libgo/go/golang_org/x/net/nettest/conntest.go

   1 // Copyright 2016 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 // Package nettest provides utilities for network testing.
   6 package nettest
   7
   8 import (
   9         "bytes"
  10         "encoding/binary"
  11         "io"
  12         "io/ioutil"
  13         "math/rand"
  14         "net"
  15         "runtime"
  16         "sync"
  17         "testing"
  18         "time"
  19 )
  20
  21 var (
  22         aLongTimeAgo = time.Unix(233431200, 0)
  23         neverTimeout = time.Time{}
  24 )
  25
  26 // MakePipe creates a connection between two endpoints and returns the pair
  27 // as c1 and c2, such that anything written to c1 is read by c2 and vice-versa.
  28 // The stop function closes all resources, including c1, c2, and the underlying
  29 // net.Listener (if there is one), and should not be nil.
  30 type MakePipe func() (c1, c2 net.Conn, stop func(), err error)
  31
  32 // TestConn tests that a net.Conn implementation properly satisfies the interface.
  33 // The tests should not produce any false positives, but may experience
  34 // false negatives. Thus, some issues may only be detected when the test is
  35 // run multiple times. For maximal effectiveness, run the tests under the
  36 // race detector.
  37 func TestConn(t *testing.T, mp MakePipe) {
  38         testConn(t, mp)
  39 }
  40
  41 type connTester func(t *testing.T, c1, c2 net.Conn)
  42
  43 func timeoutWrapper(t *testing.T, mp MakePipe, f connTester) {
  44         c1, c2, stop, err := mp()
  45         if err != nil {
  46                 t.Fatalf("unable to make pipe: %v", err)
  47         }
  48         var once sync.Once
  49         defer once.Do(func() { stop() })
  50         timer := time.AfterFunc(time.Minute, func() {
  51                 once.Do(func() {
  52                         t.Error("test timed out; terminating pipe")
  53                         stop()
  54                 })
  55         })
  56         defer timer.Stop()
  57         f(t, c1, c2)
  58 }
  59
  60 // testBasicIO tests that the data sent on c1 is properly received on c2.
  61 func testBasicIO(t *testing.T, c1, c2 net.Conn) {
  62         want := make([]byte, 1<<20)
  63         rand.New(rand.NewSource(0)).Read(want)
  64
  65         dataCh := make(chan []byte)
  66         go func() {
  67                 rd := bytes.NewReader(want)
  68                 if err := chunkedCopy(c1, rd); err != nil {
  69                         t.Errorf("unexpected c1.Write error: %v", err)
  70                 }
  71                 if err := c1.Close(); err != nil {
  72                         t.Errorf("unexpected c1.Close error: %v", err)
  73                 }
  74         }()
  75
  76         go func() {
  77                 wr := new(bytes.Buffer)
  78                 if err := chunkedCopy(wr, c2); err != nil {
  79                         t.Errorf("unexpected c2.Read error: %v", err)
  80                 }
  81                 if err := c2.Close(); err != nil {
  82                         t.Errorf("unexpected c2.Close error: %v", err)
  83                 }
  84                 dataCh <- wr.Bytes()
  85         }()
  86
  87         if got := <-dataCh; !bytes.Equal(got, want) {
  88                 t.Errorf("transmitted data differs")
  89         }
  90 }
  91
  92 // testPingPong tests that the two endpoints can synchronously send data to
  93 // each other in a typical request-response pattern.
  94 func testPingPong(t *testing.T, c1, c2 net.Conn) {
  95         var wg sync.WaitGroup
  96         defer wg.Wait()
  97
  98         pingPonger := func(c net.Conn) {
  99                 defer wg.Done()
 100                 buf := make([]byte, 8)
 101                 var prev uint64
 102                 for {
 103                         if _, err := io.ReadFull(c, buf); err != nil {
 104                                 if err == io.EOF {
 105                                         break
 106                                 }
 107                                 t.Errorf("unexpected Read error: %v", err)
 108                         }
 109
 110                         v := binary.LittleEndian.Uint64(buf)
 111                         binary.LittleEndian.PutUint64(buf, v+1)
 112                         if prev != 0 && prev+2 != v {
 113                                 t.Errorf("mismatching value: got %d, want %d", v, prev+2)
 114                         }
 115                         prev = v
 116                         if v == 1000 {
 117                                 break
 118                         }
 119
 120                         if _, err := c.Write(buf); err != nil {
 121                                 t.Errorf("unexpected Write error: %v", err)
 122                                 break
 123                         }
 124                 }
 125                 if err := c.Close(); err != nil {
 126                         t.Errorf("unexpected Close error: %v", err)
 127                 }
 128         }
 129
 130         wg.Add(2)
 131         go pingPonger(c1)
 132         go pingPonger(c2)
 133
 134         // Start off the chain reaction.
 135         if _, err := c1.Write(make([]byte, 8)); err != nil {
 136                 t.Errorf("unexpected c1.Write error: %v", err)
 137         }
 138 }
 139
 140 // testRacyRead tests that it is safe to mutate the input Read buffer
 141 // immediately after cancelation has occurred.
 142 func testRacyRead(t *testing.T, c1, c2 net.Conn) {
 143         go chunkedCopy(c2, rand.New(rand.NewSource(0)))
 144
 145         var wg sync.WaitGroup
 146         defer wg.Wait()
 147
 148         c1.SetReadDeadline(time.Now().Add(time.Millisecond))
 149         for i := 0; i < 10; i++ {
 150                 wg.Add(1)
 151                 go func() {
 152                         defer wg.Done()
 153
 154                         b1 := make([]byte, 1024)
 155                         b2 := make([]byte, 1024)
 156                         for j := 0; j < 100; j++ {
 157                                 _, err := c1.Read(b1)
 158                                 copy(b1, b2) // Mutate b1 to trigger potential race
 159                                 if err != nil {
 160                                         checkForTimeoutError(t, err)
 161                                         c1.SetReadDeadline(time.Now().Add(time.Millisecond))
 162                                 }
 163                         }
 164                 }()
 165         }
 166 }
 167
 168 // testRacyWrite tests that it is safe to mutate the input Write buffer
 169 // immediately after cancelation has occurred.
 170 func testRacyWrite(t *testing.T, c1, c2 net.Conn) {
 171         go chunkedCopy(ioutil.Discard, c2)
 172
 173         var wg sync.WaitGroup
 174         defer wg.Wait()
 175
 176         c1.SetWriteDeadline(time.Now().Add(time.Millisecond))
 177         for i := 0; i < 10; i++ {
 178                 wg.Add(1)
 179                 go func() {
 180                         defer wg.Done()
 181
 182                         b1 := make([]byte, 1024)
 183                         b2 := make([]byte, 1024)
 184                         for j := 0; j < 100; j++ {
 185                                 _, err := c1.Write(b1)
 186                                 copy(b1, b2) // Mutate b1 to trigger potential race
 187                                 if err != nil {
 188                                         checkForTimeoutError(t, err)
 189                                         c1.SetWriteDeadline(time.Now().Add(time.Millisecond))
 190                                 }
 191                         }
 192                 }()
 193         }
 194 }
 195
 196 // testReadTimeout tests that Read timeouts do not affect Write.
 197 func testReadTimeout(t *testing.T, c1, c2 net.Conn) {
 198         go chunkedCopy(ioutil.Discard, c2)
 199
 200         c1.SetReadDeadline(aLongTimeAgo)
 201         _, err := c1.Read(make([]byte, 1024))
 202         checkForTimeoutError(t, err)
 203         if _, err := c1.Write(make([]byte, 1024)); err != nil {
 204                 t.Errorf("unexpected Write error: %v", err)
 205         }
 206 }
 207
 208 // testWriteTimeout tests that Write timeouts do not affect Read.
 209 func testWriteTimeout(t *testing.T, c1, c2 net.Conn) {
 210         go chunkedCopy(c2, rand.New(rand.NewSource(0)))
 211
 212         c1.SetWriteDeadline(aLongTimeAgo)
 213         _, err := c1.Write(make([]byte, 1024))
 214         checkForTimeoutError(t, err)
 215         if _, err := c1.Read(make([]byte, 1024)); err != nil {
 216                 t.Errorf("unexpected Read error: %v", err)
 217         }
 218 }
 219
 220 // testPastTimeout tests that a deadline set in the past immediately times out
 221 // Read and Write requests.
 222 func testPastTimeout(t *testing.T, c1, c2 net.Conn) {
 223         go chunkedCopy(c2, c2)
 224
 225         testRoundtrip(t, c1)
 226
 227         c1.SetDeadline(aLongTimeAgo)
 228         n, err := c1.Write(make([]byte, 1024))
 229         if n != 0 {
 230                 t.Errorf("unexpected Write count: got %d, want 0", n)
 231         }
 232         checkForTimeoutError(t, err)
 233         n, err = c1.Read(make([]byte, 1024))
 234         if n != 0 {
 235                 t.Errorf("unexpected Read count: got %d, want 0", n)
 236         }
 237         checkForTimeoutError(t, err)
 238
 239         testRoundtrip(t, c1)
 240 }
 241
 242 // testPresentTimeout tests that a deadline set while there are pending
 243 // Read and Write operations immediately times out those operations.
 244 func testPresentTimeout(t *testing.T, c1, c2 net.Conn) {
 245         var wg sync.WaitGroup
 246         defer wg.Wait()
 247         wg.Add(3)
 248
 249         deadlineSet := make(chan bool, 1)
 250         go func() {
 251                 defer wg.Done()
 252                 time.Sleep(100 * time.Millisecond)
 253                 deadlineSet <- true
 254                 c1.SetReadDeadline(aLongTimeAgo)
 255                 c1.SetWriteDeadline(aLongTimeAgo)
 256         }()
 257         go func() {
 258                 defer wg.Done()
 259                 n, err := c1.Read(make([]byte, 1024))
 260                 if n != 0 {
 261                         t.Errorf("unexpected Read count: got %d, want 0", n)
 262                 }
 263                 checkForTimeoutError(t, err)
 264                 if len(deadlineSet) == 0 {
 265                         t.Error("Read timed out before deadline is set")
 266                 }
 267         }()
 268         go func() {
 269                 defer wg.Done()
 270                 var err error
 271                 for err == nil {
 272                         _, err = c1.Write(make([]byte, 1024))
 273                 }
 274                 checkForTimeoutError(t, err)
 275                 if len(deadlineSet) == 0 {
 276                         t.Error("Write timed out before deadline is set")
 277                 }
 278         }()
 279 }
 280
 281 // testFutureTimeout tests that a future deadline will eventually time out
 282 // Read and Write operations.
 283 func testFutureTimeout(t *testing.T, c1, c2 net.Conn) {
 284         var wg sync.WaitGroup
 285         wg.Add(2)
 286
 287         c1.SetDeadline(time.Now().Add(100 * time.Millisecond))
 288         go func() {
 289                 defer wg.Done()
 290                 _, err := c1.Read(make([]byte, 1024))
 291                 checkForTimeoutError(t, err)
 292         }()
 293         go func() {
 294                 defer wg.Done()
 295                 var err error
 296                 for err == nil {
 297                         _, err = c1.Write(make([]byte, 1024))
 298                 }
 299                 checkForTimeoutError(t, err)
 300         }()
 301         wg.Wait()
 302
 303         go chunkedCopy(c2, c2)
 304         resyncConn(t, c1)
 305         testRoundtrip(t, c1)
 306 }
 307
 308 // testCloseTimeout tests that calling Close immediately times out pending
 309 // Read and Write operations.
 310 func testCloseTimeout(t *testing.T, c1, c2 net.Conn) {
 311         go chunkedCopy(c2, c2)
 312
 313         var wg sync.WaitGroup
 314         defer wg.Wait()
 315         wg.Add(3)
 316
 317         // Test for cancelation upon connection closure.
 318         c1.SetDeadline(neverTimeout)
 319         go func() {
 320                 defer wg.Done()
 321                 time.Sleep(100 * time.Millisecond)
 322                 c1.Close()
 323         }()
 324         go func() {
 325                 defer wg.Done()
 326                 var err error
 327                 buf := make([]byte, 1024)
 328                 for err == nil {
 329                         _, err = c1.Read(buf)
 330                 }
 331         }()
 332         go func() {
 333                 defer wg.Done()
 334                 var err error
 335                 buf := make([]byte, 1024)
 336                 for err == nil {
 337                         _, err = c1.Write(buf)
 338                 }
 339         }()
 340 }
 341
 342 // testConcurrentMethods tests that the methods of net.Conn can safely
 343 // be called concurrently.
 344 func testConcurrentMethods(t *testing.T, c1, c2 net.Conn) {
 345         if runtime.GOOS == "plan9" {
 346                 t.Skip("skipping on plan9; see https://golang.org/issue/20489")
 347         }
 348         go chunkedCopy(c2, c2)
 349
 350         // The results of the calls may be nonsensical, but this should
 351         // not trigger a race detector warning.
 352         var wg sync.WaitGroup
 353         for i := 0; i < 100; i++ {
 354                 wg.Add(7)
 355                 go func() {
 356                         defer wg.Done()
 357                         c1.Read(make([]byte, 1024))
 358                 }()
 359                 go func() {
 360                         defer wg.Done()
 361                         c1.Write(make([]byte, 1024))
 362                 }()
 363                 go func() {
 364                         defer wg.Done()
 365                         c1.SetDeadline(time.Now().Add(10 * time.Millisecond))
 366                 }()
 367                 go func() {
 368                         defer wg.Done()
 369                         c1.SetReadDeadline(aLongTimeAgo)
 370                 }()
 371                 go func() {
 372                         defer wg.Done()
 373                         c1.SetWriteDeadline(aLongTimeAgo)
 374                 }()
 375                 go func() {
 376                         defer wg.Done()
 377                         c1.LocalAddr()
 378                 }()
 379                 go func() {
 380                         defer wg.Done()
 381                         c1.RemoteAddr()
 382                 }()
 383         }
 384         wg.Wait() // At worst, the deadline is set 10ms into the future
 385
 386         resyncConn(t, c1)
 387         testRoundtrip(t, c1)
 388 }
 389
 390 // checkForTimeoutError checks that the error satisfies the Error interface
 391 // and that Timeout returns true.
 392 func checkForTimeoutError(t *testing.T, err error) {
 393         if nerr, ok := err.(net.Error); ok {
 394                 if !nerr.Timeout() {
 395                         t.Errorf("err.Timeout() = false, want true")
 396                 }
 397         } else {
 398                 t.Errorf("got %T, want net.Error", err)
 399         }
 400 }
 401
 402 // testRoundtrip writes something into c and reads it back.
 403 // It assumes that everything written into c is echoed back to itself.
 404 func testRoundtrip(t *testing.T, c net.Conn) {
 405         if err := c.SetDeadline(neverTimeout); err != nil {
 406                 t.Errorf("roundtrip SetDeadline error: %v", err)
 407         }
 408
 409         const s = "Hello, world!"
 410         buf := []byte(s)
 411         if _, err := c.Write(buf); err != nil {
 412                 t.Errorf("roundtrip Write error: %v", err)
 413         }
 414         if _, err := io.ReadFull(c, buf); err != nil {
 415                 t.Errorf("roundtrip Read error: %v", err)
 416         }
 417         if string(buf) != s {
 418                 t.Errorf("roundtrip data mismatch: got %q, want %q", buf, s)
 419         }
 420 }
 421
 422 // resyncConn resynchronizes the connection into a sane state.
 423 // It assumes that everything written into c is echoed back to itself.
 424 // It assumes that 0xff is not currently on the wire or in the read buffer.
 425 func resyncConn(t *testing.T, c net.Conn) {
 426         c.SetDeadline(neverTimeout)
 427         errCh := make(chan error)
 428         go func() {
 429                 _, err := c.Write([]byte{0xff})
 430                 errCh <- err
 431         }()
 432         buf := make([]byte, 1024)
 433         for {
 434                 n, err := c.Read(buf)
 435                 if n > 0 && bytes.IndexByte(buf[:n], 0xff) == n-1 {
 436                         break
 437                 }
 438                 if err != nil {
 439                         t.Errorf("unexpected Read error: %v", err)
 440                         break
 441                 }
 442         }
 443         if err := <-errCh; err != nil {
 444                 t.Errorf("unexpected Write error: %v", err)
 445         }
 446 }
 447
 448 // chunkedCopy copies from r to w in fixed-width chunks to avoid
 449 // causing a Write that exceeds the maximum packet size for packet-based
 450 // connections like "unixpacket".
 451 // We assume that the maximum packet size is at least 1024.
 452 func chunkedCopy(w io.Writer, r io.Reader) error {
 453         b := make([]byte, 1024)
 454         _, err := io.CopyBuffer(struct{ io.Writer }{w}, struct{ io.Reader }{r}, b)
 455         return err
 456 }