81#include <security/audit/audit.h>
82
83#include <vm/uma.h>
84
85#include <ddb/ddb.h>
86
87static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table");
88static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader",
89 "file desc to leader structures");
90static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures");
91
92static uma_zone_t file_zone;
93
94
95/* Flags for do_dup() */
96#define DUP_FIXED 0x1 /* Force fixed allocation */
97#define DUP_FCNTL 0x2 /* fcntl()-style errors */
98
99static int do_dup(struct thread *td, int flags, int old, int new,
100 register_t *retval);
101static int fd_first_free(struct filedesc *, int, int);
102static int fd_last_used(struct filedesc *, int, int);
103static void fdgrowtable(struct filedesc *, int);
104static void fdunused(struct filedesc *fdp, int fd);
105static void fdused(struct filedesc *fdp, int fd);
106
107/*
108 * A process is initially started out with NDFILE descriptors stored within
109 * this structure, selected to be enough for typical applications based on
110 * the historical limit of 20 open files (and the usage of descriptors by
111 * shells). If these descriptors are exhausted, a larger descriptor table
112 * may be allocated, up to a process' resource limit; the internal arrays
113 * are then unused.
114 */
115#define NDFILE 20
116#define NDSLOTSIZE sizeof(NDSLOTTYPE)
117#define NDENTRIES (NDSLOTSIZE * __CHAR_BIT)
118#define NDSLOT(x) ((x) / NDENTRIES)
119#define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES))
120#define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES)
121
122/*
123 * Storage required per open file descriptor.
124 */
125#define OFILESIZE (sizeof(struct file *) + sizeof(char))
126
127/*
128 * Storage to hold unused ofiles that need to be reclaimed.
129 */
130struct freetable {
131 struct file **ft_table;
132 SLIST_ENTRY(freetable) ft_next;
133};
134
135/*
136 * Basic allocation of descriptors:
137 * one of the above, plus arrays for NDFILE descriptors.
138 */
139struct filedesc0 {
140 struct filedesc fd_fd;
141 /*
142 * ofiles which need to be reclaimed on free.
143 */
144 SLIST_HEAD(,freetable) fd_free;
145 /*
146 * These arrays are used when the number of open files is
147 * <= NDFILE, and are then pointed to by the pointers above.
148 */
149 struct file *fd_dfiles[NDFILE];
150 char fd_dfileflags[NDFILE];
151 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)];
152};
153
154/*
155 * Descriptor management.
156 */
157volatile int openfiles; /* actual number of open files */
158struct mtx sigio_lock; /* mtx to protect pointers to sigio */
159void (*mq_fdclose)(struct thread *td, int fd, struct file *fp);
160
161/* A mutex to protect the association between a proc and filedesc. */
162static struct mtx fdesc_mtx;
163
164/*
165 * Find the first zero bit in the given bitmap, starting at low and not
166 * exceeding size - 1.
167 */
168static int
169fd_first_free(struct filedesc *fdp, int low, int size)
170{
171 NDSLOTTYPE *map = fdp->fd_map;
172 NDSLOTTYPE mask;
173 int off, maxoff;
174
175 if (low >= size)
176 return (low);
177
178 off = NDSLOT(low);
179 if (low % NDENTRIES) {
180 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES)));
181 if ((mask &= ~map[off]) != 0UL)
182 return (off * NDENTRIES + ffsl(mask) - 1);
183 ++off;
184 }
185 for (maxoff = NDSLOTS(size); off < maxoff; ++off)
186 if (map[off] != ~0UL)
187 return (off * NDENTRIES + ffsl(~map[off]) - 1);
188 return (size);
189}
190
191/*
192 * Find the highest non-zero bit in the given bitmap, starting at low and
193 * not exceeding size - 1.
194 */
195static int
196fd_last_used(struct filedesc *fdp, int low, int size)
197{
198 NDSLOTTYPE *map = fdp->fd_map;
199 NDSLOTTYPE mask;
200 int off, minoff;
201
202 if (low >= size)
203 return (-1);
204
205 off = NDSLOT(size);
206 if (size % NDENTRIES) {
207 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES));
208 if ((mask &= map[off]) != 0)
209 return (off * NDENTRIES + flsl(mask) - 1);
210 --off;
211 }
212 for (minoff = NDSLOT(low); off >= minoff; --off)
213 if (map[off] != 0)
214 return (off * NDENTRIES + flsl(map[off]) - 1);
215 return (low - 1);
216}
217
218static int
219fdisused(struct filedesc *fdp, int fd)
220{
221 KASSERT(fd >= 0 && fd < fdp->fd_nfiles,
222 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles));
223 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0);
224}
225
226/*
227 * Mark a file descriptor as used.
228 */
229static void
230fdused(struct filedesc *fdp, int fd)
231{
232
233 FILEDESC_XLOCK_ASSERT(fdp);
234 KASSERT(!fdisused(fdp, fd),
235 ("fd already used"));
236
237 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd);
238 if (fd > fdp->fd_lastfile)
239 fdp->fd_lastfile = fd;
240 if (fd == fdp->fd_freefile)
241 fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles);
242}
243
244/*
245 * Mark a file descriptor as unused.
246 */
247static void
248fdunused(struct filedesc *fdp, int fd)
249{
250
251 FILEDESC_XLOCK_ASSERT(fdp);
252 KASSERT(fdisused(fdp, fd),
253 ("fd is already unused"));
254 KASSERT(fdp->fd_ofiles[fd] == NULL,
255 ("fd is still in use"));
256
257 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd);
258 if (fd < fdp->fd_freefile)
259 fdp->fd_freefile = fd;
260 if (fd == fdp->fd_lastfile)
261 fdp->fd_lastfile = fd_last_used(fdp, 0, fd);
262}
263
264/*
265 * System calls on descriptors.
266 */
267#ifndef _SYS_SYSPROTO_H_
268struct getdtablesize_args {
269 int dummy;
270};
271#endif
272/* ARGSUSED */
273int
274getdtablesize(struct thread *td, struct getdtablesize_args *uap)
275{
276 struct proc *p = td->td_proc;
277
278 PROC_LOCK(p);
279 td->td_retval[0] =
280 min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
281 PROC_UNLOCK(p);
282 return (0);
283}
284
285/*
286 * Duplicate a file descriptor to a particular value.
287 *
288 * Note: keep in mind that a potential race condition exists when closing
289 * descriptors from a shared descriptor table (via rfork).
290 */
291#ifndef _SYS_SYSPROTO_H_
292struct dup2_args {
293 u_int from;
294 u_int to;
295};
296#endif
297/* ARGSUSED */
298int
299dup2(struct thread *td, struct dup2_args *uap)
300{
301
302 return (do_dup(td, DUP_FIXED, (int)uap->from, (int)uap->to,
303 td->td_retval));
304}
305
306/*
307 * Duplicate a file descriptor.
308 */
309#ifndef _SYS_SYSPROTO_H_
310struct dup_args {
311 u_int fd;
312};
313#endif
314/* ARGSUSED */
315int
316dup(struct thread *td, struct dup_args *uap)
317{
318
319 return (do_dup(td, 0, (int)uap->fd, 0, td->td_retval));
320}
321
322/*
323 * The file control system call.
324 */
325#ifndef _SYS_SYSPROTO_H_
326struct fcntl_args {
327 int fd;
328 int cmd;
329 long arg;
330};
331#endif
332/* ARGSUSED */
333int
334fcntl(struct thread *td, struct fcntl_args *uap)
335{
336 struct flock fl;
337 struct oflock ofl;
338 intptr_t arg;
339 int error;
340 int cmd;
341
342 error = 0;
343 cmd = uap->cmd;
344 switch (uap->cmd) {
345 case F_OGETLK:
346 case F_OSETLK:
347 case F_OSETLKW:
348 /*
349 * Convert old flock structure to new.
350 */
351 error = copyin((void *)(intptr_t)uap->arg, &ofl, sizeof(ofl));
352 fl.l_start = ofl.l_start;
353 fl.l_len = ofl.l_len;
354 fl.l_pid = ofl.l_pid;
355 fl.l_type = ofl.l_type;
356 fl.l_whence = ofl.l_whence;
357 fl.l_sysid = 0;
358
359 switch (uap->cmd) {
360 case F_OGETLK:
361 cmd = F_GETLK;
362 break;
363 case F_OSETLK:
364 cmd = F_SETLK;
365 break;
366 case F_OSETLKW:
367 cmd = F_SETLKW;
368 break;
369 }
370 arg = (intptr_t)&fl;
371 break;
372 case F_GETLK:
373 case F_SETLK:
374 case F_SETLKW:
375 case F_SETLK_REMOTE:
376 error = copyin((void *)(intptr_t)uap->arg, &fl, sizeof(fl));
377 arg = (intptr_t)&fl;
378 break;
379 default:
380 arg = uap->arg;
381 break;
382 }
383 if (error)
384 return (error);
385 error = kern_fcntl(td, uap->fd, cmd, arg);
386 if (error)
387 return (error);
388 if (uap->cmd == F_OGETLK) {
389 ofl.l_start = fl.l_start;
390 ofl.l_len = fl.l_len;
391 ofl.l_pid = fl.l_pid;
392 ofl.l_type = fl.l_type;
393 ofl.l_whence = fl.l_whence;
394 error = copyout(&ofl, (void *)(intptr_t)uap->arg, sizeof(ofl));
395 } else if (uap->cmd == F_GETLK) {
396 error = copyout(&fl, (void *)(intptr_t)uap->arg, sizeof(fl));
397 }
398 return (error);
399}
400
401static inline struct file *
402fdtofp(int fd, struct filedesc *fdp)
403{
404 struct file *fp;
405
406 FILEDESC_LOCK_ASSERT(fdp);
407 if ((unsigned)fd >= fdp->fd_nfiles ||
408 (fp = fdp->fd_ofiles[fd]) == NULL)
409 return (NULL);
410 return (fp);
411}
412
413int
414kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg)
415{
416 struct filedesc *fdp;
417 struct flock *flp;
418 struct file *fp;
419 struct proc *p;
420 char *pop;
421 struct vnode *vp;
422 int error, flg, tmp;
423 int vfslocked;
424 u_int old, new;
425 uint64_t bsize;
426
427 vfslocked = 0;
428 error = 0;
429 flg = F_POSIX;
430 p = td->td_proc;
431 fdp = p->p_fd;
432
433 switch (cmd) {
434 case F_DUPFD:
435 tmp = arg;
436 error = do_dup(td, DUP_FCNTL, fd, tmp, td->td_retval);
437 break;
438
439 case F_DUP2FD:
440 tmp = arg;
441 error = do_dup(td, DUP_FIXED, fd, tmp, td->td_retval);
442 break;
443
444 case F_GETFD:
445 FILEDESC_SLOCK(fdp);
446 if ((fp = fdtofp(fd, fdp)) == NULL) {
447 FILEDESC_SUNLOCK(fdp);
448 error = EBADF;
449 break;
450 }
451 pop = &fdp->fd_ofileflags[fd];
452 td->td_retval[0] = (*pop & UF_EXCLOSE) ? FD_CLOEXEC : 0;
453 FILEDESC_SUNLOCK(fdp);
454 break;
455
456 case F_SETFD:
457 FILEDESC_XLOCK(fdp);
458 if ((fp = fdtofp(fd, fdp)) == NULL) {
459 FILEDESC_XUNLOCK(fdp);
460 error = EBADF;
461 break;
462 }
463 pop = &fdp->fd_ofileflags[fd];
464 *pop = (*pop &~ UF_EXCLOSE) |
465 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0);
466 FILEDESC_XUNLOCK(fdp);
467 break;
468
469 case F_GETFL:
470 FILEDESC_SLOCK(fdp);
471 if ((fp = fdtofp(fd, fdp)) == NULL) {
472 FILEDESC_SUNLOCK(fdp);
473 error = EBADF;
474 break;
475 }
476 td->td_retval[0] = OFLAGS(fp->f_flag);
477 FILEDESC_SUNLOCK(fdp);
478 break;
479
480 case F_SETFL:
481 FILEDESC_SLOCK(fdp);
482 if ((fp = fdtofp(fd, fdp)) == NULL) {
483 FILEDESC_SUNLOCK(fdp);
484 error = EBADF;
485 break;
486 }
487 fhold(fp);
488 FILEDESC_SUNLOCK(fdp);
489 do {
490 tmp = flg = fp->f_flag;
491 tmp &= ~FCNTLFLAGS;
492 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS;
493 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0);
494 tmp = fp->f_flag & FNONBLOCK;
495 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
496 if (error) {
497 fdrop(fp, td);
498 break;
499 }
500 tmp = fp->f_flag & FASYNC;
501 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td);
502 if (error == 0) {
503 fdrop(fp, td);
504 break;
505 }
506 atomic_clear_int(&fp->f_flag, FNONBLOCK);
507 tmp = 0;
508 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
509 fdrop(fp, td);
510 break;
511
512 case F_GETOWN:
513 FILEDESC_SLOCK(fdp);
514 if ((fp = fdtofp(fd, fdp)) == NULL) {
515 FILEDESC_SUNLOCK(fdp);
516 error = EBADF;
517 break;
518 }
519 fhold(fp);
520 FILEDESC_SUNLOCK(fdp);
521 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td);
522 if (error == 0)
523 td->td_retval[0] = tmp;
524 fdrop(fp, td);
525 break;
526
527 case F_SETOWN:
528 FILEDESC_SLOCK(fdp);
529 if ((fp = fdtofp(fd, fdp)) == NULL) {
530 FILEDESC_SUNLOCK(fdp);
531 error = EBADF;
532 break;
533 }
534 fhold(fp);
535 FILEDESC_SUNLOCK(fdp);
536 tmp = arg;
537 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td);
538 fdrop(fp, td);
539 break;
540
541 case F_SETLK_REMOTE:
542 error = priv_check(td, PRIV_NFS_LOCKD);
543 if (error)
544 return (error);
545 flg = F_REMOTE;
546 goto do_setlk;
547
548 case F_SETLKW:
549 flg |= F_WAIT;
550 /* FALLTHROUGH F_SETLK */
551
552 case F_SETLK:
553 do_setlk:
554 FILEDESC_SLOCK(fdp);
555 if ((fp = fdtofp(fd, fdp)) == NULL) {
556 FILEDESC_SUNLOCK(fdp);
557 error = EBADF;
558 break;
559 }
560 if (fp->f_type != DTYPE_VNODE) {
561 FILEDESC_SUNLOCK(fdp);
562 error = EBADF;
563 break;
564 }
565 flp = (struct flock *)arg;
566 if (flp->l_whence == SEEK_CUR) {
567 if (fp->f_offset < 0 ||
568 (flp->l_start > 0 &&
569 fp->f_offset > OFF_MAX - flp->l_start)) {
570 FILEDESC_SUNLOCK(fdp);
571 error = EOVERFLOW;
572 break;
573 }
574 flp->l_start += fp->f_offset;
575 }
576
577 /*
578 * VOP_ADVLOCK() may block.
579 */
580 fhold(fp);
581 FILEDESC_SUNLOCK(fdp);
582 vp = fp->f_vnode;
583 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
584 switch (flp->l_type) {
585 case F_RDLCK:
586 if ((fp->f_flag & FREAD) == 0) {
587 error = EBADF;
588 break;
589 }
590 PROC_LOCK(p->p_leader);
591 p->p_leader->p_flag |= P_ADVLOCK;
592 PROC_UNLOCK(p->p_leader);
593 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
594 flp, flg);
595 break;
596 case F_WRLCK:
597 if ((fp->f_flag & FWRITE) == 0) {
598 error = EBADF;
599 break;
600 }
601 PROC_LOCK(p->p_leader);
602 p->p_leader->p_flag |= P_ADVLOCK;
603 PROC_UNLOCK(p->p_leader);
604 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
605 flp, flg);
606 break;
607 case F_UNLCK:
608 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
609 flp, flg);
610 break;
611 case F_UNLCKSYS:
612 /*
613 * Temporary api for testing remote lock
614 * infrastructure.
615 */
616 if (flg != F_REMOTE) {
617 error = EINVAL;
618 break;
619 }
620 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
621 F_UNLCKSYS, flp, flg);
622 break;
623 default:
624 error = EINVAL;
625 break;
626 }
627 VFS_UNLOCK_GIANT(vfslocked);
628 vfslocked = 0;
629 /* Check for race with close */
630 FILEDESC_SLOCK(fdp);
631 if ((unsigned) fd >= fdp->fd_nfiles ||
632 fp != fdp->fd_ofiles[fd]) {
633 FILEDESC_SUNLOCK(fdp);
634 flp->l_whence = SEEK_SET;
635 flp->l_start = 0;
636 flp->l_len = 0;
637 flp->l_type = F_UNLCK;
638 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
639 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
640 F_UNLCK, flp, F_POSIX);
641 VFS_UNLOCK_GIANT(vfslocked);
642 vfslocked = 0;
643 } else
644 FILEDESC_SUNLOCK(fdp);
645 fdrop(fp, td);
646 break;
647
648 case F_GETLK:
649 FILEDESC_SLOCK(fdp);
650 if ((fp = fdtofp(fd, fdp)) == NULL) {
651 FILEDESC_SUNLOCK(fdp);
652 error = EBADF;
653 break;
654 }
655 if (fp->f_type != DTYPE_VNODE) {
656 FILEDESC_SUNLOCK(fdp);
657 error = EBADF;
658 break;
659 }
660 flp = (struct flock *)arg;
661 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK &&
662 flp->l_type != F_UNLCK) {
663 FILEDESC_SUNLOCK(fdp);
664 error = EINVAL;
665 break;
666 }
667 if (flp->l_whence == SEEK_CUR) {
668 if ((flp->l_start > 0 &&
669 fp->f_offset > OFF_MAX - flp->l_start) ||
670 (flp->l_start < 0 &&
671 fp->f_offset < OFF_MIN - flp->l_start)) {
672 FILEDESC_SUNLOCK(fdp);
673 error = EOVERFLOW;
674 break;
675 }
676 flp->l_start += fp->f_offset;
677 }
678 /*
679 * VOP_ADVLOCK() may block.
680 */
681 fhold(fp);
682 FILEDESC_SUNLOCK(fdp);
683 vp = fp->f_vnode;
684 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
685 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp,
686 F_POSIX);
687 VFS_UNLOCK_GIANT(vfslocked);
688 vfslocked = 0;
689 fdrop(fp, td);
690 break;
691
692 case F_RDAHEAD:
693 arg = arg ? 128 * 1024: 0;
694 /* FALLTHROUGH */
695 case F_READAHEAD:
696 FILEDESC_SLOCK(fdp);
697 if ((fp = fdtofp(fd, fdp)) == NULL) {
698 FILEDESC_SUNLOCK(fdp);
699 error = EBADF;
700 break;
701 }
702 if (fp->f_type != DTYPE_VNODE) {
703 FILEDESC_SUNLOCK(fdp);
704 error = EBADF;
705 break;
706 }
707 fhold(fp);
708 FILEDESC_SUNLOCK(fdp);
709 if (arg != 0) {
710 vp = fp->f_vnode;
711 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
712 error = vn_lock(vp, LK_SHARED);
713 if (error != 0)
714 goto readahead_vnlock_fail;
715 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize;
716 VOP_UNLOCK(vp, 0);
717 fp->f_seqcount = (arg + bsize - 1) / bsize;
718 do {
719 new = old = fp->f_flag;
720 new |= FRDAHEAD;
721 } while (!atomic_cmpset_rel_int(&fp->f_flag, old, new));
722readahead_vnlock_fail:
723 VFS_UNLOCK_GIANT(vfslocked);
724 vfslocked = 0;
725 } else {
726 do {
727 new = old = fp->f_flag;
728 new &= ~FRDAHEAD;
729 } while (!atomic_cmpset_rel_int(&fp->f_flag, old, new));
730 }
731 fdrop(fp, td);
732 break;
733
734 default:
735 error = EINVAL;
736 break;
737 }
738 VFS_UNLOCK_GIANT(vfslocked);
739 return (error);
740}
741
742/*
743 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD).
744 */
745static int
746do_dup(struct thread *td, int flags, int old, int new,
747 register_t *retval)
748{
749 struct filedesc *fdp;
750 struct proc *p;
751 struct file *fp;
752 struct file *delfp;
753 int error, holdleaders, maxfd;
754
755 p = td->td_proc;
756 fdp = p->p_fd;
757
758 /*
759 * Verify we have a valid descriptor to dup from and possibly to
760 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should
761 * return EINVAL when the new descriptor is out of bounds.
762 */
763 if (old < 0)
764 return (EBADF);
765 if (new < 0)
766 return (flags & DUP_FCNTL ? EINVAL : EBADF);
767 PROC_LOCK(p);
768 maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
769 PROC_UNLOCK(p);
770 if (new >= maxfd)
771 return (flags & DUP_FCNTL ? EINVAL : EMFILE);
772
773 FILEDESC_XLOCK(fdp);
774 if (old >= fdp->fd_nfiles || fdp->fd_ofiles[old] == NULL) {
775 FILEDESC_XUNLOCK(fdp);
776 return (EBADF);
777 }
778 if (flags & DUP_FIXED && old == new) {
779 *retval = new;
780 FILEDESC_XUNLOCK(fdp);
781 return (0);
782 }
783 fp = fdp->fd_ofiles[old];
784 fhold(fp);
785
786 /*
787 * If the caller specified a file descriptor, make sure the file
788 * table is large enough to hold it, and grab it. Otherwise, just
789 * allocate a new descriptor the usual way. Since the filedesc
790 * lock may be temporarily dropped in the process, we have to look
791 * out for a race.
792 */
793 if (flags & DUP_FIXED) {
794 if (new >= fdp->fd_nfiles)
795 fdgrowtable(fdp, new + 1);
796 if (fdp->fd_ofiles[new] == NULL)
797 fdused(fdp, new);
798 } else {
799 if ((error = fdalloc(td, new, &new)) != 0) {
800 FILEDESC_XUNLOCK(fdp);
801 fdrop(fp, td);
802 return (error);
803 }
804 }
805
806 /*
807 * If the old file changed out from under us then treat it as a
808 * bad file descriptor. Userland should do its own locking to
809 * avoid this case.
810 */
811 if (fdp->fd_ofiles[old] != fp) {
812 /* we've allocated a descriptor which we won't use */
813 if (fdp->fd_ofiles[new] == NULL)
814 fdunused(fdp, new);
815 FILEDESC_XUNLOCK(fdp);
816 fdrop(fp, td);
817 return (EBADF);
818 }
819 KASSERT(old != new,
820 ("new fd is same as old"));
821
822 /*
823 * Save info on the descriptor being overwritten. We cannot close
824 * it without introducing an ownership race for the slot, since we
825 * need to drop the filedesc lock to call closef().
826 *
827 * XXX this duplicates parts of close().
828 */
829 delfp = fdp->fd_ofiles[new];
830 holdleaders = 0;
831 if (delfp != NULL) {
832 if (td->td_proc->p_fdtol != NULL) {
833 /*
834 * Ask fdfree() to sleep to ensure that all relevant
835 * process leaders can be traversed in closef().
836 */
837 fdp->fd_holdleaderscount++;
838 holdleaders = 1;
839 }
840 }
841
842 /*
843 * Duplicate the source descriptor
844 */
845 fdp->fd_ofiles[new] = fp;
846 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE;
847 if (new > fdp->fd_lastfile)
848 fdp->fd_lastfile = new;
849 *retval = new;
850
851 /*
852 * If we dup'd over a valid file, we now own the reference to it
853 * and must dispose of it using closef() semantics (as if a
854 * close() were performed on it).
855 *
856 * XXX this duplicates parts of close().
857 */
858 if (delfp != NULL) {
859 knote_fdclose(td, new);
860 if (delfp->f_type == DTYPE_MQUEUE)
861 mq_fdclose(td, new, delfp);
862 FILEDESC_XUNLOCK(fdp);
863 (void) closef(delfp, td);
864 if (holdleaders) {
865 FILEDESC_XLOCK(fdp);
866 fdp->fd_holdleaderscount--;
867 if (fdp->fd_holdleaderscount == 0 &&
868 fdp->fd_holdleaderswakeup != 0) {
869 fdp->fd_holdleaderswakeup = 0;
870 wakeup(&fdp->fd_holdleaderscount);
871 }
872 FILEDESC_XUNLOCK(fdp);
873 }
874 } else {
875 FILEDESC_XUNLOCK(fdp);
876 }
877 return (0);
878}
879
880/*
881 * If sigio is on the list associated with a process or process group,
882 * disable signalling from the device, remove sigio from the list and
883 * free sigio.
884 */
885void
886funsetown(struct sigio **sigiop)
887{
888 struct sigio *sigio;
889
890 SIGIO_LOCK();
891 sigio = *sigiop;
892 if (sigio == NULL) {
893 SIGIO_UNLOCK();
894 return;
895 }
896 *(sigio->sio_myref) = NULL;
897 if ((sigio)->sio_pgid < 0) {
898 struct pgrp *pg = (sigio)->sio_pgrp;
899 PGRP_LOCK(pg);
900 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio,
901 sigio, sio_pgsigio);
902 PGRP_UNLOCK(pg);
903 } else {
904 struct proc *p = (sigio)->sio_proc;
905 PROC_LOCK(p);
906 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio,
907 sigio, sio_pgsigio);
908 PROC_UNLOCK(p);
909 }
910 SIGIO_UNLOCK();
911 crfree(sigio->sio_ucred);
912 free(sigio, M_SIGIO);
913}
914
915/*
916 * Free a list of sigio structures.
917 * We only need to lock the SIGIO_LOCK because we have made ourselves
918 * inaccessible to callers of fsetown and therefore do not need to lock
919 * the proc or pgrp struct for the list manipulation.
920 */
921void
922funsetownlst(struct sigiolst *sigiolst)
923{
924 struct proc *p;
925 struct pgrp *pg;
926 struct sigio *sigio;
927
928 sigio = SLIST_FIRST(sigiolst);
929 if (sigio == NULL)
930 return;
931 p = NULL;
932 pg = NULL;
933
934 /*
935 * Every entry of the list should belong
936 * to a single proc or pgrp.
937 */
938 if (sigio->sio_pgid < 0) {
939 pg = sigio->sio_pgrp;
940 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED);
941 } else /* if (sigio->sio_pgid > 0) */ {
942 p = sigio->sio_proc;
943 PROC_LOCK_ASSERT(p, MA_NOTOWNED);
944 }
945
946 SIGIO_LOCK();
947 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) {
948 *(sigio->sio_myref) = NULL;
949 if (pg != NULL) {
950 KASSERT(sigio->sio_pgid < 0,
951 ("Proc sigio in pgrp sigio list"));
952 KASSERT(sigio->sio_pgrp == pg,
953 ("Bogus pgrp in sigio list"));
954 PGRP_LOCK(pg);
955 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio,
956 sio_pgsigio);
957 PGRP_UNLOCK(pg);
958 } else /* if (p != NULL) */ {
959 KASSERT(sigio->sio_pgid > 0,
960 ("Pgrp sigio in proc sigio list"));
961 KASSERT(sigio->sio_proc == p,
962 ("Bogus proc in sigio list"));
963 PROC_LOCK(p);
964 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio,
965 sio_pgsigio);
966 PROC_UNLOCK(p);
967 }
968 SIGIO_UNLOCK();
969 crfree(sigio->sio_ucred);
970 free(sigio, M_SIGIO);
971 SIGIO_LOCK();
972 }
973 SIGIO_UNLOCK();
974}
975
976/*
977 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg).
978 *
979 * After permission checking, add a sigio structure to the sigio list for
980 * the process or process group.
981 */
982int
983fsetown(pid_t pgid, struct sigio **sigiop)
984{
985 struct proc *proc;
986 struct pgrp *pgrp;
987 struct sigio *sigio;
988 int ret;
989
990 if (pgid == 0) {
991 funsetown(sigiop);
992 return (0);
993 }
994
995 ret = 0;
996
997 /* Allocate and fill in the new sigio out of locks. */
998 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK);
999 sigio->sio_pgid = pgid;
1000 sigio->sio_ucred = crhold(curthread->td_ucred);
1001 sigio->sio_myref = sigiop;
1002
1003 sx_slock(&proctree_lock);
1004 if (pgid > 0) {
1005 proc = pfind(pgid);
1006 if (proc == NULL) {
1007 ret = ESRCH;
1008 goto fail;
1009 }
1010
1011 /*
1012 * Policy - Don't allow a process to FSETOWN a process
1013 * in another session.
1014 *
1015 * Remove this test to allow maximum flexibility or
1016 * restrict FSETOWN to the current process or process
1017 * group for maximum safety.
1018 */
1019 PROC_UNLOCK(proc);
1020 if (proc->p_session != curthread->td_proc->p_session) {
1021 ret = EPERM;
1022 goto fail;
1023 }
1024
1025 pgrp = NULL;
1026 } else /* if (pgid < 0) */ {
1027 pgrp = pgfind(-pgid);
1028 if (pgrp == NULL) {
1029 ret = ESRCH;
1030 goto fail;
1031 }
1032 PGRP_UNLOCK(pgrp);
1033
1034 /*
1035 * Policy - Don't allow a process to FSETOWN a process
1036 * in another session.
1037 *
1038 * Remove this test to allow maximum flexibility or
1039 * restrict FSETOWN to the current process or process
1040 * group for maximum safety.
1041 */
1042 if (pgrp->pg_session != curthread->td_proc->p_session) {
1043 ret = EPERM;
1044 goto fail;
1045 }
1046
1047 proc = NULL;
1048 }
1049 funsetown(sigiop);
1050 if (pgid > 0) {
1051 PROC_LOCK(proc);
1052 /*
1053 * Since funsetownlst() is called without the proctree
1054 * locked, we need to check for P_WEXIT.
1055 * XXX: is ESRCH correct?
1056 */
1057 if ((proc->p_flag & P_WEXIT) != 0) {
1058 PROC_UNLOCK(proc);
1059 ret = ESRCH;
1060 goto fail;
1061 }
1062 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio);
1063 sigio->sio_proc = proc;
1064 PROC_UNLOCK(proc);
1065 } else {
1066 PGRP_LOCK(pgrp);
1067 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio);
1068 sigio->sio_pgrp = pgrp;
1069 PGRP_UNLOCK(pgrp);
1070 }
1071 sx_sunlock(&proctree_lock);
1072 SIGIO_LOCK();
1073 *sigiop = sigio;
1074 SIGIO_UNLOCK();
1075 return (0);
1076
1077fail:
1078 sx_sunlock(&proctree_lock);
1079 crfree(sigio->sio_ucred);
1080 free(sigio, M_SIGIO);
1081 return (ret);
1082}
1083
1084/*
1085 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg).
1086 */
1087pid_t
1088fgetown(sigiop)
1089 struct sigio **sigiop;
1090{
1091 pid_t pgid;
1092
1093 SIGIO_LOCK();
1094 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0;
1095 SIGIO_UNLOCK();
1096 return (pgid);
1097}
1098
1099/*
1100 * Close a file descriptor.
1101 */
1102#ifndef _SYS_SYSPROTO_H_
1103struct close_args {
1104 int fd;
1105};
1106#endif
1107/* ARGSUSED */
1108int
1109close(td, uap)
1110 struct thread *td;
1111 struct close_args *uap;
1112{
1113
1114 return (kern_close(td, uap->fd));
1115}
1116
1117int
1118kern_close(td, fd)
1119 struct thread *td;
1120 int fd;
1121{
1122 struct filedesc *fdp;
1123 struct file *fp;
1124 int error;
1125 int holdleaders;
1126
1127 error = 0;
1128 holdleaders = 0;
1129 fdp = td->td_proc->p_fd;
1130
1131 AUDIT_SYSCLOSE(td, fd);
1132
1133 FILEDESC_XLOCK(fdp);
1134 if ((unsigned)fd >= fdp->fd_nfiles ||
1135 (fp = fdp->fd_ofiles[fd]) == NULL) {
1136 FILEDESC_XUNLOCK(fdp);
1137 return (EBADF);
1138 }
1139 fdp->fd_ofiles[fd] = NULL;
1140 fdp->fd_ofileflags[fd] = 0;
1141 fdunused(fdp, fd);
1142 if (td->td_proc->p_fdtol != NULL) {
1143 /*
1144 * Ask fdfree() to sleep to ensure that all relevant
1145 * process leaders can be traversed in closef().
1146 */
1147 fdp->fd_holdleaderscount++;
1148 holdleaders = 1;
1149 }
1150
1151 /*
1152 * We now hold the fp reference that used to be owned by the
1153 * descriptor array. We have to unlock the FILEDESC *AFTER*
1154 * knote_fdclose to prevent a race of the fd getting opened, a knote
1155 * added, and deleteing a knote for the new fd.
1156 */
1157 knote_fdclose(td, fd);
1158 if (fp->f_type == DTYPE_MQUEUE)
1159 mq_fdclose(td, fd, fp);
1160 FILEDESC_XUNLOCK(fdp);
1161
1162 error = closef(fp, td);
1163 if (holdleaders) {
1164 FILEDESC_XLOCK(fdp);
1165 fdp->fd_holdleaderscount--;
1166 if (fdp->fd_holdleaderscount == 0 &&
1167 fdp->fd_holdleaderswakeup != 0) {
1168 fdp->fd_holdleaderswakeup = 0;
1169 wakeup(&fdp->fd_holdleaderscount);
1170 }
1171 FILEDESC_XUNLOCK(fdp);
1172 }
1173 return (error);
1174}
1175
1176/*
1177 * Close open file descriptors.
1178 */
1179#ifndef _SYS_SYSPROTO_H_
1180struct closefrom_args {
1181 int lowfd;
1182};
1183#endif
1184/* ARGSUSED */
1185int
1186closefrom(struct thread *td, struct closefrom_args *uap)
1187{
1188 struct filedesc *fdp;
1189 int fd;
1190
1191 fdp = td->td_proc->p_fd;
1192 AUDIT_ARG_FD(uap->lowfd);
1193
1194 /*
1195 * Treat negative starting file descriptor values identical to
1196 * closefrom(0) which closes all files.
1197 */
1198 if (uap->lowfd < 0)
1199 uap->lowfd = 0;
1200 FILEDESC_SLOCK(fdp);
1201 for (fd = uap->lowfd; fd < fdp->fd_nfiles; fd++) {
1202 if (fdp->fd_ofiles[fd] != NULL) {
1203 FILEDESC_SUNLOCK(fdp);
1204 (void)kern_close(td, fd);
1205 FILEDESC_SLOCK(fdp);
1206 }
1207 }
1208 FILEDESC_SUNLOCK(fdp);
1209 return (0);
1210}
1211
1212#if defined(COMPAT_43)
1213/*
1214 * Return status information about a file descriptor.
1215 */
1216#ifndef _SYS_SYSPROTO_H_
1217struct ofstat_args {
1218 int fd;
1219 struct ostat *sb;
1220};
1221#endif
1222/* ARGSUSED */
1223int
1224ofstat(struct thread *td, struct ofstat_args *uap)
1225{
1226 struct ostat oub;
1227 struct stat ub;
1228 int error;
1229
1230 error = kern_fstat(td, uap->fd, &ub);
1231 if (error == 0) {
1232 cvtstat(&ub, &oub);
1233 error = copyout(&oub, uap->sb, sizeof(oub));
1234 }
1235 return (error);
1236}
1237#endif /* COMPAT_43 */
1238
1239/*
1240 * Return status information about a file descriptor.
1241 */
1242#ifndef _SYS_SYSPROTO_H_
1243struct fstat_args {
1244 int fd;
1245 struct stat *sb;
1246};
1247#endif
1248/* ARGSUSED */
1249int
1250fstat(struct thread *td, struct fstat_args *uap)
1251{
1252 struct stat ub;
1253 int error;
1254
1255 error = kern_fstat(td, uap->fd, &ub);
1256 if (error == 0)
1257 error = copyout(&ub, uap->sb, sizeof(ub));
1258 return (error);
1259}
1260
1261int
1262kern_fstat(struct thread *td, int fd, struct stat *sbp)
1263{
1264 struct file *fp;
1265 int error;
1266
1267 AUDIT_ARG_FD(fd);
1268
1269 if ((error = fget(td, fd, &fp)) != 0)
1270 return (error);
1271
1272 AUDIT_ARG_FILE(td->td_proc, fp);
1273
1274 error = fo_stat(fp, sbp, td->td_ucred, td);
1275 fdrop(fp, td);
1276#ifdef KTRACE
1277 if (error == 0 && KTRPOINT(td, KTR_STRUCT))
1278 ktrstat(sbp);
1279#endif
1280 return (error);
1281}
1282
1283/*
1284 * Return status information about a file descriptor.
1285 */
1286#ifndef _SYS_SYSPROTO_H_
1287struct nfstat_args {
1288 int fd;
1289 struct nstat *sb;
1290};
1291#endif
1292/* ARGSUSED */
1293int
1294nfstat(struct thread *td, struct nfstat_args *uap)
1295{
1296 struct nstat nub;
1297 struct stat ub;
1298 int error;
1299
1300 error = kern_fstat(td, uap->fd, &ub);
1301 if (error == 0) {
1302 cvtnstat(&ub, &nub);
1303 error = copyout(&nub, uap->sb, sizeof(nub));
1304 }
1305 return (error);
1306}
1307
1308/*
1309 * Return pathconf information about a file descriptor.
1310 */
1311#ifndef _SYS_SYSPROTO_H_
1312struct fpathconf_args {
1313 int fd;
1314 int name;
1315};
1316#endif
1317/* ARGSUSED */
1318int
1319fpathconf(struct thread *td, struct fpathconf_args *uap)
1320{
1321 struct file *fp;
1322 struct vnode *vp;
1323 int error;
1324
1325 if ((error = fget(td, uap->fd, &fp)) != 0)
1326 return (error);
1327
1328 /* If asynchronous I/O is available, it works for all descriptors. */
1329 if (uap->name == _PC_ASYNC_IO) {
1330 td->td_retval[0] = async_io_version;
1331 goto out;
1332 }
1333 vp = fp->f_vnode;
1334 if (vp != NULL) {
1335 int vfslocked;
1336 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
1337 vn_lock(vp, LK_SHARED | LK_RETRY);
1338 error = VOP_PATHCONF(vp, uap->name, td->td_retval);
1339 VOP_UNLOCK(vp, 0);
1340 VFS_UNLOCK_GIANT(vfslocked);
1341 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) {
1342 if (uap->name != _PC_PIPE_BUF) {
1343 error = EINVAL;
1344 } else {
1345 td->td_retval[0] = PIPE_BUF;
1346 error = 0;
1347 }
1348 } else {
1349 error = EOPNOTSUPP;
1350 }
1351out:
1352 fdrop(fp, td);
1353 return (error);
1354}
1355
1356/*
1357 * Grow the file table to accomodate (at least) nfd descriptors. This may
1358 * block and drop the filedesc lock, but it will reacquire it before
1359 * returning.
1360 */
1361static void
1362fdgrowtable(struct filedesc *fdp, int nfd)
1363{
1364 struct filedesc0 *fdp0;
1365 struct freetable *fo;
1366 struct file **ntable;
1367 struct file **otable;
1368 char *nfileflags;
1369 int nnfiles, onfiles;
1370 NDSLOTTYPE *nmap;
1371
1372 FILEDESC_XLOCK_ASSERT(fdp);
1373
1374 KASSERT(fdp->fd_nfiles > 0,
1375 ("zero-length file table"));
1376
1377 /* compute the size of the new table */
1378 onfiles = fdp->fd_nfiles;
1379 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */
1380 if (nnfiles <= onfiles)
1381 /* the table is already large enough */
1382 return;
1383
1384 /* allocate a new table and (if required) new bitmaps */
1385 FILEDESC_XUNLOCK(fdp);
1386 ntable = malloc((nnfiles * OFILESIZE) + sizeof(struct freetable),
1387 M_FILEDESC, M_ZERO | M_WAITOK);
1388 nfileflags = (char *)&ntable[nnfiles];
1389 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles))
1390 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE,
1391 M_FILEDESC, M_ZERO | M_WAITOK);
1392 else
1393 nmap = NULL;
1394 FILEDESC_XLOCK(fdp);
1395
1396 /*
1397 * We now have new tables ready to go. Since we dropped the
1398 * filedesc lock to call malloc(), watch out for a race.
1399 */
1400 onfiles = fdp->fd_nfiles;
1401 if (onfiles >= nnfiles) {
1402 /* we lost the race, but that's OK */
1403 free(ntable, M_FILEDESC);
1404 if (nmap != NULL)
1405 free(nmap, M_FILEDESC);
1406 return;
1407 }
1408 bcopy(fdp->fd_ofiles, ntable, onfiles * sizeof(*ntable));
1409 bcopy(fdp->fd_ofileflags, nfileflags, onfiles);
1410 otable = fdp->fd_ofiles;
1411 fdp->fd_ofileflags = nfileflags;
1412 fdp->fd_ofiles = ntable;
1413 /*
1414 * We must preserve ofiles until the process exits because we can't
1415 * be certain that no threads have references to the old table via
1416 * _fget().
1417 */
1418 if (onfiles > NDFILE) {
1419 fo = (struct freetable *)&otable[onfiles];
1420 fdp0 = (struct filedesc0 *)fdp;
1421 fo->ft_table = otable;
1422 SLIST_INSERT_HEAD(&fdp0->fd_free, fo, ft_next);
1423 }
1424 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) {
1425 bcopy(fdp->fd_map, nmap, NDSLOTS(onfiles) * sizeof(*nmap));
1426 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE))
1427 free(fdp->fd_map, M_FILEDESC);
1428 fdp->fd_map = nmap;
1429 }
1430 fdp->fd_nfiles = nnfiles;
1431}
1432
1433/*
1434 * Allocate a file descriptor for the process.
1435 */
1436int
1437fdalloc(struct thread *td, int minfd, int *result)
1438{
1439 struct proc *p = td->td_proc;
1440 struct filedesc *fdp = p->p_fd;
1441 int fd = -1, maxfd;
1442
1443 FILEDESC_XLOCK_ASSERT(fdp);
1444
1445 if (fdp->fd_freefile > minfd)
1446 minfd = fdp->fd_freefile;
1447
1448 PROC_LOCK(p);
1449 maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
1450 PROC_UNLOCK(p);
1451
1452 /*
1453 * Search the bitmap for a free descriptor. If none is found, try
1454 * to grow the file table. Keep at it until we either get a file
1455 * descriptor or run into process or system limits; fdgrowtable()
1456 * may drop the filedesc lock, so we're in a race.
1457 */
1458 for (;;) {
1459 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles);
1460 if (fd >= maxfd)
1461 return (EMFILE);
1462 if (fd < fdp->fd_nfiles)
1463 break;
1464 fdgrowtable(fdp, min(fdp->fd_nfiles * 2, maxfd));
1465 }
1466
1467 /*
1468 * Perform some sanity checks, then mark the file descriptor as
1469 * used and return it to the caller.
1470 */
1471 KASSERT(!fdisused(fdp, fd),
1472 ("fd_first_free() returned non-free descriptor"));
1473 KASSERT(fdp->fd_ofiles[fd] == NULL,
1474 ("free descriptor isn't"));
1475 fdp->fd_ofileflags[fd] = 0; /* XXX needed? */
1476 fdused(fdp, fd);
1477 *result = fd;
1478 return (0);
1479}
1480
1481/*
1482 * Check to see whether n user file descriptors are available to the process
1483 * p.
1484 */
1485int
1486fdavail(struct thread *td, int n)
1487{
1488 struct proc *p = td->td_proc;
1489 struct filedesc *fdp = td->td_proc->p_fd;
1490 struct file **fpp;
1491 int i, lim, last;
1492
1493 FILEDESC_LOCK_ASSERT(fdp);
1494
1495 PROC_LOCK(p);
1496 lim = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
1497 PROC_UNLOCK(p);
1498 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0)
1499 return (1);
1500 last = min(fdp->fd_nfiles, lim);
1501 fpp = &fdp->fd_ofiles[fdp->fd_freefile];
1502 for (i = last - fdp->fd_freefile; --i >= 0; fpp++) {
1503 if (*fpp == NULL && --n <= 0)
1504 return (1);
1505 }
1506 return (0);
1507}
1508
1509/*
1510 * Create a new open file structure and allocate a file decriptor for the
1511 * process that refers to it. We add one reference to the file for the
1512 * descriptor table and one reference for resultfp. This is to prevent us
1513 * being preempted and the entry in the descriptor table closed after we
1514 * release the FILEDESC lock.
1515 */
1516int
1517falloc(struct thread *td, struct file **resultfp, int *resultfd)
1518{
1519 struct proc *p = td->td_proc;
1520 struct file *fp;
1521 int error, i;
1522 int maxuserfiles = maxfiles - (maxfiles / 20);
1523 static struct timeval lastfail;
1524 static int curfail;
1525
1526 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO);
1527 if ((openfiles >= maxuserfiles &&
1528 priv_check(td, PRIV_MAXFILES) != 0) ||
1529 openfiles >= maxfiles) {
1530 if (ppsratecheck(&lastfail, &curfail, 1)) {
1531 printf("kern.maxfiles limit exceeded by uid %i, please see tuning(7).\n",
1532 td->td_ucred->cr_ruid);
1533 }
1534 uma_zfree(file_zone, fp);
1535 return (ENFILE);
1536 }
1537 atomic_add_int(&openfiles, 1);
1538
1539 /*
1540 * If the process has file descriptor zero open, add the new file
1541 * descriptor to the list of open files at that point, otherwise
1542 * put it at the front of the list of open files.
1543 */
1544 refcount_init(&fp->f_count, 1);
1545 if (resultfp)
1546 fhold(fp);
1547 fp->f_cred = crhold(td->td_ucred);
1548 fp->f_ops = &badfileops;
1549 fp->f_data = NULL;
1550 fp->f_vnode = NULL;
1551 FILEDESC_XLOCK(p->p_fd);
1552 if ((error = fdalloc(td, 0, &i))) {
1553 FILEDESC_XUNLOCK(p->p_fd);
1554 fdrop(fp, td);
1555 if (resultfp)
1556 fdrop(fp, td);
1557 return (error);
1558 }
1559 p->p_fd->fd_ofiles[i] = fp;
1560 FILEDESC_XUNLOCK(p->p_fd);
1561 if (resultfp)
1562 *resultfp = fp;
1563 if (resultfd)
1564 *resultfd = i;
1565 return (0);
1566}
1567
1568/*
1569 * Build a new filedesc structure from another.
1570 * Copy the current, root, and jail root vnode references.
1571 */
1572struct filedesc *
1573fdinit(struct filedesc *fdp)
1574{
1575 struct filedesc0 *newfdp;
1576
1577 newfdp = malloc(sizeof *newfdp, M_FILEDESC, M_WAITOK | M_ZERO);
1578 FILEDESC_LOCK_INIT(&newfdp->fd_fd);
1579 if (fdp != NULL) {
1580 FILEDESC_XLOCK(fdp);
1581 newfdp->fd_fd.fd_cdir = fdp->fd_cdir;
1582 if (newfdp->fd_fd.fd_cdir)
1583 VREF(newfdp->fd_fd.fd_cdir);
1584 newfdp->fd_fd.fd_rdir = fdp->fd_rdir;
1585 if (newfdp->fd_fd.fd_rdir)
1586 VREF(newfdp->fd_fd.fd_rdir);
1587 newfdp->fd_fd.fd_jdir = fdp->fd_jdir;
1588 if (newfdp->fd_fd.fd_jdir)
1589 VREF(newfdp->fd_fd.fd_jdir);
1590 FILEDESC_XUNLOCK(fdp);
1591 }
1592
1593 /* Create the file descriptor table. */
1594 newfdp->fd_fd.fd_refcnt = 1;
1595 newfdp->fd_fd.fd_holdcnt = 1;
1596 newfdp->fd_fd.fd_cmask = CMASK;
1597 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles;
1598 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags;
1599 newfdp->fd_fd.fd_nfiles = NDFILE;
1600 newfdp->fd_fd.fd_map = newfdp->fd_dmap;
1601 newfdp->fd_fd.fd_lastfile = -1;
1602 return (&newfdp->fd_fd);
1603}
1604
1605static struct filedesc *
1606fdhold(struct proc *p)
1607{
1608 struct filedesc *fdp;
1609
1610 mtx_lock(&fdesc_mtx);
1611 fdp = p->p_fd;
1612 if (fdp != NULL)
1613 fdp->fd_holdcnt++;
1614 mtx_unlock(&fdesc_mtx);
1615 return (fdp);
1616}
1617
1618static void
1619fddrop(struct filedesc *fdp)
1620{
1621 struct filedesc0 *fdp0;
1622 struct freetable *ft;
1623 int i;
1624
1625 mtx_lock(&fdesc_mtx);
1626 i = --fdp->fd_holdcnt;
1627 mtx_unlock(&fdesc_mtx);
1628 if (i > 0)
1629 return;
1630
1631 FILEDESC_LOCK_DESTROY(fdp);
1632 fdp0 = (struct filedesc0 *)fdp;
1633 while ((ft = SLIST_FIRST(&fdp0->fd_free)) != NULL) {
1634 SLIST_REMOVE_HEAD(&fdp0->fd_free, ft_next);
1635 free(ft->ft_table, M_FILEDESC);
1636 }
1637 free(fdp, M_FILEDESC);
1638}
1639
1640/*
1641 * Share a filedesc structure.
1642 */
1643struct filedesc *
1644fdshare(struct filedesc *fdp)
1645{
1646
1647 FILEDESC_XLOCK(fdp);
1648 fdp->fd_refcnt++;
1649 FILEDESC_XUNLOCK(fdp);
1650 return (fdp);
1651}
1652
1653/*
1654 * Unshare a filedesc structure, if necessary by making a copy
1655 */
1656void
1657fdunshare(struct proc *p, struct thread *td)
1658{
1659
1660 FILEDESC_XLOCK(p->p_fd);
1661 if (p->p_fd->fd_refcnt > 1) {
1662 struct filedesc *tmp;
1663
1664 FILEDESC_XUNLOCK(p->p_fd);
1665 tmp = fdcopy(p->p_fd);
1666 fdfree(td);
1667 p->p_fd = tmp;
1668 } else
1669 FILEDESC_XUNLOCK(p->p_fd);
1670}
1671
1672/*
1673 * Copy a filedesc structure. A NULL pointer in returns a NULL reference,
1674 * this is to ease callers, not catch errors.
1675 */
1676struct filedesc *
1677fdcopy(struct filedesc *fdp)
1678{
1679 struct filedesc *newfdp;
1680 int i;
1681
1682 /* Certain daemons might not have file descriptors. */
1683 if (fdp == NULL)
1684 return (NULL);
1685
1686 newfdp = fdinit(fdp);
1687 FILEDESC_SLOCK(fdp);
1688 while (fdp->fd_lastfile >= newfdp->fd_nfiles) {
1689 FILEDESC_SUNLOCK(fdp);
1690 FILEDESC_XLOCK(newfdp);
1691 fdgrowtable(newfdp, fdp->fd_lastfile + 1);
1692 FILEDESC_XUNLOCK(newfdp);
1693 FILEDESC_SLOCK(fdp);
1694 }
1695 /* copy everything except kqueue descriptors */
1696 newfdp->fd_freefile = -1;
1697 for (i = 0; i <= fdp->fd_lastfile; ++i) {
1698 if (fdisused(fdp, i) &&
1699 fdp->fd_ofiles[i]->f_type != DTYPE_KQUEUE &&
1700 fdp->fd_ofiles[i]->f_ops != &badfileops) {
1701 newfdp->fd_ofiles[i] = fdp->fd_ofiles[i];
1702 newfdp->fd_ofileflags[i] = fdp->fd_ofileflags[i];
1703 fhold(newfdp->fd_ofiles[i]);
1704 newfdp->fd_lastfile = i;
1705 } else {
1706 if (newfdp->fd_freefile == -1)
1707 newfdp->fd_freefile = i;
1708 }
1709 }
1710 newfdp->fd_cmask = fdp->fd_cmask;
1711 FILEDESC_SUNLOCK(fdp);
1712 FILEDESC_XLOCK(newfdp);
1713 for (i = 0; i <= newfdp->fd_lastfile; ++i)
1714 if (newfdp->fd_ofiles[i] != NULL)
1715 fdused(newfdp, i);
1716 if (newfdp->fd_freefile == -1)
1717 newfdp->fd_freefile = i;
1718 FILEDESC_XUNLOCK(newfdp);
1719 return (newfdp);
1720}
1721
1722/*
1723 * Release a filedesc structure.
1724 */
1725void
1726fdfree(struct thread *td)
1727{
1728 struct filedesc *fdp;
1729 struct file **fpp;
1730 int i, locked;
1731 struct filedesc_to_leader *fdtol;
1732 struct file *fp;
1733 struct vnode *cdir, *jdir, *rdir, *vp;
1734 struct flock lf;
1735
1736 /* Certain daemons might not have file descriptors. */
1737 fdp = td->td_proc->p_fd;
1738 if (fdp == NULL)
1739 return;
1740
1741 /* Check for special need to clear POSIX style locks */
1742 fdtol = td->td_proc->p_fdtol;
1743 if (fdtol != NULL) {
1744 FILEDESC_XLOCK(fdp);
1745 KASSERT(fdtol->fdl_refcount > 0,
1746 ("filedesc_to_refcount botch: fdl_refcount=%d",
1747 fdtol->fdl_refcount));
1748 if (fdtol->fdl_refcount == 1 &&
1749 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
1750 for (i = 0, fpp = fdp->fd_ofiles;
1751 i <= fdp->fd_lastfile;
1752 i++, fpp++) {
1753 if (*fpp == NULL ||
1754 (*fpp)->f_type != DTYPE_VNODE)
1755 continue;
1756 fp = *fpp;
1757 fhold(fp);
1758 FILEDESC_XUNLOCK(fdp);
1759 lf.l_whence = SEEK_SET;
1760 lf.l_start = 0;
1761 lf.l_len = 0;
1762 lf.l_type = F_UNLCK;
1763 vp = fp->f_vnode;
1764 locked = VFS_LOCK_GIANT(vp->v_mount);
1765 (void) VOP_ADVLOCK(vp,
1766 (caddr_t)td->td_proc->
1767 p_leader,
1768 F_UNLCK,
1769 &lf,
1770 F_POSIX);
1771 VFS_UNLOCK_GIANT(locked);
1772 FILEDESC_XLOCK(fdp);
1773 fdrop(fp, td);
1774 fpp = fdp->fd_ofiles + i;
1775 }
1776 }
1777 retry:
1778 if (fdtol->fdl_refcount == 1) {
1779 if (fdp->fd_holdleaderscount > 0 &&
1780 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
1781 /*
1782 * close() or do_dup() has cleared a reference
1783 * in a shared file descriptor table.
1784 */
1785 fdp->fd_holdleaderswakeup = 1;
1786 sx_sleep(&fdp->fd_holdleaderscount,
1787 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0);
1788 goto retry;
1789 }
1790 if (fdtol->fdl_holdcount > 0) {
1791 /*
1792 * Ensure that fdtol->fdl_leader remains
1793 * valid in closef().
1794 */
1795 fdtol->fdl_wakeup = 1;
1796 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK,
1797 "fdlhold", 0);
1798 goto retry;
1799 }
1800 }
1801 fdtol->fdl_refcount--;
1802 if (fdtol->fdl_refcount == 0 &&
1803 fdtol->fdl_holdcount == 0) {
1804 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev;
1805 fdtol->fdl_prev->fdl_next = fdtol->fdl_next;
1806 } else
1807 fdtol = NULL;
1808 td->td_proc->p_fdtol = NULL;
1809 FILEDESC_XUNLOCK(fdp);
1810 if (fdtol != NULL)
1811 free(fdtol, M_FILEDESC_TO_LEADER);
1812 }
1813 FILEDESC_XLOCK(fdp);
1814 i = --fdp->fd_refcnt;
1815 FILEDESC_XUNLOCK(fdp);
1816 if (i > 0)
1817 return;
1818
1819 fpp = fdp->fd_ofiles;
1820 for (i = fdp->fd_lastfile; i-- >= 0; fpp++) {
1821 if (*fpp) {
1822 FILEDESC_XLOCK(fdp);
1823 fp = *fpp;
1824 *fpp = NULL;
1825 FILEDESC_XUNLOCK(fdp);
1826 (void) closef(fp, td);
1827 }
1828 }
1829 FILEDESC_XLOCK(fdp);
1830
1831 /* XXX This should happen earlier. */
1832 mtx_lock(&fdesc_mtx);
1833 td->td_proc->p_fd = NULL;
1834 mtx_unlock(&fdesc_mtx);
1835
1836 if (fdp->fd_nfiles > NDFILE)
1837 free(fdp->fd_ofiles, M_FILEDESC);
1838 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE))
1839 free(fdp->fd_map, M_FILEDESC);
1840
1841 fdp->fd_nfiles = 0;
1842
1843 cdir = fdp->fd_cdir;
1844 fdp->fd_cdir = NULL;
1845 rdir = fdp->fd_rdir;
1846 fdp->fd_rdir = NULL;
1847 jdir = fdp->fd_jdir;
1848 fdp->fd_jdir = NULL;
1849 FILEDESC_XUNLOCK(fdp);
1850
1851 if (cdir) {
1852 locked = VFS_LOCK_GIANT(cdir->v_mount);
1853 vrele(cdir);
1854 VFS_UNLOCK_GIANT(locked);
1855 }
1856 if (rdir) {
1857 locked = VFS_LOCK_GIANT(rdir->v_mount);
1858 vrele(rdir);
1859 VFS_UNLOCK_GIANT(locked);
1860 }
1861 if (jdir) {
1862 locked = VFS_LOCK_GIANT(jdir->v_mount);
1863 vrele(jdir);
1864 VFS_UNLOCK_GIANT(locked);
1865 }
1866
1867 fddrop(fdp);
1868}
1869
1870/*
1871 * For setugid programs, we don't want to people to use that setugidness
1872 * to generate error messages which write to a file which otherwise would
1873 * otherwise be off-limits to the process. We check for filesystems where
1874 * the vnode can change out from under us after execve (like [lin]procfs).
1875 *
1876 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is
1877 * sufficient. We also don't check for setugidness since we know we are.
1878 */
1879static int
1880is_unsafe(struct file *fp)
1881{
1882 if (fp->f_type == DTYPE_VNODE) {
1883 struct vnode *vp = fp->f_vnode;
1884
1885 if ((vp->v_vflag & VV_PROCDEP) != 0)
1886 return (1);
1887 }
1888 return (0);
1889}
1890
1891/*
1892 * Make this setguid thing safe, if at all possible.
1893 */
1894void
1895setugidsafety(struct thread *td)
1896{
1897 struct filedesc *fdp;
1898 int i;
1899
1900 /* Certain daemons might not have file descriptors. */
1901 fdp = td->td_proc->p_fd;
1902 if (fdp == NULL)
1903 return;
1904
1905 /*
1906 * Note: fdp->fd_ofiles may be reallocated out from under us while
1907 * we are blocked in a close. Be careful!
1908 */
1909 FILEDESC_XLOCK(fdp);
1910 for (i = 0; i <= fdp->fd_lastfile; i++) {
1911 if (i > 2)
1912 break;
1913 if (fdp->fd_ofiles[i] && is_unsafe(fdp->fd_ofiles[i])) {
1914 struct file *fp;
1915
1916 knote_fdclose(td, i);
1917 /*
1918 * NULL-out descriptor prior to close to avoid
1919 * a race while close blocks.
1920 */
1921 fp = fdp->fd_ofiles[i];
1922 fdp->fd_ofiles[i] = NULL;
1923 fdp->fd_ofileflags[i] = 0;
1924 fdunused(fdp, i);
1925 FILEDESC_XUNLOCK(fdp);
1926 (void) closef(fp, td);
1927 FILEDESC_XLOCK(fdp);
1928 }
1929 }
1930 FILEDESC_XUNLOCK(fdp);
1931}
1932
1933/*
1934 * If a specific file object occupies a specific file descriptor, close the
1935 * file descriptor entry and drop a reference on the file object. This is a
1936 * convenience function to handle a subsequent error in a function that calls
1937 * falloc() that handles the race that another thread might have closed the
1938 * file descriptor out from under the thread creating the file object.
1939 */
1940void
1941fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td)
1942{
1943
1944 FILEDESC_XLOCK(fdp);
1945 if (fdp->fd_ofiles[idx] == fp) {
1946 fdp->fd_ofiles[idx] = NULL;
1947 fdunused(fdp, idx);
1948 FILEDESC_XUNLOCK(fdp);
1949 fdrop(fp, td);
1950 } else
1951 FILEDESC_XUNLOCK(fdp);
1952}
1953
1954/*
1955 * Close any files on exec?
1956 */
1957void
1958fdcloseexec(struct thread *td)
1959{
1960 struct filedesc *fdp;
1961 int i;
1962
1963 /* Certain daemons might not have file descriptors. */
1964 fdp = td->td_proc->p_fd;
1965 if (fdp == NULL)
1966 return;
1967
1968 FILEDESC_XLOCK(fdp);
1969
1970 /*
1971 * We cannot cache fd_ofiles or fd_ofileflags since operations
1972 * may block and rip them out from under us.
1973 */
1974 for (i = 0; i <= fdp->fd_lastfile; i++) {
1975 if (fdp->fd_ofiles[i] != NULL &&
1976 (fdp->fd_ofiles[i]->f_type == DTYPE_MQUEUE ||
1977 (fdp->fd_ofileflags[i] & UF_EXCLOSE))) {
1978 struct file *fp;
1979
1980 knote_fdclose(td, i);
1981 /*
1982 * NULL-out descriptor prior to close to avoid
1983 * a race while close blocks.
1984 */
1985 fp = fdp->fd_ofiles[i];
1986 fdp->fd_ofiles[i] = NULL;
1987 fdp->fd_ofileflags[i] = 0;
1988 fdunused(fdp, i);
1989 if (fp->f_type == DTYPE_MQUEUE)
1990 mq_fdclose(td, i, fp);
1991 FILEDESC_XUNLOCK(fdp);
1992 (void) closef(fp, td);
1993 FILEDESC_XLOCK(fdp);
1994 }
1995 }
1996 FILEDESC_XUNLOCK(fdp);
1997}
1998
1999/*
2000 * It is unsafe for set[ug]id processes to be started with file
2001 * descriptors 0..2 closed, as these descriptors are given implicit
2002 * significance in the Standard C library. fdcheckstd() will create a
2003 * descriptor referencing /dev/null for each of stdin, stdout, and
2004 * stderr that is not already open.
2005 */
2006int
2007fdcheckstd(struct thread *td)
2008{
2009 struct filedesc *fdp;
2010 register_t retval, save;
2011 int i, error, devnull;
2012
2013 fdp = td->td_proc->p_fd;
2014 if (fdp == NULL)
2015 return (0);
2016 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared"));
2017 devnull = -1;
2018 error = 0;
2019 for (i = 0; i < 3; i++) {
2020 if (fdp->fd_ofiles[i] != NULL)
2021 continue;
2022 if (devnull < 0) {
2023 save = td->td_retval[0];
2024 error = kern_open(td, "/dev/null", UIO_SYSSPACE,
2025 O_RDWR, 0);
2026 devnull = td->td_retval[0];
2027 td->td_retval[0] = save;
2028 if (error)
2029 break;
2030 KASSERT(devnull == i, ("oof, we didn't get our fd"));
2031 } else {
2032 error = do_dup(td, DUP_FIXED, devnull, i, &retval);
2033 if (error != 0)
2034 break;
2035 }
2036 }
2037 return (error);
2038}
2039
2040/*
2041 * Internal form of close. Decrement reference count on file structure.
2042 * Note: td may be NULL when closing a file that was being passed in a
2043 * message.
2044 *
2045 * XXXRW: Giant is not required for the caller, but often will be held; this
2046 * makes it moderately likely the Giant will be recursed in the VFS case.
2047 */
2048int
2049closef(struct file *fp, struct thread *td)
2050{
2051 struct vnode *vp;
2052 struct flock lf;
2053 struct filedesc_to_leader *fdtol;
2054 struct filedesc *fdp;
2055
2056 /*
2057 * POSIX record locking dictates that any close releases ALL
2058 * locks owned by this process. This is handled by setting
2059 * a flag in the unlock to free ONLY locks obeying POSIX
2060 * semantics, and not to free BSD-style file locks.
2061 * If the descriptor was in a message, POSIX-style locks
2062 * aren't passed with the descriptor, and the thread pointer
2063 * will be NULL. Callers should be careful only to pass a
2064 * NULL thread pointer when there really is no owning
2065 * context that might have locks, or the locks will be
2066 * leaked.
2067 */
2068 if (fp->f_type == DTYPE_VNODE && td != NULL) {
2069 int vfslocked;
2070
2071 vp = fp->f_vnode;
2072 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
2073 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
2074 lf.l_whence = SEEK_SET;
2075 lf.l_start = 0;
2076 lf.l_len = 0;
2077 lf.l_type = F_UNLCK;
2078 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader,
2079 F_UNLCK, &lf, F_POSIX);
2080 }
2081 fdtol = td->td_proc->p_fdtol;
2082 if (fdtol != NULL) {
2083 /*
2084 * Handle special case where file descriptor table is
2085 * shared between multiple process leaders.
2086 */
2087 fdp = td->td_proc->p_fd;
2088 FILEDESC_XLOCK(fdp);
2089 for (fdtol = fdtol->fdl_next;
2090 fdtol != td->td_proc->p_fdtol;
2091 fdtol = fdtol->fdl_next) {
2092 if ((fdtol->fdl_leader->p_flag &
2093 P_ADVLOCK) == 0)
2094 continue;
2095 fdtol->fdl_holdcount++;
2096 FILEDESC_XUNLOCK(fdp);
2097 lf.l_whence = SEEK_SET;
2098 lf.l_start = 0;
2099 lf.l_len = 0;
2100 lf.l_type = F_UNLCK;
2101 vp = fp->f_vnode;
2102 (void) VOP_ADVLOCK(vp,
2103 (caddr_t)fdtol->fdl_leader,
2104 F_UNLCK, &lf, F_POSIX);
2105 FILEDESC_XLOCK(fdp);
2106 fdtol->fdl_holdcount--;
2107 if (fdtol->fdl_holdcount == 0 &&
2108 fdtol->fdl_wakeup != 0) {
2109 fdtol->fdl_wakeup = 0;
2110 wakeup(fdtol);
2111 }
2112 }
2113 FILEDESC_XUNLOCK(fdp);
2114 }
2115 VFS_UNLOCK_GIANT(vfslocked);
2116 }
2117 return (fdrop(fp, td));
2118}
2119
2120/*
2121 * Initialize the file pointer with the specified properties.
2122 *
2123 * The ops are set with release semantics to be certain that the flags, type,
2124 * and data are visible when ops is. This is to prevent ops methods from being
2125 * called with bad data.
2126 */
2127void
2128finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops)
2129{
2130 fp->f_data = data;
2131 fp->f_flag = flag;
2132 fp->f_type = type;
2133 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops);
2134}
2135
2136struct file *
2137fget_unlocked(struct filedesc *fdp, int fd)
2138{
2139 struct file *fp;
2140 u_int count;
2141
2142 if (fd < 0 || fd >= fdp->fd_nfiles)
2143 return (NULL);
2144 /*
2145 * Fetch the descriptor locklessly. We avoid fdrop() races by
2146 * never raising a refcount above 0. To accomplish this we have
2147 * to use a cmpset loop rather than an atomic_add. The descriptor
2148 * must be re-verified once we acquire a reference to be certain
2149 * that the identity is still correct and we did not lose a race
2150 * due to preemption.
2151 */
2152 for (;;) {
2153 fp = fdp->fd_ofiles[fd];
2154 if (fp == NULL)
2155 break;
2156 count = fp->f_count;
2157 if (count == 0)
2158 continue;
2159 /*
2160 * Use an acquire barrier to prevent caching of fd_ofiles
2161 * so it is refreshed for verification.
2162 */
2163 if (atomic_cmpset_acq_int(&fp->f_count, count, count + 1) != 1)
2164 continue;
2165 if (fp == fdp->fd_ofiles[fd])
2166 break;
2167 fdrop(fp, curthread);
2168 }
2169
2170 return (fp);
2171}
2172
2173/*
2174 * Extract the file pointer associated with the specified descriptor for the
2175 * current user process.
2176 *
2177 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is
2178 * returned.
2179 *
2180 * If an error occured the non-zero error is returned and *fpp is set to
2181 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is
2182 * responsible for fdrop().
2183 */
2184static __inline int
2185_fget(struct thread *td, int fd, struct file **fpp, int flags)
2186{
2187 struct filedesc *fdp;
2188 struct file *fp;
2189
2190 *fpp = NULL;
2191 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL)
2192 return (EBADF);
2193 if ((fp = fget_unlocked(fdp, fd)) == NULL)
2194 return (EBADF);
2195 if (fp->f_ops == &badfileops) {
2196 fdrop(fp, td);
2197 return (EBADF);
2198 }
2199 /*
2200 * FREAD and FWRITE failure return EBADF as per POSIX.
2201 *
2202 * Only one flag, or 0, may be specified.
2203 */
2204 if ((flags == FREAD && (fp->f_flag & FREAD) == 0) ||
2205 (flags == FWRITE && (fp->f_flag & FWRITE) == 0)) {
2206 fdrop(fp, td);
2207 return (EBADF);
2208 }
2209 *fpp = fp;
2210 return (0);
2211}
2212
2213int
2214fget(struct thread *td, int fd, struct file **fpp)
2215{
2216
2217 return(_fget(td, fd, fpp, 0));
2218}
2219
2220int
2221fget_read(struct thread *td, int fd, struct file **fpp)
2222{
2223
2224 return(_fget(td, fd, fpp, FREAD));
2225}
2226
2227int
2228fget_write(struct thread *td, int fd, struct file **fpp)
2229{
2230
2231 return(_fget(td, fd, fpp, FWRITE));
2232}
2233
2234/*
2235 * Like fget() but loads the underlying vnode, or returns an error if the
2236 * descriptor does not represent a vnode. Note that pipes use vnodes but
2237 * never have VM objects. The returned vnode will be vref()'d.
2238 *
2239 * XXX: what about the unused flags ?
2240 */
2241static __inline int
2242_fgetvp(struct thread *td, int fd, struct vnode **vpp, int flags)
2243{
2244 struct file *fp;
2245 int error;
2246
2247 *vpp = NULL;
2248 if ((error = _fget(td, fd, &fp, flags)) != 0)
2249 return (error);
2250 if (fp->f_vnode == NULL) {
2251 error = EINVAL;
2252 } else {
2253 *vpp = fp->f_vnode;
2254 vref(*vpp);
2255 }
2256 fdrop(fp, td);
2257
2258 return (error);
2259}
2260
2261int
2262fgetvp(struct thread *td, int fd, struct vnode **vpp)
2263{
2264
2265 return (_fgetvp(td, fd, vpp, 0));
2266}
2267
2268int
2269fgetvp_read(struct thread *td, int fd, struct vnode **vpp)
2270{
2271
2272 return (_fgetvp(td, fd, vpp, FREAD));
2273}
2274
2275#ifdef notyet
2276int
2277fgetvp_write(struct thread *td, int fd, struct vnode **vpp)
2278{
2279
2280 return (_fgetvp(td, fd, vpp, FWRITE));
2281}
2282#endif
2283
2284/*
2285 * Like fget() but loads the underlying socket, or returns an error if the
2286 * descriptor does not represent a socket.
2287 *
2288 * We bump the ref count on the returned socket. XXX Also obtain the SX lock
2289 * in the future.
2290 *
2291 * Note: fgetsock() and fputsock() are deprecated, as consumers should rely
2292 * on their file descriptor reference to prevent the socket from being free'd
2293 * during use.
2294 */
2295int
2296fgetsock(struct thread *td, int fd, struct socket **spp, u_int *fflagp)
2297{
2298 struct file *fp;
2299 int error;
2300
2301 *spp = NULL;
2302 if (fflagp != NULL)
2303 *fflagp = 0;
2304 if ((error = _fget(td, fd, &fp, 0)) != 0)
2305 return (error);
2306 if (fp->f_type != DTYPE_SOCKET) {
2307 error = ENOTSOCK;
2308 } else {
2309 *spp = fp->f_data;
2310 if (fflagp)
2311 *fflagp = fp->f_flag;
2312 SOCK_LOCK(*spp);
2313 soref(*spp);
2314 SOCK_UNLOCK(*spp);
2315 }
2316 fdrop(fp, td);
2317
2318 return (error);
2319}
2320
2321/*
2322 * Drop the reference count on the socket and XXX release the SX lock in the
2323 * future. The last reference closes the socket.
2324 *
2325 * Note: fputsock() is deprecated, see comment for fgetsock().
2326 */
2327void
2328fputsock(struct socket *so)
2329{
2330
2331 ACCEPT_LOCK();
2332 SOCK_LOCK(so);
| 83#include <security/audit/audit.h>
84
85#include <vm/uma.h>
86
87#include <ddb/ddb.h>
88
89static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table");
90static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader",
91 "file desc to leader structures");
92static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures");
93
94static uma_zone_t file_zone;
95
96
97/* Flags for do_dup() */
98#define DUP_FIXED 0x1 /* Force fixed allocation */
99#define DUP_FCNTL 0x2 /* fcntl()-style errors */
100
101static int do_dup(struct thread *td, int flags, int old, int new,
102 register_t *retval);
103static int fd_first_free(struct filedesc *, int, int);
104static int fd_last_used(struct filedesc *, int, int);
105static void fdgrowtable(struct filedesc *, int);
106static void fdunused(struct filedesc *fdp, int fd);
107static void fdused(struct filedesc *fdp, int fd);
108
109/*
110 * A process is initially started out with NDFILE descriptors stored within
111 * this structure, selected to be enough for typical applications based on
112 * the historical limit of 20 open files (and the usage of descriptors by
113 * shells). If these descriptors are exhausted, a larger descriptor table
114 * may be allocated, up to a process' resource limit; the internal arrays
115 * are then unused.
116 */
117#define NDFILE 20
118#define NDSLOTSIZE sizeof(NDSLOTTYPE)
119#define NDENTRIES (NDSLOTSIZE * __CHAR_BIT)
120#define NDSLOT(x) ((x) / NDENTRIES)
121#define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES))
122#define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES)
123
124/*
125 * Storage required per open file descriptor.
126 */
127#define OFILESIZE (sizeof(struct file *) + sizeof(char))
128
129/*
130 * Storage to hold unused ofiles that need to be reclaimed.
131 */
132struct freetable {
133 struct file **ft_table;
134 SLIST_ENTRY(freetable) ft_next;
135};
136
137/*
138 * Basic allocation of descriptors:
139 * one of the above, plus arrays for NDFILE descriptors.
140 */
141struct filedesc0 {
142 struct filedesc fd_fd;
143 /*
144 * ofiles which need to be reclaimed on free.
145 */
146 SLIST_HEAD(,freetable) fd_free;
147 /*
148 * These arrays are used when the number of open files is
149 * <= NDFILE, and are then pointed to by the pointers above.
150 */
151 struct file *fd_dfiles[NDFILE];
152 char fd_dfileflags[NDFILE];
153 NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)];
154};
155
156/*
157 * Descriptor management.
158 */
159volatile int openfiles; /* actual number of open files */
160struct mtx sigio_lock; /* mtx to protect pointers to sigio */
161void (*mq_fdclose)(struct thread *td, int fd, struct file *fp);
162
163/* A mutex to protect the association between a proc and filedesc. */
164static struct mtx fdesc_mtx;
165
166/*
167 * Find the first zero bit in the given bitmap, starting at low and not
168 * exceeding size - 1.
169 */
170static int
171fd_first_free(struct filedesc *fdp, int low, int size)
172{
173 NDSLOTTYPE *map = fdp->fd_map;
174 NDSLOTTYPE mask;
175 int off, maxoff;
176
177 if (low >= size)
178 return (low);
179
180 off = NDSLOT(low);
181 if (low % NDENTRIES) {
182 mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES)));
183 if ((mask &= ~map[off]) != 0UL)
184 return (off * NDENTRIES + ffsl(mask) - 1);
185 ++off;
186 }
187 for (maxoff = NDSLOTS(size); off < maxoff; ++off)
188 if (map[off] != ~0UL)
189 return (off * NDENTRIES + ffsl(~map[off]) - 1);
190 return (size);
191}
192
193/*
194 * Find the highest non-zero bit in the given bitmap, starting at low and
195 * not exceeding size - 1.
196 */
197static int
198fd_last_used(struct filedesc *fdp, int low, int size)
199{
200 NDSLOTTYPE *map = fdp->fd_map;
201 NDSLOTTYPE mask;
202 int off, minoff;
203
204 if (low >= size)
205 return (-1);
206
207 off = NDSLOT(size);
208 if (size % NDENTRIES) {
209 mask = ~(~(NDSLOTTYPE)0 << (size % NDENTRIES));
210 if ((mask &= map[off]) != 0)
211 return (off * NDENTRIES + flsl(mask) - 1);
212 --off;
213 }
214 for (minoff = NDSLOT(low); off >= minoff; --off)
215 if (map[off] != 0)
216 return (off * NDENTRIES + flsl(map[off]) - 1);
217 return (low - 1);
218}
219
220static int
221fdisused(struct filedesc *fdp, int fd)
222{
223 KASSERT(fd >= 0 && fd < fdp->fd_nfiles,
224 ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles));
225 return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0);
226}
227
228/*
229 * Mark a file descriptor as used.
230 */
231static void
232fdused(struct filedesc *fdp, int fd)
233{
234
235 FILEDESC_XLOCK_ASSERT(fdp);
236 KASSERT(!fdisused(fdp, fd),
237 ("fd already used"));
238
239 fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd);
240 if (fd > fdp->fd_lastfile)
241 fdp->fd_lastfile = fd;
242 if (fd == fdp->fd_freefile)
243 fdp->fd_freefile = fd_first_free(fdp, fd, fdp->fd_nfiles);
244}
245
246/*
247 * Mark a file descriptor as unused.
248 */
249static void
250fdunused(struct filedesc *fdp, int fd)
251{
252
253 FILEDESC_XLOCK_ASSERT(fdp);
254 KASSERT(fdisused(fdp, fd),
255 ("fd is already unused"));
256 KASSERT(fdp->fd_ofiles[fd] == NULL,
257 ("fd is still in use"));
258
259 fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd);
260 if (fd < fdp->fd_freefile)
261 fdp->fd_freefile = fd;
262 if (fd == fdp->fd_lastfile)
263 fdp->fd_lastfile = fd_last_used(fdp, 0, fd);
264}
265
266/*
267 * System calls on descriptors.
268 */
269#ifndef _SYS_SYSPROTO_H_
270struct getdtablesize_args {
271 int dummy;
272};
273#endif
274/* ARGSUSED */
275int
276getdtablesize(struct thread *td, struct getdtablesize_args *uap)
277{
278 struct proc *p = td->td_proc;
279
280 PROC_LOCK(p);
281 td->td_retval[0] =
282 min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
283 PROC_UNLOCK(p);
284 return (0);
285}
286
287/*
288 * Duplicate a file descriptor to a particular value.
289 *
290 * Note: keep in mind that a potential race condition exists when closing
291 * descriptors from a shared descriptor table (via rfork).
292 */
293#ifndef _SYS_SYSPROTO_H_
294struct dup2_args {
295 u_int from;
296 u_int to;
297};
298#endif
299/* ARGSUSED */
300int
301dup2(struct thread *td, struct dup2_args *uap)
302{
303
304 return (do_dup(td, DUP_FIXED, (int)uap->from, (int)uap->to,
305 td->td_retval));
306}
307
308/*
309 * Duplicate a file descriptor.
310 */
311#ifndef _SYS_SYSPROTO_H_
312struct dup_args {
313 u_int fd;
314};
315#endif
316/* ARGSUSED */
317int
318dup(struct thread *td, struct dup_args *uap)
319{
320
321 return (do_dup(td, 0, (int)uap->fd, 0, td->td_retval));
322}
323
324/*
325 * The file control system call.
326 */
327#ifndef _SYS_SYSPROTO_H_
328struct fcntl_args {
329 int fd;
330 int cmd;
331 long arg;
332};
333#endif
334/* ARGSUSED */
335int
336fcntl(struct thread *td, struct fcntl_args *uap)
337{
338 struct flock fl;
339 struct oflock ofl;
340 intptr_t arg;
341 int error;
342 int cmd;
343
344 error = 0;
345 cmd = uap->cmd;
346 switch (uap->cmd) {
347 case F_OGETLK:
348 case F_OSETLK:
349 case F_OSETLKW:
350 /*
351 * Convert old flock structure to new.
352 */
353 error = copyin((void *)(intptr_t)uap->arg, &ofl, sizeof(ofl));
354 fl.l_start = ofl.l_start;
355 fl.l_len = ofl.l_len;
356 fl.l_pid = ofl.l_pid;
357 fl.l_type = ofl.l_type;
358 fl.l_whence = ofl.l_whence;
359 fl.l_sysid = 0;
360
361 switch (uap->cmd) {
362 case F_OGETLK:
363 cmd = F_GETLK;
364 break;
365 case F_OSETLK:
366 cmd = F_SETLK;
367 break;
368 case F_OSETLKW:
369 cmd = F_SETLKW;
370 break;
371 }
372 arg = (intptr_t)&fl;
373 break;
374 case F_GETLK:
375 case F_SETLK:
376 case F_SETLKW:
377 case F_SETLK_REMOTE:
378 error = copyin((void *)(intptr_t)uap->arg, &fl, sizeof(fl));
379 arg = (intptr_t)&fl;
380 break;
381 default:
382 arg = uap->arg;
383 break;
384 }
385 if (error)
386 return (error);
387 error = kern_fcntl(td, uap->fd, cmd, arg);
388 if (error)
389 return (error);
390 if (uap->cmd == F_OGETLK) {
391 ofl.l_start = fl.l_start;
392 ofl.l_len = fl.l_len;
393 ofl.l_pid = fl.l_pid;
394 ofl.l_type = fl.l_type;
395 ofl.l_whence = fl.l_whence;
396 error = copyout(&ofl, (void *)(intptr_t)uap->arg, sizeof(ofl));
397 } else if (uap->cmd == F_GETLK) {
398 error = copyout(&fl, (void *)(intptr_t)uap->arg, sizeof(fl));
399 }
400 return (error);
401}
402
403static inline struct file *
404fdtofp(int fd, struct filedesc *fdp)
405{
406 struct file *fp;
407
408 FILEDESC_LOCK_ASSERT(fdp);
409 if ((unsigned)fd >= fdp->fd_nfiles ||
410 (fp = fdp->fd_ofiles[fd]) == NULL)
411 return (NULL);
412 return (fp);
413}
414
415int
416kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg)
417{
418 struct filedesc *fdp;
419 struct flock *flp;
420 struct file *fp;
421 struct proc *p;
422 char *pop;
423 struct vnode *vp;
424 int error, flg, tmp;
425 int vfslocked;
426 u_int old, new;
427 uint64_t bsize;
428
429 vfslocked = 0;
430 error = 0;
431 flg = F_POSIX;
432 p = td->td_proc;
433 fdp = p->p_fd;
434
435 switch (cmd) {
436 case F_DUPFD:
437 tmp = arg;
438 error = do_dup(td, DUP_FCNTL, fd, tmp, td->td_retval);
439 break;
440
441 case F_DUP2FD:
442 tmp = arg;
443 error = do_dup(td, DUP_FIXED, fd, tmp, td->td_retval);
444 break;
445
446 case F_GETFD:
447 FILEDESC_SLOCK(fdp);
448 if ((fp = fdtofp(fd, fdp)) == NULL) {
449 FILEDESC_SUNLOCK(fdp);
450 error = EBADF;
451 break;
452 }
453 pop = &fdp->fd_ofileflags[fd];
454 td->td_retval[0] = (*pop & UF_EXCLOSE) ? FD_CLOEXEC : 0;
455 FILEDESC_SUNLOCK(fdp);
456 break;
457
458 case F_SETFD:
459 FILEDESC_XLOCK(fdp);
460 if ((fp = fdtofp(fd, fdp)) == NULL) {
461 FILEDESC_XUNLOCK(fdp);
462 error = EBADF;
463 break;
464 }
465 pop = &fdp->fd_ofileflags[fd];
466 *pop = (*pop &~ UF_EXCLOSE) |
467 (arg & FD_CLOEXEC ? UF_EXCLOSE : 0);
468 FILEDESC_XUNLOCK(fdp);
469 break;
470
471 case F_GETFL:
472 FILEDESC_SLOCK(fdp);
473 if ((fp = fdtofp(fd, fdp)) == NULL) {
474 FILEDESC_SUNLOCK(fdp);
475 error = EBADF;
476 break;
477 }
478 td->td_retval[0] = OFLAGS(fp->f_flag);
479 FILEDESC_SUNLOCK(fdp);
480 break;
481
482 case F_SETFL:
483 FILEDESC_SLOCK(fdp);
484 if ((fp = fdtofp(fd, fdp)) == NULL) {
485 FILEDESC_SUNLOCK(fdp);
486 error = EBADF;
487 break;
488 }
489 fhold(fp);
490 FILEDESC_SUNLOCK(fdp);
491 do {
492 tmp = flg = fp->f_flag;
493 tmp &= ~FCNTLFLAGS;
494 tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS;
495 } while(atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0);
496 tmp = fp->f_flag & FNONBLOCK;
497 error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
498 if (error) {
499 fdrop(fp, td);
500 break;
501 }
502 tmp = fp->f_flag & FASYNC;
503 error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td);
504 if (error == 0) {
505 fdrop(fp, td);
506 break;
507 }
508 atomic_clear_int(&fp->f_flag, FNONBLOCK);
509 tmp = 0;
510 (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td);
511 fdrop(fp, td);
512 break;
513
514 case F_GETOWN:
515 FILEDESC_SLOCK(fdp);
516 if ((fp = fdtofp(fd, fdp)) == NULL) {
517 FILEDESC_SUNLOCK(fdp);
518 error = EBADF;
519 break;
520 }
521 fhold(fp);
522 FILEDESC_SUNLOCK(fdp);
523 error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td);
524 if (error == 0)
525 td->td_retval[0] = tmp;
526 fdrop(fp, td);
527 break;
528
529 case F_SETOWN:
530 FILEDESC_SLOCK(fdp);
531 if ((fp = fdtofp(fd, fdp)) == NULL) {
532 FILEDESC_SUNLOCK(fdp);
533 error = EBADF;
534 break;
535 }
536 fhold(fp);
537 FILEDESC_SUNLOCK(fdp);
538 tmp = arg;
539 error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td);
540 fdrop(fp, td);
541 break;
542
543 case F_SETLK_REMOTE:
544 error = priv_check(td, PRIV_NFS_LOCKD);
545 if (error)
546 return (error);
547 flg = F_REMOTE;
548 goto do_setlk;
549
550 case F_SETLKW:
551 flg |= F_WAIT;
552 /* FALLTHROUGH F_SETLK */
553
554 case F_SETLK:
555 do_setlk:
556 FILEDESC_SLOCK(fdp);
557 if ((fp = fdtofp(fd, fdp)) == NULL) {
558 FILEDESC_SUNLOCK(fdp);
559 error = EBADF;
560 break;
561 }
562 if (fp->f_type != DTYPE_VNODE) {
563 FILEDESC_SUNLOCK(fdp);
564 error = EBADF;
565 break;
566 }
567 flp = (struct flock *)arg;
568 if (flp->l_whence == SEEK_CUR) {
569 if (fp->f_offset < 0 ||
570 (flp->l_start > 0 &&
571 fp->f_offset > OFF_MAX - flp->l_start)) {
572 FILEDESC_SUNLOCK(fdp);
573 error = EOVERFLOW;
574 break;
575 }
576 flp->l_start += fp->f_offset;
577 }
578
579 /*
580 * VOP_ADVLOCK() may block.
581 */
582 fhold(fp);
583 FILEDESC_SUNLOCK(fdp);
584 vp = fp->f_vnode;
585 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
586 switch (flp->l_type) {
587 case F_RDLCK:
588 if ((fp->f_flag & FREAD) == 0) {
589 error = EBADF;
590 break;
591 }
592 PROC_LOCK(p->p_leader);
593 p->p_leader->p_flag |= P_ADVLOCK;
594 PROC_UNLOCK(p->p_leader);
595 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
596 flp, flg);
597 break;
598 case F_WRLCK:
599 if ((fp->f_flag & FWRITE) == 0) {
600 error = EBADF;
601 break;
602 }
603 PROC_LOCK(p->p_leader);
604 p->p_leader->p_flag |= P_ADVLOCK;
605 PROC_UNLOCK(p->p_leader);
606 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK,
607 flp, flg);
608 break;
609 case F_UNLCK:
610 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK,
611 flp, flg);
612 break;
613 case F_UNLCKSYS:
614 /*
615 * Temporary api for testing remote lock
616 * infrastructure.
617 */
618 if (flg != F_REMOTE) {
619 error = EINVAL;
620 break;
621 }
622 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
623 F_UNLCKSYS, flp, flg);
624 break;
625 default:
626 error = EINVAL;
627 break;
628 }
629 VFS_UNLOCK_GIANT(vfslocked);
630 vfslocked = 0;
631 /* Check for race with close */
632 FILEDESC_SLOCK(fdp);
633 if ((unsigned) fd >= fdp->fd_nfiles ||
634 fp != fdp->fd_ofiles[fd]) {
635 FILEDESC_SUNLOCK(fdp);
636 flp->l_whence = SEEK_SET;
637 flp->l_start = 0;
638 flp->l_len = 0;
639 flp->l_type = F_UNLCK;
640 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
641 (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader,
642 F_UNLCK, flp, F_POSIX);
643 VFS_UNLOCK_GIANT(vfslocked);
644 vfslocked = 0;
645 } else
646 FILEDESC_SUNLOCK(fdp);
647 fdrop(fp, td);
648 break;
649
650 case F_GETLK:
651 FILEDESC_SLOCK(fdp);
652 if ((fp = fdtofp(fd, fdp)) == NULL) {
653 FILEDESC_SUNLOCK(fdp);
654 error = EBADF;
655 break;
656 }
657 if (fp->f_type != DTYPE_VNODE) {
658 FILEDESC_SUNLOCK(fdp);
659 error = EBADF;
660 break;
661 }
662 flp = (struct flock *)arg;
663 if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK &&
664 flp->l_type != F_UNLCK) {
665 FILEDESC_SUNLOCK(fdp);
666 error = EINVAL;
667 break;
668 }
669 if (flp->l_whence == SEEK_CUR) {
670 if ((flp->l_start > 0 &&
671 fp->f_offset > OFF_MAX - flp->l_start) ||
672 (flp->l_start < 0 &&
673 fp->f_offset < OFF_MIN - flp->l_start)) {
674 FILEDESC_SUNLOCK(fdp);
675 error = EOVERFLOW;
676 break;
677 }
678 flp->l_start += fp->f_offset;
679 }
680 /*
681 * VOP_ADVLOCK() may block.
682 */
683 fhold(fp);
684 FILEDESC_SUNLOCK(fdp);
685 vp = fp->f_vnode;
686 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
687 error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp,
688 F_POSIX);
689 VFS_UNLOCK_GIANT(vfslocked);
690 vfslocked = 0;
691 fdrop(fp, td);
692 break;
693
694 case F_RDAHEAD:
695 arg = arg ? 128 * 1024: 0;
696 /* FALLTHROUGH */
697 case F_READAHEAD:
698 FILEDESC_SLOCK(fdp);
699 if ((fp = fdtofp(fd, fdp)) == NULL) {
700 FILEDESC_SUNLOCK(fdp);
701 error = EBADF;
702 break;
703 }
704 if (fp->f_type != DTYPE_VNODE) {
705 FILEDESC_SUNLOCK(fdp);
706 error = EBADF;
707 break;
708 }
709 fhold(fp);
710 FILEDESC_SUNLOCK(fdp);
711 if (arg != 0) {
712 vp = fp->f_vnode;
713 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
714 error = vn_lock(vp, LK_SHARED);
715 if (error != 0)
716 goto readahead_vnlock_fail;
717 bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize;
718 VOP_UNLOCK(vp, 0);
719 fp->f_seqcount = (arg + bsize - 1) / bsize;
720 do {
721 new = old = fp->f_flag;
722 new |= FRDAHEAD;
723 } while (!atomic_cmpset_rel_int(&fp->f_flag, old, new));
724readahead_vnlock_fail:
725 VFS_UNLOCK_GIANT(vfslocked);
726 vfslocked = 0;
727 } else {
728 do {
729 new = old = fp->f_flag;
730 new &= ~FRDAHEAD;
731 } while (!atomic_cmpset_rel_int(&fp->f_flag, old, new));
732 }
733 fdrop(fp, td);
734 break;
735
736 default:
737 error = EINVAL;
738 break;
739 }
740 VFS_UNLOCK_GIANT(vfslocked);
741 return (error);
742}
743
744/*
745 * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD).
746 */
747static int
748do_dup(struct thread *td, int flags, int old, int new,
749 register_t *retval)
750{
751 struct filedesc *fdp;
752 struct proc *p;
753 struct file *fp;
754 struct file *delfp;
755 int error, holdleaders, maxfd;
756
757 p = td->td_proc;
758 fdp = p->p_fd;
759
760 /*
761 * Verify we have a valid descriptor to dup from and possibly to
762 * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should
763 * return EINVAL when the new descriptor is out of bounds.
764 */
765 if (old < 0)
766 return (EBADF);
767 if (new < 0)
768 return (flags & DUP_FCNTL ? EINVAL : EBADF);
769 PROC_LOCK(p);
770 maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
771 PROC_UNLOCK(p);
772 if (new >= maxfd)
773 return (flags & DUP_FCNTL ? EINVAL : EMFILE);
774
775 FILEDESC_XLOCK(fdp);
776 if (old >= fdp->fd_nfiles || fdp->fd_ofiles[old] == NULL) {
777 FILEDESC_XUNLOCK(fdp);
778 return (EBADF);
779 }
780 if (flags & DUP_FIXED && old == new) {
781 *retval = new;
782 FILEDESC_XUNLOCK(fdp);
783 return (0);
784 }
785 fp = fdp->fd_ofiles[old];
786 fhold(fp);
787
788 /*
789 * If the caller specified a file descriptor, make sure the file
790 * table is large enough to hold it, and grab it. Otherwise, just
791 * allocate a new descriptor the usual way. Since the filedesc
792 * lock may be temporarily dropped in the process, we have to look
793 * out for a race.
794 */
795 if (flags & DUP_FIXED) {
796 if (new >= fdp->fd_nfiles)
797 fdgrowtable(fdp, new + 1);
798 if (fdp->fd_ofiles[new] == NULL)
799 fdused(fdp, new);
800 } else {
801 if ((error = fdalloc(td, new, &new)) != 0) {
802 FILEDESC_XUNLOCK(fdp);
803 fdrop(fp, td);
804 return (error);
805 }
806 }
807
808 /*
809 * If the old file changed out from under us then treat it as a
810 * bad file descriptor. Userland should do its own locking to
811 * avoid this case.
812 */
813 if (fdp->fd_ofiles[old] != fp) {
814 /* we've allocated a descriptor which we won't use */
815 if (fdp->fd_ofiles[new] == NULL)
816 fdunused(fdp, new);
817 FILEDESC_XUNLOCK(fdp);
818 fdrop(fp, td);
819 return (EBADF);
820 }
821 KASSERT(old != new,
822 ("new fd is same as old"));
823
824 /*
825 * Save info on the descriptor being overwritten. We cannot close
826 * it without introducing an ownership race for the slot, since we
827 * need to drop the filedesc lock to call closef().
828 *
829 * XXX this duplicates parts of close().
830 */
831 delfp = fdp->fd_ofiles[new];
832 holdleaders = 0;
833 if (delfp != NULL) {
834 if (td->td_proc->p_fdtol != NULL) {
835 /*
836 * Ask fdfree() to sleep to ensure that all relevant
837 * process leaders can be traversed in closef().
838 */
839 fdp->fd_holdleaderscount++;
840 holdleaders = 1;
841 }
842 }
843
844 /*
845 * Duplicate the source descriptor
846 */
847 fdp->fd_ofiles[new] = fp;
848 fdp->fd_ofileflags[new] = fdp->fd_ofileflags[old] &~ UF_EXCLOSE;
849 if (new > fdp->fd_lastfile)
850 fdp->fd_lastfile = new;
851 *retval = new;
852
853 /*
854 * If we dup'd over a valid file, we now own the reference to it
855 * and must dispose of it using closef() semantics (as if a
856 * close() were performed on it).
857 *
858 * XXX this duplicates parts of close().
859 */
860 if (delfp != NULL) {
861 knote_fdclose(td, new);
862 if (delfp->f_type == DTYPE_MQUEUE)
863 mq_fdclose(td, new, delfp);
864 FILEDESC_XUNLOCK(fdp);
865 (void) closef(delfp, td);
866 if (holdleaders) {
867 FILEDESC_XLOCK(fdp);
868 fdp->fd_holdleaderscount--;
869 if (fdp->fd_holdleaderscount == 0 &&
870 fdp->fd_holdleaderswakeup != 0) {
871 fdp->fd_holdleaderswakeup = 0;
872 wakeup(&fdp->fd_holdleaderscount);
873 }
874 FILEDESC_XUNLOCK(fdp);
875 }
876 } else {
877 FILEDESC_XUNLOCK(fdp);
878 }
879 return (0);
880}
881
882/*
883 * If sigio is on the list associated with a process or process group,
884 * disable signalling from the device, remove sigio from the list and
885 * free sigio.
886 */
887void
888funsetown(struct sigio **sigiop)
889{
890 struct sigio *sigio;
891
892 SIGIO_LOCK();
893 sigio = *sigiop;
894 if (sigio == NULL) {
895 SIGIO_UNLOCK();
896 return;
897 }
898 *(sigio->sio_myref) = NULL;
899 if ((sigio)->sio_pgid < 0) {
900 struct pgrp *pg = (sigio)->sio_pgrp;
901 PGRP_LOCK(pg);
902 SLIST_REMOVE(&sigio->sio_pgrp->pg_sigiolst, sigio,
903 sigio, sio_pgsigio);
904 PGRP_UNLOCK(pg);
905 } else {
906 struct proc *p = (sigio)->sio_proc;
907 PROC_LOCK(p);
908 SLIST_REMOVE(&sigio->sio_proc->p_sigiolst, sigio,
909 sigio, sio_pgsigio);
910 PROC_UNLOCK(p);
911 }
912 SIGIO_UNLOCK();
913 crfree(sigio->sio_ucred);
914 free(sigio, M_SIGIO);
915}
916
917/*
918 * Free a list of sigio structures.
919 * We only need to lock the SIGIO_LOCK because we have made ourselves
920 * inaccessible to callers of fsetown and therefore do not need to lock
921 * the proc or pgrp struct for the list manipulation.
922 */
923void
924funsetownlst(struct sigiolst *sigiolst)
925{
926 struct proc *p;
927 struct pgrp *pg;
928 struct sigio *sigio;
929
930 sigio = SLIST_FIRST(sigiolst);
931 if (sigio == NULL)
932 return;
933 p = NULL;
934 pg = NULL;
935
936 /*
937 * Every entry of the list should belong
938 * to a single proc or pgrp.
939 */
940 if (sigio->sio_pgid < 0) {
941 pg = sigio->sio_pgrp;
942 PGRP_LOCK_ASSERT(pg, MA_NOTOWNED);
943 } else /* if (sigio->sio_pgid > 0) */ {
944 p = sigio->sio_proc;
945 PROC_LOCK_ASSERT(p, MA_NOTOWNED);
946 }
947
948 SIGIO_LOCK();
949 while ((sigio = SLIST_FIRST(sigiolst)) != NULL) {
950 *(sigio->sio_myref) = NULL;
951 if (pg != NULL) {
952 KASSERT(sigio->sio_pgid < 0,
953 ("Proc sigio in pgrp sigio list"));
954 KASSERT(sigio->sio_pgrp == pg,
955 ("Bogus pgrp in sigio list"));
956 PGRP_LOCK(pg);
957 SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio,
958 sio_pgsigio);
959 PGRP_UNLOCK(pg);
960 } else /* if (p != NULL) */ {
961 KASSERT(sigio->sio_pgid > 0,
962 ("Pgrp sigio in proc sigio list"));
963 KASSERT(sigio->sio_proc == p,
964 ("Bogus proc in sigio list"));
965 PROC_LOCK(p);
966 SLIST_REMOVE(&p->p_sigiolst, sigio, sigio,
967 sio_pgsigio);
968 PROC_UNLOCK(p);
969 }
970 SIGIO_UNLOCK();
971 crfree(sigio->sio_ucred);
972 free(sigio, M_SIGIO);
973 SIGIO_LOCK();
974 }
975 SIGIO_UNLOCK();
976}
977
978/*
979 * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg).
980 *
981 * After permission checking, add a sigio structure to the sigio list for
982 * the process or process group.
983 */
984int
985fsetown(pid_t pgid, struct sigio **sigiop)
986{
987 struct proc *proc;
988 struct pgrp *pgrp;
989 struct sigio *sigio;
990 int ret;
991
992 if (pgid == 0) {
993 funsetown(sigiop);
994 return (0);
995 }
996
997 ret = 0;
998
999 /* Allocate and fill in the new sigio out of locks. */
1000 sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK);
1001 sigio->sio_pgid = pgid;
1002 sigio->sio_ucred = crhold(curthread->td_ucred);
1003 sigio->sio_myref = sigiop;
1004
1005 sx_slock(&proctree_lock);
1006 if (pgid > 0) {
1007 proc = pfind(pgid);
1008 if (proc == NULL) {
1009 ret = ESRCH;
1010 goto fail;
1011 }
1012
1013 /*
1014 * Policy - Don't allow a process to FSETOWN a process
1015 * in another session.
1016 *
1017 * Remove this test to allow maximum flexibility or
1018 * restrict FSETOWN to the current process or process
1019 * group for maximum safety.
1020 */
1021 PROC_UNLOCK(proc);
1022 if (proc->p_session != curthread->td_proc->p_session) {
1023 ret = EPERM;
1024 goto fail;
1025 }
1026
1027 pgrp = NULL;
1028 } else /* if (pgid < 0) */ {
1029 pgrp = pgfind(-pgid);
1030 if (pgrp == NULL) {
1031 ret = ESRCH;
1032 goto fail;
1033 }
1034 PGRP_UNLOCK(pgrp);
1035
1036 /*
1037 * Policy - Don't allow a process to FSETOWN a process
1038 * in another session.
1039 *
1040 * Remove this test to allow maximum flexibility or
1041 * restrict FSETOWN to the current process or process
1042 * group for maximum safety.
1043 */
1044 if (pgrp->pg_session != curthread->td_proc->p_session) {
1045 ret = EPERM;
1046 goto fail;
1047 }
1048
1049 proc = NULL;
1050 }
1051 funsetown(sigiop);
1052 if (pgid > 0) {
1053 PROC_LOCK(proc);
1054 /*
1055 * Since funsetownlst() is called without the proctree
1056 * locked, we need to check for P_WEXIT.
1057 * XXX: is ESRCH correct?
1058 */
1059 if ((proc->p_flag & P_WEXIT) != 0) {
1060 PROC_UNLOCK(proc);
1061 ret = ESRCH;
1062 goto fail;
1063 }
1064 SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio);
1065 sigio->sio_proc = proc;
1066 PROC_UNLOCK(proc);
1067 } else {
1068 PGRP_LOCK(pgrp);
1069 SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio);
1070 sigio->sio_pgrp = pgrp;
1071 PGRP_UNLOCK(pgrp);
1072 }
1073 sx_sunlock(&proctree_lock);
1074 SIGIO_LOCK();
1075 *sigiop = sigio;
1076 SIGIO_UNLOCK();
1077 return (0);
1078
1079fail:
1080 sx_sunlock(&proctree_lock);
1081 crfree(sigio->sio_ucred);
1082 free(sigio, M_SIGIO);
1083 return (ret);
1084}
1085
1086/*
1087 * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg).
1088 */
1089pid_t
1090fgetown(sigiop)
1091 struct sigio **sigiop;
1092{
1093 pid_t pgid;
1094
1095 SIGIO_LOCK();
1096 pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0;
1097 SIGIO_UNLOCK();
1098 return (pgid);
1099}
1100
1101/*
1102 * Close a file descriptor.
1103 */
1104#ifndef _SYS_SYSPROTO_H_
1105struct close_args {
1106 int fd;
1107};
1108#endif
1109/* ARGSUSED */
1110int
1111close(td, uap)
1112 struct thread *td;
1113 struct close_args *uap;
1114{
1115
1116 return (kern_close(td, uap->fd));
1117}
1118
1119int
1120kern_close(td, fd)
1121 struct thread *td;
1122 int fd;
1123{
1124 struct filedesc *fdp;
1125 struct file *fp;
1126 int error;
1127 int holdleaders;
1128
1129 error = 0;
1130 holdleaders = 0;
1131 fdp = td->td_proc->p_fd;
1132
1133 AUDIT_SYSCLOSE(td, fd);
1134
1135 FILEDESC_XLOCK(fdp);
1136 if ((unsigned)fd >= fdp->fd_nfiles ||
1137 (fp = fdp->fd_ofiles[fd]) == NULL) {
1138 FILEDESC_XUNLOCK(fdp);
1139 return (EBADF);
1140 }
1141 fdp->fd_ofiles[fd] = NULL;
1142 fdp->fd_ofileflags[fd] = 0;
1143 fdunused(fdp, fd);
1144 if (td->td_proc->p_fdtol != NULL) {
1145 /*
1146 * Ask fdfree() to sleep to ensure that all relevant
1147 * process leaders can be traversed in closef().
1148 */
1149 fdp->fd_holdleaderscount++;
1150 holdleaders = 1;
1151 }
1152
1153 /*
1154 * We now hold the fp reference that used to be owned by the
1155 * descriptor array. We have to unlock the FILEDESC *AFTER*
1156 * knote_fdclose to prevent a race of the fd getting opened, a knote
1157 * added, and deleteing a knote for the new fd.
1158 */
1159 knote_fdclose(td, fd);
1160 if (fp->f_type == DTYPE_MQUEUE)
1161 mq_fdclose(td, fd, fp);
1162 FILEDESC_XUNLOCK(fdp);
1163
1164 error = closef(fp, td);
1165 if (holdleaders) {
1166 FILEDESC_XLOCK(fdp);
1167 fdp->fd_holdleaderscount--;
1168 if (fdp->fd_holdleaderscount == 0 &&
1169 fdp->fd_holdleaderswakeup != 0) {
1170 fdp->fd_holdleaderswakeup = 0;
1171 wakeup(&fdp->fd_holdleaderscount);
1172 }
1173 FILEDESC_XUNLOCK(fdp);
1174 }
1175 return (error);
1176}
1177
1178/*
1179 * Close open file descriptors.
1180 */
1181#ifndef _SYS_SYSPROTO_H_
1182struct closefrom_args {
1183 int lowfd;
1184};
1185#endif
1186/* ARGSUSED */
1187int
1188closefrom(struct thread *td, struct closefrom_args *uap)
1189{
1190 struct filedesc *fdp;
1191 int fd;
1192
1193 fdp = td->td_proc->p_fd;
1194 AUDIT_ARG_FD(uap->lowfd);
1195
1196 /*
1197 * Treat negative starting file descriptor values identical to
1198 * closefrom(0) which closes all files.
1199 */
1200 if (uap->lowfd < 0)
1201 uap->lowfd = 0;
1202 FILEDESC_SLOCK(fdp);
1203 for (fd = uap->lowfd; fd < fdp->fd_nfiles; fd++) {
1204 if (fdp->fd_ofiles[fd] != NULL) {
1205 FILEDESC_SUNLOCK(fdp);
1206 (void)kern_close(td, fd);
1207 FILEDESC_SLOCK(fdp);
1208 }
1209 }
1210 FILEDESC_SUNLOCK(fdp);
1211 return (0);
1212}
1213
1214#if defined(COMPAT_43)
1215/*
1216 * Return status information about a file descriptor.
1217 */
1218#ifndef _SYS_SYSPROTO_H_
1219struct ofstat_args {
1220 int fd;
1221 struct ostat *sb;
1222};
1223#endif
1224/* ARGSUSED */
1225int
1226ofstat(struct thread *td, struct ofstat_args *uap)
1227{
1228 struct ostat oub;
1229 struct stat ub;
1230 int error;
1231
1232 error = kern_fstat(td, uap->fd, &ub);
1233 if (error == 0) {
1234 cvtstat(&ub, &oub);
1235 error = copyout(&oub, uap->sb, sizeof(oub));
1236 }
1237 return (error);
1238}
1239#endif /* COMPAT_43 */
1240
1241/*
1242 * Return status information about a file descriptor.
1243 */
1244#ifndef _SYS_SYSPROTO_H_
1245struct fstat_args {
1246 int fd;
1247 struct stat *sb;
1248};
1249#endif
1250/* ARGSUSED */
1251int
1252fstat(struct thread *td, struct fstat_args *uap)
1253{
1254 struct stat ub;
1255 int error;
1256
1257 error = kern_fstat(td, uap->fd, &ub);
1258 if (error == 0)
1259 error = copyout(&ub, uap->sb, sizeof(ub));
1260 return (error);
1261}
1262
1263int
1264kern_fstat(struct thread *td, int fd, struct stat *sbp)
1265{
1266 struct file *fp;
1267 int error;
1268
1269 AUDIT_ARG_FD(fd);
1270
1271 if ((error = fget(td, fd, &fp)) != 0)
1272 return (error);
1273
1274 AUDIT_ARG_FILE(td->td_proc, fp);
1275
1276 error = fo_stat(fp, sbp, td->td_ucred, td);
1277 fdrop(fp, td);
1278#ifdef KTRACE
1279 if (error == 0 && KTRPOINT(td, KTR_STRUCT))
1280 ktrstat(sbp);
1281#endif
1282 return (error);
1283}
1284
1285/*
1286 * Return status information about a file descriptor.
1287 */
1288#ifndef _SYS_SYSPROTO_H_
1289struct nfstat_args {
1290 int fd;
1291 struct nstat *sb;
1292};
1293#endif
1294/* ARGSUSED */
1295int
1296nfstat(struct thread *td, struct nfstat_args *uap)
1297{
1298 struct nstat nub;
1299 struct stat ub;
1300 int error;
1301
1302 error = kern_fstat(td, uap->fd, &ub);
1303 if (error == 0) {
1304 cvtnstat(&ub, &nub);
1305 error = copyout(&nub, uap->sb, sizeof(nub));
1306 }
1307 return (error);
1308}
1309
1310/*
1311 * Return pathconf information about a file descriptor.
1312 */
1313#ifndef _SYS_SYSPROTO_H_
1314struct fpathconf_args {
1315 int fd;
1316 int name;
1317};
1318#endif
1319/* ARGSUSED */
1320int
1321fpathconf(struct thread *td, struct fpathconf_args *uap)
1322{
1323 struct file *fp;
1324 struct vnode *vp;
1325 int error;
1326
1327 if ((error = fget(td, uap->fd, &fp)) != 0)
1328 return (error);
1329
1330 /* If asynchronous I/O is available, it works for all descriptors. */
1331 if (uap->name == _PC_ASYNC_IO) {
1332 td->td_retval[0] = async_io_version;
1333 goto out;
1334 }
1335 vp = fp->f_vnode;
1336 if (vp != NULL) {
1337 int vfslocked;
1338 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
1339 vn_lock(vp, LK_SHARED | LK_RETRY);
1340 error = VOP_PATHCONF(vp, uap->name, td->td_retval);
1341 VOP_UNLOCK(vp, 0);
1342 VFS_UNLOCK_GIANT(vfslocked);
1343 } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) {
1344 if (uap->name != _PC_PIPE_BUF) {
1345 error = EINVAL;
1346 } else {
1347 td->td_retval[0] = PIPE_BUF;
1348 error = 0;
1349 }
1350 } else {
1351 error = EOPNOTSUPP;
1352 }
1353out:
1354 fdrop(fp, td);
1355 return (error);
1356}
1357
1358/*
1359 * Grow the file table to accomodate (at least) nfd descriptors. This may
1360 * block and drop the filedesc lock, but it will reacquire it before
1361 * returning.
1362 */
1363static void
1364fdgrowtable(struct filedesc *fdp, int nfd)
1365{
1366 struct filedesc0 *fdp0;
1367 struct freetable *fo;
1368 struct file **ntable;
1369 struct file **otable;
1370 char *nfileflags;
1371 int nnfiles, onfiles;
1372 NDSLOTTYPE *nmap;
1373
1374 FILEDESC_XLOCK_ASSERT(fdp);
1375
1376 KASSERT(fdp->fd_nfiles > 0,
1377 ("zero-length file table"));
1378
1379 /* compute the size of the new table */
1380 onfiles = fdp->fd_nfiles;
1381 nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */
1382 if (nnfiles <= onfiles)
1383 /* the table is already large enough */
1384 return;
1385
1386 /* allocate a new table and (if required) new bitmaps */
1387 FILEDESC_XUNLOCK(fdp);
1388 ntable = malloc((nnfiles * OFILESIZE) + sizeof(struct freetable),
1389 M_FILEDESC, M_ZERO | M_WAITOK);
1390 nfileflags = (char *)&ntable[nnfiles];
1391 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles))
1392 nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE,
1393 M_FILEDESC, M_ZERO | M_WAITOK);
1394 else
1395 nmap = NULL;
1396 FILEDESC_XLOCK(fdp);
1397
1398 /*
1399 * We now have new tables ready to go. Since we dropped the
1400 * filedesc lock to call malloc(), watch out for a race.
1401 */
1402 onfiles = fdp->fd_nfiles;
1403 if (onfiles >= nnfiles) {
1404 /* we lost the race, but that's OK */
1405 free(ntable, M_FILEDESC);
1406 if (nmap != NULL)
1407 free(nmap, M_FILEDESC);
1408 return;
1409 }
1410 bcopy(fdp->fd_ofiles, ntable, onfiles * sizeof(*ntable));
1411 bcopy(fdp->fd_ofileflags, nfileflags, onfiles);
1412 otable = fdp->fd_ofiles;
1413 fdp->fd_ofileflags = nfileflags;
1414 fdp->fd_ofiles = ntable;
1415 /*
1416 * We must preserve ofiles until the process exits because we can't
1417 * be certain that no threads have references to the old table via
1418 * _fget().
1419 */
1420 if (onfiles > NDFILE) {
1421 fo = (struct freetable *)&otable[onfiles];
1422 fdp0 = (struct filedesc0 *)fdp;
1423 fo->ft_table = otable;
1424 SLIST_INSERT_HEAD(&fdp0->fd_free, fo, ft_next);
1425 }
1426 if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) {
1427 bcopy(fdp->fd_map, nmap, NDSLOTS(onfiles) * sizeof(*nmap));
1428 if (NDSLOTS(onfiles) > NDSLOTS(NDFILE))
1429 free(fdp->fd_map, M_FILEDESC);
1430 fdp->fd_map = nmap;
1431 }
1432 fdp->fd_nfiles = nnfiles;
1433}
1434
1435/*
1436 * Allocate a file descriptor for the process.
1437 */
1438int
1439fdalloc(struct thread *td, int minfd, int *result)
1440{
1441 struct proc *p = td->td_proc;
1442 struct filedesc *fdp = p->p_fd;
1443 int fd = -1, maxfd;
1444
1445 FILEDESC_XLOCK_ASSERT(fdp);
1446
1447 if (fdp->fd_freefile > minfd)
1448 minfd = fdp->fd_freefile;
1449
1450 PROC_LOCK(p);
1451 maxfd = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
1452 PROC_UNLOCK(p);
1453
1454 /*
1455 * Search the bitmap for a free descriptor. If none is found, try
1456 * to grow the file table. Keep at it until we either get a file
1457 * descriptor or run into process or system limits; fdgrowtable()
1458 * may drop the filedesc lock, so we're in a race.
1459 */
1460 for (;;) {
1461 fd = fd_first_free(fdp, minfd, fdp->fd_nfiles);
1462 if (fd >= maxfd)
1463 return (EMFILE);
1464 if (fd < fdp->fd_nfiles)
1465 break;
1466 fdgrowtable(fdp, min(fdp->fd_nfiles * 2, maxfd));
1467 }
1468
1469 /*
1470 * Perform some sanity checks, then mark the file descriptor as
1471 * used and return it to the caller.
1472 */
1473 KASSERT(!fdisused(fdp, fd),
1474 ("fd_first_free() returned non-free descriptor"));
1475 KASSERT(fdp->fd_ofiles[fd] == NULL,
1476 ("free descriptor isn't"));
1477 fdp->fd_ofileflags[fd] = 0; /* XXX needed? */
1478 fdused(fdp, fd);
1479 *result = fd;
1480 return (0);
1481}
1482
1483/*
1484 * Check to see whether n user file descriptors are available to the process
1485 * p.
1486 */
1487int
1488fdavail(struct thread *td, int n)
1489{
1490 struct proc *p = td->td_proc;
1491 struct filedesc *fdp = td->td_proc->p_fd;
1492 struct file **fpp;
1493 int i, lim, last;
1494
1495 FILEDESC_LOCK_ASSERT(fdp);
1496
1497 PROC_LOCK(p);
1498 lim = min((int)lim_cur(p, RLIMIT_NOFILE), maxfilesperproc);
1499 PROC_UNLOCK(p);
1500 if ((i = lim - fdp->fd_nfiles) > 0 && (n -= i) <= 0)
1501 return (1);
1502 last = min(fdp->fd_nfiles, lim);
1503 fpp = &fdp->fd_ofiles[fdp->fd_freefile];
1504 for (i = last - fdp->fd_freefile; --i >= 0; fpp++) {
1505 if (*fpp == NULL && --n <= 0)
1506 return (1);
1507 }
1508 return (0);
1509}
1510
1511/*
1512 * Create a new open file structure and allocate a file decriptor for the
1513 * process that refers to it. We add one reference to the file for the
1514 * descriptor table and one reference for resultfp. This is to prevent us
1515 * being preempted and the entry in the descriptor table closed after we
1516 * release the FILEDESC lock.
1517 */
1518int
1519falloc(struct thread *td, struct file **resultfp, int *resultfd)
1520{
1521 struct proc *p = td->td_proc;
1522 struct file *fp;
1523 int error, i;
1524 int maxuserfiles = maxfiles - (maxfiles / 20);
1525 static struct timeval lastfail;
1526 static int curfail;
1527
1528 fp = uma_zalloc(file_zone, M_WAITOK | M_ZERO);
1529 if ((openfiles >= maxuserfiles &&
1530 priv_check(td, PRIV_MAXFILES) != 0) ||
1531 openfiles >= maxfiles) {
1532 if (ppsratecheck(&lastfail, &curfail, 1)) {
1533 printf("kern.maxfiles limit exceeded by uid %i, please see tuning(7).\n",
1534 td->td_ucred->cr_ruid);
1535 }
1536 uma_zfree(file_zone, fp);
1537 return (ENFILE);
1538 }
1539 atomic_add_int(&openfiles, 1);
1540
1541 /*
1542 * If the process has file descriptor zero open, add the new file
1543 * descriptor to the list of open files at that point, otherwise
1544 * put it at the front of the list of open files.
1545 */
1546 refcount_init(&fp->f_count, 1);
1547 if (resultfp)
1548 fhold(fp);
1549 fp->f_cred = crhold(td->td_ucred);
1550 fp->f_ops = &badfileops;
1551 fp->f_data = NULL;
1552 fp->f_vnode = NULL;
1553 FILEDESC_XLOCK(p->p_fd);
1554 if ((error = fdalloc(td, 0, &i))) {
1555 FILEDESC_XUNLOCK(p->p_fd);
1556 fdrop(fp, td);
1557 if (resultfp)
1558 fdrop(fp, td);
1559 return (error);
1560 }
1561 p->p_fd->fd_ofiles[i] = fp;
1562 FILEDESC_XUNLOCK(p->p_fd);
1563 if (resultfp)
1564 *resultfp = fp;
1565 if (resultfd)
1566 *resultfd = i;
1567 return (0);
1568}
1569
1570/*
1571 * Build a new filedesc structure from another.
1572 * Copy the current, root, and jail root vnode references.
1573 */
1574struct filedesc *
1575fdinit(struct filedesc *fdp)
1576{
1577 struct filedesc0 *newfdp;
1578
1579 newfdp = malloc(sizeof *newfdp, M_FILEDESC, M_WAITOK | M_ZERO);
1580 FILEDESC_LOCK_INIT(&newfdp->fd_fd);
1581 if (fdp != NULL) {
1582 FILEDESC_XLOCK(fdp);
1583 newfdp->fd_fd.fd_cdir = fdp->fd_cdir;
1584 if (newfdp->fd_fd.fd_cdir)
1585 VREF(newfdp->fd_fd.fd_cdir);
1586 newfdp->fd_fd.fd_rdir = fdp->fd_rdir;
1587 if (newfdp->fd_fd.fd_rdir)
1588 VREF(newfdp->fd_fd.fd_rdir);
1589 newfdp->fd_fd.fd_jdir = fdp->fd_jdir;
1590 if (newfdp->fd_fd.fd_jdir)
1591 VREF(newfdp->fd_fd.fd_jdir);
1592 FILEDESC_XUNLOCK(fdp);
1593 }
1594
1595 /* Create the file descriptor table. */
1596 newfdp->fd_fd.fd_refcnt = 1;
1597 newfdp->fd_fd.fd_holdcnt = 1;
1598 newfdp->fd_fd.fd_cmask = CMASK;
1599 newfdp->fd_fd.fd_ofiles = newfdp->fd_dfiles;
1600 newfdp->fd_fd.fd_ofileflags = newfdp->fd_dfileflags;
1601 newfdp->fd_fd.fd_nfiles = NDFILE;
1602 newfdp->fd_fd.fd_map = newfdp->fd_dmap;
1603 newfdp->fd_fd.fd_lastfile = -1;
1604 return (&newfdp->fd_fd);
1605}
1606
1607static struct filedesc *
1608fdhold(struct proc *p)
1609{
1610 struct filedesc *fdp;
1611
1612 mtx_lock(&fdesc_mtx);
1613 fdp = p->p_fd;
1614 if (fdp != NULL)
1615 fdp->fd_holdcnt++;
1616 mtx_unlock(&fdesc_mtx);
1617 return (fdp);
1618}
1619
1620static void
1621fddrop(struct filedesc *fdp)
1622{
1623 struct filedesc0 *fdp0;
1624 struct freetable *ft;
1625 int i;
1626
1627 mtx_lock(&fdesc_mtx);
1628 i = --fdp->fd_holdcnt;
1629 mtx_unlock(&fdesc_mtx);
1630 if (i > 0)
1631 return;
1632
1633 FILEDESC_LOCK_DESTROY(fdp);
1634 fdp0 = (struct filedesc0 *)fdp;
1635 while ((ft = SLIST_FIRST(&fdp0->fd_free)) != NULL) {
1636 SLIST_REMOVE_HEAD(&fdp0->fd_free, ft_next);
1637 free(ft->ft_table, M_FILEDESC);
1638 }
1639 free(fdp, M_FILEDESC);
1640}
1641
1642/*
1643 * Share a filedesc structure.
1644 */
1645struct filedesc *
1646fdshare(struct filedesc *fdp)
1647{
1648
1649 FILEDESC_XLOCK(fdp);
1650 fdp->fd_refcnt++;
1651 FILEDESC_XUNLOCK(fdp);
1652 return (fdp);
1653}
1654
1655/*
1656 * Unshare a filedesc structure, if necessary by making a copy
1657 */
1658void
1659fdunshare(struct proc *p, struct thread *td)
1660{
1661
1662 FILEDESC_XLOCK(p->p_fd);
1663 if (p->p_fd->fd_refcnt > 1) {
1664 struct filedesc *tmp;
1665
1666 FILEDESC_XUNLOCK(p->p_fd);
1667 tmp = fdcopy(p->p_fd);
1668 fdfree(td);
1669 p->p_fd = tmp;
1670 } else
1671 FILEDESC_XUNLOCK(p->p_fd);
1672}
1673
1674/*
1675 * Copy a filedesc structure. A NULL pointer in returns a NULL reference,
1676 * this is to ease callers, not catch errors.
1677 */
1678struct filedesc *
1679fdcopy(struct filedesc *fdp)
1680{
1681 struct filedesc *newfdp;
1682 int i;
1683
1684 /* Certain daemons might not have file descriptors. */
1685 if (fdp == NULL)
1686 return (NULL);
1687
1688 newfdp = fdinit(fdp);
1689 FILEDESC_SLOCK(fdp);
1690 while (fdp->fd_lastfile >= newfdp->fd_nfiles) {
1691 FILEDESC_SUNLOCK(fdp);
1692 FILEDESC_XLOCK(newfdp);
1693 fdgrowtable(newfdp, fdp->fd_lastfile + 1);
1694 FILEDESC_XUNLOCK(newfdp);
1695 FILEDESC_SLOCK(fdp);
1696 }
1697 /* copy everything except kqueue descriptors */
1698 newfdp->fd_freefile = -1;
1699 for (i = 0; i <= fdp->fd_lastfile; ++i) {
1700 if (fdisused(fdp, i) &&
1701 fdp->fd_ofiles[i]->f_type != DTYPE_KQUEUE &&
1702 fdp->fd_ofiles[i]->f_ops != &badfileops) {
1703 newfdp->fd_ofiles[i] = fdp->fd_ofiles[i];
1704 newfdp->fd_ofileflags[i] = fdp->fd_ofileflags[i];
1705 fhold(newfdp->fd_ofiles[i]);
1706 newfdp->fd_lastfile = i;
1707 } else {
1708 if (newfdp->fd_freefile == -1)
1709 newfdp->fd_freefile = i;
1710 }
1711 }
1712 newfdp->fd_cmask = fdp->fd_cmask;
1713 FILEDESC_SUNLOCK(fdp);
1714 FILEDESC_XLOCK(newfdp);
1715 for (i = 0; i <= newfdp->fd_lastfile; ++i)
1716 if (newfdp->fd_ofiles[i] != NULL)
1717 fdused(newfdp, i);
1718 if (newfdp->fd_freefile == -1)
1719 newfdp->fd_freefile = i;
1720 FILEDESC_XUNLOCK(newfdp);
1721 return (newfdp);
1722}
1723
1724/*
1725 * Release a filedesc structure.
1726 */
1727void
1728fdfree(struct thread *td)
1729{
1730 struct filedesc *fdp;
1731 struct file **fpp;
1732 int i, locked;
1733 struct filedesc_to_leader *fdtol;
1734 struct file *fp;
1735 struct vnode *cdir, *jdir, *rdir, *vp;
1736 struct flock lf;
1737
1738 /* Certain daemons might not have file descriptors. */
1739 fdp = td->td_proc->p_fd;
1740 if (fdp == NULL)
1741 return;
1742
1743 /* Check for special need to clear POSIX style locks */
1744 fdtol = td->td_proc->p_fdtol;
1745 if (fdtol != NULL) {
1746 FILEDESC_XLOCK(fdp);
1747 KASSERT(fdtol->fdl_refcount > 0,
1748 ("filedesc_to_refcount botch: fdl_refcount=%d",
1749 fdtol->fdl_refcount));
1750 if (fdtol->fdl_refcount == 1 &&
1751 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
1752 for (i = 0, fpp = fdp->fd_ofiles;
1753 i <= fdp->fd_lastfile;
1754 i++, fpp++) {
1755 if (*fpp == NULL ||
1756 (*fpp)->f_type != DTYPE_VNODE)
1757 continue;
1758 fp = *fpp;
1759 fhold(fp);
1760 FILEDESC_XUNLOCK(fdp);
1761 lf.l_whence = SEEK_SET;
1762 lf.l_start = 0;
1763 lf.l_len = 0;
1764 lf.l_type = F_UNLCK;
1765 vp = fp->f_vnode;
1766 locked = VFS_LOCK_GIANT(vp->v_mount);
1767 (void) VOP_ADVLOCK(vp,
1768 (caddr_t)td->td_proc->
1769 p_leader,
1770 F_UNLCK,
1771 &lf,
1772 F_POSIX);
1773 VFS_UNLOCK_GIANT(locked);
1774 FILEDESC_XLOCK(fdp);
1775 fdrop(fp, td);
1776 fpp = fdp->fd_ofiles + i;
1777 }
1778 }
1779 retry:
1780 if (fdtol->fdl_refcount == 1) {
1781 if (fdp->fd_holdleaderscount > 0 &&
1782 (td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
1783 /*
1784 * close() or do_dup() has cleared a reference
1785 * in a shared file descriptor table.
1786 */
1787 fdp->fd_holdleaderswakeup = 1;
1788 sx_sleep(&fdp->fd_holdleaderscount,
1789 FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0);
1790 goto retry;
1791 }
1792 if (fdtol->fdl_holdcount > 0) {
1793 /*
1794 * Ensure that fdtol->fdl_leader remains
1795 * valid in closef().
1796 */
1797 fdtol->fdl_wakeup = 1;
1798 sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK,
1799 "fdlhold", 0);
1800 goto retry;
1801 }
1802 }
1803 fdtol->fdl_refcount--;
1804 if (fdtol->fdl_refcount == 0 &&
1805 fdtol->fdl_holdcount == 0) {
1806 fdtol->fdl_next->fdl_prev = fdtol->fdl_prev;
1807 fdtol->fdl_prev->fdl_next = fdtol->fdl_next;
1808 } else
1809 fdtol = NULL;
1810 td->td_proc->p_fdtol = NULL;
1811 FILEDESC_XUNLOCK(fdp);
1812 if (fdtol != NULL)
1813 free(fdtol, M_FILEDESC_TO_LEADER);
1814 }
1815 FILEDESC_XLOCK(fdp);
1816 i = --fdp->fd_refcnt;
1817 FILEDESC_XUNLOCK(fdp);
1818 if (i > 0)
1819 return;
1820
1821 fpp = fdp->fd_ofiles;
1822 for (i = fdp->fd_lastfile; i-- >= 0; fpp++) {
1823 if (*fpp) {
1824 FILEDESC_XLOCK(fdp);
1825 fp = *fpp;
1826 *fpp = NULL;
1827 FILEDESC_XUNLOCK(fdp);
1828 (void) closef(fp, td);
1829 }
1830 }
1831 FILEDESC_XLOCK(fdp);
1832
1833 /* XXX This should happen earlier. */
1834 mtx_lock(&fdesc_mtx);
1835 td->td_proc->p_fd = NULL;
1836 mtx_unlock(&fdesc_mtx);
1837
1838 if (fdp->fd_nfiles > NDFILE)
1839 free(fdp->fd_ofiles, M_FILEDESC);
1840 if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE))
1841 free(fdp->fd_map, M_FILEDESC);
1842
1843 fdp->fd_nfiles = 0;
1844
1845 cdir = fdp->fd_cdir;
1846 fdp->fd_cdir = NULL;
1847 rdir = fdp->fd_rdir;
1848 fdp->fd_rdir = NULL;
1849 jdir = fdp->fd_jdir;
1850 fdp->fd_jdir = NULL;
1851 FILEDESC_XUNLOCK(fdp);
1852
1853 if (cdir) {
1854 locked = VFS_LOCK_GIANT(cdir->v_mount);
1855 vrele(cdir);
1856 VFS_UNLOCK_GIANT(locked);
1857 }
1858 if (rdir) {
1859 locked = VFS_LOCK_GIANT(rdir->v_mount);
1860 vrele(rdir);
1861 VFS_UNLOCK_GIANT(locked);
1862 }
1863 if (jdir) {
1864 locked = VFS_LOCK_GIANT(jdir->v_mount);
1865 vrele(jdir);
1866 VFS_UNLOCK_GIANT(locked);
1867 }
1868
1869 fddrop(fdp);
1870}
1871
1872/*
1873 * For setugid programs, we don't want to people to use that setugidness
1874 * to generate error messages which write to a file which otherwise would
1875 * otherwise be off-limits to the process. We check for filesystems where
1876 * the vnode can change out from under us after execve (like [lin]procfs).
1877 *
1878 * Since setugidsafety calls this only for fd 0, 1 and 2, this check is
1879 * sufficient. We also don't check for setugidness since we know we are.
1880 */
1881static int
1882is_unsafe(struct file *fp)
1883{
1884 if (fp->f_type == DTYPE_VNODE) {
1885 struct vnode *vp = fp->f_vnode;
1886
1887 if ((vp->v_vflag & VV_PROCDEP) != 0)
1888 return (1);
1889 }
1890 return (0);
1891}
1892
1893/*
1894 * Make this setguid thing safe, if at all possible.
1895 */
1896void
1897setugidsafety(struct thread *td)
1898{
1899 struct filedesc *fdp;
1900 int i;
1901
1902 /* Certain daemons might not have file descriptors. */
1903 fdp = td->td_proc->p_fd;
1904 if (fdp == NULL)
1905 return;
1906
1907 /*
1908 * Note: fdp->fd_ofiles may be reallocated out from under us while
1909 * we are blocked in a close. Be careful!
1910 */
1911 FILEDESC_XLOCK(fdp);
1912 for (i = 0; i <= fdp->fd_lastfile; i++) {
1913 if (i > 2)
1914 break;
1915 if (fdp->fd_ofiles[i] && is_unsafe(fdp->fd_ofiles[i])) {
1916 struct file *fp;
1917
1918 knote_fdclose(td, i);
1919 /*
1920 * NULL-out descriptor prior to close to avoid
1921 * a race while close blocks.
1922 */
1923 fp = fdp->fd_ofiles[i];
1924 fdp->fd_ofiles[i] = NULL;
1925 fdp->fd_ofileflags[i] = 0;
1926 fdunused(fdp, i);
1927 FILEDESC_XUNLOCK(fdp);
1928 (void) closef(fp, td);
1929 FILEDESC_XLOCK(fdp);
1930 }
1931 }
1932 FILEDESC_XUNLOCK(fdp);
1933}
1934
1935/*
1936 * If a specific file object occupies a specific file descriptor, close the
1937 * file descriptor entry and drop a reference on the file object. This is a
1938 * convenience function to handle a subsequent error in a function that calls
1939 * falloc() that handles the race that another thread might have closed the
1940 * file descriptor out from under the thread creating the file object.
1941 */
1942void
1943fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td)
1944{
1945
1946 FILEDESC_XLOCK(fdp);
1947 if (fdp->fd_ofiles[idx] == fp) {
1948 fdp->fd_ofiles[idx] = NULL;
1949 fdunused(fdp, idx);
1950 FILEDESC_XUNLOCK(fdp);
1951 fdrop(fp, td);
1952 } else
1953 FILEDESC_XUNLOCK(fdp);
1954}
1955
1956/*
1957 * Close any files on exec?
1958 */
1959void
1960fdcloseexec(struct thread *td)
1961{
1962 struct filedesc *fdp;
1963 int i;
1964
1965 /* Certain daemons might not have file descriptors. */
1966 fdp = td->td_proc->p_fd;
1967 if (fdp == NULL)
1968 return;
1969
1970 FILEDESC_XLOCK(fdp);
1971
1972 /*
1973 * We cannot cache fd_ofiles or fd_ofileflags since operations
1974 * may block and rip them out from under us.
1975 */
1976 for (i = 0; i <= fdp->fd_lastfile; i++) {
1977 if (fdp->fd_ofiles[i] != NULL &&
1978 (fdp->fd_ofiles[i]->f_type == DTYPE_MQUEUE ||
1979 (fdp->fd_ofileflags[i] & UF_EXCLOSE))) {
1980 struct file *fp;
1981
1982 knote_fdclose(td, i);
1983 /*
1984 * NULL-out descriptor prior to close to avoid
1985 * a race while close blocks.
1986 */
1987 fp = fdp->fd_ofiles[i];
1988 fdp->fd_ofiles[i] = NULL;
1989 fdp->fd_ofileflags[i] = 0;
1990 fdunused(fdp, i);
1991 if (fp->f_type == DTYPE_MQUEUE)
1992 mq_fdclose(td, i, fp);
1993 FILEDESC_XUNLOCK(fdp);
1994 (void) closef(fp, td);
1995 FILEDESC_XLOCK(fdp);
1996 }
1997 }
1998 FILEDESC_XUNLOCK(fdp);
1999}
2000
2001/*
2002 * It is unsafe for set[ug]id processes to be started with file
2003 * descriptors 0..2 closed, as these descriptors are given implicit
2004 * significance in the Standard C library. fdcheckstd() will create a
2005 * descriptor referencing /dev/null for each of stdin, stdout, and
2006 * stderr that is not already open.
2007 */
2008int
2009fdcheckstd(struct thread *td)
2010{
2011 struct filedesc *fdp;
2012 register_t retval, save;
2013 int i, error, devnull;
2014
2015 fdp = td->td_proc->p_fd;
2016 if (fdp == NULL)
2017 return (0);
2018 KASSERT(fdp->fd_refcnt == 1, ("the fdtable should not be shared"));
2019 devnull = -1;
2020 error = 0;
2021 for (i = 0; i < 3; i++) {
2022 if (fdp->fd_ofiles[i] != NULL)
2023 continue;
2024 if (devnull < 0) {
2025 save = td->td_retval[0];
2026 error = kern_open(td, "/dev/null", UIO_SYSSPACE,
2027 O_RDWR, 0);
2028 devnull = td->td_retval[0];
2029 td->td_retval[0] = save;
2030 if (error)
2031 break;
2032 KASSERT(devnull == i, ("oof, we didn't get our fd"));
2033 } else {
2034 error = do_dup(td, DUP_FIXED, devnull, i, &retval);
2035 if (error != 0)
2036 break;
2037 }
2038 }
2039 return (error);
2040}
2041
2042/*
2043 * Internal form of close. Decrement reference count on file structure.
2044 * Note: td may be NULL when closing a file that was being passed in a
2045 * message.
2046 *
2047 * XXXRW: Giant is not required for the caller, but often will be held; this
2048 * makes it moderately likely the Giant will be recursed in the VFS case.
2049 */
2050int
2051closef(struct file *fp, struct thread *td)
2052{
2053 struct vnode *vp;
2054 struct flock lf;
2055 struct filedesc_to_leader *fdtol;
2056 struct filedesc *fdp;
2057
2058 /*
2059 * POSIX record locking dictates that any close releases ALL
2060 * locks owned by this process. This is handled by setting
2061 * a flag in the unlock to free ONLY locks obeying POSIX
2062 * semantics, and not to free BSD-style file locks.
2063 * If the descriptor was in a message, POSIX-style locks
2064 * aren't passed with the descriptor, and the thread pointer
2065 * will be NULL. Callers should be careful only to pass a
2066 * NULL thread pointer when there really is no owning
2067 * context that might have locks, or the locks will be
2068 * leaked.
2069 */
2070 if (fp->f_type == DTYPE_VNODE && td != NULL) {
2071 int vfslocked;
2072
2073 vp = fp->f_vnode;
2074 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
2075 if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) {
2076 lf.l_whence = SEEK_SET;
2077 lf.l_start = 0;
2078 lf.l_len = 0;
2079 lf.l_type = F_UNLCK;
2080 (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader,
2081 F_UNLCK, &lf, F_POSIX);
2082 }
2083 fdtol = td->td_proc->p_fdtol;
2084 if (fdtol != NULL) {
2085 /*
2086 * Handle special case where file descriptor table is
2087 * shared between multiple process leaders.
2088 */
2089 fdp = td->td_proc->p_fd;
2090 FILEDESC_XLOCK(fdp);
2091 for (fdtol = fdtol->fdl_next;
2092 fdtol != td->td_proc->p_fdtol;
2093 fdtol = fdtol->fdl_next) {
2094 if ((fdtol->fdl_leader->p_flag &
2095 P_ADVLOCK) == 0)
2096 continue;
2097 fdtol->fdl_holdcount++;
2098 FILEDESC_XUNLOCK(fdp);
2099 lf.l_whence = SEEK_SET;
2100 lf.l_start = 0;
2101 lf.l_len = 0;
2102 lf.l_type = F_UNLCK;
2103 vp = fp->f_vnode;
2104 (void) VOP_ADVLOCK(vp,
2105 (caddr_t)fdtol->fdl_leader,
2106 F_UNLCK, &lf, F_POSIX);
2107 FILEDESC_XLOCK(fdp);
2108 fdtol->fdl_holdcount--;
2109 if (fdtol->fdl_holdcount == 0 &&
2110 fdtol->fdl_wakeup != 0) {
2111 fdtol->fdl_wakeup = 0;
2112 wakeup(fdtol);
2113 }
2114 }
2115 FILEDESC_XUNLOCK(fdp);
2116 }
2117 VFS_UNLOCK_GIANT(vfslocked);
2118 }
2119 return (fdrop(fp, td));
2120}
2121
2122/*
2123 * Initialize the file pointer with the specified properties.
2124 *
2125 * The ops are set with release semantics to be certain that the flags, type,
2126 * and data are visible when ops is. This is to prevent ops methods from being
2127 * called with bad data.
2128 */
2129void
2130finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops)
2131{
2132 fp->f_data = data;
2133 fp->f_flag = flag;
2134 fp->f_type = type;
2135 atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops);
2136}
2137
2138struct file *
2139fget_unlocked(struct filedesc *fdp, int fd)
2140{
2141 struct file *fp;
2142 u_int count;
2143
2144 if (fd < 0 || fd >= fdp->fd_nfiles)
2145 return (NULL);
2146 /*
2147 * Fetch the descriptor locklessly. We avoid fdrop() races by
2148 * never raising a refcount above 0. To accomplish this we have
2149 * to use a cmpset loop rather than an atomic_add. The descriptor
2150 * must be re-verified once we acquire a reference to be certain
2151 * that the identity is still correct and we did not lose a race
2152 * due to preemption.
2153 */
2154 for (;;) {
2155 fp = fdp->fd_ofiles[fd];
2156 if (fp == NULL)
2157 break;
2158 count = fp->f_count;
2159 if (count == 0)
2160 continue;
2161 /*
2162 * Use an acquire barrier to prevent caching of fd_ofiles
2163 * so it is refreshed for verification.
2164 */
2165 if (atomic_cmpset_acq_int(&fp->f_count, count, count + 1) != 1)
2166 continue;
2167 if (fp == fdp->fd_ofiles[fd])
2168 break;
2169 fdrop(fp, curthread);
2170 }
2171
2172 return (fp);
2173}
2174
2175/*
2176 * Extract the file pointer associated with the specified descriptor for the
2177 * current user process.
2178 *
2179 * If the descriptor doesn't exist or doesn't match 'flags', EBADF is
2180 * returned.
2181 *
2182 * If an error occured the non-zero error is returned and *fpp is set to
2183 * NULL. Otherwise *fpp is held and set and zero is returned. Caller is
2184 * responsible for fdrop().
2185 */
2186static __inline int
2187_fget(struct thread *td, int fd, struct file **fpp, int flags)
2188{
2189 struct filedesc *fdp;
2190 struct file *fp;
2191
2192 *fpp = NULL;
2193 if (td == NULL || (fdp = td->td_proc->p_fd) == NULL)
2194 return (EBADF);
2195 if ((fp = fget_unlocked(fdp, fd)) == NULL)
2196 return (EBADF);
2197 if (fp->f_ops == &badfileops) {
2198 fdrop(fp, td);
2199 return (EBADF);
2200 }
2201 /*
2202 * FREAD and FWRITE failure return EBADF as per POSIX.
2203 *
2204 * Only one flag, or 0, may be specified.
2205 */
2206 if ((flags == FREAD && (fp->f_flag & FREAD) == 0) ||
2207 (flags == FWRITE && (fp->f_flag & FWRITE) == 0)) {
2208 fdrop(fp, td);
2209 return (EBADF);
2210 }
2211 *fpp = fp;
2212 return (0);
2213}
2214
2215int
2216fget(struct thread *td, int fd, struct file **fpp)
2217{
2218
2219 return(_fget(td, fd, fpp, 0));
2220}
2221
2222int
2223fget_read(struct thread *td, int fd, struct file **fpp)
2224{
2225
2226 return(_fget(td, fd, fpp, FREAD));
2227}
2228
2229int
2230fget_write(struct thread *td, int fd, struct file **fpp)
2231{
2232
2233 return(_fget(td, fd, fpp, FWRITE));
2234}
2235
2236/*
2237 * Like fget() but loads the underlying vnode, or returns an error if the
2238 * descriptor does not represent a vnode. Note that pipes use vnodes but
2239 * never have VM objects. The returned vnode will be vref()'d.
2240 *
2241 * XXX: what about the unused flags ?
2242 */
2243static __inline int
2244_fgetvp(struct thread *td, int fd, struct vnode **vpp, int flags)
2245{
2246 struct file *fp;
2247 int error;
2248
2249 *vpp = NULL;
2250 if ((error = _fget(td, fd, &fp, flags)) != 0)
2251 return (error);
2252 if (fp->f_vnode == NULL) {
2253 error = EINVAL;
2254 } else {
2255 *vpp = fp->f_vnode;
2256 vref(*vpp);
2257 }
2258 fdrop(fp, td);
2259
2260 return (error);
2261}
2262
2263int
2264fgetvp(struct thread *td, int fd, struct vnode **vpp)
2265{
2266
2267 return (_fgetvp(td, fd, vpp, 0));
2268}
2269
2270int
2271fgetvp_read(struct thread *td, int fd, struct vnode **vpp)
2272{
2273
2274 return (_fgetvp(td, fd, vpp, FREAD));
2275}
2276
2277#ifdef notyet
2278int
2279fgetvp_write(struct thread *td, int fd, struct vnode **vpp)
2280{
2281
2282 return (_fgetvp(td, fd, vpp, FWRITE));
2283}
2284#endif
2285
2286/*
2287 * Like fget() but loads the underlying socket, or returns an error if the
2288 * descriptor does not represent a socket.
2289 *
2290 * We bump the ref count on the returned socket. XXX Also obtain the SX lock
2291 * in the future.
2292 *
2293 * Note: fgetsock() and fputsock() are deprecated, as consumers should rely
2294 * on their file descriptor reference to prevent the socket from being free'd
2295 * during use.
2296 */
2297int
2298fgetsock(struct thread *td, int fd, struct socket **spp, u_int *fflagp)
2299{
2300 struct file *fp;
2301 int error;
2302
2303 *spp = NULL;
2304 if (fflagp != NULL)
2305 *fflagp = 0;
2306 if ((error = _fget(td, fd, &fp, 0)) != 0)
2307 return (error);
2308 if (fp->f_type != DTYPE_SOCKET) {
2309 error = ENOTSOCK;
2310 } else {
2311 *spp = fp->f_data;
2312 if (fflagp)
2313 *fflagp = fp->f_flag;
2314 SOCK_LOCK(*spp);
2315 soref(*spp);
2316 SOCK_UNLOCK(*spp);
2317 }
2318 fdrop(fp, td);
2319
2320 return (error);
2321}
2322
2323/*
2324 * Drop the reference count on the socket and XXX release the SX lock in the
2325 * future. The last reference closes the socket.
2326 *
2327 * Note: fputsock() is deprecated, see comment for fgetsock().
2328 */
2329void
2330fputsock(struct socket *so)
2331{
2332
2333 ACCEPT_LOCK();
2334 SOCK_LOCK(so);
|
2334}
2335
2336/*
2337 * Handle the last reference to a file being closed.
2338 */
2339int
2340_fdrop(struct file *fp, struct thread *td)
2341{
2342 int error;
2343
2344 error = 0;
2345 if (fp->f_count != 0)
2346 panic("fdrop: count %d", fp->f_count);
2347 if (fp->f_ops != &badfileops)
2348 error = fo_close(fp, td);
2349 /*
2350 * The f_cdevpriv cannot be assigned non-NULL value while we
2351 * are destroying the file.
2352 */
2353 if (fp->f_cdevpriv != NULL)
2354 devfs_fpdrop(fp);
2355 atomic_subtract_int(&openfiles, 1);
2356 crfree(fp->f_cred);
2357 uma_zfree(file_zone, fp);
2358
2359 return (error);
2360}
2361
2362/*
2363 * Apply an advisory lock on a file descriptor.
2364 *
2365 * Just attempt to get a record lock of the requested type on the entire file
2366 * (l_whence = SEEK_SET, l_start = 0, l_len = 0).
2367 */
2368#ifndef _SYS_SYSPROTO_H_
2369struct flock_args {
2370 int fd;
2371 int how;
2372};
2373#endif
2374/* ARGSUSED */
2375int
2376flock(struct thread *td, struct flock_args *uap)
2377{
2378 struct file *fp;
2379 struct vnode *vp;
2380 struct flock lf;
2381 int vfslocked;
2382 int error;
2383
2384 if ((error = fget(td, uap->fd, &fp)) != 0)
2385 return (error);
2386 if (fp->f_type != DTYPE_VNODE) {
2387 fdrop(fp, td);
2388 return (EOPNOTSUPP);
2389 }
2390
2391 vp = fp->f_vnode;
2392 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
2393 lf.l_whence = SEEK_SET;
2394 lf.l_start = 0;
2395 lf.l_len = 0;
2396 if (uap->how & LOCK_UN) {
2397 lf.l_type = F_UNLCK;
2398 atomic_clear_int(&fp->f_flag, FHASLOCK);
2399 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
2400 goto done2;
2401 }
2402 if (uap->how & LOCK_EX)
2403 lf.l_type = F_WRLCK;
2404 else if (uap->how & LOCK_SH)
2405 lf.l_type = F_RDLCK;
2406 else {
2407 error = EBADF;
2408 goto done2;
2409 }
2410 atomic_set_int(&fp->f_flag, FHASLOCK);
2411 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf,
2412 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT);
2413done2:
2414 fdrop(fp, td);
2415 VFS_UNLOCK_GIANT(vfslocked);
2416 return (error);
2417}
2418/*
2419 * Duplicate the specified descriptor to a free descriptor.
2420 */
2421int
2422dupfdopen(struct thread *td, struct filedesc *fdp, int indx, int dfd, int mode, int error)
2423{
2424 struct file *wfp;
2425 struct file *fp;
2426
2427 /*
2428 * If the to-be-dup'd fd number is greater than the allowed number
2429 * of file descriptors, or the fd to be dup'd has already been
2430 * closed, then reject.
2431 */
2432 FILEDESC_XLOCK(fdp);
2433 if (dfd < 0 || dfd >= fdp->fd_nfiles ||
2434 (wfp = fdp->fd_ofiles[dfd]) == NULL) {
2435 FILEDESC_XUNLOCK(fdp);
2436 return (EBADF);
2437 }
2438
2439 /*
2440 * There are two cases of interest here.
2441 *
2442 * For ENODEV simply dup (dfd) to file descriptor (indx) and return.
2443 *
2444 * For ENXIO steal away the file structure from (dfd) and store it in
2445 * (indx). (dfd) is effectively closed by this operation.
2446 *
2447 * Any other error code is just returned.
2448 */
2449 switch (error) {
2450 case ENODEV:
2451 /*
2452 * Check that the mode the file is being opened for is a
2453 * subset of the mode of the existing descriptor.
2454 */
2455 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) {
2456 FILEDESC_XUNLOCK(fdp);
2457 return (EACCES);
2458 }
2459 fp = fdp->fd_ofiles[indx];
2460 fdp->fd_ofiles[indx] = wfp;
2461 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd];
2462 if (fp == NULL)
2463 fdused(fdp, indx);
2464 fhold(wfp);
2465 FILEDESC_XUNLOCK(fdp);
2466 if (fp != NULL)
2467 /*
2468 * We now own the reference to fp that the ofiles[]
2469 * array used to own. Release it.
2470 */
2471 fdrop(fp, td);
2472 return (0);
2473
2474 case ENXIO:
2475 /*
2476 * Steal away the file pointer from dfd and stuff it into indx.
2477 */
2478 fp = fdp->fd_ofiles[indx];
2479 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd];
2480 fdp->fd_ofiles[dfd] = NULL;
2481 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd];
2482 fdp->fd_ofileflags[dfd] = 0;
2483 fdunused(fdp, dfd);
2484 if (fp == NULL)
2485 fdused(fdp, indx);
2486 FILEDESC_XUNLOCK(fdp);
2487
2488 /*
2489 * We now own the reference to fp that the ofiles[] array
2490 * used to own. Release it.
2491 */
2492 if (fp != NULL)
2493 fdrop(fp, td);
2494 return (0);
2495
2496 default:
2497 FILEDESC_XUNLOCK(fdp);
2498 return (error);
2499 }
2500 /* NOTREACHED */
2501}
2502
2503/*
2504 * Scan all active processes and prisons to see if any of them have a current
2505 * or root directory of `olddp'. If so, replace them with the new mount point.
2506 */
2507void
2508mountcheckdirs(struct vnode *olddp, struct vnode *newdp)
2509{
2510 struct filedesc *fdp;
2511 struct prison *pr;
2512 struct proc *p;
2513 int nrele;
2514
2515 if (vrefcnt(olddp) == 1)
2516 return;
2517 nrele = 0;
2518 sx_slock(&allproc_lock);
2519 FOREACH_PROC_IN_SYSTEM(p) {
2520 fdp = fdhold(p);
2521 if (fdp == NULL)
2522 continue;
2523 FILEDESC_XLOCK(fdp);
2524 if (fdp->fd_cdir == olddp) {
2525 vref(newdp);
2526 fdp->fd_cdir = newdp;
2527 nrele++;
2528 }
2529 if (fdp->fd_rdir == olddp) {
2530 vref(newdp);
2531 fdp->fd_rdir = newdp;
2532 nrele++;
2533 }
2534 if (fdp->fd_jdir == olddp) {
2535 vref(newdp);
2536 fdp->fd_jdir = newdp;
2537 nrele++;
2538 }
2539 FILEDESC_XUNLOCK(fdp);
2540 fddrop(fdp);
2541 }
2542 sx_sunlock(&allproc_lock);
2543 if (rootvnode == olddp) {
2544 vref(newdp);
2545 rootvnode = newdp;
2546 nrele++;
2547 }
2548 mtx_lock(&prison0.pr_mtx);
2549 if (prison0.pr_root == olddp) {
2550 vref(newdp);
2551 prison0.pr_root = newdp;
2552 nrele++;
2553 }
2554 mtx_unlock(&prison0.pr_mtx);
2555 sx_slock(&allprison_lock);
2556 TAILQ_FOREACH(pr, &allprison, pr_list) {
2557 mtx_lock(&pr->pr_mtx);
2558 if (pr->pr_root == olddp) {
2559 vref(newdp);
2560 pr->pr_root = newdp;
2561 nrele++;
2562 }
2563 mtx_unlock(&pr->pr_mtx);
2564 }
2565 sx_sunlock(&allprison_lock);
2566 while (nrele--)
2567 vrele(olddp);
2568}
2569
2570struct filedesc_to_leader *
2571filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader)
2572{
2573 struct filedesc_to_leader *fdtol;
2574
2575 fdtol = malloc(sizeof(struct filedesc_to_leader),
2576 M_FILEDESC_TO_LEADER,
2577 M_WAITOK);
2578 fdtol->fdl_refcount = 1;
2579 fdtol->fdl_holdcount = 0;
2580 fdtol->fdl_wakeup = 0;
2581 fdtol->fdl_leader = leader;
2582 if (old != NULL) {
2583 FILEDESC_XLOCK(fdp);
2584 fdtol->fdl_next = old->fdl_next;
2585 fdtol->fdl_prev = old;
2586 old->fdl_next = fdtol;
2587 fdtol->fdl_next->fdl_prev = fdtol;
2588 FILEDESC_XUNLOCK(fdp);
2589 } else {
2590 fdtol->fdl_next = fdtol;
2591 fdtol->fdl_prev = fdtol;
2592 }
2593 return (fdtol);
2594}
2595
2596/*
2597 * Get file structures globally.
2598 */
2599static int
2600sysctl_kern_file(SYSCTL_HANDLER_ARGS)
2601{
2602 struct xfile xf;
2603 struct filedesc *fdp;
2604 struct file *fp;
2605 struct proc *p;
2606 int error, n;
2607
2608 error = sysctl_wire_old_buffer(req, 0);
2609 if (error != 0)
2610 return (error);
2611 if (req->oldptr == NULL) {
2612 n = 0;
2613 sx_slock(&allproc_lock);
2614 FOREACH_PROC_IN_SYSTEM(p) {
2615 if (p->p_state == PRS_NEW)
2616 continue;
2617 fdp = fdhold(p);
2618 if (fdp == NULL)
2619 continue;
2620 /* overestimates sparse tables. */
2621 if (fdp->fd_lastfile > 0)
2622 n += fdp->fd_lastfile;
2623 fddrop(fdp);
2624 }
2625 sx_sunlock(&allproc_lock);
2626 return (SYSCTL_OUT(req, 0, n * sizeof(xf)));
2627 }
2628 error = 0;
2629 bzero(&xf, sizeof(xf));
2630 xf.xf_size = sizeof(xf);
2631 sx_slock(&allproc_lock);
2632 FOREACH_PROC_IN_SYSTEM(p) {
2633 if (p->p_state == PRS_NEW)
2634 continue;
2635 PROC_LOCK(p);
2636 if (p_cansee(req->td, p) != 0) {
2637 PROC_UNLOCK(p);
2638 continue;
2639 }
2640 xf.xf_pid = p->p_pid;
2641 xf.xf_uid = p->p_ucred->cr_uid;
2642 PROC_UNLOCK(p);
2643 fdp = fdhold(p);
2644 if (fdp == NULL)
2645 continue;
2646 FILEDESC_SLOCK(fdp);
2647 for (n = 0; fdp->fd_refcnt > 0 && n < fdp->fd_nfiles; ++n) {
2648 if ((fp = fdp->fd_ofiles[n]) == NULL)
2649 continue;
2650 xf.xf_fd = n;
2651 xf.xf_file = fp;
2652 xf.xf_data = fp->f_data;
2653 xf.xf_vnode = fp->f_vnode;
2654 xf.xf_type = fp->f_type;
2655 xf.xf_count = fp->f_count;
2656 xf.xf_msgcount = 0;
2657 xf.xf_offset = fp->f_offset;
2658 xf.xf_flag = fp->f_flag;
2659 error = SYSCTL_OUT(req, &xf, sizeof(xf));
2660 if (error)
2661 break;
2662 }
2663 FILEDESC_SUNLOCK(fdp);
2664 fddrop(fdp);
2665 if (error)
2666 break;
2667 }
2668 sx_sunlock(&allproc_lock);
2669 return (error);
2670}
2671
2672SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD,
2673 0, 0, sysctl_kern_file, "S,xfile", "Entire file table");
2674
2675#ifdef KINFO_OFILE_SIZE
2676CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE);
2677#endif
2678
2679#ifdef COMPAT_FREEBSD7
2680static int
2681export_vnode_for_osysctl(struct vnode *vp, int type,
2682 struct kinfo_ofile *kif, struct filedesc *fdp, struct sysctl_req *req)
2683{
2684 int error;
2685 char *fullpath, *freepath;
2686 int vfslocked;
2687
2688 bzero(kif, sizeof(*kif));
2689 kif->kf_structsize = sizeof(*kif);
2690
2691 vref(vp);
2692 kif->kf_fd = type;
2693 kif->kf_type = KF_TYPE_VNODE;
2694 /* This function only handles directories. */
2695 if (vp->v_type != VDIR) {
2696 vrele(vp);
2697 return (ENOTDIR);
2698 }
2699 kif->kf_vnode_type = KF_VTYPE_VDIR;
2700
2701 /*
2702 * This is not a true file descriptor, so we set a bogus refcount
2703 * and offset to indicate these fields should be ignored.
2704 */
2705 kif->kf_ref_count = -1;
2706 kif->kf_offset = -1;
2707
2708 freepath = NULL;
2709 fullpath = "-";
2710 FILEDESC_SUNLOCK(fdp);
2711 vn_fullpath(curthread, vp, &fullpath, &freepath);
2712 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
2713 vrele(vp);
2714 VFS_UNLOCK_GIANT(vfslocked);
2715 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
2716 if (freepath != NULL)
2717 free(freepath, M_TEMP);
2718 error = SYSCTL_OUT(req, kif, sizeof(*kif));
2719 FILEDESC_SLOCK(fdp);
2720 return (error);
2721}
2722
2723/*
2724 * Get per-process file descriptors for use by procstat(1), et al.
2725 */
2726static int
2727sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS)
2728{
2729 char *fullpath, *freepath;
2730 struct kinfo_ofile *kif;
2731 struct filedesc *fdp;
2732 int error, i, *name;
2733 struct socket *so;
2734 struct vnode *vp;
2735 struct file *fp;
2736 struct proc *p;
2737 struct tty *tp;
2738 int vfslocked;
2739
2740 name = (int *)arg1;
2741 if ((p = pfind((pid_t)name[0])) == NULL)
2742 return (ESRCH);
2743 if ((error = p_candebug(curthread, p))) {
2744 PROC_UNLOCK(p);
2745 return (error);
2746 }
2747 fdp = fdhold(p);
2748 PROC_UNLOCK(p);
2749 if (fdp == NULL)
2750 return (ENOENT);
2751 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK);
2752 FILEDESC_SLOCK(fdp);
2753 if (fdp->fd_cdir != NULL)
2754 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif,
2755 fdp, req);
2756 if (fdp->fd_rdir != NULL)
2757 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif,
2758 fdp, req);
2759 if (fdp->fd_jdir != NULL)
2760 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif,
2761 fdp, req);
2762 for (i = 0; i < fdp->fd_nfiles; i++) {
2763 if ((fp = fdp->fd_ofiles[i]) == NULL)
2764 continue;
2765 bzero(kif, sizeof(*kif));
2766 kif->kf_structsize = sizeof(*kif);
2767 vp = NULL;
2768 so = NULL;
2769 tp = NULL;
2770 kif->kf_fd = i;
2771 switch (fp->f_type) {
2772 case DTYPE_VNODE:
2773 kif->kf_type = KF_TYPE_VNODE;
2774 vp = fp->f_vnode;
2775 break;
2776
2777 case DTYPE_SOCKET:
2778 kif->kf_type = KF_TYPE_SOCKET;
2779 so = fp->f_data;
2780 break;
2781
2782 case DTYPE_PIPE:
2783 kif->kf_type = KF_TYPE_PIPE;
2784 break;
2785
2786 case DTYPE_FIFO:
2787 kif->kf_type = KF_TYPE_FIFO;
2788 vp = fp->f_vnode;
2789 break;
2790
2791 case DTYPE_KQUEUE:
2792 kif->kf_type = KF_TYPE_KQUEUE;
2793 break;
2794
2795 case DTYPE_CRYPTO:
2796 kif->kf_type = KF_TYPE_CRYPTO;
2797 break;
2798
2799 case DTYPE_MQUEUE:
2800 kif->kf_type = KF_TYPE_MQUEUE;
2801 break;
2802
2803 case DTYPE_SHM:
2804 kif->kf_type = KF_TYPE_SHM;
2805 break;
2806
2807 case DTYPE_SEM:
2808 kif->kf_type = KF_TYPE_SEM;
2809 break;
2810
2811 case DTYPE_PTS:
2812 kif->kf_type = KF_TYPE_PTS;
2813 tp = fp->f_data;
2814 break;
2815
2816 default:
2817 kif->kf_type = KF_TYPE_UNKNOWN;
2818 break;
2819 }
2820 kif->kf_ref_count = fp->f_count;
2821 if (fp->f_flag & FREAD)
2822 kif->kf_flags |= KF_FLAG_READ;
2823 if (fp->f_flag & FWRITE)
2824 kif->kf_flags |= KF_FLAG_WRITE;
2825 if (fp->f_flag & FAPPEND)
2826 kif->kf_flags |= KF_FLAG_APPEND;
2827 if (fp->f_flag & FASYNC)
2828 kif->kf_flags |= KF_FLAG_ASYNC;
2829 if (fp->f_flag & FFSYNC)
2830 kif->kf_flags |= KF_FLAG_FSYNC;
2831 if (fp->f_flag & FNONBLOCK)
2832 kif->kf_flags |= KF_FLAG_NONBLOCK;
2833 if (fp->f_flag & O_DIRECT)
2834 kif->kf_flags |= KF_FLAG_DIRECT;
2835 if (fp->f_flag & FHASLOCK)
2836 kif->kf_flags |= KF_FLAG_HASLOCK;
2837 kif->kf_offset = fp->f_offset;
2838 if (vp != NULL) {
2839 vref(vp);
2840 switch (vp->v_type) {
2841 case VNON:
2842 kif->kf_vnode_type = KF_VTYPE_VNON;
2843 break;
2844 case VREG:
2845 kif->kf_vnode_type = KF_VTYPE_VREG;
2846 break;
2847 case VDIR:
2848 kif->kf_vnode_type = KF_VTYPE_VDIR;
2849 break;
2850 case VBLK:
2851 kif->kf_vnode_type = KF_VTYPE_VBLK;
2852 break;
2853 case VCHR:
2854 kif->kf_vnode_type = KF_VTYPE_VCHR;
2855 break;
2856 case VLNK:
2857 kif->kf_vnode_type = KF_VTYPE_VLNK;
2858 break;
2859 case VSOCK:
2860 kif->kf_vnode_type = KF_VTYPE_VSOCK;
2861 break;
2862 case VFIFO:
2863 kif->kf_vnode_type = KF_VTYPE_VFIFO;
2864 break;
2865 case VBAD:
2866 kif->kf_vnode_type = KF_VTYPE_VBAD;
2867 break;
2868 default:
2869 kif->kf_vnode_type = KF_VTYPE_UNKNOWN;
2870 break;
2871 }
2872 /*
2873 * It is OK to drop the filedesc lock here as we will
2874 * re-validate and re-evaluate its properties when
2875 * the loop continues.
2876 */
2877 freepath = NULL;
2878 fullpath = "-";
2879 FILEDESC_SUNLOCK(fdp);
2880 vn_fullpath(curthread, vp, &fullpath, &freepath);
2881 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
2882 vrele(vp);
2883 VFS_UNLOCK_GIANT(vfslocked);
2884 strlcpy(kif->kf_path, fullpath,
2885 sizeof(kif->kf_path));
2886 if (freepath != NULL)
2887 free(freepath, M_TEMP);
2888 FILEDESC_SLOCK(fdp);
2889 }
2890 if (so != NULL) {
2891 struct sockaddr *sa;
2892
2893 if (so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa)
2894 == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) {
2895 bcopy(sa, &kif->kf_sa_local, sa->sa_len);
2896 free(sa, M_SONAME);
2897 }
2898 if (so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa)
2899 == 0 && sa->sa_len <= sizeof(kif->kf_sa_peer)) {
2900 bcopy(sa, &kif->kf_sa_peer, sa->sa_len);
2901 free(sa, M_SONAME);
2902 }
2903 kif->kf_sock_domain =
2904 so->so_proto->pr_domain->dom_family;
2905 kif->kf_sock_type = so->so_type;
2906 kif->kf_sock_protocol = so->so_proto->pr_protocol;
2907 }
2908 if (tp != NULL) {
2909 strlcpy(kif->kf_path, tty_devname(tp),
2910 sizeof(kif->kf_path));
2911 }
2912 error = SYSCTL_OUT(req, kif, sizeof(*kif));
2913 if (error)
2914 break;
2915 }
2916 FILEDESC_SUNLOCK(fdp);
2917 fddrop(fdp);
2918 free(kif, M_TEMP);
2919 return (0);
2920}
2921
2922static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, CTLFLAG_RD,
2923 sysctl_kern_proc_ofiledesc, "Process ofiledesc entries");
2924#endif /* COMPAT_FREEBSD7 */
2925
2926#ifdef KINFO_FILE_SIZE
2927CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE);
2928#endif
2929
2930static int
2931export_vnode_for_sysctl(struct vnode *vp, int type,
2932 struct kinfo_file *kif, struct filedesc *fdp, struct sysctl_req *req)
2933{
2934 int error;
2935 char *fullpath, *freepath;
2936 int vfslocked;
2937
2938 bzero(kif, sizeof(*kif));
2939
2940 vref(vp);
2941 kif->kf_fd = type;
2942 kif->kf_type = KF_TYPE_VNODE;
2943 /* This function only handles directories. */
2944 if (vp->v_type != VDIR) {
2945 vrele(vp);
2946 return (ENOTDIR);
2947 }
2948 kif->kf_vnode_type = KF_VTYPE_VDIR;
2949
2950 /*
2951 * This is not a true file descriptor, so we set a bogus refcount
2952 * and offset to indicate these fields should be ignored.
2953 */
2954 kif->kf_ref_count = -1;
2955 kif->kf_offset = -1;
2956
2957 freepath = NULL;
2958 fullpath = "-";
2959 FILEDESC_SUNLOCK(fdp);
2960 vn_fullpath(curthread, vp, &fullpath, &freepath);
2961 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
2962 vrele(vp);
2963 VFS_UNLOCK_GIANT(vfslocked);
2964 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
2965 if (freepath != NULL)
2966 free(freepath, M_TEMP);
2967 /* Pack record size down */
2968 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) +
2969 strlen(kif->kf_path) + 1;
2970 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t));
2971 error = SYSCTL_OUT(req, kif, kif->kf_structsize);
2972 FILEDESC_SLOCK(fdp);
2973 return (error);
2974}
2975
2976/*
2977 * Get per-process file descriptors for use by procstat(1), et al.
2978 */
2979static int
2980sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS)
2981{
2982 char *fullpath, *freepath;
2983 struct kinfo_file *kif;
2984 struct filedesc *fdp;
2985 int error, i, *name;
2986 struct socket *so;
2987 struct vnode *vp;
2988 struct file *fp;
2989 struct proc *p;
2990 struct tty *tp;
2991 int vfslocked;
2992 size_t oldidx;
2993
2994 name = (int *)arg1;
2995 if ((p = pfind((pid_t)name[0])) == NULL)
2996 return (ESRCH);
2997 if ((error = p_candebug(curthread, p))) {
2998 PROC_UNLOCK(p);
2999 return (error);
3000 }
3001 fdp = fdhold(p);
3002 PROC_UNLOCK(p);
3003 if (fdp == NULL)
3004 return (ENOENT);
3005 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK);
3006 FILEDESC_SLOCK(fdp);
3007 if (fdp->fd_cdir != NULL)
3008 export_vnode_for_sysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif,
3009 fdp, req);
3010 if (fdp->fd_rdir != NULL)
3011 export_vnode_for_sysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif,
3012 fdp, req);
3013 if (fdp->fd_jdir != NULL)
3014 export_vnode_for_sysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif,
3015 fdp, req);
3016 for (i = 0; i < fdp->fd_nfiles; i++) {
3017 if ((fp = fdp->fd_ofiles[i]) == NULL)
3018 continue;
3019 bzero(kif, sizeof(*kif));
3020 vp = NULL;
3021 so = NULL;
3022 tp = NULL;
3023 kif->kf_fd = i;
3024 switch (fp->f_type) {
3025 case DTYPE_VNODE:
3026 kif->kf_type = KF_TYPE_VNODE;
3027 vp = fp->f_vnode;
3028 break;
3029
3030 case DTYPE_SOCKET:
3031 kif->kf_type = KF_TYPE_SOCKET;
3032 so = fp->f_data;
3033 break;
3034
3035 case DTYPE_PIPE:
3036 kif->kf_type = KF_TYPE_PIPE;
3037 break;
3038
3039 case DTYPE_FIFO:
3040 kif->kf_type = KF_TYPE_FIFO;
3041 vp = fp->f_vnode;
3042 break;
3043
3044 case DTYPE_KQUEUE:
3045 kif->kf_type = KF_TYPE_KQUEUE;
3046 break;
3047
3048 case DTYPE_CRYPTO:
3049 kif->kf_type = KF_TYPE_CRYPTO;
3050 break;
3051
3052 case DTYPE_MQUEUE:
3053 kif->kf_type = KF_TYPE_MQUEUE;
3054 break;
3055
3056 case DTYPE_SHM:
3057 kif->kf_type = KF_TYPE_SHM;
3058 break;
3059
3060 case DTYPE_SEM:
3061 kif->kf_type = KF_TYPE_SEM;
3062 break;
3063
3064 case DTYPE_PTS:
3065 kif->kf_type = KF_TYPE_PTS;
3066 tp = fp->f_data;
3067 break;
3068
3069 default:
3070 kif->kf_type = KF_TYPE_UNKNOWN;
3071 break;
3072 }
3073 kif->kf_ref_count = fp->f_count;
3074 if (fp->f_flag & FREAD)
3075 kif->kf_flags |= KF_FLAG_READ;
3076 if (fp->f_flag & FWRITE)
3077 kif->kf_flags |= KF_FLAG_WRITE;
3078 if (fp->f_flag & FAPPEND)
3079 kif->kf_flags |= KF_FLAG_APPEND;
3080 if (fp->f_flag & FASYNC)
3081 kif->kf_flags |= KF_FLAG_ASYNC;
3082 if (fp->f_flag & FFSYNC)
3083 kif->kf_flags |= KF_FLAG_FSYNC;
3084 if (fp->f_flag & FNONBLOCK)
3085 kif->kf_flags |= KF_FLAG_NONBLOCK;
3086 if (fp->f_flag & O_DIRECT)
3087 kif->kf_flags |= KF_FLAG_DIRECT;
3088 if (fp->f_flag & FHASLOCK)
3089 kif->kf_flags |= KF_FLAG_HASLOCK;
3090 kif->kf_offset = fp->f_offset;
3091 if (vp != NULL) {
3092 vref(vp);
3093 switch (vp->v_type) {
3094 case VNON:
3095 kif->kf_vnode_type = KF_VTYPE_VNON;
3096 break;
3097 case VREG:
3098 kif->kf_vnode_type = KF_VTYPE_VREG;
3099 break;
3100 case VDIR:
3101 kif->kf_vnode_type = KF_VTYPE_VDIR;
3102 break;
3103 case VBLK:
3104 kif->kf_vnode_type = KF_VTYPE_VBLK;
3105 break;
3106 case VCHR:
3107 kif->kf_vnode_type = KF_VTYPE_VCHR;
3108 break;
3109 case VLNK:
3110 kif->kf_vnode_type = KF_VTYPE_VLNK;
3111 break;
3112 case VSOCK:
3113 kif->kf_vnode_type = KF_VTYPE_VSOCK;
3114 break;
3115 case VFIFO:
3116 kif->kf_vnode_type = KF_VTYPE_VFIFO;
3117 break;
3118 case VBAD:
3119 kif->kf_vnode_type = KF_VTYPE_VBAD;
3120 break;
3121 default:
3122 kif->kf_vnode_type = KF_VTYPE_UNKNOWN;
3123 break;
3124 }
3125 /*
3126 * It is OK to drop the filedesc lock here as we will
3127 * re-validate and re-evaluate its properties when
3128 * the loop continues.
3129 */
3130 freepath = NULL;
3131 fullpath = "-";
3132 FILEDESC_SUNLOCK(fdp);
3133 vn_fullpath(curthread, vp, &fullpath, &freepath);
3134 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
3135 vrele(vp);
3136 VFS_UNLOCK_GIANT(vfslocked);
3137 strlcpy(kif->kf_path, fullpath,
3138 sizeof(kif->kf_path));
3139 if (freepath != NULL)
3140 free(freepath, M_TEMP);
3141 FILEDESC_SLOCK(fdp);
3142 }
3143 if (so != NULL) {
3144 struct sockaddr *sa;
3145
3146 if (so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa)
3147 == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) {
3148 bcopy(sa, &kif->kf_sa_local, sa->sa_len);
3149 free(sa, M_SONAME);
3150 }
3151 if (so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa)
3152 == 0 && sa->sa_len <= sizeof(kif->kf_sa_peer)) {
3153 bcopy(sa, &kif->kf_sa_peer, sa->sa_len);
3154 free(sa, M_SONAME);
3155 }
3156 kif->kf_sock_domain =
3157 so->so_proto->pr_domain->dom_family;
3158 kif->kf_sock_type = so->so_type;
3159 kif->kf_sock_protocol = so->so_proto->pr_protocol;
3160 }
3161 if (tp != NULL) {
3162 strlcpy(kif->kf_path, tty_devname(tp),
3163 sizeof(kif->kf_path));
3164 }
3165 /* Pack record size down */
3166 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) +
3167 strlen(kif->kf_path) + 1;
3168 kif->kf_structsize = roundup(kif->kf_structsize,
3169 sizeof(uint64_t));
3170 oldidx = req->oldidx;
3171 error = SYSCTL_OUT(req, kif, kif->kf_structsize);
3172 if (error) {
3173 if (error == ENOMEM) {
3174 /*
3175 * The hack to keep the ABI of sysctl
3176 * kern.proc.filedesc intact, but not
3177 * to account a partially copied
3178 * kinfo_file into the oldidx.
3179 */
3180 req->oldidx = oldidx;
3181 error = 0;
3182 }
3183 break;
3184 }
3185 }
3186 FILEDESC_SUNLOCK(fdp);
3187 fddrop(fdp);
3188 free(kif, M_TEMP);
3189 return (error);
3190}
3191
3192static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, CTLFLAG_RD,
3193 sysctl_kern_proc_filedesc, "Process filedesc entries");
3194
3195#ifdef DDB
3196/*
3197 * For the purposes of debugging, generate a human-readable string for the
3198 * file type.
3199 */
3200static const char *
3201file_type_to_name(short type)
3202{
3203
3204 switch (type) {
3205 case 0:
3206 return ("zero");
3207 case DTYPE_VNODE:
3208 return ("vnod");
3209 case DTYPE_SOCKET:
3210 return ("sock");
3211 case DTYPE_PIPE:
3212 return ("pipe");
3213 case DTYPE_FIFO:
3214 return ("fifo");
3215 case DTYPE_KQUEUE:
3216 return ("kque");
3217 case DTYPE_CRYPTO:
3218 return ("crpt");
3219 case DTYPE_MQUEUE:
3220 return ("mque");
3221 case DTYPE_SHM:
3222 return ("shm");
3223 case DTYPE_SEM:
3224 return ("ksem");
3225 default:
3226 return ("unkn");
3227 }
3228}
3229
3230/*
3231 * For the purposes of debugging, identify a process (if any, perhaps one of
3232 * many) that references the passed file in its file descriptor array. Return
3233 * NULL if none.
3234 */
3235static struct proc *
3236file_to_first_proc(struct file *fp)
3237{
3238 struct filedesc *fdp;
3239 struct proc *p;
3240 int n;
3241
3242 FOREACH_PROC_IN_SYSTEM(p) {
3243 if (p->p_state == PRS_NEW)
3244 continue;
3245 fdp = p->p_fd;
3246 if (fdp == NULL)
3247 continue;
3248 for (n = 0; n < fdp->fd_nfiles; n++) {
3249 if (fp == fdp->fd_ofiles[n])
3250 return (p);
3251 }
3252 }
3253 return (NULL);
3254}
3255
3256static void
3257db_print_file(struct file *fp, int header)
3258{
3259 struct proc *p;
3260
3261 if (header)
3262 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n",
3263 "File", "Type", "Data", "Flag", "GCFl", "Count",
3264 "MCount", "Vnode", "FPID", "FCmd");
3265 p = file_to_first_proc(fp);
3266 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp,
3267 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag,
3268 0, fp->f_count, 0, fp->f_vnode,
3269 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-");
3270}
3271
3272DB_SHOW_COMMAND(file, db_show_file)
3273{
3274 struct file *fp;
3275
3276 if (!have_addr) {
3277 db_printf("usage: show file <addr>\n");
3278 return;
3279 }
3280 fp = (struct file *)addr;
3281 db_print_file(fp, 1);
3282}
3283
3284DB_SHOW_COMMAND(files, db_show_files)
3285{
3286 struct filedesc *fdp;
3287 struct file *fp;
3288 struct proc *p;
3289 int header;
3290 int n;
3291
3292 header = 1;
3293 FOREACH_PROC_IN_SYSTEM(p) {
3294 if (p->p_state == PRS_NEW)
3295 continue;
3296 if ((fdp = p->p_fd) == NULL)
3297 continue;
3298 for (n = 0; n < fdp->fd_nfiles; ++n) {
3299 if ((fp = fdp->fd_ofiles[n]) == NULL)
3300 continue;
3301 db_print_file(fp, header);
3302 header = 0;
3303 }
3304 }
3305}
3306#endif
3307
3308SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW,
3309 &maxfilesperproc, 0, "Maximum files allowed open per process");
3310
3311SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW,
3312 &maxfiles, 0, "Maximum number of files");
3313
3314SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD,
3315 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files");
3316
3317/* ARGSUSED*/
3318static void
3319filelistinit(void *dummy)
3320{
3321
3322 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL,
3323 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
3324 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF);
3325 mtx_init(&fdesc_mtx, "fdesc", NULL, MTX_DEF);
3326}
3327SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL);
3328
3329/*-------------------------------------------------------------------*/
3330
3331static int
3332badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td)
3333{
3334
3335 return (EBADF);
3336}
3337
3338static int
3339badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, struct thread *td)
3340{
3341
3342 return (EINVAL);
3343}
3344
3345static int
3346badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, struct thread *td)
3347{
3348
3349 return (EBADF);
3350}
3351
3352static int
3353badfo_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td)
3354{
3355
3356 return (0);
3357}
3358
3359static int
3360badfo_kqfilter(struct file *fp, struct knote *kn)
3361{
3362
3363 return (EBADF);
3364}
3365
3366static int
3367badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, struct thread *td)
3368{
3369
3370 return (EBADF);
3371}
3372
3373static int
3374badfo_close(struct file *fp, struct thread *td)
3375{
3376
3377 return (EBADF);
3378}
3379
3380struct fileops badfileops = {
3381 .fo_read = badfo_readwrite,
3382 .fo_write = badfo_readwrite,
3383 .fo_truncate = badfo_truncate,
3384 .fo_ioctl = badfo_ioctl,
3385 .fo_poll = badfo_poll,
3386 .fo_kqfilter = badfo_kqfilter,
3387 .fo_stat = badfo_stat,
3388 .fo_close = badfo_close,
3389};
3390
3391
3392/*-------------------------------------------------------------------*/
3393
3394/*
3395 * File Descriptor pseudo-device driver (/dev/fd/).
3396 *
3397 * Opening minor device N dup()s the file (if any) connected to file
3398 * descriptor N belonging to the calling process. Note that this driver
3399 * consists of only the ``open()'' routine, because all subsequent
3400 * references to this file will be direct to the other driver.
3401 *
3402 * XXX: we could give this one a cloning event handler if necessary.
3403 */
3404
3405/* ARGSUSED */
3406static int
3407fdopen(struct cdev *dev, int mode, int type, struct thread *td)
3408{
3409
3410 /*
3411 * XXX Kludge: set curthread->td_dupfd to contain the value of the
3412 * the file descriptor being sought for duplication. The error
3413 * return ensures that the vnode for this device will be released
3414 * by vn_open. Open will detect this special error and take the
3415 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN
3416 * will simply report the error.
3417 */
3418 td->td_dupfd = dev2unit(dev);
3419 return (ENODEV);
3420}
3421
3422static struct cdevsw fildesc_cdevsw = {
3423 .d_version = D_VERSION,
3424 .d_open = fdopen,
3425 .d_name = "FD",
3426};
3427
3428static void
3429fildesc_drvinit(void *unused)
3430{
3431 struct cdev *dev;
3432
3433 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL,
3434 UID_ROOT, GID_WHEEL, 0666, "fd/0");
3435 make_dev_alias(dev, "stdin");
3436 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL,
3437 UID_ROOT, GID_WHEEL, 0666, "fd/1");
3438 make_dev_alias(dev, "stdout");
3439 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL,
3440 UID_ROOT, GID_WHEEL, 0666, "fd/2");
3441 make_dev_alias(dev, "stderr");
3442}
3443
3444SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL);
| 2338}
2339
2340/*
2341 * Handle the last reference to a file being closed.
2342 */
2343int
2344_fdrop(struct file *fp, struct thread *td)
2345{
2346 int error;
2347
2348 error = 0;
2349 if (fp->f_count != 0)
2350 panic("fdrop: count %d", fp->f_count);
2351 if (fp->f_ops != &badfileops)
2352 error = fo_close(fp, td);
2353 /*
2354 * The f_cdevpriv cannot be assigned non-NULL value while we
2355 * are destroying the file.
2356 */
2357 if (fp->f_cdevpriv != NULL)
2358 devfs_fpdrop(fp);
2359 atomic_subtract_int(&openfiles, 1);
2360 crfree(fp->f_cred);
2361 uma_zfree(file_zone, fp);
2362
2363 return (error);
2364}
2365
2366/*
2367 * Apply an advisory lock on a file descriptor.
2368 *
2369 * Just attempt to get a record lock of the requested type on the entire file
2370 * (l_whence = SEEK_SET, l_start = 0, l_len = 0).
2371 */
2372#ifndef _SYS_SYSPROTO_H_
2373struct flock_args {
2374 int fd;
2375 int how;
2376};
2377#endif
2378/* ARGSUSED */
2379int
2380flock(struct thread *td, struct flock_args *uap)
2381{
2382 struct file *fp;
2383 struct vnode *vp;
2384 struct flock lf;
2385 int vfslocked;
2386 int error;
2387
2388 if ((error = fget(td, uap->fd, &fp)) != 0)
2389 return (error);
2390 if (fp->f_type != DTYPE_VNODE) {
2391 fdrop(fp, td);
2392 return (EOPNOTSUPP);
2393 }
2394
2395 vp = fp->f_vnode;
2396 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
2397 lf.l_whence = SEEK_SET;
2398 lf.l_start = 0;
2399 lf.l_len = 0;
2400 if (uap->how & LOCK_UN) {
2401 lf.l_type = F_UNLCK;
2402 atomic_clear_int(&fp->f_flag, FHASLOCK);
2403 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK);
2404 goto done2;
2405 }
2406 if (uap->how & LOCK_EX)
2407 lf.l_type = F_WRLCK;
2408 else if (uap->how & LOCK_SH)
2409 lf.l_type = F_RDLCK;
2410 else {
2411 error = EBADF;
2412 goto done2;
2413 }
2414 atomic_set_int(&fp->f_flag, FHASLOCK);
2415 error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf,
2416 (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT);
2417done2:
2418 fdrop(fp, td);
2419 VFS_UNLOCK_GIANT(vfslocked);
2420 return (error);
2421}
2422/*
2423 * Duplicate the specified descriptor to a free descriptor.
2424 */
2425int
2426dupfdopen(struct thread *td, struct filedesc *fdp, int indx, int dfd, int mode, int error)
2427{
2428 struct file *wfp;
2429 struct file *fp;
2430
2431 /*
2432 * If the to-be-dup'd fd number is greater than the allowed number
2433 * of file descriptors, or the fd to be dup'd has already been
2434 * closed, then reject.
2435 */
2436 FILEDESC_XLOCK(fdp);
2437 if (dfd < 0 || dfd >= fdp->fd_nfiles ||
2438 (wfp = fdp->fd_ofiles[dfd]) == NULL) {
2439 FILEDESC_XUNLOCK(fdp);
2440 return (EBADF);
2441 }
2442
2443 /*
2444 * There are two cases of interest here.
2445 *
2446 * For ENODEV simply dup (dfd) to file descriptor (indx) and return.
2447 *
2448 * For ENXIO steal away the file structure from (dfd) and store it in
2449 * (indx). (dfd) is effectively closed by this operation.
2450 *
2451 * Any other error code is just returned.
2452 */
2453 switch (error) {
2454 case ENODEV:
2455 /*
2456 * Check that the mode the file is being opened for is a
2457 * subset of the mode of the existing descriptor.
2458 */
2459 if (((mode & (FREAD|FWRITE)) | wfp->f_flag) != wfp->f_flag) {
2460 FILEDESC_XUNLOCK(fdp);
2461 return (EACCES);
2462 }
2463 fp = fdp->fd_ofiles[indx];
2464 fdp->fd_ofiles[indx] = wfp;
2465 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd];
2466 if (fp == NULL)
2467 fdused(fdp, indx);
2468 fhold(wfp);
2469 FILEDESC_XUNLOCK(fdp);
2470 if (fp != NULL)
2471 /*
2472 * We now own the reference to fp that the ofiles[]
2473 * array used to own. Release it.
2474 */
2475 fdrop(fp, td);
2476 return (0);
2477
2478 case ENXIO:
2479 /*
2480 * Steal away the file pointer from dfd and stuff it into indx.
2481 */
2482 fp = fdp->fd_ofiles[indx];
2483 fdp->fd_ofiles[indx] = fdp->fd_ofiles[dfd];
2484 fdp->fd_ofiles[dfd] = NULL;
2485 fdp->fd_ofileflags[indx] = fdp->fd_ofileflags[dfd];
2486 fdp->fd_ofileflags[dfd] = 0;
2487 fdunused(fdp, dfd);
2488 if (fp == NULL)
2489 fdused(fdp, indx);
2490 FILEDESC_XUNLOCK(fdp);
2491
2492 /*
2493 * We now own the reference to fp that the ofiles[] array
2494 * used to own. Release it.
2495 */
2496 if (fp != NULL)
2497 fdrop(fp, td);
2498 return (0);
2499
2500 default:
2501 FILEDESC_XUNLOCK(fdp);
2502 return (error);
2503 }
2504 /* NOTREACHED */
2505}
2506
2507/*
2508 * Scan all active processes and prisons to see if any of them have a current
2509 * or root directory of `olddp'. If so, replace them with the new mount point.
2510 */
2511void
2512mountcheckdirs(struct vnode *olddp, struct vnode *newdp)
2513{
2514 struct filedesc *fdp;
2515 struct prison *pr;
2516 struct proc *p;
2517 int nrele;
2518
2519 if (vrefcnt(olddp) == 1)
2520 return;
2521 nrele = 0;
2522 sx_slock(&allproc_lock);
2523 FOREACH_PROC_IN_SYSTEM(p) {
2524 fdp = fdhold(p);
2525 if (fdp == NULL)
2526 continue;
2527 FILEDESC_XLOCK(fdp);
2528 if (fdp->fd_cdir == olddp) {
2529 vref(newdp);
2530 fdp->fd_cdir = newdp;
2531 nrele++;
2532 }
2533 if (fdp->fd_rdir == olddp) {
2534 vref(newdp);
2535 fdp->fd_rdir = newdp;
2536 nrele++;
2537 }
2538 if (fdp->fd_jdir == olddp) {
2539 vref(newdp);
2540 fdp->fd_jdir = newdp;
2541 nrele++;
2542 }
2543 FILEDESC_XUNLOCK(fdp);
2544 fddrop(fdp);
2545 }
2546 sx_sunlock(&allproc_lock);
2547 if (rootvnode == olddp) {
2548 vref(newdp);
2549 rootvnode = newdp;
2550 nrele++;
2551 }
2552 mtx_lock(&prison0.pr_mtx);
2553 if (prison0.pr_root == olddp) {
2554 vref(newdp);
2555 prison0.pr_root = newdp;
2556 nrele++;
2557 }
2558 mtx_unlock(&prison0.pr_mtx);
2559 sx_slock(&allprison_lock);
2560 TAILQ_FOREACH(pr, &allprison, pr_list) {
2561 mtx_lock(&pr->pr_mtx);
2562 if (pr->pr_root == olddp) {
2563 vref(newdp);
2564 pr->pr_root = newdp;
2565 nrele++;
2566 }
2567 mtx_unlock(&pr->pr_mtx);
2568 }
2569 sx_sunlock(&allprison_lock);
2570 while (nrele--)
2571 vrele(olddp);
2572}
2573
2574struct filedesc_to_leader *
2575filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader)
2576{
2577 struct filedesc_to_leader *fdtol;
2578
2579 fdtol = malloc(sizeof(struct filedesc_to_leader),
2580 M_FILEDESC_TO_LEADER,
2581 M_WAITOK);
2582 fdtol->fdl_refcount = 1;
2583 fdtol->fdl_holdcount = 0;
2584 fdtol->fdl_wakeup = 0;
2585 fdtol->fdl_leader = leader;
2586 if (old != NULL) {
2587 FILEDESC_XLOCK(fdp);
2588 fdtol->fdl_next = old->fdl_next;
2589 fdtol->fdl_prev = old;
2590 old->fdl_next = fdtol;
2591 fdtol->fdl_next->fdl_prev = fdtol;
2592 FILEDESC_XUNLOCK(fdp);
2593 } else {
2594 fdtol->fdl_next = fdtol;
2595 fdtol->fdl_prev = fdtol;
2596 }
2597 return (fdtol);
2598}
2599
2600/*
2601 * Get file structures globally.
2602 */
2603static int
2604sysctl_kern_file(SYSCTL_HANDLER_ARGS)
2605{
2606 struct xfile xf;
2607 struct filedesc *fdp;
2608 struct file *fp;
2609 struct proc *p;
2610 int error, n;
2611
2612 error = sysctl_wire_old_buffer(req, 0);
2613 if (error != 0)
2614 return (error);
2615 if (req->oldptr == NULL) {
2616 n = 0;
2617 sx_slock(&allproc_lock);
2618 FOREACH_PROC_IN_SYSTEM(p) {
2619 if (p->p_state == PRS_NEW)
2620 continue;
2621 fdp = fdhold(p);
2622 if (fdp == NULL)
2623 continue;
2624 /* overestimates sparse tables. */
2625 if (fdp->fd_lastfile > 0)
2626 n += fdp->fd_lastfile;
2627 fddrop(fdp);
2628 }
2629 sx_sunlock(&allproc_lock);
2630 return (SYSCTL_OUT(req, 0, n * sizeof(xf)));
2631 }
2632 error = 0;
2633 bzero(&xf, sizeof(xf));
2634 xf.xf_size = sizeof(xf);
2635 sx_slock(&allproc_lock);
2636 FOREACH_PROC_IN_SYSTEM(p) {
2637 if (p->p_state == PRS_NEW)
2638 continue;
2639 PROC_LOCK(p);
2640 if (p_cansee(req->td, p) != 0) {
2641 PROC_UNLOCK(p);
2642 continue;
2643 }
2644 xf.xf_pid = p->p_pid;
2645 xf.xf_uid = p->p_ucred->cr_uid;
2646 PROC_UNLOCK(p);
2647 fdp = fdhold(p);
2648 if (fdp == NULL)
2649 continue;
2650 FILEDESC_SLOCK(fdp);
2651 for (n = 0; fdp->fd_refcnt > 0 && n < fdp->fd_nfiles; ++n) {
2652 if ((fp = fdp->fd_ofiles[n]) == NULL)
2653 continue;
2654 xf.xf_fd = n;
2655 xf.xf_file = fp;
2656 xf.xf_data = fp->f_data;
2657 xf.xf_vnode = fp->f_vnode;
2658 xf.xf_type = fp->f_type;
2659 xf.xf_count = fp->f_count;
2660 xf.xf_msgcount = 0;
2661 xf.xf_offset = fp->f_offset;
2662 xf.xf_flag = fp->f_flag;
2663 error = SYSCTL_OUT(req, &xf, sizeof(xf));
2664 if (error)
2665 break;
2666 }
2667 FILEDESC_SUNLOCK(fdp);
2668 fddrop(fdp);
2669 if (error)
2670 break;
2671 }
2672 sx_sunlock(&allproc_lock);
2673 return (error);
2674}
2675
2676SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD,
2677 0, 0, sysctl_kern_file, "S,xfile", "Entire file table");
2678
2679#ifdef KINFO_OFILE_SIZE
2680CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE);
2681#endif
2682
2683#ifdef COMPAT_FREEBSD7
2684static int
2685export_vnode_for_osysctl(struct vnode *vp, int type,
2686 struct kinfo_ofile *kif, struct filedesc *fdp, struct sysctl_req *req)
2687{
2688 int error;
2689 char *fullpath, *freepath;
2690 int vfslocked;
2691
2692 bzero(kif, sizeof(*kif));
2693 kif->kf_structsize = sizeof(*kif);
2694
2695 vref(vp);
2696 kif->kf_fd = type;
2697 kif->kf_type = KF_TYPE_VNODE;
2698 /* This function only handles directories. */
2699 if (vp->v_type != VDIR) {
2700 vrele(vp);
2701 return (ENOTDIR);
2702 }
2703 kif->kf_vnode_type = KF_VTYPE_VDIR;
2704
2705 /*
2706 * This is not a true file descriptor, so we set a bogus refcount
2707 * and offset to indicate these fields should be ignored.
2708 */
2709 kif->kf_ref_count = -1;
2710 kif->kf_offset = -1;
2711
2712 freepath = NULL;
2713 fullpath = "-";
2714 FILEDESC_SUNLOCK(fdp);
2715 vn_fullpath(curthread, vp, &fullpath, &freepath);
2716 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
2717 vrele(vp);
2718 VFS_UNLOCK_GIANT(vfslocked);
2719 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
2720 if (freepath != NULL)
2721 free(freepath, M_TEMP);
2722 error = SYSCTL_OUT(req, kif, sizeof(*kif));
2723 FILEDESC_SLOCK(fdp);
2724 return (error);
2725}
2726
2727/*
2728 * Get per-process file descriptors for use by procstat(1), et al.
2729 */
2730static int
2731sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS)
2732{
2733 char *fullpath, *freepath;
2734 struct kinfo_ofile *kif;
2735 struct filedesc *fdp;
2736 int error, i, *name;
2737 struct socket *so;
2738 struct vnode *vp;
2739 struct file *fp;
2740 struct proc *p;
2741 struct tty *tp;
2742 int vfslocked;
2743
2744 name = (int *)arg1;
2745 if ((p = pfind((pid_t)name[0])) == NULL)
2746 return (ESRCH);
2747 if ((error = p_candebug(curthread, p))) {
2748 PROC_UNLOCK(p);
2749 return (error);
2750 }
2751 fdp = fdhold(p);
2752 PROC_UNLOCK(p);
2753 if (fdp == NULL)
2754 return (ENOENT);
2755 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK);
2756 FILEDESC_SLOCK(fdp);
2757 if (fdp->fd_cdir != NULL)
2758 export_vnode_for_osysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif,
2759 fdp, req);
2760 if (fdp->fd_rdir != NULL)
2761 export_vnode_for_osysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif,
2762 fdp, req);
2763 if (fdp->fd_jdir != NULL)
2764 export_vnode_for_osysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif,
2765 fdp, req);
2766 for (i = 0; i < fdp->fd_nfiles; i++) {
2767 if ((fp = fdp->fd_ofiles[i]) == NULL)
2768 continue;
2769 bzero(kif, sizeof(*kif));
2770 kif->kf_structsize = sizeof(*kif);
2771 vp = NULL;
2772 so = NULL;
2773 tp = NULL;
2774 kif->kf_fd = i;
2775 switch (fp->f_type) {
2776 case DTYPE_VNODE:
2777 kif->kf_type = KF_TYPE_VNODE;
2778 vp = fp->f_vnode;
2779 break;
2780
2781 case DTYPE_SOCKET:
2782 kif->kf_type = KF_TYPE_SOCKET;
2783 so = fp->f_data;
2784 break;
2785
2786 case DTYPE_PIPE:
2787 kif->kf_type = KF_TYPE_PIPE;
2788 break;
2789
2790 case DTYPE_FIFO:
2791 kif->kf_type = KF_TYPE_FIFO;
2792 vp = fp->f_vnode;
2793 break;
2794
2795 case DTYPE_KQUEUE:
2796 kif->kf_type = KF_TYPE_KQUEUE;
2797 break;
2798
2799 case DTYPE_CRYPTO:
2800 kif->kf_type = KF_TYPE_CRYPTO;
2801 break;
2802
2803 case DTYPE_MQUEUE:
2804 kif->kf_type = KF_TYPE_MQUEUE;
2805 break;
2806
2807 case DTYPE_SHM:
2808 kif->kf_type = KF_TYPE_SHM;
2809 break;
2810
2811 case DTYPE_SEM:
2812 kif->kf_type = KF_TYPE_SEM;
2813 break;
2814
2815 case DTYPE_PTS:
2816 kif->kf_type = KF_TYPE_PTS;
2817 tp = fp->f_data;
2818 break;
2819
2820 default:
2821 kif->kf_type = KF_TYPE_UNKNOWN;
2822 break;
2823 }
2824 kif->kf_ref_count = fp->f_count;
2825 if (fp->f_flag & FREAD)
2826 kif->kf_flags |= KF_FLAG_READ;
2827 if (fp->f_flag & FWRITE)
2828 kif->kf_flags |= KF_FLAG_WRITE;
2829 if (fp->f_flag & FAPPEND)
2830 kif->kf_flags |= KF_FLAG_APPEND;
2831 if (fp->f_flag & FASYNC)
2832 kif->kf_flags |= KF_FLAG_ASYNC;
2833 if (fp->f_flag & FFSYNC)
2834 kif->kf_flags |= KF_FLAG_FSYNC;
2835 if (fp->f_flag & FNONBLOCK)
2836 kif->kf_flags |= KF_FLAG_NONBLOCK;
2837 if (fp->f_flag & O_DIRECT)
2838 kif->kf_flags |= KF_FLAG_DIRECT;
2839 if (fp->f_flag & FHASLOCK)
2840 kif->kf_flags |= KF_FLAG_HASLOCK;
2841 kif->kf_offset = fp->f_offset;
2842 if (vp != NULL) {
2843 vref(vp);
2844 switch (vp->v_type) {
2845 case VNON:
2846 kif->kf_vnode_type = KF_VTYPE_VNON;
2847 break;
2848 case VREG:
2849 kif->kf_vnode_type = KF_VTYPE_VREG;
2850 break;
2851 case VDIR:
2852 kif->kf_vnode_type = KF_VTYPE_VDIR;
2853 break;
2854 case VBLK:
2855 kif->kf_vnode_type = KF_VTYPE_VBLK;
2856 break;
2857 case VCHR:
2858 kif->kf_vnode_type = KF_VTYPE_VCHR;
2859 break;
2860 case VLNK:
2861 kif->kf_vnode_type = KF_VTYPE_VLNK;
2862 break;
2863 case VSOCK:
2864 kif->kf_vnode_type = KF_VTYPE_VSOCK;
2865 break;
2866 case VFIFO:
2867 kif->kf_vnode_type = KF_VTYPE_VFIFO;
2868 break;
2869 case VBAD:
2870 kif->kf_vnode_type = KF_VTYPE_VBAD;
2871 break;
2872 default:
2873 kif->kf_vnode_type = KF_VTYPE_UNKNOWN;
2874 break;
2875 }
2876 /*
2877 * It is OK to drop the filedesc lock here as we will
2878 * re-validate and re-evaluate its properties when
2879 * the loop continues.
2880 */
2881 freepath = NULL;
2882 fullpath = "-";
2883 FILEDESC_SUNLOCK(fdp);
2884 vn_fullpath(curthread, vp, &fullpath, &freepath);
2885 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
2886 vrele(vp);
2887 VFS_UNLOCK_GIANT(vfslocked);
2888 strlcpy(kif->kf_path, fullpath,
2889 sizeof(kif->kf_path));
2890 if (freepath != NULL)
2891 free(freepath, M_TEMP);
2892 FILEDESC_SLOCK(fdp);
2893 }
2894 if (so != NULL) {
2895 struct sockaddr *sa;
2896
2897 if (so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa)
2898 == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) {
2899 bcopy(sa, &kif->kf_sa_local, sa->sa_len);
2900 free(sa, M_SONAME);
2901 }
2902 if (so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa)
2903 == 0 && sa->sa_len <= sizeof(kif->kf_sa_peer)) {
2904 bcopy(sa, &kif->kf_sa_peer, sa->sa_len);
2905 free(sa, M_SONAME);
2906 }
2907 kif->kf_sock_domain =
2908 so->so_proto->pr_domain->dom_family;
2909 kif->kf_sock_type = so->so_type;
2910 kif->kf_sock_protocol = so->so_proto->pr_protocol;
2911 }
2912 if (tp != NULL) {
2913 strlcpy(kif->kf_path, tty_devname(tp),
2914 sizeof(kif->kf_path));
2915 }
2916 error = SYSCTL_OUT(req, kif, sizeof(*kif));
2917 if (error)
2918 break;
2919 }
2920 FILEDESC_SUNLOCK(fdp);
2921 fddrop(fdp);
2922 free(kif, M_TEMP);
2923 return (0);
2924}
2925
2926static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, CTLFLAG_RD,
2927 sysctl_kern_proc_ofiledesc, "Process ofiledesc entries");
2928#endif /* COMPAT_FREEBSD7 */
2929
2930#ifdef KINFO_FILE_SIZE
2931CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE);
2932#endif
2933
2934static int
2935export_vnode_for_sysctl(struct vnode *vp, int type,
2936 struct kinfo_file *kif, struct filedesc *fdp, struct sysctl_req *req)
2937{
2938 int error;
2939 char *fullpath, *freepath;
2940 int vfslocked;
2941
2942 bzero(kif, sizeof(*kif));
2943
2944 vref(vp);
2945 kif->kf_fd = type;
2946 kif->kf_type = KF_TYPE_VNODE;
2947 /* This function only handles directories. */
2948 if (vp->v_type != VDIR) {
2949 vrele(vp);
2950 return (ENOTDIR);
2951 }
2952 kif->kf_vnode_type = KF_VTYPE_VDIR;
2953
2954 /*
2955 * This is not a true file descriptor, so we set a bogus refcount
2956 * and offset to indicate these fields should be ignored.
2957 */
2958 kif->kf_ref_count = -1;
2959 kif->kf_offset = -1;
2960
2961 freepath = NULL;
2962 fullpath = "-";
2963 FILEDESC_SUNLOCK(fdp);
2964 vn_fullpath(curthread, vp, &fullpath, &freepath);
2965 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
2966 vrele(vp);
2967 VFS_UNLOCK_GIANT(vfslocked);
2968 strlcpy(kif->kf_path, fullpath, sizeof(kif->kf_path));
2969 if (freepath != NULL)
2970 free(freepath, M_TEMP);
2971 /* Pack record size down */
2972 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) +
2973 strlen(kif->kf_path) + 1;
2974 kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t));
2975 error = SYSCTL_OUT(req, kif, kif->kf_structsize);
2976 FILEDESC_SLOCK(fdp);
2977 return (error);
2978}
2979
2980/*
2981 * Get per-process file descriptors for use by procstat(1), et al.
2982 */
2983static int
2984sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS)
2985{
2986 char *fullpath, *freepath;
2987 struct kinfo_file *kif;
2988 struct filedesc *fdp;
2989 int error, i, *name;
2990 struct socket *so;
2991 struct vnode *vp;
2992 struct file *fp;
2993 struct proc *p;
2994 struct tty *tp;
2995 int vfslocked;
2996 size_t oldidx;
2997
2998 name = (int *)arg1;
2999 if ((p = pfind((pid_t)name[0])) == NULL)
3000 return (ESRCH);
3001 if ((error = p_candebug(curthread, p))) {
3002 PROC_UNLOCK(p);
3003 return (error);
3004 }
3005 fdp = fdhold(p);
3006 PROC_UNLOCK(p);
3007 if (fdp == NULL)
3008 return (ENOENT);
3009 kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK);
3010 FILEDESC_SLOCK(fdp);
3011 if (fdp->fd_cdir != NULL)
3012 export_vnode_for_sysctl(fdp->fd_cdir, KF_FD_TYPE_CWD, kif,
3013 fdp, req);
3014 if (fdp->fd_rdir != NULL)
3015 export_vnode_for_sysctl(fdp->fd_rdir, KF_FD_TYPE_ROOT, kif,
3016 fdp, req);
3017 if (fdp->fd_jdir != NULL)
3018 export_vnode_for_sysctl(fdp->fd_jdir, KF_FD_TYPE_JAIL, kif,
3019 fdp, req);
3020 for (i = 0; i < fdp->fd_nfiles; i++) {
3021 if ((fp = fdp->fd_ofiles[i]) == NULL)
3022 continue;
3023 bzero(kif, sizeof(*kif));
3024 vp = NULL;
3025 so = NULL;
3026 tp = NULL;
3027 kif->kf_fd = i;
3028 switch (fp->f_type) {
3029 case DTYPE_VNODE:
3030 kif->kf_type = KF_TYPE_VNODE;
3031 vp = fp->f_vnode;
3032 break;
3033
3034 case DTYPE_SOCKET:
3035 kif->kf_type = KF_TYPE_SOCKET;
3036 so = fp->f_data;
3037 break;
3038
3039 case DTYPE_PIPE:
3040 kif->kf_type = KF_TYPE_PIPE;
3041 break;
3042
3043 case DTYPE_FIFO:
3044 kif->kf_type = KF_TYPE_FIFO;
3045 vp = fp->f_vnode;
3046 break;
3047
3048 case DTYPE_KQUEUE:
3049 kif->kf_type = KF_TYPE_KQUEUE;
3050 break;
3051
3052 case DTYPE_CRYPTO:
3053 kif->kf_type = KF_TYPE_CRYPTO;
3054 break;
3055
3056 case DTYPE_MQUEUE:
3057 kif->kf_type = KF_TYPE_MQUEUE;
3058 break;
3059
3060 case DTYPE_SHM:
3061 kif->kf_type = KF_TYPE_SHM;
3062 break;
3063
3064 case DTYPE_SEM:
3065 kif->kf_type = KF_TYPE_SEM;
3066 break;
3067
3068 case DTYPE_PTS:
3069 kif->kf_type = KF_TYPE_PTS;
3070 tp = fp->f_data;
3071 break;
3072
3073 default:
3074 kif->kf_type = KF_TYPE_UNKNOWN;
3075 break;
3076 }
3077 kif->kf_ref_count = fp->f_count;
3078 if (fp->f_flag & FREAD)
3079 kif->kf_flags |= KF_FLAG_READ;
3080 if (fp->f_flag & FWRITE)
3081 kif->kf_flags |= KF_FLAG_WRITE;
3082 if (fp->f_flag & FAPPEND)
3083 kif->kf_flags |= KF_FLAG_APPEND;
3084 if (fp->f_flag & FASYNC)
3085 kif->kf_flags |= KF_FLAG_ASYNC;
3086 if (fp->f_flag & FFSYNC)
3087 kif->kf_flags |= KF_FLAG_FSYNC;
3088 if (fp->f_flag & FNONBLOCK)
3089 kif->kf_flags |= KF_FLAG_NONBLOCK;
3090 if (fp->f_flag & O_DIRECT)
3091 kif->kf_flags |= KF_FLAG_DIRECT;
3092 if (fp->f_flag & FHASLOCK)
3093 kif->kf_flags |= KF_FLAG_HASLOCK;
3094 kif->kf_offset = fp->f_offset;
3095 if (vp != NULL) {
3096 vref(vp);
3097 switch (vp->v_type) {
3098 case VNON:
3099 kif->kf_vnode_type = KF_VTYPE_VNON;
3100 break;
3101 case VREG:
3102 kif->kf_vnode_type = KF_VTYPE_VREG;
3103 break;
3104 case VDIR:
3105 kif->kf_vnode_type = KF_VTYPE_VDIR;
3106 break;
3107 case VBLK:
3108 kif->kf_vnode_type = KF_VTYPE_VBLK;
3109 break;
3110 case VCHR:
3111 kif->kf_vnode_type = KF_VTYPE_VCHR;
3112 break;
3113 case VLNK:
3114 kif->kf_vnode_type = KF_VTYPE_VLNK;
3115 break;
3116 case VSOCK:
3117 kif->kf_vnode_type = KF_VTYPE_VSOCK;
3118 break;
3119 case VFIFO:
3120 kif->kf_vnode_type = KF_VTYPE_VFIFO;
3121 break;
3122 case VBAD:
3123 kif->kf_vnode_type = KF_VTYPE_VBAD;
3124 break;
3125 default:
3126 kif->kf_vnode_type = KF_VTYPE_UNKNOWN;
3127 break;
3128 }
3129 /*
3130 * It is OK to drop the filedesc lock here as we will
3131 * re-validate and re-evaluate its properties when
3132 * the loop continues.
3133 */
3134 freepath = NULL;
3135 fullpath = "-";
3136 FILEDESC_SUNLOCK(fdp);
3137 vn_fullpath(curthread, vp, &fullpath, &freepath);
3138 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
3139 vrele(vp);
3140 VFS_UNLOCK_GIANT(vfslocked);
3141 strlcpy(kif->kf_path, fullpath,
3142 sizeof(kif->kf_path));
3143 if (freepath != NULL)
3144 free(freepath, M_TEMP);
3145 FILEDESC_SLOCK(fdp);
3146 }
3147 if (so != NULL) {
3148 struct sockaddr *sa;
3149
3150 if (so->so_proto->pr_usrreqs->pru_sockaddr(so, &sa)
3151 == 0 && sa->sa_len <= sizeof(kif->kf_sa_local)) {
3152 bcopy(sa, &kif->kf_sa_local, sa->sa_len);
3153 free(sa, M_SONAME);
3154 }
3155 if (so->so_proto->pr_usrreqs->pru_peeraddr(so, &sa)
3156 == 0 && sa->sa_len <= sizeof(kif->kf_sa_peer)) {
3157 bcopy(sa, &kif->kf_sa_peer, sa->sa_len);
3158 free(sa, M_SONAME);
3159 }
3160 kif->kf_sock_domain =
3161 so->so_proto->pr_domain->dom_family;
3162 kif->kf_sock_type = so->so_type;
3163 kif->kf_sock_protocol = so->so_proto->pr_protocol;
3164 }
3165 if (tp != NULL) {
3166 strlcpy(kif->kf_path, tty_devname(tp),
3167 sizeof(kif->kf_path));
3168 }
3169 /* Pack record size down */
3170 kif->kf_structsize = offsetof(struct kinfo_file, kf_path) +
3171 strlen(kif->kf_path) + 1;
3172 kif->kf_structsize = roundup(kif->kf_structsize,
3173 sizeof(uint64_t));
3174 oldidx = req->oldidx;
3175 error = SYSCTL_OUT(req, kif, kif->kf_structsize);
3176 if (error) {
3177 if (error == ENOMEM) {
3178 /*
3179 * The hack to keep the ABI of sysctl
3180 * kern.proc.filedesc intact, but not
3181 * to account a partially copied
3182 * kinfo_file into the oldidx.
3183 */
3184 req->oldidx = oldidx;
3185 error = 0;
3186 }
3187 break;
3188 }
3189 }
3190 FILEDESC_SUNLOCK(fdp);
3191 fddrop(fdp);
3192 free(kif, M_TEMP);
3193 return (error);
3194}
3195
3196static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, CTLFLAG_RD,
3197 sysctl_kern_proc_filedesc, "Process filedesc entries");
3198
3199#ifdef DDB
3200/*
3201 * For the purposes of debugging, generate a human-readable string for the
3202 * file type.
3203 */
3204static const char *
3205file_type_to_name(short type)
3206{
3207
3208 switch (type) {
3209 case 0:
3210 return ("zero");
3211 case DTYPE_VNODE:
3212 return ("vnod");
3213 case DTYPE_SOCKET:
3214 return ("sock");
3215 case DTYPE_PIPE:
3216 return ("pipe");
3217 case DTYPE_FIFO:
3218 return ("fifo");
3219 case DTYPE_KQUEUE:
3220 return ("kque");
3221 case DTYPE_CRYPTO:
3222 return ("crpt");
3223 case DTYPE_MQUEUE:
3224 return ("mque");
3225 case DTYPE_SHM:
3226 return ("shm");
3227 case DTYPE_SEM:
3228 return ("ksem");
3229 default:
3230 return ("unkn");
3231 }
3232}
3233
3234/*
3235 * For the purposes of debugging, identify a process (if any, perhaps one of
3236 * many) that references the passed file in its file descriptor array. Return
3237 * NULL if none.
3238 */
3239static struct proc *
3240file_to_first_proc(struct file *fp)
3241{
3242 struct filedesc *fdp;
3243 struct proc *p;
3244 int n;
3245
3246 FOREACH_PROC_IN_SYSTEM(p) {
3247 if (p->p_state == PRS_NEW)
3248 continue;
3249 fdp = p->p_fd;
3250 if (fdp == NULL)
3251 continue;
3252 for (n = 0; n < fdp->fd_nfiles; n++) {
3253 if (fp == fdp->fd_ofiles[n])
3254 return (p);
3255 }
3256 }
3257 return (NULL);
3258}
3259
3260static void
3261db_print_file(struct file *fp, int header)
3262{
3263 struct proc *p;
3264
3265 if (header)
3266 db_printf("%8s %4s %8s %8s %4s %5s %6s %8s %5s %12s\n",
3267 "File", "Type", "Data", "Flag", "GCFl", "Count",
3268 "MCount", "Vnode", "FPID", "FCmd");
3269 p = file_to_first_proc(fp);
3270 db_printf("%8p %4s %8p %08x %04x %5d %6d %8p %5d %12s\n", fp,
3271 file_type_to_name(fp->f_type), fp->f_data, fp->f_flag,
3272 0, fp->f_count, 0, fp->f_vnode,
3273 p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-");
3274}
3275
3276DB_SHOW_COMMAND(file, db_show_file)
3277{
3278 struct file *fp;
3279
3280 if (!have_addr) {
3281 db_printf("usage: show file <addr>\n");
3282 return;
3283 }
3284 fp = (struct file *)addr;
3285 db_print_file(fp, 1);
3286}
3287
3288DB_SHOW_COMMAND(files, db_show_files)
3289{
3290 struct filedesc *fdp;
3291 struct file *fp;
3292 struct proc *p;
3293 int header;
3294 int n;
3295
3296 header = 1;
3297 FOREACH_PROC_IN_SYSTEM(p) {
3298 if (p->p_state == PRS_NEW)
3299 continue;
3300 if ((fdp = p->p_fd) == NULL)
3301 continue;
3302 for (n = 0; n < fdp->fd_nfiles; ++n) {
3303 if ((fp = fdp->fd_ofiles[n]) == NULL)
3304 continue;
3305 db_print_file(fp, header);
3306 header = 0;
3307 }
3308 }
3309}
3310#endif
3311
3312SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW,
3313 &maxfilesperproc, 0, "Maximum files allowed open per process");
3314
3315SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW,
3316 &maxfiles, 0, "Maximum number of files");
3317
3318SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD,
3319 __DEVOLATILE(int *, &openfiles), 0, "System-wide number of open files");
3320
3321/* ARGSUSED*/
3322static void
3323filelistinit(void *dummy)
3324{
3325
3326 file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL,
3327 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
3328 mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF);
3329 mtx_init(&fdesc_mtx, "fdesc", NULL, MTX_DEF);
3330}
3331SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL);
3332
3333/*-------------------------------------------------------------------*/
3334
3335static int
3336badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td)
3337{
3338
3339 return (EBADF);
3340}
3341
3342static int
3343badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, struct thread *td)
3344{
3345
3346 return (EINVAL);
3347}
3348
3349static int
3350badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, struct thread *td)
3351{
3352
3353 return (EBADF);
3354}
3355
3356static int
3357badfo_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td)
3358{
3359
3360 return (0);
3361}
3362
3363static int
3364badfo_kqfilter(struct file *fp, struct knote *kn)
3365{
3366
3367 return (EBADF);
3368}
3369
3370static int
3371badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred, struct thread *td)
3372{
3373
3374 return (EBADF);
3375}
3376
3377static int
3378badfo_close(struct file *fp, struct thread *td)
3379{
3380
3381 return (EBADF);
3382}
3383
3384struct fileops badfileops = {
3385 .fo_read = badfo_readwrite,
3386 .fo_write = badfo_readwrite,
3387 .fo_truncate = badfo_truncate,
3388 .fo_ioctl = badfo_ioctl,
3389 .fo_poll = badfo_poll,
3390 .fo_kqfilter = badfo_kqfilter,
3391 .fo_stat = badfo_stat,
3392 .fo_close = badfo_close,
3393};
3394
3395
3396/*-------------------------------------------------------------------*/
3397
3398/*
3399 * File Descriptor pseudo-device driver (/dev/fd/).
3400 *
3401 * Opening minor device N dup()s the file (if any) connected to file
3402 * descriptor N belonging to the calling process. Note that this driver
3403 * consists of only the ``open()'' routine, because all subsequent
3404 * references to this file will be direct to the other driver.
3405 *
3406 * XXX: we could give this one a cloning event handler if necessary.
3407 */
3408
3409/* ARGSUSED */
3410static int
3411fdopen(struct cdev *dev, int mode, int type, struct thread *td)
3412{
3413
3414 /*
3415 * XXX Kludge: set curthread->td_dupfd to contain the value of the
3416 * the file descriptor being sought for duplication. The error
3417 * return ensures that the vnode for this device will be released
3418 * by vn_open. Open will detect this special error and take the
3419 * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN
3420 * will simply report the error.
3421 */
3422 td->td_dupfd = dev2unit(dev);
3423 return (ENODEV);
3424}
3425
3426static struct cdevsw fildesc_cdevsw = {
3427 .d_version = D_VERSION,
3428 .d_open = fdopen,
3429 .d_name = "FD",
3430};
3431
3432static void
3433fildesc_drvinit(void *unused)
3434{
3435 struct cdev *dev;
3436
3437 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL,
3438 UID_ROOT, GID_WHEEL, 0666, "fd/0");
3439 make_dev_alias(dev, "stdin");
3440 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL,
3441 UID_ROOT, GID_WHEEL, 0666, "fd/1");
3442 make_dev_alias(dev, "stdout");
3443 dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL,
3444 UID_ROOT, GID_WHEEL, 0666, "fd/2");
3445 make_dev_alias(dev, "stderr");
3446}
3447
3448SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL);
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