transdep/messages/zonecut/request.go

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2018-01-23 20:25:00 +00:00
package zonecut
import (
"github.com/miekg/dns"
"github.com/ANSSI-FR/transdep/tools"
"strings"
"time"
"github.com/ANSSI-FR/transdep/errors"
)
type RequestTopic struct {
// domain is the topic of the request: the name whose delegation info is sought.
Domain string
// exceptions is the list of exceptions we are willing to make for this request w.r.t to the DNS standard
Exceptions tools.Exceptions
}
// Request contains the elements of a request for a delegation information
type Request struct {
topic RequestTopic
// ansChan is the channel used to return the result of the request from the worker goroutine to the calling goroutine
ansChan chan *result
}
// NewRequest builds a new request instance
func NewRequest(name string, exceptions tools.Exceptions) *Request {
zcr := new(Request)
zcr.topic.Domain = strings.ToLower(dns.Fqdn(name))
zcr.topic.Exceptions = exceptions
zcr.ansChan = make(chan *result, 1)
return zcr
}
func (zcr *Request) Domain() string {
return zcr.topic.Domain
}
func (zcr *Request) Exceptions() tools.Exceptions {
return zcr.topic.Exceptions
}
func (zcr *Request) RequestTopic() RequestTopic {
return zcr.topic
}
func (zcr *Request) Equal(other *Request) bool {
return zcr.topic == other.topic
}
// Result returns the result of this request. It blocks for the default timeout duration or until an answer is provided.
// An error is returned upon timeout or if an incident occurred during the discovery of the delegation information.
// The entry might value nil even if error is nil too, if the request topic is not a zone apex.
func (zcr *Request) Result() (*Entry, *errors.ErrorStack) {
return zcr.ResultWithSpecificTimeout(tools.DEFAULT_TIMEOUT_DURATION)
}
// ResultWithSpecificTimeout is identical to Result except a timeout duration may be specified.
func (zcr *Request) ResultWithSpecificTimeout(dur time.Duration) (*Entry, *errors.ErrorStack) {
select {
case res := <-zcr.ansChan:
return res.Result, res.Err
case _ = <-tools.StartTimeout(dur):
return nil, errors.NewErrorStack(errors.NewTimeoutError("zone cut retrieval", zcr.topic.Domain))
}
}
// SetResult is used to set/pass along the result associated to this request
// This function is meant to be called only once, though the implemention does not currently prevent this.
func (zcr *Request) SetResult(res *Entry, err *errors.ErrorStack) {
if err != nil {
err = err.Copy()
}
zcr.ansChan <- &result{res, err}
}