1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/lockd/clntxdr.c
4 *
5 * XDR functions to encode/decode NLM version 3 RPC arguments and results.
6 * NLM version 3 is backwards compatible with NLM versions 1 and 2.
7 *
8 * NLM client-side only.
9 *
10 * Copyright (C) 2010, Oracle. All rights reserved.
11 */
12
13#include <linux/types.h>
14#include <linux/sunrpc/xdr.h>
15#include <linux/sunrpc/clnt.h>
16#include <linux/sunrpc/stats.h>
17#include <linux/lockd/lockd.h>
18
19#include <uapi/linux/nfs2.h>
20
21#define NLMDBG_FACILITY NLMDBG_XDR
22
23#if (NLMCLNT_OHSIZE > XDR_MAX_NETOBJ)
24# error "NLM host name cannot be larger than XDR_MAX_NETOBJ!"
25#endif
26
27/*
28 * Declare the space requirements for NLM arguments and replies as
29 * number of 32bit-words
30 */
31#define NLM_cookie_sz (1+(NLM_MAXCOOKIELEN>>2))
32#define NLM_caller_sz (1+(NLMCLNT_OHSIZE>>2))
33#define NLM_owner_sz (1+(NLMCLNT_OHSIZE>>2))
34#define NLM_fhandle_sz (1+(NFS2_FHSIZE>>2))
35#define NLM_lock_sz (3+NLM_caller_sz+NLM_owner_sz+NLM_fhandle_sz)
36#define NLM_holder_sz (4+NLM_owner_sz)
37
38#define NLM_testargs_sz (NLM_cookie_sz+1+NLM_lock_sz)
39#define NLM_lockargs_sz (NLM_cookie_sz+4+NLM_lock_sz)
40#define NLM_cancargs_sz (NLM_cookie_sz+2+NLM_lock_sz)
41#define NLM_unlockargs_sz (NLM_cookie_sz+NLM_lock_sz)
42
43#define NLM_testres_sz (NLM_cookie_sz+1+NLM_holder_sz)
44#define NLM_res_sz (NLM_cookie_sz+1)
45#define NLM_norep_sz (0)
46
47
48static s32 loff_t_to_s32(loff_t offset)
49{
50 s32 res;
51
52 if (offset >= NLM_OFFSET_MAX)
53 res = NLM_OFFSET_MAX;
54 else if (offset <= -NLM_OFFSET_MAX)
55 res = -NLM_OFFSET_MAX;
56 else
57 res = offset;
58 return res;
59}
60
61static void nlm_compute_offsets(const struct nlm_lock *lock,
62 u32 *l_offset, u32 *l_len)
63{
64 const struct file_lock *fl = &lock->fl;
65
66 *l_offset = loff_t_to_s32(offset: fl->fl_start);
67 if (fl->fl_end == OFFSET_MAX)
68 *l_len = 0;
69 else
70 *l_len = loff_t_to_s32(offset: fl->fl_end - fl->fl_start + 1);
71}
72
73/*
74 * Encode/decode NLMv3 basic data types
75 *
76 * Basic NLMv3 data types are not defined in an IETF standards
77 * document. X/Open has a description of these data types that
78 * is useful. See Chapter 10 of "Protocols for Interworking:
79 * XNFS, Version 3W".
80 *
81 * Not all basic data types have their own encoding and decoding
82 * functions. For run-time efficiency, some data types are encoded
83 * or decoded inline.
84 */
85
86static void encode_bool(struct xdr_stream *xdr, const int value)
87{
88 __be32 *p;
89
90 p = xdr_reserve_space(xdr, nbytes: 4);
91 *p = value ? xdr_one : xdr_zero;
92}
93
94static void encode_int32(struct xdr_stream *xdr, const s32 value)
95{
96 __be32 *p;
97
98 p = xdr_reserve_space(xdr, nbytes: 4);
99 *p = cpu_to_be32(value);
100}
101
102/*
103 * typedef opaque netobj<MAXNETOBJ_SZ>
104 */
105static void encode_netobj(struct xdr_stream *xdr,
106 const u8 *data, const unsigned int length)
107{
108 __be32 *p;
109
110 p = xdr_reserve_space(xdr, nbytes: 4 + length);
111 xdr_encode_opaque(p, ptr: data, len: length);
112}
113
114static int decode_netobj(struct xdr_stream *xdr,
115 struct xdr_netobj *obj)
116{
117 ssize_t ret;
118
119 ret = xdr_stream_decode_opaque_inline(xdr, ptr: (void *)&obj->data,
120 XDR_MAX_NETOBJ);
121 if (unlikely(ret < 0))
122 return -EIO;
123 obj->len = ret;
124 return 0;
125}
126
127/*
128 * netobj cookie;
129 */
130static void encode_cookie(struct xdr_stream *xdr,
131 const struct nlm_cookie *cookie)
132{
133 encode_netobj(xdr, data: (u8 *)&cookie->data, length: cookie->len);
134}
135
136static int decode_cookie(struct xdr_stream *xdr,
137 struct nlm_cookie *cookie)
138{
139 u32 length;
140 __be32 *p;
141
142 p = xdr_inline_decode(xdr, nbytes: 4);
143 if (unlikely(p == NULL))
144 goto out_overflow;
145 length = be32_to_cpup(p: p++);
146 /* apparently HPUX can return empty cookies */
147 if (length == 0)
148 goto out_hpux;
149 if (length > NLM_MAXCOOKIELEN)
150 goto out_size;
151 p = xdr_inline_decode(xdr, nbytes: length);
152 if (unlikely(p == NULL))
153 goto out_overflow;
154 cookie->len = length;
155 memcpy(cookie->data, p, length);
156 return 0;
157out_hpux:
158 cookie->len = 4;
159 memset(cookie->data, 0, 4);
160 return 0;
161out_size:
162 dprintk("NFS: returned cookie was too long: %u\n", length);
163 return -EIO;
164out_overflow:
165 return -EIO;
166}
167
168/*
169 * netobj fh;
170 */
171static void encode_fh(struct xdr_stream *xdr, const struct nfs_fh *fh)
172{
173 encode_netobj(xdr, data: (u8 *)&fh->data, NFS2_FHSIZE);
174}
175
176/*
177 * enum nlm_stats {
178 * LCK_GRANTED = 0,
179 * LCK_DENIED = 1,
180 * LCK_DENIED_NOLOCKS = 2,
181 * LCK_BLOCKED = 3,
182 * LCK_DENIED_GRACE_PERIOD = 4
183 * };
184 *
185 *
186 * struct nlm_stat {
187 * nlm_stats stat;
188 * };
189 *
190 * NB: we don't swap bytes for the NLM status values. The upper
191 * layers deal directly with the status value in network byte
192 * order.
193 */
194
195static void encode_nlm_stat(struct xdr_stream *xdr,
196 const __be32 stat)
197{
198 __be32 *p;
199
200 WARN_ON_ONCE(be32_to_cpu(stat) > NLM_LCK_DENIED_GRACE_PERIOD);
201 p = xdr_reserve_space(xdr, nbytes: 4);
202 *p = stat;
203}
204
205static int decode_nlm_stat(struct xdr_stream *xdr,
206 __be32 *stat)
207{
208 __be32 *p;
209
210 p = xdr_inline_decode(xdr, nbytes: 4);
211 if (unlikely(p == NULL))
212 goto out_overflow;
213 if (unlikely(ntohl(*p) > ntohl(nlm_lck_denied_grace_period)))
214 goto out_enum;
215 *stat = *p;
216 return 0;
217out_enum:
218 dprintk("%s: server returned invalid nlm_stats value: %u\n",
219 __func__, be32_to_cpup(p));
220 return -EIO;
221out_overflow:
222 return -EIO;
223}
224
225/*
226 * struct nlm_holder {
227 * bool exclusive;
228 * int uppid;
229 * netobj oh;
230 * unsigned l_offset;
231 * unsigned l_len;
232 * };
233 */
234static void encode_nlm_holder(struct xdr_stream *xdr,
235 const struct nlm_res *result)
236{
237 const struct nlm_lock *lock = &result->lock;
238 u32 l_offset, l_len;
239 __be32 *p;
240
241 encode_bool(xdr, value: lock->fl.fl_type == F_RDLCK);
242 encode_int32(xdr, value: lock->svid);
243 encode_netobj(xdr, data: lock->oh.data, length: lock->oh.len);
244
245 p = xdr_reserve_space(xdr, nbytes: 4 + 4);
246 nlm_compute_offsets(lock, l_offset: &l_offset, l_len: &l_len);
247 *p++ = cpu_to_be32(l_offset);
248 *p = cpu_to_be32(l_len);
249}
250
251static int decode_nlm_holder(struct xdr_stream *xdr, struct nlm_res *result)
252{
253 struct nlm_lock *lock = &result->lock;
254 struct file_lock *fl = &lock->fl;
255 u32 exclusive, l_offset, l_len;
256 int error;
257 __be32 *p;
258 s32 end;
259
260 memset(lock, 0, sizeof(*lock));
261 locks_init_lock(fl);
262
263 p = xdr_inline_decode(xdr, nbytes: 4 + 4);
264 if (unlikely(p == NULL))
265 goto out_overflow;
266 exclusive = be32_to_cpup(p: p++);
267 lock->svid = be32_to_cpup(p);
268 fl->fl_pid = (pid_t)lock->svid;
269
270 error = decode_netobj(xdr, obj: &lock->oh);
271 if (unlikely(error))
272 goto out;
273
274 p = xdr_inline_decode(xdr, nbytes: 4 + 4);
275 if (unlikely(p == NULL))
276 goto out_overflow;
277
278 fl->fl_flags = FL_POSIX;
279 fl->fl_type = exclusive != 0 ? F_WRLCK : F_RDLCK;
280 l_offset = be32_to_cpup(p: p++);
281 l_len = be32_to_cpup(p);
282 end = l_offset + l_len - 1;
283
284 fl->fl_start = (loff_t)l_offset;
285 if (l_len == 0 || end < 0)
286 fl->fl_end = OFFSET_MAX;
287 else
288 fl->fl_end = (loff_t)end;
289 error = 0;
290out:
291 return error;
292out_overflow:
293 return -EIO;
294}
295
296/*
297 * string caller_name<LM_MAXSTRLEN>;
298 */
299static void encode_caller_name(struct xdr_stream *xdr, const char *name)
300{
301 /* NB: client-side does not set lock->len */
302 u32 length = strlen(name);
303 __be32 *p;
304
305 p = xdr_reserve_space(xdr, nbytes: 4 + length);
306 xdr_encode_opaque(p, ptr: name, len: length);
307}
308
309/*
310 * struct nlm_lock {
311 * string caller_name<LM_MAXSTRLEN>;
312 * netobj fh;
313 * netobj oh;
314 * int uppid;
315 * unsigned l_offset;
316 * unsigned l_len;
317 * };
318 */
319static void encode_nlm_lock(struct xdr_stream *xdr,
320 const struct nlm_lock *lock)
321{
322 u32 l_offset, l_len;
323 __be32 *p;
324
325 encode_caller_name(xdr, name: lock->caller);
326 encode_fh(xdr, fh: &lock->fh);
327 encode_netobj(xdr, data: lock->oh.data, length: lock->oh.len);
328
329 p = xdr_reserve_space(xdr, nbytes: 4 + 4 + 4);
330 *p++ = cpu_to_be32(lock->svid);
331
332 nlm_compute_offsets(lock, l_offset: &l_offset, l_len: &l_len);
333 *p++ = cpu_to_be32(l_offset);
334 *p = cpu_to_be32(l_len);
335}
336
337
338/*
339 * NLMv3 XDR encode functions
340 *
341 * NLMv3 argument types are defined in Chapter 10 of The Open Group's
342 * "Protocols for Interworking: XNFS, Version 3W".
343 */
344
345/*
346 * struct nlm_testargs {
347 * netobj cookie;
348 * bool exclusive;
349 * struct nlm_lock alock;
350 * };
351 */
352static void nlm_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, cookie: &args->cookie);
360 encode_bool(xdr, value: lock->fl.fl_type == F_WRLCK);
361 encode_nlm_lock(xdr, lock);
362}
363
364/*
365 * struct nlm_lockargs {
366 * netobj cookie;
367 * bool block;
368 * bool exclusive;
369 * struct nlm_lock alock;
370 * bool reclaim;
371 * int state;
372 * };
373 */
374static void nlm_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, cookie: &args->cookie);
382 encode_bool(xdr, value: args->block);
383 encode_bool(xdr, value: lock->fl.fl_type == F_WRLCK);
384 encode_nlm_lock(xdr, lock);
385 encode_bool(xdr, value: args->reclaim);
386 encode_int32(xdr, value: args->state);
387}
388
389/*
390 * struct nlm_cancargs {
391 * netobj cookie;
392 * bool block;
393 * bool exclusive;
394 * struct nlm_lock alock;
395 * };
396 */
397static void nlm_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, cookie: &args->cookie);
405 encode_bool(xdr, value: args->block);
406 encode_bool(xdr, value: lock->fl.fl_type == F_WRLCK);
407 encode_nlm_lock(xdr, lock);
408}
409
410/*
411 * struct nlm_unlockargs {
412 * netobj cookie;
413 * struct nlm_lock alock;
414 * };
415 */
416static void nlm_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, cookie: &args->cookie);
424 encode_nlm_lock(xdr, lock);
425}
426
427/*
428 * struct nlm_res {
429 * netobj cookie;
430 * nlm_stat stat;
431 * };
432 */
433static void nlm_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, cookie: &result->cookie);
440 encode_nlm_stat(xdr, stat: result->status);
441}
442
443/*
444 * union nlm_testrply switch (nlm_stats stat) {
445 * case LCK_DENIED:
446 * struct nlm_holder holder;
447 * default:
448 * void;
449 * };
450 *
451 * struct nlm_testres {
452 * netobj cookie;
453 * nlm_testrply test_stat;
454 * };
455 */
456static void encode_nlm_testrply(struct xdr_stream *xdr,
457 const struct nlm_res *result)
458{
459 if (result->status == nlm_lck_denied)
460 encode_nlm_holder(xdr, result);
461}
462
463static void nlm_xdr_enc_testres(struct rpc_rqst *req,
464 struct xdr_stream *xdr,
465 const void *data)
466{
467 const struct nlm_res *result = data;
468
469 encode_cookie(xdr, cookie: &result->cookie);
470 encode_nlm_stat(xdr, stat: result->status);
471 encode_nlm_testrply(xdr, result);
472}
473
474
475/*
476 * NLMv3 XDR decode functions
477 *
478 * NLMv3 result types are defined in Chapter 10 of The Open Group's
479 * "Protocols for Interworking: XNFS, Version 3W".
480 */
481
482/*
483 * union nlm_testrply switch (nlm_stats stat) {
484 * case LCK_DENIED:
485 * struct nlm_holder holder;
486 * default:
487 * void;
488 * };
489 *
490 * struct nlm_testres {
491 * netobj cookie;
492 * nlm_testrply test_stat;
493 * };
494 */
495static int decode_nlm_testrply(struct xdr_stream *xdr,
496 struct nlm_res *result)
497{
498 int error;
499
500 error = decode_nlm_stat(xdr, stat: &result->status);
501 if (unlikely(error))
502 goto out;
503 if (result->status == nlm_lck_denied)
504 error = decode_nlm_holder(xdr, result);
505out:
506 return error;
507}
508
509static int nlm_xdr_dec_testres(struct rpc_rqst *req,
510 struct xdr_stream *xdr,
511 void *data)
512{
513 struct nlm_res *result = data;
514 int error;
515
516 error = decode_cookie(xdr, cookie: &result->cookie);
517 if (unlikely(error))
518 goto out;
519 error = decode_nlm_testrply(xdr, result);
520out:
521 return error;
522}
523
524/*
525 * struct nlm_res {
526 * netobj cookie;
527 * nlm_stat stat;
528 * };
529 */
530static int nlm_xdr_dec_res(struct rpc_rqst *req,
531 struct xdr_stream *xdr,
532 void *data)
533{
534 struct nlm_res *result = data;
535 int error;
536
537 error = decode_cookie(xdr, cookie: &result->cookie);
538 if (unlikely(error))
539 goto out;
540 error = decode_nlm_stat(xdr, stat: &result->status);
541out:
542 return error;
543}
544
545
546/*
547 * For NLM, a void procedure really returns nothing
548 */
549#define nlm_xdr_dec_norep NULL
550
551#define PROC(proc, argtype, restype) \
552[NLMPROC_##proc] = { \
553 .p_proc = NLMPROC_##proc, \
554 .p_encode = nlm_xdr_enc_##argtype, \
555 .p_decode = nlm_xdr_dec_##restype, \
556 .p_arglen = NLM_##argtype##_sz, \
557 .p_replen = NLM_##restype##_sz, \
558 .p_statidx = NLMPROC_##proc, \
559 .p_name = #proc, \
560 }
561
562static const struct rpc_procinfo nlm_procedures[] = {
563 PROC(TEST, testargs, testres),
564 PROC(LOCK, lockargs, res),
565 PROC(CANCEL, cancargs, res),
566 PROC(UNLOCK, unlockargs, res),
567 PROC(GRANTED, testargs, res),
568 PROC(TEST_MSG, testargs, norep),
569 PROC(LOCK_MSG, lockargs, norep),
570 PROC(CANCEL_MSG, cancargs, norep),
571 PROC(UNLOCK_MSG, unlockargs, norep),
572 PROC(GRANTED_MSG, testargs, norep),
573 PROC(TEST_RES, testres, norep),
574 PROC(LOCK_RES, res, norep),
575 PROC(CANCEL_RES, res, norep),
576 PROC(UNLOCK_RES, res, norep),
577 PROC(GRANTED_RES, res, norep),
578};
579
580static unsigned int nlm_version1_counts[ARRAY_SIZE(nlm_procedures)];
581static const struct rpc_version nlm_version1 = {
582 .number = 1,
583 .nrprocs = ARRAY_SIZE(nlm_procedures),
584 .procs = nlm_procedures,
585 .counts = nlm_version1_counts,
586};
587
588static unsigned int nlm_version3_counts[ARRAY_SIZE(nlm_procedures)];
589static const struct rpc_version nlm_version3 = {
590 .number = 3,
591 .nrprocs = ARRAY_SIZE(nlm_procedures),
592 .procs = nlm_procedures,
593 .counts = nlm_version3_counts,
594};
595
596static const struct rpc_version *nlm_versions[] = {
597 [1] = &nlm_version1,
598 [3] = &nlm_version3,
599#ifdef CONFIG_LOCKD_V4
600 [4] = &nlm_version4,
601#endif
602};
603
604static struct rpc_stat nlm_rpc_stats;
605
606const struct rpc_program nlm_program = {
607 .name = "lockd",
608 .number = NLM_PROGRAM,
609 .nrvers = ARRAY_SIZE(nlm_versions),
610 .version = nlm_versions,
611 .stats = &nlm_rpc_stats,
612};
613

source code of linux/fs/lockd/clntxdr.c