/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1999-2001 Robert N. M. Watson
 * All rights reserved.
 *
 * This software was developed by Robert Watson for the TrustedBSD Project.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */
/*
 * Developed by the TrustedBSD Project.
 * Support for extended filesystem attributes.
 */

#ifndef _UFS_UFS_EXTATTR_H_
#define _UFS_UFS_EXTATTR_H_

#define UFS_EXTATTR_MAGIC               0x00b5d5ec
#define UFS_EXTATTR_VERSION             0x00000003
#define UFS_EXTATTR_FSROOTSUBDIR        ".attribute"
#define UFS_EXTATTR_SUBDIR_SYSTEM       "system"
#define UFS_EXTATTR_SUBDIR_USER         "user"
#define UFS_EXTATTR_MAXEXTATTRNAME      65      /* including null */

#define UFS_EXTATTR_ATTR_FLAG_INUSE     0x00000001      /* attr has been set */
#define UFS_EXTATTR_PERM_KERNEL         0x00000000
#define UFS_EXTATTR_PERM_ROOT           0x00000001
#define UFS_EXTATTR_PERM_OWNER          0x00000002
#define UFS_EXTATTR_PERM_ANYONE         0x00000003

#define UFS_EXTATTR_UEPM_INITIALIZED    0x00000001
#define UFS_EXTATTR_UEPM_STARTED        0x00000002

#define UFS_EXTATTR_CMD_START           0x00000001
#define UFS_EXTATTR_CMD_STOP            0x00000002
#define UFS_EXTATTR_CMD_ENABLE          0x00000003
#define UFS_EXTATTR_CMD_DISABLE         0x00000004

struct ufs_extattr_fileheader {
        u_int   uef_magic;      /* magic number for sanity checking */
        u_int   uef_version;    /* version of attribute file */
        u_int   uef_size;       /* size of attributes, w/o header */
};

struct ufs_extattr_header {
        u_int   ueh_flags;      /* flags for attribute */
        u_int   ueh_len;        /* local defined length; <= uef_size */
        uint32_t        ueh_i_gen;      /* generation number for sanity */
        /* data follows the header */
};

/*
 * This structure defines the required fields of an extended-attribute header.
 */
struct extattr {
        uint32_t ea_length;         /* length of this attribute */
        uint8_t ea_namespace;       /* name space of this attribute */
        uint8_t ea_contentpadlen;   /* bytes of padding at end of attribute */
        uint8_t ea_namelength;      /* length of attribute name */
        char    ea_name[1];         /* attribute name (NOT nul-terminated) */
        /* padding, if any, to align attribute content to 8 byte boundary */
        /* extended attribute content follows */
};

/*
 * These macros are used to access and manipulate an extended attribute:
 *
 * EXTATTR_NEXT(eap) returns a pointer to the next extended attribute
 *      following eap.
 * EXTATTR_CONTENT(eap) returns a pointer to the extended attribute
 *      content referenced by eap.
 * EXTATTR_CONTENT_SIZE(eap) returns the size of the extended attribute
 *      content referenced by eap.
 */
#define EXTATTR_NEXT(eap) \
        ((struct extattr *)(__DECONST(char *, (eap)) + (eap)->ea_length))
#define EXTATTR_CONTENT(eap) \
        (void *)(((u_char *)(eap)) + EXTATTR_BASE_LENGTH(eap))
#define EXTATTR_CONTENT_SIZE(eap) \
        ((eap)->ea_length - EXTATTR_BASE_LENGTH(eap) - (eap)->ea_contentpadlen)
/* -1 below compensates for ea_name[1] */
#define EXTATTR_BASE_LENGTH(eap) \
        roundup2((sizeof(struct extattr) - 1 + (eap)->ea_namelength), 8)

struct vnode;
LIST_HEAD(ufs_extattr_list_head, ufs_extattr_list_entry);
struct ufs_extattr_list_entry {
        LIST_ENTRY(ufs_extattr_list_entry)      uele_entries;
        struct ufs_extattr_fileheader           uele_fileheader;
        int     uele_attrnamespace;
        char    uele_attrname[UFS_EXTATTR_MAXEXTATTRNAME];
        struct vnode    *uele_backing_vnode;
};

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

struct ucred;
struct ufs_extattr_per_mount {
        struct sx       uepm_lock;
        struct ufs_extattr_list_head    uepm_list;
        struct ucred    *uepm_ucred;
        int     uepm_flags;
};

#ifdef _KERNEL

struct vop_getextattr_args;
struct vop_deleteextattr_args;
struct vop_setextattr_args;

void    ufs_extattr_uepm_init(struct ufs_extattr_per_mount *uepm);
void    ufs_extattr_uepm_destroy(struct ufs_extattr_per_mount *uepm);
int     ufs_extattr_start(struct mount *mp, struct thread *td);
int     ufs_extattr_autostart(struct mount *mp, struct thread *td);
int     ufs_extattr_stop(struct mount *mp, struct thread *td);
int     ufs_extattrctl(struct mount *mp, int cmd, struct vnode *filename,
            int attrnamespace, const char *attrname);
int     ufs_getextattr(struct vop_getextattr_args *ap);
int     ufs_deleteextattr(struct vop_deleteextattr_args *ap);
int     ufs_setextattr(struct vop_setextattr_args *ap);
void    ufs_extattr_vnode_inactive(struct vnode *vp);

#endif /* !_KERNEL */

#endif /* !_UFS_UFS_EXTATTR_H_ */