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
|
// Copyright 2019 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.
package memfs
import (
"bytes"
"testing"
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/fspath"
"gvisor.dev/gvisor/pkg/sentry/context"
"gvisor.dev/gvisor/pkg/sentry/context/contexttest"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/usermem"
"gvisor.dev/gvisor/pkg/sentry/vfs"
"gvisor.dev/gvisor/pkg/syserror"
)
const fileName = "mypipe"
func TestSeparateFDs(t *testing.T) {
ctx, creds, vfsObj, root := setup(t)
defer root.DecRef()
// Open the read side. This is done in a concurrently because opening
// One end the pipe blocks until the other end is opened.
pop := vfs.PathOperation{
Root: root,
Start: root,
Path: fspath.Parse(fileName),
FollowFinalSymlink: true,
}
rfdchan := make(chan *vfs.FileDescription)
go func() {
openOpts := vfs.OpenOptions{Flags: linux.O_RDONLY}
rfd, _ := vfsObj.OpenAt(ctx, creds, &pop, &openOpts)
rfdchan <- rfd
}()
// Open the write side.
openOpts := vfs.OpenOptions{Flags: linux.O_WRONLY}
wfd, err := vfsObj.OpenAt(ctx, creds, &pop, &openOpts)
if err != nil {
t.Fatalf("failed to open pipe for writing %q: %v", fileName, err)
}
defer wfd.DecRef()
rfd, ok := <-rfdchan
if !ok {
t.Fatalf("failed to open pipe for reading %q", fileName)
}
defer rfd.DecRef()
const msg = "vamos azul"
checkEmpty(ctx, t, rfd)
checkWrite(ctx, t, wfd, msg)
checkRead(ctx, t, rfd, msg)
}
func TestNonblockingRead(t *testing.T) {
ctx, creds, vfsObj, root := setup(t)
defer root.DecRef()
// Open the read side as nonblocking.
pop := vfs.PathOperation{
Root: root,
Start: root,
Path: fspath.Parse(fileName),
FollowFinalSymlink: true,
}
openOpts := vfs.OpenOptions{Flags: linux.O_RDONLY | linux.O_NONBLOCK}
rfd, err := vfsObj.OpenAt(ctx, creds, &pop, &openOpts)
if err != nil {
t.Fatalf("failed to open pipe for reading %q: %v", fileName, err)
}
defer rfd.DecRef()
// Open the write side.
openOpts = vfs.OpenOptions{Flags: linux.O_WRONLY}
wfd, err := vfsObj.OpenAt(ctx, creds, &pop, &openOpts)
if err != nil {
t.Fatalf("failed to open pipe for writing %q: %v", fileName, err)
}
defer wfd.DecRef()
const msg = "geh blau"
checkEmpty(ctx, t, rfd)
checkWrite(ctx, t, wfd, msg)
checkRead(ctx, t, rfd, msg)
}
func TestNonblockingWriteError(t *testing.T) {
ctx, creds, vfsObj, root := setup(t)
defer root.DecRef()
// Open the write side as nonblocking, which should return ENXIO.
pop := vfs.PathOperation{
Root: root,
Start: root,
Path: fspath.Parse(fileName),
FollowFinalSymlink: true,
}
openOpts := vfs.OpenOptions{Flags: linux.O_WRONLY | linux.O_NONBLOCK}
_, err := vfsObj.OpenAt(ctx, creds, &pop, &openOpts)
if err != syserror.ENXIO {
t.Fatalf("expected ENXIO, but got error: %v", err)
}
}
func TestSingleFD(t *testing.T) {
ctx, creds, vfsObj, root := setup(t)
defer root.DecRef()
// Open the pipe as readable and writable.
pop := vfs.PathOperation{
Root: root,
Start: root,
Path: fspath.Parse(fileName),
FollowFinalSymlink: true,
}
openOpts := vfs.OpenOptions{Flags: linux.O_RDWR}
fd, err := vfsObj.OpenAt(ctx, creds, &pop, &openOpts)
if err != nil {
t.Fatalf("failed to open pipe for writing %q: %v", fileName, err)
}
defer fd.DecRef()
const msg = "forza blu"
checkEmpty(ctx, t, fd)
checkWrite(ctx, t, fd, msg)
checkRead(ctx, t, fd, msg)
}
// setup creates a VFS with a pipe in the root directory at path fileName. The
// returned VirtualDentry must be DecRef()'d be the caller. It calls t.Fatal
// upon failure.
func setup(t *testing.T) (context.Context, *auth.Credentials, *vfs.VirtualFilesystem, vfs.VirtualDentry) {
ctx := contexttest.Context(t)
creds := auth.CredentialsFromContext(ctx)
// Create VFS.
vfsObj := vfs.New()
vfsObj.MustRegisterFilesystemType("memfs", FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
AllowUserMount: true,
})
mntns, err := vfsObj.NewMountNamespace(ctx, creds, "", "memfs", &vfs.GetFilesystemOptions{})
if err != nil {
t.Fatalf("failed to create tmpfs root mount: %v", err)
}
// Create the pipe.
root := mntns.Root()
pop := vfs.PathOperation{
Root: root,
Start: root,
Path: fspath.Parse(fileName),
}
mknodOpts := vfs.MknodOptions{Mode: linux.ModeNamedPipe | 0644}
if err := vfsObj.MknodAt(ctx, creds, &pop, &mknodOpts); err != nil {
t.Fatalf("failed to create file %q: %v", fileName, err)
}
// Sanity check: the file pipe exists and has the correct mode.
stat, err := vfsObj.StatAt(ctx, creds, &vfs.PathOperation{
Root: root,
Start: root,
Path: fspath.Parse(fileName),
FollowFinalSymlink: true,
}, &vfs.StatOptions{})
if err != nil {
t.Fatalf("stat(%q) failed: %v", fileName, err)
}
if stat.Mode&^linux.S_IFMT != 0644 {
t.Errorf("got wrong permissions (%0o)", stat.Mode)
}
if stat.Mode&linux.S_IFMT != linux.ModeNamedPipe {
t.Errorf("got wrong file type (%0o)", stat.Mode)
}
return ctx, creds, vfsObj, root
}
// checkEmpty calls t.Fatal if the pipe in fd is not empty.
func checkEmpty(ctx context.Context, t *testing.T, fd *vfs.FileDescription) {
readData := make([]byte, 1)
dst := usermem.BytesIOSequence(readData)
bytesRead, err := fd.Read(ctx, dst, vfs.ReadOptions{})
if err != syserror.ErrWouldBlock {
t.Fatalf("expected ErrWouldBlock reading from empty pipe %q, but got: %v", fileName, err)
}
if bytesRead != 0 {
t.Fatalf("expected to read 0 bytes, but got %d", bytesRead)
}
}
// checkWrite calls t.Fatal if it fails to write all of msg to fd.
func checkWrite(ctx context.Context, t *testing.T, fd *vfs.FileDescription, msg string) {
writeData := []byte(msg)
src := usermem.BytesIOSequence(writeData)
bytesWritten, err := fd.Write(ctx, src, vfs.WriteOptions{})
if err != nil {
t.Fatalf("error writing to pipe %q: %v", fileName, err)
}
if bytesWritten != int64(len(writeData)) {
t.Fatalf("expected to write %d bytes, but wrote %d", len(writeData), bytesWritten)
}
}
// checkRead calls t.Fatal if it fails to read msg from fd.
func checkRead(ctx context.Context, t *testing.T, fd *vfs.FileDescription, msg string) {
readData := make([]byte, len(msg))
dst := usermem.BytesIOSequence(readData)
bytesRead, err := fd.Read(ctx, dst, vfs.ReadOptions{})
if err != nil {
t.Fatalf("error reading from pipe %q: %v", fileName, err)
}
if bytesRead != int64(len(msg)) {
t.Fatalf("expected to read %d bytes, but got %d", len(msg), bytesRead)
}
if !bytes.Equal(readData, []byte(msg)) {
t.Fatalf("expected to read %q from pipe, but got %q", msg, string(readData))
}
}
|
