xref: /netbsd/sys/miscfs/kernfs/kernfs.h (revision 3c14d572)
1 /*	$NetBSD: kernfs.h,v 1.44 2020/04/07 08:14:42 jdolecek Exp $	*/
2 
3 /*
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software donated to Berkeley by
8  * Jan-Simon Pendry.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)kernfs.h	8.6 (Berkeley) 3/29/95
35  */
36 
37 #define	_PATH_KERNFS	"/kern"		/* Default mountpoint */
38 
39 #ifdef _KERNEL
40 #include <sys/queue.h>
41 #include <sys/tree.h>
42 #include <sys/mutex.h>
43 
44 /*
45  * The different types of node in a kernfs filesystem
46  */
47 typedef enum {
48 	KFSkern,		/* the filesystem itself (.) */
49 	KFSroot,		/* the filesystem root (..) */
50 	KFSnull,		/* none aplicable */
51 	KFStime,		/* time */
52 	KFSboottime,		/* boottime */
53 	KFSint,			/* integer */
54 	KFSstring,		/* string */
55 	KFShostname,		/* hostname */
56 	KFSavenrun,		/* loadavg */
57 	KFSdevice,		/* device file (rootdev/rrootdev) */
58 	KFSmsgbuf,		/* msgbuf */
59 	KFSsubdir,		/* directory */
60 	KFSlasttype,		/* last used type */
61 	KFSmaxtype = (1<<6) - 1	/* last possible type */
62 } kfstype;
63 
64 /*
65  * Control data for the kern file system.
66  */
67 struct kern_target {
68 	u_char		kt_type;
69 	u_char		kt_namlen;
70 	const char	*kt_name;
71 	void		*kt_data;
72 	kfstype		kt_tag;
73 	u_char		kt_vtype;
74 	mode_t		kt_mode;
75 };
76 
77 struct dyn_kern_target {
78 	struct kern_target		dkt_kt;
79 	SIMPLEQ_ENTRY(dyn_kern_target)	dkt_queue;
80 };
81 
82 struct kernfs_subdir {
83 	SIMPLEQ_HEAD(,dyn_kern_target)	ks_entries;
84 	unsigned int			ks_nentries;
85 	unsigned int			ks_dirs;
86 	const struct kern_target	*ks_parent;
87 };
88 
89 struct kernfs_node {
90 	LIST_ENTRY(kernfs_node) kfs_hash; /* hash chain */
91 	TAILQ_ENTRY(kernfs_node) kfs_list; /* flat list */
92 	struct vnode	*kfs_vnode;	/* vnode associated with this kernfs_node */
93 	kfstype		kfs_type;	/* type of kernfs node */
94 	mode_t		kfs_mode;	/* mode bits for stat() */
95 	long		kfs_fileno;	/* unique file id */
96 	const struct kern_target *kfs_kt;
97 	void		*kfs_v;		/* dynamic node private data */
98 	long		kfs_cookie;	/* fileno cookie */
99 };
100 
101 struct kernfs_mount {
102 	TAILQ_HEAD(, kernfs_node) nodelist;
103 	long fileno_cookie;
104 };
105 
106 #define UIO_MX	32
107 
108 #define KERNFS_FILENO(kt, typ, cookie) \
109 	((kt >= &kern_targets[0] && kt < &kern_targets[static_nkern_targets]) \
110 	    ? 2 + ((kt) - &kern_targets[0]) \
111 	      : (((cookie + 1) << 6) | (typ)))
112 #define KERNFS_TYPE_FILENO(typ, cookie) \
113 	(((cookie + 1) << 6) | (typ))
114 
115 #define VFSTOKERNFS(mp)	((struct kernfs_mount *)((mp)->mnt_data))
116 #define	VTOKERN(vp)	((struct kernfs_node *)(vp)->v_data)
117 #define KERNFSTOV(kfs)	((kfs)->kfs_vnode)
118 
119 #define KERNFS_MAXNAMLEN	255
120 
121 extern const struct kern_target kern_targets[];
122 extern int nkern_targets;
123 extern const int static_nkern_targets;
124 extern int (**kernfs_vnodeop_p)(void *);
125 extern int (**kernfs_specop_p)(void *);
126 extern struct vfsops kernfs_vfsops;
127 extern dev_t rrootdev;
128 extern kmutex_t kfs_lock;
129 
130 int kernfs_root(struct mount *, int, struct vnode **);
131 
132 /*
133  * Data types for the kernfs file operations.
134  */
135 typedef enum {
136 	KERNFS_XREAD,
137 	KERNFS_XWRITE,
138 	KERNFS_FILEOP_CLOSE,
139 	KERNFS_FILEOP_GETATTR,
140 	KERNFS_FILEOP_IOCTL,
141 	KERNFS_FILEOP_OPEN,
142 	KERNFS_FILEOP_READ,
143 	KERNFS_FILEOP_WRITE,
144 } kfsfileop;
145 
146 struct kernfs_fileop {
147 	kfstype				kf_type;
148 	kfsfileop			kf_fileop;
149 	union {
150 		int			(*_kf_vop)(void *);
151 		int			(*_kf_xread)
152 			(const struct kernfs_node *, char **, size_t);
153 		int			(*_kf_xwrite)
154 			(const struct kernfs_node *, char *, size_t);
155 	} _kf_opfn;
156 	SPLAY_ENTRY(kernfs_fileop)	kf_node;
157 };
158 
159 #define	kf_vop		_kf_opfn._kf_vop
160 #define	kf_xread	_kf_opfn._kf_xread
161 #define	kf_xwrite	_kf_opfn._kf_xwrite
162 
163 typedef struct kern_target kernfs_parentdir_t;
164 typedef struct dyn_kern_target kernfs_entry_t;
165 
166 /*
167  * Functions for adding kernfs datatypes and nodes.
168  */
169 kfstype kernfs_alloctype(int, const struct kernfs_fileop *);
170 #define	KERNFS_ALLOCTYPE(kf) kernfs_alloctype(sizeof((kf)) / \
171 	sizeof((kf)[0]), (kf))
172 #define	KERNFS_ALLOCENTRY(dkt, km_flags)				\
173 	dkt = (kernfs_entry_t *)kmem_zalloc(				\
174 		sizeof(struct dyn_kern_target), (km_flags))
175 #define	KERNFS_INITENTRY(dkt, type, name, data, tag, vtype, mode) do {	\
176 	(dkt)->dkt_kt.kt_type = (type);					\
177 	(dkt)->dkt_kt.kt_namlen = strlen((name));			\
178 	(dkt)->dkt_kt.kt_name = (name);					\
179 	(dkt)->dkt_kt.kt_data = (data);					\
180 	(dkt)->dkt_kt.kt_tag = (tag);					\
181 	(dkt)->dkt_kt.kt_vtype = (vtype);				\
182 	(dkt)->dkt_kt.kt_mode = (mode);					\
183 } while (/*CONSTCOND*/0)
184 #define	KERNFS_ENTOPARENTDIR(dkt) &(dkt)->dkt_kt
185 int kernfs_addentry(kernfs_parentdir_t *, kernfs_entry_t *);
186 
187 #ifdef IPSEC
188 __weak_extern(key_freesp)
189 __weak_extern(key_getspbyid)
190 __weak_extern(key_setdumpsa_spi)
191 __weak_extern(key_setdumpsp)
192 __weak_extern(satailq)
193 __weak_extern(sptailq)
194 #endif
195 
196 #endif /* _KERNEL */
197