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
|
package sandbox_test
import (
"bytes"
"context"
"encoding/gob"
"log"
"os"
"os/exec"
"strings"
"syscall"
"testing"
"time"
"git.gensokyo.uk/security/hakurei/hst"
"git.gensokyo.uk/security/hakurei/internal"
"git.gensokyo.uk/security/hakurei/internal/hlog"
"git.gensokyo.uk/security/hakurei/ldd"
"git.gensokyo.uk/security/hakurei/sandbox"
"git.gensokyo.uk/security/hakurei/sandbox/seccomp"
"git.gensokyo.uk/security/hakurei/sandbox/vfs"
)
const (
ignore = "\x00"
ignoreV = -1
)
func TestContainer(t *testing.T) {
{
oldVerbose := hlog.Load()
oldOutput := sandbox.GetOutput()
internal.InstallFmsg(true)
t.Cleanup(func() { hlog.Store(oldVerbose) })
t.Cleanup(func() { sandbox.SetOutput(oldOutput) })
}
testCases := []struct {
name string
flags sandbox.HardeningFlags
ops *sandbox.Ops
mnt []*vfs.MountInfoEntry
host string
}{
{"minimal", 0, new(sandbox.Ops), nil, "test-minimal"},
{"allow", sandbox.FAllowUserns | sandbox.FAllowNet | sandbox.FAllowTTY,
new(sandbox.Ops), nil, "test-minimal"},
{"tmpfs", 0,
new(sandbox.Ops).
Tmpfs(hst.Tmp, 0, 0755),
[]*vfs.MountInfoEntry{
e("/", hst.Tmp, "rw,nosuid,nodev,relatime", "tmpfs", "tmpfs", ignore),
}, "test-tmpfs"},
{"dev", sandbox.FAllowTTY, // go test output is not a tty
new(sandbox.Ops).
Dev("/dev").
Mqueue("/dev/mqueue"),
[]*vfs.MountInfoEntry{
e("/", "/dev", "rw,nosuid,nodev,relatime", "tmpfs", "devtmpfs", ignore),
e("/null", "/dev/null", "rw,nosuid", "devtmpfs", "devtmpfs", ignore),
e("/zero", "/dev/zero", "rw,nosuid", "devtmpfs", "devtmpfs", ignore),
e("/full", "/dev/full", "rw,nosuid", "devtmpfs", "devtmpfs", ignore),
e("/random", "/dev/random", "rw,nosuid", "devtmpfs", "devtmpfs", ignore),
e("/urandom", "/dev/urandom", "rw,nosuid", "devtmpfs", "devtmpfs", ignore),
e("/tty", "/dev/tty", "rw,nosuid", "devtmpfs", "devtmpfs", ignore),
e("/", "/dev/pts", "rw,nosuid,noexec,relatime", "devpts", "devpts", "rw,mode=620,ptmxmode=666"),
e("/", "/dev/mqueue", "rw,nosuid,nodev,noexec,relatime", "mqueue", "mqueue", "rw"),
}, ""},
}
for _, tc := range testCases {
t.Run(tc.name, func(t *testing.T) {
ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
defer cancel()
container := sandbox.New(ctx, "/usr/bin/sandbox.test", "-test.v",
"-test.run=TestHelperCheckContainer", "--", "check", tc.host)
container.Uid = 1000
container.Gid = 100
container.Hostname = tc.host
container.CommandContext = commandContext
container.Flags |= tc.flags
container.Stdout, container.Stderr = os.Stdout, os.Stderr
container.Ops = tc.ops
if container.Args[5] == "" {
if name, err := os.Hostname(); err != nil {
t.Fatalf("cannot get hostname: %v", err)
} else {
container.Args[5] = name
}
}
container.
Tmpfs("/tmp", 0, 0755).
Bind(os.Args[0], os.Args[0], 0).
Mkdir("/usr/bin", 0755).
Link(os.Args[0], "/usr/bin/sandbox.test").
Place("/etc/hostname", []byte(container.Args[5]))
// in case test has cgo enabled
var libPaths []string
if entries, err := ldd.ExecFilter(ctx,
commandContext,
func(v []byte) []byte {
return bytes.SplitN(v, []byte("TestHelperInit\n"), 2)[1]
}, os.Args[0]); err != nil {
log.Fatalf("ldd: %v", err)
} else {
libPaths = ldd.Path(entries)
}
for _, name := range libPaths {
container.Bind(name, name, 0)
}
// needs /proc to check mountinfo
container.Proc("/proc")
mnt := make([]*vfs.MountInfoEntry, 0, 3+len(libPaths))
mnt = append(mnt, e("/sysroot", "/", "rw,nosuid,nodev,relatime", "tmpfs", "rootfs", ignore))
mnt = append(mnt, tc.mnt...)
mnt = append(mnt,
e("/", "/tmp", "rw,nosuid,nodev,relatime", "tmpfs", "tmpfs", ignore),
e(ignore, os.Args[0], "ro,nosuid,nodev,relatime", ignore, ignore, ignore),
e(ignore, "/etc/hostname", "ro,nosuid,nodev,relatime", "tmpfs", "rootfs", ignore),
)
for _, name := range libPaths {
mnt = append(mnt, e(ignore, name, "ro,nosuid,nodev,relatime", ignore, ignore, ignore))
}
mnt = append(mnt, e("/", "/proc", "rw,nosuid,nodev,noexec,relatime", "proc", "proc", "rw"))
want := new(bytes.Buffer)
if err := gob.NewEncoder(want).Encode(mnt); err != nil {
t.Fatalf("cannot serialise expected mount points: %v", err)
}
container.Stdin = want
if err := container.Start(); err != nil {
hlog.PrintBaseError(err, "start:")
t.Fatalf("cannot start container: %v", err)
} else if err = container.Serve(); err != nil {
hlog.PrintBaseError(err, "serve:")
t.Errorf("cannot serve setup params: %v", err)
}
if err := container.Wait(); err != nil {
hlog.PrintBaseError(err, "wait:")
t.Fatalf("wait: %v", err)
}
})
}
}
func e(root, target, vfsOptstr, fsType, source, fsOptstr string) *vfs.MountInfoEntry {
return &vfs.MountInfoEntry{
ID: ignoreV,
Parent: ignoreV,
Devno: vfs.DevT{ignoreV, ignoreV},
Root: root,
Target: target,
VfsOptstr: vfsOptstr,
OptFields: []string{ignore},
FsType: fsType,
Source: source,
FsOptstr: fsOptstr,
}
}
func TestContainerString(t *testing.T) {
container := sandbox.New(t.Context(), "ldd", "/usr/bin/env")
container.Flags |= sandbox.FAllowDevel
container.Seccomp |= seccomp.FilterMultiarch
want := `argv: ["ldd" "/usr/bin/env"], flags: 0x2, seccomp: 0x2e`
if got := container.String(); got != want {
t.Errorf("String: %s, want %s", got, want)
}
}
func TestHelperInit(t *testing.T) {
if len(os.Args) != 5 || os.Args[4] != "init" {
return
}
sandbox.SetOutput(hlog.Output{})
sandbox.Init(hlog.Prepare, internal.InstallFmsg)
}
func TestHelperCheckContainer(t *testing.T) {
if len(os.Args) != 6 || os.Args[4] != "check" {
return
}
t.Run("user", func(t *testing.T) {
if uid := syscall.Getuid(); uid != 1000 {
t.Errorf("Getuid: %d, want 1000", uid)
}
if gid := syscall.Getgid(); gid != 100 {
t.Errorf("Getgid: %d, want 100", gid)
}
})
t.Run("hostname", func(t *testing.T) {
if name, err := os.Hostname(); err != nil {
t.Fatalf("cannot get hostname: %v", err)
} else if name != os.Args[5] {
t.Errorf("Hostname: %q, want %q", name, os.Args[5])
}
if p, err := os.ReadFile("/etc/hostname"); err != nil {
t.Fatalf("%v", err)
} else if string(p) != os.Args[5] {
t.Errorf("/etc/hostname: %q, want %q", string(p), os.Args[5])
}
})
t.Run("mount", func(t *testing.T) {
var mnt []*vfs.MountInfoEntry
if err := gob.NewDecoder(os.Stdin).Decode(&mnt); err != nil {
t.Fatalf("cannot receive expected mount points: %v", err)
}
var d *vfs.MountInfoDecoder
if f, err := os.Open("/proc/self/mountinfo"); err != nil {
t.Fatalf("cannot open mountinfo: %v", err)
} else {
d = vfs.NewMountInfoDecoder(f)
}
i := 0
for cur := range d.Entries() {
if i == len(mnt) {
t.Errorf("got more than %d entries", len(mnt))
break
}
// ugly hack but should be reliable and is less likely to false negative than comparing by parsed flags
cur.VfsOptstr = strings.TrimSuffix(cur.VfsOptstr, ",relatime")
cur.VfsOptstr = strings.TrimSuffix(cur.VfsOptstr, ",noatime")
mnt[i].VfsOptstr = strings.TrimSuffix(mnt[i].VfsOptstr, ",relatime")
mnt[i].VfsOptstr = strings.TrimSuffix(mnt[i].VfsOptstr, ",noatime")
if !cur.EqualWithIgnore(mnt[i], "\x00") {
t.Errorf("[FAIL] %s", cur)
} else {
t.Logf("[ OK ] %s", cur)
}
i++
}
if err := d.Err(); err != nil {
t.Errorf("cannot parse mountinfo: %v", err)
}
if i != len(mnt) {
t.Errorf("got %d entries, want %d", i, len(mnt))
}
})
}
func commandContext(ctx context.Context) *exec.Cmd {
return exec.CommandContext(ctx, os.Args[0], "-test.v",
"-test.run=TestHelperInit", "--", "init")
}
|
