2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1990, 1993
5 * The Regents of the University of California. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * @(#)filedesc.h 8.1 (Berkeley) 6/2/93
35 #ifndef _SYS_FILEDESC_H_
36 #define _SYS_FILEDESC_H_
38 #include <sys/types.h>
39 #include <sys/caprights.h>
40 #include <sys/queue.h>
41 #include <sys/event.h>
43 #include <sys/mutex.h>
44 #include <sys/priority.h>
48 #include <sys/smr_types.h>
50 #include <machine/_limits.h>
53 cap_rights_t fc_rights; /* per-descriptor capability rights */
54 u_long *fc_ioctls; /* per-descriptor allowed ioctls */
55 int16_t fc_nioctls; /* fc_ioctls array size */
56 uint32_t fc_fcntls; /* per-descriptor allowed fcntls */
60 struct file *fde_file; /* file structure for open file */
61 struct filecaps fde_caps; /* per-descriptor rights */
62 uint8_t fde_flags; /* per-process open file flags */
63 seqc_t fde_seqc; /* keep file and caps in sync */
65 #define fde_rights fde_caps.fc_rights
66 #define fde_fcntls fde_caps.fc_fcntls
67 #define fde_ioctls fde_caps.fc_ioctls
68 #define fde_nioctls fde_caps.fc_nioctls
72 fde_copy(struct filedescent *from, struct filedescent *to)
75 to->fde_file = from->fde_file;
76 to->fde_caps = from->fde_caps;
77 to->fde_flags = from->fde_flags;
82 int fdt_nfiles; /* number of open files allocated */
83 struct filedescent fdt_ofiles[0]; /* open files */
85 #define fd_seqc(fdt, fd) (&(fdt)->fdt_ofiles[(fd)].fde_seqc)
87 #define NDSLOTTYPE u_long
90 * This struct is copy-on-write and allocated from an SMR zone.
91 * All fields are constant after initialization apart from the reference count.
92 * The ABI root directory is initialized as the root directory and changed
93 * during process transiting to or from non-native ABI.
95 * Check pwd_* routines for usage.
99 struct vnode *pwd_cdir; /* current directory */
100 struct vnode *pwd_rdir; /* root directory */
101 struct vnode *pwd_jdir; /* jail root directory */
102 struct vnode *pwd_adir; /* abi root directory */
104 typedef SMR_POINTER(struct pwd *) smrpwd_t;
107 struct mtx pd_lock; /* protects members of this struct */
108 smrpwd_t pd_pwd; /* directories */
110 u_short pd_cmask; /* mask for file creation */
114 * This structure is used for the management of descriptors. It may be
115 * shared by multiple processes.
118 struct fdescenttbl *fd_files; /* open files table */
119 NDSLOTTYPE *fd_map; /* bitmap of free fds */
120 int fd_freefile; /* approx. next free file */
121 int fd_refcnt; /* thread reference count */
122 int fd_holdcnt; /* hold count on structure + mutex */
123 struct sx fd_sx; /* protects members of this struct */
124 struct kqlist fd_kqlist; /* list of kqueues on this filedesc */
125 int fd_holdleaderscount; /* block fdfree() for shared close() */
126 int fd_holdleaderswakeup; /* fdfree() needs wakeup */
130 * Structure to keep track of (process leader, struct fildedesc) tuples.
131 * Each process has a pointer to such a structure when detailed tracking
132 * is needed, e.g., when rfork(RFPROC | RFMEM) causes a file descriptor
133 * table to be shared by processes having different "p_leader" pointers
134 * and thus distinct POSIX style locks.
136 * fdl_refcount and fdl_holdcount are protected by struct filedesc mtx.
138 struct filedesc_to_leader {
139 int fdl_refcount; /* references from struct proc */
140 int fdl_holdcount; /* temporary hold during closef */
141 int fdl_wakeup; /* fdfree() waits on closef() */
142 struct proc *fdl_leader; /* owner of POSIX locks */
144 struct filedesc_to_leader *fdl_prev;
145 struct filedesc_to_leader *fdl_next;
147 #define fd_nfiles fd_files->fdt_nfiles
148 #define fd_ofiles fd_files->fdt_ofiles
151 * Per-process open flags.
153 #define UF_EXCLOSE 0x01 /* auto-close on exec */
157 /* Lock a paths descriptor table. */
158 #define PWDDESC_LOCK(pdp) (&(pdp)->pd_lock)
159 #define PWDDESC_LOCK_INIT(pdp) \
160 mtx_init(PWDDESC_LOCK(pdp), "pwddesc", NULL, MTX_DEF)
161 #define PWDDESC_LOCK_DESTROY(pdp) mtx_destroy(PWDDESC_LOCK(pdp))
162 #define PWDDESC_XLOCK(pdp) mtx_lock(PWDDESC_LOCK(pdp))
163 #define PWDDESC_XUNLOCK(pdp) mtx_unlock(PWDDESC_LOCK(pdp))
164 #define PWDDESC_LOCK_ASSERT(pdp, what) \
165 mtx_assert(PWDDESC_LOCK(pdp), (what))
166 #define PWDDESC_ASSERT_XLOCKED(pdp) \
167 PWDDESC_LOCK_ASSERT((pdp), MA_OWNED)
168 #define PWDDESC_ASSERT_UNLOCKED(pdp) \
169 PWDDESC_LOCK_ASSERT((pdp), MA_NOTOWNED)
171 #define PWDDESC_XLOCKED_LOAD_PWD(pdp) ({ \
172 struct pwddesc *_pdp = (pdp); \
174 _pwd = smr_serialized_load(&(_pdp)->pd_pwd, \
175 (PWDDESC_ASSERT_XLOCKED(_pdp), true)); \
179 /* Lock a file descriptor table. */
180 #define FILEDESC_LOCK_INIT(fdp) sx_init(&(fdp)->fd_sx, "filedesc structure")
181 #define FILEDESC_LOCK_DESTROY(fdp) sx_destroy(&(fdp)->fd_sx)
182 #define FILEDESC_LOCK(fdp) (&(fdp)->fd_sx)
183 #define FILEDESC_XLOCK(fdp) sx_xlock(&(fdp)->fd_sx)
184 #define FILEDESC_XUNLOCK(fdp) sx_xunlock(&(fdp)->fd_sx)
185 #define FILEDESC_SLOCK(fdp) sx_slock(&(fdp)->fd_sx)
186 #define FILEDESC_SUNLOCK(fdp) sx_sunlock(&(fdp)->fd_sx)
188 #define FILEDESC_LOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_LOCKED | \
190 #define FILEDESC_XLOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_XLOCKED | \
192 #define FILEDESC_UNLOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_UNLOCKED)
194 #define FILEDESC_IS_ONLY_USER(fdp) ({ \
195 struct filedesc *_fdp = (fdp); \
196 MPASS(curproc->p_fd == _fdp); \
197 (curproc->p_numthreads == 1 && refcount_load(&_fdp->fd_refcnt) == 1); \
203 * Accessor for libkvm et al.
205 #define PWDDESC_KVM_LOAD_PWD(pdp) ({ \
206 struct pwddesc *_pdp = (pdp); \
208 _pwd = smr_kvm_load(&(_pdp)->pd_pwd); \
216 /* Operation types for kern_dup(). */
218 FDDUP_NORMAL, /* dup() behavior. */
219 FDDUP_FCNTL, /* fcntl()-style errors. */
220 FDDUP_FIXED, /* Force fixed allocation. */
224 /* Flags for kern_dup(). */
225 #define FDDUP_FLAG_CLOEXEC 0x1 /* Atomically set UF_EXCLOSE. */
227 /* For backward compatibility. */
228 #define falloc(td, resultfp, resultfd, flags) \
229 falloc_caps(td, resultfp, resultfd, flags, NULL)
235 filecaps_init(struct filecaps *fcaps)
238 bzero(fcaps, sizeof(*fcaps));
239 fcaps->fc_nioctls = -1;
241 bool filecaps_copy(const struct filecaps *src, struct filecaps *dst,
243 void filecaps_move(struct filecaps *src, struct filecaps *dst);
244 void filecaps_free(struct filecaps *fcaps);
246 int closef(struct file *fp, struct thread *td);
247 void closef_nothread(struct file *fp);
248 int descrip_check_write_mp(struct filedesc *fdp, struct mount *mp);
249 int dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode,
250 int openerror, int *indxp);
251 int falloc_caps(struct thread *td, struct file **resultfp, int *resultfd,
252 int flags, struct filecaps *fcaps);
253 void falloc_abort(struct thread *td, struct file *fp);
254 int _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n);
255 #define falloc_noinstall(td, resultfp) _falloc_noinstall(td, resultfp, 1)
256 void _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags,
257 struct filecaps *fcaps);
258 int finstall(struct thread *td, struct file *fp, int *resultfd, int flags,
259 struct filecaps *fcaps);
260 int finstall_refed(struct thread *td, struct file *fp, int *resultfd, int flags,
261 struct filecaps *fcaps);
262 int fdalloc(struct thread *td, int minfd, int *result);
263 int fdallocn(struct thread *td, int minfd, int *fds, int n);
264 int fdcheckstd(struct thread *td);
265 void fdclose(struct thread *td, struct file *fp, int idx);
266 void fdcloseexec(struct thread *td);
267 void fdsetugidsafety(struct thread *td);
268 struct filedesc *fdcopy(struct filedesc *fdp);
269 void fdunshare(struct thread *td);
270 void fdescfree(struct thread *td);
271 int fdlastfile(struct filedesc *fdp);
272 int fdlastfile_single(struct filedesc *fdp);
273 struct filedesc *fdinit(void);
274 struct filedesc *fdshare(struct filedesc *fdp);
275 struct filedesc_to_leader *
276 filedesc_to_leader_alloc(struct filedesc_to_leader *old,
277 struct filedesc *fdp, struct proc *leader);
278 struct filedesc_to_leader *
279 filedesc_to_leader_share(struct filedesc_to_leader *fdtol,
280 struct filedesc *fdp);
281 int getvnode(struct thread *td, int fd, cap_rights_t *rightsp,
283 int getvnode_path(struct thread *td, int fd, cap_rights_t *rightsp,
285 void mountcheckdirs(struct vnode *olddp, struct vnode *newdp);
287 int fget_cap_noref(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
288 struct file **fpp, struct filecaps *havecapsp);
289 int fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp,
290 struct file **fpp, struct filecaps *havecapsp);
291 /* Return a referenced file from an unlocked descriptor. */
292 int fget_unlocked(struct thread *td, int fd, cap_rights_t *needrightsp,
294 /* Return a file pointer without a ref. FILEDESC_IS_ONLY_USER must be true. */
295 int fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp,
297 #define fput_only_user(fdp, fp) ({ \
298 MPASS(FILEDESC_IS_ONLY_USER(fdp)); \
299 MPASS(refcount_load(&fp->f_count) > 0); \
302 /* Requires a FILEDESC_{S,X}LOCK held and returns without a ref. */
303 static __inline struct file *
304 fget_noref(struct filedesc *fdp, int fd)
307 FILEDESC_LOCK_ASSERT(fdp);
309 if (__predict_false((u_int)fd >= (u_int)fdp->fd_nfiles))
312 return (fdp->fd_ofiles[fd].fde_file);
315 static __inline struct filedescent *
316 fdeget_noref(struct filedesc *fdp, int fd)
318 struct filedescent *fde;
320 FILEDESC_LOCK_ASSERT(fdp);
322 if (__predict_false((u_int)fd >= (u_int)fdp->fd_nfiles))
325 fde = &fdp->fd_ofiles[fd];
326 if (__predict_false(fde->fde_file == NULL))
334 fd_modified(struct filedesc *fdp, int fd, seqc_t seqc)
337 return (!seqc_consistent(fd_seqc(fdp->fd_files, fd), seqc));
341 /* cdir/rdir/jdir manipulation functions. */
342 struct pwddesc *pdcopy(struct pwddesc *pdp);
343 void pdescfree(struct thread *td);
344 struct pwddesc *pdinit(struct pwddesc *pdp, bool keeplock);
345 struct pwddesc *pdshare(struct pwddesc *pdp);
346 void pdunshare(struct thread *td);
348 void pwd_altroot(struct thread *td, struct vnode *altroot_vp);
349 void pwd_chdir(struct thread *td, struct vnode *vp);
350 int pwd_chroot(struct thread *td, struct vnode *vp);
351 int pwd_chroot_chdir(struct thread *td, struct vnode *vp);
352 void pwd_ensure_dirs(void);
353 void pwd_set_rootvnode(void);
355 struct pwd *pwd_hold_pwddesc(struct pwddesc *pdp);
356 bool pwd_hold_smr(struct pwd *pwd);
357 struct pwd *pwd_hold_proc(struct proc *p);
358 struct pwd *pwd_hold(struct thread *td);
359 void pwd_drop(struct pwd *pwd);
361 pwd_set(struct pwddesc *pdp, struct pwd *newpwd)
363 smr_serialized_store(&pdp->pd_pwd, newpwd,
364 (PWDDESC_ASSERT_XLOCKED(pdp), true));
366 #define pwd_get_smr() vfs_smr_entered_load(&curproc->p_pd->pd_pwd)
370 #endif /* !_SYS_FILEDESC_H_ */