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 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 #ifdef __KERNEL__
121
ino_t_to_u32(ino_t ino)122 static inline __u32 ino_t_to_u32(ino_t ino)
123 {
124 return (__u32) ino;
125 }
126
u32_to_ino_t(__u32 uino)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 */
169