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