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1/*
2 * linux/fs/nfs/nfs2xdr.c
3 *
4 * XDR functions to encode/decode NFS RPC arguments and results.
5 *
6 * Copyright (C) 1992, 1993, 1994 Rick Sladkey
7 * Copyright (C) 1996 Olaf Kirch
8 * 04 Aug 1998 Ion Badulescu <ionut@cs.columbia.edu>
9 * FIFO's need special handling in NFSv2
10 */
11
12#include <linux/param.h>
13#include <linux/time.h>
14#include <linux/mm.h>
15#include <linux/errno.h>
16#include <linux/string.h>
17#include <linux/in.h>
18#include <linux/pagemap.h>
19#include <linux/proc_fs.h>
20#include <linux/sunrpc/clnt.h>
21#include <linux/nfs.h>
22#include <linux/nfs2.h>
23#include <linux/nfs_fs.h>
24#include "internal.h"
25
26#define NFSDBG_FACILITY NFSDBG_XDR
27
28/* Mapping from NFS error code to "errno" error code. */
29#define errno_NFSERR_IO EIO
30
31/*
32 * Declare the space requirements for NFS arguments and replies as
33 * number of 32bit-words
34 */
35#define NFS_fhandle_sz (8)
36#define NFS_sattr_sz (8)
37#define NFS_filename_sz (1+(NFS2_MAXNAMLEN>>2))
38#define NFS_path_sz (1+(NFS2_MAXPATHLEN>>2))
39#define NFS_fattr_sz (17)
40#define NFS_info_sz (5)
41#define NFS_entry_sz (NFS_filename_sz+3)
42
43#define NFS_diropargs_sz (NFS_fhandle_sz+NFS_filename_sz)
44#define NFS_removeargs_sz (NFS_fhandle_sz+NFS_filename_sz)
45#define NFS_sattrargs_sz (NFS_fhandle_sz+NFS_sattr_sz)
46#define NFS_readlinkargs_sz (NFS_fhandle_sz)
47#define NFS_readargs_sz (NFS_fhandle_sz+3)
48#define NFS_writeargs_sz (NFS_fhandle_sz+4)
49#define NFS_createargs_sz (NFS_diropargs_sz+NFS_sattr_sz)
50#define NFS_renameargs_sz (NFS_diropargs_sz+NFS_diropargs_sz)
51#define NFS_linkargs_sz (NFS_fhandle_sz+NFS_diropargs_sz)
52#define NFS_symlinkargs_sz (NFS_diropargs_sz+1+NFS_sattr_sz)
53#define NFS_readdirargs_sz (NFS_fhandle_sz+2)
54
55#define NFS_attrstat_sz (1+NFS_fattr_sz)
56#define NFS_diropres_sz (1+NFS_fhandle_sz+NFS_fattr_sz)
57#define NFS_readlinkres_sz (2)
58#define NFS_readres_sz (1+NFS_fattr_sz+1)
59#define NFS_writeres_sz (NFS_attrstat_sz)
60#define NFS_stat_sz (1)
61#define NFS_readdirres_sz (1)
62#define NFS_statfsres_sz (1+NFS_info_sz)
63
64static int nfs_stat_to_errno(enum nfs_stat);
65
66/*
67 * While encoding arguments, set up the reply buffer in advance to
68 * receive reply data directly into the page cache.
69 */
70static void prepare_reply_buffer(struct rpc_rqst *req, struct page **pages,
71 unsigned int base, unsigned int len,
72 unsigned int bufsize)
73{
74 struct rpc_auth *auth = req->rq_cred->cr_auth;
75 unsigned int replen;
76
77 replen = RPC_REPHDRSIZE + auth->au_rslack + bufsize;
78 xdr_inline_pages(&req->rq_rcv_buf, replen << 2, pages, base, len);
79}
80
81/*
82 * Handle decode buffer overflows out-of-line.
83 */
84static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
85{
86 dprintk("NFS: %s prematurely hit the end of our receive buffer. "
87 "Remaining buffer length is %tu words.\n",
88 func, xdr->end - xdr->p);
89}
90
91
92/*
93 * Encode/decode NFSv2 basic data types
94 *
95 * Basic NFSv2 data types are defined in section 2.3 of RFC 1094:
96 * "NFS: Network File System Protocol Specification".
97 *
98 * Not all basic data types have their own encoding and decoding
99 * functions. For run-time efficiency, some data types are encoded
100 * or decoded inline.
101 */
102
103/*
104 * typedef opaque nfsdata<>;
105 */
106static int decode_nfsdata(struct xdr_stream *xdr, struct nfs_readres *result)
107{
108 u32 recvd, count;
109 size_t hdrlen;
110 __be32 *p;
111
112 p = xdr_inline_decode(xdr, 4);
113 if (unlikely(p == NULL))
114 goto out_overflow;
115 count = be32_to_cpup(p);
116 hdrlen = (u8 *)xdr->p - (u8 *)xdr->iov->iov_base;
117 recvd = xdr->buf->len - hdrlen;
118 if (unlikely(count > recvd))
119 goto out_cheating;
120out:
121 xdr_read_pages(xdr, count);
122 result->eof = 0; /* NFSv2 does not pass EOF flag on the wire. */
123 result->count = count;
124 return count;
125out_cheating:
126 dprintk("NFS: server cheating in read result: "
127 "count %u > recvd %u\n", count, recvd);
128 count = recvd;
129 goto out;
130out_overflow:
131 print_overflow_msg(__func__, xdr);
132 return -EIO;
133}
134
135/*
136 * enum stat {
137 * NFS_OK = 0,
138 * NFSERR_PERM = 1,
139 * NFSERR_NOENT = 2,
140 * NFSERR_IO = 5,
141 * NFSERR_NXIO = 6,
142 * NFSERR_ACCES = 13,
143 * NFSERR_EXIST = 17,
144 * NFSERR_NODEV = 19,
145 * NFSERR_NOTDIR = 20,
146 * NFSERR_ISDIR = 21,
147 * NFSERR_FBIG = 27,
148 * NFSERR_NOSPC = 28,
149 * NFSERR_ROFS = 30,
150 * NFSERR_NAMETOOLONG = 63,
151 * NFSERR_NOTEMPTY = 66,
152 * NFSERR_DQUOT = 69,
153 * NFSERR_STALE = 70,
154 * NFSERR_WFLUSH = 99
155 * };
156 */
157static int decode_stat(struct xdr_stream *xdr, enum nfs_stat *status)
158{
159 __be32 *p;
160
161 p = xdr_inline_decode(xdr, 4);
162 if (unlikely(p == NULL))
163 goto out_overflow;
164 *status = be32_to_cpup(p);
165 return 0;
166out_overflow:
167 print_overflow_msg(__func__, xdr);
168 return -EIO;
169}
170
171/*
172 * 2.3.2. ftype
173 *
174 * enum ftype {
175 * NFNON = 0,
176 * NFREG = 1,
177 * NFDIR = 2,
178 * NFBLK = 3,
179 * NFCHR = 4,
180 * NFLNK = 5
181 * };
182 *
183 */
184static __be32 *xdr_decode_ftype(__be32 *p, u32 *type)
185{
186 *type = be32_to_cpup(p++);
187 if (unlikely(*type > NF2FIFO))
188 *type = NFBAD;
189 return p;
190}
191
192/*
193 * 2.3.3. fhandle
194 *
195 * typedef opaque fhandle[FHSIZE];
196 */
197static void encode_fhandle(struct xdr_stream *xdr, const struct nfs_fh *fh)
198{
199 __be32 *p;
200
201 BUG_ON(fh->size != NFS2_FHSIZE);
202 p = xdr_reserve_space(xdr, NFS2_FHSIZE);
203 memcpy(p, fh->data, NFS2_FHSIZE);
204}
205
206static int decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
207{
208 __be32 *p;
209
210 p = xdr_inline_decode(xdr, NFS2_FHSIZE);
211 if (unlikely(p == NULL))
212 goto out_overflow;
213 fh->size = NFS2_FHSIZE;
214 memcpy(fh->data, p, NFS2_FHSIZE);
215 return 0;
216out_overflow:
217 print_overflow_msg(__func__, xdr);
218 return -EIO;
219}
220
221/*
222 * 2.3.4. timeval
223 *
224 * struct timeval {
225 * unsigned int seconds;
226 * unsigned int useconds;
227 * };
228 */
229static __be32 *xdr_encode_time(__be32 *p, const struct timespec *timep)
230{
231 *p++ = cpu_to_be32(timep->tv_sec);
232 if (timep->tv_nsec != 0)
233 *p++ = cpu_to_be32(timep->tv_nsec / NSEC_PER_USEC);
234 else
235 *p++ = cpu_to_be32(0);
236 return p;
237}
238
239/*
240 * Passing the invalid value useconds=1000000 is a Sun convention for
241 * "set to current server time". It's needed to make permissions checks
242 * for the "touch" program across v2 mounts to Solaris and Irix servers
243 * work correctly. See description of sattr in section 6.1 of "NFS
244 * Illustrated" by Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5.
245 */
246static __be32 *xdr_encode_current_server_time(__be32 *p,
247 const struct timespec *timep)
248{
249 *p++ = cpu_to_be32(timep->tv_sec);
250 *p++ = cpu_to_be32(1000000);
251 return p;
252}
253
254static __be32 *xdr_decode_time(__be32 *p, struct timespec *timep)
255{
256 timep->tv_sec = be32_to_cpup(p++);
257 timep->tv_nsec = be32_to_cpup(p++) * NSEC_PER_USEC;
258 return p;
259}
260
261/*
262 * 2.3.5. fattr
263 *
264 * struct fattr {
265 * ftype type;
266 * unsigned int mode;
267 * unsigned int nlink;
268 * unsigned int uid;
269 * unsigned int gid;
270 * unsigned int size;
271 * unsigned int blocksize;
272 * unsigned int rdev;
273 * unsigned int blocks;
274 * unsigned int fsid;
275 * unsigned int fileid;
276 * timeval atime;
277 * timeval mtime;
278 * timeval ctime;
279 * };
280 *
281 */
282static int decode_fattr(struct xdr_stream *xdr, struct nfs_fattr *fattr)
283{
284 u32 rdev, type;
285 __be32 *p;
286
287 p = xdr_inline_decode(xdr, NFS_fattr_sz << 2);
288 if (unlikely(p == NULL))
289 goto out_overflow;
290
291 fattr->valid |= NFS_ATTR_FATTR_V2;
292
293 p = xdr_decode_ftype(p, &type);
294
295 fattr->mode = be32_to_cpup(p++);
296 fattr->nlink = be32_to_cpup(p++);
297 fattr->uid = be32_to_cpup(p++);
298 fattr->gid = be32_to_cpup(p++);
299 fattr->size = be32_to_cpup(p++);
300 fattr->du.nfs2.blocksize = be32_to_cpup(p++);
301
302 rdev = be32_to_cpup(p++);
303 fattr->rdev = new_decode_dev(rdev);
304 if (type == (u32)NFCHR && rdev == (u32)NFS2_FIFO_DEV) {
305 fattr->mode = (fattr->mode & ~S_IFMT) | S_IFIFO;
306 fattr->rdev = 0;
307 }
308
309 fattr->du.nfs2.blocks = be32_to_cpup(p++);
310 fattr->fsid.major = be32_to_cpup(p++);
311 fattr->fsid.minor = 0;
312 fattr->fileid = be32_to_cpup(p++);
313
314 p = xdr_decode_time(p, &fattr->atime);
315 p = xdr_decode_time(p, &fattr->mtime);
316 xdr_decode_time(p, &fattr->ctime);
317 fattr->change_attr = nfs_timespec_to_change_attr(&fattr->ctime);
318
319 return 0;
320out_overflow:
321 print_overflow_msg(__func__, xdr);
322 return -EIO;
323}
324
325/*
326 * 2.3.6. sattr
327 *
328 * struct sattr {
329 * unsigned int mode;
330 * unsigned int uid;
331 * unsigned int gid;
332 * unsigned int size;
333 * timeval atime;
334 * timeval mtime;
335 * };
336 */
337
338#define NFS2_SATTR_NOT_SET (0xffffffff)
339
340static __be32 *xdr_time_not_set(__be32 *p)
341{
342 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
343 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
344 return p;
345}
346
347static void encode_sattr(struct xdr_stream *xdr, const struct iattr *attr)
348{
349 __be32 *p;
350
351 p = xdr_reserve_space(xdr, NFS_sattr_sz << 2);
352
353 if (attr->ia_valid & ATTR_MODE)
354 *p++ = cpu_to_be32(attr->ia_mode);
355 else
356 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
357 if (attr->ia_valid & ATTR_UID)
358 *p++ = cpu_to_be32(attr->ia_uid);
359 else
360 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
361 if (attr->ia_valid & ATTR_GID)
362 *p++ = cpu_to_be32(attr->ia_gid);
363 else
364 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
365 if (attr->ia_valid & ATTR_SIZE)
366 *p++ = cpu_to_be32((u32)attr->ia_size);
367 else
368 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
369
370 if (attr->ia_valid & ATTR_ATIME_SET)
371 p = xdr_encode_time(p, &attr->ia_atime);
372 else if (attr->ia_valid & ATTR_ATIME)
373 p = xdr_encode_current_server_time(p, &attr->ia_atime);
374 else
375 p = xdr_time_not_set(p);
376 if (attr->ia_valid & ATTR_MTIME_SET)
377 xdr_encode_time(p, &attr->ia_mtime);
378 else if (attr->ia_valid & ATTR_MTIME)
379 xdr_encode_current_server_time(p, &attr->ia_mtime);
380 else
381 xdr_time_not_set(p);
382}
383
384/*
385 * 2.3.7. filename
386 *
387 * typedef string filename<MAXNAMLEN>;
388 */
389static void encode_filename(struct xdr_stream *xdr,
390 const char *name, u32 length)
391{
392 __be32 *p;
393
394 BUG_ON(length > NFS2_MAXNAMLEN);
395 p = xdr_reserve_space(xdr, 4 + length);
396 xdr_encode_opaque(p, name, length);
397}
398
399static int decode_filename_inline(struct xdr_stream *xdr,
400 const char **name, u32 *length)
401{
402 __be32 *p;
403 u32 count;
404
405 p = xdr_inline_decode(xdr, 4);
406 if (unlikely(p == NULL))
407 goto out_overflow;
408 count = be32_to_cpup(p);
409 if (count > NFS3_MAXNAMLEN)
410 goto out_nametoolong;
411 p = xdr_inline_decode(xdr, count);
412 if (unlikely(p == NULL))
413 goto out_overflow;
414 *name = (const char *)p;
415 *length = count;
416 return 0;
417out_nametoolong:
418 dprintk("NFS: returned filename too long: %u\n", count);
419 return -ENAMETOOLONG;
420out_overflow:
421 print_overflow_msg(__func__, xdr);
422 return -EIO;
423}
424
425/*
426 * 2.3.8. path
427 *
428 * typedef string path<MAXPATHLEN>;
429 */
430static void encode_path(struct xdr_stream *xdr, struct page **pages, u32 length)
431{
432 __be32 *p;
433
434 BUG_ON(length > NFS2_MAXPATHLEN);
435 p = xdr_reserve_space(xdr, 4);
436 *p = cpu_to_be32(length);
437 xdr_write_pages(xdr, pages, 0, length);
438}
439
440static int decode_path(struct xdr_stream *xdr)
441{
442 u32 length, recvd;
443 size_t hdrlen;
444 __be32 *p;
445
446 p = xdr_inline_decode(xdr, 4);
447 if (unlikely(p == NULL))
448 goto out_overflow;
449 length = be32_to_cpup(p);
450 if (unlikely(length >= xdr->buf->page_len || length > NFS_MAXPATHLEN))
451 goto out_size;
452 hdrlen = (u8 *)xdr->p - (u8 *)xdr->iov->iov_base;
453 recvd = xdr->buf->len - hdrlen;
454 if (unlikely(length > recvd))
455 goto out_cheating;
456
457 xdr_read_pages(xdr, length);
458 xdr_terminate_string(xdr->buf, length);
459 return 0;
460out_size:
461 dprintk("NFS: returned pathname too long: %u\n", length);
462 return -ENAMETOOLONG;
463out_cheating:
464 dprintk("NFS: server cheating in pathname result: "
465 "length %u > received %u\n", length, recvd);
466 return -EIO;
467out_overflow:
468 print_overflow_msg(__func__, xdr);
469 return -EIO;
470}
471
472/*
473 * 2.3.9. attrstat
474 *
475 * union attrstat switch (stat status) {
476 * case NFS_OK:
477 * fattr attributes;
478 * default:
479 * void;
480 * };
481 */
482static int decode_attrstat(struct xdr_stream *xdr, struct nfs_fattr *result)
483{
484 enum nfs_stat status;
485 int error;
486
487 error = decode_stat(xdr, &status);
488 if (unlikely(error))
489 goto out;
490 if (status != NFS_OK)
491 goto out_default;
492 error = decode_fattr(xdr, result);
493out:
494 return error;
495out_default:
496 return nfs_stat_to_errno(status);
497}
498
499/*
500 * 2.3.10. diropargs
501 *
502 * struct diropargs {
503 * fhandle dir;
504 * filename name;
505 * };
506 */
507static void encode_diropargs(struct xdr_stream *xdr, const struct nfs_fh *fh,
508 const char *name, u32 length)
509{
510 encode_fhandle(xdr, fh);
511 encode_filename(xdr, name, length);
512}
513
514/*
515 * 2.3.11. diropres
516 *
517 * union diropres switch (stat status) {
518 * case NFS_OK:
519 * struct {
520 * fhandle file;
521 * fattr attributes;
522 * } diropok;
523 * default:
524 * void;
525 * };
526 */
527static int decode_diropok(struct xdr_stream *xdr, struct nfs_diropok *result)
528{
529 int error;
530
531 error = decode_fhandle(xdr, result->fh);
532 if (unlikely(error))
533 goto out;
534 error = decode_fattr(xdr, result->fattr);
535out:
536 return error;
537}
538
539static int decode_diropres(struct xdr_stream *xdr, struct nfs_diropok *result)
540{
541 enum nfs_stat status;
542 int error;
543
544 error = decode_stat(xdr, &status);
545 if (unlikely(error))
546 goto out;
547 if (status != NFS_OK)
548 goto out_default;
549 error = decode_diropok(xdr, result);
550out:
551 return error;
552out_default:
553 return nfs_stat_to_errno(status);
554}
555
556
557/*
558 * NFSv2 XDR encode functions
559 *
560 * NFSv2 argument types are defined in section 2.2 of RFC 1094:
561 * "NFS: Network File System Protocol Specification".
562 */
563
564static void nfs2_xdr_enc_fhandle(struct rpc_rqst *req,
565 struct xdr_stream *xdr,
566 const struct nfs_fh *fh)
567{
568 encode_fhandle(xdr, fh);
569}
570
571/*
572 * 2.2.3. sattrargs
573 *
574 * struct sattrargs {
575 * fhandle file;
576 * sattr attributes;
577 * };
578 */
579static void nfs2_xdr_enc_sattrargs(struct rpc_rqst *req,
580 struct xdr_stream *xdr,
581 const struct nfs_sattrargs *args)
582{
583 encode_fhandle(xdr, args->fh);
584 encode_sattr(xdr, args->sattr);
585}
586
587static void nfs2_xdr_enc_diropargs(struct rpc_rqst *req,
588 struct xdr_stream *xdr,
589 const struct nfs_diropargs *args)
590{
591 encode_diropargs(xdr, args->fh, args->name, args->len);
592}
593
594static void nfs2_xdr_enc_readlinkargs(struct rpc_rqst *req,
595 struct xdr_stream *xdr,
596 const struct nfs_readlinkargs *args)
597{
598 encode_fhandle(xdr, args->fh);
599 prepare_reply_buffer(req, args->pages, args->pgbase,
600 args->pglen, NFS_readlinkres_sz);
601}
602
603/*
604 * 2.2.7. readargs
605 *
606 * struct readargs {
607 * fhandle file;
608 * unsigned offset;
609 * unsigned count;
610 * unsigned totalcount;
611 * };
612 */
613static void encode_readargs(struct xdr_stream *xdr,
614 const struct nfs_readargs *args)
615{
616 u32 offset = args->offset;
617 u32 count = args->count;
618 __be32 *p;
619
620 encode_fhandle(xdr, args->fh);
621
622 p = xdr_reserve_space(xdr, 4 + 4 + 4);
623 *p++ = cpu_to_be32(offset);
624 *p++ = cpu_to_be32(count);
625 *p = cpu_to_be32(count);
626}
627
628static void nfs2_xdr_enc_readargs(struct rpc_rqst *req,
629 struct xdr_stream *xdr,
630 const struct nfs_readargs *args)
631{
632 encode_readargs(xdr, args);
633 prepare_reply_buffer(req, args->pages, args->pgbase,
634 args->count, NFS_readres_sz);
635 req->rq_rcv_buf.flags |= XDRBUF_READ;
636}
637
638/*
639 * 2.2.9. writeargs
640 *
641 * struct writeargs {
642 * fhandle file;
643 * unsigned beginoffset;
644 * unsigned offset;
645 * unsigned totalcount;
646 * nfsdata data;
647 * };
648 */
649static void encode_writeargs(struct xdr_stream *xdr,
650 const struct nfs_writeargs *args)
651{
652 u32 offset = args->offset;
653 u32 count = args->count;
654 __be32 *p;
655
656 encode_fhandle(xdr, args->fh);
657
658 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
659 *p++ = cpu_to_be32(offset);
660 *p++ = cpu_to_be32(offset);
661 *p++ = cpu_to_be32(count);
662
663 /* nfsdata */
664 *p = cpu_to_be32(count);
665 xdr_write_pages(xdr, args->pages, args->pgbase, count);
666}
667
668static void nfs2_xdr_enc_writeargs(struct rpc_rqst *req,
669 struct xdr_stream *xdr,
670 const struct nfs_writeargs *args)
671{
672 encode_writeargs(xdr, args);
673 xdr->buf->flags |= XDRBUF_WRITE;
674}
675
676/*
677 * 2.2.10. createargs
678 *
679 * struct createargs {
680 * diropargs where;
681 * sattr attributes;
682 * };
683 */
684static void nfs2_xdr_enc_createargs(struct rpc_rqst *req,
685 struct xdr_stream *xdr,
686 const struct nfs_createargs *args)
687{
688 encode_diropargs(xdr, args->fh, args->name, args->len);
689 encode_sattr(xdr, args->sattr);
690}
691
692static void nfs2_xdr_enc_removeargs(struct rpc_rqst *req,
693 struct xdr_stream *xdr,
694 const struct nfs_removeargs *args)
695{
696 encode_diropargs(xdr, args->fh, args->name.name, args->name.len);
697}
698
699/*
700 * 2.2.12. renameargs
701 *
702 * struct renameargs {
703 * diropargs from;
704 * diropargs to;
705 * };
706 */
707static void nfs2_xdr_enc_renameargs(struct rpc_rqst *req,
708 struct xdr_stream *xdr,
709 const struct nfs_renameargs *args)
710{
711 const struct qstr *old = args->old_name;
712 const struct qstr *new = args->new_name;
713
714 encode_diropargs(xdr, args->old_dir, old->name, old->len);
715 encode_diropargs(xdr, args->new_dir, new->name, new->len);
716}
717
718/*
719 * 2.2.13. linkargs
720 *
721 * struct linkargs {
722 * fhandle from;
723 * diropargs to;
724 * };
725 */
726static void nfs2_xdr_enc_linkargs(struct rpc_rqst *req,
727 struct xdr_stream *xdr,
728 const struct nfs_linkargs *args)
729{
730 encode_fhandle(xdr, args->fromfh);
731 encode_diropargs(xdr, args->tofh, args->toname, args->tolen);
732}
733
734/*
735 * 2.2.14. symlinkargs
736 *
737 * struct symlinkargs {
738 * diropargs from;
739 * path to;
740 * sattr attributes;
741 * };
742 */
743static void nfs2_xdr_enc_symlinkargs(struct rpc_rqst *req,
744 struct xdr_stream *xdr,
745 const struct nfs_symlinkargs *args)
746{
747 encode_diropargs(xdr, args->fromfh, args->fromname, args->fromlen);
748 encode_path(xdr, args->pages, args->pathlen);
749 encode_sattr(xdr, args->sattr);
750}
751
752/*
753 * 2.2.17. readdirargs
754 *
755 * struct readdirargs {
756 * fhandle dir;
757 * nfscookie cookie;
758 * unsigned count;
759 * };
760 */
761static void encode_readdirargs(struct xdr_stream *xdr,
762 const struct nfs_readdirargs *args)
763{
764 __be32 *p;
765
766 encode_fhandle(xdr, args->fh);
767
768 p = xdr_reserve_space(xdr, 4 + 4);
769 *p++ = cpu_to_be32(args->cookie);
770 *p = cpu_to_be32(args->count);
771}
772
773static void nfs2_xdr_enc_readdirargs(struct rpc_rqst *req,
774 struct xdr_stream *xdr,
775 const struct nfs_readdirargs *args)
776{
777 encode_readdirargs(xdr, args);
778 prepare_reply_buffer(req, args->pages, 0,
779 args->count, NFS_readdirres_sz);
780}
781
782/*
783 * NFSv2 XDR decode functions
784 *
785 * NFSv2 result types are defined in section 2.2 of RFC 1094:
786 * "NFS: Network File System Protocol Specification".
787 */
788
789static int nfs2_xdr_dec_stat(struct rpc_rqst *req, struct xdr_stream *xdr,
790 void *__unused)
791{
792 enum nfs_stat status;
793 int error;
794
795 error = decode_stat(xdr, &status);
796 if (unlikely(error))
797 goto out;
798 if (status != NFS_OK)
799 goto out_default;
800out:
801 return error;
802out_default:
803 return nfs_stat_to_errno(status);
804}
805
806static int nfs2_xdr_dec_attrstat(struct rpc_rqst *req, struct xdr_stream *xdr,
807 struct nfs_fattr *result)
808{
809 return decode_attrstat(xdr, result);
810}
811
812static int nfs2_xdr_dec_diropres(struct rpc_rqst *req, struct xdr_stream *xdr,
813 struct nfs_diropok *result)
814{
815 return decode_diropres(xdr, result);
816}
817
818/*
819 * 2.2.6. readlinkres
820 *
821 * union readlinkres switch (stat status) {
822 * case NFS_OK:
823 * path data;
824 * default:
825 * void;
826 * };
827 */
828static int nfs2_xdr_dec_readlinkres(struct rpc_rqst *req,
829 struct xdr_stream *xdr, void *__unused)
830{
831 enum nfs_stat status;
832 int error;
833
834 error = decode_stat(xdr, &status);
835 if (unlikely(error))
836 goto out;
837 if (status != NFS_OK)
838 goto out_default;
839 error = decode_path(xdr);
840out:
841 return error;
842out_default:
843 return nfs_stat_to_errno(status);
844}
845
846/*
847 * 2.2.7. readres
848 *
849 * union readres switch (stat status) {
850 * case NFS_OK:
851 * fattr attributes;
852 * nfsdata data;
853 * default:
854 * void;
855 * };
856 */
857static int nfs2_xdr_dec_readres(struct rpc_rqst *req, struct xdr_stream *xdr,
858 struct nfs_readres *result)
859{
860 enum nfs_stat status;
861 int error;
862
863 error = decode_stat(xdr, &status);
864 if (unlikely(error))
865 goto out;
866 if (status != NFS_OK)
867 goto out_default;
868 error = decode_fattr(xdr, result->fattr);
869 if (unlikely(error))
870 goto out;
871 error = decode_nfsdata(xdr, result);
872out:
873 return error;
874out_default:
875 return nfs_stat_to_errno(status);
876}
877
878static int nfs2_xdr_dec_writeres(struct rpc_rqst *req, struct xdr_stream *xdr,
879 struct nfs_writeres *result)
880{
881 /* All NFSv2 writes are "file sync" writes */
882 result->verf->committed = NFS_FILE_SYNC;
883 return decode_attrstat(xdr, result->fattr);
884}
885
886/**
887 * nfs2_decode_dirent - Decode a single NFSv2 directory entry stored in
888 * the local page cache.
889 * @xdr: XDR stream where entry resides
890 * @entry: buffer to fill in with entry data
891 * @plus: boolean indicating whether this should be a readdirplus entry
892 *
893 * Returns zero if successful, otherwise a negative errno value is
894 * returned.
895 *
896 * This function is not invoked during READDIR reply decoding, but
897 * rather whenever an application invokes the getdents(2) system call
898 * on a directory already in our cache.
899 *
900 * 2.2.17. entry
901 *
902 * struct entry {
903 * unsigned fileid;
904 * filename name;
905 * nfscookie cookie;
906 * entry *nextentry;
907 * };
908 */
909int nfs2_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
910 int plus)
911{
912 __be32 *p;
913 int error;
914
915 p = xdr_inline_decode(xdr, 4);
916 if (unlikely(p == NULL))
917 goto out_overflow;
918 if (*p++ == xdr_zero) {
919 p = xdr_inline_decode(xdr, 4);
920 if (unlikely(p == NULL))
921 goto out_overflow;
922 if (*p++ == xdr_zero)
923 return -EAGAIN;
924 entry->eof = 1;
925 return -EBADCOOKIE;
926 }
927
928 p = xdr_inline_decode(xdr, 4);
929 if (unlikely(p == NULL))
930 goto out_overflow;
931 entry->ino = be32_to_cpup(p);
932
933 error = decode_filename_inline(xdr, &entry->name, &entry->len);
934 if (unlikely(error))
935 return error;
936
937 /*
938 * The type (size and byte order) of nfscookie isn't defined in
939 * RFC 1094. This implementation assumes that it's an XDR uint32.
940 */
941 entry->prev_cookie = entry->cookie;
942 p = xdr_inline_decode(xdr, 4);
943 if (unlikely(p == NULL))
944 goto out_overflow;
945 entry->cookie = be32_to_cpup(p);
946
947 entry->d_type = DT_UNKNOWN;
948
949 return 0;
950
951out_overflow:
952 print_overflow_msg(__func__, xdr);
953 return -EAGAIN;
954}
955
956/*
957 * 2.2.17. readdirres
958 *
959 * union readdirres switch (stat status) {
960 * case NFS_OK:
961 * struct {
962 * entry *entries;
963 * bool eof;
964 * } readdirok;
965 * default:
966 * void;
967 * };
968 *
969 * Read the directory contents into the page cache, but don't
970 * touch them. The actual decoding is done by nfs2_decode_dirent()
971 * during subsequent nfs_readdir() calls.
972 */
973static int decode_readdirok(struct xdr_stream *xdr)
974{
975 u32 recvd, pglen;
976 size_t hdrlen;
977
978 pglen = xdr->buf->page_len;
979 hdrlen = (u8 *)xdr->p - (u8 *)xdr->iov->iov_base;
980 recvd = xdr->buf->len - hdrlen;
981 if (unlikely(pglen > recvd))
982 goto out_cheating;
983out:
984 xdr_read_pages(xdr, pglen);
985 return pglen;
986out_cheating:
987 dprintk("NFS: server cheating in readdir result: "
988 "pglen %u > recvd %u\n", pglen, recvd);
989 pglen = recvd;
990 goto out;
991}
992
993static int nfs2_xdr_dec_readdirres(struct rpc_rqst *req,
994 struct xdr_stream *xdr, void *__unused)
995{
996 enum nfs_stat status;
997 int error;
998
999 error = decode_stat(xdr, &status);
1000 if (unlikely(error))
1001 goto out;
1002 if (status != NFS_OK)
1003 goto out_default;
1004 error = decode_readdirok(xdr);
1005out:
1006 return error;
1007out_default:
1008 return nfs_stat_to_errno(status);
1009}
1010
1011/*
1012 * 2.2.18. statfsres
1013 *
1014 * union statfsres (stat status) {
1015 * case NFS_OK:
1016 * struct {
1017 * unsigned tsize;
1018 * unsigned bsize;
1019 * unsigned blocks;
1020 * unsigned bfree;
1021 * unsigned bavail;
1022 * } info;
1023 * default:
1024 * void;
1025 * };
1026 */
1027static int decode_info(struct xdr_stream *xdr, struct nfs2_fsstat *result)
1028{
1029 __be32 *p;
1030
1031 p = xdr_inline_decode(xdr, NFS_info_sz << 2);
1032 if (unlikely(p == NULL))
1033 goto out_overflow;
1034 result->tsize = be32_to_cpup(p++);
1035 result->bsize = be32_to_cpup(p++);
1036 result->blocks = be32_to_cpup(p++);
1037 result->bfree = be32_to_cpup(p++);
1038 result->bavail = be32_to_cpup(p);
1039 return 0;
1040out_overflow:
1041 print_overflow_msg(__func__, xdr);
1042 return -EIO;
1043}
1044
1045static int nfs2_xdr_dec_statfsres(struct rpc_rqst *req, struct xdr_stream *xdr,
1046 struct nfs2_fsstat *result)
1047{
1048 enum nfs_stat status;
1049 int error;
1050
1051 error = decode_stat(xdr, &status);
1052 if (unlikely(error))
1053 goto out;
1054 if (status != NFS_OK)
1055 goto out_default;
1056 error = decode_info(xdr, result);
1057out:
1058 return error;
1059out_default:
1060 return nfs_stat_to_errno(status);
1061}
1062
1063
1064/*
1065 * We need to translate between nfs status return values and
1066 * the local errno values which may not be the same.
1067 */
1068static const struct {
1069 int stat;
1070 int errno;
1071} nfs_errtbl[] = {
1072 { NFS_OK, 0 },
1073 { NFSERR_PERM, -EPERM },
1074 { NFSERR_NOENT, -ENOENT },
1075 { NFSERR_IO, -errno_NFSERR_IO},
1076 { NFSERR_NXIO, -ENXIO },
1077/* { NFSERR_EAGAIN, -EAGAIN }, */
1078 { NFSERR_ACCES, -EACCES },
1079 { NFSERR_EXIST, -EEXIST },
1080 { NFSERR_XDEV, -EXDEV },
1081 { NFSERR_NODEV, -ENODEV },
1082 { NFSERR_NOTDIR, -ENOTDIR },
1083 { NFSERR_ISDIR, -EISDIR },
1084 { NFSERR_INVAL, -EINVAL },
1085 { NFSERR_FBIG, -EFBIG },
1086 { NFSERR_NOSPC, -ENOSPC },
1087 { NFSERR_ROFS, -EROFS },
1088 { NFSERR_MLINK, -EMLINK },
1089 { NFSERR_NAMETOOLONG, -ENAMETOOLONG },
1090 { NFSERR_NOTEMPTY, -ENOTEMPTY },
1091 { NFSERR_DQUOT, -EDQUOT },
1092 { NFSERR_STALE, -ESTALE },
1093 { NFSERR_REMOTE, -EREMOTE },
1094#ifdef EWFLUSH
1095 { NFSERR_WFLUSH, -EWFLUSH },
1096#endif
1097 { NFSERR_BADHANDLE, -EBADHANDLE },
1098 { NFSERR_NOT_SYNC, -ENOTSYNC },
1099 { NFSERR_BAD_COOKIE, -EBADCOOKIE },
1100 { NFSERR_NOTSUPP, -ENOTSUPP },
1101 { NFSERR_TOOSMALL, -ETOOSMALL },
1102 { NFSERR_SERVERFAULT, -EREMOTEIO },
1103 { NFSERR_BADTYPE, -EBADTYPE },
1104 { NFSERR_JUKEBOX, -EJUKEBOX },
1105 { -1, -EIO }
1106};
1107
1108/**
1109 * nfs_stat_to_errno - convert an NFS status code to a local errno
1110 * @status: NFS status code to convert
1111 *
1112 * Returns a local errno value, or -EIO if the NFS status code is
1113 * not recognized. This function is used jointly by NFSv2 and NFSv3.
1114 */
1115static int nfs_stat_to_errno(enum nfs_stat status)
1116{
1117 int i;
1118
1119 for (i = 0; nfs_errtbl[i].stat != -1; i++) {
1120 if (nfs_errtbl[i].stat == (int)status)
1121 return nfs_errtbl[i].errno;
1122 }
1123 dprintk("NFS: Unrecognized nfs status value: %u\n", status);
1124 return nfs_errtbl[i].errno;
1125}
1126
1127#define PROC(proc, argtype, restype, timer) \
1128[NFSPROC_##proc] = { \
1129 .p_proc = NFSPROC_##proc, \
1130 .p_encode = (kxdreproc_t)nfs2_xdr_enc_##argtype, \
1131 .p_decode = (kxdrdproc_t)nfs2_xdr_dec_##restype, \
1132 .p_arglen = NFS_##argtype##_sz, \
1133 .p_replen = NFS_##restype##_sz, \
1134 .p_timer = timer, \
1135 .p_statidx = NFSPROC_##proc, \
1136 .p_name = #proc, \
1137 }
1138struct rpc_procinfo nfs_procedures[] = {
1139 PROC(GETATTR, fhandle, attrstat, 1),
1140 PROC(SETATTR, sattrargs, attrstat, 0),
1141 PROC(LOOKUP, diropargs, diropres, 2),
1142 PROC(READLINK, readlinkargs, readlinkres, 3),
1143 PROC(READ, readargs, readres, 3),
1144 PROC(WRITE, writeargs, writeres, 4),
1145 PROC(CREATE, createargs, diropres, 0),
1146 PROC(REMOVE, removeargs, stat, 0),
1147 PROC(RENAME, renameargs, stat, 0),
1148 PROC(LINK, linkargs, stat, 0),
1149 PROC(SYMLINK, symlinkargs, stat, 0),
1150 PROC(MKDIR, createargs, diropres, 0),
1151 PROC(RMDIR, diropargs, stat, 0),
1152 PROC(READDIR, readdirargs, readdirres, 3),
1153 PROC(STATFS, fhandle, statfsres, 0),
1154};
1155
1156const struct rpc_version nfs_version2 = {
1157 .number = 2,
1158 .nrprocs = ARRAY_SIZE(nfs_procedures),
1159 .procs = nfs_procedures
1160};