lnpeer: channel_update decorator

electrum/lnpeer.py

@@ -60,6 +60,12 @@ if TYPE_CHECKING:
 
 LN_P2P_NETWORK_TIMEOUT = 20
 
+def channel_update(func):
+    def wrapper(peer, payload):
+        channel_id = payload["channel_id"]
+        chan = peer.channels[channel_id]
+        return func(peer, chan, payload)
+    return wrapper
 
 def channel_id_from_funding_tx(funding_txid: str, funding_index: int) -> Tuple[bytes, bytes]:
     funding_txid_bytes = bytes.fromhex(funding_txid)[::-1]
@@ -1004,11 +1010,10 @@ class Peer(Logger):
 
         return msg_hash, node_signature, bitcoin_signature
 
-    def on_update_fail_htlc(self, payload):
-        channel_id = payload["channel_id"]
+    @channel_update
+    def on_update_fail_htlc(self, chan, payload):
         htlc_id = int.from_bytes(payload["id"], "big")
         reason = payload["reason"]
-        chan = self.channels[channel_id]
         self.logger.info(f"on_update_fail_htlc. chan {chan.short_channel_id}. htlc_id {htlc_id}")
         chan.receive_fail_htlc(htlc_id, reason)
         self.maybe_send_commitment(chan)
@@ -1081,23 +1086,23 @@ class Peer(Logger):
         chan.receive_new_commitment(payload["signature"], htlc_sigs)
         self.send_revoke_and_ack(chan)
 
-    def on_update_fulfill_htlc(self, update_fulfill_htlc_msg):
-        chan = self.channels[update_fulfill_htlc_msg["channel_id"]]
-        preimage = update_fulfill_htlc_msg["payment_preimage"]
+    @channel_update
+    def on_update_fulfill_htlc(self, chan, payload):
+        preimage = payload["payment_preimage"]
         payment_hash = sha256(preimage)
-        htlc_id = int.from_bytes(update_fulfill_htlc_msg["id"], "big")
+        htlc_id = int.from_bytes(payload["id"], "big")
         self.logger.info(f"on_update_fulfill_htlc. chan {chan.short_channel_id}. htlc_id {htlc_id}")
         chan.receive_htlc_settle(preimage, htlc_id)
         self.lnworker.save_preimage(payment_hash, preimage)
         self.maybe_send_commitment(chan)
 
-    def on_update_fail_malformed_htlc(self, payload):
+    @channel_update
+    def on_update_fail_malformed_htlc(self, chan, payload):
         self.logger.info(f"on_update_fail_malformed_htlc. error {payload['data'].decode('ascii')}")
 
-    def on_update_add_htlc(self, payload):
+    @channel_update
+    def on_update_add_htlc(self, chan, payload):
         payment_hash = payload["payment_hash"]
-        channel_id = payload['channel_id']
-        chan = self.channels[channel_id]
         htlc_id = int.from_bytes(payload["id"], 'big')
         self.logger.info(f"on_update_add_htlc. chan {chan.short_channel_id}. htlc_id {htlc_id}")
         cltv_expiry = int.from_bytes(payload["cltv_expiry"], 'big')
@@ -1106,7 +1111,7 @@ class Peer(Logger):
         if chan.get_state() != channel_states.OPEN:
             raise RemoteMisbehaving(f"received update_add_htlc while chan.get_state() != OPEN. state was {chan.get_state()}")
         if cltv_expiry > bitcoin.NLOCKTIME_BLOCKHEIGHT_MAX:
-            asyncio.ensure_future(self.lnworker.try_force_closing(channel_id))
+            asyncio.ensure_future(self.lnworker.try_force_closing(chan.channel_id))
             raise RemoteMisbehaving(f"received update_add_htlc with cltv_expiry > BLOCKHEIGHT_MAX. value was {cltv_expiry}")
         # add htlc
         htlc = UpdateAddHtlc(
@@ -1243,10 +1248,9 @@ class Peer(Logger):
         self.lnworker.save_channel(chan)
         self.maybe_send_commitment(chan)
 
-    def on_update_fee(self, payload):
-        channel_id = payload["channel_id"]
-        feerate =int.from_bytes(payload["feerate_per_kw"], "big")
-        chan = self.channels[channel_id]
+    @channel_update
+    def on_update_fee(self, chan, payload):
+        feerate = int.from_bytes(payload["feerate_per_kw"], "big")
         chan.update_fee(feerate, False)
 
     async def maybe_update_fee(self, chan: Channel):