Drop Arcs around paths, and add more debug info for looked-up ASNs

[dnsseed-rust] / src / bgp_client.rs

diff --git a/src/bgp_client.rs b/src/bgp_client.rs
index 04be1360c930cc6d01f65bd57f5f44340c4777a9..e38cffb97208d6fdb5a85c239d6ba7a95b4b0735 100644 (file)
--- a/src/bgp_client.rs
+++ b/src/bgp_client.rs
@@ -22,15 +22,18 @@ use futures::sync::mpsc;
 use crate::printer::{Printer, Stat};
 use crate::timeout_stream::TimeoutStream;
 
-struct Route {
-       path: Vec<u32>,
+const PATH_SUFFIX_LEN: usize = 3;
+#[derive(Clone)]
+struct Route { // 32 bytes
+       path_suffix: [u32; PATH_SUFFIX_LEN],
+       path_len: u32,
        pref: u32,
        med: u32,
 }
 
 struct RoutingTable {
-       v4_table: HashMap<(Ipv4Addr, u8), HashMap<u32, Arc<Route>>>,
-       v6_table: HashMap<(Ipv6Addr, u8), HashMap<u32, Arc<Route>>>,
+       v4_table: HashMap<(Ipv4Addr, u8), HashMap<u32, Route>>,
+       v6_table: HashMap<(Ipv6Addr, u8), HashMap<u32, Route>>,
 }
 
 impl RoutingTable {
@@ -41,7 +44,7 @@ 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, $addr_bits: expr) => { {
                                //TODO: Optimize this (probably means making the tables btrees)!
@@ -54,11 +57,11 @@ impl RoutingTable {
                                        let lookup_addr = <$addrty>::from(lookup);
                                        if let Some(routes) = $table.get(&(lookup_addr, $addr_bits - i as u8)).map(|hm| hm.values()) {
                                                if routes.len() > 0 {
-                                                       return routes.map(|x| Arc::clone(&x)).collect();
+                                                       return ($addr_bits - i as u8, routes.collect());
                                                }
                                        }
                                }
-                               vec![]
+                               (0, vec![])
                        } }
                }
                match ip {
@@ -87,7 +90,7 @@ impl RoutingTable {
                };
        }
 
-       fn announce(&mut self, prefix: NLRIEncoding, route: Arc<Route>) {
+       fn announce(&mut self, prefix: NLRIEncoding, route: Route) {
                match prefix {
                        NLRIEncoding::IP(p) => {
                                let (ip, len) = <(IpAddr, u8)>::from(&p);
@@ -175,25 +178,48 @@ 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 +241,25 @@ 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 +319,8 @@ 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()));