dnsforward: imp docs

internal/dnsforward/recursiondetector.go

@@ -6,13 +6,15 @@ import (
 	"time"
 
 	"github.com/AdguardTeam/AdGuardHome/internal/aghnet"
-	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
 	"github.com/AdguardTeam/golibs/cache"
 	"github.com/AdguardTeam/golibs/log"
 	"github.com/miekg/dns"
 )
 
 // uint* sizes in bytes to improve readability.
+//
+// TODO(e.burkov): Remove when there will be a more regardful way to define
+// those.  See https://github.com/golang/go/issues/29982.
 const (
 	uint16sz = 2
 	uint64sz = 8
@@ -36,7 +38,7 @@ func (rd *recursionDetector) check(msg dns.Msg) (ok bool) {
 		return false
 	}
 
-	expire := time.Unix(0, int64(aghos.NativeEndian.Uint64(expireData)))
+	expire := time.Unix(0, int64(binary.BigEndian.Uint64(expireData)))
 
 	return time.Now().Before(expire)
 }
@@ -52,7 +54,7 @@ func (rd *recursionDetector) add(msg dns.Msg) {
 	key := msgToSignature(msg)
 	expire64 := uint64(now.Add(rd.ttl).UnixNano())
 	expire := make([]byte, uint64sz)
-	aghos.NativeEndian.PutUint64(expire, expire64)
+	binary.BigEndian.PutUint64(expire, expire64)
 
 	rd.recentRequests.Set(key, expire)
 }
@@ -76,7 +78,9 @@ func newRecursionDetector(ttl time.Duration, suspectsNum uint) (rd *recursionDet
 // msgToSignature converts msg into it's signature represented in bytes.
 func msgToSignature(msg dns.Msg) (sig []byte) {
 	sig = make([]byte, uint16sz*2+aghnet.MaxDomainNameLen)
-	byteOrder := aghos.NativeEndian
+	// The binary.BigEndian byte order is used everywhere except when the
+	// real machine's endianess is needed.
+	byteOrder := binary.BigEndian
 	byteOrder.PutUint16(sig[0:], msg.Id)
 	q := msg.Question[0]
 	byteOrder.PutUint16(sig[uint16sz:], q.Qtype)
@@ -103,7 +107,7 @@ func msgToSignatureSlow(msg dns.Msg) (sig []byte) {
 		qtype: q.Qtype,
 	}
 	copy(signature.name[:], q.Name)
-	if err := binary.Write(b, aghos.NativeEndian, signature); err != nil {
+	if err := binary.Write(b, binary.BigEndian, signature); err != nil {
 		log.Debug("writing message signature: %s", err)
 	}
 

internal/dnsforward/recursiondetector_test.go

@@ -1,10 +1,10 @@
 package dnsforward
 
 import (
+	"encoding/binary"
 	"testing"
 	"time"
 
-	"github.com/AdguardTeam/AdGuardHome/internal/aghos"
 	"github.com/miekg/dns"
 	"github.com/stretchr/testify/assert"
 )
@@ -33,10 +33,10 @@ func TestRecursionDetector_Check(t *testing.T) {
 	// Manually add the message with big ttl.
 	key := msgToSignature(sampleMsg)
 	expire := make([]byte, uint64sz)
-	aghos.NativeEndian.PutUint64(expire, uint64(time.Now().Add(recTTL).UnixNano()))
+	binary.BigEndian.PutUint64(expire, uint64(time.Now().Add(recTTL).UnixNano()))
 	rd.recentRequests.Set(key, expire)
 
-	// Add an expired message cause
+	// Add an expired message.
 	sampleMsg.Id = nonRecID
 	rd.add(sampleMsg)