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