lnhtlc: move 'next_htlc_id' from ChannelConfig to lnhtlc log

electrum/lnchannel.py

@@ -243,10 +243,10 @@ class Channel(Logger):
             htlc = UpdateAddHtlc(**htlc)
         assert isinstance(htlc, UpdateAddHtlc)
         self._check_can_pay(htlc.amount_msat)
-        htlc = htlc._replace(htlc_id=self.config[LOCAL].next_htlc_id)
+        if htlc.htlc_id is None:
+            htlc = htlc._replace(htlc_id=self.hm.get_next_htlc_id(LOCAL))
         self.hm.send_htlc(htlc)
         self.logger.info("add_htlc")
-        self.config[LOCAL]=self.config[LOCAL]._replace(next_htlc_id=htlc.htlc_id + 1)
         return htlc
 
     def receive_htlc(self, htlc: UpdateAddHtlc) -> UpdateAddHtlc:
@@ -260,14 +260,14 @@ class Channel(Logger):
         if isinstance(htlc, dict):  # legacy conversion  # FIXME remove
             htlc = UpdateAddHtlc(**htlc)
         assert isinstance(htlc, UpdateAddHtlc)
-        htlc = htlc._replace(htlc_id=self.config[REMOTE].next_htlc_id)
+        if htlc.htlc_id is None:  # used in unit tests
+            htlc = htlc._replace(htlc_id=self.hm.get_next_htlc_id(REMOTE))
         if 0 <= self.available_to_spend(REMOTE) < htlc.amount_msat:
             raise RemoteMisbehaving('Remote dipped below channel reserve.' +\
                     f' Available at remote: {self.available_to_spend(REMOTE)},' +\
                     f' HTLC amount: {htlc.amount_msat}')
         self.hm.recv_htlc(htlc)
         self.logger.info("receive_htlc")
-        self.config[REMOTE]=self.config[REMOTE]._replace(next_htlc_id=htlc.htlc_id + 1)
         return htlc
 
     def sign_next_commitment(self):

electrum/lnhtlc.py

@@ -18,6 +18,7 @@ class HTLCManager:
                 'fails': {},
                 'fee_updates': [],
                 'revack_pending': False,
+                'next_htlc_id': 0,
             }
             log = {LOCAL: deepcopy(initial), REMOTE: deepcopy(initial)}
         else:
@@ -54,6 +55,9 @@ class HTLCManager:
     def _set_revack_pending(self, sub: HTLCOwner, pending: bool) -> None:
         self.log[sub]['revack_pending'] = pending
 
+    def get_next_htlc_id(self, sub: HTLCOwner) -> int:
+        return self.log[sub]['next_htlc_id']
+
     def to_save(self):
         log = deepcopy(self.log)
         for sub in (LOCAL, REMOTE):
@@ -75,14 +79,22 @@ class HTLCManager:
 
     def send_htlc(self, htlc: UpdateAddHtlc) -> UpdateAddHtlc:
         htlc_id = htlc.htlc_id
+        if htlc_id != self.get_next_htlc_id(LOCAL):
+            raise Exception(f"unexpected local htlc_id. next should be "
+                            f"{self.get_next_htlc_id(LOCAL)} but got {htlc_id}")
         self.log[LOCAL]['adds'][htlc_id] = htlc
         self.log[LOCAL]['locked_in'][htlc_id] = {LOCAL: None, REMOTE: self.ctn_latest(REMOTE)+1}
+        self.log[LOCAL]['next_htlc_id'] += 1
         return htlc
 
     def recv_htlc(self, htlc: UpdateAddHtlc) -> None:
         htlc_id = htlc.htlc_id
+        if htlc_id != self.get_next_htlc_id(REMOTE):
+            raise Exception(f"unexpected remote htlc_id. next should be "
+                            f"{self.get_next_htlc_id(REMOTE)} but got {htlc_id}")
         self.log[REMOTE]['adds'][htlc_id] = htlc
         self.log[REMOTE]['locked_in'][htlc_id] = {LOCAL: self.ctn_latest(LOCAL)+1, REMOTE: None}
+        self.log[REMOTE]['next_htlc_id'] += 1
 
     def send_settle(self, htlc_id: int) -> None:
         self.log[REMOTE]['settles'][htlc_id] = {LOCAL: None, REMOTE: self.ctn_latest(REMOTE) + 1}

electrum/lnpeer.py

@@ -434,7 +434,6 @@ class Peer(Logger):
             max_accepted_htlcs=5,
             initial_msat=initial_msat,
             ctn=-1,
-            next_htlc_id=0,
             reserve_sat=546,
             per_commitment_secret_seed=keypair_generator(LnKeyFamily.REVOCATION_ROOT).privkey,
             funding_locked_received=False,
@@ -518,7 +517,6 @@ class Peer(Logger):
             max_accepted_htlcs=max_accepted_htlcs,
             initial_msat=push_msat,
             ctn = -1,
-            next_htlc_id = 0,
             reserve_sat = remote_reserve_sat,
             htlc_minimum_msat = htlc_min,
 
@@ -621,7 +619,6 @@ class Peer(Logger):
                     max_accepted_htlcs=int.from_bytes(payload['max_accepted_htlcs'], 'big'), # TODO validate
                     initial_msat=remote_balance_sat,
                     ctn = -1,
-                    next_htlc_id = 0,
                     reserve_sat = remote_reserve_sat,
                     htlc_minimum_msat=int.from_bytes(payload['htlc_minimum_msat'], 'big'), # TODO validate
                     next_per_commitment_point=payload['first_per_commitment_point'],
@@ -1142,11 +1139,14 @@ class Peer(Logger):
         processed_onion = process_onion_packet(onion_packet, associated_data=payment_hash, our_onion_private_key=self.privkey)
         chan = self.channels[channel_id]
         assert chan.get_state() == "OPEN"
-        assert htlc_id == chan.config[REMOTE].next_htlc_id, (htlc_id, chan.config[REMOTE].next_htlc_id)  # TODO fail channel instead
         if cltv_expiry >= 500_000_000:
             pass  # TODO fail the channel
         # add htlc
-        htlc = UpdateAddHtlc(amount_msat=amount_msat_htlc, payment_hash=payment_hash, cltv_expiry=cltv_expiry, timestamp=int(time.time()))
+        htlc = UpdateAddHtlc(amount_msat=amount_msat_htlc,
+                             payment_hash=payment_hash,
+                             cltv_expiry=cltv_expiry,
+                             timestamp=int(time.time()),
+                             htlc_id=htlc_id)
         htlc = chan.receive_htlc(htlc)
         local_ctn = chan.get_current_ctn(LOCAL)
         remote_ctn = chan.get_current_ctn(REMOTE)

electrum/lnutil.py

@@ -35,7 +35,6 @@ OnlyPubkeyKeypair = namedtuple("OnlyPubkeyKeypair", ["pubkey"])
 class LocalConfig(NamedTuple):
     # shared channel config fields (DUPLICATED code!!)
     ctn: int
-    next_htlc_id: int
     payment_basepoint: 'Keypair'
     multisig_key: 'Keypair'
     htlc_basepoint: 'Keypair'
@@ -59,7 +58,6 @@ class LocalConfig(NamedTuple):
 class RemoteConfig(NamedTuple):
     # shared channel config fields (DUPLICATED code!!)
     ctn: int
-    next_htlc_id: int
     payment_basepoint: 'Keypair'
     multisig_key: 'Keypair'
     htlc_basepoint: 'Keypair'

electrum/tests/test_lnchannel.py

@@ -59,7 +59,6 @@ def create_channel_state(funding_txid, funding_index, funding_sat, is_initiator,
                 max_accepted_htlcs=5,
                 initial_msat=remote_amount,
                 ctn = -1,
-                next_htlc_id = 0,
                 reserve_sat=0,
                 htlc_minimum_msat=1,
 
@@ -79,7 +78,6 @@ def create_channel_state(funding_txid, funding_index, funding_sat, is_initiator,
                 max_accepted_htlcs=5,
                 initial_msat=local_amount,
                 ctn = 0,
-                next_htlc_id = 0,
                 reserve_sat=0,
 
                 per_commitment_secret_seed=seed,