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/systm.h>
65 #include <sys/counter.h>
66 #include <sys/module.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/vnode.h>
79 #include <sys/sdt.h>
80 #include <sys/sysctl.h>
81
82 #include "fuse.h"
83 #include "fuse_file.h"
84 #include "fuse_internal.h"
85 #include "fuse_io.h"
86 #include "fuse_ipc.h"
87 #include "fuse_node.h"
88
89 MALLOC_DEFINE(M_FUSE_FILEHANDLE, "fuse_filefilehandle", "FUSE file handle");
90
91 SDT_PROVIDER_DECLARE(fusefs);
92 /*
93 * Fuse trace probe:
94 * arg0: verbosity. Higher numbers give more verbose messages
95 * arg1: Textual message
96 */
97 SDT_PROBE_DEFINE2(fusefs, , file, trace, "int", "char*");
98
99 static counter_u64_t fuse_fh_count;
100
101 SYSCTL_COUNTER_U64(_vfs_fusefs_stats, OID_AUTO, filehandle_count, CTLFLAG_RD,
102 &fuse_fh_count, "number of open FUSE filehandles");
103
104 /* Get the FUFH type for a particular access mode */
105 static inline fufh_type_t
fflags_2_fufh_type(int fflags)106 fflags_2_fufh_type(int fflags)
107 {
108 if ((fflags & FREAD) && (fflags & FWRITE))
109 return FUFH_RDWR;
110 else if (fflags & (FWRITE))
111 return FUFH_WRONLY;
112 else if (fflags & (FREAD))
113 return FUFH_RDONLY;
114 else if (fflags & (FEXEC))
115 return FUFH_EXEC;
116 else
117 panic("FUSE: What kind of a flag is this (%x)?", fflags);
118 }
119
120 int
fuse_filehandle_open(struct vnode * vp,int a_mode,struct fuse_filehandle ** fufhp,struct thread * td,struct ucred * cred)121 fuse_filehandle_open(struct vnode *vp, int a_mode,
122 struct fuse_filehandle **fufhp, struct thread *td, struct ucred *cred)
123 {
124 struct mount *mp = vnode_mount(vp);
125 struct fuse_data *data = fuse_get_mpdata(mp);
126 struct fuse_dispatcher fdi;
127 const struct fuse_open_out default_foo = {
128 .fh = 0,
129 .open_flags = FOPEN_KEEP_CACHE,
130 .padding = 0
131 };
132 struct fuse_open_in *foi = NULL;
133 const struct fuse_open_out *foo;
134 fufh_type_t fufh_type;
135 int dataflags = data->dataflags;
136 int err = 0;
137 int oflags = 0;
138 int op = FUSE_OPEN;
139 int relop = FUSE_RELEASE;
140 int fsess_no_op_support = FSESS_NO_OPEN_SUPPORT;
141
142 fufh_type = fflags_2_fufh_type(a_mode);
143 oflags = fufh_type_2_fflags(fufh_type);
144
145 if (vnode_isdir(vp)) {
146 op = FUSE_OPENDIR;
147 relop = FUSE_RELEASEDIR;
148 fsess_no_op_support = FSESS_NO_OPENDIR_SUPPORT;
149 /* vn_open_vnode already rejects FWRITE on directories */
150 MPASS(fufh_type == FUFH_RDONLY || fufh_type == FUFH_EXEC);
151 }
152 fdisp_init(&fdi, sizeof(*foi));
153 if (fsess_not_impl(mp, op) && dataflags & fsess_no_op_support) {
154 /* The operation implicitly succeeds */
155 foo = &default_foo;
156 } else {
157 fdisp_make_vp(&fdi, op, vp, td, cred);
158
159 foi = fdi.indata;
160 foi->flags = oflags;
161
162 err = fdisp_wait_answ(&fdi);
163 if (err == ENOSYS && dataflags & fsess_no_op_support) {
164 /* The operation implicitly succeeds */
165 foo = &default_foo;
166 fsess_set_notimpl(mp, op);
167 fsess_set_notimpl(mp, relop);
168 err = 0;
169 } else if (err) {
170 SDT_PROBE2(fusefs, , file, trace, 1,
171 "OUCH ... daemon didn't give fh");
172 if (err == ENOENT)
173 fuse_internal_vnode_disappear(vp);
174 goto out;
175 } else {
176 foo = fdi.answ;
177 }
178 }
179
180 fuse_filehandle_init(vp, fufh_type, fufhp, td, cred, foo);
181 fuse_vnode_open(vp, foo->open_flags, td);
182
183 out:
184 if (foi)
185 fdisp_destroy(&fdi);
186 return err;
187 }
188
189 int
fuse_filehandle_close(struct vnode * vp,struct fuse_filehandle * fufh,struct thread * td,struct ucred * cred)190 fuse_filehandle_close(struct vnode *vp, struct fuse_filehandle *fufh,
191 struct thread *td, struct ucred *cred)
192 {
193 struct mount *mp = vnode_mount(vp);
194 struct fuse_dispatcher fdi;
195 struct fuse_release_in *fri;
196
197 int err = 0;
198 int op = FUSE_RELEASE;
199
200 if (fuse_isdeadfs(vp)) {
201 goto out;
202 }
203 if (vnode_isdir(vp))
204 op = FUSE_RELEASEDIR;
205
206 if (fsess_not_impl(mp, op))
207 goto out;
208
209 fdisp_init(&fdi, sizeof(*fri));
210 fdisp_make_vp(&fdi, op, vp, td, cred);
211 fri = fdi.indata;
212 fri->fh = fufh->fh_id;
213 fri->flags = fufh_type_2_fflags(fufh->fufh_type);
214 /*
215 * If the file has a POSIX lock then we're supposed to set lock_owner.
216 * If not, then lock_owner is undefined. So we may as well always set
217 * it.
218 */
219 fri->lock_owner = td->td_proc->p_pid;
220
221 err = fdisp_wait_answ(&fdi);
222 fdisp_destroy(&fdi);
223
224 out:
225 counter_u64_add(fuse_fh_count, -1);
226 LIST_REMOVE(fufh, next);
227 free(fufh, M_FUSE_FILEHANDLE);
228
229 return err;
230 }
231
232 /*
233 * Check for a valid file handle, first the type requested, but if that
234 * isn't valid, try for FUFH_RDWR.
235 * Return true if there is any file handle with the correct credentials and
236 * a fufh type that includes the provided one.
237 * A pid of 0 means "don't care"
238 */
239 bool
fuse_filehandle_validrw(struct vnode * vp,int mode,struct ucred * cred,pid_t pid)240 fuse_filehandle_validrw(struct vnode *vp, int mode,
241 struct ucred *cred, pid_t pid)
242 {
243 struct fuse_vnode_data *fvdat = VTOFUD(vp);
244 struct fuse_filehandle *fufh;
245 fufh_type_t fufh_type = fflags_2_fufh_type(mode);
246
247 /*
248 * Unlike fuse_filehandle_get, we want to search for a filehandle with
249 * the exact cred, and no fallback
250 */
251 LIST_FOREACH(fufh, &fvdat->handles, next) {
252 if (fufh->fufh_type == fufh_type &&
253 fufh->uid == cred->cr_uid &&
254 fufh->gid == cred->cr_rgid &&
255 (pid == 0 || fufh->pid == pid))
256 return true;
257 }
258
259 if (fufh_type == FUFH_EXEC)
260 return false;
261
262 /* Fallback: find a RDWR list entry with the right cred */
263 LIST_FOREACH(fufh, &fvdat->handles, next) {
264 if (fufh->fufh_type == FUFH_RDWR &&
265 fufh->uid == cred->cr_uid &&
266 fufh->gid == cred->cr_rgid &&
267 (pid == 0 || fufh->pid == pid))
268 return true;
269 }
270
271 return false;
272 }
273
274 int
fuse_filehandle_get(struct vnode * vp,int fflag,struct fuse_filehandle ** fufhp,struct ucred * cred,pid_t pid)275 fuse_filehandle_get(struct vnode *vp, int fflag,
276 struct fuse_filehandle **fufhp, struct ucred *cred, pid_t pid)
277 {
278 struct fuse_vnode_data *fvdat = VTOFUD(vp);
279 struct fuse_filehandle *fufh;
280 fufh_type_t fufh_type;
281
282 fufh_type = fflags_2_fufh_type(fflag);
283 /* cred can be NULL for in-kernel clients */
284 if (cred == NULL)
285 goto fallback;
286
287 LIST_FOREACH(fufh, &fvdat->handles, next) {
288 if (fufh->fufh_type == fufh_type &&
289 fufh->uid == cred->cr_uid &&
290 fufh->gid == cred->cr_rgid &&
291 (pid == 0 || fufh->pid == pid))
292 goto found;
293 }
294
295 fallback:
296 /* Fallback: find a list entry with the right flags */
297 LIST_FOREACH(fufh, &fvdat->handles, next) {
298 if (fufh->fufh_type == fufh_type)
299 break;
300 }
301
302 if (fufh == NULL)
303 return EBADF;
304
305 found:
306 if (fufhp != NULL)
307 *fufhp = fufh;
308 return 0;
309 }
310
311 /* Get a file handle with any kind of flags */
312 int
fuse_filehandle_get_anyflags(struct vnode * vp,struct fuse_filehandle ** fufhp,struct ucred * cred,pid_t pid)313 fuse_filehandle_get_anyflags(struct vnode *vp,
314 struct fuse_filehandle **fufhp, struct ucred *cred, pid_t pid)
315 {
316 struct fuse_vnode_data *fvdat = VTOFUD(vp);
317 struct fuse_filehandle *fufh;
318
319 if (cred == NULL)
320 goto fallback;
321
322 LIST_FOREACH(fufh, &fvdat->handles, next) {
323 if (fufh->uid == cred->cr_uid &&
324 fufh->gid == cred->cr_rgid &&
325 (pid == 0 || fufh->pid == pid))
326 goto found;
327 }
328
329 fallback:
330 /* Fallback: find any list entry */
331 fufh = LIST_FIRST(&fvdat->handles);
332
333 if (fufh == NULL)
334 return EBADF;
335
336 found:
337 if (fufhp != NULL)
338 *fufhp = fufh;
339 return 0;
340 }
341
342 int
fuse_filehandle_getrw(struct vnode * vp,int fflag,struct fuse_filehandle ** fufhp,struct ucred * cred,pid_t pid)343 fuse_filehandle_getrw(struct vnode *vp, int fflag,
344 struct fuse_filehandle **fufhp, struct ucred *cred, pid_t pid)
345 {
346 int err;
347
348 err = fuse_filehandle_get(vp, fflag, fufhp, cred, pid);
349 if (err)
350 err = fuse_filehandle_get(vp, FREAD | FWRITE, fufhp, cred, pid);
351 return err;
352 }
353
354 void
fuse_filehandle_init(struct vnode * vp,fufh_type_t fufh_type,struct fuse_filehandle ** fufhp,struct thread * td,const struct ucred * cred,const struct fuse_open_out * foo)355 fuse_filehandle_init(struct vnode *vp, fufh_type_t fufh_type,
356 struct fuse_filehandle **fufhp, struct thread *td, const struct ucred *cred,
357 const struct fuse_open_out *foo)
358 {
359 struct fuse_vnode_data *fvdat = VTOFUD(vp);
360 struct fuse_filehandle *fufh;
361
362 fufh = malloc(sizeof(struct fuse_filehandle), M_FUSE_FILEHANDLE,
363 M_WAITOK);
364 MPASS(fufh != NULL);
365 fufh->fh_id = foo->fh;
366 fufh->fufh_type = fufh_type;
367 fufh->gid = cred->cr_rgid;
368 fufh->uid = cred->cr_uid;
369 fufh->pid = td->td_proc->p_pid;
370 fufh->fuse_open_flags = foo->open_flags;
371 if (!FUFH_IS_VALID(fufh)) {
372 panic("FUSE: init: invalid filehandle id (type=%d)", fufh_type);
373 }
374 LIST_INSERT_HEAD(&fvdat->handles, fufh, next);
375 if (fufhp != NULL)
376 *fufhp = fufh;
377
378 counter_u64_add(fuse_fh_count, 1);
379
380 if (foo->open_flags & FOPEN_DIRECT_IO) {
381 ASSERT_VOP_ELOCKED(vp, __func__);
382 VTOFUD(vp)->flag |= FN_DIRECTIO;
383 fuse_io_invalbuf(vp, td);
384 } else {
385 if ((foo->open_flags & FOPEN_KEEP_CACHE) == 0)
386 fuse_io_invalbuf(vp, td);
387 VTOFUD(vp)->flag &= ~FN_DIRECTIO;
388 }
389
390 }
391
392 void
fuse_file_init(void)393 fuse_file_init(void)
394 {
395 fuse_fh_count = counter_u64_alloc(M_WAITOK);
396 }
397
398 void
fuse_file_destroy(void)399 fuse_file_destroy(void)
400 {
401 counter_u64_free(fuse_fh_count);
402 }
403