ln: revoke before sending bare ctx in pay(), remove subtraction of trimmed amt from fee

lib/lnbase.py

@@ -563,7 +563,6 @@ class Peer(PrintError):
             max_accepted_htlcs=int.from_bytes(payload["max_accepted_htlcs"], 'big')
         )
         funding_txn_minimum_depth = int.from_bytes(payload['minimum_depth'], 'big')
-        print('remote dust limit', remote_config.dust_limit_sat)
         assert remote_config.dust_limit_sat < 600
         assert int.from_bytes(payload['htlc_minimum_msat'], 'big') < 600 * 1000
         assert remote_config.max_htlc_value_in_flight_msat >= 198 * 1000 * 1000, remote_config.max_htlc_value_in_flight_msat
@@ -571,7 +570,6 @@ class Peer(PrintError):
         self.print_error('funding_txn_minimum_depth', funding_txn_minimum_depth)
         # create funding tx
         redeem_script = funding_output_script(local_config, remote_config)
-        print("REDEEM SCRIPT", redeem_script)
         funding_address = bitcoin.redeem_script_to_address('p2wsh', redeem_script)
         funding_output = (bitcoin.TYPE_ADDRESS, funding_address, funding_sat)
         funding_tx = wallet.mktx([funding_output], password, config, 1000)
@@ -866,6 +864,7 @@ class Peer(PrintError):
             self.send_message(gen_msg("commitment_signed", channel_id=chan.channel_id, signature=sig_64, num_htlcs=1, htlc_signature=htlc_sigs[0]))
             while (await self.commitment_signed[chan.channel_id].get())["htlc_signature"] != b"":
                 self.revoke(chan)
+            # TODO process above commitment transactions
             await self.receive_revoke(chan)
             chan.fail_htlc(htlc)
             sig_64, htlc_sigs = chan.sign_next_commitment()
@@ -878,12 +877,15 @@ class Peer(PrintError):
             failure_coro.cancel()
             update_fulfill_htlc_msg = fulfill_coro.result()
 
-        chan.receive_htlc_settle(update_fulfill_htlc_msg["payment_preimage"], int.from_bytes(update_fulfill_htlc_msg["id"], "big"))
+        preimage = update_fulfill_htlc_msg["payment_preimage"]
+        chan.receive_htlc_settle(preimage, int.from_bytes(update_fulfill_htlc_msg["id"], "big"))
 
         while (await self.commitment_signed[chan.channel_id].get())["htlc_signature"] != b"":
             self.revoke(chan)
         # TODO process above commitment transactions
 
+        self.revoke(chan)
+
         bare_ctx = chan.make_commitment(chan.remote_state.ctn + 1, False, chan.remote_state.next_per_commitment_point,
             msat_remote, msat_local)
 
@@ -893,6 +895,7 @@ class Peer(PrintError):
         await self.receive_revoke(chan)
 
         self.lnworker.save_channel(chan)
+        return bh2u(preimage)
 
     async def receive_revoke(self, m):
         revoke_and_ack_msg = await self.revoke_and_ack[m.channel_id].get()

lib/lnhtlc.py

@@ -417,13 +417,10 @@ class HTLCStateMachine(PrintError):
         local_htlc_pubkey = derive_pubkey(self.local_config.htlc_basepoint.pubkey, this_point)
         local_revocation_pubkey = derive_blinded_pubkey(self.local_config.revocation_basepoint.pubkey, this_point)
 
-        trimmed = 0
-
         with PendingFeerateApplied(self):
             htlcs_in_local = []
             for htlc in self.htlcs_in_local:
                 if htlc.amount_msat // 1000 - HTLC_SUCCESS_WEIGHT * (self.remote_state.feerate // 1000) < self.remote_config.dust_limit_sat:
-                    trimmed += htlc.amount_msat // 1000
                     continue
                 htlcs_in_local.append(
                     ( make_received_htlc(local_revocation_pubkey, local_htlc_pubkey, remote_htlc_pubkey, htlc.payment_hash, htlc.cltv_expiry), htlc.amount_msat + htlc.total_fee))
@@ -431,14 +428,13 @@ class HTLCStateMachine(PrintError):
             htlcs_in_remote = []
             for htlc in self.htlcs_in_remote:
                 if htlc.amount_msat // 1000 - HTLC_TIMEOUT_WEIGHT * (self.remote_state.feerate // 1000) < self.remote_config.dust_limit_sat:
-                    trimmed += htlc.amount_msat // 1000
                     continue
                 htlcs_in_remote.append(
                     ( make_offered_htlc(local_revocation_pubkey, local_htlc_pubkey, remote_htlc_pubkey, htlc.payment_hash), htlc.amount_msat + htlc.total_fee))
 
             commit = self.make_commitment(self.remote_state.ctn + 1,
                 False, this_point,
-                remote_msat - total_fee_remote, local_msat - total_fee_local, htlcs_in_local + htlcs_in_remote, trimmed)
+                remote_msat - total_fee_remote, local_msat - total_fee_local, htlcs_in_local + htlcs_in_remote)
             return commit
 
     @property
@@ -453,13 +449,10 @@ class HTLCStateMachine(PrintError):
         local_htlc_pubkey = derive_pubkey(self.local_config.htlc_basepoint.pubkey, this_point)
         remote_revocation_pubkey = derive_blinded_pubkey(self.remote_config.revocation_basepoint.pubkey, this_point)
 
-        trimmed = 0
-
         with PendingFeerateApplied(self):
             htlcs_in_local = []
             for htlc in self.htlcs_in_local:
                 if htlc.amount_msat // 1000 - HTLC_TIMEOUT_WEIGHT * (self.local_state.feerate // 1000) < self.local_config.dust_limit_sat:
-                    trimmed += htlc.amount_msat // 1000
                     continue
                 htlcs_in_local.append(
                     ( make_offered_htlc(remote_revocation_pubkey, remote_htlc_pubkey, local_htlc_pubkey, htlc.payment_hash), htlc.amount_msat + htlc.total_fee))
@@ -467,14 +460,13 @@ class HTLCStateMachine(PrintError):
             htlcs_in_remote = []
             for htlc in self.htlcs_in_remote:
                 if htlc.amount_msat // 1000 - HTLC_SUCCESS_WEIGHT * (self.local_state.feerate // 1000) < self.local_config.dust_limit_sat:
-                    trimmed += htlc.amount_msat // 1000
                     continue
                 htlcs_in_remote.append(
                     ( make_received_htlc(remote_revocation_pubkey, remote_htlc_pubkey, local_htlc_pubkey, htlc.payment_hash, htlc.cltv_expiry), htlc.amount_msat + htlc.total_fee))
 
             commit = self.make_commitment(self.local_state.ctn + 1,
                 True, this_point,
-                local_msat - total_fee_local, remote_msat - total_fee_remote, htlcs_in_local + htlcs_in_remote, trimmed)
+                local_msat - total_fee_local, remote_msat - total_fee_remote, htlcs_in_local + htlcs_in_remote)
             return commit
 
     def gen_htlc_indices(self, subject, just_unsettled=True):
@@ -579,7 +571,7 @@ class HTLCStateMachine(PrintError):
     def __str__(self):
         return self.serialize()
 
-    def make_commitment(chan, ctn, for_us, pcp, local_msat, remote_msat, htlcs=[], trimmed=0):
+    def make_commitment(chan, ctn, for_us, pcp, local_msat, remote_msat, htlcs=[]):
         conf = chan.local_config if for_us else chan.remote_config
         other_conf = chan.local_config if not for_us else chan.remote_config
         payment_pubkey = derive_pubkey(other_conf.payment_basepoint.pubkey, pcp)
@@ -602,5 +594,4 @@ class HTLCStateMachine(PrintError):
             chan.local_state.feerate if for_us else chan.remote_state.feerate,
             for_us,
             chan.constraints.is_initiator,
-            htlcs=htlcs,
-            trimmed=trimmed)
+            htlcs=htlcs)

lib/lnutil.py

@@ -228,7 +228,7 @@ def make_commitment(ctn, local_funding_pubkey, remote_funding_pubkey,
                     delayed_pubkey, to_self_delay, funding_txid,
                     funding_pos, funding_sat, local_amount, remote_amount,
                     dust_limit_sat, local_feerate, for_us, we_are_initiator,
-                    htlcs, trimmed=0):
+                    htlcs):
 
     pubkeys = sorted([bh2u(local_funding_pubkey), bh2u(remote_funding_pubkey)])
     payments = [payment_basepoint, remote_payment_basepoint]
@@ -256,7 +256,6 @@ def make_commitment(ctn, local_funding_pubkey, remote_funding_pubkey,
     remote_address = bitcoin.pubkey_to_address('p2wpkh', bh2u(remote_payment_pubkey))
     # TODO trim htlc outputs here while also considering 2nd stage htlc transactions
     fee = local_feerate * overall_weight(len(htlcs))
-    fee -= trimmed * 1000
     assert type(fee) is int
     we_pay_fee = for_us == we_are_initiator
     to_local_amt = local_amount - (fee if we_pay_fee else 0)