Move HTLC tx generation in OnchainTxHandler
[rust-lightning] / lightning / src / ln / onchaintx.rs
index 68c71dd88837cd904e6b69db3a347267f00842d2..b2115c0f8ac973c86d0827e0b3aaa0d8dd8291f9 100644 (file)
@@ -15,6 +15,7 @@ use secp256k1;
 
 use ln::msgs::DecodeError;
 use ln::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
+use ln::channelmanager::PaymentPreimage;
 use ln::chan_utils::{HTLCType, LocalCommitmentTransaction};
 use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
 use chain::keysinterface::ChannelKeys;
@@ -22,7 +23,7 @@ use util::logger::Logger;
 use util::ser::{ReadableArgs, Readable, Writer, Writeable};
 use util::byte_utils;
 
-use std::collections::{HashMap, hash_map, HashSet};
+use std::collections::{HashMap, hash_map};
 use std::sync::Arc;
 use std::cmp;
 use std::ops::Deref;
@@ -144,6 +145,7 @@ pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
        funding_redeemscript: Script,
        local_commitment: Option<LocalCommitmentTransaction>,
        prev_local_commitment: Option<LocalCommitmentTransaction>,
+       local_csv: u16,
 
        key_storage: ChanSigner,
 
@@ -187,6 +189,8 @@ impl<ChanSigner: ChannelKeys + Writeable> OnchainTxHandler<ChanSigner> {
                self.local_commitment.write(writer)?;
                self.prev_local_commitment.write(writer)?;
 
+               self.local_csv.write(writer)?;
+
                self.key_storage.write(writer)?;
 
                writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
@@ -228,9 +232,12 @@ impl<ChanSigner: ChannelKeys + Readable> ReadableArgs<Arc<Logger>> for OnchainTx
        fn read<R: ::std::io::Read>(reader: &mut R, logger: Arc<Logger>) -> Result<Self, DecodeError> {
                let destination_script = Readable::read(reader)?;
                let funding_redeemscript = Readable::read(reader)?;
+
                let local_commitment = Readable::read(reader)?;
                let prev_local_commitment = Readable::read(reader)?;
 
+               let local_csv = Readable::read(reader)?;
+
                let key_storage = Readable::read(reader)?;
 
                let pending_claim_requests_len: u64 = Readable::read(reader)?;
@@ -281,6 +288,7 @@ impl<ChanSigner: ChannelKeys + Readable> ReadableArgs<Arc<Logger>> for OnchainTx
                        funding_redeemscript,
                        local_commitment,
                        prev_local_commitment,
+                       local_csv,
                        key_storage,
                        claimable_outpoints,
                        pending_claim_requests,
@@ -292,7 +300,7 @@ impl<ChanSigner: ChannelKeys + Readable> ReadableArgs<Arc<Logger>> for OnchainTx
 }
 
 impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
-       pub(super) fn new(destination_script: Script, keys: ChanSigner, funding_redeemscript: Script, logger: Arc<Logger>) -> Self {
+       pub(super) fn new(destination_script: Script, keys: ChanSigner, funding_redeemscript: Script, local_csv: u16, logger: Arc<Logger>) -> Self {
 
                let key_storage = keys;
 
@@ -301,6 +309,7 @@ impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
                        funding_redeemscript,
                        local_commitment: None,
                        prev_local_commitment: None,
+                       local_csv,
                        key_storage,
                        pending_claim_requests: HashMap::new(),
                        claimable_outpoints: HashMap::new(),
@@ -357,7 +366,7 @@ 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>(&self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: F) -> Option<(Option<u32>, u64, Transaction)>
+       fn generate_claim_tx<F: Deref>(&mut self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: F) -> Option<(Option<u32>, u64, Transaction)>
                where F::Target: FeeEstimator
        {
                if cached_claim_datas.per_input_material.len() == 0 { return None } // But don't prune pending claiming request yet, we may have to resurrect HTLCs
@@ -436,13 +445,14 @@ impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
                                        inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
                                        amt += *amount;
                                },
-                               &InputMaterial::LocalHTLC { .. } => { return None; }
+                               &InputMaterial::LocalHTLC { .. } => {
+                                       dynamic_fee = false;
+                               },
                                &InputMaterial::Funding { .. } => {
                                        dynamic_fee = false;
                                }
                        }
                }
-
                if dynamic_fee {
                        let predicted_weight = bumped_tx.get_weight() + inputs_witnesses_weight;
                        let mut new_feerate;
@@ -504,16 +514,31 @@ impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
                } else {
                        for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
                                match per_outp_material {
-                                       &InputMaterial::LocalHTLC { .. } => {
-                                               //TODO : Given that Local Commitment Transaction and HTLC-Timeout/HTLC-Success are counter-signed by peer, we can't
-                                               // RBF them. Need a Lightning specs change and package relay modification :
-                                               // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-November/016518.html
+                                       &InputMaterial::LocalHTLC { ref preimage, ref amount } => {
+                                               let mut htlc_tx = None;
+                                               if let Some(ref mut local_commitment) = self.local_commitment {
+                                                       if local_commitment.txid() == outp.txid {
+                                                               self.key_storage.sign_htlc_transaction(local_commitment, outp.vout, *preimage, self.local_csv, &self.secp_ctx);
+                                                               htlc_tx = local_commitment.htlc_with_valid_witness(outp.vout).clone();
+                                                       }
+                                               }
+                                               if let Some(ref mut prev_local_commitment) = self.prev_local_commitment {
+                                                       if prev_local_commitment.txid() == outp.txid {
+                                                               self.key_storage.sign_htlc_transaction(prev_local_commitment, outp.vout, *preimage, self.local_csv, &self.secp_ctx);
+                                                               htlc_tx = prev_local_commitment.htlc_with_valid_witness(outp.vout).clone();
+                                                       }
+                                               }
+                                               if let Some(htlc_tx) = htlc_tx {
+                                                       let feerate = (amount - htlc_tx.output[0].value) * 1000 / htlc_tx.get_weight() as u64;
+                                                       // Timer set to $NEVER given we can't bump tx without anchor outputs
+                                                       log_trace!(self, "Going to broadcast Local HTLC-{} claiming HTLC output {} from {}...", if preimage.is_some() { "Success" } else { "Timeout" }, outp.vout, outp.txid);
+                                                       return Some((None, feerate, htlc_tx));
+                                               }
                                                return None;
                                        },
                                        &InputMaterial::Funding { ref channel_value } => {
-                                               if self.local_commitment.is_some() {
-                                                       let mut local_commitment = self.local_commitment.clone().unwrap();
-                                                       self.key_storage.sign_local_commitment(&mut local_commitment, &self.funding_redeemscript, *channel_value, &self.secp_ctx);
+                                               if let Some(ref mut local_commitment) = self.local_commitment {
+                                                       self.key_storage.sign_local_commitment(local_commitment, &self.funding_redeemscript, *channel_value, &self.secp_ctx);
                                                        let signed_tx = local_commitment.with_valid_witness().clone();
                                                        let mut amt_outputs = 0;
                                                        for outp in signed_tx.output.iter() {
@@ -579,7 +604,7 @@ impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
                        }
                }
 
-               let mut bump_candidates = HashSet::new();
+               let mut bump_candidates = HashMap::new();
                for tx in txn_matched {
                        // Scan all input to verify is one of the outpoint spent is of interest for us
                        let mut claimed_outputs_material = Vec::new();
@@ -636,7 +661,7 @@ impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
                                                        }
                                                        //TODO: recompute soonest_timelock to avoid wasting a bit on fees
                                                        if at_least_one_drop {
-                                                               bump_candidates.insert(first_claim_txid_height.0.clone());
+                                                               bump_candidates.insert(first_claim_txid_height.0.clone(), claim_material.clone());
                                                        }
                                                }
                                                break; //No need to iterate further, either tx is our or their
@@ -684,27 +709,25 @@ impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
                for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
                        if let Some(h) = claim_data.height_timer {
                                if h == height {
-                                       bump_candidates.insert(*first_claim_txid);
+                                       bump_candidates.insert(*first_claim_txid, (*claim_data).clone());
                                }
                        }
                }
 
                // Build, bump and rebroadcast tx accordingly
                log_trace!(self, "Bumping {} candidates", bump_candidates.len());
-               for first_claim_txid in bump_candidates.iter() {
-                       if let Some((new_timer, new_feerate)) = {
-                               if let Some(claim_material) = self.pending_claim_requests.get(first_claim_txid) {
-                                       if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
-                                               log_trace!(self, "Broadcast onchain {}", log_tx!(bump_tx));
-                                               broadcaster.broadcast_transaction(&bump_tx);
-                                               Some((new_timer, new_feerate))
-                                       } else { None }
-                               } else { unreachable!(); }
-                       } {
-                               if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
-                                       claim_material.height_timer = new_timer;
-                                       claim_material.feerate_previous = new_feerate;
-                               } else { unreachable!(); }
+               let mut pending_claim_updates = Vec::with_capacity(bump_candidates.len());
+               for (first_claim_txid, claim_material) in bump_candidates.iter() {
+                       if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
+                               log_trace!(self, "Broadcast onchain {}", log_tx!(bump_tx));
+                               broadcaster.broadcast_transaction(&bump_tx);
+                               pending_claim_updates.push((*first_claim_txid, new_timer, new_feerate));
+                       }
+               }
+               for updates in pending_claim_updates {
+                       if let Some(claim_material) = self.pending_claim_requests.get_mut(&updates.0) {
+                               claim_material.height_timer = updates.1;
+                               claim_material.feerate_previous = updates.2;
                        }
                }
        }
@@ -787,4 +810,15 @@ impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
                }
                None
        }
+
+       pub(super) fn get_fully_signed_htlc_tx(&mut self, txid: Sha256dHash, htlc_index: u32, preimage: Option<PaymentPreimage>) -> Option<Transaction> {
+               //TODO: store preimage in OnchainTxHandler
+               if let Some(ref mut local_commitment) = self.local_commitment {
+                       if local_commitment.txid() == txid {
+                               self.key_storage.sign_htlc_transaction(local_commitment, htlc_index, preimage, self.local_csv, &self.secp_ctx);
+                               return local_commitment.htlc_with_valid_witness(htlc_index).clone();
+                       }
+               }
+               None
+       }
 }