Rewrite edns0 (#561)

* Add edns0 code rewrite

* check arg count

* change `new`; set EDNS0 if request doesn't have it set

* change set to replace_or_append

* change to append_or_replace

* return error in new

* update documents

* fixt UT

* return error

* go fmt

* Rework for more general EDNS0 use

Also changed how rules are created and validated. Implements
EDNS0 NSID in addition to local.

* go fmt

* README updates, NSID tests and fixes

* gofmt -s -w

* Fix tests for rewrite syntax change

* Add tests, fix error message

* Review nits

* Missed on nit

* More tests, integration test, fix edns0 parse issue

* Fix README, use RewriteIgnored

* go fmt
This commit is contained in:
John Belamaric 2017-03-06 16:32:17 -05:00 committed by Miek Gieben
parent d1bb4ea130
commit ef315ef3e2
13 changed files with 564 additions and 262 deletions

View file

@ -1,26 +1,30 @@
// Package rewrite is middleware for rewriting requests internally to something different.
package rewrite
import (
"fmt"
"strings"
"github.com/miekg/dns"
)
// ClassRule is a class rewrite rule.
type ClassRule struct {
type classRule struct {
fromClass, toClass uint16
}
// New initializes rule.
func (rule ClassRule) New(args ...string) Rule {
from, to := args[0], strings.Join(args[1:], " ")
return &ClassRule{dns.StringToClass[from], dns.StringToClass[to]}
func newClassRule(fromS, toS string) (Rule, error) {
var from, to uint16
var ok bool
if from, ok = dns.StringToClass[strings.ToUpper(fromS)]; !ok {
return nil, fmt.Errorf("invalid class %q", strings.ToUpper(fromS))
}
if to, ok = dns.StringToClass[strings.ToUpper(toS)]; !ok {
return nil, fmt.Errorf("invalid class %q", strings.ToUpper(toS))
}
return &classRule{fromClass: from, toClass: to}, nil
}
// Rewrite rewrites the the current request.
func (rule ClassRule) Rewrite(r *dns.Msg) Result {
func (rule *classRule) Rewrite(r *dns.Msg) Result {
if rule.fromClass > 0 && rule.toClass > 0 {
if r.Question[0].Qclass == rule.fromClass {
r.Question[0].Qclass = rule.toClass