From b32e9553abcb1d9312353fc6cf1f99a54228840f Mon Sep 17 00:00:00 2001 From: Valentine Wallace Date: Wed, 23 Feb 2022 22:20:43 -0500 Subject: [PATCH] Fix bug where we encode flags field into all updates on htlc fail Failing an HTLC with onion error channel_disabled requires encoding a 'flags' field into the failure packet. However, we were encoding this 'flags' field for all failures packets that were failing on update_add_htlc with an update (error 0x1000 UPDATE). Discovered in the course of adding phantom payment failure tests, which also added testing for this bug --- lightning/src/ln/channelmanager.rs | 4 ++- lightning/src/ln/onion_route_tests.rs | 43 +++++++++++++++++++++++++++ 2 files changed, 46 insertions(+), 1 deletion(-) diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs index e8aee263..47d6e142 100644 --- a/lightning/src/ln/channelmanager.rs +++ b/lightning/src/ln/channelmanager.rs @@ -4511,7 +4511,9 @@ impl ChannelMana onion_utils::build_first_hop_failure_packet(incoming_shared_secret, error_code, &{ let mut res = Vec::with_capacity(8 + 128); // TODO: underspecified, follow https://github.com/lightningnetwork/lightning-rfc/issues/791 - res.extend_from_slice(&byte_utils::be16_to_array(0)); + if error_code == 0x1000 | 20 { + res.extend_from_slice(&byte_utils::be16_to_array(0)); + } res.extend_from_slice(&upd.encode_with_len()[..]); res }[..]) diff --git a/lightning/src/ln/onion_route_tests.rs b/lightning/src/ln/onion_route_tests.rs index d2844c6e..2aeecd10 100644 --- a/lightning/src/ln/onion_route_tests.rs +++ b/lightning/src/ln/onion_route_tests.rs @@ -898,3 +898,46 @@ fn test_phantom_failure_too_low_recv_amt() { .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); +} -- 2.30.2