type RuleSet … // PermitAll returns a RuleSet which allows all types of connections func PermitAll() RuleSet { … } // PermitNone returns a RuleSet which disallows all types of connections func PermitNone() RuleSet { … } type PermitCommand … func (p *PermitCommand) Allow(ctx context.Context, req *Request) (context.Context, bool) { … }