1 /*-
2 * Copyright (c) 1982, 1986, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)sys_generic.c 8.5 (Berkeley) 1/21/94
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD: releng/10.3/sys/kern/sys_generic.c 280258 2015-03-19 13:37:36Z rwatson $");
39
40 #include "opt_capsicum.h"
41 #include "opt_compat.h"
42 #include "opt_ktrace.h"
43
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/sysproto.h>
47 #include <sys/capsicum.h>
48 #include <sys/filedesc.h>
49 #include <sys/filio.h>
50 #include <sys/fcntl.h>
51 #include <sys/file.h>
52 #include <sys/lock.h>
53 #include <sys/proc.h>
54 #include <sys/signalvar.h>
55 #include <sys/socketvar.h>
56 #include <sys/uio.h>
57 #include <sys/kernel.h>
58 #include <sys/ktr.h>
59 #include <sys/limits.h>
60 #include <sys/malloc.h>
61 #include <sys/poll.h>
62 #include <sys/resourcevar.h>
63 #include <sys/selinfo.h>
64 #include <sys/sleepqueue.h>
65 #include <sys/syscallsubr.h>
66 #include <sys/sysctl.h>
67 #include <sys/sysent.h>
68 #include <sys/vnode.h>
69 #include <sys/bio.h>
70 #include <sys/buf.h>
71 #include <sys/condvar.h>
72 #ifdef KTRACE
73 #include <sys/ktrace.h>
74 #endif
75
76 #include <security/audit/audit.h>
77
78 /*
79 * The following macro defines how many bytes will be allocated from
80 * the stack instead of memory allocated when passing the IOCTL data
81 * structures from userspace and to the kernel. Some IOCTLs having
82 * small data structures are used very frequently and this small
83 * buffer on the stack gives a significant speedup improvement for
84 * those requests. The value of this define should be greater or equal
85 * to 64 bytes and should also be power of two. The data structure is
86 * currently hard-aligned to a 8-byte boundary on the stack. This
87 * should currently be sufficient for all supported platforms.
88 */
89 #define SYS_IOCTL_SMALL_SIZE 128 /* bytes */
90 #define SYS_IOCTL_SMALL_ALIGN 8 /* bytes */
91
92 int iosize_max_clamp = 1;
93 SYSCTL_INT(_debug, OID_AUTO, iosize_max_clamp, CTLFLAG_RW,
94 &iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX");
95 int devfs_iosize_max_clamp = 1;
96 SYSCTL_INT(_debug, OID_AUTO, devfs_iosize_max_clamp, CTLFLAG_RW,
97 &devfs_iosize_max_clamp, 0, "Clamp max i/o size to INT_MAX for devices");
98
99 /*
100 * Assert that the return value of read(2) and write(2) syscalls fits
101 * into a register. If not, an architecture will need to provide the
102 * usermode wrappers to reconstruct the result.
103 */
104 CTASSERT(sizeof(register_t) >= sizeof(size_t));
105
106 static MALLOC_DEFINE(M_IOCTLOPS, "ioctlops", "ioctl data buffer");
107 static MALLOC_DEFINE(M_SELECT, "select", "select() buffer");
108 MALLOC_DEFINE(M_IOV, "iov", "large iov's");
109
110 static int pollout(struct thread *, struct pollfd *, struct pollfd *,
111 u_int);
112 static int pollscan(struct thread *, struct pollfd *, u_int);
113 static int pollrescan(struct thread *);
114 static int selscan(struct thread *, fd_mask **, fd_mask **, int);
115 static int selrescan(struct thread *, fd_mask **, fd_mask **);
116 static void selfdalloc(struct thread *, void *);
117 static void selfdfree(struct seltd *, struct selfd *);
118 static int dofileread(struct thread *, int, struct file *, struct uio *,
119 off_t, int);
120 static int dofilewrite(struct thread *, int, struct file *, struct uio *,
121 off_t, int);
122 static void doselwakeup(struct selinfo *, int);
123 static void seltdinit(struct thread *);
124 static int seltdwait(struct thread *, sbintime_t, sbintime_t);
125 static void seltdclear(struct thread *);
126
127 /*
128 * One seltd per-thread allocated on demand as needed.
129 *
130 * t - protected by st_mtx
131 * k - Only accessed by curthread or read-only
132 */
133 struct seltd {
134 STAILQ_HEAD(, selfd) st_selq; /* (k) List of selfds. */
135 struct selfd *st_free1; /* (k) free fd for read set. */
136 struct selfd *st_free2; /* (k) free fd for write set. */
137 struct mtx st_mtx; /* Protects struct seltd */
138 struct cv st_wait; /* (t) Wait channel. */
139 int st_flags; /* (t) SELTD_ flags. */
140 };
141
142 #define SELTD_PENDING 0x0001 /* We have pending events. */
143 #define SELTD_RESCAN 0x0002 /* Doing a rescan. */
144
145 /*
146 * One selfd allocated per-thread per-file-descriptor.
147 * f - protected by sf_mtx
148 */
149 struct selfd {
150 STAILQ_ENTRY(selfd) sf_link; /* (k) fds owned by this td. */
151 TAILQ_ENTRY(selfd) sf_threads; /* (f) fds on this selinfo. */
152 struct selinfo *sf_si; /* (f) selinfo when linked. */
153 struct mtx *sf_mtx; /* Pointer to selinfo mtx. */
154 struct seltd *sf_td; /* (k) owning seltd. */
155 void *sf_cookie; /* (k) fd or pollfd. */
156 };
157
158 static uma_zone_t selfd_zone;
159 static struct mtx_pool *mtxpool_select;
160
161 #ifndef _SYS_SYSPROTO_H_
162 struct read_args {
163 int fd;
164 void *buf;
165 size_t nbyte;
166 };
167 #endif
168 int
169 sys_read(td, uap)
170 struct thread *td;
171 struct read_args *uap;
172 {
173 struct uio auio;
174 struct iovec aiov;
175 int error;
176
177 if (uap->nbyte > IOSIZE_MAX)
178 return (EINVAL);
179 aiov.iov_base = uap->buf;
180 aiov.iov_len = uap->nbyte;
181 auio.uio_iov = &aiov;
182 auio.uio_iovcnt = 1;
183 auio.uio_resid = uap->nbyte;
184 auio.uio_segflg = UIO_USERSPACE;
185 error = kern_readv(td, uap->fd, &auio);
186 return(error);
187 }
188
189 /*
190 * Positioned read system call
191 */
192 #ifndef _SYS_SYSPROTO_H_
193 struct pread_args {
194 int fd;
195 void *buf;
196 size_t nbyte;
197 int pad;
198 off_t offset;
199 };
200 #endif
201 int
202 sys_pread(td, uap)
203 struct thread *td;
204 struct pread_args *uap;
205 {
206 struct uio auio;
207 struct iovec aiov;
208 int error;
209
210 if (uap->nbyte > IOSIZE_MAX)
211 return (EINVAL);
212 aiov.iov_base = uap->buf;
213 aiov.iov_len = uap->nbyte;
214 auio.uio_iov = &aiov;
215 auio.uio_iovcnt = 1;
216 auio.uio_resid = uap->nbyte;
217 auio.uio_segflg = UIO_USERSPACE;
218 error = kern_preadv(td, uap->fd, &auio, uap->offset);
219 return(error);
220 }
221
222 int
223 freebsd6_pread(td, uap)
224 struct thread *td;
225 struct freebsd6_pread_args *uap;
226 {
227 struct pread_args oargs;
228
229 oargs.fd = uap->fd;
230 oargs.buf = uap->buf;
231 oargs.nbyte = uap->nbyte;
232 oargs.offset = uap->offset;
233 return (sys_pread(td, &oargs));
234 }
235
236 /*
237 * Scatter read system call.
238 */
239 #ifndef _SYS_SYSPROTO_H_
240 struct readv_args {
241 int fd;
242 struct iovec *iovp;
243 u_int iovcnt;
244 };
245 #endif
246 int
247 sys_readv(struct thread *td, struct readv_args *uap)
248 {
249 struct uio *auio;
250 int error;
251
252 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
253 if (error)
254 return (error);
255 error = kern_readv(td, uap->fd, auio);
256 free(auio, M_IOV);
257 return (error);
258 }
259
260 int
261 kern_readv(struct thread *td, int fd, struct uio *auio)
262 {
263 struct file *fp;
264 cap_rights_t rights;
265 int error;
266
267 error = fget_read(td, fd, cap_rights_init(&rights, CAP_READ), &fp);
268 if (error)
269 return (error);
270 error = dofileread(td, fd, fp, auio, (off_t)-1, 0);
271 fdrop(fp, td);
272 return (error);
273 }
274
275 /*
276 * Scatter positioned read system call.
277 */
278 #ifndef _SYS_SYSPROTO_H_
279 struct preadv_args {
280 int fd;
281 struct iovec *iovp;
282 u_int iovcnt;
283 off_t offset;
284 };
285 #endif
286 int
287 sys_preadv(struct thread *td, struct preadv_args *uap)
288 {
289 struct uio *auio;
290 int error;
291
292 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
293 if (error)
294 return (error);
295 error = kern_preadv(td, uap->fd, auio, uap->offset);
296 free(auio, M_IOV);
297 return (error);
298 }
299
300 int
301 kern_preadv(td, fd, auio, offset)
302 struct thread *td;
303 int fd;
304 struct uio *auio;
305 off_t offset;
306 {
307 struct file *fp;
308 cap_rights_t rights;
309 int error;
310
311 error = fget_read(td, fd, cap_rights_init(&rights, CAP_PREAD), &fp);
312 if (error)
313 return (error);
314 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
315 error = ESPIPE;
316 else if (offset < 0 && fp->f_vnode->v_type != VCHR)
317 error = EINVAL;
318 else
319 error = dofileread(td, fd, fp, auio, offset, FOF_OFFSET);
320 fdrop(fp, td);
321 return (error);
322 }
323
324 /*
325 * Common code for readv and preadv that reads data in
326 * from a file using the passed in uio, offset, and flags.
327 */
328 static int
329 dofileread(td, fd, fp, auio, offset, flags)
330 struct thread *td;
331 int fd;
332 struct file *fp;
333 struct uio *auio;
334 off_t offset;
335 int flags;
336 {
337 ssize_t cnt;
338 int error;
339 #ifdef KTRACE
340 struct uio *ktruio = NULL;
341 #endif
342
343 /* Finish zero length reads right here */
344 if (auio->uio_resid == 0) {
345 td->td_retval[0] = 0;
346 return(0);
347 }
348 auio->uio_rw = UIO_READ;
349 auio->uio_offset = offset;
350 auio->uio_td = td;
351 #ifdef KTRACE
352 if (KTRPOINT(td, KTR_GENIO))
353 ktruio = cloneuio(auio);
354 #endif
355 cnt = auio->uio_resid;
356 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) {
357 if (auio->uio_resid != cnt && (error == ERESTART ||
358 error == EINTR || error == EWOULDBLOCK))
359 error = 0;
360 }
361 cnt -= auio->uio_resid;
362 #ifdef KTRACE
363 if (ktruio != NULL) {
364 ktruio->uio_resid = cnt;
365 ktrgenio(fd, UIO_READ, ktruio, error);
366 }
367 #endif
368 td->td_retval[0] = cnt;
369 return (error);
370 }
371
372 #ifndef _SYS_SYSPROTO_H_
373 struct write_args {
374 int fd;
375 const void *buf;
376 size_t nbyte;
377 };
378 #endif
379 int
380 sys_write(td, uap)
381 struct thread *td;
382 struct write_args *uap;
383 {
384 struct uio auio;
385 struct iovec aiov;
386 int error;
387
388 if (uap->nbyte > IOSIZE_MAX)
389 return (EINVAL);
390 aiov.iov_base = (void *)(uintptr_t)uap->buf;
391 aiov.iov_len = uap->nbyte;
392 auio.uio_iov = &aiov;
393 auio.uio_iovcnt = 1;
394 auio.uio_resid = uap->nbyte;
395 auio.uio_segflg = UIO_USERSPACE;
396 error = kern_writev(td, uap->fd, &auio);
397 return(error);
398 }
399
400 /*
401 * Positioned write system call.
402 */
403 #ifndef _SYS_SYSPROTO_H_
404 struct pwrite_args {
405 int fd;
406 const void *buf;
407 size_t nbyte;
408 int pad;
409 off_t offset;
410 };
411 #endif
412 int
413 sys_pwrite(td, uap)
414 struct thread *td;
415 struct pwrite_args *uap;
416 {
417 struct uio auio;
418 struct iovec aiov;
419 int error;
420
421 if (uap->nbyte > IOSIZE_MAX)
422 return (EINVAL);
423 aiov.iov_base = (void *)(uintptr_t)uap->buf;
424 aiov.iov_len = uap->nbyte;
425 auio.uio_iov = &aiov;
426 auio.uio_iovcnt = 1;
427 auio.uio_resid = uap->nbyte;
428 auio.uio_segflg = UIO_USERSPACE;
429 error = kern_pwritev(td, uap->fd, &auio, uap->offset);
430 return(error);
431 }
432
433 int
434 freebsd6_pwrite(td, uap)
435 struct thread *td;
436 struct freebsd6_pwrite_args *uap;
437 {
438 struct pwrite_args oargs;
439
440 oargs.fd = uap->fd;
441 oargs.buf = uap->buf;
442 oargs.nbyte = uap->nbyte;
443 oargs.offset = uap->offset;
444 return (sys_pwrite(td, &oargs));
445 }
446
447 /*
448 * Gather write system call.
449 */
450 #ifndef _SYS_SYSPROTO_H_
451 struct writev_args {
452 int fd;
453 struct iovec *iovp;
454 u_int iovcnt;
455 };
456 #endif
457 int
458 sys_writev(struct thread *td, struct writev_args *uap)
459 {
460 struct uio *auio;
461 int error;
462
463 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
464 if (error)
465 return (error);
466 error = kern_writev(td, uap->fd, auio);
467 free(auio, M_IOV);
468 return (error);
469 }
470
471 int
472 kern_writev(struct thread *td, int fd, struct uio *auio)
473 {
474 struct file *fp;
475 cap_rights_t rights;
476 int error;
477
478 error = fget_write(td, fd, cap_rights_init(&rights, CAP_WRITE), &fp);
479 if (error)
480 return (error);
481 error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0);
482 fdrop(fp, td);
483 return (error);
484 }
485
486 /*
487 * Gather positioned write system call.
488 */
489 #ifndef _SYS_SYSPROTO_H_
490 struct pwritev_args {
491 int fd;
492 struct iovec *iovp;
493 u_int iovcnt;
494 off_t offset;
495 };
496 #endif
497 int
498 sys_pwritev(struct thread *td, struct pwritev_args *uap)
499 {
500 struct uio *auio;
501 int error;
502
503 error = copyinuio(uap->iovp, uap->iovcnt, &auio);
504 if (error)
505 return (error);
506 error = kern_pwritev(td, uap->fd, auio, uap->offset);
507 free(auio, M_IOV);
508 return (error);
509 }
510
511 int
512 kern_pwritev(td, fd, auio, offset)
513 struct thread *td;
514 struct uio *auio;
515 int fd;
516 off_t offset;
517 {
518 struct file *fp;
519 cap_rights_t rights;
520 int error;
521
522 error = fget_write(td, fd, cap_rights_init(&rights, CAP_PWRITE), &fp);
523 if (error)
524 return (error);
525 if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE))
526 error = ESPIPE;
527 else if (offset < 0 && fp->f_vnode->v_type != VCHR)
528 error = EINVAL;
529 else
530 error = dofilewrite(td, fd, fp, auio, offset, FOF_OFFSET);
531 fdrop(fp, td);
532 return (error);
533 }
534
535 /*
536 * Common code for writev and pwritev that writes data to
537 * a file using the passed in uio, offset, and flags.
538 */
539 static int
540 dofilewrite(td, fd, fp, auio, offset, flags)
541 struct thread *td;
542 int fd;
543 struct file *fp;
544 struct uio *auio;
545 off_t offset;
546 int flags;
547 {
548 ssize_t cnt;
549 int error;
550 #ifdef KTRACE
551 struct uio *ktruio = NULL;
552 #endif
553
554 auio->uio_rw = UIO_WRITE;
555 auio->uio_td = td;
556 auio->uio_offset = offset;
557 #ifdef KTRACE
558 if (KTRPOINT(td, KTR_GENIO))
559 ktruio = cloneuio(auio);
560 #endif
561 cnt = auio->uio_resid;
562 if (fp->f_type == DTYPE_VNODE &&
563 (fp->f_vnread_flags & FDEVFS_VNODE) == 0)
564 bwillwrite();
565 if ((error = fo_write(fp, auio, td->td_ucred, flags, td))) {
566 if (auio->uio_resid != cnt && (error == ERESTART ||
567 error == EINTR || error == EWOULDBLOCK))
568 error = 0;
569 /* Socket layer is responsible for issuing SIGPIPE. */
570 if (fp->f_type != DTYPE_SOCKET && error == EPIPE) {
571 PROC_LOCK(td->td_proc);
572 tdsignal(td, SIGPIPE);
573 PROC_UNLOCK(td->td_proc);
574 }
575 }
576 cnt -= auio->uio_resid;
577 #ifdef KTRACE
578 if (ktruio != NULL) {
579 ktruio->uio_resid = cnt;
580 ktrgenio(fd, UIO_WRITE, ktruio, error);
581 }
582 #endif
583 td->td_retval[0] = cnt;
584 return (error);
585 }
586
587 /*
588 * Truncate a file given a file descriptor.
589 *
590 * Can't use fget_write() here, since must return EINVAL and not EBADF if the
591 * descriptor isn't writable.
592 */
593 int
594 kern_ftruncate(td, fd, length)
595 struct thread *td;
596 int fd;
597 off_t length;
598 {
599 struct file *fp;
600 cap_rights_t rights;
601 int error;
602
603 AUDIT_ARG_FD(fd);
604 if (length < 0)
605 return (EINVAL);
606 error = fget(td, fd, cap_rights_init(&rights, CAP_FTRUNCATE), &fp);
607 if (error)
608 return (error);
609 AUDIT_ARG_FILE(td->td_proc, fp);
610 if (!(fp->f_flag & FWRITE)) {
611 fdrop(fp, td);
612 return (EINVAL);
613 }
614 error = fo_truncate(fp, length, td->td_ucred, td);
615 fdrop(fp, td);
616 return (error);
617 }
618
619 #ifndef _SYS_SYSPROTO_H_
620 struct ftruncate_args {
621 int fd;
622 int pad;
623 off_t length;
624 };
625 #endif
626 int
627 sys_ftruncate(td, uap)
628 struct thread *td;
629 struct ftruncate_args *uap;
630 {
631
632 return (kern_ftruncate(td, uap->fd, uap->length));
633 }
634
635 #if defined(COMPAT_43)
636 #ifndef _SYS_SYSPROTO_H_
637 struct oftruncate_args {
638 int fd;
639 long length;
640 };
641 #endif
642 int
643 oftruncate(td, uap)
644 struct thread *td;
645 struct oftruncate_args *uap;
646 {
647
648 return (kern_ftruncate(td, uap->fd, uap->length));
649 }
650 #endif /* COMPAT_43 */
651
652 #ifndef _SYS_SYSPROTO_H_
653 struct ioctl_args {
654 int fd;
655 u_long com;
656 caddr_t data;
657 };
658 #endif
659 /* ARGSUSED */
660 int
661 sys_ioctl(struct thread *td, struct ioctl_args *uap)
662 {
663 u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN);
664 u_long com;
665 int arg, error;
666 u_int size;
667 caddr_t data;
668
669 if (uap->com > 0xffffffff) {
670 printf(
671 "WARNING pid %d (%s): ioctl sign-extension ioctl %lx\n",
672 td->td_proc->p_pid, td->td_name, uap->com);
673 uap->com &= 0xffffffff;
674 }
675 com = uap->com;
676
677 /*
678 * Interpret high order word to find amount of data to be
679 * copied to/from the user's address space.
680 */
681 size = IOCPARM_LEN(com);
682 if ((size > IOCPARM_MAX) ||
683 ((com & (IOC_VOID | IOC_IN | IOC_OUT)) == 0) ||
684 #if defined(COMPAT_FREEBSD5) || defined(COMPAT_FREEBSD4) || defined(COMPAT_43)
685 ((com & IOC_OUT) && size == 0) ||
686 #else
687 ((com & (IOC_IN | IOC_OUT)) && size == 0) ||
688 #endif
689 ((com & IOC_VOID) && size > 0 && size != sizeof(int)))
690 return (ENOTTY);
691
692 if (size > 0) {
693 if (com & IOC_VOID) {
694 /* Integer argument. */
695 arg = (intptr_t)uap->data;
696 data = (void *)&arg;
697 size = 0;
698 } else {
699 if (size > SYS_IOCTL_SMALL_SIZE)
700 data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK);
701 else
702 data = smalldata;
703 }
704 } else
705 data = (void *)&uap->data;
706 if (com & IOC_IN) {
707 error = copyin(uap->data, data, (u_int)size);
708 if (error != 0)
709 goto out;
710 } else if (com & IOC_OUT) {
711 /*
712 * Zero the buffer so the user always
713 * gets back something deterministic.
714 */
715 bzero(data, size);
716 }
717
718 error = kern_ioctl(td, uap->fd, com, data);
719
720 if (error == 0 && (com & IOC_OUT))
721 error = copyout(data, uap->data, (u_int)size);
722
723 out:
724 if (size > SYS_IOCTL_SMALL_SIZE)
725 free(data, M_IOCTLOPS);
726 return (error);
727 }
728
729 int
730 kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data)
731 {
732 struct file *fp;
733 struct filedesc *fdp;
734 #ifndef CAPABILITIES
735 cap_rights_t rights;
736 #endif
737 int error, tmp, locked;
738
739 AUDIT_ARG_FD(fd);
740 AUDIT_ARG_CMD(com);
741
742 fdp = td->td_proc->p_fd;
743
744 switch (com) {
745 case FIONCLEX:
746 case FIOCLEX:
747 FILEDESC_XLOCK(fdp);
748 locked = LA_XLOCKED;
749 break;
750 default:
751 #ifdef CAPABILITIES
752 FILEDESC_SLOCK(fdp);
753 locked = LA_SLOCKED;
754 #else
755 locked = LA_UNLOCKED;
756 #endif
757 break;
758 }
759
760 #ifdef CAPABILITIES
761 if ((fp = fget_locked(fdp, fd)) == NULL) {
762 error = EBADF;
763 goto out;
764 }
765 if ((error = cap_ioctl_check(fdp, fd, com)) != 0) {
766 fp = NULL; /* fhold() was not called yet */
767 goto out;
768 }
769 fhold(fp);
770 if (locked == LA_SLOCKED) {
771 FILEDESC_SUNLOCK(fdp);
772 locked = LA_UNLOCKED;
773 }
774 #else
775 error = fget(td, fd, cap_rights_init(&rights, CAP_IOCTL), &fp);
776 if (error != 0) {
777 fp = NULL;
778 goto out;
779 }
780 #endif
781 if ((fp->f_flag & (FREAD | FWRITE)) == 0) {
782 error = EBADF;
783 goto out;
784 }
785
786 switch (com) {
787 case FIONCLEX:
788 fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE;
789 goto out;
790 case FIOCLEX:
791 fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE;
792 goto out;
793 case FIONBIO:
794 if ((tmp = *(int *)data))
795 atomic_set_int(&fp->f_flag, FNONBLOCK);
796 else
797 atomic_clear_int(&fp->f_flag, FNONBLOCK);
798 data = (void *)&tmp;
799 break;
800 case FIOASYNC:
801 if ((tmp = *(int *)data))
802 atomic_set_int(&fp->f_flag, FASYNC);
803 else
804 atomic_clear_int(&fp->f_flag, FASYNC);
805 data = (void *)&tmp;
806 break;
807 }
808
809 error = fo_ioctl(fp, com, data, td->td_ucred, td);
810 out:
811 switch (locked) {
812 case LA_XLOCKED:
813 FILEDESC_XUNLOCK(fdp);
814 break;
815 #ifdef CAPABILITIES
816 case LA_SLOCKED:
817 FILEDESC_SUNLOCK(fdp);
818 break;
819 #endif
820 default:
821 FILEDESC_UNLOCK_ASSERT(fdp);
822 break;
823 }
824 if (fp != NULL)
825 fdrop(fp, td);
826 return (error);
827 }
828
829 int
830 poll_no_poll(int events)
831 {
832 /*
833 * Return true for read/write. If the user asked for something
834 * special, return POLLNVAL, so that clients have a way of
835 * determining reliably whether or not the extended
836 * functionality is present without hard-coding knowledge
837 * of specific filesystem implementations.
838 */
839 if (events & ~POLLSTANDARD)
840 return (POLLNVAL);
841
842 return (events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
843 }
844
845 int
846 sys_pselect(struct thread *td, struct pselect_args *uap)
847 {
848 struct timespec ts;
849 struct timeval tv, *tvp;
850 sigset_t set, *uset;
851 int error;
852
853 if (uap->ts != NULL) {
854 error = copyin(uap->ts, &ts, sizeof(ts));
855 if (error != 0)
856 return (error);
857 TIMESPEC_TO_TIMEVAL(&tv, &ts);
858 tvp = &tv;
859 } else
860 tvp = NULL;
861 if (uap->sm != NULL) {
862 error = copyin(uap->sm, &set, sizeof(set));
863 if (error != 0)
864 return (error);
865 uset = &set;
866 } else
867 uset = NULL;
868 return (kern_pselect(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
869 uset, NFDBITS));
870 }
871
872 int
873 kern_pselect(struct thread *td, int nd, fd_set *in, fd_set *ou, fd_set *ex,
874 struct timeval *tvp, sigset_t *uset, int abi_nfdbits)
875 {
876 int error;
877
878 if (uset != NULL) {
879 error = kern_sigprocmask(td, SIG_SETMASK, uset,
880 &td->td_oldsigmask, 0);
881 if (error != 0)
882 return (error);
883 td->td_pflags |= TDP_OLDMASK;
884 /*
885 * Make sure that ast() is called on return to
886 * usermode and TDP_OLDMASK is cleared, restoring old
887 * sigmask.
888 */
889 thread_lock(td);
890 td->td_flags |= TDF_ASTPENDING;
891 thread_unlock(td);
892 }
893 error = kern_select(td, nd, in, ou, ex, tvp, abi_nfdbits);
894 return (error);
895 }
896
897 #ifndef _SYS_SYSPROTO_H_
898 struct select_args {
899 int nd;
900 fd_set *in, *ou, *ex;
901 struct timeval *tv;
902 };
903 #endif
904 int
905 sys_select(struct thread *td, struct select_args *uap)
906 {
907 struct timeval tv, *tvp;
908 int error;
909
910 if (uap->tv != NULL) {
911 error = copyin(uap->tv, &tv, sizeof(tv));
912 if (error)
913 return (error);
914 tvp = &tv;
915 } else
916 tvp = NULL;
917
918 return (kern_select(td, uap->nd, uap->in, uap->ou, uap->ex, tvp,
919 NFDBITS));
920 }
921
922 /*
923 * In the unlikely case when user specified n greater then the last
924 * open file descriptor, check that no bits are set after the last
925 * valid fd. We must return EBADF if any is set.
926 *
927 * There are applications that rely on the behaviour.
928 *
929 * nd is fd_lastfile + 1.
930 */
931 static int
932 select_check_badfd(fd_set *fd_in, int nd, int ndu, int abi_nfdbits)
933 {
934 char *addr, *oaddr;
935 int b, i, res;
936 uint8_t bits;
937
938 if (nd >= ndu || fd_in == NULL)
939 return (0);
940
941 oaddr = NULL;
942 bits = 0; /* silence gcc */
943 for (i = nd; i < ndu; i++) {
944 b = i / NBBY;
945 #if BYTE_ORDER == LITTLE_ENDIAN
946 addr = (char *)fd_in + b;
947 #else
948 addr = (char *)fd_in;
949 if (abi_nfdbits == NFDBITS) {
950 addr += rounddown(b, sizeof(fd_mask)) +
951 sizeof(fd_mask) - 1 - b % sizeof(fd_mask);
952 } else {
953 addr += rounddown(b, sizeof(uint32_t)) +
954 sizeof(uint32_t) - 1 - b % sizeof(uint32_t);
955 }
956 #endif
957 if (addr != oaddr) {
958 res = fubyte(addr);
959 if (res == -1)
960 return (EFAULT);
961 oaddr = addr;
962 bits = res;
963 }
964 if ((bits & (1 << (i % NBBY))) != 0)
965 return (EBADF);
966 }
967 return (0);
968 }
969
970 int
971 kern_select(struct thread *td, int nd, fd_set *fd_in, fd_set *fd_ou,
972 fd_set *fd_ex, struct timeval *tvp, int abi_nfdbits)
973 {
974 struct filedesc *fdp;
975 /*
976 * The magic 2048 here is chosen to be just enough for FD_SETSIZE
977 * infds with the new FD_SETSIZE of 1024, and more than enough for
978 * FD_SETSIZE infds, outfds and exceptfds with the old FD_SETSIZE
979 * of 256.
980 */
981 fd_mask s_selbits[howmany(2048, NFDBITS)];
982 fd_mask *ibits[3], *obits[3], *selbits, *sbp;
983 struct timeval rtv;
984 sbintime_t asbt, precision, rsbt;
985 u_int nbufbytes, ncpbytes, ncpubytes, nfdbits;
986 int error, lf, ndu;
987
988 if (nd < 0)
989 return (EINVAL);
990 fdp = td->td_proc->p_fd;
991 ndu = nd;
992 lf = fdp->fd_lastfile;
993 if (nd > lf + 1)
994 nd = lf + 1;
995
996 error = select_check_badfd(fd_in, nd, ndu, abi_nfdbits);
997 if (error != 0)
998 return (error);
999 error = select_check_badfd(fd_ou, nd, ndu, abi_nfdbits);
1000 if (error != 0)
1001 return (error);
1002 error = select_check_badfd(fd_ex, nd, ndu, abi_nfdbits);
1003 if (error != 0)
1004 return (error);
1005
1006 /*
1007 * Allocate just enough bits for the non-null fd_sets. Use the
1008 * preallocated auto buffer if possible.
1009 */
1010 nfdbits = roundup(nd, NFDBITS);
1011 ncpbytes = nfdbits / NBBY;
1012 ncpubytes = roundup(nd, abi_nfdbits) / NBBY;
1013 nbufbytes = 0;
1014 if (fd_in != NULL)
1015 nbufbytes += 2 * ncpbytes;
1016 if (fd_ou != NULL)
1017 nbufbytes += 2 * ncpbytes;
1018 if (fd_ex != NULL)
1019 nbufbytes += 2 * ncpbytes;
1020 if (nbufbytes <= sizeof s_selbits)
1021 selbits = &s_selbits[0];
1022 else
1023 selbits = malloc(nbufbytes, M_SELECT, M_WAITOK);
1024
1025 /*
1026 * Assign pointers into the bit buffers and fetch the input bits.
1027 * Put the output buffers together so that they can be bzeroed
1028 * together.
1029 */
1030 sbp = selbits;
1031 #define getbits(name, x) \
1032 do { \
1033 if (name == NULL) { \
1034 ibits[x] = NULL; \
1035 obits[x] = NULL; \
1036 } else { \
1037 ibits[x] = sbp + nbufbytes / 2 / sizeof *sbp; \
1038 obits[x] = sbp; \
1039 sbp += ncpbytes / sizeof *sbp; \
1040 error = copyin(name, ibits[x], ncpubytes); \
1041 if (error != 0) \
1042 goto done; \
1043 bzero((char *)ibits[x] + ncpubytes, \
1044 ncpbytes - ncpubytes); \
1045 } \
1046 } while (0)
1047 getbits(fd_in, 0);
1048 getbits(fd_ou, 1);
1049 getbits(fd_ex, 2);
1050 #undef getbits
1051
1052 #if BYTE_ORDER == BIG_ENDIAN && defined(__LP64__)
1053 /*
1054 * XXX: swizzle_fdset assumes that if abi_nfdbits != NFDBITS,
1055 * we are running under 32-bit emulation. This should be more
1056 * generic.
1057 */
1058 #define swizzle_fdset(bits) \
1059 if (abi_nfdbits != NFDBITS && bits != NULL) { \
1060 int i; \
1061 for (i = 0; i < ncpbytes / sizeof *sbp; i++) \
1062 bits[i] = (bits[i] >> 32) | (bits[i] << 32); \
1063 }
1064 #else
1065 #define swizzle_fdset(bits)
1066 #endif
1067
1068 /* Make sure the bit order makes it through an ABI transition */
1069 swizzle_fdset(ibits[0]);
1070 swizzle_fdset(ibits[1]);
1071 swizzle_fdset(ibits[2]);
1072
1073 if (nbufbytes != 0)
1074 bzero(selbits, nbufbytes / 2);
1075
1076 precision = 0;
1077 if (tvp != NULL) {
1078 rtv = *tvp;
1079 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 ||
1080 rtv.tv_usec >= 1000000) {
1081 error = EINVAL;
1082 goto done;
1083 }
1084 if (!timevalisset(&rtv))
1085 asbt = 0;
1086 else if (rtv.tv_sec <= INT32_MAX) {
1087 rsbt = tvtosbt(rtv);
1088 precision = rsbt;
1089 precision >>= tc_precexp;
1090 if (TIMESEL(&asbt, rsbt))
1091 asbt += tc_tick_sbt;
1092 if (asbt <= INT64_MAX - rsbt)
1093 asbt += rsbt;
1094 else
1095 asbt = -1;
1096 } else
1097 asbt = -1;
1098 } else
1099 asbt = -1;
1100 seltdinit(td);
1101 /* Iterate until the timeout expires or descriptors become ready. */
1102 for (;;) {
1103 error = selscan(td, ibits, obits, nd);
1104 if (error || td->td_retval[0] != 0)
1105 break;
1106 error = seltdwait(td, asbt, precision);
1107 if (error)
1108 break;
1109 error = selrescan(td, ibits, obits);
1110 if (error || td->td_retval[0] != 0)
1111 break;
1112 }
1113 seltdclear(td);
1114
1115 done:
1116 /* select is not restarted after signals... */
1117 if (error == ERESTART)
1118 error = EINTR;
1119 if (error == EWOULDBLOCK)
1120 error = 0;
1121
1122 /* swizzle bit order back, if necessary */
1123 swizzle_fdset(obits[0]);
1124 swizzle_fdset(obits[1]);
1125 swizzle_fdset(obits[2]);
1126 #undef swizzle_fdset
1127
1128 #define putbits(name, x) \
1129 if (name && (error2 = copyout(obits[x], name, ncpubytes))) \
1130 error = error2;
1131 if (error == 0) {
1132 int error2;
1133
1134 putbits(fd_in, 0);
1135 putbits(fd_ou, 1);
1136 putbits(fd_ex, 2);
1137 #undef putbits
1138 }
1139 if (selbits != &s_selbits[0])
1140 free(selbits, M_SELECT);
1141
1142 return (error);
1143 }
1144 /*
1145 * Convert a select bit set to poll flags.
1146 *
1147 * The backend always returns POLLHUP/POLLERR if appropriate and we
1148 * return this as a set bit in any set.
1149 */
1150 static int select_flags[3] = {
1151 POLLRDNORM | POLLHUP | POLLERR,
1152 POLLWRNORM | POLLHUP | POLLERR,
1153 POLLRDBAND | POLLERR
1154 };
1155
1156 /*
1157 * Compute the fo_poll flags required for a fd given by the index and
1158 * bit position in the fd_mask array.
1159 */
1160 static __inline int
1161 selflags(fd_mask **ibits, int idx, fd_mask bit)
1162 {
1163 int flags;
1164 int msk;
1165
1166 flags = 0;
1167 for (msk = 0; msk < 3; msk++) {
1168 if (ibits[msk] == NULL)
1169 continue;
1170 if ((ibits[msk][idx] & bit) == 0)
1171 continue;
1172 flags |= select_flags[msk];
1173 }
1174 return (flags);
1175 }
1176
1177 /*
1178 * Set the appropriate output bits given a mask of fired events and the
1179 * input bits originally requested.
1180 */
1181 static __inline int
1182 selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events)
1183 {
1184 int msk;
1185 int n;
1186
1187 n = 0;
1188 for (msk = 0; msk < 3; msk++) {
1189 if ((events & select_flags[msk]) == 0)
1190 continue;
1191 if (ibits[msk] == NULL)
1192 continue;
1193 if ((ibits[msk][idx] & bit) == 0)
1194 continue;
1195 /*
1196 * XXX Check for a duplicate set. This can occur because a
1197 * socket calls selrecord() twice for each poll() call
1198 * resulting in two selfds per real fd. selrescan() will
1199 * call selsetbits twice as a result.
1200 */
1201 if ((obits[msk][idx] & bit) != 0)
1202 continue;
1203 obits[msk][idx] |= bit;
1204 n++;
1205 }
1206
1207 return (n);
1208 }
1209
1210 static __inline int
1211 getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp)
1212 {
1213 cap_rights_t rights;
1214
1215 cap_rights_init(&rights, CAP_EVENT);
1216
1217 return (fget_unlocked(fdp, fd, &rights, 0, fpp, NULL));
1218 }
1219
1220 /*
1221 * Traverse the list of fds attached to this thread's seltd and check for
1222 * completion.
1223 */
1224 static int
1225 selrescan(struct thread *td, fd_mask **ibits, fd_mask **obits)
1226 {
1227 struct filedesc *fdp;
1228 struct selinfo *si;
1229 struct seltd *stp;
1230 struct selfd *sfp;
1231 struct selfd *sfn;
1232 struct file *fp;
1233 fd_mask bit;
1234 int fd, ev, n, idx;
1235 int error;
1236
1237 fdp = td->td_proc->p_fd;
1238 stp = td->td_sel;
1239 n = 0;
1240 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
1241 fd = (int)(uintptr_t)sfp->sf_cookie;
1242 si = sfp->sf_si;
1243 selfdfree(stp, sfp);
1244 /* If the selinfo wasn't cleared the event didn't fire. */
1245 if (si != NULL)
1246 continue;
1247 error = getselfd_cap(fdp, fd, &fp);
1248 if (error)
1249 return (error);
1250 idx = fd / NFDBITS;
1251 bit = (fd_mask)1 << (fd % NFDBITS);
1252 ev = fo_poll(fp, selflags(ibits, idx, bit), td->td_ucred, td);
1253 fdrop(fp, td);
1254 if (ev != 0)
1255 n += selsetbits(ibits, obits, idx, bit, ev);
1256 }
1257 stp->st_flags = 0;
1258 td->td_retval[0] = n;
1259 return (0);
1260 }
1261
1262 /*
1263 * Perform the initial filedescriptor scan and register ourselves with
1264 * each selinfo.
1265 */
1266 static int
1267 selscan(td, ibits, obits, nfd)
1268 struct thread *td;
1269 fd_mask **ibits, **obits;
1270 int nfd;
1271 {
1272 struct filedesc *fdp;
1273 struct file *fp;
1274 fd_mask bit;
1275 int ev, flags, end, fd;
1276 int n, idx;
1277 int error;
1278
1279 fdp = td->td_proc->p_fd;
1280 n = 0;
1281 for (idx = 0, fd = 0; fd < nfd; idx++) {
1282 end = imin(fd + NFDBITS, nfd);
1283 for (bit = 1; fd < end; bit <<= 1, fd++) {
1284 /* Compute the list of events we're interested in. */
1285 flags = selflags(ibits, idx, bit);
1286 if (flags == 0)
1287 continue;
1288 error = getselfd_cap(fdp, fd, &fp);
1289 if (error)
1290 return (error);
1291 selfdalloc(td, (void *)(uintptr_t)fd);
1292 ev = fo_poll(fp, flags, td->td_ucred, td);
1293 fdrop(fp, td);
1294 if (ev != 0)
1295 n += selsetbits(ibits, obits, idx, bit, ev);
1296 }
1297 }
1298
1299 td->td_retval[0] = n;
1300 return (0);
1301 }
1302
1303 int
1304 sys_poll(struct thread *td, struct poll_args *uap)
1305 {
1306 struct timespec ts, *tsp;
1307
1308 if (uap->timeout != INFTIM) {
1309 if (uap->timeout < 0)
1310 return (EINVAL);
1311 ts.tv_sec = uap->timeout / 1000;
1312 ts.tv_nsec = (uap->timeout % 1000) * 1000000;
1313 tsp = &ts;
1314 } else
1315 tsp = NULL;
1316
1317 return (kern_poll(td, uap->fds, uap->nfds, tsp, NULL));
1318 }
1319
1320 int
1321 kern_poll(struct thread *td, struct pollfd *fds, u_int nfds,
1322 struct timespec *tsp, sigset_t *uset)
1323 {
1324 struct pollfd *bits;
1325 struct pollfd smallbits[32];
1326 sbintime_t sbt, precision, tmp;
1327 time_t over;
1328 struct timespec ts;
1329 int error;
1330 size_t ni;
1331
1332 precision = 0;
1333 if (tsp != NULL) {
1334 if (tsp->tv_sec < 0)
1335 return (EINVAL);
1336 if (tsp->tv_nsec < 0 || tsp->tv_nsec >= 1000000000)
1337 return (EINVAL);
1338 if (tsp->tv_sec == 0 && tsp->tv_nsec == 0)
1339 sbt = 0;
1340 else {
1341 ts = *tsp;
1342 if (ts.tv_sec > INT32_MAX / 2) {
1343 over = ts.tv_sec - INT32_MAX / 2;
1344 ts.tv_sec -= over;
1345 } else
1346 over = 0;
1347 tmp = tstosbt(ts);
1348 precision = tmp;
1349 precision >>= tc_precexp;
1350 if (TIMESEL(&sbt, tmp))
1351 sbt += tc_tick_sbt;
1352 sbt += tmp;
1353 }
1354 } else
1355 sbt = -1;
1356
1357 if (nfds > maxfilesperproc && nfds > FD_SETSIZE)
1358 return (EINVAL);
1359 ni = nfds * sizeof(struct pollfd);
1360 if (ni > sizeof(smallbits))
1361 bits = malloc(ni, M_TEMP, M_WAITOK);
1362 else
1363 bits = smallbits;
1364 error = copyin(fds, bits, ni);
1365 if (error)
1366 goto done;
1367
1368 if (uset != NULL) {
1369 error = kern_sigprocmask(td, SIG_SETMASK, uset,
1370 &td->td_oldsigmask, 0);
1371 if (error)
1372 goto done;
1373 td->td_pflags |= TDP_OLDMASK;
1374 /*
1375 * Make sure that ast() is called on return to
1376 * usermode and TDP_OLDMASK is cleared, restoring old
1377 * sigmask.
1378 */
1379 thread_lock(td);
1380 td->td_flags |= TDF_ASTPENDING;
1381 thread_unlock(td);
1382 }
1383
1384 seltdinit(td);
1385 /* Iterate until the timeout expires or descriptors become ready. */
1386 for (;;) {
1387 error = pollscan(td, bits, nfds);
1388 if (error || td->td_retval[0] != 0)
1389 break;
1390 error = seltdwait(td, sbt, precision);
1391 if (error)
1392 break;
1393 error = pollrescan(td);
1394 if (error || td->td_retval[0] != 0)
1395 break;
1396 }
1397 seltdclear(td);
1398
1399 done:
1400 /* poll is not restarted after signals... */
1401 if (error == ERESTART)
1402 error = EINTR;
1403 if (error == EWOULDBLOCK)
1404 error = 0;
1405 if (error == 0) {
1406 error = pollout(td, bits, fds, nfds);
1407 if (error)
1408 goto out;
1409 }
1410 out:
1411 if (ni > sizeof(smallbits))
1412 free(bits, M_TEMP);
1413 return (error);
1414 }
1415
1416 int
1417 sys_ppoll(struct thread *td, struct ppoll_args *uap)
1418 {
1419 struct timespec ts, *tsp;
1420 sigset_t set, *ssp;
1421 int error;
1422
1423 if (uap->ts != NULL) {
1424 error = copyin(uap->ts, &ts, sizeof(ts));
1425 if (error)
1426 return (error);
1427 tsp = &ts;
1428 } else
1429 tsp = NULL;
1430 if (uap->set != NULL) {
1431 error = copyin(uap->set, &set, sizeof(set));
1432 if (error)
1433 return (error);
1434 ssp = &set;
1435 } else
1436 ssp = NULL;
1437 /*
1438 * fds is still a pointer to user space. kern_poll() will
1439 * take care of copyin that array to the kernel space.
1440 */
1441
1442 return (kern_poll(td, uap->fds, uap->nfds, tsp, ssp));
1443 }
1444
1445 static int
1446 pollrescan(struct thread *td)
1447 {
1448 struct seltd *stp;
1449 struct selfd *sfp;
1450 struct selfd *sfn;
1451 struct selinfo *si;
1452 struct filedesc *fdp;
1453 struct file *fp;
1454 struct pollfd *fd;
1455 #ifdef CAPABILITIES
1456 cap_rights_t rights;
1457 #endif
1458 int n;
1459
1460 n = 0;
1461 fdp = td->td_proc->p_fd;
1462 stp = td->td_sel;
1463 FILEDESC_SLOCK(fdp);
1464 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn) {
1465 fd = (struct pollfd *)sfp->sf_cookie;
1466 si = sfp->sf_si;
1467 selfdfree(stp, sfp);
1468 /* If the selinfo wasn't cleared the event didn't fire. */
1469 if (si != NULL)
1470 continue;
1471 fp = fdp->fd_ofiles[fd->fd].fde_file;
1472 #ifdef CAPABILITIES
1473 if (fp == NULL ||
1474 cap_check(cap_rights(fdp, fd->fd),
1475 cap_rights_init(&rights, CAP_EVENT)) != 0)
1476 #else
1477 if (fp == NULL)
1478 #endif
1479 {
1480 fd->revents = POLLNVAL;
1481 n++;
1482 continue;
1483 }
1484
1485 /*
1486 * Note: backend also returns POLLHUP and
1487 * POLLERR if appropriate.
1488 */
1489 fd->revents = fo_poll(fp, fd->events, td->td_ucred, td);
1490 if (fd->revents != 0)
1491 n++;
1492 }
1493 FILEDESC_SUNLOCK(fdp);
1494 stp->st_flags = 0;
1495 td->td_retval[0] = n;
1496 return (0);
1497 }
1498
1499
1500 static int
1501 pollout(td, fds, ufds, nfd)
1502 struct thread *td;
1503 struct pollfd *fds;
1504 struct pollfd *ufds;
1505 u_int nfd;
1506 {
1507 int error = 0;
1508 u_int i = 0;
1509 u_int n = 0;
1510
1511 for (i = 0; i < nfd; i++) {
1512 error = copyout(&fds->revents, &ufds->revents,
1513 sizeof(ufds->revents));
1514 if (error)
1515 return (error);
1516 if (fds->revents != 0)
1517 n++;
1518 fds++;
1519 ufds++;
1520 }
1521 td->td_retval[0] = n;
1522 return (0);
1523 }
1524
1525 static int
1526 pollscan(td, fds, nfd)
1527 struct thread *td;
1528 struct pollfd *fds;
1529 u_int nfd;
1530 {
1531 struct filedesc *fdp = td->td_proc->p_fd;
1532 struct file *fp;
1533 #ifdef CAPABILITIES
1534 cap_rights_t rights;
1535 #endif
1536 int i, n = 0;
1537
1538 FILEDESC_SLOCK(fdp);
1539 for (i = 0; i < nfd; i++, fds++) {
1540 if (fds->fd > fdp->fd_lastfile) {
1541 fds->revents = POLLNVAL;
1542 n++;
1543 } else if (fds->fd < 0) {
1544 fds->revents = 0;
1545 } else {
1546 fp = fdp->fd_ofiles[fds->fd].fde_file;
1547 #ifdef CAPABILITIES
1548 if (fp == NULL ||
1549 cap_check(cap_rights(fdp, fds->fd),
1550 cap_rights_init(&rights, CAP_EVENT)) != 0)
1551 #else
1552 if (fp == NULL)
1553 #endif
1554 {
1555 fds->revents = POLLNVAL;
1556 n++;
1557 } else {
1558 /*
1559 * Note: backend also returns POLLHUP and
1560 * POLLERR if appropriate.
1561 */
1562 selfdalloc(td, fds);
1563 fds->revents = fo_poll(fp, fds->events,
1564 td->td_ucred, td);
1565 /*
1566 * POSIX requires POLLOUT to be never
1567 * set simultaneously with POLLHUP.
1568 */
1569 if ((fds->revents & POLLHUP) != 0)
1570 fds->revents &= ~POLLOUT;
1571
1572 if (fds->revents != 0)
1573 n++;
1574 }
1575 }
1576 }
1577 FILEDESC_SUNLOCK(fdp);
1578 td->td_retval[0] = n;
1579 return (0);
1580 }
1581
1582 /*
1583 * OpenBSD poll system call.
1584 *
1585 * XXX this isn't quite a true representation.. OpenBSD uses select ops.
1586 */
1587 #ifndef _SYS_SYSPROTO_H_
1588 struct openbsd_poll_args {
1589 struct pollfd *fds;
1590 u_int nfds;
1591 int timeout;
1592 };
1593 #endif
1594 int
1595 sys_openbsd_poll(td, uap)
1596 register struct thread *td;
1597 register struct openbsd_poll_args *uap;
1598 {
1599 return (sys_poll(td, (struct poll_args *)uap));
1600 }
1601
1602 /*
1603 * XXX This was created specifically to support netncp and netsmb. This
1604 * allows the caller to specify a socket to wait for events on. It returns
1605 * 0 if any events matched and an error otherwise. There is no way to
1606 * determine which events fired.
1607 */
1608 int
1609 selsocket(struct socket *so, int events, struct timeval *tvp, struct thread *td)
1610 {
1611 struct timeval rtv;
1612 sbintime_t asbt, precision, rsbt;
1613 int error;
1614
1615 precision = 0; /* stupid gcc! */
1616 if (tvp != NULL) {
1617 rtv = *tvp;
1618 if (rtv.tv_sec < 0 || rtv.tv_usec < 0 ||
1619 rtv.tv_usec >= 1000000)
1620 return (EINVAL);
1621 if (!timevalisset(&rtv))
1622 asbt = 0;
1623 else if (rtv.tv_sec <= INT32_MAX) {
1624 rsbt = tvtosbt(rtv);
1625 precision = rsbt;
1626 precision >>= tc_precexp;
1627 if (TIMESEL(&asbt, rsbt))
1628 asbt += tc_tick_sbt;
1629 if (asbt <= INT64_MAX - rsbt)
1630 asbt += rsbt;
1631 else
1632 asbt = -1;
1633 } else
1634 asbt = -1;
1635 } else
1636 asbt = -1;
1637 seltdinit(td);
1638 /*
1639 * Iterate until the timeout expires or the socket becomes ready.
1640 */
1641 for (;;) {
1642 selfdalloc(td, NULL);
1643 error = sopoll(so, events, NULL, td);
1644 /* error here is actually the ready events. */
1645 if (error)
1646 return (0);
1647 error = seltdwait(td, asbt, precision);
1648 if (error)
1649 break;
1650 }
1651 seltdclear(td);
1652 /* XXX Duplicates ncp/smb behavior. */
1653 if (error == ERESTART)
1654 error = 0;
1655 return (error);
1656 }
1657
1658 /*
1659 * Preallocate two selfds associated with 'cookie'. Some fo_poll routines
1660 * have two select sets, one for read and another for write.
1661 */
1662 static void
1663 selfdalloc(struct thread *td, void *cookie)
1664 {
1665 struct seltd *stp;
1666
1667 stp = td->td_sel;
1668 if (stp->st_free1 == NULL)
1669 stp->st_free1 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO);
1670 stp->st_free1->sf_td = stp;
1671 stp->st_free1->sf_cookie = cookie;
1672 if (stp->st_free2 == NULL)
1673 stp->st_free2 = uma_zalloc(selfd_zone, M_WAITOK|M_ZERO);
1674 stp->st_free2->sf_td = stp;
1675 stp->st_free2->sf_cookie = cookie;
1676 }
1677
1678 static void
1679 selfdfree(struct seltd *stp, struct selfd *sfp)
1680 {
1681 STAILQ_REMOVE(&stp->st_selq, sfp, selfd, sf_link);
1682 mtx_lock(sfp->sf_mtx);
1683 if (sfp->sf_si)
1684 TAILQ_REMOVE(&sfp->sf_si->si_tdlist, sfp, sf_threads);
1685 mtx_unlock(sfp->sf_mtx);
1686 uma_zfree(selfd_zone, sfp);
1687 }
1688
1689 /* Drain the waiters tied to all the selfd belonging the specified selinfo. */
1690 void
1691 seldrain(sip)
1692 struct selinfo *sip;
1693 {
1694
1695 /*
1696 * This feature is already provided by doselwakeup(), thus it is
1697 * enough to go for it.
1698 * Eventually, the context, should take care to avoid races
1699 * between thread calling select()/poll() and file descriptor
1700 * detaching, but, again, the races are just the same as
1701 * selwakeup().
1702 */
1703 doselwakeup(sip, -1);
1704 }
1705
1706 /*
1707 * Record a select request.
1708 */
1709 void
1710 selrecord(selector, sip)
1711 struct thread *selector;
1712 struct selinfo *sip;
1713 {
1714 struct selfd *sfp;
1715 struct seltd *stp;
1716 struct mtx *mtxp;
1717
1718 stp = selector->td_sel;
1719 /*
1720 * Don't record when doing a rescan.
1721 */
1722 if (stp->st_flags & SELTD_RESCAN)
1723 return;
1724 /*
1725 * Grab one of the preallocated descriptors.
1726 */
1727 sfp = NULL;
1728 if ((sfp = stp->st_free1) != NULL)
1729 stp->st_free1 = NULL;
1730 else if ((sfp = stp->st_free2) != NULL)
1731 stp->st_free2 = NULL;
1732 else
1733 panic("selrecord: No free selfd on selq");
1734 mtxp = sip->si_mtx;
1735 if (mtxp == NULL)
1736 mtxp = mtx_pool_find(mtxpool_select, sip);
1737 /*
1738 * Initialize the sfp and queue it in the thread.
1739 */
1740 sfp->sf_si = sip;
1741 sfp->sf_mtx = mtxp;
1742 STAILQ_INSERT_TAIL(&stp->st_selq, sfp, sf_link);
1743 /*
1744 * Now that we've locked the sip, check for initialization.
1745 */
1746 mtx_lock(mtxp);
1747 if (sip->si_mtx == NULL) {
1748 sip->si_mtx = mtxp;
1749 TAILQ_INIT(&sip->si_tdlist);
1750 }
1751 /*
1752 * Add this thread to the list of selfds listening on this selinfo.
1753 */
1754 TAILQ_INSERT_TAIL(&sip->si_tdlist, sfp, sf_threads);
1755 mtx_unlock(sip->si_mtx);
1756 }
1757
1758 /* Wake up a selecting thread. */
1759 void
1760 selwakeup(sip)
1761 struct selinfo *sip;
1762 {
1763 doselwakeup(sip, -1);
1764 }
1765
1766 /* Wake up a selecting thread, and set its priority. */
1767 void
1768 selwakeuppri(sip, pri)
1769 struct selinfo *sip;
1770 int pri;
1771 {
1772 doselwakeup(sip, pri);
1773 }
1774
1775 /*
1776 * Do a wakeup when a selectable event occurs.
1777 */
1778 static void
1779 doselwakeup(sip, pri)
1780 struct selinfo *sip;
1781 int pri;
1782 {
1783 struct selfd *sfp;
1784 struct selfd *sfn;
1785 struct seltd *stp;
1786
1787 /* If it's not initialized there can't be any waiters. */
1788 if (sip->si_mtx == NULL)
1789 return;
1790 /*
1791 * Locking the selinfo locks all selfds associated with it.
1792 */
1793 mtx_lock(sip->si_mtx);
1794 TAILQ_FOREACH_SAFE(sfp, &sip->si_tdlist, sf_threads, sfn) {
1795 /*
1796 * Once we remove this sfp from the list and clear the
1797 * sf_si seltdclear will know to ignore this si.
1798 */
1799 TAILQ_REMOVE(&sip->si_tdlist, sfp, sf_threads);
1800 sfp->sf_si = NULL;
1801 stp = sfp->sf_td;
1802 mtx_lock(&stp->st_mtx);
1803 stp->st_flags |= SELTD_PENDING;
1804 cv_broadcastpri(&stp->st_wait, pri);
1805 mtx_unlock(&stp->st_mtx);
1806 }
1807 mtx_unlock(sip->si_mtx);
1808 }
1809
1810 static void
1811 seltdinit(struct thread *td)
1812 {
1813 struct seltd *stp;
1814
1815 if ((stp = td->td_sel) != NULL)
1816 goto out;
1817 td->td_sel = stp = malloc(sizeof(*stp), M_SELECT, M_WAITOK|M_ZERO);
1818 mtx_init(&stp->st_mtx, "sellck", NULL, MTX_DEF);
1819 cv_init(&stp->st_wait, "select");
1820 out:
1821 stp->st_flags = 0;
1822 STAILQ_INIT(&stp->st_selq);
1823 }
1824
1825 static int
1826 seltdwait(struct thread *td, sbintime_t sbt, sbintime_t precision)
1827 {
1828 struct seltd *stp;
1829 int error;
1830
1831 stp = td->td_sel;
1832 /*
1833 * An event of interest may occur while we do not hold the seltd
1834 * locked so check the pending flag before we sleep.
1835 */
1836 mtx_lock(&stp->st_mtx);
1837 /*
1838 * Any further calls to selrecord will be a rescan.
1839 */
1840 stp->st_flags |= SELTD_RESCAN;
1841 if (stp->st_flags & SELTD_PENDING) {
1842 mtx_unlock(&stp->st_mtx);
1843 return (0);
1844 }
1845 if (sbt == 0)
1846 error = EWOULDBLOCK;
1847 else if (sbt != -1)
1848 error = cv_timedwait_sig_sbt(&stp->st_wait, &stp->st_mtx,
1849 sbt, precision, C_ABSOLUTE);
1850 else
1851 error = cv_wait_sig(&stp->st_wait, &stp->st_mtx);
1852 mtx_unlock(&stp->st_mtx);
1853
1854 return (error);
1855 }
1856
1857 void
1858 seltdfini(struct thread *td)
1859 {
1860 struct seltd *stp;
1861
1862 stp = td->td_sel;
1863 if (stp == NULL)
1864 return;
1865 if (stp->st_free1)
1866 uma_zfree(selfd_zone, stp->st_free1);
1867 if (stp->st_free2)
1868 uma_zfree(selfd_zone, stp->st_free2);
1869 td->td_sel = NULL;
1870 free(stp, M_SELECT);
1871 }
1872
1873 /*
1874 * Remove the references to the thread from all of the objects we were
1875 * polling.
1876 */
1877 static void
1878 seltdclear(struct thread *td)
1879 {
1880 struct seltd *stp;
1881 struct selfd *sfp;
1882 struct selfd *sfn;
1883
1884 stp = td->td_sel;
1885 STAILQ_FOREACH_SAFE(sfp, &stp->st_selq, sf_link, sfn)
1886 selfdfree(stp, sfp);
1887 stp->st_flags = 0;
1888 }
1889
1890 static void selectinit(void *);
1891 SYSINIT(select, SI_SUB_SYSCALLS, SI_ORDER_ANY, selectinit, NULL);
1892 static void
1893 selectinit(void *dummy __unused)
1894 {
1895
1896 selfd_zone = uma_zcreate("selfd", sizeof(struct selfd), NULL, NULL,
1897 NULL, NULL, UMA_ALIGN_PTR, 0);
1898 mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF);
1899 }
Cache object: c0ffc707f399de121840d618dc40416c
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