xref: /f-stack/freebsd/sys/fcntl.h (revision 22ce4aff)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1983, 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  * (c) UNIX System Laboratories, Inc.
7  * All or some portions of this file are derived from material licensed
8  * to the University of California by American Telephone and Telegraph
9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10  * the permission of UNIX System Laboratories, Inc.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)fcntl.h	8.3 (Berkeley) 1/21/94
37  * $FreeBSD$
38  */
39 
40 #ifndef _SYS_FCNTL_H_
41 #define	_SYS_FCNTL_H_
42 
43 /*
44  * This file includes the definitions for open and fcntl
45  * described by POSIX for <fcntl.h>; it also includes
46  * related kernel definitions.
47  */
48 
49 #include <sys/cdefs.h>
50 #include <sys/_types.h>
51 
52 #ifndef _MODE_T_DECLARED
53 typedef	__mode_t	mode_t;
54 #define	_MODE_T_DECLARED
55 #endif
56 
57 #ifndef _OFF_T_DECLARED
58 typedef	__off_t		off_t;
59 #define	_OFF_T_DECLARED
60 #endif
61 
62 #ifndef _PID_T_DECLARED
63 typedef	__pid_t		pid_t;
64 #define	_PID_T_DECLARED
65 #endif
66 
67 /*
68  * File status flags: these are used by open(2), fcntl(2).
69  * They are also used (indirectly) in the kernel file structure f_flags,
70  * which is a superset of the open/fcntl flags.  Open flags and f_flags
71  * are inter-convertible using OFLAGS(fflags) and FFLAGS(oflags).
72  * Open/fcntl flags begin with O_; kernel-internal flags begin with F.
73  */
74 /* open-only flags */
75 #define	O_RDONLY	0x0000		/* open for reading only */
76 #define	O_WRONLY	0x0001		/* open for writing only */
77 #define	O_RDWR		0x0002		/* open for reading and writing */
78 #define	O_ACCMODE	0x0003		/* mask for above modes */
79 
80 /*
81  * Kernel encoding of open mode; separate read and write bits that are
82  * independently testable: 1 greater than the above.
83  *
84  * XXX
85  * FREAD and FWRITE are excluded from the #ifdef _KERNEL so that TIOCFLUSH,
86  * which was documented to use FREAD/FWRITE, continues to work.
87  */
88 #if __BSD_VISIBLE
89 #define	FREAD		0x0001
90 #define	FWRITE		0x0002
91 #endif
92 #define	O_NONBLOCK	0x0004		/* no delay */
93 #define	O_APPEND	0x0008		/* set append mode */
94 #if __BSD_VISIBLE
95 #define	O_SHLOCK	0x0010		/* open with shared file lock */
96 #define	O_EXLOCK	0x0020		/* open with exclusive file lock */
97 #define	O_ASYNC		0x0040		/* signal pgrp when data ready */
98 #define	O_FSYNC		0x0080		/* synchronous writes */
99 #endif
100 #define	O_SYNC		0x0080		/* POSIX synonym for O_FSYNC */
101 #if __POSIX_VISIBLE >= 200809
102 #define	O_NOFOLLOW	0x0100		/* don't follow symlinks */
103 #endif
104 #define	O_CREAT		0x0200		/* create if nonexistent */
105 #define	O_TRUNC		0x0400		/* truncate to zero length */
106 #define	O_EXCL		0x0800		/* error if already exists */
107 #ifdef _KERNEL
108 #define	FHASLOCK	0x4000		/* descriptor holds advisory lock */
109 #endif
110 
111 /* Defined by POSIX 1003.1; BSD default, but must be distinct from O_RDONLY. */
112 #define	O_NOCTTY	0x8000		/* don't assign controlling terminal */
113 
114 #if __BSD_VISIBLE
115 /* Attempt to bypass buffer cache */
116 #define	O_DIRECT	0x00010000
117 #endif
118 
119 #if __POSIX_VISIBLE >= 200809
120 #define	O_DIRECTORY	0x00020000	/* Fail if not directory */
121 #define	O_EXEC		0x00040000	/* Open for execute only */
122 #define	O_SEARCH	O_EXEC
123 #endif
124 #ifdef	_KERNEL
125 #define	FEXEC		O_EXEC
126 #define	FSEARCH		O_SEARCH
127 #endif
128 
129 #if __POSIX_VISIBLE >= 200809
130 /* Defined by POSIX 1003.1-2008; BSD default, but reserve for future use. */
131 #define	O_TTY_INIT	0x00080000	/* Restore default termios attributes */
132 
133 #define	O_CLOEXEC	0x00100000
134 #endif
135 
136 #if __BSD_VISIBLE
137 #define	O_VERIFY	0x00200000	/* open only after verification */
138 /* #define O_UNUSED1	0x00400000   */	/* Was O_BENEATH */
139 #define	O_RESOLVE_BENEATH 0x00800000	/* Do not allow name resolution to walk
140 					   out of cwd */
141 #endif
142 
143 #define	O_DSYNC		0x01000000	/* POSIX data sync */
144 
145 /*
146  * XXX missing O_RSYNC.
147  */
148 
149 #ifdef _KERNEL
150 
151 /* Only for devfs d_close() flags. */
152 #define	FLASTCLOSE	O_DIRECTORY
153 #define	FREVOKE		O_VERIFY
154 /* Only for fo_close() from half-succeeded open */
155 #define	FOPENFAILED	O_TTY_INIT
156 
157 /* convert from open() flags to/from fflags; convert O_RD/WR to FREAD/FWRITE */
158 #define	FFLAGS(oflags)	((oflags) & O_EXEC ? (oflags) : (oflags) + 1)
159 #define	OFLAGS(fflags)	((fflags) & O_EXEC ? (fflags) : (fflags) - 1)
160 
161 /* bits to save after open */
162 #define	FMASK	(FREAD|FWRITE|FAPPEND|FASYNC|FFSYNC|FDSYNC|FNONBLOCK|O_DIRECT|FEXEC)
163 /* bits settable by fcntl(F_SETFL, ...) */
164 #define	FCNTLFLAGS	(FAPPEND|FASYNC|FFSYNC|FDSYNC|FNONBLOCK|FRDAHEAD|O_DIRECT)
165 
166 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
167     defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
168 /*
169  * Set by shm_open(3) in older libc's to get automatic MAP_ASYNC
170  * behavior for POSIX shared memory objects (which are otherwise
171  * implemented as plain files).
172  */
173 #define	FPOSIXSHM	O_NOFOLLOW
174 #undef FCNTLFLAGS
175 #define	FCNTLFLAGS	(FAPPEND|FASYNC|FFSYNC|FNONBLOCK|FPOSIXSHM|FRDAHEAD| \
176 			 O_DIRECT)
177 #endif
178 #endif
179 
180 /*
181  * The O_* flags used to have only F* names, which were used in the kernel
182  * and by fcntl.  We retain the F* names for the kernel f_flag field
183  * and for backward compatibility for fcntl.  These flags are deprecated.
184  */
185 #if __BSD_VISIBLE
186 #define	FAPPEND		O_APPEND	/* kernel/compat */
187 #define	FASYNC		O_ASYNC		/* kernel/compat */
188 #define	FFSYNC		O_FSYNC		/* kernel */
189 #define	FDSYNC		O_DSYNC		/* kernel */
190 #define	FNONBLOCK	O_NONBLOCK	/* kernel */
191 #define	FNDELAY		O_NONBLOCK	/* compat */
192 #define	O_NDELAY	O_NONBLOCK	/* compat */
193 #endif
194 
195 /*
196  * Historically, we ran out of bits in f_flag (which was once a short).
197  * However, the flag bits not set in FMASK are only meaningful in the
198  * initial open syscall.  Those bits were thus given a
199  * different meaning for fcntl(2).
200  */
201 #if __BSD_VISIBLE
202 /* Read ahead */
203 #define	FRDAHEAD	O_CREAT
204 #endif
205 
206 #if __POSIX_VISIBLE >= 200809
207 /*
208  * Magic value that specify the use of the current working directory
209  * to determine the target of relative file paths in the openat() and
210  * similar syscalls.
211  */
212 #define	AT_FDCWD		-100
213 
214 /*
215  * Miscellaneous flags for the *at() syscalls.
216  */
217 #define	AT_EACCESS		0x0100	/* Check access using effective user
218 					   and group ID */
219 #define	AT_SYMLINK_NOFOLLOW	0x0200	/* Do not follow symbolic links */
220 #define	AT_SYMLINK_FOLLOW	0x0400	/* Follow symbolic link */
221 #define	AT_REMOVEDIR		0x0800	/* Remove directory instead of file */
222 /* #define AT_UNUSED1		0x1000 *//* Was AT_BENEATH */
223 #define	AT_RESOLVE_BENEATH	0x2000	/* Do not allow name resolution
224 					   to walk out of dirfd */
225 #endif
226 
227 /*
228  * Constants used for fcntl(2)
229  */
230 
231 /* command values */
232 #define	F_DUPFD		0		/* duplicate file descriptor */
233 #define	F_GETFD		1		/* get file descriptor flags */
234 #define	F_SETFD		2		/* set file descriptor flags */
235 #define	F_GETFL		3		/* get file status flags */
236 #define	F_SETFL		4		/* set file status flags */
237 #if __XSI_VISIBLE || __POSIX_VISIBLE >= 200112
238 #define	F_GETOWN	5		/* get SIGIO/SIGURG proc/pgrp */
239 #define	F_SETOWN	6		/* set SIGIO/SIGURG proc/pgrp */
240 #endif
241 #if __BSD_VISIBLE
242 #define	F_OGETLK	7		/* get record locking information */
243 #define	F_OSETLK	8		/* set record locking information */
244 #define	F_OSETLKW	9		/* F_SETLK; wait if blocked */
245 #define	F_DUP2FD	10		/* duplicate file descriptor to arg */
246 #endif
247 #define	F_GETLK		11		/* get record locking information */
248 #define	F_SETLK		12		/* set record locking information */
249 #define	F_SETLKW	13		/* F_SETLK; wait if blocked */
250 #if __BSD_VISIBLE
251 #define	F_SETLK_REMOTE	14		/* debugging support for remote locks */
252 #define	F_READAHEAD	15		/* read ahead */
253 #define	F_RDAHEAD	16		/* Darwin compatible read ahead */
254 #endif
255 #if __POSIX_VISIBLE >= 200809
256 #define	F_DUPFD_CLOEXEC	17		/* Like F_DUPFD, but FD_CLOEXEC is set */
257 #endif
258 #if __BSD_VISIBLE
259 #define	F_DUP2FD_CLOEXEC 18		/* Like F_DUP2FD, but FD_CLOEXEC is set */
260 #define	F_ADD_SEALS	19
261 #define	F_GET_SEALS	20
262 #define	F_ISUNIONSTACK	21		/* Kludge for libc, don't use it. */
263 
264 /* Seals (F_ADD_SEALS, F_GET_SEALS). */
265 #define	F_SEAL_SEAL	0x0001		/* Prevent adding sealings */
266 #define	F_SEAL_SHRINK	0x0002		/* May not shrink */
267 #define	F_SEAL_GROW	0x0004		/* May not grow */
268 #define	F_SEAL_WRITE	0x0008		/* May not write */
269 #endif	/* __BSD_VISIBLE */
270 
271 /* file descriptor flags (F_GETFD, F_SETFD) */
272 #define	FD_CLOEXEC	1		/* close-on-exec flag */
273 
274 /* record locking flags (F_GETLK, F_SETLK, F_SETLKW) */
275 #define	F_RDLCK		1		/* shared or read lock */
276 #define	F_UNLCK		2		/* unlock */
277 #define	F_WRLCK		3		/* exclusive or write lock */
278 #if __BSD_VISIBLE
279 #define	F_UNLCKSYS	4		/* purge locks for a given system ID */
280 #define	F_CANCEL	5		/* cancel an async lock request */
281 #endif
282 #ifdef _KERNEL
283 #define	F_WAIT		0x010		/* Wait until lock is granted */
284 #define	F_FLOCK		0x020	 	/* Use flock(2) semantics for lock */
285 #define	F_POSIX		0x040	 	/* Use POSIX semantics for lock */
286 #define	F_REMOTE	0x080		/* Lock owner is remote NFS client */
287 #define	F_NOINTR	0x100		/* Ignore signals when waiting */
288 #endif
289 
290 /*
291  * Advisory file segment locking data type -
292  * information passed to system by user
293  */
294 struct flock {
295 	off_t	l_start;	/* starting offset */
296 	off_t	l_len;		/* len = 0 means until end of file */
297 	pid_t	l_pid;		/* lock owner */
298 	short	l_type;		/* lock type: read/write, etc. */
299 	short	l_whence;	/* type of l_start */
300 	int	l_sysid;	/* remote system id or zero for local */
301 };
302 
303 #if __BSD_VISIBLE
304 /*
305  * Old advisory file segment locking data type,
306  * before adding l_sysid.
307  */
308 struct __oflock {
309 	off_t	l_start;	/* starting offset */
310 	off_t	l_len;		/* len = 0 means until end of file */
311 	pid_t	l_pid;		/* lock owner */
312 	short	l_type;		/* lock type: read/write, etc. */
313 	short	l_whence;	/* type of l_start */
314 };
315 #endif
316 
317 #if __BSD_VISIBLE
318 /* lock operations for flock(2) */
319 #define	LOCK_SH		0x01		/* shared file lock */
320 #define	LOCK_EX		0x02		/* exclusive file lock */
321 #define	LOCK_NB		0x04		/* don't block when locking */
322 #define	LOCK_UN		0x08		/* unlock file */
323 #endif
324 
325 #if __POSIX_VISIBLE >= 200112
326 /*
327  * Advice to posix_fadvise
328  */
329 #define	POSIX_FADV_NORMAL	0	/* no special treatment */
330 #define	POSIX_FADV_RANDOM	1	/* expect random page references */
331 #define	POSIX_FADV_SEQUENTIAL	2	/* expect sequential page references */
332 #define	POSIX_FADV_WILLNEED	3	/* will need these pages */
333 #define	POSIX_FADV_DONTNEED	4	/* dont need these pages */
334 #define	POSIX_FADV_NOREUSE	5	/* access data only once */
335 #endif
336 
337 #ifdef __BSD_VISIBLE
338 /*
339  * Magic value that specify that corresponding file descriptor to filename
340  * is unknown and sanitary check should be omitted in the funlinkat() and
341  * similar syscalls.
342  */
343 #define	FD_NONE			-200
344 #endif
345 
346 #ifndef _KERNEL
347 __BEGIN_DECLS
348 int	open(const char *, int, ...);
349 int	creat(const char *, mode_t);
350 int	fcntl(int, int, ...);
351 #if __BSD_VISIBLE
352 int	flock(int, int);
353 #endif
354 #if __POSIX_VISIBLE >= 200809
355 int	openat(int, const char *, int, ...);
356 #endif
357 #if __POSIX_VISIBLE >= 200112
358 int	posix_fadvise(int, off_t, off_t, int);
359 int	posix_fallocate(int, off_t, off_t);
360 #endif
361 __END_DECLS
362 #endif
363 
364 #endif /* !_SYS_FCNTL_H_ */
365