Switch from glide to dep. Check in vendor/

vendor/golang.org/x/net/ipv6/control.go

@@ -0,0 +1,187 @@
+// 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)
+}