landlock.h (11708B)
- /* 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 defines a set of *handled access rights*, a set of actions on
- * different object types, which should be denied by default when the ruleset is
- * enacted. Vice versa, access rights that are not specifically listed here are
- * not going to be denied by this ruleset when it is enacted.
- *
- * For historical reasons, the %LANDLOCK_ACCESS_FS_REFER right is always denied
- * by default, even when its bit is not set in @handled_access_fs. In order to
- * add new rules with this access right, the bit must still be set explicitly
- * (cf. `Filesystem flags`_).
- *
- * The explicit listing of *handled access rights* is required for backwards
- * compatibility reasons. In most use cases, processes that use Landlock will
- * *handle* a wide range or all access rights that they know about at build time
- * (and that they have tested with a kernel that supported them all).
- *
- * This structure can grow in future Landlock versions.
- */
- struct landlock_ruleset_attr {
- /**
- * @handled_access_fs: Bitmask of handled filesystem actions
- * (cf. `Filesystem flags`_).
- */
- __u64 handled_access_fs;
- /**
- * @handled_access_net: Bitmask of handled network actions (cf. `Network
- * flags`_).
- */
- __u64 handled_access_net;
- /**
- * @scoped: Bitmask of scopes (cf. `Scope flags`_)
- * restricting a Landlock domain from accessing outside
- * resources (e.g. IPCs).
- */
- __u64 scoped;
- };
- /*
- * 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 network actions 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 the ephemeral port range. This can be
- * configured with 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. When
- * opening files for writing, you will often additionally need the
- * %LANDLOCK_ACCESS_FS_TRUNCATE right. In many cases, these system calls
- * truncate existing files when overwriting them (e.g., :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.
- *
- * The following access rights apply to TCP port numbers:
- *
- * - %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 */
- /**
- * DOC: scope
- *
- * Scope flags
- * ~~~~~~~~~~~
- *
- * These flags enable to isolate a sandboxed process from a set of IPC actions.
- * Setting a flag for a ruleset will isolate the Landlock domain to forbid
- * connections to resources outside the domain.
- *
- * Scopes:
- *
- * - %LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET: Restrict a sandboxed process from
- * connecting to an abstract UNIX socket created by a process outside the
- * related Landlock domain (e.g. a parent domain or a non-sandboxed process).
- * - %LANDLOCK_SCOPE_SIGNAL: Restrict a sandboxed process from sending a signal
- * to another process outside the domain.
- */
- /* clang-format off */
- #define LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET (1ULL << 0)
- #define LANDLOCK_SCOPE_SIGNAL (1ULL << 1)
- /* clang-format on*/
- #endif /* _LINUX_LANDLOCK_H */