xref: /freebsd/sys/fs/fuse/fuse_ipc.h (revision 1da7f3f6f72b2245e458fc7195733268ae4a1136)
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_WARN_READLINK_EMBEDDED_NUL 0x1000000 /* corrupt READLINK output */
243 #define FSESS_MNTOPTS_MASK	( \
244 	FSESS_DAEMON_CAN_SPY | FSESS_PUSH_SYMLINKS_IN | \
245 	FSESS_DEFAULT_PERMISSIONS | FSESS_INTR)
246 
247 extern int fuse_data_cache_mode;
248 
249 static inline struct fuse_data *
250 fuse_get_mpdata(struct mount *mp)
251 {
252 	return mp->mnt_data;
253 }
254 
255 static inline bool
256 fsess_is_impl(struct mount *mp, int opcode)
257 {
258 	struct fuse_data *data = fuse_get_mpdata(mp);
259 
260 	return ((data->isimpl & (1ULL << opcode)) != 0);
261 
262 }
263 
264 static inline bool
265 fsess_maybe_impl(struct mount *mp, int opcode)
266 {
267 	struct fuse_data *data = fuse_get_mpdata(mp);
268 
269 	return ((data->notimpl & (1ULL << opcode)) == 0);
270 
271 }
272 
273 static inline bool
274 fsess_not_impl(struct mount *mp, int opcode)
275 {
276 	struct fuse_data *data = fuse_get_mpdata(mp);
277 
278 	return ((data->notimpl & (1ULL << opcode)) != 0);
279 
280 }
281 
282 static inline void
283 fsess_set_impl(struct mount *mp, int opcode)
284 {
285 	struct fuse_data *data = fuse_get_mpdata(mp);
286 
287 	data->isimpl |= (1ULL << opcode);
288 }
289 
290 static inline void
291 fsess_set_notimpl(struct mount *mp, int opcode)
292 {
293 	struct fuse_data *data = fuse_get_mpdata(mp);
294 
295 	data->notimpl |= (1ULL << opcode);
296 }
297 
298 static inline bool
299 fsess_opt_datacache(struct mount *mp)
300 {
301 	struct fuse_data *data = fuse_get_mpdata(mp);
302 
303 	return (data->cache_mode != FUSE_CACHE_UC);
304 }
305 
306 static inline bool
307 fsess_opt_mmap(struct mount *mp)
308 {
309 	return (fsess_opt_datacache(mp));
310 }
311 
312 static inline bool
313 fsess_opt_writeback(struct mount *mp)
314 {
315 	struct fuse_data *data = fuse_get_mpdata(mp);
316 
317 	return (data->cache_mode == FUSE_CACHE_WB);
318 }
319 
320 /* Insert a new upgoing message */
321 static inline void
322 fuse_ms_push(struct fuse_ticket *ftick)
323 {
324 	mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
325 	refcount_acquire(&ftick->tk_refcount);
326 	STAILQ_INSERT_TAIL(&ftick->tk_data->ms_head, ftick, tk_ms_link);
327 	ftick->tk_data->ms_count++;
328 }
329 
330 /* Insert a new upgoing message to the front of the queue */
331 static inline void
332 fuse_ms_push_head(struct fuse_ticket *ftick)
333 {
334 	mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
335 	refcount_acquire(&ftick->tk_refcount);
336 	STAILQ_INSERT_HEAD(&ftick->tk_data->ms_head, ftick, tk_ms_link);
337 	ftick->tk_data->ms_count++;
338 }
339 
340 static inline struct fuse_ticket *
341 fuse_ms_pop(struct fuse_data *data)
342 {
343 	struct fuse_ticket *ftick = NULL;
344 
345 	mtx_assert(&data->ms_mtx, MA_OWNED);
346 
347 	if ((ftick = STAILQ_FIRST(&data->ms_head))) {
348 		STAILQ_REMOVE_HEAD(&data->ms_head, tk_ms_link);
349 		data->ms_count--;
350 #ifdef INVARIANTS
351 		MPASS(data->ms_count >= 0);
352 		ftick->tk_ms_link.stqe_next = NULL;
353 #endif
354 	}
355 
356 	return (ftick);
357 }
358 
359 static inline void
360 fuse_aw_push(struct fuse_ticket *ftick)
361 {
362 	mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
363 	refcount_acquire(&ftick->tk_refcount);
364 	TAILQ_INSERT_TAIL(&ftick->tk_data->aw_head, ftick, tk_aw_link);
365 }
366 
367 static inline void
368 fuse_aw_remove(struct fuse_ticket *ftick)
369 {
370 	mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
371 	TAILQ_REMOVE(&ftick->tk_data->aw_head, ftick, tk_aw_link);
372 #ifdef INVARIANTS
373 	ftick->tk_aw_link.tqe_next = NULL;
374 	ftick->tk_aw_link.tqe_prev = NULL;
375 #endif
376 }
377 
378 static inline struct fuse_ticket *
379 fuse_aw_pop(struct fuse_data *data)
380 {
381 	struct fuse_ticket *ftick;
382 
383 	mtx_assert(&data->aw_mtx, MA_OWNED);
384 
385 	if ((ftick = TAILQ_FIRST(&data->aw_head)) != NULL)
386 		fuse_aw_remove(ftick);
387 
388 	return (ftick);
389 }
390 
391 struct fuse_ticket *fuse_ticket_fetch(struct fuse_data *data);
392 int fuse_ticket_drop(struct fuse_ticket *ftick);
393 void fuse_insert_callback(struct fuse_ticket *ftick, fuse_handler_t *handler);
394 void fuse_insert_message(struct fuse_ticket *ftick, bool irq);
395 
396 static inline bool
397 fuse_libabi_geq(struct fuse_data *data, uint32_t abi_maj, uint32_t abi_min)
398 {
399 	return (data->fuse_libabi_major > abi_maj ||
400 	    (data->fuse_libabi_major == abi_maj &&
401 	     data->fuse_libabi_minor >= abi_min));
402 }
403 
404 /* Print msg as a warning to the console, but no more than once per session */
405 void fuse_warn(struct fuse_data *data, unsigned flag, const char *msg);
406 
407 struct fuse_data *fdata_alloc(struct cdev *dev, struct ucred *cred);
408 void fdata_trydestroy(struct fuse_data *data);
409 void fdata_set_dead(struct fuse_data *data);
410 
411 static inline bool
412 fdata_get_dead(struct fuse_data *data)
413 {
414 	return (data->dataflags & FSESS_DEAD);
415 }
416 
417 struct fuse_dispatcher {
418 	struct fuse_ticket    *tick;
419 	struct fuse_in_header *finh;
420 
421 	void    *indata;
422 	size_t   iosize;
423 	uint64_t nodeid;
424 	int      answ_stat;
425 	void    *answ;
426 };
427 
428 static inline void
429 fdisp_init(struct fuse_dispatcher *fdisp, size_t iosize)
430 {
431 	fdisp->iosize = iosize;
432 	fdisp->tick = NULL;
433 }
434 
435 static inline void
436 fdisp_destroy(struct fuse_dispatcher *fdisp)
437 {
438 	fuse_ticket_drop(fdisp->tick);
439 #ifdef INVARIANTS
440 	fdisp->tick = NULL;
441 #endif
442 }
443 
444 void fdisp_make(struct fuse_dispatcher *fdip, enum fuse_opcode op,
445     struct mount *mp, uint64_t nid, struct thread *td, struct ucred *cred);
446 
447 void fdisp_make_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
448     struct vnode *vp, struct thread *td, struct ucred *cred);
449 
450 void fdisp_refresh_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
451     struct vnode *vp, struct thread *td, struct ucred *cred);
452 
453 int fdisp_wait_answ(struct fuse_dispatcher *fdip);
454 
455 static inline int
456 fdisp_simple_putget_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
457     struct vnode *vp, struct thread *td, struct ucred *cred)
458 {
459 	fdisp_make_vp(fdip, op, vp, td, cred);
460 	return (fdisp_wait_answ(fdip));
461 }
462 
463 #endif /* _FUSE_IPC_H_ */
464