86 lines
3 KiB
Go
86 lines
3 KiB
Go
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// Copyright 2013 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package ipv6
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import (
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"fmt"
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"net"
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"sync"
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)
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// Note that RFC 3542 obsoletes RFC 2292 but OS X Snow Leopard and the
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// former still support RFC 2292 only. Please be aware that almost
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// all protocol implementations prohibit using a combination of RFC
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// 2292 and RFC 3542 for some practical reasons.
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type rawOpt struct {
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sync.RWMutex
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cflags ControlFlags
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}
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func (c *rawOpt) set(f ControlFlags) { c.cflags |= f }
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func (c *rawOpt) clear(f ControlFlags) { c.cflags &^= f }
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func (c *rawOpt) isset(f ControlFlags) bool { return c.cflags&f != 0 }
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// A ControlFlags represents per packet basis IP-level socket option
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// control flags.
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type ControlFlags uint
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const (
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FlagTrafficClass ControlFlags = 1 << iota // pass the traffic class on the received packet
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FlagHopLimit // pass the hop limit on the received packet
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FlagSrc // pass the source address on the received packet
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FlagDst // pass the destination address on the received packet
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FlagInterface // pass the interface index on the received packet
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FlagPathMTU // pass the path MTU on the received packet path
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)
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const flagPacketInfo = FlagDst | FlagInterface
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// A ControlMessage represents per packet basis IP-level socket
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// options.
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type ControlMessage struct {
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// Receiving socket options: SetControlMessage allows to
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// receive the options from the protocol stack using ReadFrom
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// method of PacketConn.
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//
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// Specifying socket options: ControlMessage for WriteTo
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// method of PacketConn allows to send the options to the
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// protocol stack.
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//
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TrafficClass int // traffic class, must be 1 <= value <= 255 when specifying
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HopLimit int // hop limit, must be 1 <= value <= 255 when specifying
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Src net.IP // source address, specifying only
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Dst net.IP // destination address, receiving only
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IfIndex int // interface index, must be 1 <= value when specifying
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NextHop net.IP // next hop address, specifying only
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MTU int // path MTU, receiving only
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}
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func (cm *ControlMessage) String() string {
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if cm == nil {
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return "<nil>"
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}
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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)
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}
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// Ancillary data socket options
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const (
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ctlTrafficClass = iota // header field
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ctlHopLimit // header field
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ctlPacketInfo // inbound or outbound packet path
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ctlNextHop // nexthop
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ctlPathMTU // path mtu
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ctlMax
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)
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// A ctlOpt represents a binding for ancillary data socket option.
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type ctlOpt struct {
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name int // option name, must be equal or greater than 1
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length int // option length
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marshal func([]byte, *ControlMessage) []byte
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parse func(*ControlMessage, []byte)
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}
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