xref: /freebsd-13-stable/sys/sys/fcntl.h (revision 4b40a16f0d188422227478889b38cc341d50f88f)
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  */
38 
39 #ifndef _SYS_FCNTL_H_
40 #define	_SYS_FCNTL_H_
41 
42 /*
43  * This file includes the definitions for open and fcntl
44  * described by POSIX for <fcntl.h>; it also includes
45  * related kernel definitions.
46  */
47 
48 #include <sys/cdefs.h>
49 #include <sys/_types.h>
50 
51 #ifndef _MODE_T_DECLARED
52 typedef	__mode_t	mode_t;
53 #define	_MODE_T_DECLARED
54 #endif
55 
56 #ifndef _OFF_T_DECLARED
57 typedef	__off_t		off_t;
58 #define	_OFF_T_DECLARED
59 #endif
60 
61 #ifndef _PID_T_DECLARED
62 typedef	__pid_t		pid_t;
63 #define	_PID_T_DECLARED
64 #endif
65 
66 /*
67  * File status flags: these are used by open(2), fcntl(2).
68  * They are also used (indirectly) in the kernel file structure f_flags,
69  * which is a superset of the open/fcntl flags.  Open flags and f_flags
70  * are inter-convertible using OFLAGS(fflags) and FFLAGS(oflags).
71  * Open/fcntl flags begin with O_; kernel-internal flags begin with F.
72  */
73 /* open-only flags */
74 #define	O_RDONLY	0x0000		/* open for reading only */
75 #define	O_WRONLY	0x0001		/* open for writing only */
76 #define	O_RDWR		0x0002		/* open for reading and writing */
77 #define	O_ACCMODE	0x0003		/* mask for above modes */
78 
79 /*
80  * Kernel encoding of open mode; separate read and write bits that are
81  * independently testable: 1 greater than the above.
82  *
83  * XXX
84  * FREAD and FWRITE are excluded from the #ifdef _KERNEL so that TIOCFLUSH,
85  * which was documented to use FREAD/FWRITE, continues to work.
86  */
87 #if __BSD_VISIBLE
88 #define	FREAD		0x0001
89 #define	FWRITE		0x0002
90 #endif
91 #define	O_NONBLOCK	0x0004		/* no delay */
92 #define	O_APPEND	0x0008		/* set append mode */
93 #if __BSD_VISIBLE
94 #define	O_SHLOCK	0x0010		/* open with shared file lock */
95 #define	O_EXLOCK	0x0020		/* open with exclusive file lock */
96 #define	O_ASYNC		0x0040		/* signal pgrp when data ready */
97 #define	O_FSYNC		0x0080		/* synchronous writes */
98 #endif
99 #define	O_SYNC		0x0080		/* POSIX synonym for O_FSYNC */
100 #if __POSIX_VISIBLE >= 200809
101 #define	O_NOFOLLOW	0x0100		/* don't follow symlinks */
102 #endif
103 #define	O_CREAT		0x0200		/* create if nonexistent */
104 #define	O_TRUNC		0x0400		/* truncate to zero length */
105 #define	O_EXCL		0x0800		/* error if already exists */
106 #ifdef _KERNEL
107 #define	FHASLOCK	0x4000		/* descriptor holds advisory lock */
108 #endif
109 
110 /* Defined by POSIX 1003.1; BSD default, but must be distinct from O_RDONLY. */
111 #define	O_NOCTTY	0x8000		/* don't assign controlling terminal */
112 
113 #if __BSD_VISIBLE
114 /* Attempt to bypass buffer cache */
115 #define	O_DIRECT	0x00010000
116 #endif
117 
118 #if __POSIX_VISIBLE >= 200809
119 #define	O_DIRECTORY	0x00020000	/* Fail if not directory */
120 #define	O_EXEC		0x00040000	/* Open for execute only */
121 #define	O_SEARCH	O_EXEC
122 #endif
123 #ifdef	_KERNEL
124 #define	FEXEC		O_EXEC
125 #define	FSEARCH		O_SEARCH
126 #endif
127 
128 #if __POSIX_VISIBLE >= 200809
129 /* Defined by POSIX 1003.1-2008; BSD default, but reserve for future use. */
130 #define	O_TTY_INIT	0x00080000	/* Restore default termios attributes */
131 
132 #define	O_CLOEXEC	0x00100000
133 #endif
134 
135 #if __BSD_VISIBLE
136 #define	O_VERIFY	0x00200000	/* open only after verification */
137 #define O_PATH		0x00400000	/* fd is only a path */
138 #define	O_RESOLVE_BENEATH 0x00800000	/* Do not allow name resolution to walk
139 					   out of cwd */
140 #endif
141 
142 #define	O_DSYNC		0x01000000	/* POSIX data sync */
143 #if __BSD_VISIBLE
144 #define	O_EMPTY_PATH	0x02000000
145 #endif
146 
147 /*
148  * XXX missing O_RSYNC.
149  */
150 
151 #ifdef _KERNEL
152 
153 /* Only for devfs d_close() flags. */
154 #define	FLASTCLOSE	O_DIRECTORY
155 #define	FREVOKE		O_VERIFY
156 /* Only for fo_close() from half-succeeded open */
157 #define	FOPENFAILED	O_TTY_INIT
158 /* Only for O_PATH files which passed ACCESS FREAD check on open */
159 #define	FKQALLOWED	O_RESOLVE_BENEATH
160 
161 /* convert from open() flags to/from fflags; convert O_RD/WR to FREAD/FWRITE */
162 #define	FFLAGS(oflags)	((oflags) & O_EXEC ? (oflags) : (oflags) + 1)
163 #define	OFLAGS(fflags)	\
164     (((fflags) & (O_EXEC | O_PATH)) != 0 ? (fflags) : (fflags) - 1)
165 
166 /* bits to save after open */
167 #define	FMASK	(FREAD|FWRITE|FAPPEND|FASYNC|FFSYNC|FDSYNC|FNONBLOCK| \
168 		 O_DIRECT|FEXEC|O_PATH)
169 /* bits settable by fcntl(F_SETFL, ...) */
170 #define	FCNTLFLAGS	(FAPPEND|FASYNC|FFSYNC|FDSYNC|FNONBLOCK|FRDAHEAD|O_DIRECT)
171 
172 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
173     defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
174 /*
175  * Set by shm_open(3) in older libc's to get automatic MAP_ASYNC
176  * behavior for POSIX shared memory objects (which are otherwise
177  * implemented as plain files).
178  */
179 #define	FPOSIXSHM	O_NOFOLLOW
180 #undef FCNTLFLAGS
181 #define	FCNTLFLAGS	(FAPPEND|FASYNC|FFSYNC|FNONBLOCK|FPOSIXSHM|FRDAHEAD| \
182 			 O_DIRECT)
183 #endif
184 #endif
185 
186 /*
187  * The O_* flags used to have only F* names, which were used in the kernel
188  * and by fcntl.  We retain the F* names for the kernel f_flag field
189  * and for backward compatibility for fcntl.  These flags are deprecated.
190  */
191 #if __BSD_VISIBLE
192 #define	FAPPEND		O_APPEND	/* kernel/compat */
193 #define	FASYNC		O_ASYNC		/* kernel/compat */
194 #define	FFSYNC		O_FSYNC		/* kernel */
195 #define	FDSYNC		O_DSYNC		/* kernel */
196 #define	FNONBLOCK	O_NONBLOCK	/* kernel */
197 #define	FNDELAY		O_NONBLOCK	/* compat */
198 #define	O_NDELAY	O_NONBLOCK	/* compat */
199 #endif
200 
201 /*
202  * Historically, we ran out of bits in f_flag (which was once a short).
203  * However, the flag bits not set in FMASK are only meaningful in the
204  * initial open syscall.  Those bits were thus given a
205  * different meaning for fcntl(2).
206  */
207 #if __BSD_VISIBLE
208 /* Read ahead */
209 #define	FRDAHEAD	O_CREAT
210 #endif
211 
212 #if __POSIX_VISIBLE >= 200809
213 /*
214  * Magic value that specify the use of the current working directory
215  * to determine the target of relative file paths in the openat() and
216  * similar syscalls.
217  */
218 #define	AT_FDCWD		-100
219 
220 /*
221  * Miscellaneous flags for the *at() syscalls.
222  */
223 #define	AT_EACCESS		0x0100	/* Check access using effective user
224 					   and group ID */
225 #define	AT_SYMLINK_NOFOLLOW	0x0200	/* Do not follow symbolic links */
226 #define	AT_SYMLINK_FOLLOW	0x0400	/* Follow symbolic link */
227 #define	AT_REMOVEDIR		0x0800	/* Remove directory instead of file */
228 #endif	/* __POSIX_VISIBLE >= 200809 */
229 #if __BSD_VISIBLE
230 /* #define AT_UNUSED1		0x1000 *//* Was AT_BENEATH */
231 #define	AT_RESOLVE_BENEATH	0x2000	/* Do not allow name resolution
232 					   to walk out of dirfd */
233 #define	AT_EMPTY_PATH		0x4000	/* Operate on dirfd if path is empty */
234 #endif	/* __BSD_VISIBLE */
235 
236 /*
237  * Constants used for fcntl(2)
238  */
239 
240 /* command values */
241 #define	F_DUPFD		0		/* duplicate file descriptor */
242 #define	F_GETFD		1		/* get file descriptor flags */
243 #define	F_SETFD		2		/* set file descriptor flags */
244 #define	F_GETFL		3		/* get file status flags */
245 #define	F_SETFL		4		/* set file status flags */
246 #if __XSI_VISIBLE || __POSIX_VISIBLE >= 200112
247 #define	F_GETOWN	5		/* get SIGIO/SIGURG proc/pgrp */
248 #define	F_SETOWN	6		/* set SIGIO/SIGURG proc/pgrp */
249 #endif
250 #if __BSD_VISIBLE
251 #define	F_OGETLK	7		/* get record locking information */
252 #define	F_OSETLK	8		/* set record locking information */
253 #define	F_OSETLKW	9		/* F_SETLK; wait if blocked */
254 #define	F_DUP2FD	10		/* duplicate file descriptor to arg */
255 #endif
256 #define	F_GETLK		11		/* get record locking information */
257 #define	F_SETLK		12		/* set record locking information */
258 #define	F_SETLKW	13		/* F_SETLK; wait if blocked */
259 #if __BSD_VISIBLE
260 #define	F_SETLK_REMOTE	14		/* debugging support for remote locks */
261 #define	F_READAHEAD	15		/* read ahead */
262 #define	F_RDAHEAD	16		/* Darwin compatible read ahead */
263 #endif
264 #if __POSIX_VISIBLE >= 200809
265 #define	F_DUPFD_CLOEXEC	17		/* Like F_DUPFD, but FD_CLOEXEC is set */
266 #endif
267 #if __BSD_VISIBLE
268 #define	F_DUP2FD_CLOEXEC 18		/* Like F_DUP2FD, but FD_CLOEXEC is set */
269 #define	F_ADD_SEALS	19
270 #define	F_GET_SEALS	20
271 #define	F_ISUNIONSTACK	21		/* Kludge for libc, don't use it. */
272 #define	F_KINFO		22		/* Return kinfo_file for this fd */
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 #endif
327 
328 #if __BSD_VISIBLE
329 /* lock operations for flock(2) */
330 #define	LOCK_SH		0x01		/* shared file lock */
331 #define	LOCK_EX		0x02		/* exclusive file lock */
332 #define	LOCK_NB		0x04		/* don't block when locking */
333 #define	LOCK_UN		0x08		/* unlock file */
334 #endif
335 
336 #if __POSIX_VISIBLE >= 200112
337 /*
338  * Advice to posix_fadvise
339  */
340 #define	POSIX_FADV_NORMAL	0	/* no special treatment */
341 #define	POSIX_FADV_RANDOM	1	/* expect random page references */
342 #define	POSIX_FADV_SEQUENTIAL	2	/* expect sequential page references */
343 #define	POSIX_FADV_WILLNEED	3	/* will need these pages */
344 #define	POSIX_FADV_DONTNEED	4	/* dont need these pages */
345 #define	POSIX_FADV_NOREUSE	5	/* access data only once */
346 #endif
347 
348 #ifdef __BSD_VISIBLE
349 /*
350  * Magic value that specify that corresponding file descriptor to filename
351  * is unknown and sanitary check should be omitted in the funlinkat() and
352  * similar syscalls.
353  */
354 #define	FD_NONE			-200
355 #endif
356 
357 #ifndef _KERNEL
358 __BEGIN_DECLS
359 int	open(const char *, int, ...);
360 int	creat(const char *, mode_t);
361 int	fcntl(int, int, ...);
362 #if __BSD_VISIBLE
363 int	flock(int, int);
364 #endif
365 #if __POSIX_VISIBLE >= 200809
366 int	openat(int, const char *, int, ...);
367 #endif
368 #if __POSIX_VISIBLE >= 200112
369 int	posix_fadvise(int, off_t, off_t, int);
370 int	posix_fallocate(int, off_t, off_t);
371 #endif
372 __END_DECLS
373 #endif
374 
375 #endif /* !_SYS_FCNTL_H_ */
376