lnworker/config: check if zeroconf is enabled when forwarding

On LSP side we were only checking if ACCEPT_ZEROCONF_CHANNELS
is enabled while forwarding a non-trampoline htlc.
During trampoline forwarding the config was ignored.

The ACCEPT_* prefix implied this was only for accepting inbound
zeroconf channels, but it also controls whether we open them when
forwarding HTLCs.

Renames the config var to OPEN_ZEROCONF_CHANNELS
to clarify it enables zeroconf channel opens in both directions,
and add the missing check when forwarding trampoline HTLCs.

electrum/lnworker.py

@@ -1010,7 +1010,7 @@ class LNWallet(Logger):
             features = LNWALLET_FEATURES
             if self.config.ENABLE_ANCHOR_CHANNELS:
                 features |= LnFeatures.OPTION_ANCHORS_ZERO_FEE_HTLC_OPT
-            if self.config.ACCEPT_ZEROCONF_CHANNELS:
+            if self.config.OPEN_ZEROCONF_CHANNELS:
                 features |= LnFeatures.OPTION_ZEROCONF_OPT
             if self.config.EXPERIMENTAL_LN_FORWARD_PAYMENTS or self.config.EXPERIMENTAL_LN_FORWARD_TRAMPOLINE_PAYMENTS:
                 features |= LnFeatures.OPTION_ONION_MESSAGE_OPT
@@ -1485,6 +1485,7 @@ class LNWallet(Logger):
         payment_hash: bytes,
         next_onion: OnionPacket,
     ) -> str:
+        assert self.config.OPEN_ZEROCONF_CHANNELS
         # if an exception is raised during negotiation, we raise an OnionRoutingFailure.
         # this will cancel the incoming HTLC
 
@@ -3351,7 +3352,7 @@ class LNWallet(Logger):
         return False
 
     def can_get_zeroconf_channel(self) -> bool:
-        if not self.config.ACCEPT_ZEROCONF_CHANNELS and self.config.ZEROCONF_TRUSTED_NODE:
+        if not self.config.OPEN_ZEROCONF_CHANNELS and self.config.ZEROCONF_TRUSTED_NODE:
             # check if zeroconf is accepted and client has trusted zeroconf node configured
             return False
         try:
@@ -3998,7 +3999,7 @@ class LNWallet(Logger):
 
         # do we have a connection to the node?
         next_peer = self.lnpeermgr.get_peer_by_pubkey(outgoing_node_id)
-        if next_peer and next_peer.accepts_zeroconf():
+        if next_peer and next_peer.accepts_zeroconf() and self.features.supports(LnFeatures.OPTION_ZEROCONF_OPT):
             self.logger.info(f'JIT: found next_peer')
             for next_chan in next_peer.channels.values():
                 if next_chan.can_pay(amt_to_forward):

electrum/simple_config.py

@@ -954,7 +954,7 @@ Warning: setting this to too low will result in lots of payment failures."""),
     # anchor outputs channels
     ENABLE_ANCHOR_CHANNELS = ConfigVar('enable_anchor_channels', default=True, type_=bool)
     # zeroconf channels
-    ACCEPT_ZEROCONF_CHANNELS = ConfigVar('accept_zeroconf_channels', default=False, type_=bool)
+    OPEN_ZEROCONF_CHANNELS = ConfigVar('open_zeroconf_channels', default=False, type_=bool)
     ZEROCONF_TRUSTED_NODE = ConfigVar('zeroconf_trusted_node', default='', type_=str)
     ZEROCONF_MIN_OPENING_FEE = ConfigVar('zeroconf_min_opening_fee', default=5000, type_=int)
     LN_UTXO_RESERVE = ConfigVar(

electrum/wallet.py

@@ -3458,7 +3458,7 @@ class Abstract_Wallet(ABC, Logger, EventListener):
             zeroconf_nodeid = extract_nodeid(self.config.ZEROCONF_TRUSTED_NODE)[0]
         except Exception:
             zeroconf_nodeid = None
-        can_get_zeroconf_channel = (self.lnworker and self.config.ACCEPT_ZEROCONF_CHANNELS
+        can_get_zeroconf_channel = (self.lnworker and self.config.OPEN_ZEROCONF_CHANNELS
                                     and self.lnworker.lnpeermgr.get_peer_by_pubkey(zeroconf_nodeid) is not None)
         status = self.get_invoice_status(req)
 

tests/regtest.py

@@ -151,12 +151,12 @@ class TestLightningABC(TestLightning):
 class TestLightningJIT(TestLightning):
     agents = {
         'alice': {
-            'accept_zeroconf_channels': 'true',
+            'open_zeroconf_channels': 'true',
         },
         'bob': {
             'lightning_listen': 'localhost:9735',
             'lightning_forward_payments': 'true',
-            'accept_zeroconf_channels': 'true',
+            'open_zeroconf_channels': 'true',
         },
         'carol': {
         }
@@ -170,13 +170,13 @@ class TestLightningJITTrampoline(TestLightningJIT):
     agents = {
         'alice': {
             'use_gossip': 'false',
-            'accept_zeroconf_channels': 'true',
+            'open_zeroconf_channels': 'true',
         },
         'bob': {
             'lightning_listen': 'localhost:9735',
             'lightning_forward_payments': 'true',
             'lightning_forward_trampoline_payments': 'true',
-            'accept_zeroconf_channels': 'true',
+            'open_zeroconf_channels': 'true',
         },
         'carol': {
             'use_gossip': 'false',