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 * $FreeBSD: stable/12/sys/fs/fuse/fuse_ipc.h 372422 2022-08-20 02:57:37Z asomers $
63 */
64
65 #ifndef _FUSE_IPC_H_
66 #define _FUSE_IPC_H_
67
68 #include <sys/param.h>
69 #include <sys/refcount.h>
70
71 enum fuse_data_cache_mode {
72 FUSE_CACHE_UC,
73 FUSE_CACHE_WT,
74 FUSE_CACHE_WB,
75 };
76
77 struct fuse_iov {
78 void *base;
79 size_t len;
80 size_t allocated_size;
81 int credit;
82 };
83
84 void fiov_init(struct fuse_iov *fiov, size_t size);
85 void fiov_teardown(struct fuse_iov *fiov);
86 void fiov_refresh(struct fuse_iov *fiov);
87 void fiov_adjust(struct fuse_iov *fiov, size_t size);
88
89 #define FUSE_DIMALLOC(fiov, spc1, spc2, amnt) do { \
90 fiov_adjust(fiov, (sizeof(*(spc1)) + (amnt))); \
91 (spc1) = (fiov)->base; \
92 (spc2) = (char *)(fiov)->base + (sizeof(*(spc1))); \
93 } while (0)
94
95 #define FU_AT_LEAST(siz) max((siz), 160)
96
97 #define FUSE_ASSERT_AW_DONE(ftick) \
98 KASSERT((ftick)->tk_aw_link.tqe_next == NULL && \
99 (ftick)->tk_aw_link.tqe_prev == NULL, \
100 ("FUSE: ticket still on answer delivery list %p", (ftick)))
101
102 #define FUSE_ASSERT_MS_DONE(ftick) \
103 KASSERT((ftick)->tk_ms_link.stqe_next == NULL, \
104 ("FUSE: ticket still on message list %p", (ftick)))
105
106 struct fuse_ticket;
107 struct fuse_data;
108
109 typedef int fuse_handler_t(struct fuse_ticket *ftick, struct uio *uio);
110
111 struct fuse_ticket {
112 /* fields giving the identity of the ticket */
113 uint64_t tk_unique;
114 struct fuse_data *tk_data;
115 int tk_flag;
116 u_int tk_refcount;
117 /*
118 * If this ticket's operation has been interrupted, this will hold the
119 * unique value of the FUSE_INTERRUPT operation. Otherwise, it will be
120 * 0.
121 */
122 uint64_t irq_unique;
123
124 /* fields for initiating an upgoing message */
125 struct fuse_iov tk_ms_fiov;
126 STAILQ_ENTRY(fuse_ticket) tk_ms_link;
127
128 /* fields for handling answers coming from userspace */
129 struct fuse_iov tk_aw_fiov;
130 struct fuse_out_header tk_aw_ohead;
131 int tk_aw_errno;
132 struct mtx tk_aw_mtx;
133 fuse_handler_t *tk_aw_handler;
134 TAILQ_ENTRY(fuse_ticket) tk_aw_link;
135 };
136
137 #define FT_ANSW 0x01 /* request of ticket has already been answered */
138 #define FT_DIRTY 0x04 /* ticket has been used */
139
140 static inline struct fuse_iov *
fticket_resp(struct fuse_ticket * ftick)141 fticket_resp(struct fuse_ticket *ftick)
142 {
143 return (&ftick->tk_aw_fiov);
144 }
145
146 static inline bool
fticket_answered(struct fuse_ticket * ftick)147 fticket_answered(struct fuse_ticket *ftick)
148 {
149 mtx_assert(&ftick->tk_aw_mtx, MA_OWNED);
150 return (ftick->tk_flag & FT_ANSW);
151 }
152
153 static inline void
fticket_set_answered(struct fuse_ticket * ftick)154 fticket_set_answered(struct fuse_ticket *ftick)
155 {
156 mtx_assert(&ftick->tk_aw_mtx, MA_OWNED);
157 ftick->tk_flag |= FT_ANSW;
158 }
159
160 static inline struct fuse_in_header*
fticket_in_header(struct fuse_ticket * ftick)161 fticket_in_header(struct fuse_ticket *ftick)
162 {
163 return (struct fuse_in_header *)(ftick->tk_ms_fiov.base);
164 }
165
166 static inline enum fuse_opcode
fticket_opcode(struct fuse_ticket * ftick)167 fticket_opcode(struct fuse_ticket *ftick)
168 {
169 return fticket_in_header(ftick)->opcode;
170 }
171
172 int fticket_pull(struct fuse_ticket *ftick, struct uio *uio);
173
174 /*
175 * The data representing a FUSE session.
176 */
177 struct fuse_data {
178 struct cdev *fdev;
179 struct mount *mp;
180 struct vnode *vroot;
181 struct ucred *daemoncred;
182 int dataflags;
183 int ref;
184
185 struct mtx ms_mtx;
186 STAILQ_HEAD(, fuse_ticket) ms_head;
187 int ms_count;
188
189 struct mtx aw_mtx;
190 TAILQ_HEAD(, fuse_ticket) aw_head;
191
192 /*
193 * Holds the next value of the FUSE operation unique value.
194 * Also, serves as a wakeup channel to prevent any operations from
195 * being created before INIT completes.
196 */
197 u_long ticketer;
198
199 struct sx rename_lock;
200
201 uint32_t fuse_libabi_major;
202 uint32_t fuse_libabi_minor;
203
204 uint32_t max_readahead_blocks;
205 uint32_t max_write;
206 uint32_t max_read;
207
208 struct selinfo ks_rsel;
209
210 int daemon_timeout;
211 unsigned time_gran;
212 uint64_t notimpl;
213 uint64_t mnt_flag;
214 enum fuse_data_cache_mode cache_mode;
215 };
216
217 #define FSESS_DEAD 0x0001 /* session is to be closed */
218 #define FSESS_INITED 0x0004 /* session has been inited */
219 #define FSESS_DAEMON_CAN_SPY 0x0010 /* let non-owners access this fs */
220 /* (and being observed by the daemon) */
221 #define FSESS_PUSH_SYMLINKS_IN 0x0020 /* prefix absolute symlinks with mp */
222 #define FSESS_DEFAULT_PERMISSIONS 0x0040 /* kernel does permission checking */
223 #define FSESS_ASYNC_READ 0x1000 /* allow multiple reads of some file */
224 #define FSESS_POSIX_LOCKS 0x2000 /* daemon supports POSIX locks */
225 #define FSESS_EXPORT_SUPPORT 0x10000 /* daemon supports NFS-style lookups */
226 #define FSESS_INTR 0x20000 /* interruptible mounts */
227 #define FSESS_WARN_SHORT_WRITE 0x40000 /* Short write without direct_io */
228 #define FSESS_WARN_WROTE_LONG 0x80000 /* Wrote more data than provided */
229 #define FSESS_WARN_LSEXTATTR_LONG 0x100000 /* Returned too many extattrs */
230 #define FSESS_WARN_CACHE_INCOHERENT 0x200000 /* Read cache incoherent */
231 #define FSESS_WARN_WB_CACHE_INCOHERENT 0x400000 /* WB cache incoherent */
232 #define FSESS_WARN_ILLEGAL_INODE 0x800000 /* Illegal inode for new file */
233 #define FSESS_MNTOPTS_MASK ( \
234 FSESS_DAEMON_CAN_SPY | FSESS_PUSH_SYMLINKS_IN | \
235 FSESS_DEFAULT_PERMISSIONS | FSESS_INTR)
236
237 extern int fuse_data_cache_mode;
238
239 static inline struct fuse_data *
fuse_get_mpdata(struct mount * mp)240 fuse_get_mpdata(struct mount *mp)
241 {
242 return mp->mnt_data;
243 }
244
245 static inline bool
fsess_isimpl(struct mount * mp,int opcode)246 fsess_isimpl(struct mount *mp, int opcode)
247 {
248 struct fuse_data *data = fuse_get_mpdata(mp);
249
250 return ((data->notimpl & (1ULL << opcode)) == 0);
251
252 }
253 static inline void
fsess_set_notimpl(struct mount * mp,int opcode)254 fsess_set_notimpl(struct mount *mp, int opcode)
255 {
256 struct fuse_data *data = fuse_get_mpdata(mp);
257
258 data->notimpl |= (1ULL << opcode);
259 }
260
261 static inline bool
fsess_opt_datacache(struct mount * mp)262 fsess_opt_datacache(struct mount *mp)
263 {
264 struct fuse_data *data = fuse_get_mpdata(mp);
265
266 return (data->cache_mode != FUSE_CACHE_UC);
267 }
268
269 static inline bool
fsess_opt_mmap(struct mount * mp)270 fsess_opt_mmap(struct mount *mp)
271 {
272 return (fsess_opt_datacache(mp));
273 }
274
275 static inline bool
fsess_opt_writeback(struct mount * mp)276 fsess_opt_writeback(struct mount *mp)
277 {
278 struct fuse_data *data = fuse_get_mpdata(mp);
279
280 return (data->cache_mode == FUSE_CACHE_WB);
281 }
282
283 /* Insert a new upgoing message */
284 static inline void
fuse_ms_push(struct fuse_ticket * ftick)285 fuse_ms_push(struct fuse_ticket *ftick)
286 {
287 mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
288 refcount_acquire(&ftick->tk_refcount);
289 STAILQ_INSERT_TAIL(&ftick->tk_data->ms_head, ftick, tk_ms_link);
290 ftick->tk_data->ms_count++;
291 }
292
293 /* Insert a new upgoing message to the front of the queue */
294 static inline void
fuse_ms_push_head(struct fuse_ticket * ftick)295 fuse_ms_push_head(struct fuse_ticket *ftick)
296 {
297 mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
298 refcount_acquire(&ftick->tk_refcount);
299 STAILQ_INSERT_HEAD(&ftick->tk_data->ms_head, ftick, tk_ms_link);
300 ftick->tk_data->ms_count++;
301 }
302
303 static inline struct fuse_ticket *
fuse_ms_pop(struct fuse_data * data)304 fuse_ms_pop(struct fuse_data *data)
305 {
306 struct fuse_ticket *ftick = NULL;
307
308 mtx_assert(&data->ms_mtx, MA_OWNED);
309
310 if ((ftick = STAILQ_FIRST(&data->ms_head))) {
311 STAILQ_REMOVE_HEAD(&data->ms_head, tk_ms_link);
312 data->ms_count--;
313 #ifdef INVARIANTS
314 MPASS(data->ms_count >= 0);
315 ftick->tk_ms_link.stqe_next = NULL;
316 #endif
317 }
318
319 return (ftick);
320 }
321
322 static inline void
fuse_aw_push(struct fuse_ticket * ftick)323 fuse_aw_push(struct fuse_ticket *ftick)
324 {
325 mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
326 refcount_acquire(&ftick->tk_refcount);
327 TAILQ_INSERT_TAIL(&ftick->tk_data->aw_head, ftick, tk_aw_link);
328 }
329
330 static inline void
fuse_aw_remove(struct fuse_ticket * ftick)331 fuse_aw_remove(struct fuse_ticket *ftick)
332 {
333 mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
334 TAILQ_REMOVE(&ftick->tk_data->aw_head, ftick, tk_aw_link);
335 #ifdef INVARIANTS
336 ftick->tk_aw_link.tqe_next = NULL;
337 ftick->tk_aw_link.tqe_prev = NULL;
338 #endif
339 }
340
341 static inline struct fuse_ticket *
fuse_aw_pop(struct fuse_data * data)342 fuse_aw_pop(struct fuse_data *data)
343 {
344 struct fuse_ticket *ftick;
345
346 mtx_assert(&data->aw_mtx, MA_OWNED);
347
348 if ((ftick = TAILQ_FIRST(&data->aw_head)) != NULL)
349 fuse_aw_remove(ftick);
350
351 return (ftick);
352 }
353
354 struct fuse_ticket *fuse_ticket_fetch(struct fuse_data *data);
355 int fuse_ticket_drop(struct fuse_ticket *ftick);
356 void fuse_insert_callback(struct fuse_ticket *ftick, fuse_handler_t *handler);
357 void fuse_insert_message(struct fuse_ticket *ftick, bool irq);
358
359 static inline bool
fuse_libabi_geq(struct fuse_data * data,uint32_t abi_maj,uint32_t abi_min)360 fuse_libabi_geq(struct fuse_data *data, uint32_t abi_maj, uint32_t abi_min)
361 {
362 return (data->fuse_libabi_major > abi_maj ||
363 (data->fuse_libabi_major == abi_maj &&
364 data->fuse_libabi_minor >= abi_min));
365 }
366
367 /* Print msg as a warning to the console, but no more than once per session */
368 void fuse_warn(struct fuse_data *data, unsigned flag, const char *msg);
369
370 struct fuse_data *fdata_alloc(struct cdev *dev, struct ucred *cred);
371 void fdata_trydestroy(struct fuse_data *data);
372 void fdata_set_dead(struct fuse_data *data);
373
374 static inline bool
fdata_get_dead(struct fuse_data * data)375 fdata_get_dead(struct fuse_data *data)
376 {
377 return (data->dataflags & FSESS_DEAD);
378 }
379
380 struct fuse_dispatcher {
381 struct fuse_ticket *tick;
382 struct fuse_in_header *finh;
383
384 void *indata;
385 size_t iosize;
386 uint64_t nodeid;
387 int answ_stat;
388 void *answ;
389 };
390
391 static inline void
fdisp_init(struct fuse_dispatcher * fdisp,size_t iosize)392 fdisp_init(struct fuse_dispatcher *fdisp, size_t iosize)
393 {
394 fdisp->iosize = iosize;
395 fdisp->tick = NULL;
396 }
397
398 static inline void
fdisp_destroy(struct fuse_dispatcher * fdisp)399 fdisp_destroy(struct fuse_dispatcher *fdisp)
400 {
401 fuse_ticket_drop(fdisp->tick);
402 #ifdef INVARIANTS
403 fdisp->tick = NULL;
404 #endif
405 }
406
407 void fdisp_make(struct fuse_dispatcher *fdip, enum fuse_opcode op,
408 struct mount *mp, uint64_t nid, struct thread *td, struct ucred *cred);
409
410 void fdisp_make_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
411 struct vnode *vp, struct thread *td, struct ucred *cred);
412
413 void fdisp_refresh_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
414 struct vnode *vp, struct thread *td, struct ucred *cred);
415
416 int fdisp_wait_answ(struct fuse_dispatcher *fdip);
417
418 static inline int
fdisp_simple_putget_vp(struct fuse_dispatcher * fdip,enum fuse_opcode op,struct vnode * vp,struct thread * td,struct ucred * cred)419 fdisp_simple_putget_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
420 struct vnode *vp, struct thread *td, struct ucred *cred)
421 {
422 fdisp_make_vp(fdip, op, vp, td, cred);
423 return (fdisp_wait_answ(fdip));
424 }
425
426 #endif /* _FUSE_IPC_H_ */
427