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
|
// 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.
// Package contexttest builds a test context.Context.
package contexttest
import (
"os"
"sync/atomic"
"testing"
"time"
"gvisor.googlesource.com/gvisor/pkg/sentry/context"
"gvisor.googlesource.com/gvisor/pkg/sentry/kernel/auth"
ktime "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/time"
"gvisor.googlesource.com/gvisor/pkg/sentry/limits"
"gvisor.googlesource.com/gvisor/pkg/sentry/memutil"
"gvisor.googlesource.com/gvisor/pkg/sentry/pgalloc"
"gvisor.googlesource.com/gvisor/pkg/sentry/platform"
"gvisor.googlesource.com/gvisor/pkg/sentry/platform/ptrace"
"gvisor.googlesource.com/gvisor/pkg/sentry/uniqueid"
)
// Context returns a Context that may be used in tests. Uses ptrace as the
// platform.Platform.
//
// Note that some filesystems may require a minimal kernel for testing, which
// this test context does not provide. For such tests, see kernel/contexttest.
func Context(tb testing.TB) context.Context {
const memfileName = "contexttest-memory"
memfd, err := memutil.CreateMemFD(memfileName, 0)
if err != nil {
tb.Fatalf("error creating application memory file: %v", err)
}
memfile := os.NewFile(uintptr(memfd), memfileName)
mf, err := pgalloc.NewMemoryFile(memfile, pgalloc.MemoryFileOpts{})
if err != nil {
memfile.Close()
tb.Fatalf("error creating pgalloc.MemoryFile: %v", err)
}
p, err := ptrace.New()
if err != nil {
tb.Fatal(err)
}
// Test usage of context.Background is fine.
return &TestContext{
Context: context.Background(),
l: limits.NewLimitSet(),
mf: mf,
platform: p,
otherValues: make(map[interface{}]interface{}),
}
}
// TestContext represents a context with minimal functionality suitable for
// running tests.
type TestContext struct {
context.Context
l *limits.LimitSet
mf *pgalloc.MemoryFile
platform platform.Platform
otherValues map[interface{}]interface{}
}
// globalUniqueID tracks incremental unique identifiers for tests.
var globalUniqueID uint64
// globalUniqueIDProvider implements unix.UniqueIDProvider.
type globalUniqueIDProvider struct{}
// UniqueID implements unix.UniqueIDProvider.UniqueID.
func (*globalUniqueIDProvider) UniqueID() uint64 {
return atomic.AddUint64(&globalUniqueID, 1)
}
// lastInotifyCookie is a monotonically increasing counter for generating unique
// inotify cookies. Must be accessed using atomic ops.
var lastInotifyCookie uint32
// hostClock implements ktime.Clock.
type hostClock struct {
ktime.WallRateClock
ktime.NoClockEvents
}
// Now implements ktime.Clock.Now.
func (hostClock) Now() ktime.Time {
return ktime.FromNanoseconds(time.Now().UnixNano())
}
// RegisterValue registers additional values with this test context. Useful for
// providing values from external packages that contexttest can't depend on.
func (t *TestContext) RegisterValue(key, value interface{}) {
t.otherValues[key] = value
}
// Value implements context.Context.
func (t *TestContext) Value(key interface{}) interface{} {
switch key {
case limits.CtxLimits:
return t.l
case pgalloc.CtxMemoryFile:
return t.mf
case pgalloc.CtxMemoryFileProvider:
return t
case platform.CtxPlatform:
return t.platform
case uniqueid.CtxGlobalUniqueID:
return (*globalUniqueIDProvider).UniqueID(nil)
case uniqueid.CtxGlobalUniqueIDProvider:
return &globalUniqueIDProvider{}
case uniqueid.CtxInotifyCookie:
return atomic.AddUint32(&lastInotifyCookie, 1)
case ktime.CtxRealtimeClock:
return hostClock{}
default:
if val, ok := t.otherValues[key]; ok {
return val
}
return t.Context.Value(key)
}
}
// MemoryFile implements pgalloc.MemoryFileProvider.MemoryFile.
func (t *TestContext) MemoryFile() *pgalloc.MemoryFile {
return t.mf
}
// RootContext returns a Context that may be used in tests that need root
// credentials. Uses ptrace as the platform.Platform.
func RootContext(tb testing.TB) context.Context {
return WithCreds(Context(tb), auth.NewRootCredentials(auth.NewRootUserNamespace()))
}
// WithCreds returns a copy of ctx carrying creds.
func WithCreds(ctx context.Context, creds *auth.Credentials) context.Context {
return &authContext{ctx, creds}
}
type authContext struct {
context.Context
creds *auth.Credentials
}
// Value implements context.Context.
func (ac *authContext) Value(key interface{}) interface{} {
switch key {
case auth.CtxCredentials:
return ac.creds
default:
return ac.Context.Value(key)
}
}
// WithLimitSet returns a copy of ctx carrying l.
func WithLimitSet(ctx context.Context, l *limits.LimitSet) context.Context {
return limitContext{ctx, l}
}
type limitContext struct {
context.Context
l *limits.LimitSet
}
// Value implements context.Context.
func (lc limitContext) Value(key interface{}) interface{} {
switch key {
case limits.CtxLimits:
return lc.l
default:
return lc.Context.Value(key)
}
}
|
