root/sys/sys/fcntl.h
/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1983, 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef _SYS_FCNTL_H_
#define _SYS_FCNTL_H_

/*
 * This file includes the definitions for open and fcntl
 * described by POSIX for <fcntl.h>; it also includes
 * related kernel definitions.
 */

#include <sys/cdefs.h>
#include <sys/_types.h>

#ifndef _MODE_T_DECLARED
typedef __mode_t        mode_t;
#define _MODE_T_DECLARED
#endif

#ifndef _OFF_T_DECLARED
typedef __off_t         off_t;
#define _OFF_T_DECLARED
#endif

#ifndef _PID_T_DECLARED
typedef __pid_t         pid_t;
#define _PID_T_DECLARED
#endif

/*
 * File status flags: these are used by open(2), fcntl(2).
 * They are also used (indirectly) in the kernel file structure f_flags,
 * which is a superset of the open/fcntl flags.  Open flags and f_flags
 * are inter-convertible using OFLAGS(fflags) and FFLAGS(oflags).
 * Open/fcntl flags begin with O_; kernel-internal flags begin with F.
 */
/* open-only flags */
#define O_RDONLY        0x0000          /* open for reading only */
#define O_WRONLY        0x0001          /* open for writing only */
#define O_RDWR          0x0002          /* open for reading and writing */
#define O_ACCMODE       0x0003          /* mask for above modes */

/*
 * Kernel encoding of open mode; separate read and write bits that are
 * independently testable: 1 greater than the above.
 *
 * XXX
 * FREAD and FWRITE are excluded from the #ifdef _KERNEL so that TIOCFLUSH,
 * which was documented to use FREAD/FWRITE, continues to work.
 */
#if __BSD_VISIBLE
#define FREAD           0x0001
#define FWRITE          0x0002
#endif
#define O_NONBLOCK      0x0004          /* no delay */
#define O_APPEND        0x0008          /* set append mode */
#if __BSD_VISIBLE
#define O_SHLOCK        0x0010          /* open with shared file lock */
#define O_EXLOCK        0x0020          /* open with exclusive file lock */
#define O_ASYNC         0x0040          /* signal pgrp when data ready */
#define O_FSYNC         0x0080          /* synchronous writes */
#endif
#define O_SYNC          0x0080          /* POSIX synonym for O_FSYNC */
#if __POSIX_VISIBLE >= 200809
#define O_NOFOLLOW      0x0100          /* don't follow symlinks */
#endif
#define O_CREAT         0x0200          /* create if nonexistent */
#define O_TRUNC         0x0400          /* truncate to zero length */
#define O_EXCL          0x0800          /* error if already exists */
#ifdef _KERNEL
#define FHASLOCK        0x4000          /* descriptor holds advisory lock */
#endif

/* Defined by POSIX 1003.1; BSD default, but must be distinct from O_RDONLY. */
#define O_NOCTTY        0x8000          /* don't assign controlling terminal */

#if __BSD_VISIBLE
/* Attempt to bypass buffer cache */
#define O_DIRECT        0x00010000
#endif

#if __POSIX_VISIBLE >= 200809
#define O_DIRECTORY     0x00020000      /* Fail if not directory */
#define O_EXEC          0x00040000      /* Open for execute only */
#define O_SEARCH        O_EXEC
#endif
#ifdef  _KERNEL
#define FEXEC           O_EXEC
#define FSEARCH         O_SEARCH
#endif

#if __POSIX_VISIBLE >= 200809
/* Defined by POSIX 1003.1-2008; BSD default, but reserve for future use. */
#define O_TTY_INIT      0x00080000      /* Restore default termios attributes */

#define O_CLOEXEC       0x00100000
#endif

#if __BSD_VISIBLE
#define O_VERIFY        0x00200000      /* open only after verification */
#define O_PATH          0x00400000      /* fd is only a path */
#define O_RESOLVE_BENEATH 0x00800000    /* Do not allow name resolution to walk
                                           out of cwd */
#endif

#define O_DSYNC         0x01000000      /* POSIX data sync */
#if __BSD_VISIBLE
#define O_EMPTY_PATH    0x02000000
#define O_NAMEDATTR     0x04000000      /* NFSv4 named attributes */
#define O_XATTR         O_NAMEDATTR     /* Solaris compatibility */
#endif

#if __POSIX_VISIBLE >= 202405
#define O_CLOFORK       0x08000000
#endif

/*
 * !!! DANGER !!!
 *
 * There are very few bits left for O_* flags.  Every bit we consume for
 * local features is one bit we can't use for future source compatibility
 * with other operating systems.
 *
 * All additions should be coordinated with srcmgr@.
 */

/*
 * XXX missing O_RSYNC.
 */

#ifdef _KERNEL

/* Only for devfs d_close() flags. */
#define FLASTCLOSE      O_DIRECTORY
#define FREVOKE         O_VERIFY
/* Only for fo_close() from half-succeeded open */
#define FOPENFAILED     O_TTY_INIT
/* Only for O_PATH files which passed ACCESS FREAD check on open */
#define FKQALLOWED      O_RESOLVE_BENEATH

/* convert from open() flags to/from fflags; convert O_RD/WR to FREAD/FWRITE */
#define FFLAGS(oflags)  ((oflags) & O_EXEC ? (oflags) : (oflags) + 1)
#define OFLAGS(fflags)  \
    (((fflags) & (O_EXEC | O_PATH)) != 0 ? (fflags) : (fflags) - 1)

/* bits to save after open */
#define FMASK   (FREAD|FWRITE|FAPPEND|FASYNC|FFSYNC|FDSYNC|FNONBLOCK| \
                 O_DIRECT|FEXEC|O_PATH)
/* bits settable by fcntl(F_SETFL, ...) */
#define FCNTLFLAGS      (FAPPEND|FASYNC|FFSYNC|FDSYNC|FNONBLOCK|FRDAHEAD|O_DIRECT)

#if defined(COMPAT_FREEBSD7) || defined(COMPAT_FREEBSD6) || \
    defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4)
/*
 * Set by shm_open(3) in older libc's to get automatic MAP_ASYNC
 * behavior for POSIX shared memory objects (which are otherwise
 * implemented as plain files).
 */
#define FPOSIXSHM       O_NOFOLLOW
#undef FCNTLFLAGS
#define FCNTLFLAGS      (FAPPEND|FASYNC|FFSYNC|FNONBLOCK|FPOSIXSHM|FRDAHEAD| \
                         O_DIRECT)
#endif
#endif

/*
 * The O_* flags used to have only F* names, which were used in the kernel
 * and by fcntl.  We retain the F* names for the kernel f_flag field
 * and for backward compatibility for fcntl.  These flags are deprecated.
 */
#if __BSD_VISIBLE
#define FAPPEND         O_APPEND        /* kernel/compat */
#define FASYNC          O_ASYNC         /* kernel/compat */
#define FFSYNC          O_FSYNC         /* kernel */
#define FDSYNC          O_DSYNC         /* kernel */
#define FNONBLOCK       O_NONBLOCK      /* kernel */
#define FNDELAY         O_NONBLOCK      /* compat */
#define O_NDELAY        O_NONBLOCK      /* compat */
#endif

/*
 * Historically, we ran out of bits in f_flag (which was once a short).
 * However, the flag bits not set in FMASK are only meaningful in the
 * initial open syscall.  Those bits were thus given a
 * different meaning for fcntl(2).
 */
#if __BSD_VISIBLE
/* Read ahead */
#define FRDAHEAD        O_CREAT
#endif

#if __POSIX_VISIBLE >= 200809
/*
 * Magic value that specify the use of the current working directory
 * to determine the target of relative file paths in the openat() and
 * similar syscalls.
 */
#define AT_FDCWD                -100

/*
 * Miscellaneous flags for the *at() syscalls.
 */
#define AT_EACCESS              0x0100  /* Check access using effective user
                                           and group ID */
#define AT_SYMLINK_NOFOLLOW     0x0200  /* Do not follow symbolic links */
#define AT_SYMLINK_FOLLOW       0x0400  /* Follow symbolic link */
#define AT_REMOVEDIR            0x0800  /* Remove directory instead of file */
#endif  /* __POSIX_VISIBLE >= 200809 */
#if __BSD_VISIBLE
/* #define AT_UNUSED1           0x1000 *//* Was AT_BENEATH */
#define AT_RESOLVE_BENEATH      0x2000  /* Do not allow name resolution
                                           to walk out of dirfd */
#define AT_EMPTY_PATH           0x4000  /* Operate on dirfd if path is empty */

#define AT_RENAME_NOREPLACE     0x0001  /* Fail rename if target exists */
#define RENAME_NOREPLACE        AT_RENAME_NOREPLACE
#endif  /* __BSD_VISIBLE */

/*
 * Constants used for fcntl(2)
 */

/* command values */
#define F_DUPFD         0               /* duplicate file descriptor */
#define F_GETFD         1               /* get file descriptor flags */
#define F_SETFD         2               /* set file descriptor flags */
#define F_GETFL         3               /* get file status flags */
#define F_SETFL         4               /* set file status flags */
#if __XSI_VISIBLE || __POSIX_VISIBLE >= 200112
#define F_GETOWN        5               /* get SIGIO/SIGURG proc/pgrp */
#define F_SETOWN        6               /* set SIGIO/SIGURG proc/pgrp */
#endif
#if __BSD_VISIBLE
#define F_OGETLK        7               /* get record locking information */
#define F_OSETLK        8               /* set record locking information */
#define F_OSETLKW       9               /* F_SETLK; wait if blocked */
#define F_DUP2FD        10              /* duplicate file descriptor to arg */
#endif
#define F_GETLK         11              /* get record locking information */
#define F_SETLK         12              /* set record locking information */
#define F_SETLKW        13              /* F_SETLK; wait if blocked */
#if __BSD_VISIBLE
#define F_SETLK_REMOTE  14              /* debugging support for remote locks */
#define F_READAHEAD     15              /* read ahead */
#define F_RDAHEAD       16              /* Darwin compatible read ahead */
#endif
#if __POSIX_VISIBLE >= 200809
#define F_DUPFD_CLOEXEC 17              /* Like F_DUPFD, but FD_CLOEXEC is set */
#endif
#if __BSD_VISIBLE
#define F_DUP2FD_CLOEXEC 18             /* Like F_DUP2FD, but FD_CLOEXEC is set */
#define F_ADD_SEALS     19
#define F_GET_SEALS     20
#define F_ISUNIONSTACK  21              /* Kludge for libc, don't use it. */
#define F_KINFO         22              /* Return kinfo_file for this fd */
#endif  /* __BSD_VISIBLE */

#if __POSIX_VISIBLE >= 202405
#define F_DUPFD_CLOFORK 23              /* Like F_DUPFD, but FD_CLOFORK is set */
#endif

#if __BSD_VISIBLE
#define F_DUP3FD        24              /* Used with dup3() */

#define F_DUP3FD_SHIFT  16              /* Shift used for F_DUP3FD */

/* Seals (F_ADD_SEALS, F_GET_SEALS). */
#define F_SEAL_SEAL     0x0001          /* Prevent adding sealings */
#define F_SEAL_SHRINK   0x0002          /* May not shrink */
#define F_SEAL_GROW     0x0004          /* May not grow */
#define F_SEAL_WRITE    0x0008          /* May not write */
#endif  /* __BSD_VISIBLE */

/* file descriptor flags (F_GETFD, F_SETFD) */
#define FD_CLOEXEC      1               /* close-on-exec flag */
#define FD_RESOLVE_BENEATH 2            /* all lookups relative to fd have
                                           O_RESOLVE_BENEATH semantics */
#if __POSIX_VISIBLE >= 202405
#define FD_CLOFORK      4               /* close-on-fork flag */
#endif

/* record locking flags (F_GETLK, F_SETLK, F_SETLKW) */
#define F_RDLCK         1               /* shared or read lock */
#define F_UNLCK         2               /* unlock */
#define F_WRLCK         3               /* exclusive or write lock */
#if __BSD_VISIBLE
#define F_UNLCKSYS      4               /* purge locks for a given system ID */ 
#define F_CANCEL        5               /* cancel an async lock request */
#endif
#ifdef _KERNEL
#define F_WAIT          0x010           /* Wait until lock is granted */
#define F_FLOCK         0x020           /* Use flock(2) semantics for lock */
#define F_POSIX         0x040           /* Use POSIX semantics for lock */
#define F_REMOTE        0x080           /* Lock owner is remote NFS client */
#define F_NOINTR        0x100           /* Ignore signals when waiting */
#define F_FIRSTOPEN     0x200           /* First right to advlock file */
#endif

/*
 * Advisory file segment locking data type -
 * information passed to system by user
 */
struct flock {
        off_t   l_start;        /* starting offset */
        off_t   l_len;          /* len = 0 means until end of file */
        pid_t   l_pid;          /* lock owner */
        short   l_type;         /* lock type: read/write, etc. */
        short   l_whence;       /* type of l_start */
        int     l_sysid;        /* remote system id or zero for local */
};

#if __BSD_VISIBLE
/*
 * Old advisory file segment locking data type,
 * before adding l_sysid.
 */
struct __oflock {
        off_t   l_start;        /* starting offset */
        off_t   l_len;          /* len = 0 means until end of file */
        pid_t   l_pid;          /* lock owner */
        short   l_type;         /* lock type: read/write, etc. */
        short   l_whence;       /* type of l_start */
};

/*
 * Space control offset/length description
 */
struct spacectl_range {
        off_t   r_offset;       /* starting offset */
        off_t   r_len;  /* length */
};
#endif

#if __BSD_VISIBLE
/* lock operations for flock(2) */
#define LOCK_SH         0x01            /* shared file lock */
#define LOCK_EX         0x02            /* exclusive file lock */
#define LOCK_NB         0x04            /* don't block when locking */
#define LOCK_UN         0x08            /* unlock file */
#endif

#if __POSIX_VISIBLE >= 200112
/*
 * Advice to posix_fadvise
 */
#define POSIX_FADV_NORMAL       0       /* no special treatment */
#define POSIX_FADV_RANDOM       1       /* expect random page references */
#define POSIX_FADV_SEQUENTIAL   2       /* expect sequential page references */
#define POSIX_FADV_WILLNEED     3       /* will need these pages */
#define POSIX_FADV_DONTNEED     4       /* dont need these pages */
#define POSIX_FADV_NOREUSE      5       /* access data only once */
#endif

#ifdef __BSD_VISIBLE
/*
 * Magic value that specify that corresponding file descriptor to filename
 * is unknown and sanitary check should be omitted in the funlinkat() and
 * similar syscalls.
 */
#define FD_NONE                 -200

/*
 * Commands for fspacectl(2)
 */
#define SPACECTL_DEALLOC        1       /* deallocate space */

/*
 * fspacectl(2) flags
 */
#define SPACECTL_F_SUPPORTED    0
#endif

#ifndef _KERNEL
__BEGIN_DECLS
int     open(const char *, int, ...);
int     creat(const char *, mode_t);
int     fcntl(int, int, ...);
#if __BSD_VISIBLE
int     flock(int, int);
int     fspacectl(int, int, const struct spacectl_range *, int,
            struct spacectl_range *);
#endif
#if __POSIX_VISIBLE >= 200809
int     openat(int, const char *, int, ...);
#endif
#if __POSIX_VISIBLE >= 200112
int     posix_fadvise(int, off_t, off_t, int);
int     posix_fallocate(int, off_t, off_t);
#endif
__END_DECLS
#endif

#endif /* !_SYS_FCNTL_H_ */