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      1 /*	$NetBSD: kernfs.h,v 1.45 2025/06/27 21:36:25 andvar 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 applicable */
     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