Merge pull request #911 from TheBlueMatt/2021-05-fix-cltv-diff

lightning-invoice/src/utils.rs

@@ -92,6 +92,7 @@ where
 mod test {
 	use {Currency, Description, InvoiceDescription};
 	use lightning::ln::PaymentHash;
+	use lightning::ln::channelmanager::MIN_FINAL_CLTV_EXPIRY;
 	use lightning::ln::functional_test_utils::*;
 	use lightning::ln::features::InitFeatures;
 	use lightning::ln::msgs::ChannelMessageHandler;
@@ -107,7 +108,7 @@ mod test {
 		let _chan = create_announced_chan_between_nodes(&nodes, 0, 1, InitFeatures::known(), InitFeatures::known());
 		let invoice = ::utils::create_invoice_from_channelmanager(&nodes[1].node, nodes[1].keys_manager, Currency::BitcoinTestnet, Some(10_000), "test".to_string()).unwrap();
 		assert_eq!(invoice.amount_pico_btc(), Some(100_000));
-		assert_eq!(invoice.min_final_cltv_expiry(), 9);
+		assert_eq!(invoice.min_final_cltv_expiry(), MIN_FINAL_CLTV_EXPIRY as u64);
 		assert_eq!(invoice.description(), InvoiceDescription::Direct(&Description("test".to_string())));
 
 		let mut route_hints = invoice.routes().clone();

lightning/src/chain/channelmonitor.rs

@@ -206,7 +206,7 @@ pub(crate) const CLTV_SHARED_CLAIM_BUFFER: u32 = 12;
 /// HTLC-Success transaction.
 /// In other words, this is an upper bound on how many blocks we think it can take us to get a
 /// transaction confirmed (and we use it in a few more, equivalent, places).
-pub(crate) const CLTV_CLAIM_BUFFER: u32 = 6;
+pub(crate) const CLTV_CLAIM_BUFFER: u32 = 18;
 /// Number of blocks by which point we expect our counterparty to have seen new blocks on the
 /// network and done a full update_fail_htlc/commitment_signed dance (+ we've updated all our
 /// copies of ChannelMonitors, including watchtowers). We could enforce the contract by failing

lightning/src/ln/channelmanager.rs

@@ -563,7 +563,7 @@ pub const BREAKDOWN_TIMEOUT: u16 = 6 * 24;
 pub(crate) const MAX_LOCAL_BREAKDOWN_TIMEOUT: u16 = 2 * 6 * 24 * 7;
 
 /// The minimum number of blocks between an inbound HTLC's CLTV and the corresponding outbound
-/// HTLC's CLTV. The current default represents roughly six hours of blocks at six blocks/hour.
+/// HTLC's CLTV. The current default represents roughly seven hours of blocks at six blocks/hour.
 ///
 /// This can be increased (but not decreased) through [`ChannelConfig::cltv_expiry_delta`]
 ///
@@ -572,13 +572,16 @@ pub(crate) const MAX_LOCAL_BREAKDOWN_TIMEOUT: u16 = 2 * 6 * 24 * 7;
 // i.e. the node we forwarded the payment on to should always have enough room to reliably time out
 // the HTLC via a full update_fail_htlc/commitment_signed dance before we hit the
 // CLTV_CLAIM_BUFFER point (we static assert that it's at least 3 blocks more).
-pub const MIN_CLTV_EXPIRY_DELTA: u16 = 6 * 6;
+pub const MIN_CLTV_EXPIRY_DELTA: u16 = 6*7;
 pub(super) const CLTV_FAR_FAR_AWAY: u32 = 6 * 24 * 7; //TODO?
 
 /// Minimum CLTV difference between the current block height and received inbound payments.
 /// Invoices generated for payment to us must set their `min_final_cltv_expiry` field to at least
 /// this value.
-pub const MIN_FINAL_CLTV_EXPIRY: u32 = HTLC_FAIL_BACK_BUFFER;
+// Note that we fail if exactly HTLC_FAIL_BACK_BUFFER + 1 was used, so we need to add one for
+// any payments to succeed. Further, we don't want payments to fail if a block was found while
+// a payment was being routed, so we add an extra block to be safe.
+pub const MIN_FINAL_CLTV_EXPIRY: u32 = HTLC_FAIL_BACK_BUFFER + 3;
 
 // Check that our CLTV_EXPIRY is at least CLTV_CLAIM_BUFFER + ANTI_REORG_DELAY + LATENCY_GRACE_PERIOD_BLOCKS,
 // ie that if the next-hop peer fails the HTLC within
@@ -590,7 +593,7 @@ pub const MIN_FINAL_CLTV_EXPIRY: u32 = HTLC_FAIL_BACK_BUFFER;
 #[allow(dead_code)]
 const CHECK_CLTV_EXPIRY_SANITY: u32 = MIN_CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - CLTV_CLAIM_BUFFER - ANTI_REORG_DELAY - LATENCY_GRACE_PERIOD_BLOCKS;
 
-// Check for ability of an attacker to make us fail on-chain by delaying inbound claim. See
+// Check for ability of an attacker to make us fail on-chain by delaying an HTLC claim. See
 // ChannelMontior::would_broadcast_at_height for a description of why this is needed.
 #[deny(const_err)]
 #[allow(dead_code)]

lightning/src/ln/functional_test_utils.rs

@@ -1144,7 +1144,7 @@ pub fn claim_payment<'a, 'b, 'c>(origin_node: &Node<'a, 'b, 'c>, expected_route:
 	claim_payment_along_route(origin_node, &[expected_route], false, our_payment_preimage);
 }
 
-pub const TEST_FINAL_CLTV: u32 = 50;
+pub const TEST_FINAL_CLTV: u32 = 70;
 
 pub fn route_payment<'a, 'b, 'c>(origin_node: &Node<'a, 'b, 'c>, expected_route: &[&Node<'a, 'b, 'c>], recv_value: u64) -> (PaymentPreimage, PaymentHash, PaymentSecret) {
 	let net_graph_msg_handler = &origin_node.net_graph_msg_handler;

lightning/src/ln/functional_tests.rs

@@ -4038,7 +4038,8 @@ fn do_test_htlc_timeout(send_partial_mpp: bool) {
 	};
 	connect_block(&nodes[0], &block);
 	connect_block(&nodes[1], &block);
-	for _ in CHAN_CONFIRM_DEPTH + 2 ..TEST_FINAL_CLTV + CHAN_CONFIRM_DEPTH + 2 - CLTV_CLAIM_BUFFER - LATENCY_GRACE_PERIOD_BLOCKS {
+	let block_count = TEST_FINAL_CLTV + CHAN_CONFIRM_DEPTH + 2 - CLTV_CLAIM_BUFFER - LATENCY_GRACE_PERIOD_BLOCKS;
+	for _ in CHAN_CONFIRM_DEPTH + 2..block_count {
 		block.header.prev_blockhash = block.block_hash();
 		connect_block(&nodes[0], &block);
 		connect_block(&nodes[1], &block);
@@ -4055,9 +4056,9 @@ fn do_test_htlc_timeout(send_partial_mpp: bool) {
 
 	nodes[0].node.handle_update_fail_htlc(&nodes[1].node.get_our_node_id(), &htlc_timeout_updates.update_fail_htlcs[0]);
 	commitment_signed_dance!(nodes[0], nodes[1], htlc_timeout_updates.commitment_signed, false);
-	// 100_000 msat as u64, followed by a height of TEST_FINAL_CLTV + 2 as u32
+	// 100_000 msat as u64, followed by the height at which we failed back above
 	let mut expected_failure_data = byte_utils::be64_to_array(100_000).to_vec();
-	expected_failure_data.extend_from_slice(&byte_utils::be32_to_array(TEST_FINAL_CLTV + 2));
+	expected_failure_data.extend_from_slice(&byte_utils::be32_to_array(block_count - 1));
 	expect_payment_failed!(nodes[0], our_payment_hash, true, 0x4000 | 15, &expected_failure_data[..]);
 }
 
@@ -5182,7 +5183,7 @@ fn test_duplicate_payment_hash_one_failure_one_success() {
 	let htlc_updates = get_htlc_update_msgs!(nodes[1], nodes[0].node.get_our_node_id());
 	assert!(htlc_updates.update_add_htlcs.is_empty());
 	assert_eq!(htlc_updates.update_fail_htlcs.len(), 1);
-	assert_eq!(htlc_updates.update_fail_htlcs[0].htlc_id, 1);
+	let first_htlc_id = htlc_updates.update_fail_htlcs[0].htlc_id;
 	assert!(htlc_updates.update_fulfill_htlcs.is_empty());
 	assert!(htlc_updates.update_fail_malformed_htlcs.is_empty());
 	check_added_monitors!(nodes[1], 1);
@@ -5207,7 +5208,7 @@ fn test_duplicate_payment_hash_one_failure_one_success() {
 	assert!(updates.update_add_htlcs.is_empty());
 	assert!(updates.update_fail_htlcs.is_empty());
 	assert_eq!(updates.update_fulfill_htlcs.len(), 1);
-	assert_eq!(updates.update_fulfill_htlcs[0].htlc_id, 0);
+	assert_ne!(updates.update_fulfill_htlcs[0].htlc_id, first_htlc_id);
 	assert!(updates.update_fail_malformed_htlcs.is_empty());
 	check_added_monitors!(nodes[1], 1);
 
@@ -7743,9 +7744,13 @@ fn test_bump_penalty_txn_on_revoked_htlcs() {
 	let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
 
 	let chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1000000, 59000000, InitFeatures::known(), InitFeatures::known());
-	// Lock HTLC in both directions
-	let payment_preimage = route_payment(&nodes[0], &vec!(&nodes[1])[..], 3_000_000).0;
-	route_payment(&nodes[1], &vec!(&nodes[0])[..], 3_000_000).0;
+	// Lock HTLC in both directions (using a slightly lower CLTV delay to provide timely RBF bumps)
+	let route = get_route(&nodes[0].node.get_our_node_id(), &nodes[0].net_graph_msg_handler.network_graph.read().unwrap(),
+		&nodes[1].node.get_our_node_id(), Some(InvoiceFeatures::known()), None, &Vec::new(), 3_000_000, 50, nodes[0].logger).unwrap();
+	let payment_preimage = send_along_route(&nodes[0], route, &[&nodes[1]], 3_000_000).0;
+	let route = get_route(&nodes[1].node.get_our_node_id(), &nodes[1].net_graph_msg_handler.network_graph.read().unwrap(),
+		&nodes[0].node.get_our_node_id(), Some(InvoiceFeatures::known()), None, &Vec::new(), 3_000_000, 50, nodes[0].logger).unwrap();
+	send_along_route(&nodes[1], route, &[&nodes[0]], 3_000_000);
 
 	let revoked_local_txn = get_local_commitment_txn!(nodes[1], chan.2);
 	assert_eq!(revoked_local_txn[0].input.len(), 1);
@@ -8058,7 +8063,7 @@ fn test_bump_txn_sanitize_tracking_maps() {
 	claim_payment(&nodes[0], &vec!(&nodes[1])[..], payment_preimage);
 
 	// Broadcast set of revoked txn on A
-	connect_blocks(&nodes[0], 52 - CHAN_CONFIRM_DEPTH);
+	connect_blocks(&nodes[0], TEST_FINAL_CLTV + 2 - CHAN_CONFIRM_DEPTH);
 	expect_pending_htlcs_forwardable_ignore!(nodes[0]);
 	assert_eq!(nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().len(), 0);