Move ChannelManager to Channel's new block data API
authorMatt Corallo <git@bluematt.me>
Fri, 19 Mar 2021 00:32:30 +0000 (20:32 -0400)
committerMatt Corallo <git@bluematt.me>
Mon, 5 Apr 2021 17:03:04 +0000 (13:03 -0400)
This also moves the scanning of the block for commitment
transactions into channel, unifying the error path.

lightning/src/ln/channel.rs
lightning/src/ln/channelmanager.rs

index 1279f310d4bfdbcfd134a9b53c95674fa0dd21bf..0f09fd33042893c8895589680c4bef43103fddd1 100644 (file)
@@ -7,7 +7,6 @@
 // You may not use this file except in accordance with one or both of these
 // licenses.
 
-use bitcoin::blockdata::block::BlockHeader;
 use bitcoin::blockdata::script::{Script,Builder};
 use bitcoin::blockdata::transaction::{TxIn, TxOut, Transaction, SigHashType};
 use bitcoin::blockdata::opcodes;
@@ -3502,47 +3501,63 @@ impl<Signer: Sign> Channel<Signer> {
                self.network_sync == UpdateStatus::DisabledMarked
        }
 
-       pub fn transactions_confirmed(&mut self, block_hash: &BlockHash, height: u32, txdata: &TransactionData) -> Result<(), msgs::ErrorMessage> {
+       /// When a transaction is confirmed, we check whether it is or spends the funding transaction
+       /// In the first case, we store the confirmation height and calculating the short channel id.
+       /// In the second, we simply return an Err indicating we need to be force-closed now.
+       pub fn transactions_confirmed<L: Deref>(&mut self, block_hash: &BlockHash, height: u32, txdata: &TransactionData, logger: &L)
+                       -> Result<(), msgs::ErrorMessage> where L::Target: Logger {
                let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
-               if non_shutdown_state & !(ChannelState::TheirFundingLocked as u32) == ChannelState::FundingSent as u32 {
-                       for &(index_in_block, tx) in txdata.iter() {
-                               let funding_txo = self.get_funding_txo().unwrap();
-                               if tx.txid() == funding_txo.txid {
-                                       let txo_idx = funding_txo.index as usize;
-                                       if txo_idx >= tx.output.len() || tx.output[txo_idx].script_pubkey != self.get_funding_redeemscript().to_v0_p2wsh() ||
-                                                       tx.output[txo_idx].value != self.channel_value_satoshis {
-                                               if self.is_outbound() {
-                                                       // If we generated the funding transaction and it doesn't match what it
-                                                       // should, the client is really broken and we should just panic and
-                                                       // tell them off. That said, because hash collisions happen with high
-                                                       // probability in fuzztarget mode, if we're fuzzing we just close the
-                                                       // channel and move on.
-                                                       #[cfg(not(feature = "fuzztarget"))]
-                                                       panic!("Client called ChannelManager::funding_transaction_generated with bogus transaction!");
+               for &(index_in_block, tx) in txdata.iter() {
+                       if let Some(funding_txo) = self.get_funding_txo() {
+                               // If we haven't yet sent a funding_locked, but are in FundingSent (ignoring
+                               // whether they've sent a funding_locked or not), check if we should send one.
+                               if non_shutdown_state & !(ChannelState::TheirFundingLocked as u32) == ChannelState::FundingSent as u32 {
+                                       if tx.txid() == funding_txo.txid {
+                                               let txo_idx = funding_txo.index as usize;
+                                               if txo_idx >= tx.output.len() || tx.output[txo_idx].script_pubkey != self.get_funding_redeemscript().to_v0_p2wsh() ||
+                                                               tx.output[txo_idx].value != self.channel_value_satoshis {
+                                                       if self.is_outbound() {
+                                                               // If we generated the funding transaction and it doesn't match what it
+                                                               // should, the client is really broken and we should just panic and
+                                                               // tell them off. That said, because hash collisions happen with high
+                                                               // probability in fuzztarget mode, if we're fuzzing we just close the
+                                                               // channel and move on.
+                                                               #[cfg(not(feature = "fuzztarget"))]
+                                                               panic!("Client called ChannelManager::funding_transaction_generated with bogus transaction!");
+                                                       }
+                                                       self.channel_state = ChannelState::ShutdownComplete as u32;
+                                                       self.update_time_counter += 1;
+                                                       return Err(msgs::ErrorMessage {
+                                                               channel_id: self.channel_id(),
+                                                               data: "funding tx had wrong script/value or output index".to_owned()
+                                                       });
+                                               } else {
+                                                       if self.is_outbound() {
+                                                               for input in tx.input.iter() {
+                                                                       if input.witness.is_empty() {
+                                                                               // We generated a malleable funding transaction, implying we've
+                                                                               // just exposed ourselves to funds loss to our counterparty.
+                                                                               #[cfg(not(feature = "fuzztarget"))]
+                                                                               panic!("Client called ChannelManager::funding_transaction_generated with bogus transaction!");
+                                                                       }
+                                                               }
+                                                       }
+                                                       self.funding_tx_confirmation_height = height as u64;
+                                                       self.funding_tx_confirmed_in = Some(*block_hash);
+                                                       self.short_channel_id = match scid_from_parts(height as u64, index_in_block as u64, txo_idx as u64) {
+                                                               Ok(scid) => Some(scid),
+                                                               Err(_) => panic!("Block was bogus - either height was > 16 million, had > 16 million transactions, or had > 65k outputs"),
+                                                       }
                                                }
-                                               self.channel_state = ChannelState::ShutdownComplete as u32;
-                                               self.update_time_counter += 1;
+                                       }
+                               }
+                               for inp in tx.input.iter() {
+                                       if inp.previous_output == funding_txo.into_bitcoin_outpoint() {
+                                               log_trace!(logger, "Detected channel-closing tx {} spending {}:{}, closing channel {}", tx.txid(), inp.previous_output.txid, inp.previous_output.vout, log_bytes!(self.channel_id()));
                                                return Err(msgs::ErrorMessage {
                                                        channel_id: self.channel_id(),
-                                                       data: "funding tx had wrong script/value".to_owned()
+                                                       data: "Commitment or closing transaction was confirmed on chain.".to_owned()
                                                });
-                                       } else {
-                                               if self.is_outbound() {
-                                                       for input in tx.input.iter() {
-                                                               if input.witness.is_empty() {
-                                                                       // We generated a malleable funding transaction, implying we've
-                                                                       // just exposed ourselves to funds loss to our counterparty.
-                                                                       #[cfg(not(feature = "fuzztarget"))]
-                                                                       panic!("Client called ChannelManager::funding_transaction_generated with bogus transaction!");
-                                                               }
-                                                       }
-                                               }
-                                               self.funding_tx_confirmation_height = height as u64;
-                                               self.funding_tx_confirmed_in = Some(*block_hash);
-                                               self.short_channel_id = match scid_from_parts(height as u64, index_in_block as u64, txo_idx as u64) {
-                                                       Ok(scid) => Some(scid),
-                                                       Err(_) => panic!("Block was bogus - either height was > 16 million, had > 16 million transactions, or had > 65k outputs"),
-                                               }
                                        }
                                }
                        }
@@ -3635,35 +3650,6 @@ impl<Signer: Sign> Channel<Signer> {
                Ok((None, timed_out_htlcs))
        }
 
-       /// When we receive a new block, we (a) check whether the block contains the funding
-       /// transaction (which would start us counting blocks until we send the funding_signed), and
-       /// (b) check the height of the block against outbound holding cell HTLCs in case we need to
-       /// give up on them prematurely and time them out. Everything else (e.g. commitment
-       /// transaction broadcasts, channel closure detection, HTLC transaction broadcasting, etc) is
-       /// handled by the ChannelMonitor.
-       ///
-       /// If we return Err, the channel may have been closed, at which point the standard
-       /// requirements apply - no calls may be made except those explicitly stated to be allowed
-       /// post-shutdown.
-       /// Only returns an ErrorAction of DisconnectPeer, if Err.
-       ///
-       /// May return some HTLCs (and their payment_hash) which have timed out and should be failed
-       /// back.
-       pub fn block_connected(&mut self, header: &BlockHeader, txdata: &TransactionData, height: u32) -> Result<(Option<msgs::FundingLocked>, Vec<(HTLCSource, PaymentHash)>), msgs::ErrorMessage> {
-               self.transactions_confirmed(&header.block_hash(), height, txdata)?;
-               self.update_best_block(height, header.time)
-       }
-
-       /// Called by channelmanager based on chain blocks being disconnected.
-       /// Returns true if we need to close the channel now due to funding transaction
-       /// unconfirmation/reorg.
-       pub fn block_disconnected(&mut self, header: &BlockHeader, new_height: u32) -> bool {
-               if self.update_best_block(new_height, header.time).is_err() {
-                       return true;
-               }
-               false
-       }
-
        // Methods to get unprompted messages to send to the remote end (or where we already returned
        // something in the handler for the message that prompted this message):
 
index 14fed3c40aa24f487064ee4d33fdb54318d2040f..acdc064884994e9936e307d5617c62c5e64fe29b 100644 (file)
@@ -3334,7 +3334,8 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                        let short_to_id = &mut channel_state.short_to_id;
                        let pending_msg_events = &mut channel_state.pending_msg_events;
                        channel_state.by_id.retain(|_, channel| {
-                               let res = channel.block_connected(header, txdata, height);
+                               let res = channel.transactions_confirmed(&block_hash, height, txdata, &self.logger)
+                                       .and_then(|_| channel.update_best_block(height, header.time));
                                if let Ok((chan_res, mut timed_out_pending_htlcs)) = res {
                                        for (source, payment_hash) in timed_out_pending_htlcs.drain(..) {
                                                let chan_update = self.get_channel_update(&channel).map(|u| u.encode_with_len()).unwrap(); // Cannot add/recv HTLCs before we have a short_id so unwrap is safe
@@ -3360,38 +3361,23 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                short_to_id.insert(channel.get_short_channel_id().unwrap(), channel.channel_id());
                                        }
                                } else if let Err(e) = res {
+                                       if let Some(short_id) = channel.get_short_channel_id() {
+                                               short_to_id.remove(&short_id);
+                                       }
+                                       // It looks like our counterparty went on-chain or funding transaction was
+                                       // reorged out of the main chain. Close the channel.
+                                       failed_channels.push(channel.force_shutdown(true));
+                                       if let Ok(update) = self.get_channel_update(&channel) {
+                                               pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
+                                                       msg: update
+                                               });
+                                       }
                                        pending_msg_events.push(events::MessageSendEvent::HandleError {
                                                node_id: channel.get_counterparty_node_id(),
                                                action: msgs::ErrorAction::SendErrorMessage { msg: e },
                                        });
                                        return false;
                                }
-                               if let Some(funding_txo) = channel.get_funding_txo() {
-                                       for &(_, tx) in txdata.iter() {
-                                               for inp in tx.input.iter() {
-                                                       if inp.previous_output == funding_txo.into_bitcoin_outpoint() {
-                                                               log_trace!(self.logger, "Detected channel-closing tx {} spending {}:{}, closing channel {}", tx.txid(), inp.previous_output.txid, inp.previous_output.vout, log_bytes!(channel.channel_id()));
-                                                               if let Some(short_id) = channel.get_short_channel_id() {
-                                                                       short_to_id.remove(&short_id);
-                                                               }
-                                                               // It looks like our counterparty went on-chain. Close the channel.
-                                                               failed_channels.push(channel.force_shutdown(true));
-                                                               if let Ok(update) = self.get_channel_update(&channel) {
-                                                                       pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
-                                                                               msg: update
-                                                                       });
-                                                               }
-                                                               pending_msg_events.push(events::MessageSendEvent::HandleError {
-                                                                       node_id: channel.get_counterparty_node_id(),
-                                                                       action: msgs::ErrorAction::SendErrorMessage {
-                                                                               msg: msgs::ErrorMessage { channel_id: channel.channel_id(), data: "Commitment or closing transaction was confirmed on chain.".to_owned() }
-                                                                       },
-                                                               });
-                                                               return false;
-                                                       }
-                                               }
-                                       }
-                               }
                                true
                        });
 
@@ -3456,8 +3442,8 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                        let channel_state = &mut *channel_lock;
                        let short_to_id = &mut channel_state.short_to_id;
                        let pending_msg_events = &mut channel_state.pending_msg_events;
-                       channel_state.by_id.retain(|channel_id,  v| {
-                               if v.block_disconnected(header, new_height) {
+                       channel_state.by_id.retain(|_,  v| {
+                               if let Err(err_msg) = v.update_best_block(new_height, header.time) {
                                        if let Some(short_id) = v.get_short_channel_id() {
                                                short_to_id.remove(&short_id);
                                        }
@@ -3469,9 +3455,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                        }
                                        pending_msg_events.push(events::MessageSendEvent::HandleError {
                                                node_id: v.get_counterparty_node_id(),
-                                               action: msgs::ErrorAction::SendErrorMessage {
-                                                       msg: msgs::ErrorMessage { channel_id: *channel_id, data: "Funding transaction was un-confirmed.".to_owned() }
-                                               },
+                                               action: msgs::ErrorAction::SendErrorMessage { msg: err_msg },
                                        });
                                        false
                                } else {