func (f *ICMPFilter) Block(typ ICMPType) {
	f.block(typ)
}
Block blocks incoming ICMP packets including the type field value
typ.
package ipv4
import "golang.org/x/net/internal/iana"
type ICMPType int
func (typ ICMPType) String() string {
	s, ok := icmpTypes[typ]
	if !ok {
		return "<nil>"
	}
	return s
}
func (typ ICMPType) Protocol() int {
	return iana.ProtocolICMP
}
type ICMPFilter struct {
	icmpFilter
}
func (f *ICMPFilter) Accept(typ ICMPType) {
	f.accept(typ)
}