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	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
147static inline struct fuse_iov *
148fticket_resp(struct fuse_ticket *ftick)
149{
150	return (&ftick->tk_aw_fiov);
151}
152
153static inline bool
154fticket_answered(struct fuse_ticket *ftick)
155{
156	mtx_assert(&ftick->tk_aw_mtx, MA_OWNED);
157	return (ftick->tk_flag & FT_ANSW);
158}
159
160static inline void
161fticket_set_answered(struct fuse_ticket *ftick)
162{
163	mtx_assert(&ftick->tk_aw_mtx, MA_OWNED);
164	ftick->tk_flag |= FT_ANSW;
165}
166
167static inline struct fuse_in_header*
168fticket_in_header(struct fuse_ticket *ftick)
169{
170	return (struct fuse_in_header *)(ftick->tk_ms_fiov.base);
171}
172
173static inline enum fuse_opcode
174fticket_opcode(struct fuse_ticket *ftick)
175{
176	return fticket_in_header(ftick)->opcode;
177}
178
179int fticket_pull(struct fuse_ticket *ftick, struct uio *uio);
180
181/*
182 * The data representing a FUSE session.
183 */
184struct 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	unsigned			time_gran;
221	uint64_t			notimpl;
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_MNTOPTS_MASK	( \
237	FSESS_DAEMON_CAN_SPY | FSESS_PUSH_SYMLINKS_IN | \
238	FSESS_DEFAULT_PERMISSIONS | FSESS_INTR)
239
240extern int fuse_data_cache_mode;
241
242static inline struct fuse_data *
243fuse_get_mpdata(struct mount *mp)
244{
245	return mp->mnt_data;
246}
247
248static inline bool
249fsess_isimpl(struct mount *mp, int opcode)
250{
251	struct fuse_data *data = fuse_get_mpdata(mp);
252
253	return ((data->notimpl & (1ULL << opcode)) == 0);
254
255}
256static inline void
257fsess_set_notimpl(struct mount *mp, int opcode)
258{
259	struct fuse_data *data = fuse_get_mpdata(mp);
260
261	data->notimpl |= (1ULL << opcode);
262}
263
264static inline bool
265fsess_opt_datacache(struct mount *mp)
266{
267	struct fuse_data *data = fuse_get_mpdata(mp);
268
269	return (data->cache_mode != FUSE_CACHE_UC);
270}
271
272static inline bool
273fsess_opt_mmap(struct mount *mp)
274{
275	return (fsess_opt_datacache(mp));
276}
277
278static inline bool
279fsess_opt_writeback(struct mount *mp)
280{
281	struct fuse_data *data = fuse_get_mpdata(mp);
282
283	return (data->cache_mode == FUSE_CACHE_WB);
284}
285
286/* Insert a new upgoing message */
287static inline void
288fuse_ms_push(struct fuse_ticket *ftick)
289{
290	mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
291	refcount_acquire(&ftick->tk_refcount);
292	STAILQ_INSERT_TAIL(&ftick->tk_data->ms_head, ftick, tk_ms_link);
293	ftick->tk_data->ms_count++;
294}
295
296/* Insert a new upgoing message to the front of the queue */
297static inline void
298fuse_ms_push_head(struct fuse_ticket *ftick)
299{
300	mtx_assert(&ftick->tk_data->ms_mtx, MA_OWNED);
301	refcount_acquire(&ftick->tk_refcount);
302	STAILQ_INSERT_HEAD(&ftick->tk_data->ms_head, ftick, tk_ms_link);
303	ftick->tk_data->ms_count++;
304}
305
306static inline struct fuse_ticket *
307fuse_ms_pop(struct fuse_data *data)
308{
309	struct fuse_ticket *ftick = NULL;
310
311	mtx_assert(&data->ms_mtx, MA_OWNED);
312
313	if ((ftick = STAILQ_FIRST(&data->ms_head))) {
314		STAILQ_REMOVE_HEAD(&data->ms_head, tk_ms_link);
315		data->ms_count--;
316#ifdef INVARIANTS
317		MPASS(data->ms_count >= 0);
318		ftick->tk_ms_link.stqe_next = NULL;
319#endif
320	}
321
322	return (ftick);
323}
324
325static inline void
326fuse_aw_push(struct fuse_ticket *ftick)
327{
328	mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
329	refcount_acquire(&ftick->tk_refcount);
330	TAILQ_INSERT_TAIL(&ftick->tk_data->aw_head, ftick, tk_aw_link);
331}
332
333static inline void
334fuse_aw_remove(struct fuse_ticket *ftick)
335{
336	mtx_assert(&ftick->tk_data->aw_mtx, MA_OWNED);
337	TAILQ_REMOVE(&ftick->tk_data->aw_head, ftick, tk_aw_link);
338#ifdef INVARIANTS
339	ftick->tk_aw_link.tqe_next = NULL;
340	ftick->tk_aw_link.tqe_prev = NULL;
341#endif
342}
343
344static inline struct fuse_ticket *
345fuse_aw_pop(struct fuse_data *data)
346{
347	struct fuse_ticket *ftick;
348
349	mtx_assert(&data->aw_mtx, MA_OWNED);
350
351	if ((ftick = TAILQ_FIRST(&data->aw_head)) != NULL)
352		fuse_aw_remove(ftick);
353
354	return (ftick);
355}
356
357struct fuse_ticket *fuse_ticket_fetch(struct fuse_data *data);
358int fuse_ticket_drop(struct fuse_ticket *ftick);
359void fuse_insert_callback(struct fuse_ticket *ftick, fuse_handler_t *handler);
360void fuse_insert_message(struct fuse_ticket *ftick, bool irq);
361
362static inline bool
363fuse_libabi_geq(struct fuse_data *data, uint32_t abi_maj, uint32_t abi_min)
364{
365	return (data->fuse_libabi_major > abi_maj ||
366	    (data->fuse_libabi_major == abi_maj &&
367	     data->fuse_libabi_minor >= abi_min));
368}
369
370struct fuse_data *fdata_alloc(struct cdev *dev, struct ucred *cred);
371void fdata_trydestroy(struct fuse_data *data);
372void fdata_set_dead(struct fuse_data *data);
373
374static inline bool
375fdata_get_dead(struct fuse_data *data)
376{
377	return (data->dataflags & FSESS_DEAD);
378}
379
380struct fuse_dispatcher {
381	struct fuse_ticket    *tick;
382	struct fuse_in_header *finh;
383
384	void    *indata;
385	size_t   iosize;
386	uint64_t nodeid;
387	int      answ_stat;
388	void    *answ;
389};
390
391static inline void
392fdisp_init(struct fuse_dispatcher *fdisp, size_t iosize)
393{
394	fdisp->iosize = iosize;
395	fdisp->tick = NULL;
396}
397
398static inline void
399fdisp_destroy(struct fuse_dispatcher *fdisp)
400{
401	fuse_ticket_drop(fdisp->tick);
402#ifdef INVARIANTS
403	fdisp->tick = NULL;
404#endif
405}
406
407void fdisp_refresh(struct fuse_dispatcher *fdip);
408
409void fdisp_make(struct fuse_dispatcher *fdip, enum fuse_opcode op,
410    struct mount *mp, uint64_t nid, struct thread *td, struct ucred *cred);
411
412void fdisp_make_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
413    struct vnode *vp, struct thread *td, struct ucred *cred);
414
415void fdisp_refresh_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
416    struct vnode *vp, struct thread *td, struct ucred *cred);
417
418int fdisp_wait_answ(struct fuse_dispatcher *fdip);
419
420static inline int
421fdisp_simple_putget_vp(struct fuse_dispatcher *fdip, enum fuse_opcode op,
422    struct vnode *vp, struct thread *td, struct ucred *cred)
423{
424	fdisp_make_vp(fdip, op, vp, td, cred);
425	return (fdisp_wait_answ(fdip));
426}
427
428#endif /* _FUSE_IPC_H_ */
429