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1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */2/*3 * Landlock - User space API4 *5 * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net>6 * Copyright © 2018-2020 ANSSI7 */8 9#ifndef _UAPI_LINUX_LANDLOCK_H10#define _UAPI_LINUX_LANDLOCK_H11 12#include <linux/types.h>13 14/**15 * struct landlock_ruleset_attr - Ruleset definition.16 *17 * Argument of sys_landlock_create_ruleset().18 *19 * This structure defines a set of *handled access rights*, a set of actions on20 * different object types, which should be denied by default when the ruleset is21 * enacted. Vice versa, access rights that are not specifically listed here are22 * not going to be denied by this ruleset when it is enacted.23 *24 * For historical reasons, the %LANDLOCK_ACCESS_FS_REFER right is always denied25 * by default, even when its bit is not set in @handled_access_fs. In order to26 * add new rules with this access right, the bit must still be set explicitly27 * (cf. `Filesystem flags`_).28 *29 * The explicit listing of *handled access rights* is required for backwards30 * compatibility reasons. In most use cases, processes that use Landlock will31 * *handle* a wide range or all access rights that they know about at build time32 * (and that they have tested with a kernel that supported them all).33 *34 * This structure can grow in future Landlock versions.35 */36struct landlock_ruleset_attr {37 /**38 * @handled_access_fs: Bitmask of handled filesystem actions39 * (cf. `Filesystem flags`_).40 */41 __u64 handled_access_fs;42 /**43 * @handled_access_net: Bitmask of handled network actions (cf. `Network44 * flags`_).45 */46 __u64 handled_access_net;47 /**48 * @scoped: Bitmask of scopes (cf. `Scope flags`_)49 * restricting a Landlock domain from accessing outside50 * resources (e.g. IPCs).51 */52 __u64 scoped;53};54 55/*56 * sys_landlock_create_ruleset() flags:57 *58 * - %LANDLOCK_CREATE_RULESET_VERSION: Get the highest supported Landlock ABI59 * version.60 */61/* clang-format off */62#define LANDLOCK_CREATE_RULESET_VERSION (1U << 0)63/* clang-format on */64 65/**66 * enum landlock_rule_type - Landlock rule type67 *68 * Argument of sys_landlock_add_rule().69 */70enum landlock_rule_type {71 /**72 * @LANDLOCK_RULE_PATH_BENEATH: Type of a &struct73 * landlock_path_beneath_attr .74 */75 LANDLOCK_RULE_PATH_BENEATH = 1,76 /**77 * @LANDLOCK_RULE_NET_PORT: Type of a &struct78 * landlock_net_port_attr .79 */80 LANDLOCK_RULE_NET_PORT,81};82 83/**84 * struct landlock_path_beneath_attr - Path hierarchy definition85 *86 * Argument of sys_landlock_add_rule().87 */88struct landlock_path_beneath_attr {89 /**90 * @allowed_access: Bitmask of allowed actions for this file hierarchy91 * (cf. `Filesystem flags`_).92 */93 __u64 allowed_access;94 /**95 * @parent_fd: File descriptor, preferably opened with ``O_PATH``,96 * which identifies the parent directory of a file hierarchy, or just a97 * file.98 */99 __s32 parent_fd;100 /*101 * This struct is packed to avoid trailing reserved members.102 * Cf. security/landlock/syscalls.c:build_check_abi()103 */104} __attribute__((packed));105 106/**107 * struct landlock_net_port_attr - Network port definition108 *109 * Argument of sys_landlock_add_rule().110 */111struct landlock_net_port_attr {112 /**113 * @allowed_access: Bitmask of allowed network actions for a port114 * (cf. `Network flags`_).115 */116 __u64 allowed_access;117 /**118 * @port: Network port in host endianness.119 *120 * It should be noted that port 0 passed to :manpage:`bind(2)` will bind121 * to an available port from the ephemeral port range. This can be122 * configured with the ``/proc/sys/net/ipv4/ip_local_port_range`` sysctl123 * (also used for IPv6).124 *125 * A Landlock rule with port 0 and the ``LANDLOCK_ACCESS_NET_BIND_TCP``126 * right means that requesting to bind on port 0 is allowed and it will127 * automatically translate to binding on the related port range.128 */129 __u64 port;130};131 132/**133 * DOC: fs_access134 *135 * A set of actions on kernel objects may be defined by an attribute (e.g.136 * &struct landlock_path_beneath_attr) including a bitmask of access.137 *138 * Filesystem flags139 * ~~~~~~~~~~~~~~~~140 *141 * These flags enable to restrict a sandboxed process to a set of actions on142 * files and directories. Files or directories opened before the sandboxing143 * are not subject to these restrictions.144 *145 * The following access rights apply only to files:146 *147 * - %LANDLOCK_ACCESS_FS_EXECUTE: Execute a file.148 * - %LANDLOCK_ACCESS_FS_WRITE_FILE: Open a file with write access. When149 * opening files for writing, you will often additionally need the150 * %LANDLOCK_ACCESS_FS_TRUNCATE right. In many cases, these system calls151 * truncate existing files when overwriting them (e.g., :manpage:`creat(2)`).152 * - %LANDLOCK_ACCESS_FS_READ_FILE: Open a file with read access.153 * - %LANDLOCK_ACCESS_FS_TRUNCATE: Truncate a file with :manpage:`truncate(2)`,154 * :manpage:`ftruncate(2)`, :manpage:`creat(2)`, or :manpage:`open(2)` with155 * ``O_TRUNC``. This access right is available since the third version of the156 * Landlock ABI.157 *158 * Whether an opened file can be truncated with :manpage:`ftruncate(2)` or used159 * with `ioctl(2)` is determined during :manpage:`open(2)`, in the same way as160 * read and write permissions are checked during :manpage:`open(2)` using161 * %LANDLOCK_ACCESS_FS_READ_FILE and %LANDLOCK_ACCESS_FS_WRITE_FILE.162 *163 * A directory can receive access rights related to files or directories. The164 * following access right is applied to the directory itself, and the165 * directories beneath it:166 *167 * - %LANDLOCK_ACCESS_FS_READ_DIR: Open a directory or list its content.168 *169 * However, the following access rights only apply to the content of a170 * directory, not the directory itself:171 *172 * - %LANDLOCK_ACCESS_FS_REMOVE_DIR: Remove an empty directory or rename one.173 * - %LANDLOCK_ACCESS_FS_REMOVE_FILE: Unlink (or rename) a file.174 * - %LANDLOCK_ACCESS_FS_MAKE_CHAR: Create (or rename or link) a character175 * device.176 * - %LANDLOCK_ACCESS_FS_MAKE_DIR: Create (or rename) a directory.177 * - %LANDLOCK_ACCESS_FS_MAKE_REG: Create (or rename or link) a regular file.178 * - %LANDLOCK_ACCESS_FS_MAKE_SOCK: Create (or rename or link) a UNIX domain179 * socket.180 * - %LANDLOCK_ACCESS_FS_MAKE_FIFO: Create (or rename or link) a named pipe.181 * - %LANDLOCK_ACCESS_FS_MAKE_BLOCK: Create (or rename or link) a block device.182 * - %LANDLOCK_ACCESS_FS_MAKE_SYM: Create (or rename or link) a symbolic link.183 * - %LANDLOCK_ACCESS_FS_REFER: Link or rename a file from or to a different184 * directory (i.e. reparent a file hierarchy).185 *186 * This access right is available since the second version of the Landlock187 * ABI.188 *189 * This is the only access right which is denied by default by any ruleset,190 * even if the right is not specified as handled at ruleset creation time.191 * The only way to make a ruleset grant this right is to explicitly allow it192 * for a specific directory by adding a matching rule to the ruleset.193 *194 * In particular, when using the first Landlock ABI version, Landlock will195 * always deny attempts to reparent files between different directories.196 *197 * In addition to the source and destination directories having the198 * %LANDLOCK_ACCESS_FS_REFER access right, the attempted link or rename199 * operation must meet the following constraints:200 *201 * * The reparented file may not gain more access rights in the destination202 * directory than it previously had in the source directory. If this is203 * attempted, the operation results in an ``EXDEV`` error.204 *205 * * When linking or renaming, the ``LANDLOCK_ACCESS_FS_MAKE_*`` right for the206 * respective file type must be granted for the destination directory.207 * Otherwise, the operation results in an ``EACCES`` error.208 *209 * * When renaming, the ``LANDLOCK_ACCESS_FS_REMOVE_*`` right for the210 * respective file type must be granted for the source directory. Otherwise,211 * the operation results in an ``EACCES`` error.212 *213 * If multiple requirements are not met, the ``EACCES`` error code takes214 * precedence over ``EXDEV``.215 *216 * The following access right applies both to files and directories:217 *218 * - %LANDLOCK_ACCESS_FS_IOCTL_DEV: Invoke :manpage:`ioctl(2)` commands on an opened219 * character or block device.220 *221 * This access right applies to all `ioctl(2)` commands implemented by device222 * drivers. However, the following common IOCTL commands continue to be223 * invokable independent of the %LANDLOCK_ACCESS_FS_IOCTL_DEV right:224 *225 * * IOCTL commands targeting file descriptors (``FIOCLEX``, ``FIONCLEX``),226 * * IOCTL commands targeting file descriptions (``FIONBIO``, ``FIOASYNC``),227 * * IOCTL commands targeting file systems (``FIFREEZE``, ``FITHAW``,228 * ``FIGETBSZ``, ``FS_IOC_GETFSUUID``, ``FS_IOC_GETFSSYSFSPATH``)229 * * Some IOCTL commands which do not make sense when used with devices, but230 * whose implementations are safe and return the right error codes231 * (``FS_IOC_FIEMAP``, ``FICLONE``, ``FICLONERANGE``, ``FIDEDUPERANGE``)232 *233 * This access right is available since the fifth version of the Landlock234 * ABI.235 *236 * .. warning::237 *238 * It is currently not possible to restrict some file-related actions239 * accessible through these syscall families: :manpage:`chdir(2)`,240 * :manpage:`stat(2)`, :manpage:`flock(2)`, :manpage:`chmod(2)`,241 * :manpage:`chown(2)`, :manpage:`setxattr(2)`, :manpage:`utime(2)`,242 * :manpage:`fcntl(2)`, :manpage:`access(2)`.243 * Future Landlock evolutions will enable to restrict them.244 */245/* clang-format off */246#define LANDLOCK_ACCESS_FS_EXECUTE (1ULL << 0)247#define LANDLOCK_ACCESS_FS_WRITE_FILE (1ULL << 1)248#define LANDLOCK_ACCESS_FS_READ_FILE (1ULL << 2)249#define LANDLOCK_ACCESS_FS_READ_DIR (1ULL << 3)250#define LANDLOCK_ACCESS_FS_REMOVE_DIR (1ULL << 4)251#define LANDLOCK_ACCESS_FS_REMOVE_FILE (1ULL << 5)252#define LANDLOCK_ACCESS_FS_MAKE_CHAR (1ULL << 6)253#define LANDLOCK_ACCESS_FS_MAKE_DIR (1ULL << 7)254#define LANDLOCK_ACCESS_FS_MAKE_REG (1ULL << 8)255#define LANDLOCK_ACCESS_FS_MAKE_SOCK (1ULL << 9)256#define LANDLOCK_ACCESS_FS_MAKE_FIFO (1ULL << 10)257#define LANDLOCK_ACCESS_FS_MAKE_BLOCK (1ULL << 11)258#define LANDLOCK_ACCESS_FS_MAKE_SYM (1ULL << 12)259#define LANDLOCK_ACCESS_FS_REFER (1ULL << 13)260#define LANDLOCK_ACCESS_FS_TRUNCATE (1ULL << 14)261#define LANDLOCK_ACCESS_FS_IOCTL_DEV (1ULL << 15)262/* clang-format on */263 264/**265 * DOC: net_access266 *267 * Network flags268 * ~~~~~~~~~~~~~~~~269 *270 * These flags enable to restrict a sandboxed process to a set of network271 * actions. This is supported since the Landlock ABI version 4.272 *273 * The following access rights apply to TCP port numbers:274 *275 * - %LANDLOCK_ACCESS_NET_BIND_TCP: Bind a TCP socket to a local port.276 * - %LANDLOCK_ACCESS_NET_CONNECT_TCP: Connect an active TCP socket to277 * a remote port.278 */279/* clang-format off */280#define LANDLOCK_ACCESS_NET_BIND_TCP (1ULL << 0)281#define LANDLOCK_ACCESS_NET_CONNECT_TCP (1ULL << 1)282/* clang-format on */283 284/**285 * DOC: scope286 *287 * Scope flags288 * ~~~~~~~~~~~289 *290 * These flags enable to isolate a sandboxed process from a set of IPC actions.291 * Setting a flag for a ruleset will isolate the Landlock domain to forbid292 * connections to resources outside the domain.293 *294 * Scopes:295 *296 * - %LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET: Restrict a sandboxed process from297 * connecting to an abstract UNIX socket created by a process outside the298 * related Landlock domain (e.g. a parent domain or a non-sandboxed process).299 * - %LANDLOCK_SCOPE_SIGNAL: Restrict a sandboxed process from sending a signal300 * to another process outside the domain.301 */302/* clang-format off */303#define LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET (1ULL << 0)304#define LANDLOCK_SCOPE_SIGNAL (1ULL << 1)305/* clang-format on*/306 307#endif /* _UAPI_LINUX_LANDLOCK_H */308