xref: /freebsd/sys/fs/fuse/fuse_ipc.h (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)
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 *
139 fticket_resp(struct fuse_ticket *ftick)
140 {
141 	return (&ftick->tk_aw_fiov);
142 }
143 
144 static inline bool
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
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*
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
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_NO_OPEN_SUPPORT     0x0080 /* can elide FUSE_OPEN ops */
231 #define FSESS_NO_OPENDIR_SUPPORT  0x0100 /* can elide FUSE_OPENDIR ops */
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_WARN_ILLEGAL_INODE  0x800000 /* Illegal inode for new file */
242 #define FSESS_MNTOPTS_MASK	( \
243 	FSESS_DAEMON_CAN_SPY | FSESS_PUSH_SYMLINKS_IN | \
244 	FSESS_DEFAULT_PERMISSIONS | FSESS_INTR)
245 
246 extern int fuse_data_cache_mode;
247 
248 static inline struct fuse_data *
249 fuse_get_mpdata(struct mount *mp)
250 {
251 	return mp->mnt_data;
252 }
253 
254 static inline bool
255 fsess_is_impl(struct mount *mp, int opcode)
256 {
257 	struct fuse_data *data = fuse_get_mpdata(mp);
258 
259 	return ((data->isimpl & (1ULL << opcode)) != 0);
260 
261 }
262 
263 static inline bool
264 fsess_maybe_impl(struct mount *mp, int opcode)
265 {
266 	struct fuse_data *data = fuse_get_mpdata(mp);
267 
268 	return ((data->notimpl & (1ULL << opcode)) == 0);
269 
270 }
271 
272 static inline bool
273 fsess_not_impl(struct mount *mp, int opcode)
274 {
275 	struct fuse_data *data = fuse_get_mpdata(mp);
276 
277 	return ((data->notimpl & (1ULL << opcode)) != 0);
278 
279 }
280 
281 static inline void
282 fsess_set_impl(struct mount *mp, int opcode)
283 {
284 	struct fuse_data *data = fuse_get_mpdata(mp);
285 
286 	data->isimpl |= (1ULL << opcode);
287 }
288 
289 static inline void
290 fsess_set_notimpl(struct mount *mp, int opcode)
291 {
292 	struct fuse_data *data = fuse_get_mpdata(mp);
293 
294 	data->notimpl |= (1ULL << opcode);
295 }
296 
297 static inline bool
298 fsess_opt_datacache(struct mount *mp)
299 {
300 	struct fuse_data *data = fuse_get_mpdata(mp);
301 
302 	return (data->cache_mode != FUSE_CACHE_UC);
303 }
304 
305 static inline bool
306 fsess_opt_mmap(struct mount *mp)
307 {
308 	return (fsess_opt_datacache(mp));
309 }
310 
311 static inline bool
312 fsess_opt_writeback(struct mount *mp)
313 {
314 	struct fuse_data *data = fuse_get_mpdata(mp);
315 
316 	return (data->cache_mode == FUSE_CACHE_WB);
317 }
318 
319 /* Insert a new upgoing message */
320 static inline void
321 fuse_ms_push(struct fuse_ticket *ftick)
322 {
323 	mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
324 	refcount_acquire(&ftick->tk_refcount);
325 	STAILQ_INSERT_TAIL(&ftick->tk_data->ms_head, ftick, tk_ms_link);
326 	ftick->tk_data->ms_count++;
327 }
328 
329 /* Insert a new upgoing message to the front of the queue */
330 static inline void
331 fuse_ms_push_head(struct fuse_ticket *ftick)
332 {
333 	mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
334 	refcount_acquire(&ftick->tk_refcount);
335 	STAILQ_INSERT_HEAD(&ftick->tk_data->ms_head, ftick, tk_ms_link);
336 	ftick->tk_data->ms_count++;
337 }
338 
339 static inline struct fuse_ticket *
340 fuse_ms_pop(struct fuse_data *data)
341 {
342 	struct fuse_ticket *ftick = NULL;
343 
344 	mtx_assert(&data->ms_mtx, MA_OWNED);
345 
346 	if ((ftick = STAILQ_FIRST(&data->ms_head))) {
347 		STAILQ_REMOVE_HEAD(&data->ms_head, tk_ms_link);
348 		data->ms_count--;
349 #ifdef INVARIANTS
350 		MPASS(data->ms_count >= 0);
351 		ftick->tk_ms_link.stqe_next = NULL;
352 #endif
353 	}
354 
355 	return (ftick);
356 }
357 
358 static inline void
359 fuse_aw_push(struct fuse_ticket *ftick)
360 {
361 	mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
362 	refcount_acquire(&ftick->tk_refcount);
363 	TAILQ_INSERT_TAIL(&ftick->tk_data->aw_head, ftick, tk_aw_link);
364 }
365 
366 static inline void
367 fuse_aw_remove(struct fuse_ticket *ftick)
368 {
369 	mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
370 	TAILQ_REMOVE(&ftick->tk_data->aw_head, ftick, tk_aw_link);
371 #ifdef INVARIANTS
372 	ftick->tk_aw_link.tqe_next = NULL;
373 	ftick->tk_aw_link.tqe_prev = NULL;
374 #endif
375 }
376 
377 static inline struct fuse_ticket *
378 fuse_aw_pop(struct fuse_data *data)
379 {
380 	struct fuse_ticket *ftick;
381 
382 	mtx_assert(&data->aw_mtx, MA_OWNED);
383 
384 	if ((ftick = TAILQ_FIRST(&data->aw_head)) != NULL)
385 		fuse_aw_remove(ftick);
386 
387 	return (ftick);
388 }
389 
390 struct fuse_ticket *fuse_ticket_fetch(struct fuse_data *data);
391 int fuse_ticket_drop(struct fuse_ticket *ftick);
392 void fuse_insert_callback(struct fuse_ticket *ftick, fuse_handler_t *handler);
393 void fuse_insert_message(struct fuse_ticket *ftick, bool irq);
394 
395 static inline bool
396 fuse_libabi_geq(struct fuse_data *data, uint32_t abi_maj, uint32_t abi_min)
397 {
398 	return (data->fuse_libabi_major > abi_maj ||
399 	    (data->fuse_libabi_major == abi_maj &&
400 	     data->fuse_libabi_minor >= abi_min));
401 }
402 
403 /* Print msg as a warning to the console, but no more than once per session */
404 void fuse_warn(struct fuse_data *data, unsigned flag, const char *msg);
405 
406 struct fuse_data *fdata_alloc(struct cdev *dev, struct ucred *cred);
407 void fdata_trydestroy(struct fuse_data *data);
408 void fdata_set_dead(struct fuse_data *data);
409 
410 static inline bool
411 fdata_get_dead(struct fuse_data *data)
412 {
413 	return (data->dataflags & FSESS_DEAD);
414 }
415 
416 struct fuse_dispatcher {
417 	struct fuse_ticket    *tick;
418 	struct fuse_in_header *finh;
419 
420 	void    *indata;
421 	size_t   iosize;
422 	uint64_t nodeid;
423 	int      answ_stat;
424 	void    *answ;
425 };
426 
427 static inline void
428 fdisp_init(struct fuse_dispatcher *fdisp, size_t iosize)
429 {
430 	fdisp->iosize = iosize;
431 	fdisp->tick = NULL;
432 }
433 
434 static inline void
435 fdisp_destroy(struct fuse_dispatcher *fdisp)
436 {
437 	fuse_ticket_drop(fdisp->tick);
438 #ifdef INVARIANTS
439 	fdisp->tick = NULL;
440 #endif
441 }
442 
443 void fdisp_make(struct fuse_dispatcher *fdip, enum fuse_opcode op,
444     struct mount *mp, uint64_t nid, struct thread *td, struct ucred *cred);
445 
446 void fdisp_make_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
447     struct vnode *vp, struct thread *td, struct ucred *cred);
448 
449 void fdisp_refresh_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
450     struct vnode *vp, struct thread *td, struct ucred *cred);
451 
452 int fdisp_wait_answ(struct fuse_dispatcher *fdip);
453 
454 static inline int
455 fdisp_simple_putget_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
456     struct vnode *vp, struct thread *td, struct ucred *cred)
457 {
458 	fdisp_make_vp(fdip, op, vp, td, cred);
459 	return (fdisp_wait_answ(fdip));
460 }
461 
462 #endif /* _FUSE_IPC_H_ */
463