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Author: arik-so

lightning-rapid-gossip-sync/src/processing.rs

@@ -60,15 +60,13 @@ impl<NG: Deref<Target=NetworkGraph<L>>, L: Deref> RapidGossipSync<NG, L> where L
 	) -> Result<u32, GraphSyncError> {
 		log_trace!(self.logger, "Processing RGS data...");
 		let mut protocol_prefix = [0u8; 3];
-		let mut version_prefix = [0u8; 1];
 
 		read_cursor.read_exact(&mut protocol_prefix)?;
 		if protocol_prefix != GOSSIP_PREFIX {
 			return Err(DecodeError::UnknownVersion.into());
 		}
 
-		read_cursor.read_exact(&mut version_prefix)?;
-		let version = version_prefix[0];
+		let version: u8 = Readable::read(&mut read_cursor)?;
 		if version != 1 && version != 2 {
 			return Err(DecodeError::UnknownVersion.into());
 		}
@@ -120,13 +118,28 @@ impl<NG: Deref<Target=NetworkGraph<L>>, L: Deref> RapidGossipSync<NG, L> where L
 			for _ in 0..node_id_count {
 				let mut pubkey_bytes = [0u8; 33];
 				read_cursor.read_exact(&mut pubkey_bytes)?;
-				let node_detail_flag = pubkey_bytes[0];
+
+				/*
+				We encode additional information in the pubkey parity byte with the following mapping:
+
+				7-6: expect extra data after the pubkey (01 => u8, 10 => u16, 11 => u32)
+				5-3: index of new features among default (1-6). If index is 7 (all 3 bits are set, it's
+				outside the present default range). 0 means no feature changes.
+				2: addresses have changed
+
+				1: used for all keys
+				0: used for odd keys
+				*/
+				let node_detail_flag = pubkey_bytes.first().ok_or(DecodeError::ShortRead)?;
+
 				let has_address_details = (node_detail_flag & (1 << 2)) > 0;
 				let feature_detail_marker = (node_detail_flag & (0b111 << 3)) >> 3;
-				// println!("feature detail marker: {}", feature_detail_marker);
 				let additional_data_marker = (node_detail_flag & (0b11 << 6)) >> 6;
+
+				// extract the relevant bits for pubkey parity
 				let key_parity = node_detail_flag & 0b_0000_0011;
 				pubkey_bytes[0] = key_parity;
+
 				let current_pubkey = PublicKey::from_slice(&pubkey_bytes)?;
 				let current_node_id = NodeId::from_pubkey(&current_pubkey);
 				node_ids.push(current_pubkey);
@@ -155,7 +168,7 @@ impl<NG: Deref<Target=NetworkGraph<L>>, L: Deref> RapidGossipSync<NG, L> where L
 				if has_address_details {
 					let address_count: u8 = Readable::read(read_cursor)?;
 					let mut node_addresses: Vec<SocketAddress> = Vec::new();
-					for _ in 0..address_count {
+					for address_index in 0..address_count {
 						let current_byte_count: u8 = Readable::read(read_cursor)?;
 						let mut address_reader = FixedLengthReader::new(&mut read_cursor, current_byte_count as u64);
 						let mut address_bytes = Vec::new();
@@ -164,6 +177,13 @@ impl<NG: Deref<Target=NetworkGraph<L>>, L: Deref> RapidGossipSync<NG, L> where L
 						let mut address_cursor = io::Cursor::new(&address_bytes);
 						if let Ok(current_address) = Readable::read(&mut address_cursor) {
 							node_addresses.push(current_address);
+						} else {
+							// Do not crash to allow future socket address forwards compatibility
+							log_gossip!(
+								self.logger,
+								"Failure to parse address at index {} for node ID {}: {:?}",
+								address_index, current_node_id, address_bytes
+							);
 						}
 					}
 					synthetic_node_announcement.addresses = node_addresses;