1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/lockd/clntxdr.c
4 *
5 * XDR functions to encode/decode NLM version 1 and 3 RPC
6 * arguments and results. NLM version 2 is not specified
7 * by a standard, thus it is not implemented.
8 *
9 * NLM client-side only.
10 *
11 * Copyright (C) 2010, Oracle. All rights reserved.
12 */
13
14#include <linux/types.h>
15#include <linux/sunrpc/xdr.h>
16#include <linux/sunrpc/clnt.h>
17#include <linux/sunrpc/stats.h>
18#include <linux/lockd/lockd.h>
19
20#include <uapi/linux/nfs2.h>
21
22#define NLMDBG_FACILITY NLMDBG_XDR
23
24#if (NLMCLNT_OHSIZE > XDR_MAX_NETOBJ)
25# error "NLM host name cannot be larger than XDR_MAX_NETOBJ!"
26#endif
27
28/*
29 * Declare the space requirements for NLM arguments and replies as
30 * number of 32bit-words
31 */
32#define NLM_cookie_sz (1+(NLM_MAXCOOKIELEN>>2))
33#define NLM_caller_sz (1+(NLMCLNT_OHSIZE>>2))
34#define NLM_owner_sz (1+(NLMCLNT_OHSIZE>>2))
35#define NLM_fhandle_sz (1+(NFS2_FHSIZE>>2))
36#define NLM_lock_sz (3+NLM_caller_sz+NLM_owner_sz+NLM_fhandle_sz)
37#define NLM_holder_sz (4+NLM_owner_sz)
38
39#define NLM_testargs_sz (NLM_cookie_sz+1+NLM_lock_sz)
40#define NLM_lockargs_sz (NLM_cookie_sz+4+NLM_lock_sz)
41#define NLM_cancargs_sz (NLM_cookie_sz+2+NLM_lock_sz)
42#define NLM_unlockargs_sz (NLM_cookie_sz+NLM_lock_sz)
43
44#define NLM_testres_sz (NLM_cookie_sz+1+NLM_holder_sz)
45#define NLM_res_sz (NLM_cookie_sz+1)
46#define NLM_norep_sz (0)
47
48
49static s32 loff_t_to_s32(loff_t offset)
50{
51 s32 res;
52
53 if (offset >= NLM_OFFSET_MAX)
54 res = NLM_OFFSET_MAX;
55 else if (offset <= -NLM_OFFSET_MAX)
56 res = -NLM_OFFSET_MAX;
57 else
58 res = offset;
59 return res;
60}
61
62static void nlm_compute_offsets(const struct nlm_lock *lock,
63 u32 *l_offset, u32 *l_len)
64{
65 const struct file_lock *fl = &lock->fl;
66
67 *l_offset = loff_t_to_s32(offset: fl->fl_start);
68 if (fl->fl_end == OFFSET_MAX)
69 *l_len = 0;
70 else
71 *l_len = loff_t_to_s32(offset: fl->fl_end - fl->fl_start + 1);
72}
73
74/*
75 * Encode/decode NLMv3 basic data types
76 *
77 * Basic NLMv3 data types are not defined in an IETF standards
78 * document. X/Open has a description of these data types that
79 * is useful. See Chapter 10 of "Protocols for Interworking:
80 * XNFS, Version 3W".
81 *
82 * Not all basic data types have their own encoding and decoding
83 * functions. For run-time efficiency, some data types are encoded
84 * or decoded inline.
85 */
86
87static void encode_bool(struct xdr_stream *xdr, const int value)
88{
89 __be32 *p;
90
91 p = xdr_reserve_space(xdr, nbytes: 4);
92 *p = value ? xdr_one : xdr_zero;
93}
94
95static void encode_int32(struct xdr_stream *xdr, const s32 value)
96{
97 __be32 *p;
98
99 p = xdr_reserve_space(xdr, nbytes: 4);
100 *p = cpu_to_be32(value);
101}
102
103/*
104 * typedef opaque netobj<MAXNETOBJ_SZ>
105 */
106static void encode_netobj(struct xdr_stream *xdr,
107 const u8 *data, const unsigned int length)
108{
109 __be32 *p;
110
111 p = xdr_reserve_space(xdr, nbytes: 4 + length);
112 xdr_encode_opaque(p, ptr: data, len: length);
113}
114
115static int decode_netobj(struct xdr_stream *xdr,
116 struct xdr_netobj *obj)
117{
118 ssize_t ret;
119
120 ret = xdr_stream_decode_opaque_inline(xdr, ptr: (void *)&obj->data,
121 XDR_MAX_NETOBJ);
122 if (unlikely(ret < 0))
123 return -EIO;
124 obj->len = ret;
125 return 0;
126}
127
128/*
129 * netobj cookie;
130 */
131static void encode_cookie(struct xdr_stream *xdr,
132 const struct nlm_cookie *cookie)
133{
134 encode_netobj(xdr, data: (u8 *)&cookie->data, length: cookie->len);
135}
136
137static int decode_cookie(struct xdr_stream *xdr,
138 struct nlm_cookie *cookie)
139{
140 u32 length;
141 __be32 *p;
142
143 p = xdr_inline_decode(xdr, nbytes: 4);
144 if (unlikely(p == NULL))
145 goto out_overflow;
146 length = be32_to_cpup(p: p++);
147 /* apparently HPUX can return empty cookies */
148 if (length == 0)
149 goto out_hpux;
150 if (length > NLM_MAXCOOKIELEN)
151 goto out_size;
152 p = xdr_inline_decode(xdr, nbytes: length);
153 if (unlikely(p == NULL))
154 goto out_overflow;
155 cookie->len = length;
156 memcpy(to: cookie->data, from: p, len: length);
157 return 0;
158out_hpux:
159 cookie->len = 4;
160 memset(s: cookie->data, c: 0, n: 4);
161 return 0;
162out_size:
163 dprintk("NFS: returned cookie was too long: %u\n", length);
164 return -EIO;
165out_overflow:
166 return -EIO;
167}
168
169/*
170 * netobj fh;
171 */
172static void encode_fh(struct xdr_stream *xdr, const struct nfs_fh *fh)
173{
174 encode_netobj(xdr, data: (u8 *)&fh->data, NFS2_FHSIZE);
175}
176
177/*
178 * enum nlm_stats {
179 * LCK_GRANTED = 0,
180 * LCK_DENIED = 1,
181 * LCK_DENIED_NOLOCKS = 2,
182 * LCK_BLOCKED = 3,
183 * LCK_DENIED_GRACE_PERIOD = 4
184 * };
185 *
186 *
187 * struct nlm_stat {
188 * nlm_stats stat;
189 * };
190 *
191 * NB: we don't swap bytes for the NLM status values. The upper
192 * layers deal directly with the status value in network byte
193 * order.
194 */
195
196static void encode_nlm_stat(struct xdr_stream *xdr,
197 const __be32 stat)
198{
199 __be32 *p;
200
201 WARN_ON_ONCE(be32_to_cpu(stat) > NLM_LCK_DENIED_GRACE_PERIOD);
202 p = xdr_reserve_space(xdr, nbytes: 4);
203 *p = stat;
204}
205
206static int decode_nlm_stat(struct xdr_stream *xdr,
207 __be32 *stat)
208{
209 __be32 *p;
210
211 p = xdr_inline_decode(xdr, nbytes: 4);
212 if (unlikely(p == NULL))
213 goto out_overflow;
214 if (unlikely(ntohl(*p) > ntohl(nlm_lck_denied_grace_period)))
215 goto out_enum;
216 *stat = *p;
217 return 0;
218out_enum:
219 dprintk("%s: server returned invalid nlm_stats value: %u\n",
220 __func__, be32_to_cpup(p));
221 return -EIO;
222out_overflow:
223 return -EIO;
224}
225
226/*
227 * struct nlm_holder {
228 * bool exclusive;
229 * int uppid;
230 * netobj oh;
231 * unsigned l_offset;
232 * unsigned l_len;
233 * };
234 */
235static void encode_nlm_holder(struct xdr_stream *xdr,
236 const struct nlm_res *result)
237{
238 const struct nlm_lock *lock = &result->lock;
239 u32 l_offset, l_len;
240 __be32 *p;
241
242 encode_bool(xdr, value: lock->fl.c.flc_type == F_RDLCK);
243 encode_int32(xdr, value: lock->svid);
244 encode_netobj(xdr, data: lock->oh.data, length: lock->oh.len);
245
246 p = xdr_reserve_space(xdr, nbytes: 4 + 4);
247 nlm_compute_offsets(lock, l_offset: &l_offset, l_len: &l_len);
248 *p++ = cpu_to_be32(l_offset);
249 *p = cpu_to_be32(l_len);
250}
251
252static int decode_nlm_holder(struct xdr_stream *xdr, struct nlm_res *result)
253{
254 struct nlm_lock *lock = &result->lock;
255 struct file_lock *fl = &lock->fl;
256 u32 exclusive, l_offset, l_len;
257 int error;
258 __be32 *p;
259 s32 end;
260
261 memset(s: lock, c: 0, n: sizeof(*lock));
262 locks_init_lock(fl);
263
264 p = xdr_inline_decode(xdr, nbytes: 4 + 4);
265 if (unlikely(p == NULL))
266 goto out_overflow;
267 exclusive = be32_to_cpup(p: p++);
268 lock->svid = be32_to_cpup(p);
269 fl->c.flc_pid = (pid_t)lock->svid;
270
271 error = decode_netobj(xdr, obj: &lock->oh);
272 if (unlikely(error))
273 goto out;
274
275 p = xdr_inline_decode(xdr, nbytes: 4 + 4);
276 if (unlikely(p == NULL))
277 goto out_overflow;
278
279 fl->c.flc_flags = FL_POSIX;
280 fl->c.flc_type = exclusive != 0 ? F_WRLCK : F_RDLCK;
281 l_offset = be32_to_cpup(p: p++);
282 l_len = be32_to_cpup(p);
283 end = l_offset + l_len - 1;
284
285 fl->fl_start = (loff_t)l_offset;
286 if (l_len == 0 || end < 0)
287 fl->fl_end = OFFSET_MAX;
288 else
289 fl->fl_end = (loff_t)end;
290 error = 0;
291out:
292 return error;
293out_overflow:
294 return -EIO;
295}
296
297/*
298 * string caller_name<LM_MAXSTRLEN>;
299 */
300static void encode_caller_name(struct xdr_stream *xdr, const char *name)
301{
302 /* NB: client-side does not set lock->len */
303 u32 length = strlen(name);
304 __be32 *p;
305
306 p = xdr_reserve_space(xdr, nbytes: 4 + length);
307 xdr_encode_opaque(p, ptr: name, len: length);
308}
309
310/*
311 * struct nlm_lock {
312 * string caller_name<LM_MAXSTRLEN>;
313 * netobj fh;
314 * netobj oh;
315 * int uppid;
316 * unsigned l_offset;
317 * unsigned l_len;
318 * };
319 */
320static void encode_nlm_lock(struct xdr_stream *xdr,
321 const struct nlm_lock *lock)
322{
323 u32 l_offset, l_len;
324 __be32 *p;
325
326 encode_caller_name(xdr, name: lock->caller);
327 encode_fh(xdr, fh: &lock->fh);
328 encode_netobj(xdr, data: lock->oh.data, length: lock->oh.len);
329
330 p = xdr_reserve_space(xdr, nbytes: 4 + 4 + 4);
331 *p++ = cpu_to_be32(lock->svid);
332
333 nlm_compute_offsets(lock, l_offset: &l_offset, l_len: &l_len);
334 *p++ = cpu_to_be32(l_offset);
335 *p = cpu_to_be32(l_len);
336}
337
338
339/*
340 * NLMv3 XDR encode functions
341 *
342 * NLMv3 argument types are defined in Chapter 10 of The Open Group's
343 * "Protocols for Interworking: XNFS, Version 3W".
344 */
345
346/*
347 * struct nlm_testargs {
348 * netobj cookie;
349 * bool exclusive;
350 * struct nlm_lock alock;
351 * };
352 */
353static void nlm_xdr_enc_testargs(struct rpc_rqst *req,
354 struct xdr_stream *xdr,
355 const void *data)
356{
357 const struct nlm_args *args = data;
358 const struct nlm_lock *lock = &args->lock;
359
360 encode_cookie(xdr, cookie: &args->cookie);
361 encode_bool(xdr, value: lock->fl.c.flc_type == F_WRLCK);
362 encode_nlm_lock(xdr, lock);
363}
364
365/*
366 * struct nlm_lockargs {
367 * netobj cookie;
368 * bool block;
369 * bool exclusive;
370 * struct nlm_lock alock;
371 * bool reclaim;
372 * int state;
373 * };
374 */
375static void nlm_xdr_enc_lockargs(struct rpc_rqst *req,
376 struct xdr_stream *xdr,
377 const void *data)
378{
379 const struct nlm_args *args = data;
380 const struct nlm_lock *lock = &args->lock;
381
382 encode_cookie(xdr, cookie: &args->cookie);
383 encode_bool(xdr, value: args->block);
384 encode_bool(xdr, value: lock->fl.c.flc_type == F_WRLCK);
385 encode_nlm_lock(xdr, lock);
386 encode_bool(xdr, value: args->reclaim);
387 encode_int32(xdr, value: args->state);
388}
389
390/*
391 * struct nlm_cancargs {
392 * netobj cookie;
393 * bool block;
394 * bool exclusive;
395 * struct nlm_lock alock;
396 * };
397 */
398static void nlm_xdr_enc_cancargs(struct rpc_rqst *req,
399 struct xdr_stream *xdr,
400 const void *data)
401{
402 const struct nlm_args *args = data;
403 const struct nlm_lock *lock = &args->lock;
404
405 encode_cookie(xdr, cookie: &args->cookie);
406 encode_bool(xdr, value: args->block);
407 encode_bool(xdr, value: lock->fl.c.flc_type == F_WRLCK);
408 encode_nlm_lock(xdr, lock);
409}
410
411/*
412 * struct nlm_unlockargs {
413 * netobj cookie;
414 * struct nlm_lock alock;
415 * };
416 */
417static void nlm_xdr_enc_unlockargs(struct rpc_rqst *req,
418 struct xdr_stream *xdr,
419 const void *data)
420{
421 const struct nlm_args *args = data;
422 const struct nlm_lock *lock = &args->lock;
423
424 encode_cookie(xdr, cookie: &args->cookie);
425 encode_nlm_lock(xdr, lock);
426}
427
428/*
429 * struct nlm_res {
430 * netobj cookie;
431 * nlm_stat stat;
432 * };
433 */
434static void nlm_xdr_enc_res(struct rpc_rqst *req,
435 struct xdr_stream *xdr,
436 const void *data)
437{
438 const struct nlm_res *result = data;
439
440 encode_cookie(xdr, cookie: &result->cookie);
441 encode_nlm_stat(xdr, stat: result->status);
442}
443
444/*
445 * union nlm_testrply switch (nlm_stats stat) {
446 * case LCK_DENIED:
447 * struct nlm_holder holder;
448 * default:
449 * void;
450 * };
451 *
452 * struct nlm_testres {
453 * netobj cookie;
454 * nlm_testrply test_stat;
455 * };
456 */
457static void encode_nlm_testrply(struct xdr_stream *xdr,
458 const struct nlm_res *result)
459{
460 if (result->status == nlm_lck_denied)
461 encode_nlm_holder(xdr, result);
462}
463
464static void nlm_xdr_enc_testres(struct rpc_rqst *req,
465 struct xdr_stream *xdr,
466 const void *data)
467{
468 const struct nlm_res *result = data;
469
470 encode_cookie(xdr, cookie: &result->cookie);
471 encode_nlm_stat(xdr, stat: result->status);
472 encode_nlm_testrply(xdr, result);
473}
474
475
476/*
477 * NLMv3 XDR decode functions
478 *
479 * NLMv3 result types are defined in Chapter 10 of The Open Group's
480 * "Protocols for Interworking: XNFS, Version 3W".
481 */
482
483/*
484 * union nlm_testrply switch (nlm_stats stat) {
485 * case LCK_DENIED:
486 * struct nlm_holder holder;
487 * default:
488 * void;
489 * };
490 *
491 * struct nlm_testres {
492 * netobj cookie;
493 * nlm_testrply test_stat;
494 * };
495 */
496static int decode_nlm_testrply(struct xdr_stream *xdr,
497 struct nlm_res *result)
498{
499 int error;
500
501 error = decode_nlm_stat(xdr, stat: &result->status);
502 if (unlikely(error))
503 goto out;
504 if (result->status == nlm_lck_denied)
505 error = decode_nlm_holder(xdr, result);
506out:
507 return error;
508}
509
510static int nlm_xdr_dec_testres(struct rpc_rqst *req,
511 struct xdr_stream *xdr,
512 void *data)
513{
514 struct nlm_res *result = data;
515 int error;
516
517 error = decode_cookie(xdr, cookie: &result->cookie);
518 if (unlikely(error))
519 goto out;
520 error = decode_nlm_testrply(xdr, result);
521out:
522 return error;
523}
524
525/*
526 * struct nlm_res {
527 * netobj cookie;
528 * nlm_stat stat;
529 * };
530 */
531static int nlm_xdr_dec_res(struct rpc_rqst *req,
532 struct xdr_stream *xdr,
533 void *data)
534{
535 struct nlm_res *result = data;
536 int error;
537
538 error = decode_cookie(xdr, cookie: &result->cookie);
539 if (unlikely(error))
540 goto out;
541 error = decode_nlm_stat(xdr, stat: &result->status);
542out:
543 return error;
544}
545
546
547/*
548 * For NLM, a void procedure really returns nothing
549 */
550#define nlm_xdr_dec_norep NULL
551
552#define PROC(proc, argtype, restype) \
553[NLMPROC_##proc] = { \
554 .p_proc = NLMPROC_##proc, \
555 .p_encode = nlm_xdr_enc_##argtype, \
556 .p_decode = nlm_xdr_dec_##restype, \
557 .p_arglen = NLM_##argtype##_sz, \
558 .p_replen = NLM_##restype##_sz, \
559 .p_statidx = NLMPROC_##proc, \
560 .p_name = #proc, \
561 }
562
563static const struct rpc_procinfo nlm_procedures[] = {
564 PROC(TEST, testargs, testres),
565 PROC(LOCK, lockargs, res),
566 PROC(CANCEL, cancargs, res),
567 PROC(UNLOCK, unlockargs, res),
568 PROC(GRANTED, testargs, res),
569 PROC(TEST_MSG, testargs, norep),
570 PROC(LOCK_MSG, lockargs, norep),
571 PROC(CANCEL_MSG, cancargs, norep),
572 PROC(UNLOCK_MSG, unlockargs, norep),
573 PROC(GRANTED_MSG, testargs, norep),
574 PROC(TEST_RES, testres, norep),
575 PROC(LOCK_RES, res, norep),
576 PROC(CANCEL_RES, res, norep),
577 PROC(UNLOCK_RES, res, norep),
578 PROC(GRANTED_RES, res, norep),
579};
580
581static unsigned int nlm_version1_counts[ARRAY_SIZE(nlm_procedures)];
582static const struct rpc_version nlm_version1 = {
583 .number = 1,
584 .nrprocs = ARRAY_SIZE(nlm_procedures),
585 .procs = nlm_procedures,
586 .counts = nlm_version1_counts,
587};
588
589static unsigned int nlm_version3_counts[ARRAY_SIZE(nlm_procedures)];
590static const struct rpc_version nlm_version3 = {
591 .number = 3,
592 .nrprocs = ARRAY_SIZE(nlm_procedures),
593 .procs = nlm_procedures,
594 .counts = nlm_version3_counts,
595};
596
597static const struct rpc_version *nlm_versions[] = {
598 [1] = &nlm_version1,
599 [3] = &nlm_version3,
600#ifdef CONFIG_LOCKD_V4
601 [4] = &nlm_version4,
602#endif
603};
604
605static struct rpc_stat nlm_rpc_stats;
606
607const struct rpc_program nlm_program = {
608 .name = "lockd",
609 .number = NLM_PROGRAM,
610 .nrvers = ARRAY_SIZE(nlm_versions),
611 .version = nlm_versions,
612 .stats = &nlm_rpc_stats,
613};
614