[fuzz] Make router_target a bit easier for fuzzers to explore

It turns out (somewhat obviously) that expecting a fuzzer to
correctly build multiple signatures which verify against multiple
public keys in the same message was a bit too daunting, so we now
skip message signatures in routing messages.

We also take this opportunity to simplify the target itself somewhat,
avoiding reading public keys over and over and instead generating
routes to all the public keys that appeared in messages while running.

Author: TheBlueMatt

fuzz/src/router.rs

@@ -11,20 +11,22 @@ use bitcoin::blockdata::script::Builder;
 use bitcoin::blockdata::transaction::TxOut;
 use bitcoin::hash_types::BlockHash;
 
+use bitcoin::secp256k1;
+
 use lightning::chain;
 use lightning::ln::channelmanager::ChannelDetails;
 use lightning::ln::features::InitFeatures;
 use lightning::ln::msgs;
-use lightning::ln::msgs::RoutingMessageHandler;
 use lightning::routing::router::{get_route, RouteHint};
 use lightning::util::logger::Logger;
 use lightning::util::ser::Readable;
-use lightning::routing::network_graph::{NetGraphMsgHandler, RoutingFees};
+use lightning::routing::network_graph::{NetworkGraph, RoutingFees};
 
 use bitcoin::secp256k1::key::PublicKey;
 
 use utils::test_logger;
 
+use std::collections::HashSet;
 use std::sync::Arc;
 use std::sync::atomic::{AtomicUsize, Ordering};
 
@@ -150,16 +152,12 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
 	}
 
 	let logger: Arc<dyn Logger> = Arc::new(test_logger::TestLogger::new("".to_owned(), out));
-	let chain_source = if get_slice!(1)[0] % 2 == 0 {
-		None
-	} else {
-		Some(Arc::new(FuzzChainSource {
-			input: Arc::clone(&input),
-		}))
-	};
 
 	let our_pubkey = get_pubkey!();
-	let net_graph_msg_handler = NetGraphMsgHandler::new(chain_source, Arc::clone(&logger));
+	let mut net_graph = NetworkGraph::new();
+
+	let mut node_pks = HashSet::new();
+	let mut scid = 42;
 
 	loop {
 		match get_slice!(1)[0] {
@@ -169,39 +167,44 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
 				if addr_len > (37+1)*4 {
 					return;
 				}
-				let _ = net_graph_msg_handler.handle_node_announcement(&decode_msg_with_len16!(msgs::NodeAnnouncement, 64, 288));
+				let msg = decode_msg_with_len16!(msgs::NodeAnnouncement, 64, 288);
+				node_pks.insert(msg.contents.node_id);
+				let _ = net_graph.update_node_from_announcement::<secp256k1::VerifyOnly>(&msg, None);
 			},
 			1 => {
-				let _ = net_graph_msg_handler.handle_channel_announcement(&decode_msg_with_len16!(msgs::ChannelAnnouncement, 64*4, 32+8+33*4));
+				let msg = decode_msg_with_len16!(msgs::ChannelAnnouncement, 64*4, 32+8+33*4);
+				node_pks.insert(msg.contents.node_id_1);
+				node_pks.insert(msg.contents.node_id_2);
+				let _ = net_graph.update_channel_from_announcement::<secp256k1::VerifyOnly>(&msg, None, None);
 			},
 			2 => {
-				let _ = net_graph_msg_handler.handle_channel_update(&decode_msg!(msgs::ChannelUpdate, 136));
+				let msg = decode_msg_with_len16!(msgs::ChannelAnnouncement, 64*4, 32+8+33*4);
+				node_pks.insert(msg.contents.node_id_1);
+				node_pks.insert(msg.contents.node_id_2);
+				let val = slice_to_be64(get_slice!(8));
+				let _ = net_graph.update_channel_from_announcement::<secp256k1::VerifyOnly>(&msg, Some(val), None);
 			},
 			3 => {
-				match get_slice!(1)[0] {
-					0 => {
-						net_graph_msg_handler.handle_htlc_fail_channel_update(&msgs::HTLCFailChannelUpdate::ChannelUpdateMessage {msg: decode_msg!(msgs::ChannelUpdate, 136)});
-					},
-					1 => {
-						let short_channel_id = slice_to_be64(get_slice!(8));
-						net_graph_msg_handler.handle_htlc_fail_channel_update(&msgs::HTLCFailChannelUpdate::ChannelClosed {short_channel_id, is_permanent: false});
-					},
-					_ => return,
-				}
+				let _ = net_graph.update_channel(&decode_msg!(msgs::ChannelUpdate, 136), None);
 			},
 			4 => {
-				let target = get_pubkey!();
+				let short_channel_id = slice_to_be64(get_slice!(8));
+				net_graph.close_channel_from_update(short_channel_id, false);
+			},
+			_ if node_pks.is_empty() => {},
+			_ => {
 				let mut first_hops_vec = Vec::new();
 				let first_hops = match get_slice!(1)[0] {
 					0 => None,
-					1 => {
-						let count = slice_to_be16(get_slice!(2));
+					count => {
 						for _ in 0..count {
+							scid += 1;
+							let rnid = node_pks.iter().skip(slice_to_be16(get_slice!(2))as usize % node_pks.len()).next().unwrap();
 							first_hops_vec.push(ChannelDetails {
 								channel_id: [0; 32],
-								short_channel_id: Some(slice_to_be64(get_slice!(8))),
-								remote_network_id: get_pubkey!(),
-								counterparty_features: InitFeatures::empty(),
+								short_channel_id: Some(scid),
+								remote_network_id: *rnid,
+								counterparty_features: InitFeatures::known(),
 								channel_value_satoshis: slice_to_be64(get_slice!(8)),
 								user_id: 0,
 								inbound_capacity_msat: 0,
@@ -211,15 +214,16 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
 						}
 						Some(&first_hops_vec[..])
 					},
-					_ => return,
 				};
 				let mut last_hops_vec = Vec::new();
-				let last_hops = {
-					let count = slice_to_be16(get_slice!(2));
+				{
+					let count = get_slice!(1)[0];
 					for _ in 0..count {
+						scid += 1;
+						let rnid = node_pks.iter().skip(slice_to_be16(get_slice!(2))as usize % node_pks.len()).next().unwrap();
 						last_hops_vec.push(RouteHint {
-							src_node_id: get_pubkey!(),
-							short_channel_id: slice_to_be64(get_slice!(8)),
+							src_node_id: *rnid,
+							short_channel_id: scid,
 							fees: RoutingFees {
 								base_msat: slice_to_be32(get_slice!(4)),
 								proportional_millionths: slice_to_be32(get_slice!(4)),
@@ -228,14 +232,15 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
 							htlc_minimum_msat: slice_to_be64(get_slice!(8)),
 						});
 					}
-					&last_hops_vec[..]
-				};
-				let _ = get_route(&our_pubkey, &net_graph_msg_handler.network_graph.read().unwrap(), &target,
-					first_hops.map(|c| c.iter().collect::<Vec<_>>()).as_ref().map(|a| a.as_slice()),
-					&last_hops.iter().collect::<Vec<_>>(),
-					slice_to_be64(get_slice!(8)), slice_to_be32(get_slice!(4)), Arc::clone(&logger));
+				}
+				let last_hops = &last_hops_vec[..];
+				for target in node_pks.iter() {
+					let _ = get_route(&our_pubkey, &net_graph, target,
+						first_hops.map(|c| c.iter().collect::<Vec<_>>()).as_ref().map(|a| a.as_slice()),
+						&last_hops.iter().collect::<Vec<_>>(),
+						slice_to_be64(get_slice!(8)), slice_to_be32(get_slice!(4)), Arc::clone(&logger));
+				}
 			},
-			_ => return,
 		}
 	}
 }