/usr/share/gocode/src/code.google.com/p/go.net/ipv6/mockicmp_test.go is in golang-go.net-dev 0.0~hg20131201-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 | // Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package ipv6_test
import (
"code.google.com/p/go.net/ipv6"
"errors"
"net"
)
const (
ipv6PseudoHeaderLen = 2*net.IPv6len + 8
ianaProtocolIPv6ICMP = 58
)
func ipv6PseudoHeader(src, dst net.IP, nextHeader int) []byte {
b := make([]byte, ipv6PseudoHeaderLen)
copy(b[:net.IPv6len], src)
copy(b[net.IPv6len:], dst)
b[len(b)-1] = byte(nextHeader)
return b
}
// icmpMessage represents an ICMP message.
type icmpMessage struct {
Type ipv6.ICMPType // type
Code int // code
Checksum int // checksum
Body icmpMessageBody // body
}
// icmpMessageBody represents an ICMP message body.
type icmpMessageBody interface {
Len() int
Marshal() ([]byte, error)
}
// Marshal returns the binary enconding of the ICMP echo request or
// reply message m.
func (m *icmpMessage) Marshal(psh []byte) ([]byte, error) {
b := []byte{byte(m.Type), byte(m.Code), 0, 0}
if psh != nil {
b = append(psh, b...)
}
if m.Body != nil && m.Body.Len() != 0 {
mb, err := m.Body.Marshal()
if err != nil {
return nil, err
}
b = append(b, mb...)
}
if psh == nil {
return b, nil
}
off, l := 2*net.IPv6len, len(b)-len(psh)
b[off], b[off+1], b[off+2], b[off+3] = byte(l>>24), byte(l>>16), byte(l>>8), byte(l)
csumcv := len(b) - 1 // checksum coverage
s := uint32(0)
for i := 0; i < csumcv; i += 2 {
s += uint32(b[i+1])<<8 | uint32(b[i])
}
if csumcv&1 == 0 {
s += uint32(b[csumcv])
}
s = s>>16 + s&0xffff
s = s + s>>16
// Place checksum back in header; using ^= avoids the
// assumption the checksum bytes are zero.
b[len(psh)+2] ^= byte(^s)
b[len(psh)+3] ^= byte(^s >> 8)
return b[len(psh):], nil
}
// parseICMPMessage parses b as an ICMP message.
func parseICMPMessage(b []byte) (*icmpMessage, error) {
msglen := len(b)
if msglen < 4 {
return nil, errors.New("message too short")
}
m := &icmpMessage{Type: ipv6.ICMPType(b[0]), Code: int(b[1]), Checksum: int(b[2])<<8 | int(b[3])}
if msglen > 4 {
var err error
switch m.Type {
case ipv6.ICMPTypeEchoRequest, ipv6.ICMPTypeEchoReply:
m.Body, err = parseICMPEcho(b[4:])
if err != nil {
return nil, err
}
}
}
return m, nil
}
// imcpEcho represenets an ICMP echo request or reply message body.
type icmpEcho struct {
ID int // identifier
Seq int // sequence number
Data []byte // data
}
func (p *icmpEcho) Len() int {
if p == nil {
return 0
}
return 4 + len(p.Data)
}
// Marshal returns the binary enconding of the ICMP echo request or
// reply message body p.
func (p *icmpEcho) Marshal() ([]byte, error) {
b := make([]byte, 4+len(p.Data))
b[0], b[1] = byte(p.ID>>8), byte(p.ID)
b[2], b[3] = byte(p.Seq>>8), byte(p.Seq)
copy(b[4:], p.Data)
return b, nil
}
// parseICMPEcho parses b as an ICMP echo request or reply message
// body.
func parseICMPEcho(b []byte) (*icmpEcho, error) {
bodylen := len(b)
p := &icmpEcho{ID: int(b[0])<<8 | int(b[1]), Seq: int(b[2])<<8 | int(b[3])}
if bodylen > 4 {
p.Data = make([]byte, bodylen-4)
copy(p.Data, b[4:])
}
return p, nil
}
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