mirror of
				https://github.com/nadoo/glider.git
				synced 2025-11-04 15:52:38 +08:00 
			
		
		
		
	dns: fixed a bug in compressed domain offset calculation
This commit is contained in:
		
							parent
							
								
									40f3315007
								
							
						
					
					
						commit
						41ddbb1168
					
				@ -3,9 +3,7 @@ package dns
 | 
			
		||||
import (
 | 
			
		||||
	"bytes"
 | 
			
		||||
	"encoding/binary"
 | 
			
		||||
	"encoding/hex"
 | 
			
		||||
	"errors"
 | 
			
		||||
	"fmt"
 | 
			
		||||
	"math/rand"
 | 
			
		||||
	"net"
 | 
			
		||||
	"strings"
 | 
			
		||||
@ -117,8 +115,6 @@ func UnmarshalMessage(b []byte) (*Message, error) {
 | 
			
		||||
	msg := NewMessage()
 | 
			
		||||
	msg.unMarshaled = b
 | 
			
		||||
 | 
			
		||||
	fmt.Printf("msg.unMarshaled:\n%s\n", hex.Dump(msg.unMarshaled))
 | 
			
		||||
 | 
			
		||||
	err := UnmarshalHeader(b[:HeaderLen], msg.Header)
 | 
			
		||||
	if err != nil {
 | 
			
		||||
		return nil, err
 | 
			
		||||
@ -286,7 +282,7 @@ func (m *Message) UnmarshalQuestion(b []byte, q *Question) (n int, err error) {
 | 
			
		||||
		return 0, errors.New("unmarshal question must not be nil")
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	domain, idx := m.GetDomain(b)
 | 
			
		||||
	domain, idx := m.UnmarshalDomain(b)
 | 
			
		||||
	q.QNAME = domain
 | 
			
		||||
	q.QTYPE = binary.BigEndian.Uint16(b[idx : idx+2])
 | 
			
		||||
	q.QCLASS = binary.BigEndian.Uint16(b[idx+2 : idx+4])
 | 
			
		||||
@ -347,9 +343,7 @@ func (m *Message) UnmarshalRR(start int, rr *RR) (n int, err error) {
 | 
			
		||||
 | 
			
		||||
	p := m.unMarshaled[start:]
 | 
			
		||||
 | 
			
		||||
	fmt.Printf("rr bytes:\n%s\n", hex.Dump(p[:10]))
 | 
			
		||||
 | 
			
		||||
	domain, n := m.GetDomain(p)
 | 
			
		||||
	domain, n := m.UnmarshalDomain(p)
 | 
			
		||||
	rr.NAME = domain
 | 
			
		||||
 | 
			
		||||
	if len(p) <= n+10 {
 | 
			
		||||
@ -370,8 +364,6 @@ func (m *Message) UnmarshalRR(start int, rr *RR) (n int, err error) {
 | 
			
		||||
 | 
			
		||||
	n = n + 10 + int(rr.RDLENGTH)
 | 
			
		||||
 | 
			
		||||
	fmt.Printf("rr: %+#v\n", rr)
 | 
			
		||||
 | 
			
		||||
	return n, nil
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
@ -388,8 +380,8 @@ func MarshalDomain(domain string) []byte {
 | 
			
		||||
	return buf.Bytes()
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
// GetDomain gets domain from bytes
 | 
			
		||||
func (m *Message) GetDomain(b []byte) (string, int) {
 | 
			
		||||
// UnmarshalDomain gets domain from bytes
 | 
			
		||||
func (m *Message) UnmarshalDomain(b []byte) (string, int) {
 | 
			
		||||
	var idx, size int
 | 
			
		||||
	var labels = []string{}
 | 
			
		||||
 | 
			
		||||
@ -401,7 +393,7 @@ func (m *Message) GetDomain(b []byte) (string, int) {
 | 
			
		||||
		// +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
 | 
			
		||||
		if b[idx]&0xC0 == 0xC0 {
 | 
			
		||||
			offset := binary.BigEndian.Uint16(b[idx : idx+2])
 | 
			
		||||
			lable := m.GetDomainByPoint(int(offset & 0x3F))
 | 
			
		||||
			lable := m.UnmarshalDomainPoint(int(offset & 0x3FFF))
 | 
			
		||||
			labels = append(labels, lable)
 | 
			
		||||
			idx += 2
 | 
			
		||||
			break
 | 
			
		||||
@ -420,9 +412,8 @@ func (m *Message) GetDomain(b []byte) (string, int) {
 | 
			
		||||
	return domain, idx
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
// GetDomainByPoint gets domain from
 | 
			
		||||
func (m *Message) GetDomainByPoint(offset int) string {
 | 
			
		||||
	domain, _ := m.GetDomain(m.unMarshaled[offset:])
 | 
			
		||||
	fmt.Printf("GetDomainByPoint: %02x\n", offset)
 | 
			
		||||
// UnmarshalDomainPoint gets domain from offset point
 | 
			
		||||
func (m *Message) UnmarshalDomainPoint(offset int) string {
 | 
			
		||||
	domain, _ := m.UnmarshalDomain(m.unMarshaled[offset:])
 | 
			
		||||
	return domain
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
		Loading…
	
		Reference in New Issue
	
	Block a user