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More -Wwrite-strings cleanup and make sure you can actually play it.
[dragonfly.git] / sys / kern / kern_descrip.c
blob651942a2abea202c5b5395b123a102bb732484da
1 /*
2 * Copyright (c) 1982, 1986, 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94
39 * $FreeBSD: src/sys/kern/kern_descrip.c,v 1.81.2.19 2004/02/28 00:43:31 tegge Exp $
40 * $DragonFly: src/sys/kern/kern_descrip.c,v 1.41 2005/04/08 17:39:31 joerg Exp $
41 */
42
43 #include "opt_compat.h"
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/malloc.h>
47 #include <sys/sysproto.h>
48 #include <sys/conf.h>
49 #include <sys/filedesc.h>
50 #include <sys/kernel.h>
51 #include <sys/sysctl.h>
52 #include <sys/vnode.h>
53 #include <sys/proc.h>
54 #include <sys/nlookup.h>
55 #include <sys/file.h>
56 #include <sys/stat.h>
57 #include <sys/filio.h>
58 #include <sys/fcntl.h>
59 #include <sys/unistd.h>
60 #include <sys/resourcevar.h>
61 #include <sys/event.h>
62 #include <sys/kern_syscall.h>
63 #include <sys/kcore.h>
64 #include <sys/kinfo.h>
65
66 #include <vm/vm.h>
67 #include <vm/vm_extern.h>
68
69 #include <sys/file2.h>
70
71 static MALLOC_DEFINE(M_FILEDESC, "file desc", "Open file descriptor table");
72 static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "file desc to leader",
73 "file desc to leader structures");
74 MALLOC_DEFINE(M_FILE, "file", "Open file structure");
75 static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures");
76
77 static d_open_t fdopen;
78 #define NUMFDESC 64
79
80 #define CDEV_MAJOR 22
81 static struct cdevsw fildesc_cdevsw = {
82 /* name */ "FD",
83 /* maj */ CDEV_MAJOR,
84 /* flags */ 0,
85 /* port */ NULL,
86 /* clone */ NULL,
87
88 /* open */ fdopen,
89 /* close */ noclose,
90 /* read */ noread,
91 /* write */ nowrite,
92 /* ioctl */ noioctl,
93 /* poll */ nopoll,
94 /* mmap */ nommap,
95 /* strategy */ nostrategy,
96 /* dump */ nodump,
97 /* psize */ nopsize
98 };
99
100 static int badfo_readwrite (struct file *fp, struct uio *uio,
101 struct ucred *cred, int flags, struct thread *td);
102 static int badfo_ioctl (struct file *fp, u_long com, caddr_t data,
103 struct thread *td);
104 static int badfo_poll (struct file *fp, int events,
105 struct ucred *cred, struct thread *td);
106 static int badfo_kqfilter (struct file *fp, struct knote *kn);
107 static int badfo_stat (struct file *fp, struct stat *sb, struct thread *td);
108 static int badfo_close (struct file *fp, struct thread *td);
109
110 /*
111 * Descriptor management.
112 */
113 struct filelist filehead; /* head of list of open files */
114 int nfiles; /* actual number of open files */
115 extern int cmask;
116
117 /*
118 * System calls on descriptors.
119 */
120 /* ARGSUSED */
121 int
122 getdtablesize(struct getdtablesize_args *uap)
123 {
124 struct proc *p = curproc;
125
126 uap->sysmsg_result =
127 min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc);
128 return (0);
129 }
130
131 /*
132 * Duplicate a file descriptor to a particular value.
133 *
134 * note: keep in mind that a potential race condition exists when closing
135 * descriptors from a shared descriptor table (via rfork).
136 */
137 /* ARGSUSED */
138 int
139 dup2(struct dup2_args *uap)
140 {
141 int error;
142
143 error = kern_dup(DUP_FIXED, uap->from, uap->to, uap->sysmsg_fds);
144
145 return (error);
146 }
147
148 /*
149 * Duplicate a file descriptor.
150 */
151 /* ARGSUSED */
152 int
153 dup(struct dup_args *uap)
154 {
155 int error;
156
157 error = kern_dup(DUP_VARIABLE, uap->fd, 0, uap->sysmsg_fds);
158
159 return (error);
160 }
161
162 int
163 kern_fcntl(int fd, int cmd, union fcntl_dat *dat)
164 {
165 struct thread *td = curthread;
166 struct proc *p = td->td_proc;
167 struct filedesc *fdp = p->p_fd;
168 struct file *fp;
169 char *pop;
170 struct vnode *vp;
171 u_int newmin;
172 int tmp, error, flg = F_POSIX;
173
174 KKASSERT(p);
175
176 if ((unsigned)fd >= fdp->fd_nfiles ||
177 (fp = fdp->fd_ofiles[fd]) == NULL)
178 return (EBADF);
179 pop = &fdp->fd_ofileflags[fd];
180
181 switch (cmd) {
182 case F_DUPFD:
183 newmin = dat->fc_fd;
184 if (newmin >= p->p_rlimit[RLIMIT_NOFILE].rlim_cur ||
185 newmin > maxfilesperproc)
186 return (EINVAL);
187 error = kern_dup(DUP_VARIABLE, fd, newmin, &dat->fc_fd);
188 return (error);
189
190 case F_GETFD:
191 dat->fc_cloexec = (*pop & UF_EXCLOSE) ? FD_CLOEXEC : 0;
192 return (0);
193
194 case F_SETFD:
195 *pop = (*pop &~ UF_EXCLOSE) |
196 (dat->fc_cloexec & FD_CLOEXEC ? UF_EXCLOSE : 0);
197 return (0);
198
199 case F_GETFL:
200 dat->fc_flags = OFLAGS(fp->f_flag);
201 return (0);
202
203 case F_SETFL:
204 fhold(fp);
205 fp->f_flag &= ~FCNTLFLAGS;
206 fp->f_flag |= FFLAGS(dat->fc_flags & ~O_ACCMODE) & FCNTLFLAGS;
207 tmp = fp->f_flag & FNONBLOCK;
208 error = fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, td);
209 if (error) {
210 fdrop(fp, td);
211 return (error);
212 }
213 tmp = fp->f_flag & FASYNC;
214 error = fo_ioctl(fp, FIOASYNC, (caddr_t)&tmp, td);
215 if (!error) {
216 fdrop(fp, td);
217 return (0);
218 }
219 fp->f_flag &= ~FNONBLOCK;
220 tmp = 0;
221 fo_ioctl(fp, FIONBIO, (caddr_t)&tmp, td);
222 fdrop(fp, td);
223 return (error);
224
225 case F_GETOWN:
226 fhold(fp);
227 error = fo_ioctl(fp, FIOGETOWN, (caddr_t)&dat->fc_owner, td);
228 fdrop(fp, td);
229 return(error);
230
231 case F_SETOWN:
232 fhold(fp);
233 error = fo_ioctl(fp, FIOSETOWN, (caddr_t)&dat->fc_owner, td);
234 fdrop(fp, td);
235 return(error);
236
237 case F_SETLKW:
238 flg |= F_WAIT;
239 /* Fall into F_SETLK */
240
241 case F_SETLK:
242 if (fp->f_type != DTYPE_VNODE)
243 return (EBADF);
244 vp = (struct vnode *)fp->f_data;
245
246 /*
247 * copyin/lockop may block
248 */
249 fhold(fp);
250 if (dat->fc_flock.l_whence == SEEK_CUR)
251 dat->fc_flock.l_start += fp->f_offset;
252
253 switch (dat->fc_flock.l_type) {
254 case F_RDLCK:
255 if ((fp->f_flag & FREAD) == 0) {
256 error = EBADF;
257 break;
258 }
259 p->p_leader->p_flag |= P_ADVLOCK;
260 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
261 &dat->fc_flock, flg);
262 break;
263 case F_WRLCK:
264 if ((fp->f_flag & FWRITE) == 0) {
265 error = EBADF;
266 break;
267 }
268 p->p_leader->p_flag |= P_ADVLOCK;
269 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
270 &dat->fc_flock, flg);
271 break;
272 case F_UNLCK:
273 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
274 &dat->fc_flock, F_POSIX);
275 break;
276 default:
277 error = EINVAL;
278 break;
279 }
280 /* Check for race with close */
281 if ((unsigned) fd >= fdp->fd_nfiles ||
282 fp != fdp->fd_ofiles[fd]) {
283 dat->fc_flock.l_whence = SEEK_SET;
284 dat->fc_flock.l_start = 0;
285 dat->fc_flock.l_len = 0;
286 dat->fc_flock.l_type = F_UNLCK;
287 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
288 F_UNLCK, &dat->fc_flock, F_POSIX);
289 }
290 fdrop(fp, td);
291 return(error);
292
293 case F_GETLK:
294 if (fp->f_type != DTYPE_VNODE)
295 return (EBADF);
296 vp = (struct vnode *)fp->f_data;
297 /*
298 * copyin/lockop may block
299 */
300 fhold(fp);
301 if (dat->fc_flock.l_type != F_RDLCK &&
302 dat->fc_flock.l_type != F_WRLCK &&
303 dat->fc_flock.l_type != F_UNLCK) {
304 fdrop(fp, td);
305 return (EINVAL);
306 }
307 if (dat->fc_flock.l_whence == SEEK_CUR)
308 dat->fc_flock.l_start += fp->f_offset;
309 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK,
310 &dat->fc_flock, F_POSIX);
311 fdrop(fp, td);
312 return(error);
313 default:
314 return (EINVAL);
315 }
316 /* NOTREACHED */
317 }
318
319 /*
320 * The file control system call.
321 */
322 int
323 fcntl(struct fcntl_args *uap)
324 {
325 union fcntl_dat dat;
326 int error;
327
328 switch (uap->cmd) {
329 case F_DUPFD:
330 dat.fc_fd = uap->arg;
331 break;
332 case F_SETFD:
333 dat.fc_cloexec = uap->arg;
334 break;
335 case F_SETFL:
336 dat.fc_flags = uap->arg;
337 break;
338 case F_SETOWN:
339 dat.fc_owner = uap->arg;
340 break;
341 case F_SETLKW:
342 case F_SETLK:
343 case F_GETLK:
344 error = copyin((caddr_t)uap->arg, &dat.fc_flock,
345 sizeof(struct flock));
346 if (error)
347 return (error);
348 break;
349 }
350
351 error = kern_fcntl(uap->fd, uap->cmd, &dat);
352
353 if (error == 0) {
354 switch (uap->cmd) {
355 case F_DUPFD:
356 uap->sysmsg_result = dat.fc_fd;
357 break;
358 case F_GETFD:
359 uap->sysmsg_result = dat.fc_cloexec;
360 break;
361 case F_GETFL:
362 uap->sysmsg_result = dat.fc_flags;
363 break;
364 case F_GETOWN:
365 uap->sysmsg_result = dat.fc_owner;
366 case F_GETLK:
367 error = copyout(&dat.fc_flock, (caddr_t)uap->arg,
368 sizeof(struct flock));
369 break;
370 }
371 }
372
373 return (error);
374 }
375
376 /*
377 * Common code for dup, dup2, and fcntl(F_DUPFD).
378 *
379 * The type flag can be either DUP_FIXED or DUP_VARIABLE. DUP_FIXED tells
380 * kern_dup() to destructively dup over an existing file descriptor if new
381 * is already open. DUP_VARIABLE tells kern_dup() to find the lowest
382 * unused file descriptor that is greater than or equal to new.
383 */
384 int
385 kern_dup(enum dup_type type, int old, int new, int *res)
386 {
387 struct thread *td = curthread;
388 struct proc *p = td->td_proc;
389 struct filedesc *fdp = p->p_fd;
390 struct file *fp;
391 struct file *delfp;
392 int holdleaders;
393 int error, newfd;
394
395 /*
396 * Verify that we have a valid descriptor to dup from and
397 * possibly to dup to.
398 */
399 if (old < 0 || new < 0 || new > p->p_rlimit[RLIMIT_NOFILE].rlim_cur ||
400 new >= maxfilesperproc)
401 return (EBADF);
402 if (old >= fdp->fd_nfiles || fdp->fd_ofiles[old] == NULL)
403 return (EBADF);
404 if (type == DUP_FIXED && old == new) {
405 *res = new;
406 return (0);
407 }
408 fp = fdp->fd_ofiles[old];
409 fhold(fp);
410
411 /*
412 * Expand the table for the new descriptor if needed. This may
413 * block and drop and reacquire the fidedesc lock.
414 */
415 if (type == DUP_VARIABLE || new >= fdp->fd_nfiles) {
416 error = fdalloc(p, new, &newfd);
417 if (error) {
418 fdrop(fp, td);
419 return (error);
420 }
421 }
422 if (type == DUP_VARIABLE)
423 new = newfd;
424
425 /*
426 * If the old file changed out from under us then treat it as a
427 * bad file descriptor. Userland should do its own locking to
428 * avoid this case.
429 */
430 if (fdp->fd_ofiles[old] != fp) {
431 if (fdp->fd_ofiles[new] == NULL) {
432 if (new < fdp->fd_freefile)
433 fdp->fd_freefile = new;
434 while (fdp->fd_lastfile > 0 &&
435 fdp->fd_ofiles[fdp->fd_lastfile] == NULL)
436 fdp->fd_lastfile--;
437 }
438 fdrop(fp, td);
439 return (EBADF);
440 }
441 KASSERT(old != new, ("new fd is same as old"));
442
443 /*
444 * Save info on the descriptor being overwritten. We have
445 * to do the unmap now, but we cannot close it without
446 * introducing an ownership race for the slot.
447 */
448 delfp = fdp->fd_ofiles[new];
449 if (delfp != NULL && p->p_fdtol != NULL) {
450 /*
451 * Ask fdfree() to sleep to ensure that all relevant
452 * process leaders can be traversed in closef().
453 */
454 fdp->fd_holdleaderscount++;
455 holdleaders = 1;
456 } else
457 holdleaders = 0;
458 KASSERT(delfp == NULL || type == DUP_FIXED,
459 ("dup() picked an open file"));
460 #if 0
461 if (delfp && (fdp->fd_ofileflags[new] & UF_MAPPED))
462 (void) munmapfd(p, new);
463 #endif
464
465 /*
466 * Duplicate the source descriptor, update lastfile
467 */
468 fdp->fd_ofiles[new] = fp;
469 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE;
470 if (new > fdp->fd_lastfile)
471 fdp->fd_lastfile = new;
472 *res = new;
473
474 /*
475 * If we dup'd over a valid file, we now own the reference to it
476 * and must dispose of it using closef() semantics (as if a
477 * close() were performed on it).
478 */
479 if (delfp) {
480 (void) closef(delfp, td);
481 if (holdleaders) {
482 fdp->fd_holdleaderscount--;
483 if (fdp->fd_holdleaderscount == 0 &&
484 fdp->fd_holdleaderswakeup != 0) {
485 fdp->fd_holdleaderswakeup = 0;
486 wakeup(&fdp->fd_holdleaderscount);
487 }
488 }
489 }
490 return (0);
491 }
492
493 /*
494 * If sigio is on the list associated with a process or process group,
495 * disable signalling from the device, remove sigio from the list and
496 * free sigio.
497 */
498 void
499 funsetown(struct sigio *sigio)
500 {
501 int s;
502
503 if (sigio == NULL)
504 return;
505 s = splhigh();
506 *(sigio->sio_myref) = NULL;
507 splx(s);
508 if (sigio->sio_pgid < 0) {
509 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio,
510 sigio, sio_pgsigio);
511 } else /* if ((*sigiop)->sio_pgid > 0) */ {
512 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio,
513 sigio, sio_pgsigio);
514 }
515 crfree(sigio->sio_ucred);
516 free(sigio, M_SIGIO);
517 }
518
519 /* Free a list of sigio structures. */
520 void
521 funsetownlst(struct sigiolst *sigiolst)
522 {
523 struct sigio *sigio;
524
525 while ((sigio = SLIST_FIRST(sigiolst)) != NULL)
526 funsetown(sigio);
527 }
528
529 /*
530 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg).
531 *
532 * After permission checking, add a sigio structure to the sigio list for
533 * the process or process group.
534 */
535 int
536 fsetown(pid_t pgid, struct sigio **sigiop)
537 {
538 struct proc *proc;
539 struct pgrp *pgrp;
540 struct sigio *sigio;
541 int s;
542
543 if (pgid == 0) {
544 funsetown(*sigiop);
545 return (0);
546 }
547 if (pgid > 0) {
548 proc = pfind(pgid);
549 if (proc == NULL)
550 return (ESRCH);
551
552 /*
553 * Policy - Don't allow a process to FSETOWN a process
554 * in another session.
555 *
556 * Remove this test to allow maximum flexibility or
557 * restrict FSETOWN to the current process or process
558 * group for maximum safety.
559 */
560 if (proc->p_session != curproc->p_session)
561 return (EPERM);
562
563 pgrp = NULL;
564 } else /* if (pgid < 0) */ {
565 pgrp = pgfind(-pgid);
566 if (pgrp == NULL)
567 return (ESRCH);
568
569 /*
570 * Policy - Don't allow a process to FSETOWN a process
571 * in another session.
572 *
573 * Remove this test to allow maximum flexibility or
574 * restrict FSETOWN to the current process or process
575 * group for maximum safety.
576 */
577 if (pgrp->pg_session != curproc->p_session)
578 return (EPERM);
579
580 proc = NULL;
581 }
582 funsetown(*sigiop);
583 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK);
584 if (pgid > 0) {
585 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio);
586 sigio->sio_proc = proc;
587 } else {
588 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio);
589 sigio->sio_pgrp = pgrp;
590 }
591 sigio->sio_pgid = pgid;
592 sigio->sio_ucred = crhold(curproc->p_ucred);
593 /* It would be convenient if p_ruid was in ucred. */
594 sigio->sio_ruid = curproc->p_ucred->cr_ruid;
595 sigio->sio_myref = sigiop;
596 s = splhigh();
597 *sigiop = sigio;
598 splx(s);
599 return (0);
600 }
601
602 /*
603 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg).
604 */
605 pid_t
606 fgetown(struct sigio *sigio)
607 {
608 return (sigio != NULL ? sigio->sio_pgid : 0);
609 }
610
611 /*
612 * Close many file descriptors.
613 */
614 /* ARGSUSED */
615
616 int
617 closefrom(struct closefrom_args *uap)
618 {
619 return(kern_closefrom(uap->fd));
620 }
621
622 int
623 kern_closefrom(int fd)
624 {
625 struct thread *td = curthread;
626 struct proc *p = td->td_proc;
627 struct filedesc *fdp;
628
629 KKASSERT(p);
630 fdp = p->p_fd;
631
632 if (fd < 0 || fd > fdp->fd_lastfile)
633 return (0);
634
635 do {
636 if (kern_close(fdp->fd_lastfile) == EINTR)
637 return (EINTR);
638 } while (fdp->fd_lastfile > fd);
639
640 return (0);
641 }
642
643 /*
644 * Close a file descriptor.
645 */
646 /* ARGSUSED */
647
648 int
649 close(struct close_args *uap)
650 {
651 return(kern_close(uap->fd));
652 }
653
654 int
655 kern_close(int fd)
656 {
657 struct thread *td = curthread;
658 struct proc *p = td->td_proc;
659 struct filedesc *fdp;
660 struct file *fp;
661 int error;
662 int holdleaders;
663
664 KKASSERT(p);
665 fdp = p->p_fd;
666
667 if ((unsigned)fd >= fdp->fd_nfiles ||
668 (fp = fdp->fd_ofiles[fd]) == NULL)
669 return (EBADF);
670 #if 0
671 if (fdp->fd_ofileflags[fd] & UF_MAPPED)
672 (void) munmapfd(p, fd);
673 #endif
674 fdp->fd_ofiles[fd] = NULL;
675 fdp->fd_ofileflags[fd] = 0;
676 holdleaders = 0;
677 if (p->p_fdtol != NULL) {
678 /*
679 * Ask fdfree() to sleep to ensure that all relevant
680 * process leaders can be traversed in closef().
681 */
682 fdp->fd_holdleaderscount++;
683 holdleaders = 1;
684 }
685
686 /*
687 * we now hold the fp reference that used to be owned by the descriptor
688 * array.
689 */
690 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL)
691 fdp->fd_lastfile--;
692 if (fd < fdp->fd_freefile)
693 fdp->fd_freefile = fd;
694 if (fd < fdp->fd_knlistsize)
695 knote_fdclose(p, fd);
696 error = closef(fp, td);
697 if (holdleaders) {
698 fdp->fd_holdleaderscount--;
699 if (fdp->fd_holdleaderscount == 0 &&
700 fdp->fd_holdleaderswakeup != 0) {
701 fdp->fd_holdleaderswakeup = 0;
702 wakeup(&fdp->fd_holdleaderscount);
703 }
704 }
705 return (error);
706 }
707
708 int
709 kern_fstat(int fd, struct stat *ub)
710 {
711 struct thread *td = curthread;
712 struct proc *p = td->td_proc;
713 struct filedesc *fdp;
714 struct file *fp;
715 int error;
716
717 KKASSERT(p);
718
719 fdp = p->p_fd;
720 if ((unsigned)fd >= fdp->fd_nfiles ||
721 (fp = fdp->fd_ofiles[fd]) == NULL)
722 return (EBADF);
723 fhold(fp);
724 error = fo_stat(fp, ub, td);
725 fdrop(fp, td);
726
727 return (error);
728 }
729
730 /*
731 * Return status information about a file descriptor.
732 */
733 int
734 fstat(struct fstat_args *uap)
735 {
736 struct stat st;
737 int error;
738
739 error = kern_fstat(uap->fd, &st);
740
741 if (error == 0)
742 error = copyout(&st, uap->sb, sizeof(st));
743 return (error);
744 }
745
746 /*
747 * XXX: This is for source compatibility with NetBSD. Probably doesn't
748 * belong here.
749 */
750 int
751 nfstat(struct nfstat_args *uap)
752 {
753 struct stat st;
754 struct nstat nst;
755 int error;
756
757 error = kern_fstat(uap->fd, &st);
758
759 if (error == 0) {
760 cvtnstat(&st, &nst);
761 error = copyout(&nst, uap->sb, sizeof (nst));
762 }
763 return (error);
764 }
765
766 /*
767 * Return pathconf information about a file descriptor.
768 */
769 /* ARGSUSED */
770 int
771 fpathconf(struct fpathconf_args *uap)
772 {
773 struct thread *td = curthread;
774 struct proc *p = td->td_proc;
775 struct filedesc *fdp;
776 struct file *fp;
777 struct vnode *vp;
778 int error = 0;
779
780 KKASSERT(p);
781 fdp = p->p_fd;
782 if ((unsigned)uap->fd >= fdp->fd_nfiles ||
783 (fp = fdp->fd_ofiles[uap->fd]) == NULL)
784 return (EBADF);
785
786 fhold(fp);
787
788 switch (fp->f_type) {
789 case DTYPE_PIPE:
790 case DTYPE_SOCKET:
791 if (uap->name != _PC_PIPE_BUF) {
792 error = EINVAL;
793 } else {
794 uap->sysmsg_result = PIPE_BUF;
795 error = 0;
796 }
797 break;
798 case DTYPE_FIFO:
799 case DTYPE_VNODE:
800 vp = (struct vnode *)fp->f_data;
801 error = VOP_PATHCONF(vp, uap->name, uap->sysmsg_fds);
802 break;
803 default:
804 error = EOPNOTSUPP;
805 break;
806 }
807 fdrop(fp, td);
808 return(error);
809 }
810
811 /*
812 * Allocate a file descriptor for the process.
813 */
814 static int fdexpand;
815 SYSCTL_INT(_debug, OID_AUTO, fdexpand, CTLFLAG_RD, &fdexpand, 0, "");
816
817 int
818 fdalloc(struct proc *p, int want, int *result)
819 {
820 struct filedesc *fdp = p->p_fd;
821 int i;
822 int lim, last, nfiles;
823 struct file **newofile;
824 char *newofileflags;
825
826 /*
827 * Search for a free descriptor starting at the higher
828 * of want or fd_freefile. If that fails, consider
829 * expanding the ofile array.
830 */
831 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc);
832 for (;;) {
833 last = min(fdp->fd_nfiles, lim);
834 if ((i = want) < fdp->fd_freefile)
835 i = fdp->fd_freefile;
836 for (; i < last; i++) {
837 if (fdp->fd_ofiles[i] == NULL) {
838 fdp->fd_ofileflags[i] = 0;
839 if (i > fdp->fd_lastfile)
840 fdp->fd_lastfile = i;
841 if (want <= fdp->fd_freefile)
842 fdp->fd_freefile = i;
843 *result = i;
844 return (0);
845 }
846 }
847
848 /*
849 * No space in current array. Expand?
850 */
851 if (fdp->fd_nfiles >= lim)
852 return (EMFILE);
853 if (fdp->fd_nfiles < NDEXTENT)
854 nfiles = NDEXTENT;
855 else
856 nfiles = 2 * fdp->fd_nfiles;
857 newofile = malloc(nfiles * OFILESIZE, M_FILEDESC, M_WAITOK);
858
859 /*
860 * deal with file-table extend race that might have occured
861 * when malloc was blocked.
862 */
863 if (fdp->fd_nfiles >= nfiles) {
864 free(newofile, M_FILEDESC);
865 continue;
866 }
867 newofileflags = (char *) &newofile[nfiles];
868 /*
869 * Copy the existing ofile and ofileflags arrays
870 * and zero the new portion of each array.
871 */
872 bcopy(fdp->fd_ofiles, newofile,
873 (i = sizeof(struct file *) * fdp->fd_nfiles));
874 bzero((char *)newofile + i, nfiles * sizeof(struct file *) - i);
875 bcopy(fdp->fd_ofileflags, newofileflags,
876 (i = sizeof(char) * fdp->fd_nfiles));
877 bzero(newofileflags + i, nfiles * sizeof(char) - i);
878 if (fdp->fd_nfiles > NDFILE)
879 free(fdp->fd_ofiles, M_FILEDESC);
880 fdp->fd_ofiles = newofile;
881 fdp->fd_ofileflags = newofileflags;
882 fdp->fd_nfiles = nfiles;
883 fdexpand++;
884 }
885 return (0);
886 }
887
888 /*
889 * Check to see whether n user file descriptors
890 * are available to the process p.
891 */
892 int
893 fdavail(struct proc *p, int n)
894 {
895 struct filedesc *fdp = p->p_fd;
896 struct file **fpp;
897 int i, lim, last;
898
899 lim = min((int)p->p_rlimit[RLIMIT_NOFILE].rlim_cur, maxfilesperproc);
900 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0)
901 return (1);
902
903 last = min(fdp->fd_nfiles, lim);
904 fpp = &fdp->fd_ofiles[fdp->fd_freefile];
905 for (i = last - fdp->fd_freefile; --i >= 0; fpp++) {
906 if (*fpp == NULL && --n <= 0)
907 return (1);
908 }
909 return (0);
910 }
911
912 /*
913 * falloc:
914 * Create a new open file structure and allocate a file decriptor
915 * for the process that refers to it. If p is NULL, no descriptor
916 * is allocated and the file pointer is returned unassociated with
917 * any process. resultfd is only used if p is not NULL and may
918 * separately be NULL indicating that you don't need the returned fd.
919 *
920 * A held file pointer is returned. If a descriptor has been allocated
921 * an additional hold on the fp will be made due to the fd_ofiles[]
922 * reference.
923 */
924 int
925 falloc(struct proc *p, struct file **resultfp, int *resultfd)
926 {
927 static struct timeval lastfail;
928 static int curfail;
929 struct file *fp;
930 int error;
931
932 fp = NULL;
933
934 /*
935 * Handle filetable full issues and root overfill.
936 */
937 if (nfiles >= maxfiles - maxfilesrootres &&
938 ((p && p->p_ucred->cr_ruid != 0) || nfiles >= maxfiles)) {
939 if (ppsratecheck(&lastfail, &curfail, 1)) {
940 printf("kern.maxfiles limit exceeded by uid %d, please see tuning(7).\n",
941 (p ? p->p_ucred->cr_ruid : -1));
942 }
943 error = ENFILE;
944 goto done;
945 }
946
947 /*
948 * Allocate a new file descriptor.
949 */
950 nfiles++;
951 fp = malloc(sizeof(struct file), M_FILE, M_WAITOK | M_ZERO);
952 fp->f_count = 1;
953 fp->f_ops = &badfileops;
954 fp->f_seqcount = 1;
955 if (p)
956 fp->f_cred = crhold(p->p_ucred);
957 else
958 fp->f_cred = crhold(proc0.p_ucred);
959 LIST_INSERT_HEAD(&filehead, fp, f_list);
960 if (resultfd) {
961 if ((error = fsetfd(p, fp, resultfd)) != 0) {
962 fdrop(fp, p->p_thread);
963 fp = NULL;
964 }
965 } else {
966 error = 0;
967 }
968 done:
969 *resultfp = fp;
970 return (error);
971 }
972
973 /*
974 * Associate a file pointer with a file descriptor. On success the fp
975 * will have an additional ref representing the fd_ofiles[] association.
976 */
977 int
978 fsetfd(struct proc *p, struct file *fp, int *resultfd)
979 {
980 int i;
981 int error;
982
983 KKASSERT(p);
984
985 i = -1;
986 if ((error = fdalloc(p, 0, &i)) == 0) {
987 fhold(fp);
988 p->p_fd->fd_ofiles[i] = fp;
989 }
990 *resultfd = i;
991 return (0);
992 }
993
994 void
995 fsetcred(struct file *fp, struct ucred *cr)
996 {
997 crhold(cr);
998 crfree(fp->f_cred);
999 fp->f_cred = cr;
1000 }
1001
1002 /*
1003 * Free a file descriptor.
1004 */
1005 void
1006 ffree(struct file *fp)
1007 {
1008 KASSERT((fp->f_count == 0), ("ffree: fp_fcount not 0!"));
1009 LIST_REMOVE(fp, f_list);
1010 crfree(fp->f_cred);
1011 if (fp->f_ncp) {
1012 cache_drop(fp->f_ncp);
1013 fp->f_ncp = NULL;
1014 }
1015 nfiles--;
1016 free(fp, M_FILE);
1017 }
1018
1019 /*
1020 * Build a new filedesc structure.
1021 */
1022 struct filedesc *
1023 fdinit(struct proc *p)
1024 {
1025 struct filedesc0 *newfdp;
1026 struct filedesc *fdp = p->p_fd;
1027
1028 newfdp = malloc(sizeof(struct filedesc0), M_FILEDESC, M_WAITOK|M_ZERO);
1029 if (fdp->fd_cdir) {
1030 newfdp->fd_fd.fd_cdir = fdp->fd_cdir;
1031 vref(newfdp->fd_fd.fd_cdir);
1032 newfdp->fd_fd.fd_ncdir = cache_hold(fdp->fd_ncdir);
1033 }
1034
1035 /*
1036 * rdir may not be set in e.g. proc0 or anything vm_fork'd off of
1037 * proc0, but should unconditionally exist in other processes.
1038 */
1039 if (fdp->fd_rdir) {
1040 newfdp->fd_fd.fd_rdir = fdp->fd_rdir;
1041 vref(newfdp->fd_fd.fd_rdir);
1042 newfdp->fd_fd.fd_nrdir = cache_hold(fdp->fd_nrdir);
1043 }
1044 if (fdp->fd_jdir) {
1045 newfdp->fd_fd.fd_jdir = fdp->fd_jdir;
1046 vref(newfdp->fd_fd.fd_jdir);
1047 newfdp->fd_fd.fd_njdir = cache_hold(fdp->fd_njdir);
1048 }
1049
1050 /* Create the file descriptor table. */
1051 newfdp->fd_fd.fd_refcnt = 1;
1052 newfdp->fd_fd.fd_cmask = cmask;
1053 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles;
1054 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags;
1055 newfdp->fd_fd.fd_nfiles = NDFILE;
1056 newfdp->fd_fd.fd_knlistsize = -1;
1057
1058 return (&newfdp->fd_fd);
1059 }
1060
1061 /*
1062 * Share a filedesc structure.
1063 */
1064 struct filedesc *
1065 fdshare(struct proc *p)
1066 {
1067 p->p_fd->fd_refcnt++;
1068 return (p->p_fd);
1069 }
1070
1071 /*
1072 * Copy a filedesc structure.
1073 */
1074 struct filedesc *
1075 fdcopy(struct proc *p)
1076 {
1077 struct filedesc *newfdp, *fdp = p->p_fd;
1078 struct file **fpp;
1079 int i;
1080
1081 /* Certain daemons might not have file descriptors. */
1082 if (fdp == NULL)
1083 return (NULL);
1084
1085 newfdp = malloc(sizeof(struct filedesc0), M_FILEDESC, M_WAITOK);
1086 bcopy(fdp, newfdp, sizeof(struct filedesc));
1087 if (newfdp->fd_cdir) {
1088 vref(newfdp->fd_cdir);
1089 newfdp->fd_ncdir = cache_hold(newfdp->fd_ncdir);
1090 }
1091 /*
1092 * We must check for fd_rdir here, at least for now because
1093 * the init process is created before we have access to the
1094 * rootvode to take a reference to it.
1095 */
1096 if (newfdp->fd_rdir) {
1097 vref(newfdp->fd_rdir);
1098 newfdp->fd_nrdir = cache_hold(newfdp->fd_nrdir);
1099 }
1100 if (newfdp->fd_jdir) {
1101 vref(newfdp->fd_jdir);
1102 newfdp->fd_njdir = cache_hold(newfdp->fd_njdir);
1103 }
1104 newfdp->fd_refcnt = 1;
1105
1106 /*
1107 * If the number of open files fits in the internal arrays
1108 * of the open file structure, use them, otherwise allocate
1109 * additional memory for the number of descriptors currently
1110 * in use.
1111 */
1112 if (newfdp->fd_lastfile < NDFILE) {
1113 newfdp->fd_ofiles = ((struct filedesc0 *) newfdp)->fd_dfiles;
1114 newfdp->fd_ofileflags =
1115 ((struct filedesc0 *) newfdp)->fd_dfileflags;
1116 i = NDFILE;
1117 } else {
1118 /*
1119 * Compute the smallest multiple of NDEXTENT needed
1120 * for the file descriptors currently in use,
1121 * allowing the table to shrink.
1122 */
1123 i = newfdp->fd_nfiles;
1124 while (i > 2 * NDEXTENT && i > newfdp->fd_lastfile * 2)
1125 i /= 2;
1126 newfdp->fd_ofiles = malloc(i * OFILESIZE, M_FILEDESC, M_WAITOK);
1127 newfdp->fd_ofileflags = (char *) &newfdp->fd_ofiles[i];
1128 }
1129 newfdp->fd_nfiles = i;
1130 bcopy(fdp->fd_ofiles, newfdp->fd_ofiles, i * sizeof(struct file **));
1131 bcopy(fdp->fd_ofileflags, newfdp->fd_ofileflags, i * sizeof(char));
1132
1133 /*
1134 * kq descriptors cannot be copied.
1135 */
1136 if (newfdp->fd_knlistsize != -1) {
1137 fpp = &newfdp->fd_ofiles[newfdp->fd_lastfile];
1138 for (i = newfdp->fd_lastfile; i >= 0; i--, fpp--) {
1139 if (*fpp != NULL && (*fpp)->f_type == DTYPE_KQUEUE) {
1140 *fpp = NULL;
1141 if (i < newfdp->fd_freefile)
1142 newfdp->fd_freefile = i;
1143 }
1144 if (*fpp == NULL && i == newfdp->fd_lastfile && i > 0)
1145 newfdp->fd_lastfile--;
1146 }
1147 newfdp->fd_knlist = NULL;
1148 newfdp->fd_knlistsize = -1;
1149 newfdp->fd_knhash = NULL;
1150 newfdp->fd_knhashmask = 0;
1151 }
1152
1153 fpp = newfdp->fd_ofiles;
1154 for (i = newfdp->fd_lastfile; i-- >= 0; fpp++) {
1155 if (*fpp != NULL)
1156 fhold(*fpp);
1157 }
1158 return (newfdp);
1159 }
1160
1161 /*
1162 * Release a filedesc structure.
1163 */
1164 void
1165 fdfree(struct proc *p)
1166 {
1167 struct thread *td = p->p_thread;
1168 struct filedesc *fdp = p->p_fd;
1169 struct file **fpp;
1170 int i;
1171 struct filedesc_to_leader *fdtol;
1172 struct file *fp;
1173 struct vnode *vp;
1174 struct flock lf;
1175
1176 /* Certain daemons might not have file descriptors. */
1177 if (fdp == NULL)
1178 return;
1179
1180 /* Check for special need to clear POSIX style locks */
1181 fdtol = p->p_fdtol;
1182 if (fdtol != NULL) {
1183 KASSERT(fdtol->fdl_refcount > 0,
1184 ("filedesc_to_refcount botch: fdl_refcount=%d",
1185 fdtol->fdl_refcount));
1186 if (fdtol->fdl_refcount == 1 &&
1187 (p->p_leader->p_flag & P_ADVLOCK) != 0) {
1188 i = 0;
1189 fpp = fdp->fd_ofiles;
1190 for (i = 0, fpp = fdp->fd_ofiles;
1191 i <= fdp->fd_lastfile;
1192 i++, fpp++) {
1193 if (*fpp == NULL ||
1194 (*fpp)->f_type != DTYPE_VNODE)
1195 continue;
1196 fp = *fpp;
1197 fhold(fp);
1198 lf.l_whence = SEEK_SET;
1199 lf.l_start = 0;
1200 lf.l_len = 0;
1201 lf.l_type = F_UNLCK;
1202 vp = (struct vnode *)fp->f_data;
1203 (void) VOP_ADVLOCK(vp,
1204 (caddr_t)p->p_leader,
1205 F_UNLCK,
1206 &lf,
1207 F_POSIX);
1208 fdrop(fp, p->p_thread);
1209 fpp = fdp->fd_ofiles + i;
1210 }
1211 }
1212 retry:
1213 if (fdtol->fdl_refcount == 1) {
1214 if (fdp->fd_holdleaderscount > 0 &&
1215 (p->p_leader->p_flag & P_ADVLOCK) != 0) {
1216 /*
1217 * close() or do_dup() has cleared a reference
1218 * in a shared file descriptor table.
1219 */
1220 fdp->fd_holdleaderswakeup = 1;
1221 tsleep(&fdp->fd_holdleaderscount,
1222 0, "fdlhold", 0);
1223 goto retry;
1224 }
1225 if (fdtol->fdl_holdcount > 0) {
1226 /*
1227 * Ensure that fdtol->fdl_leader
1228 * remains valid in closef().
1229 */
1230 fdtol->fdl_wakeup = 1;
1231 tsleep(fdtol, 0, "fdlhold", 0);
1232 goto retry;
1233 }
1234 }
1235 fdtol->fdl_refcount--;
1236 if (fdtol->fdl_refcount == 0 &&
1237 fdtol->fdl_holdcount == 0) {
1238 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev;
1239 fdtol->fdl_prev->fdl_next = fdtol->fdl_next;
1240 } else
1241 fdtol = NULL;
1242 p->p_fdtol = NULL;
1243 if (fdtol != NULL)
1244 free(fdtol, M_FILEDESC_TO_LEADER);
1245 }
1246 if (--fdp->fd_refcnt > 0)
1247 return;
1248 /*
1249 * we are the last reference to the structure, we can
1250 * safely assume it will not change out from under us.
1251 */
1252 fpp = fdp->fd_ofiles;
1253 for (i = fdp->fd_lastfile; i-- >= 0; fpp++) {
1254 if (*fpp)
1255 (void) closef(*fpp, td);
1256 }
1257 if (fdp->fd_nfiles > NDFILE)
1258 free(fdp->fd_ofiles, M_FILEDESC);
1259 if (fdp->fd_cdir) {
1260 cache_drop(fdp->fd_ncdir);
1261 vrele(fdp->fd_cdir);
1262 }
1263 if (fdp->fd_rdir) {
1264 cache_drop(fdp->fd_nrdir);
1265 vrele(fdp->fd_rdir);
1266 }
1267 if (fdp->fd_jdir) {
1268 cache_drop(fdp->fd_njdir);
1269 vrele(fdp->fd_jdir);
1270 }
1271 if (fdp->fd_knlist)
1272 free(fdp->fd_knlist, M_KQUEUE);
1273 if (fdp->fd_knhash)
1274 free(fdp->fd_knhash, M_KQUEUE);
1275 free(fdp, M_FILEDESC);
1276 }
1277
1278 /*
1279 * For setugid programs, we don't want to people to use that setugidness
1280 * to generate error messages which write to a file which otherwise would
1281 * otherwise be off-limits to the process.
1282 *
1283 * This is a gross hack to plug the hole. A better solution would involve
1284 * a special vop or other form of generalized access control mechanism. We
1285 * go ahead and just reject all procfs file systems accesses as dangerous.
1286 *
1287 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is
1288 * sufficient. We also don't for check setugidness since we know we are.
1289 */
1290 static int
1291 is_unsafe(struct file *fp)
1292 {
1293 if (fp->f_type == DTYPE_VNODE &&
1294 ((struct vnode *)(fp->f_data))->v_tag == VT_PROCFS)
1295 return (1);
1296 return (0);
1297 }
1298
1299 /*
1300 * Make this setguid thing safe, if at all possible.
1301 */
1302 void
1303 setugidsafety(struct proc *p)
1304 {
1305 struct thread *td = p->p_thread;
1306 struct filedesc *fdp = p->p_fd;
1307 int i;
1308
1309 /* Certain daemons might not have file descriptors. */
1310 if (fdp == NULL)
1311 return;
1312
1313 /*
1314 * note: fdp->fd_ofiles may be reallocated out from under us while
1315 * we are blocked in a close. Be careful!
1316 */
1317 for (i = 0; i <= fdp->fd_lastfile; i++) {
1318 if (i > 2)
1319 break;
1320 if (fdp->fd_ofiles[i] && is_unsafe(fdp->fd_ofiles[i])) {
1321 struct file *fp;
1322
1323 #if 0
1324 if ((fdp->fd_ofileflags[i] & UF_MAPPED) != 0)
1325 (void) munmapfd(p, i);
1326 #endif
1327 if (i < fdp->fd_knlistsize)
1328 knote_fdclose(p, i);
1329 /*
1330 * NULL-out descriptor prior to close to avoid
1331 * a race while close blocks.
1332 */
1333 fp = fdp->fd_ofiles[i];
1334 fdp->fd_ofiles[i] = NULL;
1335 fdp->fd_ofileflags[i] = 0;
1336 if (i < fdp->fd_freefile)
1337 fdp->fd_freefile = i;
1338 (void) closef(fp, td);
1339 }
1340 }
1341 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL)
1342 fdp->fd_lastfile--;
1343 }
1344
1345 /*
1346 * Close any files on exec?
1347 */
1348 void
1349 fdcloseexec(struct proc *p)
1350 {
1351 struct thread *td = p->p_thread;
1352 struct filedesc *fdp = p->p_fd;
1353 int i;
1354
1355 /* Certain daemons might not have file descriptors. */
1356 if (fdp == NULL)
1357 return;
1358
1359 /*
1360 * We cannot cache fd_ofiles or fd_ofileflags since operations
1361 * may block and rip them out from under us.
1362 */
1363 for (i = 0; i <= fdp->fd_lastfile; i++) {
1364 if (fdp->fd_ofiles[i] != NULL &&
1365 (fdp->fd_ofileflags[i] & UF_EXCLOSE)) {
1366 struct file *fp;
1367
1368 #if 0
1369 if (fdp->fd_ofileflags[i] & UF_MAPPED)
1370 (void) munmapfd(p, i);
1371 #endif
1372 if (i < fdp->fd_knlistsize)
1373 knote_fdclose(p, i);
1374 /*
1375 * NULL-out descriptor prior to close to avoid
1376 * a race while close blocks.
1377 */
1378 fp = fdp->fd_ofiles[i];
1379 fdp->fd_ofiles[i] = NULL;
1380 fdp->fd_ofileflags[i] = 0;
1381 if (i < fdp->fd_freefile)
1382 fdp->fd_freefile = i;
1383 (void) closef(fp, td);
1384 }
1385 }
1386 while (fdp->fd_lastfile > 0 && fdp->fd_ofiles[fdp->fd_lastfile] == NULL)
1387 fdp->fd_lastfile--;
1388 }
1389
1390 /*
1391 * It is unsafe for set[ug]id processes to be started with file
1392 * descriptors 0..2 closed, as these descriptors are given implicit
1393 * significance in the Standard C library. fdcheckstd() will create a
1394 * descriptor referencing /dev/null for each of stdin, stdout, and
1395 * stderr that is not already open.
1396 */
1397 int
1398 fdcheckstd(struct proc *p)
1399 {
1400 struct thread *td = p->p_thread;
1401 struct nlookupdata nd;
1402 struct filedesc *fdp;
1403 struct file *fp;
1404 register_t retval;
1405 int fd, i, error, flags, devnull;
1406
1407 fdp = p->p_fd;
1408 if (fdp == NULL)
1409 return (0);
1410 devnull = -1;
1411 error = 0;
1412 for (i = 0; i < 3; i++) {
1413 if (fdp->fd_ofiles[i] != NULL)
1414 continue;
1415 if (devnull < 0) {
1416 if ((error = falloc(p, &fp, NULL)) != 0)
1417 break;
1418
1419 error = nlookup_init(&nd, "/dev/null", UIO_SYSSPACE,
1420 NLC_FOLLOW|NLC_LOCKVP);
1421 flags = FREAD | FWRITE;
1422 if (error == 0)
1423 error = vn_open(&nd, fp, flags, 0);
1424 if (error == 0)
1425 error = fsetfd(p, fp, &fd);
1426 fdrop(fp, td);
1427 nlookup_done(&nd);
1428 if (error)
1429 break;
1430 KKASSERT(i == fd);
1431 devnull = fd;
1432 } else {
1433 error = kern_dup(DUP_FIXED, devnull, i, &retval);
1434 if (error != 0)
1435 break;
1436 }
1437 }
1438 return (error);
1439 }
1440
1441 /*
1442 * Internal form of close.
1443 * Decrement reference count on file structure.
1444 * Note: td and/or p may be NULL when closing a file
1445 * that was being passed in a message.
1446 */
1447 int
1448 closef(struct file *fp, struct thread *td)
1449 {
1450 struct vnode *vp;
1451 struct flock lf;
1452 struct filedesc_to_leader *fdtol;
1453 struct proc *p;
1454
1455 if (fp == NULL)
1456 return (0);
1457 if (td == NULL) {
1458 td = curthread;
1459 p = NULL; /* allow no proc association */
1460 } else {
1461 p = td->td_proc; /* can also be NULL */
1462 }
1463 /*
1464 * POSIX record locking dictates that any close releases ALL
1465 * locks owned by this process. This is handled by setting
1466 * a flag in the unlock to free ONLY locks obeying POSIX
1467 * semantics, and not to free BSD-style file locks.
1468 * If the descriptor was in a message, POSIX-style locks
1469 * aren't passed with the descriptor.
1470 */
1471 if (p != NULL &&
1472 fp->f_type == DTYPE_VNODE) {
1473 if ((p->p_leader->p_flag & P_ADVLOCK) != 0) {
1474 lf.l_whence = SEEK_SET;
1475 lf.l_start = 0;
1476 lf.l_len = 0;
1477 lf.l_type = F_UNLCK;
1478 vp = (struct vnode *)fp->f_data;
1479 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
1480 &lf, F_POSIX);
1481 }
1482 fdtol = p->p_fdtol;
1483 if (fdtol != NULL) {
1484 /*
1485 * Handle special case where file descriptor table
1486 * is shared between multiple process leaders.
1487 */
1488 for (fdtol = fdtol->fdl_next;
1489 fdtol != p->p_fdtol;
1490 fdtol = fdtol->fdl_next) {
1491 if ((fdtol->fdl_leader->p_flag &
1492 P_ADVLOCK) == 0)
1493 continue;
1494 fdtol->fdl_holdcount++;
1495 lf.l_whence = SEEK_SET;
1496 lf.l_start = 0;
1497 lf.l_len = 0;
1498 lf.l_type = F_UNLCK;
1499 vp = (struct vnode *)fp->f_data;
1500 (void) VOP_ADVLOCK(vp,
1501 (caddr_t)p->p_leader,
1502 F_UNLCK, &lf, F_POSIX);
1503 fdtol->fdl_holdcount--;
1504 if (fdtol->fdl_holdcount == 0 &&
1505 fdtol->fdl_wakeup != 0) {
1506 fdtol->fdl_wakeup = 0;
1507 wakeup(fdtol);
1508 }
1509 }
1510 }
1511 }
1512 return (fdrop(fp, td));
1513 }
1514
1515 int
1516 fdrop(struct file *fp, struct thread *td)
1517 {
1518 struct flock lf;
1519 struct vnode *vp;
1520 int error;
1521
1522 if (--fp->f_count > 0)
1523 return (0);
1524 if (fp->f_count < 0)
1525 panic("fdrop: count < 0");
1526 if ((fp->f_flag & FHASLOCK) && fp->f_type == DTYPE_VNODE) {
1527 lf.l_whence = SEEK_SET;
1528 lf.l_start = 0;
1529 lf.l_len = 0;
1530 lf.l_type = F_UNLCK;
1531 vp = (struct vnode *)fp->f_data;
1532 (void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
1533 }
1534 if (fp->f_ops != &badfileops)
1535 error = fo_close(fp, td);
1536 else
1537 error = 0;
1538 ffree(fp);
1539 return (error);
1540 }
1541
1542 /*
1543 * Apply an advisory lock on a file descriptor.
1544 *
1545 * Just attempt to get a record lock of the requested type on
1546 * the entire file (l_whence = SEEK_SET, l_start = 0, l_len = 0).
1547 */
1548 /* ARGSUSED */
1549 int
1550 flock(struct flock_args *uap)
1551 {
1552 struct proc *p = curproc;
1553 struct filedesc *fdp = p->p_fd;
1554 struct file *fp;
1555 struct vnode *vp;
1556 struct flock lf;
1557
1558 if ((unsigned)uap->fd >= fdp->fd_nfiles ||
1559 (fp = fdp->fd_ofiles[uap->fd]) == NULL)
1560 return (EBADF);
1561 if (fp->f_type != DTYPE_VNODE)
1562 return (EOPNOTSUPP);
1563 vp = (struct vnode *)fp->f_data;
1564 lf.l_whence = SEEK_SET;
1565 lf.l_start = 0;
1566 lf.l_len = 0;
1567 if (uap->how & LOCK_UN) {
1568 lf.l_type = F_UNLCK;
1569 fp->f_flag &= ~FHASLOCK;
1570 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK));
1571 }
1572 if (uap->how & LOCK_EX)
1573 lf.l_type = F_WRLCK;
1574 else if (uap->how & LOCK_SH)
1575 lf.l_type = F_RDLCK;
1576 else
1577 return (EBADF);
1578 fp->f_flag |= FHASLOCK;
1579 if (uap->how & LOCK_NB)
1580 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK));
1581 return (VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, F_FLOCK|F_WAIT));
1582 }
1583
1584 /*
1585 * File Descriptor pseudo-device driver (/dev/fd/).
1586 *
1587 * Opening minor device N dup()s the file (if any) connected to file
1588 * descriptor N belonging to the calling process. Note that this driver
1589 * consists of only the ``open()'' routine, because all subsequent
1590 * references to this file will be direct to the other driver.
1591 */
1592 /* ARGSUSED */
1593 static int
1594 fdopen(dev_t dev, int mode, int type, struct thread *td)
1595 {
1596 KKASSERT(td->td_proc != NULL);
1597
1598 /*
1599 * XXX Kludge: set curproc->p_dupfd to contain the value of the
1600 * the file descriptor being sought for duplication. The error
1601 * return ensures that the vnode for this device will be released
1602 * by vn_open. Open will detect this special error and take the
1603 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN
1604 * will simply report the error.
1605 */
1606 td->td_proc->p_dupfd = minor(dev);
1607 return (ENODEV);
1608 }
1609
1610 /*
1611 * Duplicate the specified descriptor to a free descriptor.
1612 */
1613 int
1614 dupfdopen(struct filedesc *fdp, int indx, int dfd, int mode, int error)
1615 {
1616 struct file *wfp;
1617 struct file *fp;
1618
1619 /*
1620 * If the to-be-dup'd fd number is greater than the allowed number
1621 * of file descriptors, or the fd to be dup'd has already been
1622 * closed, then reject.
1623 */
1624 if ((u_int)dfd >= fdp->fd_nfiles ||
1625 (wfp = fdp->fd_ofiles[dfd]) == NULL) {
1626 return (EBADF);
1627 }
1628
1629 /*
1630 * There are two cases of interest here.
1631 *
1632 * For ENODEV simply dup (dfd) to file descriptor
1633 * (indx) and return.
1634 *
1635 * For ENXIO steal away the file structure from (dfd) and
1636 * store it in (indx). (dfd) is effectively closed by
1637 * this operation.
1638 *
1639 * Any other error code is just returned.
1640 */
1641 switch (error) {
1642 case ENODEV:
1643 /*
1644 * Check that the mode the file is being opened for is a
1645 * subset of the mode of the existing descriptor.
1646 */
1647 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag)
1648 return (EACCES);
1649 fp = fdp->fd_ofiles[indx];
1650 #if 0
1651 if (fp && fdp->fd_ofileflags[indx] & UF_MAPPED)
1652 (void) munmapfd(p, indx);
1653 #endif
1654 fdp->fd_ofiles[indx] = wfp;
1655 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd];
1656 fhold(wfp);
1657 if (indx > fdp->fd_lastfile)
1658 fdp->fd_lastfile = indx;
1659 /*
1660 * we now own the reference to fp that the ofiles[] array
1661 * used to own. Release it.
1662 */
1663 if (fp)
1664 fdrop(fp, curthread);
1665 return (0);
1666
1667 case ENXIO:
1668 /*
1669 * Steal away the file pointer from dfd, and stuff it into indx.
1670 */
1671 fp = fdp->fd_ofiles[indx];
1672 #if 0
1673 if (fp && fdp->fd_ofileflags[indx] & UF_MAPPED)
1674 (void) munmapfd(p, indx);
1675 #endif
1676 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd];
1677 fdp->fd_ofiles[dfd] = NULL;
1678 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd];
1679 fdp->fd_ofileflags[dfd] = 0;
1680
1681 /*
1682 * we now own the reference to fp that the ofiles[] array
1683 * used to own. Release it.
1684 */
1685 if (fp)
1686 fdrop(fp, curthread);
1687 /*
1688 * Complete the clean up of the filedesc structure by
1689 * recomputing the various hints.
1690 */
1691 if (indx > fdp->fd_lastfile) {
1692 fdp->fd_lastfile = indx;
1693 } else {
1694 while (fdp->fd_lastfile > 0 &&
1695 fdp->fd_ofiles[fdp->fd_lastfile] == NULL) {
1696 fdp->fd_lastfile--;
1697 }
1698 if (dfd < fdp->fd_freefile)
1699 fdp->fd_freefile = dfd;
1700 }
1701 return (0);
1702
1703 default:
1704 return (error);
1705 }
1706 /* NOTREACHED */
1707 }
1708
1709
1710 struct filedesc_to_leader *
1711 filedesc_to_leader_alloc(struct filedesc_to_leader *old,
1712 struct proc *leader)
1713 {
1714 struct filedesc_to_leader *fdtol;
1715
1716 fdtol = malloc(sizeof(struct filedesc_to_leader),
1717 M_FILEDESC_TO_LEADER, M_WAITOK);
1718 fdtol->fdl_refcount = 1;
1719 fdtol->fdl_holdcount = 0;
1720 fdtol->fdl_wakeup = 0;
1721 fdtol->fdl_leader = leader;
1722 if (old != NULL) {
1723 fdtol->fdl_next = old->fdl_next;
1724 fdtol->fdl_prev = old;
1725 old->fdl_next = fdtol;
1726 fdtol->fdl_next->fdl_prev = fdtol;
1727 } else {
1728 fdtol->fdl_next = fdtol;
1729 fdtol->fdl_prev = fdtol;
1730 }
1731 return fdtol;
1732 }
1733
1734 /*
1735 * Get file structures.
1736 */
1737 static int
1738 sysctl_kern_file(SYSCTL_HANDLER_ARGS)
1739 {
1740 struct kinfo_file kf;
1741 struct filedesc *fdp;
1742 struct file *fp;
1743 struct proc *p;
1744 int count;
1745 int error;
1746 int n;
1747
1748 /*
1749 * Note: because the number of file descriptors is calculated
1750 * in different ways for sizing vs returning the data,
1751 * there is information leakage from the first loop. However,
1752 * it is of a similar order of magnitude to the leakage from
1753 * global system statistics such as kern.openfiles.
1754 *
1755 * When just doing a count, note that we cannot just count
1756 * the elements and add f_count via the filehead list because
1757 * threaded processes share their descriptor table and f_count might
1758 * still be '1' in that case.
1759 */
1760 count = 0;
1761 error = 0;
1762 LIST_FOREACH(p, &allproc, p_list) {
1763 if (p->p_stat == SIDL)
1764 continue;
1765 if (!PRISON_CHECK(req->td->td_proc->p_ucred, p->p_ucred) != 0)
1766 continue;
1767 if ((fdp = p->p_fd) == NULL)
1768 continue;
1769 for (n = 0; n < fdp->fd_nfiles; ++n) {
1770 if ((fp = fdp->fd_ofiles[n]) == NULL)
1771 continue;
1772 if (req->oldptr == NULL) {
1773 ++count;
1774 } else {
1775 kcore_make_file(&kf, fp, p->p_pid,
1776 p->p_ucred->cr_uid, n);
1777 error = SYSCTL_OUT(req, &kf, sizeof(kf));
1778 if (error)
1779 break;
1780 }
1781 }
1782 if (error)
1783 break;
1784 }
1785
1786 /*
1787 * When just calculating the size, overestimate a bit to try to
1788 * prevent system activity from causing the buffer-fill call
1789 * to fail later on.
1790 */
1791 if (req->oldptr == NULL) {
1792 count = (count + 16) + (count / 10);
1793 error = SYSCTL_OUT(req, NULL, count * sizeof(kf));
1794 }
1795 return (error);
1796 }
1797
1798 SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD,
1799 0, 0, sysctl_kern_file, "S,file", "Entire file table");
1800
1801 SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW,
1802 &maxfilesperproc, 0, "Maximum files allowed open per process");
1803
1804 SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW,
1805 &maxfiles, 0, "Maximum number of files");
1806
1807 SYSCTL_INT(_kern, OID_AUTO, maxfilesrootres, CTLFLAG_RW,
1808 &maxfilesrootres, 0, "Descriptors reserved for root use");
1809
1810 SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD,
1811 &nfiles, 0, "System-wide number of open files");
1812
1813 static void
1814 fildesc_drvinit(void *unused)
1815 {
1816 int fd;
1817
1818 cdevsw_add(&fildesc_cdevsw, 0, 0);
1819 for (fd = 0; fd < NUMFDESC; fd++) {
1820 make_dev(&fildesc_cdevsw, fd,
1821 UID_BIN, GID_BIN, 0666, "fd/%d", fd);
1822 }
1823 make_dev(&fildesc_cdevsw, 0, UID_ROOT, GID_WHEEL, 0666, "stdin");
1824 make_dev(&fildesc_cdevsw, 1, UID_ROOT, GID_WHEEL, 0666, "stdout");
1825 make_dev(&fildesc_cdevsw, 2, UID_ROOT, GID_WHEEL, 0666, "stderr");
1826 }
1827
1828 struct fileops badfileops = {
1829 NULL, /* port */
1830 NULL, /* clone */
1831 badfo_readwrite,
1832 badfo_readwrite,
1833 badfo_ioctl,
1834 badfo_poll,
1835 badfo_kqfilter,
1836 badfo_stat,
1837 badfo_close
1838 };
1839
1840 static int
1841 badfo_readwrite(
1842 struct file *fp,
1843 struct uio *uio,
1844 struct ucred *cred,
1845 int flags,
1846 struct thread *td
1847 ) {
1848 return (EBADF);
1849 }
1850
1851 static int
1852 badfo_ioctl(struct file *fp, u_long com, caddr_t data, struct thread *td)
1853 {
1854 return (EBADF);
1855 }
1856
1857 static int
1858 badfo_poll(struct file *fp, int events, struct ucred *cred, struct thread *td)
1859 {
1860 return (0);
1861 }
1862
1863 static int
1864 badfo_kqfilter(struct file *fp, struct knote *kn)
1865 {
1866 return (0);
1867 }
1868
1869 static int
1870 badfo_stat(struct file *fp, struct stat *sb, struct thread *td)
1871 {
1872 return (EBADF);
1873 }
1874
1875 static int
1876 badfo_close(struct file *fp, struct thread *td)
1877 {
1878 return (EBADF);
1879 }
1880
1881 SYSINIT(fildescdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,
1882 fildesc_drvinit,NULL)
DragonFly BSD