linux/include/linux/nfsd/nfsfh.h
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   1/*
   2 * include/linux/nfsd/nfsfh.h
   3 *
   4 * This file describes the layout of the file handles as passed
   5 * over the wire.
   6 *
   7 * Earlier versions of knfsd used to sign file handles using keyed MD5
   8 * or SHA. I've removed this code, because it doesn't give you more
   9 * security than blocking external access to port 2049 on your firewall.
  10 *
  11 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
  12 */
  13
  14#ifndef _LINUX_NFSD_FH_H
  15#define _LINUX_NFSD_FH_H
  16
  17#include <linux/types.h>
  18#include <linux/nfs.h>
  19#include <linux/nfs2.h>
  20#include <linux/nfs3.h>
  21#include <linux/nfs4.h>
  22#ifdef __KERNEL__
  23# include <linux/sunrpc/svc.h>
  24#endif
  25
  26/*
  27 * This is the old "dentry style" Linux NFSv2 file handle.
  28 *
  29 * The xino and xdev fields are currently used to transport the
  30 * ino/dev of the exported inode.
  31 */
  32struct nfs_fhbase_old {
  33        __u32           fb_dcookie;     /* dentry cookie - always 0xfeebbaca */
  34        __u32           fb_ino;         /* our inode number */
  35        __u32           fb_dirino;      /* dir inode number, 0 for directories */
  36        __u32           fb_dev;         /* our device */
  37        __u32           fb_xdev;
  38        __u32           fb_xino;
  39        __u32           fb_generation;
  40};
  41
  42/*
  43 * This is the new flexible, extensible style NFSv2/v3 file handle.
  44 * by Neil Brown <neilb@cse.unsw.edu.au> - March 2000
  45 *
  46 * The file handle starts with a sequence of four-byte words.
  47 * The first word contains a version number (1) and three descriptor bytes
  48 * that tell how the remaining 3 variable length fields should be handled.
  49 * These three bytes are auth_type, fsid_type and fileid_type.
  50 *
  51 * All four-byte values are in host-byte-order.
  52 *
  53 * The auth_type field specifies how the filehandle can be authenticated
  54 * This might allow a file to be confirmed to be in a writable part of a
  55 * filetree without checking the path from it up to the root.
  56 * Current values:
  57 *     0  - No authentication.  fb_auth is 0 bytes long
  58 * Possible future values:
  59 *     1  - 4 bytes taken from MD5 hash of the remainer of the file handle
  60 *          prefixed by a secret and with the important export flags.
  61 *
  62 * The fsid_type identifies how the filesystem (or export point) is
  63 *    encoded.
  64 *  Current values:
  65 *     0  - 4 byte device id (ms-2-bytes major, ls-2-bytes minor), 4byte inode number
  66 *        NOTE: we cannot use the kdev_t device id value, because kdev_t.h
  67 *              says we mustn't.  We must break it up and reassemble.
  68 *     1  - 4 byte user specified identifier
  69 *     2  - 4 byte major, 4 byte minor, 4 byte inode number - DEPRECATED
  70 *     3  - 4 byte device id, encoded for user-space, 4 byte inode number
  71 *     4  - 4 byte inode number and 4 byte uuid
  72 *     5  - 8 byte uuid
  73 *     6  - 16 byte uuid
  74 *     7  - 8 byte inode number and 16 byte uuid
  75 *
  76 * The fileid_type identified how the file within the filesystem is encoded.
  77 * This is (will be) passed to, and set by, the underlying filesystem if it supports
  78 * filehandle operations.  The filesystem must not use the value '0' or '0xff' and may
  79 * only use the values 1 and 2 as defined below:
  80 *  Current values:
  81 *    0   - The root, or export point, of the filesystem.  fb_fileid is 0 bytes.
  82 *    1   - 32bit inode number, 32 bit generation number.
  83 *    2   - 32bit inode number, 32 bit generation number, 32 bit parent directory inode number.
  84 *
  85 */
  86struct nfs_fhbase_new {
  87        __u8            fb_version;     /* == 1, even => nfs_fhbase_old */
  88        __u8            fb_auth_type;
  89        __u8            fb_fsid_type;
  90        __u8            fb_fileid_type;
  91        __u32           fb_auth[1];
  92/*      __u32           fb_fsid[0]; floating */
  93/*      __u32           fb_fileid[0]; floating */
  94};
  95
  96struct knfsd_fh {
  97        unsigned int    fh_size;        /* significant for NFSv3.
  98                                         * Points to the current size while building
  99                                         * a new file handle
 100                                         */
 101        union {
 102                struct nfs_fhbase_old   fh_old;
 103                __u32                   fh_pad[NFS4_FHSIZE/4];
 104                struct nfs_fhbase_new   fh_new;
 105        } fh_base;
 106};
 107
 108#define ofh_dcookie             fh_base.fh_old.fb_dcookie
 109#define ofh_ino                 fh_base.fh_old.fb_ino
 110#define ofh_dirino              fh_base.fh_old.fb_dirino
 111#define ofh_dev                 fh_base.fh_old.fb_dev
 112#define ofh_xdev                fh_base.fh_old.fb_xdev
 113#define ofh_xino                fh_base.fh_old.fb_xino
 114#define ofh_generation          fh_base.fh_old.fb_generation
 115
 116#define fh_version              fh_base.fh_new.fb_version
 117#define fh_fsid_type            fh_base.fh_new.fb_fsid_type
 118#define fh_auth_type            fh_base.fh_new.fb_auth_type
 119#define fh_fileid_type          fh_base.fh_new.fb_fileid_type
 120#define fh_auth                 fh_base.fh_new.fb_auth
 121#define fh_fsid                 fh_base.fh_new.fb_auth
 122
 123#ifdef __KERNEL__
 124
 125static inline __u32 ino_t_to_u32(ino_t ino)
 126{
 127        return (__u32) ino;
 128}
 129
 130static inline ino_t u32_to_ino_t(__u32 uino)
 131{
 132        return (ino_t) uino;
 133}
 134
 135/*
 136 * This is the internal representation of an NFS handle used in knfsd.
 137 * pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
 138 */
 139typedef struct svc_fh {
 140        struct knfsd_fh         fh_handle;      /* FH data */
 141        struct dentry *         fh_dentry;      /* validated dentry */
 142        struct svc_export *     fh_export;      /* export pointer */
 143        int                     fh_maxsize;     /* max size for fh_handle */
 144
 145        unsigned char           fh_locked;      /* inode locked by us */
 146
 147#ifdef CONFIG_NFSD_V3
 148        unsigned char           fh_post_saved;  /* post-op attrs saved */
 149        unsigned char           fh_pre_saved;   /* pre-op attrs saved */
 150
 151        /* Pre-op attributes saved during fh_lock */
 152        __u64                   fh_pre_size;    /* size before operation */
 153        struct timespec         fh_pre_mtime;   /* mtime before oper */
 154        struct timespec         fh_pre_ctime;   /* ctime before oper */
 155        /*
 156         * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode)
 157         *  to find out if it is valid.
 158         */
 159        u64                     fh_pre_change;
 160
 161        /* Post-op attributes saved in fh_unlock */
 162        struct kstat            fh_post_attr;   /* full attrs after operation */
 163        u64                     fh_post_change; /* nfsv4 change; see above */
 164#endif /* CONFIG_NFSD_V3 */
 165
 166} svc_fh;
 167
 168#endif /* __KERNEL__ */
 169
 170
 171#endif /* _LINUX_NFSD_FH_H */
 172