summaryrefslogtreecommitdiff
path: root/fs/nfs/mount_clnt.c
blob: 618d815c309336108e2bfa82ded3ccb6910d7d8f (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
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
/*
 * In-kernel MOUNT protocol client
 *
 * Copyright (C) 1997, Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/types.h>
#include <linux/socket.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/uio.h>
#include <linux/net.h>
#include <linux/in.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/sched.h>
#include <linux/nfs_fs.h>
#include "internal.h"

#ifdef RPC_DEBUG
# define NFSDBG_FACILITY	NFSDBG_MOUNT
#endif

/*
 * Defined by RFC 1094, section A.3; and RFC 1813, section 5.1.4
 */
#define MNTPATHLEN		(1024)

/*
 * XDR data type sizes
 */
#define encode_dirpath_sz	(1 + XDR_QUADLEN(MNTPATHLEN))
#define MNT_status_sz		(1)
#define MNT_fhs_status_sz	(1)
#define MNT_fhandle_sz		XDR_QUADLEN(NFS2_FHSIZE)
#define MNT_fhandle3_sz		(1 + XDR_QUADLEN(NFS3_FHSIZE))
#define MNT_authflav3_sz	(1 + NFS_MAX_SECFLAVORS)

/*
 * XDR argument and result sizes
 */
#define MNT_enc_dirpath_sz	encode_dirpath_sz
#define MNT_dec_mountres_sz	(MNT_status_sz + MNT_fhandle_sz)
#define MNT_dec_mountres3_sz	(MNT_status_sz + MNT_fhandle_sz + \
				 MNT_authflav3_sz)

/*
 * Defined by RFC 1094, section A.5
 */
enum {
	MOUNTPROC_NULL		= 0,
	MOUNTPROC_MNT		= 1,
	MOUNTPROC_DUMP		= 2,
	MOUNTPROC_UMNT		= 3,
	MOUNTPROC_UMNTALL	= 4,
	MOUNTPROC_EXPORT	= 5,
};

/*
 * Defined by RFC 1813, section 5.2
 */
enum {
	MOUNTPROC3_NULL		= 0,
	MOUNTPROC3_MNT		= 1,
	MOUNTPROC3_DUMP		= 2,
	MOUNTPROC3_UMNT		= 3,
	MOUNTPROC3_UMNTALL	= 4,
	MOUNTPROC3_EXPORT	= 5,
};

static struct rpc_program	mnt_program;

/*
 * Defined by OpenGroup XNFS Version 3W, chapter 8
 */
enum mountstat {
	MNT_OK			= 0,
	MNT_EPERM		= 1,
	MNT_ENOENT		= 2,
	MNT_EACCES		= 13,
	MNT_EINVAL		= 22,
};

static struct {
	u32 status;
	int errno;
} mnt_errtbl[] = {
	{ .status = MNT_OK,			.errno = 0,		},
	{ .status = MNT_EPERM,			.errno = -EPERM,	},
	{ .status = MNT_ENOENT,			.errno = -ENOENT,	},
	{ .status = MNT_EACCES,			.errno = -EACCES,	},
	{ .status = MNT_EINVAL,			.errno = -EINVAL,	},
};

/*
 * Defined by RFC 1813, section 5.1.5
 */
enum mountstat3 {
	MNT3_OK			= 0,		/* no error */
	MNT3ERR_PERM		= 1,		/* Not owner */
	MNT3ERR_NOENT		= 2,		/* No such file or directory */
	MNT3ERR_IO		= 5,		/* I/O error */
	MNT3ERR_ACCES		= 13,		/* Permission denied */
	MNT3ERR_NOTDIR		= 20,		/* Not a directory */
	MNT3ERR_INVAL		= 22,		/* Invalid argument */
	MNT3ERR_NAMETOOLONG	= 63,		/* Filename too long */
	MNT3ERR_NOTSUPP		= 10004,	/* Operation not supported */
	MNT3ERR_SERVERFAULT	= 10006,	/* A failure on the server */
};

static struct {
	u32 status;
	int errno;
} mnt3_errtbl[] = {
	{ .status = MNT3_OK,			.errno = 0,		},
	{ .status = MNT3ERR_PERM,		.errno = -EPERM,	},
	{ .status = MNT3ERR_NOENT,		.errno = -ENOENT,	},
	{ .status = MNT3ERR_IO,			.errno = -EIO,		},
	{ .status = MNT3ERR_ACCES,		.errno = -EACCES,	},
	{ .status = MNT3ERR_NOTDIR,		.errno = -ENOTDIR,	},
	{ .status = MNT3ERR_INVAL,		.errno = -EINVAL,	},
	{ .status = MNT3ERR_NAMETOOLONG,	.errno = -ENAMETOOLONG,	},
	{ .status = MNT3ERR_NOTSUPP,		.errno = -ENOTSUPP,	},
	{ .status = MNT3ERR_SERVERFAULT,	.errno = -ESERVERFAULT,	},
};

struct mountres {
	int errno;
	struct nfs_fh *fh;
	unsigned int *auth_count;
	rpc_authflavor_t *auth_flavors;
};

struct mnt_fhstatus {
	u32 status;
	struct nfs_fh *fh;
};

/**
 * nfs_mount - Obtain an NFS file handle for the given host and path
 * @info: pointer to mount request arguments
 *
 * Uses default timeout parameters specified by underlying transport.
 */
int nfs_mount(struct nfs_mount_request *info)
{
	struct mountres	result = {
		.fh		= info->fh,
		.auth_count	= info->auth_flav_len,
		.auth_flavors	= info->auth_flavs,
	};
	struct rpc_message msg	= {
		.rpc_argp	= info->dirpath,
		.rpc_resp	= &result,
	};
	struct rpc_create_args args = {
		.protocol	= info->protocol,
		.address	= info->sap,
		.addrsize	= info->salen,
		.servername	= info->hostname,
		.program	= &mnt_program,
		.version	= info->version,
		.authflavor	= RPC_AUTH_UNIX,
	};
	struct rpc_clnt		*mnt_clnt;
	int			status;

	dprintk("NFS: sending MNT request for %s:%s\n",
		(info->hostname ? info->hostname : "server"),
			info->dirpath);

	if (info->noresvport)
		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;

	mnt_clnt = rpc_create(&args);
	if (IS_ERR(mnt_clnt))
		goto out_clnt_err;

	if (info->version == NFS_MNT3_VERSION)
		msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
	else
		msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC_MNT];

	status = rpc_call_sync(mnt_clnt, &msg, 0);
	rpc_shutdown_client(mnt_clnt);

	if (status < 0)
		goto out_call_err;
	if (result.errno != 0)
		goto out_mnt_err;

	dprintk("NFS: MNT request succeeded\n");
	status = 0;

out:
	return status;

out_clnt_err:
	status = PTR_ERR(mnt_clnt);
	dprintk("NFS: failed to create MNT RPC client, status=%d\n", status);
	goto out;

out_call_err:
	dprintk("NFS: MNT request failed, status=%d\n", status);
	goto out;

out_mnt_err:
	dprintk("NFS: MNT server returned result %d\n", result.errno);
	status = result.errno;
	goto out;
}

/*
 * XDR encode/decode functions for MOUNT
 */

static int encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
{
	const u32 pathname_len = strlen(pathname);
	__be32 *p;

	if (unlikely(pathname_len > MNTPATHLEN))
		return -EIO;

	p = xdr_reserve_space(xdr, sizeof(u32) + pathname_len);
	if (unlikely(p == NULL))
		return -EIO;
	xdr_encode_opaque(p, pathname, pathname_len);

	return 0;
}

static int mnt_enc_dirpath(struct rpc_rqst *req, __be32 *p,
			   const char *dirpath)
{
	struct xdr_stream xdr;

	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	return encode_mntdirpath(&xdr, dirpath);
}

static int xdr_decode_fhstatus(struct rpc_rqst *req, __be32 *p,
			       struct mnt_fhstatus *res)
{
	struct nfs_fh *fh = res->fh;

	if ((res->status = ntohl(*p++)) == 0) {
		fh->size = NFS2_FHSIZE;
		memcpy(fh->data, p, NFS2_FHSIZE);
	}
	return 0;
}

/*
 * RFC 1094: "A non-zero status indicates some sort of error.  In this
 * case, the status is a UNIX error number."  This can be problematic
 * if the server and client use different errno values for the same
 * error.
 *
 * However, the OpenGroup XNFS spec provides a simple mapping that is
 * independent of local errno values on the server and the client.
 */
static int decode_status(struct xdr_stream *xdr, struct mountres *res)
{
	unsigned int i;
	u32 status;
	__be32 *p;

	p = xdr_inline_decode(xdr, sizeof(status));
	if (unlikely(p == NULL))
		return -EIO;
	status = ntohl(*p);

	for (i = 0; i <= ARRAY_SIZE(mnt_errtbl); i++) {
		if (mnt_errtbl[i].status == status) {
			res->errno = mnt_errtbl[i].errno;
			return 0;
		}
	}

	dprintk("NFS: unrecognized MNT status code: %u\n", status);
	res->errno = -EACCES;
	return 0;
}

static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res)
{
	struct nfs_fh *fh = res->fh;
	__be32 *p;

	p = xdr_inline_decode(xdr, NFS2_FHSIZE);
	if (unlikely(p == NULL))
		return -EIO;

	fh->size = NFS2_FHSIZE;
	memcpy(fh->data, p, NFS2_FHSIZE);
	return 0;
}

static int mnt_dec_mountres(struct rpc_rqst *req, __be32 *p,
			    struct mountres *res)
{
	struct xdr_stream xdr;
	int status;

	xdr_init_decode(&xdr, &req->rq_rcv_buf, p);

	status = decode_status(&xdr, res);
	if (unlikely(status != 0 || res->errno != 0))
		return status;
	return decode_fhandle(&xdr, res);
}

static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
{
	unsigned int i;
	u32 status;
	__be32 *p;

	p = xdr_inline_decode(xdr, sizeof(status));
	if (unlikely(p == NULL))
		return -EIO;
	status = ntohl(*p);

	for (i = 0; i <= ARRAY_SIZE(mnt3_errtbl); i++) {
		if (mnt3_errtbl[i].status == status) {
			res->errno = mnt3_errtbl[i].errno;
			return 0;
		}
	}

	dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
	res->errno = -EACCES;
	return 0;
}

static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
{
	struct nfs_fh *fh = res->fh;
	u32 size;
	__be32 *p;

	p = xdr_inline_decode(xdr, sizeof(size));
	if (unlikely(p == NULL))
		return -EIO;

	size = ntohl(*p++);
	if (size > NFS3_FHSIZE || size == 0)
		return -EIO;

	p = xdr_inline_decode(xdr, size);
	if (unlikely(p == NULL))
		return -EIO;

	fh->size = size;
	memcpy(fh->data, p, size);
	return 0;
}

static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
{
	rpc_authflavor_t *flavors = res->auth_flavors;
	unsigned int *count = res->auth_count;
	u32 entries, i;
	__be32 *p;

	if (*count == 0)
		return 0;

	p = xdr_inline_decode(xdr, sizeof(entries));
	if (unlikely(p == NULL))
		return -EIO;
	entries = ntohl(*p);
	dprintk("NFS: received %u auth flavors\n", entries);
	if (entries > NFS_MAX_SECFLAVORS)
		entries = NFS_MAX_SECFLAVORS;

	p = xdr_inline_decode(xdr, sizeof(u32) * entries);
	if (unlikely(p == NULL))
		return -EIO;

	if (entries > *count)
		entries = *count;

	for (i = 0; i < entries; i++) {
		flavors[i] = ntohl(*p++);
		dprintk("NFS:\tflavor %u: %d\n", i, flavors[i]);
	}
	*count = i;

	return 0;
}

static int mnt_dec_mountres3(struct rpc_rqst *req, __be32 *p,
			     struct mountres *res)
{
	struct xdr_stream xdr;
	int status;

	xdr_init_decode(&xdr, &req->rq_rcv_buf, p);

	status = decode_fhs_status(&xdr, res);
	if (unlikely(status != 0 || res->errno != 0))
		return status;
	status = decode_fhandle3(&xdr, res);
	if (unlikely(status != 0)) {
		res->errno = -EBADHANDLE;
		return 0;
	}
	return decode_auth_flavors(&xdr, res);
}

static int xdr_decode_fhstatus3(struct rpc_rqst *req, __be32 *p,
				struct mnt_fhstatus *res)
{
	struct nfs_fh *fh = res->fh;
	unsigned size;

	if ((res->status = ntohl(*p++)) == 0) {
		size = ntohl(*p++);
		if (size <= NFS3_FHSIZE && size != 0) {
			fh->size = size;
			memcpy(fh->data, p, size);
		} else
			res->status = -EBADHANDLE;
	}
	return 0;
}

static struct rpc_procinfo mnt_procedures[] = {
	[MOUNTPROC_MNT] = {
		.p_proc		= MOUNTPROC_MNT,
		.p_encode	= (kxdrproc_t)mnt_enc_dirpath,
		.p_decode	= (kxdrproc_t)mnt_dec_mountres,
		.p_arglen	= MNT_enc_dirpath_sz,
		.p_replen	= MNT_dec_mountres_sz,
		.p_statidx	= MOUNTPROC_MNT,
		.p_name		= "MOUNT",
	},
};

static struct rpc_procinfo mnt3_procedures[] = {
	[MOUNTPROC3_MNT] = {
		.p_proc		= MOUNTPROC3_MNT,
		.p_encode	= (kxdrproc_t)mnt_enc_dirpath,
		.p_decode	= (kxdrproc_t)mnt_dec_mountres3,
		.p_arglen	= MNT_enc_dirpath_sz,
		.p_replen	= MNT_dec_mountres3_sz,
		.p_statidx	= MOUNTPROC3_MNT,
		.p_name		= "MOUNT",
	},
};


static struct rpc_version mnt_version1 = {
	.number		= 1,
	.nrprocs	= 2,
	.procs		= mnt_procedures,
};

static struct rpc_version mnt_version3 = {
	.number		= 3,
	.nrprocs	= 2,
	.procs		= mnt3_procedures,
};

static struct rpc_version *mnt_version[] = {
	NULL,
	&mnt_version1,
	NULL,
	&mnt_version3,
};

static struct rpc_stat mnt_stats;

static struct rpc_program mnt_program = {
	.name		= "mount",
	.number		= NFS_MNT_PROGRAM,
	.nrvers		= ARRAY_SIZE(mnt_version),
	.version	= mnt_version,
	.stats		= &mnt_stats,
};