AMD64 - Fix many compile-time warnings. int/ptr type mismatches, %llx, etc.
[dragonfly.git] / sys / kern / kern_descrip.c
CommitLineData
984263bc 1/*
29d211fb
MD
2 * Copyright (c) 2005 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Jeffrey Hsu.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 *
984263bc
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35 * Copyright (c) 1982, 1986, 1989, 1991, 1993
36 * The Regents of the University of California. All rights reserved.
37 * (c) UNIX System Laboratories, Inc.
38 * All or some portions of this file are derived from material licensed
39 * to the University of California by American Telephone and Telegraph
40 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
41 * the permission of UNIX System Laboratories, Inc.
42 *
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
45 * are met:
46 * 1. Redistributions of source code must retain the above copyright
47 * notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 * notice, this list of conditions and the following disclaimer in the
50 * documentation and/or other materials provided with the distribution.
51 * 3. All advertising materials mentioning features or use of this software
52 * must display the following acknowledgement:
53 * This product includes software developed by the University of
54 * California, Berkeley and its contributors.
55 * 4. Neither the name of the University nor the names of its contributors
56 * may be used to endorse or promote products derived from this software
57 * without specific prior written permission.
58 *
59 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
62 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
69 * SUCH DAMAGE.
70 *
71 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94
c4cb6d8b 72 * $FreeBSD: src/sys/kern/kern_descrip.c,v 1.81.2.19 2004/02/28 00:43:31 tegge Exp $
8f9f2535 73 * $DragonFly: src/sys/kern/kern_descrip.c,v 1.79 2008/08/31 13:18:28 aggelos Exp $
984263bc
MD
74 */
75
76#include "opt_compat.h"
77#include <sys/param.h>
78#include <sys/systm.h>
79#include <sys/malloc.h>
80#include <sys/sysproto.h>
81#include <sys/conf.h>
fef8985e 82#include <sys/device.h>
984263bc
MD
83#include <sys/filedesc.h>
84#include <sys/kernel.h>
85#include <sys/sysctl.h>
86#include <sys/vnode.h>
87#include <sys/proc.h>
fad57d0e 88#include <sys/nlookup.h>
984263bc
MD
89#include <sys/file.h>
90#include <sys/stat.h>
91#include <sys/filio.h>
92#include <sys/fcntl.h>
93#include <sys/unistd.h>
94#include <sys/resourcevar.h>
95#include <sys/event.h>
dda4b42b 96#include <sys/kern_syscall.h>
1c55bd1c 97#include <sys/kcore.h>
7b124c9f 98#include <sys/kinfo.h>
ea8f324c 99#include <sys/un.h>
984263bc
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100
101#include <vm/vm.h>
102#include <vm/vm_extern.h>
103
e43a034f 104#include <sys/thread2.h>
dadab5e9 105#include <sys/file2.h>
85fceac1 106#include <sys/spinlock2.h>
dadab5e9 107
5b287bba
MD
108static void fsetfd_locked(struct filedesc *fdp, struct file *fp, int fd);
109static void fdreserve_locked (struct filedesc *fdp, int fd0, int incr);
110static struct file *funsetfd_locked (struct filedesc *fdp, int fd);
85fceac1 111static int checkfpclosed(struct filedesc *fdp, int fd, struct file *fp);
5b287bba 112static void ffree(struct file *fp);
fa541be6 113
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114static MALLOC_DEFINE(M_FILEDESC, "file desc", "Open file descriptor table");
115static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "file desc to leader",
116 "file desc to leader structures");
117MALLOC_DEFINE(M_FILE, "file", "Open file structure");
118static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures");
119
120static d_open_t fdopen;
121#define NUMFDESC 64
122
123#define CDEV_MAJOR 22
fef8985e
MD
124static struct dev_ops fildesc_ops = {
125 { "FD", CDEV_MAJOR, 0 },
126 .d_open = fdopen,
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MD
127};
128
402ed7e1 129static int badfo_readwrite (struct file *fp, struct uio *uio,
87de5057 130 struct ucred *cred, int flags);
402ed7e1 131static int badfo_ioctl (struct file *fp, u_long com, caddr_t data,
87de5057
MD
132 struct ucred *cred);
133static int badfo_poll (struct file *fp, int events, struct ucred *cred);
402ed7e1 134static int badfo_kqfilter (struct file *fp, struct knote *kn);
87de5057
MD
135static int badfo_stat (struct file *fp, struct stat *sb, struct ucred *cred);
136static int badfo_close (struct file *fp);
137static int badfo_shutdown (struct file *fp, int how);
984263bc
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138
139/*
140 * Descriptor management.
141 */
2dd63755
MD
142static struct filelist filehead = LIST_HEAD_INITIALIZER(&filehead);
143static struct spinlock filehead_spin = SPINLOCK_INITIALIZER(&filehead_spin);
144static int nfiles; /* actual number of open files */
984263bc
MD
145extern int cmask;
146
147/*
8247b2f9 148 * Fixup fd_freefile and fd_lastfile after a descriptor has been cleared.
5b287bba
MD
149 *
150 * MPSAFE - must be called with fdp->fd_spin exclusively held
8247b2f9
MD
151 */
152static __inline
153void
5b287bba 154fdfixup_locked(struct filedesc *fdp, int fd)
8247b2f9
MD
155{
156 if (fd < fdp->fd_freefile) {
157 fdp->fd_freefile = fd;
158 }
159 while (fdp->fd_lastfile >= 0 &&
160 fdp->fd_files[fdp->fd_lastfile].fp == NULL &&
161 fdp->fd_files[fdp->fd_lastfile].reserved == 0
162 ) {
163 --fdp->fd_lastfile;
164 }
165}
166
167/*
984263bc 168 * System calls on descriptors.
5b287bba
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169 *
170 * MPSAFE
984263bc 171 */
984263bc 172int
753fd850 173sys_getdtablesize(struct getdtablesize_args *uap)
984263bc 174{
41c20dac 175 struct proc *p = curproc;
5b287bba 176 struct plimit *limit = p->p_limit;
984263bc 177
5b287bba 178 spin_lock_rd(&limit->p_spin);
c7114eea 179 uap->sysmsg_result =
5b287bba
MD
180 min((int)limit->pl_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc);
181 spin_unlock_rd(&limit->p_spin);
984263bc
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182 return (0);
183}
184
185/*
186 * Duplicate a file descriptor to a particular value.
187 *
188 * note: keep in mind that a potential race condition exists when closing
189 * descriptors from a shared descriptor table (via rfork).
5b287bba
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190 *
191 * MPSAFE
984263bc 192 */
984263bc 193int
753fd850 194sys_dup2(struct dup2_args *uap)
984263bc 195{
dda4b42b 196 int error;
973c11b9 197 int fd = 0;
dda4b42b 198
973c11b9
MD
199 error = kern_dup(DUP_FIXED, uap->from, uap->to, &fd);
200 uap->sysmsg_fds[0] = fd;
dda4b42b
DRJ
201
202 return (error);
984263bc
MD
203}
204
205/*
206 * Duplicate a file descriptor.
5b287bba
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207 *
208 * MPSAFE
984263bc 209 */
984263bc 210int
753fd850 211sys_dup(struct dup_args *uap)
984263bc 212{
dda4b42b 213 int error;
973c11b9 214 int fd = 0;
984263bc 215
973c11b9
MD
216 error = kern_dup(DUP_VARIABLE, uap->fd, 0, &fd);
217 uap->sysmsg_fds[0] = fd;
dda4b42b
DRJ
218
219 return (error);
984263bc
MD
220}
221
5b287bba
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222/*
223 * MPALMOSTSAFE - acquires mplock for fp operations
224 */
984263bc 225int
87de5057 226kern_fcntl(int fd, int cmd, union fcntl_dat *dat, struct ucred *cred)
984263bc 227{
dadab5e9
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228 struct thread *td = curthread;
229 struct proc *p = td->td_proc;
41c20dac 230 struct file *fp;
984263bc 231 struct vnode *vp;
984263bc 232 u_int newmin;
9ba76b73 233 u_int oflags;
3a907475 234 u_int nflags;
dda4b42b 235 int tmp, error, flg = F_POSIX;
984263bc 236
dadab5e9
MD
237 KKASSERT(p);
238
5b287bba
MD
239 /*
240 * Operations on file descriptors that do not require a file pointer.
241 */
dda4b42b 242 switch (cmd) {
984263bc 243 case F_GETFD:
85fceac1
MD
244 error = fgetfdflags(p->p_fd, fd, &tmp);
245 if (error == 0)
246 dat->fc_cloexec = (tmp & UF_EXCLOSE) ? FD_CLOEXEC : 0;
5b287bba 247 return (error);
984263bc
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248
249 case F_SETFD:
85fceac1
MD
250 if (dat->fc_cloexec & FD_CLOEXEC)
251 error = fsetfdflags(p->p_fd, fd, UF_EXCLOSE);
252 else
253 error = fclrfdflags(p->p_fd, fd, UF_EXCLOSE);
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MD
254 return (error);
255 case F_DUPFD:
256 newmin = dat->fc_fd;
257 error = kern_dup(DUP_VARIABLE, fd, newmin, &dat->fc_fd);
258 return (error);
259 default:
85fceac1 260 break;
5b287bba 261 }
984263bc 262
5b287bba
MD
263 /*
264 * Operations on file pointers
265 */
266 if ((fp = holdfp(p->p_fd, fd, -1)) == NULL)
267 return (EBADF);
268
269 get_mplock();
270 switch (cmd) {
984263bc 271 case F_GETFL:
dda4b42b 272 dat->fc_flags = OFLAGS(fp->f_flag);
85fceac1
MD
273 error = 0;
274 break;
984263bc
MD
275
276 case F_SETFL:
3a907475
MD
277 oflags = fp->f_flag;
278 nflags = FFLAGS(dat->fc_flags & ~O_ACCMODE) & FCNTLFLAGS;
279 nflags |= oflags & ~FCNTLFLAGS;
280
f58b505b 281 error = 0;
3a907475
MD
282 if (((nflags ^ oflags) & O_APPEND) && (oflags & FAPPENDONLY))
283 error = EINVAL;
284 if (error == 0 && ((nflags ^ oflags) & FASYNC)) {
e8cdd284 285 tmp = nflags & FASYNC;
f58b505b
MD
286 error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, cred);
287 }
3a907475
MD
288 if (error == 0)
289 fp->f_flag = nflags;
85fceac1 290 break;
984263bc
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291
292 case F_GETOWN:
87de5057 293 error = fo_ioctl(fp, FIOGETOWN, (caddr_t)&dat->fc_owner, cred);
85fceac1 294 break;
984263bc
MD
295
296 case F_SETOWN:
87de5057 297 error = fo_ioctl(fp, FIOSETOWN, (caddr_t)&dat->fc_owner, cred);
85fceac1 298 break;
984263bc
MD
299
300 case F_SETLKW:
301 flg |= F_WAIT;
302 /* Fall into F_SETLK */
303
304 case F_SETLK:
85fceac1
MD
305 if (fp->f_type != DTYPE_VNODE) {
306 error = EBADF;
307 break;
308 }
984263bc
MD
309 vp = (struct vnode *)fp->f_data;
310
311 /*
312 * copyin/lockop may block
313 */
dda4b42b
DRJ
314 if (dat->fc_flock.l_whence == SEEK_CUR)
315 dat->fc_flock.l_start += fp->f_offset;
984263bc 316
dda4b42b 317 switch (dat->fc_flock.l_type) {
984263bc
MD
318 case F_RDLCK:
319 if ((fp->f_flag & FREAD) == 0) {
320 error = EBADF;
321 break;
322 }
323 p->p_leader->p_flag |= P_ADVLOCK;
324 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
dda4b42b 325 &dat->fc_flock, flg);
984263bc
MD
326 break;
327 case F_WRLCK:
328 if ((fp->f_flag & FWRITE) == 0) {
329 error = EBADF;
330 break;
331 }
332 p->p_leader->p_flag |= P_ADVLOCK;
333 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
dda4b42b 334 &dat->fc_flock, flg);
984263bc
MD
335 break;
336 case F_UNLCK:
337 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
dda4b42b 338 &dat->fc_flock, F_POSIX);
984263bc
MD
339 break;
340 default:
341 error = EINVAL;
342 break;
343 }
85fceac1
MD
344
345 /*
346 * It is possible to race a close() on the descriptor while
347 * we were blocked getting the lock. If this occurs the
348 * close might not have caught the lock.
349 */
350 if (checkfpclosed(p->p_fd, fd, fp)) {
dda4b42b
DRJ
351 dat->fc_flock.l_whence = SEEK_SET;
352 dat->fc_flock.l_start = 0;
353 dat->fc_flock.l_len = 0;
354 dat->fc_flock.l_type = F_UNLCK;
984263bc 355 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
dda4b42b 356 F_UNLCK, &dat->fc_flock, F_POSIX);
984263bc 357 }
85fceac1 358 break;
984263bc
MD
359
360 case F_GETLK:
85fceac1
MD
361 if (fp->f_type != DTYPE_VNODE) {
362 error = EBADF;
363 break;
364 }
984263bc
MD
365 vp = (struct vnode *)fp->f_data;
366 /*
367 * copyin/lockop may block
368 */
dda4b42b
DRJ
369 if (dat->fc_flock.l_type != F_RDLCK &&
370 dat->fc_flock.l_type != F_WRLCK &&
371 dat->fc_flock.l_type != F_UNLCK) {
85fceac1
MD
372 error = EINVAL;
373 break;
984263bc 374 }
dda4b42b
DRJ
375 if (dat->fc_flock.l_whence == SEEK_CUR)
376 dat->fc_flock.l_start += fp->f_offset;
984263bc 377 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK,
dda4b42b 378 &dat->fc_flock, F_POSIX);
85fceac1 379 break;
984263bc 380 default:
85fceac1
MD
381 error = EINVAL;
382 break;
984263bc 383 }
5b287bba
MD
384 rel_mplock();
385
85fceac1
MD
386 fdrop(fp);
387 return (error);
984263bc
MD
388}
389
390/*
dda4b42b 391 * The file control system call.
5b287bba
MD
392 *
393 * MPSAFE
dda4b42b
DRJ
394 */
395int
753fd850 396sys_fcntl(struct fcntl_args *uap)
dda4b42b
DRJ
397{
398 union fcntl_dat dat;
399 int error;
400
401 switch (uap->cmd) {
402 case F_DUPFD:
403 dat.fc_fd = uap->arg;
404 break;
405 case F_SETFD:
406 dat.fc_cloexec = uap->arg;
407 break;
408 case F_SETFL:
409 dat.fc_flags = uap->arg;
410 break;
411 case F_SETOWN:
412 dat.fc_owner = uap->arg;
413 break;
414 case F_SETLKW:
415 case F_SETLK:
416 case F_GETLK:
417 error = copyin((caddr_t)uap->arg, &dat.fc_flock,
5b287bba 418 sizeof(struct flock));
dda4b42b
DRJ
419 if (error)
420 return (error);
421 break;
422 }
423
87de5057 424 error = kern_fcntl(uap->fd, uap->cmd, &dat, curproc->p_ucred);
dda4b42b
DRJ
425
426 if (error == 0) {
427 switch (uap->cmd) {
428 case F_DUPFD:
429 uap->sysmsg_result = dat.fc_fd;
430 break;
431 case F_GETFD:
432 uap->sysmsg_result = dat.fc_cloexec;
433 break;
434 case F_GETFL:
435 uap->sysmsg_result = dat.fc_flags;
436 break;
437 case F_GETOWN:
438 uap->sysmsg_result = dat.fc_owner;
439 case F_GETLK:
440 error = copyout(&dat.fc_flock, (caddr_t)uap->arg,
441 sizeof(struct flock));
442 break;
443 }
444 }
445
446 return (error);
447}
448
449/*
984263bc 450 * Common code for dup, dup2, and fcntl(F_DUPFD).
dda4b42b
DRJ
451 *
452 * The type flag can be either DUP_FIXED or DUP_VARIABLE. DUP_FIXED tells
453 * kern_dup() to destructively dup over an existing file descriptor if new
454 * is already open. DUP_VARIABLE tells kern_dup() to find the lowest
455 * unused file descriptor that is greater than or equal to new.
5b287bba
MD
456 *
457 * MPSAFE
984263bc 458 */
dda4b42b
DRJ
459int
460kern_dup(enum dup_type type, int old, int new, int *res)
984263bc 461{
dda4b42b
DRJ
462 struct thread *td = curthread;
463 struct proc *p = td->td_proc;
464 struct filedesc *fdp = p->p_fd;
984263bc
MD
465 struct file *fp;
466 struct file *delfp;
259b8ea0 467 int oldflags;
984263bc 468 int holdleaders;
dda4b42b
DRJ
469 int error, newfd;
470
471 /*
472 * Verify that we have a valid descriptor to dup from and
473 * possibly to dup to.
474 */
259b8ea0 475retry:
5b287bba
MD
476 spin_lock_wr(&fdp->fd_spin);
477 if (new < 0 || new > p->p_rlimit[RLIMIT_NOFILE].rlim_cur ||
478 new >= maxfilesperproc) {
479 spin_unlock_wr(&fdp->fd_spin);
480 return (EINVAL);
481 }
482 if ((unsigned)old >= fdp->fd_nfiles || fdp->fd_files[old].fp == NULL) {
483 spin_unlock_wr(&fdp->fd_spin);
dda4b42b 484 return (EBADF);
5b287bba 485 }
dda4b42b
DRJ
486 if (type == DUP_FIXED && old == new) {
487 *res = new;
5b287bba 488 spin_unlock_wr(&fdp->fd_spin);
dda4b42b
DRJ
489 return (0);
490 }
0679adc4 491 fp = fdp->fd_files[old].fp;
259b8ea0 492 oldflags = fdp->fd_files[old].fileflags;
5b287bba 493 fhold(fp); /* MPSAFE - can be called with a spinlock held */
dda4b42b
DRJ
494
495 /*
259b8ea0
MD
496 * Allocate a new descriptor if DUP_VARIABLE, or expand the table
497 * if the requested descriptor is beyond the current table size.
498 *
499 * This can block. Retry if the source descriptor no longer matches
500 * or if our expectation in the expansion case races.
501 *
502 * If we are not expanding or allocating a new decriptor, then reset
503 * the target descriptor to a reserved state so we have a uniform
504 * setup for the next code block.
dda4b42b
DRJ
505 */
506 if (type == DUP_VARIABLE || new >= fdp->fd_nfiles) {
5b287bba 507 spin_unlock_wr(&fdp->fd_spin);
dda4b42b 508 error = fdalloc(p, new, &newfd);
5b287bba 509 spin_lock_wr(&fdp->fd_spin);
dda4b42b 510 if (error) {
5b287bba 511 spin_unlock_wr(&fdp->fd_spin);
9f87144f 512 fdrop(fp);
dda4b42b
DRJ
513 return (error);
514 }
5b287bba
MD
515 /*
516 * Check for ripout
517 */
259b8ea0 518 if (old >= fdp->fd_nfiles || fdp->fd_files[old].fp != fp) {
5b287bba
MD
519 fsetfd_locked(fdp, NULL, newfd);
520 spin_unlock_wr(&fdp->fd_spin);
259b8ea0
MD
521 fdrop(fp);
522 goto retry;
523 }
5b287bba
MD
524 /*
525 * Check for expansion race
526 */
259b8ea0 527 if (type != DUP_VARIABLE && new != newfd) {
5b287bba
MD
528 fsetfd_locked(fdp, NULL, newfd);
529 spin_unlock_wr(&fdp->fd_spin);
259b8ea0
MD
530 fdrop(fp);
531 goto retry;
532 }
5b287bba
MD
533 /*
534 * Check for ripout, newfd reused old (this case probably
535 * can't occur).
536 */
259b8ea0 537 if (old == newfd) {
5b287bba
MD
538 fsetfd_locked(fdp, NULL, newfd);
539 spin_unlock_wr(&fdp->fd_spin);
259b8ea0
MD
540 fdrop(fp);
541 goto retry;
542 }
dda4b42b 543 new = newfd;
259b8ea0
MD
544 delfp = NULL;
545 } else {
546 if (fdp->fd_files[new].reserved) {
5b287bba 547 spin_unlock_wr(&fdp->fd_spin);
259b8ea0 548 fdrop(fp);
6ea70f76 549 kprintf("Warning: dup(): target descriptor %d is reserved, waiting for it to be resolved\n", new);
259b8ea0
MD
550 tsleep(fdp, 0, "fdres", hz);
551 goto retry;
552 }
dda4b42b 553
259b8ea0
MD
554 /*
555 * If the target descriptor was never allocated we have
556 * to allocate it. If it was we have to clean out the
5b287bba
MD
557 * old descriptor. delfp inherits the ref from the
558 * descriptor table.
259b8ea0
MD
559 */
560 delfp = fdp->fd_files[new].fp;
561 fdp->fd_files[new].fp = NULL;
562 fdp->fd_files[new].reserved = 1;
563 if (delfp == NULL) {
5b287bba 564 fdreserve_locked(fdp, new, 1);
259b8ea0
MD
565 if (new > fdp->fd_lastfile)
566 fdp->fd_lastfile = new;
dda4b42b 567 }
259b8ea0 568
dda4b42b 569 }
984263bc
MD
570
571 /*
5b287bba
MD
572 * NOTE: still holding an exclusive spinlock
573 */
574
575 /*
259b8ea0
MD
576 * If a descriptor is being overwritten we may hve to tell
577 * fdfree() to sleep to ensure that all relevant process
578 * leaders can be traversed in closef().
984263bc 579 */
984263bc 580 if (delfp != NULL && p->p_fdtol != NULL) {
984263bc
MD
581 fdp->fd_holdleaderscount++;
582 holdleaders = 1;
259b8ea0 583 } else {
984263bc 584 holdleaders = 0;
259b8ea0 585 }
dda4b42b 586 KASSERT(delfp == NULL || type == DUP_FIXED,
259b8ea0 587 ("dup() picked an open file"));
984263bc
MD
588
589 /*
259b8ea0
MD
590 * Duplicate the source descriptor, update lastfile. If the new
591 * descriptor was not allocated and we aren't replacing an existing
592 * descriptor we have to mark the descriptor as being in use.
593 *
594 * The fd_files[] array inherits fp's hold reference.
984263bc 595 */
5b287bba 596 fsetfd_locked(fdp, fp, new);
259b8ea0 597 fdp->fd_files[new].fileflags = oldflags & ~UF_EXCLOSE;
5b287bba
MD
598 spin_unlock_wr(&fdp->fd_spin);
599 fdrop(fp);
dda4b42b 600 *res = new;
984263bc
MD
601
602 /*
603 * If we dup'd over a valid file, we now own the reference to it
604 * and must dispose of it using closef() semantics (as if a
605 * close() were performed on it).
606 */
607 if (delfp) {
b8477cda 608 closef(delfp, p);
984263bc 609 if (holdleaders) {
5b287bba 610 spin_lock_wr(&fdp->fd_spin);
984263bc
MD
611 fdp->fd_holdleaderscount--;
612 if (fdp->fd_holdleaderscount == 0 &&
613 fdp->fd_holdleaderswakeup != 0) {
614 fdp->fd_holdleaderswakeup = 0;
5b287bba 615 spin_unlock_wr(&fdp->fd_spin);
984263bc 616 wakeup(&fdp->fd_holdleaderscount);
5b287bba
MD
617 } else {
618 spin_unlock_wr(&fdp->fd_spin);
984263bc
MD
619 }
620 }
621 }
622 return (0);
623}
624
625/*
626 * If sigio is on the list associated with a process or process group,
627 * disable signalling from the device, remove sigio from the list and
628 * free sigio.
629 */
630void
7bf8660a 631funsetown(struct sigio *sigio)
984263bc 632{
984263bc
MD
633 if (sigio == NULL)
634 return;
e43a034f 635 crit_enter();
984263bc 636 *(sigio->sio_myref) = NULL;
e43a034f 637 crit_exit();
984263bc
MD
638 if (sigio->sio_pgid < 0) {
639 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio,
640 sigio, sio_pgsigio);
641 } else /* if ((*sigiop)->sio_pgid > 0) */ {
642 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio,
643 sigio, sio_pgsigio);
644 }
645 crfree(sigio->sio_ucred);
efda3bd0 646 kfree(sigio, M_SIGIO);
984263bc
MD
647}
648
649/* Free a list of sigio structures. */
650void
7bf8660a 651funsetownlst(struct sigiolst *sigiolst)
984263bc
MD
652{
653 struct sigio *sigio;
654
655 while ((sigio = SLIST_FIRST(sigiolst)) != NULL)
656 funsetown(sigio);
657}
658
659/*
660 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg).
661 *
662 * After permission checking, add a sigio structure to the sigio list for
663 * the process or process group.
664 */
665int
7bf8660a 666fsetown(pid_t pgid, struct sigio **sigiop)
984263bc
MD
667{
668 struct proc *proc;
669 struct pgrp *pgrp;
670 struct sigio *sigio;
984263bc
MD
671
672 if (pgid == 0) {
673 funsetown(*sigiop);
674 return (0);
675 }
676 if (pgid > 0) {
677 proc = pfind(pgid);
678 if (proc == NULL)
679 return (ESRCH);
680
681 /*
682 * Policy - Don't allow a process to FSETOWN a process
683 * in another session.
684 *
685 * Remove this test to allow maximum flexibility or
686 * restrict FSETOWN to the current process or process
687 * group for maximum safety.
688 */
689 if (proc->p_session != curproc->p_session)
690 return (EPERM);
691
692 pgrp = NULL;
693 } else /* if (pgid < 0) */ {
694 pgrp = pgfind(-pgid);
695 if (pgrp == NULL)
696 return (ESRCH);
697
698 /*
699 * Policy - Don't allow a process to FSETOWN a process
700 * in another session.
701 *
702 * Remove this test to allow maximum flexibility or
703 * restrict FSETOWN to the current process or process
704 * group for maximum safety.
705 */
706 if (pgrp->pg_session != curproc->p_session)
707 return (EPERM);
708
709 proc = NULL;
710 }
711 funsetown(*sigiop);
efda3bd0 712 sigio = kmalloc(sizeof(struct sigio), M_SIGIO, M_WAITOK);
984263bc
MD
713 if (pgid > 0) {
714 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio);
715 sigio->sio_proc = proc;
716 } else {
717 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio);
718 sigio->sio_pgrp = pgrp;
719 }
720 sigio->sio_pgid = pgid;
e9a372eb 721 sigio->sio_ucred = crhold(curproc->p_ucred);
984263bc 722 /* It would be convenient if p_ruid was in ucred. */
41c20dac 723 sigio->sio_ruid = curproc->p_ucred->cr_ruid;
984263bc 724 sigio->sio_myref = sigiop;
e43a034f 725 crit_enter();
984263bc 726 *sigiop = sigio;
e43a034f 727 crit_exit();
984263bc
MD
728 return (0);
729}
730
731/*
732 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg).
733 */
734pid_t
7bf8660a 735fgetown(struct sigio *sigio)
984263bc
MD
736{
737 return (sigio != NULL ? sigio->sio_pgid : 0);
738}
739
740/*
4336d5df 741 * Close many file descriptors.
5b287bba
MD
742 *
743 * MPSAFE
4336d5df 744 */
4336d5df 745int
753fd850 746sys_closefrom(struct closefrom_args *uap)
4336d5df
JS
747{
748 return(kern_closefrom(uap->fd));
749}
750
5b287bba
MD
751/*
752 * Close all file descriptors greater then or equal to fd
753 *
754 * MPSAFE
755 */
4336d5df
JS
756int
757kern_closefrom(int fd)
758{
759 struct thread *td = curthread;
760 struct proc *p = td->td_proc;
761 struct filedesc *fdp;
4336d5df
JS
762
763 KKASSERT(p);
764 fdp = p->p_fd;
765
5b287bba
MD
766 if (fd < 0)
767 return (EINVAL);
5e8cfac8 768
259b8ea0
MD
769 /*
770 * NOTE: This function will skip unassociated descriptors and
771 * reserved descriptors that have not yet been assigned.
772 * fd_lastfile can change as a side effect of kern_close().
773 */
5b287bba 774 spin_lock_wr(&fdp->fd_spin);
259b8ea0
MD
775 while (fd <= fdp->fd_lastfile) {
776 if (fdp->fd_files[fd].fp != NULL) {
5b287bba
MD
777 spin_unlock_wr(&fdp->fd_spin);
778 /* ok if this races another close */
259b8ea0
MD
779 if (kern_close(fd) == EINTR)
780 return (EINTR);
5b287bba 781 spin_lock_wr(&fdp->fd_spin);
259b8ea0
MD
782 }
783 ++fd;
784 }
5b287bba 785 spin_unlock_wr(&fdp->fd_spin);
4336d5df
JS
786 return (0);
787}
788
789/*
984263bc 790 * Close a file descriptor.
5b287bba
MD
791 *
792 * MPSAFE
984263bc 793 */
984263bc 794int
753fd850 795sys_close(struct close_args *uap)
984263bc 796{
12693083
MD
797 return(kern_close(uap->fd));
798}
799
5b287bba
MD
800/*
801 * MPALMOSTSAFE - acquires mplock around knote_fdclose() calls
802 */
12693083
MD
803int
804kern_close(int fd)
805{
dadab5e9
MD
806 struct thread *td = curthread;
807 struct proc *p = td->td_proc;
808 struct filedesc *fdp;
41c20dac 809 struct file *fp;
984263bc
MD
810 int error;
811 int holdleaders;
812
dadab5e9
MD
813 KKASSERT(p);
814 fdp = p->p_fd;
815
5b287bba
MD
816 spin_lock_wr(&fdp->fd_spin);
817 if ((fp = funsetfd_locked(fdp, fd)) == NULL) {
818 spin_unlock_wr(&fdp->fd_spin);
984263bc 819 return (EBADF);
5b287bba 820 }
984263bc
MD
821 holdleaders = 0;
822 if (p->p_fdtol != NULL) {
823 /*
824 * Ask fdfree() to sleep to ensure that all relevant
825 * process leaders can be traversed in closef().
826 */
827 fdp->fd_holdleaderscount++;
828 holdleaders = 1;
829 }
830
831 /*
832 * we now hold the fp reference that used to be owned by the descriptor
833 * array.
834 */
5b287bba
MD
835 spin_unlock_wr(&fdp->fd_spin);
836 if (fd < fdp->fd_knlistsize) {
837 get_mplock();
7749886d
MD
838 if (fd < fdp->fd_knlistsize)
839 knote_fdclose(p, fd);
5b287bba
MD
840 rel_mplock();
841 }
b8477cda 842 error = closef(fp, p);
984263bc 843 if (holdleaders) {
5b287bba 844 spin_lock_wr(&fdp->fd_spin);
984263bc
MD
845 fdp->fd_holdleaderscount--;
846 if (fdp->fd_holdleaderscount == 0 &&
847 fdp->fd_holdleaderswakeup != 0) {
848 fdp->fd_holdleaderswakeup = 0;
5b287bba 849 spin_unlock_wr(&fdp->fd_spin);
984263bc 850 wakeup(&fdp->fd_holdleaderscount);
5b287bba
MD
851 } else {
852 spin_unlock_wr(&fdp->fd_spin);
984263bc
MD
853 }
854 }
855 return (error);
856}
857
004d2de5
MD
858/*
859 * shutdown_args(int fd, int how)
860 */
861int
862kern_shutdown(int fd, int how)
863{
864 struct thread *td = curthread;
865 struct proc *p = td->td_proc;
004d2de5
MD
866 struct file *fp;
867 int error;
868
869 KKASSERT(p);
870
5b287bba 871 if ((fp = holdfp(p->p_fd, fd, -1)) == NULL)
004d2de5 872 return (EBADF);
87de5057 873 error = fo_shutdown(fp, how);
9f87144f 874 fdrop(fp);
004d2de5
MD
875
876 return (error);
877}
878
879int
753fd850 880sys_shutdown(struct shutdown_args *uap)
004d2de5
MD
881{
882 int error;
883
884 error = kern_shutdown(uap->s, uap->how);
885
886 return (error);
887}
888
984263bc 889int
8f6f8622 890kern_fstat(int fd, struct stat *ub)
984263bc 891{
dadab5e9
MD
892 struct thread *td = curthread;
893 struct proc *p = td->td_proc;
41c20dac 894 struct file *fp;
984263bc
MD
895 int error;
896
dadab5e9 897 KKASSERT(p);
8f6f8622 898
5b287bba 899 if ((fp = holdfp(p->p_fd, fd, -1)) == NULL)
984263bc 900 return (EBADF);
87de5057 901 error = fo_stat(fp, ub, p->p_ucred);
9f87144f 902 fdrop(fp);
8f6f8622 903
984263bc
MD
904 return (error);
905}
984263bc
MD
906
907/*
908 * Return status information about a file descriptor.
909 */
984263bc 910int
753fd850 911sys_fstat(struct fstat_args *uap)
984263bc 912{
8f6f8622 913 struct stat st;
984263bc
MD
914 int error;
915
8f6f8622
DRJ
916 error = kern_fstat(uap->fd, &st);
917
984263bc 918 if (error == 0)
8f6f8622 919 error = copyout(&st, uap->sb, sizeof(st));
984263bc
MD
920 return (error);
921}
922
923/*
984263bc
MD
924 * Return pathconf information about a file descriptor.
925 */
984263bc
MD
926/* ARGSUSED */
927int
753fd850 928sys_fpathconf(struct fpathconf_args *uap)
984263bc 929{
dadab5e9
MD
930 struct thread *td = curthread;
931 struct proc *p = td->td_proc;
984263bc
MD
932 struct file *fp;
933 struct vnode *vp;
934 int error = 0;
935
dadab5e9 936 KKASSERT(p);
984263bc 937
5b287bba
MD
938 if ((fp = holdfp(p->p_fd, uap->fd, -1)) == NULL)
939 return (EBADF);
984263bc
MD
940
941 switch (fp->f_type) {
942 case DTYPE_PIPE:
943 case DTYPE_SOCKET:
944 if (uap->name != _PC_PIPE_BUF) {
945 error = EINVAL;
946 } else {
c7114eea 947 uap->sysmsg_result = PIPE_BUF;
984263bc
MD
948 error = 0;
949 }
950 break;
951 case DTYPE_FIFO:
952 case DTYPE_VNODE:
953 vp = (struct vnode *)fp->f_data;
c7114eea 954 error = VOP_PATHCONF(vp, uap->name, uap->sysmsg_fds);
984263bc
MD
955 break;
956 default:
957 error = EOPNOTSUPP;
958 break;
959 }
9f87144f 960 fdrop(fp);
984263bc
MD
961 return(error);
962}
963
984263bc
MD
964static int fdexpand;
965SYSCTL_INT(_debug, OID_AUTO, fdexpand, CTLFLAG_RD, &fdexpand, 0, "");
966
5b287bba
MD
967/*
968 * Grow the file table so it can hold through descriptor (want).
969 *
970 * The fdp's spinlock must be held exclusively on entry and may be held
971 * exclusively on return. The spinlock may be cycled by the routine.
972 *
973 * MPSAFE
974 */
69908319 975static void
5b287bba 976fdgrow_locked(struct filedesc *fdp, int want)
69908319 977{
0679adc4
MD
978 struct fdnode *newfiles;
979 struct fdnode *oldfiles;
69908319
JH
980 int nf, extra;
981
982 nf = fdp->fd_nfiles;
983 do {
984 /* nf has to be of the form 2^n - 1 */
985 nf = 2 * nf + 1;
986 } while (nf <= want);
987
5b287bba 988 spin_unlock_wr(&fdp->fd_spin);
efda3bd0 989 newfiles = kmalloc(nf * sizeof(struct fdnode), M_FILEDESC, M_WAITOK);
5b287bba 990 spin_lock_wr(&fdp->fd_spin);
69908319
JH
991
992 /*
5b287bba
MD
993 * We could have raced another extend while we were not holding
994 * the spinlock.
69908319
JH
995 */
996 if (fdp->fd_nfiles >= nf) {
5b287bba 997 spin_unlock_wr(&fdp->fd_spin);
efda3bd0 998 kfree(newfiles, M_FILEDESC);
5b287bba 999 spin_lock_wr(&fdp->fd_spin);
69908319
JH
1000 return;
1001 }
69908319
JH
1002 /*
1003 * Copy the existing ofile and ofileflags arrays
1004 * and zero the new portion of each array.
1005 */
1006 extra = nf - fdp->fd_nfiles;
0679adc4
MD
1007 bcopy(fdp->fd_files, newfiles, fdp->fd_nfiles * sizeof(struct fdnode));
1008 bzero(&newfiles[fdp->fd_nfiles], extra * sizeof(struct fdnode));
1009
1010 oldfiles = fdp->fd_files;
1011 fdp->fd_files = newfiles;
69908319 1012 fdp->fd_nfiles = nf;
0679adc4 1013
5b287bba
MD
1014 if (oldfiles != fdp->fd_builtin_files) {
1015 spin_unlock_wr(&fdp->fd_spin);
efda3bd0 1016 kfree(oldfiles, M_FILEDESC);
5b287bba
MD
1017 spin_lock_wr(&fdp->fd_spin);
1018 }
69908319
JH
1019 fdexpand++;
1020}
1021
1022/*
1023 * Number of nodes in right subtree, including the root.
1024 */
1025static __inline int
1026right_subtree_size(int n)
1027{
1028 return (n ^ (n | (n + 1)));
1029}
1030
1031/*
1032 * Bigger ancestor.
1033 */
1034static __inline int
1035right_ancestor(int n)
1036{
1037 return (n | (n + 1));
1038}
1039
1040/*
1041 * Smaller ancestor.
1042 */
1043static __inline int
1044left_ancestor(int n)
1045{
1046 return ((n & (n + 1)) - 1);
1047}
1048
5b287bba
MD
1049/*
1050 * Traverse the in-place binary tree buttom-up adjusting the allocation
1051 * count so scans can determine where free descriptors are located.
1052 *
1053 * MPSAFE - caller must be holding an exclusive spinlock on fdp
1054 */
fa541be6 1055static
69908319 1056void
5b287bba 1057fdreserve_locked(struct filedesc *fdp, int fd, int incr)
69908319
JH
1058{
1059 while (fd >= 0) {
0679adc4
MD
1060 fdp->fd_files[fd].allocated += incr;
1061 KKASSERT(fdp->fd_files[fd].allocated >= 0);
69908319
JH
1062 fd = left_ancestor(fd);
1063 }
1064}
1065
1066/*
259b8ea0
MD
1067 * Reserve a file descriptor for the process. If no error occurs, the
1068 * caller MUST at some point call fsetfd() or assign a file pointer
1069 * or dispose of the reservation.
5b287bba
MD
1070 *
1071 * MPSAFE
69908319 1072 */
984263bc 1073int
dda4b42b 1074fdalloc(struct proc *p, int want, int *result)
984263bc 1075{
41c20dac 1076 struct filedesc *fdp = p->p_fd;
69908319
JH
1077 int fd, rsize, rsum, node, lim;
1078
5b287bba 1079 spin_lock_rd(&p->p_limit->p_spin);
69908319 1080 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc);
5b287bba 1081 spin_unlock_rd(&p->p_limit->p_spin);
69908319
JH
1082 if (want >= lim)
1083 return (EMFILE);
5b287bba 1084 spin_lock_wr(&fdp->fd_spin);
69908319 1085 if (want >= fdp->fd_nfiles)
5b287bba 1086 fdgrow_locked(fdp, want);
984263bc
MD
1087
1088 /*
1089 * Search for a free descriptor starting at the higher
1090 * of want or fd_freefile. If that fails, consider
1091 * expanding the ofile array.
259b8ea0
MD
1092 *
1093 * NOTE! the 'allocated' field is a cumulative recursive allocation
1094 * count. If we happen to see a value of 0 then we can shortcut
1095 * our search. Otherwise we run through through the tree going
1096 * down branches we know have free descriptor(s) until we hit a
1097 * leaf node. The leaf node will be free but will not necessarily
1098 * have an allocated field of 0.
984263bc 1099 */
69908319
JH
1100retry:
1101 /* move up the tree looking for a subtree with a free node */
1102 for (fd = max(want, fdp->fd_freefile); fd < min(fdp->fd_nfiles, lim);
1103 fd = right_ancestor(fd)) {
0679adc4 1104 if (fdp->fd_files[fd].allocated == 0)
69908319 1105 goto found;
984263bc 1106
69908319 1107 rsize = right_subtree_size(fd);
0679adc4 1108 if (fdp->fd_files[fd].allocated == rsize)
69908319 1109 continue; /* right subtree full */
984263bc
MD
1110
1111 /*
69908319
JH
1112 * Free fd is in the right subtree of the tree rooted at fd.
1113 * Call that subtree R. Look for the smallest (leftmost)
1114 * subtree of R with an unallocated fd: continue moving
1115 * down the left branch until encountering a full left
1116 * subtree, then move to the right.
984263bc 1117 */
69908319
JH
1118 for (rsum = 0, rsize /= 2; rsize > 0; rsize /= 2) {
1119 node = fd + rsize;
0679adc4
MD
1120 rsum += fdp->fd_files[node].allocated;
1121 if (fdp->fd_files[fd].allocated == rsum + rsize) {
69908319 1122 fd = node; /* move to the right */
0679adc4 1123 if (fdp->fd_files[node].allocated == 0)
69908319
JH
1124 goto found;
1125 rsum = 0;
1126 }
984263bc 1127 }
69908319 1128 goto found;
984263bc 1129 }
69908319
JH
1130
1131 /*
1132 * No space in current array. Expand?
1133 */
5b287bba
MD
1134 if (fdp->fd_nfiles >= lim) {
1135 spin_unlock_wr(&fdp->fd_spin);
69908319 1136 return (EMFILE);
5b287bba
MD
1137 }
1138 fdgrow_locked(fdp, want);
69908319
JH
1139 goto retry;
1140
1141found:
1142 KKASSERT(fd < fdp->fd_nfiles);
69908319
JH
1143 if (fd > fdp->fd_lastfile)
1144 fdp->fd_lastfile = fd;
1145 if (want <= fdp->fd_freefile)
1146 fdp->fd_freefile = fd;
1147 *result = fd;
0679adc4 1148 KKASSERT(fdp->fd_files[fd].fp == NULL);
259b8ea0
MD
1149 KKASSERT(fdp->fd_files[fd].reserved == 0);
1150 fdp->fd_files[fd].fileflags = 0;
1151 fdp->fd_files[fd].reserved = 1;
5b287bba
MD
1152 fdreserve_locked(fdp, fd, 1);
1153 spin_unlock_wr(&fdp->fd_spin);
984263bc
MD
1154 return (0);
1155}
1156
1157/*
1158 * Check to see whether n user file descriptors
1159 * are available to the process p.
5b287bba
MD
1160 *
1161 * MPSAFE
984263bc
MD
1162 */
1163int
7bf8660a 1164fdavail(struct proc *p, int n)
984263bc 1165{
41c20dac 1166 struct filedesc *fdp = p->p_fd;
0679adc4 1167 struct fdnode *fdnode;
41c20dac 1168 int i, lim, last;
984263bc 1169
5b287bba 1170 spin_lock_rd(&p->p_limit->p_spin);
984263bc 1171 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc);
5b287bba 1172 spin_unlock_rd(&p->p_limit->p_spin);
984263bc 1173
5b287bba
MD
1174 spin_lock_rd(&fdp->fd_spin);
1175 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0) {
1176 spin_unlock_rd(&fdp->fd_spin);
1177 return (1);
1178 }
984263bc 1179 last = min(fdp->fd_nfiles, lim);
0679adc4
MD
1180 fdnode = &fdp->fd_files[fdp->fd_freefile];
1181 for (i = last - fdp->fd_freefile; --i >= 0; ++fdnode) {
5b287bba
MD
1182 if (fdnode->fp == NULL && --n <= 0) {
1183 spin_unlock_rd(&fdp->fd_spin);
984263bc 1184 return (1);
5b287bba 1185 }
984263bc 1186 }
5b287bba 1187 spin_unlock_rd(&fdp->fd_spin);
984263bc
MD
1188 return (0);
1189}
1190
1191/*
b8477cda
MD
1192 * Revoke open descriptors referencing (f_data, f_type)
1193 *
1194 * Any revoke executed within a prison is only able to
1195 * revoke descriptors for processes within that prison.
1196 *
1197 * Returns 0 on success or an error code.
1198 */
1199struct fdrevoke_info {
1200 void *data;
1201 short type;
1202 short unused;
1203 int count;
ea8f324c 1204 int intransit;
b8477cda
MD
1205 struct ucred *cred;
1206 struct file *nfp;
1207};
1208
ea8f324c
MD
1209static int fdrevoke_check_callback(struct file *fp, void *vinfo);
1210static int fdrevoke_proc_callback(struct proc *p, void *vinfo);
b8477cda
MD
1211
1212int
1213fdrevoke(void *f_data, short f_type, struct ucred *cred)
1214{
1215 struct fdrevoke_info info;
1216 int error;
1217
1218 bzero(&info, sizeof(info));
1219 info.data = f_data;
1220 info.type = f_type;
1221 info.cred = cred;
1222 error = falloc(NULL, &info.nfp, NULL);
1223 if (error)
1224 return (error);
ea8f324c
MD
1225
1226 /*
1227 * Scan the file pointer table once. dups do not dup file pointers,
1228 * only descriptors, so there is no leak. Set FREVOKED on the fps
1229 * being revoked.
1230 */
1231 allfiles_scan_exclusive(fdrevoke_check_callback, &info);
1232
1233 /*
1234 * If any fps were marked track down the related descriptors
1235 * and close them. Any dup()s at this point will notice
1236 * the FREVOKED already set in the fp and do the right thing.
1237 *
1238 * Any fps with non-zero msgcounts (aka sent over a unix-domain
1239 * socket) bumped the intransit counter and will require a
1240 * scan. Races against fps leaving the socket are closed by
1241 * the socket code checking for FREVOKED.
1242 */
1243 if (info.count)
1244 allproc_scan(fdrevoke_proc_callback, &info);
1245 if (info.intransit)
1246 unp_revoke_gc(info.nfp);
b8477cda 1247 fdrop(info.nfp);
ea8f324c 1248 return(0);
b8477cda
MD
1249}
1250
ea8f324c
MD
1251/*
1252 * Locate matching file pointers directly.
1253 */
b8477cda 1254static int
ea8f324c
MD
1255fdrevoke_check_callback(struct file *fp, void *vinfo)
1256{
1257 struct fdrevoke_info *info = vinfo;
1258
1259 /*
1260 * File pointers already flagged for revokation are skipped.
1261 */
1262 if (fp->f_flag & FREVOKED)
1263 return(0);
1264
1265 /*
1266 * If revoking from a prison file pointers created outside of
1267 * that prison, or file pointers without creds, cannot be revoked.
1268 */
1269 if (info->cred->cr_prison &&
1270 (fp->f_cred == NULL ||
1271 info->cred->cr_prison != fp->f_cred->cr_prison)) {
1272 return(0);
1273 }
1274
1275 /*
1276 * If the file pointer matches then mark it for revocation. The
1277 * flag is currently only used by unp_revoke_gc().
1278 *
1279 * info->count is a heuristic and can race in a SMP environment.
1280 */
1281 if (info->data == fp->f_data && info->type == fp->f_type) {
1282 atomic_set_int(&fp->f_flag, FREVOKED);
1283 info->count += fp->f_count;
1284 if (fp->f_msgcount)
1285 ++info->intransit;
1286 }
1287 return(0);
1288}
1289
1290/*
1291 * Locate matching file pointers via process descriptor tables.
1292 */
1293static int
1294fdrevoke_proc_callback(struct proc *p, void *vinfo)
b8477cda
MD
1295{
1296 struct fdrevoke_info *info = vinfo;
1297 struct filedesc *fdp;
1298 struct file *fp;
1299 int n;
1300
1301 if (p->p_stat == SIDL || p->p_stat == SZOMB)
1302 return(0);
1303 if (info->cred->cr_prison &&
1304 info->cred->cr_prison != p->p_ucred->cr_prison) {
1305 return(0);
1306 }
1307
1308 /*
1309 * If the controlling terminal of the process matches the
1310 * vnode being revoked we clear the controlling terminal.
1311 *
1312 * The normal spec_close() may not catch this because it
1313 * uses curproc instead of p.
1314 */
1315 if (p->p_session && info->type == DTYPE_VNODE &&
1316 info->data == p->p_session->s_ttyvp) {
1317 p->p_session->s_ttyvp = NULL;
1318 vrele(info->data);
1319 }
1320
1321 /*
1322 * Locate and close any matching file descriptors.
1323 */
1324 if ((fdp = p->p_fd) == NULL)
1325 return(0);
1326 spin_lock_wr(&fdp->fd_spin);
1327 for (n = 0; n < fdp->fd_nfiles; ++n) {
1328 if ((fp = fdp->fd_files[n].fp) == NULL)
1329 continue;
ea8f324c 1330 if (fp->f_flag & FREVOKED) {
b8477cda
MD
1331 fhold(info->nfp);
1332 fdp->fd_files[n].fp = info->nfp;
1333 spin_unlock_wr(&fdp->fd_spin);
1334 closef(fp, p);
1335 spin_lock_wr(&fdp->fd_spin);
ea8f324c 1336 --info->count;
b8477cda
MD
1337 }
1338 }
1339 spin_unlock_wr(&fdp->fd_spin);
1340 return(0);
1341}
1342
1343/*
39f91578 1344 * falloc:
259b8ea0
MD
1345 * Create a new open file structure and reserve a file decriptor
1346 * for the process that refers to it.
1347 *
1348 * Root creds are checked using p, or assumed if p is NULL. If
1349 * resultfd is non-NULL then p must also be non-NULL. No file
1350 * descriptor is reserved if resultfd is NULL.
fad57d0e 1351 *
259b8ea0
MD
1352 * A file pointer with a refcount of 1 is returned. Note that the
1353 * file pointer is NOT associated with the descriptor. If falloc
1354 * returns success, fsetfd() MUST be called to either associate the
1355 * file pointer or clear the reservation.
5b287bba 1356 *
2dd63755 1357 * MPSAFE
984263bc
MD
1358 */
1359int
39f91578 1360falloc(struct proc *p, struct file **resultfp, int *resultfd)
984263bc 1361{
c4cb6d8b
HP
1362 static struct timeval lastfail;
1363 static int curfail;
fad57d0e
MD
1364 struct file *fp;
1365 int error;
c4cb6d8b 1366
fad57d0e
MD
1367 fp = NULL;
1368
1369 /*
1370 * Handle filetable full issues and root overfill.
1371 */
60ee93b9 1372 if (nfiles >= maxfiles - maxfilesrootres &&
9b3f1fd5 1373 ((p && p->p_ucred->cr_ruid != 0) || nfiles >= maxfiles)) {
c4cb6d8b 1374 if (ppsratecheck(&lastfail, &curfail, 1)) {
6ea70f76 1375 kprintf("kern.maxfiles limit exceeded by uid %d, please see tuning(7).\n",
9b3f1fd5 1376 (p ? p->p_ucred->cr_ruid : -1));
c4cb6d8b 1377 }
fad57d0e
MD
1378 error = ENFILE;
1379 goto done;
984263bc 1380 }
fad57d0e 1381
984263bc
MD
1382 /*
1383 * Allocate a new file descriptor.
984263bc 1384 */
efda3bd0 1385 fp = kmalloc(sizeof(struct file), M_FILE, M_WAITOK | M_ZERO);
85fceac1 1386 spin_init(&fp->f_spin);
984263bc 1387 fp->f_count = 1;
984263bc
MD
1388 fp->f_ops = &badfileops;
1389 fp->f_seqcount = 1;
fad57d0e 1390 if (p)
a235f7bb 1391 fp->f_cred = crhold(p->p_ucred);
fad57d0e
MD
1392 else
1393 fp->f_cred = crhold(proc0.p_ucred);
2dd63755
MD
1394 spin_lock_wr(&filehead_spin);
1395 nfiles++;
fad57d0e 1396 LIST_INSERT_HEAD(&filehead, fp, f_list);
2dd63755 1397 spin_unlock_wr(&filehead_spin);
fad57d0e 1398 if (resultfd) {
259b8ea0 1399 if ((error = fdalloc(p, 0, resultfd)) != 0) {
9f87144f 1400 fdrop(fp);
fad57d0e 1401 fp = NULL;
39f91578 1402 }
a235f7bb 1403 } else {
fad57d0e 1404 error = 0;
984263bc 1405 }
fad57d0e
MD
1406done:
1407 *resultfp = fp;
64f33bc8 1408 return (error);
fad57d0e
MD
1409}
1410
1411/*
85fceac1
MD
1412 * MPSAFE
1413 */
1414static
1415int
1416checkfpclosed(struct filedesc *fdp, int fd, struct file *fp)
1417{
1418 int error;
1419
1420 spin_lock_rd(&fdp->fd_spin);
1421 if ((unsigned) fd >= fdp->fd_nfiles || fp != fdp->fd_files[fd].fp)
1422 error = EBADF;
1423 else
1424 error = 0;
1425 spin_unlock_rd(&fdp->fd_spin);
1426 return (error);
1427}
1428
1429/*
259b8ea0
MD
1430 * Associate a file pointer with a previously reserved file descriptor.
1431 * This function always succeeds.
1432 *
1433 * If fp is NULL, the file descriptor is returned to the pool.
fad57d0e 1434 */
fad57d0e 1435
5b287bba
MD
1436/*
1437 * MPSAFE (exclusive spinlock must be held on call)
1438 */
1439static void
1440fsetfd_locked(struct filedesc *fdp, struct file *fp, int fd)
1441{
259b8ea0
MD
1442 KKASSERT((unsigned)fd < fdp->fd_nfiles);
1443 KKASSERT(fdp->fd_files[fd].reserved != 0);
1444 if (fp) {
fad57d0e 1445 fhold(fp);
259b8ea0
MD
1446 fdp->fd_files[fd].fp = fp;
1447 fdp->fd_files[fd].reserved = 0;
d9b2033e
MD
1448 if (fp->f_type == DTYPE_KQUEUE) {
1449 if (fdp->fd_knlistsize < 0)
1450 fdp->fd_knlistsize = 0;
1451 }
259b8ea0
MD
1452 } else {
1453 fdp->fd_files[fd].reserved = 0;
5b287bba
MD
1454 fdreserve_locked(fdp, fd, -1);
1455 fdfixup_locked(fdp, fd);
fad57d0e 1456 }
984263bc
MD
1457}
1458
5b287bba
MD
1459/*
1460 * MPSAFE
1461 */
1462void
1463fsetfd(struct proc *p, struct file *fp, int fd)
1464{
1465 struct filedesc *fdp = p->p_fd;
1466
1467 spin_lock_wr(&fdp->fd_spin);
1468 fsetfd_locked(fdp, fp, fd);
1469 spin_unlock_wr(&fdp->fd_spin);
1470}
1471
1472/*
1473 * MPSAFE (exclusive spinlock must be held on call)
1474 */
fa541be6 1475static
259b8ea0 1476struct file *
5b287bba 1477funsetfd_locked(struct filedesc *fdp, int fd)
69908319 1478{
259b8ea0
MD
1479 struct file *fp;
1480
1481 if ((unsigned)fd >= fdp->fd_nfiles)
1482 return (NULL);
1483 if ((fp = fdp->fd_files[fd].fp) == NULL)
1484 return (NULL);
0679adc4
MD
1485 fdp->fd_files[fd].fp = NULL;
1486 fdp->fd_files[fd].fileflags = 0;
259b8ea0 1487
5b287bba
MD
1488 fdreserve_locked(fdp, fd, -1);
1489 fdfixup_locked(fdp, fd);
259b8ea0 1490 return(fp);
69908319
JH
1491}
1492
85fceac1
MD
1493/*
1494 * MPSAFE
1495 */
1496int
1497fgetfdflags(struct filedesc *fdp, int fd, int *flagsp)
1498{
1499 int error;
1500
1501 spin_lock_rd(&fdp->fd_spin);
1502 if (((u_int)fd) >= fdp->fd_nfiles) {
1503 error = EBADF;
1504 } else if (fdp->fd_files[fd].fp == NULL) {
1505 error = EBADF;
1506 } else {
1507 *flagsp = fdp->fd_files[fd].fileflags;
1508 error = 0;
1509 }
1510 spin_unlock_rd(&fdp->fd_spin);
1511 return (error);
1512}
1513
1514/*
1515 * MPSAFE
1516 */
228b401d
MD
1517int
1518fsetfdflags(struct filedesc *fdp, int fd, int add_flags)
1519{
85fceac1
MD
1520 int error;
1521
1522 spin_lock_wr(&fdp->fd_spin);
1523 if (((u_int)fd) >= fdp->fd_nfiles) {
1524 error = EBADF;
1525 } else if (fdp->fd_files[fd].fp == NULL) {
1526 error = EBADF;
1527 } else {
1528 fdp->fd_files[fd].fileflags |= add_flags;
1529 error = 0;
1530 }
1531 spin_unlock_wr(&fdp->fd_spin);
1532 return (error);
228b401d
MD
1533}
1534
85fceac1
MD
1535/*
1536 * MPSAFE
1537 */
228b401d
MD
1538int
1539fclrfdflags(struct filedesc *fdp, int fd, int rem_flags)
1540{
85fceac1
MD
1541 int error;
1542
1543 spin_lock_wr(&fdp->fd_spin);
1544 if (((u_int)fd) >= fdp->fd_nfiles) {
1545 error = EBADF;
1546 } else if (fdp->fd_files[fd].fp == NULL) {
1547 error = EBADF;
1548 } else {
1549 fdp->fd_files[fd].fileflags &= ~rem_flags;
1550 error = 0;
1551 }
1552 spin_unlock_wr(&fdp->fd_spin);
1553 return (error);
228b401d
MD
1554}
1555
69908319 1556void
a235f7bb
MD
1557fsetcred(struct file *fp, struct ucred *cr)
1558{
1559 crhold(cr);
1560 crfree(fp->f_cred);
1561 fp->f_cred = cr;
1562}
1563
984263bc
MD
1564/*
1565 * Free a file descriptor.
1566 */
5b287bba 1567static
984263bc 1568void
7bf8660a 1569ffree(struct file *fp)
984263bc
MD
1570{
1571 KASSERT((fp->f_count == 0), ("ffree: fp_fcount not 0!"));
2dd63755 1572 spin_lock_wr(&filehead_spin);
984263bc 1573 LIST_REMOVE(fp, f_list);
2dd63755
MD
1574 nfiles--;
1575 spin_unlock_wr(&filehead_spin);
984263bc 1576 crfree(fp->f_cred);
28623bf9
MD
1577 if (fp->f_nchandle.ncp)
1578 cache_drop(&fp->f_nchandle);
efda3bd0 1579 kfree(fp, M_FILE);
984263bc
MD
1580}
1581
1582/*
228b401d
MD
1583 * called from init_main, initialize filedesc0 for proc0.
1584 */
1585void
1586fdinit_bootstrap(struct proc *p0, struct filedesc *fdp0, int cmask)
1587{
1588 p0->p_fd = fdp0;
1589 p0->p_fdtol = NULL;
1590 fdp0->fd_refcnt = 1;
1591 fdp0->fd_cmask = cmask;
1592 fdp0->fd_files = fdp0->fd_builtin_files;
1593 fdp0->fd_nfiles = NDFILE;
259b8ea0 1594 fdp0->fd_lastfile = -1;
85fceac1 1595 spin_init(&fdp0->fd_spin);
228b401d
MD
1596}
1597
1598/*
984263bc 1599 * Build a new filedesc structure.
5b287bba
MD
1600 *
1601 * NOT MPSAFE (vref)
984263bc
MD
1602 */
1603struct filedesc *
7bf8660a 1604fdinit(struct proc *p)
984263bc 1605{
0679adc4 1606 struct filedesc *newfdp;
41c20dac 1607 struct filedesc *fdp = p->p_fd;
984263bc 1608
efda3bd0 1609 newfdp = kmalloc(sizeof(struct filedesc), M_FILEDESC, M_WAITOK|M_ZERO);
5b287bba 1610 spin_lock_rd(&fdp->fd_spin);
bccde7a3 1611 if (fdp->fd_cdir) {
0679adc4
MD
1612 newfdp->fd_cdir = fdp->fd_cdir;
1613 vref(newfdp->fd_cdir);
28623bf9 1614 cache_copy(&fdp->fd_ncdir, &newfdp->fd_ncdir);
690a3127 1615 }
bccde7a3
MD
1616
1617 /*
1618 * rdir may not be set in e.g. proc0 or anything vm_fork'd off of
1619 * proc0, but should unconditionally exist in other processes.
1620 */
1621 if (fdp->fd_rdir) {
0679adc4
MD
1622 newfdp->fd_rdir = fdp->fd_rdir;
1623 vref(newfdp->fd_rdir);
28623bf9 1624 cache_copy(&fdp->fd_nrdir, &newfdp->fd_nrdir);
bccde7a3
MD
1625 }
1626 if (fdp->fd_jdir) {
0679adc4
MD
1627 newfdp->fd_jdir = fdp->fd_jdir;
1628 vref(newfdp->fd_jdir);
28623bf9 1629 cache_copy(&fdp->fd_njdir, &newfdp->fd_njdir);
690a3127 1630 }
5b287bba 1631 spin_unlock_rd(&fdp->fd_spin);
690a3127 1632
984263bc 1633 /* Create the file descriptor table. */
0679adc4
MD
1634 newfdp->fd_refcnt = 1;
1635 newfdp->fd_cmask = cmask;
1636 newfdp->fd_files = newfdp->fd_builtin_files;
1637 newfdp->fd_nfiles = NDFILE;
1638 newfdp->fd_knlistsize = -1;
259b8ea0 1639 newfdp->fd_lastfile = -1;
85fceac1 1640 spin_init(&newfdp->fd_spin);
0679adc4
MD
1641
1642 return (newfdp);
984263bc
MD
1643}
1644
1645/*
1646 * Share a filedesc structure.
5b287bba
MD
1647 *
1648 * MPSAFE
984263bc
MD
1649 */
1650struct filedesc *
7bf8660a 1651fdshare(struct proc *p)
984263bc 1652{
5b287bba
MD
1653 struct filedesc *fdp;
1654
1655 fdp = p->p_fd;
1656 spin_lock_wr(&fdp->fd_spin);
1657 fdp->fd_refcnt++;
1658 spin_unlock_wr(&fdp->fd_spin);
1659 return (fdp);
984263bc
MD
1660}
1661
1662/*
1663 * Copy a filedesc structure.
5b287bba
MD
1664 *
1665 * MPSAFE
984263bc
MD
1666 */
1667struct filedesc *
7bf8660a 1668fdcopy(struct proc *p)
984263bc 1669{
5b287bba
MD
1670 struct filedesc *fdp = p->p_fd;
1671 struct filedesc *newfdp;
0679adc4 1672 struct fdnode *fdnode;
41c20dac 1673 int i;
5b287bba 1674 int ni;
984263bc 1675
5b287bba
MD
1676 /*
1677 * Certain daemons might not have file descriptors.
1678 */
984263bc
MD
1679 if (fdp == NULL)
1680 return (NULL);
1681
5b287bba
MD
1682 /*
1683 * Allocate the new filedesc and fd_files[] array. This can race
1684 * with operations by other threads on the fdp so we have to be
1685 * careful.
1686 */
efda3bd0 1687 newfdp = kmalloc(sizeof(struct filedesc), M_FILEDESC, M_WAITOK | M_ZERO);
5b287bba
MD
1688again:
1689 spin_lock_rd(&fdp->fd_spin);
1690 if (fdp->fd_lastfile < NDFILE) {
1691 newfdp->fd_files = newfdp->fd_builtin_files;
1692 i = NDFILE;
1693 } else {
1694 /*
1695 * We have to allocate (N^2-1) entries for our in-place
1696 * binary tree. Allow the table to shrink.
1697 */
1698 i = fdp->fd_nfiles;
1699 ni = (i - 1) / 2;
1700 while (ni > fdp->fd_lastfile && ni > NDFILE) {
1701 i = ni;
1702 ni = (i - 1) / 2;
1703 }
1704 spin_unlock_rd(&fdp->fd_spin);
77652cad 1705 newfdp->fd_files = kmalloc(i * sizeof(struct fdnode),
5b287bba
MD
1706 M_FILEDESC, M_WAITOK | M_ZERO);
1707
1708 /*
1709 * Check for race, retry
1710 */
1711 spin_lock_rd(&fdp->fd_spin);
1712 if (i <= fdp->fd_lastfile) {
1713 spin_unlock_rd(&fdp->fd_spin);
efda3bd0 1714 kfree(newfdp->fd_files, M_FILEDESC);
5b287bba
MD
1715 goto again;
1716 }
1717 }
1718
1719 /*
1720 * Dup the remaining fields. vref() and cache_hold() can be
1721 * safely called while holding the read spinlock on fdp.
1722 *
1723 * The read spinlock on fdp is still being held.
1724 *
1725 * NOTE: vref and cache_hold calls for the case where the vnode
1726 * or cache entry already has at least one ref may be called
1727 * while holding spin locks.
1728 */
1729 if ((newfdp->fd_cdir = fdp->fd_cdir) != NULL) {
597aea93 1730 vref(newfdp->fd_cdir);
28623bf9 1731 cache_copy(&fdp->fd_ncdir, &newfdp->fd_ncdir);
690a3127 1732 }
6bdbb368
DR
1733 /*
1734 * We must check for fd_rdir here, at least for now because
1735 * the init process is created before we have access to the
1736 * rootvode to take a reference to it.
1737 */
5b287bba 1738 if ((newfdp->fd_rdir = fdp->fd_rdir) != NULL) {
597aea93 1739 vref(newfdp->fd_rdir);
28623bf9 1740 cache_copy(&fdp->fd_nrdir, &newfdp->fd_nrdir);
690a3127 1741 }
5b287bba 1742 if ((newfdp->fd_jdir = fdp->fd_jdir) != NULL) {
597aea93 1743 vref(newfdp->fd_jdir);
28623bf9 1744 cache_copy(&fdp->fd_njdir, &newfdp->fd_njdir);
690a3127 1745 }
984263bc 1746 newfdp->fd_refcnt = 1;
984263bc 1747 newfdp->fd_nfiles = i;
5b287bba
MD
1748 newfdp->fd_lastfile = fdp->fd_lastfile;
1749 newfdp->fd_freefile = fdp->fd_freefile;
1750 newfdp->fd_cmask = fdp->fd_cmask;
1751 newfdp->fd_knlist = NULL;
1752 newfdp->fd_knlistsize = -1;
1753 newfdp->fd_knhash = NULL;
1754 newfdp->fd_knhashmask = 0;
1755 spin_init(&newfdp->fd_spin);
984263bc
MD
1756
1757 /*
5b287bba
MD
1758 * Copy the descriptor table through (i). This also copies the
1759 * allocation state. Then go through and ref the file pointers
1760 * and clean up any KQ descriptors.
1761 *
259b8ea0
MD
1762 * kq descriptors cannot be copied. Since we haven't ref'd the
1763 * copied files yet we can ignore the return value from funsetfd().
5b287bba
MD
1764 *
1765 * The read spinlock on fdp is still being held.
984263bc 1766 */
5b287bba
MD
1767 bcopy(fdp->fd_files, newfdp->fd_files, i * sizeof(struct fdnode));
1768 for (i = 0 ; i < newfdp->fd_nfiles; ++i) {
259b8ea0
MD
1769 fdnode = &newfdp->fd_files[i];
1770 if (fdnode->reserved) {
5b287bba 1771 fdreserve_locked(newfdp, i, -1);
259b8ea0 1772 fdnode->reserved = 0;
5b287bba
MD
1773 fdfixup_locked(newfdp, i);
1774 } else if (fdnode->fp) {
1775 if (fdnode->fp->f_type == DTYPE_KQUEUE) {
1776 (void)funsetfd_locked(newfdp, i);
1777 } else {
1778 fhold(fdnode->fp);
1779 }
259b8ea0 1780 }
984263bc 1781 }
5b287bba 1782 spin_unlock_rd(&fdp->fd_spin);
984263bc
MD
1783 return (newfdp);
1784}
1785
1786/*
1787 * Release a filedesc structure.
5b287bba
MD
1788 *
1789 * NOT MPSAFE (MPSAFE for refs > 1, but the final cleanup code is not MPSAFE)
984263bc
MD
1790 */
1791void
41c20dac 1792fdfree(struct proc *p)
984263bc 1793{
41c20dac 1794 struct filedesc *fdp = p->p_fd;
0679adc4 1795 struct fdnode *fdnode;
41c20dac 1796 int i;
984263bc
MD
1797 struct filedesc_to_leader *fdtol;
1798 struct file *fp;
1799 struct vnode *vp;
1800 struct flock lf;
1801
1802 /* Certain daemons might not have file descriptors. */
1803 if (fdp == NULL)
1804 return;
1805
5b287bba
MD
1806 /*
1807 * Severe messing around to follow
1808 */
1809 spin_lock_wr(&fdp->fd_spin);
1810
984263bc
MD
1811 /* Check for special need to clear POSIX style locks */
1812 fdtol = p->p_fdtol;
1813 if (fdtol != NULL) {
1814 KASSERT(fdtol->fdl_refcount > 0,
1815 ("filedesc_to_refcount botch: fdl_refcount=%d",
1816 fdtol->fdl_refcount));
1817 if (fdtol->fdl_refcount == 1 &&
1818 (p->p_leader->p_flag & P_ADVLOCK) != 0) {
259b8ea0
MD
1819 for (i = 0; i <= fdp->fd_lastfile; ++i) {
1820 fdnode = &fdp->fd_files[i];
0679adc4 1821 if (fdnode->fp == NULL ||
259b8ea0 1822 fdnode->fp->f_type != DTYPE_VNODE) {
984263bc 1823 continue;
259b8ea0 1824 }
0679adc4 1825 fp = fdnode->fp;
984263bc 1826 fhold(fp);
5b287bba
MD
1827 spin_unlock_wr(&fdp->fd_spin);
1828
984263bc
MD
1829 lf.l_whence = SEEK_SET;
1830 lf.l_start = 0;
1831 lf.l_len = 0;
1832 lf.l_type = F_UNLCK;
1833 vp = (struct vnode *)fp->f_data;
1834 (void) VOP_ADVLOCK(vp,
1835 (caddr_t)p->p_leader,
1836 F_UNLCK,
1837 &lf,
1838 F_POSIX);
9f87144f 1839 fdrop(fp);
5b287bba 1840 spin_lock_wr(&fdp->fd_spin);
984263bc
MD
1841 }
1842 }
1843 retry:
1844 if (fdtol->fdl_refcount == 1) {
1845 if (fdp->fd_holdleaderscount > 0 &&
1846 (p->p_leader->p_flag & P_ADVLOCK) != 0) {
1847 /*
1848 * close() or do_dup() has cleared a reference
1849 * in a shared file descriptor table.
1850 */
1851 fdp->fd_holdleaderswakeup = 1;
7749886d
MD
1852 msleep(&fdp->fd_holdleaderscount,
1853 &fdp->fd_spin, 0, "fdlhold", 0);
984263bc
MD
1854 goto retry;
1855 }
1856 if (fdtol->fdl_holdcount > 0) {
1857 /*
1858 * Ensure that fdtol->fdl_leader
1859 * remains valid in closef().
1860 */
1861 fdtol->fdl_wakeup = 1;
7749886d 1862 msleep(fdtol, &fdp->fd_spin, 0, "fdlhold", 0);
984263bc
MD
1863 goto retry;
1864 }
1865 }
1866 fdtol->fdl_refcount--;
1867 if (fdtol->fdl_refcount == 0 &&
1868 fdtol->fdl_holdcount == 0) {
1869 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev;
1870 fdtol->fdl_prev->fdl_next = fdtol->fdl_next;
5b287bba 1871 } else {
984263bc 1872 fdtol = NULL;
5b287bba 1873 }
984263bc 1874 p->p_fdtol = NULL;
5b287bba
MD
1875 if (fdtol != NULL) {
1876 spin_unlock_wr(&fdp->fd_spin);
efda3bd0 1877 kfree(fdtol, M_FILEDESC_TO_LEADER);
5b287bba
MD
1878 spin_lock_wr(&fdp->fd_spin);
1879 }
984263bc 1880 }
5b287bba
MD
1881 if (--fdp->fd_refcnt > 0) {
1882 spin_unlock_wr(&fdp->fd_spin);
984263bc 1883 return;
5b287bba
MD
1884 }
1885 spin_unlock_wr(&fdp->fd_spin);
1886
984263bc
MD
1887 /*
1888 * we are the last reference to the structure, we can
1889 * safely assume it will not change out from under us.
1890 */
0679adc4
MD
1891 for (i = 0; i <= fdp->fd_lastfile; ++i) {
1892 if (fdp->fd_files[i].fp)
b8477cda 1893 closef(fdp->fd_files[i].fp, p);
984263bc 1894 }
0679adc4 1895 if (fdp->fd_files != fdp->fd_builtin_files)
efda3bd0 1896 kfree(fdp->fd_files, M_FILEDESC);
690a3127 1897 if (fdp->fd_cdir) {
28623bf9 1898 cache_drop(&fdp->fd_ncdir);
984263bc 1899 vrele(fdp->fd_cdir);
690a3127 1900 }
bccde7a3 1901 if (fdp->fd_rdir) {
28623bf9 1902 cache_drop(&fdp->fd_nrdir);
bccde7a3
MD
1903 vrele(fdp->fd_rdir);
1904 }
690a3127 1905 if (fdp->fd_jdir) {
28623bf9 1906 cache_drop(&fdp->fd_njdir);
984263bc 1907 vrele(fdp->fd_jdir);
690a3127 1908 }
984263bc 1909 if (fdp->fd_knlist)
efda3bd0 1910 kfree(fdp->fd_knlist, M_KQUEUE);
984263bc 1911 if (fdp->fd_knhash)
efda3bd0
MD
1912 kfree(fdp->fd_knhash, M_KQUEUE);
1913 kfree(fdp, M_FILEDESC);
984263bc
MD
1914}
1915
1916/*
fa541be6 1917 * Retrieve and reference the file pointer associated with a descriptor.
85fceac1
MD
1918 *
1919 * MPSAFE
fa541be6
MD
1920 */
1921struct file *
1922holdfp(struct filedesc *fdp, int fd, int flag)
1923{
1924 struct file* fp;
1925
85fceac1
MD
1926 spin_lock_rd(&fdp->fd_spin);
1927 if (((u_int)fd) >= fdp->fd_nfiles) {
1928 fp = NULL;
1929 goto done;
1930 }
fa541be6 1931 if ((fp = fdp->fd_files[fd].fp) == NULL)
85fceac1
MD
1932 goto done;
1933 if ((fp->f_flag & flag) == 0 && flag != -1) {
1934 fp = NULL;
1935 goto done;
1936 }
fa541be6 1937 fhold(fp);
85fceac1
MD
1938done:
1939 spin_unlock_rd(&fdp->fd_spin);
fa541be6
MD
1940 return (fp);
1941}
1942
1943/*
1944 * holdsock() - load the struct file pointer associated
1945 * with a socket into *fpp. If an error occurs, non-zero
1946 * will be returned and *fpp will be set to NULL.
5b287bba
MD
1947 *
1948 * MPSAFE
fa541be6
MD
1949 */
1950int
5b287bba 1951holdsock(struct filedesc *fdp, int fd, struct file **fpp)
fa541be6
MD
1952{
1953 struct file *fp;
5b287bba 1954 int error;
fa541be6 1955
5b287bba
MD
1956 spin_lock_rd(&fdp->fd_spin);
1957 if ((unsigned)fd >= fdp->fd_nfiles) {
1958 error = EBADF;
1959 fp = NULL;
1960 goto done;
1961 }
1962 if ((fp = fdp->fd_files[fd].fp) == NULL) {
1963 error = EBADF;
1964 goto done;
1965 }
1966 if (fp->f_type != DTYPE_SOCKET) {
1967 error = ENOTSOCK;
1968 goto done;
1969 }
fa541be6 1970 fhold(fp);
5b287bba
MD
1971 error = 0;
1972done:
1973 spin_unlock_rd(&fdp->fd_spin);
fa541be6
MD
1974 *fpp = fp;
1975 return (error);
1976}
1977
1978/*
5b287bba
MD
1979 * Convert a user file descriptor to a held file pointer.
1980 *
1981 * MPSAFE
228b401d
MD
1982 */
1983int
5b287bba 1984holdvnode(struct filedesc *fdp, int fd, struct file **fpp)
228b401d
MD
1985{
1986 struct file *fp;
5b287bba
MD
1987 int error;
1988
1989 spin_lock_rd(&fdp->fd_spin);
1990 if ((unsigned)fd >= fdp->fd_nfiles) {
1991 error = EBADF;
1992 fp = NULL;
1993 goto done;
1994 }
1995 if ((fp = fdp->fd_files[fd].fp) == NULL) {
1996 error = EBADF;
1997 goto done;
1998 }
1999 if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) {
8f9f2535 2000 fp = NULL;
5b287bba
MD
2001 error = EINVAL;
2002 goto done;
2003 }
2004 fhold(fp);
2005 error = 0;
2006done:
2007 spin_unlock_rd(&fdp->fd_spin);
228b401d 2008 *fpp = fp;
5b287bba 2009 return (error);
228b401d
MD
2010}
2011
2012/*
984263bc
MD
2013 * For setugid programs, we don't want to people to use that setugidness
2014 * to generate error messages which write to a file which otherwise would
2015 * otherwise be off-limits to the process.
2016 *
2017 * This is a gross hack to plug the hole. A better solution would involve
2018 * a special vop or other form of generalized access control mechanism. We
2019 * go ahead and just reject all procfs file systems accesses as dangerous.
2020 *
2021 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is
2022 * sufficient. We also don't for check setugidness since we know we are.
2023 */
2024static int
2025is_unsafe(struct file *fp)
2026{
2027 if (fp->f_type == DTYPE_VNODE &&
2028 ((struct vnode *)(fp->f_data))->v_tag == VT_PROCFS)
2029 return (1);
2030 return (0);
2031}
2032
2033/*
2034 * Make this setguid thing safe, if at all possible.
5b287bba
MD
2035 *
2036 * NOT MPSAFE - scans fdp without spinlocks, calls knote_fdclose()
984263bc
MD
2037 */
2038void
dadab5e9 2039setugidsafety(struct proc *p)
984263bc
MD
2040{
2041 struct filedesc *fdp = p->p_fd;
41c20dac 2042 int i;
984263bc
MD
2043
2044 /* Certain daemons might not have file descriptors. */
2045 if (fdp == NULL)
2046 return;
2047
2048 /*
0679adc4 2049 * note: fdp->fd_files may be reallocated out from under us while
984263bc
MD
2050 * we are blocked in a close. Be careful!
2051 */
2052 for (i = 0; i <= fdp->fd_lastfile; i++) {
2053 if (i > 2)
2054 break;
0679adc4 2055 if (fdp->fd_files[i].fp && is_unsafe(fdp->fd_files[i].fp)) {
984263bc
MD
2056 struct file *fp;
2057
984263bc
MD
2058 if (i < fdp->fd_knlistsize)
2059 knote_fdclose(p, i);
2060 /*
2061 * NULL-out descriptor prior to close to avoid
2062 * a race while close blocks.
2063 */
5b287bba 2064 if ((fp = funsetfd_locked(fdp, i)) != NULL)
b8477cda 2065 closef(fp, p);
984263bc
MD
2066 }
2067 }
984263bc
MD
2068}
2069
2070/*
2071 * Close any files on exec?
5b287bba
MD
2072 *
2073 * NOT MPSAFE - scans fdp without spinlocks, calls knote_fdclose()
984263bc
MD
2074 */
2075void
dadab5e9 2076fdcloseexec(struct proc *p)
984263bc
MD
2077{
2078 struct filedesc *fdp = p->p_fd;
41c20dac 2079 int i;
984263bc
MD
2080
2081 /* Certain daemons might not have file descriptors. */
2082 if (fdp == NULL)
2083 return;
2084
2085 /*
0679adc4
MD
2086 * We cannot cache fd_files since operations may block and rip
2087 * them out from under us.
984263bc
MD
2088 */
2089 for (i = 0; i <= fdp->fd_lastfile; i++) {
0679adc4
MD
2090 if (fdp->fd_files[i].fp != NULL &&
2091 (fdp->fd_files[i].fileflags & UF_EXCLOSE)) {
984263bc
MD
2092 struct file *fp;
2093
984263bc
MD
2094 if (i < fdp->fd_knlistsize)
2095 knote_fdclose(p, i);
2096 /*
2097 * NULL-out descriptor prior to close to avoid
2098 * a race while close blocks.
2099 */
5b287bba 2100 if ((fp = funsetfd_locked(fdp, i)) != NULL)
b8477cda 2101 closef(fp, p);
984263bc
MD
2102 }
2103 }
984263bc
MD
2104}
2105
2106/*
2107 * It is unsafe for set[ug]id processes to be started with file
2108 * descriptors 0..2 closed, as these descriptors are given implicit
2109 * significance in the Standard C library. fdcheckstd() will create a
2110 * descriptor referencing /dev/null for each of stdin, stdout, and
2111 * stderr that is not already open.
5b287bba
MD
2112 *
2113 * NOT MPSAFE - calls falloc, vn_open, etc
984263bc
MD
2114 */
2115int
dadab5e9 2116fdcheckstd(struct proc *p)
984263bc 2117{
fad57d0e 2118 struct nlookupdata nd;
dadab5e9
MD
2119 struct filedesc *fdp;
2120 struct file *fp;
973c11b9 2121 int retval;
259b8ea0 2122 int i, error, flags, devnull;
984263bc 2123
ea8f324c
MD
2124 fdp = p->p_fd;
2125 if (fdp == NULL)
2126 return (0);
2127 devnull = -1;
2128 error = 0;
2129 for (i = 0; i < 3; i++) {
0679adc4 2130 if (fdp->fd_files[i].fp != NULL)
fad57d0e
MD
2131 continue;
2132 if (devnull < 0) {
259b8ea0 2133 if ((error = falloc(p, &fp, &devnull)) != 0)
fad57d0e
MD
2134 break;
2135
2136 error = nlookup_init(&nd, "/dev/null", UIO_SYSSPACE,
2137 NLC_FOLLOW|NLC_LOCKVP);
2138 flags = FREAD | FWRITE;
2139 if (error == 0)
2140 error = vn_open(&nd, fp, flags, 0);
2141 if (error == 0)
259b8ea0
MD
2142 fsetfd(p, fp, devnull);
2143 else
2144 fsetfd(p, NULL, devnull);
9f87144f 2145 fdrop(fp);
fad57d0e
MD
2146 nlookup_done(&nd);
2147 if (error)
2148 break;
259b8ea0 2149 KKASSERT(i == devnull);
fad57d0e
MD
2150 } else {
2151 error = kern_dup(DUP_FIXED, devnull, i, &retval);
2152 if (error != 0)
2153 break;
2154 }
ea8f324c
MD
2155 }
2156 return (error);
984263bc
MD
2157}
2158
2159/*
2160 * Internal form of close.
2161 * Decrement reference count on file structure.
dadab5e9 2162 * Note: td and/or p may be NULL when closing a file
984263bc 2163 * that was being passed in a message.
5b287bba
MD
2164 *
2165 * MPALMOSTSAFE - acquires mplock for VOP operations
984263bc
MD
2166 */
2167int
b8477cda 2168closef(struct file *fp, struct proc *p)
984263bc
MD
2169{
2170 struct vnode *vp;
2171 struct flock lf;
2172 struct filedesc_to_leader *fdtol;
2173
2174 if (fp == NULL)
2175 return (0);
b8477cda 2176
984263bc
MD
2177 /*
2178 * POSIX record locking dictates that any close releases ALL
2179 * locks owned by this process. This is handled by setting
2180 * a flag in the unlock to free ONLY locks obeying POSIX
2181 * semantics, and not to free BSD-style file locks.
2182 * If the descriptor was in a message, POSIX-style locks
2183 * aren't passed with the descriptor.
2184 */
7749886d
MD
2185 if (p != NULL && fp->f_type == DTYPE_VNODE &&
2186 (((struct vnode *)fp->f_data)->v_flag & VMAYHAVELOCKS)
2187 ) {
2188 get_mplock();
984263bc
MD
2189 if ((p->p_leader->p_flag & P_ADVLOCK) != 0) {
2190 lf.l_whence = SEEK_SET;
2191 lf.l_start = 0;
2192 lf.l_len = 0;
2193 lf.l_type = F_UNLCK;
2194 vp = (struct vnode *)fp->f_data;
2195 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
2196 &lf, F_POSIX);
2197 }
2198 fdtol = p->p_fdtol;
2199 if (fdtol != NULL) {
2200 /*
2201 * Handle special case where file descriptor table
2202 * is shared between multiple process leaders.
2203 */
2204 for (fdtol = fdtol->fdl_next;
2205 fdtol != p->p_fdtol;
2206 fdtol = fdtol->fdl_next) {
2207 if ((fdtol->fdl_leader->p_flag &
2208 P_ADVLOCK) == 0)
2209 continue;
2210 fdtol->fdl_holdcount++;
2211 lf.l_whence = SEEK_SET;
2212 lf.l_start = 0;
2213 lf.l_len = 0;
2214 lf.l_type = F_UNLCK;
2215 vp = (struct vnode *)fp->f_data;
2216 (void) VOP_ADVLOCK(vp,
661fc1a0 2217 (caddr_t)fdtol->fdl_leader,
984263bc
MD
2218 F_UNLCK, &lf, F_POSIX);
2219 fdtol->fdl_holdcount--;
2220 if (fdtol->fdl_holdcount == 0 &&
2221 fdtol->fdl_wakeup != 0) {
2222 fdtol->fdl_wakeup = 0;
2223 wakeup(fdtol);
2224 }
2225 }
2226 }
7749886d 2227 rel_mplock();
984263bc 2228 }
9f87144f 2229 return (fdrop(fp));
984263bc
MD
2230}
2231
85fceac1
MD
2232/*
2233 * MPSAFE
2234 *
2235 * fhold() can only be called if f_count is already at least 1 (i.e. the
2236 * caller of fhold() already has a reference to the file pointer in some
5b287bba
MD
2237 * manner or other).
2238 *
bc1eb676
MD
2239 * f_count is not spin-locked. Instead, atomic ops are used for
2240 * incrementing, decrementing, and handling the 1->0 transition.
85fceac1
MD
2241 */
2242void
2243fhold(struct file *fp)
2244{
2245 atomic_add_int(&fp->f_count, 1);
2246}
2247
2248/*
bc1eb676 2249 * fdrop() - drop a reference to a descriptor
85fceac1 2250 *
5b287bba 2251 * MPALMOSTSAFE - acquires mplock for final close sequence
85fceac1 2252 */
984263bc 2253int
9f87144f 2254fdrop(struct file *fp)
984263bc
MD
2255{
2256 struct flock lf;
2257 struct vnode *vp;
2258 int error;
2259
bc1eb676
MD
2260 /*
2261 * A combined fetch and subtract is needed to properly detect
2262 * 1->0 transitions, otherwise two cpus dropping from a ref
2263 * count of 2 might both try to run the 1->0 code.
2264 */
2265 if (atomic_fetchadd_int(&fp->f_count, -1) > 1)
984263bc 2266 return (0);
85fceac1 2267
5b287bba
MD
2268 get_mplock();
2269
85fceac1
MD
2270 /*
2271 * The last reference has gone away, we own the fp structure free
2272 * and clear.
2273 */
984263bc
MD
2274 if (fp->f_count < 0)
2275 panic("fdrop: count < 0");
7749886d
MD
2276 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE &&
2277 (((struct vnode *)fp->f_data)->v_flag & VMAYHAVELOCKS)
2278 ) {
984263bc
MD
2279 lf.l_whence = SEEK_SET;
2280 lf.l_start = 0;
2281 lf.l_len = 0;
2282 lf.l_type = F_UNLCK;
2283 vp = (struct vnode *)fp->f_data;
71c18fe3 2284 (void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, 0);
984263bc
MD
2285 }
2286 if (fp->f_ops != &badfileops)
87de5057 2287 error = fo_close(fp);
984263bc
MD
2288 else
2289 error = 0;
2290 ffree(fp);
5b287bba 2291 rel_mplock();
984263bc
MD
2292 return (error);
2293}
2294
2295/*
2296 * Apply an advisory lock on a file descriptor.
2297 *
2298 * Just attempt to get a record lock of the requested type on
2299 * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0).
2300 */
984263bc 2301int
753fd850 2302sys_flock(struct flock_args *uap)
984263bc 2303{
41c20dac 2304 struct proc *p = curproc;
41c20dac 2305 struct file *fp;
984263bc
MD
2306 struct vnode *vp;
2307 struct flock lf;
5b287bba 2308 int error;
984263bc 2309
5b287bba 2310 if ((fp = holdfp(p->p_fd, uap->fd, -1)) == NULL)
984263bc 2311 return (EBADF);
5b287bba
MD
2312 if (fp->f_type != DTYPE_VNODE) {
2313 error = EOPNOTSUPP;
2314 goto done;
2315 }
984263bc
MD
2316 vp = (struct vnode *)fp->f_data;
2317 lf.l_whence = SEEK_SET;
2318 lf.l_start = 0;
2319 lf.l_len = 0;
2320 if (uap->how & LOCK_UN) {
2321 lf.l_type = F_UNLCK;
2322 fp->f_flag &= ~FHASLOCK;
5b287bba
MD
2323 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, 0);
2324 goto done;
984263bc
MD
2325 }
2326 if (uap->how & LOCK_EX)
2327 lf.l_type = F_WRLCK;
2328 else if (uap->how & LOCK_SH)
2329 lf.l_type = F_RDLCK;
5b287bba
MD
2330 else {
2331 error = EBADF;
2332 goto done;
2333 }
984263bc
MD
2334 fp->f_flag |= FHASLOCK;
2335 if (uap->how & LOCK_NB)
5b287bba
MD
2336 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, 0);
2337 else
2338 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_WAIT);
2339done:
2340 fdrop(fp);
2341 return (error);
984263bc
MD
2342}
2343
2344/*
2345 * File Descriptor pseudo-device driver (/dev/fd/).
2346 *
2347 * Opening minor device N dup()s the file (if any) connected to file
2348 * descriptor N belonging to the calling process. Note that this driver
2349 * consists of only the ``open()'' routine, because all subsequent
2350 * references to this file will be direct to the other driver.
2351 */
2352/* ARGSUSED */
2353static int
fef8985e 2354fdopen(struct dev_open_args *ap)
984263bc 2355{
fef8985e
MD
2356 thread_t td = curthread;
2357
fbfe4e7d 2358 KKASSERT(td->td_lwp != NULL);
984263bc
MD
2359
2360 /*
fbfe4e7d 2361 * XXX Kludge: set curlwp->lwp_dupfd to contain the value of the
984263bc
MD
2362 * the file descriptor being sought for duplication. The error
2363 * return ensures that the vnode for this device will be released
2364 * by vn_open. Open will detect this special error and take the
2365 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN
2366 * will simply report the error.
2367 */
fef8985e 2368 td->td_lwp->lwp_dupfd = minor(ap->a_head.a_dev);
984263bc
MD
2369 return (ENODEV);
2370}
2371
2372/*
259b8ea0
MD
2373 * The caller has reserved the file descriptor dfd for us. On success we
2374 * must fsetfd() it. On failure the caller will clean it up.
5b287bba
MD
2375 *
2376 * NOT MPSAFE - isn't getting spinlocks, possibly other things
984263bc
MD
2377 */
2378int
259b8ea0 2379dupfdopen(struct proc *p, int dfd, int sfd, int mode, int error)
984263bc 2380{
259b8ea0 2381 struct filedesc *fdp = p->p_fd;
41c20dac 2382 struct file *wfp;
259b8ea0 2383 struct file *xfp;
ea8f324c 2384 int werror;
984263bc 2385
259b8ea0 2386 if ((wfp = holdfp(fdp, sfd, -1)) == NULL)
984263bc 2387 return (EBADF);
984263bc
MD
2388
2389 /*
ea8f324c
MD
2390 * Close a revoke/dup race. Duping a descriptor marked as revoked
2391 * will dup a dummy descriptor instead of the real one.
2392 */
2393 if (wfp->f_flag & FREVOKED) {
2394 kprintf("Warning: attempt to dup() a revoked descriptor\n");
2395 fdrop(wfp);
2396 wfp = NULL;
2397 werror = falloc(NULL, &wfp, NULL);
2398 if (werror)
2399 return (werror);
2400 }
2401
2402 /*
984263bc
MD
2403 * There are two cases of interest here.
2404 *
259b8ea0 2405 * For ENODEV simply dup sfd to file descriptor dfd and return.
984263bc 2406 *
259b8ea0
MD
2407 * For ENXIO steal away the file structure from sfd and store it
2408 * dfd. sfd is effectively closed by this operation.
984263bc
MD
2409 *
2410 * Any other error code is just returned.
2411 */
2412 switch (error) {
2413 case ENODEV:
2414 /*
2415 * Check that the mode the file is being opened for is a
2416 * subset of the mode of the existing descriptor.
2417 */
ea8f324c
MD
2418 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) {
2419 error = EACCES;
2420 break;
2421 }
259b8ea0
MD
2422 fdp->fd_files[dfd].fileflags = fdp->fd_files[sfd].fileflags;
2423 fsetfd(p, wfp, dfd);
2424 error = 0;
2425 break;
984263bc
MD
2426 case ENXIO:
2427 /*
2428 * Steal away the file pointer from dfd, and stuff it into indx.
2429 */
259b8ea0
MD
2430 fdp->fd_files[dfd].fileflags = fdp->fd_files[sfd].fileflags;
2431 fsetfd(p, wfp, dfd);
5b287bba 2432 if ((xfp = funsetfd_locked(fdp, sfd)) != NULL)
259b8ea0 2433 fdrop(xfp);
259b8ea0
MD
2434 error = 0;
2435 break;
984263bc 2436 default:
259b8ea0 2437 break;
984263bc 2438 }
259b8ea0
MD
2439 fdrop(wfp);
2440 return (error);
984263bc
MD
2441}
2442
5b287bba
MD
2443/*
2444 * NOT MPSAFE - I think these refer to a common file descriptor table
2445 * and we need to spinlock that to link fdtol in.
2446 */
984263bc
MD
2447struct filedesc_to_leader *
2448filedesc_to_leader_alloc(struct filedesc_to_leader *old,
2449 struct proc *leader)
2450{
2451 struct filedesc_to_leader *fdtol;
2452
77652cad 2453 fdtol = kmalloc(sizeof(struct filedesc_to_leader),
7bf8660a 2454 M_FILEDESC_TO_LEADER, M_WAITOK);
984263bc
MD
2455 fdtol->fdl_refcount = 1;
2456 fdtol->fdl_holdcount = 0;
2457 fdtol->fdl_wakeup = 0;
2458 fdtol->fdl_leader = leader;
2459 if (old != NULL) {
2460 fdtol->fdl_next = old->fdl_next;
2461 fdtol->fdl_prev = old;
2462 old->fdl_next = fdtol;
2463 fdtol->fdl_next->fdl_prev = fdtol;
2464 } else {
2465 fdtol->fdl_next = fdtol;
2466 fdtol->fdl_prev = fdtol;
2467 }
2468 return fdtol;
2469}
2470
2471/*
2dd63755 2472 * Scan all file pointers in the system. The callback is made with
ea8f324c 2473 * the master list spinlock held exclusively.
2dd63755
MD
2474 *
2475 * MPSAFE
2dd63755
MD
2476 */
2477void
2478allfiles_scan_exclusive(int (*callback)(struct file *, void *), void *data)
2479{
2480 struct file *fp;
2481 int res;
2482
2483 spin_lock_wr(&filehead_spin);
2484 LIST_FOREACH(fp, &filehead, f_list) {
2dd63755 2485 res = callback(fp, data);
2dd63755
MD
2486 if (res < 0)
2487 break;
2488 }
2489 spin_unlock_wr(&filehead_spin);
2490}
2491
2492/*
984263bc 2493 * Get file structures.
5b287bba
MD
2494 *
2495 * NOT MPSAFE - process list scan, SYSCTL_OUT (probably not mpsafe)
984263bc 2496 */
8fa76237
MD
2497
2498struct sysctl_kern_file_info {
2499 int count;
2500 int error;
2501 struct sysctl_req *req;
2502};
2503
2504static int sysctl_kern_file_callback(struct proc *p, void *data);
2505
984263bc
MD
2506static int
2507sysctl_kern_file(SYSCTL_HANDLER_ARGS)
2508{
8fa76237 2509 struct sysctl_kern_file_info info;
984263bc
MD
2510
2511 /*
7b124c9f
JS
2512 * Note: because the number of file descriptors is calculated
2513 * in different ways for sizing vs returning the data,
2514 * there is information leakage from the first loop. However,
2515 * it is of a similar order of magnitude to the leakage from
2516 * global system statistics such as kern.openfiles.
6d132b4d
MD
2517 *
2518 * When just doing a count, note that we cannot just count
2519 * the elements and add f_count via the filehead list because
2520 * threaded processes share their descriptor table and f_count might
2521 * still be '1' in that case.
e38910da
MD
2522 *
2523 * Since the SYSCTL op can block, we must hold the process to
2524 * prevent it being ripped out from under us either in the
2525 * file descriptor loop or in the greater LIST_FOREACH. The
2526 * process may be in varying states of disrepair. If the process
2527 * is in SZOMB we may have caught it just as it is being removed
2528 * from the allproc list, we must skip it in that case to maintain
2529 * an unbroken chain through the allproc list.
984263bc 2530 */
8fa76237
MD
2531 info.count = 0;
2532 info.error = 0;
2533 info.req = req;
2534 allproc_scan(sysctl_kern_file_callback, &info);
6d132b4d
MD
2535
2536 /*
2537 * When just calculating the size, overestimate a bit to try to
2538 * prevent system activity from causing the buffer-fill call
2539 * to fail later on.
2540 */
2541 if (req->oldptr == NULL) {
8fa76237
MD
2542 info.count = (info.count + 16) + (info.count / 10);
2543 info.error = SYSCTL_OUT(req, NULL,
2544 info.count * sizeof(struct kinfo_file));
6d132b4d 2545 }
8fa76237
MD
2546 return (info.error);
2547}
2548
2549static int
2550sysctl_kern_file_callback(struct proc *p, void *data)
2551{
2552 struct sysctl_kern_file_info *info = data;
2553 struct kinfo_file kf;
2554 struct filedesc *fdp;
2555 struct file *fp;
2556 uid_t uid;
2557 int n;
2558
416d05d7 2559 if (p->p_stat == SIDL || p->p_stat == SZOMB)
8fa76237
MD
2560 return(0);
2561 if (!PRISON_CHECK(info->req->td->td_proc->p_ucred, p->p_ucred) != 0)
2562 return(0);
2563 if ((fdp = p->p_fd) == NULL)
2564 return(0);
2565 spin_lock_rd(&fdp->fd_spin);
2566 for (n = 0; n < fdp->fd_nfiles; ++n) {
2567 if ((fp = fdp->fd_files[n].fp) == NULL)
2568 continue;
2569 if (info->req->oldptr == NULL) {
2570 ++info->count;
2571 } else {
2572 uid = p->p_ucred ? p->p_ucred->cr_uid : -1;
2573 kcore_make_file(&kf, fp, p->p_pid, uid, n);
2574 spin_unlock_rd(&fdp->fd_spin);
2575 info->error = SYSCTL_OUT(info->req, &kf, sizeof(kf));
2576 spin_lock_rd(&fdp->fd_spin);
2577 if (info->error)
2578 break;
2579 }
2580 }
2581 spin_unlock_rd(&fdp->fd_spin);
2582 if (info->error)
2583 return(-1);
2584 return(0);
984263bc
MD
2585}
2586
2587SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD,
2588 0, 0, sysctl_kern_file, "S,file", "Entire file table");
2589
2590SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW,
2591 &maxfilesperproc, 0, "Maximum files allowed open per process");
2592
2593SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW,
2594 &maxfiles, 0, "Maximum number of files");
2595
60ee93b9
MD
2596SYSCTL_INT(_kern, OID_AUTO, maxfilesrootres, CTLFLAG_RW,
2597 &maxfilesrootres, 0, "Descriptors reserved for root use");
2598
984263bc
MD
2599SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD,
2600 &nfiles, 0, "System-wide number of open files");
2601
2602static void
2603fildesc_drvinit(void *unused)
2604{
2605 int fd;
2606
fef8985e 2607 dev_ops_add(&fildesc_ops, 0, 0);
e4c9c0c8 2608 for (fd = 0; fd < NUMFDESC; fd++) {
fef8985e 2609 make_dev(&fildesc_ops, fd,
984263bc 2610 UID_BIN, GID_BIN, 0666, "fd/%d", fd);
e4c9c0c8 2611 }
fef8985e
MD
2612 make_dev(&fildesc_ops, 0, UID_ROOT, GID_WHEEL, 0666, "stdin");
2613 make_dev(&fildesc_ops, 1, UID_ROOT, GID_WHEEL, 0666, "stdout");
2614 make_dev(&fildesc_ops, 2, UID_ROOT, GID_WHEEL, 0666, "stderr");
984263bc
MD
2615}
2616
d9b2033e
MD
2617/*
2618 * MPSAFE
2619 */
984263bc 2620struct fileops badfileops = {
b2d248cb
MD
2621 .fo_read = badfo_readwrite,
2622 .fo_write = badfo_readwrite,
2623 .fo_ioctl = badfo_ioctl,
2624 .fo_poll = badfo_poll,
2625 .fo_kqfilter = badfo_kqfilter,
2626 .fo_stat = badfo_stat,
2627 .fo_close = badfo_close,
2628 .fo_shutdown = badfo_shutdown
984263bc
MD
2629};
2630
d9b2033e
MD
2631/*
2632 * MPSAFE
2633 */
984263bc 2634static int
dadab5e9
MD
2635badfo_readwrite(
2636 struct file *fp,
2637 struct uio *uio,
2638 struct ucred *cred,
87de5057 2639 int flags
dadab5e9 2640) {
984263bc
MD
2641 return (EBADF);
2642}
2643
d9b2033e
MD
2644/*
2645 * MPSAFE
2646 */
984263bc 2647static int
87de5057 2648badfo_ioctl(struct file *fp, u_long com, caddr_t data, struct ucred *cred)
984263bc 2649{
984263bc
MD
2650 return (EBADF);
2651}
2652
d9b2033e
MD
2653/*
2654 * MPSAFE
2655 */
984263bc 2656static int
87de5057 2657badfo_poll(struct file *fp, int events, struct ucred *cred)
984263bc 2658{
984263bc
MD
2659 return (0);
2660}
2661
d9b2033e
MD
2662/*
2663 * MPSAFE
2664 */
984263bc 2665static int
dadab5e9 2666badfo_kqfilter(struct file *fp, struct knote *kn)
984263bc 2667{
984263bc
MD
2668 return (0);
2669}
2670
2671static int
87de5057 2672badfo_stat(struct file *fp, struct stat *sb, struct ucred *cred)
984263bc 2673{
984263bc
MD
2674 return (EBADF);
2675}
2676
d9b2033e
MD
2677/*
2678 * MPSAFE
2679 */
984263bc 2680static int
87de5057 2681badfo_close(struct file *fp)
984263bc 2682{
984263bc
MD
2683 return (EBADF);
2684}
2685
d9b2033e
MD
2686/*
2687 * MPSAFE
2688 */
004d2de5 2689static int
87de5057 2690badfo_shutdown(struct file *fp, int how)
004d2de5
MD
2691{
2692 return (EBADF);
2693}
2694
d9b2033e
MD
2695/*
2696 * MPSAFE
2697 */
004d2de5 2698int
87de5057 2699nofo_shutdown(struct file *fp, int how)
004d2de5
MD
2700{
2701 return (EOPNOTSUPP);
2702}
2703
984263bc
MD
2704SYSINIT(fildescdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,
2705 fildesc_drvinit,NULL)