Pull out regenerating RAA/CS in channel_reestablish handling

Author: TheBlueMatt

src/ln/channel.rs

@@ -2082,6 +2082,71 @@ impl Channel {
 		Ok(())
 	}
 
+	fn get_last_revoke_and_ack(&self) -> msgs::RevokeAndACK {
+		let next_per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &self.build_local_commitment_secret(self.cur_local_commitment_transaction_number));
+		let per_commitment_secret = chan_utils::build_commitment_secret(self.local_keys.commitment_seed, self.cur_local_commitment_transaction_number + 2);
+		msgs::RevokeAndACK {
+			channel_id: self.channel_id,
+			per_commitment_secret,
+			next_per_commitment_point,
+		}
+	}
+
+	fn get_last_commitment_update(&self) -> msgs::CommitmentUpdate {
+		let mut update_add_htlcs = Vec::new();
+		let mut update_fulfill_htlcs = Vec::new();
+		let mut update_fail_htlcs = Vec::new();
+		let mut update_fail_malformed_htlcs = Vec::new();
+
+		for htlc in self.pending_outbound_htlcs.iter() {
+			if let &OutboundHTLCState::LocalAnnounced(ref onion_packet) = &htlc.state {
+				update_add_htlcs.push(msgs::UpdateAddHTLC {
+					channel_id: self.channel_id(),
+					htlc_id: htlc.htlc_id,
+					amount_msat: htlc.amount_msat,
+					payment_hash: htlc.payment_hash,
+					cltv_expiry: htlc.cltv_expiry,
+					onion_routing_packet: (**onion_packet).clone(),
+				});
+			}
+		}
+
+		for htlc in self.pending_inbound_htlcs.iter() {
+			if let &InboundHTLCState::LocalRemoved(ref reason) = &htlc.state {
+				match reason {
+					&InboundHTLCRemovalReason::FailRelay(ref err_packet) => {
+						update_fail_htlcs.push(msgs::UpdateFailHTLC {
+							channel_id: self.channel_id(),
+							htlc_id: htlc.htlc_id,
+							reason: err_packet.clone()
+						});
+					},
+					&InboundHTLCRemovalReason::FailMalformed((ref sha256_of_onion, ref failure_code)) => {
+						update_fail_malformed_htlcs.push(msgs::UpdateFailMalformedHTLC {
+							channel_id: self.channel_id(),
+							htlc_id: htlc.htlc_id,
+							sha256_of_onion: sha256_of_onion.clone(),
+							failure_code: failure_code.clone(),
+						});
+					},
+					&InboundHTLCRemovalReason::Fulfill(ref payment_preimage) => {
+						update_fulfill_htlcs.push(msgs::UpdateFulfillHTLC {
+							channel_id: self.channel_id(),
+							htlc_id: htlc.htlc_id,
+							payment_preimage: payment_preimage.clone(),
+						});
+					},
+				}
+			}
+		}
+
+		msgs::CommitmentUpdate {
+			update_add_htlcs, update_fulfill_htlcs, update_fail_htlcs, update_fail_malformed_htlcs,
+			update_fee: None, //TODO: We need to support re-generating any update_fees in the last commitment_signed!
+			commitment_signed: self.send_commitment_no_state_update().expect("It looks like we failed to re-generate a commitment_signed we had previously sent?").0,
+		}
+	}
+
 	/// May panic if some calls other than message-handling calls (which will all Err immediately)
 	/// have been called between remove_uncommitted_htlcs_and_mark_paused and this call.
 	pub fn channel_reestablish(&mut self, msg: &msgs::ChannelReestablish) -> Result<(Option<msgs::FundingLocked>, Option<msgs::RevokeAndACK>, Option<msgs::CommitmentUpdate>, Option<ChannelMonitor>, RAACommitmentOrder), ChannelError> {
@@ -2106,13 +2171,7 @@ impl Channel {
 			// Note that if we need to repeat our FundingLocked we'll do that in the next if block.
 			None
 		} else if msg.next_remote_commitment_number == (INITIAL_COMMITMENT_NUMBER - 1) - self.cur_local_commitment_transaction_number {
-			let next_per_commitment_point = PublicKey::from_secret_key(&self.secp_ctx, &self.build_local_commitment_secret(self.cur_local_commitment_transaction_number));
-			let per_commitment_secret = chan_utils::build_commitment_secret(self.local_keys.commitment_seed, self.cur_local_commitment_transaction_number + 2);
-			Some(msgs::RevokeAndACK {
-				channel_id: self.channel_id,
-				per_commitment_secret,
-				next_per_commitment_point,
-			})
+			Some(self.get_last_revoke_and_ack())
 		} else {
 			return Err(ChannelError::Close("Peer attempted to reestablish channel with a very old local commitment transaction"));
 		};
@@ -2172,59 +2231,8 @@ impl Channel {
 			} else {
 				log_debug!(self, "Reconnected channel {} with only lost remote commitment tx", log_bytes!(self.channel_id()));
 			}
-			let mut update_add_htlcs = Vec::new();
-			let mut update_fulfill_htlcs = Vec::new();
-			let mut update_fail_htlcs = Vec::new();
-			let mut update_fail_malformed_htlcs = Vec::new();
-
-			for htlc in self.pending_outbound_htlcs.iter() {
-				if let &OutboundHTLCState::LocalAnnounced(ref onion_packet) = &htlc.state {
-					update_add_htlcs.push(msgs::UpdateAddHTLC {
-						channel_id: self.channel_id(),
-						htlc_id: htlc.htlc_id,
-						amount_msat: htlc.amount_msat,
-						payment_hash: htlc.payment_hash,
-						cltv_expiry: htlc.cltv_expiry,
-						onion_routing_packet: (**onion_packet).clone(),
-					});
-				}
-			}
-
-			for htlc in self.pending_inbound_htlcs.iter() {
-				if let &InboundHTLCState::LocalRemoved(ref reason) = &htlc.state {
-					match reason {
-						&InboundHTLCRemovalReason::FailRelay(ref err_packet) => {
-							update_fail_htlcs.push(msgs::UpdateFailHTLC {
-								channel_id: self.channel_id(),
-								htlc_id: htlc.htlc_id,
-								reason: err_packet.clone()
-							});
-						},
-						&InboundHTLCRemovalReason::FailMalformed((ref sha256_of_onion, ref failure_code)) => {
-							update_fail_malformed_htlcs.push(msgs::UpdateFailMalformedHTLC {
-								channel_id: self.channel_id(),
-								htlc_id: htlc.htlc_id,
-								sha256_of_onion: sha256_of_onion.clone(),
-								failure_code: failure_code.clone(),
-							});
-						},
-						&InboundHTLCRemovalReason::Fulfill(ref payment_preimage) => {
-							update_fulfill_htlcs.push(msgs::UpdateFulfillHTLC {
-								channel_id: self.channel_id(),
-								htlc_id: htlc.htlc_id,
-								payment_preimage: payment_preimage.clone(),
-							});
-						},
-					}
-				}
-			}
 
-			return Ok((resend_funding_locked, required_revoke,
-					Some(msgs::CommitmentUpdate {
-						update_add_htlcs, update_fulfill_htlcs, update_fail_htlcs, update_fail_malformed_htlcs,
-						update_fee: None, //TODO: We need to support re-generating any update_fees in the last commitment_signed!
-						commitment_signed: self.send_commitment_no_state_update().expect("It looks like we failed to re-generate a commitment_signed we had previously sent?").0,
-					}), None, order));
+			return Ok((resend_funding_locked, required_revoke, Some(self.get_last_commitment_update()), None, order));
 		} else {
 			return Err(ChannelError::Close("Peer attempted to reestablish channel with a very old remote commitment transaction"));
 		}