blob: 8d7f380884cbbe91a27e74e77ba4fc5a886d84aa (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
|
// Copyright (c) Tailscale Inc & contributors
// SPDX-License-Identifier: BSD-3-Clause
package packet
import (
"encoding/binary"
"tailscale.com/types/ipproto"
)
// UDP6Header is an IPv6+UDP header.
type UDP6Header struct {
IP6Header
SrcPort uint16
DstPort uint16
}
// Len implements Header.
func (h UDP6Header) Len() int {
return h.IP6Header.Len() + udpHeaderLength
}
// Marshal implements Header.
func (h UDP6Header) Marshal(buf []byte) error {
if len(buf) < h.Len() {
return errSmallBuffer
}
if len(buf) > maxPacketLength {
return errLargePacket
}
// The caller does not need to set this.
h.IPProto = ipproto.UDP
length := len(buf) - h.IP6Header.Len()
binary.BigEndian.PutUint16(buf[40:42], h.SrcPort)
binary.BigEndian.PutUint16(buf[42:44], h.DstPort)
binary.BigEndian.PutUint16(buf[44:46], uint16(length))
binary.BigEndian.PutUint16(buf[46:48], 0) // blank checksum
// UDP checksum with IP pseudo header.
h.IP6Header.marshalPseudo(buf, ipproto.UDP)
binary.BigEndian.PutUint16(buf[46:48], ip4Checksum(buf[:]))
h.IP6Header.Marshal(buf)
return nil
}
// ToResponse implements Header.
func (h *UDP6Header) ToResponse() {
h.SrcPort, h.DstPort = h.DstPort, h.SrcPort
h.IP6Header.ToResponse()
}
|
