summaryrefslogtreecommitdiffstats
path: root/fs/lockd/clnt4xdr.c
blob: 1a1c3e21ed2c47b8d8984968f3221213f392124a (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
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
/*
 * linux/fs/lockd/clnt4xdr.c
 *
 * XDR functions to encode/decode NLM version 4 RPC arguments and results.
 *
 * NLM client-side only.
 *
 * Copyright (C) 2010, Oracle.  All rights reserved.
 */

#include <linux/types.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/stats.h>
#include <linux/lockd/lockd.h>

#define NLMDBG_FACILITY		NLMDBG_XDR

#if (NLMCLNT_OHSIZE > XDR_MAX_NETOBJ)
#  error "NLM host name cannot be larger than XDR_MAX_NETOBJ!"
#endif

#if (NLMCLNT_OHSIZE > NLM_MAXSTRLEN)
#  error "NLM host name cannot be larger than NLM's maximum string length!"
#endif

/*
 * Declare the space requirements for NLM arguments and replies as
 * number of 32bit-words
 */
#define NLM4_void_sz		(0)
#define NLM4_cookie_sz		(1+(NLM_MAXCOOKIELEN>>2))
#define NLM4_caller_sz		(1+(NLMCLNT_OHSIZE>>2))
#define NLM4_owner_sz		(1+(NLMCLNT_OHSIZE>>2))
#define NLM4_fhandle_sz		(1+(NFS3_FHSIZE>>2))
#define NLM4_lock_sz		(5+NLM4_caller_sz+NLM4_owner_sz+NLM4_fhandle_sz)
#define NLM4_holder_sz		(6+NLM4_owner_sz)

#define NLM4_testargs_sz	(NLM4_cookie_sz+1+NLM4_lock_sz)
#define NLM4_lockargs_sz	(NLM4_cookie_sz+4+NLM4_lock_sz)
#define NLM4_cancargs_sz	(NLM4_cookie_sz+2+NLM4_lock_sz)
#define NLM4_unlockargs_sz	(NLM4_cookie_sz+NLM4_lock_sz)

#define NLM4_testres_sz		(NLM4_cookie_sz+1+NLM4_holder_sz)
#define NLM4_res_sz		(NLM4_cookie_sz+1)
#define NLM4_norep_sz		(0)


static s64 loff_t_to_s64(loff_t offset)
{
	s64 res;

	if (offset >= NLM4_OFFSET_MAX)
		res = NLM4_OFFSET_MAX;
	else if (offset <= -NLM4_OFFSET_MAX)
		res = -NLM4_OFFSET_MAX;
	else
		res = offset;
	return res;
}

static void nlm4_compute_offsets(const struct nlm_lock *lock,
				 u64 *l_offset, u64 *l_len)
{
	const struct file_lock *fl = &lock->fl;

	BUG_ON(fl->fl_start > NLM4_OFFSET_MAX);
	BUG_ON(fl->fl_end > NLM4_OFFSET_MAX &&
				fl->fl_end != OFFSET_MAX);

	*l_offset = loff_t_to_s64(fl->fl_start);
	if (fl->fl_end == OFFSET_MAX)
		*l_len = 0;
	else
		*l_len = loff_t_to_s64(fl->fl_end - fl->fl_start + 1);
}

/*
 * Handle decode buffer overflows out-of-line.
 */
static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
{
	dprintk("lockd: %s prematurely hit the end of our receive buffer. "
		"Remaining buffer length is %tu words.\n",
		func, xdr->end - xdr->p);
}


/*
 * Encode/decode NLMv4 basic data types
 *
 * Basic NLMv4 data types are defined in Appendix II, section 6.1.4
 * of RFC 1813: "NFS Version 3 Protocol Specification" and in Chapter
 * 10 of X/Open's "Protocols for Interworking: XNFS, Version 3W".
 *
 * Not all basic data types have their own encoding and decoding
 * functions.  For run-time efficiency, some data types are encoded
 * or decoded inline.
 */

static void encode_bool(struct xdr_stream *xdr, const int value)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, 4);
	*p = value ? xdr_one : xdr_zero;
}

static void encode_int32(struct xdr_stream *xdr, const s32 value)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, 4);
	*p = cpu_to_be32(value);
}

/*
 *	typedef opaque netobj<MAXNETOBJ_SZ>
 */
static void encode_netobj(struct xdr_stream *xdr,
			  const u8 *data, const unsigned int length)
{
	__be32 *p;

	BUG_ON(length > XDR_MAX_NETOBJ);
	p = xdr_reserve_space(xdr, 4 + length);
	xdr_encode_opaque(p, data, length);
}

static int decode_netobj(struct xdr_stream *xdr,
			 struct xdr_netobj *obj)
{
	u32 length;
	__be32 *p;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(p == NULL))
		goto out_overflow;
	length = be32_to_cpup(p++);
	if (unlikely(length > XDR_MAX_NETOBJ))
		goto out_size;
	obj->len = length;
	obj->data = (u8 *)p;
	return 0;
out_size:
	dprintk("NFS: returned netobj was too long: %u\n", length);
	return -EIO;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

/*
 *	netobj cookie;
 */
static void encode_cookie(struct xdr_stream *xdr,
			  const struct nlm_cookie *cookie)
{
	BUG_ON(cookie->len > NLM_MAXCOOKIELEN);
	encode_netobj(xdr, (u8 *)&cookie->data, cookie->len);
}

static int decode_cookie(struct xdr_stream *xdr,
			     struct nlm_cookie *cookie)
{
	u32 length;
	__be32 *p;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(p == NULL))
		goto out_overflow;
	length = be32_to_cpup(p++);
	/* apparently HPUX can return empty cookies */
	if (length == 0)
		goto out_hpux;
	if (length > NLM_MAXCOOKIELEN)
		goto out_size;
	p = xdr_inline_decode(xdr, length);
	if (unlikely(p == NULL))
		goto out_overflow;
	cookie->len = length;
	memcpy(cookie->data, p, length);
	return 0;
out_hpux:
	cookie->len = 4;
	memset(cookie->data, 0, 4);
	return 0;
out_size:
	dprintk("NFS: returned cookie was too long: %u\n", length);
	return -EIO;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

/*
 *	netobj fh;
 */
static void encode_fh(struct xdr_stream *xdr, const struct nfs_fh *fh)
{
	BUG_ON(fh->size > NFS3_FHSIZE);
	encode_netobj(xdr, (u8 *)&fh->data, fh->size);
}

/*
 *	enum nlm4_stats {
 *		NLM4_GRANTED = 0,
 *		NLM4_DENIED = 1,
 *		NLM4_DENIED_NOLOCKS = 2,
 *		NLM4_BLOCKED = 3,
 *		NLM4_DENIED_GRACE_PERIOD = 4,
 *		NLM4_DEADLCK = 5,
 *		NLM4_ROFS = 6,
 *		NLM4_STALE_FH = 7,
 *		NLM4_FBIG = 8,
 *		NLM4_FAILED = 9
 *	};
 *
 *	struct nlm4_stat {
 *		nlm4_stats stat;
 *	};
 *
 * NB: we don't swap bytes for the NLM status values.  The upper
 * layers deal directly with the status value in network byte
 * order.
 */
static void encode_nlm4_stat(struct xdr_stream *xdr,
			     const __be32 stat)
{
	__be32 *p;

	BUG_ON(be32_to_cpu(stat) > NLM_FAILED);
	p = xdr_reserve_space(xdr, 4);
	*p = stat;
}

static int decode_nlm4_stat(struct xdr_stream *xdr, __be32 *stat)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, 4);
	if (unlikely(p == NULL))
		goto out_overflow;
	if (unlikely(*p > nlm4_failed))
		goto out_bad_xdr;
	*stat = *p;
	return 0;
out_bad_xdr:
	dprintk("%s: server returned invalid nlm4_stats value: %u\n",
			__func__, be32_to_cpup(p));
	return -EIO;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

/*
 *	struct nlm4_holder {
 *		bool	exclusive;
 *		int32	svid;
 *		netobj	oh;
 *		uint64	l_offset;
 *		uint64	l_len;
 *	};
 */
static void encode_nlm4_holder(struct xdr_stream *xdr,
			       const struct nlm_res *result)
{
	const struct nlm_lock *lock = &result->lock;
	u64 l_offset, l_len;
	__be32 *p;

	encode_bool(xdr, lock->fl.fl_type == F_RDLCK);
	encode_int32(xdr, lock->svid);
	encode_netobj(xdr, lock->oh.data, lock->oh.len);

	p = xdr_reserve_space(xdr, 4 + 4);
	nlm4_compute_offsets(lock, &l_offset, &l_len);
	p = xdr_encode_hyper(p, l_offset);
	xdr_encode_hyper(p, l_len);
}

static int decode_nlm4_holder(struct xdr_stream *xdr, struct nlm_res *result)
{
	struct nlm_lock *lock = &result->lock;
	struct file_lock *fl = &lock->fl;
	u64 l_offset, l_len;
	u32 exclusive;
	int error;
	__be32 *p;
	s32 end;

	memset(lock, 0, sizeof(*lock));
	locks_init_lock(fl);

	p = xdr_inline_decode(xdr, 4 + 4);
	if (unlikely(p == NULL))
		goto out_overflow;
	exclusive = be32_to_cpup(p++);
	lock->svid = be32_to_cpup(p);
	fl->fl_pid = (pid_t)lock->svid;

	error = decode_netobj(xdr, &lock->oh);
	if (unlikely(error))
		goto out;

	p = xdr_inline_decode(xdr, 8 + 8);
	if (unlikely(p == NULL))
		goto out_overflow;

	fl->fl_flags = FL_POSIX;
	fl->fl_type  = exclusive != 0 ? F_WRLCK : F_RDLCK;
	p = xdr_decode_hyper(p, &l_offset);
	xdr_decode_hyper(p, &l_len);
	end = l_offset + l_len - 1;

	fl->fl_start = (loff_t)l_offset;
	if (l_len == 0 || end < 0)
		fl->fl_end = OFFSET_MAX;
	else
		fl->fl_end = (loff_t)end;
	error = 0;
out:
	return error;
out_overflow:
	print_overflow_msg(__func__, xdr);
	return -EIO;
}

/*
 *	string caller_name<LM_MAXSTRLEN>;
 */
static void encode_caller_name(struct xdr_stream *xdr, const char *name)
{
	/* NB: client-side does not set lock->len */
	u32 length = strlen(name);
	__be32 *p;

	BUG_ON(length > NLM_MAXSTRLEN);
	p = xdr_reserve_space(xdr, 4 + length);
	xdr_encode_opaque(p, name, length);
}

/*
 *	struct nlm4_lock {
 *		string	caller_name<LM_MAXSTRLEN>;
 *		netobj	fh;
 *		netobj	oh;
 *		int32	svid;
 *		uint64	l_offset;
 *		uint64	l_len;
 *	};
 */
static void encode_nlm4_lock(struct xdr_stream *xdr,
			     const struct nlm_lock *lock)
{
	u64 l_offset, l_len;
	__be32 *p;

	encode_caller_name(xdr, lock->caller);
	encode_fh(xdr, &lock->fh);
	encode_netobj(xdr, lock->oh.data, lock->oh.len);

	p = xdr_reserve_space(xdr, 4 + 8 + 8);
	*p++ = cpu_to_be32(lock->svid);

	nlm4_compute_offsets(lock, &l_offset, &l_len);
	p = xdr_encode_hyper(p, l_offset);
	xdr_encode_hyper(p, l_len);
}


/*
 * NLMv4 XDR encode functions
 *
 * NLMv4 argument types are defined in Appendix II of RFC 1813:
 * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
 * "Protocols for Interworking: XNFS, Version 3W".
 */

/*
 *	struct nlm4_testargs {
 *		netobj cookie;
 *		bool exclusive;
 *		struct nlm4_lock alock;
 *	};
 */
static int nlm4_xdr_enc_testargs(struct rpc_rqst *req, __be32 *p,
				 const struct nlm_args *args)
{
	const struct nlm_lock *lock = &args->lock;
	struct xdr_stream xdr;

	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	encode_cookie(&xdr, &args->cookie);
	encode_bool(&xdr, lock->fl.fl_type == F_WRLCK);
	encode_nlm4_lock(&xdr, lock);
	return 0;
}

/*
 *	struct nlm4_lockargs {
 *		netobj cookie;
 *		bool block;
 *		bool exclusive;
 *		struct nlm4_lock alock;
 *		bool reclaim;
 *		int state;
 *	};
 */
static int nlm4_xdr_enc_lockargs(struct rpc_rqst *req, __be32 *p,
				 const struct nlm_args *args)
{
	const struct nlm_lock *lock = &args->lock;
	struct xdr_stream xdr;

	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	encode_cookie(&xdr, &args->cookie);
	encode_bool(&xdr, args->block);
	encode_bool(&xdr, lock->fl.fl_type == F_WRLCK);
	encode_nlm4_lock(&xdr, lock);
	encode_bool(&xdr, args->reclaim);
	encode_int32(&xdr, args->state);
	return 0;
}

/*
 *	struct nlm4_cancargs {
 *		netobj cookie;
 *		bool block;
 *		bool exclusive;
 *		struct nlm4_lock alock;
 *	};
 */
static int nlm4_xdr_enc_cancargs(struct rpc_rqst *req, __be32 *p,
				 const struct nlm_args *args)
{
	const struct nlm_lock *lock = &args->lock;
	struct xdr_stream xdr;

	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	encode_cookie(&xdr, &args->cookie);
	encode_bool(&xdr, args->block);
	encode_bool(&xdr, lock->fl.fl_type == F_WRLCK);
	encode_nlm4_lock(&xdr, lock);
	return 0;
}

/*
 *	struct nlm4_unlockargs {
 *		netobj cookie;
 *		struct nlm4_lock alock;
 *	};
 */
static int nlm4_xdr_enc_unlockargs(struct rpc_rqst *req, __be32 *p,
				   const struct nlm_args *args)
{
	const struct nlm_lock *lock = &args->lock;
	struct xdr_stream xdr;

	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	encode_cookie(&xdr, &args->cookie);
	encode_nlm4_lock(&xdr, lock);
	return 0;
}

/*
 *	struct nlm4_res {
 *		netobj cookie;
 *		nlm4_stat stat;
 *	};
 */
static int nlm4_xdr_enc_res(struct rpc_rqst *req, __be32 *p,
			    const struct nlm_res *result)
{
	struct xdr_stream xdr;

	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	encode_cookie(&xdr, &result->cookie);
	encode_nlm4_stat(&xdr, result->status);
	return 0;
}

/*
 *	union nlm4_testrply switch (nlm4_stats stat) {
 *	case NLM4_DENIED:
 *		struct nlm4_holder holder;
 *	default:
 *		void;
 *	};
 *
 *	struct nlm4_testres {
 *		netobj cookie;
 *		nlm4_testrply test_stat;
 *	};
 */
static int nlm4_xdr_enc_testres(struct rpc_rqst *req, __be32 *p,
				const struct nlm_res *result)
{
	struct xdr_stream xdr;

	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	encode_cookie(&xdr, &result->cookie);
	encode_nlm4_stat(&xdr, result->status);
	if (result->status == nlm_lck_denied)
		encode_nlm4_holder(&xdr, result);
	return 0;
}


/*
 * NLMv4 XDR decode functions
 *
 * NLMv4 argument types are defined in Appendix II of RFC 1813:
 * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
 * "Protocols for Interworking: XNFS, Version 3W".
 */

/*
 *	union nlm4_testrply switch (nlm4_stats stat) {
 *	case NLM4_DENIED:
 *		struct nlm4_holder holder;
 *	default:
 *		void;
 *	};
 *
 *	struct nlm4_testres {
 *		netobj cookie;
 *		nlm4_testrply test_stat;
 *	};
 */
static int decode_nlm4_testrply(struct xdr_stream *xdr,
				struct nlm_res *result)
{
	int error;

	error = decode_nlm4_stat(xdr, &result->status);
	if (unlikely(error))
		goto out;
	if (result->status == nlm_lck_denied)
		error = decode_nlm4_holder(xdr, result);
out:
	return error;
}

static int nlm4_xdr_dec_testres(struct rpc_rqst *req, __be32 *p,
				struct nlm_res *result)
{
	struct xdr_stream xdr;
	int error;

	xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
	error = decode_cookie(&xdr, &result->cookie);
	if (unlikely(error))
		goto out;
	error = decode_nlm4_testrply(&xdr, result);
out:
	return error;
}

/*
 *	struct nlm4_res {
 *		netobj cookie;
 *		nlm4_stat stat;
 *	};
 */
static int nlm4_xdr_dec_res(struct rpc_rqst *req, __be32 *p,
			    struct nlm_res *result)
{
	struct xdr_stream xdr;
	int error;

	xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
	error = decode_cookie(&xdr, &result->cookie);
	if (unlikely(error))
		goto out;
	error = decode_nlm4_stat(&xdr, &result->status);
out:
	return error;
}


/*
 * For NLM, a void procedure really returns nothing
 */
#define nlm4_xdr_dec_norep	NULL

#define PROC(proc, argtype, restype)					\
[NLMPROC_##proc] = {							\
	.p_proc      = NLMPROC_##proc,					\
	.p_encode    = (kxdrproc_t)nlm4_xdr_enc_##argtype,		\
	.p_decode    = (kxdrproc_t)nlm4_xdr_dec_##restype,		\
	.p_arglen    = NLM4_##argtype##_sz,				\
	.p_replen    = NLM4_##restype##_sz,				\
	.p_statidx   = NLMPROC_##proc,					\
	.p_name      = #proc,						\
	}

static struct rpc_procinfo	nlm4_procedures[] = {
	PROC(TEST,		testargs,	testres),
	PROC(LOCK,		lockargs,	res),
	PROC(CANCEL,		cancargs,	res),
	PROC(UNLOCK,		unlockargs,	res),
	PROC(GRANTED,		testargs,	res),
	PROC(TEST_MSG,		testargs,	norep),
	PROC(LOCK_MSG,		lockargs,	norep),
	PROC(CANCEL_MSG,	cancargs,	norep),
	PROC(UNLOCK_MSG,	unlockargs,	norep),
	PROC(GRANTED_MSG,	testargs,	norep),
	PROC(TEST_RES,		testres,	norep),
	PROC(LOCK_RES,		res,		norep),
	PROC(CANCEL_RES,	res,		norep),
	PROC(UNLOCK_RES,	res,		norep),
	PROC(GRANTED_RES,	res,		norep),
};

struct rpc_version	nlm_version4 = {
	.number		= 4,
	.nrprocs	= ARRAY_SIZE(nlm4_procedures),
	.procs		= nlm4_procedures,
};