Claim HTLC output on-chain if preimage is recv'd after force-close
authorValentine Wallace <vwallace@protonmail.com>
Thu, 5 Nov 2020 21:37:24 +0000 (16:37 -0500)
committerValentine Wallace <vwallace@protonmail.com>
Mon, 16 Nov 2020 20:41:31 +0000 (15:41 -0500)
If we receive a preimage for an outgoing HTLC that solves an output on a
backwards force-closed channel, we need to claim the output on-chain.

Note that this commit also gets rid of the channel monitor redundantly setting
`self.counterparty_payment_script` in `check_spend_counterparty_transaction`.

Co-authored-by: Antoine Riard <ariard@student.42.fr>
Co-authored-by: Valentine Wallace <vwallace@protonmail.com>
lightning/src/chain/channelmonitor.rs
lightning/src/ln/functional_tests.rs
lightning/src/ln/onchaintx.rs

index 425baeddf75e3933c309f4723c4706db999d5a07..bb8d8c32de483215aee393202b7f9a74e4e29cb6 100644 (file)
@@ -1165,6 +1165,41 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                    L::Target: Logger,
        {
                self.payment_preimages.insert(payment_hash.clone(), payment_preimage.clone());
+
+               // If the channel is force closed, try to claim the output from this preimage.
+               // First check if a counterparty commitment transaction has been broadcasted:
+               macro_rules! claim_htlcs {
+                       ($commitment_number: expr, $txid: expr) => {
+                               let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs($commitment_number, $txid, None);
+                               self.onchain_tx_handler.update_claims_view(&Vec::new(), htlc_claim_reqs, None, broadcaster, fee_estimator, logger);
+                       }
+               }
+               if let Some(txid) = self.current_counterparty_commitment_txid {
+                       if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
+                               claim_htlcs!(*commitment_number, txid);
+                               return;
+                       }
+               }
+               if let Some(txid) = self.prev_counterparty_commitment_txid {
+                       if let Some(commitment_number) = self.counterparty_commitment_txn_on_chain.get(&txid) {
+                               claim_htlcs!(*commitment_number, txid);
+                               return;
+                       }
+               }
+
+               // Then if a holder commitment transaction has been seen on-chain, broadcast transactions
+               // claiming the HTLC output from each of the holder commitment transactions.
+               // Note that we can't just use `self.holder_tx_signed`, because that only covers the case where
+               // *we* sign a holder commitment transaction, not when e.g. a watchtower broadcasts one of our
+               // holder commitment transactions.
+               if self.broadcasted_holder_revokable_script.is_some() {
+                       let (claim_reqs, _) = self.get_broadcasted_holder_claims(&self.current_holder_commitment_tx);
+                       self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, None, broadcaster, fee_estimator, logger);
+                       if let Some(ref tx) = self.prev_holder_signed_commitment_tx {
+                               let (claim_reqs, _) = self.get_broadcasted_holder_claims(&tx);
+                               self.onchain_tx_handler.update_claims_view(&Vec::new(), claim_reqs, None, broadcaster, fee_estimator, logger);
+                       }
+               }
        }
 
        pub(crate) fn broadcast_latest_holder_commitment_txn<B: Deref, L: Deref>(&mut self, broadcaster: &B, logger: &L)
@@ -1463,39 +1498,55 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                                check_htlc_fails!(txid, "previous", 'prev_loop);
                        }
 
+                       let htlc_claim_reqs = self.get_counterparty_htlc_output_claim_reqs(commitment_number, commitment_txid, Some(tx));
+                       for req in htlc_claim_reqs {
+                               claimable_outpoints.push(req);
+                       }
+
+               }
+               (claimable_outpoints, (commitment_txid, watch_outputs))
+       }
+
+       fn get_counterparty_htlc_output_claim_reqs(&self, commitment_number: u64, commitment_txid: Txid, tx: Option<&Transaction>) -> Vec<ClaimRequest> {
+               let mut claims = Vec::new();
+               if let Some(htlc_outputs) = self.counterparty_claimable_outpoints.get(&commitment_txid) {
                        if let Some(revocation_points) = self.their_cur_revocation_points {
                                let revocation_point_option =
+                                       // If the counterparty commitment tx is the latest valid state, use their latest
+                                       // per-commitment point
                                        if revocation_points.0 == commitment_number { Some(&revocation_points.1) }
                                        else if let Some(point) = revocation_points.2.as_ref() {
+                                               // If counterparty commitment tx is the state previous to the latest valid state, use
+                                               // their previous per-commitment point (non-atomicity of revocation means it's valid for
+                                               // them to temporarily have two valid commitment txns from our viewpoint)
                                                if revocation_points.0 == commitment_number + 1 { Some(point) } else { None }
                                        } else { None };
                                if let Some(revocation_point) = revocation_point_option {
-                                       self.counterparty_payment_script = {
-                                               // Note that the Network here is ignored as we immediately drop the address for the
-                                               // script_pubkey version
-                                               let payment_hash160 = WPubkeyHash::hash(&self.keys.pubkeys().payment_point.serialize());
-                                               Builder::new().push_opcode(opcodes::all::OP_PUSHBYTES_0).push_slice(&payment_hash160[..]).into_script()
-                                       };
-
-                                       // Then, try to find htlc outputs
-                                       for (_, &(ref htlc, _)) in per_commitment_data.iter().enumerate() {
+                                       for (_, &(ref htlc, _)) in htlc_outputs.iter().enumerate() {
                                                if let Some(transaction_output_index) = htlc.transaction_output_index {
-                                                       if transaction_output_index as usize >= tx.output.len() ||
-                                                                       tx.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
-                                                               return (claimable_outpoints, (commitment_txid, watch_outputs)); // Corrupted per_commitment_data, fuck this user
+                                                       if let Some(transaction) = tx {
+                                                               if transaction_output_index as usize >= transaction.output.len() ||
+                                                                       transaction.output[transaction_output_index as usize].value != htlc.amount_msat / 1000 {
+                                                                               return claims; // Corrupted per_commitment_data, fuck this user
+                                                                       }
                                                        }
-                                                       let preimage = if htlc.offered { if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) { Some(*p) } else { None } } else { None };
+                                                       let preimage =
+                                                               if htlc.offered {
+                                                                       if let Some(p) = self.payment_preimages.get(&htlc.payment_hash) {
+                                                                               Some(*p)
+                                                                       } else { None }
+                                                               } else { None };
                                                        let aggregable = if !htlc.offered { false } else { true };
                                                        if preimage.is_some() || !htlc.offered {
                                                                let witness_data = InputMaterial::CounterpartyHTLC { per_commitment_point: *revocation_point, counterparty_delayed_payment_base_key: self.counterparty_tx_cache.counterparty_delayed_payment_base_key, counterparty_htlc_base_key: self.counterparty_tx_cache.counterparty_htlc_base_key, preimage, htlc: htlc.clone() };
-                                                               claimable_outpoints.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
+                                                               claims.push(ClaimRequest { absolute_timelock: htlc.cltv_expiry, aggregable, outpoint: BitcoinOutPoint { txid: commitment_txid, vout: transaction_output_index }, witness_data });
                                                        }
                                                }
                                        }
                                }
                        }
                }
-               (claimable_outpoints, (commitment_txid, watch_outputs))
+               claims
        }
 
        /// Attempts to claim a counterparty HTLC-Success/HTLC-Timeout's outputs using the revocation key
@@ -1816,7 +1867,7 @@ impl<ChanSigner: ChannelKeys> ChannelMonitor<ChanSigner> {
                        }
                }
 
-               self.onchain_tx_handler.block_connected(&txn_matched, claimable_outpoints, height, &*broadcaster, &*fee_estimator, &*logger);
+               self.onchain_tx_handler.update_claims_view(&txn_matched, claimable_outpoints, Some(height), &&*broadcaster, &&*fee_estimator, &&*logger);
                self.last_block_hash = block_hash;
 
                // Determine new outputs to watch by comparing against previously known outputs to watch,
index d243ab288ae476ff214e6ee89e2e556fa03ff0d6..b3e5697c66834c268b12cc1da97a7653f58c3e51 100644 (file)
@@ -8503,3 +8503,187 @@ fn test_htlc_no_detection() {
         connect_blocks(&nodes[0], ANTI_REORG_DELAY - 1, 201, true, header_201.block_hash());
         expect_payment_failed!(nodes[0], our_payment_hash, true);
 }
+
+fn do_test_onchain_htlc_settlement_after_close(broadcast_alice: bool, go_onchain_before_fulfill: bool) {
+       // If we route an HTLC, then learn the HTLC's preimage after the upstream channel has been
+       // force-closed, we must claim that HTLC on-chain. (Given an HTLC forwarded from Alice --> Bob -->
+       // Carol, Alice would be the upstream node, and Carol the downstream.)
+       //
+       // Steps of the test:
+       // 1) Alice sends a HTLC to Carol through Bob.
+       // 2) Carol doesn't settle the HTLC.
+       // 3) If broadcast_alice is true, Alice force-closes her channel with Bob. Else Bob force closes.
+       // Steps 4 and 5 may be reordered depending on go_onchain_before_fulfill.
+       // 4) Bob sees the Alice's commitment on his chain or vice versa. An offered output is present
+       //    but can't be claimed as Bob doesn't have yet knowledge of the preimage.
+       // 5) Carol release the preimage to Bob off-chain.
+       // 6) Bob claims the offered output on the broadcasted commitment.
+       let chanmon_cfgs = create_chanmon_cfgs(3);
+       let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
+       let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[None, None, None]);
+       let nodes = create_network(3, &node_cfgs, &node_chanmgrs);
+
+       // Create some initial channels
+       let chan_ab = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100000, 10001, InitFeatures::known(), InitFeatures::known());
+       create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 100000, 10001, InitFeatures::known(), InitFeatures::known());
+
+       // Steps (1) and (2):
+       // Send an HTLC Alice --> Bob --> Carol, but Carol doesn't settle the HTLC back.
+       let (payment_preimage, _payment_hash) = route_payment(&nodes[0], &vec!(&nodes[1], &nodes[2]), 3_000_000);
+
+       // Check that Alice's commitment transaction now contains an output for this HTLC.
+       let alice_txn = get_local_commitment_txn!(nodes[0], chan_ab.2);
+       check_spends!(alice_txn[0], chan_ab.3);
+       assert_eq!(alice_txn[0].output.len(), 2);
+       check_spends!(alice_txn[1], alice_txn[0]); // 2nd transaction is a non-final HTLC-timeout
+       assert_eq!(alice_txn[1].input[0].witness.last().unwrap().len(), OFFERED_HTLC_SCRIPT_WEIGHT);
+       assert_eq!(alice_txn.len(), 2);
+
+       // Steps (3) and (4):
+       // If `go_onchain_before_fufill`, broadcast the relevant commitment transaction and check that Bob
+       // responds by (1) broadcasting a channel update and (2) adding a new ChannelMonitor.
+       let mut force_closing_node = 0; // Alice force-closes
+       if !broadcast_alice { force_closing_node = 1; } // Bob force-closes
+       nodes[force_closing_node].node.force_close_channel(&chan_ab.2);
+       check_closed_broadcast!(nodes[force_closing_node], false);
+       check_added_monitors!(nodes[force_closing_node], 1);
+       if go_onchain_before_fulfill {
+               let txn_to_broadcast = match broadcast_alice {
+                       true => alice_txn.clone(),
+                       false => get_local_commitment_txn!(nodes[1], chan_ab.2)
+               };
+               let header = BlockHeader { version: 0x20000000, prev_blockhash: Default::default(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42};
+               connect_block(&nodes[1], &Block { header, txdata: vec![txn_to_broadcast[0].clone()]}, 1);
+               let mut bob_txn = nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap();
+               if broadcast_alice {
+                       check_closed_broadcast!(nodes[1], false);
+                       check_added_monitors!(nodes[1], 1);
+               }
+               assert_eq!(bob_txn.len(), 1);
+               check_spends!(bob_txn[0], chan_ab.3);
+       }
+
+       // Step (5):
+       // Carol then claims the funds and sends an update_fulfill message to Bob, and they go through the
+       // process of removing the HTLC from their commitment transactions.
+       assert!(nodes[2].node.claim_funds(payment_preimage, &None, 3_000_000));
+       check_added_monitors!(nodes[2], 1);
+       let carol_updates = get_htlc_update_msgs!(nodes[2], nodes[1].node.get_our_node_id());
+       assert!(carol_updates.update_add_htlcs.is_empty());
+       assert!(carol_updates.update_fail_htlcs.is_empty());
+       assert!(carol_updates.update_fail_malformed_htlcs.is_empty());
+       assert!(carol_updates.update_fee.is_none());
+       assert_eq!(carol_updates.update_fulfill_htlcs.len(), 1);
+
+       nodes[1].node.handle_update_fulfill_htlc(&nodes[2].node.get_our_node_id(), &carol_updates.update_fulfill_htlcs[0]);
+       // If Alice broadcasted but Bob doesn't know yet, here he prepares to tell her about the preimage.
+       if !go_onchain_before_fulfill && broadcast_alice {
+               let events = nodes[1].node.get_and_clear_pending_msg_events();
+               assert_eq!(events.len(), 1);
+               match events[0] {
+                       MessageSendEvent::UpdateHTLCs { ref node_id, .. } => {
+                               assert_eq!(*node_id, nodes[0].node.get_our_node_id());
+                       },
+                       _ => panic!("Unexpected event"),
+               };
+       }
+       nodes[1].node.handle_commitment_signed(&nodes[2].node.get_our_node_id(), &carol_updates.commitment_signed);
+       // One monitor update for the preimage to update the Bob<->Alice channel, one monitor update
+       // Carol<->Bob's updated commitment transaction info.
+       check_added_monitors!(nodes[1], 2);
+
+       let events = nodes[1].node.get_and_clear_pending_msg_events();
+       assert_eq!(events.len(), 2);
+       let bob_revocation = match events[0] {
+               MessageSendEvent::SendRevokeAndACK { ref node_id, ref msg } => {
+                       assert_eq!(*node_id, nodes[2].node.get_our_node_id());
+                       (*msg).clone()
+               },
+               _ => panic!("Unexpected event"),
+       };
+       let bob_updates = match events[1] {
+               MessageSendEvent::UpdateHTLCs { ref node_id, ref updates } => {
+                       assert_eq!(*node_id, nodes[2].node.get_our_node_id());
+                       (*updates).clone()
+               },
+               _ => panic!("Unexpected event"),
+       };
+
+       nodes[2].node.handle_revoke_and_ack(&nodes[1].node.get_our_node_id(), &bob_revocation);
+       check_added_monitors!(nodes[2], 1);
+       nodes[2].node.handle_commitment_signed(&nodes[1].node.get_our_node_id(), &bob_updates.commitment_signed);
+       check_added_monitors!(nodes[2], 1);
+
+       let events = nodes[2].node.get_and_clear_pending_msg_events();
+       assert_eq!(events.len(), 1);
+       let carol_revocation = match events[0] {
+               MessageSendEvent::SendRevokeAndACK { ref node_id, ref msg } => {
+                       assert_eq!(*node_id, nodes[1].node.get_our_node_id());
+                       (*msg).clone()
+               },
+               _ => panic!("Unexpected event"),
+       };
+       nodes[1].node.handle_revoke_and_ack(&nodes[2].node.get_our_node_id(), &carol_revocation);
+       check_added_monitors!(nodes[1], 1);
+
+       // If this test requires the force-closed channel to not be on-chain until after the fulfill,
+       // here's where we put said channel's commitment tx on-chain.
+       let mut txn_to_broadcast = alice_txn.clone();
+       if !broadcast_alice { txn_to_broadcast = get_local_commitment_txn!(nodes[1], chan_ab.2); }
+       if !go_onchain_before_fulfill {
+               let header = BlockHeader { version: 0x20000000, prev_blockhash: Default::default(), merkle_root: Default::default(), time: 42, bits: 42, nonce: 42};
+               connect_block(&nodes[1], &Block { header, txdata: vec![txn_to_broadcast[0].clone()]}, 1);
+               // If Bob was the one to force-close, he will have already passed these checks earlier.
+               if broadcast_alice {
+                       check_closed_broadcast!(nodes[1], false);
+                       check_added_monitors!(nodes[1], 1);
+               }
+               let mut bob_txn = nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap();
+               if broadcast_alice {
+                       // In `connect_block()`, the ChainMonitor and ChannelManager are separately notified about a
+                       // new block being connected. The ChannelManager being notified triggers a monitor update,
+                       // which triggers broadcasting our commitment tx and an HTLC-claiming tx. The ChainMonitor
+                       // being notified triggers the HTLC-claiming tx redundantly, resulting in 3 total txs being
+                       // broadcasted.
+                       assert_eq!(bob_txn.len(), 3);
+                       check_spends!(bob_txn[1], chan_ab.3);
+               } else {
+                       assert_eq!(bob_txn.len(), 2);
+                       check_spends!(bob_txn[0], chan_ab.3);
+               }
+       }
+
+       // Step (6):
+       // Finally, check that Bob broadcasted a preimage-claiming transaction for the HTLC output on the
+       // broadcasted commitment transaction.
+       {
+               let bob_txn = nodes[1].tx_broadcaster.txn_broadcasted.lock().unwrap().clone();
+               if go_onchain_before_fulfill {
+                       // Bob should now have an extra broadcasted tx, for the preimage-claiming transaction.
+                       assert_eq!(bob_txn.len(), 2);
+               }
+               let script_weight = match broadcast_alice {
+                       true => OFFERED_HTLC_SCRIPT_WEIGHT,
+                       false => ACCEPTED_HTLC_SCRIPT_WEIGHT
+               };
+               // If Alice force-closed and Bob didn't receive her commitment transaction until after he
+               // received Carol's fulfill, he broadcasts the HTLC-output-claiming transaction first. Else if
+               // Bob force closed or if he found out about Alice's commitment tx before receiving Carol's
+               // fulfill, then he broadcasts the HTLC-output-claiming transaction second.
+               if broadcast_alice && !go_onchain_before_fulfill {
+                       check_spends!(bob_txn[0], txn_to_broadcast[0]);
+                       assert_eq!(bob_txn[0].input[0].witness.last().unwrap().len(), script_weight);
+               } else {
+                       check_spends!(bob_txn[1], txn_to_broadcast[0]);
+                       assert_eq!(bob_txn[1].input[0].witness.last().unwrap().len(), script_weight);
+               }
+       }
+}
+
+#[test]
+fn test_onchain_htlc_settlement_after_close() {
+       do_test_onchain_htlc_settlement_after_close(true, true);
+       do_test_onchain_htlc_settlement_after_close(false, true); // Technically redundant, but may as well
+       do_test_onchain_htlc_settlement_after_close(true, false);
+       do_test_onchain_htlc_settlement_after_close(false, false);
+}
index 2f1565631ea9fe9ce94244dd3bab6ab71f480a75..3484d8983f60fc0e9367993b5b5de3b4979dc8ff 100644 (file)
@@ -282,6 +282,8 @@ pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
 
        onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
 
+       latest_height: u32,
+
        secp_ctx: Secp256k1<secp256k1::All>,
 }
 
@@ -328,6 +330,7 @@ impl<ChanSigner: ChannelKeys + Writeable> OnchainTxHandler<ChanSigner> {
                                }
                        }
                }
+               self.latest_height.write(writer)?;
                Ok(())
        }
 }
@@ -387,6 +390,7 @@ impl<ChanSigner: ChannelKeys + Readable> Readable for OnchainTxHandler<ChanSigne
                        }
                        onchain_events_waiting_threshold_conf.insert(height_target, events);
                }
+               let latest_height = Readable::read(reader)?;
 
                Ok(OnchainTxHandler {
                        destination_script,
@@ -399,6 +403,7 @@ impl<ChanSigner: ChannelKeys + Readable> Readable for OnchainTxHandler<ChanSigne
                        claimable_outpoints,
                        pending_claim_requests,
                        onchain_events_waiting_threshold_conf,
+                       latest_height,
                        secp_ctx: Secp256k1::new(),
                })
        }
@@ -420,6 +425,7 @@ impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
                        pending_claim_requests: HashMap::new(),
                        claimable_outpoints: HashMap::new(),
                        onchain_events_waiting_threshold_conf: HashMap::new(),
+                       latest_height: 0,
 
                        secp_ctx: Secp256k1::new(),
                }
@@ -471,7 +477,7 @@ impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
 
        /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize coutnerparty onchain) lays on the assumption of claim transactions getting confirmed before timelock expiration
        /// (CSV or CLTV following cases). In case of high-fee spikes, claim tx may stuck in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or Child-Pay-For-Parent.
-       fn generate_claim_tx<F: Deref, L: Deref>(&mut self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: F, logger: L) -> Option<(Option<u32>, u32, Transaction)>
+       fn generate_claim_tx<F: Deref, L: Deref>(&mut self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: &F, logger: &L) -> Option<(Option<u32>, u32, Transaction)>
                where F::Target: FeeEstimator,
                                        L::Target: Logger,
        {
@@ -657,12 +663,20 @@ impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
                None
        }
 
-       pub(crate) fn block_connected<B: Deref, F: Deref, L: Deref>(&mut self, txn_matched: &[&Transaction], claimable_outpoints: Vec<ClaimRequest>, height: u32, broadcaster: B, fee_estimator: F, logger: L)
+       /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
+       /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
+       /// Formerly this was named `block_connected`, but it is now also used for claiming an HTLC output
+       /// if we receive a preimage after force-close.
+       pub(crate) fn update_claims_view<B: Deref, F: Deref, L: Deref>(&mut self, txn_matched: &[&Transaction], claimable_outpoints: Vec<ClaimRequest>, latest_height: Option<u32>, broadcaster: &B, fee_estimator: &F, logger: &L)
                where B::Target: BroadcasterInterface,
                      F::Target: FeeEstimator,
                                        L::Target: Logger,
        {
-               log_trace!(logger, "Block at height {} connected with {} claim requests", height, claimable_outpoints.len());
+               let height = match latest_height {
+                       Some(h) => h,
+                       None => self.latest_height,
+               };
+               log_trace!(logger, "Updating claims view at height {} with {} matched transactions and {} claim requests", height, txn_matched.len(), claimable_outpoints.len());
                let mut new_claims = Vec::new();
                let mut aggregated_claim = HashMap::new();
                let mut aggregated_soonest = ::std::u32::MAX;
@@ -855,7 +869,7 @@ impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
                        }
                }
                for (_, claim_material) in bump_candidates.iter_mut() {
-                       if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
+                       if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &&*fee_estimator, &&*logger) {
                                claim_material.height_timer = new_timer;
                                claim_material.feerate_previous = new_feerate;
                                broadcaster.broadcast_transaction(&bump_tx);