From 1265ce0cd508817c1bfebbb1ebdafae5ef82e40d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lucas=20Serv=C3=A9n=20Mar=C3=ADn?= <lserven@gmail.com>
Date: Tue, 24 Sep 2019 16:11:22 +0200
Subject: [PATCH] pkg/route: filter invalid route updates

This commit fixes the underlying issue that caused crashes when
receiving a nil route update, as reported in
https://github.com/squat/kilo/issues/17.
---
 pkg/route/route.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/pkg/route/route.go b/pkg/route/route.go
index 9de04ae..feb880d 100644
--- a/pkg/route/route.go
+++ b/pkg/route/route.go
@@ -91,6 +91,10 @@ func (t *Table) Run(stop <-chan struct{}) (<-chan error, error) {
 			case unix.RTM_DELROUTE:
 				t.mu.Lock()
 				for _, r := range t.routes {
+					// Filter out invalid routes.
+					if r == nil || r.Dst == nil {
+						continue
+					}
 					// If any deleted route's destination matches a destination
 					// in the table, reset the corresponding route just in case.
 					if r.Dst.IP.Equal(e.Route.Dst.IP) && r.Dst.Mask.String() == e.Route.Dst.Mask.String() {