ipv6 support wip

config.yaml

@@ -21,6 +21,12 @@ bgp:
     - asn:nnnn
     - asn:nnnn
   origin: igp
+  # family will determine whether we want to peer over an ipv4 or ipv6 session
+  # one gocast instance can only peer over one session. Multiple sessions are not
+  # supported. The default is 4
+  family: 4
+  # router ID is required when family 6 is specified
+  router_id: 1.1.1.1
 
 # optional list of apps to register on startup
 apps:

config/config.go

@@ -15,7 +15,7 @@ type AgentConfig struct {
 	CleanupTimer        time.Duration `yaml:"cleanup_timer"`
 	ConsulAddr          string        `yaml:"consul_addr"`
 	ConsulQueryInterval time.Duration `yaml:"consul_query_interval"`
-	ConsulToken			string		  `yaml:"consul_token"`
+	ConsulToken         string        `yaml:"consul_token"`
 }
 
 type BgpConfig struct {
@@ -25,6 +25,8 @@ type BgpConfig struct {
 	PeerIP      string `yaml:"peer_ip"`
 	Communities []string
 	Origin      string
+	Family      int
+	RouterID    string `yaml:"router_id"`
 }
 
 type VipConfig struct {

controller/bgp.go

@@ -32,10 +32,13 @@ func NewController(config c.BgpConfig) (*Controller, error) {
 	c := &Controller{}
 	var gw net.IP
 	var err error
+	if config.Family == 0 {
+		config.Family = 4
+	}
 	if config.PeerIP == "" {
-		gw, err := gateway()
+		gw, err := gateway(config.Family)
 		if err != nil {
-			return nil, fmt.Errorf("Unable to get gw ip: %v", err)
+			return nil, fmt.Errorf("unable to get gw ip: %v", err)
 		}
 		c.peerIP = gw
 	} else {
@@ -44,7 +47,7 @@ func NewController(config c.BgpConfig) (*Controller, error) {
 	if config.LocalIP == "" {
 		gw, err = via(c.peerIP)
 		if err != nil {
-			return nil, fmt.Errorf("Unable to get gw ip: %v", err)
+			return nil, fmt.Errorf("unable to get gw ip: %v", err)
 		}
 		c.localIP, err = localAddress(gw)
 		if err != nil {
@@ -62,16 +65,23 @@ func NewController(config c.BgpConfig) (*Controller, error) {
 	case "unknown":
 		c.origin = 2
 	}
+	var rid string
+	if config.Family == 4 {
+		rid = c.localIP.String()
+	}
+	if config.RouterID != "" {
+		rid = config.RouterID
+	}
 	s := gobgp.NewBgpServer()
 	go s.Serve()
 	if err := s.StartBgp(context.Background(), &api.StartBgpRequest{
 		Global: &api.Global{
 			As:         uint32(config.LocalAS),
-			RouterId:   c.localIP.String(),
+			RouterId:   rid,
 			ListenPort: -1, // gobgp won't listen on tcp:179
 		},
 	}); err != nil {
-		return nil, fmt.Errorf("Unable to start bgp: %v", err)
+		return nil, fmt.Errorf("unable to start bgp: %v", err)
 	}
 	c.s = s
 	c.peerAS = config.PeerAS

controller/system.go

@@ -18,8 +18,12 @@ func getCmdList(mainCmd string) []string {
 	return cmdList
 }
 
-func gateway() (net.IP, error) {
+func gateway(family int) (net.IP, error) {
-	cmd := `ip route | grep "^default" | cut -d" " -f3`
+	prefix := "ip"
+	if family == 6 {
+		prefix = "ip -6"
+	}
+	cmd := fmt.Sprintf(`%s route | grep "^default" | cut -d" " -f3`, prefix)
 	cmdList := getCmdList(cmd)
 	out, err := exec.Command(execCmd, cmdList...).Output()
 	if err != nil {
@@ -29,7 +33,11 @@ func gateway() (net.IP, error) {
 }
 
 func via(dest net.IP) (net.IP, error) {
-	cmd := fmt.Sprintf(`ip route get %s | grep via | cut -d" " -f3`, dest.String())
+	prefix := "ip"
+	if dest.To4() == nil {
+		prefix = "ip -6"
+	}
+	cmd := fmt.Sprintf(`%s route get %s | grep via | cut -d" " -f3`, prefix, dest.String())
 	cmdList := getCmdList(cmd)
 	out, err := exec.Command(execCmd, cmdList...).Output()
 	if err != nil {
@@ -66,7 +74,11 @@ func addLoopback(name string, addr *net.IPNet) error {
 	if len(label) > 15 {
 		label = label[:15]
 	}
-	cmd := fmt.Sprintf("ip address add %s/%d dev lo label %s", addr.IP.String(), prefixLen, label)
+	prefix := "ip"
+	if addr.IP.To4() == nil {
+		prefix = "ip -6"
+	}
+	cmd := fmt.Sprintf("%s address add %s/%d dev lo label %s", prefix, addr.IP.String(), prefixLen, label)
 	cmdList := getCmdList(cmd)
 	_, err := exec.Command(execCmd, cmdList...).Output()
 	if err != nil {
@@ -76,8 +88,12 @@ func addLoopback(name string, addr *net.IPNet) error {
 }
 
 func deleteLoopback(addr *net.IPNet) error {
+	prefix := "ip"
+	if addr.IP.To4() == nil {
+		prefix = "ip -6"
+	}
 	prefixLen, _ := addr.Mask.Size()
-	cmd := fmt.Sprintf("ip address delete %s/%d dev lo", addr.IP.String(), prefixLen)
+	cmd := fmt.Sprintf("%s address delete %s/%d dev lo", prefix, addr.IP.String(), prefixLen)
 	cmdList := getCmdList(cmd)
 	_, err := exec.Command(execCmd, cmdList...).Output()
 	if err != nil {
@@ -87,9 +103,13 @@ func deleteLoopback(addr *net.IPNet) error {
 }
 
 func natRule(op string, vip, localAddr net.IP, protocol, lport, dport string) error {
+	prefix := "iptables"
+	if vip.To4() == nil {
+		prefix = "ip6tables"
+	}
 	cmd := fmt.Sprintf(
-		"iptables -t nat -%s PREROUTING -p %s -d %s --dport %s -j DNAT --to-destination %s:%s",
+		"%s -t nat -%s PREROUTING -p %s -d %s --dport %s -j DNAT --to-destination %s:%s",
-		op, protocol, vip.String(), lport, localAddr.String(), dport,
+		prefix, op, protocol, vip.String(), lport, localAddr.String(), dport,
 	)
 	cmdList := getCmdList(cmd)
 	_, err := exec.Command(execCmd, cmdList...).Output()