1 files changed, 172 insertions, 0 deletions
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go
new file mode 100644
index 000000000..15654cbbd
--- /dev/null
+++ b/pkg/tcpip/network/ipv6/ipv6.go
@@ -0,0 +1,172 @@
+// Copyright 2016 The Netstack 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 contains the implementation of the ipv6 network protocol. To use
+// it in the networking stack, this package must be added to the project, and
+// activated on the stack by passing ipv6.ProtocolName (or "ipv6") as one of the
+// network protocols when calling stack.New(). Then endpoints can be created
+// by passing ipv6.ProtocolNumber as the network protocol number when calling
+// Stack.NewEndpoint().
+package ipv6
+
+import (
+	"gvisor.googlesource.com/gvisor/pkg/tcpip"
+	"gvisor.googlesource.com/gvisor/pkg/tcpip/buffer"
+	"gvisor.googlesource.com/gvisor/pkg/tcpip/header"
+	"gvisor.googlesource.com/gvisor/pkg/tcpip/stack"
+)
+
+const (
+	// ProtocolName is the string representation of the ipv6 protocol name.
+	ProtocolName = "ipv6"
+
+	// ProtocolNumber is the ipv6 protocol number.
+	ProtocolNumber = header.IPv6ProtocolNumber
+
+	// maxTotalSize is maximum size that can be encoded in the 16-bit
+	// PayloadLength field of the ipv6 header.
+	maxPayloadSize = 0xffff
+)
+
+type address [header.IPv6AddressSize]byte
+
+type endpoint struct {
+	nicid      tcpip.NICID
+	id         stack.NetworkEndpointID
+	address    address
+	linkEP     stack.LinkEndpoint
+	dispatcher stack.TransportDispatcher
+}
+
+func newEndpoint(nicid tcpip.NICID, addr tcpip.Address, dispatcher stack.TransportDispatcher, linkEP stack.LinkEndpoint) *endpoint {
+	e := &endpoint{nicid: nicid, linkEP: linkEP, dispatcher: dispatcher}
+	copy(e.address[:], addr)
+	e.id = stack.NetworkEndpointID{tcpip.Address(e.address[:])}
+	return e
+}
+
+// MTU implements stack.NetworkEndpoint.MTU. It returns the link-layer MTU minus
+// the network layer max header length.
+func (e *endpoint) MTU() uint32 {
+	return calculateMTU(e.linkEP.MTU())
+}
+
+// NICID returns the ID of the NIC this endpoint belongs to.
+func (e *endpoint) NICID() tcpip.NICID {
+	return e.nicid
+}
+
+// ID returns the ipv6 endpoint ID.
+func (e *endpoint) ID() *stack.NetworkEndpointID {
+	return &e.id
+}
+
+// Capabilities implements stack.NetworkEndpoint.Capabilities.
+func (e *endpoint) Capabilities() stack.LinkEndpointCapabilities {
+	return e.linkEP.Capabilities()
+}
+
+// MaxHeaderLength returns the maximum length needed by ipv6 headers (and
+// underlying protocols).
+func (e *endpoint) MaxHeaderLength() uint16 {
+	return e.linkEP.MaxHeaderLength() + header.IPv6MinimumSize
+}
+
+// WritePacket writes a packet to the given destination address and protocol.
+func (e *endpoint) WritePacket(r *stack.Route, hdr *buffer.Prependable, payload buffer.View, protocol tcpip.TransportProtocolNumber) *tcpip.Error {
+	length := uint16(hdr.UsedLength())
+	if payload != nil {
+		length += uint16(len(payload))
+	}
+	ip := header.IPv6(hdr.Prepend(header.IPv6MinimumSize))
+	ip.Encode(&header.IPv6Fields{
+		PayloadLength: length,
+		NextHeader:    uint8(protocol),
+		HopLimit:      65,
+		SrcAddr:       tcpip.Address(e.address[:]),
+		DstAddr:       r.RemoteAddress,
+	})
+
+	return e.linkEP.WritePacket(r, hdr, payload, ProtocolNumber)
+}
+
+// HandlePacket is called by the link layer when new ipv6 packets arrive for
+// this endpoint.
+func (e *endpoint) HandlePacket(r *stack.Route, vv *buffer.VectorisedView) {
+	h := header.IPv6(vv.First())
+	if !h.IsValid(vv.Size()) {
+		return
+	}
+
+	vv.TrimFront(header.IPv6MinimumSize)
+	vv.CapLength(int(h.PayloadLength()))
+
+	p := h.TransportProtocol()
+	if p == header.ICMPv6ProtocolNumber {
+		e.handleICMP(r, vv)
+		return
+	}
+
+	e.dispatcher.DeliverTransportPacket(r, p, vv)
+}
+
+// Close cleans up resources associated with the endpoint.
+func (*endpoint) Close() {}
+
+type protocol struct{}
+
+// NewProtocol creates a new protocol ipv6 protocol descriptor. This is exported
+// only for tests that short-circuit the stack. Regular use of the protocol is
+// done via the stack, which gets a protocol descriptor from the init() function
+// below.
+func NewProtocol() stack.NetworkProtocol {
+	return &protocol{}
+}
+
+// Number returns the ipv6 protocol number.
+func (p *protocol) Number() tcpip.NetworkProtocolNumber {
+	return ProtocolNumber
+}
+
+// MinimumPacketSize returns the minimum valid ipv6 packet size.
+func (p *protocol) MinimumPacketSize() int {
+	return header.IPv6MinimumSize
+}
+
+// ParseAddresses implements NetworkProtocol.ParseAddresses.
+func (*protocol) ParseAddresses(v buffer.View) (src, dst tcpip.Address) {
+	h := header.IPv6(v)
+	return h.SourceAddress(), h.DestinationAddress()
+}
+
+// NewEndpoint creates a new ipv6 endpoint.
+func (p *protocol) NewEndpoint(nicid tcpip.NICID, addr tcpip.Address, linkAddrCache stack.LinkAddressCache, dispatcher stack.TransportDispatcher, linkEP stack.LinkEndpoint) (stack.NetworkEndpoint, *tcpip.Error) {
+	return newEndpoint(nicid, addr, dispatcher, linkEP), nil
+}
+
+// SetOption implements NetworkProtocol.SetOption.
+func (p *protocol) SetOption(option interface{}) *tcpip.Error {
+	return tcpip.ErrUnknownProtocolOption
+}
+
+// Option implements NetworkProtocol.Option.
+func (p *protocol) Option(option interface{}) *tcpip.Error {
+	return tcpip.ErrUnknownProtocolOption
+}
+
+// calculateMTU calculates the network-layer payload MTU based on the link-layer
+// payload mtu.
+func calculateMTU(mtu uint32) uint32 {
+	mtu -= header.IPv6MinimumSize
+	if mtu <= maxPayloadSize {
+		return mtu
+	}
+	return maxPayloadSize
+}
+
+func init() {
+	stack.RegisterNetworkProtocolFactory(ProtocolName, func() stack.NetworkProtocol {
+		return &protocol{}
+	})
+}