Handle 1-conf funding_locked in channel no matter the event order
[rust-lightning] / lightning / src / ln / channel.rs
index 0f09fd33042893c8895589680c4bef43103fddd1..174eed9b9185669dcc704f81d5b849d62837d641 100644 (file)
@@ -3501,11 +3501,57 @@ impl<Signer: Sign> Channel<Signer> {
                self.network_sync == UpdateStatus::DisabledMarked
        }
 
+       fn check_get_funding_locked(&mut self, height: u32) -> Option<msgs::FundingLocked> {
+               if self.funding_tx_confirmation_height == 0 {
+                       return None;
+               }
+
+               let funding_tx_confirmations = height as i64 - self.funding_tx_confirmation_height as i64 + 1;
+               if funding_tx_confirmations <= 0 {
+                       self.funding_tx_confirmation_height = 0;
+               }
+
+               if funding_tx_confirmations < self.minimum_depth as i64 {
+                       return None;
+               }
+
+               let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
+               let need_commitment_update = if non_shutdown_state == ChannelState::FundingSent as u32 {
+                       self.channel_state |= ChannelState::OurFundingLocked as u32;
+                       true
+               } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::TheirFundingLocked as u32) {
+                       self.channel_state = ChannelState::ChannelFunded as u32 | (self.channel_state & MULTI_STATE_FLAGS);
+                       self.update_time_counter += 1;
+                       true
+               } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::OurFundingLocked as u32) {
+                       // We got a reorg but not enough to trigger a force close, just ignore.
+                       false
+               } else if self.channel_state < ChannelState::ChannelFunded as u32 {
+                       panic!("Started confirming a channel in a state pre-FundingSent?: {}", self.channel_state);
+               } else {
+                       // We got a reorg but not enough to trigger a force close, just ignore.
+                       false
+               };
+
+               if need_commitment_update {
+                       if self.channel_state & (ChannelState::MonitorUpdateFailed as u32) == 0 {
+                               let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
+                               return Some(msgs::FundingLocked {
+                                       channel_id: self.channel_id,
+                                       next_per_commitment_point,
+                               });
+                       } else {
+                               self.monitor_pending_funding_locked = true;
+                       }
+               }
+               None
+       }
+
        /// 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 {
+                       -> Result<Option<msgs::FundingLocked>, msgs::ErrorMessage> where L::Target: Logger {
                let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
                for &(index_in_block, tx) in txdata.iter() {
                        if let Some(funding_txo) = self.get_funding_txo() {
@@ -3550,6 +3596,12 @@ impl<Signer: Sign> Channel<Signer> {
                                                        }
                                                }
                                        }
+                                       // If we allow 1-conf funding, we may need to check for funding_locked here and
+                                       // send it immediately instead of waiting for an update_best_block call (which
+                                       // may have already happened for this block).
+                                       if let Some(funding_locked) = self.check_get_funding_locked(height) {
+                                               return Ok(Some(funding_locked));
+                                       }
                                }
                                for inp in tx.input.iter() {
                                        if inp.previous_output == funding_txo.into_bitcoin_outpoint() {
@@ -3562,7 +3614,7 @@ impl<Signer: Sign> Channel<Signer> {
                                }
                        }
                }
-               Ok(())
+               Ok(None)
        }
 
        /// When a new block is connected, we check the height of the block against outbound holding
@@ -3592,59 +3644,32 @@ impl<Signer: Sign> Channel<Signer> {
                });
 
                self.update_time_counter = cmp::max(self.update_time_counter, highest_header_time);
-               if self.funding_tx_confirmation_height > 0 {
-                       let funding_tx_confirmations = height as i64 - self.funding_tx_confirmation_height as i64 + 1;
-                       if funding_tx_confirmations <= 0 {
-                               self.funding_tx_confirmation_height = 0;
+
+               if let Some(funding_locked) = self.check_get_funding_locked(height) {
+                       return Ok((Some(funding_locked), timed_out_htlcs));
+               }
+
+               let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
+               if non_shutdown_state >= ChannelState::ChannelFunded as u32 ||
+                  (non_shutdown_state & ChannelState::OurFundingLocked as u32) == ChannelState::OurFundingLocked as u32 {
+                       let mut funding_tx_confirmations = height as i64 - self.funding_tx_confirmation_height as i64 + 1;
+                       if self.funding_tx_confirmation_height == 0 {
+                               // Note that check_get_funding_locked may reset funding_tx_confirmation_height to
+                               // zero if it has been reorged out, however in either case, our state flags
+                               // indicate we've already sent a funding_locked
+                               funding_tx_confirmations = 0;
                        }
 
-                       let non_shutdown_state = self.channel_state & (!MULTI_STATE_FLAGS);
-                       if (non_shutdown_state >= ChannelState::ChannelFunded as u32 ||
-                          (non_shutdown_state & ChannelState::OurFundingLocked as u32) == ChannelState::OurFundingLocked as u32) &&
-                           funding_tx_confirmations < self.minimum_depth as i64 / 2 {
+                       // If we've sent funding_locked (or have both sent and received funding_locked), and
+                       // the funding transaction's confirmation count has dipped below minimum_depth / 2,
+                       // close the channel and hope we can get the latest state on chain (because presumably
+                       // the funding transaction is at least still in the mempool of most nodes).
+                       if funding_tx_confirmations < self.minimum_depth as i64 / 2 {
                                return Err(msgs::ErrorMessage {
                                        channel_id: self.channel_id(),
                                        data: format!("Funding transaction was un-confirmed. Locked at {} confs, now have {} confs.", self.minimum_depth, funding_tx_confirmations),
                                });
                        }
-
-                       if funding_tx_confirmations == self.minimum_depth as i64 {
-                               let need_commitment_update = if non_shutdown_state == ChannelState::FundingSent as u32 {
-                                       self.channel_state |= ChannelState::OurFundingLocked as u32;
-                                       true
-                               } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::TheirFundingLocked as u32) {
-                                       self.channel_state = ChannelState::ChannelFunded as u32 | (self.channel_state & MULTI_STATE_FLAGS);
-                                       self.update_time_counter += 1;
-                                       true
-                               } else if non_shutdown_state == (ChannelState::FundingSent as u32 | ChannelState::OurFundingLocked as u32) {
-                                       // We got a reorg but not enough to trigger a force close, just update
-                                       // funding_tx_confirmed_in and return.
-                                       false
-                               } else if self.channel_state < ChannelState::ChannelFunded as u32 {
-                                       panic!("Started confirming a channel in a state pre-FundingSent?: {}", self.channel_state);
-                               } else {
-                                       // We got a reorg but not enough to trigger a force close, just update
-                                       // funding_tx_confirmed_in and return.
-                                       false
-                               };
-
-                               //TODO: Note that this must be a duplicate of the previous commitment point they sent us,
-                               //as otherwise we will have a commitment transaction that they can't revoke (well, kinda,
-                               //they can by sending two revoke_and_acks back-to-back, but not really). This appears to be
-                               //a protocol oversight, but I assume I'm just missing something.
-                               if need_commitment_update {
-                                       if self.channel_state & (ChannelState::MonitorUpdateFailed as u32) == 0 {
-                                               let next_per_commitment_point = self.holder_signer.get_per_commitment_point(self.cur_holder_commitment_transaction_number, &self.secp_ctx);
-                                               return Ok((Some(msgs::FundingLocked {
-                                                       channel_id: self.channel_id,
-                                                       next_per_commitment_point,
-                                               }), timed_out_htlcs));
-                                       } else {
-                                               self.monitor_pending_funding_locked = true;
-                                               return Ok((None, timed_out_htlcs));
-                                       }
-                               }
-                       }
                }
 
                Ok((None, timed_out_htlcs))