/usr/share/gocode/src/code.google.com/p/go.net/ipv6/control_rfc2292_darwin.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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 | // 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
import (
"net"
"os"
"syscall"
"unsafe"
)
const pktinfo = FlagDst | FlagInterface
func setControlMessage(fd int, opt *rawOpt, cf ControlFlags, on bool) error {
opt.Lock()
defer opt.Unlock()
if cf&FlagHopLimit != 0 {
if err := setIPv6ReceiveHopLimit(fd, on); err != nil {
return err
}
if on {
opt.set(FlagHopLimit)
} else {
opt.clear(FlagHopLimit)
}
}
if cf&pktinfo != 0 {
if err := setIPv6ReceivePacketInfo(fd, on); err != nil {
return err
}
if on {
opt.set(cf & pktinfo)
} else {
opt.clear(cf & pktinfo)
}
}
return nil
}
func newControlMessage(opt *rawOpt) (oob []byte) {
opt.Lock()
defer opt.Unlock()
l, off := 0, 0
if opt.isset(FlagHopLimit) {
l += syscall.CmsgSpace(4)
}
if opt.isset(pktinfo) {
l += syscall.CmsgSpace(syscall.SizeofInet6Pktinfo)
}
if l > 0 {
oob = make([]byte, l)
if opt.isset(FlagHopLimit) {
m := (*syscall.Cmsghdr)(unsafe.Pointer(&oob[off]))
m.Level = ianaProtocolIPv6
m.Type = syscall.IPV6_2292HOPLIMIT
m.SetLen(syscall.CmsgLen(4))
off += syscall.CmsgSpace(4)
}
if opt.isset(pktinfo) {
m := (*syscall.Cmsghdr)(unsafe.Pointer(&oob[off]))
m.Level = ianaProtocolIPv6
m.Type = syscall.IPV6_2292PKTINFO
m.SetLen(syscall.CmsgLen(syscall.SizeofInet6Pktinfo))
off += syscall.CmsgSpace(syscall.SizeofInet6Pktinfo)
}
}
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 != ianaProtocolIPv6 {
continue
}
switch m.Header.Type {
case syscall.IPV6_2292HOPLIMIT:
cm.HopLimit = int(*(*byte)(unsafe.Pointer(&m.Data[:1][0])))
case syscall.IPV6_2292PKTINFO:
pi := (*syscall.Inet6Pktinfo)(unsafe.Pointer(&m.Data[0]))
cm.IfIndex = int(pi.Ifindex)
cm.Dst = pi.Addr[:]
}
}
return cm, nil
}
func marshalControlMessage(cm *ControlMessage) (oob []byte) {
if cm == nil {
return
}
l, off := 0, 0
if cm.HopLimit > 0 {
l += syscall.CmsgSpace(4)
}
pion := false
if cm.Src.To4() == nil && cm.Src.To16() != nil || cm.IfIndex != 0 {
pion = true
l += syscall.CmsgSpace(syscall.SizeofInet6Pktinfo)
}
if len(cm.NextHop) == net.IPv6len {
l += syscall.CmsgSpace(syscall.SizeofSockaddrInet6)
}
if l > 0 {
oob = make([]byte, l)
if cm.HopLimit > 0 {
m := (*syscall.Cmsghdr)(unsafe.Pointer(&oob[off]))
m.Level = ianaProtocolIPv6
m.Type = syscall.IPV6_2292HOPLIMIT
m.SetLen(syscall.CmsgLen(4))
data := oob[off+syscall.CmsgLen(0):]
*(*byte)(unsafe.Pointer(&data[:1][0])) = byte(cm.HopLimit)
off += syscall.CmsgSpace(4)
}
if pion {
m := (*syscall.Cmsghdr)(unsafe.Pointer(&oob[off]))
m.Level = ianaProtocolIPv6
m.Type = syscall.IPV6_2292PKTINFO
m.SetLen(syscall.CmsgLen(syscall.SizeofInet6Pktinfo))
pi := (*syscall.Inet6Pktinfo)(unsafe.Pointer(&oob[off+syscall.CmsgLen(0)]))
if ip := cm.Src.To16(); ip != nil && ip.To4() == nil {
copy(pi.Addr[:], ip)
}
if cm.IfIndex != 0 {
pi.Ifindex = uint32(cm.IfIndex)
}
off += syscall.CmsgSpace(syscall.SizeofInet6Pktinfo)
}
if len(cm.NextHop) == net.IPv6len {
m := (*syscall.Cmsghdr)(unsafe.Pointer(&oob[off]))
m.Level = ianaProtocolIPv6
m.Type = syscall.IPV6_2292NEXTHOP
m.SetLen(syscall.CmsgLen(syscall.SizeofSockaddrInet6))
sa := (*syscall.RawSockaddrInet6)(unsafe.Pointer(&oob[off+syscall.CmsgLen(0)]))
sa.Len = syscall.SizeofSockaddrInet6
sa.Family = syscall.AF_INET6
copy(sa.Addr[:], cm.NextHop)
off += syscall.CmsgSpace(syscall.SizeofSockaddrInet6)
}
}
return
}
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