xref: /linux/fs/lockd/clnt4xdr.c (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/fs/lockd/clnt4xdr.c
4  *
5  * XDR functions to encode/decode NLM version 4 RPC arguments and results.
6  *
7  * NLM client-side only.
8  *
9  * Copyright (C) 2010, Oracle.  All rights reserved.
10  */
11 
12 #include <linux/types.h>
13 #include <linux/sunrpc/xdr.h>
14 #include <linux/sunrpc/clnt.h>
15 #include <linux/sunrpc/stats.h>
16 #include <linux/lockd/lockd.h>
17 
18 #include <uapi/linux/nfs3.h>
19 
20 #define NLMDBG_FACILITY		NLMDBG_XDR
21 
22 #if (NLMCLNT_OHSIZE > XDR_MAX_NETOBJ)
23 #  error "NLM host name cannot be larger than XDR_MAX_NETOBJ!"
24 #endif
25 
26 #if (NLMCLNT_OHSIZE > NLM_MAXSTRLEN)
27 #  error "NLM host name cannot be larger than NLM's maximum string length!"
28 #endif
29 
30 /*
31  * Declare the space requirements for NLM arguments and replies as
32  * number of 32bit-words
33  */
34 #define NLM4_void_sz		(0)
35 #define NLM4_cookie_sz		(1+(NLM_MAXCOOKIELEN>>2))
36 #define NLM4_caller_sz		(1+(NLMCLNT_OHSIZE>>2))
37 #define NLM4_owner_sz		(1+(NLMCLNT_OHSIZE>>2))
38 #define NLM4_fhandle_sz		(1+(NFS3_FHSIZE>>2))
39 #define NLM4_lock_sz		(5+NLM4_caller_sz+NLM4_owner_sz+NLM4_fhandle_sz)
40 #define NLM4_holder_sz		(6+NLM4_owner_sz)
41 
42 #define NLM4_testargs_sz	(NLM4_cookie_sz+1+NLM4_lock_sz)
43 #define NLM4_lockargs_sz	(NLM4_cookie_sz+4+NLM4_lock_sz)
44 #define NLM4_cancargs_sz	(NLM4_cookie_sz+2+NLM4_lock_sz)
45 #define NLM4_unlockargs_sz	(NLM4_cookie_sz+NLM4_lock_sz)
46 
47 #define NLM4_testres_sz		(NLM4_cookie_sz+1+NLM4_holder_sz)
48 #define NLM4_res_sz		(NLM4_cookie_sz+1)
49 #define NLM4_norep_sz		(0)
50 
51 
loff_t_to_s64(loff_t offset)52 static s64 loff_t_to_s64(loff_t offset)
53 {
54 	s64 res;
55 
56 	if (offset >= NLM4_OFFSET_MAX)
57 		res = NLM4_OFFSET_MAX;
58 	else if (offset <= -NLM4_OFFSET_MAX)
59 		res = -NLM4_OFFSET_MAX;
60 	else
61 		res = offset;
62 	return res;
63 }
64 
nlm4_compute_offsets(const struct nlm_lock * lock,u64 * l_offset,u64 * l_len)65 static void nlm4_compute_offsets(const struct nlm_lock *lock,
66 				 u64 *l_offset, u64 *l_len)
67 {
68 	const struct file_lock *fl = &lock->fl;
69 
70 	*l_offset = loff_t_to_s64(fl->fl_start);
71 	if (fl->fl_end == OFFSET_MAX)
72 		*l_len = 0;
73 	else
74 		*l_len = loff_t_to_s64(fl->fl_end - fl->fl_start + 1);
75 }
76 
77 /*
78  * Encode/decode NLMv4 basic data types
79  *
80  * Basic NLMv4 data types are defined in Appendix II, section 6.1.4
81  * of RFC 1813: "NFS Version 3 Protocol Specification" and in Chapter
82  * 10 of X/Open's "Protocols for Interworking: XNFS, Version 3W".
83  *
84  * Not all basic data types have their own encoding and decoding
85  * functions.  For run-time efficiency, some data types are encoded
86  * or decoded inline.
87  */
88 
encode_bool(struct xdr_stream * xdr,const int value)89 static void encode_bool(struct xdr_stream *xdr, const int value)
90 {
91 	__be32 *p;
92 
93 	p = xdr_reserve_space(xdr, 4);
94 	*p = value ? xdr_one : xdr_zero;
95 }
96 
encode_int32(struct xdr_stream * xdr,const s32 value)97 static void encode_int32(struct xdr_stream *xdr, const s32 value)
98 {
99 	__be32 *p;
100 
101 	p = xdr_reserve_space(xdr, 4);
102 	*p = cpu_to_be32(value);
103 }
104 
105 /*
106  *	typedef opaque netobj<MAXNETOBJ_SZ>
107  */
encode_netobj(struct xdr_stream * xdr,const u8 * data,const unsigned int length)108 static void encode_netobj(struct xdr_stream *xdr,
109 			  const u8 *data, const unsigned int length)
110 {
111 	__be32 *p;
112 
113 	p = xdr_reserve_space(xdr, 4 + length);
114 	xdr_encode_opaque(p, data, length);
115 }
116 
decode_netobj(struct xdr_stream * xdr,struct xdr_netobj * obj)117 static int decode_netobj(struct xdr_stream *xdr,
118 			 struct xdr_netobj *obj)
119 {
120 	ssize_t ret;
121 
122 	ret = xdr_stream_decode_opaque_inline(xdr, (void *)&obj->data,
123 						XDR_MAX_NETOBJ);
124 	if (unlikely(ret < 0))
125 		return -EIO;
126 	obj->len = ret;
127 	return 0;
128 }
129 
130 /*
131  *	netobj cookie;
132  */
encode_cookie(struct xdr_stream * xdr,const struct nlm_cookie * cookie)133 static void encode_cookie(struct xdr_stream *xdr,
134 			  const struct nlm_cookie *cookie)
135 {
136 	encode_netobj(xdr, (u8 *)&cookie->data, cookie->len);
137 }
138 
decode_cookie(struct xdr_stream * xdr,struct nlm_cookie * cookie)139 static int decode_cookie(struct xdr_stream *xdr,
140 			     struct nlm_cookie *cookie)
141 {
142 	u32 length;
143 	__be32 *p;
144 
145 	p = xdr_inline_decode(xdr, 4);
146 	if (unlikely(p == NULL))
147 		goto out_overflow;
148 	length = be32_to_cpup(p++);
149 	/* apparently HPUX can return empty cookies */
150 	if (length == 0)
151 		goto out_hpux;
152 	if (length > NLM_MAXCOOKIELEN)
153 		goto out_size;
154 	p = xdr_inline_decode(xdr, length);
155 	if (unlikely(p == NULL))
156 		goto out_overflow;
157 	cookie->len = length;
158 	memcpy(cookie->data, p, length);
159 	return 0;
160 out_hpux:
161 	cookie->len = 4;
162 	memset(cookie->data, 0, 4);
163 	return 0;
164 out_size:
165 	dprintk("NFS: returned cookie was too long: %u\n", length);
166 	return -EIO;
167 out_overflow:
168 	return -EIO;
169 }
170 
171 /*
172  *	netobj fh;
173  */
encode_fh(struct xdr_stream * xdr,const struct nfs_fh * fh)174 static void encode_fh(struct xdr_stream *xdr, const struct nfs_fh *fh)
175 {
176 	encode_netobj(xdr, (u8 *)&fh->data, fh->size);
177 }
178 
179 /*
180  *	enum nlm4_stats {
181  *		NLM4_GRANTED = 0,
182  *		NLM4_DENIED = 1,
183  *		NLM4_DENIED_NOLOCKS = 2,
184  *		NLM4_BLOCKED = 3,
185  *		NLM4_DENIED_GRACE_PERIOD = 4,
186  *		NLM4_DEADLCK = 5,
187  *		NLM4_ROFS = 6,
188  *		NLM4_STALE_FH = 7,
189  *		NLM4_FBIG = 8,
190  *		NLM4_FAILED = 9
191  *	};
192  *
193  *	struct nlm4_stat {
194  *		nlm4_stats stat;
195  *	};
196  *
197  * NB: we don't swap bytes for the NLM status values.  The upper
198  * layers deal directly with the status value in network byte
199  * order.
200  */
encode_nlm4_stat(struct xdr_stream * xdr,const __be32 stat)201 static void encode_nlm4_stat(struct xdr_stream *xdr,
202 			     const __be32 stat)
203 {
204 	__be32 *p;
205 
206 	BUG_ON(be32_to_cpu(stat) > NLM_FAILED);
207 	p = xdr_reserve_space(xdr, 4);
208 	*p = stat;
209 }
210 
decode_nlm4_stat(struct xdr_stream * xdr,__be32 * stat)211 static int decode_nlm4_stat(struct xdr_stream *xdr, __be32 *stat)
212 {
213 	__be32 *p;
214 
215 	p = xdr_inline_decode(xdr, 4);
216 	if (unlikely(p == NULL))
217 		goto out_overflow;
218 	if (unlikely(ntohl(*p) > ntohl(nlm4_failed)))
219 		goto out_bad_xdr;
220 	*stat = *p;
221 	return 0;
222 out_bad_xdr:
223 	dprintk("%s: server returned invalid nlm4_stats value: %u\n",
224 			__func__, be32_to_cpup(p));
225 	return -EIO;
226 out_overflow:
227 	return -EIO;
228 }
229 
230 /*
231  *	struct nlm4_holder {
232  *		bool	exclusive;
233  *		int32	svid;
234  *		netobj	oh;
235  *		uint64	l_offset;
236  *		uint64	l_len;
237  *	};
238  */
encode_nlm4_holder(struct xdr_stream * xdr,const struct nlm_res * result)239 static void encode_nlm4_holder(struct xdr_stream *xdr,
240 			       const struct nlm_res *result)
241 {
242 	const struct nlm_lock *lock = &result->lock;
243 	u64 l_offset, l_len;
244 	__be32 *p;
245 
246 	encode_bool(xdr, lock->fl.c.flc_type == F_RDLCK);
247 	encode_int32(xdr, lock->svid);
248 	encode_netobj(xdr, lock->oh.data, lock->oh.len);
249 
250 	p = xdr_reserve_space(xdr, 4 + 4);
251 	nlm4_compute_offsets(lock, &l_offset, &l_len);
252 	p = xdr_encode_hyper(p, l_offset);
253 	xdr_encode_hyper(p, l_len);
254 }
255 
decode_nlm4_holder(struct xdr_stream * xdr,struct nlm_res * result)256 static int decode_nlm4_holder(struct xdr_stream *xdr, struct nlm_res *result)
257 {
258 	struct nlm_lock *lock = &result->lock;
259 	struct file_lock *fl = &lock->fl;
260 	u64 l_offset, l_len;
261 	u32 exclusive;
262 	int error;
263 	__be32 *p;
264 
265 	memset(lock, 0, sizeof(*lock));
266 	locks_init_lock(fl);
267 
268 	p = xdr_inline_decode(xdr, 4 + 4);
269 	if (unlikely(p == NULL))
270 		goto out_overflow;
271 	exclusive = be32_to_cpup(p++);
272 	lock->svid = be32_to_cpup(p);
273 	fl->c.flc_pid = (pid_t)lock->svid;
274 
275 	error = decode_netobj(xdr, &lock->oh);
276 	if (unlikely(error))
277 		goto out;
278 
279 	p = xdr_inline_decode(xdr, 8 + 8);
280 	if (unlikely(p == NULL))
281 		goto out_overflow;
282 
283 	fl->c.flc_flags = FL_POSIX;
284 	fl->c.flc_type  = exclusive != 0 ? F_WRLCK : F_RDLCK;
285 	p = xdr_decode_hyper(p, &l_offset);
286 	xdr_decode_hyper(p, &l_len);
287 	nlm4svc_set_file_lock_range(fl, l_offset, l_len);
288 	error = 0;
289 out:
290 	return error;
291 out_overflow:
292 	return -EIO;
293 }
294 
295 /*
296  *	string caller_name<LM_MAXSTRLEN>;
297  */
encode_caller_name(struct xdr_stream * xdr,const char * name)298 static void encode_caller_name(struct xdr_stream *xdr, const char *name)
299 {
300 	/* NB: client-side does not set lock->len */
301 	u32 length = strlen(name);
302 	__be32 *p;
303 
304 	p = xdr_reserve_space(xdr, 4 + length);
305 	xdr_encode_opaque(p, name, length);
306 }
307 
308 /*
309  *	struct nlm4_lock {
310  *		string	caller_name<LM_MAXSTRLEN>;
311  *		netobj	fh;
312  *		netobj	oh;
313  *		int32	svid;
314  *		uint64	l_offset;
315  *		uint64	l_len;
316  *	};
317  */
encode_nlm4_lock(struct xdr_stream * xdr,const struct nlm_lock * lock)318 static void encode_nlm4_lock(struct xdr_stream *xdr,
319 			     const struct nlm_lock *lock)
320 {
321 	u64 l_offset, l_len;
322 	__be32 *p;
323 
324 	encode_caller_name(xdr, lock->caller);
325 	encode_fh(xdr, &lock->fh);
326 	encode_netobj(xdr, lock->oh.data, lock->oh.len);
327 
328 	p = xdr_reserve_space(xdr, 4 + 8 + 8);
329 	*p++ = cpu_to_be32(lock->svid);
330 
331 	nlm4_compute_offsets(lock, &l_offset, &l_len);
332 	p = xdr_encode_hyper(p, l_offset);
333 	xdr_encode_hyper(p, l_len);
334 }
335 
336 
337 /*
338  * NLMv4 XDR encode functions
339  *
340  * NLMv4 argument types are defined in Appendix II of RFC 1813:
341  * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
342  * "Protocols for Interworking: XNFS, Version 3W".
343  */
344 
345 /*
346  *	struct nlm4_testargs {
347  *		netobj cookie;
348  *		bool exclusive;
349  *		struct nlm4_lock alock;
350  *	};
351  */
nlm4_xdr_enc_testargs(struct rpc_rqst * req,struct xdr_stream * xdr,const void * data)352 static void nlm4_xdr_enc_testargs(struct rpc_rqst *req,
353 				  struct xdr_stream *xdr,
354 				  const void *data)
355 {
356 	const struct nlm_args *args = data;
357 	const struct nlm_lock *lock = &args->lock;
358 
359 	encode_cookie(xdr, &args->cookie);
360 	encode_bool(xdr, lock->fl.c.flc_type == F_WRLCK);
361 	encode_nlm4_lock(xdr, lock);
362 }
363 
364 /*
365  *	struct nlm4_lockargs {
366  *		netobj cookie;
367  *		bool block;
368  *		bool exclusive;
369  *		struct nlm4_lock alock;
370  *		bool reclaim;
371  *		int state;
372  *	};
373  */
nlm4_xdr_enc_lockargs(struct rpc_rqst * req,struct xdr_stream * xdr,const void * data)374 static void nlm4_xdr_enc_lockargs(struct rpc_rqst *req,
375 				  struct xdr_stream *xdr,
376 				  const void *data)
377 {
378 	const struct nlm_args *args = data;
379 	const struct nlm_lock *lock = &args->lock;
380 
381 	encode_cookie(xdr, &args->cookie);
382 	encode_bool(xdr, args->block);
383 	encode_bool(xdr, lock->fl.c.flc_type == F_WRLCK);
384 	encode_nlm4_lock(xdr, lock);
385 	encode_bool(xdr, args->reclaim);
386 	encode_int32(xdr, args->state);
387 }
388 
389 /*
390  *	struct nlm4_cancargs {
391  *		netobj cookie;
392  *		bool block;
393  *		bool exclusive;
394  *		struct nlm4_lock alock;
395  *	};
396  */
nlm4_xdr_enc_cancargs(struct rpc_rqst * req,struct xdr_stream * xdr,const void * data)397 static void nlm4_xdr_enc_cancargs(struct rpc_rqst *req,
398 				  struct xdr_stream *xdr,
399 				  const void *data)
400 {
401 	const struct nlm_args *args = data;
402 	const struct nlm_lock *lock = &args->lock;
403 
404 	encode_cookie(xdr, &args->cookie);
405 	encode_bool(xdr, args->block);
406 	encode_bool(xdr, lock->fl.c.flc_type == F_WRLCK);
407 	encode_nlm4_lock(xdr, lock);
408 }
409 
410 /*
411  *	struct nlm4_unlockargs {
412  *		netobj cookie;
413  *		struct nlm4_lock alock;
414  *	};
415  */
nlm4_xdr_enc_unlockargs(struct rpc_rqst * req,struct xdr_stream * xdr,const void * data)416 static void nlm4_xdr_enc_unlockargs(struct rpc_rqst *req,
417 				    struct xdr_stream *xdr,
418 				    const void *data)
419 {
420 	const struct nlm_args *args = data;
421 	const struct nlm_lock *lock = &args->lock;
422 
423 	encode_cookie(xdr, &args->cookie);
424 	encode_nlm4_lock(xdr, lock);
425 }
426 
427 /*
428  *	struct nlm4_res {
429  *		netobj cookie;
430  *		nlm4_stat stat;
431  *	};
432  */
nlm4_xdr_enc_res(struct rpc_rqst * req,struct xdr_stream * xdr,const void * data)433 static void nlm4_xdr_enc_res(struct rpc_rqst *req,
434 			     struct xdr_stream *xdr,
435 			     const void *data)
436 {
437 	const struct nlm_res *result = data;
438 
439 	encode_cookie(xdr, &result->cookie);
440 	encode_nlm4_stat(xdr, result->status);
441 }
442 
443 /*
444  *	union nlm4_testrply switch (nlm4_stats stat) {
445  *	case NLM4_DENIED:
446  *		struct nlm4_holder holder;
447  *	default:
448  *		void;
449  *	};
450  *
451  *	struct nlm4_testres {
452  *		netobj cookie;
453  *		nlm4_testrply test_stat;
454  *	};
455  */
nlm4_xdr_enc_testres(struct rpc_rqst * req,struct xdr_stream * xdr,const void * data)456 static void nlm4_xdr_enc_testres(struct rpc_rqst *req,
457 				 struct xdr_stream *xdr,
458 				 const void *data)
459 {
460 	const struct nlm_res *result = data;
461 
462 	encode_cookie(xdr, &result->cookie);
463 	encode_nlm4_stat(xdr, result->status);
464 	if (result->status == nlm_lck_denied)
465 		encode_nlm4_holder(xdr, result);
466 }
467 
468 
469 /*
470  * NLMv4 XDR decode functions
471  *
472  * NLMv4 argument types are defined in Appendix II of RFC 1813:
473  * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
474  * "Protocols for Interworking: XNFS, Version 3W".
475  */
476 
477 /*
478  *	union nlm4_testrply switch (nlm4_stats stat) {
479  *	case NLM4_DENIED:
480  *		struct nlm4_holder holder;
481  *	default:
482  *		void;
483  *	};
484  *
485  *	struct nlm4_testres {
486  *		netobj cookie;
487  *		nlm4_testrply test_stat;
488  *	};
489  */
decode_nlm4_testrply(struct xdr_stream * xdr,struct nlm_res * result)490 static int decode_nlm4_testrply(struct xdr_stream *xdr,
491 				struct nlm_res *result)
492 {
493 	int error;
494 
495 	error = decode_nlm4_stat(xdr, &result->status);
496 	if (unlikely(error))
497 		goto out;
498 	if (result->status == nlm_lck_denied)
499 		error = decode_nlm4_holder(xdr, result);
500 out:
501 	return error;
502 }
503 
nlm4_xdr_dec_testres(struct rpc_rqst * req,struct xdr_stream * xdr,void * data)504 static int nlm4_xdr_dec_testres(struct rpc_rqst *req,
505 				struct xdr_stream *xdr,
506 				void *data)
507 {
508 	struct nlm_res *result = data;
509 	int error;
510 
511 	error = decode_cookie(xdr, &result->cookie);
512 	if (unlikely(error))
513 		goto out;
514 	error = decode_nlm4_testrply(xdr, result);
515 out:
516 	return error;
517 }
518 
519 /*
520  *	struct nlm4_res {
521  *		netobj cookie;
522  *		nlm4_stat stat;
523  *	};
524  */
nlm4_xdr_dec_res(struct rpc_rqst * req,struct xdr_stream * xdr,void * data)525 static int nlm4_xdr_dec_res(struct rpc_rqst *req,
526 			    struct xdr_stream *xdr,
527 			    void *data)
528 {
529 	struct nlm_res *result = data;
530 	int error;
531 
532 	error = decode_cookie(xdr, &result->cookie);
533 	if (unlikely(error))
534 		goto out;
535 	error = decode_nlm4_stat(xdr, &result->status);
536 out:
537 	return error;
538 }
539 
540 
541 /*
542  * For NLM, a void procedure really returns nothing
543  */
544 #define nlm4_xdr_dec_norep	NULL
545 
546 #define PROC(proc, argtype, restype)					\
547 [NLMPROC_##proc] = {							\
548 	.p_proc      = NLMPROC_##proc,					\
549 	.p_encode    = nlm4_xdr_enc_##argtype,				\
550 	.p_decode    = nlm4_xdr_dec_##restype,				\
551 	.p_arglen    = NLM4_##argtype##_sz,				\
552 	.p_replen    = NLM4_##restype##_sz,				\
553 	.p_statidx   = NLMPROC_##proc,					\
554 	.p_name      = #proc,						\
555 	}
556 
557 static const struct rpc_procinfo nlm4_procedures[] = {
558 	PROC(TEST,		testargs,	testres),
559 	PROC(LOCK,		lockargs,	res),
560 	PROC(CANCEL,		cancargs,	res),
561 	PROC(UNLOCK,		unlockargs,	res),
562 	PROC(GRANTED,		testargs,	res),
563 	PROC(TEST_MSG,		testargs,	norep),
564 	PROC(LOCK_MSG,		lockargs,	norep),
565 	PROC(CANCEL_MSG,	cancargs,	norep),
566 	PROC(UNLOCK_MSG,	unlockargs,	norep),
567 	PROC(GRANTED_MSG,	testargs,	norep),
568 	PROC(TEST_RES,		testres,	norep),
569 	PROC(LOCK_RES,		res,		norep),
570 	PROC(CANCEL_RES,	res,		norep),
571 	PROC(UNLOCK_RES,	res,		norep),
572 	PROC(GRANTED_RES,	res,		norep),
573 };
574 
575 static unsigned int nlm_version4_counts[ARRAY_SIZE(nlm4_procedures)];
576 const struct rpc_version nlm_version4 = {
577 	.number		= 4,
578 	.nrprocs	= ARRAY_SIZE(nlm4_procedures),
579 	.procs		= nlm4_procedures,
580 	.counts		= nlm_version4_counts,
581 };
582