From: Matt Corallo Date: Sat, 18 Apr 2020 20:35:01 +0000 (-0400) Subject: Delay creating outbound ChannelMonitor until funding_signed rcpt X-Git-Tag: v0.0.12~78^2~1 X-Git-Url: http://git.bitcoin.ninja/?a=commitdiff_plain;h=5d0bfa383425ecbf308fdf819dbf7ad19e6c5ca4;p=rust-lightning Delay creating outbound ChannelMonitor until funding_signed rcpt Previously, we created the initial ChannelMonitor on outbound channels when we generated the funding_created message. This was somewhat unnecessary as, at that time, we hadn't yet received clearance to broadcast our initial funding transaction, and thus there should never be any use for a ChannelMonitor. It also complicated ChannelMonitor a bit as, at this point, we didn't have an initial local commitment transaction. By moving the creation of the initial ChannelMonitor to when we receive our counterparty's funding_signed, we can ensure that any ChannelMonitor will always have both a latest remote commitment tx and a latest local commitment tx for broadcast. This also fixes a strange API where we would close a channel unceremoniously on peer-disconnection if we hadn't yet received the funding_signed, but we'd already have a ChannelMonitor for that channel. While it isn't strictly a bug (some potential DoS issues aside), it is strange that these two definitions of a channel being open were not in sync. --- diff --git a/lightning/src/ln/chanmon_update_fail_tests.rs b/lightning/src/ln/chanmon_update_fail_tests.rs index 71e4d376f..5d8c47377 100644 --- a/lightning/src/ln/chanmon_update_fail_tests.rs +++ b/lightning/src/ln/chanmon_update_fail_tests.rs @@ -1629,12 +1629,9 @@ fn monitor_update_claim_fail_no_response() { claim_payment(&nodes[0], &[&nodes[1]], payment_preimage_2, 1_000_000); } -// Note that restore_between_fails with !fail_on_generate is useless -// Also note that !fail_on_generate && !fail_on_signed is useless -// Finally, note that !fail_on_signed is not possible with fail_on_generate && !restore_between_fails // confirm_a_first and restore_b_before_conf are wholly unrelated to earlier bools and // restore_b_before_conf has no meaning if !confirm_a_first -fn do_during_funding_monitor_fail(fail_on_generate: bool, restore_between_fails: bool, fail_on_signed: bool, confirm_a_first: bool, restore_b_before_conf: bool) { +fn do_during_funding_monitor_fail(confirm_a_first: bool, restore_b_before_conf: bool) { // Test that if the monitor update generated by funding_transaction_generated fails we continue // the channel setup happily after the update is restored. let chanmon_cfgs = create_chanmon_cfgs(2); @@ -1648,11 +1645,8 @@ fn do_during_funding_monitor_fail(fail_on_generate: bool, restore_between_fails: let (temporary_channel_id, funding_tx, funding_output) = create_funding_transaction(&nodes[0], 100000, 43); - if fail_on_generate { - *nodes[0].chan_monitor.update_ret.lock().unwrap() = Err(ChannelMonitorUpdateErr::TemporaryFailure); - } nodes[0].node.funding_transaction_generated(&temporary_channel_id, funding_output); - check_added_monitors!(nodes[0], 1); + check_added_monitors!(nodes[0], 0); *nodes[1].chan_monitor.update_ret.lock().unwrap() = Err(ChannelMonitorUpdateErr::TemporaryFailure); let funding_created_msg = get_event_msg!(nodes[0], MessageSendEvent::SendFundingCreated, nodes[1].node.get_our_node_id()); @@ -1660,40 +1654,16 @@ fn do_during_funding_monitor_fail(fail_on_generate: bool, restore_between_fails: nodes[1].node.handle_funding_created(&nodes[0].node.get_our_node_id(), &funding_created_msg); check_added_monitors!(nodes[1], 1); - if restore_between_fails { - assert!(fail_on_generate); - *nodes[0].chan_monitor.update_ret.lock().unwrap() = Ok(()); - let (outpoint, latest_update) = nodes[0].chan_monitor.latest_monitor_update_id.lock().unwrap().get(&channel_id).unwrap().clone(); - nodes[0].node.channel_monitor_updated(&outpoint, latest_update); - check_added_monitors!(nodes[0], 0); - assert!(nodes[0].node.get_and_clear_pending_events().is_empty()); - assert!(nodes[0].node.get_and_clear_pending_msg_events().is_empty()); - } - - if fail_on_signed { - *nodes[0].chan_monitor.update_ret.lock().unwrap() = Err(ChannelMonitorUpdateErr::TemporaryFailure); - } else { - assert!(restore_between_fails || !fail_on_generate); // We can't switch to good now (there's no monitor update) - assert!(fail_on_generate); // Somebody has to fail - } + *nodes[0].chan_monitor.update_ret.lock().unwrap() = Err(ChannelMonitorUpdateErr::TemporaryFailure); nodes[0].node.handle_funding_signed(&nodes[1].node.get_our_node_id(), &get_event_msg!(nodes[1], MessageSendEvent::SendFundingSigned, nodes[0].node.get_our_node_id())); - if fail_on_signed || !restore_between_fails { - assert!(nodes[0].node.get_and_clear_pending_msg_events().is_empty()); - if fail_on_generate && !restore_between_fails { - nodes[0].logger.assert_log("lightning::ln::channelmanager".to_string(), "Previous monitor update failure prevented funding_signed from allowing funding broadcast".to_string(), 1); - check_added_monitors!(nodes[0], 1); - } else { - nodes[0].logger.assert_log("lightning::ln::channelmanager".to_string(), "Failed to update ChannelMonitor".to_string(), 1); - check_added_monitors!(nodes[0], 1); - } - assert!(nodes[0].node.get_and_clear_pending_events().is_empty()); - *nodes[0].chan_monitor.update_ret.lock().unwrap() = Ok(()); - let (outpoint, latest_update) = nodes[0].chan_monitor.latest_monitor_update_id.lock().unwrap().get(&channel_id).unwrap().clone(); - nodes[0].node.channel_monitor_updated(&outpoint, latest_update); - check_added_monitors!(nodes[0], 0); - } else { - check_added_monitors!(nodes[0], 1); - } + assert!(nodes[0].node.get_and_clear_pending_msg_events().is_empty()); + nodes[0].logger.assert_log("lightning::ln::channelmanager".to_string(), "Failed to update ChannelMonitor".to_string(), 1); + check_added_monitors!(nodes[0], 1); + assert!(nodes[0].node.get_and_clear_pending_events().is_empty()); + *nodes[0].chan_monitor.update_ret.lock().unwrap() = Ok(()); + let (outpoint, latest_update) = nodes[0].chan_monitor.latest_monitor_update_id.lock().unwrap().get(&channel_id).unwrap().clone(); + nodes[0].node.channel_monitor_updated(&outpoint, latest_update); + check_added_monitors!(nodes[0], 0); let events = nodes[0].node.get_and_clear_pending_events(); assert_eq!(events.len(), 1); @@ -1757,8 +1727,7 @@ fn do_during_funding_monitor_fail(fail_on_generate: bool, restore_between_fails: #[test] fn during_funding_monitor_fail() { - do_during_funding_monitor_fail(false, false, true, true, true); - do_during_funding_monitor_fail(true, false, true, false, false); - do_during_funding_monitor_fail(true, true, true, true, false); - do_during_funding_monitor_fail(true, true, false, false, false); + do_during_funding_monitor_fail(true, true); + do_during_funding_monitor_fail(true, false); + do_during_funding_monitor_fail(false, false); } diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs index 59bdae041..e2c0132fe 100644 --- a/lightning/src/ln/channel.rs +++ b/lightning/src/ln/channel.rs @@ -1539,22 +1539,25 @@ impl Channel { /// Handles a funding_signed message from the remote end. /// If this call is successful, broadcast the funding transaction (and not before!) - pub fn funding_signed(&mut self, msg: &msgs::FundingSigned) -> Result, ChannelError)> { + pub fn funding_signed(&mut self, msg: &msgs::FundingSigned) -> Result, ChannelError> { if !self.channel_outbound { - return Err((None, ChannelError::Close("Received funding_signed for an inbound channel?"))); + return Err(ChannelError::Close("Received funding_signed for an inbound channel?")); } if self.channel_state & !(ChannelState::MonitorUpdateFailed as u32) != ChannelState::FundingCreated as u32 { - return Err((None, ChannelError::Close("Received funding_signed in strange state!"))); + return Err(ChannelError::Close("Received funding_signed in strange state!")); } if self.commitment_secrets.get_min_seen_secret() != (1 << 48) || - self.cur_remote_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER - 1 || + self.cur_remote_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER || self.cur_local_commitment_transaction_number != INITIAL_COMMITMENT_NUMBER { panic!("Should not have advanced channel commitment tx numbers prior to funding_created"); } let funding_script = self.get_funding_redeemscript(); - let local_keys = self.build_local_transaction_keys(self.cur_local_commitment_transaction_number).map_err(|e| (None, e))?; + let remote_keys = self.build_remote_transaction_keys()?; + let remote_initial_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, false, self.feerate_per_kw).0; + + let local_keys = self.build_local_transaction_keys(self.cur_local_commitment_transaction_number)?; let local_initial_commitment_tx = self.build_commitment_transaction(self.cur_local_commitment_transaction_number, &local_keys, true, false, self.feerate_per_kw).0; let local_sighash = hash_to_message!(&bip143::SighashComponents::new(&local_initial_commitment_tx).sighash_all(&local_initial_commitment_tx.input[0], &funding_script, self.channel_value_satoshis)[..]); @@ -1562,27 +1565,39 @@ impl Channel { // They sign the "local" commitment transaction, allowing us to broadcast the tx if we wish. if let Err(_) = self.secp_ctx.verify(&local_sighash, &msg.signature, their_funding_pubkey) { - return Err((None, ChannelError::Close("Invalid funding_signed signature from peer"))); + return Err(ChannelError::Close("Invalid funding_signed signature from peer")); } - self.latest_monitor_update_id += 1; - let monitor_update = ChannelMonitorUpdate { - update_id: self.latest_monitor_update_id, - updates: vec![ChannelMonitorUpdateStep::LatestLocalCommitmentTXInfo { - commitment_tx: LocalCommitmentTransaction::new_missing_local_sig(local_initial_commitment_tx, &msg.signature, &PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.funding_key()), their_funding_pubkey, local_keys, self.feerate_per_kw, Vec::new()), - htlc_outputs: Vec::new(), - }] - }; - self.channel_monitor.as_mut().unwrap().update_monitor_ooo(monitor_update.clone()).unwrap(); - self.channel_state = ChannelState::FundingSent as u32 | (self.channel_state & (ChannelState::MonitorUpdateFailed as u32)); - self.cur_local_commitment_transaction_number -= 1; + let their_pubkeys = self.their_pubkeys.as_ref().unwrap(); + let funding_redeemscript = self.get_funding_redeemscript(); + let funding_txo = self.funding_txo.as_ref().unwrap(); + let funding_txo_script = funding_redeemscript.to_v0_p2wsh(); + macro_rules! create_monitor { + () => { { + let mut channel_monitor = ChannelMonitor::new(self.local_keys.clone(), + &self.shutdown_pubkey, self.our_to_self_delay, + &self.destination_script, (funding_txo.clone(), funding_txo_script.clone()), + &their_pubkeys.htlc_basepoint, &their_pubkeys.delayed_payment_basepoint, + self.their_to_self_delay, funding_redeemscript.clone(), self.channel_value_satoshis, + self.get_commitment_transaction_number_obscure_factor(), + self.logger.clone()); - if self.channel_state & (ChannelState::MonitorUpdateFailed as u32) == 0 { - Ok(monitor_update) - } else { - Err((Some(monitor_update), - ChannelError::Ignore("Previous monitor update failure prevented funding_signed from allowing funding broadcast"))) + channel_monitor.provide_latest_remote_commitment_tx_info(&remote_initial_commitment_tx, Vec::new(), self.cur_remote_commitment_transaction_number, self.their_cur_commitment_point.unwrap()); + channel_monitor.provide_latest_local_commitment_tx_info(LocalCommitmentTransaction::new_missing_local_sig(local_initial_commitment_tx.clone(), &msg.signature, &PublicKey::from_secret_key(&self.secp_ctx, self.local_keys.funding_key()), their_funding_pubkey, local_keys.clone(), self.feerate_per_kw, Vec::new()), Vec::new()).unwrap(); + + channel_monitor + } } } + + self.channel_monitor = Some(create_monitor!()); + let channel_monitor = create_monitor!(); + + assert_eq!(self.channel_state & (ChannelState::MonitorUpdateFailed as u32), 0); // We have no had any monitor(s) yet to fail update! + self.channel_state = ChannelState::FundingSent as u32; + self.cur_local_commitment_transaction_number -= 1; + self.cur_remote_commitment_transaction_number -= 1; + + Ok(channel_monitor) } pub fn funding_locked(&mut self, msg: &msgs::FundingLocked) -> Result<(), ChannelError> { @@ -2951,7 +2966,7 @@ impl Channel { /// May only be called after funding has been initiated (ie is_funding_initiated() is true) pub fn channel_monitor(&mut self) -> &mut ChannelMonitor { - if self.channel_state < ChannelState::FundingCreated as u32 { + if self.channel_state < ChannelState::FundingSent as u32 { panic!("Can't get a channel monitor until funding has been created"); } self.channel_monitor.as_mut().unwrap() @@ -3105,7 +3120,7 @@ impl Channel { /// Returns true if funding_created was sent/received. pub fn is_funding_initiated(&self) -> bool { - self.channel_state >= ChannelState::FundingCreated as u32 + self.channel_state >= ChannelState::FundingSent as u32 } /// Returns true if this channel is fully shut down. True here implies that no further actions @@ -3337,11 +3352,11 @@ impl Channel { } /// If an Err is returned, it is a ChannelError::Close (for get_outbound_funding_created) - fn get_outbound_funding_created_signature(&mut self) -> Result<(Signature, Transaction), ChannelError> { + fn get_outbound_funding_created_signature(&mut self) -> Result { let remote_keys = self.build_remote_transaction_keys()?; let remote_initial_commitment_tx = self.build_commitment_transaction(self.cur_remote_commitment_transaction_number, &remote_keys, false, false, self.feerate_per_kw).0; - Ok((self.local_keys.sign_remote_commitment(self.feerate_per_kw, &remote_initial_commitment_tx, &remote_keys, &Vec::new(), self.our_to_self_delay, &self.secp_ctx) - .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed"))?.0, remote_initial_commitment_tx)) + Ok(self.local_keys.sign_remote_commitment(self.feerate_per_kw, &remote_initial_commitment_tx, &remote_keys, &Vec::new(), self.our_to_self_delay, &self.secp_ctx) + .map_err(|_| ChannelError::Close("Failed to get signatures for new commitment_signed"))?.0) } /// Updates channel state with knowledge of the funding transaction's txid/index, and generates @@ -3351,7 +3366,7 @@ impl Channel { /// Note that channel_id changes during this call! /// Do NOT broadcast the funding transaction until after a successful funding_signed call! /// If an Err is returned, it is a ChannelError::Close. - pub fn get_outbound_funding_created(&mut self, funding_txo: OutPoint) -> Result<(msgs::FundingCreated, ChannelMonitor), ChannelError> { + pub fn get_outbound_funding_created(&mut self, funding_txo: OutPoint) -> Result { if !self.channel_outbound { panic!("Tried to create outbound funding_created message on an inbound channel!"); } @@ -3365,7 +3380,7 @@ impl Channel { } self.funding_txo = Some(funding_txo.clone()); - let (our_signature, commitment_tx) = match self.get_outbound_funding_created_signature() { + let our_signature = match self.get_outbound_funding_created_signature() { Ok(res) => res, Err(e) => { log_error!(self, "Got bad signatures: {:?}!", e); @@ -3378,37 +3393,15 @@ impl Channel { // Now that we're past error-generating stuff, update our local state: - let their_pubkeys = self.their_pubkeys.as_ref().unwrap(); - let funding_redeemscript = self.get_funding_redeemscript(); - let funding_txo_script = funding_redeemscript.to_v0_p2wsh(); - macro_rules! create_monitor { - () => { { - let mut channel_monitor = ChannelMonitor::new(self.local_keys.clone(), - &self.shutdown_pubkey, self.our_to_self_delay, - &self.destination_script, (funding_txo, funding_txo_script.clone()), - &their_pubkeys.htlc_basepoint, &their_pubkeys.delayed_payment_basepoint, - self.their_to_self_delay, funding_redeemscript.clone(), self.channel_value_satoshis, - self.get_commitment_transaction_number_obscure_factor(), - self.logger.clone()); - - channel_monitor.provide_latest_remote_commitment_tx_info(&commitment_tx, Vec::new(), self.cur_remote_commitment_transaction_number, self.their_cur_commitment_point.unwrap()); - channel_monitor - } } - } - - self.channel_monitor = Some(create_monitor!()); - let channel_monitor = create_monitor!(); - self.channel_state = ChannelState::FundingCreated as u32; self.channel_id = funding_txo.to_channel_id(); - self.cur_remote_commitment_transaction_number -= 1; - Ok((msgs::FundingCreated { - temporary_channel_id: temporary_channel_id, + Ok(msgs::FundingCreated { + temporary_channel_id, funding_txid: funding_txo.txid, funding_output_index: funding_txo.index, signature: our_signature - }, channel_monitor)) + }) } /// Gets an UnsignedChannelAnnouncement, as well as a signature covering it using our @@ -4385,7 +4378,7 @@ mod tests { value: 10000000, script_pubkey: output_script.clone(), }]}; let funding_outpoint = OutPoint::new(tx.txid(), 0); - let (funding_created_msg, _) = node_a_chan.get_outbound_funding_created(funding_outpoint).unwrap(); + let funding_created_msg = node_a_chan.get_outbound_funding_created(funding_outpoint).unwrap(); let (funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg).unwrap(); // Node B --> Node A: funding signed diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs index 5d52e4a8d..0acc59df6 100644 --- a/lightning/src/ln/channelmanager.rs +++ b/lightning/src/ln/channelmanager.rs @@ -1412,7 +1412,7 @@ impl ChannelMan pub fn funding_transaction_generated(&self, temporary_channel_id: &[u8; 32], funding_txo: OutPoint) { let _ = self.total_consistency_lock.read().unwrap(); - let (mut chan, msg, chan_monitor) = { + let (chan, msg) = { let (res, chan) = match self.channel_state.lock().unwrap().by_id.remove(temporary_channel_id) { Some(mut chan) => { (chan.get_outbound_funding_created(funding_txo) @@ -1425,30 +1425,11 @@ impl ChannelMan }; match handle_error!(self, res, chan.get_their_node_id()) { Ok(funding_msg) => { - (chan, funding_msg.0, funding_msg.1) + (chan, funding_msg) }, Err(_) => { return; } } }; - // Because we have exclusive ownership of the channel here we can release the channel_state - // lock before add_monitor - if let Err(e) = self.monitor.add_monitor(chan_monitor.get_funding_txo(), chan_monitor) { - match e { - ChannelMonitorUpdateErr::PermanentFailure => { - match handle_error!(self, Err(MsgHandleErrInternal::from_finish_shutdown("ChannelMonitor storage failure", *temporary_channel_id, chan.force_shutdown(true), None)), chan.get_their_node_id()) { - Err(_) => { return; }, - Ok(()) => unreachable!(), - } - }, - ChannelMonitorUpdateErr::TemporaryFailure => { - // Its completely fine to continue with a FundingCreated until the monitor - // update is persisted, as long as we don't generate the FundingBroadcastSafe - // until the monitor has been safely persisted (as funding broadcast is not, - // in fact, safe). - chan.monitor_update_failed(false, false, Vec::new(), Vec::new()); - }, - } - } let mut channel_state = self.channel_state.lock().unwrap(); channel_state.pending_msg_events.push(events::MessageSendEvent::SendFundingCreated { @@ -2337,17 +2318,11 @@ impl ChannelMan if chan.get().get_their_node_id() != *their_node_id { return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!", msg.channel_id)); } - let monitor_update = match chan.get_mut().funding_signed(&msg) { - Err((None, e)) => try_chan_entry!(self, Err(e), channel_state, chan), - Err((Some(monitor_update), e)) => { - assert!(chan.get().is_awaiting_monitor_update()); - let _ = self.monitor.update_monitor(chan.get().get_funding_txo().unwrap(), monitor_update); - try_chan_entry!(self, Err(e), channel_state, chan); - unreachable!(); - }, + let monitor = match chan.get_mut().funding_signed(&msg) { Ok(update) => update, + Err(e) => try_chan_entry!(self, Err(e), channel_state, chan), }; - if let Err(e) = self.monitor.update_monitor(chan.get().get_funding_txo().unwrap(), monitor_update) { + if let Err(e) = self.monitor.add_monitor(chan.get().get_funding_txo().unwrap(), monitor) { return_monitor_err!(self, e, channel_state, chan, RAACommitmentOrder::RevokeAndACKFirst, false, false); } (chan.get().get_funding_txo().unwrap(), chan.get().get_user_id()) diff --git a/lightning/src/ln/functional_test_utils.rs b/lightning/src/ln/functional_test_utils.rs index a18bc969a..55f734a32 100644 --- a/lightning/src/ln/functional_test_utils.rs +++ b/lightning/src/ln/functional_test_utils.rs @@ -295,6 +295,16 @@ macro_rules! unwrap_send_err { } } +macro_rules! check_added_monitors { + ($node: expr, $count: expr) => { + { + let mut added_monitors = $node.chan_monitor.added_monitors.lock().unwrap(); + assert_eq!(added_monitors.len(), $count); + added_monitors.clear(); + } + } +} + pub fn create_funding_transaction<'a, 'b, 'c>(node: &Node<'a, 'b, 'c>, expected_chan_value: u64, expected_user_chan_id: u64) -> ([u8; 32], Transaction, OutPoint) { let chan_id = *node.network_chan_count.borrow(); @@ -322,13 +332,8 @@ pub fn create_chan_between_nodes_with_value_init<'a, 'b, 'c>(node_a: &Node<'a, ' let (temporary_channel_id, tx, funding_output) = create_funding_transaction(node_a, channel_value, 42); - { - node_a.node.funding_transaction_generated(&temporary_channel_id, funding_output); - let mut added_monitors = node_a.chan_monitor.added_monitors.lock().unwrap(); - assert_eq!(added_monitors.len(), 1); - assert_eq!(added_monitors[0].0, funding_output); - added_monitors.clear(); - } + node_a.node.funding_transaction_generated(&temporary_channel_id, funding_output); + check_added_monitors!(node_a, 0); node_b.node.handle_funding_created(&node_a.node.get_our_node_id(), &get_event_msg!(node_a, MessageSendEvent::SendFundingCreated, node_b.node.get_our_node_id())); { @@ -620,16 +625,6 @@ impl SendEvent { } } -macro_rules! check_added_monitors { - ($node: expr, $count: expr) => { - { - let mut added_monitors = $node.chan_monitor.added_monitors.lock().unwrap(); - assert_eq!(added_monitors.len(), $count); - added_monitors.clear(); - } - } -} - macro_rules! commitment_signed_dance { ($node_a: expr, $node_b: expr, $commitment_signed: expr, $fail_backwards: expr, true /* skip last step */) => { { diff --git a/lightning/src/ln/functional_tests.rs b/lightning/src/ln/functional_tests.rs index 11cf69b40..9d8a0bc24 100644 --- a/lightning/src/ln/functional_tests.rs +++ b/lightning/src/ln/functional_tests.rs @@ -451,13 +451,8 @@ fn do_test_sanity_on_in_flight_opens(steps: u8) { let (temporary_channel_id, tx, funding_output) = create_funding_transaction(&nodes[0], 100000, 42); if steps & 0x0f == 3 { return; } - { - nodes[0].node.funding_transaction_generated(&temporary_channel_id, funding_output); - let mut added_monitors = nodes[0].chan_monitor.added_monitors.lock().unwrap(); - assert_eq!(added_monitors.len(), 1); - assert_eq!(added_monitors[0].0, funding_output); - added_monitors.clear(); - } + nodes[0].node.funding_transaction_generated(&temporary_channel_id, funding_output); + check_added_monitors!(nodes[0], 0); let funding_created = get_event_msg!(nodes[0], MessageSendEvent::SendFundingCreated, nodes[1].node.get_our_node_id()); if steps & 0x0f == 4 { return; }