xref: /linux/include/uapi/linux/fcntl.h (revision 579a3297b268f0281644ead7ff574a2b4bc64d3c)
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 */
88 struct 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 */
194