summaryrefslogtreecommitdiffstats
path: root/include/linux/nfsd/nfsfh.h
blob: 0798b7781a6e89dbfd258b72e521511cd7d9134a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
/*
 * include/linux/nfsd/nfsfh.h
 *
 * This file describes the layout of the file handles as passed
 * over the wire.
 *
 * Earlier versions of knfsd used to sign file handles using keyed MD5
 * or SHA. I've removed this code, because it doesn't give you more
 * security than blocking external access to port 2049 on your firewall.
 *
 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
 */

#ifndef _LINUX_NFSD_FH_H
#define _LINUX_NFSD_FH_H

#include <asm/types.h>
#ifdef __KERNEL__
# include <linux/config.h>
# include <linux/types.h>
# include <linux/string.h>
# include <linux/fs.h>
#endif
#include <linux/nfsd/const.h>
#include <linux/nfsd/debug.h>

/*
 * This is the old "dentry style" Linux NFSv2 file handle.
 *
 * The xino and xdev fields are currently used to transport the
 * ino/dev of the exported inode.
 */
struct nfs_fhbase_old {
	__u32		fb_dcookie;	/* dentry cookie - always 0xfeebbaca */
	__u32		fb_ino;		/* our inode number */
	__u32		fb_dirino;	/* dir inode number, 0 for directories */
	__u32		fb_dev;		/* our device */
	__u32		fb_xdev;
	__u32		fb_xino;
	__u32		fb_generation;
};

/*
 * This is the new flexible, extensible style NFSv2/v3 file handle.
 * by Neil Brown <neilb@cse.unsw.edu.au> - March 2000
 *
 * The file handle is seens as a list of 4byte words.
 * The first word contains a version number (1) and four descriptor bytes
 * that tell how the remaining 3 variable length fields should be handled.
 * These three bytes are auth_type, fsid_type and fileid_type.
 *
 * All 4byte values are in host-byte-order.
 *
 * The auth_type field specifies how the filehandle can be authenticated
 * This might allow a file to be confirmed to be in a writable part of a
 * filetree without checking the path from it upto the root.
 * Current values:
 *     0  - No authentication.  fb_auth is 0 bytes long
 * Possible future values:
 *     1  - 4 bytes taken from MD5 hash of the remainer of the file handle
 *          prefixed by a secret and with the important export flags.
 *
 * The fsid_type identifies how the filesystem (or export point) is
 *    encoded.
 *  Current values:
 *     0  - 4 byte device id (ms-2-bytes major, ls-2-bytes minor), 4byte inode number
 *        NOTE: we cannot use the kdev_t device id value, because kdev_t.h
 *              says we mustn't.  We must break it up and reassemble.
 *     1  - 4 byte user specified identifier
 *     2  - 4 byte major, 4 byte minor, 4 byte inode number - DEPRECATED
 *     3  - 4 byte device id, encoded for user-space, 4 byte inode number
 *
 * The fileid_type identified how the file within the filesystem is encoded.
 * This is (will be) passed to, and set by, the underlying filesystem if it supports
 * filehandle operations.  The filesystem must not use the value '0' or '0xff' and may
 * only use the values 1 and 2 as defined below:
 *  Current values:
 *    0   - The root, or export point, of the filesystem.  fb_fileid is 0 bytes.
 *    1   - 32bit inode number, 32 bit generation number.
 *    2   - 32bit inode number, 32 bit generation number, 32 bit parent directory inode number.
 *
 */
struct nfs_fhbase_new {
	__u8		fb_version;	/* == 1, even => nfs_fhbase_old */
	__u8		fb_auth_type;
	__u8		fb_fsid_type;
	__u8		fb_fileid_type;
	__u32		fb_auth[1];
/*	__u32		fb_fsid[0]; floating */
/*	__u32		fb_fileid[0]; floating */
};

struct knfsd_fh {
	unsigned int	fh_size;	/* significant for NFSv3.
					 * Points to the current size while building
					 * a new file handle
					 */
	union {
		struct nfs_fhbase_old	fh_old;
		__u32			fh_pad[NFS4_FHSIZE/4];
		struct nfs_fhbase_new	fh_new;
	} fh_base;
};

#define ofh_dcookie		fh_base.fh_old.fb_dcookie
#define ofh_ino			fh_base.fh_old.fb_ino
#define ofh_dirino		fh_base.fh_old.fb_dirino
#define ofh_dev			fh_base.fh_old.fb_dev
#define ofh_xdev		fh_base.fh_old.fb_xdev
#define ofh_xino		fh_base.fh_old.fb_xino
#define ofh_generation		fh_base.fh_old.fb_generation

#define	fh_version		fh_base.fh_new.fb_version
#define	fh_fsid_type		fh_base.fh_new.fb_fsid_type
#define	fh_auth_type		fh_base.fh_new.fb_auth_type
#define	fh_fileid_type		fh_base.fh_new.fb_fileid_type
#define	fh_auth			fh_base.fh_new.fb_auth
#define	fh_fsid			fh_base.fh_new.fb_auth

#ifdef __KERNEL__

static inline __u32 ino_t_to_u32(ino_t ino)
{
	return (__u32) ino;
}

static inline ino_t u32_to_ino_t(__u32 uino)
{
	return (ino_t) uino;
}

/*
 * This is the internal representation of an NFS handle used in knfsd.
 * pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
 */
typedef struct svc_fh {
	struct knfsd_fh		fh_handle;	/* FH data */
	struct dentry *		fh_dentry;	/* validated dentry */
	struct svc_export *	fh_export;	/* export pointer */
	int			fh_maxsize;	/* max size for fh_handle */

	unsigned char		fh_locked;	/* inode locked by us */

#ifdef CONFIG_NFSD_V3
	unsigned char		fh_post_saved;	/* post-op attrs saved */
	unsigned char		fh_pre_saved;	/* pre-op attrs saved */

	/* Pre-op attributes saved during fh_lock */
	__u64			fh_pre_size;	/* size before operation */
	struct timespec		fh_pre_mtime;	/* mtime before oper */
	struct timespec		fh_pre_ctime;	/* ctime before oper */

	/* Post-op attributes saved in fh_unlock */
	umode_t			fh_post_mode;	/* i_mode */
	nlink_t			fh_post_nlink;	/* i_nlink */
	uid_t			fh_post_uid;	/* i_uid */
	gid_t			fh_post_gid;	/* i_gid */
	__u64			fh_post_size;	/* i_size */
	unsigned long		fh_post_blocks; /* i_blocks */
	unsigned long		fh_post_blksize;/* i_blksize */
	__u32			fh_post_rdev[2];/* i_rdev */
	struct timespec		fh_post_atime;	/* i_atime */
	struct timespec		fh_post_mtime;	/* i_mtime */
	struct timespec		fh_post_ctime;	/* i_ctime */
#endif /* CONFIG_NFSD_V3 */

} svc_fh;

static inline void mk_fsid_v0(u32 *fsidv, dev_t dev, ino_t ino)
{
	fsidv[0] = htonl((MAJOR(dev)<<16) |
			MINOR(dev));
	fsidv[1] = ino_t_to_u32(ino);
}

static inline void mk_fsid_v1(u32 *fsidv, u32 fsid)
{
	fsidv[0] = fsid;
}

static inline void mk_fsid_v2(u32 *fsidv, dev_t dev, ino_t ino)
{
	fsidv[0] = htonl(MAJOR(dev));
	fsidv[1] = htonl(MINOR(dev));
	fsidv[2] = ino_t_to_u32(ino);
}

static inline void mk_fsid_v3(u32 *fsidv, dev_t dev, ino_t ino)
{
	fsidv[0] = new_encode_dev(dev);
	fsidv[1] = ino_t_to_u32(ino);
}

static inline int key_len(int type)
{
	switch(type) {
	case 0: return 8;
	case 1: return 4;
	case 2: return 12;
	case 3: return 8;
	default: return 0;
	}
}

/*
 * Shorthand for dprintk()'s
 */
extern char * SVCFH_fmt(struct svc_fh *fhp);

/*
 * Function prototypes
 */
u32	fh_verify(struct svc_rqst *, struct svc_fh *, int, int);
int	fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
int	fh_update(struct svc_fh *);
void	fh_put(struct svc_fh *);

static __inline__ struct svc_fh *
fh_copy(struct svc_fh *dst, struct svc_fh *src)
{
	if (src->fh_dentry || src->fh_locked) {
		struct dentry *dentry = src->fh_dentry;
		printk(KERN_ERR "fh_copy: copying %s/%s, already verified!\n",
			dentry->d_parent->d_name.name, dentry->d_name.name);
	}
			
	*dst = *src;
	return dst;
}

static __inline__ struct svc_fh *
fh_init(struct svc_fh *fhp, int maxsize)
{
	memset(fhp, 0, sizeof(*fhp));
	fhp->fh_maxsize = maxsize;
	return fhp;
}

#ifdef CONFIG_NFSD_V3
/*
 * Fill in the pre_op attr for the wcc data
 */
static inline void
fill_pre_wcc(struct svc_fh *fhp)
{
	struct inode    *inode;

	inode = fhp->fh_dentry->d_inode;
	if (!fhp->fh_pre_saved) {
		fhp->fh_pre_mtime = inode->i_mtime;
		fhp->fh_pre_ctime = inode->i_ctime;
			fhp->fh_pre_size  = inode->i_size;
			fhp->fh_pre_saved = 1;
	}
}

/*
 * Fill in the post_op attr for the wcc data
 */
static inline void
fill_post_wcc(struct svc_fh *fhp)
{
	struct inode    *inode = fhp->fh_dentry->d_inode;

	if (fhp->fh_post_saved)
		printk("nfsd: inode locked twice during operation.\n");

	fhp->fh_post_mode       = inode->i_mode;
	fhp->fh_post_nlink      = inode->i_nlink;
	fhp->fh_post_uid	= inode->i_uid;
	fhp->fh_post_gid	= inode->i_gid;
	fhp->fh_post_size       = inode->i_size;
	if (inode->i_blksize) {
		fhp->fh_post_blksize    = inode->i_blksize;
		fhp->fh_post_blocks     = inode->i_blocks;
	} else {
		fhp->fh_post_blksize    = BLOCK_SIZE;
		/* how much do we care for accuracy with MinixFS? */
		fhp->fh_post_blocks     = (inode->i_size+511) >> 9;
	}
	fhp->fh_post_rdev[0]    = htonl((u32)imajor(inode));
	fhp->fh_post_rdev[1]    = htonl((u32)iminor(inode));
	fhp->fh_post_atime      = inode->i_atime;
	fhp->fh_post_mtime      = inode->i_mtime;
	fhp->fh_post_ctime      = inode->i_ctime;
	fhp->fh_post_saved      = 1;
}
#else
#define	fill_pre_wcc(ignored)
#define fill_post_wcc(notused)
#endif /* CONFIG_NFSD_V3 */


/*
 * Lock a file handle/inode
 * NOTE: both fh_lock and fh_unlock are done "by hand" in
 * vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once
 * so, any changes here should be reflected there.
 */
static inline void
fh_lock(struct svc_fh *fhp)
{
	struct dentry	*dentry = fhp->fh_dentry;
	struct inode	*inode;

	dfprintk(FILEOP, "nfsd: fh_lock(%s) locked = %d\n",
			SVCFH_fmt(fhp), fhp->fh_locked);

	if (!fhp->fh_dentry) {
		printk(KERN_ERR "fh_lock: fh not verified!\n");
		return;
	}
	if (fhp->fh_locked) {
		printk(KERN_WARNING "fh_lock: %s/%s already locked!\n",
			dentry->d_parent->d_name.name, dentry->d_name.name);
		return;
	}

	inode = dentry->d_inode;
	mutex_lock(&inode->i_mutex);
	fill_pre_wcc(fhp);
	fhp->fh_locked = 1;
}

/*
 * Unlock a file handle/inode
 */
static inline void
fh_unlock(struct svc_fh *fhp)
{
	if (!fhp->fh_dentry)
		printk(KERN_ERR "fh_unlock: fh not verified!\n");

	if (fhp->fh_locked) {
		fill_post_wcc(fhp);
		mutex_unlock(&fhp->fh_dentry->d_inode->i_mutex);
		fhp->fh_locked = 0;
	}
}
#endif /* __KERNEL__ */


#endif /* _LINUX_NFSD_FH_H */