xref: /freebsd/sys/fs/fuse/fuse_internal.c (revision 389e4940069316fe667ffa263fa7d6390d0a960f) 
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  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  *
45  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55  * SUCH DAMAGE.
56  */
57 
58 #include <sys/cdefs.h>
59 __FBSDID("$FreeBSD$");
60 
61 #include <sys/types.h>
62 #include <sys/module.h>
63 #include <sys/systm.h>
64 #include <sys/errno.h>
65 #include <sys/param.h>
66 #include <sys/kernel.h>
67 #include <sys/conf.h>
68 #include <sys/uio.h>
69 #include <sys/malloc.h>
70 #include <sys/queue.h>
71 #include <sys/lock.h>
72 #include <sys/mutex.h>
73 #include <sys/sx.h>
74 #include <sys/proc.h>
75 #include <sys/mount.h>
76 #include <sys/vnode.h>
77 #include <sys/namei.h>
78 #include <sys/stat.h>
79 #include <sys/unistd.h>
80 #include <sys/filedesc.h>
81 #include <sys/file.h>
82 #include <sys/fcntl.h>
83 #include <sys/dirent.h>
84 #include <sys/bio.h>
85 #include <sys/buf.h>
86 #include <sys/sysctl.h>
87 #include <sys/priv.h>
88 
89 #include "fuse.h"
90 #include "fuse_file.h"
91 #include "fuse_internal.h"
92 #include "fuse_ipc.h"
93 #include "fuse_node.h"
94 #include "fuse_file.h"
95 #include "fuse_param.h"
96 
97 #define FUSE_DEBUG_MODULE INTERNAL
98 #include "fuse_debug.h"
99 
100 #ifdef ZERO_PAD_INCOMPLETE_BUFS
101 static int isbzero(void *buf, size_t len);
102 
103 #endif
104 
105 /* access */
106 
107 int
108 fuse_internal_access(struct vnode *vp,
109     mode_t mode,
110     struct fuse_access_param *facp,
111     struct thread *td,
112     struct ucred *cred)
113 {
114 	int err = 0;
115 	uint32_t mask = 0;
116 	int dataflags;
117 	int vtype;
118 	struct mount *mp;
119 	struct fuse_dispatcher fdi;
120 	struct fuse_access_in *fai;
121 	struct fuse_data *data;
122 
123 	/* NOT YET DONE */
124 	/*
125 	 * If this vnop gives you trouble, just return 0 here for a lazy
126 	 * kludge.
127 	 */
128 	/* return 0;*/
129 
130 	fuse_trace_printf_func();
131 
132 	mp = vnode_mount(vp);
133 	vtype = vnode_vtype(vp);
134 
135 	data = fuse_get_mpdata(mp);
136 	dataflags = data->dataflags;
137 
138 	if ((mode & VWRITE) && vfs_isrdonly(mp)) {
139 		return EACCES;
140 	}
141 	/* Unless explicitly permitted, deny everyone except the fs owner. */
142 	    if (vnode_isvroot(vp) && !(facp->facc_flags & FACCESS_NOCHECKSPY)) {
143 		if (!(dataflags & FSESS_DAEMON_CAN_SPY)) {
144 			int denied = fuse_match_cred(data->daemoncred,
145 			    cred);
146 
147 			if (denied) {
148 				return EPERM;
149 			}
150 		}
151 		facp->facc_flags |= FACCESS_NOCHECKSPY;
152 	}
153 	if (!(facp->facc_flags & FACCESS_DO_ACCESS)) {
154 		return 0;
155 	}
156 	if (((vtype == VREG) && (mode & VEXEC))) {
157 #ifdef NEED_MOUNT_ARGUMENT_FOR_THIS
158 		/* Let	 the kernel handle this through open / close heuristics.*/
159 		    return ENOTSUP;
160 #else
161 		    /* 	Let the kernel handle this. */
162 		    return 0;
163 #endif
164 	}
165 	if (!fsess_isimpl(mp, FUSE_ACCESS)) {
166 		/* Let the kernel handle this. */
167 		    return 0;
168 	}
169 	if (dataflags & FSESS_DEFAULT_PERMISSIONS) {
170 		/* Let the kernel handle this. */
171 		    return 0;
172 	}
173 	if ((mode & VADMIN) != 0) {
174 		err = priv_check_cred(cred, PRIV_VFS_ADMIN, 0);
175 		if (err) {
176 			return err;
177 		}
178 	}
179 	if ((mode & (VWRITE | VAPPEND | VADMIN)) != 0) {
180 		mask |= W_OK;
181 	}
182 	if ((mode & VREAD) != 0) {
183 		mask |= R_OK;
184 	}
185 	if ((mode & VEXEC) != 0) {
186 		mask |= X_OK;
187 	}
188 	bzero(&fdi, sizeof(fdi));
189 
190 	fdisp_init(&fdi, sizeof(*fai));
191 	fdisp_make_vp(&fdi, FUSE_ACCESS, vp, td, cred);
192 
193 	fai = fdi.indata;
194 	fai->mask = F_OK;
195 	fai->mask |= mask;
196 
197 	err = fdisp_wait_answ(&fdi);
198 	fdisp_destroy(&fdi);
199 
200 	if (err == ENOSYS) {
201 		fsess_set_notimpl(mp, FUSE_ACCESS);
202 		err = 0;
203 	}
204 	return err;
205 }
206 
207 /* fsync */
208 
209 int
210 fuse_internal_fsync_callback(struct fuse_ticket *tick, struct uio *uio)
211 {
212 	fuse_trace_printf_func();
213 
214 	if (tick->tk_aw_ohead.error == ENOSYS) {
215 		fsess_set_notimpl(tick->tk_data->mp, fticket_opcode(tick));
216 	}
217 	return 0;
218 }
219 
220 int
221 fuse_internal_fsync(struct vnode *vp,
222     struct thread *td,
223     struct ucred *cred,
224     struct fuse_filehandle *fufh)
225 {
226 	int op = FUSE_FSYNC;
227 	struct fuse_fsync_in *ffsi;
228 	struct fuse_dispatcher fdi;
229 
230 	fuse_trace_printf_func();
231 
232 	if (vnode_isdir(vp)) {
233 		op = FUSE_FSYNCDIR;
234 	}
235 	fdisp_init(&fdi, sizeof(*ffsi));
236 	fdisp_make_vp(&fdi, op, vp, td, cred);
237 	ffsi = fdi.indata;
238 	ffsi->fh = fufh->fh_id;
239 
240 	ffsi->fsync_flags = 1;		/* datasync */
241 
242 	fuse_insert_callback(fdi.tick, fuse_internal_fsync_callback);
243 	fuse_insert_message(fdi.tick);
244 
245 	fdisp_destroy(&fdi);
246 
247 	return 0;
248 
249 }
250 
251 /* readdir */
252 
253 int
254 fuse_internal_readdir(struct vnode *vp,
255     struct uio *uio,
256     struct fuse_filehandle *fufh,
257     struct fuse_iov *cookediov)
258 {
259 	int err = 0;
260 	struct fuse_dispatcher fdi;
261 	struct fuse_read_in *fri;
262 
263 	if (uio_resid(uio) == 0) {
264 		return 0;
265 	}
266 	fdisp_init(&fdi, 0);
267 
268 	/*
269 	 * Note that we DO NOT have a UIO_SYSSPACE here (so no need for p2p
270 	 * I/O).
271 	 */
272 
273 	while (uio_resid(uio) > 0) {
274 
275 		fdi.iosize = sizeof(*fri);
276 		fdisp_make_vp(&fdi, FUSE_READDIR, vp, NULL, NULL);
277 
278 		fri = fdi.indata;
279 		fri->fh = fufh->fh_id;
280 		fri->offset = uio_offset(uio);
281 		fri->size = min(uio_resid(uio), FUSE_DEFAULT_IOSIZE);
282 		/* mp->max_read */
283 
284 		    if ((err = fdisp_wait_answ(&fdi))) {
285 			break;
286 		}
287 		if ((err = fuse_internal_readdir_processdata(uio, fri->size, fdi.answ,
288 		    fdi.iosize, cookediov))) {
289 			break;
290 		}
291 	}
292 
293 	fdisp_destroy(&fdi);
294 	return ((err == -1) ? 0 : err);
295 }
296 
297 int
298 fuse_internal_readdir_processdata(struct uio *uio,
299     size_t reqsize,
300     void *buf,
301     size_t bufsize,
302     void *param)
303 {
304 	int err = 0;
305 	int cou = 0;
306 	int bytesavail;
307 	size_t freclen;
308 
309 	struct dirent *de;
310 	struct fuse_dirent *fudge;
311 	struct fuse_iov *cookediov = param;
312 
313 	if (bufsize < FUSE_NAME_OFFSET) {
314 		return -1;
315 	}
316 	for (;;) {
317 
318 		if (bufsize < FUSE_NAME_OFFSET) {
319 			err = -1;
320 			break;
321 		}
322 		fudge = (struct fuse_dirent *)buf;
323 		freclen = FUSE_DIRENT_SIZE(fudge);
324 
325 		cou++;
326 
327 		if (bufsize < freclen) {
328 			err = ((cou == 1) ? -1 : 0);
329 			break;
330 		}
331 #ifdef ZERO_PAD_INCOMPLETE_BUFS
332 		if (isbzero(buf, FUSE_NAME_OFFSET)) {
333 			err = -1;
334 			break;
335 		}
336 #endif
337 
338 		if (!fudge->namelen || fudge->namelen > MAXNAMLEN) {
339 			err = EINVAL;
340 			break;
341 		}
342 		bytesavail = GENERIC_DIRSIZ((struct pseudo_dirent *)
343 					    &fudge->namelen);
344 
345 		if (bytesavail > uio_resid(uio)) {
346 			err = -1;
347 			break;
348 		}
349 		fiov_refresh(cookediov);
350 		fiov_adjust(cookediov, bytesavail);
351 
352 		de = (struct dirent *)cookediov->base;
353 		de->d_fileno = fudge->ino;	/* XXX: truncation */
354 		de->d_reclen = bytesavail;
355 		de->d_type = fudge->type;
356 		de->d_namlen = fudge->namelen;
357 		memcpy((char *)cookediov->base + sizeof(struct dirent) -
358 		       MAXNAMLEN - 1,
359 		       (char *)buf + FUSE_NAME_OFFSET, fudge->namelen);
360 		((char *)cookediov->base)[bytesavail - 1] = '\0';
361 
362 		err = uiomove(cookediov->base, cookediov->len, uio);
363 		if (err) {
364 			break;
365 		}
366 		buf = (char *)buf + freclen;
367 		bufsize -= freclen;
368 		uio_setoffset(uio, fudge->off);
369 	}
370 
371 	return err;
372 }
373 
374 /* remove */
375 
376 #define INVALIDATE_CACHED_VATTRS_UPON_UNLINK 1
377 int
378 fuse_internal_remove(struct vnode *dvp,
379     struct vnode *vp,
380     struct componentname *cnp,
381     enum fuse_opcode op)
382 {
383 	struct fuse_dispatcher fdi;
384 
385 	struct vattr *vap = VTOVA(vp);
386 
387 #if INVALIDATE_CACHED_VATTRS_UPON_UNLINK
388 	int need_invalidate = 0;
389 	uint64_t target_nlink = 0;
390 
391 #endif
392 	int err = 0;
393 
394 	debug_printf("dvp=%p, cnp=%p, op=%d\n", vp, cnp, op);
395 
396 	fdisp_init(&fdi, cnp->cn_namelen + 1);
397 	fdisp_make_vp(&fdi, op, dvp, cnp->cn_thread, cnp->cn_cred);
398 
399 	memcpy(fdi.indata, cnp->cn_nameptr, cnp->cn_namelen);
400 	((char *)fdi.indata)[cnp->cn_namelen] = '\0';
401 
402 #if INVALIDATE_CACHED_VATTRS_UPON_UNLINK
403 	if (vap->va_nlink > 1) {
404 		need_invalidate = 1;
405 		target_nlink = vap->va_nlink;
406 	}
407 #endif
408 
409 	err = fdisp_wait_answ(&fdi);
410 	fdisp_destroy(&fdi);
411 	return err;
412 }
413 
414 /* rename */
415 
416 int
417 fuse_internal_rename(struct vnode *fdvp,
418     struct componentname *fcnp,
419     struct vnode *tdvp,
420     struct componentname *tcnp)
421 {
422 	struct fuse_dispatcher fdi;
423 	struct fuse_rename_in *fri;
424 	int err = 0;
425 
426 	fdisp_init(&fdi, sizeof(*fri) + fcnp->cn_namelen + tcnp->cn_namelen + 2);
427 	fdisp_make_vp(&fdi, FUSE_RENAME, fdvp, tcnp->cn_thread, tcnp->cn_cred);
428 
429 	fri = fdi.indata;
430 	fri->newdir = VTOI(tdvp);
431 	memcpy((char *)fdi.indata + sizeof(*fri), fcnp->cn_nameptr,
432 	    fcnp->cn_namelen);
433 	((char *)fdi.indata)[sizeof(*fri) + fcnp->cn_namelen] = '\0';
434 	memcpy((char *)fdi.indata + sizeof(*fri) + fcnp->cn_namelen + 1,
435 	    tcnp->cn_nameptr, tcnp->cn_namelen);
436 	((char *)fdi.indata)[sizeof(*fri) + fcnp->cn_namelen +
437 	    tcnp->cn_namelen + 1] = '\0';
438 
439 	err = fdisp_wait_answ(&fdi);
440 	fdisp_destroy(&fdi);
441 	return err;
442 }
443 
444 /* strategy */
445 
446 /* entity creation */
447 
448 void
449 fuse_internal_newentry_makerequest(struct mount *mp,
450     uint64_t dnid,
451     struct componentname *cnp,
452     enum fuse_opcode op,
453     void *buf,
454     size_t bufsize,
455     struct fuse_dispatcher *fdip)
456 {
457 	debug_printf("fdip=%p\n", fdip);
458 
459 	fdip->iosize = bufsize + cnp->cn_namelen + 1;
460 
461 	fdisp_make(fdip, op, mp, dnid, cnp->cn_thread, cnp->cn_cred);
462 	memcpy(fdip->indata, buf, bufsize);
463 	memcpy((char *)fdip->indata + bufsize, cnp->cn_nameptr, cnp->cn_namelen);
464 	((char *)fdip->indata)[bufsize + cnp->cn_namelen] = '\0';
465 }
466 
467 int
468 fuse_internal_newentry_core(struct vnode *dvp,
469     struct vnode **vpp,
470     struct componentname *cnp,
471     enum vtype vtyp,
472     struct fuse_dispatcher *fdip)
473 {
474 	int err = 0;
475 	struct fuse_entry_out *feo;
476 	struct mount *mp = vnode_mount(dvp);
477 
478 	if ((err = fdisp_wait_answ(fdip))) {
479 		return err;
480 	}
481 	feo = fdip->answ;
482 
483 	if ((err = fuse_internal_checkentry(feo, vtyp))) {
484 		return err;
485 	}
486 	err = fuse_vnode_get(mp, feo->nodeid, dvp, vpp, cnp, vtyp);
487 	if (err) {
488 		fuse_internal_forget_send(mp, cnp->cn_thread, cnp->cn_cred,
489 		    feo->nodeid, 1);
490 		return err;
491 	}
492 	cache_attrs(*vpp, feo);
493 
494 	return err;
495 }
496 
497 int
498 fuse_internal_newentry(struct vnode *dvp,
499     struct vnode **vpp,
500     struct componentname *cnp,
501     enum fuse_opcode op,
502     void *buf,
503     size_t bufsize,
504     enum vtype vtype)
505 {
506 	int err;
507 	struct fuse_dispatcher fdi;
508 	struct mount *mp = vnode_mount(dvp);
509 
510 	fdisp_init(&fdi, 0);
511 	fuse_internal_newentry_makerequest(mp, VTOI(dvp), cnp, op, buf,
512 	    bufsize, &fdi);
513 	err = fuse_internal_newentry_core(dvp, vpp, cnp, vtype, &fdi);
514 	fdisp_destroy(&fdi);
515 
516 	return err;
517 }
518 
519 /* entity destruction */
520 
521 int
522 fuse_internal_forget_callback(struct fuse_ticket *ftick, struct uio *uio)
523 {
524 	fuse_internal_forget_send(ftick->tk_data->mp, curthread, NULL,
525 	    ((struct fuse_in_header *)ftick->tk_ms_fiov.base)->nodeid, 1);
526 
527 	return 0;
528 }
529 
530 void
531 fuse_internal_forget_send(struct mount *mp,
532     struct thread *td,
533     struct ucred *cred,
534     uint64_t nodeid,
535     uint64_t nlookup)
536 {
537 
538 	struct fuse_dispatcher fdi;
539 	struct fuse_forget_in *ffi;
540 
541 	debug_printf("mp=%p, nodeid=%ju, nlookup=%ju\n",
542 	    mp, (uintmax_t)nodeid, (uintmax_t)nlookup);
543 
544 	/*
545          * KASSERT(nlookup > 0, ("zero-times forget for vp #%llu",
546          *         (long long unsigned) nodeid));
547          */
548 
549 	fdisp_init(&fdi, sizeof(*ffi));
550 	fdisp_make(&fdi, FUSE_FORGET, mp, nodeid, td, cred);
551 
552 	ffi = fdi.indata;
553 	ffi->nlookup = nlookup;
554 
555 	fuse_insert_message(fdi.tick);
556 	fdisp_destroy(&fdi);
557 }
558 
559 void
560 fuse_internal_vnode_disappear(struct vnode *vp)
561 {
562 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
563 
564 	ASSERT_VOP_ELOCKED(vp, "fuse_internal_vnode_disappear");
565 	fvdat->flag |= FN_REVOKED;
566 	cache_purge(vp);
567 }
568 
569 /* fuse start/stop */
570 
571 int
572 fuse_internal_init_callback(struct fuse_ticket *tick, struct uio *uio)
573 {
574 	int err = 0;
575 	struct fuse_data *data = tick->tk_data;
576 	struct fuse_init_out *fiio;
577 
578 	if ((err = tick->tk_aw_ohead.error)) {
579 		goto out;
580 	}
581 	if ((err = fticket_pull(tick, uio))) {
582 		goto out;
583 	}
584 	fiio = fticket_resp(tick)->base;
585 
586 	/* XXX: Do we want to check anything further besides this? */
587 	if (fiio->major < 7) {
588 		debug_printf("userpace version too low\n");
589 		err = EPROTONOSUPPORT;
590 		goto out;
591 	}
592 	data->fuse_libabi_major = fiio->major;
593 	data->fuse_libabi_minor = fiio->minor;
594 
595 	if (fuse_libabi_geq(data, 7, 5)) {
596 		if (fticket_resp(tick)->len == sizeof(struct fuse_init_out)) {
597 			data->max_write = fiio->max_write;
598 		} else {
599 			err = EINVAL;
600 		}
601 	} else {
602 		/* Old fix values */
603 		data->max_write = 4096;
604 	}
605 
606 out:
607 	if (err) {
608 		fdata_set_dead(data);
609 	}
610 	FUSE_LOCK();
611 	data->dataflags |= FSESS_INITED;
612 	wakeup(&data->ticketer);
613 	FUSE_UNLOCK();
614 
615 	return 0;
616 }
617 
618 void
619 fuse_internal_send_init(struct fuse_data *data, struct thread *td)
620 {
621 	struct fuse_init_in *fiii;
622 	struct fuse_dispatcher fdi;
623 
624 	fdisp_init(&fdi, sizeof(*fiii));
625 	fdisp_make(&fdi, FUSE_INIT, data->mp, 0, td, NULL);
626 	fiii = fdi.indata;
627 	fiii->major = FUSE_KERNEL_VERSION;
628 	fiii->minor = FUSE_KERNEL_MINOR_VERSION;
629 	fiii->max_readahead = FUSE_DEFAULT_IOSIZE * 16;
630 	fiii->flags = 0;
631 
632 	fuse_insert_callback(fdi.tick, fuse_internal_init_callback);
633 	fuse_insert_message(fdi.tick);
634 	fdisp_destroy(&fdi);
635 }
636 
637 #ifdef ZERO_PAD_INCOMPLETE_BUFS
638 static int
639 isbzero(void *buf, size_t len)
640 {
641 	int i;
642 
643 	for (i = 0; i < len; i++) {
644 		if (((char *)buf)[i])
645 			return (0);
646 	}
647 
648 	return (1);
649 }
650 
651 #endif
652