wgengine/router: rename config.Settings to config.Config, make pointer.

Signed-off-by: David Anderson <danderson@tailscale.com>

wgengine/router/router_freebsd.go

@@ -55,15 +55,18 @@ func (r *freebsdRouter) Up() error {
 	return nil
 }
 
-func (r *freebsdRouter) Set(rs Settings) error {
-	if len(rs.LocalAddrs) == 0 {
+func (r *freebsdRouter) Set(cfg *Config) error {
+	if cfg == nil {
+		cfg = &shutdownConfig
+	}
+	if len(cfg.LocalAddrs) == 0 {
 		return nil
 	}
 	// TODO: support configuring multiple local addrs on interface.
-	if len(rs.LocalAddrs) != 1 {
+	if len(cfg.LocalAddrs) != 1 {
 		return errors.New("freebsd doesn't support setting multiple local addrs yet")
 	}
-	localAddr := rs.LocalAddrs[0]
+	localAddr := cfg.LocalAddrs[0]
 
 	var errq error
 
@@ -95,7 +98,7 @@ func (r *freebsdRouter) Set(rs Settings) error {
 	}
 
 	newRoutes := make(map[netaddr.IPPrefix]struct{})
-	for _, route := range rs.Routes {
+	for _, route := range cfg.Routes {
 		newRoutes[route] = struct{}{}
 	}
 	// Delete any pre-existing routes.
@@ -139,7 +142,7 @@ func (r *freebsdRouter) Set(rs Settings) error {
 	r.local = localAddr
 	r.routes = newRoutes
 
-	if err := r.replaceResolvConf(rs.DNS, rs.DNSDomains); err != nil {
+	if err := r.replaceResolvConf(cfg.DNS, cfg.DNSDomains); err != nil {
 		errq = fmt.Errorf("replacing resolv.conf failed: %v", err)
 	}