/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 * Copyright (c) 2000
 *      Poul-Henning Kamp.  All rights reserved.
 * Copyright (c) 2002
 *      Dima Dorfman.  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. 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.
 * From: FreeBSD: src/sys/miscfs/kernfs/kernfs.h 1.14
 */

#ifndef _FS_DEVFS_DEVFS_H_
#define _FS_DEVFS_DEVFS_H_

#define DEVFS_MAGIC     0xdb0a087a

/*
 * Identifiers.  The ruleset and rule numbers are 16-bit values.  The
 * "rule ID" is a combination of the ruleset and rule number; it
 * should be able to univocally describe a rule in the system.  In
 * this implementation, the upper 16 bits of the rule ID is the
 * ruleset number; the lower 16 bits, the rule number within the
 * aforementioned ruleset.
 */
typedef uint16_t devfs_rnum;
typedef uint16_t devfs_rsnum;
typedef uint32_t devfs_rid;

/*
 * Identifier manipulators.
 */
#define rid2rsn(rid)    ((rid) >> 16)
#define rid2rn(rid)     ((rid) & 0xffff)
#define mkrid(rsn, rn)  ((rn) | ((rsn) << 16))

/*
 * Plain DEVFS rule.  This gets shared between kernel and userland
 * verbatim, so it shouldn't contain any pointers or other kernel- or
 * userland-specific values.
 */
struct devfs_rule {
        uint32_t dr_magic;                      /* Magic number. */
        devfs_rid dr_id;                        /* Identifier. */

        /*
         * Conditions under which this rule should be applied.  These
         * are ANDed together since OR can be simulated by using
         * multiple rules.  dr_icond determines which of the other
         * variables we should process.
         */
        int     dr_icond;
#define DRC_DSWFLAGS    0x001
#define DRC_PATHPTRN    0x002
        int     dr_dswflags;                    /* cdevsw flags to match. */
#define DEVFS_MAXPTRNLEN        200
        char    dr_pathptrn[DEVFS_MAXPTRNLEN];  /* Pattern to match path. */

        /*
         * Things to change.  dr_iacts determines which of the other
         * variables we should process.
         */
        int     dr_iacts;
#define DRA_BACTS       0x001
#define DRA_UID         0x002
#define DRA_GID         0x004
#define DRA_MODE        0x008
#define DRA_INCSET      0x010
        int     dr_bacts;                       /* Boolean (on/off) action. */
#define DRB_HIDE        0x001                   /* Hide entry (DE_WHITEOUT). */
#define DRB_UNHIDE      0x002                   /* Unhide entry. */
        uid_t   dr_uid;
        gid_t   dr_gid;
        mode_t  dr_mode;
        devfs_rsnum dr_incset;                  /* Included ruleset. */
};

/*
 * Rule-related ioctls.
 */
#define DEVFSIO_RADD            _IOWR('D', 0, struct devfs_rule)
#define DEVFSIO_RDEL            _IOW('D', 1, devfs_rid)
#define DEVFSIO_RAPPLY          _IOW('D', 2, struct devfs_rule)
#define DEVFSIO_RAPPLYID        _IOW('D', 3, devfs_rid)
#define DEVFSIO_RGETNEXT        _IOWR('D', 4, struct devfs_rule)

#define DEVFSIO_SUSE            _IOW('D', 10, devfs_rsnum)
#define DEVFSIO_SAPPLY          _IOW('D', 11, devfs_rsnum)
#define DEVFSIO_SGETNEXT        _IOWR('D', 12, devfs_rsnum)

/* XXX: DEVFSIO_RS_GET_INFO for refcount, active if any, etc. */

#ifdef _KERNEL

#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_DEVFS);
#endif

#endif /* _KERNEL */

struct componentname;

TAILQ_HEAD(devfs_dlist_head, devfs_dirent);

struct devfs_dirent {
        struct cdev_priv        *de_cdp;
        int                     de_inode;
        int                     de_flags;
#define DE_WHITEOUT     0x01
#define DE_DOT          0x02
#define DE_DOTDOT       0x04
#define DE_DOOMED       0x08
#define DE_COVERED      0x10
#define DE_USER         0x20
        int                     de_holdcnt;
        struct dirent           *de_dirent;
        TAILQ_ENTRY(devfs_dirent) de_list;
        struct devfs_dlist_head de_dlist;
        struct devfs_dirent     *de_dir;
        int                     de_links;
        mode_t                  de_mode;
        uid_t                   de_uid;
        gid_t                   de_gid;
        struct label            *de_label;
        struct timespec         de_atime;
        struct timespec         de_mtime;
        struct timespec         de_ctime;
        struct vnode            *de_vnode;
        char                    *de_symlink;
        int                     de_usecount;
};

#include <sys/_lock.h>
#include <sys/_sx.h>

struct devfs_mount {
        u_int                   dm_idx;
        struct mount            *dm_mount;
        struct devfs_dirent     *dm_rootdir;
        unsigned                dm_generation;
        int                     dm_holdcnt;
        struct sx               dm_lock;
        devfs_rsnum             dm_ruleset;
};

#define DEVFS_ROOTINO 2

#ifdef _KERNEL

extern unsigned devfs_rule_depth;

#define VFSTODEVFS(mp)  ((struct devfs_mount *)((mp)->mnt_data))

#define DEVFS_DE_HOLD(de)       ((de)->de_holdcnt++)
#define DEVFS_DE_DROP(de)       (--(de)->de_holdcnt == 0)

#define DEVFS_DMP_HOLD(dmp)     ((dmp)->dm_holdcnt++)
#define DEVFS_DMP_DROP(dmp)     (--(dmp)->dm_holdcnt == 0)

#define DEVFS_DEL_NORECURSE     0x01

void    devfs_rules_apply(struct devfs_mount *, struct devfs_dirent *);
void    devfs_rules_cleanup(struct devfs_mount *);
int     devfs_rules_ioctl(struct devfs_mount *, u_long, caddr_t,
            struct thread *);
void    devfs_ruleset_set(devfs_rsnum rsnum, struct devfs_mount *dm);
void    devfs_ruleset_apply(struct devfs_mount *dm);
int     devfs_allocv(struct devfs_dirent *, struct mount *, int,
            struct vnode **);
char    *devfs_fqpn(char *, struct devfs_mount *, struct devfs_dirent *,
            struct componentname *);
void    devfs_delete(struct devfs_mount *, struct devfs_dirent *, int);
void    devfs_dirent_free(struct devfs_dirent *);
int     devfs_populate_needed(struct devfs_mount *dm);
void    devfs_populate(struct devfs_mount *);
void    devfs_cleanup(struct devfs_mount *);
void    devfs_unmount_final(struct devfs_mount *);
struct devfs_dirent     *devfs_newdirent(char *, int);
struct devfs_dirent     *devfs_parent_dirent(struct devfs_dirent *);
struct devfs_dirent     *devfs_vmkdir(struct devfs_mount *, char *, int,
                            struct devfs_dirent *, u_int);
struct devfs_dirent     *devfs_find(struct devfs_dirent *, const char *, int,
                            int);

void    devfs_ctty_ref(struct vnode *);
void    devfs_ctty_unref(struct vnode *);
int     devfs_usecount(struct vnode *);

#endif /* _KERNEL */

#endif /* !_FS_DEVFS_DEVFS_H_ */