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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
// 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.
// +build darwin dragonfly freebsd linux netbsd openbsd solaris
package ipv6
import (
"os"
"syscall"
"golang.org/x/net/internal/iana"
)
func setControlMessage(s uintptr, opt *rawOpt, cf ControlFlags, on bool) error {
opt.Lock()
defer opt.Unlock()
if cf&FlagTrafficClass != 0 && sockOpts[ssoReceiveTrafficClass].name > 0 {
if err := setInt(s, &sockOpts[ssoReceiveTrafficClass], boolint(on)); err != nil {
return err
}
if on {
opt.set(FlagTrafficClass)
} else {
opt.clear(FlagTrafficClass)
}
}
if cf&FlagHopLimit != 0 && sockOpts[ssoReceiveHopLimit].name > 0 {
if err := setInt(s, &sockOpts[ssoReceiveHopLimit], boolint(on)); err != nil {
return err
}
if on {
opt.set(FlagHopLimit)
} else {
opt.clear(FlagHopLimit)
}
}
if cf&flagPacketInfo != 0 && sockOpts[ssoReceivePacketInfo].name > 0 {
if err := setInt(s, &sockOpts[ssoReceivePacketInfo], boolint(on)); err != nil {
return err
}
if on {
opt.set(cf & flagPacketInfo)
} else {
opt.clear(cf & flagPacketInfo)
}
}
if cf&FlagPathMTU != 0 && sockOpts[ssoReceivePathMTU].name > 0 {
if err := setInt(s, &sockOpts[ssoReceivePathMTU], boolint(on)); err != nil {
return err
}
if on {
opt.set(FlagPathMTU)
} else {
opt.clear(FlagPathMTU)
}
}
return nil
}
func newControlMessage(opt *rawOpt) (oob []byte) {
opt.RLock()
var l int
if opt.isset(FlagTrafficClass) && ctlOpts[ctlTrafficClass].name > 0 {
l += syscall.CmsgSpace(ctlOpts[ctlTrafficClass].length)
}
if opt.isset(FlagHopLimit) && ctlOpts[ctlHopLimit].name > 0 {
l += syscall.CmsgSpace(ctlOpts[ctlHopLimit].length)
}
if opt.isset(flagPacketInfo) && ctlOpts[ctlPacketInfo].name > 0 {
l += syscall.CmsgSpace(ctlOpts[ctlPacketInfo].length)
}
if opt.isset(FlagPathMTU) && ctlOpts[ctlPathMTU].name > 0 {
l += syscall.CmsgSpace(ctlOpts[ctlPathMTU].length)
}
if l > 0 {
oob = make([]byte, l)
b := oob
if opt.isset(FlagTrafficClass) && ctlOpts[ctlTrafficClass].name > 0 {
b = ctlOpts[ctlTrafficClass].marshal(b, nil)
}
if opt.isset(FlagHopLimit) && ctlOpts[ctlHopLimit].name > 0 {
b = ctlOpts[ctlHopLimit].marshal(b, nil)
}
if opt.isset(flagPacketInfo) && ctlOpts[ctlPacketInfo].name > 0 {
b = ctlOpts[ctlPacketInfo].marshal(b, nil)
}
if opt.isset(FlagPathMTU) && ctlOpts[ctlPathMTU].name > 0 {
b = ctlOpts[ctlPathMTU].marshal(b, nil)
}
}
opt.RUnlock()
return
}
func parseControlMessage(b []byte) (*ControlMessage, error) {
if len(b) == 0 {
return nil, nil
}
cmsgs, err := syscall.ParseSocketControlMessage(b)
if err != nil {
return nil, os.NewSyscallError("parse socket control message", err)
}
cm := &ControlMessage{}
for _, m := range cmsgs {
if m.Header.Level != iana.ProtocolIPv6 {
continue
}
switch int(m.Header.Type) {
case ctlOpts[ctlTrafficClass].name:
ctlOpts[ctlTrafficClass].parse(cm, m.Data[:])
case ctlOpts[ctlHopLimit].name:
ctlOpts[ctlHopLimit].parse(cm, m.Data[:])
case ctlOpts[ctlPacketInfo].name:
ctlOpts[ctlPacketInfo].parse(cm, m.Data[:])
case ctlOpts[ctlPathMTU].name:
ctlOpts[ctlPathMTU].parse(cm, m.Data[:])
}
}
return cm, nil
}
func marshalControlMessage(cm *ControlMessage) (oob []byte) {
if cm == nil {
return
}
var l int
tclass := false
if ctlOpts[ctlTrafficClass].name > 0 && cm.TrafficClass > 0 {
tclass = true
l += syscall.CmsgSpace(ctlOpts[ctlTrafficClass].length)
}
hoplimit := false
if ctlOpts[ctlHopLimit].name > 0 && cm.HopLimit > 0 {
hoplimit = true
l += syscall.CmsgSpace(ctlOpts[ctlHopLimit].length)
}
pktinfo := false
if ctlOpts[ctlPacketInfo].name > 0 && (cm.Src.To16() != nil && cm.Src.To4() == nil || cm.IfIndex > 0) {
pktinfo = true
l += syscall.CmsgSpace(ctlOpts[ctlPacketInfo].length)
}
nexthop := false
if ctlOpts[ctlNextHop].name > 0 && cm.NextHop.To16() != nil && cm.NextHop.To4() == nil {
nexthop = true
l += syscall.CmsgSpace(ctlOpts[ctlNextHop].length)
}
if l > 0 {
oob = make([]byte, l)
b := oob
if tclass {
b = ctlOpts[ctlTrafficClass].marshal(b, cm)
}
if hoplimit {
b = ctlOpts[ctlHopLimit].marshal(b, cm)
}
if pktinfo {
b = ctlOpts[ctlPacketInfo].marshal(b, cm)
}
if nexthop {
b = ctlOpts[ctlNextHop].marshal(b, cm)
}
}
return
}
|
