1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2007-2009 Google Inc. and Amit Singh
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are
9 * met:
10 *
11 * * Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * * Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following disclaimer
15 * in the documentation and/or other materials provided with the
16 * distribution.
17 * * Neither the name of Google Inc. nor the names of its
18 * contributors may be used to endorse or promote products derived from
19 * this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 *
33 * Copyright (C) 2005 Csaba Henk.
34 * All rights reserved.
35 *
36 * Copyright (c) 2019 The FreeBSD Foundation
37 *
38 * Portions of this software were developed by BFF Storage Systems, LLC under
39 * sponsorship from the FreeBSD Foundation.
40 *
41 * Redistribution and use in source and binary forms, with or without
42 * modification, are permitted provided that the following conditions
43 * are met:
44 * 1. Redistributions of source code must retain the above copyright
45 * notice, this list of conditions and the following disclaimer.
46 * 2. Redistributions in binary form must reproduce the above copyright
47 * notice, this list of conditions and the following disclaimer in the
48 * documentation and/or other materials provided with the distribution.
49 *
50 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60 * SUCH DAMAGE.
61 */
62
63 #include <sys/param.h>
64 #include <sys/module.h>
65 #include <sys/systm.h>
66 #include <sys/counter.h>
67 #include <sys/errno.h>
68 #include <sys/kernel.h>
69 #include <sys/conf.h>
70 #include <sys/uio.h>
71 #include <sys/malloc.h>
72 #include <sys/queue.h>
73 #include <sys/lock.h>
74 #include <sys/sx.h>
75 #include <sys/mutex.h>
76 #include <sys/proc.h>
77 #include <sys/mount.h>
78 #include <sys/sdt.h>
79 #include <sys/vnode.h>
80 #include <sys/signalvar.h>
81 #include <sys/syscallsubr.h>
82 #include <sys/sysctl.h>
83 #include <vm/uma.h>
84
85 #include "fuse.h"
86 #include "fuse_node.h"
87 #include "fuse_ipc.h"
88 #include "fuse_internal.h"
89
90 SDT_PROVIDER_DECLARE(fusefs);
91 /*
92 * Fuse trace probe:
93 * arg0: verbosity. Higher numbers give more verbose messages
94 * arg1: Textual message
95 */
96 SDT_PROBE_DEFINE2(fusefs, , ipc, trace, "int", "char*");
97
98 static void fdisp_make_pid(struct fuse_dispatcher *fdip, enum fuse_opcode op,
99 struct fuse_data *data, uint64_t nid, pid_t pid, struct ucred *cred);
100 static void fuse_interrupt_send(struct fuse_ticket *otick, int err);
101 static struct fuse_ticket *fticket_alloc(struct fuse_data *data);
102 static void fticket_refresh(struct fuse_ticket *ftick);
103 static inline void fticket_reset(struct fuse_ticket *ftick);
104 static void fticket_destroy(struct fuse_ticket *ftick);
105 static int fticket_wait_answer(struct fuse_ticket *ftick);
106 static inline int
107 fticket_aw_pull_uio(struct fuse_ticket *ftick,
108 struct uio *uio);
109
110 static int fuse_body_audit(struct fuse_ticket *ftick, size_t blen);
111
112 static fuse_handler_t fuse_standard_handler;
113
114 static counter_u64_t fuse_ticket_count;
115 SYSCTL_COUNTER_U64(_vfs_fusefs_stats, OID_AUTO, ticket_count, CTLFLAG_RD,
116 &fuse_ticket_count, "Number of allocated tickets");
117
118 static long fuse_iov_permanent_bufsize = 1 << 19;
119
120 SYSCTL_LONG(_vfs_fusefs, OID_AUTO, iov_permanent_bufsize, CTLFLAG_RW,
121 &fuse_iov_permanent_bufsize, 0,
122 "limit for permanently stored buffer size for fuse_iovs");
123 static int fuse_iov_credit = 16;
124
125 SYSCTL_INT(_vfs_fusefs, OID_AUTO, iov_credit, CTLFLAG_RW,
126 &fuse_iov_credit, 0,
127 "how many times is an oversized fuse_iov tolerated");
128
129 MALLOC_DEFINE(M_FUSEMSG, "fuse_msgbuf", "fuse message buffer");
130 static uma_zone_t ticket_zone;
131
132 /*
133 * TODO: figure out how to timeout INTERRUPT requests, because the daemon may
134 * leagally never respond
135 */
136 static int
fuse_interrupt_callback(struct fuse_ticket * tick,struct uio * uio)137 fuse_interrupt_callback(struct fuse_ticket *tick, struct uio *uio)
138 {
139 struct fuse_ticket *otick, *x_tick;
140 struct fuse_interrupt_in *fii;
141 struct fuse_data *data = tick->tk_data;
142 bool found = false;
143
144 fii = (struct fuse_interrupt_in*)((char*)tick->tk_ms_fiov.base +
145 sizeof(struct fuse_in_header));
146
147 fuse_lck_mtx_lock(data->aw_mtx);
148 TAILQ_FOREACH_SAFE(otick, &data->aw_head, tk_aw_link, x_tick) {
149 if (otick->tk_unique == fii->unique) {
150 found = true;
151 break;
152 }
153 }
154 fuse_lck_mtx_unlock(data->aw_mtx);
155
156 if (!found) {
157 /* Original is already complete. Just return */
158 return 0;
159 }
160
161 /* Clear the original ticket's interrupt association */
162 otick->irq_unique = 0;
163
164 if (tick->tk_aw_ohead.error == ENOSYS) {
165 fsess_set_notimpl(data->mp, FUSE_INTERRUPT);
166 return 0;
167 } else if (tick->tk_aw_ohead.error == EAGAIN) {
168 /*
169 * There are two reasons we might get this:
170 * 1) the daemon received the INTERRUPT request before the
171 * original, or
172 * 2) the daemon received the INTERRUPT request after it
173 * completed the original request.
174 * In the first case we should re-send the INTERRUPT. In the
175 * second, we should ignore it.
176 */
177 /* Resend */
178 fuse_interrupt_send(otick, EINTR);
179 return 0;
180 } else {
181 /* Illegal FUSE_INTERRUPT response */
182 return EINVAL;
183 }
184 }
185
186 /* Interrupt the operation otick. Return err as its error code */
187 void
fuse_interrupt_send(struct fuse_ticket * otick,int err)188 fuse_interrupt_send(struct fuse_ticket *otick, int err)
189 {
190 struct fuse_dispatcher fdi;
191 struct fuse_interrupt_in *fii;
192 struct fuse_in_header *ftick_hdr;
193 struct fuse_data *data = otick->tk_data;
194 struct fuse_ticket *tick, *xtick;
195 struct ucred reused_creds;
196
197 if (otick->irq_unique == 0) {
198 /*
199 * If the daemon hasn't yet received otick, then we can answer
200 * it ourselves and return.
201 */
202 fuse_lck_mtx_lock(data->ms_mtx);
203 STAILQ_FOREACH_SAFE(tick, &otick->tk_data->ms_head, tk_ms_link,
204 xtick) {
205 if (tick == otick) {
206 STAILQ_REMOVE(&otick->tk_data->ms_head, tick,
207 fuse_ticket, tk_ms_link);
208 otick->tk_data->ms_count--;
209 otick->tk_ms_link.stqe_next = NULL;
210 fuse_lck_mtx_unlock(data->ms_mtx);
211
212 fuse_lck_mtx_lock(otick->tk_aw_mtx);
213 if (!fticket_answered(otick)) {
214 fticket_set_answered(otick);
215 otick->tk_aw_errno = err;
216 wakeup(otick);
217 }
218 fuse_lck_mtx_unlock(otick->tk_aw_mtx);
219
220 fuse_ticket_drop(tick);
221 return;
222 }
223 }
224 fuse_lck_mtx_unlock(data->ms_mtx);
225
226 /*
227 * If the fuse daemon doesn't support interrupts, then there's
228 * nothing more that we can do
229 */
230 if (fsess_not_impl(data->mp, FUSE_INTERRUPT))
231 return;
232
233 /*
234 * If the fuse daemon has already received otick, then we must
235 * send FUSE_INTERRUPT.
236 */
237 ftick_hdr = fticket_in_header(otick);
238 reused_creds.cr_uid = ftick_hdr->uid;
239 reused_creds.cr_gid = ftick_hdr->gid;
240 fdisp_init(&fdi, sizeof(*fii));
241 fdisp_make_pid(&fdi, FUSE_INTERRUPT, data, ftick_hdr->nodeid,
242 ftick_hdr->pid, &reused_creds);
243
244 fii = fdi.indata;
245 fii->unique = otick->tk_unique;
246 fuse_insert_callback(fdi.tick, fuse_interrupt_callback);
247
248 otick->irq_unique = fdi.tick->tk_unique;
249 /* Interrupt ops should be delivered ASAP */
250 fuse_insert_message(fdi.tick, true);
251 fdisp_destroy(&fdi);
252 } else {
253 /* This ticket has already been interrupted */
254 }
255 }
256
257 void
fiov_init(struct fuse_iov * fiov,size_t size)258 fiov_init(struct fuse_iov *fiov, size_t size)
259 {
260 uint32_t msize = FU_AT_LEAST(size);
261
262 fiov->len = 0;
263
264 fiov->base = malloc(msize, M_FUSEMSG, M_WAITOK | M_ZERO);
265
266 fiov->allocated_size = msize;
267 fiov->credit = fuse_iov_credit;
268 }
269
270 void
fiov_teardown(struct fuse_iov * fiov)271 fiov_teardown(struct fuse_iov *fiov)
272 {
273 MPASS(fiov->base != NULL);
274 free(fiov->base, M_FUSEMSG);
275 }
276
277 void
fiov_adjust(struct fuse_iov * fiov,size_t size)278 fiov_adjust(struct fuse_iov *fiov, size_t size)
279 {
280 if (fiov->allocated_size < size ||
281 (fuse_iov_permanent_bufsize >= 0 &&
282 fiov->allocated_size - size > fuse_iov_permanent_bufsize &&
283 --fiov->credit < 0)) {
284 fiov->base = realloc(fiov->base, FU_AT_LEAST(size), M_FUSEMSG,
285 M_WAITOK | M_ZERO);
286 if (!fiov->base) {
287 panic("FUSE: realloc failed");
288 }
289 fiov->allocated_size = FU_AT_LEAST(size);
290 fiov->credit = fuse_iov_credit;
291 /* Clear data buffer after reallocation */
292 bzero(fiov->base, size);
293 } else if (size > fiov->len) {
294 /* Clear newly extended portion of data buffer */
295 bzero((char*)fiov->base + fiov->len, size - fiov->len);
296 }
297 fiov->len = size;
298 }
299
300 /* Resize the fiov if needed, and clear it's buffer */
301 void
fiov_refresh(struct fuse_iov * fiov)302 fiov_refresh(struct fuse_iov *fiov)
303 {
304 fiov_adjust(fiov, 0);
305 }
306
307 static int
fticket_ctor(void * mem,int size,void * arg,int flags)308 fticket_ctor(void *mem, int size, void *arg, int flags)
309 {
310 struct fuse_ticket *ftick = mem;
311 struct fuse_data *data = arg;
312
313 FUSE_ASSERT_MS_DONE(ftick);
314 FUSE_ASSERT_AW_DONE(ftick);
315
316 ftick->tk_data = data;
317 ftick->irq_unique = 0;
318 refcount_init(&ftick->tk_refcount, 1);
319 counter_u64_add(fuse_ticket_count, 1);
320
321 fticket_refresh(ftick);
322
323 return 0;
324 }
325
326 static void
fticket_dtor(void * mem,int size,void * arg)327 fticket_dtor(void *mem, int size, void *arg)
328 {
329 #ifdef INVARIANTS
330 struct fuse_ticket *ftick = mem;
331 #endif
332
333 FUSE_ASSERT_MS_DONE(ftick);
334 FUSE_ASSERT_AW_DONE(ftick);
335
336 counter_u64_add(fuse_ticket_count, -1);
337 }
338
339 static int
fticket_init(void * mem,int size,int flags)340 fticket_init(void *mem, int size, int flags)
341 {
342 struct fuse_ticket *ftick = mem;
343
344 bzero(ftick, sizeof(struct fuse_ticket));
345
346 fiov_init(&ftick->tk_ms_fiov, sizeof(struct fuse_in_header));
347
348 mtx_init(&ftick->tk_aw_mtx, "fuse answer delivery mutex", NULL, MTX_DEF);
349 fiov_init(&ftick->tk_aw_fiov, 0);
350
351 return 0;
352 }
353
354 static void
fticket_fini(void * mem,int size)355 fticket_fini(void *mem, int size)
356 {
357 struct fuse_ticket *ftick = mem;
358
359 fiov_teardown(&ftick->tk_ms_fiov);
360 fiov_teardown(&ftick->tk_aw_fiov);
361 mtx_destroy(&ftick->tk_aw_mtx);
362 }
363
364 static inline struct fuse_ticket *
fticket_alloc(struct fuse_data * data)365 fticket_alloc(struct fuse_data *data)
366 {
367 return uma_zalloc_arg(ticket_zone, data, M_WAITOK);
368 }
369
370 static inline void
fticket_destroy(struct fuse_ticket * ftick)371 fticket_destroy(struct fuse_ticket *ftick)
372 {
373 return uma_zfree(ticket_zone, ftick);
374 }
375
376 /* Prepare the ticket to be reused and clear its data buffers */
377 static inline void
fticket_refresh(struct fuse_ticket * ftick)378 fticket_refresh(struct fuse_ticket *ftick)
379 {
380 fticket_reset(ftick);
381
382 fiov_refresh(&ftick->tk_ms_fiov);
383 fiov_refresh(&ftick->tk_aw_fiov);
384 }
385
386 /* Prepare the ticket to be reused, but don't clear its data buffers */
387 static inline void
fticket_reset(struct fuse_ticket * ftick)388 fticket_reset(struct fuse_ticket *ftick)
389 {
390 struct fuse_data *data = ftick->tk_data;
391
392 FUSE_ASSERT_MS_DONE(ftick);
393 FUSE_ASSERT_AW_DONE(ftick);
394
395 bzero(&ftick->tk_aw_ohead, sizeof(struct fuse_out_header));
396
397 ftick->tk_aw_errno = 0;
398 ftick->tk_flag = 0;
399
400 /* May be truncated to 32 bits on LP32 arches */
401 ftick->tk_unique = atomic_fetchadd_long(&data->ticketer, 1);
402 if (ftick->tk_unique == 0)
403 ftick->tk_unique = atomic_fetchadd_long(&data->ticketer, 1);
404 }
405
406 static int
fticket_wait_answer(struct fuse_ticket * ftick)407 fticket_wait_answer(struct fuse_ticket *ftick)
408 {
409 struct thread *td = curthread;
410 sigset_t blockedset, oldset;
411 int err = 0, stops_deferred;
412 struct fuse_data *data = ftick->tk_data;
413 bool interrupted = false;
414
415 if (fsess_maybe_impl(ftick->tk_data->mp, FUSE_INTERRUPT) &&
416 data->dataflags & FSESS_INTR) {
417 SIGEMPTYSET(blockedset);
418 } else {
419 /* Block all signals except (implicitly) SIGKILL */
420 SIGFILLSET(blockedset);
421 }
422 stops_deferred = sigdeferstop(SIGDEFERSTOP_SILENT);
423 kern_sigprocmask(td, SIG_BLOCK, NULL, &oldset, 0);
424
425 fuse_lck_mtx_lock(ftick->tk_aw_mtx);
426
427 retry:
428 if (fticket_answered(ftick)) {
429 goto out;
430 }
431
432 if (fdata_get_dead(data)) {
433 err = ENOTCONN;
434 fticket_set_answered(ftick);
435 goto out;
436 }
437 kern_sigprocmask(td, SIG_BLOCK, &blockedset, NULL, 0);
438 err = msleep(ftick, &ftick->tk_aw_mtx, PCATCH, "fu_ans",
439 data->daemon_timeout * hz);
440 kern_sigprocmask(td, SIG_SETMASK, &oldset, NULL, 0);
441 if (err == EWOULDBLOCK) {
442 SDT_PROBE2(fusefs, , ipc, trace, 3,
443 "fticket_wait_answer: EWOULDBLOCK");
444 err = ETIMEDOUT;
445 fticket_set_answered(ftick);
446 } else if ((err == EINTR || err == ERESTART)) {
447 /*
448 * Whether we get EINTR or ERESTART depends on whether
449 * SA_RESTART was set by sigaction(2).
450 *
451 * Try to interrupt the operation and wait for an EINTR response
452 * to the original operation. If the file system does not
453 * support FUSE_INTERRUPT, then we'll just wait for it to
454 * complete like normal. If it does support FUSE_INTERRUPT,
455 * then it will either respond EINTR to the original operation,
456 * or EAGAIN to the interrupt.
457 */
458 sigset_t tmpset;
459
460 SDT_PROBE2(fusefs, , ipc, trace, 4,
461 "fticket_wait_answer: interrupt");
462 fuse_lck_mtx_unlock(ftick->tk_aw_mtx);
463 fuse_interrupt_send(ftick, err);
464
465 PROC_LOCK(td->td_proc);
466 mtx_lock(&td->td_proc->p_sigacts->ps_mtx);
467 tmpset = td->td_proc->p_siglist;
468 SIGSETOR(tmpset, td->td_siglist);
469 mtx_unlock(&td->td_proc->p_sigacts->ps_mtx);
470 PROC_UNLOCK(td->td_proc);
471
472 fuse_lck_mtx_lock(ftick->tk_aw_mtx);
473 if (!interrupted && !SIGISMEMBER(tmpset, SIGKILL)) {
474 /*
475 * Block all signals while we wait for an interrupt
476 * response. The protocol doesn't discriminate between
477 * different signals.
478 */
479 SIGFILLSET(blockedset);
480 interrupted = true;
481 goto retry;
482 } else {
483 /*
484 * Return immediately for fatal signals, or if this is
485 * the second interruption. We should only be
486 * interrupted twice if the thread is stopped, for
487 * example during sigexit.
488 */
489 }
490 } else if (err) {
491 SDT_PROBE2(fusefs, , ipc, trace, 6,
492 "fticket_wait_answer: other error");
493 } else {
494 SDT_PROBE2(fusefs, , ipc, trace, 7, "fticket_wait_answer: OK");
495 }
496 out:
497 if (!(err || fticket_answered(ftick))) {
498 SDT_PROBE2(fusefs, , ipc, trace, 1,
499 "FUSE: requester was woken up but still no answer");
500 err = ENXIO;
501 }
502 fuse_lck_mtx_unlock(ftick->tk_aw_mtx);
503 sigallowstop(stops_deferred);
504
505 return err;
506 }
507
508 static inline
509 int
fticket_aw_pull_uio(struct fuse_ticket * ftick,struct uio * uio)510 fticket_aw_pull_uio(struct fuse_ticket *ftick, struct uio *uio)
511 {
512 int err = 0;
513 size_t len = uio_resid(uio);
514
515 if (len) {
516 fiov_adjust(fticket_resp(ftick), len);
517 err = uiomove(fticket_resp(ftick)->base, len, uio);
518 }
519 return err;
520 }
521
522 int
fticket_pull(struct fuse_ticket * ftick,struct uio * uio)523 fticket_pull(struct fuse_ticket *ftick, struct uio *uio)
524 {
525 int err = 0;
526
527 if (ftick->tk_aw_ohead.error) {
528 return 0;
529 }
530 err = fuse_body_audit(ftick, uio_resid(uio));
531 if (!err) {
532 err = fticket_aw_pull_uio(ftick, uio);
533 }
534 return err;
535 }
536
537 struct fuse_data *
fdata_alloc(struct cdev * fdev,struct ucred * cred)538 fdata_alloc(struct cdev *fdev, struct ucred *cred)
539 {
540 struct fuse_data *data;
541
542 data = malloc(sizeof(struct fuse_data), M_FUSEMSG, M_WAITOK | M_ZERO);
543
544 data->fdev = fdev;
545 mtx_init(&data->ms_mtx, "fuse message list mutex", NULL, MTX_DEF);
546 STAILQ_INIT(&data->ms_head);
547 data->ms_count = 0;
548 knlist_init_mtx(&data->ks_rsel.si_note, &data->ms_mtx);
549 mtx_init(&data->aw_mtx, "fuse answer list mutex", NULL, MTX_DEF);
550 TAILQ_INIT(&data->aw_head);
551 data->daemoncred = crhold(cred);
552 data->daemon_timeout = FUSE_DEFAULT_DAEMON_TIMEOUT;
553 sx_init(&data->rename_lock, "fuse rename lock");
554 data->ref = 1;
555
556 return data;
557 }
558
559 void
fdata_trydestroy(struct fuse_data * data)560 fdata_trydestroy(struct fuse_data *data)
561 {
562 data->ref--;
563 MPASS(data->ref >= 0);
564 if (data->ref != 0)
565 return;
566
567 /* Driving off stage all that stuff thrown at device... */
568 sx_destroy(&data->rename_lock);
569 crfree(data->daemoncred);
570 mtx_destroy(&data->aw_mtx);
571 knlist_delete(&data->ks_rsel.si_note, curthread, 0);
572 knlist_destroy(&data->ks_rsel.si_note);
573 mtx_destroy(&data->ms_mtx);
574
575 free(data, M_FUSEMSG);
576 }
577
578 void
fdata_set_dead(struct fuse_data * data)579 fdata_set_dead(struct fuse_data *data)
580 {
581 FUSE_LOCK();
582 if (fdata_get_dead(data)) {
583 FUSE_UNLOCK();
584 return;
585 }
586 fuse_lck_mtx_lock(data->ms_mtx);
587 data->dataflags |= FSESS_DEAD;
588 wakeup_one(data);
589 selwakeuppri(&data->ks_rsel, PZERO);
590 wakeup(&data->ticketer);
591 fuse_lck_mtx_unlock(data->ms_mtx);
592 FUSE_UNLOCK();
593 }
594
595 struct fuse_ticket *
fuse_ticket_fetch(struct fuse_data * data)596 fuse_ticket_fetch(struct fuse_data *data)
597 {
598 int err = 0;
599 struct fuse_ticket *ftick;
600
601 ftick = fticket_alloc(data);
602
603 if (!(data->dataflags & FSESS_INITED)) {
604 /* Sleep until get answer for INIT message */
605 FUSE_LOCK();
606 if (!(data->dataflags & FSESS_INITED) && data->ticketer > 2) {
607 err = msleep(&data->ticketer, &fuse_mtx, PCATCH | PDROP,
608 "fu_ini", 0);
609 if (err)
610 fdata_set_dead(data);
611 } else
612 FUSE_UNLOCK();
613 }
614 return ftick;
615 }
616
617 int
fuse_ticket_drop(struct fuse_ticket * ftick)618 fuse_ticket_drop(struct fuse_ticket *ftick)
619 {
620 int die;
621
622 die = refcount_release(&ftick->tk_refcount);
623 if (die)
624 fticket_destroy(ftick);
625
626 return die;
627 }
628
629 void
fuse_insert_callback(struct fuse_ticket * ftick,fuse_handler_t * handler)630 fuse_insert_callback(struct fuse_ticket *ftick, fuse_handler_t * handler)
631 {
632 if (fdata_get_dead(ftick->tk_data)) {
633 return;
634 }
635 ftick->tk_aw_handler = handler;
636
637 fuse_lck_mtx_lock(ftick->tk_data->aw_mtx);
638 fuse_aw_push(ftick);
639 fuse_lck_mtx_unlock(ftick->tk_data->aw_mtx);
640 }
641
642 /*
643 * Insert a new upgoing ticket into the message queue
644 *
645 * If urgent is true, insert at the front of the queue. Otherwise, insert in
646 * FIFO order.
647 */
648 void
fuse_insert_message(struct fuse_ticket * ftick,bool urgent)649 fuse_insert_message(struct fuse_ticket *ftick, bool urgent)
650 {
651 if (ftick->tk_flag & FT_DIRTY) {
652 panic("FUSE: ticket reused without being refreshed");
653 }
654 ftick->tk_flag |= FT_DIRTY;
655
656 if (fdata_get_dead(ftick->tk_data)) {
657 return;
658 }
659 fuse_lck_mtx_lock(ftick->tk_data->ms_mtx);
660 if (urgent)
661 fuse_ms_push_head(ftick);
662 else
663 fuse_ms_push(ftick);
664 wakeup_one(ftick->tk_data);
665 selwakeuppri(&ftick->tk_data->ks_rsel, PZERO);
666 KNOTE_LOCKED(&ftick->tk_data->ks_rsel.si_note, 0);
667 fuse_lck_mtx_unlock(ftick->tk_data->ms_mtx);
668 }
669
670 static int
fuse_body_audit(struct fuse_ticket * ftick,size_t blen)671 fuse_body_audit(struct fuse_ticket *ftick, size_t blen)
672 {
673 int err = 0;
674 enum fuse_opcode opcode;
675
676 opcode = fticket_opcode(ftick);
677
678 switch (opcode) {
679 case FUSE_BMAP:
680 err = (blen == sizeof(struct fuse_bmap_out)) ? 0 : EINVAL;
681 break;
682
683 case FUSE_LINK:
684 case FUSE_LOOKUP:
685 case FUSE_MKDIR:
686 case FUSE_MKNOD:
687 case FUSE_SYMLINK:
688 if (fuse_libabi_geq(ftick->tk_data, 7, 9)) {
689 err = (blen == sizeof(struct fuse_entry_out)) ?
690 0 : EINVAL;
691 } else {
692 err = (blen == FUSE_COMPAT_ENTRY_OUT_SIZE) ? 0 : EINVAL;
693 }
694 break;
695
696 case FUSE_FORGET:
697 panic("FUSE: a handler has been intalled for FUSE_FORGET");
698 break;
699
700 case FUSE_GETATTR:
701 case FUSE_SETATTR:
702 if (fuse_libabi_geq(ftick->tk_data, 7, 9)) {
703 err = (blen == sizeof(struct fuse_attr_out)) ?
704 0 : EINVAL;
705 } else {
706 err = (blen == FUSE_COMPAT_ATTR_OUT_SIZE) ? 0 : EINVAL;
707 }
708 break;
709
710 case FUSE_READLINK:
711 err = (PAGE_SIZE >= blen) ? 0 : EINVAL;
712 break;
713
714 case FUSE_UNLINK:
715 err = (blen == 0) ? 0 : EINVAL;
716 break;
717
718 case FUSE_RMDIR:
719 err = (blen == 0) ? 0 : EINVAL;
720 break;
721
722 case FUSE_RENAME:
723 err = (blen == 0) ? 0 : EINVAL;
724 break;
725
726 case FUSE_OPEN:
727 err = (blen == sizeof(struct fuse_open_out)) ? 0 : EINVAL;
728 break;
729
730 case FUSE_READ:
731 err = (((struct fuse_read_in *)(
732 (char *)ftick->tk_ms_fiov.base +
733 sizeof(struct fuse_in_header)
734 ))->size >= blen) ? 0 : EINVAL;
735 break;
736
737 case FUSE_WRITE:
738 err = (blen == sizeof(struct fuse_write_out)) ? 0 : EINVAL;
739 break;
740
741 case FUSE_STATFS:
742 if (fuse_libabi_geq(ftick->tk_data, 7, 4)) {
743 err = (blen == sizeof(struct fuse_statfs_out)) ?
744 0 : EINVAL;
745 } else {
746 err = (blen == FUSE_COMPAT_STATFS_SIZE) ? 0 : EINVAL;
747 }
748 break;
749
750 case FUSE_RELEASE:
751 err = (blen == 0) ? 0 : EINVAL;
752 break;
753
754 case FUSE_FSYNC:
755 err = (blen == 0) ? 0 : EINVAL;
756 break;
757
758 case FUSE_SETXATTR:
759 err = (blen == 0) ? 0 : EINVAL;
760 break;
761
762 case FUSE_GETXATTR:
763 case FUSE_LISTXATTR:
764 /*
765 * These can have varying response lengths, and 0 length
766 * isn't necessarily invalid.
767 */
768 err = 0;
769 break;
770
771 case FUSE_REMOVEXATTR:
772 err = (blen == 0) ? 0 : EINVAL;
773 break;
774
775 case FUSE_FLUSH:
776 err = (blen == 0) ? 0 : EINVAL;
777 break;
778
779 case FUSE_INIT:
780 if (blen == sizeof(struct fuse_init_out) ||
781 blen == FUSE_COMPAT_INIT_OUT_SIZE ||
782 blen == FUSE_COMPAT_22_INIT_OUT_SIZE) {
783 err = 0;
784 } else {
785 err = EINVAL;
786 }
787 break;
788
789 case FUSE_OPENDIR:
790 err = (blen == sizeof(struct fuse_open_out)) ? 0 : EINVAL;
791 break;
792
793 case FUSE_READDIR:
794 err = (((struct fuse_read_in *)(
795 (char *)ftick->tk_ms_fiov.base +
796 sizeof(struct fuse_in_header)
797 ))->size >= blen) ? 0 : EINVAL;
798 break;
799
800 case FUSE_RELEASEDIR:
801 err = (blen == 0) ? 0 : EINVAL;
802 break;
803
804 case FUSE_FSYNCDIR:
805 err = (blen == 0) ? 0 : EINVAL;
806 break;
807
808 case FUSE_GETLK:
809 err = (blen == sizeof(struct fuse_lk_out)) ? 0 : EINVAL;
810 break;
811
812 case FUSE_SETLK:
813 err = (blen == 0) ? 0 : EINVAL;
814 break;
815
816 case FUSE_SETLKW:
817 err = (blen == 0) ? 0 : EINVAL;
818 break;
819
820 case FUSE_ACCESS:
821 err = (blen == 0) ? 0 : EINVAL;
822 break;
823
824 case FUSE_CREATE:
825 if (fuse_libabi_geq(ftick->tk_data, 7, 9)) {
826 err = (blen == sizeof(struct fuse_entry_out) +
827 sizeof(struct fuse_open_out)) ? 0 : EINVAL;
828 } else {
829 err = (blen == FUSE_COMPAT_ENTRY_OUT_SIZE +
830 sizeof(struct fuse_open_out)) ? 0 : EINVAL;
831 }
832 break;
833
834 case FUSE_DESTROY:
835 err = (blen == 0) ? 0 : EINVAL;
836 break;
837
838 case FUSE_FALLOCATE:
839 err = (blen == 0) ? 0 : EINVAL;
840 break;
841
842 case FUSE_LSEEK:
843 err = (blen == sizeof(struct fuse_lseek_out)) ? 0 : EINVAL;
844 break;
845
846 case FUSE_COPY_FILE_RANGE:
847 err = (blen == sizeof(struct fuse_write_out)) ? 0 : EINVAL;
848 break;
849
850 default:
851 panic("FUSE: opcodes out of sync (%d)\n", opcode);
852 }
853
854 return err;
855 }
856
857 static inline void
fuse_setup_ihead(struct fuse_in_header * ihead,struct fuse_ticket * ftick,uint64_t nid,enum fuse_opcode op,size_t blen,pid_t pid,struct ucred * cred)858 fuse_setup_ihead(struct fuse_in_header *ihead, struct fuse_ticket *ftick,
859 uint64_t nid, enum fuse_opcode op, size_t blen, pid_t pid,
860 struct ucred *cred)
861 {
862 ihead->len = sizeof(*ihead) + blen;
863 ihead->unique = ftick->tk_unique;
864 ihead->nodeid = nid;
865 ihead->opcode = op;
866
867 ihead->pid = pid;
868 ihead->uid = cred->cr_uid;
869 ihead->gid = cred->cr_gid;
870 }
871
872 /*
873 * fuse_standard_handler just pulls indata and wakes up pretender.
874 * Doesn't try to interpret data, that's left for the pretender.
875 * Though might do a basic size verification before the pull-in takes place
876 */
877
878 static int
fuse_standard_handler(struct fuse_ticket * ftick,struct uio * uio)879 fuse_standard_handler(struct fuse_ticket *ftick, struct uio *uio)
880 {
881 int err = 0;
882
883 err = fticket_pull(ftick, uio);
884
885 fuse_lck_mtx_lock(ftick->tk_aw_mtx);
886
887 if (!fticket_answered(ftick)) {
888 fticket_set_answered(ftick);
889 ftick->tk_aw_errno = err;
890 wakeup(ftick);
891 }
892 fuse_lck_mtx_unlock(ftick->tk_aw_mtx);
893
894 return err;
895 }
896
897 /*
898 * Reinitialize a dispatcher from a pid and node id, without resizing or
899 * clearing its data buffers
900 */
901 static void
fdisp_refresh_pid(struct fuse_dispatcher * fdip,enum fuse_opcode op,struct mount * mp,uint64_t nid,pid_t pid,struct ucred * cred)902 fdisp_refresh_pid(struct fuse_dispatcher *fdip, enum fuse_opcode op,
903 struct mount *mp, uint64_t nid, pid_t pid, struct ucred *cred)
904 {
905 MPASS(fdip->tick);
906 MPASS2(sizeof(fdip->finh) + fdip->iosize <= fdip->tick->tk_ms_fiov.len,
907 "Must use fdisp_make_pid to increase the size of the fiov");
908 fticket_reset(fdip->tick);
909
910 FUSE_DIMALLOC(&fdip->tick->tk_ms_fiov, fdip->finh,
911 fdip->indata, fdip->iosize);
912
913 fuse_setup_ihead(fdip->finh, fdip->tick, nid, op, fdip->iosize, pid,
914 cred);
915 }
916
917 /* Initialize a dispatcher from a pid and node id */
918 static void
fdisp_make_pid(struct fuse_dispatcher * fdip,enum fuse_opcode op,struct fuse_data * data,uint64_t nid,pid_t pid,struct ucred * cred)919 fdisp_make_pid(struct fuse_dispatcher *fdip, enum fuse_opcode op,
920 struct fuse_data *data, uint64_t nid, pid_t pid, struct ucred *cred)
921 {
922 if (fdip->tick) {
923 fticket_refresh(fdip->tick);
924 } else {
925 fdip->tick = fuse_ticket_fetch(data);
926 }
927
928 /* FUSE_DIMALLOC will bzero the fiovs when it enlarges them */
929 FUSE_DIMALLOC(&fdip->tick->tk_ms_fiov, fdip->finh,
930 fdip->indata, fdip->iosize);
931
932 fuse_setup_ihead(fdip->finh, fdip->tick, nid, op, fdip->iosize, pid, cred);
933 }
934
935 void
fdisp_make(struct fuse_dispatcher * fdip,enum fuse_opcode op,struct mount * mp,uint64_t nid,struct thread * td,struct ucred * cred)936 fdisp_make(struct fuse_dispatcher *fdip, enum fuse_opcode op, struct mount *mp,
937 uint64_t nid, struct thread *td, struct ucred *cred)
938 {
939 struct fuse_data *data = fuse_get_mpdata(mp);
940 RECTIFY_TDCR(td, cred);
941
942 return fdisp_make_pid(fdip, op, data, nid, td->td_proc->p_pid, cred);
943 }
944
945 void
fdisp_make_vp(struct fuse_dispatcher * fdip,enum fuse_opcode op,struct vnode * vp,struct thread * td,struct ucred * cred)946 fdisp_make_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
947 struct vnode *vp, struct thread *td, struct ucred *cred)
948 {
949 struct mount *mp = vnode_mount(vp);
950 struct fuse_data *data = fuse_get_mpdata(mp);
951
952 RECTIFY_TDCR(td, cred);
953 return fdisp_make_pid(fdip, op, data, VTOI(vp),
954 td->td_proc->p_pid, cred);
955 }
956
957 /* Refresh a fuse_dispatcher so it can be reused, but don't zero its data */
958 void
fdisp_refresh_vp(struct fuse_dispatcher * fdip,enum fuse_opcode op,struct vnode * vp,struct thread * td,struct ucred * cred)959 fdisp_refresh_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
960 struct vnode *vp, struct thread *td, struct ucred *cred)
961 {
962 RECTIFY_TDCR(td, cred);
963 return fdisp_refresh_pid(fdip, op, vnode_mount(vp), VTOI(vp),
964 td->td_proc->p_pid, cred);
965 }
966
967 SDT_PROBE_DEFINE2(fusefs, , ipc, fdisp_wait_answ_error, "char*", "int");
968
969 int
fdisp_wait_answ(struct fuse_dispatcher * fdip)970 fdisp_wait_answ(struct fuse_dispatcher *fdip)
971 {
972 int err = 0;
973
974 fdip->answ_stat = 0;
975 fuse_insert_callback(fdip->tick, fuse_standard_handler);
976 fuse_insert_message(fdip->tick, false);
977
978 if ((err = fticket_wait_answer(fdip->tick))) {
979 fuse_lck_mtx_lock(fdip->tick->tk_aw_mtx);
980
981 if (fticket_answered(fdip->tick)) {
982 /*
983 * Just between noticing the interrupt and getting here,
984 * the standard handler has completed his job.
985 * So we drop the ticket and exit as usual.
986 */
987 SDT_PROBE2(fusefs, , ipc, fdisp_wait_answ_error,
988 "IPC: interrupted, already answered", err);
989 fuse_lck_mtx_unlock(fdip->tick->tk_aw_mtx);
990 goto out;
991 } else {
992 /*
993 * So we were faster than the standard handler.
994 * Then by setting the answered flag we get *him*
995 * to drop the ticket.
996 */
997 SDT_PROBE2(fusefs, , ipc, fdisp_wait_answ_error,
998 "IPC: interrupted, setting to answered", err);
999 fticket_set_answered(fdip->tick);
1000 fuse_lck_mtx_unlock(fdip->tick->tk_aw_mtx);
1001 return err;
1002 }
1003 }
1004
1005 if (fdip->tick->tk_aw_errno == ENOTCONN) {
1006 /* The daemon died while we were waiting for a response */
1007 err = ENOTCONN;
1008 goto out;
1009 } else if (fdip->tick->tk_aw_errno) {
1010 /*
1011 * There was some sort of communication error with the daemon
1012 * that the client wouldn't understand.
1013 */
1014 SDT_PROBE2(fusefs, , ipc, fdisp_wait_answ_error,
1015 "IPC: explicit EIO-ing", fdip->tick->tk_aw_errno);
1016 err = EIO;
1017 goto out;
1018 }
1019 if ((err = fdip->tick->tk_aw_ohead.error)) {
1020 SDT_PROBE2(fusefs, , ipc, fdisp_wait_answ_error,
1021 "IPC: setting status", fdip->tick->tk_aw_ohead.error);
1022 /*
1023 * This means a "proper" fuse syscall error.
1024 * We record this value so the caller will
1025 * be able to know it's not a boring messaging
1026 * failure, if she wishes so (and if not, she can
1027 * just simply propagate the return value of this routine).
1028 * [XXX Maybe a bitflag would do the job too,
1029 * if other flags needed, this will be converted thusly.]
1030 */
1031 fdip->answ_stat = err;
1032 goto out;
1033 }
1034 fdip->answ = fticket_resp(fdip->tick)->base;
1035 fdip->iosize = fticket_resp(fdip->tick)->len;
1036
1037 return 0;
1038
1039 out:
1040 return err;
1041 }
1042
1043 void
fuse_ipc_init(void)1044 fuse_ipc_init(void)
1045 {
1046 ticket_zone = uma_zcreate("fuse_ticket", sizeof(struct fuse_ticket),
1047 fticket_ctor, fticket_dtor, fticket_init, fticket_fini,
1048 UMA_ALIGN_PTR, 0);
1049 fuse_ticket_count = counter_u64_alloc(M_WAITOK);
1050 }
1051
1052 void
fuse_ipc_destroy(void)1053 fuse_ipc_destroy(void)
1054 {
1055 counter_u64_free(fuse_ticket_count);
1056 uma_zdestroy(ticket_zone);
1057 }
1058
1059 SDT_PROBE_DEFINE3(fusefs,, ipc, warn, "struct fuse_data*", "unsigned", "char*");
1060 void
fuse_warn(struct fuse_data * data,unsigned flag,const char * msg)1061 fuse_warn(struct fuse_data *data, unsigned flag, const char *msg)
1062 {
1063 SDT_PROBE3(fusefs, , ipc, warn, data, flag, msg);
1064 if (!(data->dataflags & flag)) {
1065 printf("WARNING: FUSE protocol violation for server mounted at "
1066 "%s: %s "
1067 "This warning will not be repeated.\n",
1068 data->mp->mnt_stat.f_mntonname, msg);
1069 data->dataflags |= flag;
1070 }
1071 }
1072