use option varonion: actually use TLV payloads, and signal support

electrum/lnonion.py

@@ -161,6 +161,9 @@ class OnionHopsDataSingle:  # called HopData in lnd
             assert len(ret.hmac) == PER_HOP_HMAC_SIZE
             return ret
 
+    def __repr__(self):
+        return f"<OnionHopsDataSingle. is_tlv_payload={self.is_tlv_payload}. payload={self.payload}. hmac={self.hmac}>"
+
 
 class OnionPacket:
 
@@ -265,22 +268,24 @@ def calc_hops_data_for_payment(route: 'LNPaymentRoute', amount_msat: int, final_
     if len(route) > NUM_MAX_EDGES_IN_PAYMENT_PATH:
         raise PaymentFailure(f"too long route ({len(route)} edges)")
 
+    # payload that will be seen by the last hop:
     amt = amount_msat
     cltv = final_cltv
     hop_payload = {
         "amt_to_forward": {"amt_to_forward": amt},
         "outgoing_cltv_value": {"outgoing_cltv_value": cltv},
-        "short_channel_id": {"short_channel_id": b"\x00" * 8},  # TODO omit if tlv
     }
-    hops_data = [OnionHopsDataSingle(is_tlv_payload=False,  # TODO
+    hops_data = [OnionHopsDataSingle(is_tlv_payload=route[-1].has_feature_varonion(),
                                      payload=hop_payload)]
-    for route_edge in reversed(route[1:]):
+    # payloads, backwards from last hop (but excluding the first edge):
+    for edge_index in range(len(route) - 1, 0, -1):
+        route_edge = route[edge_index]
         hop_payload = {
             "amt_to_forward": {"amt_to_forward": amt},
             "outgoing_cltv_value": {"outgoing_cltv_value": cltv},
             "short_channel_id": {"short_channel_id": route_edge.short_channel_id},
         }
-        hops_data += [OnionHopsDataSingle(is_tlv_payload=False,  # TODO
+        hops_data += [OnionHopsDataSingle(is_tlv_payload=route[edge_index-1].has_feature_varonion(),
                                           payload=hop_payload)]
         amt += route_edge.fee_for_edge(amt)
         cltv += route_edge.cltv_expiry_delta

electrum/lnpeer.py

@@ -1040,12 +1040,15 @@ class Peer(Logger):
     def pay(self, route: 'LNPaymentRoute', chan: Channel, amount_msat: int,
             payment_hash: bytes, min_final_cltv_expiry: int) -> UpdateAddHtlc:
         assert amount_msat > 0, "amount_msat is not greater zero"
+        assert len(route) > 0
         if not chan.can_send_update_add_htlc():
             raise PaymentFailure("Channel cannot send update_add_htlc")
+        # add features learned during "init" for direct neighbour:
+        route[0].node_features |= self.features
         local_height = self.network.get_local_height()
         # create onion packet
         final_cltv = local_height + min_final_cltv_expiry
-        hops_data, amount_msat, cltv = calc_hops_data_for_payment(route, amount_msat, final_cltv)  # TODO varonion
+        hops_data, amount_msat, cltv = calc_hops_data_for_payment(route, amount_msat, final_cltv)
         assert final_cltv <= cltv, (final_cltv, cltv)
         secret_key = os.urandom(32)
         onion = new_onion_packet([x.node_id for x in route], secret_key, hops_data, associated_data=payment_hash)
@@ -1055,7 +1058,8 @@ class Peer(Logger):
         htlc = UpdateAddHtlc(amount_msat=amount_msat, payment_hash=payment_hash, cltv_expiry=cltv, timestamp=int(time.time()))
         htlc = chan.add_htlc(htlc)
         chan.set_onion_key(htlc.htlc_id, secret_key)
-        self.logger.info(f"starting payment. len(route)={len(route)}. route: {route}. htlc: {htlc}")
+        self.logger.info(f"starting payment. len(route)={len(route)}. route: {route}. "
+                         f"htlc: {htlc}. hops_data={hops_data!r}")
         self.send_message(
             "update_add_htlc",
             channel_id=chan.channel_id,

electrum/lnrouter.py

@@ -27,11 +27,13 @@ import queue
 from collections import defaultdict
 from typing import Sequence, List, Tuple, Optional, Dict, NamedTuple, TYPE_CHECKING, Set
 
+import attr
+
 from .util import bh2u, profiler
 from .logging import Logger
-from .lnutil import NUM_MAX_EDGES_IN_PAYMENT_PATH, ShortChannelID
-from .channel_db import ChannelDB, Policy
-from .lnutil import NBLOCK_CLTV_EXPIRY_TOO_FAR_INTO_FUTURE
+from .lnutil import (NUM_MAX_EDGES_IN_PAYMENT_PATH, ShortChannelID, LnFeatures,
+                     NBLOCK_CLTV_EXPIRY_TOO_FAR_INTO_FUTURE)
+from .channel_db import ChannelDB, Policy, NodeInfo
 
 if TYPE_CHECKING:
     from .lnchannel import Channel
@@ -48,13 +50,15 @@ def fee_for_edge_msat(forwarded_amount_msat: int, fee_base_msat: int, fee_propor
            + (forwarded_amount_msat * fee_proportional_millionths // 1_000_000)
 
 
-class RouteEdge(NamedTuple):
+@attr.s
+class RouteEdge:
     """if you travel through short_channel_id, you will reach node_id"""
-    node_id: bytes
-    short_channel_id: ShortChannelID
-    fee_base_msat: int
-    fee_proportional_millionths: int
-    cltv_expiry_delta: int
+    node_id = attr.ib(type=bytes, kw_only=True)
+    short_channel_id = attr.ib(type=ShortChannelID, kw_only=True)
+    fee_base_msat = attr.ib(type=int, kw_only=True)
+    fee_proportional_millionths = attr.ib(type=int, kw_only=True)
+    cltv_expiry_delta = attr.ib(type=int, kw_only=True)
+    node_features = attr.ib(type=int, kw_only=True)  # note: for end node!
 
     def fee_for_edge(self, amount_msat: int) -> int:
         return fee_for_edge_msat(forwarded_amount_msat=amount_msat,
@@ -63,14 +67,16 @@ class RouteEdge(NamedTuple):
 
     @classmethod
     def from_channel_policy(cls, channel_policy: 'Policy',
-                            short_channel_id: bytes, end_node: bytes) -> 'RouteEdge':
+                            short_channel_id: bytes, end_node: bytes, *,
+                            node_info: Optional[NodeInfo]) -> 'RouteEdge':
         assert isinstance(short_channel_id, bytes)
         assert type(end_node) is bytes
-        return RouteEdge(end_node,
-                         ShortChannelID.normalize(short_channel_id),
-                         channel_policy.fee_base_msat,
-                         channel_policy.fee_proportional_millionths,
-                         channel_policy.cltv_expiry_delta)
+        return RouteEdge(node_id=end_node,
+                         short_channel_id=ShortChannelID.normalize(short_channel_id),
+                         fee_base_msat=channel_policy.fee_base_msat,
+                         fee_proportional_millionths=channel_policy.fee_proportional_millionths,
+                         cltv_expiry_delta=channel_policy.cltv_expiry_delta,
+                         node_features=node_info.features if node_info else 0)
 
     def is_sane_to_use(self, amount_msat: int) -> bool:
         # TODO revise ad-hoc heuristics
@@ -82,6 +88,10 @@ class RouteEdge(NamedTuple):
             return False
         return True
 
+    def has_feature_varonion(self) -> bool:
+        features = self.node_features
+        return bool(features & LnFeatures.VAR_ONION_REQ or features & LnFeatures.VAR_ONION_OPT)
+
 
 LNPaymentRoute = Sequence[RouteEdge]
 
@@ -154,7 +164,9 @@ class LNPathFinder(Logger):
         if channel_policy.htlc_maximum_msat is not None and \
                 payment_amt_msat > channel_policy.htlc_maximum_msat:
             return float('inf'), 0  # payment amount too large
-        route_edge = RouteEdge.from_channel_policy(channel_policy, short_channel_id, end_node)
+        node_info = self.channel_db.get_node_info_for_node_id(node_id=end_node)
+        route_edge = RouteEdge.from_channel_policy(channel_policy, short_channel_id, end_node,
+                                                   node_info=node_info)
         if not route_edge.is_sane_to_use(payment_amt_msat):
             return float('inf'), 0  # thanks but no thanks
 
@@ -268,6 +280,8 @@ class LNPathFinder(Logger):
                                                                  my_channels=my_channels)
             if channel_policy is None:
                 raise NoChannelPolicy(short_channel_id)
-            route.append(RouteEdge.from_channel_policy(channel_policy, short_channel_id, node_id))
+            node_info = self.channel_db.get_node_info_for_node_id(node_id=node_id)
+            route.append(RouteEdge.from_channel_policy(channel_policy, short_channel_id, node_id,
+                                                       node_info=node_info))
             prev_node_id = node_id
         return route

electrum/lnutil.py

@@ -8,8 +8,8 @@ import json
 from collections import namedtuple, defaultdict
 from typing import NamedTuple, List, Tuple, Mapping, Optional, TYPE_CHECKING, Union, Dict, Set, Sequence
 import re
-import attr
 
+import attr
 from aiorpcx import NetAddress
 
 from .util import bfh, bh2u, inv_dict, UserFacingException
@@ -838,6 +838,7 @@ LN_FEATURES_IMPLEMENTED = (
         | LnFeatures.OPTION_DATA_LOSS_PROTECT_OPT | LnFeatures.OPTION_DATA_LOSS_PROTECT_REQ
         | LnFeatures.GOSSIP_QUERIES_OPT | LnFeatures.GOSSIP_QUERIES_REQ
         | LnFeatures.OPTION_STATIC_REMOTEKEY_OPT | LnFeatures.OPTION_STATIC_REMOTEKEY_REQ
+        | LnFeatures.VAR_ONION_OPT | LnFeatures.VAR_ONION_REQ
 )
 
 

electrum/lnworker.py

@@ -150,6 +150,7 @@ class LNWorker(Logger):
         self.features = LnFeatures(0)
         self.features |= LnFeatures.OPTION_DATA_LOSS_PROTECT_OPT
         self.features |= LnFeatures.OPTION_STATIC_REMOTEKEY_OPT
+        self.features |= LnFeatures.VAR_ONION_OPT
 
     def channels_for_peer(self, node_id):
         return {}
@@ -1047,7 +1048,7 @@ class LNWallet(LNWorker):
         return addr
 
     @profiler
-    def _create_route_from_invoice(self, decoded_invoice) -> LNPaymentRoute:
+    def _create_route_from_invoice(self, decoded_invoice: 'LnAddr') -> LNPaymentRoute:
         amount_msat = int(decoded_invoice.amount * COIN * 1000)
         invoice_pubkey = decoded_invoice.pubkey.serialize()
         # use 'r' field from invoice
@@ -1091,8 +1092,13 @@ class LNWallet(LNWorker):
                     fee_base_msat = channel_policy.fee_base_msat
                     fee_proportional_millionths = channel_policy.fee_proportional_millionths
                     cltv_expiry_delta = channel_policy.cltv_expiry_delta
-                route.append(RouteEdge(node_pubkey, short_channel_id, fee_base_msat, fee_proportional_millionths,
-                                       cltv_expiry_delta))
+                node_info = self.channel_db.get_node_info_for_node_id(node_id=node_pubkey)
+                route.append(RouteEdge(node_id=node_pubkey,
+                                       short_channel_id=short_channel_id,
+                                       fee_base_msat=fee_base_msat,
+                                       fee_proportional_millionths=fee_proportional_millionths,
+                                       cltv_expiry_delta=cltv_expiry_delta,
+                                       node_features=node_info.features if node_info else 0))
                 prev_node_id = node_pubkey
             # test sanity
             if not is_route_sane_to_use(route, amount_msat, decoded_invoice.get_min_final_cltv_expiry()):
@@ -1111,6 +1117,11 @@ class LNWallet(LNWorker):
             if not is_route_sane_to_use(route, amount_msat, decoded_invoice.get_min_final_cltv_expiry()):
                 self.logger.info(f"rejecting insane route {route}")
                 raise NoPathFound()
+        assert len(route) > 0
+        assert route[-1].node_id == invoice_pubkey
+        # add features from invoice
+        invoice_features = decoded_invoice.get_tag('9') or 0
+        route[-1].node_features |= invoice_features
         return route
 
     def add_request(self, amount_sat, message, expiry):
@@ -1141,7 +1152,8 @@ class LNWallet(LNWorker):
         lnaddr = LnAddr(payment_hash, amount_btc,
                         tags=[('d', message),
                               ('c', MIN_FINAL_CLTV_EXPIRY_FOR_INVOICE),
-                              ('x', expiry)]
+                              ('x', expiry),
+                              ('9', self.features.for_invoice())]
                         + routing_hints,
                         date = timestamp)
         invoice = lnencode(lnaddr, self.node_keypair.privkey)