xref: /freebsd/sys/sys/fcntl.h (revision 19261079)
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_PATH		0x00400000	/* fd is only a path */
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 #if __BSD_VISIBLE
145 #define	O_EMPTY_PATH	0x02000000
146 #endif
147 
148 /*
149  * XXX missing O_RSYNC.
150  */
151 
152 #ifdef _KERNEL
153 
154 /* Only for devfs d_close() flags. */
155 #define	FLASTCLOSE	O_DIRECTORY
156 #define	FREVOKE		O_VERIFY
157 /* Only for fo_close() from half-succeeded open */
158 #define	FOPENFAILED	O_TTY_INIT
159 /* Only for O_PATH files which passed ACCESS FREAD check on open */
160 #define	FKQALLOWED	O_RESOLVE_BENEATH
161 
162 /* convert from open() flags to/from fflags; convert O_RD/WR to FREAD/FWRITE */
163 #define	FFLAGS(oflags)	((oflags) & O_EXEC ? (oflags) : (oflags) + 1)
164 #define	OFLAGS(fflags)	\
165     (((fflags) & (O_EXEC | O_PATH)) != 0 ? (fflags) : (fflags) - 1)
166 
167 /* bits to save after open */
168 #define	FMASK	(FREAD|FWRITE|FAPPEND|FASYNC|FFSYNC|FDSYNC|FNONBLOCK| \
169 		 O_DIRECT|FEXEC|O_PATH)
170 /* bits settable by fcntl(F_SETFL, ...) */
171 #define	FCNTLFLAGS	(FAPPEND|FASYNC|FFSYNC|FDSYNC|FNONBLOCK|FRDAHEAD|O_DIRECT)
172 
173 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
174     defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
175 /*
176  * Set by shm_open(3) in older libc's to get automatic MAP_ASYNC
177  * behavior for POSIX shared memory objects (which are otherwise
178  * implemented as plain files).
179  */
180 #define	FPOSIXSHM	O_NOFOLLOW
181 #undef FCNTLFLAGS
182 #define	FCNTLFLAGS	(FAPPEND|FASYNC|FFSYNC|FNONBLOCK|FPOSIXSHM|FRDAHEAD| \
183 			 O_DIRECT)
184 #endif
185 #endif
186 
187 /*
188  * The O_* flags used to have only F* names, which were used in the kernel
189  * and by fcntl.  We retain the F* names for the kernel f_flag field
190  * and for backward compatibility for fcntl.  These flags are deprecated.
191  */
192 #if __BSD_VISIBLE
193 #define	FAPPEND		O_APPEND	/* kernel/compat */
194 #define	FASYNC		O_ASYNC		/* kernel/compat */
195 #define	FFSYNC		O_FSYNC		/* kernel */
196 #define	FDSYNC		O_DSYNC		/* kernel */
197 #define	FNONBLOCK	O_NONBLOCK	/* kernel */
198 #define	FNDELAY		O_NONBLOCK	/* compat */
199 #define	O_NDELAY	O_NONBLOCK	/* compat */
200 #endif
201 
202 /*
203  * Historically, we ran out of bits in f_flag (which was once a short).
204  * However, the flag bits not set in FMASK are only meaningful in the
205  * initial open syscall.  Those bits were thus given a
206  * different meaning for fcntl(2).
207  */
208 #if __BSD_VISIBLE
209 /* Read ahead */
210 #define	FRDAHEAD	O_CREAT
211 #endif
212 
213 #if __POSIX_VISIBLE >= 200809
214 /*
215  * Magic value that specify the use of the current working directory
216  * to determine the target of relative file paths in the openat() and
217  * similar syscalls.
218  */
219 #define	AT_FDCWD		-100
220 
221 /*
222  * Miscellaneous flags for the *at() syscalls.
223  */
224 #define	AT_EACCESS		0x0100	/* Check access using effective user
225 					   and group ID */
226 #define	AT_SYMLINK_NOFOLLOW	0x0200	/* Do not follow symbolic links */
227 #define	AT_SYMLINK_FOLLOW	0x0400	/* Follow symbolic link */
228 #define	AT_REMOVEDIR		0x0800	/* Remove directory instead of file */
229 #endif	/* __POSIX_VISIBLE >= 200809 */
230 #if __BSD_VISIBLE
231 /* #define AT_UNUSED1		0x1000 *//* Was AT_BENEATH */
232 #define	AT_RESOLVE_BENEATH	0x2000	/* Do not allow name resolution
233 					   to walk out of dirfd */
234 #define	AT_EMPTY_PATH		0x4000	/* Operate on dirfd if path is empty */
235 #endif	/* __BSD_VISIBLE */
236 
237 /*
238  * Constants used for fcntl(2)
239  */
240 
241 /* command values */
242 #define	F_DUPFD		0		/* duplicate file descriptor */
243 #define	F_GETFD		1		/* get file descriptor flags */
244 #define	F_SETFD		2		/* set file descriptor flags */
245 #define	F_GETFL		3		/* get file status flags */
246 #define	F_SETFL		4		/* set file status flags */
247 #if __XSI_VISIBLE || __POSIX_VISIBLE >= 200112
248 #define	F_GETOWN	5		/* get SIGIO/SIGURG proc/pgrp */
249 #define	F_SETOWN	6		/* set SIGIO/SIGURG proc/pgrp */
250 #endif
251 #if __BSD_VISIBLE
252 #define	F_OGETLK	7		/* get record locking information */
253 #define	F_OSETLK	8		/* set record locking information */
254 #define	F_OSETLKW	9		/* F_SETLK; wait if blocked */
255 #define	F_DUP2FD	10		/* duplicate file descriptor to arg */
256 #endif
257 #define	F_GETLK		11		/* get record locking information */
258 #define	F_SETLK		12		/* set record locking information */
259 #define	F_SETLKW	13		/* F_SETLK; wait if blocked */
260 #if __BSD_VISIBLE
261 #define	F_SETLK_REMOTE	14		/* debugging support for remote locks */
262 #define	F_READAHEAD	15		/* read ahead */
263 #define	F_RDAHEAD	16		/* Darwin compatible read ahead */
264 #endif
265 #if __POSIX_VISIBLE >= 200809
266 #define	F_DUPFD_CLOEXEC	17		/* Like F_DUPFD, but FD_CLOEXEC is set */
267 #endif
268 #if __BSD_VISIBLE
269 #define	F_DUP2FD_CLOEXEC 18		/* Like F_DUP2FD, but FD_CLOEXEC is set */
270 #define	F_ADD_SEALS	19
271 #define	F_GET_SEALS	20
272 #define	F_ISUNIONSTACK	21		/* Kludge for libc, don't use it. */
273 
274 /* Seals (F_ADD_SEALS, F_GET_SEALS). */
275 #define	F_SEAL_SEAL	0x0001		/* Prevent adding sealings */
276 #define	F_SEAL_SHRINK	0x0002		/* May not shrink */
277 #define	F_SEAL_GROW	0x0004		/* May not grow */
278 #define	F_SEAL_WRITE	0x0008		/* May not write */
279 #endif	/* __BSD_VISIBLE */
280 
281 /* file descriptor flags (F_GETFD, F_SETFD) */
282 #define	FD_CLOEXEC	1		/* close-on-exec flag */
283 
284 /* record locking flags (F_GETLK, F_SETLK, F_SETLKW) */
285 #define	F_RDLCK		1		/* shared or read lock */
286 #define	F_UNLCK		2		/* unlock */
287 #define	F_WRLCK		3		/* exclusive or write lock */
288 #if __BSD_VISIBLE
289 #define	F_UNLCKSYS	4		/* purge locks for a given system ID */
290 #define	F_CANCEL	5		/* cancel an async lock request */
291 #endif
292 #ifdef _KERNEL
293 #define	F_WAIT		0x010		/* Wait until lock is granted */
294 #define	F_FLOCK		0x020	 	/* Use flock(2) semantics for lock */
295 #define	F_POSIX		0x040	 	/* Use POSIX semantics for lock */
296 #define	F_REMOTE	0x080		/* Lock owner is remote NFS client */
297 #define	F_NOINTR	0x100		/* Ignore signals when waiting */
298 #define	F_FIRSTOPEN	0x200		/* First right to advlock file */
299 #endif
300 
301 /*
302  * Advisory file segment locking data type -
303  * information passed to system by user
304  */
305 struct flock {
306 	off_t	l_start;	/* starting offset */
307 	off_t	l_len;		/* len = 0 means until end of file */
308 	pid_t	l_pid;		/* lock owner */
309 	short	l_type;		/* lock type: read/write, etc. */
310 	short	l_whence;	/* type of l_start */
311 	int	l_sysid;	/* remote system id or zero for local */
312 };
313 
314 #if __BSD_VISIBLE
315 /*
316  * Old advisory file segment locking data type,
317  * before adding l_sysid.
318  */
319 struct __oflock {
320 	off_t	l_start;	/* starting offset */
321 	off_t	l_len;		/* len = 0 means until end of file */
322 	pid_t	l_pid;		/* lock owner */
323 	short	l_type;		/* lock type: read/write, etc. */
324 	short	l_whence;	/* type of l_start */
325 };
326 
327 /*
328  * Space control offset/length description
329  */
330 struct spacectl_range {
331 	off_t	r_offset;	/* starting offset */
332 	off_t	r_len;	/* length */
333 };
334 #endif
335 
336 #if __BSD_VISIBLE
337 /* lock operations for flock(2) */
338 #define	LOCK_SH		0x01		/* shared file lock */
339 #define	LOCK_EX		0x02		/* exclusive file lock */
340 #define	LOCK_NB		0x04		/* don't block when locking */
341 #define	LOCK_UN		0x08		/* unlock file */
342 #endif
343 
344 #if __POSIX_VISIBLE >= 200112
345 /*
346  * Advice to posix_fadvise
347  */
348 #define	POSIX_FADV_NORMAL	0	/* no special treatment */
349 #define	POSIX_FADV_RANDOM	1	/* expect random page references */
350 #define	POSIX_FADV_SEQUENTIAL	2	/* expect sequential page references */
351 #define	POSIX_FADV_WILLNEED	3	/* will need these pages */
352 #define	POSIX_FADV_DONTNEED	4	/* dont need these pages */
353 #define	POSIX_FADV_NOREUSE	5	/* access data only once */
354 #endif
355 
356 #ifdef __BSD_VISIBLE
357 /*
358  * Magic value that specify that corresponding file descriptor to filename
359  * is unknown and sanitary check should be omitted in the funlinkat() and
360  * similar syscalls.
361  */
362 #define	FD_NONE			-200
363 
364 /*
365  * Commands for fspacectl(2)
366  */
367 #define SPACECTL_DEALLOC	1	/* deallocate space */
368 
369 /*
370  * fspacectl(2) flags
371  */
372 #define SPACECTL_F_SUPPORTED	0
373 #endif
374 
375 #ifndef _KERNEL
376 __BEGIN_DECLS
377 int	open(const char *, int, ...);
378 int	creat(const char *, mode_t);
379 int	fcntl(int, int, ...);
380 #if __BSD_VISIBLE
381 int	flock(int, int);
382 int	fspacectl(int, int, const struct spacectl_range *, int,
383 	    struct spacectl_range *);
384 #endif
385 #if __POSIX_VISIBLE >= 200809
386 int	openat(int, const char *, int, ...);
387 #endif
388 #if __POSIX_VISIBLE >= 200112
389 int	posix_fadvise(int, off_t, off_t, int);
390 int	posix_fallocate(int, off_t, off_t);
391 #endif
392 __END_DECLS
393 #endif
394 
395 #endif /* !_SYS_FCNTL_H_ */
396