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 #ifndef _FUSE_IPC_H_
64 #define _FUSE_IPC_H_
65
66 #include <sys/param.h>
67 #include <sys/refcount.h>
68
69 enum fuse_data_cache_mode {
70 FUSE_CACHE_UC,
71 FUSE_CACHE_WT,
72 FUSE_CACHE_WB,
73 };
74
75 struct fuse_iov {
76 void *base;
77 size_t len;
78 size_t allocated_size;
79 int credit;
80 };
81
82 void fiov_init(struct fuse_iov *fiov, size_t size);
83 void fiov_teardown(struct fuse_iov *fiov);
84 void fiov_refresh(struct fuse_iov *fiov);
85 void fiov_adjust(struct fuse_iov *fiov, size_t size);
86
87 #define FUSE_DIMALLOC(fiov, spc1, spc2, amnt) do { \
88 fiov_adjust(fiov, (sizeof(*(spc1)) + (amnt))); \
89 (spc1) = (fiov)->base; \
90 (spc2) = (char *)(fiov)->base + (sizeof(*(spc1))); \
91 } while (0)
92
93 #define FU_AT_LEAST(siz) max((siz), 160)
94
95 #define FUSE_ASSERT_AW_DONE(ftick) \
96 KASSERT((ftick)->tk_aw_link.tqe_next == NULL && \
97 (ftick)->tk_aw_link.tqe_prev == NULL, \
98 ("FUSE: ticket still on answer delivery list %p", (ftick)))
99
100 #define FUSE_ASSERT_MS_DONE(ftick) \
101 KASSERT((ftick)->tk_ms_link.stqe_next == NULL, \
102 ("FUSE: ticket still on message list %p", (ftick)))
103
104 struct fuse_ticket;
105 struct fuse_data;
106
107 typedef int fuse_handler_t(struct fuse_ticket *ftick, struct uio *uio);
108
109 struct fuse_ticket {
110 /* fields giving the identity of the ticket */
111 uint64_t tk_unique;
112 struct fuse_data *tk_data;
113 int tk_flag;
114 u_int tk_refcount;
115 /*
116 * If this ticket's operation has been interrupted, this will hold the
117 * unique value of the FUSE_INTERRUPT operation. Otherwise, it will be
118 * 0.
119 */
120 uint64_t irq_unique;
121
122 /* fields for initiating an upgoing message */
123 struct fuse_iov tk_ms_fiov;
124 STAILQ_ENTRY(fuse_ticket) tk_ms_link;
125
126 /* fields for handling answers coming from userspace */
127 struct fuse_iov tk_aw_fiov;
128 struct fuse_out_header tk_aw_ohead;
129 int tk_aw_errno;
130 struct mtx tk_aw_mtx;
131 fuse_handler_t *tk_aw_handler;
132 TAILQ_ENTRY(fuse_ticket) tk_aw_link;
133 };
134
135 #define FT_ANSW 0x01 /* request of ticket has already been answered */
136 #define FT_DIRTY 0x04 /* ticket has been used */
137
138 static inline struct fuse_iov *
fticket_resp(struct fuse_ticket * ftick)139 fticket_resp(struct fuse_ticket *ftick)
140 {
141 return (&ftick->tk_aw_fiov);
142 }
143
144 static inline bool
fticket_answered(struct fuse_ticket * ftick)145 fticket_answered(struct fuse_ticket *ftick)
146 {
147 mtx_assert(&ftick->tk_aw_mtx, MA_OWNED);
148 return (ftick->tk_flag & FT_ANSW);
149 }
150
151 static inline void
fticket_set_answered(struct fuse_ticket * ftick)152 fticket_set_answered(struct fuse_ticket *ftick)
153 {
154 mtx_assert(&ftick->tk_aw_mtx, MA_OWNED);
155 ftick->tk_flag |= FT_ANSW;
156 }
157
158 static inline struct fuse_in_header*
fticket_in_header(struct fuse_ticket * ftick)159 fticket_in_header(struct fuse_ticket *ftick)
160 {
161 return (struct fuse_in_header *)(ftick->tk_ms_fiov.base);
162 }
163
164 static inline enum fuse_opcode
fticket_opcode(struct fuse_ticket * ftick)165 fticket_opcode(struct fuse_ticket *ftick)
166 {
167 return fticket_in_header(ftick)->opcode;
168 }
169
170 int fticket_pull(struct fuse_ticket *ftick, struct uio *uio);
171
172 /*
173 * The data representing a FUSE session.
174 */
175 struct fuse_data {
176 struct cdev *fdev;
177 struct mount *mp;
178 struct vnode *vroot;
179 struct ucred *daemoncred;
180 int dataflags;
181 int ref;
182
183 struct mtx ms_mtx;
184 STAILQ_HEAD(, fuse_ticket) ms_head;
185 int ms_count;
186
187 struct mtx aw_mtx;
188 TAILQ_HEAD(, fuse_ticket) aw_head;
189
190 /*
191 * Holds the next value of the FUSE operation unique value.
192 * Also, serves as a wakeup channel to prevent any operations from
193 * being created before INIT completes.
194 */
195 u_long ticketer;
196
197 struct sx rename_lock;
198
199 uint32_t fuse_libabi_major;
200 uint32_t fuse_libabi_minor;
201
202 uint32_t max_readahead_blocks;
203 uint32_t max_write;
204 uint32_t max_read;
205
206 struct selinfo ks_rsel;
207
208 int daemon_timeout;
209 int linux_errnos;
210 unsigned time_gran;
211 /* A bitmask of FUSE RPCs that are not implemented by the server */
212 uint64_t notimpl;
213 /*
214 * A bitmask of FUSE RPCs that are implemented by the server.
215 * If an operation is not present in either notimpl or isimpl, then it
216 * may be implemented by the server, but the kernel doesn't know for
217 * sure.
218 */
219 uint64_t isimpl;
220 uint64_t mnt_flag;
221 enum fuse_data_cache_mode cache_mode;
222 };
223
224 #define FSESS_DEAD 0x0001 /* session is to be closed */
225 #define FSESS_INITED 0x0004 /* session has been inited */
226 #define FSESS_DAEMON_CAN_SPY 0x0010 /* let non-owners access this fs */
227 /* (and being observed by the daemon) */
228 #define FSESS_PUSH_SYMLINKS_IN 0x0020 /* prefix absolute symlinks with mp */
229 #define FSESS_DEFAULT_PERMISSIONS 0x0040 /* kernel does permission checking */
230 #define FSESS_ASYNC_READ 0x1000 /* allow multiple reads of some file */
231 #define FSESS_POSIX_LOCKS 0x2000 /* daemon supports POSIX locks */
232 #define FSESS_EXPORT_SUPPORT 0x10000 /* daemon supports NFS-style lookups */
233 #define FSESS_INTR 0x20000 /* interruptible mounts */
234 #define FSESS_WARN_SHORT_WRITE 0x40000 /* Short write without direct_io */
235 #define FSESS_WARN_WROTE_LONG 0x80000 /* Wrote more data than provided */
236 #define FSESS_WARN_LSEXTATTR_LONG 0x100000 /* Returned too many extattrs */
237 #define FSESS_WARN_CACHE_INCOHERENT 0x200000 /* Read cache incoherent */
238 #define FSESS_WARN_WB_CACHE_INCOHERENT 0x400000 /* WB cache incoherent */
239 #define FSESS_WARN_ILLEGAL_INODE 0x800000 /* Illegal inode for new file */
240 #define FSESS_WARN_READLINK_EMBEDDED_NUL 0x1000000 /* corrupt READLINK output */
241 #define FSESS_WARN_DOT_LOOKUP 0x2000000 /* Inconsistent . LOOKUP response */
242 #define FSESS_WARN_INODE_MISMATCH 0x4000000 /* ino != nodeid */
243 #define FSESS_MNTOPTS_MASK ( \
244 FSESS_DAEMON_CAN_SPY | FSESS_PUSH_SYMLINKS_IN | \
245 FSESS_DEFAULT_PERMISSIONS | FSESS_INTR)
246 #define FSESS_SETXATTR_EXT 0x8000000 /* extended fuse_setxattr_in */
247
248 extern int fuse_data_cache_mode;
249
250 static inline struct fuse_data *
fuse_get_mpdata(struct mount * mp)251 fuse_get_mpdata(struct mount *mp)
252 {
253 return mp->mnt_data;
254 }
255
256 static inline bool
fsess_is_impl(struct mount * mp,int opcode)257 fsess_is_impl(struct mount *mp, int opcode)
258 {
259 struct fuse_data *data = fuse_get_mpdata(mp);
260
261 return ((data->isimpl & (1ULL << opcode)) != 0);
262
263 }
264
265 static inline bool
fsess_maybe_impl(struct mount * mp,int opcode)266 fsess_maybe_impl(struct mount *mp, int opcode)
267 {
268 struct fuse_data *data = fuse_get_mpdata(mp);
269
270 return ((data->notimpl & (1ULL << opcode)) == 0);
271
272 }
273
274 static inline bool
fsess_not_impl(struct mount * mp,int opcode)275 fsess_not_impl(struct mount *mp, int opcode)
276 {
277 struct fuse_data *data = fuse_get_mpdata(mp);
278
279 return ((data->notimpl & (1ULL << opcode)) != 0);
280
281 }
282
283 static inline void
fsess_set_impl(struct mount * mp,int opcode)284 fsess_set_impl(struct mount *mp, int opcode)
285 {
286 struct fuse_data *data = fuse_get_mpdata(mp);
287
288 data->isimpl |= (1ULL << opcode);
289 }
290
291 static inline void
fsess_set_notimpl(struct mount * mp,int opcode)292 fsess_set_notimpl(struct mount *mp, int opcode)
293 {
294 struct fuse_data *data = fuse_get_mpdata(mp);
295
296 data->notimpl |= (1ULL << opcode);
297 }
298
299 static inline bool
fsess_opt_datacache(struct mount * mp)300 fsess_opt_datacache(struct mount *mp)
301 {
302 struct fuse_data *data = fuse_get_mpdata(mp);
303
304 return (data->cache_mode != FUSE_CACHE_UC);
305 }
306
307 static inline bool
fsess_opt_mmap(struct mount * mp)308 fsess_opt_mmap(struct mount *mp)
309 {
310 return (fsess_opt_datacache(mp));
311 }
312
313 static inline bool
fsess_opt_writeback(struct mount * mp)314 fsess_opt_writeback(struct mount *mp)
315 {
316 struct fuse_data *data = fuse_get_mpdata(mp);
317
318 return (data->cache_mode == FUSE_CACHE_WB);
319 }
320
321 /* Insert a new upgoing message */
322 static inline void
fuse_ms_push(struct fuse_ticket * ftick)323 fuse_ms_push(struct fuse_ticket *ftick)
324 {
325 mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
326 refcount_acquire(&ftick->tk_refcount);
327 STAILQ_INSERT_TAIL(&ftick->tk_data->ms_head, ftick, tk_ms_link);
328 ftick->tk_data->ms_count++;
329 }
330
331 /* Insert a new upgoing message to the front of the queue */
332 static inline void
fuse_ms_push_head(struct fuse_ticket * ftick)333 fuse_ms_push_head(struct fuse_ticket *ftick)
334 {
335 mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
336 refcount_acquire(&ftick->tk_refcount);
337 STAILQ_INSERT_HEAD(&ftick->tk_data->ms_head, ftick, tk_ms_link);
338 ftick->tk_data->ms_count++;
339 }
340
341 static inline struct fuse_ticket *
fuse_ms_pop(struct fuse_data * data)342 fuse_ms_pop(struct fuse_data *data)
343 {
344 struct fuse_ticket *ftick = NULL;
345
346 mtx_assert(&data->ms_mtx, MA_OWNED);
347
348 if ((ftick = STAILQ_FIRST(&data->ms_head))) {
349 STAILQ_REMOVE_HEAD(&data->ms_head, tk_ms_link);
350 data->ms_count--;
351 #ifdef INVARIANTS
352 MPASS(data->ms_count >= 0);
353 ftick->tk_ms_link.stqe_next = NULL;
354 #endif
355 }
356
357 return (ftick);
358 }
359
360 static inline void
fuse_aw_push(struct fuse_ticket * ftick)361 fuse_aw_push(struct fuse_ticket *ftick)
362 {
363 mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
364 refcount_acquire(&ftick->tk_refcount);
365 TAILQ_INSERT_TAIL(&ftick->tk_data->aw_head, ftick, tk_aw_link);
366 }
367
368 static inline void
fuse_aw_remove(struct fuse_ticket * ftick)369 fuse_aw_remove(struct fuse_ticket *ftick)
370 {
371 mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
372 TAILQ_REMOVE(&ftick->tk_data->aw_head, ftick, tk_aw_link);
373 #ifdef INVARIANTS
374 ftick->tk_aw_link.tqe_next = NULL;
375 ftick->tk_aw_link.tqe_prev = NULL;
376 #endif
377 }
378
379 static inline struct fuse_ticket *
fuse_aw_pop(struct fuse_data * data)380 fuse_aw_pop(struct fuse_data *data)
381 {
382 struct fuse_ticket *ftick;
383
384 mtx_assert(&data->aw_mtx, MA_OWNED);
385
386 if ((ftick = TAILQ_FIRST(&data->aw_head)) != NULL)
387 fuse_aw_remove(ftick);
388
389 return (ftick);
390 }
391
392 struct fuse_ticket *fuse_ticket_fetch(struct fuse_data *data);
393 int fuse_ticket_drop(struct fuse_ticket *ftick);
394 void fuse_insert_callback(struct fuse_ticket *ftick, fuse_handler_t *handler);
395 void fuse_insert_message(struct fuse_ticket *ftick, bool irq);
396
397 static inline bool
fuse_libabi_geq(struct fuse_data * data,uint32_t abi_maj,uint32_t abi_min)398 fuse_libabi_geq(struct fuse_data *data, uint32_t abi_maj, uint32_t abi_min)
399 {
400 return (data->fuse_libabi_major > abi_maj ||
401 (data->fuse_libabi_major == abi_maj &&
402 data->fuse_libabi_minor >= abi_min));
403 }
404
405 /* Print msg as a warning to the console, but no more than once per session */
406 void fuse_warn(struct fuse_data *data, unsigned flag, const char *msg);
407
408 struct fuse_data *fdata_alloc(struct cdev *dev, struct ucred *cred);
409 void fdata_trydestroy(struct fuse_data *data);
410 void fdata_set_dead(struct fuse_data *data);
411
412 static inline bool
fdata_get_dead(struct fuse_data * data)413 fdata_get_dead(struct fuse_data *data)
414 {
415 return (data->dataflags & FSESS_DEAD);
416 }
417
418 struct fuse_dispatcher {
419 struct fuse_ticket *tick;
420 struct fuse_in_header *finh;
421
422 void *indata;
423 size_t iosize;
424 uint64_t nodeid;
425 int answ_stat;
426 void *answ;
427 };
428
429 static inline void
fdisp_init(struct fuse_dispatcher * fdisp,size_t iosize)430 fdisp_init(struct fuse_dispatcher *fdisp, size_t iosize)
431 {
432 fdisp->iosize = iosize;
433 fdisp->tick = NULL;
434 }
435
436 static inline void
fdisp_destroy(struct fuse_dispatcher * fdisp)437 fdisp_destroy(struct fuse_dispatcher *fdisp)
438 {
439 fuse_ticket_drop(fdisp->tick);
440 #ifdef INVARIANTS
441 fdisp->tick = NULL;
442 #endif
443 }
444
445 void fdisp_make(struct fuse_dispatcher *fdip, enum fuse_opcode op,
446 struct mount *mp, uint64_t nid, struct thread *td, struct ucred *cred);
447
448 void fdisp_make_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
449 struct vnode *vp, struct thread *td, struct ucred *cred);
450
451 void fdisp_refresh_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
452 struct vnode *vp, struct thread *td, struct ucred *cred);
453
454 int fdisp_wait_answ(struct fuse_dispatcher *fdip);
455
456 static inline int
fdisp_simple_putget_vp(struct fuse_dispatcher * fdip,enum fuse_opcode op,struct vnode * vp,struct thread * td,struct ucred * cred)457 fdisp_simple_putget_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
458 struct vnode *vp, struct thread *td, struct ucred *cred)
459 {
460 fdisp_make_vp(fdip, op, vp, td, cred);
461 return (fdisp_wait_answ(fdip));
462 }
463
464 #endif /* _FUSE_IPC_H_ */
465