1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2001 Dag-Erling Co��dan Sm��rgrav
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
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer
12 *    in this position and unchanged.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 *      $FreeBSD$
31 */
32
33#ifndef _PSEUDOFS_H_INCLUDED
34#define _PSEUDOFS_H_INCLUDED
35
36#include <sys/jail.h>
37
38/*
39 * Opaque structures
40 */
41struct mntarg;
42struct mount;
43struct nameidata;
44struct proc;
45struct sbuf;
46struct statfs;
47struct thread;
48struct uio;
49struct vfsconf;
50struct vnode;
51
52/*
53 * Limits and constants
54 */
55#define PFS_NAMELEN		128
56#define PFS_FSNAMELEN		16	/* equal to MFSNAMELEN */
57#define PFS_DELEN		(offsetof(struct dirent, d_name) + PFS_NAMELEN)
58
59typedef enum {
60	pfstype_none = 0,
61	pfstype_root,
62	pfstype_dir,
63	pfstype_this,
64	pfstype_parent,
65	pfstype_file,
66	pfstype_symlink,
67	pfstype_procdir
68} pfs_type_t;
69
70/*
71 * Flags
72 */
73#define PFS_RD		0x0001	/* readable */
74#define PFS_WR		0x0002	/* writeable */
75#define PFS_RDWR	(PFS_RD|PFS_WR)
76#define PFS_RAWRD	0x0004	/* raw reader */
77#define	PFS_RAWWR	0x0008	/* raw writer */
78#define PFS_RAW		(PFS_RAWRD|PFS_RAWWR)
79#define PFS_PROCDEP	0x0010	/* process-dependent */
80#define PFS_NOWAIT	0x0020 /* allow malloc to fail */
81#define PFS_AUTODRAIN	0x0040	/* sbuf_print can sleep to drain */
82
83/*
84 * Data structures
85 */
86struct pfs_info;
87struct pfs_node;
88
89/*
90 * Init / uninit callback
91 */
92#define PFS_INIT_ARGS \
93	struct pfs_info *pi, struct vfsconf *vfc
94#define PFS_INIT_ARGNAMES \
95	pi, vfc
96#define PFS_INIT_PROTO(name) \
97	int name(PFS_INIT_ARGS);
98typedef int (*pfs_init_t)(PFS_INIT_ARGS);
99
100/*
101 * Filler callback
102 * Called with proc held but unlocked
103 */
104#define PFS_FILL_ARGS \
105	struct thread *td, struct proc *p, struct pfs_node *pn, \
106	struct sbuf *sb, struct uio *uio
107#define PFS_FILL_ARGNAMES \
108	td, p, pn, sb, uio
109#define PFS_FILL_PROTO(name) \
110	int name(PFS_FILL_ARGS);
111typedef int (*pfs_fill_t)(PFS_FILL_ARGS);
112
113/*
114 * Attribute callback
115 * Called with proc locked
116 */
117struct vattr;
118#define PFS_ATTR_ARGS \
119	struct thread *td, struct proc *p, struct pfs_node *pn, \
120	struct vattr *vap
121#define PFS_ATTR_ARGNAMES \
122	td, p, pn, vap
123#define PFS_ATTR_PROTO(name) \
124	int name(PFS_ATTR_ARGS);
125typedef int (*pfs_attr_t)(PFS_ATTR_ARGS);
126
127/*
128 * Visibility callback
129 * Called with proc locked
130 */
131#define PFS_VIS_ARGS \
132	struct thread *td, struct proc *p, struct pfs_node *pn
133#define PFS_VIS_ARGNAMES \
134	td, p, pn
135#define PFS_VIS_PROTO(name) \
136	int name(PFS_VIS_ARGS);
137typedef int (*pfs_vis_t)(PFS_VIS_ARGS);
138
139/*
140 * Ioctl callback
141 * Called with proc locked
142 */
143#define PFS_IOCTL_ARGS \
144	struct thread *td, struct proc *p, struct pfs_node *pn, \
145	unsigned long cmd, void *data
146#define PFS_IOCTL_ARGNAMES \
147	td, p, pn, cmd, data
148#define PFS_IOCTL_PROTO(name) \
149	int name(PFS_IOCTL_ARGS);
150typedef int (*pfs_ioctl_t)(PFS_IOCTL_ARGS);
151
152/*
153 * Getextattr callback
154 * Called with proc locked
155 */
156#define PFS_GETEXTATTR_ARGS \
157	struct thread *td, struct proc *p, struct pfs_node *pn, \
158	int attrnamespace, const char *name, struct uio *uio,	\
159	size_t *size, struct ucred *cred
160#define PFS_GETEXTATTR_ARGNAMES \
161	td, p, pn, attrnamespace, name, uio, size, cred
162#define PFS_GETEXTATTR_PROTO(name) \
163	int name(PFS_GETEXTATTR_ARGS);
164struct ucred;
165typedef int (*pfs_getextattr_t)(PFS_GETEXTATTR_ARGS);
166
167/*
168 * Last-close callback
169 * Called with proc locked
170 */
171#define PFS_CLOSE_ARGS \
172	struct thread *td, struct proc *p, struct pfs_node *pn
173#define PFS_CLOSE_ARGNAMES \
174	td, p, pn
175#define PFS_CLOSE_PROTO(name) \
176	int name(PFS_CLOSE_ARGS);
177typedef int (*pfs_close_t)(PFS_CLOSE_ARGS);
178
179/*
180 * Destroy callback
181 */
182#define PFS_DESTROY_ARGS \
183	struct pfs_node *pn
184#define PFS_DESTROY_ARGNAMES \
185	pn
186#define PFS_DESTROY_PROTO(name) \
187	int name(PFS_DESTROY_ARGS);
188typedef int (*pfs_destroy_t)(PFS_DESTROY_ARGS);
189
190/*
191 * pfs_info: describes a pseudofs instance
192 *
193 * The pi_mutex is only used to avoid using the global subr_unit lock
194 * for unrhdr.  The rest of struct pfs_info is only modified during
195 * vfs_init() and vfs_uninit() of the consumer filesystem.
196 */
197struct pfs_info {
198	char			 pi_name[PFS_FSNAMELEN];
199	pfs_init_t		 pi_init;
200	pfs_init_t		 pi_uninit;
201
202	/* members below this line are initialized at run time */
203	struct pfs_node		*pi_root;
204	struct mtx		 pi_mutex;
205	struct unrhdr		*pi_unrhdr;
206};
207
208/*
209 * pfs_node: describes a node (file or directory) within a pseudofs
210 *
211 * - Fields marked (o) are protected by the node's own mutex.
212 * - Fields marked (p) are protected by the node's parent's mutex.
213 * - Remaining fields are not protected by any lock and are assumed to be
214 *   immutable once the node has been created.
215 *
216 * To prevent deadlocks, if a node's mutex is to be held at the same time
217 * as its parent's (e.g. when adding or removing nodes to a directory),
218 * the parent's mutex must always be acquired first.  Unfortunately, this
219 * is not enforcable by WITNESS.
220 */
221struct pfs_node {
222	char			 pn_name[PFS_NAMELEN];
223	pfs_type_t		 pn_type;
224	int			 pn_flags;
225	struct mtx		 pn_mutex;
226	void			*pn_data;		/* (o) */
227
228	pfs_fill_t		 pn_fill;
229	pfs_ioctl_t		 pn_ioctl;
230	pfs_close_t		 pn_close;
231	pfs_attr_t		 pn_attr;
232	pfs_vis_t		 pn_vis;
233	pfs_getextattr_t	 pn_getextattr;
234	pfs_destroy_t		 pn_destroy;
235
236	struct pfs_info		*pn_info;
237	u_int32_t		 pn_fileno;		/* (o) */
238
239	struct pfs_node		*pn_parent;		/* (o) */
240	struct pfs_node		*pn_nodes;		/* (o) */
241	struct pfs_node		*pn_last_node;		/* (o) */
242	struct pfs_node		*pn_next;		/* (p) */
243};
244
245/*
246 * VFS interface
247 */
248int		 pfs_mount	(struct pfs_info *pi, struct mount *mp);
249int		 pfs_cmount	(struct mntarg *ma, void *data, uint64_t flags);
250int		 pfs_unmount	(struct mount *mp, int mntflags);
251int		 pfs_root	(struct mount *mp, int flags,
252				 struct vnode **vpp);
253int		 pfs_statfs	(struct mount *mp, struct statfs *sbp);
254int		 pfs_init	(struct pfs_info *pi, struct vfsconf *vfc);
255int		 pfs_uninit	(struct pfs_info *pi, struct vfsconf *vfc);
256
257/*
258 * Directory structure construction and manipulation
259 */
260struct pfs_node	*pfs_create_dir	(struct pfs_node *parent, const char *name,
261				 pfs_attr_t attr, pfs_vis_t vis,
262				 pfs_destroy_t destroy, int flags);
263struct pfs_node	*pfs_create_file(struct pfs_node *parent, const char *name,
264				 pfs_fill_t fill, pfs_attr_t attr,
265				 pfs_vis_t vis, pfs_destroy_t destroy,
266				 int flags);
267struct pfs_node	*pfs_create_link(struct pfs_node *parent, const char *name,
268				 pfs_fill_t fill, pfs_attr_t attr,
269				 pfs_vis_t vis, pfs_destroy_t destroy,
270				 int flags);
271struct pfs_node	*pfs_find_node	(struct pfs_node *parent, const char *name);
272void		 pfs_purge	(struct pfs_node *pn);
273int		 pfs_destroy	(struct pfs_node *pn);
274
275/*
276 * Now for some initialization magic...
277 */
278#define PSEUDOFS(name, version, flags)					\
279									\
280static struct pfs_info name##_info = {					\
281	#name,								\
282	name##_init,							\
283	name##_uninit,							\
284};									\
285									\
286static int								\
287_##name##_mount(struct mount *mp) {					\
288	return (pfs_mount(&name##_info, mp));				\
289}									\
290									\
291static int								\
292_##name##_init(struct vfsconf *vfc) {					\
293	return (pfs_init(&name##_info, vfc));				\
294}									\
295									\
296static int								\
297_##name##_uninit(struct vfsconf *vfc) {					\
298	return (pfs_uninit(&name##_info, vfc));				\
299}									\
300									\
301static struct vfsops name##_vfsops = {					\
302	.vfs_cmount =		pfs_cmount,				\
303	.vfs_init =		_##name##_init,				\
304	.vfs_mount =		_##name##_mount,			\
305	.vfs_root =		pfs_root,				\
306	.vfs_statfs =		pfs_statfs,				\
307	.vfs_uninit =		_##name##_uninit,			\
308	.vfs_unmount =		pfs_unmount,				\
309};									\
310VFS_SET(name##_vfsops, name, VFCF_SYNTHETIC | flags);			\
311MODULE_VERSION(name, version);						\
312MODULE_DEPEND(name, pseudofs, 1, 1, 1);
313
314#endif
315