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#ifndef _UAPI_LINUX_LANDLOCK_H#define _UAPI_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). * * @quiet_access_fs and @quiet_access_net are bitmasks of actions for which a * denial by this layer will not trigger a log if the corresponding object (or * its children, for filesystem rules) is marked with the "quiet" bit via * %LANDLOCK_ADD_RULE_QUIET, even if logging would normally take place per * landlock_restrict_self() flags. @quiet_scoped is similar, except that it * does not require marking any objects as quiet - if the ruleset is created * with any bits set in @quiet_scoped, then denial of such scoped resources will * not trigger any log. These 3 fields are available since Landlock ABI version * 10. * * @quiet_access_fs, @quiet_access_net and @quiet_scoped must be a subset of * @handled_access_fs, @handled_access_net and @scoped respectively. * * 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; /** * @quiet_access_fs: Bitmask of filesystem actions which should not be * logged if per-object quiet flag is set. */ __u64 quiet_access_fs; /** * @quiet_access_net: Bitmask of network actions which should not be * logged if per-object quiet flag is set. */ __u64 quiet_access_net; /** * @quiet_scoped: Bitmask of scoped actions which should not be logged. */ __u64 quiet_scoped;};
/** * DOC: landlock_create_ruleset_flags * * **Flags** * * %LANDLOCK_CREATE_RULESET_VERSION * Get the highest supported Landlock ABI version (starting at 1). * * %LANDLOCK_CREATE_RULESET_ERRATA * Get a bitmask of fixed issues for the current Landlock ABI version. *//* clang-format off */#define LANDLOCK_CREATE_RULESET_VERSION (1U << 0)#define LANDLOCK_CREATE_RULESET_ERRATA (1U << 1)/* clang-format on */
/** * DOC: landlock_add_rule_flags * * **Flags** * * %LANDLOCK_ADD_RULE_QUIET * Together with the quiet_* fields in struct landlock_ruleset_attr, * this flag controls whether Landlock will log audit messages when * access to the objects covered by this rule is denied by this layer. * * If logging is enabled, when Landlock denies an access, it will * suppress the log if all of the following are true: * * - this layer is the innermost layer that denied the access; * - all accesses denied by this layer are part of the quiet_* fields * in the related struct landlock_ruleset_attr; * - the object (or one of its parents, for filesystem rules) is * marked as "quiet" via %LANDLOCK_ADD_RULE_QUIET. * * Because logging is only suppressed by a layer if the layer denies * access, a sandboxed program cannot use this flag to "hide" access * denials, without denying itself the access in the first place. * * The effect of this flag does not depend on the value of * allowed_access in the passed in rule_attr. When this flag is * present, the caller is also allowed to pass in an empty * allowed_access. */
/* clang-format off */#define LANDLOCK_ADD_RULE_QUIET (1U << 0)/* clang-format on */
/** * DOC: landlock_restrict_self_flags * * **Flags** * * By default, denied accesses originating from programs that sandbox themselves * are logged via the audit subsystem. Such events typically indicate unexpected * behavior, such as bugs or exploitation attempts. However, to avoid excessive * logging, access requests denied by a domain not created by the originating * program are not logged by default. The rationale is that programs should know * their own behavior, but not necessarily the behavior of other programs. This * default configuration is suitable for most programs that sandbox themselves. * For specific use cases, the following flags allow programs to modify this * default logging behavior. * * The %LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF and * %LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON flags apply to the newly created * Landlock domain. * * %LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF * Disables logging of denied accesses originating from the thread creating * the Landlock domain, as well as its children, as long as they continue * running the same executable code (i.e., without an intervening * :manpage:`execve(2)` call). This is intended for programs that execute * unknown code without invoking :manpage:`execve(2)`, such as script * interpreters. Programs that only sandbox themselves should not set this * flag, so users can be notified of unauthorized access attempts via system * logs. * * %LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON * Enables logging of denied accesses after an :manpage:`execve(2)` call, * providing visibility into unauthorized access attempts by newly executed * programs within the created Landlock domain. This flag is recommended * only when all potential executables in the domain are expected to comply * with the access restrictions, as excessive audit log entries could make * it more difficult to identify critical events. * * %LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF * Disables logging of denied accesses originating from nested Landlock * domains created by the caller or its descendants. This flag should be set * according to runtime configuration, not hardcoded, to avoid suppressing * important security events. It is useful for container runtimes or * sandboxing tools that may launch programs which themselves create * Landlock domains and could otherwise generate excessive logs. Unlike * ``LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF``, this flag only affects * future nested domains, not the one being created. It can also be used * with a @ruleset_fd value of -1 to mute subdomain logs without creating a * domain. When combined with %LANDLOCK_RESTRICT_SELF_TSYNC and a * @ruleset_fd value of -1, this configuration is propagated to all threads * of the current process. * * The following flag supports policy enforcement in multithreaded processes: * * %LANDLOCK_RESTRICT_SELF_TSYNC * Applies the new Landlock configuration atomically to all threads of the * current process, including the Landlock domain and logging * configuration. This overrides the Landlock configuration of sibling * threads, irrespective of previously established Landlock domains and * logging configurations on these threads. * * If the calling thread is running with no_new_privs, this operation * enables no_new_privs on the sibling threads as well. *//* clang-format off */#define LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF (1U << 0)#define LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON (1U << 1)#define LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF (1U << 2)#define LANDLOCK_RESTRICT_SELF_TSYNC (1U << 3)/* 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), and within that range, on a per-socket basis * with ``setsockopt(IP_LOCAL_PORT_RANGE)``. * * A Landlock rule with port 0 and the %LANDLOCK_ACCESS_NET_BIND_TCP or * %LANDLOCK_ACCESS_NET_BIND_UDP right means that requesting to bind on * port 0 is allowed and it will automatically translate to binding on a * kernel-assigned ephemeral port. */ __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. * - %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. * - %LANDLOCK_ACCESS_FS_RESOLVE_UNIX: Look up pathname UNIX domain sockets * (:manpage:`unix(7)`). On UNIX domain sockets, this restricts both calls to * :manpage:`connect(2)` as well as calls to :manpage:`sendmsg(2)` with an * explicit recipient address. * * This access right only applies to connections to UNIX server sockets which * were created outside of the newly created Landlock domain (e.g. from within * a parent domain or from an unrestricted process). Newly created UNIX * servers within the same Landlock domain continue to be accessible. In this * regard, %LANDLOCK_ACCESS_FS_RESOLVE_UNIX has the same semantics as the * ``LANDLOCK_SCOPE_*`` flags. * * If a resolve attempt is denied, the operation returns an ``EACCES`` error, * in line with other filesystem access rights (but different to denials for * abstract UNIX domain sockets). * * This access right is available since the ninth version of the Landlock ABI. * * The rationale for this design is described in * :ref:`Documentation/security/landlock.rst <scoped-flags-interaction>`. * * 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``. * * .. 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)#define LANDLOCK_ACCESS_FS_RESOLVE_UNIX (1ULL << 16)/* clang-format on */
/** * DOC: net_access * * Network flags * ~~~~~~~~~~~~~~~~ * * These flags enable to restrict a sandboxed process to a set of network * actions. * * The following access rights apply to TCP port numbers: * * - %LANDLOCK_ACCESS_NET_BIND_TCP: Bind TCP sockets to the given local * port. Support added in Landlock ABI version 4. * - %LANDLOCK_ACCESS_NET_CONNECT_TCP: Connect TCP sockets to the given * remote port. Support added in Landlock ABI version 4. * * And similarly for UDP port numbers: * * - %LANDLOCK_ACCESS_NET_BIND_UDP: Bind UDP sockets to the given local * port. Support added in Landlock ABI version 10. * - %LANDLOCK_ACCESS_NET_CONNECT_SEND_UDP: Set the remote port of UDP * sockets to the given port, or send datagrams to the given remote port * ignoring any destination pre-set on a socket. Support added in * Landlock ABI version 10. * * .. note:: Setting a remote address or sending a first datagram * auto-binds UDP sockets to an ephemeral local source port if not * already bound. To allow this if both %LANDLOCK_ACCESS_NET_BIND_UDP * and %LANDLOCK_ACCESS_NET_CONNECT_SEND_UDP are handled, you need to * either: * * - use a socket already bound to a port before the ruleset started * being enforced; * - or grant %LANDLOCK_ACCESS_NET_BIND_UDP on port 0, meaning "any * port in the ephemeral port range"; * - or grant %LANDLOCK_ACCESS_NET_BIND_UDP on a specific port, and * call :manpage:`bind(2)` on that port before trying to * :manpage:`connect(2)` or send datagrams. * * .. note:: Sending datagrams to an ``AF_UNSPEC`` destination address * family is not supported for IPv6 UDP sockets: you will need to use a * ``NULL`` address instead. *//* clang-format off */#define LANDLOCK_ACCESS_NET_BIND_TCP (1ULL << 0)#define LANDLOCK_ACCESS_NET_CONNECT_TCP (1ULL << 1)#define LANDLOCK_ACCESS_NET_BIND_UDP (1ULL << 2)#define LANDLOCK_ACCESS_NET_CONNECT_SEND_UDP (1ULL << 3)/* 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. * * This is supported since Landlock ABI version 6. * * 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 /* _UAPI_LINUX_LANDLOCK_H */