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/cdefs.h>
64__FBSDID("$FreeBSD$");
65
66#include <sys/param.h>
67#include <sys/systm.h>
68#include <sys/counter.h>
69#include <sys/module.h>
70#include <sys/errno.h>
71#include <sys/kernel.h>
72#include <sys/conf.h>
73#include <sys/uio.h>
74#include <sys/malloc.h>
75#include <sys/queue.h>
76#include <sys/lock.h>
77#include <sys/sx.h>
78#include <sys/mutex.h>
79#include <sys/proc.h>
80#include <sys/mount.h>
81#include <sys/vnode.h>
82#include <sys/sdt.h>
83#include <sys/sysctl.h>
84
85#include "fuse.h"
86#include "fuse_file.h"
87#include "fuse_internal.h"
88#include "fuse_io.h"
89#include "fuse_ipc.h"
90#include "fuse_node.h"
91
92MALLOC_DEFINE(M_FUSE_FILEHANDLE, "fuse_filefilehandle", "FUSE file handle");
93
94SDT_PROVIDER_DECLARE(fusefs);
95/*
96 * Fuse trace probe:
97 * arg0: verbosity.  Higher numbers give more verbose messages
98 * arg1: Textual message
99 */
100SDT_PROBE_DEFINE2(fusefs, , file, trace, "int", "char*");
101
102static counter_u64_t fuse_fh_count;
103
104SYSCTL_COUNTER_U64(_vfs_fusefs_stats, OID_AUTO, filehandle_count, CTLFLAG_RD,
105    &fuse_fh_count, "number of open FUSE filehandles");
106
107/* Get the FUFH type for a particular access mode */
108static inline fufh_type_t
109fflags_2_fufh_type(int fflags)
110{
111	if ((fflags & FREAD) && (fflags & FWRITE))
112		return FUFH_RDWR;
113	else if (fflags & (FWRITE))
114		return FUFH_WRONLY;
115	else if (fflags & (FREAD))
116		return FUFH_RDONLY;
117	else if (fflags & (FEXEC))
118		return FUFH_EXEC;
119	else
120		panic("FUSE: What kind of a flag is this (%x)?", fflags);
121}
122
123int
124fuse_filehandle_open(struct vnode *vp, int a_mode,
125    struct fuse_filehandle **fufhp, struct thread *td, struct ucred *cred)
126{
127	struct fuse_dispatcher fdi;
128	struct fuse_open_in *foi;
129	struct fuse_open_out *foo;
130	fufh_type_t fufh_type;
131
132	int err = 0;
133	int oflags = 0;
134	int op = FUSE_OPEN;
135
136	fufh_type = fflags_2_fufh_type(a_mode);
137	oflags = fufh_type_2_fflags(fufh_type);
138
139	if (vnode_isdir(vp)) {
140		op = FUSE_OPENDIR;
141		/* vn_open_vnode already rejects FWRITE on directories */
142		MPASS(fufh_type == FUFH_RDONLY || fufh_type == FUFH_EXEC);
143	}
144	fdisp_init(&fdi, sizeof(*foi));
145	fdisp_make_vp(&fdi, op, vp, td, cred);
146
147	foi = fdi.indata;
148	foi->flags = oflags;
149
150	if ((err = fdisp_wait_answ(&fdi))) {
151		SDT_PROBE2(fusefs, , file, trace, 1,
152			"OUCH ... daemon didn't give fh");
153		if (err == ENOENT) {
154			fuse_internal_vnode_disappear(vp);
155		}
156		goto out;
157	}
158	foo = fdi.answ;
159
160	fuse_filehandle_init(vp, fufh_type, fufhp, td, cred, foo);
161	fuse_vnode_open(vp, foo->open_flags, td);
162
163out:
164	fdisp_destroy(&fdi);
165	return err;
166}
167
168int
169fuse_filehandle_close(struct vnode *vp, struct fuse_filehandle *fufh,
170    struct thread *td, struct ucred *cred)
171{
172	struct fuse_dispatcher fdi;
173	struct fuse_release_in *fri;
174
175	int err = 0;
176	int op = FUSE_RELEASE;
177
178	if (fuse_isdeadfs(vp)) {
179		goto out;
180	}
181	if (vnode_isdir(vp))
182		op = FUSE_RELEASEDIR;
183	fdisp_init(&fdi, sizeof(*fri));
184	fdisp_make_vp(&fdi, op, vp, td, cred);
185	fri = fdi.indata;
186	fri->fh = fufh->fh_id;
187	fri->flags = fufh_type_2_fflags(fufh->fufh_type);
188	/*
189	 * If the file has a POSIX lock then we're supposed to set lock_owner.
190	 * If not, then lock_owner is undefined.  So we may as well always set
191	 * it.
192	 */
193	fri->lock_owner = td->td_proc->p_pid;
194
195	err = fdisp_wait_answ(&fdi);
196	fdisp_destroy(&fdi);
197
198out:
199	counter_u64_add(fuse_fh_count, -1);
200	LIST_REMOVE(fufh, next);
201	free(fufh, M_FUSE_FILEHANDLE);
202
203	return err;
204}
205
206/*
207 * Check for a valid file handle, first the type requested, but if that
208 * isn't valid, try for FUFH_RDWR.
209 * Return true if there is any file handle with the correct credentials and
210 * a fufh type that includes the provided one.
211 * A pid of 0 means "don't care"
212 */
213bool
214fuse_filehandle_validrw(struct vnode *vp, int mode,
215	struct ucred *cred, pid_t pid)
216{
217	struct fuse_vnode_data *fvdat = VTOFUD(vp);
218	struct fuse_filehandle *fufh;
219	fufh_type_t fufh_type = fflags_2_fufh_type(mode);
220
221	/*
222	 * Unlike fuse_filehandle_get, we want to search for a filehandle with
223	 * the exact cred, and no fallback
224	 */
225	LIST_FOREACH(fufh, &fvdat->handles, next) {
226		if (fufh->fufh_type == fufh_type &&
227		    fufh->uid == cred->cr_uid &&
228		    fufh->gid == cred->cr_rgid &&
229		    (pid == 0 || fufh->pid == pid))
230			return true;
231	}
232
233	if (fufh_type == FUFH_EXEC)
234		return false;
235
236	/* Fallback: find a RDWR list entry with the right cred */
237	LIST_FOREACH(fufh, &fvdat->handles, next) {
238		if (fufh->fufh_type == FUFH_RDWR &&
239		    fufh->uid == cred->cr_uid &&
240		    fufh->gid == cred->cr_rgid &&
241		    (pid == 0 || fufh->pid == pid))
242			return true;
243	}
244
245	return false;
246}
247
248int
249fuse_filehandle_get(struct vnode *vp, int fflag,
250    struct fuse_filehandle **fufhp, struct ucred *cred, pid_t pid)
251{
252	struct fuse_vnode_data *fvdat = VTOFUD(vp);
253	struct fuse_filehandle *fufh;
254	fufh_type_t fufh_type;
255
256	fufh_type = fflags_2_fufh_type(fflag);
257	/* cred can be NULL for in-kernel clients */
258	if (cred == NULL)
259		goto fallback;
260
261	LIST_FOREACH(fufh, &fvdat->handles, next) {
262		if (fufh->fufh_type == fufh_type &&
263		    fufh->uid == cred->cr_uid &&
264		    fufh->gid == cred->cr_rgid &&
265		    (pid == 0 || fufh->pid == pid))
266			goto found;
267	}
268
269fallback:
270	/* Fallback: find a list entry with the right flags */
271	LIST_FOREACH(fufh, &fvdat->handles, next) {
272		if (fufh->fufh_type == fufh_type)
273			break;
274	}
275
276	if (fufh == NULL)
277		return EBADF;
278
279found:
280	if (fufhp != NULL)
281		*fufhp = fufh;
282	return 0;
283}
284
285/* Get a file handle with any kind of flags */
286int
287fuse_filehandle_get_anyflags(struct vnode *vp,
288    struct fuse_filehandle **fufhp, struct ucred *cred, pid_t pid)
289{
290	struct fuse_vnode_data *fvdat = VTOFUD(vp);
291	struct fuse_filehandle *fufh;
292
293	if (cred == NULL)
294		goto fallback;
295
296	LIST_FOREACH(fufh, &fvdat->handles, next) {
297		if (fufh->uid == cred->cr_uid &&
298		    fufh->gid == cred->cr_rgid &&
299		    (pid == 0 || fufh->pid == pid))
300			goto found;
301	}
302
303fallback:
304	/* Fallback: find any list entry */
305	fufh = LIST_FIRST(&fvdat->handles);
306
307	if (fufh == NULL)
308		return EBADF;
309
310found:
311	if (fufhp != NULL)
312		*fufhp = fufh;
313	return 0;
314}
315
316int
317fuse_filehandle_getrw(struct vnode *vp, int fflag,
318    struct fuse_filehandle **fufhp, struct ucred *cred, pid_t pid)
319{
320	int err;
321
322	err = fuse_filehandle_get(vp, fflag, fufhp, cred, pid);
323	if (err)
324		err = fuse_filehandle_get(vp, FREAD | FWRITE, fufhp, cred, pid);
325	return err;
326}
327
328void
329fuse_filehandle_init(struct vnode *vp, fufh_type_t fufh_type,
330    struct fuse_filehandle **fufhp, struct thread *td, struct ucred *cred,
331    struct fuse_open_out *foo)
332{
333	struct fuse_vnode_data *fvdat = VTOFUD(vp);
334	struct fuse_filehandle *fufh;
335
336	fufh = malloc(sizeof(struct fuse_filehandle), M_FUSE_FILEHANDLE,
337		M_WAITOK);
338	MPASS(fufh != NULL);
339	fufh->fh_id = foo->fh;
340	fufh->fufh_type = fufh_type;
341	fufh->gid = cred->cr_rgid;
342	fufh->uid = cred->cr_uid;
343	fufh->pid = td->td_proc->p_pid;
344	fufh->fuse_open_flags = foo->open_flags;
345	if (!FUFH_IS_VALID(fufh)) {
346		panic("FUSE: init: invalid filehandle id (type=%d)", fufh_type);
347	}
348	LIST_INSERT_HEAD(&fvdat->handles, fufh, next);
349	if (fufhp != NULL)
350		*fufhp = fufh;
351
352	counter_u64_add(fuse_fh_count, 1);
353
354	if (foo->open_flags & FOPEN_DIRECT_IO) {
355		ASSERT_VOP_ELOCKED(vp, __func__);
356		VTOFUD(vp)->flag |= FN_DIRECTIO;
357		fuse_io_invalbuf(vp, td);
358	} else {
359		if ((foo->open_flags & FOPEN_KEEP_CACHE) == 0)
360			fuse_io_invalbuf(vp, td);
361	        VTOFUD(vp)->flag &= ~FN_DIRECTIO;
362	}
363
364}
365
366void
367fuse_file_init(void)
368{
369	fuse_fh_count = counter_u64_alloc(M_WAITOK);
370}
371
372void
373fuse_file_destroy(void)
374{
375	counter_u64_free(fuse_fh_count);
376}
377