Add tests for defaulting to creating tlv onions

[rust-lightning] / lightning / src / ln / onion_route_tests.rs

// This file is Copyright its original authors, visible in version control
// history.
//
// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
// You may not use this file except in accordance with one or both of these
// licenses.

//! Tests of the onion error messages/codes which are returned when routing a payment fails.
//! These tests work by standing up full nodes and route payments across the network, checking the
//! returned errors decode to the correct thing.

use chain::channelmonitor::{CLTV_CLAIM_BUFFER, LATENCY_GRACE_PERIOD_BLOCKS};
use chain::keysinterface::{KeysInterface, Recipient};
use ln::{PaymentHash, PaymentSecret};
use ln::channelmanager::{HTLCForwardInfo, CLTV_FAR_FAR_AWAY, MIN_CLTV_EXPIRY_DELTA, PendingHTLCInfo, PendingHTLCRouting};
use ln::onion_utils;
use routing::network_graph::{NetworkUpdate, RoutingFees, NodeId};
use routing::router::{get_route, PaymentParameters, Route, RouteHint, RouteHintHop};
use ln::features::{InitFeatures, InvoiceFeatures, NodeFeatures};
use ln::msgs;
use ln::msgs::{ChannelMessageHandler, ChannelUpdate, OptionalField};
use util::events::{Event, MessageSendEvent, MessageSendEventsProvider};
use util::ser::{Writeable, Writer};
use util::{byte_utils, test_utils};
use util::config::UserConfig;

use bitcoin::hash_types::BlockHash;

use bitcoin::hashes::Hash;
use bitcoin::hashes::sha256::Hash as Sha256;

use bitcoin::secp256k1;
use bitcoin::secp256k1::Secp256k1;
use bitcoin::secp256k1::key::{PublicKey, SecretKey};

use io;
use prelude::*;
use core::default::Default;

use ln::functional_test_utils::*;

fn run_onion_failure_test<F1,F2>(_name: &str, test_case: u8, nodes: &Vec<Node>, route: &Route, payment_hash: &PaymentHash, payment_secret: &PaymentSecret, callback_msg: F1, callback_node: F2, expected_retryable: bool, expected_error_code: Option<u16>, expected_channel_update: Option<NetworkUpdate>, expected_short_channel_id: Option<u64>)
        where F1: for <'a> FnMut(&'a mut msgs::UpdateAddHTLC),
                                F2: FnMut(),
{
        run_onion_failure_test_with_fail_intercept(_name, test_case, nodes, route, payment_hash, payment_secret, callback_msg, |_|{}, callback_node, expected_retryable, expected_error_code, expected_channel_update, expected_short_channel_id);
}

// test_case
// 0: node1 fails backward
// 1: final node fails backward
// 2: payment completed but the user rejects the payment
// 3: final node fails backward (but tamper onion payloads from node0)
// 100: trigger error in the intermediate node and tamper returning fail_htlc
// 200: trigger error in the final node and tamper returning fail_htlc
fn run_onion_failure_test_with_fail_intercept<F1,F2,F3>(_name: &str, test_case: u8, nodes: &Vec<Node>, route: &Route, payment_hash: &PaymentHash, payment_secret: &PaymentSecret, mut callback_msg: F1, mut callback_fail: F2, mut callback_node: F3, expected_retryable: bool, expected_error_code: Option<u16>, expected_channel_update: Option<NetworkUpdate>, expected_short_channel_id: Option<u64>)
        where F1: for <'a> FnMut(&'a mut msgs::UpdateAddHTLC),
                                F2: for <'a> FnMut(&'a mut msgs::UpdateFailHTLC),
                                F3: FnMut(),
{
        macro_rules! expect_event {
                ($node: expr, $event_type: path) => {{
                        let events = $node.node.get_and_clear_pending_events();
                        assert_eq!(events.len(), 1);
                        match events[0] {
                                $event_type { .. } => {},
                                _ => panic!("Unexpected event"),
                        }
                }}
        }

        macro_rules! expect_htlc_forward {
                ($node: expr) => {{
                        expect_event!($node, Event::PendingHTLCsForwardable);
                        $node.node.process_pending_htlc_forwards();
                }}
        }

        // 0 ~~> 2 send payment
        nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(*payment_secret)).unwrap();
        check_added_monitors!(nodes[0], 1);
        let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
        // temper update_add (0 => 1)
        let mut update_add_0 = update_0.update_add_htlcs[0].clone();
        if test_case == 0 || test_case == 3 || test_case == 100 {
                callback_msg(&mut update_add_0);
                callback_node();
        }
        // 0 => 1 update_add & CS
        nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add_0);
        commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true);

        let update_1_0 = match test_case {
                0|100 => { // intermediate node failure; fail backward to 0
                        let update_1_0 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
                        assert!(update_1_0.update_fail_htlcs.len()+update_1_0.update_fail_malformed_htlcs.len()==1 && (update_1_0.update_fail_htlcs.len()==1 || update_1_0.update_fail_malformed_htlcs.len()==1));
                        update_1_0
                },
                1|2|3|200 => { // final node failure; forwarding to 2
                        assert!(nodes[1].node.get_and_clear_pending_msg_events().is_empty());
                        // forwarding on 1
                        if test_case != 200 {
                                callback_node();
                        }
                        expect_htlc_forward!(&nodes[1]);

                        let update_1 = get_htlc_update_msgs!(nodes[1], nodes[2].node.get_our_node_id());
                        check_added_monitors!(&nodes[1], 1);
                        assert_eq!(update_1.update_add_htlcs.len(), 1);
                        // tamper update_add (1 => 2)
                        let mut update_add_1 = update_1.update_add_htlcs[0].clone();
                        if test_case != 3 && test_case != 200 {
                                callback_msg(&mut update_add_1);
                        }

                        // 1 => 2
                        nodes[2].node.handle_update_add_htlc(&nodes[1].node.get_our_node_id(), &update_add_1);
                        commitment_signed_dance!(nodes[2], nodes[1], update_1.commitment_signed, false, true);

                        if test_case == 2 || test_case == 200 {
                                expect_htlc_forward!(&nodes[2]);
                                expect_event!(&nodes[2], Event::PaymentReceived);
                                callback_node();
                                expect_pending_htlcs_forwardable!(nodes[2]);
                        }

                        let update_2_1 = get_htlc_update_msgs!(nodes[2], nodes[1].node.get_our_node_id());
                        if test_case == 2 || test_case == 200 {
                                check_added_monitors!(&nodes[2], 1);
                        }
                        assert!(update_2_1.update_fail_htlcs.len() == 1);

                        let mut fail_msg = update_2_1.update_fail_htlcs[0].clone();
                        if test_case == 200 {
                                callback_fail(&mut fail_msg);
                        }

                        // 2 => 1
                        nodes[1].node.handle_update_fail_htlc(&nodes[2].node.get_our_node_id(), &fail_msg);
                        commitment_signed_dance!(nodes[1], nodes[2], update_2_1.commitment_signed, true);

                        // backward fail on 1
                        let update_1_0 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
                        assert!(update_1_0.update_fail_htlcs.len() == 1);
                        update_1_0
                },
                _ => unreachable!(),
        };

        // 1 => 0 commitment_signed_dance
        if update_1_0.update_fail_htlcs.len() > 0 {
                let mut fail_msg = update_1_0.update_fail_htlcs[0].clone();
                if test_case == 100 {
                        callback_fail(&mut fail_msg);
                }
                nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
        } else {
                nodes[0].node.handle_update_fail_malformed_htlc(&nodes[1].node.get_our_node_id(), &update_1_0.update_fail_malformed_htlcs[0]);
        };

        commitment_signed_dance!(nodes[0], nodes[1], update_1_0.commitment_signed, false, true);

        let events = nodes[0].node.get_and_clear_pending_events();
        assert_eq!(events.len(), 1);
        if let &Event::PaymentPathFailed { ref rejected_by_dest, ref network_update, ref all_paths_failed, ref short_channel_id, ref error_code, .. } = &events[0] {
                assert_eq!(*rejected_by_dest, !expected_retryable);
                assert_eq!(*all_paths_failed, true);
                assert_eq!(*error_code, expected_error_code);
                if expected_channel_update.is_some() {
                        match network_update {
                                Some(update) => match update {
                                        &NetworkUpdate::ChannelUpdateMessage { .. } => {
                                                if let NetworkUpdate::ChannelUpdateMessage { .. } = expected_channel_update.unwrap() {} else {
                                                        panic!("channel_update not found!");
                                                }
                                        },
                                        &NetworkUpdate::ChannelClosed { ref short_channel_id, ref is_permanent } => {
                                                if let NetworkUpdate::ChannelClosed { short_channel_id: ref expected_short_channel_id, is_permanent: ref expected_is_permanent } = expected_channel_update.unwrap() {
                                                        assert!(*short_channel_id == *expected_short_channel_id);
                                                        assert!(*is_permanent == *expected_is_permanent);
                                                } else {
                                                        panic!("Unexpected message event");
                                                }
                                        },
                                        &NetworkUpdate::NodeFailure { ref node_id, ref is_permanent } => {
                                                if let NetworkUpdate::NodeFailure { node_id: ref expected_node_id, is_permanent: ref expected_is_permanent } = expected_channel_update.unwrap() {
                                                        assert!(*node_id == *expected_node_id);
                                                        assert!(*is_permanent == *expected_is_permanent);
                                                } else {
                                                        panic!("Unexpected message event");
                                                }
                                        },
                                }
                                None => panic!("Expected channel update"),
                        }
                } else {
                        assert!(network_update.is_none());
                }
                if let Some(expected_short_channel_id) = expected_short_channel_id {
                        match short_channel_id {
                                Some(short_channel_id) => assert_eq!(*short_channel_id, expected_short_channel_id),
                                None => panic!("Expected short channel id"),
                        }
                } else {
                        assert!(short_channel_id.is_none());
                }
        } else {
                panic!("Unexpected event");
        }
}

impl msgs::ChannelUpdate {
        fn dummy(short_channel_id: u64) -> msgs::ChannelUpdate {
                use bitcoin::secp256k1::ffi::Signature as FFISignature;
                use bitcoin::secp256k1::Signature;
                msgs::ChannelUpdate {
                        signature: Signature::from(unsafe { FFISignature::new() }),
                        contents: msgs::UnsignedChannelUpdate {
                                chain_hash: BlockHash::hash(&vec![0u8][..]),
                                short_channel_id,
                                timestamp: 0,
                                flags: 0,
                                cltv_expiry_delta: 0,
                                htlc_minimum_msat: 0,
                                htlc_maximum_msat: OptionalField::Absent,
                                fee_base_msat: 0,
                                fee_proportional_millionths: 0,
                                excess_data: vec![],
                        }
                }
        }
}

struct BogusOnionHopData {
        data: Vec<u8>
}
impl BogusOnionHopData {
        fn new(orig: msgs::OnionHopData) -> Self {
                Self { data: orig.encode() }
        }
}
impl Writeable for BogusOnionHopData {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
                writer.write_all(&self.data[..])
        }
}

const BADONION: u16 = 0x8000;
const PERM: u16 = 0x4000;
const NODE: u16 = 0x2000;
const UPDATE: u16 = 0x1000;

#[test]
fn test_fee_failures() {
        // Tests that the fee required when forwarding remains consistent over time. This was
        // previously broken, with forwarding fees floating based on the fee estimator at the time of
        // forwarding.
        //
        // When this test was written, the default base fee floated based on the HTLC count.
        // It is now fixed, so we simply set the fee to the expected value here.
        let mut config = test_default_channel_config();
        config.channel_options.forwarding_fee_base_msat = 196;

        let chanmon_cfgs = create_chanmon_cfgs(3);
        let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
        let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[Some(config), Some(config), Some(config)]);
        let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
        let channels = [create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known()), create_announced_chan_between_nodes(&nodes, 1, 2, InitFeatures::known(), InitFeatures::known())];

        // positive case
        let (route, payment_hash_success, payment_preimage_success, payment_secret_success) = get_route_and_payment_hash!(nodes[0], nodes[2], 40_000);
        nodes[0].node.send_payment(&route, payment_hash_success, &Some(payment_secret_success)).unwrap();
        check_added_monitors!(nodes[0], 1);
        pass_along_route(&nodes[0], &[&[&nodes[1], &nodes[2]]], 40_000, payment_hash_success, payment_secret_success);
        claim_payment(&nodes[0], &[&nodes[1], &nodes[2]], payment_preimage_success);

        // If the hop gives fee_insufficient but enough fees were provided, then the previous hop
        // malleated the payment before forwarding, taking funds when they shouldn't have.
        let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[2]);
        let short_channel_id = channels[0].0.contents.short_channel_id;
        run_onion_failure_test("fee_insufficient", 0, &nodes, &route, &payment_hash, &payment_secret, |msg| {
                msg.amount_msat -= 1;
        }, || {}, true, Some(UPDATE|12), Some(NetworkUpdate::ChannelClosed { short_channel_id, is_permanent: true}), Some(short_channel_id));

        // In an earlier version, we spuriously failed to forward payments if the expected feerate
        // changed between the channel open and the payment.
        {
                let mut feerate_lock = chanmon_cfgs[1].fee_estimator.sat_per_kw.lock().unwrap();
                *feerate_lock *= 2;
        }

        let (payment_preimage_success, payment_hash_success, payment_secret_success) = get_payment_preimage_hash!(nodes[2]);
        nodes[0].node.send_payment(&route, payment_hash_success, &Some(payment_secret_success)).unwrap();
        check_added_monitors!(nodes[0], 1);
        pass_along_route(&nodes[0], &[&[&nodes[1], &nodes[2]]], 40_000, payment_hash_success, payment_secret_success);
        claim_payment(&nodes[0], &[&nodes[1], &nodes[2]], payment_preimage_success);
}

#[test]
fn test_onion_failure() {
        // When we check for amount_below_minimum below, we want to test that we're using the *right*
        // amount, thus we need different htlc_minimum_msat values. We set node[2]'s htlc_minimum_msat
        // to 2000, which is above the default value of 1000 set in create_node_chanmgrs.
        // This exposed a previous bug because we were using the wrong value all the way down in
        // Channel::get_counterparty_htlc_minimum_msat().
        let mut node_2_cfg: UserConfig = Default::default();
        node_2_cfg.own_channel_config.our_htlc_minimum_msat = 2000;
        node_2_cfg.channel_options.announced_channel = true;
        node_2_cfg.peer_channel_config_limits.force_announced_channel_preference = false;

        // When this test was written, the default base fee floated based on the HTLC count.
        // It is now fixed, so we simply set the fee to the expected value here.
        let mut config = test_default_channel_config();
        config.channel_options.forwarding_fee_base_msat = 196;

        let chanmon_cfgs = create_chanmon_cfgs(3);
        let node_cfgs = create_node_cfgs(3, &chanmon_cfgs);
        let node_chanmgrs = create_node_chanmgrs(3, &node_cfgs, &[Some(config), Some(config), Some(node_2_cfg)]);
        let mut nodes = create_network(3, &node_cfgs, &node_chanmgrs);
        let channels = [create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known()), create_announced_chan_between_nodes(&nodes, 1, 2, InitFeatures::known(), InitFeatures::known())];
        for node in nodes.iter() {
                *node.keys_manager.override_random_bytes.lock().unwrap() = Some([3; 32]);
        }
        let (route, payment_hash, _, payment_secret) = get_route_and_payment_hash!(nodes[0], nodes[2], 40000);
        // positive case
        send_payment(&nodes[0], &vec!(&nodes[1], &nodes[2])[..], 40000);

        // intermediate node failure
        let short_channel_id = channels[1].0.contents.short_channel_id;
        run_onion_failure_test("invalid_realm", 0, &nodes, &route, &payment_hash, &payment_secret, |msg| {
                let session_priv = SecretKey::from_slice(&[3; 32]).unwrap();
                let cur_height = nodes[0].best_block_info().1 + 1;
                let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
                let (mut onion_payloads, _htlc_msat, _htlc_cltv) = onion_utils::build_onion_payloads(&route.paths[0], 40000, &None, cur_height, &None).unwrap();
                let mut new_payloads = Vec::new();
                for payload in onion_payloads.drain(..) {
                        new_payloads.push(BogusOnionHopData::new(payload));
                }
                // break the first (non-final) hop payload by swapping the realm (0) byte for a byte
                // describing a length-1 TLV payload, which is obviously bogus.
                new_payloads[0].data[0] = 1;
                msg.onion_routing_packet = onion_utils::construct_onion_packet_bogus_hopdata(new_payloads, onion_keys, [0; 32], &payment_hash);
        }, ||{}, true, Some(PERM|22), Some(NetworkUpdate::ChannelClosed{short_channel_id, is_permanent: true}), Some(short_channel_id));

        // final node failure
        let short_channel_id = channels[1].0.contents.short_channel_id;
        run_onion_failure_test("invalid_realm", 3, &nodes, &route, &payment_hash, &payment_secret, |msg| {
                let session_priv = SecretKey::from_slice(&[3; 32]).unwrap();
                let cur_height = nodes[0].best_block_info().1 + 1;
                let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
                let (mut onion_payloads, _htlc_msat, _htlc_cltv) = onion_utils::build_onion_payloads(&route.paths[0], 40000, &None, cur_height, &None).unwrap();
                let mut new_payloads = Vec::new();
                for payload in onion_payloads.drain(..) {
                        new_payloads.push(BogusOnionHopData::new(payload));
                }
                // break the last-hop payload by swapping the realm (0) byte for a byte describing a
                // length-1 TLV payload, which is obviously bogus.
                new_payloads[1].data[0] = 1;
                msg.onion_routing_packet = onion_utils::construct_onion_packet_bogus_hopdata(new_payloads, onion_keys, [0; 32], &payment_hash);
        }, ||{}, false, Some(PERM|22), Some(NetworkUpdate::ChannelClosed{short_channel_id, is_permanent: true}), Some(short_channel_id));

        // the following three with run_onion_failure_test_with_fail_intercept() test only the origin node
        // receiving simulated fail messages
        // intermediate node failure
        run_onion_failure_test_with_fail_intercept("temporary_node_failure", 100, &nodes, &route, &payment_hash, &payment_secret, |msg| {
                // trigger error
                msg.amount_msat -= 1;
        }, |msg| {
                // and tamper returning error message
                let session_priv = SecretKey::from_slice(&[3; 32]).unwrap();
                let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
                msg.reason = onion_utils::build_first_hop_failure_packet(&onion_keys[0].shared_secret[..], NODE|2, &[0;0]);
        }, ||{}, true, Some(NODE|2), Some(NetworkUpdate::NodeFailure{node_id: route.paths[0][0].pubkey, is_permanent: false}), Some(route.paths[0][0].short_channel_id));

        // final node failure
        run_onion_failure_test_with_fail_intercept("temporary_node_failure", 200, &nodes, &route, &payment_hash, &payment_secret, |_msg| {}, |msg| {
                // and tamper returning error message
                let session_priv = SecretKey::from_slice(&[3; 32]).unwrap();
                let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
                msg.reason = onion_utils::build_first_hop_failure_packet(&onion_keys[1].shared_secret[..], NODE|2, &[0;0]);
        }, ||{
                nodes[2].node.fail_htlc_backwards(&payment_hash);
        }, true, Some(NODE|2), Some(NetworkUpdate::NodeFailure{node_id: route.paths[0][1].pubkey, is_permanent: false}), Some(route.paths[0][1].short_channel_id));
        let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[2]);

        // intermediate node failure
        run_onion_failure_test_with_fail_intercept("permanent_node_failure", 100, &nodes, &route, &payment_hash, &payment_secret, |msg| {
                msg.amount_msat -= 1;
        }, |msg| {
                let session_priv = SecretKey::from_slice(&[3; 32]).unwrap();
                let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
                msg.reason = onion_utils::build_first_hop_failure_packet(&onion_keys[0].shared_secret[..], PERM|NODE|2, &[0;0]);
        }, ||{}, true, Some(PERM|NODE|2), Some(NetworkUpdate::NodeFailure{node_id: route.paths[0][0].pubkey, is_permanent: true}), Some(route.paths[0][0].short_channel_id));

        // final node failure
        run_onion_failure_test_with_fail_intercept("permanent_node_failure", 200, &nodes, &route, &payment_hash, &payment_secret, |_msg| {}, |msg| {
                let session_priv = SecretKey::from_slice(&[3; 32]).unwrap();
                let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
                msg.reason = onion_utils::build_first_hop_failure_packet(&onion_keys[1].shared_secret[..], PERM|NODE|2, &[0;0]);
        }, ||{
                nodes[2].node.fail_htlc_backwards(&payment_hash);
        }, false, Some(PERM|NODE|2), Some(NetworkUpdate::NodeFailure{node_id: route.paths[0][1].pubkey, is_permanent: true}), Some(route.paths[0][1].short_channel_id));
        let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[2]);

        // intermediate node failure
        run_onion_failure_test_with_fail_intercept("required_node_feature_missing", 100, &nodes, &route, &payment_hash, &payment_secret, |msg| {
                msg.amount_msat -= 1;
        }, |msg| {
                let session_priv = SecretKey::from_slice(&[3; 32]).unwrap();
                let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
                msg.reason = onion_utils::build_first_hop_failure_packet(&onion_keys[0].shared_secret[..], PERM|NODE|3, &[0;0]);
        }, ||{
                nodes[2].node.fail_htlc_backwards(&payment_hash);
        }, true, Some(PERM|NODE|3), Some(NetworkUpdate::NodeFailure{node_id: route.paths[0][0].pubkey, is_permanent: true}), Some(route.paths[0][0].short_channel_id));

        // final node failure
        run_onion_failure_test_with_fail_intercept("required_node_feature_missing", 200, &nodes, &route, &payment_hash, &payment_secret, |_msg| {}, |msg| {
                let session_priv = SecretKey::from_slice(&[3; 32]).unwrap();
                let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
                msg.reason = onion_utils::build_first_hop_failure_packet(&onion_keys[1].shared_secret[..], PERM|NODE|3, &[0;0]);
        }, ||{
                nodes[2].node.fail_htlc_backwards(&payment_hash);
        }, false, Some(PERM|NODE|3), Some(NetworkUpdate::NodeFailure{node_id: route.paths[0][1].pubkey, is_permanent: true}), Some(route.paths[0][1].short_channel_id));
        let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[2]);

        // Our immediate peer sent UpdateFailMalformedHTLC because it couldn't understand the onion in
        // the UpdateAddHTLC that we sent.
        let short_channel_id = channels[0].0.contents.short_channel_id;
        run_onion_failure_test("invalid_onion_version", 0, &nodes, &route, &payment_hash, &payment_secret, |msg| { msg.onion_routing_packet.version = 1; }, ||{}, true,
                Some(BADONION|PERM|4), None, Some(short_channel_id));

        run_onion_failure_test("invalid_onion_hmac", 0, &nodes, &route, &payment_hash, &payment_secret, |msg| { msg.onion_routing_packet.hmac = [3; 32]; }, ||{}, true,
                Some(BADONION|PERM|5), None, Some(short_channel_id));

        run_onion_failure_test("invalid_onion_key", 0, &nodes, &route, &payment_hash, &payment_secret, |msg| { msg.onion_routing_packet.public_key = Err(secp256k1::Error::InvalidPublicKey);}, ||{}, true,
                Some(BADONION|PERM|6), None, Some(short_channel_id));

        let short_channel_id = channels[1].0.contents.short_channel_id;
        run_onion_failure_test_with_fail_intercept("temporary_channel_failure", 100, &nodes, &route, &payment_hash, &payment_secret, |msg| {
                msg.amount_msat -= 1;
        }, |msg| {
                let session_priv = SecretKey::from_slice(&[3; 32]).unwrap();
                let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
                msg.reason = onion_utils::build_first_hop_failure_packet(&onion_keys[0].shared_secret[..], UPDATE|7, &ChannelUpdate::dummy(short_channel_id).encode_with_len()[..]);
        }, ||{}, true, Some(UPDATE|7), Some(NetworkUpdate::ChannelUpdateMessage{msg: ChannelUpdate::dummy(short_channel_id)}), Some(short_channel_id));

        let short_channel_id = channels[1].0.contents.short_channel_id;
        run_onion_failure_test_with_fail_intercept("permanent_channel_failure", 100, &nodes, &route, &payment_hash, &payment_secret, |msg| {
                msg.amount_msat -= 1;
        }, |msg| {
                let session_priv = SecretKey::from_slice(&[3; 32]).unwrap();
                let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
                msg.reason = onion_utils::build_first_hop_failure_packet(&onion_keys[0].shared_secret[..], PERM|8, &[0;0]);
                // short_channel_id from the processing node
        }, ||{}, true, Some(PERM|8), Some(NetworkUpdate::ChannelClosed{short_channel_id, is_permanent: true}), Some(short_channel_id));

        let short_channel_id = channels[1].0.contents.short_channel_id;
        run_onion_failure_test_with_fail_intercept("required_channel_feature_missing", 100, &nodes, &route, &payment_hash, &payment_secret, |msg| {
                msg.amount_msat -= 1;
        }, |msg| {
                let session_priv = SecretKey::from_slice(&[3; 32]).unwrap();
                let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
                msg.reason = onion_utils::build_first_hop_failure_packet(&onion_keys[0].shared_secret[..], PERM|9, &[0;0]);
                // short_channel_id from the processing node
        }, ||{}, true, Some(PERM|9), Some(NetworkUpdate::ChannelClosed{short_channel_id, is_permanent: true}), Some(short_channel_id));

        let mut bogus_route = route.clone();
        bogus_route.paths[0][1].short_channel_id -= 1;
        let short_channel_id = bogus_route.paths[0][1].short_channel_id;
        run_onion_failure_test("unknown_next_peer", 0, &nodes, &bogus_route, &payment_hash, &payment_secret, |_| {}, ||{}, true, Some(PERM|10),
          Some(NetworkUpdate::ChannelClosed{short_channel_id, is_permanent:true}), Some(short_channel_id));

        let short_channel_id = channels[1].0.contents.short_channel_id;
        let amt_to_forward = nodes[1].node.channel_state.lock().unwrap().by_id.get(&channels[1].2).unwrap().get_counterparty_htlc_minimum_msat() - 1;
        let mut bogus_route = route.clone();
        let route_len = bogus_route.paths[0].len();
        bogus_route.paths[0][route_len-1].fee_msat = amt_to_forward;
        run_onion_failure_test("amount_below_minimum", 0, &nodes, &bogus_route, &payment_hash, &payment_secret, |_| {}, ||{}, true, Some(UPDATE|11), Some(NetworkUpdate::ChannelUpdateMessage{msg: ChannelUpdate::dummy(short_channel_id)}), Some(short_channel_id));

        // Clear pending payments so that the following positive test has the correct payment hash.
        for node in nodes.iter() {
                node.node.clear_pending_payments();
        }

        // Test a positive test-case with one extra msat, meeting the minimum.
        bogus_route.paths[0][route_len-1].fee_msat = amt_to_forward + 1;
        let preimage = send_along_route(&nodes[0], bogus_route, &[&nodes[1], &nodes[2]], amt_to_forward+1).0;
        claim_payment(&nodes[0], &[&nodes[1], &nodes[2]], preimage);

        //TODO: with new config API, we will be able to generate both valid and
        //invalid channel_update cases.
        let short_channel_id = channels[0].0.contents.short_channel_id;
        run_onion_failure_test("fee_insufficient", 0, &nodes, &route, &payment_hash, &payment_secret, |msg| {
                msg.amount_msat -= 1;
        }, || {}, true, Some(UPDATE|12), Some(NetworkUpdate::ChannelClosed { short_channel_id, is_permanent: true}), Some(short_channel_id));

        let short_channel_id = channels[0].0.contents.short_channel_id;
        run_onion_failure_test("incorrect_cltv_expiry", 0, &nodes, &route, &payment_hash, &payment_secret, |msg| {
                // need to violate: cltv_expiry - cltv_expiry_delta >= outgoing_cltv_value
                msg.cltv_expiry -= 1;
        }, || {}, true, Some(UPDATE|13), Some(NetworkUpdate::ChannelClosed { short_channel_id, is_permanent: true}), Some(short_channel_id));

        let short_channel_id = channels[1].0.contents.short_channel_id;
        run_onion_failure_test("expiry_too_soon", 0, &nodes, &route, &payment_hash, &payment_secret, |msg| {
                let height = msg.cltv_expiry - CLTV_CLAIM_BUFFER - LATENCY_GRACE_PERIOD_BLOCKS + 1;
                connect_blocks(&nodes[0], height - nodes[0].best_block_info().1);
                connect_blocks(&nodes[1], height - nodes[1].best_block_info().1);
                connect_blocks(&nodes[2], height - nodes[2].best_block_info().1);
        }, ||{}, true, Some(UPDATE|14), Some(NetworkUpdate::ChannelUpdateMessage{msg: ChannelUpdate::dummy(short_channel_id)}), Some(short_channel_id));

        run_onion_failure_test("unknown_payment_hash", 2, &nodes, &route, &payment_hash, &payment_secret, |_| {}, || {
                nodes[2].node.fail_htlc_backwards(&payment_hash);
        }, false, Some(PERM|15), None, None);
        let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[2]);

        run_onion_failure_test("final_expiry_too_soon", 1, &nodes, &route, &payment_hash, &payment_secret, |msg| {
                let height = msg.cltv_expiry - CLTV_CLAIM_BUFFER - LATENCY_GRACE_PERIOD_BLOCKS + 1;
                connect_blocks(&nodes[0], height - nodes[0].best_block_info().1);
                connect_blocks(&nodes[1], height - nodes[1].best_block_info().1);
                connect_blocks(&nodes[2], height - nodes[2].best_block_info().1);
        }, || {}, true, Some(17), None, None);

        run_onion_failure_test("final_incorrect_cltv_expiry", 1, &nodes, &route, &payment_hash, &payment_secret, |_| {}, || {
                for (_, pending_forwards) in nodes[1].node.channel_state.lock().unwrap().forward_htlcs.iter_mut() {
                        for f in pending_forwards.iter_mut() {
                                match f {
                                        &mut HTLCForwardInfo::AddHTLC { ref mut forward_info, .. } =>
                                                forward_info.outgoing_cltv_value += 1,
                                        _ => {},
                                }
                        }
                }
        }, true, Some(18), None, Some(channels[1].0.contents.short_channel_id));

        run_onion_failure_test("final_incorrect_htlc_amount", 1, &nodes, &route, &payment_hash, &payment_secret, |_| {}, || {
                // violate amt_to_forward > msg.amount_msat
                for (_, pending_forwards) in nodes[1].node.channel_state.lock().unwrap().forward_htlcs.iter_mut() {
                        for f in pending_forwards.iter_mut() {
                                match f {
                                        &mut HTLCForwardInfo::AddHTLC { ref mut forward_info, .. } =>
                                                forward_info.amt_to_forward -= 1,
                                        _ => {},
                                }
                        }
                }
        }, true, Some(19), None, Some(channels[1].0.contents.short_channel_id));

        let short_channel_id = channels[1].0.contents.short_channel_id;
        run_onion_failure_test("channel_disabled", 0, &nodes, &route, &payment_hash, &payment_secret, |_| {}, || {
                // disconnect event to the channel between nodes[1] ~ nodes[2]
                nodes[1].node.peer_disconnected(&nodes[2].node.get_our_node_id(), false);
                nodes[2].node.peer_disconnected(&nodes[1].node.get_our_node_id(), false);
        }, true, Some(UPDATE|20), Some(NetworkUpdate::ChannelUpdateMessage{msg: ChannelUpdate::dummy(short_channel_id)}), Some(short_channel_id));
        reconnect_nodes(&nodes[1], &nodes[2], (false, false), (0, 0), (0, 0), (0, 0), (0, 0), (0, 0), (false, false));

        run_onion_failure_test("expiry_too_far", 0, &nodes, &route, &payment_hash, &payment_secret, |msg| {
                let session_priv = SecretKey::from_slice(&[3; 32]).unwrap();
                let mut route = route.clone();
                let height = nodes[2].best_block_info().1;
                route.paths[0][1].cltv_expiry_delta += CLTV_FAR_FAR_AWAY + route.paths[0][0].cltv_expiry_delta + 1;
                let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
                let (onion_payloads, _, htlc_cltv) = onion_utils::build_onion_payloads(&route.paths[0], 40000, &None, height, &None).unwrap();
                let onion_packet = onion_utils::construct_onion_packet(onion_payloads, onion_keys, [0; 32], &payment_hash);
                msg.cltv_expiry = htlc_cltv;
                msg.onion_routing_packet = onion_packet;
        }, ||{}, true, Some(21), Some(NetworkUpdate::NodeFailure{node_id: route.paths[0][0].pubkey, is_permanent: true}), Some(route.paths[0][0].short_channel_id));

        run_onion_failure_test_with_fail_intercept("mpp_timeout", 200, &nodes, &route, &payment_hash, &payment_secret, |_msg| {}, |msg| {
                // Tamper returning error message
                let session_priv = SecretKey::from_slice(&[3; 32]).unwrap();
                let onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
                msg.reason = onion_utils::build_first_hop_failure_packet(&onion_keys[1].shared_secret[..], 23, &[0;0]);
        }, ||{
                nodes[2].node.fail_htlc_backwards(&payment_hash);
        }, true, Some(23), None, None);
}

#[test]
fn test_default_to_onion_payload_tlv_format() {
        // Tests that we default to creating tlv format onion payloads when no `NodeAnnouncementInfo`
        // `features` for a node in the `network_graph` exists, or when the node isn't in the
        // `network_graph`, and no other known `features` for the node exists.
        let mut priv_channels_conf = UserConfig::default();
        priv_channels_conf.channel_options.announced_channel = false;
        let chanmon_cfgs = create_chanmon_cfgs(5);
        let node_cfgs = create_node_cfgs(5, &chanmon_cfgs);
        let node_chanmgrs = create_node_chanmgrs(5, &node_cfgs, &[None, None, None, None, Some(priv_channels_conf)]);
        let mut nodes = create_network(5, &node_cfgs, &node_chanmgrs);

        create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
        create_announced_chan_between_nodes(&nodes, 1, 2, InitFeatures::known(), InitFeatures::known());
        create_announced_chan_between_nodes(&nodes, 2, 3, InitFeatures::known(), InitFeatures::known());
        create_unannounced_chan_between_nodes_with_value(&nodes, 3, 4, 100000, 10001, InitFeatures::known(), InitFeatures::known());

        let payment_params = PaymentParameters::from_node_id(nodes[3].node.get_our_node_id());
        let origin_node = &nodes[0];
        let network_graph = origin_node.network_graph;

        // Clears all the `NodeAnnouncementInfo` for all nodes of `nodes[0]`'s `network_graph`, so that
        // their `features` aren't used when creating the `route`.
        network_graph.clear_nodes_announcement_info();

        let (announced_route, _, _, _) = get_route_and_payment_hash!(
                origin_node, nodes[3], payment_params, 10_000, TEST_FINAL_CLTV);

        let hops = &announced_route.paths[0];
        // Assert that the hop between `nodes[1]` and `nodes[2]` defaults to supporting variable length
        // onions, as `nodes[0]` has no `NodeAnnouncementInfo` `features` for `node[2]`
        assert!(hops[1].node_features.supports_variable_length_onion());
        // Assert that the hop between `nodes[2]` and `nodes[3]` defaults to supporting variable length
        // onions, as `nodes[0]` has no `NodeAnnouncementInfo` `features` for `node[3]`, and no `InvoiceFeatures`
        // for the `payment_params`, which would otherwise have been used.
        assert!(hops[2].node_features.supports_variable_length_onion());
        // Note that we do not assert that `hops[0]` (the channel between `nodes[0]` and `nodes[1]`)
        // supports variable length onions, as the `InitFeatures` exchanged in the init message
        // between the nodes will be used when creating the route. We therefore do not default to
        // supporting variable length onions for that hop, as the `InitFeatures` in this case are
        // `InitFeatures::known()`.

        let unannounced_chan = &nodes[4].node.list_usable_channels()[0];

        let last_hop = RouteHint(vec![RouteHintHop {
                src_node_id: nodes[3].node.get_our_node_id(),
                short_channel_id: unannounced_chan.short_channel_id.unwrap(),
                fees: RoutingFees {
                        base_msat: 0,
                        proportional_millionths: 0,
                },
                cltv_expiry_delta: 42,
                htlc_minimum_msat: None,
                htlc_maximum_msat: None,
        }]);

        let unannounced_chan_params = PaymentParameters::from_node_id(nodes[4].node.get_our_node_id()).with_route_hints(vec![last_hop]);
        let (unannounced_route, _, _, _) = get_route_and_payment_hash!(
                origin_node, nodes[4], unannounced_chan_params, 10_000, TEST_FINAL_CLTV);

        let unannounced_chan_hop = &unannounced_route.paths[0][3];
        // Ensure that `nodes[4]` doesn't exist in `nodes[0]`'s `network_graph`, as it's not public.
        assert!(&network_graph.read_only().nodes().get(&NodeId::from_pubkey(&nodes[4].node.get_our_node_id())).is_none());
        // Assert that the hop between `nodes[3]` and `nodes[4]` defaults to supporting variable length
        // onions, even though `nodes[4]` as `nodes[0]` doesn't exists in `nodes[0]`'s `network_graph`,
        // and no `InvoiceFeatures` for the `payment_params` exists, which would otherwise have been
        // used.
        assert!(unannounced_chan_hop.node_features.supports_variable_length_onion());

        let cur_height = nodes[0].best_block_info().1 + 1;
        let (announced_route_payloads, _htlc_msat, _htlc_cltv) = onion_utils::build_onion_payloads(&announced_route.paths[0], 40000, &None, cur_height, &None).unwrap();
        let (unannounced_route_paylods, _htlc_msat, _htlc_cltv) = onion_utils::build_onion_payloads(&unannounced_route.paths[0], 40000, &None, cur_height, &None).unwrap();

        for onion_payloads in vec![announced_route_payloads, unannounced_route_paylods] {
                for onion_payload in onion_payloads.iter() {
                        match onion_payload.format {
                                msgs::OnionHopDataFormat::Legacy {..} => {
                                        panic!("Generated a `msgs::OnionHopDataFormat::Legacy` payload, even though that shouldn't have happend.");
                                }
                                _ => {}
                        }
                }
        }
}

#[test]
fn test_do_not_default_to_onion_payload_tlv_format_when_unsupported() {
        // Tests that we do not default to creating tlv onions if either of these types features
        // exists, which specifies no support for variable length onions for a specific hop, when
        // creating a route:
        // 1. `InitFeatures` to the counterparty node exchanged with the init message to the node.
        // 2. `NodeFeatures` in the `NodeAnnouncementInfo` of a node in sender node's `network_graph`.
        // 3. `InvoiceFeatures` specified by the receiving node, when no `NodeAnnouncementInfo`
        // `features` exists for the receiver in the sender's `network_graph`.
        let chanmon_cfgs = create_chanmon_cfgs(4);
        let mut node_cfgs = create_node_cfgs(4, &chanmon_cfgs);

        // Set `node[1]` config to `InitFeatures::empty()` which return `false` for
        // `supports_variable_length_onion()`
        let mut node_1_cfg = &mut node_cfgs[1];
        node_1_cfg.features = InitFeatures::empty();

        let node_chanmgrs = create_node_chanmgrs(4, &node_cfgs, &[None, None, None, None]);
        let mut nodes = create_network(4, &node_cfgs, &node_chanmgrs);

        create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
        create_announced_chan_between_nodes(&nodes, 1, 2, InitFeatures::known(), InitFeatures::known());
        create_announced_chan_between_nodes(&nodes, 2, 3, InitFeatures::known(), InitFeatures::known());

        let payment_params = PaymentParameters::from_node_id(nodes[3].node.get_our_node_id())
                .with_features(InvoiceFeatures::empty());
        let origin_node = &nodes[0];
        let network_graph = origin_node.network_graph;
        network_graph.clear_nodes_announcement_info();

        // Set `NodeAnnouncementInfo` `features` which do not support variable length onions for
        // `nodes[2]` in `nodes[0]`'s `network_graph`.
        let nodes_2_unsigned_node_announcement = msgs::UnsignedNodeAnnouncement {
                features: NodeFeatures::empty(),
                timestamp: 0,
                node_id: nodes[2].node.get_our_node_id(),
                rgb: [32; 3],
                alias: [16;32],
                addresses: Vec::new(),
                excess_address_data: Vec::new(),
                excess_data: Vec::new(),
        };
        let _res = network_graph.update_node_from_unsigned_announcement(&nodes_2_unsigned_node_announcement);

        let (route, _, _, _) = get_route_and_payment_hash!(
                origin_node, nodes[3], payment_params, 10_000, TEST_FINAL_CLTV);

        let hops = &route.paths[0];

        // Assert that the hop between `nodes[0]` and `nodes[1]` doesn't support variable length
        // onions, as as the `InitFeatures` exchanged (`InitFeatures::empty()`) in the init message
        // between the nodes when setting up the channel is used when creating the `route` and that we
        // therefore do not default to supporting variable length onions. Despite `nodes[0]` having no
        // `NodeAnnouncementInfo` `features` for `node[1]`.
        assert!(!hops[0].node_features.supports_variable_length_onion());
        // Assert that the hop between `nodes[1]` and `nodes[2]` uses the `features` from
        // `nodes_2_unsigned_node_announcement` that doesn't support variable length onions.
        assert!(!hops[1].node_features.supports_variable_length_onion());
        // Assert that the hop between `nodes[2]` and `nodes[3]` uses the `InvoiceFeatures` set to the
        // `payment_params`, that doesn't support variable length onions. We therefore do not end up
        // defaulting to supporting variable length onions, despite `nodes[0]` having no
        // `NodeAnnouncementInfo` `features` for `node[3]`.
        assert!(!hops[2].node_features.supports_variable_length_onion());

        let cur_height = nodes[0].best_block_info().1 + 1;
        let (onion_payloads, _htlc_msat, _htlc_cltv) = onion_utils::build_onion_payloads(&route.paths[0], 40000, &None, cur_height, &None).unwrap();

        for onion_payload in onion_payloads.iter() {
                match onion_payload.format {
                        msgs::OnionHopDataFormat::Legacy {..} => {}
                        _ => {
                                panic!("Should have only have generated `msgs::OnionHopDataFormat::Legacy` payloads");
                        }
                }
        }
}

macro_rules! get_phantom_route {
        ($nodes: expr, $amt: expr, $channel: expr) => {{
                let secp_ctx = Secp256k1::new();
                let phantom_secret = $nodes[1].keys_manager.get_node_secret(Recipient::PhantomNode).unwrap();
                let phantom_pubkey = PublicKey::from_secret_key(&secp_ctx, &phantom_secret);
                let phantom_route_hint = $nodes[1].node.get_phantom_route_hints();
                let payment_params = PaymentParameters::from_node_id(phantom_pubkey)
                        .with_features(InvoiceFeatures::known())
                        .with_route_hints(vec![RouteHint(vec![
                                        RouteHintHop {
                                                src_node_id: $nodes[0].node.get_our_node_id(),
                                                short_channel_id: $channel.0.contents.short_channel_id,
                                                fees: RoutingFees {
                                                        base_msat: $channel.0.contents.fee_base_msat,
                                                        proportional_millionths: $channel.0.contents.fee_proportional_millionths,
                                                },
                                                cltv_expiry_delta: $channel.0.contents.cltv_expiry_delta,
                                                htlc_minimum_msat: None,
                                                htlc_maximum_msat: None,
                                        },
                                        RouteHintHop {
                                                src_node_id: phantom_route_hint.real_node_pubkey,
                                                short_channel_id: phantom_route_hint.phantom_scid,
                                                fees: RoutingFees {
                                                        base_msat: 0,
                                                        proportional_millionths: 0,
                                                },
                                                cltv_expiry_delta: MIN_CLTV_EXPIRY_DELTA,
                                                htlc_minimum_msat: None,
                                                htlc_maximum_msat: None,
                                        }
                ])]);
                let scorer = test_utils::TestScorer::with_penalty(0);
                let network_graph = $nodes[0].network_graph.read_only();
                (get_route(
                        &$nodes[0].node.get_our_node_id(), &payment_params, &network_graph,
                        Some(&$nodes[0].node.list_usable_channels().iter().collect::<Vec<_>>()),
                        $amt, TEST_FINAL_CLTV, $nodes[0].logger, &scorer, &[0u8; 32]
                ).unwrap(), phantom_route_hint.phantom_scid)
        }
}}

#[test]
fn test_phantom_onion_hmac_failure() {
        let chanmon_cfgs = create_chanmon_cfgs(2);
        let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
        let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
        let nodes = create_network(2, &node_cfgs, &node_chanmgrs);

        let channel = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());

        // Get the route.
        let recv_value_msat = 10_000;
        let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[1], Some(recv_value_msat));
        let (route, phantom_scid) = get_phantom_route!(nodes, recv_value_msat, channel);

        // Route the HTLC through to the destination.
        nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(payment_secret)).unwrap();
        check_added_monitors!(nodes[0], 1);
        let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
        let mut update_add = update_0.update_add_htlcs[0].clone();

        nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add);
        commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true);

        // Modify the payload so the phantom hop's HMAC is bogus.
        let sha256_of_onion = {
                let mut channel_state = nodes[1].node.channel_state.lock().unwrap();
                let mut pending_forward = channel_state.forward_htlcs.get_mut(&phantom_scid).unwrap();
                match pending_forward[0] {
                        HTLCForwardInfo::AddHTLC {
                                forward_info: PendingHTLCInfo {
                                        routing: PendingHTLCRouting::Forward { ref mut onion_packet, .. },
                                        ..
                                }, ..
                        } => {
                                onion_packet.hmac[onion_packet.hmac.len() - 1] ^= 1;
                                Sha256::hash(&onion_packet.hop_data).into_inner().to_vec()
                        },
                        _ => panic!("Unexpected forward"),
                }
        };
        expect_pending_htlcs_forwardable_ignore!(nodes[1]);
        nodes[1].node.process_pending_htlc_forwards();
        expect_pending_htlcs_forwardable_ignore!(nodes[1]);
        nodes[1].node.process_pending_htlc_forwards();
        let update_1 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
        check_added_monitors!(&nodes[1], 1);
        assert!(update_1.update_fail_htlcs.len() == 1);
        let fail_msg = update_1.update_fail_htlcs[0].clone();
        nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
        commitment_signed_dance!(nodes[0], nodes[1], update_1.commitment_signed, false);

        // Ensure the payment fails with the expected error.
        let mut fail_conditions = PaymentFailedConditions::new()
                .blamed_scid(phantom_scid)
                .blamed_chan_closed(true)
                .expected_htlc_error_data(0x8000 | 0x4000 | 5, &sha256_of_onion);
        expect_payment_failed_conditions!(nodes[0], payment_hash, false, fail_conditions);
}

#[test]
fn test_phantom_invalid_onion_payload() {
        let chanmon_cfgs = create_chanmon_cfgs(2);
        let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
        let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
        let mut nodes = create_network(2, &node_cfgs, &node_chanmgrs);

        let channel = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());

        // Get the route.
        let recv_value_msat = 10_000;
        let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[1], Some(recv_value_msat));
        let (route, phantom_scid) = get_phantom_route!(nodes, recv_value_msat, channel);

        // We'll use the session priv later when constructing an invalid onion packet.
        let session_priv = [3; 32];
        *nodes[0].keys_manager.override_random_bytes.lock().unwrap() = Some(session_priv);
        nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(payment_secret)).unwrap();
        check_added_monitors!(nodes[0], 1);
        let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
        let mut update_add = update_0.update_add_htlcs[0].clone();

        nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add);
        commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true);

        // Modify the onion packet to have an invalid payment amount.
        for (_, pending_forwards) in nodes[1].node.channel_state.lock().unwrap().forward_htlcs.iter_mut() {
                for f in pending_forwards.iter_mut() {
                        match f {
                                &mut HTLCForwardInfo::AddHTLC {
                                        forward_info: PendingHTLCInfo {
                                                routing: PendingHTLCRouting::Forward { ref mut onion_packet, .. },
                                                ..
                                        }, ..
                                } => {
                                        // Construct the onion payloads for the entire route and an invalid amount.
                                        let height = nodes[0].best_block_info().1;
                                        let session_priv = SecretKey::from_slice(&session_priv).unwrap();
                                        let mut onion_keys = onion_utils::construct_onion_keys(&Secp256k1::new(), &route.paths[0], &session_priv).unwrap();
                                        let (mut onion_payloads, _, _) = onion_utils::build_onion_payloads(&route.paths[0], msgs::MAX_VALUE_MSAT + 1, &Some(payment_secret), height + 1, &None).unwrap();
                                        // We only want to construct the onion packet for the last hop, not the entire route, so
                                        // remove the first hop's payload and its keys.
                                        onion_keys.remove(0);
                                        onion_payloads.remove(0);

                                        let new_onion_packet = onion_utils::construct_onion_packet(onion_payloads, onion_keys, [0; 32], &payment_hash);
                                        onion_packet.hop_data = new_onion_packet.hop_data;
                                        onion_packet.hmac = new_onion_packet.hmac;
                                },
                                _ => panic!("Unexpected forward"),
                        }
                }
        }
        expect_pending_htlcs_forwardable_ignore!(nodes[1]);
        nodes[1].node.process_pending_htlc_forwards();
        expect_pending_htlcs_forwardable_ignore!(nodes[1]);
        nodes[1].node.process_pending_htlc_forwards();
        let update_1 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
        check_added_monitors!(&nodes[1], 1);
        assert!(update_1.update_fail_htlcs.len() == 1);
        let fail_msg = update_1.update_fail_htlcs[0].clone();
        nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
        commitment_signed_dance!(nodes[0], nodes[1], update_1.commitment_signed, false);

        // Ensure the payment fails with the expected error.
        let error_data = Vec::new();
        let mut fail_conditions = PaymentFailedConditions::new()
                .blamed_scid(phantom_scid)
                .blamed_chan_closed(true)
                .expected_htlc_error_data(0x4000 | 22, &error_data);
        expect_payment_failed_conditions!(nodes[0], payment_hash, true, fail_conditions);
}

#[test]
fn test_phantom_final_incorrect_cltv_expiry() {
        let chanmon_cfgs = create_chanmon_cfgs(2);
        let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
        let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
        let nodes = create_network(2, &node_cfgs, &node_chanmgrs);

        let channel = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());

        // Get the route.
        let recv_value_msat = 10_000;
        let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[1], Some(recv_value_msat));
        let (route, phantom_scid) = get_phantom_route!(nodes, recv_value_msat, channel);

        // Route the HTLC through to the destination.
        nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(payment_secret)).unwrap();
        check_added_monitors!(nodes[0], 1);
        let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
        let mut update_add = update_0.update_add_htlcs[0].clone();

        nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add);
        commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true);

        // Modify the payload so the phantom hop's HMAC is bogus.
        for (_, pending_forwards) in nodes[1].node.channel_state.lock().unwrap().forward_htlcs.iter_mut() {
                for f in pending_forwards.iter_mut() {
                        match f {
                                &mut HTLCForwardInfo::AddHTLC {
                                        forward_info: PendingHTLCInfo { ref mut outgoing_cltv_value, .. }, ..
                                } => {
                                        *outgoing_cltv_value += 1;
                                },
                                _ => panic!("Unexpected forward"),
                        }
                }
        }
        expect_pending_htlcs_forwardable_ignore!(nodes[1]);
        nodes[1].node.process_pending_htlc_forwards();
        expect_pending_htlcs_forwardable_ignore!(nodes[1]);
        nodes[1].node.process_pending_htlc_forwards();
        let update_1 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
        check_added_monitors!(&nodes[1], 1);
        assert!(update_1.update_fail_htlcs.len() == 1);
        let fail_msg = update_1.update_fail_htlcs[0].clone();
        nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
        commitment_signed_dance!(nodes[0], nodes[1], update_1.commitment_signed, false);

        // Ensure the payment fails with the expected error.
        let expected_cltv = 82;
        let error_data = byte_utils::be32_to_array(expected_cltv).to_vec();
        let mut fail_conditions = PaymentFailedConditions::new()
                .blamed_scid(phantom_scid)
                .expected_htlc_error_data(18, &error_data);
        expect_payment_failed_conditions!(nodes[0], payment_hash, false, fail_conditions);
}

#[test]
fn test_phantom_failure_too_low_cltv() {
        let chanmon_cfgs = create_chanmon_cfgs(2);
        let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
        let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
        let nodes = create_network(2, &node_cfgs, &node_chanmgrs);

        let channel = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());

        // Get the route.
        let recv_value_msat = 10_000;
        let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[1], Some(recv_value_msat));
        let (mut route, phantom_scid) = get_phantom_route!(nodes, recv_value_msat, channel);

        // Modify the route to have a too-low cltv.
        route.paths[0][1].cltv_expiry_delta = 5;

        // Route the HTLC through to the destination.
        nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(payment_secret)).unwrap();
        check_added_monitors!(nodes[0], 1);
        let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
        let mut update_add = update_0.update_add_htlcs[0].clone();

        nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add);
        commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true);

        expect_pending_htlcs_forwardable_ignore!(nodes[1]);
        nodes[1].node.process_pending_htlc_forwards();
        expect_pending_htlcs_forwardable_ignore!(nodes[1]);
        nodes[1].node.process_pending_htlc_forwards();
        let update_1 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
        check_added_monitors!(&nodes[1], 1);
        assert!(update_1.update_fail_htlcs.len() == 1);
        let fail_msg = update_1.update_fail_htlcs[0].clone();
        nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
        commitment_signed_dance!(nodes[0], nodes[1], update_1.commitment_signed, false);

        // Ensure the payment fails with the expected error.
        let error_data = Vec::new();
        let mut fail_conditions = PaymentFailedConditions::new()
                .blamed_scid(phantom_scid)
                .expected_htlc_error_data(17, &error_data);
        expect_payment_failed_conditions!(nodes[0], payment_hash, false, fail_conditions);
}

#[test]
fn test_phantom_failure_too_low_recv_amt() {
        let chanmon_cfgs = create_chanmon_cfgs(2);
        let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
        let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
        let nodes = create_network(2, &node_cfgs, &node_chanmgrs);

        let channel = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());

        // Get the route with a too-low amount.
        let recv_amt_msat = 10_000;
        let bad_recv_amt_msat = recv_amt_msat - 10;
        let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[1], Some(recv_amt_msat));
        let (mut route, phantom_scid) = get_phantom_route!(nodes, bad_recv_amt_msat, channel);

        // Route the HTLC through to the destination.
        nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(payment_secret)).unwrap();
        check_added_monitors!(nodes[0], 1);
        let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
        let mut update_add = update_0.update_add_htlcs[0].clone();

        nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add);
        commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true);

        expect_pending_htlcs_forwardable_ignore!(nodes[1]);
        nodes[1].node.process_pending_htlc_forwards();
        expect_pending_htlcs_forwardable_ignore!(nodes[1]);
        nodes[1].node.process_pending_htlc_forwards();
        expect_pending_htlcs_forwardable_ignore!(nodes[1]);
        nodes[1].node.process_pending_htlc_forwards();
        let update_1 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
        check_added_monitors!(&nodes[1], 1);
        assert!(update_1.update_fail_htlcs.len() == 1);
        let fail_msg = update_1.update_fail_htlcs[0].clone();
        nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
        commitment_signed_dance!(nodes[0], nodes[1], update_1.commitment_signed, false);

        // Ensure the payment fails with the expected error.
        let mut error_data = byte_utils::be64_to_array(bad_recv_amt_msat).to_vec();
        error_data.extend_from_slice(
                &byte_utils::be32_to_array(nodes[1].node.best_block.read().unwrap().height()),
        );
        let mut fail_conditions = PaymentFailedConditions::new()
                .blamed_scid(phantom_scid)
                .expected_htlc_error_data(0x4000 | 15, &error_data);
        expect_payment_failed_conditions!(nodes[0], payment_hash, true, fail_conditions);
}

#[test]
fn test_phantom_dust_exposure_failure() {
        // Set the max dust exposure to the dust limit.
        let max_dust_exposure = 546;
        let mut receiver_config = UserConfig::default();
        receiver_config.channel_options.max_dust_htlc_exposure_msat = max_dust_exposure;
        receiver_config.channel_options.announced_channel = true;

        let chanmon_cfgs = create_chanmon_cfgs(2);
        let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
        let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, Some(receiver_config)]);
        let nodes = create_network(2, &node_cfgs, &node_chanmgrs);

        let channel = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());

        // Get the route with an amount exceeding the dust exposure threshold of nodes[1].
        let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[1], Some(max_dust_exposure + 1));
        let (mut route, _) = get_phantom_route!(nodes, max_dust_exposure + 1, channel);

        // Route the HTLC through to the destination.
        nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(payment_secret)).unwrap();
        check_added_monitors!(nodes[0], 1);
        let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
        let mut update_add = update_0.update_add_htlcs[0].clone();

        nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add);
        commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true);

        let update_1 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
        assert!(update_1.update_fail_htlcs.len() == 1);
        let fail_msg = update_1.update_fail_htlcs[0].clone();
        nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
        commitment_signed_dance!(nodes[0], nodes[1], update_1.commitment_signed, false);

        // Ensure the payment fails with the expected error.
        let mut error_data = channel.1.encode_with_len();
        let mut fail_conditions = PaymentFailedConditions::new()
                .blamed_scid(channel.0.contents.short_channel_id)
                .blamed_chan_closed(false)
                .expected_htlc_error_data(0x1000 | 7, &error_data);
                expect_payment_failed_conditions!(nodes[0], payment_hash, false, fail_conditions);
}

#[test]
fn test_phantom_failure_reject_payment() {
        // Test that the user can successfully fail back a phantom node payment.
        let chanmon_cfgs = create_chanmon_cfgs(2);
        let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
        let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
        let nodes = create_network(2, &node_cfgs, &node_chanmgrs);

        let channel = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());

        // Get the route with a too-low amount.
        let recv_amt_msat = 10_000;
        let (_, payment_hash, payment_secret) = get_payment_preimage_hash!(nodes[1], Some(recv_amt_msat));
        let (mut route, phantom_scid) = get_phantom_route!(nodes, recv_amt_msat, channel);

        // Route the HTLC through to the destination.
        nodes[0].node.send_payment(&route, payment_hash.clone(), &Some(payment_secret)).unwrap();
        check_added_monitors!(nodes[0], 1);
        let update_0 = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
        let mut update_add = update_0.update_add_htlcs[0].clone();

        nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &update_add);
        commitment_signed_dance!(nodes[1], nodes[0], &update_0.commitment_signed, false, true);

        expect_pending_htlcs_forwardable_ignore!(nodes[1]);
        nodes[1].node.process_pending_htlc_forwards();
        expect_pending_htlcs_forwardable_ignore!(nodes[1]);
        nodes[1].node.process_pending_htlc_forwards();
        expect_payment_received!(nodes[1], payment_hash, payment_secret, recv_amt_msat);
        assert!(nodes[1].node.fail_htlc_backwards(&payment_hash));
        expect_pending_htlcs_forwardable_ignore!(nodes[1]);
        nodes[1].node.process_pending_htlc_forwards();

        let update_1 = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
        check_added_monitors!(&nodes[1], 1);
        assert!(update_1.update_fail_htlcs.len() == 1);
        let fail_msg = update_1.update_fail_htlcs[0].clone();
        nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &fail_msg);
        commitment_signed_dance!(nodes[0], nodes[1], update_1.commitment_signed, false);

        // Ensure the payment fails with the expected error.
        let mut error_data = byte_utils::be64_to_array(recv_amt_msat).to_vec();
        error_data.extend_from_slice(
                &byte_utils::be32_to_array(nodes[1].node.best_block.read().unwrap().height()),
        );
        let mut fail_conditions = PaymentFailedConditions::new()
                .blamed_scid(phantom_scid)
                .expected_htlc_error_data(0x4000 | 15, &error_data);
        expect_payment_failed_conditions!(nodes[0], payment_hash, true, fail_conditions);
}