nfsfh.h

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/*
 * include/linux/nfsd/nfsfh.h
 *
 * This file describes the layout of the file handles as passed
 * over the wire.
 *
 * Earlier versions of knfsd used to sign file handles using keyed MD5
 * or SHA. I've removed this code, because it doesn't give you more
 * security than blocking external access to port 2049 on your firewall.
 *
 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <[email protected]>
 */

#ifndef _UAPI_LINUX_NFSD_FH_H
#define _UAPI_LINUX_NFSD_FH_H

#include <linux/types.h>
#include <linux/nfs.h>
#include <linux/nfs2.h>
#include <linux/nfs3.h>
#include <linux/nfs4.h>

/*
 * This is the old "dentry style" Linux NFSv2 file handle.
 *
 * The xino and xdev fields are currently used to transport the
 * ino/dev of the exported inode.
 */
struct nfs_fhbase_old {
    __u32       fb_dcookie; /* dentry cookie - always 0xfeebbaca */
    __u32       fb_ino;     /* our inode number */
    __u32       fb_dirino;  /* dir inode number, 0 for directories */
    __u32       fb_dev;     /* our device */
    __u32       fb_xdev;
    __u32       fb_xino;
    __u32       fb_generation;
};

/*
 * This is the new flexible, extensible style NFSv2/v3 file handle.
 * by Neil Brown <[email protected]> - March 2000
 *
 * The file handle starts with a sequence of four-byte words.
 * The first word contains a version number (1) and three descriptor bytes
 * that tell how the remaining 3 variable length fields should be handled.
 * These three bytes are auth_type, fsid_type and fileid_type.
 *
 * All four-byte values are in host-byte-order.
 *
 * The auth_type field specifies how the filehandle can be authenticated
 * This might allow a file to be confirmed to be in a writable part of a
 * filetree without checking the path from it up to the root.
 * Current values:
 *     0  - No authentication.  fb_auth is 0 bytes long
 * Possible future values:
 *     1  - 4 bytes taken from MD5 hash of the remainer of the file handle
 *          prefixed by a secret and with the important export flags.
 *
 * The fsid_type identifies how the filesystem (or export point) is
 *    encoded.
 *  Current values:
 *     0  - 4 byte device id (ms-2-bytes major, ls-2-bytes minor), 4byte inode number
 *        NOTE: we cannot use the kdev_t device id value, because kdev_t.h
 *              says we mustn't.  We must break it up and reassemble.
 *     1  - 4 byte user specified identifier
 *     2  - 4 byte major, 4 byte minor, 4 byte inode number - DEPRECATED
 *     3  - 4 byte device id, encoded for user-space, 4 byte inode number
 *     4  - 4 byte inode number and 4 byte uuid
 *     5  - 8 byte uuid
 *     6  - 16 byte uuid
 *     7  - 8 byte inode number and 16 byte uuid
 *
 * The fileid_type identified how the file within the filesystem is encoded.
 * This is (will be) passed to, and set by, the underlying filesystem if it supports
 * filehandle operations.  The filesystem must not use the value '0' or '0xff' and may
 * only use the values 1 and 2 as defined below:
 *  Current values:
 *    0   - The root, or export point, of the filesystem.  fb_fileid is 0 bytes.
 *    1   - 32bit inode number, 32 bit generation number.
 *    2   - 32bit inode number, 32 bit generation number, 32 bit parent directory inode number.
 *
 */
struct nfs_fhbase_new {
    __u8        fb_version; /* == 1, even => nfs_fhbase_old */
    __u8        fb_auth_type;
    __u8        fb_fsid_type;
    __u8        fb_fileid_type;
    __u32       fb_auth[1];
/*  __u32       fb_fsid[0]; floating */
/*  __u32       fb_fileid[0]; floating */
};

struct knfsd_fh {
    unsigned int    fh_size;    /* significant for NFSv3.
                     * Points to the current size while building
                     * a new file handle
                     */
    union {
        struct nfs_fhbase_old   fh_old;
        __u32           fh_pad[NFS4_FHSIZE/4];
        struct nfs_fhbase_new   fh_new;
    } fh_base;
};

#define ofh_dcookie     fh_base.fh_old.fb_dcookie
#define ofh_ino         fh_base.fh_old.fb_ino
#define ofh_dirino      fh_base.fh_old.fb_dirino
#define ofh_dev         fh_base.fh_old.fb_dev
#define ofh_xdev        fh_base.fh_old.fb_xdev
#define ofh_xino        fh_base.fh_old.fb_xino
#define ofh_generation      fh_base.fh_old.fb_generation

#define fh_version      fh_base.fh_new.fb_version
#define fh_fsid_type        fh_base.fh_new.fb_fsid_type
#define fh_auth_type        fh_base.fh_new.fb_auth_type
#define fh_fileid_type      fh_base.fh_new.fb_fileid_type
#define fh_auth         fh_base.fh_new.fb_auth
#define fh_fsid         fh_base.fh_new.fb_auth



#endif /* _UAPI_LINUX_NFSD_FH_H */