fcntl.h

  1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
  2#ifndef _UAPI_LINUX_FCNTL_H
  3#define _UAPI_LINUX_FCNTL_H
  4
  5#include <asm/fcntl.h>
  6#include <linux/openat2.h>
  7#include <linux/types.h>
  8
  9#define F_SETLEASE	(F_LINUX_SPECIFIC_BASE + 0)
 10#define F_GETLEASE	(F_LINUX_SPECIFIC_BASE + 1)
 11
 12/*
 13 * Request nofications on a directory.
 14 * See below for events that may be notified.
 15 */
 16#define F_NOTIFY	(F_LINUX_SPECIFIC_BASE + 2)
 17
 18#define F_DUPFD_QUERY	(F_LINUX_SPECIFIC_BASE + 3)
 19
 20/* Was the file just created? */
 21#define F_CREATED_QUERY	(F_LINUX_SPECIFIC_BASE + 4)
 22
 23/*
 24 * Cancel a blocking posix lock; internal use only until we expose an
 25 * asynchronous lock api to userspace:
 26 */
 27#define F_CANCELLK	(F_LINUX_SPECIFIC_BASE + 5)
 28
 29/* Create a file descriptor with FD_CLOEXEC set. */
 30#define F_DUPFD_CLOEXEC	(F_LINUX_SPECIFIC_BASE + 6)
 31
 32/*
 33 * Set and get of pipe page size array
 34 */
 35#define F_SETPIPE_SZ	(F_LINUX_SPECIFIC_BASE + 7)
 36#define F_GETPIPE_SZ	(F_LINUX_SPECIFIC_BASE + 8)
 37
 38/*
 39 * Set/Get seals
 40 */
 41#define F_ADD_SEALS	(F_LINUX_SPECIFIC_BASE + 9)
 42#define F_GET_SEALS	(F_LINUX_SPECIFIC_BASE + 10)
 43
 44/*
 45 * Types of seals
 46 */
 47#define F_SEAL_SEAL	0x0001	/* prevent further seals from being set */
 48#define F_SEAL_SHRINK	0x0002	/* prevent file from shrinking */
 49#define F_SEAL_GROW	0x0004	/* prevent file from growing */
 50#define F_SEAL_WRITE	0x0008	/* prevent writes */
 51#define F_SEAL_FUTURE_WRITE	0x0010  /* prevent future writes while mapped */
 52#define F_SEAL_EXEC	0x0020  /* prevent chmod modifying exec bits */
 53/* (1U << 31) is reserved for signed error codes */
 54
 55/*
 56 * Set/Get write life time hints. {GET,SET}_RW_HINT operate on the
 57 * underlying inode, while {GET,SET}_FILE_RW_HINT operate only on
 58 * the specific file.
 59 */
 60#define F_GET_RW_HINT		(F_LINUX_SPECIFIC_BASE + 11)
 61#define F_SET_RW_HINT		(F_LINUX_SPECIFIC_BASE + 12)
 62#define F_GET_FILE_RW_HINT	(F_LINUX_SPECIFIC_BASE + 13)
 63#define F_SET_FILE_RW_HINT	(F_LINUX_SPECIFIC_BASE + 14)
 64
 65/*
 66 * Valid hint values for F_{GET,SET}_RW_HINT. 0 is "not set", or can be
 67 * used to clear any hints previously set.
 68 */
 69#define RWH_WRITE_LIFE_NOT_SET	0
 70#define RWH_WRITE_LIFE_NONE	1
 71#define RWH_WRITE_LIFE_SHORT	2
 72#define RWH_WRITE_LIFE_MEDIUM	3
 73#define RWH_WRITE_LIFE_LONG	4
 74#define RWH_WRITE_LIFE_EXTREME	5
 75
 76/*
 77 * The originally introduced spelling is remained from the first
 78 * versions of the patch set that introduced the feature, see commit
 79 * v4.13-rc1~212^2~51.
 80 */
 81#define RWF_WRITE_LIFE_NOT_SET	RWH_WRITE_LIFE_NOT_SET
 82
 83/* Set/Get delegations */
 84#define F_GETDELEG		(F_LINUX_SPECIFIC_BASE + 15)
 85#define F_SETDELEG		(F_LINUX_SPECIFIC_BASE + 16)
 86
 87/* Argument structure for F_GETDELEG and F_SETDELEG */
 88struct delegation {
 89	__u32	d_flags;	/* Must be 0 */
 90	__u16	d_type;		/* F_RDLCK, F_WRLCK, F_UNLCK */
 91	__u16	__pad;		/* Must be 0 */
 92};
 93
 94/*
 95 * Types of directory notifications that may be requested.
 96 */
 97#define DN_ACCESS	0x00000001	/* File accessed */
 98#define DN_MODIFY	0x00000002	/* File modified */
 99#define DN_CREATE	0x00000004	/* File created */
100#define DN_DELETE	0x00000008	/* File removed */
101#define DN_RENAME	0x00000010	/* File renamed */
102#define DN_ATTRIB	0x00000020	/* File changed attibutes */
103#define DN_MULTISHOT	0x80000000	/* Don't remove notifier */
104
105/* Reserved kernel ranges [-100], [-10000, -40000]. */
106#define AT_FDCWD		-100    /* Special value for dirfd used to
107					   indicate openat should use the
108					   current working directory. */
109
110/*
111 * The concept of process and threads in userland and the kernel is a confusing
112 * one - within the kernel every thread is a 'task' with its own individual PID,
113 * however from userland's point of view threads are grouped by a single PID,
114 * which is that of the 'thread group leader', typically the first thread
115 * spawned.
116 *
117 * To cut the Gideon knot, for internal kernel usage, we refer to
118 * PIDFD_SELF_THREAD to refer to the current thread (or task from a kernel
119 * perspective), and PIDFD_SELF_THREAD_GROUP to refer to the current thread
120 * group leader...
121 */
122#define PIDFD_SELF_THREAD		-10000 /* Current thread. */
123#define PIDFD_SELF_THREAD_GROUP		-10001 /* Current thread group leader. */
124
125#define FD_PIDFS_ROOT			-10002 /* Root of the pidfs filesystem */
126#define FD_NSFS_ROOT			-10003 /* Root of the nsfs filesystem */
127#define FD_INVALID			-10009 /* Invalid file descriptor: -10000 - EBADF = -10009 */
128
129/* Generic flags for the *at(2) family of syscalls. */
130
131/* Reserved for per-syscall flags	0xff. */
132#define AT_SYMLINK_NOFOLLOW		0x100   /* Do not follow symbolic
133						   links. */
134/* Reserved for per-syscall flags	0x200 */
135#define AT_SYMLINK_FOLLOW		0x400   /* Follow symbolic links. */
136#define AT_NO_AUTOMOUNT			0x800	/* Suppress terminal automount
137						   traversal. */
138#define AT_EMPTY_PATH			0x1000	/* Allow empty relative
139						   pathname to operate on dirfd
140						   directly. */
141/*
142 * These flags are currently statx(2)-specific, but they could be made generic
143 * in the future and so they should not be used for other per-syscall flags.
144 */
145#define AT_STATX_SYNC_TYPE		0x6000	/* Type of synchronisation required from statx() */
146#define AT_STATX_SYNC_AS_STAT		0x0000	/* - Do whatever stat() does */
147#define AT_STATX_FORCE_SYNC		0x2000	/* - Force the attributes to be sync'd with the server */
148#define AT_STATX_DONT_SYNC		0x4000	/* - Don't sync attributes with the server */
149
150#define AT_RECURSIVE			0x8000	/* Apply to the entire subtree */
151
152/*
153 * Per-syscall flags for the *at(2) family of syscalls.
154 *
155 * These are flags that are so syscall-specific that a user passing these flags
156 * to the wrong syscall is so "clearly wrong" that we can safely call such
157 * usage "undefined behaviour".
158 *
159 * For example, the constants AT_REMOVEDIR and AT_EACCESS have the same value.
160 * AT_EACCESS is meaningful only to faccessat, while AT_REMOVEDIR is meaningful
161 * only to unlinkat. The two functions do completely different things and
162 * therefore, the flags can be allowed to overlap. For example, passing
163 * AT_REMOVEDIR to faccessat would be undefined behavior and thus treating it
164 * equivalent to AT_EACCESS is valid undefined behavior.
165 *
166 * Note for implementers: When picking a new per-syscall AT_* flag, try to
167 * reuse already existing flags first. This leaves us with as many unused bits
168 * as possible, so we can use them for generic bits in the future if necessary.
169 */
170
171/* Flags for renameat2(2) (must match legacy RENAME_* flags). */
172#define AT_RENAME_NOREPLACE	0x0001
173#define AT_RENAME_EXCHANGE	0x0002
174#define AT_RENAME_WHITEOUT	0x0004
175
176/* Flag for faccessat(2). */
177#define AT_EACCESS		0x200	/* Test access permitted for
178                                           effective IDs, not real IDs.  */
179/* Flag for unlinkat(2). */
180#define AT_REMOVEDIR		0x200   /* Remove directory instead of
181                                           unlinking file.  */
182/* Flags for name_to_handle_at(2). */
183#define AT_HANDLE_FID		0x200	/* File handle is needed to compare
184					   object identity and may not be
185					   usable with open_by_handle_at(2). */
186#define AT_HANDLE_MNT_ID_UNIQUE	0x001	/* Return the u64 unique mount ID. */
187#define AT_HANDLE_CONNECTABLE	0x002	/* Request a connectable file handle */
188
189/* Flags for execveat2(2). */
190#define AT_EXECVE_CHECK		0x10000	/* Only perform a check if execution
191					   would be allowed. */
192
193#endif /* _UAPI_LINUX_FCNTL_H */