From: Matt Corallo Date: Sun, 1 Dec 2019 23:08:59 +0000 (-0500) Subject: Drop prepends in BGP paths since it doesn't change our results X-Git-Url: http://git.bitcoin.ninja/?a=commitdiff_plain;h=0c6846d425dea8331a586420c74f367cef879687;p=dnsseed-rust Drop prepends in BGP paths since it doesn't change our results --- diff --git a/src/bgp_client.rs b/src/bgp_client.rs index 04be136..10880a6 100644 --- a/src/bgp_client.rs +++ b/src/bgp_client.rs @@ -22,8 +22,10 @@ use futures::sync::mpsc; use crate::printer::{Printer, Stat}; use crate::timeout_stream::TimeoutStream; +const PATH_SUFFIX_LEN: usize = 3; struct Route { - path: Vec, + path_suffix: [u32; PATH_SUFFIX_LEN], + path_len: u32, pref: u32, med: u32, } @@ -180,20 +182,27 @@ impl BGPClient { 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 disconnect(&self) { @@ -215,15 +224,25 @@ 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, })