millionths': 1000,
+ 'cltv_expiry_delta': 576,
+ },
+ {
+ 'fee_base_msat': 12000,
+ 'fee_proportional_millionths': 3000,
+ 'cltv_expiry_delta': 576,
+ },
+ {
+ 'fee_base_msat': 100000,
+ 'fee_proportional_millionths': 3000,
+ 'cltv_expiry_delta': 576,
+ },
+]
+
+
+def encode_routing_info(r_tags):
+ result = bitstring.BitArray()
+ for route in r_tags:
+ result.append(bitstring.pack('uint:8', len(route)))
+ for step in route:
+ pubkey, channel, feebase, feerate, cltv = step
+ result.append(bitstring.BitArray(pubkey) + bitstring.BitArray(channel) + bitstring.pack('intbe:32', feebase) + bitstring.pack('intbe:32', feerate) + bitstring.pack('intbe:16', cltv))
+ return result.tobytes()
+
+
+def create_trampoline_route(
+ amount_msat:int,
+ bucket_amount_msat:int,
+ min_cltv_expiry:int,
+ invoice_pubkey:bytes,
+ invoice_features:int,
+ trampoline_node_id,
+ r_tags, t_tags,
+ trampoline_fee_level,
+ trampoline2_list) -> LNPaymentRoute:
+
+ invoice_features = LnFeatures(invoice_features)
+ # We do not set trampoline_routing_opt in our invoices, because the spec is not ready
+ # Do not use t_tags if the flag is set, because we the format is not decided yet
+ if invoice_features.supports(LnFeatures.OPTION_TRAMPOLINE_ROUTING_OPT):
+ is_legacy = False
+ if len(r_tags) > 0 and len(r_tags[0]) == 1:
+ pubkey, scid, feebase, feerate, cltv = r_tags[0][0]
+ t_tag = pubkey, feebase, feerate, cltv
+ else:
+ t_tag = None
+ elif len(t_tags) > 0:
+ is_legacy = False
+ t_tag = t_tags[0]
+ else:
+ is_legacy = True
+
+ # fee level. the same fee is used for all trampolines
+ if trampoline_fee_level < len(TRAMPOLINE_FEES):
+ params = TRAMPOLINE_FEES[trampoline_fee_level]
+ else:
+ raise NoPathFound()
+ # add optional second trampoline
+ trampoline2 = None
+ if is_legacy:
+ for node_id in trampoline2_list:
+ if node_id != trampoline_node_id:
+ trampoline2 = node_id
+ break
+ # node_features is only used to determine is_tlv
+ trampoline_features = LnFeatures.VAR_ONION_OPT
+ # hop to trampoline
+ route = []
+ # trampoline hop
+ route.append(
+ TrampolineEdge(
+ node_id=trampoline_node_id,
+ fee_base_msat=params['fee_base_msat'],
+ fee_proportional_millionths=params['fee_proportional_millionths'],
+ cltv_expiry_delta=params['cltv_expiry_delta'],
+ node_features=trampoline_features))
+ if trampoline2:
+ route.append(
+ TrampolineEdge(
+ node_id=trampoline2,
+ fee_base_msat=params['fee_base_msat'],
+ fee_proportional_millionths=params['fee_proportional_millionths'],
+ cltv_expiry_delta=params['cltv_expiry_delta'],
+ node_features=trampoline_features))
+ # add routing info
+ if is_legacy:
+ invoice_routing_info = encode_routing_info(r_tags)
+ route[-1].invoice_routing_info = invoice_routing_info
+ route[-1].invoice_features = invoice_features
+ else:
+ if t_tag:
+ pubkey, feebase, feerate, cltv = t_tag
+ if route[-1].node_id != pubkey:
+ route.append(
+ TrampolineEdge(
+ node_id=pubkey,
+ fee_base_msat=feebase,
+ fee_proportional_millionths=feerate,
+ cltv_expiry_delta=cltv,
+ node_features=trampoline_features))
+ # Fake edge (not part of actual route, needed by calc_hops_data)
+ route.append(
+ TrampolineEdge(
+ node_id=invoice_pubkey,
+ fee_base_msat=0,
+ fee_proportional_millionths=0,
+ cltv_expiry_delta=0,
+ node_features=trampoline_features))
+ # check that we can pay amount and fees
+ for edge in route[::-1]:
+ amount_msat += edge.fee_for_edge(amount_msat)
+ if not is_route_sane_to_use(route, amount_msat, min_cltv_expiry):
+ raise NoPathFound()
+ _logger.info(f'created route with trampoline: fee_level={trampoline_fee_level}, is legacy: {is_legacy}')
+ _logger.info(f'first trampoline: {trampoline_node_id.hex()}')
+ _logger.info(f'second trampoline: {trampoline2.hex() if trampoline2 else None}')
+ _logger.info(f'params: {params}')
+ return route
+
+
+def create_trampoline_onion(route, amount_msat, final_cltv, total_msat, payment_hash, payment_secret):
+ # all edges are trampoline
+ hops_data, amount_msat, cltv = calc_hops_data_for_payment(
+ route,
+ amount_msat,
+ final_cltv,
+ total_msat=total_msat,
+ payment_secret=payment_secret)
+ # 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):
+ 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"] = {
+ "payment_secret":payment_secret,
+ "total_msat": total_msat,
+ }
+ 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
+
+
+def create_trampoline_route_and_onion(
+ *,
+ amount_msat,
+ bucket_amount_msat,
+ min_cltv_expiry,
+ invoice_pubkey,
+ invoice_features,
+ node_id,
+ r_tags, t_tags,
+ payment_hash,
+ payment_secret,
+ local_height:int,
+ trampoline_fee_level,
+ trampoline2_list):
+ # create route for the trampoline_onion
+ trampoline_route = create_trampoline_route(
+ amount_msat,
+ bucket_amount_msat,
+ min_cltv_expiry,
+ invoice_pubkey,
+ invoice_features,
+ node_id,
+ r_tags, t_tags,
+ trampoline_fee_level,
+ trampoline2_list)
+ # compute onion and fees
+ final_cltv = local_height + min_cltv_expiry
+ trampoline_onion, bucket_amount_with_fees, bucket_cltv = create_trampoline_onion(
+ trampoline_route,
+ bucket_amount_msat,
+ final_cltv,
+ amount_msat,
+ payment_hash,
+ payment_secret)
+ bucket_cltv_delta = bucket_cltv - local_height
+ bucket_cltv_delta += trampoline_route[0].cltv_expiry_delta
+ # trampoline fee for this very trampoline
+ trampoline_fee = trampoline_route[0].fee_for_edge(bucket_amount_with_fees)
+ return trampoline_onion, trampoline_fee, bucket_amount_with_fees, bucket_cltv_delta
