Root/fs/lockd/clnt4xdr.c

1/*
2 * linux/fs/lockd/clnt4xdr.c
3 *
4 * XDR functions to encode/decode NLM version 4 RPC arguments and results.
5 *
6 * NLM client-side only.
7 *
8 * Copyright (C) 2010, Oracle. All rights reserved.
9 */
10
11#include <linux/types.h>
12#include <linux/sunrpc/xdr.h>
13#include <linux/sunrpc/clnt.h>
14#include <linux/sunrpc/stats.h>
15#include <linux/lockd/lockd.h>
16
17#define NLMDBG_FACILITY NLMDBG_XDR
18
19#if (NLMCLNT_OHSIZE > XDR_MAX_NETOBJ)
20# error "NLM host name cannot be larger than XDR_MAX_NETOBJ!"
21#endif
22
23#if (NLMCLNT_OHSIZE > NLM_MAXSTRLEN)
24# error "NLM host name cannot be larger than NLM's maximum string length!"
25#endif
26
27/*
28 * Declare the space requirements for NLM arguments and replies as
29 * number of 32bit-words
30 */
31#define NLM4_void_sz (0)
32#define NLM4_cookie_sz (1+(NLM_MAXCOOKIELEN>>2))
33#define NLM4_caller_sz (1+(NLMCLNT_OHSIZE>>2))
34#define NLM4_owner_sz (1+(NLMCLNT_OHSIZE>>2))
35#define NLM4_fhandle_sz (1+(NFS3_FHSIZE>>2))
36#define NLM4_lock_sz (5+NLM4_caller_sz+NLM4_owner_sz+NLM4_fhandle_sz)
37#define NLM4_holder_sz (6+NLM4_owner_sz)
38
39#define NLM4_testargs_sz (NLM4_cookie_sz+1+NLM4_lock_sz)
40#define NLM4_lockargs_sz (NLM4_cookie_sz+4+NLM4_lock_sz)
41#define NLM4_cancargs_sz (NLM4_cookie_sz+2+NLM4_lock_sz)
42#define NLM4_unlockargs_sz (NLM4_cookie_sz+NLM4_lock_sz)
43
44#define NLM4_testres_sz (NLM4_cookie_sz+1+NLM4_holder_sz)
45#define NLM4_res_sz (NLM4_cookie_sz+1)
46#define NLM4_norep_sz (0)
47
48
49static s64 loff_t_to_s64(loff_t offset)
50{
51    s64 res;
52
53    if (offset >= NLM4_OFFSET_MAX)
54        res = NLM4_OFFSET_MAX;
55    else if (offset <= -NLM4_OFFSET_MAX)
56        res = -NLM4_OFFSET_MAX;
57    else
58        res = offset;
59    return res;
60}
61
62static void nlm4_compute_offsets(const struct nlm_lock *lock,
63                 u64 *l_offset, u64 *l_len)
64{
65    const struct file_lock *fl = &lock->fl;
66
67    BUG_ON(fl->fl_start > NLM4_OFFSET_MAX);
68    BUG_ON(fl->fl_end > NLM4_OFFSET_MAX &&
69                fl->fl_end != OFFSET_MAX);
70
71    *l_offset = loff_t_to_s64(fl->fl_start);
72    if (fl->fl_end == OFFSET_MAX)
73        *l_len = 0;
74    else
75        *l_len = loff_t_to_s64(fl->fl_end - fl->fl_start + 1);
76}
77
78/*
79 * Handle decode buffer overflows out-of-line.
80 */
81static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
82{
83    dprintk("lockd: %s prematurely hit the end of our receive buffer. "
84        "Remaining buffer length is %tu words.\n",
85        func, xdr->end - xdr->p);
86}
87
88
89/*
90 * Encode/decode NLMv4 basic data types
91 *
92 * Basic NLMv4 data types are defined in Appendix II, section 6.1.4
93 * of RFC 1813: "NFS Version 3 Protocol Specification" and in Chapter
94 * 10 of X/Open's "Protocols for Interworking: XNFS, Version 3W".
95 *
96 * Not all basic data types have their own encoding and decoding
97 * functions. For run-time efficiency, some data types are encoded
98 * or decoded inline.
99 */
100
101static void encode_bool(struct xdr_stream *xdr, const int value)
102{
103    __be32 *p;
104
105    p = xdr_reserve_space(xdr, 4);
106    *p = value ? xdr_one : xdr_zero;
107}
108
109static void encode_int32(struct xdr_stream *xdr, const s32 value)
110{
111    __be32 *p;
112
113    p = xdr_reserve_space(xdr, 4);
114    *p = cpu_to_be32(value);
115}
116
117/*
118 * typedef opaque netobj<MAXNETOBJ_SZ>
119 */
120static void encode_netobj(struct xdr_stream *xdr,
121              const u8 *data, const unsigned int length)
122{
123    __be32 *p;
124
125    BUG_ON(length > XDR_MAX_NETOBJ);
126    p = xdr_reserve_space(xdr, 4 + length);
127    xdr_encode_opaque(p, data, length);
128}
129
130static int decode_netobj(struct xdr_stream *xdr,
131             struct xdr_netobj *obj)
132{
133    u32 length;
134    __be32 *p;
135
136    p = xdr_inline_decode(xdr, 4);
137    if (unlikely(p == NULL))
138        goto out_overflow;
139    length = be32_to_cpup(p++);
140    if (unlikely(length > XDR_MAX_NETOBJ))
141        goto out_size;
142    obj->len = length;
143    obj->data = (u8 *)p;
144    return 0;
145out_size:
146    dprintk("NFS: returned netobj was too long: %u\n", length);
147    return -EIO;
148out_overflow:
149    print_overflow_msg(__func__, xdr);
150    return -EIO;
151}
152
153/*
154 * netobj cookie;
155 */
156static void encode_cookie(struct xdr_stream *xdr,
157              const struct nlm_cookie *cookie)
158{
159    BUG_ON(cookie->len > NLM_MAXCOOKIELEN);
160    encode_netobj(xdr, (u8 *)&cookie->data, cookie->len);
161}
162
163static int decode_cookie(struct xdr_stream *xdr,
164                 struct nlm_cookie *cookie)
165{
166    u32 length;
167    __be32 *p;
168
169    p = xdr_inline_decode(xdr, 4);
170    if (unlikely(p == NULL))
171        goto out_overflow;
172    length = be32_to_cpup(p++);
173    /* apparently HPUX can return empty cookies */
174    if (length == 0)
175        goto out_hpux;
176    if (length > NLM_MAXCOOKIELEN)
177        goto out_size;
178    p = xdr_inline_decode(xdr, length);
179    if (unlikely(p == NULL))
180        goto out_overflow;
181    cookie->len = length;
182    memcpy(cookie->data, p, length);
183    return 0;
184out_hpux:
185    cookie->len = 4;
186    memset(cookie->data, 0, 4);
187    return 0;
188out_size:
189    dprintk("NFS: returned cookie was too long: %u\n", length);
190    return -EIO;
191out_overflow:
192    print_overflow_msg(__func__, xdr);
193    return -EIO;
194}
195
196/*
197 * netobj fh;
198 */
199static void encode_fh(struct xdr_stream *xdr, const struct nfs_fh *fh)
200{
201    BUG_ON(fh->size > NFS3_FHSIZE);
202    encode_netobj(xdr, (u8 *)&fh->data, fh->size);
203}
204
205/*
206 * enum nlm4_stats {
207 * NLM4_GRANTED = 0,
208 * NLM4_DENIED = 1,
209 * NLM4_DENIED_NOLOCKS = 2,
210 * NLM4_BLOCKED = 3,
211 * NLM4_DENIED_GRACE_PERIOD = 4,
212 * NLM4_DEADLCK = 5,
213 * NLM4_ROFS = 6,
214 * NLM4_STALE_FH = 7,
215 * NLM4_FBIG = 8,
216 * NLM4_FAILED = 9
217 * };
218 *
219 * struct nlm4_stat {
220 * nlm4_stats stat;
221 * };
222 *
223 * NB: we don't swap bytes for the NLM status values. The upper
224 * layers deal directly with the status value in network byte
225 * order.
226 */
227static void encode_nlm4_stat(struct xdr_stream *xdr,
228                 const __be32 stat)
229{
230    __be32 *p;
231
232    BUG_ON(be32_to_cpu(stat) > NLM_FAILED);
233    p = xdr_reserve_space(xdr, 4);
234    *p = stat;
235}
236
237static int decode_nlm4_stat(struct xdr_stream *xdr, __be32 *stat)
238{
239    __be32 *p;
240
241    p = xdr_inline_decode(xdr, 4);
242    if (unlikely(p == NULL))
243        goto out_overflow;
244    if (unlikely(*p > nlm4_failed))
245        goto out_bad_xdr;
246    *stat = *p;
247    return 0;
248out_bad_xdr:
249    dprintk("%s: server returned invalid nlm4_stats value: %u\n",
250            __func__, be32_to_cpup(p));
251    return -EIO;
252out_overflow:
253    print_overflow_msg(__func__, xdr);
254    return -EIO;
255}
256
257/*
258 * struct nlm4_holder {
259 * bool exclusive;
260 * int32 svid;
261 * netobj oh;
262 * uint64 l_offset;
263 * uint64 l_len;
264 * };
265 */
266static void encode_nlm4_holder(struct xdr_stream *xdr,
267                   const struct nlm_res *result)
268{
269    const struct nlm_lock *lock = &result->lock;
270    u64 l_offset, l_len;
271    __be32 *p;
272
273    encode_bool(xdr, lock->fl.fl_type == F_RDLCK);
274    encode_int32(xdr, lock->svid);
275    encode_netobj(xdr, lock->oh.data, lock->oh.len);
276
277    p = xdr_reserve_space(xdr, 4 + 4);
278    nlm4_compute_offsets(lock, &l_offset, &l_len);
279    p = xdr_encode_hyper(p, l_offset);
280    xdr_encode_hyper(p, l_len);
281}
282
283static int decode_nlm4_holder(struct xdr_stream *xdr, struct nlm_res *result)
284{
285    struct nlm_lock *lock = &result->lock;
286    struct file_lock *fl = &lock->fl;
287    u64 l_offset, l_len;
288    u32 exclusive;
289    int error;
290    __be32 *p;
291    s32 end;
292
293    memset(lock, 0, sizeof(*lock));
294    locks_init_lock(fl);
295
296    p = xdr_inline_decode(xdr, 4 + 4);
297    if (unlikely(p == NULL))
298        goto out_overflow;
299    exclusive = be32_to_cpup(p++);
300    lock->svid = be32_to_cpup(p);
301    fl->fl_pid = (pid_t)lock->svid;
302
303    error = decode_netobj(xdr, &lock->oh);
304    if (unlikely(error))
305        goto out;
306
307    p = xdr_inline_decode(xdr, 8 + 8);
308    if (unlikely(p == NULL))
309        goto out_overflow;
310
311    fl->fl_flags = FL_POSIX;
312    fl->fl_type = exclusive != 0 ? F_WRLCK : F_RDLCK;
313    p = xdr_decode_hyper(p, &l_offset);
314    xdr_decode_hyper(p, &l_len);
315    end = l_offset + l_len - 1;
316
317    fl->fl_start = (loff_t)l_offset;
318    if (l_len == 0 || end < 0)
319        fl->fl_end = OFFSET_MAX;
320    else
321        fl->fl_end = (loff_t)end;
322    error = 0;
323out:
324    return error;
325out_overflow:
326    print_overflow_msg(__func__, xdr);
327    return -EIO;
328}
329
330/*
331 * string caller_name<LM_MAXSTRLEN>;
332 */
333static void encode_caller_name(struct xdr_stream *xdr, const char *name)
334{
335    /* NB: client-side does not set lock->len */
336    u32 length = strlen(name);
337    __be32 *p;
338
339    BUG_ON(length > NLM_MAXSTRLEN);
340    p = xdr_reserve_space(xdr, 4 + length);
341    xdr_encode_opaque(p, name, length);
342}
343
344/*
345 * struct nlm4_lock {
346 * string caller_name<LM_MAXSTRLEN>;
347 * netobj fh;
348 * netobj oh;
349 * int32 svid;
350 * uint64 l_offset;
351 * uint64 l_len;
352 * };
353 */
354static void encode_nlm4_lock(struct xdr_stream *xdr,
355                 const struct nlm_lock *lock)
356{
357    u64 l_offset, l_len;
358    __be32 *p;
359
360    encode_caller_name(xdr, lock->caller);
361    encode_fh(xdr, &lock->fh);
362    encode_netobj(xdr, lock->oh.data, lock->oh.len);
363
364    p = xdr_reserve_space(xdr, 4 + 8 + 8);
365    *p++ = cpu_to_be32(lock->svid);
366
367    nlm4_compute_offsets(lock, &l_offset, &l_len);
368    p = xdr_encode_hyper(p, l_offset);
369    xdr_encode_hyper(p, l_len);
370}
371
372
373/*
374 * NLMv4 XDR encode functions
375 *
376 * NLMv4 argument types are defined in Appendix II of RFC 1813:
377 * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
378 * "Protocols for Interworking: XNFS, Version 3W".
379 */
380
381/*
382 * struct nlm4_testargs {
383 * netobj cookie;
384 * bool exclusive;
385 * struct nlm4_lock alock;
386 * };
387 */
388static void nlm4_xdr_enc_testargs(struct rpc_rqst *req,
389                  struct xdr_stream *xdr,
390                  const struct nlm_args *args)
391{
392    const struct nlm_lock *lock = &args->lock;
393
394    encode_cookie(xdr, &args->cookie);
395    encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
396    encode_nlm4_lock(xdr, lock);
397}
398
399/*
400 * struct nlm4_lockargs {
401 * netobj cookie;
402 * bool block;
403 * bool exclusive;
404 * struct nlm4_lock alock;
405 * bool reclaim;
406 * int state;
407 * };
408 */
409static void nlm4_xdr_enc_lockargs(struct rpc_rqst *req,
410                  struct xdr_stream *xdr,
411                  const struct nlm_args *args)
412{
413    const struct nlm_lock *lock = &args->lock;
414
415    encode_cookie(xdr, &args->cookie);
416    encode_bool(xdr, args->block);
417    encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
418    encode_nlm4_lock(xdr, lock);
419    encode_bool(xdr, args->reclaim);
420    encode_int32(xdr, args->state);
421}
422
423/*
424 * struct nlm4_cancargs {
425 * netobj cookie;
426 * bool block;
427 * bool exclusive;
428 * struct nlm4_lock alock;
429 * };
430 */
431static void nlm4_xdr_enc_cancargs(struct rpc_rqst *req,
432                  struct xdr_stream *xdr,
433                  const struct nlm_args *args)
434{
435    const struct nlm_lock *lock = &args->lock;
436
437    encode_cookie(xdr, &args->cookie);
438    encode_bool(xdr, args->block);
439    encode_bool(xdr, lock->fl.fl_type == F_WRLCK);
440    encode_nlm4_lock(xdr, lock);
441}
442
443/*
444 * struct nlm4_unlockargs {
445 * netobj cookie;
446 * struct nlm4_lock alock;
447 * };
448 */
449static void nlm4_xdr_enc_unlockargs(struct rpc_rqst *req,
450                    struct xdr_stream *xdr,
451                    const struct nlm_args *args)
452{
453    const struct nlm_lock *lock = &args->lock;
454
455    encode_cookie(xdr, &args->cookie);
456    encode_nlm4_lock(xdr, lock);
457}
458
459/*
460 * struct nlm4_res {
461 * netobj cookie;
462 * nlm4_stat stat;
463 * };
464 */
465static void nlm4_xdr_enc_res(struct rpc_rqst *req,
466                 struct xdr_stream *xdr,
467                 const struct nlm_res *result)
468{
469    encode_cookie(xdr, &result->cookie);
470    encode_nlm4_stat(xdr, result->status);
471}
472
473/*
474 * union nlm4_testrply switch (nlm4_stats stat) {
475 * case NLM4_DENIED:
476 * struct nlm4_holder holder;
477 * default:
478 * void;
479 * };
480 *
481 * struct nlm4_testres {
482 * netobj cookie;
483 * nlm4_testrply test_stat;
484 * };
485 */
486static void nlm4_xdr_enc_testres(struct rpc_rqst *req,
487                 struct xdr_stream *xdr,
488                 const struct nlm_res *result)
489{
490    encode_cookie(xdr, &result->cookie);
491    encode_nlm4_stat(xdr, result->status);
492    if (result->status == nlm_lck_denied)
493        encode_nlm4_holder(xdr, result);
494}
495
496
497/*
498 * NLMv4 XDR decode functions
499 *
500 * NLMv4 argument types are defined in Appendix II of RFC 1813:
501 * "NFS Version 3 Protocol Specification" and Chapter 10 of X/Open's
502 * "Protocols for Interworking: XNFS, Version 3W".
503 */
504
505/*
506 * union nlm4_testrply switch (nlm4_stats stat) {
507 * case NLM4_DENIED:
508 * struct nlm4_holder holder;
509 * default:
510 * void;
511 * };
512 *
513 * struct nlm4_testres {
514 * netobj cookie;
515 * nlm4_testrply test_stat;
516 * };
517 */
518static int decode_nlm4_testrply(struct xdr_stream *xdr,
519                struct nlm_res *result)
520{
521    int error;
522
523    error = decode_nlm4_stat(xdr, &result->status);
524    if (unlikely(error))
525        goto out;
526    if (result->status == nlm_lck_denied)
527        error = decode_nlm4_holder(xdr, result);
528out:
529    return error;
530}
531
532static int nlm4_xdr_dec_testres(struct rpc_rqst *req,
533                struct xdr_stream *xdr,
534                struct nlm_res *result)
535{
536    int error;
537
538    error = decode_cookie(xdr, &result->cookie);
539    if (unlikely(error))
540        goto out;
541    error = decode_nlm4_testrply(xdr, result);
542out:
543    return error;
544}
545
546/*
547 * struct nlm4_res {
548 * netobj cookie;
549 * nlm4_stat stat;
550 * };
551 */
552static int nlm4_xdr_dec_res(struct rpc_rqst *req,
553                struct xdr_stream *xdr,
554                struct nlm_res *result)
555{
556    int error;
557
558    error = decode_cookie(xdr, &result->cookie);
559    if (unlikely(error))
560        goto out;
561    error = decode_nlm4_stat(xdr, &result->status);
562out:
563    return error;
564}
565
566
567/*
568 * For NLM, a void procedure really returns nothing
569 */
570#define nlm4_xdr_dec_norep NULL
571
572#define PROC(proc, argtype, restype) \
573[NLMPROC_##proc] = { \
574    .p_proc = NLMPROC_##proc, \
575    .p_encode = (kxdreproc_t)nlm4_xdr_enc_##argtype, \
576    .p_decode = (kxdrdproc_t)nlm4_xdr_dec_##restype, \
577    .p_arglen = NLM4_##argtype##_sz, \
578    .p_replen = NLM4_##restype##_sz, \
579    .p_statidx = NLMPROC_##proc, \
580    .p_name = #proc, \
581    }
582
583static struct rpc_procinfo nlm4_procedures[] = {
584    PROC(TEST, testargs, testres),
585    PROC(LOCK, lockargs, res),
586    PROC(CANCEL, cancargs, res),
587    PROC(UNLOCK, unlockargs, res),
588    PROC(GRANTED, testargs, res),
589    PROC(TEST_MSG, testargs, norep),
590    PROC(LOCK_MSG, lockargs, norep),
591    PROC(CANCEL_MSG, cancargs, norep),
592    PROC(UNLOCK_MSG, unlockargs, norep),
593    PROC(GRANTED_MSG, testargs, norep),
594    PROC(TEST_RES, testres, norep),
595    PROC(LOCK_RES, res, norep),
596    PROC(CANCEL_RES, res, norep),
597    PROC(UNLOCK_RES, res, norep),
598    PROC(GRANTED_RES, res, norep),
599};
600
601struct rpc_version nlm_version4 = {
602    .number = 4,
603    .nrprocs = ARRAY_SIZE(nlm4_procedures),
604    .procs = nlm4_procedures,
605};
606

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