cmd/tailscaled, wgengine: remove --fake, replace with netstack

And add a --socks5-server flag.

And fix a race in SOCKS5 replies where the response header was written
concurrently with the copy from the backend.

Co-authored with Naman Sood.

Updates #707
Updates #504

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick 2021-03-01 10:08:53 -08:00
parent d74cddcc56
commit 38dc6fe758
9 changed files with 142 additions and 105 deletions

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@ -96,7 +96,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
💣 tailscale.com/net/netstat from tailscale.com/ipn/ipnserver
tailscale.com/net/packet from tailscale.com/wgengine+
tailscale.com/net/portmapper from tailscale.com/net/netcheck+
tailscale.com/net/socks5 from tailscale.com/wgengine/netstack
tailscale.com/net/socks5 from tailscale.com/cmd/tailscaled
tailscale.com/net/stun from tailscale.com/net/netcheck+
tailscale.com/net/tlsdial from tailscale.com/control/controlclient+
tailscale.com/net/tsaddr from tailscale.com/ipn/ipnlocal+

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@ -14,6 +14,7 @@ import (
"flag"
"fmt"
"log"
"net"
"net/http"
"net/http/pprof"
"os"
@ -21,19 +22,23 @@ import (
"runtime"
"runtime/debug"
"strconv"
"sync"
"syscall"
"time"
"tailscale.com/ipn/ipnserver"
"tailscale.com/logpolicy"
"tailscale.com/net/socks5"
"tailscale.com/paths"
"tailscale.com/types/flagtype"
"tailscale.com/types/logger"
"tailscale.com/types/netmap"
"tailscale.com/version"
"tailscale.com/wgengine"
"tailscale.com/wgengine/magicsock"
"tailscale.com/wgengine/netstack"
"tailscale.com/wgengine/router"
"tailscale.com/wgengine/tstun"
)
// globalStateKey is the ipn.StateKey that tailscaled loads on
@ -62,13 +67,13 @@ func defaultTunName() string {
var args struct {
cleanup bool
fake bool
debug string
tunname string
port uint16
statepath string
socketpath string
verbose int
socksAddr string // listen address for SOCKS5 server
}
var (
@ -94,9 +99,9 @@ func main() {
printVersion := false
flag.IntVar(&args.verbose, "verbose", 0, "log verbosity level; 0 is default, 1 or higher are increasingly verbose")
flag.BoolVar(&args.cleanup, "cleanup", false, "clean up system state and exit")
flag.BoolVar(&args.fake, "fake", false, "use userspace fake tunnel+routing instead of kernel TUN interface")
flag.StringVar(&args.debug, "debug", "", "listen address ([ip]:port) of optional debug server")
flag.StringVar(&args.tunname, "tun", defaultTunName(), "tunnel interface name")
flag.StringVar(&args.socksAddr, "socks5-server", "", `optional [ip]:port to run a SOCK5 server (e.g. "localhost:1080")`)
flag.StringVar(&args.tunname, "tun", defaultTunName(), `tunnel interface name; use "userspace-networking" (beta) to not use TUN`)
flag.Var(flagtype.PortValue(&args.port, magicsock.DefaultPort), "port", "UDP port to listen on for WireGuard and peer-to-peer traffic; 0 means automatically select")
flag.StringVar(&args.statepath, "state", paths.DefaultTailscaledStateFile(), "path of state file")
flag.StringVar(&args.socketpath, "socket", paths.DefaultTailscaledSocket(), "path of the service unix socket")
@ -190,23 +195,73 @@ func run() error {
go runDebugServer(debugMux, args.debug)
}
var e wgengine.Engine
if args.fake {
var impl wgengine.FakeImplFactory
if args.tunname == "userspace-networking" {
impl = netstack.Create
var socksListener net.Listener
if args.socksAddr != "" {
var err error
socksListener, err = net.Listen("tcp", args.socksAddr)
if err != nil {
log.Fatalf("SOCKS5 listener: %v", err)
}
e, err = wgengine.NewFakeUserspaceEngine(logf, 0, impl)
} else {
e, err = wgengine.NewUserspaceEngine(logf, wgengine.Config{
TUNName: args.tunname,
ListenPort: args.port,
})
}
conf := wgengine.Config{
ListenPort: args.port,
}
if args.tunname == "userspace-networking" {
conf.TUN = tstun.NewFakeTUN()
conf.RouterGen = router.NewFake
} else {
conf.TUNName = args.tunname
}
e, err := wgengine.NewUserspaceEngine(logf, conf)
if err != nil {
logf("wgengine.New: %v", err)
return err
}
var ns *netstack.Impl
if args.tunname == "userspace-networking" {
tunDev, magicConn := e.(wgengine.InternalsGetter).GetInternals()
ns, err = netstack.Create(logf, tunDev, e, magicConn)
if err != nil {
log.Fatalf("netstack.Create: %v", err)
}
if err := ns.Start(); err != nil {
log.Fatalf("failed to start netstack: %v", err)
}
}
if socksListener != nil {
srv := &socks5.Server{
Logf: logger.WithPrefix(logf, "socks5: "),
}
if args.tunname == "userspace-networking" {
srv.Dialer = func(ctx context.Context, network, addr string) (net.Conn, error) {
return ns.DialContextTCP(ctx, addr)
}
} else {
var mu sync.Mutex
var dns netstack.DNSMap
e.AddNetworkMapCallback(func(nm *netmap.NetworkMap) {
mu.Lock()
defer mu.Unlock()
dns = netstack.DNSMapFromNetworkMap(nm)
})
srv.Dialer = func(ctx context.Context, network, addr string) (net.Conn, error) {
ipp, err := dns.Resolve(ctx, addr)
if err != nil {
return nil, err
}
var d net.Dialer
return d.DialContext(ctx, network, ipp.String())
}
}
go func() {
log.Fatalf("SOCKS5 server exited: %v", srv.Serve(socksListener))
}()
}
e = wgengine.NewWatchdog(e)
ctx, cancel := context.WithCancel(context.Background())

View File

@ -41,7 +41,7 @@ func TestLocalLogLines(t *testing.T) {
// set up a LocalBackend, super bare bones. No functional data.
store := &ipn.MemoryStore{}
e, err := wgengine.NewFakeUserspaceEngine(logListen.Logf, 0, nil)
e, err := wgengine.NewFakeUserspaceEngine(logListen.Logf, 0)
if err != nil {
t.Fatal(err)
}

View File

@ -56,7 +56,7 @@ func TestRunMultipleAccepts(t *testing.T) {
}
}
eng, err := wgengine.NewFakeUserspaceEngine(logf, 0, nil)
eng, err := wgengine.NewFakeUserspaceEngine(logf, 0)
if err != nil {
t.Fatal(err)
}

View File

@ -108,7 +108,7 @@ func (s *Server) Serve(l net.Listener) error {
conn := &Conn{clientConn: c, srv: s}
err := conn.Run()
if err != nil {
s.logf("socks5: client connection failed: %v", err)
s.logf("client connection failed: %v", err)
conn.clientConn.Close()
}
}()
@ -123,7 +123,6 @@ type Conn struct {
srv *Server
clientConn net.Conn
serverConn net.Conn
request *request
}
@ -153,11 +152,7 @@ func (c *Conn) handleRequest() error {
return fmt.Errorf("unsupported command %v", req.command)
}
c.request = req
return c.createReply()
}
func (c *Conn) createReply() error {
var err error
ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
srv, err := c.srv.dial(
@ -171,14 +166,12 @@ func (c *Conn) createReply() error {
c.clientConn.Write(buf)
return err
}
c.serverConn = srv
serverAddr, serverPortStr, err := net.SplitHostPort(c.serverConn.LocalAddr().String())
defer srv.Close()
serverAddr, serverPortStr, err := net.SplitHostPort(srv.LocalAddr().String())
if err != nil {
return err
}
serverPort, _ := strconv.Atoi(serverPortStr)
go io.Copy(c.clientConn, c.serverConn)
go io.Copy(c.serverConn, c.clientConn)
var bindAddrType addrType
if ip := net.ParseIP(serverAddr); ip != nil {
@ -190,7 +183,6 @@ func (c *Conn) createReply() error {
} else {
bindAddrType = domainName
}
res := &response{
reply: success,
bindAddrType: bindAddrType,
@ -203,7 +195,23 @@ func (c *Conn) createReply() error {
buf, _ = res.marshal()
}
c.clientConn.Write(buf)
return err
errc := make(chan error, 2)
go func() {
_, err := io.Copy(c.clientConn, srv)
if err != nil {
err = fmt.Errorf("from backend to client: %w", err)
}
errc <- err
}()
go func() {
_, err := io.Copy(srv, c.clientConn)
if err != nil {
err = fmt.Errorf("from client to backend: %w", err)
}
errc <- err
}()
return <-errc
}
// parseClientGreeting parses a request initiation packet

View File

@ -33,7 +33,6 @@ import (
"gvisor.dev/gvisor/pkg/waiter"
"inet.af/netaddr"
"tailscale.com/net/packet"
"tailscale.com/net/socks5"
"tailscale.com/types/logger"
"tailscale.com/types/netmap"
"tailscale.com/util/dnsname"
@ -55,13 +54,13 @@ type Impl struct {
logf logger.Logf
mu sync.Mutex
dns map[string]netaddr.IP // Magic DNS names (both base + FQDN) => first IP
dns DNSMap
}
const nicID = 1
// Create creates and populates a new Impl.
func Create(logf logger.Logf, tundev *tstun.TUN, e wgengine.Engine, mc *magicsock.Conn) (wgengine.FakeImpl, error) {
func Create(logf logger.Logf, tundev *tstun.TUN, e wgengine.Engine, mc *magicsock.Conn) (*Impl, error) {
if mc == nil {
return nil, errors.New("nil magicsock.Conn")
}
@ -121,33 +120,40 @@ func (ns *Impl) Start() error {
ns.ipstack.SetTransportProtocolHandler(udp.ProtocolNumber, udpFwd.HandlePacket)
go ns.injectOutbound()
ns.tundev.PostFilterIn = ns.injectInbound
go ns.socks5Server()
return nil
}
func (ns *Impl) updateDNS(nm *netmap.NetworkMap) {
ns.mu.Lock()
defer ns.mu.Unlock()
ns.dns = make(map[string]netaddr.IP)
// DNSMap maps MagicDNS names (both base + FQDN) to their first IP.
// It should not be mutated once created.
type DNSMap map[string]netaddr.IP
func DNSMapFromNetworkMap(nm *netmap.NetworkMap) DNSMap {
ret := make(DNSMap)
suffix := nm.MagicDNSSuffix()
if nm.Name != "" && len(nm.Addresses) > 0 {
ip := nm.Addresses[0].IP
ns.dns[strings.TrimRight(nm.Name, ".")] = ip
ret[strings.TrimRight(nm.Name, ".")] = ip
if dnsname.HasSuffix(nm.Name, suffix) {
ns.dns[dnsname.TrimSuffix(nm.Name, suffix)] = ip
ret[dnsname.TrimSuffix(nm.Name, suffix)] = ip
}
}
for _, p := range nm.Peers {
if p.Name != "" && len(p.Addresses) > 0 {
ip := p.Addresses[0].IP
ns.dns[strings.TrimRight(p.Name, ".")] = ip
ret[strings.TrimRight(p.Name, ".")] = ip
if dnsname.HasSuffix(p.Name, suffix) {
ns.dns[dnsname.TrimSuffix(p.Name, suffix)] = ip
ret[dnsname.TrimSuffix(p.Name, suffix)] = ip
}
}
}
return ret
}
func (ns *Impl) updateDNS(nm *netmap.NetworkMap) {
ns.mu.Lock()
defer ns.mu.Unlock()
ns.dns = DNSMapFromNetworkMap(nm)
}
func (ns *Impl) updateIPs(nm *netmap.NetworkMap) {
@ -198,8 +204,9 @@ func (ns *Impl) updateIPs(nm *netmap.NetworkMap) {
}
}
// resolve resolves addr into an IP:port.
func (ns *Impl) resolve(ctx context.Context, addr string) (netaddr.IPPort, error) {
// Resolve resolves addr into an IP:port using first the MagicDNS contents
// of m, else using the system resolver.
func (m DNSMap) Resolve(ctx context.Context, addr string) (netaddr.IPPort, error) {
ipp, pippErr := netaddr.ParseIPPort(addr)
if pippErr == nil {
return ipp, nil
@ -222,9 +229,7 @@ func (ns *Impl) resolve(ctx context.Context, addr string) (netaddr.IPPort, error
// Host is not an IP, so assume it's a DNS name.
// Try MagicDNS first, else otherwise a real DNS lookup.
ns.mu.Lock()
ip := ns.dns[host]
ns.mu.Unlock()
ip := m[host]
if !ip.IsZero() {
return netaddr.IPPort{IP: ip, Port: uint16(port16)}, nil
}
@ -242,8 +247,12 @@ func (ns *Impl) resolve(ctx context.Context, addr string) (netaddr.IPPort, error
return netaddr.IPPort{IP: ip, Port: uint16(port16)}, nil
}
func (ns *Impl) dialContextTCP(ctx context.Context, addr string) (*gonet.TCPConn, error) {
remoteIPPort, err := ns.resolve(ctx, addr)
func (ns *Impl) DialContextTCP(ctx context.Context, addr string) (*gonet.TCPConn, error) {
ns.mu.Lock()
dnsMap := ns.dns
ns.mu.Unlock()
remoteIPPort, err := dnsMap.Resolve(ctx, addr)
if err != nil {
return nil, err
}
@ -342,7 +351,7 @@ func (ns *Impl) forwardTCP(client *gonet.TCPConn, wq *waiter.Queue, address stri
}
cancel()
}()
server, err := ns.dialContextTCP(ctx, address)
server, err := ns.DialContextTCP(ctx, address)
if err != nil {
ns.logf("netstack: could not connect to server %s: %s", address, err)
return
@ -361,21 +370,6 @@ func (ns *Impl) forwardTCP(client *gonet.TCPConn, wq *waiter.Queue, address stri
ns.logf("[v2] netstack: forwarder connection to %s closed", address)
}
func (ns *Impl) socks5Server() {
ln, err := net.Listen("tcp", "localhost:1080")
if err != nil {
ns.logf("could not start SOCKS5 listener: %v", err)
return
}
srv := &socks5.Server{
Logf: ns.logf,
Dialer: func(ctx context.Context, network, addr string) (net.Conn, error) {
return ns.dialContextTCP(ctx, addr)
},
}
ns.logf("SOCKS5 server exited: %v", srv.Serve(ln))
}
func (ns *Impl) acceptUDP(r *udp.ForwarderRequest) {
ns.logf("[v2] UDP ForwarderRequest: %v", r)
var wq waiter.Queue

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@ -131,6 +131,15 @@ type userspaceEngine struct {
// Lock ordering: magicsock.Conn.mu, wgLock, then mu.
}
// InternalsGetter is implemented by Engines that can export their internals.
type InternalsGetter interface {
GetInternals() (*tstun.TUN, *magicsock.Conn)
}
func (e *userspaceEngine) GetInternals() (*tstun.TUN, *magicsock.Conn) {
return e.tundev, e.magicConn
}
// RouterGen is the signature for a function that creates a
// router.Router.
type RouterGen func(logf logger.Logf, wgdev *device.Device, tundev tun.Device) (router.Router, error)
@ -157,36 +166,18 @@ type Config struct {
// If zero, a port is automatically selected.
ListenPort uint16
// Fake determines whether this engine is running in fake mode,
// which disables such features as DNS configuration and unrestricted ICMP Echo responses.
// Fake determines whether this engine should automatically
// reply to ICMP pings.
Fake bool
// FakeImplFactory, if non-nil, creates a FakeImpl to use as a fake engine
// implementation. Two values are typical: nil, for a basic ping-only fake
// implementation, and netstack.Create, which creates a userspace network
// stack using gvisor's netstack. The desire to keep netstack out of some
// binaries is why the FakeImpl interface exists, so wgengine need not
// depend on gvisor.
FakeImplFactory FakeImplFactory
}
// FakeImpl is a fake or alternate version of Engine that can be started. See
// Config.FakeImplFactory for details.
type FakeImpl interface {
Start() error
}
// FakeImplFactory is the type of a function used to create FakeImpls.
type FakeImplFactory func(logger.Logf, *tstun.TUN, Engine, *magicsock.Conn) (FakeImpl, error)
func NewFakeUserspaceEngine(logf logger.Logf, listenPort uint16, impl FakeImplFactory) (Engine, error) {
func NewFakeUserspaceEngine(logf logger.Logf, listenPort uint16) (Engine, error) {
logf("Starting userspace wireguard engine (with fake TUN device)")
return NewUserspaceEngine(logf, Config{
TUN: tstun.NewFakeTUN(),
RouterGen: router.NewFake,
ListenPort: listenPort,
Fake: true,
FakeImplFactory: impl,
TUN: tstun.NewFakeTUN(),
RouterGen: router.NewFake,
ListenPort: listenPort,
Fake: true,
})
}
@ -292,18 +283,7 @@ func newUserspaceEngine(logf logger.Logf, rawTUNDev tun.Device, conf Config) (_
// Respond to all pings only in fake mode.
if conf.Fake {
if f := conf.FakeImplFactory; f != nil {
impl, err := f(logf, e.tundev, e, e.magicConn)
if err != nil {
return nil, err
}
if err := impl.Start(); err != nil {
return nil, err
}
} else {
// Respond to all pings only in fake mode.
e.tundev.PostFilterIn = echoRespondToAll
}
e.tundev.PostFilterIn = echoRespondToAll
}
e.tundev.PreFilterOut = e.handleLocalPackets

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@ -84,7 +84,7 @@ func TestNoteReceiveActivity(t *testing.T) {
}
func TestUserspaceEngineReconfig(t *testing.T) {
e, err := NewFakeUserspaceEngine(t.Logf, 0, nil)
e, err := NewFakeUserspaceEngine(t.Logf, 0)
if err != nil {
t.Fatal(err)
}

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@ -17,7 +17,7 @@ func TestWatchdog(t *testing.T) {
t.Run("default watchdog does not fire", func(t *testing.T) {
t.Parallel()
e, err := NewFakeUserspaceEngine(t.Logf, 0, nil)
e, err := NewFakeUserspaceEngine(t.Logf, 0)
if err != nil {
t.Fatal(err)
}
@ -35,7 +35,7 @@ func TestWatchdog(t *testing.T) {
t.Run("watchdog fires on blocked getStatus", func(t *testing.T) {
t.Parallel()
e, err := NewFakeUserspaceEngine(t.Logf, 0, nil)
e, err := NewFakeUserspaceEngine(t.Logf, 0)
if err != nil {
t.Fatal(err)
}