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 data->ref = 1;
554
555 return data;
556 }
557
558 void
fdata_trydestroy(struct fuse_data * data)559 fdata_trydestroy(struct fuse_data *data)
560 {
561 data->ref--;
562 MPASS(data->ref >= 0);
563 if (data->ref != 0)
564 return;
565
566 /* Driving off stage all that stuff thrown at device... */
567 crfree(data->daemoncred);
568 mtx_destroy(&data->aw_mtx);
569 knlist_delete(&data->ks_rsel.si_note, curthread, 0);
570 knlist_destroy(&data->ks_rsel.si_note);
571 mtx_destroy(&data->ms_mtx);
572
573 free(data, M_FUSEMSG);
574 }
575
576 void
fdata_set_dead(struct fuse_data * data)577 fdata_set_dead(struct fuse_data *data)
578 {
579 FUSE_LOCK();
580 if (fdata_get_dead(data)) {
581 FUSE_UNLOCK();
582 return;
583 }
584 fuse_lck_mtx_lock(data->ms_mtx);
585 data->dataflags |= FSESS_DEAD;
586 wakeup_one(data);
587 selwakeuppri(&data->ks_rsel, PZERO);
588 wakeup(&data->ticketer);
589 fuse_lck_mtx_unlock(data->ms_mtx);
590 FUSE_UNLOCK();
591 }
592
593 struct fuse_ticket *
fuse_ticket_fetch(struct fuse_data * data)594 fuse_ticket_fetch(struct fuse_data *data)
595 {
596 int err = 0;
597 struct fuse_ticket *ftick;
598
599 ftick = fticket_alloc(data);
600
601 if (!(data->dataflags & FSESS_INITED)) {
602 /* Sleep until get answer for INIT message */
603 FUSE_LOCK();
604 if (!(data->dataflags & FSESS_INITED) && data->ticketer > 2) {
605 err = msleep(&data->ticketer, &fuse_mtx, PCATCH | PDROP,
606 "fu_ini", 0);
607 if (err)
608 fdata_set_dead(data);
609 } else
610 FUSE_UNLOCK();
611 }
612 return ftick;
613 }
614
615 int
fuse_ticket_drop(struct fuse_ticket * ftick)616 fuse_ticket_drop(struct fuse_ticket *ftick)
617 {
618 int die;
619
620 die = refcount_release(&ftick->tk_refcount);
621 if (die)
622 fticket_destroy(ftick);
623
624 return die;
625 }
626
627 void
fuse_insert_callback(struct fuse_ticket * ftick,fuse_handler_t * handler)628 fuse_insert_callback(struct fuse_ticket *ftick, fuse_handler_t * handler)
629 {
630 if (fdata_get_dead(ftick->tk_data)) {
631 return;
632 }
633 ftick->tk_aw_handler = handler;
634
635 fuse_lck_mtx_lock(ftick->tk_data->aw_mtx);
636 fuse_aw_push(ftick);
637 fuse_lck_mtx_unlock(ftick->tk_data->aw_mtx);
638 }
639
640 /*
641 * Insert a new upgoing ticket into the message queue
642 *
643 * If urgent is true, insert at the front of the queue. Otherwise, insert in
644 * FIFO order.
645 */
646 void
fuse_insert_message(struct fuse_ticket * ftick,bool urgent)647 fuse_insert_message(struct fuse_ticket *ftick, bool urgent)
648 {
649 if (ftick->tk_flag & FT_DIRTY) {
650 panic("FUSE: ticket reused without being refreshed");
651 }
652 ftick->tk_flag |= FT_DIRTY;
653
654 if (fdata_get_dead(ftick->tk_data)) {
655 return;
656 }
657 fuse_lck_mtx_lock(ftick->tk_data->ms_mtx);
658 if (urgent)
659 fuse_ms_push_head(ftick);
660 else
661 fuse_ms_push(ftick);
662 wakeup_one(ftick->tk_data);
663 selwakeuppri(&ftick->tk_data->ks_rsel, PZERO);
664 KNOTE_LOCKED(&ftick->tk_data->ks_rsel.si_note, 0);
665 fuse_lck_mtx_unlock(ftick->tk_data->ms_mtx);
666 }
667
668 static int
fuse_body_audit(struct fuse_ticket * ftick,size_t blen)669 fuse_body_audit(struct fuse_ticket *ftick, size_t blen)
670 {
671 int err = 0;
672 enum fuse_opcode opcode;
673
674 opcode = fticket_opcode(ftick);
675
676 switch (opcode) {
677 case FUSE_BMAP:
678 err = (blen == sizeof(struct fuse_bmap_out)) ? 0 : EINVAL;
679 break;
680
681 case FUSE_LINK:
682 case FUSE_LOOKUP:
683 case FUSE_MKDIR:
684 case FUSE_MKNOD:
685 case FUSE_SYMLINK:
686 if (fuse_libabi_geq(ftick->tk_data, 7, 9)) {
687 err = (blen == sizeof(struct fuse_entry_out)) ?
688 0 : EINVAL;
689 } else {
690 err = (blen == FUSE_COMPAT_ENTRY_OUT_SIZE) ? 0 : EINVAL;
691 }
692 break;
693
694 case FUSE_FORGET:
695 panic("FUSE: a handler has been installed for FUSE_FORGET");
696 break;
697
698 case FUSE_GETATTR:
699 case FUSE_SETATTR:
700 if (fuse_libabi_geq(ftick->tk_data, 7, 9)) {
701 err = (blen == sizeof(struct fuse_attr_out)) ?
702 0 : EINVAL;
703 } else {
704 err = (blen == FUSE_COMPAT_ATTR_OUT_SIZE) ? 0 : EINVAL;
705 }
706 break;
707
708 case FUSE_READLINK:
709 err = (PAGE_SIZE >= blen) ? 0 : EINVAL;
710 break;
711
712 case FUSE_UNLINK:
713 err = (blen == 0) ? 0 : EINVAL;
714 break;
715
716 case FUSE_RMDIR:
717 err = (blen == 0) ? 0 : EINVAL;
718 break;
719
720 case FUSE_RENAME:
721 err = (blen == 0) ? 0 : EINVAL;
722 break;
723
724 case FUSE_OPEN:
725 err = (blen == sizeof(struct fuse_open_out)) ? 0 : EINVAL;
726 break;
727
728 case FUSE_READ:
729 err = (((struct fuse_read_in *)(
730 (char *)ftick->tk_ms_fiov.base +
731 sizeof(struct fuse_in_header)
732 ))->size >= blen) ? 0 : EINVAL;
733 break;
734
735 case FUSE_WRITE:
736 err = (blen == sizeof(struct fuse_write_out)) ? 0 : EINVAL;
737 break;
738
739 case FUSE_STATFS:
740 if (fuse_libabi_geq(ftick->tk_data, 7, 4)) {
741 err = (blen == sizeof(struct fuse_statfs_out)) ?
742 0 : EINVAL;
743 } else {
744 err = (blen == FUSE_COMPAT_STATFS_SIZE) ? 0 : EINVAL;
745 }
746 break;
747
748 case FUSE_RELEASE:
749 err = (blen == 0) ? 0 : EINVAL;
750 break;
751
752 case FUSE_FSYNC:
753 err = (blen == 0) ? 0 : EINVAL;
754 break;
755
756 case FUSE_SETXATTR:
757 err = (blen == 0) ? 0 : EINVAL;
758 break;
759
760 case FUSE_GETXATTR:
761 case FUSE_LISTXATTR:
762 /*
763 * These can have varying response lengths, and 0 length
764 * isn't necessarily invalid.
765 */
766 err = 0;
767 break;
768
769 case FUSE_REMOVEXATTR:
770 err = (blen == 0) ? 0 : EINVAL;
771 break;
772
773 case FUSE_FLUSH:
774 err = (blen == 0) ? 0 : EINVAL;
775 break;
776
777 case FUSE_INIT:
778 if (blen == sizeof(struct fuse_init_out) ||
779 blen == FUSE_COMPAT_INIT_OUT_SIZE ||
780 blen == FUSE_COMPAT_22_INIT_OUT_SIZE) {
781 err = 0;
782 } else {
783 err = EINVAL;
784 }
785 break;
786
787 case FUSE_OPENDIR:
788 err = (blen == sizeof(struct fuse_open_out)) ? 0 : EINVAL;
789 break;
790
791 case FUSE_READDIR:
792 err = (((struct fuse_read_in *)(
793 (char *)ftick->tk_ms_fiov.base +
794 sizeof(struct fuse_in_header)
795 ))->size >= blen) ? 0 : EINVAL;
796 break;
797
798 case FUSE_RELEASEDIR:
799 err = (blen == 0) ? 0 : EINVAL;
800 break;
801
802 case FUSE_FSYNCDIR:
803 err = (blen == 0) ? 0 : EINVAL;
804 break;
805
806 case FUSE_GETLK:
807 err = (blen == sizeof(struct fuse_lk_out)) ? 0 : EINVAL;
808 break;
809
810 case FUSE_SETLK:
811 err = (blen == 0) ? 0 : EINVAL;
812 break;
813
814 case FUSE_SETLKW:
815 err = (blen == 0) ? 0 : EINVAL;
816 break;
817
818 case FUSE_ACCESS:
819 err = (blen == 0) ? 0 : EINVAL;
820 break;
821
822 case FUSE_CREATE:
823 if (fuse_libabi_geq(ftick->tk_data, 7, 9)) {
824 err = (blen == sizeof(struct fuse_entry_out) +
825 sizeof(struct fuse_open_out)) ? 0 : EINVAL;
826 } else {
827 err = (blen == FUSE_COMPAT_ENTRY_OUT_SIZE +
828 sizeof(struct fuse_open_out)) ? 0 : EINVAL;
829 }
830 break;
831
832 case FUSE_DESTROY:
833 err = (blen == 0) ? 0 : EINVAL;
834 break;
835
836 case FUSE_IOCTL:
837 err = (blen >= sizeof(struct fuse_ioctl_out)) ? 0 : EINVAL;
838 break;
839
840 case FUSE_FALLOCATE:
841 err = (blen == 0) ? 0 : EINVAL;
842 break;
843
844 case FUSE_LSEEK:
845 err = (blen == sizeof(struct fuse_lseek_out)) ? 0 : EINVAL;
846 break;
847
848 case FUSE_COPY_FILE_RANGE:
849 err = (blen == sizeof(struct fuse_write_out)) ? 0 : EINVAL;
850 break;
851
852 default:
853 panic("FUSE: opcodes out of sync (%d)\n", opcode);
854 }
855
856 return err;
857 }
858
859 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)860 fuse_setup_ihead(struct fuse_in_header *ihead, struct fuse_ticket *ftick,
861 uint64_t nid, enum fuse_opcode op, size_t blen, pid_t pid,
862 struct ucred *cred)
863 {
864 ihead->len = sizeof(*ihead) + blen;
865 ihead->unique = ftick->tk_unique;
866 ihead->nodeid = nid;
867 ihead->opcode = op;
868
869 ihead->pid = pid;
870 ihead->uid = cred->cr_uid;
871 ihead->gid = cred->cr_gid;
872 }
873
874 /*
875 * fuse_standard_handler just pulls indata and wakes up pretender.
876 * Doesn't try to interpret data, that's left for the pretender.
877 * Though might do a basic size verification before the pull-in takes place
878 */
879
880 static int
fuse_standard_handler(struct fuse_ticket * ftick,struct uio * uio)881 fuse_standard_handler(struct fuse_ticket *ftick, struct uio *uio)
882 {
883 int err = 0;
884
885 err = fticket_pull(ftick, uio);
886
887 fuse_lck_mtx_lock(ftick->tk_aw_mtx);
888
889 if (!fticket_answered(ftick)) {
890 fticket_set_answered(ftick);
891 ftick->tk_aw_errno = err;
892 wakeup(ftick);
893 }
894 fuse_lck_mtx_unlock(ftick->tk_aw_mtx);
895
896 return err;
897 }
898
899 /*
900 * Reinitialize a dispatcher from a pid and node id, without resizing or
901 * clearing its data buffers
902 */
903 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)904 fdisp_refresh_pid(struct fuse_dispatcher *fdip, enum fuse_opcode op,
905 struct mount *mp, uint64_t nid, pid_t pid, struct ucred *cred)
906 {
907 MPASS(fdip->tick);
908 MPASS2(sizeof(fdip->finh) + fdip->iosize <= fdip->tick->tk_ms_fiov.len,
909 "Must use fdisp_make_pid to increase the size of the fiov");
910 fticket_reset(fdip->tick);
911
912 FUSE_DIMALLOC(&fdip->tick->tk_ms_fiov, fdip->finh,
913 fdip->indata, fdip->iosize);
914
915 fuse_setup_ihead(fdip->finh, fdip->tick, nid, op, fdip->iosize, pid,
916 cred);
917 }
918
919 /* Initialize a dispatcher from a pid and node id */
920 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)921 fdisp_make_pid(struct fuse_dispatcher *fdip, enum fuse_opcode op,
922 struct fuse_data *data, uint64_t nid, pid_t pid, struct ucred *cred)
923 {
924 if (fdip->tick) {
925 fticket_refresh(fdip->tick);
926 } else {
927 fdip->tick = fuse_ticket_fetch(data);
928 }
929
930 /* FUSE_DIMALLOC will bzero the fiovs when it enlarges them */
931 FUSE_DIMALLOC(&fdip->tick->tk_ms_fiov, fdip->finh,
932 fdip->indata, fdip->iosize);
933
934 fuse_setup_ihead(fdip->finh, fdip->tick, nid, op, fdip->iosize, pid, cred);
935 }
936
937 void
fdisp_make(struct fuse_dispatcher * fdip,enum fuse_opcode op,struct mount * mp,uint64_t nid,struct thread * td,struct ucred * cred)938 fdisp_make(struct fuse_dispatcher *fdip, enum fuse_opcode op, struct mount *mp,
939 uint64_t nid, struct thread *td, struct ucred *cred)
940 {
941 struct fuse_data *data = fuse_get_mpdata(mp);
942 RECTIFY_TDCR(td, cred);
943
944 return fdisp_make_pid(fdip, op, data, nid, td->td_proc->p_pid, cred);
945 }
946
947 void
fdisp_make_vp(struct fuse_dispatcher * fdip,enum fuse_opcode op,struct vnode * vp,struct thread * td,struct ucred * cred)948 fdisp_make_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
949 struct vnode *vp, struct thread *td, struct ucred *cred)
950 {
951 struct mount *mp = vnode_mount(vp);
952 struct fuse_data *data = fuse_get_mpdata(mp);
953
954 RECTIFY_TDCR(td, cred);
955 return fdisp_make_pid(fdip, op, data, VTOI(vp),
956 td->td_proc->p_pid, cred);
957 }
958
959 /* Refresh a fuse_dispatcher so it can be reused, but don't zero its data */
960 void
fdisp_refresh_vp(struct fuse_dispatcher * fdip,enum fuse_opcode op,struct vnode * vp,struct thread * td,struct ucred * cred)961 fdisp_refresh_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
962 struct vnode *vp, struct thread *td, struct ucred *cred)
963 {
964 RECTIFY_TDCR(td, cred);
965 return fdisp_refresh_pid(fdip, op, vnode_mount(vp), VTOI(vp),
966 td->td_proc->p_pid, cred);
967 }
968
969 SDT_PROBE_DEFINE2(fusefs, , ipc, fdisp_wait_answ_error, "char*", "int");
970
971 int
fdisp_wait_answ(struct fuse_dispatcher * fdip)972 fdisp_wait_answ(struct fuse_dispatcher *fdip)
973 {
974 int err = 0;
975
976 fdip->answ_stat = 0;
977 fuse_insert_callback(fdip->tick, fuse_standard_handler);
978 fuse_insert_message(fdip->tick, false);
979
980 if ((err = fticket_wait_answer(fdip->tick))) {
981 fuse_lck_mtx_lock(fdip->tick->tk_aw_mtx);
982
983 if (fticket_answered(fdip->tick)) {
984 /*
985 * Just between noticing the interrupt and getting here,
986 * the standard handler has completed his job.
987 * So we drop the ticket and exit as usual.
988 */
989 SDT_PROBE2(fusefs, , ipc, fdisp_wait_answ_error,
990 "IPC: interrupted, already answered", err);
991 fuse_lck_mtx_unlock(fdip->tick->tk_aw_mtx);
992 goto out;
993 } else {
994 /*
995 * So we were faster than the standard handler.
996 * Then by setting the answered flag we get *him*
997 * to drop the ticket.
998 */
999 SDT_PROBE2(fusefs, , ipc, fdisp_wait_answ_error,
1000 "IPC: interrupted, setting to answered", err);
1001 fticket_set_answered(fdip->tick);
1002 fuse_lck_mtx_unlock(fdip->tick->tk_aw_mtx);
1003 return err;
1004 }
1005 }
1006
1007 if (fdip->tick->tk_aw_errno == ENOTCONN) {
1008 /* The daemon died while we were waiting for a response */
1009 err = ENOTCONN;
1010 goto out;
1011 } else if (fdip->tick->tk_aw_errno) {
1012 /*
1013 * There was some sort of communication error with the daemon
1014 * that the client wouldn't understand.
1015 */
1016 SDT_PROBE2(fusefs, , ipc, fdisp_wait_answ_error,
1017 "IPC: explicit EIO-ing", fdip->tick->tk_aw_errno);
1018 err = EIO;
1019 goto out;
1020 }
1021 if ((err = fdip->tick->tk_aw_ohead.error)) {
1022 SDT_PROBE2(fusefs, , ipc, fdisp_wait_answ_error,
1023 "IPC: setting status", fdip->tick->tk_aw_ohead.error);
1024 /*
1025 * This means a "proper" fuse syscall error.
1026 * We record this value so the caller will
1027 * be able to know it's not a boring messaging
1028 * failure, if she wishes so (and if not, she can
1029 * just simply propagate the return value of this routine).
1030 * [XXX Maybe a bitflag would do the job too,
1031 * if other flags needed, this will be converted thusly.]
1032 */
1033 fdip->answ_stat = err;
1034 goto out;
1035 }
1036 fdip->answ = fticket_resp(fdip->tick)->base;
1037 fdip->iosize = fticket_resp(fdip->tick)->len;
1038
1039 return 0;
1040
1041 out:
1042 return err;
1043 }
1044
1045 void
fuse_ipc_init(void)1046 fuse_ipc_init(void)
1047 {
1048 ticket_zone = uma_zcreate("fuse_ticket", sizeof(struct fuse_ticket),
1049 fticket_ctor, fticket_dtor, fticket_init, fticket_fini,
1050 UMA_ALIGN_PTR, 0);
1051 fuse_ticket_count = counter_u64_alloc(M_WAITOK);
1052 }
1053
1054 void
fuse_ipc_destroy(void)1055 fuse_ipc_destroy(void)
1056 {
1057 counter_u64_free(fuse_ticket_count);
1058 uma_zdestroy(ticket_zone);
1059 }
1060
1061 SDT_PROBE_DEFINE3(fusefs,, ipc, warn, "struct fuse_data*", "unsigned", "char*");
1062 void
fuse_warn(struct fuse_data * data,unsigned flag,const char * msg)1063 fuse_warn(struct fuse_data *data, unsigned flag, const char *msg)
1064 {
1065 SDT_PROBE3(fusefs, , ipc, warn, data, flag, msg);
1066 if (!(data->dataflags & flag)) {
1067 printf("WARNING: FUSE protocol violation for server mounted at "
1068 "%s: %s "
1069 "This warning will not be repeated.\n",
1070 data->mp->mnt_stat.f_mntonname, msg);
1071 data->dataflags |= flag;
1072 }
1073 }
1074