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