1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux 1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 /* 2 /*
3 * Landlock - User space API 3 * Landlock - User space API
4 * 4 *
5 * Copyright © 2017-2020 Mickaël Salaün <mi 5 * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net>
6 * Copyright © 2018-2020 ANSSI 6 * Copyright © 2018-2020 ANSSI
7 */ 7 */
8 8
9 #ifndef _UAPI_LINUX_LANDLOCK_H 9 #ifndef _UAPI_LINUX_LANDLOCK_H
10 #define _UAPI_LINUX_LANDLOCK_H 10 #define _UAPI_LINUX_LANDLOCK_H
11 11
12 #include <linux/types.h> 12 #include <linux/types.h>
13 13
14 /** 14 /**
15 * struct landlock_ruleset_attr - Ruleset defi !! 15 * struct landlock_ruleset_attr - Ruleset definition
16 * 16 *
17 * Argument of sys_landlock_create_ruleset(). !! 17 * Argument of sys_landlock_create_ruleset(). This structure can grow in
18 * !! 18 * future versions.
19 * This structure defines a set of *handled ac <<
20 * different object types, which should be den <<
21 * enacted. Vice versa, access rights that ar <<
22 * not going to be denied by this ruleset when <<
23 * <<
24 * For historical reasons, the %LANDLOCK_ACCES <<
25 * by default, even when its bit is not set in <<
26 * add new rules with this access right, the b <<
27 * (cf. `Filesystem flags`_). <<
28 * <<
29 * The explicit listing of *handled access rig <<
30 * compatibility reasons. In most use cases, <<
31 * *handle* a wide range or all access rights <<
32 * (and that they have tested with a kernel th <<
33 * <<
34 * This structure can grow in future Landlock <<
35 */ 19 */
36 struct landlock_ruleset_attr { 20 struct landlock_ruleset_attr {
37 /** 21 /**
38 * @handled_access_fs: Bitmask of hand !! 22 * @handled_access_fs: Bitmask of actions (cf. `Filesystem flags`_)
39 * (cf. `Filesystem flags`_). !! 23 * that is handled by this ruleset and should then be forbidden if no
>> 24 * rule explicitly allow them: it is a deny-by-default list that should
>> 25 * contain as much Landlock access rights as possible. Indeed, all
>> 26 * Landlock filesystem access rights that are not part of
>> 27 * handled_access_fs are allowed. This is needed for backward
>> 28 * compatibility reasons. One exception is the
>> 29 * %LANDLOCK_ACCESS_FS_REFER access right, which is always implicitly
>> 30 * handled, but must still be explicitly handled to add new rules with
>> 31 * this access right.
40 */ 32 */
41 __u64 handled_access_fs; 33 __u64 handled_access_fs;
42 /** 34 /**
43 * @handled_access_net: Bitmask of han !! 35 * @handled_access_net: Bitmask of actions (cf. `Network flags`_)
44 * flags`_). !! 36 * that is handled by this ruleset and should then be forbidden if no
>> 37 * rule explicitly allow them.
45 */ 38 */
46 __u64 handled_access_net; 39 __u64 handled_access_net;
47 /** <<
48 * @scoped: Bitmask of scopes (cf. `Sc <<
49 * restricting a Landlock domain from <<
50 * resources (e.g. IPCs). <<
51 */ <<
52 __u64 scoped; <<
53 }; 40 };
54 41
55 /* 42 /*
56 * sys_landlock_create_ruleset() flags: 43 * sys_landlock_create_ruleset() flags:
57 * 44 *
58 * - %LANDLOCK_CREATE_RULESET_VERSION: Get the 45 * - %LANDLOCK_CREATE_RULESET_VERSION: Get the highest supported Landlock ABI
59 * version. 46 * version.
60 */ 47 */
61 /* clang-format off */ 48 /* clang-format off */
62 #define LANDLOCK_CREATE_RULESET_VERSION 49 #define LANDLOCK_CREATE_RULESET_VERSION (1U << 0)
63 /* clang-format on */ 50 /* clang-format on */
64 51
65 /** 52 /**
66 * enum landlock_rule_type - Landlock rule typ 53 * enum landlock_rule_type - Landlock rule type
67 * 54 *
68 * Argument of sys_landlock_add_rule(). 55 * Argument of sys_landlock_add_rule().
69 */ 56 */
70 enum landlock_rule_type { 57 enum landlock_rule_type {
71 /** 58 /**
72 * @LANDLOCK_RULE_PATH_BENEATH: Type o 59 * @LANDLOCK_RULE_PATH_BENEATH: Type of a &struct
73 * landlock_path_beneath_attr . 60 * landlock_path_beneath_attr .
74 */ 61 */
75 LANDLOCK_RULE_PATH_BENEATH = 1, 62 LANDLOCK_RULE_PATH_BENEATH = 1,
76 /** 63 /**
77 * @LANDLOCK_RULE_NET_PORT: Type of a 64 * @LANDLOCK_RULE_NET_PORT: Type of a &struct
78 * landlock_net_port_attr . 65 * landlock_net_port_attr .
79 */ 66 */
80 LANDLOCK_RULE_NET_PORT, 67 LANDLOCK_RULE_NET_PORT,
81 }; 68 };
82 69
83 /** 70 /**
84 * struct landlock_path_beneath_attr - Path hi 71 * struct landlock_path_beneath_attr - Path hierarchy definition
85 * 72 *
86 * Argument of sys_landlock_add_rule(). 73 * Argument of sys_landlock_add_rule().
87 */ 74 */
88 struct landlock_path_beneath_attr { 75 struct landlock_path_beneath_attr {
89 /** 76 /**
90 * @allowed_access: Bitmask of allowed 77 * @allowed_access: Bitmask of allowed actions for this file hierarchy
91 * (cf. `Filesystem flags`_). 78 * (cf. `Filesystem flags`_).
92 */ 79 */
93 __u64 allowed_access; 80 __u64 allowed_access;
94 /** 81 /**
95 * @parent_fd: File descriptor, prefer 82 * @parent_fd: File descriptor, preferably opened with ``O_PATH``,
96 * which identifies the parent directo 83 * which identifies the parent directory of a file hierarchy, or just a
97 * file. 84 * file.
98 */ 85 */
99 __s32 parent_fd; 86 __s32 parent_fd;
100 /* 87 /*
101 * This struct is packed to avoid trai 88 * This struct is packed to avoid trailing reserved members.
102 * Cf. security/landlock/syscalls.c:bu 89 * Cf. security/landlock/syscalls.c:build_check_abi()
103 */ 90 */
104 } __attribute__((packed)); 91 } __attribute__((packed));
105 92
106 /** 93 /**
107 * struct landlock_net_port_attr - Network por 94 * struct landlock_net_port_attr - Network port definition
108 * 95 *
109 * Argument of sys_landlock_add_rule(). 96 * Argument of sys_landlock_add_rule().
110 */ 97 */
111 struct landlock_net_port_attr { 98 struct landlock_net_port_attr {
112 /** 99 /**
113 * @allowed_access: Bitmask of allowed !! 100 * @allowed_access: Bitmask of allowed access network for a port
114 * (cf. `Network flags`_). 101 * (cf. `Network flags`_).
115 */ 102 */
116 __u64 allowed_access; 103 __u64 allowed_access;
117 /** 104 /**
118 * @port: Network port in host endiann 105 * @port: Network port in host endianness.
119 * 106 *
120 * It should be noted that port 0 pass !! 107 * It should be noted that port 0 passed to :manpage:`bind(2)` will
121 * to an available port from the ephem !! 108 * bind to an available port from a specific port range. This can be
122 * configured with the ``/proc/sys/net !! 109 * configured thanks to the ``/proc/sys/net/ipv4/ip_local_port_range``
123 * (also used for IPv6). !! 110 * sysctl (also used for IPv6). A Landlock rule with port 0 and the
124 * !! 111 * ``LANDLOCK_ACCESS_NET_BIND_TCP`` right means that requesting to bind
125 * A Landlock rule with port 0 and the !! 112 * on port 0 is allowed and it will automatically translate to binding
126 * right means that requesting to bind !! 113 * on the related port range.
127 * automatically translate to binding <<
128 */ 114 */
129 __u64 port; 115 __u64 port;
130 }; 116 };
131 117
132 /** 118 /**
133 * DOC: fs_access 119 * DOC: fs_access
134 * 120 *
135 * A set of actions on kernel objects may be d 121 * A set of actions on kernel objects may be defined by an attribute (e.g.
136 * &struct landlock_path_beneath_attr) includi 122 * &struct landlock_path_beneath_attr) including a bitmask of access.
137 * 123 *
138 * Filesystem flags 124 * Filesystem flags
139 * ~~~~~~~~~~~~~~~~ 125 * ~~~~~~~~~~~~~~~~
140 * 126 *
141 * These flags enable to restrict a sandboxed 127 * These flags enable to restrict a sandboxed process to a set of actions on
142 * files and directories. Files or directorie 128 * files and directories. Files or directories opened before the sandboxing
143 * are not subject to these restrictions. 129 * are not subject to these restrictions.
144 * 130 *
145 * The following access rights apply only to f 131 * The following access rights apply only to files:
146 * 132 *
147 * - %LANDLOCK_ACCESS_FS_EXECUTE: Execute a fi 133 * - %LANDLOCK_ACCESS_FS_EXECUTE: Execute a file.
148 * - %LANDLOCK_ACCESS_FS_WRITE_FILE: Open a fi !! 134 * - %LANDLOCK_ACCESS_FS_WRITE_FILE: Open a file with write access. Note that
149 * opening files for writing, you will often !! 135 * you might additionally need the %LANDLOCK_ACCESS_FS_TRUNCATE right in order
150 * %LANDLOCK_ACCESS_FS_TRUNCATE right. In m !! 136 * to overwrite files with :manpage:`open(2)` using ``O_TRUNC`` or
151 * truncate existing files when overwriting !! 137 * :manpage:`creat(2)`.
152 * - %LANDLOCK_ACCESS_FS_READ_FILE: Open a fil 138 * - %LANDLOCK_ACCESS_FS_READ_FILE: Open a file with read access.
153 * - %LANDLOCK_ACCESS_FS_TRUNCATE: Truncate a 139 * - %LANDLOCK_ACCESS_FS_TRUNCATE: Truncate a file with :manpage:`truncate(2)`,
154 * :manpage:`ftruncate(2)`, :manpage:`creat( 140 * :manpage:`ftruncate(2)`, :manpage:`creat(2)`, or :manpage:`open(2)` with
155 * ``O_TRUNC``. This access right is availa 141 * ``O_TRUNC``. This access right is available since the third version of the
156 * Landlock ABI. 142 * Landlock ABI.
157 * 143 *
158 * Whether an opened file can be truncated wit 144 * Whether an opened file can be truncated with :manpage:`ftruncate(2)` or used
159 * with `ioctl(2)` is determined during :manpa 145 * with `ioctl(2)` is determined during :manpage:`open(2)`, in the same way as
160 * read and write permissions are checked duri 146 * read and write permissions are checked during :manpage:`open(2)` using
161 * %LANDLOCK_ACCESS_FS_READ_FILE and %LANDLOCK 147 * %LANDLOCK_ACCESS_FS_READ_FILE and %LANDLOCK_ACCESS_FS_WRITE_FILE.
162 * 148 *
163 * A directory can receive access rights relat 149 * A directory can receive access rights related to files or directories. The
164 * following access right is applied to the di 150 * following access right is applied to the directory itself, and the
165 * directories beneath it: 151 * directories beneath it:
166 * 152 *
167 * - %LANDLOCK_ACCESS_FS_READ_DIR: Open a dire 153 * - %LANDLOCK_ACCESS_FS_READ_DIR: Open a directory or list its content.
168 * 154 *
169 * However, the following access rights only a 155 * However, the following access rights only apply to the content of a
170 * directory, not the directory itself: 156 * directory, not the directory itself:
171 * 157 *
172 * - %LANDLOCK_ACCESS_FS_REMOVE_DIR: Remove an 158 * - %LANDLOCK_ACCESS_FS_REMOVE_DIR: Remove an empty directory or rename one.
173 * - %LANDLOCK_ACCESS_FS_REMOVE_FILE: Unlink ( 159 * - %LANDLOCK_ACCESS_FS_REMOVE_FILE: Unlink (or rename) a file.
174 * - %LANDLOCK_ACCESS_FS_MAKE_CHAR: Create (or 160 * - %LANDLOCK_ACCESS_FS_MAKE_CHAR: Create (or rename or link) a character
175 * device. 161 * device.
176 * - %LANDLOCK_ACCESS_FS_MAKE_DIR: Create (or 162 * - %LANDLOCK_ACCESS_FS_MAKE_DIR: Create (or rename) a directory.
177 * - %LANDLOCK_ACCESS_FS_MAKE_REG: Create (or 163 * - %LANDLOCK_ACCESS_FS_MAKE_REG: Create (or rename or link) a regular file.
178 * - %LANDLOCK_ACCESS_FS_MAKE_SOCK: Create (or 164 * - %LANDLOCK_ACCESS_FS_MAKE_SOCK: Create (or rename or link) a UNIX domain
179 * socket. 165 * socket.
180 * - %LANDLOCK_ACCESS_FS_MAKE_FIFO: Create (or 166 * - %LANDLOCK_ACCESS_FS_MAKE_FIFO: Create (or rename or link) a named pipe.
181 * - %LANDLOCK_ACCESS_FS_MAKE_BLOCK: Create (o 167 * - %LANDLOCK_ACCESS_FS_MAKE_BLOCK: Create (or rename or link) a block device.
182 * - %LANDLOCK_ACCESS_FS_MAKE_SYM: Create (or 168 * - %LANDLOCK_ACCESS_FS_MAKE_SYM: Create (or rename or link) a symbolic link.
183 * - %LANDLOCK_ACCESS_FS_REFER: Link or rename 169 * - %LANDLOCK_ACCESS_FS_REFER: Link or rename a file from or to a different
184 * directory (i.e. reparent a file hierarchy 170 * directory (i.e. reparent a file hierarchy).
185 * 171 *
186 * This access right is available since the 172 * This access right is available since the second version of the Landlock
187 * ABI. 173 * ABI.
188 * 174 *
189 * This is the only access right which is de 175 * This is the only access right which is denied by default by any ruleset,
190 * even if the right is not specified as han 176 * even if the right is not specified as handled at ruleset creation time.
191 * The only way to make a ruleset grant this 177 * The only way to make a ruleset grant this right is to explicitly allow it
192 * for a specific directory by adding a matc 178 * for a specific directory by adding a matching rule to the ruleset.
193 * 179 *
194 * In particular, when using the first Landl 180 * In particular, when using the first Landlock ABI version, Landlock will
195 * always deny attempts to reparent files be 181 * always deny attempts to reparent files between different directories.
196 * 182 *
197 * In addition to the source and destination 183 * In addition to the source and destination directories having the
198 * %LANDLOCK_ACCESS_FS_REFER access right, t 184 * %LANDLOCK_ACCESS_FS_REFER access right, the attempted link or rename
199 * operation must meet the following constra 185 * operation must meet the following constraints:
200 * 186 *
201 * * The reparented file may not gain more a 187 * * The reparented file may not gain more access rights in the destination
202 * directory than it previously had in the 188 * directory than it previously had in the source directory. If this is
203 * attempted, the operation results in an 189 * attempted, the operation results in an ``EXDEV`` error.
204 * 190 *
205 * * When linking or renaming, the ``LANDLOC 191 * * When linking or renaming, the ``LANDLOCK_ACCESS_FS_MAKE_*`` right for the
206 * respective file type must be granted fo 192 * respective file type must be granted for the destination directory.
207 * Otherwise, the operation results in an 193 * Otherwise, the operation results in an ``EACCES`` error.
208 * 194 *
209 * * When renaming, the ``LANDLOCK_ACCESS_FS 195 * * When renaming, the ``LANDLOCK_ACCESS_FS_REMOVE_*`` right for the
210 * respective file type must be granted fo 196 * respective file type must be granted for the source directory. Otherwise,
211 * the operation results in an ``EACCES`` 197 * the operation results in an ``EACCES`` error.
212 * 198 *
213 * If multiple requirements are not met, the 199 * If multiple requirements are not met, the ``EACCES`` error code takes
214 * precedence over ``EXDEV``. 200 * precedence over ``EXDEV``.
215 * 201 *
216 * The following access right applies both to 202 * The following access right applies both to files and directories:
217 * 203 *
218 * - %LANDLOCK_ACCESS_FS_IOCTL_DEV: Invoke :ma 204 * - %LANDLOCK_ACCESS_FS_IOCTL_DEV: Invoke :manpage:`ioctl(2)` commands on an opened
219 * character or block device. 205 * character or block device.
220 * 206 *
221 * This access right applies to all `ioctl(2 207 * This access right applies to all `ioctl(2)` commands implemented by device
222 * drivers. However, the following common I 208 * drivers. However, the following common IOCTL commands continue to be
223 * invokable independent of the %LANDLOCK_AC 209 * invokable independent of the %LANDLOCK_ACCESS_FS_IOCTL_DEV right:
224 * 210 *
225 * * IOCTL commands targeting file descripto 211 * * IOCTL commands targeting file descriptors (``FIOCLEX``, ``FIONCLEX``),
226 * * IOCTL commands targeting file descripti 212 * * IOCTL commands targeting file descriptions (``FIONBIO``, ``FIOASYNC``),
227 * * IOCTL commands targeting file systems ( 213 * * IOCTL commands targeting file systems (``FIFREEZE``, ``FITHAW``,
228 * ``FIGETBSZ``, ``FS_IOC_GETFSUUID``, ``F 214 * ``FIGETBSZ``, ``FS_IOC_GETFSUUID``, ``FS_IOC_GETFSSYSFSPATH``)
229 * * Some IOCTL commands which do not make s 215 * * Some IOCTL commands which do not make sense when used with devices, but
230 * whose implementations are safe and retu 216 * whose implementations are safe and return the right error codes
231 * (``FS_IOC_FIEMAP``, ``FICLONE``, ``FICL 217 * (``FS_IOC_FIEMAP``, ``FICLONE``, ``FICLONERANGE``, ``FIDEDUPERANGE``)
232 * 218 *
233 * This access right is available since the 219 * This access right is available since the fifth version of the Landlock
234 * ABI. 220 * ABI.
235 * 221 *
236 * .. warning:: 222 * .. warning::
237 * 223 *
238 * It is currently not possible to restrict 224 * It is currently not possible to restrict some file-related actions
239 * accessible through these syscall families 225 * accessible through these syscall families: :manpage:`chdir(2)`,
240 * :manpage:`stat(2)`, :manpage:`flock(2)`, 226 * :manpage:`stat(2)`, :manpage:`flock(2)`, :manpage:`chmod(2)`,
241 * :manpage:`chown(2)`, :manpage:`setxattr(2 227 * :manpage:`chown(2)`, :manpage:`setxattr(2)`, :manpage:`utime(2)`,
242 * :manpage:`fcntl(2)`, :manpage:`access(2)` 228 * :manpage:`fcntl(2)`, :manpage:`access(2)`.
243 * Future Landlock evolutions will enable to 229 * Future Landlock evolutions will enable to restrict them.
244 */ 230 */
245 /* clang-format off */ 231 /* clang-format off */
246 #define LANDLOCK_ACCESS_FS_EXECUTE 232 #define LANDLOCK_ACCESS_FS_EXECUTE (1ULL << 0)
247 #define LANDLOCK_ACCESS_FS_WRITE_FILE 233 #define LANDLOCK_ACCESS_FS_WRITE_FILE (1ULL << 1)
248 #define LANDLOCK_ACCESS_FS_READ_FILE 234 #define LANDLOCK_ACCESS_FS_READ_FILE (1ULL << 2)
249 #define LANDLOCK_ACCESS_FS_READ_DIR 235 #define LANDLOCK_ACCESS_FS_READ_DIR (1ULL << 3)
250 #define LANDLOCK_ACCESS_FS_REMOVE_DIR 236 #define LANDLOCK_ACCESS_FS_REMOVE_DIR (1ULL << 4)
251 #define LANDLOCK_ACCESS_FS_REMOVE_FILE 237 #define LANDLOCK_ACCESS_FS_REMOVE_FILE (1ULL << 5)
252 #define LANDLOCK_ACCESS_FS_MAKE_CHAR 238 #define LANDLOCK_ACCESS_FS_MAKE_CHAR (1ULL << 6)
253 #define LANDLOCK_ACCESS_FS_MAKE_DIR 239 #define LANDLOCK_ACCESS_FS_MAKE_DIR (1ULL << 7)
254 #define LANDLOCK_ACCESS_FS_MAKE_REG 240 #define LANDLOCK_ACCESS_FS_MAKE_REG (1ULL << 8)
255 #define LANDLOCK_ACCESS_FS_MAKE_SOCK 241 #define LANDLOCK_ACCESS_FS_MAKE_SOCK (1ULL << 9)
256 #define LANDLOCK_ACCESS_FS_MAKE_FIFO 242 #define LANDLOCK_ACCESS_FS_MAKE_FIFO (1ULL << 10)
257 #define LANDLOCK_ACCESS_FS_MAKE_BLOCK 243 #define LANDLOCK_ACCESS_FS_MAKE_BLOCK (1ULL << 11)
258 #define LANDLOCK_ACCESS_FS_MAKE_SYM 244 #define LANDLOCK_ACCESS_FS_MAKE_SYM (1ULL << 12)
259 #define LANDLOCK_ACCESS_FS_REFER 245 #define LANDLOCK_ACCESS_FS_REFER (1ULL << 13)
260 #define LANDLOCK_ACCESS_FS_TRUNCATE 246 #define LANDLOCK_ACCESS_FS_TRUNCATE (1ULL << 14)
261 #define LANDLOCK_ACCESS_FS_IOCTL_DEV 247 #define LANDLOCK_ACCESS_FS_IOCTL_DEV (1ULL << 15)
262 /* clang-format on */ 248 /* clang-format on */
263 249
264 /** 250 /**
265 * DOC: net_access 251 * DOC: net_access
266 * 252 *
267 * Network flags 253 * Network flags
268 * ~~~~~~~~~~~~~~~~ 254 * ~~~~~~~~~~~~~~~~
269 * 255 *
270 * These flags enable to restrict a sandboxed 256 * These flags enable to restrict a sandboxed process to a set of network
271 * actions. This is supported since the Landlo 257 * actions. This is supported since the Landlock ABI version 4.
272 * 258 *
273 * The following access rights apply to TCP po !! 259 * TCP sockets with allowed actions:
274 * 260 *
275 * - %LANDLOCK_ACCESS_NET_BIND_TCP: Bind a TCP 261 * - %LANDLOCK_ACCESS_NET_BIND_TCP: Bind a TCP socket to a local port.
276 * - %LANDLOCK_ACCESS_NET_CONNECT_TCP: Connect 262 * - %LANDLOCK_ACCESS_NET_CONNECT_TCP: Connect an active TCP socket to
277 * a remote port. 263 * a remote port.
278 */ 264 */
279 /* clang-format off */ 265 /* clang-format off */
280 #define LANDLOCK_ACCESS_NET_BIND_TCP 266 #define LANDLOCK_ACCESS_NET_BIND_TCP (1ULL << 0)
281 #define LANDLOCK_ACCESS_NET_CONNECT_TCP 267 #define LANDLOCK_ACCESS_NET_CONNECT_TCP (1ULL << 1)
282 /* clang-format on */ 268 /* clang-format on */
283 <<
284 /** <<
285 * DOC: scope <<
286 * <<
287 * Scope flags <<
288 * ~~~~~~~~~~~ <<
289 * <<
290 * These flags enable to isolate a sandboxed p <<
291 * Setting a flag for a ruleset will isolate t <<
292 * connections to resources outside the domain <<
293 * <<
294 * Scopes: <<
295 * <<
296 * - %LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET: Res <<
297 * connecting to an abstract UNIX socket cre <<
298 * related Landlock domain (e.g. a parent do <<
299 * - %LANDLOCK_SCOPE_SIGNAL: Restrict a sandbo <<
300 * to another process outside the domain. <<
301 */ <<
302 /* clang-format off */ <<
303 #define LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET <<
304 #define LANDLOCK_SCOPE_SIGNAL <<
305 /* clang-format on*/ <<
306 <<
307 #endif /* _UAPI_LINUX_LANDLOCK_H */ 269 #endif /* _UAPI_LINUX_LANDLOCK_H */
308 270
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.