xref: /freebsd/sys/fs/pseudofs/pseudofs.h (revision 2b743a9e9ddc6736208dc8ca1ce06ce64ad20a19)
1 /*-
2  * Copyright (c) 2001 Dag-Erling Co�dan Sm�rgrav
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer
10  *    in this position and unchanged.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  *      $FreeBSD$
29  */
30 
31 #ifndef _PSEUDOFS_H_INCLUDED
32 #define _PSEUDOFS_H_INCLUDED
33 
34 /*
35  * Opaque structures
36  */
37 struct mntarg;
38 struct mount;
39 struct nameidata;
40 struct proc;
41 struct sbuf;
42 struct statfs;
43 struct thread;
44 struct uio;
45 struct vfsconf;
46 struct vnode;
47 
48 /*
49  * Limits and constants
50  */
51 #define PFS_NAMELEN		24
52 #define PFS_FSNAMELEN		16	/* equal to MFSNAMELEN */
53 #define PFS_DELEN		(8 + PFS_NAMELEN)
54 
55 typedef enum {
56 	pfstype_none = 0,
57 	pfstype_root,
58 	pfstype_dir,
59 	pfstype_this,
60 	pfstype_parent,
61 	pfstype_file,
62 	pfstype_symlink,
63 	pfstype_procdir
64 } pfs_type_t;
65 
66 /*
67  * Flags
68  */
69 #define PFS_RD		0x0001	/* readable */
70 #define PFS_WR		0x0002	/* writeable */
71 #define PFS_RDWR	(PFS_RD|PFS_WR)
72 #define PFS_RAWRD	0x0004	/* raw reader */
73 #define	PFS_RAWWR	0x0008	/* raw writer */
74 #define PFS_RAW		(PFS_RAWRD|PFS_RAWWR)
75 #define PFS_PROCDEP	0x0010	/* process-dependent */
76 #define PFS_DISABLED	0x8000	/* node is disabled */
77 
78 /*
79  * Data structures
80  */
81 struct pfs_info;
82 struct pfs_node;
83 struct pfs_bitmap;
84 
85 /*
86  * Init / uninit callback
87  */
88 #define PFS_INIT_ARGS \
89 	struct pfs_info *pi, struct vfsconf *vfc
90 #define PFS_INIT_PROTO(name) \
91 	int name(PFS_INIT_ARGS);
92 typedef int (*pfs_init_t)(PFS_INIT_ARGS);
93 
94 /*
95  * Filler callback
96  */
97 #define PFS_FILL_ARGS \
98 	struct thread *td, struct proc *p, struct pfs_node *pn, \
99 	struct sbuf *sb, struct uio *uio
100 #define PFS_FILL_PROTO(name) \
101 	int name(PFS_FILL_ARGS);
102 typedef int (*pfs_fill_t)(PFS_FILL_ARGS);
103 
104 /*
105  * Attribute callback
106  */
107 struct vattr;
108 #define PFS_ATTR_ARGS \
109 	struct thread *td, struct proc *p, struct pfs_node *pn, \
110 	struct vattr *vap
111 #define PFS_ATTR_PROTO(name) \
112 	int name(PFS_ATTR_ARGS);
113 typedef int (*pfs_attr_t)(PFS_ATTR_ARGS);
114 
115 struct pfs_bitmap;		/* opaque */
116 
117 /*
118  * Visibility callback
119  */
120 #define PFS_VIS_ARGS \
121 	struct thread *td, struct proc *p, struct pfs_node *pn
122 #define PFS_VIS_PROTO(name) \
123 	int name(PFS_VIS_ARGS);
124 typedef int (*pfs_vis_t)(PFS_VIS_ARGS);
125 
126 /*
127  * Ioctl callback
128  */
129 #define PFS_IOCTL_ARGS \
130 	struct thread *td, struct proc *p, struct pfs_node *pn, \
131 	unsigned long cmd, void *data
132 #define PFS_IOCTL_PROTO(name) \
133 	int name(PFS_IOCTL_ARGS);
134 typedef int (*pfs_ioctl_t)(PFS_IOCTL_ARGS);
135 
136 /*
137  * Getextattr callback
138  */
139 #define PFS_GETEXTATTR_ARGS \
140 	struct thread *td, struct proc *p, struct pfs_node *pn, \
141 	int attrnamespace, const char *name, struct uio *uio,	\
142 	size_t *size, struct ucred *cred
143 #define PFS_GETEXTATTR_PROTO(name) \
144 	int name(PFS_GETEXTATTR_ARGS);
145 struct ucred;
146 typedef int (*pfs_getextattr_t)(PFS_GETEXTATTR_ARGS);
147 
148 /*
149  * Last-close callback
150  */
151 #define PFS_CLOSE_ARGS \
152 	struct thread *td, struct proc *p, struct pfs_node *pn
153 #define PFS_CLOSE_PROTO(name) \
154 	int name(PFS_CLOSE_ARGS);
155 typedef int (*pfs_close_t)(PFS_CLOSE_ARGS);
156 
157 /*
158  * pfs_info: describes a pseudofs instance
159  */
160 struct pfs_info {
161 	char			 pi_name[PFS_FSNAMELEN];
162 	pfs_init_t		 pi_init;
163 	pfs_init_t		 pi_uninit;
164 	/* members below this line aren't initialized */
165 	struct pfs_node		*pi_root;
166 	/* currently, the mutex is only used to protect the bitmap */
167 	struct mtx		 pi_mutex;
168 	struct unrhdr		*pi_unrhdr;
169 };
170 
171 /*
172  * pfs_node: describes a node (file or directory) within a pseudofs
173  */
174 struct pfs_node {
175 	char			 pn_name[PFS_NAMELEN];
176 	pfs_type_t		 pn_type;
177 	union {
178 		void		*_pn_dummy;
179 		pfs_fill_t	 _pn_func;
180 		struct pfs_node	*_pn_nodes;
181 	} u1;
182 #define pn_func		u1._pn_func
183 #define pn_nodes	u1._pn_nodes
184 	pfs_ioctl_t		 pn_ioctl;
185 	pfs_close_t		 pn_close;
186 	pfs_attr_t		 pn_attr;
187 	pfs_vis_t		 pn_vis;
188 	pfs_getextattr_t	 pn_getextattr;
189 	void			*pn_data;
190 	int			 pn_flags;
191 
192 	struct pfs_info		*pn_info;
193 	struct pfs_node		*pn_parent;
194 	struct pfs_node		*pn_next;
195 	u_int32_t		 pn_fileno;
196 };
197 
198 /*
199  * VFS interface
200  */
201 int		 pfs_mount	(struct pfs_info *pi, struct mount *mp,
202 				 struct thread *td);
203 int		 pfs_cmount	(struct mntarg *ma, void *data, int flags,
204 				 struct thread *td);
205 int		 pfs_unmount	(struct mount *mp, int mntflags,
206 				 struct thread *td);
207 int		 pfs_root	(struct mount *mp, int flags,
208 				 struct vnode **vpp, struct thread *td);
209 int		 pfs_statfs	(struct mount *mp, struct statfs *sbp,
210 				 struct thread *td);
211 int		 pfs_init	(struct pfs_info *pi, struct vfsconf *vfc);
212 int		 pfs_uninit	(struct pfs_info *pi, struct vfsconf *vfc);
213 
214 /*
215  * Directory structure construction and manipulation
216  */
217 struct pfs_node	*pfs_create_dir	(struct pfs_node *parent, const char *name,
218 				 pfs_attr_t attr, pfs_vis_t vis, int flags);
219 struct pfs_node	*pfs_create_file(struct pfs_node *parent, const char *name,
220 				 pfs_fill_t fill, pfs_attr_t attr,
221 				 pfs_vis_t vis, int flags);
222 struct pfs_node	*pfs_create_link(struct pfs_node *parent, const char *name,
223 				 pfs_fill_t fill, pfs_attr_t attr,
224 				 pfs_vis_t vis, int flags);
225 struct pfs_node	*pfs_find_node	(struct pfs_node *parent, const char *name);
226 int		 pfs_disable	(struct pfs_node *pn);
227 int		 pfs_enable	(struct pfs_node *pn);
228 int		 pfs_destroy	(struct pfs_node *pn);
229 
230 /*
231  * Now for some initialization magic...
232  */
233 #define PSEUDOFS(name, version)						\
234 									\
235 static struct pfs_info name##_info = {					\
236 	#name,								\
237 	name##_init,							\
238 	name##_uninit,							\
239 };									\
240 									\
241 static int								\
242 _##name##_mount(struct mount *mp, struct thread *td) {			\
243 	return pfs_mount(&name##_info, mp, td);				\
244 }									\
245 									\
246 static int								\
247 _##name##_init(struct vfsconf *vfc) {					\
248 	return pfs_init(&name##_info, vfc);				\
249 }									\
250 									\
251 static int								\
252 _##name##_uninit(struct vfsconf *vfc) {					\
253 	return pfs_uninit(&name##_info, vfc);				\
254 }									\
255 									\
256 static struct vfsops name##_vfsops = {					\
257 	.vfs_cmount =		pfs_cmount,				\
258 	.vfs_init =		_##name##_init,				\
259 	.vfs_mount =		_##name##_mount,			\
260 	.vfs_root =		pfs_root,				\
261 	.vfs_statfs =		pfs_statfs,				\
262 	.vfs_uninit =		_##name##_uninit,			\
263 	.vfs_unmount =		pfs_unmount,				\
264 };									\
265 VFS_SET(name##_vfsops, name, VFCF_SYNTHETIC);				\
266 MODULE_VERSION(name, version);						\
267 MODULE_DEPEND(name, pseudofs, 1, 1, 1);
268 
269 #endif
270