Recommend funding_tx to apply anti-fee sniping

[rust-lightning] / lightning / src / ln / channelmanager.rs

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index 9002885a699ea06595ba6c98ee3a56342507aa30..9fd4a24f444bac25c23eac3312cda797faa4590e 100644 (file)
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -2783,6 +2783,9 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
        /// Returns an [`APIError::APIMisuseError`] if the funding_transaction spent non-SegWit outputs
        /// or if no output was found which matches the parameters in [`Event::FundingGenerationReady`].
        ///
+       /// Returns [`APIError::APIMisuseError`] if the funding transaction is not final for propagation
+       /// across the p2p network.
+       ///
        /// Returns [`APIError::ChannelUnavailable`] if a funding transaction has already been provided
        /// for the channel or if the channel has been closed as indicated by [`Event::ChannelClosed`].
        ///
@@ -2798,6 +2801,11 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
        /// not currently support replacing a funding transaction on an existing channel. Instead,
        /// create a new channel with a conflicting funding transaction.
        ///
+       /// Note to keep the miner incentives aligned in moving the blockchain forward, we recommend
+       /// the wallet software generating the funding transaction to apply anti-fee sniping as
+       /// implemented by Bitcoin Core wallet. See <https://bitcoinops.org/en/topics/fee-sniping/>
+       /// for more details.
+       ///
        /// [`Event::FundingGenerationReady`]: crate::util::events::Event::FundingGenerationReady
        /// [`Event::ChannelClosed`]: crate::util::events::Event::ChannelClosed
        pub fn funding_transaction_generated(&self, temporary_channel_id: &[u8; 32], counterparty_node_id: &PublicKey, funding_transaction: Transaction) -> Result<(), APIError> {
@@ -2810,6 +2818,18 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                });
                        }
                }
+               {
+                       let height = self.best_block.read().unwrap().height();
+                       // Transactions are evaluated as final by network mempools at the next block. However, the modules
+                       // constituting our Lightning node might not have perfect sync about their blockchain views. Thus, if
+                       // the wallet module is in advance on the LDK view, allow one more block of headroom.
+                       // TODO: updated if/when https://github.com/rust-bitcoin/rust-bitcoin/pull/994 landed and rust-bitcoin bumped.
+                       if !funding_transaction.input.iter().all(|input| input.sequence == 0xffffffff) && funding_transaction.lock_time < 500_000_000 && funding_transaction.lock_time > height + 2 {
+                               return Err(APIError::APIMisuseError {
+                                       err: "Funding transaction absolute timelock is non-final".to_owned()
+                               });
+                       }
+               }
                self.funding_transaction_generated_intern(temporary_channel_id, counterparty_node_id, funding_transaction, |chan, tx| {
                        let mut output_index = None;
                        let expected_spk = chan.get_funding_redeemscript().to_v0_p2wsh();
@@ -7365,8 +7385,8 @@ mod tests {
                        final_cltv_expiry_delta: TEST_FINAL_CLTV,
                };
                let route = find_route(
-                       &nodes[0].node.get_our_node_id(), &route_params, nodes[0].network_graph, None,
-                       nodes[0].logger, &scorer, &random_seed_bytes
+                       &nodes[0].node.get_our_node_id(), &route_params, &nodes[0].network_graph.read_only(),
+                       None, nodes[0].logger, &scorer, &random_seed_bytes
                ).unwrap();
                nodes[0].node.send_spontaneous_payment(&route, Some(payment_preimage)).unwrap();
                check_added_monitors!(nodes[0], 1);
@@ -7396,8 +7416,8 @@ mod tests {
                // To start (2), send a keysend payment but don't claim it.
                let payment_preimage = PaymentPreimage([42; 32]);
                let route = find_route(
-                       &nodes[0].node.get_our_node_id(), &route_params, nodes[0].network_graph, None,
-                       nodes[0].logger, &scorer, &random_seed_bytes
+                       &nodes[0].node.get_our_node_id(), &route_params, &nodes[0].network_graph.read_only(),
+                       None, nodes[0].logger, &scorer, &random_seed_bytes
                ).unwrap();
                let (payment_hash, _) = nodes[0].node.send_spontaneous_payment(&route, Some(payment_preimage)).unwrap();
                check_added_monitors!(nodes[0], 1);
@@ -7460,8 +7480,9 @@ mod tests {
                let scorer = test_utils::TestScorer::with_penalty(0);
                let random_seed_bytes = chanmon_cfgs[1].keys_manager.get_secure_random_bytes();
                let route = find_route(
-                       &payer_pubkey, &route_params, network_graph, Some(&first_hops.iter().collect::<Vec<_>>()),
-                       nodes[0].logger, &scorer, &random_seed_bytes
+                       &payer_pubkey, &route_params, &network_graph.read_only(),
+                       Some(&first_hops.iter().collect::<Vec<_>>()), nodes[0].logger, &scorer,
+                       &random_seed_bytes
                ).unwrap();
 
                let test_preimage = PaymentPreimage([42; 32]);
@@ -7504,8 +7525,9 @@ mod tests {
                let scorer = test_utils::TestScorer::with_penalty(0);
                let random_seed_bytes = chanmon_cfgs[1].keys_manager.get_secure_random_bytes();
                let route = find_route(
-                       &payer_pubkey, &route_params, network_graph, Some(&first_hops.iter().collect::<Vec<_>>()),
-                       nodes[0].logger, &scorer, &random_seed_bytes
+                       &payer_pubkey, &route_params, &network_graph.read_only(),
+                       Some(&first_hops.iter().collect::<Vec<_>>()), nodes[0].logger, &scorer,
+                       &random_seed_bytes
                ).unwrap();
 
                let test_preimage = PaymentPreimage([42; 32]);
@@ -7697,7 +7719,7 @@ pub mod bench {
                        _ => panic!(),
                }
 
-               let dummy_graph = NetworkGraph::new(genesis_hash);
+               let dummy_graph = NetworkGraph::new(genesis_hash, &logger_a);
 
                let mut payment_count: u64 = 0;
                macro_rules! send_payment {