1 /* $NetBSD: kern_descrip.c,v 1.123.2.3 2005/05/24 19:38:34 riz Exp $ */
2
3 /*
4 * Copyright (c) 1982, 1986, 1989, 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)kern_descrip.c 8.8 (Berkeley) 2/14/95
37 */
38
39 #include <sys/cdefs.h>
40 __KERNEL_RCSID(0, "$NetBSD: kern_descrip.c,v 1.123.2.3 2005/05/24 19:38:34 riz Exp $");
41
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/filedesc.h>
45 #include <sys/kernel.h>
46 #include <sys/vnode.h>
47 #include <sys/proc.h>
48 #include <sys/file.h>
49 #include <sys/namei.h>
50 #include <sys/socket.h>
51 #include <sys/socketvar.h>
52 #include <sys/stat.h>
53 #include <sys/ioctl.h>
54 #include <sys/fcntl.h>
55 #include <sys/malloc.h>
56 #include <sys/pool.h>
57 #include <sys/syslog.h>
58 #include <sys/unistd.h>
59 #include <sys/resourcevar.h>
60 #include <sys/conf.h>
61 #include <sys/event.h>
62
63 #include <sys/mount.h>
64 #include <sys/sa.h>
65 #include <sys/syscallargs.h>
66
67 /*
68 * Descriptor management.
69 */
70 struct filelist filehead; /* head of list of open files */
71 int nfiles; /* actual number of open files */
72 struct pool file_pool; /* memory pool for file structures */
73 struct pool cwdi_pool; /* memory pool for cwdinfo structures */
74 struct pool filedesc0_pool; /* memory pool for filedesc0 structures */
75
76 /* Global file list lock */
77 static struct simplelock filelist_slock = SIMPLELOCK_INITIALIZER;
78
79 MALLOC_DEFINE(M_FILE, "file", "Open file structure");
80 MALLOC_DEFINE(M_FILEDESC, "file desc", "Open file descriptor table");
81 MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer");
82
83 static __inline void fd_used(struct filedesc *, int);
84 static __inline void fd_unused(struct filedesc *, int);
85 static __inline int find_next_zero(uint32_t *, int, u_int);
86 int finishdup(struct proc *, int, int, register_t *);
87 int find_last_set(struct filedesc *, int);
88 int fcntl_forfs(int, struct proc *, int, void *);
89
90 dev_type_open(filedescopen);
91
92 const struct cdevsw filedesc_cdevsw = {
93 filedescopen, noclose, noread, nowrite, noioctl,
94 nostop, notty, nopoll, nommap, nokqfilter,
95 };
96
97 static __inline int
98 find_next_zero(uint32_t *bitmap, int want, u_int bits)
99 {
100 int i, off, maxoff;
101 uint32_t sub;
102
103 if (want > bits)
104 return -1;
105
106 off = want >> NDENTRYSHIFT;
107 i = want & NDENTRYMASK;
108 if (i) {
109 sub = bitmap[off] | ((u_int)~0 >> (NDENTRIES - i));
110 if (sub != ~0)
111 goto found;
112 off++;
113 }
114
115 maxoff = NDLOSLOTS(bits);
116 while (off < maxoff) {
117 if ((sub = bitmap[off]) != ~0)
118 goto found;
119 off++;
120 }
121
122 return (-1);
123
124 found:
125 return (off << NDENTRYSHIFT) + ffs(~sub) - 1;
126 }
127
128 int
129 find_last_set(struct filedesc *fd, int last)
130 {
131 int off, i;
132 struct file **ofiles = fd->fd_ofiles;
133 uint32_t *bitmap = fd->fd_lomap;
134
135 off = (last - 1) >> NDENTRYSHIFT;
136
137 while (off >= 0 && !bitmap[off])
138 off--;
139
140 if (off < 0)
141 return (-1);
142
143 i = ((off + 1) << NDENTRYSHIFT) - 1;
144 if (i >= last)
145 i = last - 1;
146
147 while (i > 0 && ofiles[i] == NULL)
148 i--;
149
150 return (i);
151 }
152
153 static __inline void
154 fd_used(struct filedesc *fdp, int fd)
155 {
156 u_int off = fd >> NDENTRYSHIFT;
157
158 KDASSERT((fdp->fd_lomap[off] & (1 << (fd & NDENTRYMASK))) == 0);
159
160 fdp->fd_lomap[off] |= 1 << (fd & NDENTRYMASK);
161 if (fdp->fd_lomap[off] == ~0) {
162 KDASSERT((fdp->fd_himap[off >> NDENTRYSHIFT] &
163 (1 << (off & NDENTRYMASK))) == 0);
164 fdp->fd_himap[off >> NDENTRYSHIFT] |= 1 << (off & NDENTRYMASK);
165 }
166
167 if (fd > fdp->fd_lastfile)
168 fdp->fd_lastfile = fd;
169 }
170
171 static __inline void
172 fd_unused(struct filedesc *fdp, int fd)
173 {
174 u_int off = fd >> NDENTRYSHIFT;
175
176 if (fd < fdp->fd_freefile)
177 fdp->fd_freefile = fd;
178
179 if (fdp->fd_lomap[off] == ~0) {
180 KDASSERT((fdp->fd_himap[off >> NDENTRYSHIFT] &
181 (1 << (off & NDENTRYMASK))) != 0);
182 fdp->fd_himap[off >> NDENTRYSHIFT] &=
183 ~(1 << (off & NDENTRYMASK));
184 }
185 KDASSERT((fdp->fd_lomap[off] & (1 << (fd & NDENTRYMASK))) != 0);
186 fdp->fd_lomap[off] &= ~(1 << (fd & NDENTRYMASK));
187
188 #ifdef DIAGNOSTIC
189 if (fd > fdp->fd_lastfile)
190 panic("fd_unused: fd_lastfile inconsistent");
191 #endif
192 if (fd == fdp->fd_lastfile)
193 fdp->fd_lastfile = find_last_set(fdp, fd);
194 }
195
196 /*
197 * Lookup the file structure corresponding to a file descriptor
198 * and return it locked.
199 * Note: typical usage is: `fp = fd_getfile(..); FILE_USE(fp);'
200 * The locking strategy has been optimised for this case, i.e.
201 * fd_getfile() returns the file locked while FILE_USE() will increment
202 * the file's use count and unlock.
203 */
204 struct file *
205 fd_getfile(struct filedesc *fdp, int fd)
206 {
207 struct file *fp;
208
209 if ((u_int) fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL)
210 return (NULL);
211
212 simple_lock(&fp->f_slock);
213 if (FILE_IS_USABLE(fp) == 0) {
214 simple_unlock(&fp->f_slock);
215 return (NULL);
216 }
217
218 return (fp);
219 }
220
221 /*
222 * System calls on descriptors.
223 */
224
225 /*
226 * Duplicate a file descriptor.
227 */
228 /* ARGSUSED */
229 int
230 sys_dup(struct lwp *l, void *v, register_t *retval)
231 {
232 struct sys_dup_args /* {
233 syscallarg(int) fd;
234 } */ *uap = v;
235 struct file *fp;
236 struct filedesc *fdp;
237 struct proc *p;
238 int old, new, error;
239
240 p = l->l_proc;
241 fdp = p->p_fd;
242 old = SCARG(uap, fd);
243
244 restart:
245 if ((fp = fd_getfile(fdp, old)) == NULL)
246 return (EBADF);
247
248 FILE_USE(fp);
249
250 if ((error = fdalloc(p, 0, &new)) != 0) {
251 if (error == ENOSPC) {
252 fdexpand(p);
253 FILE_UNUSE(fp, p);
254 goto restart;
255 }
256 FILE_UNUSE(fp, p);
257 return (error);
258 }
259
260 /* finishdup() will unuse the descriptors for us */
261 return (finishdup(p, old, new, retval));
262 }
263
264 /*
265 * Duplicate a file descriptor to a particular value.
266 */
267 /* ARGSUSED */
268 int
269 sys_dup2(struct lwp *l, void *v, register_t *retval)
270 {
271 struct sys_dup2_args /* {
272 syscallarg(int) from;
273 syscallarg(int) to;
274 } */ *uap = v;
275 struct file *fp;
276 struct filedesc *fdp;
277 struct proc *p;
278 int old, new, i, error;
279
280 p = l->l_proc;
281 fdp = p->p_fd;
282 old = SCARG(uap, from);
283 new = SCARG(uap, to);
284
285 restart:
286 if ((fp = fd_getfile(fdp, old)) == NULL)
287 return (EBADF);
288
289 if ((u_int)new >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur ||
290 (u_int)new >= maxfiles) {
291 simple_unlock(&fp->f_slock);
292 return (EBADF);
293 }
294
295 if (old == new) {
296 simple_unlock(&fp->f_slock);
297 *retval = new;
298 return (0);
299 }
300
301 FILE_USE(fp);
302
303 if (new >= fdp->fd_nfiles) {
304 if ((error = fdalloc(p, new, &i)) != 0) {
305 if (error == ENOSPC) {
306 fdexpand(p);
307 FILE_UNUSE(fp, p);
308 goto restart;
309 }
310 FILE_UNUSE(fp, p);
311 return (error);
312 }
313 if (new != i)
314 panic("dup2: fdalloc");
315 } else if (fdp->fd_ofiles[new] == NULL) {
316 /*
317 * Mark `new' slot "used" only if it was empty.
318 */
319 fd_used(fdp, new);
320 }
321
322 /*
323 * finishdup() will close the file that's in the `new'
324 * slot, if there's one there.
325 */
326
327 /* finishdup() will unuse the descriptors for us */
328 return (finishdup(p, old, new, retval));
329 }
330
331 /*
332 * The file control system call.
333 */
334 /* ARGSUSED */
335 int
336 sys_fcntl(struct lwp *l, void *v, register_t *retval)
337 {
338 struct sys_fcntl_args /* {
339 syscallarg(int) fd;
340 syscallarg(int) cmd;
341 syscallarg(void *) arg;
342 } */ *uap = v;
343 struct filedesc *fdp;
344 struct file *fp;
345 struct proc *p;
346 struct vnode *vp;
347 int fd, i, tmp, error, flg, cmd, newmin;
348 struct flock fl;
349
350 p = l->l_proc;
351 fd = SCARG(uap, fd);
352 cmd = SCARG(uap, cmd);
353 fdp = p->p_fd;
354 error = 0;
355 flg = F_POSIX;
356
357 switch (cmd) {
358 case F_CLOSEM:
359 if (fd < 0)
360 return EBADF;
361 while (fdp->fd_lastfile >= fd)
362 fdrelease(p, fdp->fd_lastfile);
363 return 0;
364
365 case F_MAXFD:
366 *retval = fdp->fd_lastfile;
367 return 0;
368
369 default:
370 /* Handled below */
371 break;
372 }
373
374 restart:
375 if ((fp = fd_getfile(fdp, fd)) == NULL)
376 return (EBADF);
377
378 FILE_USE(fp);
379
380 if ((cmd & F_FSCTL)) {
381 error = fcntl_forfs(fd, p, cmd, SCARG(uap, arg));
382 goto out;
383 }
384
385 switch (cmd) {
386
387 case F_DUPFD:
388 newmin = (long)SCARG(uap, arg);
389 if ((u_int)newmin >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur ||
390 (u_int)newmin >= maxfiles) {
391 error = EINVAL;
392 goto out;
393 }
394 if ((error = fdalloc(p, newmin, &i)) != 0) {
395 if (error == ENOSPC) {
396 fdexpand(p);
397 FILE_UNUSE(fp, p);
398 goto restart;
399 }
400 goto out;
401 }
402
403 /* finishdup() will unuse the descriptors for us */
404 return (finishdup(p, fd, i, retval));
405
406 case F_GETFD:
407 *retval = fdp->fd_ofileflags[fd] & UF_EXCLOSE ? 1 : 0;
408 break;
409
410 case F_SETFD:
411 if ((long)SCARG(uap, arg) & 1)
412 fdp->fd_ofileflags[fd] |= UF_EXCLOSE;
413 else
414 fdp->fd_ofileflags[fd] &= ~UF_EXCLOSE;
415 break;
416
417 case F_GETFL:
418 *retval = OFLAGS(fp->f_flag);
419 break;
420
421 case F_SETFL:
422 tmp = FFLAGS((long)SCARG(uap, arg)) & FCNTLFLAGS;
423 error = (*fp->f_ops->fo_fcntl)(fp, F_SETFL, &tmp, p);
424 if (error)
425 break;
426 i = tmp ^ fp->f_flag;
427 if (i & FNONBLOCK) {
428 int fl = tmp & FNONBLOCK;
429 error = (*fp->f_ops->fo_ioctl)(fp, FIONBIO, &fl, p);
430 if (error)
431 goto reset_fcntl;
432 }
433 if (i & FASYNC) {
434 int fl = tmp & FASYNC;
435 error = (*fp->f_ops->fo_ioctl)(fp, FIOASYNC, &fl, p);
436 if (error) {
437 if (i & FNONBLOCK) {
438 tmp = fp->f_flag & FNONBLOCK;
439 (void)(*fp->f_ops->fo_ioctl)(fp,
440 FIONBIO, &tmp, p);
441 }
442 goto reset_fcntl;
443 }
444 }
445 fp->f_flag = (fp->f_flag & ~FCNTLFLAGS) | tmp;
446 break;
447 reset_fcntl:
448 (void)(*fp->f_ops->fo_fcntl)(fp, F_SETFL, &fp->f_flag, p);
449 break;
450
451 case F_GETOWN:
452 error = (*fp->f_ops->fo_ioctl)(fp, FIOGETOWN, retval, p);
453 break;
454
455 case F_SETOWN:
456 tmp = (int)(intptr_t) SCARG(uap, arg);
457 error = (*fp->f_ops->fo_ioctl)(fp, FIOSETOWN, &tmp, p);
458 break;
459
460 case F_SETLKW:
461 flg |= F_WAIT;
462 /* Fall into F_SETLK */
463
464 case F_SETLK:
465 if (fp->f_type != DTYPE_VNODE) {
466 error = EINVAL;
467 goto out;
468 }
469 vp = (struct vnode *)fp->f_data;
470 /* Copy in the lock structure */
471 error = copyin(SCARG(uap, arg), &fl, sizeof(fl));
472 if (error)
473 goto out;
474 if (fl.l_whence == SEEK_CUR)
475 fl.l_start += fp->f_offset;
476 switch (fl.l_type) {
477 case F_RDLCK:
478 if ((fp->f_flag & FREAD) == 0) {
479 error = EBADF;
480 goto out;
481 }
482 p->p_flag |= P_ADVLOCK;
483 error = VOP_ADVLOCK(vp, p, F_SETLK, &fl, flg);
484 goto out;
485
486 case F_WRLCK:
487 if ((fp->f_flag & FWRITE) == 0) {
488 error = EBADF;
489 goto out;
490 }
491 p->p_flag |= P_ADVLOCK;
492 error = VOP_ADVLOCK(vp, p, F_SETLK, &fl, flg);
493 goto out;
494
495 case F_UNLCK:
496 error = VOP_ADVLOCK(vp, p, F_UNLCK, &fl, F_POSIX);
497 goto out;
498
499 default:
500 error = EINVAL;
501 goto out;
502 }
503
504 case F_GETLK:
505 if (fp->f_type != DTYPE_VNODE) {
506 error = EINVAL;
507 goto out;
508 }
509 vp = (struct vnode *)fp->f_data;
510 /* Copy in the lock structure */
511 error = copyin(SCARG(uap, arg), &fl, sizeof(fl));
512 if (error)
513 goto out;
514 if (fl.l_whence == SEEK_CUR)
515 fl.l_start += fp->f_offset;
516 if (fl.l_type != F_RDLCK &&
517 fl.l_type != F_WRLCK &&
518 fl.l_type != F_UNLCK) {
519 error = EINVAL;
520 goto out;
521 }
522 error = VOP_ADVLOCK(vp, p, F_GETLK, &fl, F_POSIX);
523 if (error)
524 goto out;
525 error = copyout(&fl, SCARG(uap, arg), sizeof(fl));
526 break;
527
528 default:
529 error = EINVAL;
530 }
531
532 out:
533 FILE_UNUSE(fp, p);
534 return (error);
535 }
536
537 /*
538 * Common code for dup, dup2, and fcntl(F_DUPFD).
539 */
540 int
541 finishdup(struct proc *p, int old, int new, register_t *retval)
542 {
543 struct filedesc *fdp;
544 struct file *fp, *delfp;
545
546 fdp = p->p_fd;
547
548 /*
549 * If there is a file in the new slot, remember it so we
550 * can close it after we've finished the dup. We need
551 * to do it after the dup is finished, since closing
552 * the file may block.
553 *
554 * Note: `old' is already used for us.
555 * Note: Caller already marked `new' slot "used".
556 */
557 delfp = fdp->fd_ofiles[new];
558
559 fp = fdp->fd_ofiles[old];
560 KDASSERT(fp != NULL);
561 fdp->fd_ofiles[new] = fp;
562 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE;
563 fp->f_count++;
564 *retval = new;
565 FILE_UNUSE(fp, p);
566
567 if (delfp != NULL) {
568 simple_lock(&delfp->f_slock);
569 FILE_USE(delfp);
570 if (new < fdp->fd_knlistsize)
571 knote_fdclose(p, new);
572 (void) closef(delfp, p);
573 }
574 return (0);
575 }
576
577 void
578 fdremove(struct filedesc *fdp, int fd)
579 {
580
581 fdp->fd_ofiles[fd] = NULL;
582 fd_unused(fdp, fd);
583 }
584
585 int
586 fdrelease(struct proc *p, int fd)
587 {
588 struct filedesc *fdp;
589 struct file **fpp, *fp;
590
591 fdp = p->p_fd;
592 fpp = &fdp->fd_ofiles[fd];
593 fp = *fpp;
594 if (fp == NULL)
595 return (EBADF);
596
597 simple_lock(&fp->f_slock);
598 if (!FILE_IS_USABLE(fp)) {
599 simple_unlock(&fp->f_slock);
600 return (EBADF);
601 }
602
603 FILE_USE(fp);
604
605 *fpp = NULL;
606 fdp->fd_ofileflags[fd] = 0;
607 if (fd < fdp->fd_knlistsize)
608 knote_fdclose(p, fd);
609 fd_unused(fdp, fd);
610 return (closef(fp, p));
611 }
612
613 /*
614 * Close a file descriptor.
615 */
616 /* ARGSUSED */
617 int
618 sys_close(struct lwp *l, void *v, register_t *retval)
619 {
620 struct sys_close_args /* {
621 syscallarg(int) fd;
622 } */ *uap = v;
623 int fd;
624 struct filedesc *fdp;
625 struct proc *p;
626
627 p = l->l_proc;
628 fd = SCARG(uap, fd);
629 fdp = p->p_fd;
630
631 if ((u_int) fd >= fdp->fd_nfiles)
632 return (EBADF);
633 #if 0
634 if (fd_getfile(fdp, fd) == NULL)
635 return (EBADF);
636 #endif
637
638 return (fdrelease(p, fd));
639 }
640
641 /*
642 * Return status information about a file descriptor.
643 */
644 /* ARGSUSED */
645 int
646 sys___fstat13(struct lwp *l, void *v, register_t *retval)
647 {
648 struct sys___fstat13_args /* {
649 syscallarg(int) fd;
650 syscallarg(struct stat *) sb;
651 } */ *uap = v;
652 int fd;
653 struct filedesc *fdp;
654 struct file *fp;
655 struct proc *p;
656 struct stat ub;
657 int error;
658
659 p = l->l_proc;
660 fd = SCARG(uap, fd);
661 fdp = p->p_fd;
662
663 if ((fp = fd_getfile(fdp, fd)) == NULL)
664 return (EBADF);
665
666 FILE_USE(fp);
667 error = (*fp->f_ops->fo_stat)(fp, &ub, p);
668 FILE_UNUSE(fp, p);
669
670 if (error == 0)
671 error = copyout(&ub, SCARG(uap, sb), sizeof(ub));
672
673 return (error);
674 }
675
676 /*
677 * Return pathconf information about a file descriptor.
678 */
679 /* ARGSUSED */
680 int
681 sys_fpathconf(struct lwp *l, void *v, register_t *retval)
682 {
683 struct sys_fpathconf_args /* {
684 syscallarg(int) fd;
685 syscallarg(int) name;
686 } */ *uap = v;
687 int fd;
688 struct filedesc *fdp;
689 struct file *fp;
690 struct proc *p;
691 struct vnode *vp;
692 int error;
693
694 p = l->l_proc;
695 fd = SCARG(uap, fd);
696 fdp = p->p_fd;
697 error = 0;
698
699 if ((fp = fd_getfile(fdp, fd)) == NULL)
700 return (EBADF);
701
702 FILE_USE(fp);
703
704 switch (fp->f_type) {
705
706 case DTYPE_SOCKET:
707 case DTYPE_PIPE:
708 if (SCARG(uap, name) != _PC_PIPE_BUF)
709 error = EINVAL;
710 else
711 *retval = PIPE_BUF;
712 break;
713
714 case DTYPE_VNODE:
715 vp = (struct vnode *)fp->f_data;
716 error = VOP_PATHCONF(vp, SCARG(uap, name), retval);
717 break;
718
719 case DTYPE_KQUEUE:
720 error = EINVAL;
721 break;
722
723 default:
724 error = EOPNOTSUPP;
725 break;
726 }
727
728 FILE_UNUSE(fp, p);
729 return (error);
730 }
731
732 /*
733 * Allocate a file descriptor for the process.
734 */
735 int fdexpanded; /* XXX: what else uses this? */
736
737 int
738 fdalloc(struct proc *p, int want, int *result)
739 {
740 struct filedesc *fdp;
741 int i, lim, last;
742 u_int off, new;
743
744 fdp = p->p_fd;
745
746 /*
747 * Search for a free descriptor starting at the higher
748 * of want or fd_freefile. If that fails, consider
749 * expanding the ofile array.
750 */
751 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles);
752 last = min(fdp->fd_nfiles, lim);
753 again:
754 if ((i = want) < fdp->fd_freefile)
755 i = fdp->fd_freefile;
756 off = i >> NDENTRYSHIFT;
757 new = find_next_zero(fdp->fd_himap, off,
758 (last + NDENTRIES - 1) >> NDENTRYSHIFT);
759 if (new != -1) {
760 i = find_next_zero(&fdp->fd_lomap[new],
761 new > off ? 0 : i & NDENTRYMASK, NDENTRIES);
762 if (i == -1) {
763 /*
764 * free file descriptor in this block was
765 * below want, try again with higher want.
766 */
767 want = (new + 1) << NDENTRYSHIFT;
768 goto again;
769 }
770 i += (new << NDENTRYSHIFT);
771 if (i < last) {
772 if (fdp->fd_ofiles[i] == NULL) {
773 fd_used(fdp, i);
774 if (want <= fdp->fd_freefile)
775 fdp->fd_freefile = i;
776 *result = i;
777 return (0);
778 }
779 }
780 }
781
782 /* No space in current array. Expand? */
783 if (fdp->fd_nfiles >= lim)
784 return (EMFILE);
785
786 /* Let the caller do it. */
787 return (ENOSPC);
788 }
789
790 void
791 fdexpand(struct proc *p)
792 {
793 struct filedesc *fdp;
794 int i, nfiles;
795 struct file **newofile;
796 char *newofileflags;
797 uint32_t *newhimap, *newlomap;
798
799 fdp = p->p_fd;
800
801 if (fdp->fd_nfiles < NDEXTENT)
802 nfiles = NDEXTENT;
803 else
804 nfiles = 2 * fdp->fd_nfiles;
805 newofile = malloc(nfiles * OFILESIZE, M_FILEDESC, M_WAITOK);
806 newofileflags = (char *) &newofile[nfiles];
807 /*
808 * Copy the existing ofile and ofileflags arrays
809 * and zero the new portion of each array.
810 */
811 memcpy(newofile, fdp->fd_ofiles,
812 (i = sizeof(struct file *) * fdp->fd_nfiles));
813 memset((char *)newofile + i, 0,
814 nfiles * sizeof(struct file *) - i);
815 memcpy(newofileflags, fdp->fd_ofileflags,
816 (i = sizeof(char) * fdp->fd_nfiles));
817 memset(newofileflags + i, 0, nfiles * sizeof(char) - i);
818 if (fdp->fd_nfiles > NDFILE)
819 free(fdp->fd_ofiles, M_FILEDESC);
820
821 if (NDHISLOTS(nfiles) > NDHISLOTS(fdp->fd_nfiles)) {
822 newhimap = malloc(NDHISLOTS(nfiles) * sizeof(uint32_t),
823 M_FILEDESC, M_WAITOK);
824 newlomap = malloc(NDLOSLOTS(nfiles) * sizeof(uint32_t),
825 M_FILEDESC, M_WAITOK);
826
827 memcpy(newhimap, fdp->fd_himap,
828 (i = NDHISLOTS(fdp->fd_nfiles) * sizeof(uint32_t)));
829 memset((char *)newhimap + i, 0,
830 NDHISLOTS(nfiles) * sizeof(uint32_t) - i);
831
832 memcpy(newlomap, fdp->fd_lomap,
833 (i = NDLOSLOTS(fdp->fd_nfiles) * sizeof(uint32_t)));
834 memset((char *)newlomap + i, 0,
835 NDLOSLOTS(nfiles) * sizeof(uint32_t) - i);
836
837 if (NDHISLOTS(fdp->fd_nfiles) > NDHISLOTS(NDFILE)) {
838 free(fdp->fd_himap, M_FILEDESC);
839 free(fdp->fd_lomap, M_FILEDESC);
840 }
841 fdp->fd_himap = newhimap;
842 fdp->fd_lomap = newlomap;
843 }
844
845 fdp->fd_ofiles = newofile;
846 fdp->fd_ofileflags = newofileflags;
847 fdp->fd_nfiles = nfiles;
848 fdexpanded++;
849 }
850
851 /*
852 * Check to see whether n user file descriptors
853 * are available to the process p.
854 */
855 int
856 fdavail(struct proc *p, int n)
857 {
858 struct filedesc *fdp;
859 struct file **fpp;
860 int i, lim;
861
862 fdp = p->p_fd;
863 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfiles);
864 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0)
865 return (1);
866 fpp = &fdp->fd_ofiles[fdp->fd_freefile];
867 for (i = min(lim,fdp->fd_nfiles) - fdp->fd_freefile; --i >= 0; fpp++)
868 if (*fpp == NULL && --n <= 0)
869 return (1);
870 return (0);
871 }
872
873 /*
874 * Initialize the data structures necessary for managing files.
875 */
876 void
877 finit(void)
878 {
879
880 pool_init(&file_pool, sizeof(struct file), 0, 0, 0, "filepl",
881 &pool_allocator_nointr);
882 pool_init(&cwdi_pool, sizeof(struct cwdinfo), 0, 0, 0, "cwdipl",
883 &pool_allocator_nointr);
884 pool_init(&filedesc0_pool, sizeof(struct filedesc0), 0, 0, 0, "fdescpl",
885 &pool_allocator_nointr);
886 }
887
888 /*
889 * Create a new open file structure and allocate
890 * a file descriptor for the process that refers to it.
891 */
892 int
893 falloc(struct proc *p, struct file **resultfp, int *resultfd)
894 {
895 struct file *fp, *fq;
896 int error, i;
897
898 restart:
899 if ((error = fdalloc(p, 0, &i)) != 0) {
900 if (error == ENOSPC) {
901 fdexpand(p);
902 goto restart;
903 }
904 return (error);
905 }
906
907 fp = pool_get(&file_pool, PR_WAITOK);
908 simple_lock(&filelist_slock);
909 if (nfiles >= maxfiles) {
910 tablefull("file", "increase kern.maxfiles or MAXFILES");
911 simple_unlock(&filelist_slock);
912 fd_unused(p->p_fd, i);
913 pool_put(&file_pool, fp);
914 return (ENFILE);
915 }
916 /*
917 * Allocate a new file descriptor.
918 * If the process has file descriptor zero open, add to the list
919 * of open files at that point, otherwise put it at the front of
920 * the list of open files.
921 */
922 nfiles++;
923 memset(fp, 0, sizeof(struct file));
924 fp->f_iflags = FIF_LARVAL;
925 if ((fq = p->p_fd->fd_ofiles[0]) != NULL) {
926 LIST_INSERT_AFTER(fq, fp, f_list);
927 } else {
928 LIST_INSERT_HEAD(&filehead, fp, f_list);
929 }
930 simple_unlock(&filelist_slock);
931 KDASSERT(p->p_fd->fd_ofiles[i] == NULL);
932 p->p_fd->fd_ofiles[i] = fp;
933 simple_lock_init(&fp->f_slock);
934 fp->f_count = 1;
935 fp->f_cred = p->p_ucred;
936 crhold(fp->f_cred);
937 if (resultfp) {
938 fp->f_usecount = 1;
939 *resultfp = fp;
940 }
941 if (resultfd)
942 *resultfd = i;
943 return (0);
944 }
945
946 /*
947 * Free a file descriptor.
948 */
949 void
950 ffree(struct file *fp)
951 {
952
953 #ifdef DIAGNOSTIC
954 if (fp->f_usecount)
955 panic("ffree");
956 #endif
957
958 simple_lock(&filelist_slock);
959 LIST_REMOVE(fp, f_list);
960 crfree(fp->f_cred);
961 #ifdef DIAGNOSTIC
962 fp->f_count = 0; /* What's the point? */
963 #endif
964 nfiles--;
965 simple_unlock(&filelist_slock);
966 pool_put(&file_pool, fp);
967 }
968
969 /*
970 * Create an initial cwdinfo structure, using the same current and root
971 * directories as p.
972 */
973 struct cwdinfo *
974 cwdinit(struct proc *p)
975 {
976 struct cwdinfo *cwdi;
977
978 cwdi = pool_get(&cwdi_pool, PR_WAITOK);
979
980 cwdi->cwdi_cdir = p->p_cwdi->cwdi_cdir;
981 if (cwdi->cwdi_cdir)
982 VREF(cwdi->cwdi_cdir);
983 cwdi->cwdi_rdir = p->p_cwdi->cwdi_rdir;
984 if (cwdi->cwdi_rdir)
985 VREF(cwdi->cwdi_rdir);
986 cwdi->cwdi_cmask = p->p_cwdi->cwdi_cmask;
987 cwdi->cwdi_refcnt = 1;
988
989 return (cwdi);
990 }
991
992 /*
993 * Make p2 share p1's cwdinfo.
994 */
995 void
996 cwdshare(struct proc *p1, struct proc *p2)
997 {
998
999 p2->p_cwdi = p1->p_cwdi;
1000 p1->p_cwdi->cwdi_refcnt++;
1001 }
1002
1003 /*
1004 * Make this process not share its cwdinfo structure, maintaining
1005 * all cwdinfo state.
1006 */
1007 void
1008 cwdunshare(struct proc *p)
1009 {
1010 struct cwdinfo *newcwdi;
1011
1012 if (p->p_cwdi->cwdi_refcnt == 1)
1013 return;
1014
1015 newcwdi = cwdinit(p);
1016 cwdfree(p);
1017 p->p_cwdi = newcwdi;
1018 }
1019
1020 /*
1021 * Release a cwdinfo structure.
1022 */
1023 void
1024 cwdfree(struct proc *p)
1025 {
1026 struct cwdinfo *cwdi;
1027
1028 cwdi = p->p_cwdi;
1029 if (--cwdi->cwdi_refcnt > 0)
1030 return;
1031
1032 p->p_cwdi = NULL;
1033
1034 vrele(cwdi->cwdi_cdir);
1035 if (cwdi->cwdi_rdir)
1036 vrele(cwdi->cwdi_rdir);
1037 pool_put(&cwdi_pool, cwdi);
1038 }
1039
1040 /*
1041 * Create an initial filedesc structure, using the same current and root
1042 * directories as p.
1043 */
1044 struct filedesc *
1045 fdinit(struct proc *p)
1046 {
1047 struct filedesc0 *newfdp;
1048
1049 newfdp = pool_get(&filedesc0_pool, PR_WAITOK);
1050 memset(newfdp, 0, sizeof(struct filedesc0));
1051
1052 fdinit1(newfdp);
1053
1054 return (&newfdp->fd_fd);
1055 }
1056
1057 /*
1058 * Initialize a file descriptor table.
1059 */
1060 void
1061 fdinit1(struct filedesc0 *newfdp)
1062 {
1063
1064 newfdp->fd_fd.fd_refcnt = 1;
1065 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles;
1066 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags;
1067 newfdp->fd_fd.fd_nfiles = NDFILE;
1068 newfdp->fd_fd.fd_knlistsize = -1;
1069 newfdp->fd_fd.fd_himap = newfdp->fd_dhimap;
1070 newfdp->fd_fd.fd_lomap = newfdp->fd_dlomap;
1071 newfdp->fd_fd.fd_lastfile = -1;
1072 }
1073
1074 /*
1075 * Make p2 share p1's filedesc structure.
1076 */
1077 void
1078 fdshare(struct proc *p1, struct proc *p2)
1079 {
1080
1081 p2->p_fd = p1->p_fd;
1082 p1->p_fd->fd_refcnt++;
1083 }
1084
1085 /*
1086 * Make this process not share its filedesc structure, maintaining
1087 * all file descriptor state.
1088 */
1089 void
1090 fdunshare(struct proc *p)
1091 {
1092 struct filedesc *newfd;
1093
1094 if (p->p_fd->fd_refcnt == 1)
1095 return;
1096
1097 newfd = fdcopy(p);
1098 fdfree(p);
1099 p->p_fd = newfd;
1100 }
1101
1102 /*
1103 * Clear a process's fd table.
1104 */
1105 void
1106 fdclear(struct proc *p)
1107 {
1108 struct filedesc *newfd;
1109
1110 newfd = fdinit(p);
1111 fdfree(p);
1112 p->p_fd = newfd;
1113 }
1114
1115 /*
1116 * Copy a filedesc structure.
1117 */
1118 struct filedesc *
1119 fdcopy(struct proc *p)
1120 {
1121 struct filedesc *newfdp, *fdp;
1122 struct file **fpp;
1123 int i;
1124
1125 fdp = p->p_fd;
1126 newfdp = pool_get(&filedesc0_pool, PR_WAITOK);
1127 memcpy(newfdp, fdp, sizeof(struct filedesc));
1128 newfdp->fd_refcnt = 1;
1129
1130 /*
1131 * If the number of open files fits in the internal arrays
1132 * of the open file structure, use them, otherwise allocate
1133 * additional memory for the number of descriptors currently
1134 * in use.
1135 */
1136 if (newfdp->fd_lastfile < NDFILE) {
1137 newfdp->fd_ofiles = ((struct filedesc0 *) newfdp)->fd_dfiles;
1138 newfdp->fd_ofileflags =
1139 ((struct filedesc0 *) newfdp)->fd_dfileflags;
1140 i = NDFILE;
1141 } else {
1142 /*
1143 * Compute the smallest multiple of NDEXTENT needed
1144 * for the file descriptors currently in use,
1145 * allowing the table to shrink.
1146 */
1147 i = newfdp->fd_nfiles;
1148 while (i >= 2 * NDEXTENT && i > newfdp->fd_lastfile * 2)
1149 i /= 2;
1150 newfdp->fd_ofiles = malloc(i * OFILESIZE, M_FILEDESC, M_WAITOK);
1151 newfdp->fd_ofileflags = (char *) &newfdp->fd_ofiles[i];
1152 }
1153 if (NDHISLOTS(i) <= NDHISLOTS(NDFILE)) {
1154 newfdp->fd_himap =
1155 ((struct filedesc0 *) newfdp)->fd_dhimap;
1156 newfdp->fd_lomap =
1157 ((struct filedesc0 *) newfdp)->fd_dlomap;
1158 } else {
1159 newfdp->fd_himap = malloc(NDHISLOTS(i) * sizeof(uint32_t),
1160 M_FILEDESC, M_WAITOK);
1161 newfdp->fd_lomap = malloc(NDLOSLOTS(i) * sizeof(uint32_t),
1162 M_FILEDESC, M_WAITOK);
1163 }
1164
1165 newfdp->fd_nfiles = i;
1166 memcpy(newfdp->fd_ofiles, fdp->fd_ofiles, i * sizeof(struct file **));
1167 memcpy(newfdp->fd_ofileflags, fdp->fd_ofileflags, i * sizeof(char));
1168 if (i < NDENTRIES * NDENTRIES)
1169 i = NDENTRIES * NDENTRIES; /* size of inlined bitmaps */
1170 memcpy(newfdp->fd_himap, fdp->fd_himap, NDHISLOTS(i)*sizeof(uint32_t));
1171 memcpy(newfdp->fd_lomap, fdp->fd_lomap, NDLOSLOTS(i)*sizeof(uint32_t));
1172 /*
1173 * kq descriptors cannot be copied.
1174 */
1175 if (newfdp->fd_knlistsize != -1) {
1176 fpp = newfdp->fd_ofiles;
1177 for (i = 0; i <= newfdp->fd_lastfile; i++, fpp++) {
1178 if (*fpp != NULL && (*fpp)->f_type == DTYPE_KQUEUE)
1179 fdremove(newfdp, i);
1180 }
1181 newfdp->fd_knlist = NULL;
1182 newfdp->fd_knlistsize = -1;
1183 newfdp->fd_knhash = NULL;
1184 newfdp->fd_knhashmask = 0;
1185 }
1186 fpp = newfdp->fd_ofiles;
1187 for (i = newfdp->fd_lastfile; i >= 0; i--, fpp++)
1188 if (*fpp != NULL)
1189 (*fpp)->f_count++;
1190 return (newfdp);
1191 }
1192
1193 /*
1194 * Release a filedesc structure.
1195 */
1196 void
1197 fdfree(struct proc *p)
1198 {
1199 struct filedesc *fdp;
1200 struct file **fpp, *fp;
1201 int i;
1202
1203 fdp = p->p_fd;
1204 if (--fdp->fd_refcnt > 0)
1205 return;
1206 fpp = fdp->fd_ofiles;
1207 for (i = fdp->fd_lastfile; i >= 0; i--, fpp++) {
1208 fp = *fpp;
1209 if (fp != NULL) {
1210 *fpp = NULL;
1211 simple_lock(&fp->f_slock);
1212 FILE_USE(fp);
1213 if ((fdp->fd_lastfile - i) < fdp->fd_knlistsize)
1214 knote_fdclose(p, fdp->fd_lastfile - i);
1215 (void) closef(fp, p);
1216 }
1217 }
1218 p->p_fd = NULL;
1219 if (fdp->fd_nfiles > NDFILE)
1220 free(fdp->fd_ofiles, M_FILEDESC);
1221 if (NDHISLOTS(fdp->fd_nfiles) > NDHISLOTS(NDFILE)) {
1222 free(fdp->fd_himap, M_FILEDESC);
1223 free(fdp->fd_lomap, M_FILEDESC);
1224 }
1225 if (fdp->fd_knlist)
1226 free(fdp->fd_knlist, M_KEVENT);
1227 if (fdp->fd_knhash)
1228 hashdone(fdp->fd_knhash, M_KEVENT);
1229 pool_put(&filedesc0_pool, fdp);
1230 }
1231
1232 /*
1233 * Internal form of close.
1234 * Decrement reference count on file structure.
1235 * Note: p may be NULL when closing a file
1236 * that was being passed in a message.
1237 *
1238 * Note: we expect the caller is holding a usecount, and expects us
1239 * to drop it (the caller thinks the file is going away forever).
1240 */
1241 int
1242 closef(struct file *fp, struct proc *p)
1243 {
1244 struct vnode *vp;
1245 struct flock lf;
1246 int error;
1247
1248 if (fp == NULL)
1249 return (0);
1250
1251 /*
1252 * POSIX record locking dictates that any close releases ALL
1253 * locks owned by this process. This is handled by setting
1254 * a flag in the unlock to free ONLY locks obeying POSIX
1255 * semantics, and not to free BSD-style file locks.
1256 * If the descriptor was in a message, POSIX-style locks
1257 * aren't passed with the descriptor.
1258 */
1259 if (p && (p->p_flag & P_ADVLOCK) && fp->f_type == DTYPE_VNODE) {
1260 lf.l_whence = SEEK_SET;
1261 lf.l_start = 0;
1262 lf.l_len = 0;
1263 lf.l_type = F_UNLCK;
1264 vp = (struct vnode *)fp->f_data;
1265 (void) VOP_ADVLOCK(vp, p, F_UNLCK, &lf, F_POSIX);
1266 }
1267
1268 /*
1269 * If WANTCLOSE is set, then the reference count on the file
1270 * is 0, but there were multiple users of the file. This can
1271 * happen if a filedesc structure is shared by multiple
1272 * processes.
1273 */
1274 simple_lock(&fp->f_slock);
1275 if (fp->f_iflags & FIF_WANTCLOSE) {
1276 /*
1277 * Another user of the file is already closing, and is
1278 * simply waiting for other users of the file to drain.
1279 * Release our usecount, and wake up the closer if it
1280 * is the only remaining use.
1281 */
1282 #ifdef DIAGNOSTIC
1283 if (fp->f_count != 0)
1284 panic("closef: wantclose and count != 0");
1285 if (fp->f_usecount < 2)
1286 panic("closef: wantclose and usecount < 2");
1287 #endif
1288 if (--fp->f_usecount == 1)
1289 wakeup(&fp->f_usecount);
1290 simple_unlock(&fp->f_slock);
1291 return (0);
1292 } else {
1293 /*
1294 * Decrement the reference count. If we were not the
1295 * last reference, then release our use and just
1296 * return.
1297 */
1298 if (--fp->f_count > 0) {
1299 #ifdef DIAGNOSTIC
1300 if (fp->f_usecount < 1)
1301 panic("closef: no wantclose and usecount < 1");
1302 #endif
1303 fp->f_usecount--;
1304 simple_unlock(&fp->f_slock);
1305 return (0);
1306 }
1307 }
1308
1309 /*
1310 * The reference count is now 0. However, there may be
1311 * multiple potential users of this file. This can happen
1312 * if multiple processes shared a single filedesc structure.
1313 *
1314 * Notify these potential users that the file is closing.
1315 * This will prevent them from adding additional uses to
1316 * the file.
1317 */
1318 fp->f_iflags |= FIF_WANTCLOSE;
1319
1320 /*
1321 * We expect the caller to add a use to the file. So, if we
1322 * are the last user, usecount will be 1. If it is not, we
1323 * must wait for the usecount to drain. When it drains back
1324 * to 1, we will be awakened so that we may proceed with the
1325 * close.
1326 */
1327 #ifdef DIAGNOSTIC
1328 if (fp->f_usecount < 1)
1329 panic("closef: usecount < 1");
1330 #endif
1331 while (fp->f_usecount > 1)
1332 (void) ltsleep(&fp->f_usecount, PRIBIO, "closef", 0,
1333 &fp->f_slock);
1334 #ifdef DIAGNOSTIC
1335 if (fp->f_usecount != 1)
1336 panic("closef: usecount != 1");
1337 #endif
1338
1339 simple_unlock(&fp->f_slock);
1340 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) {
1341 lf.l_whence = SEEK_SET;
1342 lf.l_start = 0;
1343 lf.l_len = 0;
1344 lf.l_type = F_UNLCK;
1345 vp = (struct vnode *)fp->f_data;
1346 (void) VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK);
1347 }
1348 if (fp->f_ops)
1349 error = (*fp->f_ops->fo_close)(fp, p);
1350 else
1351 error = 0;
1352
1353 /* Nothing references the file now, drop the final use (us). */
1354 fp->f_usecount--;
1355
1356 ffree(fp);
1357 return (error);
1358 }
1359
1360 /*
1361 * Apply an advisory lock on a file descriptor.
1362 *
1363 * Just attempt to get a record lock of the requested type on
1364 * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0).
1365 */
1366 /* ARGSUSED */
1367 int
1368 sys_flock(struct lwp *l, void *v, register_t *retval)
1369 {
1370 struct sys_flock_args /* {
1371 syscallarg(int) fd;
1372 syscallarg(int) how;
1373 } */ *uap = v;
1374 int fd, how, error;
1375 struct proc *p;
1376 struct filedesc *fdp;
1377 struct file *fp;
1378 struct vnode *vp;
1379 struct flock lf;
1380
1381 p = l->l_proc;
1382 fd = SCARG(uap, fd);
1383 how = SCARG(uap, how);
1384 fdp = p->p_fd;
1385 error = 0;
1386
1387 if ((fp = fd_getfile(fdp, fd)) == NULL)
1388 return (EBADF);
1389
1390 FILE_USE(fp);
1391
1392 if (fp->f_type != DTYPE_VNODE) {
1393 error = EOPNOTSUPP;
1394 goto out;
1395 }
1396
1397 vp = (struct vnode *)fp->f_data;
1398 lf.l_whence = SEEK_SET;
1399 lf.l_start = 0;
1400 lf.l_len = 0;
1401 if (how & LOCK_UN) {
1402 lf.l_type = F_UNLCK;
1403 fp->f_flag &= ~FHASLOCK;
1404 error = VOP_ADVLOCK(vp, fp, F_UNLCK, &lf, F_FLOCK);
1405 goto out;
1406 }
1407 if (how & LOCK_EX)
1408 lf.l_type = F_WRLCK;
1409 else if (how & LOCK_SH)
1410 lf.l_type = F_RDLCK;
1411 else {
1412 error = EINVAL;
1413 goto out;
1414 }
1415 fp->f_flag |= FHASLOCK;
1416 if (how & LOCK_NB)
1417 error = VOP_ADVLOCK(vp, fp, F_SETLK, &lf, F_FLOCK);
1418 else
1419 error = VOP_ADVLOCK(vp, fp, F_SETLK, &lf,
1420 F_FLOCK|F_WAIT);
1421 out:
1422 FILE_UNUSE(fp, p);
1423 return (error);
1424 }
1425
1426 /*
1427 * File Descriptor pseudo-device driver (/dev/fd/).
1428 *
1429 * Opening minor device N dup()s the file (if any) connected to file
1430 * descriptor N belonging to the calling process. Note that this driver
1431 * consists of only the ``open()'' routine, because all subsequent
1432 * references to this file will be direct to the other driver.
1433 */
1434 /* ARGSUSED */
1435 int
1436 filedescopen(dev_t dev, int mode, int type, struct proc *p)
1437 {
1438
1439 /*
1440 * XXX Kludge: set dupfd to contain the value of the
1441 * the file descriptor being sought for duplication. The error
1442 * return ensures that the vnode for this device will be released
1443 * by vn_open. Open will detect this special error and take the
1444 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN
1445 * will simply report the error.
1446 */
1447 curlwp->l_dupfd = minor(dev); /* XXX */
1448 return (ENODEV);
1449 }
1450
1451 /*
1452 * Duplicate the specified descriptor to a free descriptor.
1453 *
1454 * 'indx' has been fdalloc'ed (and will be fdremove'ed on error) by the caller.
1455 */
1456 int
1457 dupfdopen(struct proc *p, int indx, int dfd, int mode, int error)
1458 {
1459 struct filedesc *fdp;
1460 struct file *wfp;
1461
1462 fdp = p->p_fd;
1463
1464 /* should be cleared by the caller */
1465 KASSERT(fdp->fd_ofiles[indx] == NULL);
1466
1467 /*
1468 * If the to-be-dup'd fd number is greater than the allowed number
1469 * of file descriptors, or the fd to be dup'd has already been
1470 * closed, reject.
1471 */
1472
1473 /*
1474 * Note, in the case of indx == dfd, fd_getfile below returns NULL.
1475 */
1476 if ((wfp = fd_getfile(fdp, dfd)) == NULL)
1477 return (EBADF);
1478
1479 FILE_USE(wfp);
1480
1481 /*
1482 * There are two cases of interest here.
1483 *
1484 * For ENODEV simply dup (dfd) to file descriptor
1485 * (indx) and return.
1486 *
1487 * For ENXIO steal away the file structure from (dfd) and
1488 * store it in (indx). (dfd) is effectively closed by
1489 * this operation.
1490 *
1491 * Any other error code is just returned.
1492 */
1493 switch (error) {
1494 case ENODEV:
1495 /*
1496 * Check that the mode the file is being opened for is a
1497 * subset of the mode of the existing descriptor.
1498 */
1499 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) {
1500 FILE_UNUSE(wfp, p);
1501 return (EACCES);
1502 }
1503 fdp->fd_ofiles[indx] = wfp;
1504 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd];
1505 wfp->f_count++;
1506 /* 'indx' has been fd_used'ed by caller */
1507 FILE_UNUSE(wfp, p);
1508 return (0);
1509
1510 case ENXIO:
1511 /*
1512 * Steal away the file pointer from dfd, and stuff it into indx.
1513 */
1514 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd];
1515 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd];
1516 fdp->fd_ofiles[dfd] = NULL;
1517 fdp->fd_ofileflags[dfd] = 0;
1518 /*
1519 * Complete the clean up of the filedesc structure by
1520 * recomputing the various hints.
1521 */
1522 /* 'indx' has been fd_used'ed by caller */
1523 fd_unused(fdp, dfd);
1524 FILE_UNUSE(wfp, p);
1525 return (0);
1526
1527 default:
1528 FILE_UNUSE(wfp, p);
1529 return (error);
1530 }
1531 /* NOTREACHED */
1532 }
1533
1534 /*
1535 * fcntl call which is being passed to the file's fs.
1536 */
1537 int
1538 fcntl_forfs(int fd, struct proc *p, int cmd, void *arg)
1539 {
1540 struct file *fp;
1541 struct filedesc *fdp;
1542 int error;
1543 u_int size;
1544 void *data, *memp;
1545 #define STK_PARAMS 128
1546 char stkbuf[STK_PARAMS];
1547
1548 /* fd's value was validated in sys_fcntl before calling this routine */
1549 fdp = p->p_fd;
1550 fp = fdp->fd_ofiles[fd];
1551
1552 if ((fp->f_flag & (FREAD | FWRITE)) == 0)
1553 return (EBADF);
1554
1555 /*
1556 * Interpret high order word to find amount of data to be
1557 * copied to/from the user's address space.
1558 */
1559 size = (size_t)F_PARAM_LEN(cmd);
1560 if (size > F_PARAM_MAX)
1561 return (EINVAL);
1562 memp = NULL;
1563 if (size > sizeof(stkbuf)) {
1564 memp = malloc((u_long)size, M_IOCTLOPS, M_WAITOK);
1565 data = memp;
1566 } else
1567 data = stkbuf;
1568 if (cmd & F_FSIN) {
1569 if (size) {
1570 error = copyin(arg, data, size);
1571 if (error) {
1572 if (memp)
1573 free(memp, M_IOCTLOPS);
1574 return (error);
1575 }
1576 } else
1577 *(void **)data = arg;
1578 } else if ((cmd & F_FSOUT) && size)
1579 /*
1580 * Zero the buffer so the user always
1581 * gets back something deterministic.
1582 */
1583 memset(data, 0, size);
1584 else if (cmd & F_FSVOID)
1585 *(void **)data = arg;
1586
1587
1588 error = (*fp->f_ops->fo_fcntl)(fp, cmd, data, p);
1589
1590 /*
1591 * Copy any data to user, size was
1592 * already set and checked above.
1593 */
1594 if (error == 0 && (cmd & F_FSOUT) && size)
1595 error = copyout(data, arg, size);
1596 if (memp)
1597 free(memp, M_IOCTLOPS);
1598 return (error);
1599 }
1600
1601 /*
1602 * Close any files on exec?
1603 */
1604 void
1605 fdcloseexec(struct proc *p)
1606 {
1607 struct filedesc *fdp;
1608 int fd;
1609
1610 fdunshare(p);
1611 cwdunshare(p);
1612
1613 fdp = p->p_fd;
1614 for (fd = 0; fd <= fdp->fd_lastfile; fd++)
1615 if (fdp->fd_ofileflags[fd] & UF_EXCLOSE)
1616 (void) fdrelease(p, fd);
1617 }
1618
1619 /*
1620 * It is unsafe for set[ug]id processes to be started with file
1621 * descriptors 0..2 closed, as these descriptors are given implicit
1622 * significance in the Standard C library. fdcheckstd() will create a
1623 * descriptor referencing /dev/null for each of stdin, stdout, and
1624 * stderr that is not already open.
1625 */
1626 #define CHECK_UPTO 3
1627 int
1628 fdcheckstd(p)
1629 struct proc *p;
1630 {
1631 struct nameidata nd;
1632 struct filedesc *fdp;
1633 struct file *fp;
1634 struct file *devnullfp = NULL; /* Quell compiler warning */
1635 struct proc *pp;
1636 register_t retval;
1637 int fd, i, error, flags = FREAD|FWRITE, devnull = -1;
1638 char closed[CHECK_UPTO * 3 + 1], which[3 + 1];
1639
1640 closed[0] = '\0';
1641 if ((fdp = p->p_fd) == NULL)
1642 return (0);
1643 for (i = 0; i < CHECK_UPTO; i++) {
1644 if (fdp->fd_ofiles[i] != NULL)
1645 continue;
1646 snprintf(which, sizeof(which), ",%d", i);
1647 strlcat(closed, which, sizeof(closed));
1648 if (devnull < 0) {
1649 if ((error = falloc(p, &fp, &fd)) != 0)
1650 return (error);
1651 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/dev/null",
1652 p);
1653 if ((error = vn_open(&nd, flags, 0)) != 0) {
1654 FILE_UNUSE(fp, p);
1655 ffree(fp);
1656 fdremove(p->p_fd, fd);
1657 return (error);
1658 }
1659 fp->f_data = nd.ni_vp;
1660 fp->f_flag = flags;
1661 fp->f_ops = &vnops;
1662 fp->f_type = DTYPE_VNODE;
1663 VOP_UNLOCK(nd.ni_vp, 0);
1664 devnull = fd;
1665 devnullfp = fp;
1666 FILE_SET_MATURE(fp);
1667 } else {
1668 restart:
1669 if ((error = fdalloc(p, 0, &fd)) != 0) {
1670 if (error == ENOSPC) {
1671 fdexpand(p);
1672 goto restart;
1673 }
1674 return (error);
1675 }
1676
1677 simple_lock(&devnullfp->f_slock);
1678 FILE_USE(devnullfp);
1679 /* finishdup() will unuse the descriptors for us */
1680 if ((error = finishdup(p, devnull, fd, &retval)) != 0)
1681 return (error);
1682 }
1683 }
1684 if (devnullfp)
1685 FILE_UNUSE(devnullfp, p);
1686 if (closed[0] != '\0') {
1687 pp = p->p_pptr;
1688 log(LOG_WARNING, "set{u,g}id pid %d (%s) "
1689 "was invoked by uid %d ppid %d (%s) "
1690 "with fd %s closed\n",
1691 p->p_pid, p->p_comm, pp->p_ucred->cr_uid,
1692 pp->p_pid, pp->p_comm, &closed[1]);
1693 }
1694 return (0);
1695 }
1696 #undef CHECK_UPTO
1697
1698 /*
1699 * Sets descriptor owner. If the owner is a process, 'pgid'
1700 * is set to positive value, process ID. If the owner is process group,
1701 * 'pgid' is set to -pg_id.
1702 */
1703 int
1704 fsetown(struct proc *p, pid_t *pgid, int cmd, const void *data)
1705 {
1706 int id = *(int *)data;
1707 int error;
1708
1709 switch (cmd) {
1710 case TIOCSPGRP:
1711 if (id < 0)
1712 return (EINVAL);
1713 id = -id;
1714 break;
1715 default:
1716 break;
1717 }
1718
1719 if (id > 0 && !pfind(id))
1720 return (ESRCH);
1721 else if (id < 0 && (error = pgid_in_session(p, -id)))
1722 return (error);
1723
1724 *pgid = id;
1725 return (0);
1726 }
1727
1728 /*
1729 * Return descriptor owner information. If the value is positive,
1730 * it's process ID. If it's negative, it's process group ID and
1731 * needs the sign removed before use.
1732 */
1733 int
1734 fgetown(struct proc *p, pid_t pgid, int cmd, void *data)
1735 {
1736 switch (cmd) {
1737 case TIOCGPGRP:
1738 *(int *)data = -pgid;
1739 break;
1740 default:
1741 *(int *)data = pgid;
1742 break;
1743 }
1744 return (0);
1745 }
1746
1747 /*
1748 * Send signal to descriptor owner, either process or process group.
1749 */
1750 void
1751 fownsignal(pid_t pgid, int signo, int code, int band, void *fdescdata)
1752 {
1753 struct proc *p1;
1754 ksiginfo_t ksi;
1755
1756 memset(&ksi, 0, sizeof(ksi));
1757 ksi.ksi_signo = signo;
1758 ksi.ksi_code = code;
1759 ksi.ksi_band = band;
1760
1761 if (pgid > 0 && (p1 = pfind(pgid)))
1762 kpsignal(p1, &ksi, fdescdata);
1763 else if (pgid < 0)
1764 kgsignal(-pgid, &ksi, fdescdata);
1765 }
Cache object: 6464a5e4b14c3b5858744ea240b842a2
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