include/linux/nfsd/nfsfh.h

   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  */
  32 struct 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  */
  86 struct 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
  96 struct 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
 125 static inline __u32 ino_t_to_u32(ino_t ino)
 126 {
 127         return (__u32) ino;
 128 }
 129
 130 static 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  */
 139 typedef 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 */