1 files changed, 386 insertions, 149 deletions

diff --git a/tun/netstack/tun.go b/tun/netstack/tun.go
index 9d2e90a..2b73054 100644
--- a/tun/netstack/tun.go
+++ b/tun/netstack/tun.go
@@ -1,11 +1,12 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
  */
 
 package netstack
 
 import (
+	"bytes"
 	"context"
 	"crypto/rand"
 	"encoding/binary"
@@ -13,112 +14,85 @@ import (
 	"fmt"
 	"io"
 	"net"
+	"net/netip"
 	"os"
+	"regexp"
 	"strconv"
 	"strings"
+	"syscall"
 	"time"
 
 	"golang.zx2c4.com/wireguard/tun"
 
 	"golang.org/x/net/dns/dnsmessage"
+	"gvisor.dev/gvisor/pkg/buffer"
 	"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"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/icmp"
 	"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
 	"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
+	"gvisor.dev/gvisor/pkg/waiter"
 )
 
 type netTun struct {
+	ep             *channel.Endpoint
 	stack          *stack.Stack
-	dispatcher     stack.NetworkDispatcher
 	events         chan tun.Event
-	incomingPacket chan buffer.VectorisedView
+	incomingPacket chan *buffer.View
 	mtu            int
-	dnsServers     []net.IP
+	dnsServers     []netip.Addr
 	hasV4, hasV6   bool
 }
-type endpoint netTun
-type 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 (*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 []net.IP, mtu int) (tun.Device, *Net, error) {
+func CreateNetTUN(localAddresses, dnsServers []netip.Addr, mtu int) (tun.Device, *Net, error) {
 	opts := stack.Options{
 		NetworkProtocols:   []stack.NetworkProtocolFactory{ipv4.NewProtocol, ipv6.NewProtocol},
-		TransportProtocols: []stack.TransportProtocolFactory{tcp.NewProtocol, udp.NewProtocol},
+		TransportProtocols: []stack.TransportProtocolFactory{tcp.NewProtocol, udp.NewProtocol, icmp.NewProtocol6, icmp.NewProtocol4},
 		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 *buffer.View),
 		dnsServers:     dnsServers,
 		mtu:            mtu,
 	}
-	tcpipErr := dev.stack.CreateNIC(1, (*endpoint)(dev))
+	sackEnabledOpt := tcpip.TCPSACKEnabled(true) // TCP SACK is disabled by default
+	tcpipErr := dev.stack.SetTransportProtocolOption(tcp.ProtocolNumber, &sackEnabledOpt)
+	if tcpipErr != nil {
+		return nil, nil, fmt.Errorf("could not enable TCP SACK: %v", tcpipErr)
+	}
+	dev.ep.AddNotify(dev)
+	tcpipErr = dev.stack.CreateNIC(1, dev.ep)
 	if tcpipErr != nil {
 		return nil, nil, fmt.Errorf("CreateNIC: %v", tcpipErr)
 	}
 	for _, ip := range localAddresses {
-		if ip4 := ip.To4(); ip4 != nil {
-			tcpipErr = dev.stack.AddAddress(1, ipv4.ProtocolNumber, tcpip.Address(ip4))
-			if tcpipErr != nil {
-				return nil, nil, fmt.Errorf("AddAddress(%v): %v", ip4, tcpipErr)
-			}
+		var protoNumber tcpip.NetworkProtocolNumber
+		if ip.Is4() {
+			protoNumber = ipv4.ProtocolNumber
+		} else if ip.Is6() {
+			protoNumber = ipv6.ProtocolNumber
+		}
+		protoAddr := tcpip.ProtocolAddress{
+			Protocol:          protoNumber,
+			AddressWithPrefix: tcpip.AddrFromSlice(ip.AsSlice()).WithPrefix(),
+		}
+		tcpipErr := dev.stack.AddProtocolAddress(1, protoAddr, stack.AddressProperties{})
+		if tcpipErr != nil {
+			return nil, nil, fmt.Errorf("AddProtocolAddress(%v): %v", ip, tcpipErr)
+		}
+		if ip.Is4() {
 			dev.hasV4 = true
-		} else {
-			tcpipErr = dev.stack.AddAddress(1, ipv6.ProtocolNumber, tcpip.Address(ip))
-			if tcpipErr != nil {
-				return nil, nil, fmt.Errorf("AddAddress(%v): %v", ip4, tcpipErr)
-			}
+		} else if ip.Is6() {
 			dev.hasV6 = true
 		}
 	}
@@ -141,37 +115,54 @@ func (tun *netTun) File() *os.File {
 	return nil
 }
 
-func (tun *netTun) Events() chan tun.Event {
+func (tun *netTun) Events() <-chan tun.Event {
 	return tun.events
 }
 
-func (tun *netTun) Read(buf []byte, offset int) (int, error) {
+func (tun *netTun) Read(buf [][]byte, sizes []int, offset int) (int, error) {
 	view, ok := <-tun.incomingPacket
 	if !ok {
 		return 0, os.ErrClosed
 	}
-	return view.Read(buf[offset:])
-}
 
-func (tun *netTun) Write(buf []byte, offset int) (int, error) {
-	packet := buf[offset:]
-	if len(packet) == 0 {
-		return 0, nil
+	n, err := view.Read(buf[0][offset:])
+	if err != nil {
+		return 0, err
 	}
+	sizes[0] = n
+	return 1, nil
+}
 
-	pkb := stack.NewPacketBuffer(stack.PacketBufferOptions{Data: buffer.NewVectorisedView(len(packet), []buffer.View{buffer.NewViewFromBytes(packet)})})
-	switch packet[0] >> 4 {
-	case 4:
-		tun.dispatcher.DeliverNetworkPacket("", "", ipv4.ProtocolNumber, pkb)
-	case 6:
-		tun.dispatcher.DeliverNetworkPacket("", "", ipv6.ProtocolNumber, pkb)
-	}
+func (tun *netTun) Write(buf [][]byte, offset int) (int, error) {
+	for _, buf := range buf {
+		packet := buf[offset:]
+		if len(packet) == 0 {
+			continue
+		}
 
+		pkb := stack.NewPacketBuffer(stack.PacketBufferOptions{Payload: buffer.MakeWithData(packet)})
+		switch packet[0] >> 4 {
+		case 4:
+			tun.ep.InjectInbound(header.IPv4ProtocolNumber, pkb)
+		case 6:
+			tun.ep.InjectInbound(header.IPv6ProtocolNumber, pkb)
+		default:
+			return 0, syscall.EAFNOSUPPORT
+		}
+	}
 	return len(buf), nil
 }
 
-func (tun *netTun) Flush() error {
-	return nil
+func (tun *netTun) WriteNotify() {
+	pkt := tun.ep.Read()
+	if pkt.IsNil() {
+		return
+	}
+
+	view := pkt.ToView()
+	pkt.DecRef()
+
+	tun.incomingPacket <- view
 }
 
 func (tun *netTun) Close() error {
@@ -180,9 +171,13 @@ func (tun *netTun) Close() error {
 	if tun.events != nil {
 		close(tun.events)
 	}
+
+	tun.ep.Close()
+
 	if tun.incomingPacket != nil {
 		close(tun.incomingPacket)
 	}
+
 	return nil
 }
 
@@ -190,62 +185,294 @@ func (tun *netTun) MTU() (int, error) {
 	return tun.mtu, nil
 }
 
-func convertToFullAddr(ip net.IP, port int) (tcpip.FullAddress, tcpip.NetworkProtocolNumber) {
-	if ip4 := ip.To4(); ip4 != nil {
-		return tcpip.FullAddress{
-			NIC:  1,
-			Addr: tcpip.Address(ip4),
-			Port: uint16(port),
-		}, ipv4.ProtocolNumber
+func (tun *netTun) BatchSize() int {
+	return 1
+}
+
+func convertToFullAddr(endpoint netip.AddrPort) (tcpip.FullAddress, tcpip.NetworkProtocolNumber) {
+	var protoNumber tcpip.NetworkProtocolNumber
+	if endpoint.Addr().Is4() {
+		protoNumber = ipv4.ProtocolNumber
 	} else {
-		return tcpip.FullAddress{
-			NIC:  1,
-			Addr: tcpip.Address(ip),
-			Port: uint16(port),
-		}, ipv6.ProtocolNumber
+		protoNumber = ipv6.ProtocolNumber
 	}
+	return tcpip.FullAddress{
+		NIC:  1,
+		Addr: tcpip.AddrFromSlice(endpoint.Addr().AsSlice()),
+		Port: endpoint.Port(),
+	}, protoNumber
+}
+
+func (net *Net) DialContextTCPAddrPort(ctx context.Context, addr netip.AddrPort) (*gonet.TCPConn, error) {
+	fa, pn := convertToFullAddr(addr)
+	return gonet.DialContextTCP(ctx, net.stack, fa, pn)
 }
 
 func (net *Net) DialContextTCP(ctx context.Context, addr *net.TCPAddr) (*gonet.TCPConn, error) {
 	if addr == nil {
-		panic("todo: deal with auto addr semantics for nil addr")
+		return net.DialContextTCPAddrPort(ctx, netip.AddrPort{})
 	}
-	fa, pn := convertToFullAddr(addr.IP, addr.Port)
-	return gonet.DialContextTCP(ctx, net.stack, fa, pn)
+	ip, _ := netip.AddrFromSlice(addr.IP)
+	return net.DialContextTCPAddrPort(ctx, netip.AddrPortFrom(ip, uint16(addr.Port)))
+}
+
+func (net *Net) DialTCPAddrPort(addr netip.AddrPort) (*gonet.TCPConn, error) {
+	fa, pn := convertToFullAddr(addr)
+	return gonet.DialTCP(net.stack, fa, pn)
 }
 
 func (net *Net) DialTCP(addr *net.TCPAddr) (*gonet.TCPConn, error) {
 	if addr == nil {
-		panic("todo: deal with auto addr semantics for nil addr")
+		return net.DialTCPAddrPort(netip.AddrPort{})
 	}
-	fa, pn := convertToFullAddr(addr.IP, addr.Port)
-	return gonet.DialTCP(net.stack, fa, pn)
+	ip, _ := netip.AddrFromSlice(addr.IP)
+	return net.DialTCPAddrPort(netip.AddrPortFrom(ip, uint16(addr.Port)))
+}
+
+func (net *Net) ListenTCPAddrPort(addr netip.AddrPort) (*gonet.TCPListener, error) {
+	fa, pn := convertToFullAddr(addr)
+	return gonet.ListenTCP(net.stack, fa, pn)
 }
 
 func (net *Net) ListenTCP(addr *net.TCPAddr) (*gonet.TCPListener, error) {
 	if addr == nil {
-		panic("todo: deal with auto addr semantics for nil addr")
+		return net.ListenTCPAddrPort(netip.AddrPort{})
 	}
-	fa, pn := convertToFullAddr(addr.IP, addr.Port)
-	return gonet.ListenTCP(net.stack, fa, pn)
+	ip, _ := netip.AddrFromSlice(addr.IP)
+	return net.ListenTCPAddrPort(netip.AddrPortFrom(ip, uint16(addr.Port)))
 }
 
-func (net *Net) DialUDP(laddr, raddr *net.UDPAddr) (*gonet.UDPConn, error) {
+func (net *Net) DialUDPAddrPort(laddr, raddr netip.AddrPort) (*gonet.UDPConn, error) {
 	var lfa, rfa *tcpip.FullAddress
 	var pn tcpip.NetworkProtocolNumber
-	if laddr != nil {
+	if laddr.IsValid() || laddr.Port() > 0 {
 		var addr tcpip.FullAddress
-		addr, pn = convertToFullAddr(laddr.IP, laddr.Port)
+		addr, pn = convertToFullAddr(laddr)
 		lfa = &addr
 	}
-	if raddr != nil {
+	if raddr.IsValid() || raddr.Port() > 0 {
 		var addr tcpip.FullAddress
-		addr, pn = convertToFullAddr(raddr.IP, raddr.Port)
+		addr, pn = convertToFullAddr(raddr)
 		rfa = &addr
 	}
 	return gonet.DialUDP(net.stack, lfa, rfa, pn)
 }
 
+func (net *Net) ListenUDPAddrPort(laddr netip.AddrPort) (*gonet.UDPConn, error) {
+	return net.DialUDPAddrPort(laddr, netip.AddrPort{})
+}
+
+func (net *Net) DialUDP(laddr, raddr *net.UDPAddr) (*gonet.UDPConn, error) {
+	var la, ra netip.AddrPort
+	if laddr != nil {
+		ip, _ := netip.AddrFromSlice(laddr.IP)
+		la = netip.AddrPortFrom(ip, uint16(laddr.Port))
+	}
+	if raddr != nil {
+		ip, _ := netip.AddrFromSlice(raddr.IP)
+		ra = netip.AddrPortFrom(ip, uint16(raddr.Port))
+	}
+	return net.DialUDPAddrPort(la, ra)
+}
+
+func (net *Net) ListenUDP(laddr *net.UDPAddr) (*gonet.UDPConn, error) {
+	return net.DialUDP(laddr, nil)
+}
+
+type PingConn struct {
+	laddr    PingAddr
+	raddr    PingAddr
+	wq       waiter.Queue
+	ep       tcpip.Endpoint
+	deadline *time.Timer
+}
+
+type PingAddr struct{ addr netip.Addr }
+
+func (ia PingAddr) String() string {
+	return ia.addr.String()
+}
+
+func (ia PingAddr) Network() string {
+	if ia.addr.Is4() {
+		return "ping4"
+	} else if ia.addr.Is6() {
+		return "ping6"
+	}
+	return "ping"
+}
+
+func (ia PingAddr) Addr() netip.Addr {
+	return ia.addr
+}
+
+func PingAddrFromAddr(addr netip.Addr) *PingAddr {
+	return &PingAddr{addr}
+}
+
+func (net *Net) DialPingAddr(laddr, raddr netip.Addr) (*PingConn, error) {
+	if !laddr.IsValid() && !raddr.IsValid() {
+		return nil, errors.New("ping dial: invalid address")
+	}
+	v6 := laddr.Is6() || raddr.Is6()
+	bind := laddr.IsValid()
+	if !bind {
+		if v6 {
+			laddr = netip.IPv6Unspecified()
+		} else {
+			laddr = netip.IPv4Unspecified()
+		}
+	}
+
+	tn := icmp.ProtocolNumber4
+	pn := ipv4.ProtocolNumber
+	if v6 {
+		tn = icmp.ProtocolNumber6
+		pn = ipv6.ProtocolNumber
+	}
+
+	pc := &PingConn{
+		laddr:    PingAddr{laddr},
+		deadline: time.NewTimer(time.Hour << 10),
+	}
+	pc.deadline.Stop()
+
+	ep, tcpipErr := net.stack.NewEndpoint(tn, pn, &pc.wq)
+	if tcpipErr != nil {
+		return nil, fmt.Errorf("ping socket: endpoint: %s", tcpipErr)
+	}
+	pc.ep = ep
+
+	if bind {
+		fa, _ := convertToFullAddr(netip.AddrPortFrom(laddr, 0))
+		if tcpipErr = pc.ep.Bind(fa); tcpipErr != nil {
+			return nil, fmt.Errorf("ping bind: %s", tcpipErr)
+		}
+	}
+
+	if raddr.IsValid() {
+		pc.raddr = PingAddr{raddr}
+		fa, _ := convertToFullAddr(netip.AddrPortFrom(raddr, 0))
+		if tcpipErr = pc.ep.Connect(fa); tcpipErr != nil {
+			return nil, fmt.Errorf("ping connect: %s", tcpipErr)
+		}
+	}
+
+	return pc, nil
+}
+
+func (net *Net) ListenPingAddr(laddr netip.Addr) (*PingConn, error) {
+	return net.DialPingAddr(laddr, netip.Addr{})
+}
+
+func (net *Net) DialPing(laddr, raddr *PingAddr) (*PingConn, error) {
+	var la, ra netip.Addr
+	if laddr != nil {
+		la = laddr.addr
+	}
+	if raddr != nil {
+		ra = raddr.addr
+	}
+	return net.DialPingAddr(la, ra)
+}
+
+func (net *Net) ListenPing(laddr *PingAddr) (*PingConn, error) {
+	var la netip.Addr
+	if laddr != nil {
+		la = laddr.addr
+	}
+	return net.ListenPingAddr(la)
+}
+
+func (pc *PingConn) LocalAddr() net.Addr {
+	return pc.laddr
+}
+
+func (pc *PingConn) RemoteAddr() net.Addr {
+	return pc.raddr
+}
+
+func (pc *PingConn) Close() error {
+	pc.deadline.Reset(0)
+	pc.ep.Close()
+	return nil
+}
+
+func (pc *PingConn) SetWriteDeadline(t time.Time) error {
+	return errors.New("not implemented")
+}
+
+func (pc *PingConn) WriteTo(p []byte, addr net.Addr) (n int, err error) {
+	var na netip.Addr
+	switch v := addr.(type) {
+	case *PingAddr:
+		na = v.addr
+	case *net.IPAddr:
+		na, _ = netip.AddrFromSlice(v.IP)
+	default:
+		return 0, fmt.Errorf("ping write: wrong net.Addr type")
+	}
+	if !((na.Is4() && pc.laddr.addr.Is4()) || (na.Is6() && pc.laddr.addr.Is6())) {
+		return 0, fmt.Errorf("ping write: mismatched protocols")
+	}
+
+	buf := bytes.NewReader(p)
+	rfa, _ := convertToFullAddr(netip.AddrPortFrom(na, 0))
+	// won't block, no deadlines
+	n64, tcpipErr := pc.ep.Write(buf, tcpip.WriteOptions{
+		To: &rfa,
+	})
+	if tcpipErr != nil {
+		return int(n64), fmt.Errorf("ping write: %s", tcpipErr)
+	}
+
+	return int(n64), nil
+}
+
+func (pc *PingConn) Write(p []byte) (n int, err error) {
+	return pc.WriteTo(p, &pc.raddr)
+}
+
+func (pc *PingConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
+	e, notifyCh := waiter.NewChannelEntry(waiter.EventIn)
+	pc.wq.EventRegister(&e)
+	defer pc.wq.EventUnregister(&e)
+
+	select {
+	case <-pc.deadline.C:
+		return 0, nil, os.ErrDeadlineExceeded
+	case <-notifyCh:
+	}
+
+	w := tcpip.SliceWriter(p)
+
+	res, tcpipErr := pc.ep.Read(&w, tcpip.ReadOptions{
+		NeedRemoteAddr: true,
+	})
+	if tcpipErr != nil {
+		return 0, nil, fmt.Errorf("ping read: %s", tcpipErr)
+	}
+
+	remoteAddr, _ := netip.AddrFromSlice(res.RemoteAddr.Addr.AsSlice())
+	return res.Count, &PingAddr{remoteAddr}, nil
+}
+
+func (pc *PingConn) Read(p []byte) (n int, err error) {
+	n, _, err = pc.ReadFrom(p)
+	return
+}
+
+func (pc *PingConn) SetDeadline(t time.Time) error {
+	// pc.SetWriteDeadline is unimplemented
+
+	return pc.SetReadDeadline(t)
+}
+
+func (pc *PingConn) SetReadDeadline(t time.Time) error {
+	pc.deadline.Reset(time.Until(t))
+	return nil
+}
+
 var (
 	errNoSuchHost                   = errors.New("no such host")
 	errLameReferral                 = errors.New("lame referral")
@@ -421,7 +648,7 @@ func dnsStreamRoundTrip(c net.Conn, id uint16, query dnsmessage.Question, b []by
 	return p, h, nil
 }
 
-func (tnet *Net) exchange(ctx context.Context, server net.IP, q dnsmessage.Question, timeout time.Duration) (dnsmessage.Parser, dnsmessage.Header, error) {
+func (tnet *Net) exchange(ctx context.Context, server netip.Addr, q dnsmessage.Question, timeout time.Duration) (dnsmessage.Parser, dnsmessage.Header, error) {
 	q.Class = dnsmessage.ClassINET
 	id, udpReq, tcpReq, err := newRequest(q)
 	if err != nil {
@@ -435,16 +662,19 @@ func (tnet *Net) exchange(ctx context.Context, server net.IP, q dnsmessage.Quest
 		var c net.Conn
 		var err error
 		if useUDP {
-			c, err = tnet.DialUDP(nil, &net.UDPAddr{IP: server, Port: 53})
+			c, err = tnet.DialUDPAddrPort(netip.AddrPort{}, netip.AddrPortFrom(server, 53))
 		} else {
-			c, err = tnet.DialContextTCP(ctx, &net.TCPAddr{IP: server, Port: 53})
+			c, err = tnet.DialContextTCPAddrPort(ctx, netip.AddrPortFrom(server, 53))
 		}
 
 		if err != nil {
 			return dnsmessage.Parser{}, dnsmessage.Header{}, err
 		}
 		if d, ok := ctx.Deadline(); ok && !d.IsZero() {
-			c.SetDeadline(d)
+			err := c.SetDeadline(d)
+			if err != nil {
+				return dnsmessage.Parser{}, dnsmessage.Header{}, err
+			}
 		}
 		var p dnsmessage.Parser
 		var h dnsmessage.Header
@@ -588,8 +818,8 @@ func (tnet *Net) LookupContextHost(ctx context.Context, host string) ([]string,
 			zlen = zidx
 		}
 	}
-	if ip := net.ParseIP(host[:zlen]); ip != nil {
-		return []string{host[:zlen]}, nil
+	if ip, err := netip.ParseAddr(host[:zlen]); err == nil {
+		return []string{ip.String()}, nil
 	}
 
 	if !isDomainName(host) {
@@ -600,7 +830,7 @@ func (tnet *Net) LookupContextHost(ctx context.Context, host string) ([]string,
 		server string
 		error
 	}
-	var addrsV4, addrsV6 []net.IP
+	var addrsV4, addrsV6 []netip.Addr
 	lanes := 0
 	if tnet.hasV4 {
 		lanes++
@@ -655,7 +885,7 @@ func (tnet *Net) LookupContextHost(ctx context.Context, host string) ([]string,
 					}
 					break loop
 				}
-				addrsV4 = append(addrsV4, net.IP(a.A[:]))
+				addrsV4 = append(addrsV4, netip.AddrFrom4(a.A))
 
 			case dnsmessage.TypeAAAA:
 				aaaa, err := result.p.AAAAResource()
@@ -667,7 +897,7 @@ func (tnet *Net) LookupContextHost(ctx context.Context, host string) ([]string,
 					}
 					break loop
 				}
-				addrsV6 = append(addrsV6, net.IP(aaaa.AAAA[:]))
+				addrsV6 = append(addrsV6, netip.AddrFrom16(aaaa.AAAA))
 
 			default:
 				if err := result.p.SkipAnswer(); err != nil {
@@ -682,8 +912,8 @@ func (tnet *Net) LookupContextHost(ctx context.Context, host string) ([]string,
 			}
 		}
 	}
-	// We don't do RFC6724. Instead just put V6 addresess first if an IPv6 address is enabled
-	var addrs []net.IP
+	// We don't do RFC6724. Instead just put V6 addresses first if an IPv6 address is enabled
+	var addrs []netip.Addr
 	if tnet.hasV6 {
 		addrs = append(addrsV6, addrsV4...)
 	} else {
@@ -720,44 +950,48 @@ func partialDeadline(now, deadline time.Time, addrsRemaining int) (time.Time, er
 	return now.Add(timeout), nil
 }
 
+var protoSplitter = regexp.MustCompile(`^(tcp|udp|ping)(4|6)?$`)
+
 func (tnet *Net) DialContext(ctx context.Context, network, address string) (net.Conn, error) {
 	if ctx == nil {
 		panic("nil context")
 	}
-	var acceptV4, acceptV6, useUDP bool
-	if len(network) == 3 {
+	var acceptV4, acceptV6 bool
+	matches := protoSplitter.FindStringSubmatch(network)
+	if matches == nil {
+		return nil, &net.OpError{Op: "dial", Err: net.UnknownNetworkError(network)}
+	} else if len(matches[2]) == 0 {
 		acceptV4 = true
 		acceptV6 = true
-	} else if len(network) == 4 {
-		acceptV4 = network[3] == '4'
-		acceptV6 = network[3] == '6'
-	}
-	if !acceptV4 && !acceptV6 {
-		return nil, &net.OpError{Op: "dial", Err: net.UnknownNetworkError(network)}
-	}
-	if network[:3] == "udp" {
-		useUDP = true
-	} else if network[:3] != "tcp" {
-		return nil, &net.OpError{Op: "dial", Err: net.UnknownNetworkError(network)}
-	}
-	host, sport, err := net.SplitHostPort(address)
-	if err != nil {
-		return nil, &net.OpError{Op: "dial", Err: err}
+	} else {
+		acceptV4 = matches[2][0] == '4'
+		acceptV6 = !acceptV4
 	}
-	port, err := strconv.Atoi(sport)
-	if err != nil || port < 0 || port > 65535 {
-		return nil, &net.OpError{Op: "dial", Err: errNumericPort}
+	var host string
+	var port int
+	if matches[1] == "ping" {
+		host = address
+	} else {
+		var sport string
+		var err error
+		host, sport, err = net.SplitHostPort(address)
+		if err != nil {
+			return nil, &net.OpError{Op: "dial", Err: err}
+		}
+		port, err = strconv.Atoi(sport)
+		if err != nil || port < 0 || port > 65535 {
+			return nil, &net.OpError{Op: "dial", Err: errNumericPort}
+		}
 	}
 	allAddr, err := tnet.LookupContextHost(ctx, host)
 	if err != nil {
 		return nil, &net.OpError{Op: "dial", Err: err}
 	}
-	var addrs []net.IP
+	var addrs []netip.AddrPort
 	for _, addr := range allAddr {
-		if strings.IndexByte(addr, ':') != -1 && acceptV6 {
-			addrs = append(addrs, net.ParseIP(addr))
-		} else if strings.IndexByte(addr, '.') != -1 && acceptV4 {
-			addrs = append(addrs, net.ParseIP(addr))
+		ip, err := netip.ParseAddr(addr)
+		if err == nil && ((ip.Is4() && acceptV4) || (ip.Is6() && acceptV6)) {
+			addrs = append(addrs, netip.AddrPortFrom(ip, uint16(port)))
 		}
 	}
 	if len(addrs) == 0 && len(allAddr) != 0 {
@@ -795,10 +1029,13 @@ func (tnet *Net) DialContext(ctx context.Context, network, address string) (net.
 		}
 
 		var c net.Conn
-		if useUDP {
-			c, err = tnet.DialUDP(nil, &net.UDPAddr{IP: addr, Port: port})
-		} else {
-			c, err = tnet.DialContextTCP(dialCtx, &net.TCPAddr{IP: addr, Port: port})
+		switch matches[1] {
+		case "tcp":
+			c, err = tnet.DialContextTCPAddrPort(dialCtx, addr)
+		case "udp":
+			c, err = tnet.DialUDPAddrPort(netip.AddrPort{}, addr)
+		case "ping":
+			c, err = tnet.DialPingAddr(netip.Addr{}, addr.Addr())
 		}
 		if err == nil {
 			return c, nil