X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=src%2Fbgp_client.rs;h=ba3a16418087196a5dd3c335ad6ea3dfc1d391de;hb=7f3e64fc449bc64c569eb45d5e52472f56e1f3ed;hp=04be1360c930cc6d01f65bd57f5f44340c4777a9;hpb=7aaa26debb3bb875c5e49fbd39dec642cd535f88;p=dnsseed-rust

diff --git a/src/bgp_client.rs b/src/bgp_client.rs
index 04be136..ba3a164 100644
--- a/src/bgp_client.rs
+++ b/src/bgp_client.rs
@@ -1,7 +1,7 @@
 use std::sync::{Arc, Mutex};
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::cmp;
-use std::collections::HashMap;
+use std::collections::{HashMap, hash_map};
 use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr};
 use std::time::{Duration, Instant};
 
@@ -22,15 +22,63 @@ use futures::sync::mpsc;
 use crate::printer::{Printer, Stat};
 use crate::timeout_stream::TimeoutStream;
 
-struct Route {
-	path: Vec<u32>,
+const PATH_SUFFIX_LEN: usize = 2;
+#[derive(Clone)]
+struct Route { // 32 bytes with a path id u32
+	path_suffix: [u32; PATH_SUFFIX_LEN],
+	path_len: u32,
 	pref: u32,
 	med: u32,
 }
+#[allow(dead_code)]
+const ROUTE_LEN: usize = 32 - 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.
+
+#[repr(packed)]
+#[derive(PartialEq, Eq, Hash)]
+struct V4Addr {
+	addr: [u8; 4],
+	pfxlen: u8,
+}
+impl From<(Ipv4Addr, u8)> for V4Addr {
+	fn from(p: (Ipv4Addr, u8)) -> Self {
+		Self {
+			addr: p.0.octets(),
+			pfxlen: p.1,
+		}
+	}
+}
+#[allow(dead_code)]
+const V4_ALIGN: usize = 1 - std::mem::align_of::<V4Addr>();
+#[allow(dead_code)]
+const V4_SIZE: usize = 5 - std::mem::size_of::<V4Addr>();
+
+#[repr(packed)]
+#[derive(PartialEq, Eq, Hash)]
+struct V6Addr {
+	addr: [u8; 16],
+	pfxlen: u8,
+}
+impl From<(Ipv6Addr, u8)> for V6Addr {
+	fn from(p: (Ipv6Addr, u8)) -> Self {
+		Self {
+			addr: p.0.octets(),
+			pfxlen: p.1,
+		}
+	}
+}
+#[allow(dead_code)]
+const V6_ALIGN: usize = 1 - std::mem::align_of::<V6Addr>();
+#[allow(dead_code)]
+const V6_SIZE: usize = 17 - std::mem::size_of::<V6Addr>();
 
 struct RoutingTable {
-	v4_table: HashMap<(Ipv4Addr, u8), HashMap<u32, Arc<Route>>>,
-	v6_table: HashMap<(Ipv6Addr, u8), HashMap<u32, Arc<Route>>>,
+	// We really want a HashMap for the values here, but they'll only ever contain a few entries,
+	// and Vecs are way more memory-effecient in that case.
+	v4_table: HashMap<V4Addr, Vec<(u32, Route)>>,
+	v6_table: HashMap<V6Addr, Vec<(u32, Route)>>,
 }
 
 impl RoutingTable {
@@ -41,69 +89,86 @@ impl RoutingTable {
 		}
 	}
 
-	fn get_route_attrs(&self, ip: IpAddr) -> Vec<Arc<Route>> {
+	fn get_route_attrs(&self, ip: IpAddr) -> (u8, Vec<&Route>) {
 		macro_rules! lookup_res {
 			($addrty: ty, $addr: expr, $table: expr, $addr_bits: expr) => { {
 				//TODO: Optimize this (probably means making the tables btrees)!
-				for i in (0..$addr_bits).rev() {
-					let mut lookup = $addr.octets();
-					for b in 0..(i / 8) {
-						lookup[lookup.len() - b - 1] = 0;
-					}
-					lookup[lookup.len() - (i/8) - 1] &= !(((1u16 << (i % 8)) - 1) as u8);
-					let lookup_addr = <$addrty>::from(lookup);
-					if let Some(routes) = $table.get(&(lookup_addr, $addr_bits - i as u8)).map(|hm| hm.values()) {
+				let mut lookup = <$addrty>::from(($addr, $addr_bits));
+				for i in 0..$addr_bits {
+					if let Some(routes) = $table.get(&lookup) {
 						if routes.len() > 0 {
-							return routes.map(|x| Arc::clone(&x)).collect();
+							return (lookup.pfxlen, routes.iter().map(|v| &v.1).collect());
 						}
 					}
+					lookup.addr[lookup.addr.len() - (i/8) - 1] &= !(1u8 << (i % 8));
+					lookup.pfxlen -= 1;
 				}
-				vec![]
+				(0, vec![])
 			} }
 		}
 		match ip {
-			IpAddr::V4(v4a) => lookup_res!(Ipv4Addr, v4a, self.v4_table, 32),
-			IpAddr::V6(v6a) => lookup_res!(Ipv6Addr, v6a, self.v6_table, 128)
+			IpAddr::V4(v4a) => lookup_res!(V4Addr, v4a, self.v4_table, 32),
+			IpAddr::V6(v6a) => lookup_res!(V6Addr, v6a, self.v6_table, 128)
 		}
 	}
 
 	fn withdraw(&mut self, route: NLRIEncoding) {
+		macro_rules! remove {
+			($rt: expr, $v: expr, $id: expr) => { {
+				match $rt.entry($v.into()) {
+					hash_map::Entry::Occupied(mut entry) => {
+						entry.get_mut().retain(|e| e.0 != $id);
+						if entry.get_mut().is_empty() {
+							entry.remove();
+						}
+					},
+					_ => {},
+				}
+			} }
+		}
 		match route {
 			NLRIEncoding::IP(p) => {
 				let (ip, len) = <(IpAddr, u8)>::from(&p);
 				match ip {
-					IpAddr::V4(v4a) => self.v4_table.get_mut(&(v4a, len)).and_then(|hm| hm.remove(&0)),
-					IpAddr::V6(v6a) => self.v6_table.get_mut(&(v6a, len)).and_then(|hm| hm.remove(&0)),
+					IpAddr::V4(v4a) => remove!(self.v4_table, (v4a, len), 0),
+					IpAddr::V6(v6a) => remove!(self.v6_table, (v6a, len), 0),
 				}
 			},
 			NLRIEncoding::IP_WITH_PATH_ID((p, id)) => {
 				let (ip, len) = <(IpAddr, u8)>::from(&p);
 				match ip {
-					IpAddr::V4(v4a) => self.v4_table.get_mut(&(v4a, len)).and_then(|hm| hm.remove(&id)),
-					IpAddr::V6(v6a) => self.v6_table.get_mut(&(v6a, len)).and_then(|hm| hm.remove(&id)),
+					IpAddr::V4(v4a) => remove!(self.v4_table, (v4a, len), id),
+					IpAddr::V6(v6a) => remove!(self.v6_table, (v6a, len), id),
 				}
 			},
-			NLRIEncoding::IP_MPLS(_) => None,
+			NLRIEncoding::IP_MPLS(_) => (),
 		};
 	}
 
-	fn announce(&mut self, prefix: NLRIEncoding, route: Arc<Route>) {
+	fn announce(&mut self, prefix: NLRIEncoding, route: Route) {
+		macro_rules! insert {
+			($rt: expr, $v: expr, $id: expr) => { {
+				let entry = $rt.entry($v.into()).or_insert(Vec::new());
+				entry.retain(|e| e.0 != $id);
+				entry.push(($id, route));
+			} }
+		}
 		match prefix {
 			NLRIEncoding::IP(p) => {
 				let (ip, len) = <(IpAddr, u8)>::from(&p);
 				match ip {
-					IpAddr::V4(v4a) => self.v4_table.entry((v4a, len)).or_insert(HashMap::new()).insert(0, route),
-					IpAddr::V6(v6a) => self.v6_table.entry((v6a, len)).or_insert(HashMap::new()).insert(0, route),
+					IpAddr::V4(v4a) => insert!(self.v4_table, (v4a, len), 0),
+					IpAddr::V6(v6a) => insert!(self.v6_table, (v6a, len), 0),
 				}
 			},
 			NLRIEncoding::IP_WITH_PATH_ID((p, id)) => {
 				let (ip, len) = <(IpAddr, u8)>::from(&p);
 				match ip {
-					IpAddr::V4(v4a) => self.v4_table.entry((v4a, len)).or_insert(HashMap::new()).insert(id, route),
-					IpAddr::V6(v6a) => self.v6_table.entry((v6a, len)).or_insert(HashMap::new()).insert(id, route),
+					IpAddr::V4(v4a) => insert!(self.v4_table, (v4a, len), id),
+					IpAddr::V6(v6a) => insert!(self.v6_table, (v6a, len), id),
 				}
 			},
-			NLRIEncoding::IP_MPLS(_) => None,
+			NLRIEncoding::IP_MPLS(_) => (),
 		};
 	}
 }
@@ -175,25 +240,48 @@ pub struct BGPClient {
 }
 impl BGPClient {
 	pub fn get_asn(&self, addr: IpAddr) -> u32 {
-		let mut path_vecs = self.routes.lock().unwrap().get_route_attrs(addr).clone();
+		let lock = self.routes.lock().unwrap();
+		let mut path_vecs = lock.get_route_attrs(addr).1;
 		if path_vecs.is_empty() { return 0; }
 
 		path_vecs.sort_unstable_by(|path_a, path_b| {
 			path_a.pref.cmp(&path_b.pref)
-				.then(path_b.path.len().cmp(&path_a.path.len()))
+				.then(path_b.path_len.cmp(&path_a.path_len))
 				.then(path_b.med.cmp(&path_a.med))
 		});
 
 		let primary_route = path_vecs.pop().unwrap();
-		'asn_candidates: for asn in primary_route.path.iter().rev() {
+		'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.contains(asn) {
+				if !secondary_route.path_suffix.contains(asn) {
 					continue 'asn_candidates;
 				}
 			}
 			return *asn;
 		}
-		*primary_route.path.last().unwrap_or(&0)
+
+		for asn in primary_route.path_suffix.iter().rev() {
+			if *asn != 0 {
+				return *asn;
+			}
+		}
+		0
+	}
+
+	pub fn get_path(&self, addr: IpAddr) -> (u8, [u32; PATH_SUFFIX_LEN]) {
+		let lock = self.routes.lock().unwrap();
+		let (prefixlen, mut path_vecs) = lock.get_route_attrs(addr);
+		if path_vecs.is_empty() { return (0, [0; PATH_SUFFIX_LEN]); }
+
+		path_vecs.sort_unstable_by(|path_a, path_b| {
+			path_a.pref.cmp(&path_b.pref)
+				.then(path_b.path_len.cmp(&path_a.path_len))
+				.then(path_b.med.cmp(&path_a.med))
+		});
+
+		let primary_route = path_vecs.pop().unwrap();
+		(prefixlen, primary_route.path_suffix)
 	}
 
 	pub fn disconnect(&self) {
@@ -215,15 +303,25 @@ impl BGPClient {
 			}
 		}
 		if let Some(mut aspath) = as4_path.or(as_path) {
-			let mut path = Vec::new();
+			let mut pathvec = Vec::new();
 			for seg in aspath.segments.drain(..) {
 				match seg {
-					Segment::AS_SEQUENCE(mut asn) => path.append(&mut asn),
+					Segment::AS_SEQUENCE(mut asn) => pathvec.append(&mut asn),
 					Segment::AS_SET(_) => {}, // Ignore sets for now, they're not that common anyway
 				}
 			}
+			let path_len = pathvec.len() as u32;
+			pathvec.dedup_by(|a, b| (*a).eq(b)); // Drop prepends, cause we don't care in this case
+
+			let mut path_suffix = [0; PATH_SUFFIX_LEN];
+			for (idx, asn) in pathvec.iter().rev().enumerate() {
+				path_suffix[PATH_SUFFIX_LEN - idx - 1] = *asn;
+				if idx == PATH_SUFFIX_LEN - 1 { break; }
+			}
+
 			return Some(Route {
-				path: path.clone(),
+				path_suffix,
+				path_len,
 				pref,
 				med,
 			})
@@ -283,9 +381,8 @@ impl BGPClient {
 									route_table.withdraw(r);
 								}
 								if let Some(path) = Self::map_attrs(upd.attributes) {
-									let path_arc = Arc::new(path);
 									for r in upd.announced_routes {
-										route_table.announce(r, Arc::clone(&path_arc));
+										route_table.announce(r, path.clone());
 									}
 								}
 								printer.set_stat(Stat::V4RoutingTableSize(route_table.v4_table.len()));