-
Notifications
You must be signed in to change notification settings - Fork 1.3k
/
tcp_proxy.go
590 lines (539 loc) · 17.6 KB
/
tcp_proxy.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
// Copyright 2018 The gVisor Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Binary tcp_proxy is a simple TCP proxy.
package main
import (
"encoding/gob"
"flag"
"fmt"
"io"
"log"
"math/rand"
"net"
"os"
"os/signal"
"regexp"
"runtime"
"runtime/pprof"
"runtime/trace"
"strconv"
"time"
"golang.org/x/sys/unix"
"gvisor.dev/gvisor/pkg/tcpip"
"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
"gvisor.dev/gvisor/pkg/tcpip/link/fdbased"
"gvisor.dev/gvisor/pkg/tcpip/link/qdisc/fifo"
"gvisor.dev/gvisor/pkg/tcpip/link/sniffer"
"gvisor.dev/gvisor/pkg/tcpip/network/arp"
"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"
)
var (
port = flag.Int("port", 0, "bind port (all addresses)")
forward = flag.String("forward", "", "forwarding target")
client = flag.Bool("client", false, "use netstack for listen")
server = flag.Bool("server", false, "use netstack for dial")
// Netstack-specific options.
mtu = flag.Int("mtu", 1280, "mtu for network stack")
addr = flag.String("addr", "", "address for tap-based netstack")
mask = flag.Int("mask", 8, "mask size for address")
iface = flag.String("iface", "", "network interface name to bind for netstack")
sack = flag.Bool("sack", false, "enable SACK support for netstack")
rack = flag.Bool("rack", true, "enable RACK in TCP")
moderateRecvBuf = flag.Bool("moderate_recv_buf", true, "enable TCP Receive Buffer Auto-tuning")
cubic = flag.Bool("cubic", false, "enable use of CUBIC congestion control for netstack")
gso = flag.Int("gso", 0, "GSO maximum size")
swgso = flag.Bool("swgso", false, "gVisor-level GSO")
gro = flag.Bool("gro", false, "gVisor-level GRO")
clientTCPProbeFile = flag.String("client_tcp_probe_file", "", "if specified, installs a tcp probe to dump endpoint state to the specified file.")
serverTCPProbeFile = flag.String("server_tcp_probe_file", "", "if specified, installs a tcp probe to dump endpoint state to the specified file.")
cpuprofile = flag.String("cpuprofile", "", "write cpu profile to the specified file.")
memprofile = flag.String("memprofile", "", "write memory profile to the specified file.")
blockprofile = flag.String("blockprofile", "", "write a goroutine blocking profile to the specified file.")
mutexprofile = flag.String("mutexprofile", "", "write a mutex profile to the specified file.")
traceprofile = flag.String("traceprofile", "", "write a 5s trace of the benchmark to the specified file.")
useIpv6 = flag.Bool("ipv6", false, "use ipv6 instead of ipv4.")
sniff = flag.Bool("sniff", false, "log sniffed packets")
useXDP = flag.Bool("xdp", false, "use AF_XDP as a link enpoint instead of fdbased")
)
type impl interface {
dial(address string) (net.Conn, error)
listen(port int) (net.Listener, error)
printStats()
}
type netImpl struct{}
func (netImpl) dial(address string) (net.Conn, error) {
return net.Dial("tcp", address)
}
func (netImpl) listen(port int) (net.Listener, error) {
return net.Listen("tcp", fmt.Sprintf(":%d", port))
}
func (netImpl) printStats() {
}
const (
nicID = 1 // Fixed.
bufSize = 4 << 20 // 4MB.
)
type netstackImpl struct {
s *stack.Stack
addr tcpip.Address
mode string
}
func setupNetwork(ifaceName string, numChannels int) (fds []int, err error) {
// Get all interfaces in the namespace.
ifaces, err := net.Interfaces()
if err != nil {
return nil, fmt.Errorf("querying interfaces: %v", err)
}
for _, iface := range ifaces {
if iface.Name != ifaceName {
continue
}
// Create the socket.
const protocol = 0x0300 // htons(ETH_P_ALL)
fds := make([]int, numChannels)
for i := range fds {
fd, err := unix.Socket(unix.AF_PACKET, unix.SOCK_RAW, protocol)
if err != nil {
return nil, fmt.Errorf("unable to create raw socket: %v", err)
}
// Bind to the appropriate device.
ll := unix.SockaddrLinklayer{
Protocol: protocol,
Ifindex: iface.Index,
Pkttype: unix.PACKET_HOST,
}
if err := unix.Bind(fd, &ll); err != nil {
return nil, fmt.Errorf("unable to bind to %q: %v", iface.Name, err)
}
// RAW Sockets by default have a very small SO_RCVBUF of 256KB,
// up it to at least 4MB to reduce packet drops.
if err := unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_RCVBUF, bufSize); err != nil {
return nil, fmt.Errorf("setsockopt(..., SO_RCVBUF, %v,..) = %v", bufSize, err)
}
if err := unix.SetsockoptInt(fd, unix.SOL_SOCKET, unix.SO_SNDBUF, bufSize); err != nil {
return nil, fmt.Errorf("setsockopt(..., SO_SNDBUF, %v,..) = %v", bufSize, err)
}
if !*swgso && *gso != 0 {
if err := unix.SetsockoptInt(fd, unix.SOL_PACKET, unix.PACKET_VNET_HDR, 1); err != nil {
return nil, fmt.Errorf("unable to enable the PACKET_VNET_HDR option: %v", err)
}
}
fds[i] = fd
}
return fds, nil
}
return nil, fmt.Errorf("failed to find interface: %v", ifaceName)
}
func newNetstackImpl(mode string) (impl, error) {
// Parse details.
var parsedAddr tcpip.Address
if *useIpv6 {
parsedAddr = tcpip.AddrFrom16Slice(net.ParseIP(*addr).To16())
} else {
parsedAddr = tcpip.AddrFrom4Slice(net.ParseIP(*addr).To4())
}
parsedBytes := parsedAddr.AsSlice()
var parsedDest tcpip.Address // Filled in below.
var parsedMask tcpip.AddressMask // Filled in below.
var parsedDest6 tcpip.Address // Filled in below.
var parsedMask6 tcpip.AddressMask // Filled in below.
switch *mask {
case 8:
parsedDest = tcpip.AddrFrom4([4]byte{parsedBytes[0], 0, 0, 0})
parsedMask = tcpip.MaskFromBytes([]byte{0xff, 0, 0, 0})
parsedDest6 = tcpip.AddrFrom16Slice(append([]byte{parsedBytes[0]}, make([]byte, 15)...))
parsedMask6 = tcpip.MaskFromBytes(append([]byte{0xff}, make([]byte, 15)...))
case 16:
parsedDest = tcpip.AddrFrom4([4]byte{parsedBytes[0], parsedBytes[1], 0, 0})
parsedMask = tcpip.MaskFromBytes([]byte{0xff, 0xff, 0, 0})
parsedDest6 = tcpip.AddrFrom16Slice(append([]byte{parsedBytes[0], parsedBytes[1]}, make([]byte, 14)...))
parsedMask6 = tcpip.MaskFromBytes(append([]byte{0xff, 0xff}, make([]byte, 14)...))
case 24:
parsedDest = tcpip.AddrFrom4([4]byte{parsedBytes[0], parsedBytes[1], parsedBytes[2], 0})
parsedMask = tcpip.MaskFromBytes([]byte{0xff, 0xff, 0xff, 0})
parsedDest6 = tcpip.AddrFrom16Slice(append([]byte{parsedBytes[0], parsedBytes[1], parsedBytes[2]}, make([]byte, 13)...))
parsedMask6 = tcpip.MaskFromBytes(append([]byte{0xff, 0xff, 0xff}, make([]byte, 13)...))
default:
// This is just laziness; we don't expect a different mask.
return nil, fmt.Errorf("mask %d not supported", mask)
}
// Create a new network stack.
netProtos := []stack.NetworkProtocolFactory{ipv6.NewProtocol, ipv4.NewProtocol, arp.NewProtocol}
transProtos := []stack.TransportProtocolFactory{tcp.NewProtocol, udp.NewProtocol, icmp.NewProtocol4, icmp.NewProtocol6}
s := stack.New(stack.Options{
NetworkProtocols: netProtos,
TransportProtocols: transProtos,
})
// Generate a new mac for the eth device.
mac := make(net.HardwareAddr, 6)
rand.Read(mac) // Fill with random data.
mac[0] &^= 0x1 // Clear multicast bit.
mac[0] |= 0x2 // Set local assignment bit (IEEE802).
var ep stack.LinkEndpoint
var err error
if *useXDP {
ep, err = newXDPEndpoint(*iface, mac)
} else {
var fds []int
fds, err = setupNetwork(*iface, runtime.GOMAXPROCS(0))
if err != nil {
return nil, err
}
ep, err = fdbased.New(&fdbased.Options{
FDs: fds,
MTU: uint32(*mtu),
EthernetHeader: true,
Address: tcpip.LinkAddress(mac),
// Enable checksum generation as we need to generate valid
// checksums for the veth device to deliver our packets to the
// peer. But we do want to disable checksum verification as veth
// devices do perform GRO and the linux host kernel may not
// regenerate valid checksums after GRO.
TXChecksumOffload: false,
RXChecksumOffload: true,
PacketDispatchMode: fdbased.RecvMMsg,
// PacketDispatchMode: fdbased.PacketMMap,
GSOMaxSize: uint32(*gso),
GVisorGSOEnabled: *swgso,
GRO: *gro,
})
}
if err != nil {
return nil, fmt.Errorf("failed to create endpoint: %v", err)
}
if *sniff {
ep = sniffer.New(ep)
}
qDisc := fifo.New(ep, runtime.GOMAXPROCS(0), 1000)
opts := stack.NICOptions{QDisc: qDisc}
if err := s.CreateNICWithOptions(nicID, ep, opts); err != nil {
return nil, fmt.Errorf("error creating NIC %q: %v", *iface, err)
}
proto := ipv4.ProtocolNumber
if *useIpv6 {
proto = ipv6.ProtocolNumber
}
protocolAddr := tcpip.ProtocolAddress{
Protocol: proto,
AddressWithPrefix: parsedAddr.WithPrefix(),
}
if err := s.AddProtocolAddress(nicID, protocolAddr, stack.AddressProperties{}); err != nil {
return nil, fmt.Errorf("error adding IP address %+v to %q: %s", protocolAddr, *iface, err)
}
subnet4, err := tcpip.NewSubnet(parsedDest, parsedMask)
if err != nil {
return nil, fmt.Errorf("tcpip.Subnet(%s, %s): %s", parsedDest, parsedMask, err)
}
subnet6, err := tcpip.NewSubnet(parsedDest6, parsedMask6)
if err != nil {
return nil, fmt.Errorf("tcpip.Subnet(%s, %s): %s", parsedDest, parsedMask, err)
}
// Add default route; we only support
s.SetRouteTable([]tcpip.Route{
{
Destination: subnet4,
NIC: nicID,
},
{
Destination: subnet6,
NIC: nicID,
},
})
// Set protocol options.
{
opt := tcpip.TCPSACKEnabled(*sack)
if err := s.SetTransportProtocolOption(tcp.ProtocolNumber, &opt); err != nil {
return nil, fmt.Errorf("SetTransportProtocolOption(%d, &%T(%t)): %s", tcp.ProtocolNumber, opt, opt, err)
}
}
// RACK is enabled by default in netstack.
if !*rack {
opt := tcpip.TCPRecovery(0)
if err := s.SetTransportProtocolOption(tcp.ProtocolNumber, &opt); err != nil {
return nil, fmt.Errorf("disabling RACK failed: %v", err)
}
}
// Enable Receive Buffer Auto-Tuning.
{
opt := tcpip.TCPModerateReceiveBufferOption(*moderateRecvBuf)
if err := s.SetTransportProtocolOption(tcp.ProtocolNumber, &opt); err != nil {
return nil, fmt.Errorf("SetTransportProtocolOption(%d, &%T(%t)): %s", tcp.ProtocolNumber, opt, opt, err)
}
}
// Set Congestion Control to cubic if requested.
if *cubic {
opt := tcpip.CongestionControlOption("cubic")
if err := s.SetTransportProtocolOption(tcp.ProtocolNumber, &opt); err != nil {
return nil, fmt.Errorf("SetTransportProtocolOption(%d, &%T(%s)): %s", tcp.ProtocolNumber, opt, opt, err)
}
}
return netstackImpl{
s: s,
addr: parsedAddr,
mode: mode,
}, nil
}
func (n netstackImpl) dial(address string) (net.Conn, error) {
host, port, err := net.SplitHostPort(address)
if err != nil {
return nil, err
}
if host == "" {
// A host must be provided for the dial.
return nil, fmt.Errorf("no host provided")
}
portNumber, err := strconv.Atoi(port)
if err != nil {
return nil, err
}
addr := tcpip.FullAddress{
NIC: nicID,
Addr: tcpip.AddrFromSlice(net.ParseIP(host)),
Port: uint16(portNumber),
}
proto := ipv4.ProtocolNumber
if *useIpv6 {
proto = ipv6.ProtocolNumber
}
conn, err := gonet.DialTCP(n.s, addr, proto)
if err != nil {
return nil, err
}
return conn, nil
}
func (n netstackImpl) listen(port int) (net.Listener, error) {
addr := tcpip.FullAddress{
NIC: nicID,
Port: uint16(port),
}
proto := ipv4.ProtocolNumber
if *useIpv6 {
proto = ipv6.ProtocolNumber
}
listener, err := gonet.ListenTCP(n.s, addr, proto)
if err != nil {
return nil, err
}
return listener, nil
}
var zeroFieldsRegexp = regexp.MustCompile(`\s*[a-zA-Z0-9]*:0`)
func (n netstackImpl) printStats() {
// Don't show zero fields.
stats := zeroFieldsRegexp.ReplaceAllString(fmt.Sprintf("%+v", n.s.Stats()), "")
log.Printf("netstack %s Stats: %+v\n", n.mode, stats)
}
// installProbe installs a TCP Probe function that will dump endpoint
// state to the specified file. It also returns a close func() that
// can be used to close the probeFile.
func (n netstackImpl) installProbe(probeFileName string) (close func()) {
// Install Probe to dump out end point state.
probeFile, err := os.Create(probeFileName)
if err != nil {
log.Fatalf("failed to create tcp_probe file %s: %v", probeFileName, err)
}
probeEncoder := gob.NewEncoder(probeFile)
// Install a TCP Probe.
n.s.AddTCPProbe(func(state *stack.TCPEndpointState) {
probeEncoder.Encode(state)
})
return func() { probeFile.Close() }
}
func main() {
flag.Parse()
if *port == 0 {
log.Fatalf("no port provided")
}
if *forward == "" {
log.Fatalf("no forward provided")
}
// Seed the random number generator to ensure that we are given MAC addresses that don't
// for the case of the client and server stack.
rand.Seed(time.Now().UTC().UnixNano())
if *cpuprofile != "" {
f, err := os.Create(*cpuprofile)
if err != nil {
log.Fatal("could not create CPU profile: ", err)
}
defer func() {
if err := f.Close(); err != nil {
log.Print("error closing CPU profile: ", err)
}
}()
if err := pprof.StartCPUProfile(f); err != nil {
log.Fatal("could not start CPU profile: ", err)
}
defer pprof.StopCPUProfile()
}
if *traceprofile != "" {
f, err := os.Create(*traceprofile)
if err != nil {
log.Fatal("could not create trace profile: ", err)
}
defer func() {
if err := f.Close(); err != nil {
log.Print("error closing trace profile: ", err)
}
}()
go func() {
// Delay tracing to give workload sometime to start.
time.Sleep(2 * time.Second)
if err := trace.Start(f); err != nil {
log.Fatal("could not start Go trace:", err)
}
defer trace.Stop()
<-time.After(5 * time.Second)
}()
}
if *mutexprofile != "" {
runtime.SetMutexProfileFraction(100)
}
if *blockprofile != "" {
runtime.SetBlockProfileRate(1000)
}
var (
in impl
out impl
err error
)
if *server {
in, err = newNetstackImpl("server")
if *serverTCPProbeFile != "" {
defer in.(netstackImpl).installProbe(*serverTCPProbeFile)()
}
} else {
in = netImpl{}
}
if err != nil {
log.Fatalf("netstack error: %v", err)
}
if *client {
out, err = newNetstackImpl("client")
if *clientTCPProbeFile != "" {
defer out.(netstackImpl).installProbe(*clientTCPProbeFile)()
}
} else {
out = netImpl{}
}
if err != nil {
log.Fatalf("netstack error: %v", err)
}
// Dial forward before binding.
var next net.Conn
for {
next, err = out.dial(*forward)
if err == nil {
break
}
time.Sleep(50 * time.Millisecond)
log.Printf("connect failed retrying: %v", err)
}
// Bind once to the server socket.
listener, err := in.listen(*port)
if err != nil {
// Should not happen, everything must be bound by this time
// this proxy is started.
log.Fatalf("unable to listen: %v", err)
}
log.Printf("client=%v, server=%v, ready.", *client, *server)
sigs := make(chan os.Signal, 1)
signal.Notify(sigs, unix.SIGTERM)
// Accept connections and proxy data between them.
go func() {
for {
// Forward all connections.
inConn, err := listener.Accept()
if err != nil {
// This should not happen; we are listening
// successfully. Exhausted all available FDs?
log.Fatalf("accept error: %v", err)
}
log.Printf("incoming connection established.")
// Copy both ways. We wrap everything in another
// Reader/Writer to prevent optimizations that
// otherwise call splice() to move data between
// sockets. That penalizes netstack, but isn't relevant
// to real use cases where only one end of netstack is
// attached to a socket.
go io.Copy(io.MultiWriter(inConn), io.MultiReader(next))
go io.Copy(io.MultiWriter(next), io.MultiReader(inConn))
// Print stats every second.
go func() {
t := time.NewTicker(time.Second)
defer t.Stop()
for {
<-t.C
in.printStats()
out.printStats()
}
}()
for {
// Dial again.
next, err = out.dial(*forward)
if err == nil {
break
}
}
}
}()
// Wait for the SIGTERM notifying us to stop.
<-sigs
if *memprofile != "" {
f, err := os.Create(*memprofile)
if err != nil {
log.Fatal("could not create memory profile: ", err)
}
defer func() {
if err := f.Close(); err != nil {
log.Print("error closing memory profile: ", err)
}
}()
runtime.GC() // get up-to-date statistics
if err := pprof.WriteHeapProfile(f); err != nil {
log.Fatalf("Unable to write heap profile: %v", err)
}
}
if *blockprofile != "" {
f, err := os.Create(*blockprofile)
if err != nil {
log.Fatal("could not create block profile: ", err)
}
defer func() {
if err := f.Close(); err != nil {
log.Print("error closing block profile: ", err)
}
}()
if err := pprof.Lookup("block").WriteTo(f, 0); err != nil {
log.Fatalf("Unable to write block profile: %v", err)
}
}
if *mutexprofile != "" {
f, err := os.Create(*mutexprofile)
if err != nil {
log.Fatal("could not create mutex profile: ", err)
}
defer func() {
if err := f.Close(); err != nil {
log.Print("error closing mutex profile: ", err)
}
}()
if err := pprof.Lookup("mutex").WriteTo(f, 0); err != nil {
log.Fatalf("Unable to write mutex profile: %v", err)
}
}
}