xref: /freebsd/sys/sys/fcntl.h (revision 89dbe1dd2f1d37e1b369d1910f12ff737857f070)
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 
37 #ifndef _SYS_FCNTL_H_
38 #define	_SYS_FCNTL_H_
39 
40 /*
41  * This file includes the definitions for open and fcntl
42  * described by POSIX for <fcntl.h>; it also includes
43  * related kernel definitions.
44  */
45 
46 #include <sys/cdefs.h>
47 #include <sys/_types.h>
48 
49 #ifndef _MODE_T_DECLARED
50 typedef	__mode_t	mode_t;
51 #define	_MODE_T_DECLARED
52 #endif
53 
54 #ifndef _OFF_T_DECLARED
55 typedef	__off_t		off_t;
56 #define	_OFF_T_DECLARED
57 #endif
58 
59 #ifndef _PID_T_DECLARED
60 typedef	__pid_t		pid_t;
61 #define	_PID_T_DECLARED
62 #endif
63 
64 /*
65  * File status flags: these are used by open(2), fcntl(2).
66  * They are also used (indirectly) in the kernel file structure f_flags,
67  * which is a superset of the open/fcntl flags.  Open flags and f_flags
68  * are inter-convertible using OFLAGS(fflags) and FFLAGS(oflags).
69  * Open/fcntl flags begin with O_; kernel-internal flags begin with F.
70  */
71 /* open-only flags */
72 #define	O_RDONLY	0x0000		/* open for reading only */
73 #define	O_WRONLY	0x0001		/* open for writing only */
74 #define	O_RDWR		0x0002		/* open for reading and writing */
75 #define	O_ACCMODE	0x0003		/* mask for above modes */
76 
77 /*
78  * Kernel encoding of open mode; separate read and write bits that are
79  * independently testable: 1 greater than the above.
80  *
81  * XXX
82  * FREAD and FWRITE are excluded from the #ifdef _KERNEL so that TIOCFLUSH,
83  * which was documented to use FREAD/FWRITE, continues to work.
84  */
85 #if __BSD_VISIBLE
86 #define	FREAD		0x0001
87 #define	FWRITE		0x0002
88 #endif
89 #define	O_NONBLOCK	0x0004		/* no delay */
90 #define	O_APPEND	0x0008		/* set append mode */
91 #if __BSD_VISIBLE
92 #define	O_SHLOCK	0x0010		/* open with shared file lock */
93 #define	O_EXLOCK	0x0020		/* open with exclusive file lock */
94 #define	O_ASYNC		0x0040		/* signal pgrp when data ready */
95 #define	O_FSYNC		0x0080		/* synchronous writes */
96 #endif
97 #define	O_SYNC		0x0080		/* POSIX synonym for O_FSYNC */
98 #if __POSIX_VISIBLE >= 200809
99 #define	O_NOFOLLOW	0x0100		/* don't follow symlinks */
100 #endif
101 #define	O_CREAT		0x0200		/* create if nonexistent */
102 #define	O_TRUNC		0x0400		/* truncate to zero length */
103 #define	O_EXCL		0x0800		/* error if already exists */
104 #ifdef _KERNEL
105 #define	FHASLOCK	0x4000		/* descriptor holds advisory lock */
106 #endif
107 
108 /* Defined by POSIX 1003.1; BSD default, but must be distinct from O_RDONLY. */
109 #define	O_NOCTTY	0x8000		/* don't assign controlling terminal */
110 
111 #if __BSD_VISIBLE
112 /* Attempt to bypass buffer cache */
113 #define	O_DIRECT	0x00010000
114 #endif
115 
116 #if __POSIX_VISIBLE >= 200809
117 #define	O_DIRECTORY	0x00020000	/* Fail if not directory */
118 #define	O_EXEC		0x00040000	/* Open for execute only */
119 #define	O_SEARCH	O_EXEC
120 #endif
121 #ifdef	_KERNEL
122 #define	FEXEC		O_EXEC
123 #define	FSEARCH		O_SEARCH
124 #endif
125 
126 #if __POSIX_VISIBLE >= 200809
127 /* Defined by POSIX 1003.1-2008; BSD default, but reserve for future use. */
128 #define	O_TTY_INIT	0x00080000	/* Restore default termios attributes */
129 
130 #define	O_CLOEXEC	0x00100000
131 #endif
132 
133 #if __BSD_VISIBLE
134 #define	O_VERIFY	0x00200000	/* open only after verification */
135 #define O_PATH		0x00400000	/* fd is only a path */
136 #define	O_RESOLVE_BENEATH 0x00800000	/* Do not allow name resolution to walk
137 					   out of cwd */
138 #endif
139 
140 #define	O_DSYNC		0x01000000	/* POSIX data sync */
141 #if __BSD_VISIBLE
142 #define	O_EMPTY_PATH	0x02000000
143 #define	O_NAMEDATTR	0x04000000	/* NFSv4 named attributes */
144 #define	O_XATTR		O_NAMEDATTR	/* Solaris compatibility */
145 #endif
146 
147 /*
148  * !!! DANGER !!!
149  *
150  * There are very few bits left for O_* flags.  Every bit we consume for
151  * local features is one bit we can't use for future source compatibility
152  * with other operating systems.
153  *
154  * All additions should be coordinated with srcmgr@.
155  */
156 
157 /*
158  * XXX missing O_RSYNC.
159  */
160 
161 #ifdef _KERNEL
162 
163 /* Only for devfs d_close() flags. */
164 #define	FLASTCLOSE	O_DIRECTORY
165 #define	FREVOKE		O_VERIFY
166 /* Only for fo_close() from half-succeeded open */
167 #define	FOPENFAILED	O_TTY_INIT
168 /* Only for O_PATH files which passed ACCESS FREAD check on open */
169 #define	FKQALLOWED	O_RESOLVE_BENEATH
170 
171 /* convert from open() flags to/from fflags; convert O_RD/WR to FREAD/FWRITE */
172 #define	FFLAGS(oflags)	((oflags) & O_EXEC ? (oflags) : (oflags) + 1)
173 #define	OFLAGS(fflags)	\
174     (((fflags) & (O_EXEC | O_PATH)) != 0 ? (fflags) : (fflags) - 1)
175 
176 /* bits to save after open */
177 #define	FMASK	(FREAD|FWRITE|FAPPEND|FASYNC|FFSYNC|FDSYNC|FNONBLOCK| \
178 		 O_DIRECT|FEXEC|O_PATH)
179 /* bits settable by fcntl(F_SETFL, ...) */
180 #define	FCNTLFLAGS	(FAPPEND|FASYNC|FFSYNC|FDSYNC|FNONBLOCK|FRDAHEAD|O_DIRECT)
181 
182 #if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
183     defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
184 /*
185  * Set by shm_open(3) in older libc's to get automatic MAP_ASYNC
186  * behavior for POSIX shared memory objects (which are otherwise
187  * implemented as plain files).
188  */
189 #define	FPOSIXSHM	O_NOFOLLOW
190 #undef FCNTLFLAGS
191 #define	FCNTLFLAGS	(FAPPEND|FASYNC|FFSYNC|FNONBLOCK|FPOSIXSHM|FRDAHEAD| \
192 			 O_DIRECT)
193 #endif
194 #endif
195 
196 /*
197  * The O_* flags used to have only F* names, which were used in the kernel
198  * and by fcntl.  We retain the F* names for the kernel f_flag field
199  * and for backward compatibility for fcntl.  These flags are deprecated.
200  */
201 #if __BSD_VISIBLE
202 #define	FAPPEND		O_APPEND	/* kernel/compat */
203 #define	FASYNC		O_ASYNC		/* kernel/compat */
204 #define	FFSYNC		O_FSYNC		/* kernel */
205 #define	FDSYNC		O_DSYNC		/* kernel */
206 #define	FNONBLOCK	O_NONBLOCK	/* kernel */
207 #define	FNDELAY		O_NONBLOCK	/* compat */
208 #define	O_NDELAY	O_NONBLOCK	/* compat */
209 #endif
210 
211 /*
212  * Historically, we ran out of bits in f_flag (which was once a short).
213  * However, the flag bits not set in FMASK are only meaningful in the
214  * initial open syscall.  Those bits were thus given a
215  * different meaning for fcntl(2).
216  */
217 #if __BSD_VISIBLE
218 /* Read ahead */
219 #define	FRDAHEAD	O_CREAT
220 #endif
221 
222 #if __POSIX_VISIBLE >= 200809
223 /*
224  * Magic value that specify the use of the current working directory
225  * to determine the target of relative file paths in the openat() and
226  * similar syscalls.
227  */
228 #define	AT_FDCWD		-100
229 
230 /*
231  * Miscellaneous flags for the *at() syscalls.
232  */
233 #define	AT_EACCESS		0x0100	/* Check access using effective user
234 					   and group ID */
235 #define	AT_SYMLINK_NOFOLLOW	0x0200	/* Do not follow symbolic links */
236 #define	AT_SYMLINK_FOLLOW	0x0400	/* Follow symbolic link */
237 #define	AT_REMOVEDIR		0x0800	/* Remove directory instead of file */
238 #endif	/* __POSIX_VISIBLE >= 200809 */
239 #if __BSD_VISIBLE
240 /* #define AT_UNUSED1		0x1000 *//* Was AT_BENEATH */
241 #define	AT_RESOLVE_BENEATH	0x2000	/* Do not allow name resolution
242 					   to walk out of dirfd */
243 #define	AT_EMPTY_PATH		0x4000	/* Operate on dirfd if path is empty */
244 #endif	/* __BSD_VISIBLE */
245 
246 /*
247  * Constants used for fcntl(2)
248  */
249 
250 /* command values */
251 #define	F_DUPFD		0		/* duplicate file descriptor */
252 #define	F_GETFD		1		/* get file descriptor flags */
253 #define	F_SETFD		2		/* set file descriptor flags */
254 #define	F_GETFL		3		/* get file status flags */
255 #define	F_SETFL		4		/* set file status flags */
256 #if __XSI_VISIBLE || __POSIX_VISIBLE >= 200112
257 #define	F_GETOWN	5		/* get SIGIO/SIGURG proc/pgrp */
258 #define	F_SETOWN	6		/* set SIGIO/SIGURG proc/pgrp */
259 #endif
260 #if __BSD_VISIBLE
261 #define	F_OGETLK	7		/* get record locking information */
262 #define	F_OSETLK	8		/* set record locking information */
263 #define	F_OSETLKW	9		/* F_SETLK; wait if blocked */
264 #define	F_DUP2FD	10		/* duplicate file descriptor to arg */
265 #endif
266 #define	F_GETLK		11		/* get record locking information */
267 #define	F_SETLK		12		/* set record locking information */
268 #define	F_SETLKW	13		/* F_SETLK; wait if blocked */
269 #if __BSD_VISIBLE
270 #define	F_SETLK_REMOTE	14		/* debugging support for remote locks */
271 #define	F_READAHEAD	15		/* read ahead */
272 #define	F_RDAHEAD	16		/* Darwin compatible read ahead */
273 #endif
274 #if __POSIX_VISIBLE >= 200809
275 #define	F_DUPFD_CLOEXEC	17		/* Like F_DUPFD, but FD_CLOEXEC is set */
276 #endif
277 #if __BSD_VISIBLE
278 #define	F_DUP2FD_CLOEXEC 18		/* Like F_DUP2FD, but FD_CLOEXEC is set */
279 #define	F_ADD_SEALS	19
280 #define	F_GET_SEALS	20
281 #define	F_ISUNIONSTACK	21		/* Kludge for libc, don't use it. */
282 #define	F_KINFO		22		/* Return kinfo_file for this fd */
283 
284 /* Seals (F_ADD_SEALS, F_GET_SEALS). */
285 #define	F_SEAL_SEAL	0x0001		/* Prevent adding sealings */
286 #define	F_SEAL_SHRINK	0x0002		/* May not shrink */
287 #define	F_SEAL_GROW	0x0004		/* May not grow */
288 #define	F_SEAL_WRITE	0x0008		/* May not write */
289 #endif	/* __BSD_VISIBLE */
290 
291 /* file descriptor flags (F_GETFD, F_SETFD) */
292 #define	FD_CLOEXEC	1		/* close-on-exec flag */
293 #define	FD_RESOLVE_BENEATH 2		/* all lookups relative to fd have
294 					   O_RESOLVE_BENEATH semantics */
295 
296 /* record locking flags (F_GETLK, F_SETLK, F_SETLKW) */
297 #define	F_RDLCK		1		/* shared or read lock */
298 #define	F_UNLCK		2		/* unlock */
299 #define	F_WRLCK		3		/* exclusive or write lock */
300 #if __BSD_VISIBLE
301 #define	F_UNLCKSYS	4		/* purge locks for a given system ID */
302 #define	F_CANCEL	5		/* cancel an async lock request */
303 #endif
304 #ifdef _KERNEL
305 #define	F_WAIT		0x010		/* Wait until lock is granted */
306 #define	F_FLOCK		0x020	 	/* Use flock(2) semantics for lock */
307 #define	F_POSIX		0x040	 	/* Use POSIX semantics for lock */
308 #define	F_REMOTE	0x080		/* Lock owner is remote NFS client */
309 #define	F_NOINTR	0x100		/* Ignore signals when waiting */
310 #define	F_FIRSTOPEN	0x200		/* First right to advlock file */
311 #endif
312 
313 /*
314  * Advisory file segment locking data type -
315  * information passed to system by user
316  */
317 struct flock {
318 	off_t	l_start;	/* starting offset */
319 	off_t	l_len;		/* len = 0 means until end of file */
320 	pid_t	l_pid;		/* lock owner */
321 	short	l_type;		/* lock type: read/write, etc. */
322 	short	l_whence;	/* type of l_start */
323 	int	l_sysid;	/* remote system id or zero for local */
324 };
325 
326 #if __BSD_VISIBLE
327 /*
328  * Old advisory file segment locking data type,
329  * before adding l_sysid.
330  */
331 struct __oflock {
332 	off_t	l_start;	/* starting offset */
333 	off_t	l_len;		/* len = 0 means until end of file */
334 	pid_t	l_pid;		/* lock owner */
335 	short	l_type;		/* lock type: read/write, etc. */
336 	short	l_whence;	/* type of l_start */
337 };
338 
339 /*
340  * Space control offset/length description
341  */
342 struct spacectl_range {
343 	off_t	r_offset;	/* starting offset */
344 	off_t	r_len;	/* length */
345 };
346 #endif
347 
348 #if __BSD_VISIBLE
349 /* lock operations for flock(2) */
350 #define	LOCK_SH		0x01		/* shared file lock */
351 #define	LOCK_EX		0x02		/* exclusive file lock */
352 #define	LOCK_NB		0x04		/* don't block when locking */
353 #define	LOCK_UN		0x08		/* unlock file */
354 #endif
355 
356 #if __POSIX_VISIBLE >= 200112
357 /*
358  * Advice to posix_fadvise
359  */
360 #define	POSIX_FADV_NORMAL	0	/* no special treatment */
361 #define	POSIX_FADV_RANDOM	1	/* expect random page references */
362 #define	POSIX_FADV_SEQUENTIAL	2	/* expect sequential page references */
363 #define	POSIX_FADV_WILLNEED	3	/* will need these pages */
364 #define	POSIX_FADV_DONTNEED	4	/* dont need these pages */
365 #define	POSIX_FADV_NOREUSE	5	/* access data only once */
366 #endif
367 
368 #ifdef __BSD_VISIBLE
369 /*
370  * Magic value that specify that corresponding file descriptor to filename
371  * is unknown and sanitary check should be omitted in the funlinkat() and
372  * similar syscalls.
373  */
374 #define	FD_NONE			-200
375 
376 /*
377  * Commands for fspacectl(2)
378  */
379 #define SPACECTL_DEALLOC	1	/* deallocate space */
380 
381 /*
382  * fspacectl(2) flags
383  */
384 #define SPACECTL_F_SUPPORTED	0
385 #endif
386 
387 #ifndef _KERNEL
388 __BEGIN_DECLS
389 int	open(const char *, int, ...);
390 int	creat(const char *, mode_t);
391 int	fcntl(int, int, ...);
392 #if __BSD_VISIBLE
393 int	flock(int, int);
394 int	fspacectl(int, int, const struct spacectl_range *, int,
395 	    struct spacectl_range *);
396 #endif
397 #if __POSIX_VISIBLE >= 200809
398 int	openat(int, const char *, int, ...);
399 #endif
400 #if __POSIX_VISIBLE >= 200112
401 int	posix_fadvise(int, off_t, off_t, int);
402 int	posix_fallocate(int, off_t, off_t);
403 #endif
404 __END_DECLS
405 #endif
406 
407 #endif /* !_SYS_FCNTL_H_ */
408