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
71enum fuse_data_cache_mode {
72	FUSE_CACHE_UC,
73	FUSE_CACHE_WT,
74	FUSE_CACHE_WB,
75};
76
77struct fuse_iov {
78	void   *base;
79	size_t  len;
80	size_t  allocated_size;
81	int     credit;
82};
83
84void fiov_init(struct fuse_iov *fiov, size_t size);
85void fiov_teardown(struct fuse_iov *fiov);
86void fiov_refresh(struct fuse_iov *fiov);
87void 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
106struct fuse_ticket;
107struct fuse_data;
108
109typedef int fuse_handler_t(struct fuse_ticket *ftick, struct uio *uio);
110
111struct 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
140static inline struct fuse_iov *
141fticket_resp(struct fuse_ticket *ftick)
142{
143	return (&ftick->tk_aw_fiov);
144}
145
146static inline bool
147fticket_answered(struct fuse_ticket *ftick)
148{
149	mtx_assert(&ftick->tk_aw_mtx, MA_OWNED);
150	return (ftick->tk_flag & FT_ANSW);
151}
152
153static inline void
154fticket_set_answered(struct fuse_ticket *ftick)
155{
156	mtx_assert(&ftick->tk_aw_mtx, MA_OWNED);
157	ftick->tk_flag |= FT_ANSW;
158}
159
160static inline struct fuse_in_header*
161fticket_in_header(struct fuse_ticket *ftick)
162{
163	return (struct fuse_in_header *)(ftick->tk_ms_fiov.base);
164}
165
166static inline enum fuse_opcode
167fticket_opcode(struct fuse_ticket *ftick)
168{
169	return fticket_in_header(ftick)->opcode;
170}
171
172int fticket_pull(struct fuse_ticket *ftick, struct uio *uio);
173
174/*
175 * The data representing a FUSE session.
176 */
177struct 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	uint32_t			subtype;
208	char				volname[MAXPATHLEN];
209
210	struct selinfo			ks_rsel;
211
212	int				daemon_timeout;
213	int				linux_errnos;
214	unsigned			time_gran;
215	/* A bitmask of FUSE RPCs that are not implemented by the server */
216	uint64_t			notimpl;
217	/*
218	 * A bitmask of FUSE RPCs that are implemented by the server.
219	 * If an operation is not present in either notimpl or isimpl, then it
220	 * may be implemented by the server, but the kernel doesn't know for
221	 * sure.
222	 */
223	uint64_t			isimpl;
224	uint64_t			mnt_flag;
225	enum fuse_data_cache_mode	cache_mode;
226};
227
228#define FSESS_DEAD                0x0001 /* session is to be closed */
229#define FSESS_INITED              0x0004 /* session has been inited */
230#define FSESS_DAEMON_CAN_SPY      0x0010 /* let non-owners access this fs */
231                                         /* (and being observed by the daemon) */
232#define FSESS_PUSH_SYMLINKS_IN    0x0020 /* prefix absolute symlinks with mp */
233#define FSESS_DEFAULT_PERMISSIONS 0x0040 /* kernel does permission checking */
234#define FSESS_ASYNC_READ          0x1000 /* allow multiple reads of some file */
235#define FSESS_POSIX_LOCKS         0x2000 /* daemon supports POSIX locks */
236#define FSESS_EXPORT_SUPPORT      0x10000 /* daemon supports NFS-style lookups */
237#define FSESS_INTR                0x20000 /* interruptible mounts */
238#define FSESS_MNTOPTS_MASK	( \
239	FSESS_DAEMON_CAN_SPY | FSESS_PUSH_SYMLINKS_IN | \
240	FSESS_DEFAULT_PERMISSIONS | FSESS_INTR)
241
242extern int fuse_data_cache_mode;
243
244static inline struct fuse_data *
245fuse_get_mpdata(struct mount *mp)
246{
247	return mp->mnt_data;
248}
249
250static inline bool
251fsess_is_impl(struct mount *mp, int opcode)
252{
253	struct fuse_data *data = fuse_get_mpdata(mp);
254
255	return ((data->isimpl & (1ULL << opcode)) != 0);
256
257}
258
259static inline bool
260fsess_maybe_impl(struct mount *mp, int opcode)
261{
262	struct fuse_data *data = fuse_get_mpdata(mp);
263
264	return ((data->notimpl & (1ULL << opcode)) == 0);
265
266}
267
268static inline bool
269fsess_not_impl(struct mount *mp, int opcode)
270{
271	struct fuse_data *data = fuse_get_mpdata(mp);
272
273	return ((data->notimpl & (1ULL << opcode)) != 0);
274
275}
276
277static inline void
278fsess_set_impl(struct mount *mp, int opcode)
279{
280	struct fuse_data *data = fuse_get_mpdata(mp);
281
282	data->isimpl |= (1ULL << opcode);
283}
284
285static inline void
286fsess_set_notimpl(struct mount *mp, int opcode)
287{
288	struct fuse_data *data = fuse_get_mpdata(mp);
289
290	data->notimpl |= (1ULL << opcode);
291}
292
293static inline bool
294fsess_opt_datacache(struct mount *mp)
295{
296	struct fuse_data *data = fuse_get_mpdata(mp);
297
298	return (data->cache_mode != FUSE_CACHE_UC);
299}
300
301static inline bool
302fsess_opt_mmap(struct mount *mp)
303{
304	return (fsess_opt_datacache(mp));
305}
306
307static inline bool
308fsess_opt_writeback(struct mount *mp)
309{
310	struct fuse_data *data = fuse_get_mpdata(mp);
311
312	return (data->cache_mode == FUSE_CACHE_WB);
313}
314
315/* Insert a new upgoing message */
316static inline void
317fuse_ms_push(struct fuse_ticket *ftick)
318{
319	mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
320	refcount_acquire(&ftick->tk_refcount);
321	STAILQ_INSERT_TAIL(&ftick->tk_data->ms_head, ftick, tk_ms_link);
322	ftick->tk_data->ms_count++;
323}
324
325/* Insert a new upgoing message to the front of the queue */
326static inline void
327fuse_ms_push_head(struct fuse_ticket *ftick)
328{
329	mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
330	refcount_acquire(&ftick->tk_refcount);
331	STAILQ_INSERT_HEAD(&ftick->tk_data->ms_head, ftick, tk_ms_link);
332	ftick->tk_data->ms_count++;
333}
334
335static inline struct fuse_ticket *
336fuse_ms_pop(struct fuse_data *data)
337{
338	struct fuse_ticket *ftick = NULL;
339
340	mtx_assert(&data->ms_mtx, MA_OWNED);
341
342	if ((ftick = STAILQ_FIRST(&data->ms_head))) {
343		STAILQ_REMOVE_HEAD(&data->ms_head, tk_ms_link);
344		data->ms_count--;
345#ifdef INVARIANTS
346		MPASS(data->ms_count >= 0);
347		ftick->tk_ms_link.stqe_next = NULL;
348#endif
349	}
350
351	return (ftick);
352}
353
354static inline void
355fuse_aw_push(struct fuse_ticket *ftick)
356{
357	mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
358	refcount_acquire(&ftick->tk_refcount);
359	TAILQ_INSERT_TAIL(&ftick->tk_data->aw_head, ftick, tk_aw_link);
360}
361
362static inline void
363fuse_aw_remove(struct fuse_ticket *ftick)
364{
365	mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
366	TAILQ_REMOVE(&ftick->tk_data->aw_head, ftick, tk_aw_link);
367#ifdef INVARIANTS
368	ftick->tk_aw_link.tqe_next = NULL;
369	ftick->tk_aw_link.tqe_prev = NULL;
370#endif
371}
372
373static inline struct fuse_ticket *
374fuse_aw_pop(struct fuse_data *data)
375{
376	struct fuse_ticket *ftick;
377
378	mtx_assert(&data->aw_mtx, MA_OWNED);
379
380	if ((ftick = TAILQ_FIRST(&data->aw_head)) != NULL)
381		fuse_aw_remove(ftick);
382
383	return (ftick);
384}
385
386struct fuse_ticket *fuse_ticket_fetch(struct fuse_data *data);
387int fuse_ticket_drop(struct fuse_ticket *ftick);
388void fuse_insert_callback(struct fuse_ticket *ftick, fuse_handler_t *handler);
389void fuse_insert_message(struct fuse_ticket *ftick, bool irq);
390
391static inline bool
392fuse_libabi_geq(struct fuse_data *data, uint32_t abi_maj, uint32_t abi_min)
393{
394	return (data->fuse_libabi_major > abi_maj ||
395	    (data->fuse_libabi_major == abi_maj &&
396	     data->fuse_libabi_minor >= abi_min));
397}
398
399struct fuse_data *fdata_alloc(struct cdev *dev, struct ucred *cred);
400void fdata_trydestroy(struct fuse_data *data);
401void fdata_set_dead(struct fuse_data *data);
402
403static inline bool
404fdata_get_dead(struct fuse_data *data)
405{
406	return (data->dataflags & FSESS_DEAD);
407}
408
409struct fuse_dispatcher {
410	struct fuse_ticket    *tick;
411	struct fuse_in_header *finh;
412
413	void    *indata;
414	size_t   iosize;
415	uint64_t nodeid;
416	int      answ_stat;
417	void    *answ;
418};
419
420static inline void
421fdisp_init(struct fuse_dispatcher *fdisp, size_t iosize)
422{
423	fdisp->iosize = iosize;
424	fdisp->tick = NULL;
425}
426
427static inline void
428fdisp_destroy(struct fuse_dispatcher *fdisp)
429{
430	fuse_ticket_drop(fdisp->tick);
431#ifdef INVARIANTS
432	fdisp->tick = NULL;
433#endif
434}
435
436void fdisp_refresh(struct fuse_dispatcher *fdip);
437
438void fdisp_make(struct fuse_dispatcher *fdip, enum fuse_opcode op,
439    struct mount *mp, uint64_t nid, struct thread *td, struct ucred *cred);
440
441void fdisp_make_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
442    struct vnode *vp, struct thread *td, struct ucred *cred);
443
444void fdisp_refresh_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
445    struct vnode *vp, struct thread *td, struct ucred *cred);
446
447int fdisp_wait_answ(struct fuse_dispatcher *fdip);
448
449static inline int
450fdisp_simple_putget_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
451    struct vnode *vp, struct thread *td, struct ucred *cred)
452{
453	fdisp_make_vp(fdip, op, vp, td, cred);
454	return (fdisp_wait_answ(fdip));
455}
456
457#endif /* _FUSE_IPC_H_ */
458