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 */
 47typedef 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 */
 67struct 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
 77struct dyn_kern_target {
 78	struct kern_target		dkt_kt;
 79	SIMPLEQ_ENTRY(dyn_kern_target)	dkt_queue;
 80};
 81
 82struct 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
 89struct 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
101struct 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
121extern const struct kern_target kern_targets[];
122extern int nkern_targets;
123extern const int static_nkern_targets;
124extern int (**kernfs_vnodeop_p)(void *);
125extern int (**kernfs_specop_p)(void *);
126extern struct vfsops kernfs_vfsops;
127extern dev_t rrootdev;
128extern kmutex_t kfs_lock;
129
130int kernfs_root(struct mount *, int, struct vnode **);
131
132/*
133 * Data types for the kernfs file operations.
134 */
135typedef 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
146struct 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
163typedef struct kern_target kernfs_parentdir_t;
164typedef struct dyn_kern_target kernfs_entry_t;
165
166/*
167 * Functions for adding kernfs datatypes and nodes.
168 */
169kfstype 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
185int 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 */