// Performs the actual query by service name (browse) or service instance name (lookup),
// start response listeners goroutines and loops over the entries channel.
func (c *client) query(params *LookupParams) error {
var serviceName, serviceInstanceName string
serviceName = fmt.Sprintf("%s.%s.", trimDot(params.Service), trimDot(params.Domain))
if params.Instance != "" {
serviceInstanceName = fmt.Sprintf("%s.%s", params.Instance, serviceName)
}
// send the query
m := new(dns.Msg)
if serviceInstanceName != "" {
m.Question = []dns.Question{
dns.Question{serviceInstanceName, dns.TypeSRV, dns.ClassINET},
dns.Question{serviceInstanceName, dns.TypeTXT, dns.ClassINET},
}
m.RecursionDesired = false
} else {
m.SetQuestion(serviceName, dns.TypePTR)
m.RecursionDesired = false
}
if err := c.sendQuery(m); err != nil {
return err
}
return nil
}