From: Philip Robinson <simian@tari.com>
Date: Tue, 15 Jan 2019 09:52:02 +0000 (+0200)
Subject: Wrote test to explicitly test BOLT 2 requirements for update_add_htlc
X-Git-Tag: v0.0.12~243^2
X-Git-Url: http://git.bitcoin.ninja/?a=commitdiff_plain;h=a48fb848d9d4fdfa5d7773082a8a7da6952527ec;p=rust-lightning

Wrote test to explicitly test BOLT 2 requirements for update_add_htlc

(minor tweaks by @TheBlueMatt)
---

diff --git a/src/ln/channel.rs b/src/ln/channel.rs
index 237ccd840..98eb19fee 100644
--- a/src/ln/channel.rs
+++ b/src/ln/channel.rs
@@ -307,6 +307,9 @@ pub(super) struct Channel {
 	pub(super) our_dust_limit_satoshis: u64,
 	#[cfg(not(test))]
 	our_dust_limit_satoshis: u64,
+	#[cfg(test)]
+	pub(super) their_max_htlc_value_in_flight_msat: u64,
+	#[cfg(not(test))]
 	their_max_htlc_value_in_flight_msat: u64,
 	//get_our_max_htlc_value_in_flight_msat(): u64,
 	/// minimum channel reserve for **self** to maintain - set by them.
@@ -316,6 +319,9 @@ pub(super) struct Channel {
 	our_htlc_minimum_msat: u64,
 	their_to_self_delay: u16,
 	//implied by BREAKDOWN_TIMEOUT: our_to_self_delay: u16,
+	#[cfg(test)]
+	pub their_max_accepted_htlcs: u16,
+	#[cfg(not(test))]
 	their_max_accepted_htlcs: u16,
 	//implied by OUR_MAX_HTLCS: our_max_accepted_htlcs: u16,
 	minimum_depth: u32,
@@ -337,7 +343,7 @@ pub(super) struct Channel {
 	logger: Arc<Logger>,
 }
 
-const OUR_MAX_HTLCS: u16 = 50; //TODO
+pub const OUR_MAX_HTLCS: u16 = 50; //TODO
 /// Confirmation count threshold at which we close a channel. Ideally we'd keep the channel around
 /// on ice until the funding transaction gets more confirmations, but the LN protocol doesn't
 /// really allow for this, so instead we're stuck closing it out at that point.
@@ -1597,7 +1603,6 @@ impl Channel {
 			cltv_expiry: msg.cltv_expiry,
 			state: InboundHTLCState::RemoteAnnounced(pending_forward_state),
 		});
-
 		Ok(())
 	}
 
diff --git a/src/ln/functional_tests.rs b/src/ln/functional_tests.rs
index de2b42d3f..eeff90e29 100644
--- a/src/ln/functional_tests.rs
+++ b/src/ln/functional_tests.rs
@@ -21,6 +21,7 @@ use util::errors::APIError;
 use util::logger::Logger;
 use util::ser::{Writeable, Writer, ReadableArgs};
 use util::config::UserConfig;
+use util::rng;
 
 use bitcoin::util::hash::{BitcoinHash, Sha256dHash};
 use bitcoin::util::bip143;
@@ -1968,19 +1969,33 @@ fn get_announce_close_broadcast_events(nodes: &Vec<Node>, a: usize, b: usize) {
 	}
 }
 
+macro_rules! expect_payment_received {
+	($node: expr, $expected_payment_hash: expr, $expected_recv_value: expr) => {
+		let events = $node.node.get_and_clear_pending_events();
+		assert_eq!(events.len(), 1);
+		match events[0] {
+			Event::PaymentReceived { ref payment_hash, amt } => {
+				assert_eq!($expected_payment_hash, *payment_hash);
+				assert_eq!($expected_recv_value, amt);
+			},
+			_ => panic!("Unexpected event"),
+		}
+	}
+}
+
+macro_rules! get_channel_value_stat {
+	($node: expr, $channel_id: expr) => {{
+		let chan_lock = $node.node.channel_state.lock().unwrap();
+		let chan = chan_lock.by_id.get(&$channel_id).unwrap();
+		chan.get_value_stat()
+	}}
+}
+
 fn do_channel_reserve_test(test_recv: bool) {
 	use util::rng;
 	use std::sync::atomic::Ordering;
 	use ln::msgs::HandleError;
 
-	macro_rules! get_channel_value_stat {
-		($node: expr, $channel_id: expr) => {{
-			let chan_lock = $node.node.channel_state.lock().unwrap();
-			let chan = chan_lock.by_id.get(&$channel_id).unwrap();
-			chan.get_value_stat()
-		}}
-	}
-
 	let mut nodes = create_network(3);
 	let chan_1 = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1900, 1001);
 	let chan_2 = create_announced_chan_between_nodes_with_value(&nodes, 1, 2, 1900, 1001);
@@ -2009,20 +2024,6 @@ fn do_channel_reserve_test(test_recv: bool) {
 		}}
 	}
 
-	macro_rules! expect_payment_received {
-		($node: expr, $expected_payment_hash: expr, $expected_recv_value: expr) => {
-			let events = $node.node.get_and_clear_pending_events();
-			assert_eq!(events.len(), 1);
-			match events[0] {
-				Event::PaymentReceived { ref payment_hash, amt } => {
-					assert_eq!($expected_payment_hash, *payment_hash);
-					assert_eq!($expected_recv_value, amt);
-				},
-				_ => panic!("Unexpected event"),
-			}
-		}
-	};
-
 	let feemsat = 239; // somehow we know?
 	let total_fee_msat = (nodes.len() - 2) as u64 * 239;
 
@@ -6602,3 +6603,306 @@ fn test_onion_failure() {
 		msg.onion_routing_packet = onion_packet;
 	}, ||{}, true, Some(21), None);
 }
+
+// BOLT 2 Requirements for the Sender when constructing and sending an update_add_htlc message.
+// BOLT 2 Requirement: MUST NOT offer amount_msat it cannot pay for in the remote commitment transaction at the current feerate_per_kw (see "Updating Fees") while maintaining its channel reserve.
+//TODO: I don't believe this is explicitly enforced when sending an HTLC but as the Fee aspect of the BOLT specs is in flux leaving this as a TODO.
+
+#[test]
+fn test_update_add_htlc_bolt2_sender_value_below_minimum_msat() {
+	//BOLT2 Requirement: MUST offer amount_msat greater than 0.
+	//BOLT2 Requirement: MUST NOT offer amount_msat below the receiving node's htlc_minimum_msat (same validation check catches both of these)
+	let mut nodes = create_network(2);
+	let _chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100000, 95000000);
+	let mut route = nodes[0].router.get_route(&nodes[1].node.get_our_node_id(), None, &[], 100000, TEST_FINAL_CLTV).unwrap();
+	let (_, our_payment_hash) = get_payment_preimage_hash!(nodes[0]);
+
+	route.hops[0].fee_msat = 0;
+
+	let err = nodes[0].node.send_payment(route, our_payment_hash);
+
+	if let Err(APIError::ChannelUnavailable{err}) = err {
+		assert_eq!(err, "Cannot send less than their minimum HTLC value");
+	} else {
+		assert!(false);
+	}
+}
+
+#[test]
+fn test_update_add_htlc_bolt2_sender_cltv_expiry_too_high() {
+	//BOLT 2 Requirement: MUST set cltv_expiry less than 500000000.
+	//It is enforced when constructing a route.
+	let mut nodes = create_network(2);
+	let _chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100000, 0);
+	let route = nodes[0].router.get_route(&nodes[1].node.get_our_node_id(), None, &[], 100000000, 500000001).unwrap();
+	let (_, our_payment_hash) = get_payment_preimage_hash!(nodes[0]);
+
+	let err = nodes[0].node.send_payment(route, our_payment_hash);
+
+	if let Err(APIError::RouteError{err}) = err {
+		assert_eq!(err, "Channel CLTV overflowed?!");
+	} else {
+		assert!(false);
+	}
+}
+
+#[test]
+fn test_update_add_htlc_bolt2_sender_exceed_max_htlc_num_and_htlc_id_increment() {
+	//BOLT 2 Requirement: if result would be offering more than the remote's max_accepted_htlcs HTLCs, in the remote commitment transaction: MUST NOT add an HTLC.
+	//BOLT 2 Requirement: for the first HTLC it offers MUST set id to 0.
+	//BOLT 2 Requirement: MUST increase the value of id by 1 for each successive offer.
+	let mut nodes = create_network(2);
+	let chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1000000, 0);
+	let max_accepted_htlcs = nodes[1].node.channel_state.lock().unwrap().by_id.get(&chan.2).unwrap().their_max_accepted_htlcs as u64;
+
+	for i in 0..max_accepted_htlcs {
+		let route = nodes[0].router.get_route(&nodes[1].node.get_our_node_id(), None, &[], 100000, TEST_FINAL_CLTV).unwrap();
+		let (_, our_payment_hash) = get_payment_preimage_hash!(nodes[0]);
+		let mut payment_event = {
+			nodes[0].node.send_payment(route, our_payment_hash).unwrap();
+			check_added_monitors!(nodes[0], 1);
+
+			let mut events = nodes[0].node.get_and_clear_pending_msg_events();
+			assert_eq!(events.len(), 1);
+			if let MessageSendEvent::UpdateHTLCs { node_id: _, updates: msgs::CommitmentUpdate{ update_add_htlcs: ref htlcs, .. }, } = events[0] {
+				assert_eq!(htlcs[0].htlc_id, i);
+			} else {
+				assert!(false);
+			}
+			SendEvent::from_event(events.remove(0))
+		};
+		nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &payment_event.msgs[0]).unwrap();
+		check_added_monitors!(nodes[1], 0);
+		commitment_signed_dance!(nodes[1], nodes[0], payment_event.commitment_msg, false);
+
+		expect_pending_htlcs_forwardable!(nodes[1]);
+		expect_payment_received!(nodes[1], our_payment_hash, 100000);
+	}
+	let route = nodes[0].router.get_route(&nodes[1].node.get_our_node_id(), None, &[], 100000, TEST_FINAL_CLTV).unwrap();
+	let (_, our_payment_hash) = get_payment_preimage_hash!(nodes[0]);
+	let err = nodes[0].node.send_payment(route, our_payment_hash);
+
+	if let Err(APIError::ChannelUnavailable{err}) = err {
+		assert_eq!(err, "Cannot push more than their max accepted HTLCs");
+	} else {
+		assert!(false);
+	}
+}
+
+#[test]
+fn test_update_add_htlc_bolt2_sender_exceed_max_htlc_value_in_flight() {
+	//BOLT 2 Requirement: if the sum of total offered HTLCs would exceed the remote's max_htlc_value_in_flight_msat: MUST NOT add an HTLC.
+	let mut nodes = create_network(2);
+	let channel_value = 100000;
+	let chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, channel_value, 0);
+	let max_in_flight = get_channel_value_stat!(nodes[0], chan.2).their_max_htlc_value_in_flight_msat;
+
+	send_payment(&nodes[0], &vec!(&nodes[1])[..], max_in_flight);
+
+	let route = nodes[0].router.get_route(&nodes[1].node.get_our_node_id(), None, &[], max_in_flight+1, TEST_FINAL_CLTV).unwrap();
+	let (_, our_payment_hash) = get_payment_preimage_hash!(nodes[0]);
+	let err = nodes[0].node.send_payment(route, our_payment_hash);
+
+	if let Err(APIError::ChannelUnavailable{err}) = err {
+		assert_eq!(err, "Cannot send value that would put us over our max HTLC value in flight");
+	} else {
+		assert!(false);
+	}
+
+	send_payment(&nodes[0], &[&nodes[1]], max_in_flight);
+}
+
+// BOLT 2 Requirements for the Receiver when handling an update_add_htlc message.
+#[test]
+fn test_update_add_htlc_bolt2_receiver_check_amount_received_more_than_min() {
+	//BOLT2 Requirement: receiving an amount_msat equal to 0, OR less than its own htlc_minimum_msat -> SHOULD fail the channel.
+	let mut nodes = create_network(2);
+	let chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100000, 95000000);
+	let htlc_minimum_msat: u64;
+	{
+		let chan_lock = nodes[0].node.channel_state.lock().unwrap();
+		let channel = chan_lock.by_id.get(&chan.2).unwrap();
+		htlc_minimum_msat = channel.get_our_htlc_minimum_msat();
+	}
+	let route = nodes[0].router.get_route(&nodes[1].node.get_our_node_id(), None, &[], htlc_minimum_msat+1, TEST_FINAL_CLTV).unwrap();
+	let (_, our_payment_hash) = get_payment_preimage_hash!(nodes[0]);
+	nodes[0].node.send_payment(route, our_payment_hash).unwrap();
+	check_added_monitors!(nodes[0], 1);
+	let mut updates = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+	updates.update_add_htlcs[0].amount_msat = htlc_minimum_msat-1;
+	let err = nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &updates.update_add_htlcs[0]);
+	if let Err(msgs::HandleError{err, action: Some(msgs::ErrorAction::SendErrorMessage {..})}) = err {
+		assert_eq!(err, "Remote side tried to send less than our minimum HTLC value");
+	} else {
+		assert!(false);
+	}
+	assert!(nodes[1].node.list_channels().is_empty());
+	check_closed_broadcast!(nodes[1]);
+}
+
+#[test]
+fn test_update_add_htlc_bolt2_receiver_sender_can_afford_amount_sent() {
+	//BOLT2 Requirement: receiving an amount_msat that the sending node cannot afford at the current feerate_per_kw (while maintaining its channel reserve): SHOULD fail the channel
+	let mut nodes = create_network(2);
+	let chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100000, 95000000);
+
+	let their_channel_reserve = get_channel_value_stat!(nodes[0], chan.2).channel_reserve_msat;
+
+	let route = nodes[0].router.get_route(&nodes[1].node.get_our_node_id(), None, &[], 5000000-their_channel_reserve, TEST_FINAL_CLTV).unwrap();
+	let (_, our_payment_hash) = get_payment_preimage_hash!(nodes[0]);
+	nodes[0].node.send_payment(route, our_payment_hash).unwrap();
+	check_added_monitors!(nodes[0], 1);
+	let mut updates = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+
+	updates.update_add_htlcs[0].amount_msat = 5000000-their_channel_reserve+1;
+	let err = nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &updates.update_add_htlcs[0]);
+
+	if let Err(msgs::HandleError{err, action: Some(msgs::ErrorAction::SendErrorMessage {..})}) = err {
+		assert_eq!(err, "Remote HTLC add would put them over their reserve value");
+	} else {
+		assert!(false);
+	}
+
+	assert!(nodes[1].node.list_channels().is_empty());
+	check_closed_broadcast!(nodes[1]);
+}
+
+#[test]
+fn test_update_add_htlc_bolt2_receiver_check_max_htlc_limit() {
+	let secp_ctx = Secp256k1::new();
+
+	//BOLT 2 Requirement: if a sending node adds more than its max_accepted_htlcs HTLCs to its local commitment transaction: SHOULD fail the channel
+	//BOLT 2 Requirement: MUST allow multiple HTLCs with the same payment_hash.
+	let mut nodes = create_network(2);
+	let chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100000, 95000000);
+	let route = nodes[0].router.get_route(&nodes[1].node.get_our_node_id(), None, &[], 3999999, TEST_FINAL_CLTV).unwrap();
+	let (_, our_payment_hash) = get_payment_preimage_hash!(nodes[0]);
+
+	let session_priv = SecretKey::from_slice(&secp_ctx, &{
+		let mut session_key = [0; 32];
+		rng::fill_bytes(&mut session_key);
+		session_key
+	}).expect("RNG is bad!");
+
+	let cur_height = nodes[0].node.latest_block_height.load(Ordering::Acquire) as u32 + 1;
+	let onion_keys = onion_utils::construct_onion_keys(&secp_ctx, &route, &session_priv).unwrap();
+	let (onion_payloads, _htlc_msat, htlc_cltv) = onion_utils::build_onion_payloads(&route, cur_height).unwrap();
+	let onion_packet = onion_utils::construct_onion_packet(onion_payloads, onion_keys, &our_payment_hash);
+
+	let mut msg = msgs::UpdateAddHTLC {
+		channel_id: chan.2,
+		htlc_id: 0,
+		amount_msat: 1000,
+		payment_hash: our_payment_hash,
+		cltv_expiry: htlc_cltv,
+		onion_routing_packet: onion_packet.clone(),
+	};
+
+	for i in 0..super::channel::OUR_MAX_HTLCS {
+		msg.htlc_id = i as u64;
+		nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &msg).unwrap();
+	}
+	msg.htlc_id = (super::channel::OUR_MAX_HTLCS) as u64;
+	let err = nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &msg);
+
+	if let Err(msgs::HandleError{err, action: Some(msgs::ErrorAction::SendErrorMessage {..})}) = err {
+		assert_eq!(err, "Remote tried to push more than our max accepted HTLCs");
+	} else {
+		assert!(false);
+	}
+
+	assert!(nodes[1].node.list_channels().is_empty());
+	check_closed_broadcast!(nodes[1]);
+}
+
+#[test]
+fn test_update_add_htlc_bolt2_receiver_check_max_in_flight_msat() {
+	//OR adds more than its max_htlc_value_in_flight_msat worth of offered HTLCs to its local commitment transaction: SHOULD fail the channel
+	let mut nodes = create_network(2);
+	let chan = create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 1000000, 1000000);
+	let route = nodes[0].router.get_route(&nodes[1].node.get_our_node_id(), None, &[], 1000000, TEST_FINAL_CLTV).unwrap();
+	let (_, our_payment_hash) = get_payment_preimage_hash!(nodes[0]);
+	nodes[0].node.send_payment(route, our_payment_hash).unwrap();
+	check_added_monitors!(nodes[0], 1);
+	let mut updates = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+	updates.update_add_htlcs[0].amount_msat = get_channel_value_stat!(nodes[1], chan.2).their_max_htlc_value_in_flight_msat + 1;
+	let err = nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &updates.update_add_htlcs[0]);
+
+	if let Err(msgs::HandleError{err, action: Some(msgs::ErrorAction::SendErrorMessage {..})}) = err {
+		assert_eq!(err,"Remote HTLC add would put them over their max HTLC value in flight");
+	} else {
+		assert!(false);
+	}
+
+	assert!(nodes[1].node.list_channels().is_empty());
+	check_closed_broadcast!(nodes[1]);
+}
+
+#[test]
+fn test_update_add_htlc_bolt2_receiver_check_cltv_expiry() {
+	//BOLT2 Requirement: if sending node sets cltv_expiry to greater or equal to 500000000: SHOULD fail the channel.
+	let mut nodes = create_network(2);
+	create_announced_chan_between_nodes_with_value(&nodes, 0, 1, 100000, 95000000);
+	let route = nodes[0].router.get_route(&nodes[1].node.get_our_node_id(), None, &[], 3999999, TEST_FINAL_CLTV).unwrap();
+	let (_, our_payment_hash) = get_payment_preimage_hash!(nodes[0]);
+	nodes[0].node.send_payment(route, our_payment_hash).unwrap();
+	check_added_monitors!(nodes[0], 1);
+	let mut updates = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+	updates.update_add_htlcs[0].cltv_expiry = 500000000;
+	let err = nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &updates.update_add_htlcs[0]);
+
+	if let Err(msgs::HandleError{err, action: Some(msgs::ErrorAction::SendErrorMessage {..})}) = err {
+		assert_eq!(err,"Remote provided CLTV expiry in seconds instead of block height");
+	} else {
+		assert!(false);
+	}
+
+	assert!(nodes[1].node.list_channels().is_empty());
+	check_closed_broadcast!(nodes[1]);
+}
+
+#[test]
+fn test_update_add_htlc_bolt2_receiver_check_repeated_id_ignore() {
+	//BOLT 2 requirement: if the sender did not previously acknowledge the commitment of that HTLC: MUST ignore a repeated id value after a reconnection.
+	// We test this by first testing that that repeated HTLCs pass commitment signature checks
+	// after disconnect and that non-sequential htlc_ids result in a channel failure.
+	let mut nodes = create_network(2);
+	create_announced_chan_between_nodes(&nodes, 0, 1);
+	let route = nodes[0].router.get_route(&nodes[1].node.get_our_node_id(), None, &[], 1000000, TEST_FINAL_CLTV).unwrap();
+	let (_, our_payment_hash) = get_payment_preimage_hash!(nodes[0]);
+	nodes[0].node.send_payment(route, our_payment_hash).unwrap();
+	check_added_monitors!(nodes[0], 1);
+	let updates = get_htlc_update_msgs!(nodes[0], nodes[1].node.get_our_node_id());
+	nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &updates.update_add_htlcs[0]).unwrap();
+
+	//Disconnect and Reconnect
+	nodes[0].node.peer_disconnected(&nodes[1].node.get_our_node_id(), false);
+	nodes[1].node.peer_disconnected(&nodes[0].node.get_our_node_id(), false);
+	nodes[0].node.peer_connected(&nodes[1].node.get_our_node_id());
+	let reestablish_1 = get_chan_reestablish_msgs!(nodes[0], nodes[1]);
+	assert_eq!(reestablish_1.len(), 1);
+	nodes[1].node.peer_connected(&nodes[0].node.get_our_node_id());
+	let reestablish_2 = get_chan_reestablish_msgs!(nodes[1], nodes[0]);
+	assert_eq!(reestablish_2.len(), 1);
+	nodes[0].node.handle_channel_reestablish(&nodes[1].node.get_our_node_id(), &reestablish_2[0]).unwrap();
+	handle_chan_reestablish_msgs!(nodes[0], nodes[1]);
+	nodes[1].node.handle_channel_reestablish(&nodes[0].node.get_our_node_id(), &reestablish_1[0]).unwrap();
+	handle_chan_reestablish_msgs!(nodes[1], nodes[0]);
+
+	//Resend HTLC
+	nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &updates.update_add_htlcs[0]).unwrap();
+	assert_eq!(updates.commitment_signed.htlc_signatures.len(), 1);
+	nodes[1].node.handle_commitment_signed(&nodes[0].node.get_our_node_id(), &updates.commitment_signed).unwrap();
+	check_added_monitors!(nodes[1], 1);
+	let _bs_responses = get_revoke_commit_msgs!(nodes[1], nodes[0].node.get_our_node_id());
+
+	let err = nodes[1].node.handle_update_add_htlc(&nodes[0].node.get_our_node_id(), &updates.update_add_htlcs[0]);
+	if let Err(msgs::HandleError{err, action: Some(msgs::ErrorAction::SendErrorMessage {..})}) = err {
+		assert_eq!(err, "Remote skipped HTLC ID");
+	} else {
+		assert!(false);
+	}
+
+	assert!(nodes[1].node.list_channels().is_empty());
+	check_closed_broadcast!(nodes[1]);
+}