xref: /freebsd/sys/fs/fuse/fuse_ipc.h (revision 41ce62251c1ed0003fc13b8735de5f9eff4c5c03)
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 	void				*tk_ms_bufdata;
127 	size_t				tk_ms_bufsize;
128 	enum { FT_M_FIOV, FT_M_BUF }	tk_ms_type;
129 	STAILQ_ENTRY(fuse_ticket)	tk_ms_link;
130 
131 	/* fields for handling answers coming from userspace */
132 	struct fuse_iov			tk_aw_fiov;
133 	void				*tk_aw_bufdata;
134 	size_t				tk_aw_bufsize;
135 	enum { FT_A_FIOV, FT_A_BUF }	tk_aw_type;
136 
137 	struct fuse_out_header		tk_aw_ohead;
138 	int				tk_aw_errno;
139 	struct mtx			tk_aw_mtx;
140 	fuse_handler_t			*tk_aw_handler;
141 	TAILQ_ENTRY(fuse_ticket)	tk_aw_link;
142 };
143 
144 #define FT_ANSW  0x01  /* request of ticket has already been answered */
145 #define FT_DIRTY 0x04  /* ticket has been used */
146 
147 static inline struct fuse_iov *
148 fticket_resp(struct fuse_ticket *ftick)
149 {
150 	return (&ftick->tk_aw_fiov);
151 }
152 
153 static inline bool
154 fticket_answered(struct fuse_ticket *ftick)
155 {
156 	mtx_assert(&ftick->tk_aw_mtx, MA_OWNED);
157 	return (ftick->tk_flag & FT_ANSW);
158 }
159 
160 static inline void
161 fticket_set_answered(struct fuse_ticket *ftick)
162 {
163 	mtx_assert(&ftick->tk_aw_mtx, MA_OWNED);
164 	ftick->tk_flag |= FT_ANSW;
165 }
166 
167 static inline struct fuse_in_header*
168 fticket_in_header(struct fuse_ticket *ftick)
169 {
170 	return (struct fuse_in_header *)(ftick->tk_ms_fiov.base);
171 }
172 
173 static inline enum fuse_opcode
174 fticket_opcode(struct fuse_ticket *ftick)
175 {
176 	return fticket_in_header(ftick)->opcode;
177 }
178 
179 int fticket_pull(struct fuse_ticket *ftick, struct uio *uio);
180 
181 /*
182  * The data representing a FUSE session.
183  */
184 struct fuse_data {
185 	struct cdev			*fdev;
186 	struct mount			*mp;
187 	struct vnode			*vroot;
188 	struct ucred			*daemoncred;
189 	int				dataflags;
190 	int				ref;
191 
192 	struct mtx			ms_mtx;
193 	STAILQ_HEAD(, fuse_ticket)	ms_head;
194 	int				ms_count;
195 
196 	struct mtx			aw_mtx;
197 	TAILQ_HEAD(, fuse_ticket)	aw_head;
198 
199 	/*
200 	 * Holds the next value of the FUSE operation unique value.
201 	 * Also, serves as a wakeup channel to prevent any operations from
202 	 * being created before INIT completes.
203 	 */
204 	u_long				ticketer;
205 
206 	struct sx			rename_lock;
207 
208 	uint32_t			fuse_libabi_major;
209 	uint32_t			fuse_libabi_minor;
210 
211 	uint32_t			max_readahead_blocks;
212 	uint32_t			max_write;
213 	uint32_t			max_read;
214 	uint32_t			subtype;
215 	char				volname[MAXPATHLEN];
216 
217 	struct selinfo			ks_rsel;
218 
219 	int				daemon_timeout;
220 	int				linux_errnos;
221 	unsigned			time_gran;
222 	uint64_t			notimpl;
223 	uint64_t			mnt_flag;
224 	enum fuse_data_cache_mode	cache_mode;
225 };
226 
227 #define FSESS_DEAD                0x0001 /* session is to be closed */
228 #define FSESS_INITED              0x0004 /* session has been inited */
229 #define FSESS_DAEMON_CAN_SPY      0x0010 /* let non-owners access this fs */
230                                          /* (and being observed by the daemon) */
231 #define FSESS_PUSH_SYMLINKS_IN    0x0020 /* prefix absolute symlinks with mp */
232 #define FSESS_DEFAULT_PERMISSIONS 0x0040 /* kernel does permission checking */
233 #define FSESS_ASYNC_READ          0x1000 /* allow multiple reads of some file */
234 #define FSESS_POSIX_LOCKS         0x2000 /* daemon supports POSIX locks */
235 #define FSESS_EXPORT_SUPPORT      0x10000 /* daemon supports NFS-style lookups */
236 #define FSESS_INTR                0x20000 /* interruptible mounts */
237 #define FSESS_MNTOPTS_MASK	( \
238 	FSESS_DAEMON_CAN_SPY | FSESS_PUSH_SYMLINKS_IN | \
239 	FSESS_DEFAULT_PERMISSIONS | FSESS_INTR)
240 
241 extern int fuse_data_cache_mode;
242 
243 static inline struct fuse_data *
244 fuse_get_mpdata(struct mount *mp)
245 {
246 	return mp->mnt_data;
247 }
248 
249 static inline bool
250 fsess_isimpl(struct mount *mp, int opcode)
251 {
252 	struct fuse_data *data = fuse_get_mpdata(mp);
253 
254 	return ((data->notimpl & (1ULL << opcode)) == 0);
255 
256 }
257 static inline void
258 fsess_set_notimpl(struct mount *mp, int opcode)
259 {
260 	struct fuse_data *data = fuse_get_mpdata(mp);
261 
262 	data->notimpl |= (1ULL << opcode);
263 }
264 
265 static inline bool
266 fsess_opt_datacache(struct mount *mp)
267 {
268 	struct fuse_data *data = fuse_get_mpdata(mp);
269 
270 	return (data->cache_mode != FUSE_CACHE_UC);
271 }
272 
273 static inline bool
274 fsess_opt_mmap(struct mount *mp)
275 {
276 	return (fsess_opt_datacache(mp));
277 }
278 
279 static inline bool
280 fsess_opt_writeback(struct mount *mp)
281 {
282 	struct fuse_data *data = fuse_get_mpdata(mp);
283 
284 	return (data->cache_mode == FUSE_CACHE_WB);
285 }
286 
287 /* Insert a new upgoing message */
288 static inline void
289 fuse_ms_push(struct fuse_ticket *ftick)
290 {
291 	mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
292 	refcount_acquire(&ftick->tk_refcount);
293 	STAILQ_INSERT_TAIL(&ftick->tk_data->ms_head, ftick, tk_ms_link);
294 	ftick->tk_data->ms_count++;
295 }
296 
297 /* Insert a new upgoing message to the front of the queue */
298 static inline void
299 fuse_ms_push_head(struct fuse_ticket *ftick)
300 {
301 	mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
302 	refcount_acquire(&ftick->tk_refcount);
303 	STAILQ_INSERT_HEAD(&ftick->tk_data->ms_head, ftick, tk_ms_link);
304 	ftick->tk_data->ms_count++;
305 }
306 
307 static inline struct fuse_ticket *
308 fuse_ms_pop(struct fuse_data *data)
309 {
310 	struct fuse_ticket *ftick = NULL;
311 
312 	mtx_assert(&data->ms_mtx, MA_OWNED);
313 
314 	if ((ftick = STAILQ_FIRST(&data->ms_head))) {
315 		STAILQ_REMOVE_HEAD(&data->ms_head, tk_ms_link);
316 		data->ms_count--;
317 #ifdef INVARIANTS
318 		MPASS(data->ms_count >= 0);
319 		ftick->tk_ms_link.stqe_next = NULL;
320 #endif
321 	}
322 
323 	return (ftick);
324 }
325 
326 static inline void
327 fuse_aw_push(struct fuse_ticket *ftick)
328 {
329 	mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
330 	refcount_acquire(&ftick->tk_refcount);
331 	TAILQ_INSERT_TAIL(&ftick->tk_data->aw_head, ftick, tk_aw_link);
332 }
333 
334 static inline void
335 fuse_aw_remove(struct fuse_ticket *ftick)
336 {
337 	mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
338 	TAILQ_REMOVE(&ftick->tk_data->aw_head, ftick, tk_aw_link);
339 #ifdef INVARIANTS
340 	ftick->tk_aw_link.tqe_next = NULL;
341 	ftick->tk_aw_link.tqe_prev = NULL;
342 #endif
343 }
344 
345 static inline struct fuse_ticket *
346 fuse_aw_pop(struct fuse_data *data)
347 {
348 	struct fuse_ticket *ftick;
349 
350 	mtx_assert(&data->aw_mtx, MA_OWNED);
351 
352 	if ((ftick = TAILQ_FIRST(&data->aw_head)) != NULL)
353 		fuse_aw_remove(ftick);
354 
355 	return (ftick);
356 }
357 
358 struct fuse_ticket *fuse_ticket_fetch(struct fuse_data *data);
359 int fuse_ticket_drop(struct fuse_ticket *ftick);
360 void fuse_insert_callback(struct fuse_ticket *ftick, fuse_handler_t *handler);
361 void fuse_insert_message(struct fuse_ticket *ftick, bool irq);
362 
363 static inline bool
364 fuse_libabi_geq(struct fuse_data *data, uint32_t abi_maj, uint32_t abi_min)
365 {
366 	return (data->fuse_libabi_major > abi_maj ||
367 	    (data->fuse_libabi_major == abi_maj &&
368 	     data->fuse_libabi_minor >= abi_min));
369 }
370 
371 struct fuse_data *fdata_alloc(struct cdev *dev, struct ucred *cred);
372 void fdata_trydestroy(struct fuse_data *data);
373 void fdata_set_dead(struct fuse_data *data);
374 
375 static inline bool
376 fdata_get_dead(struct fuse_data *data)
377 {
378 	return (data->dataflags & FSESS_DEAD);
379 }
380 
381 struct fuse_dispatcher {
382 	struct fuse_ticket    *tick;
383 	struct fuse_in_header *finh;
384 
385 	void    *indata;
386 	size_t   iosize;
387 	uint64_t nodeid;
388 	int      answ_stat;
389 	void    *answ;
390 };
391 
392 static inline void
393 fdisp_init(struct fuse_dispatcher *fdisp, size_t iosize)
394 {
395 	fdisp->iosize = iosize;
396 	fdisp->tick = NULL;
397 }
398 
399 static inline void
400 fdisp_destroy(struct fuse_dispatcher *fdisp)
401 {
402 	fuse_ticket_drop(fdisp->tick);
403 #ifdef INVARIANTS
404 	fdisp->tick = NULL;
405 #endif
406 }
407 
408 void fdisp_refresh(struct fuse_dispatcher *fdip);
409 
410 void fdisp_make(struct fuse_dispatcher *fdip, enum fuse_opcode op,
411     struct mount *mp, uint64_t nid, struct thread *td, struct ucred *cred);
412 
413 void fdisp_make_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
414     struct vnode *vp, struct thread *td, struct ucred *cred);
415 
416 void fdisp_refresh_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
417     struct vnode *vp, struct thread *td, struct ucred *cred);
418 
419 int fdisp_wait_answ(struct fuse_dispatcher *fdip);
420 
421 static inline int
422 fdisp_simple_putget_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
423     struct vnode *vp, struct thread *td, struct ucred *cred)
424 {
425 	fdisp_make_vp(fdip, op, vp, td, cred);
426 	return (fdisp_wait_answ(fdip));
427 }
428 
429 #endif /* _FUSE_IPC_H_ */
430