github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/pkg/sentry/kernel/pipe/pipe_test.go (about)

     1  // Copyright 2018 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package pipe
    16  
    17  import (
    18  	"bytes"
    19  	"testing"
    20  
    21  	"github.com/SagerNet/gvisor/pkg/sentry/contexttest"
    22  	"github.com/SagerNet/gvisor/pkg/syserror"
    23  	"github.com/SagerNet/gvisor/pkg/usermem"
    24  	"github.com/SagerNet/gvisor/pkg/waiter"
    25  )
    26  
    27  func TestPipeRW(t *testing.T) {
    28  	ctx := contexttest.Context(t)
    29  	r, w := NewConnectedPipe(ctx, 65536)
    30  	defer r.DecRef(ctx)
    31  	defer w.DecRef(ctx)
    32  
    33  	msg := []byte("here's some bytes")
    34  	wantN := int64(len(msg))
    35  	n, err := w.Writev(ctx, usermem.BytesIOSequence(msg))
    36  	if n != wantN || err != nil {
    37  		t.Fatalf("Writev: got (%d, %v), wanted (%d, nil)", n, err, wantN)
    38  	}
    39  
    40  	buf := make([]byte, len(msg))
    41  	n, err = r.Readv(ctx, usermem.BytesIOSequence(buf))
    42  	if n != wantN || err != nil || !bytes.Equal(buf, msg) {
    43  		t.Fatalf("Readv: got (%d, %v) %q, wanted (%d, nil) %q", n, err, buf, wantN, msg)
    44  	}
    45  }
    46  
    47  func TestPipeReadBlock(t *testing.T) {
    48  	ctx := contexttest.Context(t)
    49  	r, w := NewConnectedPipe(ctx, 65536)
    50  	defer r.DecRef(ctx)
    51  	defer w.DecRef(ctx)
    52  
    53  	n, err := r.Readv(ctx, usermem.BytesIOSequence(make([]byte, 1)))
    54  	if n != 0 || err != syserror.ErrWouldBlock {
    55  		t.Fatalf("Readv: got (%d, %v), wanted (0, %v)", n, err, syserror.ErrWouldBlock)
    56  	}
    57  }
    58  
    59  func TestPipeWriteBlock(t *testing.T) {
    60  	const atomicIOBytes = 2
    61  	const capacity = MinimumPipeSize
    62  
    63  	ctx := contexttest.Context(t)
    64  	r, w := NewConnectedPipe(ctx, capacity)
    65  	defer r.DecRef(ctx)
    66  	defer w.DecRef(ctx)
    67  
    68  	msg := make([]byte, capacity+1)
    69  	n, err := w.Writev(ctx, usermem.BytesIOSequence(msg))
    70  	if wantN, wantErr := int64(capacity), syserror.ErrWouldBlock; n != wantN || err != wantErr {
    71  		t.Fatalf("Writev: got (%d, %v), wanted (%d, %v)", n, err, wantN, wantErr)
    72  	}
    73  }
    74  
    75  func TestPipeWriteUntilEnd(t *testing.T) {
    76  	const atomicIOBytes = 2
    77  
    78  	ctx := contexttest.Context(t)
    79  	r, w := NewConnectedPipe(ctx, atomicIOBytes)
    80  	defer r.DecRef(ctx)
    81  	defer w.DecRef(ctx)
    82  
    83  	msg := []byte("here's some bytes")
    84  
    85  	wDone := make(chan struct{}, 0)
    86  	rDone := make(chan struct{}, 0)
    87  	defer func() {
    88  		// Signal the reader to stop and wait until it does so.
    89  		close(wDone)
    90  		<-rDone
    91  	}()
    92  
    93  	go func() {
    94  		defer close(rDone)
    95  		// Read from r until done is closed.
    96  		ctx := contexttest.Context(t)
    97  		buf := make([]byte, len(msg)+1)
    98  		dst := usermem.BytesIOSequence(buf)
    99  		e, ch := waiter.NewChannelEntry(nil)
   100  		r.EventRegister(&e, waiter.ReadableEvents)
   101  		defer r.EventUnregister(&e)
   102  		for {
   103  			n, err := r.Readv(ctx, dst)
   104  			dst = dst.DropFirst64(n)
   105  			if err == syserror.ErrWouldBlock {
   106  				select {
   107  				case <-ch:
   108  					continue
   109  				case <-wDone:
   110  					// We expect to have 1 byte left in dst since len(buf) ==
   111  					// len(msg)+1.
   112  					if dst.NumBytes() != 1 || !bytes.Equal(buf[:len(msg)], msg) {
   113  						t.Errorf("Reader: got %q (%d bytes remaining), wanted %q", buf, dst.NumBytes(), msg)
   114  					}
   115  					return
   116  				}
   117  			}
   118  			if err != nil {
   119  				t.Errorf("Readv: got unexpected error %v", err)
   120  				return
   121  			}
   122  		}
   123  	}()
   124  
   125  	src := usermem.BytesIOSequence(msg)
   126  	e, ch := waiter.NewChannelEntry(nil)
   127  	w.EventRegister(&e, waiter.WritableEvents)
   128  	defer w.EventUnregister(&e)
   129  	for src.NumBytes() != 0 {
   130  		n, err := w.Writev(ctx, src)
   131  		src = src.DropFirst64(n)
   132  		if err == syserror.ErrWouldBlock {
   133  			<-ch
   134  			continue
   135  		}
   136  		if err != nil {
   137  			t.Fatalf("Writev: got (%d, %v)", n, err)
   138  		}
   139  	}
   140  }