Home | History | Annotate | Download | only in nfsd
      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 (at) 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 
     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 (at) cse.unsw.edu.au> - March 2000
     42  *
     43  * The file handle starts with a sequence of four-byte words.
     44  * The first word contains a version number (1) and three 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 four-byte 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 up to 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 
    121 
    122 #endif /* _LINUX_NFSD_FH_H */
    123