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