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

/*
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software donated to Berkeley by
 * Jan-Simon Pendry.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)kernfs.h    8.6 (Berkeley) 3/29/95
 */

#define _PATH_KERNFS    "/kern"         /* Default mountpoint */

#ifdef _KERNEL
#include <sys/queue.h>
#include <sys/tree.h>
#include <sys/mutex.h>

/*
 * The different types of node in a kernfs filesystem
 */
typedef enum {
        KFSkern,                /* the filesystem itself (.) */
        KFSroot,                /* the filesystem root (..) */
        KFSnull,                /* none applicable */
        KFStime,                /* time */
        KFSboottime,            /* boottime */
        KFSint,                 /* integer */
        KFSstring,              /* string */
        KFShostname,            /* hostname */
        KFSavenrun,             /* loadavg */
        KFSdevice,              /* device file (rootdev/rrootdev) */
        KFSmsgbuf,              /* msgbuf */
        KFSsubdir,              /* directory */
        KFSlasttype,            /* last used type */
        KFSmaxtype = (1<<6) - 1 /* last possible type */
} kfstype;

/*
 * Control data for the kern file system.
 */
struct kern_target {
        u_char          kt_type;
        u_char          kt_namlen;
        const char      *kt_name;
        void            *kt_data;
        kfstype         kt_tag;
        u_char          kt_vtype;
        mode_t          kt_mode;
};

struct dyn_kern_target {
        struct kern_target              dkt_kt;
        SIMPLEQ_ENTRY(dyn_kern_target)  dkt_queue;
};

struct kernfs_subdir {
        SIMPLEQ_HEAD(,dyn_kern_target)  ks_entries;
        unsigned int                    ks_nentries;
        unsigned int                    ks_dirs;
        const struct kern_target        *ks_parent;
};

struct kernfs_node {
        LIST_ENTRY(kernfs_node) kfs_hash; /* hash chain */
        TAILQ_ENTRY(kernfs_node) kfs_list; /* flat list */
        struct vnode    *kfs_vnode;     /* vnode associated with this kernfs_node */
        kfstype         kfs_type;       /* type of kernfs node */
        mode_t          kfs_mode;       /* mode bits for stat() */
        long            kfs_fileno;     /* unique file id */
        const struct kern_target *kfs_kt;
        void            *kfs_v;         /* dynamic node private data */
        long            kfs_cookie;     /* fileno cookie */
};

struct kernfs_mount {
        TAILQ_HEAD(, kernfs_node) nodelist;
        long fileno_cookie;
};

#define UIO_MX  32

#define KERNFS_FILENO(kt, typ, cookie) \
        ((kt >= &kern_targets[0] && kt < &kern_targets[static_nkern_targets]) \
            ? 2 + ((kt) - &kern_targets[0]) \
              : (((cookie + 1) << 6) | (typ)))
#define KERNFS_TYPE_FILENO(typ, cookie) \
        (((cookie + 1) << 6) | (typ))

#define VFSTOKERNFS(mp) ((struct kernfs_mount *)((mp)->mnt_data))
#define VTOKERN(vp)     ((struct kernfs_node *)(vp)->v_data)
#define KERNFSTOV(kfs)  ((kfs)->kfs_vnode)

#define KERNFS_MAXNAMLEN        255

extern const struct kern_target kern_targets[];
extern int nkern_targets;
extern const int static_nkern_targets;
extern int (**kernfs_vnodeop_p)(void *);
extern int (**kernfs_specop_p)(void *);
extern struct vfsops kernfs_vfsops;
extern dev_t rrootdev;
extern kmutex_t kfs_lock;

int kernfs_root(struct mount *, int, struct vnode **);

/*
 * Data types for the kernfs file operations.
 */
typedef enum {
        KERNFS_XREAD,
        KERNFS_XWRITE,
        KERNFS_FILEOP_CLOSE,
        KERNFS_FILEOP_GETATTR,
        KERNFS_FILEOP_IOCTL,
        KERNFS_FILEOP_OPEN,
        KERNFS_FILEOP_READ,
        KERNFS_FILEOP_WRITE,
} kfsfileop;

struct kernfs_fileop {
        kfstype                         kf_type;
        kfsfileop                       kf_fileop;
        union {
                int                     (*_kf_vop)(void *);
                int                     (*_kf_xread)
                        (const struct kernfs_node *, char **, size_t);
                int                     (*_kf_xwrite)
                        (const struct kernfs_node *, char *, size_t);
        } _kf_opfn;
        SPLAY_ENTRY(kernfs_fileop)      kf_node;
};

#define kf_vop          _kf_opfn._kf_vop
#define kf_xread        _kf_opfn._kf_xread
#define kf_xwrite       _kf_opfn._kf_xwrite

typedef struct kern_target kernfs_parentdir_t;
typedef struct dyn_kern_target kernfs_entry_t;

/*
 * Functions for adding kernfs datatypes and nodes.
 */
kfstype kernfs_alloctype(int, const struct kernfs_fileop *);
#define KERNFS_ALLOCTYPE(kf) kernfs_alloctype(sizeof((kf)) / \
        sizeof((kf)[0]), (kf))
#define KERNFS_ALLOCENTRY(dkt, km_flags)                                \
        dkt = (kernfs_entry_t *)kmem_zalloc(                            \
                sizeof(struct dyn_kern_target), (km_flags))
#define KERNFS_INITENTRY(dkt, type, name, data, tag, vtype, mode) do {  \
        (dkt)->dkt_kt.kt_type = (type);                                 \
        (dkt)->dkt_kt.kt_namlen = strlen((name));                       \
        (dkt)->dkt_kt.kt_name = (name);                                 \
        (dkt)->dkt_kt.kt_data = (data);                                 \
        (dkt)->dkt_kt.kt_tag = (tag);                                   \
        (dkt)->dkt_kt.kt_vtype = (vtype);                               \
        (dkt)->dkt_kt.kt_mode = (mode);                                 \
} while (/*CONSTCOND*/0)
#define KERNFS_ENTOPARENTDIR(dkt) &(dkt)->dkt_kt
int kernfs_addentry(kernfs_parentdir_t *, kernfs_entry_t *);

#ifdef IPSEC
__weak_extern(key_freesp)
__weak_extern(key_getspbyid)
__weak_extern(key_setdumpsa_spi)
__weak_extern(key_setdumpsp)
__weak_extern(satailq)
__weak_extern(sptailq)
#endif

#endif /* _KERNEL */