tun/netstack: bump to latest gvisor

To build with go1.19, gvisor needs
99325baf ("Bump gVisor build tags to go1.19").

However gvisor.dev/gvisor/pkg/tcpip/buffer is no longer available,
so refactor to use gvisor.dev/gvisor/pkg/tcpip/link/channel directly.

Signed-off-by: Shengjing Zhu <i@zhsj.me>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 34 insertions, 71 deletions

diff --git a/tun/netstack/tun.go b/tun/netstack/tun.go
index c26d8ed..b0e7b70 100644
--- a/tun/netstack/tun.go
+++ b/tun/netstack/tun.go
@@ -6,6 +6,7 @@
 package netstack
 
 import (
+	"bytes"
 	"context"
 	"crypto/rand"
 	"encoding/binary"
@@ -23,10 +24,11 @@ import (
 	"golang.zx2c4.com/wireguard/tun"
 
 	"golang.org/x/net/dns/dnsmessage"
+	"gvisor.dev/gvisor/pkg/bufferv2"
 	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
-	"gvisor.dev/gvisor/pkg/tcpip/buffer"
 	"gvisor.dev/gvisor/pkg/tcpip/header"
+	"gvisor.dev/gvisor/pkg/tcpip/link/channel"
 	"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
 	"gvisor.dev/gvisor/pkg/tcpip/network/ipv6"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
@@ -37,69 +39,16 @@ import (
 )
 
 type netTun struct {
+	ep             *channel.Endpoint
 	stack          *stack.Stack
-	dispatcher     stack.NetworkDispatcher
 	events         chan tun.Event
-	incomingPacket chan buffer.VectorisedView
+	incomingPacket chan *bufferv2.View
 	mtu            int
 	dnsServers     []netip.Addr
 	hasV4, hasV6   bool
 }
 
-type (
-	endpoint netTun
-	Net      netTun
-)
-
-func (e *endpoint) Attach(dispatcher stack.NetworkDispatcher) {
-	e.dispatcher = dispatcher
-}
-
-func (e *endpoint) IsAttached() bool {
-	return e.dispatcher != nil
-}
-
-func (e *endpoint) MTU() uint32 {
-	mtu, err := (*netTun)(e).MTU()
-	if err != nil {
-		panic(err)
-	}
-	return uint32(mtu)
-}
-
-func (*endpoint) Capabilities() stack.LinkEndpointCapabilities {
-	return stack.CapabilityNone
-}
-
-func (*endpoint) MaxHeaderLength() uint16 {
-	return 0
-}
-
-func (*endpoint) LinkAddress() tcpip.LinkAddress {
-	return ""
-}
-
-func (*endpoint) Wait() {}
-
-func (e *endpoint) WritePacket(_ stack.RouteInfo, _ tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer) tcpip.Error {
-	e.incomingPacket <- buffer.NewVectorisedView(pkt.Size(), pkt.Views())
-	return nil
-}
-
-func (e *endpoint) WritePackets(stack.RouteInfo, stack.PacketBufferList, tcpip.NetworkProtocolNumber) (int, tcpip.Error) {
-	panic("not implemented")
-}
-
-func (e *endpoint) WriteRawPacket(*stack.PacketBuffer) tcpip.Error {
-	panic("not implemented")
-}
-
-func (*endpoint) ARPHardwareType() header.ARPHardwareType {
-	return header.ARPHardwareNone
-}
-
-func (e *endpoint) AddHeader(tcpip.LinkAddress, tcpip.LinkAddress, tcpip.NetworkProtocolNumber, *stack.PacketBuffer) {
-}
+type Net netTun
 
 func CreateNetTUN(localAddresses, dnsServers []netip.Addr, mtu int) (tun.Device, *Net, error) {
 	opts := stack.Options{
@@ -108,13 +57,15 @@ func CreateNetTUN(localAddresses, dnsServers []netip.Addr, mtu int) (tun.Device,
 		HandleLocal:        true,
 	}
 	dev := &netTun{
+		ep:             channel.New(1024, uint32(mtu), ""),
 		stack:          stack.New(opts),
 		events:         make(chan tun.Event, 10),
-		incomingPacket: make(chan buffer.VectorisedView),
+		incomingPacket: make(chan *bufferv2.View),
 		dnsServers:     dnsServers,
 		mtu:            mtu,
 	}
-	tcpipErr := dev.stack.CreateNIC(1, (*endpoint)(dev))
+	dev.ep.AddNotify(dev)
+	tcpipErr := dev.stack.CreateNIC(1, dev.ep)
 	if tcpipErr != nil {
 		return nil, nil, fmt.Errorf("CreateNIC: %v", tcpipErr)
 	}
@@ -167,6 +118,7 @@ func (tun *netTun) Read(buf []byte, offset int) (int, error) {
 	if !ok {
 		return 0, os.ErrClosed
 	}
+
 	return view.Read(buf[offset:])
 }
 
@@ -176,17 +128,29 @@ func (tun *netTun) Write(buf []byte, offset int) (int, error) {
 		return 0, nil
 	}
 
-	pkb := stack.NewPacketBuffer(stack.PacketBufferOptions{Data: buffer.NewVectorisedView(len(packet), []buffer.View{buffer.NewViewFromBytes(packet)})})
+	pkb := stack.NewPacketBuffer(stack.PacketBufferOptions{Payload: bufferv2.MakeWithData(packet)})
 	switch packet[0] >> 4 {
 	case 4:
-		tun.dispatcher.DeliverNetworkPacket("", "", ipv4.ProtocolNumber, pkb)
+		tun.ep.InjectInbound(header.IPv4ProtocolNumber, pkb)
 	case 6:
-		tun.dispatcher.DeliverNetworkPacket("", "", ipv6.ProtocolNumber, pkb)
+		tun.ep.InjectInbound(header.IPv6ProtocolNumber, pkb)
 	}
 
 	return len(buf), nil
 }
 
+func (tun *netTun) WriteNotify() {
+	pkt := tun.ep.Read()
+	if pkt == nil {
+		return
+	}
+
+	view := pkt.ToView()
+	pkt.DecRef()
+
+	tun.incomingPacket <- view
+}
+
 func (tun *netTun) Flush() error {
 	return nil
 }
@@ -197,9 +161,9 @@ func (tun *netTun) Close() error {
 	if tun.events != nil {
 		close(tun.events)
 	}
-	if tun.incomingPacket != nil {
-		close(tun.incomingPacket)
-	}
+
+	tun.ep.Close()
+
 	return nil
 }
 
@@ -434,11 +398,10 @@ func (pc *PingConn) WriteTo(p []byte, addr net.Addr) (n int, err error) {
 		return 0, fmt.Errorf("ping write: mismatched protocols")
 	}
 
-	buf := buffer.NewViewFromBytes(p)
-	rdr := buf.Reader()
+	buf := bytes.NewReader(p)
 	rfa, _ := convertToFullAddr(netip.AddrPortFrom(na, 0))
 	// won't block, no deadlines
-	n64, tcpipErr := pc.ep.Write(&rdr, tcpip.WriteOptions{
+	n64, tcpipErr := pc.ep.Write(buf, tcpip.WriteOptions{
 		To: &rfa,
 	})
 	if tcpipErr != nil {
@@ -453,8 +416,8 @@ func (pc *PingConn) Write(p []byte) (n int, err error) {
 }
 
 func (pc *PingConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
-	e, notifyCh := waiter.NewChannelEntry(nil)
-	pc.wq.EventRegister(&e, waiter.EventIn)
+	e, notifyCh := waiter.NewChannelEntry(waiter.EventIn)
+	pc.wq.EventRegister(&e)
 	defer pc.wq.EventUnregister(&e)
 
 	select {
@@ -488,7 +451,7 @@ func (pc *PingConn) SetDeadline(t time.Time) error {
 }
 
 func (pc *PingConn) SetReadDeadline(t time.Time) error {
-	pc.deadline.Reset(t.Sub(time.Now()))
+	pc.deadline.Reset(time.Until(t))
 	return nil
 }