X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=src%2Fbgp_client.rs;h=8dfb3eba579d94cbc0c3297f1cea9a6e7fccca1a;hb=226b696cb2f4daf899be0197d619cb5e2fe9defc;hp=d2b3443b06d723840436edcd2cc7b3446776a3a6;hpb=f018bfcb43aa4846a037d8a7884a1a28b3e66516;p=dnsseed-rust

diff --git a/src/bgp_client.rs b/src/bgp_client.rs
index d2b3443..8dfb3eb 100644
--- a/src/bgp_client.rs
+++ b/src/bgp_client.rs
@@ -22,7 +22,7 @@ use futures::sync::mpsc;
 use crate::printer::{Printer, Stat};
 use crate::timeout_stream::TimeoutStream;
 
-const PATH_SUFFIX_LEN: usize = 2;
+const PATH_SUFFIX_LEN: usize = 3;
 #[derive(Clone)]
 struct Route { // 32 bytes with a path id u32
 	path_suffix: [u32; PATH_SUFFIX_LEN],
@@ -31,7 +31,7 @@ struct Route { // 32 bytes with a path id u32
 	med: u32,
 }
 #[allow(dead_code)]
-const ROUTE_LEN: usize = 32 - std::mem::size_of::<(u32, Route)>();
+const ROUTE_LEN: usize = 36 - std::mem::size_of::<(u32, Route)>();
 
 // To keep memory tight (and since we dont' need such close alignment), newtype the v4/v6 routing
 // table entries to make sure they are aligned to single bytes.
@@ -84,8 +84,8 @@ struct RoutingTable {
 impl RoutingTable {
 	fn new() -> Self {
 		Self {
-			v4_table: HashMap::new(),
-			v6_table: HashMap::new(),
+			v4_table: HashMap::with_capacity(900_000),
+			v6_table: HashMap::with_capacity(100_000),
 		}
 	}
 
@@ -259,14 +259,35 @@ impl BGPClient {
 		});
 
 		let primary_route = path_vecs.pop().unwrap();
-		'asn_candidates: for asn in primary_route.path_suffix.iter().rev() {
-			if *asn == 0 { continue 'asn_candidates; }
-			for secondary_route in path_vecs.iter() {
-				if !secondary_route.path_suffix.contains(asn) {
-					continue 'asn_candidates;
+		if path_vecs.len() > 3 {
+			// If we have at least 3 paths, try to find the last unique ASN which doesn't show up in other paths
+			// If we hit a T1 that is reasonably assumed to care about net neutrality, return the
+			// previous ASN.
+			let mut prev_asn = 0;
+			'asn_candidates: for asn in primary_route.path_suffix.iter().rev() {
+				if *asn == 0 { continue 'asn_candidates; }
+				match *asn {
+					// Included: CenturyLink (L3), Cogent, Telia, NTT, GTT, Level3,
+					//           GBLX (L3), Zayo, TI Sparkle Seabone, HE, Telefonica
+					// Left out from Caida top-20: TATA, PCCW, Vodafone, RETN, Orange, Telstra,
+					//                             Singtel, Rostelecom, DTAG
+					209|174|1299|2914|3257|3356|3549|6461|6762|6939|12956 if prev_asn != 0 => return prev_asn,
+					_ => if path_vecs.iter().any(|route| !route.path_suffix.contains(asn)) {
+						if prev_asn != 0 { return prev_asn } else {
+							// Multi-origin prefix, just give up and take the last AS in the
+							// default path
+							break 'asn_candidates;
+						}
+					} else {
+						// We only ever possibly return an ASN if it appears in all paths
+						prev_asn = *asn;
+					},
 				}
 			}
-			return *asn;
+			// All paths were the same, if the first ASN is non-0, return it.
+			if prev_asn != 0 {
+				return prev_asn;
+			}
 		}
 
 		for asn in primary_route.path_suffix.iter().rev() {