xref: /freebsd/sys/fs/fuse/fuse_ipc.h (revision d7d962ead0b6e5e8a39202d0590022082bf5bfb6)
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  * $FreeBSD$
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 *
141 fticket_resp(struct fuse_ticket *ftick)
142 {
143 	return (&ftick->tk_aw_fiov);
144 }
145 
146 static inline bool
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
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*
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
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 	int				linux_errnos;
212 	unsigned			time_gran;
213 	/* A bitmask of FUSE RPCs that are not implemented by the server */
214 	uint64_t			notimpl;
215 	/*
216 	 * A bitmask of FUSE RPCs that are implemented by the server.
217 	 * If an operation is not present in either notimpl or isimpl, then it
218 	 * may be implemented by the server, but the kernel doesn't know for
219 	 * sure.
220 	 */
221 	uint64_t			isimpl;
222 	uint64_t			mnt_flag;
223 	enum fuse_data_cache_mode	cache_mode;
224 };
225 
226 #define FSESS_DEAD                0x0001 /* session is to be closed */
227 #define FSESS_INITED              0x0004 /* session has been inited */
228 #define FSESS_DAEMON_CAN_SPY      0x0010 /* let non-owners access this fs */
229                                          /* (and being observed by the daemon) */
230 #define FSESS_PUSH_SYMLINKS_IN    0x0020 /* prefix absolute symlinks with mp */
231 #define FSESS_DEFAULT_PERMISSIONS 0x0040 /* kernel does permission checking */
232 #define FSESS_ASYNC_READ          0x1000 /* allow multiple reads of some file */
233 #define FSESS_POSIX_LOCKS         0x2000 /* daemon supports POSIX locks */
234 #define FSESS_EXPORT_SUPPORT      0x10000 /* daemon supports NFS-style lookups */
235 #define FSESS_INTR                0x20000 /* interruptible mounts */
236 #define FSESS_WARN_SHORT_WRITE    0x40000 /* Short write without direct_io */
237 #define FSESS_WARN_WROTE_LONG     0x80000 /* Wrote more data than provided */
238 #define FSESS_WARN_LSEXTATTR_LONG 0x100000 /* Returned too many extattrs */
239 #define FSESS_WARN_CACHE_INCOHERENT 0x200000	/* Read cache incoherent */
240 #define FSESS_WARN_WB_CACHE_INCOHERENT 0x400000	/* WB cache incoherent */
241 #define FSESS_MNTOPTS_MASK	( \
242 	FSESS_DAEMON_CAN_SPY | FSESS_PUSH_SYMLINKS_IN | \
243 	FSESS_DEFAULT_PERMISSIONS | FSESS_INTR)
244 
245 extern int fuse_data_cache_mode;
246 
247 static inline struct fuse_data *
248 fuse_get_mpdata(struct mount *mp)
249 {
250 	return mp->mnt_data;
251 }
252 
253 static inline bool
254 fsess_is_impl(struct mount *mp, int opcode)
255 {
256 	struct fuse_data *data = fuse_get_mpdata(mp);
257 
258 	return ((data->isimpl & (1ULL << opcode)) != 0);
259 
260 }
261 
262 static inline bool
263 fsess_maybe_impl(struct mount *mp, int opcode)
264 {
265 	struct fuse_data *data = fuse_get_mpdata(mp);
266 
267 	return ((data->notimpl & (1ULL << opcode)) == 0);
268 
269 }
270 
271 static inline bool
272 fsess_not_impl(struct mount *mp, int opcode)
273 {
274 	struct fuse_data *data = fuse_get_mpdata(mp);
275 
276 	return ((data->notimpl & (1ULL << opcode)) != 0);
277 
278 }
279 
280 static inline void
281 fsess_set_impl(struct mount *mp, int opcode)
282 {
283 	struct fuse_data *data = fuse_get_mpdata(mp);
284 
285 	data->isimpl |= (1ULL << opcode);
286 }
287 
288 static inline void
289 fsess_set_notimpl(struct mount *mp, int opcode)
290 {
291 	struct fuse_data *data = fuse_get_mpdata(mp);
292 
293 	data->notimpl |= (1ULL << opcode);
294 }
295 
296 static inline bool
297 fsess_opt_datacache(struct mount *mp)
298 {
299 	struct fuse_data *data = fuse_get_mpdata(mp);
300 
301 	return (data->cache_mode != FUSE_CACHE_UC);
302 }
303 
304 static inline bool
305 fsess_opt_mmap(struct mount *mp)
306 {
307 	return (fsess_opt_datacache(mp));
308 }
309 
310 static inline bool
311 fsess_opt_writeback(struct mount *mp)
312 {
313 	struct fuse_data *data = fuse_get_mpdata(mp);
314 
315 	return (data->cache_mode == FUSE_CACHE_WB);
316 }
317 
318 /* Insert a new upgoing message */
319 static inline void
320 fuse_ms_push(struct fuse_ticket *ftick)
321 {
322 	mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
323 	refcount_acquire(&ftick->tk_refcount);
324 	STAILQ_INSERT_TAIL(&ftick->tk_data->ms_head, ftick, tk_ms_link);
325 	ftick->tk_data->ms_count++;
326 }
327 
328 /* Insert a new upgoing message to the front of the queue */
329 static inline void
330 fuse_ms_push_head(struct fuse_ticket *ftick)
331 {
332 	mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
333 	refcount_acquire(&ftick->tk_refcount);
334 	STAILQ_INSERT_HEAD(&ftick->tk_data->ms_head, ftick, tk_ms_link);
335 	ftick->tk_data->ms_count++;
336 }
337 
338 static inline struct fuse_ticket *
339 fuse_ms_pop(struct fuse_data *data)
340 {
341 	struct fuse_ticket *ftick = NULL;
342 
343 	mtx_assert(&data->ms_mtx, MA_OWNED);
344 
345 	if ((ftick = STAILQ_FIRST(&data->ms_head))) {
346 		STAILQ_REMOVE_HEAD(&data->ms_head, tk_ms_link);
347 		data->ms_count--;
348 #ifdef INVARIANTS
349 		MPASS(data->ms_count >= 0);
350 		ftick->tk_ms_link.stqe_next = NULL;
351 #endif
352 	}
353 
354 	return (ftick);
355 }
356 
357 static inline void
358 fuse_aw_push(struct fuse_ticket *ftick)
359 {
360 	mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
361 	refcount_acquire(&ftick->tk_refcount);
362 	TAILQ_INSERT_TAIL(&ftick->tk_data->aw_head, ftick, tk_aw_link);
363 }
364 
365 static inline void
366 fuse_aw_remove(struct fuse_ticket *ftick)
367 {
368 	mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
369 	TAILQ_REMOVE(&ftick->tk_data->aw_head, ftick, tk_aw_link);
370 #ifdef INVARIANTS
371 	ftick->tk_aw_link.tqe_next = NULL;
372 	ftick->tk_aw_link.tqe_prev = NULL;
373 #endif
374 }
375 
376 static inline struct fuse_ticket *
377 fuse_aw_pop(struct fuse_data *data)
378 {
379 	struct fuse_ticket *ftick;
380 
381 	mtx_assert(&data->aw_mtx, MA_OWNED);
382 
383 	if ((ftick = TAILQ_FIRST(&data->aw_head)) != NULL)
384 		fuse_aw_remove(ftick);
385 
386 	return (ftick);
387 }
388 
389 struct fuse_ticket *fuse_ticket_fetch(struct fuse_data *data);
390 int fuse_ticket_drop(struct fuse_ticket *ftick);
391 void fuse_insert_callback(struct fuse_ticket *ftick, fuse_handler_t *handler);
392 void fuse_insert_message(struct fuse_ticket *ftick, bool irq);
393 
394 static inline bool
395 fuse_libabi_geq(struct fuse_data *data, uint32_t abi_maj, uint32_t abi_min)
396 {
397 	return (data->fuse_libabi_major > abi_maj ||
398 	    (data->fuse_libabi_major == abi_maj &&
399 	     data->fuse_libabi_minor >= abi_min));
400 }
401 
402 /* Print msg as a warning to the console, but no more than once per session */
403 void fuse_warn(struct fuse_data *data, unsigned flag, const char *msg);
404 
405 struct fuse_data *fdata_alloc(struct cdev *dev, struct ucred *cred);
406 void fdata_trydestroy(struct fuse_data *data);
407 void fdata_set_dead(struct fuse_data *data);
408 
409 static inline bool
410 fdata_get_dead(struct fuse_data *data)
411 {
412 	return (data->dataflags & FSESS_DEAD);
413 }
414 
415 struct fuse_dispatcher {
416 	struct fuse_ticket    *tick;
417 	struct fuse_in_header *finh;
418 
419 	void    *indata;
420 	size_t   iosize;
421 	uint64_t nodeid;
422 	int      answ_stat;
423 	void    *answ;
424 };
425 
426 static inline void
427 fdisp_init(struct fuse_dispatcher *fdisp, size_t iosize)
428 {
429 	fdisp->iosize = iosize;
430 	fdisp->tick = NULL;
431 }
432 
433 static inline void
434 fdisp_destroy(struct fuse_dispatcher *fdisp)
435 {
436 	fuse_ticket_drop(fdisp->tick);
437 #ifdef INVARIANTS
438 	fdisp->tick = NULL;
439 #endif
440 }
441 
442 void fdisp_make(struct fuse_dispatcher *fdip, enum fuse_opcode op,
443     struct mount *mp, uint64_t nid, struct thread *td, struct ucred *cred);
444 
445 void fdisp_make_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
446     struct vnode *vp, struct thread *td, struct ucred *cred);
447 
448 void fdisp_refresh_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
449     struct vnode *vp, struct thread *td, struct ucred *cred);
450 
451 int fdisp_wait_answ(struct fuse_dispatcher *fdip);
452 
453 static inline int
454 fdisp_simple_putget_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
455     struct vnode *vp, struct thread *td, struct ucred *cred)
456 {
457 	fdisp_make_vp(fdip, op, vp, td, cred);
458 	return (fdisp_wait_answ(fdip));
459 }
460 
461 #endif /* _FUSE_IPC_H_ */
462