/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ /* * Landlock - User space API * * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net> * Copyright © 2018-2020 ANSSI */ #ifndef _LINUX_LANDLOCK_H #define _LINUX_LANDLOCK_H #include <linux/types.h> /** * struct landlock_ruleset_attr - Ruleset definition * * Argument of sys_landlock_create_ruleset(). This structure can grow in * future versions. */ struct landlock_ruleset_attr { /** * @handled_access_fs: Bitmask of actions (cf. `Filesystem flags`_) * that is handled by this ruleset and should then be forbidden if no * rule explicitly allow them: it is a deny-by-default list that should * contain as much Landlock access rights as possible. Indeed, all * Landlock filesystem access rights that are not part of * handled_access_fs are allowed. This is needed for backward * compatibility reasons. One exception is the * %LANDLOCK_ACCESS_FS_REFER access right, which is always implicitly * handled, but must still be explicitly handled to add new rules with * this access right. */ __u64 handled_access_fs; /** * @handled_access_net: Bitmask of actions (cf. `Network flags`_) * that is handled by this ruleset and should then be forbidden if no * rule explicitly allow them. */ __u64 handled_access_net; }; /* * sys_landlock_create_ruleset() flags: * * - %LANDLOCK_CREATE_RULESET_VERSION: Get the highest supported Landlock ABI * version. */ /* clang-format off */ #define LANDLOCK_CREATE_RULESET_VERSION (1U << 0) /* clang-format on */ /** * enum landlock_rule_type - Landlock rule type * * Argument of sys_landlock_add_rule(). */ enum landlock_rule_type { /** * @LANDLOCK_RULE_PATH_BENEATH: Type of a &struct * landlock_path_beneath_attr . */ LANDLOCK_RULE_PATH_BENEATH = 1, /** * @LANDLOCK_RULE_NET_PORT: Type of a &struct * landlock_net_port_attr . */ LANDLOCK_RULE_NET_PORT, }; /** * struct landlock_path_beneath_attr - Path hierarchy definition * * Argument of sys_landlock_add_rule(). */ struct landlock_path_beneath_attr { /** * @allowed_access: Bitmask of allowed actions for this file hierarchy * (cf. `Filesystem flags`_). */ __u64 allowed_access; /** * @parent_fd: File descriptor, preferably opened with ``O_PATH``, * which identifies the parent directory of a file hierarchy, or just a * file. */ __s32 parent_fd; /* * This struct is packed to avoid trailing reserved members. * Cf. security/landlock/syscalls.c:build_check_abi() */ } __attribute__((packed)); /** * struct landlock_net_port_attr - Network port definition * * Argument of sys_landlock_add_rule(). */ struct landlock_net_port_attr { /** * @allowed_access: Bitmask of allowed access network for a port * (cf. `Network flags`_). */ __u64 allowed_access; /** * @port: Network port in host endianness. * * It should be noted that port 0 passed to :manpage:`bind(2)` will * bind to an available port from a specific port range. This can be * configured thanks to the ``/proc/sys/net/ipv4/ip_local_port_range`` * sysctl (also used for IPv6). A Landlock rule with port 0 and the * ``LANDLOCK_ACCESS_NET_BIND_TCP`` right means that requesting to bind * on port 0 is allowed and it will automatically translate to binding * on the related port range. */ __u64 port; }; /** * DOC: fs_access * * A set of actions on kernel objects may be defined by an attribute (e.g. * &struct landlock_path_beneath_attr) including a bitmask of access. * * Filesystem flags * ~~~~~~~~~~~~~~~~ * * These flags enable to restrict a sandboxed process to a set of actions on * files and directories. Files or directories opened before the sandboxing * are not subject to these restrictions. * * The following access rights apply only to files: * * - %LANDLOCK_ACCESS_FS_EXECUTE: Execute a file. * - %LANDLOCK_ACCESS_FS_WRITE_FILE: Open a file with write access. Note that * you might additionally need the %LANDLOCK_ACCESS_FS_TRUNCATE right in order * to overwrite files with :manpage:`open(2)` using ``O_TRUNC`` or * :manpage:`creat(2)`. * - %LANDLOCK_ACCESS_FS_READ_FILE: Open a file with read access. * - %LANDLOCK_ACCESS_FS_TRUNCATE: Truncate a file with :manpage:`truncate(2)`, * :manpage:`ftruncate(2)`, :manpage:`creat(2)`, or :manpage:`open(2)` with * ``O_TRUNC``. This access right is available since the third version of the * Landlock ABI. * * Whether an opened file can be truncated with :manpage:`ftruncate(2)` or used * with `ioctl(2)` is determined during :manpage:`open(2)`, in the same way as * read and write permissions are checked during :manpage:`open(2)` using * %LANDLOCK_ACCESS_FS_READ_FILE and %LANDLOCK_ACCESS_FS_WRITE_FILE. * * A directory can receive access rights related to files or directories. The * following access right is applied to the directory itself, and the * directories beneath it: * * - %LANDLOCK_ACCESS_FS_READ_DIR: Open a directory or list its content. * * However, the following access rights only apply to the content of a * directory, not the directory itself: * * - %LANDLOCK_ACCESS_FS_REMOVE_DIR: Remove an empty directory or rename one. * - %LANDLOCK_ACCESS_FS_REMOVE_FILE: Unlink (or rename) a file. * - %LANDLOCK_ACCESS_FS_MAKE_CHAR: Create (or rename or link) a character * device. * - %LANDLOCK_ACCESS_FS_MAKE_DIR: Create (or rename) a directory. * - %LANDLOCK_ACCESS_FS_MAKE_REG: Create (or rename or link) a regular file. * - %LANDLOCK_ACCESS_FS_MAKE_SOCK: Create (or rename or link) a UNIX domain * socket. * - %LANDLOCK_ACCESS_FS_MAKE_FIFO: Create (or rename or link) a named pipe. * - %LANDLOCK_ACCESS_FS_MAKE_BLOCK: Create (or rename or link) a block device. * - %LANDLOCK_ACCESS_FS_MAKE_SYM: Create (or rename or link) a symbolic link. * - %LANDLOCK_ACCESS_FS_REFER: Link or rename a file from or to a different * directory (i.e. reparent a file hierarchy). * * This access right is available since the second version of the Landlock * ABI. * * This is the only access right which is denied by default by any ruleset, * even if the right is not specified as handled at ruleset creation time. * The only way to make a ruleset grant this right is to explicitly allow it * for a specific directory by adding a matching rule to the ruleset. * * In particular, when using the first Landlock ABI version, Landlock will * always deny attempts to reparent files between different directories. * * In addition to the source and destination directories having the * %LANDLOCK_ACCESS_FS_REFER access right, the attempted link or rename * operation must meet the following constraints: * * * The reparented file may not gain more access rights in the destination * directory than it previously had in the source directory. If this is * attempted, the operation results in an ``EXDEV`` error. * * * When linking or renaming, the ``LANDLOCK_ACCESS_FS_MAKE_*`` right for the * respective file type must be granted for the destination directory. * Otherwise, the operation results in an ``EACCES`` error. * * * When renaming, the ``LANDLOCK_ACCESS_FS_REMOVE_*`` right for the * respective file type must be granted for the source directory. Otherwise, * the operation results in an ``EACCES`` error. * * If multiple requirements are not met, the ``EACCES`` error code takes * precedence over ``EXDEV``. * * The following access right applies both to files and directories: * * - %LANDLOCK_ACCESS_FS_IOCTL_DEV: Invoke :manpage:`ioctl(2)` commands on an opened * character or block device. * * This access right applies to all `ioctl(2)` commands implemented by device * drivers. However, the following common IOCTL commands continue to be * invokable independent of the %LANDLOCK_ACCESS_FS_IOCTL_DEV right: * * * IOCTL commands targeting file descriptors (``FIOCLEX``, ``FIONCLEX``), * * IOCTL commands targeting file descriptions (``FIONBIO``, ``FIOASYNC``), * * IOCTL commands targeting file systems (``FIFREEZE``, ``FITHAW``, * ``FIGETBSZ``, ``FS_IOC_GETFSUUID``, ``FS_IOC_GETFSSYSFSPATH``) * * Some IOCTL commands which do not make sense when used with devices, but * whose implementations are safe and return the right error codes * (``FS_IOC_FIEMAP``, ``FICLONE``, ``FICLONERANGE``, ``FIDEDUPERANGE``) * * This access right is available since the fifth version of the Landlock * ABI. * * .. warning:: * * It is currently not possible to restrict some file-related actions * accessible through these syscall families: :manpage:`chdir(2)`, * :manpage:`stat(2)`, :manpage:`flock(2)`, :manpage:`chmod(2)`, * :manpage:`chown(2)`, :manpage:`setxattr(2)`, :manpage:`utime(2)`, * :manpage:`fcntl(2)`, :manpage:`access(2)`. * Future Landlock evolutions will enable to restrict them. */ /* clang-format off */ #define LANDLOCK_ACCESS_FS_EXECUTE (1ULL << 0) #define LANDLOCK_ACCESS_FS_WRITE_FILE (1ULL << 1) #define LANDLOCK_ACCESS_FS_READ_FILE (1ULL << 2) #define LANDLOCK_ACCESS_FS_READ_DIR (1ULL << 3) #define LANDLOCK_ACCESS_FS_REMOVE_DIR (1ULL << 4) #define LANDLOCK_ACCESS_FS_REMOVE_FILE (1ULL << 5) #define LANDLOCK_ACCESS_FS_MAKE_CHAR (1ULL << 6) #define LANDLOCK_ACCESS_FS_MAKE_DIR (1ULL << 7) #define LANDLOCK_ACCESS_FS_MAKE_REG (1ULL << 8) #define LANDLOCK_ACCESS_FS_MAKE_SOCK (1ULL << 9) #define LANDLOCK_ACCESS_FS_MAKE_FIFO (1ULL << 10) #define LANDLOCK_ACCESS_FS_MAKE_BLOCK (1ULL << 11) #define LANDLOCK_ACCESS_FS_MAKE_SYM (1ULL << 12) #define LANDLOCK_ACCESS_FS_REFER (1ULL << 13) #define LANDLOCK_ACCESS_FS_TRUNCATE (1ULL << 14) #define LANDLOCK_ACCESS_FS_IOCTL_DEV (1ULL << 15) /* clang-format on */ /** * DOC: net_access * * Network flags * ~~~~~~~~~~~~~~~~ * * These flags enable to restrict a sandboxed process to a set of network * actions. This is supported since the Landlock ABI version 4. * * TCP sockets with allowed actions: * * - %LANDLOCK_ACCESS_NET_BIND_TCP: Bind a TCP socket to a local port. * - %LANDLOCK_ACCESS_NET_CONNECT_TCP: Connect an active TCP socket to * a remote port. */ /* clang-format off */ #define LANDLOCK_ACCESS_NET_BIND_TCP (1ULL << 0) #define LANDLOCK_ACCESS_NET_CONNECT_TCP (1ULL << 1) /* clang-format on */ #endif /* _LINUX_LANDLOCK_H */