/*
 * Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*
 * Copyright (c) 1985, 1989, 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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.
 *
 *      @(#)namei.h     8.4 (Berkeley) 8/20/94
 */

#ifndef _SYS_NAMEI_H_
#define _SYS_NAMEI_H_

#include <sys/appleapiopts.h>

#ifdef KERNEL
#define LOCKLEAF        0x0004  /* lock inode on return */
#define LOCKPARENT      0x0008  /* want parent vnode returned */
#define WANTPARENT      0x0010  /* want parent vnode returned */
#endif


#ifdef BSD_KERNEL_PRIVATE

#include <sys/queue.h>
#include <sys/uio.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/filedesc.h>

#define PATHBUFLEN      256

/*
 * Encapsulation of namei parameters.
 */
struct nameidata {
        /*
         * Arguments to namei/lookup.
         */
        user_addr_t ni_dirp;            /* pathname pointer */
        enum    uio_seg ni_segflg;      /* location of pathname */
        /*
         * Arguments to lookup.
         */
        struct  vnode *ni_startdir;     /* starting directory */
        struct  vnode *ni_rootdir;      /* logical root directory */
        struct  vnode *ni_usedvp;       /* directory passed in via USEDVP */
        /*
         * Results: returned from/manipulated by lookup
         */
        struct  vnode *ni_vp;           /* vnode of result */
        struct  vnode *ni_dvp;          /* vnode of intermediate directory */
        /*
         * Shared between namei and lookup/commit routines.
         */
        u_int   ni_pathlen;             /* remaining chars in path */
        char    *ni_next;               /* next location in pathname */
        char    ni_pathbuf[PATHBUFLEN];
        u_long  ni_loopcnt;             /* count of symlinks encountered */

        struct componentname ni_cnd;
};

#ifdef KERNEL
/*
 * namei operational modifier flags, stored in ni_cnd.flags
 */
#define NOCACHE         0x0020  /* name must not be left in cache */
#define NOFOLLOW        0x0000  /* do not follow symbolic links (pseudo) */
#define SHAREDLEAF      0x0080  /* OK to have shared leaf lock */
#define MODMASK         0x00fc  /* mask of operational modifiers */
/*
 * Namei parameter descriptors.
 *
 * SAVESTART is set only by the callers of namei. It implies SAVENAME
 * plus the addition of saving the parent directory that contains the
 * name in ni_startdir. It allows repeated calls to lookup for the
 * name being sought. The caller is responsible for releasing the
 * buffer and for vrele'ing ni_startdir.
 */
#define NOCROSSMOUNT    0x00000100 /* do not cross mount points */
#define RDONLY          0x00000200 /* lookup with read-only semantics */
#define HASBUF          0x00000400 /* has allocated pathname buffer */
#define SAVENAME        0x00000800 /* save pathanme buffer */
#define SAVESTART       0x00001000 /* save starting directory */
#define ISSYMLINK       0x00010000 /* symlink needs interpretation */
#define DONOTAUTH       0x00020000 /* do not authorize during lookup */
#define WILLBEDIR       0x00080000 /* new files will be dirs; allow trailing / */
#define AUDITVNPATH1    0x00100000 /* audit the path/vnode info */
#define AUDITVNPATH2    0x00200000 /* audit the path/vnode info */
#define USEDVP          0x00400000 /* start the lookup at ndp.ni_dvp */
#define PARAMASK        0x003fff00 /* mask of parameter descriptors */
#define FSNODELOCKHELD  0x01000000

/*
 * Initialization of an nameidata structure.
 */
#define NDINIT(ndp, op, flags, segflg, namep, ctx) { \
        (ndp)->ni_cnd.cn_nameiop = op; \
        (ndp)->ni_cnd.cn_flags = flags; \
        if ((segflg) == UIO_USERSPACE) { \
                (ndp)->ni_segflg = ((IS_64BIT_PROCESS(vfs_context_proc(ctx))) ? UIO_USERSPACE64 : UIO_USERSPACE32); \
        } \
        else if ((segflg) == UIO_SYSSPACE) { \
                (ndp)->ni_segflg = UIO_SYSSPACE32; \
        } \
        else { \
                (ndp)->ni_segflg = segflg; \
        } \
        (ndp)->ni_dirp = namep; \
        (ndp)->ni_cnd.cn_context = ctx; \
}
#endif /* KERNEL */

/*
 * This structure describes the elements in the cache of recent
 * names looked up by namei.
 */

#define NCHNAMLEN       31      /* maximum name segment length we bother with */
#define NCHASHMASK      0x7fffffff

struct  namecache {
        TAILQ_ENTRY(namecache)  nc_entry;       /* chain of all entries */
        LIST_ENTRY(namecache)   nc_hash;        /* hash chain */
        LIST_ENTRY(namecache)   nc_child;       /* chain of ncp's that are children of a vp */
        union {
          LIST_ENTRY(namecache)  nc_link;       /* chain of ncp's that 'name' a vp */
          TAILQ_ENTRY(namecache) nc_negentry;   /* chain of ncp's that 'name' a vp */
        } nc_un;
        vnode_t                 nc_dvp;         /* vnode of parent of name */
        vnode_t                 nc_vp;          /* vnode the name refers to */
        unsigned int            nc_whiteout:1,  /* name has whiteout applied */
                                nc_hashval:31;  /* hashval of stringname */
        char            *       nc_name;        /* pointer to segment name in string cache */
};


#ifdef KERNEL

int     namei(struct nameidata *ndp);
void    nameidone(struct nameidata *);
int     lookup(struct nameidata *ndp);
int     relookup(struct vnode *dvp, struct vnode **vpp,
                struct componentname *cnp);

/*
 * namecache function prototypes
 */
void    cache_purgevfs(mount_t mp);
int             cache_lookup_path(struct nameidata *ndp, struct componentname *cnp, vnode_t dp,
                          vfs_context_t context, int *trailing_slash, int *dp_authorized);

void    vnode_cache_credentials(vnode_t vp, vfs_context_t context);
void    vnode_uncache_credentials(vnode_t vp);
int             reverse_lookup(vnode_t start_vp, vnode_t *lookup_vpp, 
                                struct filedesc *fdp, vfs_context_t context, int *dp_authorized);

#endif /* KERNEL */

/*
 * Stats on usefulness of namei caches.
 */
struct  nchstats {
        long    ncs_negtotal;
        long    ncs_goodhits;           /* hits that we can really use */
        long    ncs_neghits;            /* negative hits that we can use */
        long    ncs_badhits;            /* hits we must drop */
        long    ncs_miss;               /* misses */
        long    ncs_pass2;              /* names found with passes == 2 */
        long    ncs_2passes;            /* number of times we attempt it */
        long    ncs_stolen;
        long    ncs_enters;
        long    ncs_deletes;
        long    ncs_badvid;
};
#endif /* BSD_KERNEL_PRIVATE */

#endif /* !_SYS_NAMEI_H_ */