tlnbase.pay: test if htlc can be added - electrum - Electrum Bitcoin wallet
HTML git clone https://git.parazyd.org/electrum
DIR Log
DIR Files
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DIR Submodules
---
DIR commit 4d1785799be2cfc2e34971a48f8c0c5deda21098
DIR parent 9827cda9b10b40ca211ebacc936fbd216cfa99fc
HTML Author: SomberNight <somber.night@protonmail.com>
Date: Wed, 1 Aug 2018 18:30:35 +0200
lnbase.pay: test if htlc can be added
Diffstat:
M electrum/lnbase.py | 22 +++++++++++++++++++---
M electrum/lnutil.py | 3 +++
2 files changed, 22 insertions(+), 3 deletions(-)
---
DIR diff --git a/electrum/lnbase.py b/electrum/lnbase.py
t@@ -7,7 +7,7 @@
from collections import namedtuple, defaultdict, OrderedDict, defaultdict
from .lnutil import Outpoint, ChannelConfig, LocalState, RemoteState, Keypair, OnlyPubkeyKeypair, ChannelConstraints, RevocationStore
from .lnutil import sign_and_get_sig_string, funding_output_script, get_ecdh, get_per_commitment_secret_from_seed
-from .lnutil import secret_to_pubkey, LNPeerAddr
+from .lnutil import secret_to_pubkey, LNPeerAddr, PaymentFailure
from .bitcoin import COIN
from ecdsa.util import sigdecode_der, sigencode_string_canonize, sigdecode_string
t@@ -841,9 +841,9 @@ class Peer(PrintError):
async def pay(self, path, chan, amount_msat, payment_hash, pubkey_in_invoice, min_final_cltv_expiry):
assert chan.get_state() == "OPEN"
assert amount_msat > 0, "amount_msat is not greater zero"
+
height = self.network.get_local_height()
route = self.network.path_finder.create_route_from_path(path, self.lnworker.pubkey)
- # TODO check that first edge (our channel) has enough balance to support amount_msat
hops_data = []
sum_of_deltas = sum(route_edge.channel_policy.cltv_expiry_delta for route_edge in route[1:])
total_fee = 0
t@@ -857,10 +857,19 @@ class Peer(PrintError):
hops_data += [OnionHopsDataSingle(OnionPerHop(b"\x00"*8, amount_msat.to_bytes(8, "big"), (final_cltv_expiry_without_deltas).to_bytes(4, "big")))]
onion = new_onion_packet([x.node_id for x in route], self.secret_key, hops_data, associated_data)
amount_msat += total_fee
+ # FIXME this below will probably break with multiple HTLCs
msat_local = chan.local_state.amount_msat - amount_msat
msat_remote = chan.remote_state.amount_msat + amount_msat
htlc = UpdateAddHtlc(amount_msat, payment_hash, final_cltv_expiry_with_deltas)
+ if len(chan.htlcs_in_local) + 1 > chan.remote_config.max_accepted_htlcs:
+ raise PaymentFailure('too many HTLCs already in channel')
+ if chan.htlcsum(chan.htlcs_in_local) + amount_msat > chan.remote_config.max_htlc_value_in_flight_msat:
+ raise PaymentFailure('HTLC value sum would exceed max allowed')
+ if msat_local < 0:
+ # FIXME what about channel_reserve_satoshis? will the remote fail the channel if we go below? test.
+ raise PaymentFailure('not enough local balance')
+
self.send_message(gen_msg("update_add_htlc", channel_id=chan.channel_id, id=chan.local_state.next_htlc_id, cltv_expiry=final_cltv_expiry_with_deltas, amount_msat=amount_msat, payment_hash=payment_hash, onion_routing_packet=onion.to_bytes()))
chan.add_htlc(htlc)
t@@ -876,6 +885,8 @@ class Peer(PrintError):
failure_coro = asyncio.ensure_future(self.update_fail_htlc[chan.channel_id].get())
done, pending = await asyncio.wait([fulfill_coro, failure_coro], return_when=FIRST_COMPLETED)
+ # TODO what if HTLC gets stuck in multihop payment (A->B->C->D->E; on the way back C goes offline)
+ payment_succeeded = False
if failure_coro.done():
fulfill_coro.cancel()
sig_64, htlc_sigs = chan.sign_next_commitment()
t@@ -886,6 +897,7 @@ class Peer(PrintError):
self.revoke(chan)
sig_64, htlc_sigs = chan.sign_next_commitment()
res = failure_coro.result()
+ payment_succeeded = True
else:
failure_coro.cancel()
update_fulfill_htlc_msg = fulfill_coro.result()
t@@ -901,7 +913,11 @@ class Peer(PrintError):
self.send_message(gen_msg("commitment_signed", channel_id=chan.channel_id, signature=sig_64, num_htlcs=0))
await self.receive_revoke(chan)
self.lnworker.save_channel(chan)
- return res
+
+ if payment_succeeded:
+ return res
+ else:
+ raise PaymentFailure(res)
async def receive_revoke(self, m):
revoke_and_ack_msg = await self.revoke_and_ack[m.channel_id].get()
DIR diff --git a/electrum/lnutil.py b/electrum/lnutil.py
t@@ -414,3 +414,6 @@ def get_compressed_pubkey_from_bech32(bech32_pubkey: str) -> bytes:
COMPRESSED_PUBKEY_LENGTH = 33
data_8bits = data_8bits + ((COMPRESSED_PUBKEY_LENGTH - len(data_8bits)) * [0])
return bytes(data_8bits)
+
+
+class PaymentFailure(Exception): pass