From c37ddf4f6e93d582d6708adc71deff4b65a5633c Mon Sep 17 00:00:00 2001
From: Michael Stapelberg <stapelberg@google.com>
Date: Fri, 8 Jun 2018 16:51:33 +0200
Subject: [PATCH] integrationradvd: unflake test

---
 integrationradvd_test.go | 10 ++++++++--
 internal/radvd/radvd.go  | 20 ++++++++++++--------
 2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/integrationradvd_test.go b/integrationradvd_test.go
index c75eed7..f93ec48 100644
--- a/integrationradvd_test.go
+++ b/integrationradvd_test.go
@@ -30,6 +30,8 @@ func TestRouterAdvertisement(t *testing.T) {
 		exec.Command("ip", "netns", "exec", ns, "ip", "addr", "add", "192.168.23.1/24", "dev", "veth0b"),
 		exec.Command("ip", "netns", "exec", ns, "ip", "link", "set", "veth0b", "up"),
 		exec.Command("ip", "netns", "exec", ns, "ip", "link", "set", "veth0b"),
+
+		exec.Command("/bin/sh", "-c", "echo 1 > /proc/sys/net/ipv6/conf/veth0a/forwarding"),
 	}
 
 	for _, cmd := range nsSetup {
@@ -52,8 +54,12 @@ func TestRouterAdvertisement(t *testing.T) {
 	srv.SetPrefixes([]net.IPNet{
 		net.IPNet{IP: net.ParseIP("2a02:168:4a00::"), Mask: net.CIDRMask(64, 128)},
 	})
+	conn, err := net.ListenIP("ip6:ipv6-icmp", &net.IPAddr{net.IPv6unspecified, ""})
+	if err != nil {
+		t.Fatal(err)
+	}
 	go func() {
-		if err := srv.ListenAndServe("veth0a"); err != nil {
+		if err := srv.Serve("veth0a", conn); err != nil {
 			t.Fatal(err)
 		}
 	}()
@@ -66,7 +72,7 @@ func TestRouterAdvertisement(t *testing.T) {
 	rdisc6.Stderr = os.Stderr
 	b, err := rdisc6.Output()
 	if err != nil {
-		t.Fatal(err)
+		t.Fatalf("%v: %v (output: %v)", rdisc6.Args, err, string(b))
 	}
 	t.Logf("b = %s", string(b))
 
diff --git a/internal/radvd/radvd.go b/internal/radvd/radvd.go
index 79a8590..d18c3ad 100644
--- a/internal/radvd/radvd.go
+++ b/internal/radvd/radvd.go
@@ -36,20 +36,13 @@ func (s *Server) SetPrefixes(prefixes []net.IPNet) {
 	}
 }
 
-func (s *Server) ListenAndServe(ifname string) error {
+func (s *Server) Serve(ifname string, conn net.PacketConn) error {
 	var err error
 	s.iface, err = net.InterfaceByName(ifname)
 	if err != nil {
 		return err
 	}
 
-	// TODO(correctness): would it be better to listen on
-	// net.IPv6linklocalallrouters? Just specifying that results in an error,
-	// though.
-	conn, err := net.ListenIP("ip6:ipv6-icmp", &net.IPAddr{net.IPv6unspecified, ""})
-	if err != nil {
-		return err
-	}
 	defer conn.Close()
 	s.pc = ipv6.NewPacketConn(conn)
 	s.pc.SetHopLimit(255) // as per RFC 4861, section 4.1
@@ -89,6 +82,17 @@ func (s *Server) ListenAndServe(ifname string) error {
 	return nil
 }
 
+func (s *Server) ListenAndServe(ifname string) error {
+	// TODO(correctness): would it be better to listen on
+	// net.IPv6linklocalallrouters? Just specifying that results in an error,
+	// though.
+	conn, err := net.ListenIP("ip6:ipv6-icmp", &net.IPAddr{net.IPv6unspecified, ""})
+	if err != nil {
+		return err
+	}
+	return s.Serve(ifname, conn)
+}
+
 type sourceLinkLayerAddress struct {
 	address net.HardwareAddr
 }