From 19b37b04d3d35d437209b193af641b3b9e283c3c Mon Sep 17 00:00:00 2001
From: Maximilian Wilhelm <max@sdn.clinic>
Date: Sun, 24 Jun 2018 00:56:11 +0200
Subject: [PATCH] Don't propagate path with detected AS loops to LocRIB or
other clients.
Signed-off-by: Maximilian Wilhelm <max@sdn.clinic>
---
routingtable/adjRIBIn/adj_rib_in.go | 33 +++++++++++++++++++++++----
routingtable/contributing_asn_list.go | 11 +++++++++
2 files changed, 39 insertions(+), 5 deletions(-)
diff --git a/routingtable/adjRIBIn/adj_rib_in.go b/routingtable/adjRIBIn/adj_rib_in.go
index 81416d9a..2d850024 100644
--- a/routingtable/adjRIBIn/adj_rib_in.go
+++ b/routingtable/adjRIBIn/adj_rib_in.go
@@ -3,6 +3,7 @@ package adjRIBIn
import (
"sync"
+ "github.com/bio-routing/bio-rd/protocols/bgp/packet"
"github.com/bio-routing/bio-rd/routingtable/filter"
"github.com/bio-routing/bio-rd/net"
@@ -14,16 +15,18 @@ import (
// AdjRIBIn represents an Adjacency RIB In as described in RFC4271
type AdjRIBIn struct {
routingtable.ClientManager
- rt *routingtable.RoutingTable
- mu sync.RWMutex
- exportFilter *filter.Filter
+ rt *routingtable.RoutingTable
+ mu sync.RWMutex
+ exportFilter *filter.Filter
+ contributingASNs *routingtable.ContributingASNs
}
// New creates a new Adjacency RIB In
func New(exportFilter *filter.Filter, contributingASNs *routingtable.ContributingASNs) *AdjRIBIn {
a := &AdjRIBIn{
- rt: routingtable.NewRoutingTable(),
- exportFilter: exportFilter,
+ rt: routingtable.NewRoutingTable(),
+ exportFilter: exportFilter,
+ contributingASNs: contributingASNs,
}
a.ClientManager = routingtable.NewClientManager(a)
return a
@@ -65,12 +68,32 @@ func (a *AdjRIBIn) AddPath(pfx net.Prefix, p *route.Path) error {
return nil
}
+ // Bail out - for all clients for now - if any of our ASNs is within the path
+ if a.ourASNsInPath(p) {
+ return nil
+ }
+
for _, client := range a.ClientManager.Clients() {
client.AddPath(pfx, p)
}
return nil
}
+func (a *AdjRIBIn) ourASNsInPath(p *route.Path) bool {
+ // Don't accept path via iBGP which contain our ASN
+ ASPathAttr, _ := packet.ParseASPathStr(p.BGPPath.ASPath)
+
+ for _, pathSegment := range ASPathAttr.Value.(packet.ASPath) {
+ for _, asn := range pathSegment.ASNs {
+ if a.contributingASNs.IsContributingASN(asn) {
+ return true
+ }
+ }
+ }
+
+ return false
+}
+
// RemovePath removes the path for prefix `pfx`
func (a *AdjRIBIn) RemovePath(pfx net.Prefix, p *route.Path) bool {
a.mu.Lock()
diff --git a/routingtable/contributing_asn_list.go b/routingtable/contributing_asn_list.go
index 0b0efca2..be981ce2 100644
--- a/routingtable/contributing_asn_list.go
+++ b/routingtable/contributing_asn_list.go
@@ -62,3 +62,14 @@ func (c *ContributingASNs) Remove(asn uint32) {
}
}
}
+
+// IsContributingASN checks if a given ASN is part of the contributing ASNs
+func (c *ContributingASNs) IsContributingASN(asn uint32) bool {
+ for _, cASN := range c.contributingASNs {
+ if asn == cASN.asn {
+ return true
+ }
+ }
+
+ return false
+}
--
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