.examples
.github
alerting
client
config
controller
core
docs
jsonpath
metrics
pattern
security
storage
test
util
vendor
github.com
golang.org
x
crypto
image
mod
net
bpf
context
icmp
internal
ipv4
ipv6
batch.go
control.go
control_rfc2292_unix.go
control_rfc3542_unix.go
control_stub.go
control_unix.go
control_windows.go
dgramopt.go
doc.go
endpoint.go
genericopt.go
header.go
helper.go
iana.go
icmp.go
icmp_bsd.go
icmp_linux.go
icmp_solaris.go
icmp_stub.go
icmp_windows.go
icmp_zos.go
payload.go
payload_cmsg.go
payload_nocmsg.go
sockopt.go
sockopt_posix.go
sockopt_stub.go
sys_aix.go
sys_asmreq.go
sys_asmreq_stub.go
sys_bpf.go
sys_bpf_stub.go
sys_bsd.go
sys_darwin.go
sys_freebsd.go
sys_linux.go
sys_solaris.go
sys_ssmreq.go
sys_ssmreq_stub.go
sys_stub.go
sys_windows.go
sys_zos.go
zsys_aix_ppc64.go
zsys_darwin.go
zsys_dragonfly.go
zsys_freebsd_386.go
zsys_freebsd_amd64.go
zsys_freebsd_arm.go
zsys_freebsd_arm64.go
zsys_linux_386.go
zsys_linux_amd64.go
zsys_linux_arm.go
zsys_linux_arm64.go
zsys_linux_mips.go
zsys_linux_mips64.go
zsys_linux_mips64le.go
zsys_linux_mipsle.go
zsys_linux_ppc.go
zsys_linux_ppc64.go
zsys_linux_ppc64le.go
zsys_linux_riscv64.go
zsys_linux_s390x.go
zsys_netbsd.go
zsys_openbsd.go
zsys_solaris.go
zsys_zos_s390x.go
AUTHORS
CONTRIBUTORS
LICENSE
PATENTS
oauth2
sync
sys
tools
xerrors
google.golang.org
gopkg.in
lukechampine.com
modernc.org
modules.txt
watchdog
web
.dockerignore
.gitattributes
.gitignore
Dockerfile
LICENSE
Makefile
README.md
config.yaml
go.mod
go.sum
main.go
188 lines
5.9 KiB
Go
188 lines
5.9 KiB
Go
// 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 (
|
|
"fmt"
|
|
"net"
|
|
"sync"
|
|
|
|
"golang.org/x/net/internal/iana"
|
|
"golang.org/x/net/internal/socket"
|
|
)
|
|
|
|
// Note that RFC 3542 obsoletes RFC 2292 but OS X Snow Leopard and the
|
|
// former still support RFC 2292 only. Please be aware that almost
|
|
// all protocol implementations prohibit using a combination of RFC
|
|
// 2292 and RFC 3542 for some practical reasons.
|
|
|
|
type rawOpt struct {
|
|
sync.RWMutex
|
|
cflags ControlFlags
|
|
}
|
|
|
|
func (c *rawOpt) set(f ControlFlags) { c.cflags |= f }
|
|
func (c *rawOpt) clear(f ControlFlags) { c.cflags &^= f }
|
|
func (c *rawOpt) isset(f ControlFlags) bool { return c.cflags&f != 0 }
|
|
|
|
// A ControlFlags represents per packet basis IP-level socket option
|
|
// control flags.
|
|
type ControlFlags uint
|
|
|
|
const (
|
|
FlagTrafficClass ControlFlags = 1 << iota // pass the traffic class on the received packet
|
|
FlagHopLimit // pass the hop limit on the received packet
|
|
FlagSrc // pass the source address on the received packet
|
|
FlagDst // pass the destination address on the received packet
|
|
FlagInterface // pass the interface index on the received packet
|
|
FlagPathMTU // pass the path MTU on the received packet path
|
|
)
|
|
|
|
const flagPacketInfo = FlagDst | FlagInterface
|
|
|
|
// A ControlMessage represents per packet basis IP-level socket
|
|
// options.
|
|
type ControlMessage struct {
|
|
// Receiving socket options: SetControlMessage allows to
|
|
// receive the options from the protocol stack using ReadFrom
|
|
// method of PacketConn.
|
|
//
|
|
// Specifying socket options: ControlMessage for WriteTo
|
|
// method of PacketConn allows to send the options to the
|
|
// protocol stack.
|
|
//
|
|
TrafficClass int // traffic class, must be 1 <= value <= 255 when specifying
|
|
HopLimit int // hop limit, must be 1 <= value <= 255 when specifying
|
|
Src net.IP // source address, specifying only
|
|
Dst net.IP // destination address, receiving only
|
|
IfIndex int // interface index, must be 1 <= value when specifying
|
|
NextHop net.IP // next hop address, specifying only
|
|
MTU int // path MTU, receiving only
|
|
}
|
|
|
|
func (cm *ControlMessage) String() string {
|
|
if cm == nil {
|
|
return "<nil>"
|
|
}
|
|
return fmt.Sprintf("tclass=%#x hoplim=%d src=%v dst=%v ifindex=%d nexthop=%v mtu=%d", cm.TrafficClass, cm.HopLimit, cm.Src, cm.Dst, cm.IfIndex, cm.NextHop, cm.MTU)
|
|
}
|
|
|
|
// Marshal returns the binary encoding of cm.
|
|
func (cm *ControlMessage) Marshal() []byte {
|
|
if cm == nil {
|
|
return nil
|
|
}
|
|
var l int
|
|
tclass := false
|
|
if ctlOpts[ctlTrafficClass].name > 0 && cm.TrafficClass > 0 {
|
|
tclass = true
|
|
l += socket.ControlMessageSpace(ctlOpts[ctlTrafficClass].length)
|
|
}
|
|
hoplimit := false
|
|
if ctlOpts[ctlHopLimit].name > 0 && cm.HopLimit > 0 {
|
|
hoplimit = true
|
|
l += socket.ControlMessageSpace(ctlOpts[ctlHopLimit].length)
|
|
}
|
|
pktinfo := false
|
|
if ctlOpts[ctlPacketInfo].name > 0 && (cm.Src.To16() != nil && cm.Src.To4() == nil || cm.IfIndex > 0) {
|
|
pktinfo = true
|
|
l += socket.ControlMessageSpace(ctlOpts[ctlPacketInfo].length)
|
|
}
|
|
nexthop := false
|
|
if ctlOpts[ctlNextHop].name > 0 && cm.NextHop.To16() != nil && cm.NextHop.To4() == nil {
|
|
nexthop = true
|
|
l += socket.ControlMessageSpace(ctlOpts[ctlNextHop].length)
|
|
}
|
|
var b []byte
|
|
if l > 0 {
|
|
b = make([]byte, l)
|
|
bb := b
|
|
if tclass {
|
|
bb = ctlOpts[ctlTrafficClass].marshal(bb, cm)
|
|
}
|
|
if hoplimit {
|
|
bb = ctlOpts[ctlHopLimit].marshal(bb, cm)
|
|
}
|
|
if pktinfo {
|
|
bb = ctlOpts[ctlPacketInfo].marshal(bb, cm)
|
|
}
|
|
if nexthop {
|
|
bb = ctlOpts[ctlNextHop].marshal(bb, cm)
|
|
}
|
|
}
|
|
return b
|
|
}
|
|
|
|
// Parse parses b as a control message and stores the result in cm.
|
|
func (cm *ControlMessage) Parse(b []byte) error {
|
|
ms, err := socket.ControlMessage(b).Parse()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
for _, m := range ms {
|
|
lvl, typ, l, err := m.ParseHeader()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if lvl != iana.ProtocolIPv6 {
|
|
continue
|
|
}
|
|
switch {
|
|
case typ == ctlOpts[ctlTrafficClass].name && l >= ctlOpts[ctlTrafficClass].length:
|
|
ctlOpts[ctlTrafficClass].parse(cm, m.Data(l))
|
|
case typ == ctlOpts[ctlHopLimit].name && l >= ctlOpts[ctlHopLimit].length:
|
|
ctlOpts[ctlHopLimit].parse(cm, m.Data(l))
|
|
case typ == ctlOpts[ctlPacketInfo].name && l >= ctlOpts[ctlPacketInfo].length:
|
|
ctlOpts[ctlPacketInfo].parse(cm, m.Data(l))
|
|
case typ == ctlOpts[ctlPathMTU].name && l >= ctlOpts[ctlPathMTU].length:
|
|
ctlOpts[ctlPathMTU].parse(cm, m.Data(l))
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// NewControlMessage returns a new control message.
|
|
//
|
|
// The returned message is large enough for options specified by cf.
|
|
func NewControlMessage(cf ControlFlags) []byte {
|
|
opt := rawOpt{cflags: cf}
|
|
var l int
|
|
if opt.isset(FlagTrafficClass) && ctlOpts[ctlTrafficClass].name > 0 {
|
|
l += socket.ControlMessageSpace(ctlOpts[ctlTrafficClass].length)
|
|
}
|
|
if opt.isset(FlagHopLimit) && ctlOpts[ctlHopLimit].name > 0 {
|
|
l += socket.ControlMessageSpace(ctlOpts[ctlHopLimit].length)
|
|
}
|
|
if opt.isset(flagPacketInfo) && ctlOpts[ctlPacketInfo].name > 0 {
|
|
l += socket.ControlMessageSpace(ctlOpts[ctlPacketInfo].length)
|
|
}
|
|
if opt.isset(FlagPathMTU) && ctlOpts[ctlPathMTU].name > 0 {
|
|
l += socket.ControlMessageSpace(ctlOpts[ctlPathMTU].length)
|
|
}
|
|
var b []byte
|
|
if l > 0 {
|
|
b = make([]byte, l)
|
|
}
|
|
return b
|
|
}
|
|
|
|
// Ancillary data socket options
|
|
const (
|
|
ctlTrafficClass = iota // header field
|
|
ctlHopLimit // header field
|
|
ctlPacketInfo // inbound or outbound packet path
|
|
ctlNextHop // nexthop
|
|
ctlPathMTU // path mtu
|
|
ctlMax
|
|
)
|
|
|
|
// A ctlOpt represents a binding for ancillary data socket option.
|
|
type ctlOpt struct {
|
|
name int // option name, must be equal or greater than 1
|
|
length int // option length
|
|
marshal func([]byte, *ControlMessage) []byte
|
|
parse func(*ControlMessage, []byte)
|
|
}
|