1/*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)filedesc.h 8.1 (Berkeley) 6/2/93 30 * $FreeBSD$ 31 */ 32 33#ifndef _SYS_FILEDESC_H_ 34#define _SYS_FILEDESC_H_ 35 36#include <sys/caprights.h> 37#include <sys/queue.h> 38#include <sys/event.h> 39#include <sys/lock.h> 40#include <sys/priority.h> 41#include <sys/sx.h> 42 43#include <machine/_limits.h> 44 45struct filecaps { 46 cap_rights_t fc_rights; /* per-descriptor capability rights */ 47 u_long *fc_ioctls; /* per-descriptor allowed ioctls */ 48 int16_t fc_nioctls; /* fc_ioctls array size */ 49 uint32_t fc_fcntls; /* per-descriptor allowed fcntls */ 50}; 51 52struct filedescent { 53 struct file *fde_file; /* file structure for open file */ 54 struct filecaps fde_caps; /* per-descriptor rights */ 55 uint8_t fde_flags; /* per-process open file flags */ 56}; 57#define fde_rights fde_caps.fc_rights 58#define fde_fcntls fde_caps.fc_fcntls 59#define fde_ioctls fde_caps.fc_ioctls 60#define fde_nioctls fde_caps.fc_nioctls 61 62/* 63 * This structure is used for the management of descriptors. It may be 64 * shared by multiple processes. 65 */ 66#define NDSLOTTYPE u_long 67 68struct filedesc { 69 struct filedescent *fd_ofiles; /* open files */ 70 struct vnode *fd_cdir; /* current directory */ 71 struct vnode *fd_rdir; /* root directory */ 72 struct vnode *fd_jdir; /* jail root directory */ 73 int fd_nfiles; /* number of open files allocated */ 74 NDSLOTTYPE *fd_map; /* bitmap of free fds */ 75 int fd_lastfile; /* high-water mark of fd_ofiles */ 76 int fd_freefile; /* approx. next free file */ 77 u_short fd_cmask; /* mask for file creation */ 78 u_short fd_refcnt; /* thread reference count */ 79 u_short fd_holdcnt; /* hold count on structure + mutex */ 80 struct sx fd_sx; /* protects members of this struct */ 81 struct kqlist fd_kqlist; /* list of kqueues on this filedesc */ 82 int fd_holdleaderscount; /* block fdfree() for shared close() */ 83 int fd_holdleaderswakeup; /* fdfree() needs wakeup */ 84}; 85 86/* 87 * Structure to keep track of (process leader, struct fildedesc) tuples. 88 * Each process has a pointer to such a structure when detailed tracking 89 * is needed, e.g., when rfork(RFPROC | RFMEM) causes a file descriptor 90 * table to be shared by processes having different "p_leader" pointers 91 * and thus distinct POSIX style locks. 92 * 93 * fdl_refcount and fdl_holdcount are protected by struct filedesc mtx. 94 */ 95struct filedesc_to_leader { 96 int fdl_refcount; /* references from struct proc */ 97 int fdl_holdcount; /* temporary hold during closef */ 98 int fdl_wakeup; /* fdfree() waits on closef() */ 99 struct proc *fdl_leader; /* owner of POSIX locks */ 100 /* Circular list: */ 101 struct filedesc_to_leader *fdl_prev; 102 struct filedesc_to_leader *fdl_next; 103}; 104 105/* 106 * Per-process open flags. 107 */ 108#define UF_EXCLOSE 0x01 /* auto-close on exec */ 109 110#ifdef _KERNEL 111 112/* Flags for do_dup() */ 113#define DUP_FIXED 0x1 /* Force fixed allocation. */ 114#define DUP_FCNTL 0x2 /* fcntl()-style errors. */ 115#define DUP_CLOEXEC 0x4 /* Atomically set FD_CLOEXEC. */ 116 117/* Lock a file descriptor table. */ 118#define FILEDESC_LOCK_INIT(fdp) sx_init(&(fdp)->fd_sx, "filedesc structure") 119#define FILEDESC_LOCK_DESTROY(fdp) sx_destroy(&(fdp)->fd_sx) 120#define FILEDESC_LOCK(fdp) (&(fdp)->fd_sx) 121#define FILEDESC_XLOCK(fdp) sx_xlock(&(fdp)->fd_sx) 122#define FILEDESC_XUNLOCK(fdp) sx_xunlock(&(fdp)->fd_sx) 123#define FILEDESC_SLOCK(fdp) sx_slock(&(fdp)->fd_sx) 124#define FILEDESC_SUNLOCK(fdp) sx_sunlock(&(fdp)->fd_sx) 125 126#define FILEDESC_LOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_LOCKED | \ 127 SX_NOTRECURSED) 128#define FILEDESC_XLOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_XLOCKED | \ 129 SX_NOTRECURSED) 130#define FILEDESC_UNLOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_UNLOCKED) 131 132struct thread; 133 134void filecaps_init(struct filecaps *fcaps); 135void filecaps_copy(const struct filecaps *src, struct filecaps *dst); 136void filecaps_move(struct filecaps *src, struct filecaps *dst); 137void filecaps_free(struct filecaps *fcaps); 138 139int closef(struct file *fp, struct thread *td); 140int do_dup(struct thread *td, int flags, int old, int new, 141 register_t *retval); 142int dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, 143 int openerror, int *indxp); 144int falloc(struct thread *td, struct file **resultfp, int *resultfd, 145 int flags); 146int falloc_noinstall(struct thread *td, struct file **resultfp); 147int finstall(struct thread *td, struct file *fp, int *resultfp, int flags, 148 struct filecaps *fcaps); 149int fdalloc(struct thread *td, int minfd, int *result); 150int fdallocn(struct thread *td, int minfd, int *fds, int n); 151int fdavail(struct thread *td, int n); 152int fdcheckstd(struct thread *td); 153void fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td); 154void fdcloseexec(struct thread *td); 155struct filedesc *fdcopy(struct filedesc *fdp); 156void fdunshare(struct proc *p, struct thread *td); 157void fdescfree(struct thread *td); 158struct filedesc *fdinit(struct filedesc *fdp); 159struct filedesc *fdshare(struct filedesc *fdp); 160struct filedesc_to_leader * 161 filedesc_to_leader_alloc(struct filedesc_to_leader *old, 162 struct filedesc *fdp, struct proc *leader); 163int getvnode(struct filedesc *fdp, int fd, cap_rights_t *rightsp, 164 struct file **fpp); 165void mountcheckdirs(struct vnode *olddp, struct vnode *newdp); 166void setugidsafety(struct thread *td); 167 168/* Return a referenced file from an unlocked descriptor. */ 169int fget_unlocked(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, 170 int needfcntl, struct file **fpp, cap_rights_t *haverightsp); 171 172/* Requires a FILEDESC_{S,X}LOCK held and returns without a ref. */ 173static __inline struct file * 174fget_locked(struct filedesc *fdp, int fd) 175{ 176 177 FILEDESC_LOCK_ASSERT(fdp); 178 179 if (fd < 0 || fd >= fdp->fd_nfiles) 180 return (NULL); 181 182 return (fdp->fd_ofiles[fd].fde_file); 183} 184 185#endif /* _KERNEL */ 186 187#endif /* !_SYS_FILEDESC_H_ */ 188