aboutsummaryrefslogtreecommitdiffhomepage
path: root/container/landlock.go
blob: 7f0a821f3a26f2d135f982c0c674f0233cb25cff (plain)
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
package container

import (
	"strings"
	"syscall"
	"unsafe"

	"hakurei.app/container/std"
)

// include/uapi/linux/landlock.h

const (
	LANDLOCK_CREATE_RULESET_VERSION = 1 << iota
)

// LandlockAccessFS is bitmask of handled filesystem actions.
type LandlockAccessFS uint64

const (
	LANDLOCK_ACCESS_FS_EXECUTE LandlockAccessFS = 1 << iota
	LANDLOCK_ACCESS_FS_WRITE_FILE
	LANDLOCK_ACCESS_FS_READ_FILE
	LANDLOCK_ACCESS_FS_READ_DIR
	LANDLOCK_ACCESS_FS_REMOVE_DIR
	LANDLOCK_ACCESS_FS_REMOVE_FILE
	LANDLOCK_ACCESS_FS_MAKE_CHAR
	LANDLOCK_ACCESS_FS_MAKE_DIR
	LANDLOCK_ACCESS_FS_MAKE_REG
	LANDLOCK_ACCESS_FS_MAKE_SOCK
	LANDLOCK_ACCESS_FS_MAKE_FIFO
	LANDLOCK_ACCESS_FS_MAKE_BLOCK
	LANDLOCK_ACCESS_FS_MAKE_SYM
	LANDLOCK_ACCESS_FS_REFER
	LANDLOCK_ACCESS_FS_TRUNCATE
	LANDLOCK_ACCESS_FS_IOCTL_DEV

	_LANDLOCK_ACCESS_FS_DELIM
)

func (f LandlockAccessFS) String() string {
	switch f {
	case LANDLOCK_ACCESS_FS_EXECUTE:
		return "execute"

	case LANDLOCK_ACCESS_FS_WRITE_FILE:
		return "write_file"

	case LANDLOCK_ACCESS_FS_READ_FILE:
		return "read_file"

	case LANDLOCK_ACCESS_FS_READ_DIR:
		return "read_dir"

	case LANDLOCK_ACCESS_FS_REMOVE_DIR:
		return "remove_dir"

	case LANDLOCK_ACCESS_FS_REMOVE_FILE:
		return "remove_file"

	case LANDLOCK_ACCESS_FS_MAKE_CHAR:
		return "make_char"

	case LANDLOCK_ACCESS_FS_MAKE_DIR:
		return "make_dir"

	case LANDLOCK_ACCESS_FS_MAKE_REG:
		return "make_reg"

	case LANDLOCK_ACCESS_FS_MAKE_SOCK:
		return "make_sock"

	case LANDLOCK_ACCESS_FS_MAKE_FIFO:
		return "make_fifo"

	case LANDLOCK_ACCESS_FS_MAKE_BLOCK:
		return "make_block"

	case LANDLOCK_ACCESS_FS_MAKE_SYM:
		return "make_sym"

	case LANDLOCK_ACCESS_FS_REFER:
		return "fs_refer"

	case LANDLOCK_ACCESS_FS_TRUNCATE:
		return "fs_truncate"

	case LANDLOCK_ACCESS_FS_IOCTL_DEV:
		return "fs_ioctl_dev"

	default:
		var c []LandlockAccessFS
		for i := LandlockAccessFS(1); i < _LANDLOCK_ACCESS_FS_DELIM; i <<= 1 {
			if f&i != 0 {
				c = append(c, i)
			}
		}
		if len(c) == 0 {
			return "NULL"
		}
		s := make([]string, len(c))
		for i, v := range c {
			s[i] = v.String()
		}
		return strings.Join(s, " ")
	}
}

// LandlockAccessNet is bitmask of handled network actions.
type LandlockAccessNet uint64

const (
	LANDLOCK_ACCESS_NET_BIND_TCP LandlockAccessNet = 1 << iota
	LANDLOCK_ACCESS_NET_CONNECT_TCP

	_LANDLOCK_ACCESS_NET_DELIM
)

func (f LandlockAccessNet) String() string {
	switch f {
	case LANDLOCK_ACCESS_NET_BIND_TCP:
		return "bind_tcp"

	case LANDLOCK_ACCESS_NET_CONNECT_TCP:
		return "connect_tcp"

	default:
		var c []LandlockAccessNet
		for i := LandlockAccessNet(1); i < _LANDLOCK_ACCESS_NET_DELIM; i <<= 1 {
			if f&i != 0 {
				c = append(c, i)
			}
		}
		if len(c) == 0 {
			return "NULL"
		}
		s := make([]string, len(c))
		for i, v := range c {
			s[i] = v.String()
		}
		return strings.Join(s, " ")
	}
}

// LandlockScope is bitmask of scopes restricting a Landlock domain from accessing outside resources.
type LandlockScope uint64

const (
	LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET LandlockScope = 1 << iota
	LANDLOCK_SCOPE_SIGNAL

	_LANDLOCK_SCOPE_DELIM
)

func (f LandlockScope) String() string {
	switch f {
	case LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET:
		return "abstract_unix_socket"

	case LANDLOCK_SCOPE_SIGNAL:
		return "signal"

	default:
		var c []LandlockScope
		for i := LandlockScope(1); i < _LANDLOCK_SCOPE_DELIM; i <<= 1 {
			if f&i != 0 {
				c = append(c, i)
			}
		}
		if len(c) == 0 {
			return "NULL"
		}
		s := make([]string, len(c))
		for i, v := range c {
			s[i] = v.String()
		}
		return strings.Join(s, " ")
	}
}

// RulesetAttr is equivalent to struct landlock_ruleset_attr.
type RulesetAttr struct {
	// Bitmask of handled filesystem actions.
	HandledAccessFS LandlockAccessFS
	// Bitmask of handled network actions.
	HandledAccessNet LandlockAccessNet
	// Bitmask of scopes restricting a Landlock domain from accessing outside resources (e.g. IPCs).
	Scoped LandlockScope
}

func (rulesetAttr *RulesetAttr) String() string {
	if rulesetAttr == nil {
		return "NULL"
	}
	elems := make([]string, 0, 3)
	if rulesetAttr.HandledAccessFS > 0 {
		elems = append(elems, "fs: "+rulesetAttr.HandledAccessFS.String())
	}
	if rulesetAttr.HandledAccessNet > 0 {
		elems = append(elems, "net: "+rulesetAttr.HandledAccessNet.String())
	}
	if rulesetAttr.Scoped > 0 {
		elems = append(elems, "scoped: "+rulesetAttr.Scoped.String())
	}
	if len(elems) == 0 {
		return "0"
	}
	return strings.Join(elems, ", ")
}

func (rulesetAttr *RulesetAttr) Create(flags uintptr) (fd int, err error) {
	var pointer, size uintptr
	// NULL needed for abi version
	if rulesetAttr != nil {
		pointer = uintptr(unsafe.Pointer(rulesetAttr))
		size = unsafe.Sizeof(*rulesetAttr)
	}

	rulesetFd, _, errno := syscall.Syscall(std.SYS_LANDLOCK_CREATE_RULESET, pointer, size, flags)
	fd = int(rulesetFd)
	err = errno

	if fd < 0 {
		return
	}

	if rulesetAttr != nil { // not a fd otherwise
		syscall.CloseOnExec(fd)
	}
	return fd, nil
}

func LandlockGetABI() (int, error) {
	return (*RulesetAttr)(nil).Create(LANDLOCK_CREATE_RULESET_VERSION)
}

func LandlockRestrictSelf(rulesetFd int, flags uintptr) error {
	r, _, errno := syscall.Syscall(std.SYS_LANDLOCK_RESTRICT_SELF, uintptr(rulesetFd), flags, 0)
	if r != 0 {
		return errno
	}
	return nil
}