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