435c0d9fc8
This PR switches the Nomad repository from using govendor to Go modules for managing dependencies. Aspects of the Nomad workflow remain pretty much the same. The usual Makefile targets should continue to work as they always did. The API submodule simply defers to the parent Nomad version on the repository, keeping the semantics of API versioning that currently exists.
244 lines
7.7 KiB
Go
244 lines
7.7 KiB
Go
// 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 implements IP-level socket options for the Internet
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// Protocol version 6.
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//
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// The package provides IP-level socket options that allow
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// manipulation of IPv6 facilities.
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//
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// The IPv6 protocol is defined in RFC 8200.
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// Socket interface extensions are defined in RFC 3493, RFC 3542 and
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// RFC 3678.
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// MLDv1 and MLDv2 are defined in RFC 2710 and RFC 3810.
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// Source-specific multicast is defined in RFC 4607.
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//
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// On Darwin, this package requires OS X Mavericks version 10.9 or
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// above, or equivalent.
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//
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//
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// Unicasting
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//
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// The options for unicasting are available for net.TCPConn,
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// net.UDPConn and net.IPConn which are created as network connections
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// that use the IPv6 transport. When a single TCP connection carrying
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// a data flow of multiple packets needs to indicate the flow is
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// important, Conn is used to set the traffic class field on the IPv6
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// header for each packet.
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//
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// ln, err := net.Listen("tcp6", "[::]:1024")
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// if err != nil {
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// // error handling
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// }
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// defer ln.Close()
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// for {
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// c, err := ln.Accept()
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// if err != nil {
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// // error handling
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// }
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// go func(c net.Conn) {
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// defer c.Close()
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//
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// The outgoing packets will be labeled DiffServ assured forwarding
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// class 1 low drop precedence, known as AF11 packets.
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//
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// if err := ipv6.NewConn(c).SetTrafficClass(0x28); err != nil {
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// // error handling
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// }
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// if _, err := c.Write(data); err != nil {
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// // error handling
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// }
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// }(c)
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// }
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//
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//
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// Multicasting
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//
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// The options for multicasting are available for net.UDPConn and
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// net.IPConn which are created as network connections that use the
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// IPv6 transport. A few network facilities must be prepared before
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// you begin multicasting, at a minimum joining network interfaces and
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// multicast groups.
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//
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// en0, err := net.InterfaceByName("en0")
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// if err != nil {
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// // error handling
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// }
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// en1, err := net.InterfaceByIndex(911)
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// if err != nil {
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// // error handling
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// }
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// group := net.ParseIP("ff02::114")
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//
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// First, an application listens to an appropriate address with an
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// appropriate service port.
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//
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// c, err := net.ListenPacket("udp6", "[::]:1024")
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// if err != nil {
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// // error handling
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// }
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// defer c.Close()
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//
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// Second, the application joins multicast groups, starts listening to
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// the groups on the specified network interfaces. Note that the
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// service port for transport layer protocol does not matter with this
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// operation as joining groups affects only network and link layer
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// protocols, such as IPv6 and Ethernet.
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//
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// p := ipv6.NewPacketConn(c)
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// if err := p.JoinGroup(en0, &net.UDPAddr{IP: group}); err != nil {
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// // error handling
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// }
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// if err := p.JoinGroup(en1, &net.UDPAddr{IP: group}); err != nil {
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// // error handling
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// }
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//
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// The application might set per packet control message transmissions
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// between the protocol stack within the kernel. When the application
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// needs a destination address on an incoming packet,
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// SetControlMessage of PacketConn is used to enable control message
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// transmissions.
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//
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// if err := p.SetControlMessage(ipv6.FlagDst, true); err != nil {
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// // error handling
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// }
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//
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// The application could identify whether the received packets are
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// of interest by using the control message that contains the
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// destination address of the received packet.
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//
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// b := make([]byte, 1500)
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// for {
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// n, rcm, src, err := p.ReadFrom(b)
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// if err != nil {
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// // error handling
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// }
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// if rcm.Dst.IsMulticast() {
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// if rcm.Dst.Equal(group) {
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// // joined group, do something
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// } else {
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// // unknown group, discard
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// continue
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// }
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// }
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//
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// The application can also send both unicast and multicast packets.
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//
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// p.SetTrafficClass(0x0)
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// p.SetHopLimit(16)
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// if _, err := p.WriteTo(data[:n], nil, src); err != nil {
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// // error handling
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// }
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// dst := &net.UDPAddr{IP: group, Port: 1024}
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// wcm := ipv6.ControlMessage{TrafficClass: 0xe0, HopLimit: 1}
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// for _, ifi := range []*net.Interface{en0, en1} {
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// wcm.IfIndex = ifi.Index
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// if _, err := p.WriteTo(data[:n], &wcm, dst); err != nil {
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// // error handling
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// }
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// }
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// }
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//
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//
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// More multicasting
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//
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// An application that uses PacketConn may join multiple multicast
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// groups. For example, a UDP listener with port 1024 might join two
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// different groups across over two different network interfaces by
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// using:
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//
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// c, err := net.ListenPacket("udp6", "[::]:1024")
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// if err != nil {
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// // error handling
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// }
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// defer c.Close()
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// p := ipv6.NewPacketConn(c)
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// if err := p.JoinGroup(en0, &net.UDPAddr{IP: net.ParseIP("ff02::1:114")}); err != nil {
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// // error handling
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// }
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// if err := p.JoinGroup(en0, &net.UDPAddr{IP: net.ParseIP("ff02::2:114")}); err != nil {
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// // error handling
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// }
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// if err := p.JoinGroup(en1, &net.UDPAddr{IP: net.ParseIP("ff02::2:114")}); err != nil {
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// // error handling
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// }
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//
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// It is possible for multiple UDP listeners that listen on the same
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// UDP port to join the same multicast group. The net package will
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// provide a socket that listens to a wildcard address with reusable
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// UDP port when an appropriate multicast address prefix is passed to
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// the net.ListenPacket or net.ListenUDP.
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//
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// c1, err := net.ListenPacket("udp6", "[ff02::]:1024")
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// if err != nil {
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// // error handling
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// }
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// defer c1.Close()
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// c2, err := net.ListenPacket("udp6", "[ff02::]:1024")
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// if err != nil {
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// // error handling
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// }
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// defer c2.Close()
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// p1 := ipv6.NewPacketConn(c1)
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// if err := p1.JoinGroup(en0, &net.UDPAddr{IP: net.ParseIP("ff02::114")}); err != nil {
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// // error handling
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// }
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// p2 := ipv6.NewPacketConn(c2)
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// if err := p2.JoinGroup(en0, &net.UDPAddr{IP: net.ParseIP("ff02::114")}); err != nil {
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// // error handling
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// }
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//
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// Also it is possible for the application to leave or rejoin a
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// multicast group on the network interface.
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//
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// if err := p.LeaveGroup(en0, &net.UDPAddr{IP: net.ParseIP("ff02::114")}); err != nil {
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// // error handling
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// }
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// if err := p.JoinGroup(en0, &net.UDPAddr{IP: net.ParseIP("ff01::114")}); err != nil {
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// // error handling
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// }
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//
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//
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// Source-specific multicasting
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//
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// An application that uses PacketConn on MLDv2 supported platform is
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// able to join source-specific multicast groups.
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// The application may use JoinSourceSpecificGroup and
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// LeaveSourceSpecificGroup for the operation known as "include" mode,
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//
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// ssmgroup := net.UDPAddr{IP: net.ParseIP("ff32::8000:9")}
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// ssmsource := net.UDPAddr{IP: net.ParseIP("fe80::cafe")}
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// if err := p.JoinSourceSpecificGroup(en0, &ssmgroup, &ssmsource); err != nil {
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// // error handling
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// }
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// if err := p.LeaveSourceSpecificGroup(en0, &ssmgroup, &ssmsource); err != nil {
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// // error handling
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// }
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//
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// or JoinGroup, ExcludeSourceSpecificGroup,
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// IncludeSourceSpecificGroup and LeaveGroup for the operation known
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// as "exclude" mode.
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//
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// exclsource := net.UDPAddr{IP: net.ParseIP("fe80::dead")}
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// if err := p.JoinGroup(en0, &ssmgroup); err != nil {
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// // error handling
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// }
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// if err := p.ExcludeSourceSpecificGroup(en0, &ssmgroup, &exclsource); err != nil {
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// // error handling
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// }
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// if err := p.LeaveGroup(en0, &ssmgroup); err != nil {
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// // error handling
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// }
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//
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// Note that it depends on each platform implementation what happens
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// when an application which runs on MLDv2 unsupported platform uses
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// JoinSourceSpecificGroup and LeaveSourceSpecificGroup.
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// In general the platform tries to fall back to conversations using
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// MLDv1 and starts to listen to multicast traffic.
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// In the fallback case, ExcludeSourceSpecificGroup and
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// IncludeSourceSpecificGroup may return an error.
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package ipv6 // import "golang.org/x/net/ipv6"
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// BUG(mikio): This package is not implemented on JS, NaCl and Plan 9.
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