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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/nfs/nfs2xdr.c
4 *
5 * XDR functions to encode/decode NFS RPC arguments and results.
6 *
7 * Copyright (C) 1992, 1993, 1994 Rick Sladkey
8 * Copyright (C) 1996 Olaf Kirch
9 * 04 Aug 1998 Ion Badulescu <ionut@cs.columbia.edu>
10 * FIFO's need special handling in NFSv2
11 */
12
13#include <linux/param.h>
14#include <linux/time.h>
15#include <linux/mm.h>
16#include <linux/errno.h>
17#include <linux/string.h>
18#include <linux/in.h>
19#include <linux/pagemap.h>
20#include <linux/proc_fs.h>
21#include <linux/sunrpc/clnt.h>
22#include <linux/nfs.h>
23#include <linux/nfs2.h>
24#include <linux/nfs_fs.h>
25#include <linux/nfs_common.h>
26#include "nfstrace.h"
27#include "internal.h"
28
29#define NFSDBG_FACILITY NFSDBG_XDR
30
31/*
32 * Declare the space requirements for NFS arguments and replies as
33 * number of 32bit-words
34 */
35#define NFS_pagepad_sz (1) /* Page padding */
36#define NFS_fhandle_sz (8)
37#define NFS_sattr_sz (8)
38#define NFS_filename_sz (1+(NFS2_MAXNAMLEN>>2))
39#define NFS_path_sz (1+(NFS2_MAXPATHLEN>>2))
40#define NFS_fattr_sz (17)
41#define NFS_info_sz (5)
42#define NFS_entry_sz (NFS_filename_sz+3)
43
44#define NFS_diropargs_sz (NFS_fhandle_sz+NFS_filename_sz)
45#define NFS_removeargs_sz (NFS_fhandle_sz+NFS_filename_sz)
46#define NFS_sattrargs_sz (NFS_fhandle_sz+NFS_sattr_sz)
47#define NFS_readlinkargs_sz (NFS_fhandle_sz)
48#define NFS_readargs_sz (NFS_fhandle_sz+3)
49#define NFS_writeargs_sz (NFS_fhandle_sz+4)
50#define NFS_createargs_sz (NFS_diropargs_sz+NFS_sattr_sz)
51#define NFS_renameargs_sz (NFS_diropargs_sz+NFS_diropargs_sz)
52#define NFS_linkargs_sz (NFS_fhandle_sz+NFS_diropargs_sz)
53#define NFS_symlinkargs_sz (NFS_diropargs_sz+1+NFS_sattr_sz)
54#define NFS_readdirargs_sz (NFS_fhandle_sz+2)
55
56#define NFS_attrstat_sz (1+NFS_fattr_sz)
57#define NFS_diropres_sz (1+NFS_fhandle_sz+NFS_fattr_sz)
58#define NFS_readlinkres_sz (2+NFS_pagepad_sz)
59#define NFS_readres_sz (1+NFS_fattr_sz+1+NFS_pagepad_sz)
60#define NFS_writeres_sz (NFS_attrstat_sz)
61#define NFS_stat_sz (1)
62#define NFS_readdirres_sz (1+NFS_pagepad_sz)
63#define NFS_statfsres_sz (1+NFS_info_sz)
64
65/*
66 * Encode/decode NFSv2 basic data types
67 *
68 * Basic NFSv2 data types are defined in section 2.3 of RFC 1094:
69 * "NFS: Network File System Protocol Specification".
70 *
71 * Not all basic data types have their own encoding and decoding
72 * functions. For run-time efficiency, some data types are encoded
73 * or decoded inline.
74 */
75
76static struct user_namespace *rpc_userns(const struct rpc_clnt *clnt)
77{
78 if (clnt && clnt->cl_cred)
79 return clnt->cl_cred->user_ns;
80 return &init_user_ns;
81}
82
83static struct user_namespace *rpc_rqst_userns(const struct rpc_rqst *rqstp)
84{
85 if (rqstp->rq_task)
86 return rpc_userns(rqstp->rq_task->tk_client);
87 return &init_user_ns;
88}
89
90/*
91 * typedef opaque nfsdata<>;
92 */
93static int decode_nfsdata(struct xdr_stream *xdr, struct nfs_pgio_res *result)
94{
95 u32 recvd, count;
96 __be32 *p;
97
98 p = xdr_inline_decode(xdr, 4);
99 if (unlikely(!p))
100 return -EIO;
101 count = be32_to_cpup(p);
102 recvd = xdr_read_pages(xdr, count);
103 if (unlikely(count > recvd))
104 goto out_cheating;
105out:
106 result->eof = 0; /* NFSv2 does not pass EOF flag on the wire. */
107 result->count = count;
108 return count;
109out_cheating:
110 dprintk("NFS: server cheating in read result: "
111 "count %u > recvd %u\n", count, recvd);
112 count = recvd;
113 goto out;
114}
115
116/*
117 * enum stat {
118 * NFS_OK = 0,
119 * NFSERR_PERM = 1,
120 * NFSERR_NOENT = 2,
121 * NFSERR_IO = 5,
122 * NFSERR_NXIO = 6,
123 * NFSERR_ACCES = 13,
124 * NFSERR_EXIST = 17,
125 * NFSERR_NODEV = 19,
126 * NFSERR_NOTDIR = 20,
127 * NFSERR_ISDIR = 21,
128 * NFSERR_FBIG = 27,
129 * NFSERR_NOSPC = 28,
130 * NFSERR_ROFS = 30,
131 * NFSERR_NAMETOOLONG = 63,
132 * NFSERR_NOTEMPTY = 66,
133 * NFSERR_DQUOT = 69,
134 * NFSERR_STALE = 70,
135 * NFSERR_WFLUSH = 99
136 * };
137 */
138static int decode_stat(struct xdr_stream *xdr, enum nfs_stat *status)
139{
140 __be32 *p;
141
142 p = xdr_inline_decode(xdr, 4);
143 if (unlikely(!p))
144 return -EIO;
145 if (unlikely(*p != cpu_to_be32(NFS_OK)))
146 goto out_status;
147 *status = 0;
148 return 0;
149out_status:
150 *status = be32_to_cpup(p);
151 trace_nfs_xdr_status(xdr, (int)*status);
152 return 0;
153}
154
155/*
156 * 2.3.2. ftype
157 *
158 * enum ftype {
159 * NFNON = 0,
160 * NFREG = 1,
161 * NFDIR = 2,
162 * NFBLK = 3,
163 * NFCHR = 4,
164 * NFLNK = 5
165 * };
166 *
167 */
168static __be32 *xdr_decode_ftype(__be32 *p, u32 *type)
169{
170 *type = be32_to_cpup(p++);
171 if (unlikely(*type > NF2FIFO))
172 *type = NFBAD;
173 return p;
174}
175
176/*
177 * 2.3.3. fhandle
178 *
179 * typedef opaque fhandle[FHSIZE];
180 */
181static void encode_fhandle(struct xdr_stream *xdr, const struct nfs_fh *fh)
182{
183 __be32 *p;
184
185 p = xdr_reserve_space(xdr, NFS2_FHSIZE);
186 memcpy(p, fh->data, NFS2_FHSIZE);
187}
188
189static int decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
190{
191 __be32 *p;
192
193 p = xdr_inline_decode(xdr, NFS2_FHSIZE);
194 if (unlikely(!p))
195 return -EIO;
196 fh->size = NFS2_FHSIZE;
197 memcpy(fh->data, p, NFS2_FHSIZE);
198 return 0;
199}
200
201/*
202 * 2.3.4. timeval
203 *
204 * struct timeval {
205 * unsigned int seconds;
206 * unsigned int useconds;
207 * };
208 */
209static __be32 *xdr_encode_time(__be32 *p, const struct timespec64 *timep)
210{
211 *p++ = cpu_to_be32((u32)timep->tv_sec);
212 if (timep->tv_nsec != 0)
213 *p++ = cpu_to_be32(timep->tv_nsec / NSEC_PER_USEC);
214 else
215 *p++ = cpu_to_be32(0);
216 return p;
217}
218
219/*
220 * Passing the invalid value useconds=1000000 is a Sun convention for
221 * "set to current server time". It's needed to make permissions checks
222 * for the "touch" program across v2 mounts to Solaris and Irix servers
223 * work correctly. See description of sattr in section 6.1 of "NFS
224 * Illustrated" by Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5.
225 */
226static __be32 *xdr_encode_current_server_time(__be32 *p,
227 const struct timespec64 *timep)
228{
229 *p++ = cpu_to_be32(timep->tv_sec);
230 *p++ = cpu_to_be32(1000000);
231 return p;
232}
233
234static __be32 *xdr_decode_time(__be32 *p, struct timespec64 *timep)
235{
236 timep->tv_sec = be32_to_cpup(p++);
237 timep->tv_nsec = be32_to_cpup(p++) * NSEC_PER_USEC;
238 return p;
239}
240
241/*
242 * 2.3.5. fattr
243 *
244 * struct fattr {
245 * ftype type;
246 * unsigned int mode;
247 * unsigned int nlink;
248 * unsigned int uid;
249 * unsigned int gid;
250 * unsigned int size;
251 * unsigned int blocksize;
252 * unsigned int rdev;
253 * unsigned int blocks;
254 * unsigned int fsid;
255 * unsigned int fileid;
256 * timeval atime;
257 * timeval mtime;
258 * timeval ctime;
259 * };
260 *
261 */
262static int decode_fattr(struct xdr_stream *xdr, struct nfs_fattr *fattr,
263 struct user_namespace *userns)
264{
265 u32 rdev, type;
266 __be32 *p;
267
268 p = xdr_inline_decode(xdr, NFS_fattr_sz << 2);
269 if (unlikely(!p))
270 return -EIO;
271
272 fattr->valid |= NFS_ATTR_FATTR_V2;
273
274 p = xdr_decode_ftype(p, &type);
275
276 fattr->mode = be32_to_cpup(p++);
277 fattr->nlink = be32_to_cpup(p++);
278 fattr->uid = make_kuid(userns, be32_to_cpup(p++));
279 if (!uid_valid(fattr->uid))
280 goto out_uid;
281 fattr->gid = make_kgid(userns, be32_to_cpup(p++));
282 if (!gid_valid(fattr->gid))
283 goto out_gid;
284
285 fattr->size = be32_to_cpup(p++);
286 fattr->du.nfs2.blocksize = be32_to_cpup(p++);
287
288 rdev = be32_to_cpup(p++);
289 fattr->rdev = new_decode_dev(rdev);
290 if (type == (u32)NFCHR && rdev == (u32)NFS2_FIFO_DEV) {
291 fattr->mode = (fattr->mode & ~S_IFMT) | S_IFIFO;
292 fattr->rdev = 0;
293 }
294
295 fattr->du.nfs2.blocks = be32_to_cpup(p++);
296 fattr->fsid.major = be32_to_cpup(p++);
297 fattr->fsid.minor = 0;
298 fattr->fileid = be32_to_cpup(p++);
299
300 p = xdr_decode_time(p, &fattr->atime);
301 p = xdr_decode_time(p, &fattr->mtime);
302 xdr_decode_time(p, &fattr->ctime);
303 fattr->change_attr = nfs_timespec_to_change_attr(&fattr->ctime);
304
305 return 0;
306out_uid:
307 dprintk("NFS: returned invalid uid\n");
308 return -EINVAL;
309out_gid:
310 dprintk("NFS: returned invalid gid\n");
311 return -EINVAL;
312}
313
314/*
315 * 2.3.6. sattr
316 *
317 * struct sattr {
318 * unsigned int mode;
319 * unsigned int uid;
320 * unsigned int gid;
321 * unsigned int size;
322 * timeval atime;
323 * timeval mtime;
324 * };
325 */
326
327#define NFS2_SATTR_NOT_SET (0xffffffff)
328
329static __be32 *xdr_time_not_set(__be32 *p)
330{
331 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
332 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
333 return p;
334}
335
336static void encode_sattr(struct xdr_stream *xdr, const struct iattr *attr,
337 struct user_namespace *userns)
338{
339 __be32 *p;
340
341 p = xdr_reserve_space(xdr, NFS_sattr_sz << 2);
342
343 if (attr->ia_valid & ATTR_MODE)
344 *p++ = cpu_to_be32(attr->ia_mode);
345 else
346 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
347 if (attr->ia_valid & ATTR_UID)
348 *p++ = cpu_to_be32(from_kuid_munged(userns, attr->ia_uid));
349 else
350 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
351 if (attr->ia_valid & ATTR_GID)
352 *p++ = cpu_to_be32(from_kgid_munged(userns, attr->ia_gid));
353 else
354 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
355 if (attr->ia_valid & ATTR_SIZE)
356 *p++ = cpu_to_be32((u32)attr->ia_size);
357 else
358 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
359
360 if (attr->ia_valid & ATTR_ATIME_SET)
361 p = xdr_encode_time(p, &attr->ia_atime);
362 else if (attr->ia_valid & ATTR_ATIME)
363 p = xdr_encode_current_server_time(p, &attr->ia_atime);
364 else
365 p = xdr_time_not_set(p);
366 if (attr->ia_valid & ATTR_MTIME_SET)
367 xdr_encode_time(p, &attr->ia_mtime);
368 else if (attr->ia_valid & ATTR_MTIME)
369 xdr_encode_current_server_time(p, &attr->ia_mtime);
370 else
371 xdr_time_not_set(p);
372}
373
374/*
375 * 2.3.7. filename
376 *
377 * typedef string filename<MAXNAMLEN>;
378 */
379static void encode_filename(struct xdr_stream *xdr,
380 const char *name, u32 length)
381{
382 __be32 *p;
383
384 WARN_ON_ONCE(length > NFS2_MAXNAMLEN);
385 p = xdr_reserve_space(xdr, 4 + length);
386 xdr_encode_opaque(p, name, length);
387}
388
389static int decode_filename_inline(struct xdr_stream *xdr,
390 const char **name, u32 *length)
391{
392 __be32 *p;
393 u32 count;
394
395 p = xdr_inline_decode(xdr, 4);
396 if (unlikely(!p))
397 return -EIO;
398 count = be32_to_cpup(p);
399 if (count > NFS3_MAXNAMLEN)
400 goto out_nametoolong;
401 p = xdr_inline_decode(xdr, count);
402 if (unlikely(!p))
403 return -EIO;
404 *name = (const char *)p;
405 *length = count;
406 return 0;
407out_nametoolong:
408 dprintk("NFS: returned filename too long: %u\n", count);
409 return -ENAMETOOLONG;
410}
411
412/*
413 * 2.3.8. path
414 *
415 * typedef string path<MAXPATHLEN>;
416 */
417static void encode_path(struct xdr_stream *xdr, struct page **pages, u32 length)
418{
419 __be32 *p;
420
421 p = xdr_reserve_space(xdr, 4);
422 *p = cpu_to_be32(length);
423 xdr_write_pages(xdr, pages, 0, length);
424}
425
426static int decode_path(struct xdr_stream *xdr)
427{
428 u32 length, recvd;
429 __be32 *p;
430
431 p = xdr_inline_decode(xdr, 4);
432 if (unlikely(!p))
433 return -EIO;
434 length = be32_to_cpup(p);
435 if (unlikely(length >= xdr->buf->page_len || length > NFS_MAXPATHLEN))
436 goto out_size;
437 recvd = xdr_read_pages(xdr, length);
438 if (unlikely(length > recvd))
439 goto out_cheating;
440 xdr_terminate_string(xdr->buf, length);
441 return 0;
442out_size:
443 dprintk("NFS: returned pathname too long: %u\n", length);
444 return -ENAMETOOLONG;
445out_cheating:
446 dprintk("NFS: server cheating in pathname result: "
447 "length %u > received %u\n", length, recvd);
448 return -EIO;
449}
450
451/*
452 * 2.3.9. attrstat
453 *
454 * union attrstat switch (stat status) {
455 * case NFS_OK:
456 * fattr attributes;
457 * default:
458 * void;
459 * };
460 */
461static int decode_attrstat(struct xdr_stream *xdr, struct nfs_fattr *result,
462 __u32 *op_status,
463 struct user_namespace *userns)
464{
465 enum nfs_stat status;
466 int error;
467
468 error = decode_stat(xdr, &status);
469 if (unlikely(error))
470 goto out;
471 if (op_status)
472 *op_status = status;
473 if (status != NFS_OK)
474 goto out_default;
475 error = decode_fattr(xdr, result, userns);
476out:
477 return error;
478out_default:
479 return nfs_stat_to_errno(status);
480}
481
482/*
483 * 2.3.10. diropargs
484 *
485 * struct diropargs {
486 * fhandle dir;
487 * filename name;
488 * };
489 */
490static void encode_diropargs(struct xdr_stream *xdr, const struct nfs_fh *fh,
491 const char *name, u32 length)
492{
493 encode_fhandle(xdr, fh);
494 encode_filename(xdr, name, length);
495}
496
497/*
498 * 2.3.11. diropres
499 *
500 * union diropres switch (stat status) {
501 * case NFS_OK:
502 * struct {
503 * fhandle file;
504 * fattr attributes;
505 * } diropok;
506 * default:
507 * void;
508 * };
509 */
510static int decode_diropok(struct xdr_stream *xdr, struct nfs_diropok *result,
511 struct user_namespace *userns)
512{
513 int error;
514
515 error = decode_fhandle(xdr, result->fh);
516 if (unlikely(error))
517 goto out;
518 error = decode_fattr(xdr, result->fattr, userns);
519out:
520 return error;
521}
522
523static int decode_diropres(struct xdr_stream *xdr, struct nfs_diropok *result,
524 struct user_namespace *userns)
525{
526 enum nfs_stat status;
527 int error;
528
529 error = decode_stat(xdr, &status);
530 if (unlikely(error))
531 goto out;
532 if (status != NFS_OK)
533 goto out_default;
534 error = decode_diropok(xdr, result, userns);
535out:
536 return error;
537out_default:
538 return nfs_stat_to_errno(status);
539}
540
541
542/*
543 * NFSv2 XDR encode functions
544 *
545 * NFSv2 argument types are defined in section 2.2 of RFC 1094:
546 * "NFS: Network File System Protocol Specification".
547 */
548
549static void nfs2_xdr_enc_fhandle(struct rpc_rqst *req,
550 struct xdr_stream *xdr,
551 const void *data)
552{
553 const struct nfs_fh *fh = data;
554
555 encode_fhandle(xdr, fh);
556}
557
558/*
559 * 2.2.3. sattrargs
560 *
561 * struct sattrargs {
562 * fhandle file;
563 * sattr attributes;
564 * };
565 */
566static void nfs2_xdr_enc_sattrargs(struct rpc_rqst *req,
567 struct xdr_stream *xdr,
568 const void *data)
569{
570 const struct nfs_sattrargs *args = data;
571
572 encode_fhandle(xdr, args->fh);
573 encode_sattr(xdr, args->sattr, rpc_rqst_userns(req));
574}
575
576static void nfs2_xdr_enc_diropargs(struct rpc_rqst *req,
577 struct xdr_stream *xdr,
578 const void *data)
579{
580 const struct nfs_diropargs *args = data;
581
582 encode_diropargs(xdr, args->fh, args->name, args->len);
583}
584
585static void nfs2_xdr_enc_readlinkargs(struct rpc_rqst *req,
586 struct xdr_stream *xdr,
587 const void *data)
588{
589 const struct nfs_readlinkargs *args = data;
590
591 encode_fhandle(xdr, args->fh);
592 rpc_prepare_reply_pages(req, args->pages, args->pgbase, args->pglen,
593 NFS_readlinkres_sz - NFS_pagepad_sz);
594}
595
596/*
597 * 2.2.7. readargs
598 *
599 * struct readargs {
600 * fhandle file;
601 * unsigned offset;
602 * unsigned count;
603 * unsigned totalcount;
604 * };
605 */
606static void encode_readargs(struct xdr_stream *xdr,
607 const struct nfs_pgio_args *args)
608{
609 u32 offset = args->offset;
610 u32 count = args->count;
611 __be32 *p;
612
613 encode_fhandle(xdr, args->fh);
614
615 p = xdr_reserve_space(xdr, 4 + 4 + 4);
616 *p++ = cpu_to_be32(offset);
617 *p++ = cpu_to_be32(count);
618 *p = cpu_to_be32(count);
619}
620
621static void nfs2_xdr_enc_readargs(struct rpc_rqst *req,
622 struct xdr_stream *xdr,
623 const void *data)
624{
625 const struct nfs_pgio_args *args = data;
626
627 encode_readargs(xdr, args);
628 rpc_prepare_reply_pages(req, args->pages, args->pgbase, args->count,
629 NFS_readres_sz - NFS_pagepad_sz);
630 req->rq_rcv_buf.flags |= XDRBUF_READ;
631}
632
633/*
634 * 2.2.9. writeargs
635 *
636 * struct writeargs {
637 * fhandle file;
638 * unsigned beginoffset;
639 * unsigned offset;
640 * unsigned totalcount;
641 * nfsdata data;
642 * };
643 */
644static void encode_writeargs(struct xdr_stream *xdr,
645 const struct nfs_pgio_args *args)
646{
647 u32 offset = args->offset;
648 u32 count = args->count;
649 __be32 *p;
650
651 encode_fhandle(xdr, args->fh);
652
653 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
654 *p++ = cpu_to_be32(offset);
655 *p++ = cpu_to_be32(offset);
656 *p++ = cpu_to_be32(count);
657
658 /* nfsdata */
659 *p = cpu_to_be32(count);
660 xdr_write_pages(xdr, args->pages, args->pgbase, count);
661}
662
663static void nfs2_xdr_enc_writeargs(struct rpc_rqst *req,
664 struct xdr_stream *xdr,
665 const void *data)
666{
667 const struct nfs_pgio_args *args = data;
668
669 encode_writeargs(xdr, args);
670 xdr->buf->flags |= XDRBUF_WRITE;
671}
672
673/*
674 * 2.2.10. createargs
675 *
676 * struct createargs {
677 * diropargs where;
678 * sattr attributes;
679 * };
680 */
681static void nfs2_xdr_enc_createargs(struct rpc_rqst *req,
682 struct xdr_stream *xdr,
683 const void *data)
684{
685 const struct nfs_createargs *args = data;
686
687 encode_diropargs(xdr, args->fh, args->name, args->len);
688 encode_sattr(xdr, args->sattr, rpc_rqst_userns(req));
689}
690
691static void nfs2_xdr_enc_removeargs(struct rpc_rqst *req,
692 struct xdr_stream *xdr,
693 const void *data)
694{
695 const struct nfs_removeargs *args = data;
696
697 encode_diropargs(xdr, args->fh, args->name.name, args->name.len);
698}
699
700/*
701 * 2.2.12. renameargs
702 *
703 * struct renameargs {
704 * diropargs from;
705 * diropargs to;
706 * };
707 */
708static void nfs2_xdr_enc_renameargs(struct rpc_rqst *req,
709 struct xdr_stream *xdr,
710 const void *data)
711{
712 const struct nfs_renameargs *args = data;
713 const struct qstr *old = args->old_name;
714 const struct qstr *new = args->new_name;
715
716 encode_diropargs(xdr, args->old_dir, old->name, old->len);
717 encode_diropargs(xdr, args->new_dir, new->name, new->len);
718}
719
720/*
721 * 2.2.13. linkargs
722 *
723 * struct linkargs {
724 * fhandle from;
725 * diropargs to;
726 * };
727 */
728static void nfs2_xdr_enc_linkargs(struct rpc_rqst *req,
729 struct xdr_stream *xdr,
730 const void *data)
731{
732 const struct nfs_linkargs *args = data;
733
734 encode_fhandle(xdr, args->fromfh);
735 encode_diropargs(xdr, args->tofh, args->toname, args->tolen);
736}
737
738/*
739 * 2.2.14. symlinkargs
740 *
741 * struct symlinkargs {
742 * diropargs from;
743 * path to;
744 * sattr attributes;
745 * };
746 */
747static void nfs2_xdr_enc_symlinkargs(struct rpc_rqst *req,
748 struct xdr_stream *xdr,
749 const void *data)
750{
751 const struct nfs_symlinkargs *args = data;
752
753 encode_diropargs(xdr, args->fromfh, args->fromname, args->fromlen);
754 encode_path(xdr, args->pages, args->pathlen);
755 encode_sattr(xdr, args->sattr, rpc_rqst_userns(req));
756}
757
758/*
759 * 2.2.17. readdirargs
760 *
761 * struct readdirargs {
762 * fhandle dir;
763 * nfscookie cookie;
764 * unsigned count;
765 * };
766 */
767static void encode_readdirargs(struct xdr_stream *xdr,
768 const struct nfs_readdirargs *args)
769{
770 __be32 *p;
771
772 encode_fhandle(xdr, args->fh);
773
774 p = xdr_reserve_space(xdr, 4 + 4);
775 *p++ = cpu_to_be32(args->cookie);
776 *p = cpu_to_be32(args->count);
777}
778
779static void nfs2_xdr_enc_readdirargs(struct rpc_rqst *req,
780 struct xdr_stream *xdr,
781 const void *data)
782{
783 const struct nfs_readdirargs *args = data;
784
785 encode_readdirargs(xdr, args);
786 rpc_prepare_reply_pages(req, args->pages, 0, args->count,
787 NFS_readdirres_sz - NFS_pagepad_sz);
788}
789
790/*
791 * NFSv2 XDR decode functions
792 *
793 * NFSv2 result types are defined in section 2.2 of RFC 1094:
794 * "NFS: Network File System Protocol Specification".
795 */
796
797static int nfs2_xdr_dec_stat(struct rpc_rqst *req, struct xdr_stream *xdr,
798 void *__unused)
799{
800 enum nfs_stat status;
801 int error;
802
803 error = decode_stat(xdr, &status);
804 if (unlikely(error))
805 goto out;
806 if (status != NFS_OK)
807 goto out_default;
808out:
809 return error;
810out_default:
811 return nfs_stat_to_errno(status);
812}
813
814static int nfs2_xdr_dec_attrstat(struct rpc_rqst *req, struct xdr_stream *xdr,
815 void *result)
816{
817 return decode_attrstat(xdr, result, NULL, rpc_rqst_userns(req));
818}
819
820static int nfs2_xdr_dec_diropres(struct rpc_rqst *req, struct xdr_stream *xdr,
821 void *result)
822{
823 return decode_diropres(xdr, result, rpc_rqst_userns(req));
824}
825
826/*
827 * 2.2.6. readlinkres
828 *
829 * union readlinkres switch (stat status) {
830 * case NFS_OK:
831 * path data;
832 * default:
833 * void;
834 * };
835 */
836static int nfs2_xdr_dec_readlinkres(struct rpc_rqst *req,
837 struct xdr_stream *xdr, void *__unused)
838{
839 enum nfs_stat status;
840 int error;
841
842 error = decode_stat(xdr, &status);
843 if (unlikely(error))
844 goto out;
845 if (status != NFS_OK)
846 goto out_default;
847 error = decode_path(xdr);
848out:
849 return error;
850out_default:
851 return nfs_stat_to_errno(status);
852}
853
854/*
855 * 2.2.7. readres
856 *
857 * union readres switch (stat status) {
858 * case NFS_OK:
859 * fattr attributes;
860 * nfsdata data;
861 * default:
862 * void;
863 * };
864 */
865static int nfs2_xdr_dec_readres(struct rpc_rqst *req, struct xdr_stream *xdr,
866 void *data)
867{
868 struct nfs_pgio_res *result = data;
869 enum nfs_stat status;
870 int error;
871
872 error = decode_stat(xdr, &status);
873 if (unlikely(error))
874 goto out;
875 result->op_status = status;
876 if (status != NFS_OK)
877 goto out_default;
878 error = decode_fattr(xdr, result->fattr, rpc_rqst_userns(req));
879 if (unlikely(error))
880 goto out;
881 error = decode_nfsdata(xdr, result);
882out:
883 return error;
884out_default:
885 return nfs_stat_to_errno(status);
886}
887
888static int nfs2_xdr_dec_writeres(struct rpc_rqst *req, struct xdr_stream *xdr,
889 void *data)
890{
891 struct nfs_pgio_res *result = data;
892
893 /* All NFSv2 writes are "file sync" writes */
894 result->verf->committed = NFS_FILE_SYNC;
895 return decode_attrstat(xdr, result->fattr, &result->op_status,
896 rpc_rqst_userns(req));
897}
898
899/**
900 * nfs2_decode_dirent - Decode a single NFSv2 directory entry stored in
901 * the local page cache.
902 * @xdr: XDR stream where entry resides
903 * @entry: buffer to fill in with entry data
904 * @plus: boolean indicating whether this should be a readdirplus entry
905 *
906 * Returns zero if successful, otherwise a negative errno value is
907 * returned.
908 *
909 * This function is not invoked during READDIR reply decoding, but
910 * rather whenever an application invokes the getdents(2) system call
911 * on a directory already in our cache.
912 *
913 * 2.2.17. entry
914 *
915 * struct entry {
916 * unsigned fileid;
917 * filename name;
918 * nfscookie cookie;
919 * entry *nextentry;
920 * };
921 */
922int nfs2_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
923 bool plus)
924{
925 __be32 *p;
926 int error;
927
928 p = xdr_inline_decode(xdr, 4);
929 if (unlikely(!p))
930 return -EAGAIN;
931 if (*p++ == xdr_zero) {
932 p = xdr_inline_decode(xdr, 4);
933 if (unlikely(!p))
934 return -EAGAIN;
935 if (*p++ == xdr_zero)
936 return -EAGAIN;
937 entry->eof = 1;
938 return -EBADCOOKIE;
939 }
940
941 p = xdr_inline_decode(xdr, 4);
942 if (unlikely(!p))
943 return -EAGAIN;
944 entry->ino = be32_to_cpup(p);
945
946 error = decode_filename_inline(xdr, &entry->name, &entry->len);
947 if (unlikely(error))
948 return error == -ENAMETOOLONG ? -ENAMETOOLONG : -EAGAIN;
949
950 /*
951 * The type (size and byte order) of nfscookie isn't defined in
952 * RFC 1094. This implementation assumes that it's an XDR uint32.
953 */
954 p = xdr_inline_decode(xdr, 4);
955 if (unlikely(!p))
956 return -EAGAIN;
957 entry->cookie = be32_to_cpup(p);
958
959 entry->d_type = DT_UNKNOWN;
960
961 return 0;
962}
963
964/*
965 * 2.2.17. readdirres
966 *
967 * union readdirres switch (stat status) {
968 * case NFS_OK:
969 * struct {
970 * entry *entries;
971 * bool eof;
972 * } readdirok;
973 * default:
974 * void;
975 * };
976 *
977 * Read the directory contents into the page cache, but don't
978 * touch them. The actual decoding is done by nfs2_decode_dirent()
979 * during subsequent nfs_readdir() calls.
980 */
981static int decode_readdirok(struct xdr_stream *xdr)
982{
983 return xdr_read_pages(xdr, xdr->buf->page_len);
984}
985
986static int nfs2_xdr_dec_readdirres(struct rpc_rqst *req,
987 struct xdr_stream *xdr, void *__unused)
988{
989 enum nfs_stat status;
990 int error;
991
992 error = decode_stat(xdr, &status);
993 if (unlikely(error))
994 goto out;
995 if (status != NFS_OK)
996 goto out_default;
997 error = decode_readdirok(xdr);
998out:
999 return error;
1000out_default:
1001 return nfs_stat_to_errno(status);
1002}
1003
1004/*
1005 * 2.2.18. statfsres
1006 *
1007 * union statfsres (stat status) {
1008 * case NFS_OK:
1009 * struct {
1010 * unsigned tsize;
1011 * unsigned bsize;
1012 * unsigned blocks;
1013 * unsigned bfree;
1014 * unsigned bavail;
1015 * } info;
1016 * default:
1017 * void;
1018 * };
1019 */
1020static int decode_info(struct xdr_stream *xdr, struct nfs2_fsstat *result)
1021{
1022 __be32 *p;
1023
1024 p = xdr_inline_decode(xdr, NFS_info_sz << 2);
1025 if (unlikely(!p))
1026 return -EIO;
1027 result->tsize = be32_to_cpup(p++);
1028 result->bsize = be32_to_cpup(p++);
1029 result->blocks = be32_to_cpup(p++);
1030 result->bfree = be32_to_cpup(p++);
1031 result->bavail = be32_to_cpup(p);
1032 return 0;
1033}
1034
1035static int nfs2_xdr_dec_statfsres(struct rpc_rqst *req, struct xdr_stream *xdr,
1036 void *result)
1037{
1038 enum nfs_stat status;
1039 int error;
1040
1041 error = decode_stat(xdr, &status);
1042 if (unlikely(error))
1043 goto out;
1044 if (status != NFS_OK)
1045 goto out_default;
1046 error = decode_info(xdr, result);
1047out:
1048 return error;
1049out_default:
1050 return nfs_stat_to_errno(status);
1051}
1052
1053#define PROC(proc, argtype, restype, timer) \
1054[NFSPROC_##proc] = { \
1055 .p_proc = NFSPROC_##proc, \
1056 .p_encode = nfs2_xdr_enc_##argtype, \
1057 .p_decode = nfs2_xdr_dec_##restype, \
1058 .p_arglen = NFS_##argtype##_sz, \
1059 .p_replen = NFS_##restype##_sz, \
1060 .p_timer = timer, \
1061 .p_statidx = NFSPROC_##proc, \
1062 .p_name = #proc, \
1063 }
1064const struct rpc_procinfo nfs_procedures[] = {
1065 PROC(GETATTR, fhandle, attrstat, 1),
1066 PROC(SETATTR, sattrargs, attrstat, 0),
1067 PROC(LOOKUP, diropargs, diropres, 2),
1068 PROC(READLINK, readlinkargs, readlinkres, 3),
1069 PROC(READ, readargs, readres, 3),
1070 PROC(WRITE, writeargs, writeres, 4),
1071 PROC(CREATE, createargs, diropres, 0),
1072 PROC(REMOVE, removeargs, stat, 0),
1073 PROC(RENAME, renameargs, stat, 0),
1074 PROC(LINK, linkargs, stat, 0),
1075 PROC(SYMLINK, symlinkargs, stat, 0),
1076 PROC(MKDIR, createargs, diropres, 0),
1077 PROC(RMDIR, diropargs, stat, 0),
1078 PROC(READDIR, readdirargs, readdirres, 3),
1079 PROC(STATFS, fhandle, statfsres, 0),
1080};
1081
1082static unsigned int nfs_version2_counts[ARRAY_SIZE(nfs_procedures)];
1083const struct rpc_version nfs_version2 = {
1084 .number = 2,
1085 .nrprocs = ARRAY_SIZE(nfs_procedures),
1086 .procs = nfs_procedures,
1087 .counts = nfs_version2_counts,
1088};
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_pgio_res *result)
107{
108 u32 recvd, count;
109 __be32 *p;
110
111 p = xdr_inline_decode(xdr, 4);
112 if (unlikely(p == NULL))
113 goto out_overflow;
114 count = be32_to_cpup(p);
115 recvd = xdr_read_pages(xdr, count);
116 if (unlikely(count > recvd))
117 goto out_cheating;
118out:
119 result->eof = 0; /* NFSv2 does not pass EOF flag on the wire. */
120 result->count = count;
121 return count;
122out_cheating:
123 dprintk("NFS: server cheating in read result: "
124 "count %u > recvd %u\n", count, recvd);
125 count = recvd;
126 goto out;
127out_overflow:
128 print_overflow_msg(__func__, xdr);
129 return -EIO;
130}
131
132/*
133 * enum stat {
134 * NFS_OK = 0,
135 * NFSERR_PERM = 1,
136 * NFSERR_NOENT = 2,
137 * NFSERR_IO = 5,
138 * NFSERR_NXIO = 6,
139 * NFSERR_ACCES = 13,
140 * NFSERR_EXIST = 17,
141 * NFSERR_NODEV = 19,
142 * NFSERR_NOTDIR = 20,
143 * NFSERR_ISDIR = 21,
144 * NFSERR_FBIG = 27,
145 * NFSERR_NOSPC = 28,
146 * NFSERR_ROFS = 30,
147 * NFSERR_NAMETOOLONG = 63,
148 * NFSERR_NOTEMPTY = 66,
149 * NFSERR_DQUOT = 69,
150 * NFSERR_STALE = 70,
151 * NFSERR_WFLUSH = 99
152 * };
153 */
154static int decode_stat(struct xdr_stream *xdr, enum nfs_stat *status)
155{
156 __be32 *p;
157
158 p = xdr_inline_decode(xdr, 4);
159 if (unlikely(p == NULL))
160 goto out_overflow;
161 *status = be32_to_cpup(p);
162 return 0;
163out_overflow:
164 print_overflow_msg(__func__, xdr);
165 return -EIO;
166}
167
168/*
169 * 2.3.2. ftype
170 *
171 * enum ftype {
172 * NFNON = 0,
173 * NFREG = 1,
174 * NFDIR = 2,
175 * NFBLK = 3,
176 * NFCHR = 4,
177 * NFLNK = 5
178 * };
179 *
180 */
181static __be32 *xdr_decode_ftype(__be32 *p, u32 *type)
182{
183 *type = be32_to_cpup(p++);
184 if (unlikely(*type > NF2FIFO))
185 *type = NFBAD;
186 return p;
187}
188
189/*
190 * 2.3.3. fhandle
191 *
192 * typedef opaque fhandle[FHSIZE];
193 */
194static void encode_fhandle(struct xdr_stream *xdr, const struct nfs_fh *fh)
195{
196 __be32 *p;
197
198 p = xdr_reserve_space(xdr, NFS2_FHSIZE);
199 memcpy(p, fh->data, NFS2_FHSIZE);
200}
201
202static int decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
203{
204 __be32 *p;
205
206 p = xdr_inline_decode(xdr, NFS2_FHSIZE);
207 if (unlikely(p == NULL))
208 goto out_overflow;
209 fh->size = NFS2_FHSIZE;
210 memcpy(fh->data, p, NFS2_FHSIZE);
211 return 0;
212out_overflow:
213 print_overflow_msg(__func__, xdr);
214 return -EIO;
215}
216
217/*
218 * 2.3.4. timeval
219 *
220 * struct timeval {
221 * unsigned int seconds;
222 * unsigned int useconds;
223 * };
224 */
225static __be32 *xdr_encode_time(__be32 *p, const struct timespec *timep)
226{
227 *p++ = cpu_to_be32(timep->tv_sec);
228 if (timep->tv_nsec != 0)
229 *p++ = cpu_to_be32(timep->tv_nsec / NSEC_PER_USEC);
230 else
231 *p++ = cpu_to_be32(0);
232 return p;
233}
234
235/*
236 * Passing the invalid value useconds=1000000 is a Sun convention for
237 * "set to current server time". It's needed to make permissions checks
238 * for the "touch" program across v2 mounts to Solaris and Irix servers
239 * work correctly. See description of sattr in section 6.1 of "NFS
240 * Illustrated" by Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5.
241 */
242static __be32 *xdr_encode_current_server_time(__be32 *p,
243 const struct timespec *timep)
244{
245 *p++ = cpu_to_be32(timep->tv_sec);
246 *p++ = cpu_to_be32(1000000);
247 return p;
248}
249
250static __be32 *xdr_decode_time(__be32 *p, struct timespec *timep)
251{
252 timep->tv_sec = be32_to_cpup(p++);
253 timep->tv_nsec = be32_to_cpup(p++) * NSEC_PER_USEC;
254 return p;
255}
256
257/*
258 * 2.3.5. fattr
259 *
260 * struct fattr {
261 * ftype type;
262 * unsigned int mode;
263 * unsigned int nlink;
264 * unsigned int uid;
265 * unsigned int gid;
266 * unsigned int size;
267 * unsigned int blocksize;
268 * unsigned int rdev;
269 * unsigned int blocks;
270 * unsigned int fsid;
271 * unsigned int fileid;
272 * timeval atime;
273 * timeval mtime;
274 * timeval ctime;
275 * };
276 *
277 */
278static int decode_fattr(struct xdr_stream *xdr, struct nfs_fattr *fattr)
279{
280 u32 rdev, type;
281 __be32 *p;
282
283 p = xdr_inline_decode(xdr, NFS_fattr_sz << 2);
284 if (unlikely(p == NULL))
285 goto out_overflow;
286
287 fattr->valid |= NFS_ATTR_FATTR_V2;
288
289 p = xdr_decode_ftype(p, &type);
290
291 fattr->mode = be32_to_cpup(p++);
292 fattr->nlink = be32_to_cpup(p++);
293 fattr->uid = make_kuid(&init_user_ns, be32_to_cpup(p++));
294 if (!uid_valid(fattr->uid))
295 goto out_uid;
296 fattr->gid = make_kgid(&init_user_ns, be32_to_cpup(p++));
297 if (!gid_valid(fattr->gid))
298 goto out_gid;
299
300 fattr->size = be32_to_cpup(p++);
301 fattr->du.nfs2.blocksize = be32_to_cpup(p++);
302
303 rdev = be32_to_cpup(p++);
304 fattr->rdev = new_decode_dev(rdev);
305 if (type == (u32)NFCHR && rdev == (u32)NFS2_FIFO_DEV) {
306 fattr->mode = (fattr->mode & ~S_IFMT) | S_IFIFO;
307 fattr->rdev = 0;
308 }
309
310 fattr->du.nfs2.blocks = be32_to_cpup(p++);
311 fattr->fsid.major = be32_to_cpup(p++);
312 fattr->fsid.minor = 0;
313 fattr->fileid = be32_to_cpup(p++);
314
315 p = xdr_decode_time(p, &fattr->atime);
316 p = xdr_decode_time(p, &fattr->mtime);
317 xdr_decode_time(p, &fattr->ctime);
318 fattr->change_attr = nfs_timespec_to_change_attr(&fattr->ctime);
319
320 return 0;
321out_uid:
322 dprintk("NFS: returned invalid uid\n");
323 return -EINVAL;
324out_gid:
325 dprintk("NFS: returned invalid gid\n");
326 return -EINVAL;
327out_overflow:
328 print_overflow_msg(__func__, xdr);
329 return -EIO;
330}
331
332/*
333 * 2.3.6. sattr
334 *
335 * struct sattr {
336 * unsigned int mode;
337 * unsigned int uid;
338 * unsigned int gid;
339 * unsigned int size;
340 * timeval atime;
341 * timeval mtime;
342 * };
343 */
344
345#define NFS2_SATTR_NOT_SET (0xffffffff)
346
347static __be32 *xdr_time_not_set(__be32 *p)
348{
349 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
350 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
351 return p;
352}
353
354static void encode_sattr(struct xdr_stream *xdr, const struct iattr *attr)
355{
356 __be32 *p;
357
358 p = xdr_reserve_space(xdr, NFS_sattr_sz << 2);
359
360 if (attr->ia_valid & ATTR_MODE)
361 *p++ = cpu_to_be32(attr->ia_mode);
362 else
363 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
364 if (attr->ia_valid & ATTR_UID)
365 *p++ = cpu_to_be32(from_kuid(&init_user_ns, attr->ia_uid));
366 else
367 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
368 if (attr->ia_valid & ATTR_GID)
369 *p++ = cpu_to_be32(from_kgid(&init_user_ns, attr->ia_gid));
370 else
371 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
372 if (attr->ia_valid & ATTR_SIZE)
373 *p++ = cpu_to_be32((u32)attr->ia_size);
374 else
375 *p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
376
377 if (attr->ia_valid & ATTR_ATIME_SET)
378 p = xdr_encode_time(p, &attr->ia_atime);
379 else if (attr->ia_valid & ATTR_ATIME)
380 p = xdr_encode_current_server_time(p, &attr->ia_atime);
381 else
382 p = xdr_time_not_set(p);
383 if (attr->ia_valid & ATTR_MTIME_SET)
384 xdr_encode_time(p, &attr->ia_mtime);
385 else if (attr->ia_valid & ATTR_MTIME)
386 xdr_encode_current_server_time(p, &attr->ia_mtime);
387 else
388 xdr_time_not_set(p);
389}
390
391/*
392 * 2.3.7. filename
393 *
394 * typedef string filename<MAXNAMLEN>;
395 */
396static void encode_filename(struct xdr_stream *xdr,
397 const char *name, u32 length)
398{
399 __be32 *p;
400
401 WARN_ON_ONCE(length > NFS2_MAXNAMLEN);
402 p = xdr_reserve_space(xdr, 4 + length);
403 xdr_encode_opaque(p, name, length);
404}
405
406static int decode_filename_inline(struct xdr_stream *xdr,
407 const char **name, u32 *length)
408{
409 __be32 *p;
410 u32 count;
411
412 p = xdr_inline_decode(xdr, 4);
413 if (unlikely(p == NULL))
414 goto out_overflow;
415 count = be32_to_cpup(p);
416 if (count > NFS3_MAXNAMLEN)
417 goto out_nametoolong;
418 p = xdr_inline_decode(xdr, count);
419 if (unlikely(p == NULL))
420 goto out_overflow;
421 *name = (const char *)p;
422 *length = count;
423 return 0;
424out_nametoolong:
425 dprintk("NFS: returned filename too long: %u\n", count);
426 return -ENAMETOOLONG;
427out_overflow:
428 print_overflow_msg(__func__, xdr);
429 return -EIO;
430}
431
432/*
433 * 2.3.8. path
434 *
435 * typedef string path<MAXPATHLEN>;
436 */
437static void encode_path(struct xdr_stream *xdr, struct page **pages, u32 length)
438{
439 __be32 *p;
440
441 p = xdr_reserve_space(xdr, 4);
442 *p = cpu_to_be32(length);
443 xdr_write_pages(xdr, pages, 0, length);
444}
445
446static int decode_path(struct xdr_stream *xdr)
447{
448 u32 length, recvd;
449 __be32 *p;
450
451 p = xdr_inline_decode(xdr, 4);
452 if (unlikely(p == NULL))
453 goto out_overflow;
454 length = be32_to_cpup(p);
455 if (unlikely(length >= xdr->buf->page_len || length > NFS_MAXPATHLEN))
456 goto out_size;
457 recvd = xdr_read_pages(xdr, length);
458 if (unlikely(length > recvd))
459 goto out_cheating;
460 xdr_terminate_string(xdr->buf, length);
461 return 0;
462out_size:
463 dprintk("NFS: returned pathname too long: %u\n", length);
464 return -ENAMETOOLONG;
465out_cheating:
466 dprintk("NFS: server cheating in pathname result: "
467 "length %u > received %u\n", length, recvd);
468 return -EIO;
469out_overflow:
470 print_overflow_msg(__func__, xdr);
471 return -EIO;
472}
473
474/*
475 * 2.3.9. attrstat
476 *
477 * union attrstat switch (stat status) {
478 * case NFS_OK:
479 * fattr attributes;
480 * default:
481 * void;
482 * };
483 */
484static int decode_attrstat(struct xdr_stream *xdr, struct nfs_fattr *result,
485 __u32 *op_status)
486{
487 enum nfs_stat status;
488 int error;
489
490 error = decode_stat(xdr, &status);
491 if (unlikely(error))
492 goto out;
493 if (op_status)
494 *op_status = status;
495 if (status != NFS_OK)
496 goto out_default;
497 error = decode_fattr(xdr, result);
498out:
499 return error;
500out_default:
501 return nfs_stat_to_errno(status);
502}
503
504/*
505 * 2.3.10. diropargs
506 *
507 * struct diropargs {
508 * fhandle dir;
509 * filename name;
510 * };
511 */
512static void encode_diropargs(struct xdr_stream *xdr, const struct nfs_fh *fh,
513 const char *name, u32 length)
514{
515 encode_fhandle(xdr, fh);
516 encode_filename(xdr, name, length);
517}
518
519/*
520 * 2.3.11. diropres
521 *
522 * union diropres switch (stat status) {
523 * case NFS_OK:
524 * struct {
525 * fhandle file;
526 * fattr attributes;
527 * } diropok;
528 * default:
529 * void;
530 * };
531 */
532static int decode_diropok(struct xdr_stream *xdr, struct nfs_diropok *result)
533{
534 int error;
535
536 error = decode_fhandle(xdr, result->fh);
537 if (unlikely(error))
538 goto out;
539 error = decode_fattr(xdr, result->fattr);
540out:
541 return error;
542}
543
544static int decode_diropres(struct xdr_stream *xdr, struct nfs_diropok *result)
545{
546 enum nfs_stat status;
547 int error;
548
549 error = decode_stat(xdr, &status);
550 if (unlikely(error))
551 goto out;
552 if (status != NFS_OK)
553 goto out_default;
554 error = decode_diropok(xdr, result);
555out:
556 return error;
557out_default:
558 return nfs_stat_to_errno(status);
559}
560
561
562/*
563 * NFSv2 XDR encode functions
564 *
565 * NFSv2 argument types are defined in section 2.2 of RFC 1094:
566 * "NFS: Network File System Protocol Specification".
567 */
568
569static void nfs2_xdr_enc_fhandle(struct rpc_rqst *req,
570 struct xdr_stream *xdr,
571 const struct nfs_fh *fh)
572{
573 encode_fhandle(xdr, fh);
574}
575
576/*
577 * 2.2.3. sattrargs
578 *
579 * struct sattrargs {
580 * fhandle file;
581 * sattr attributes;
582 * };
583 */
584static void nfs2_xdr_enc_sattrargs(struct rpc_rqst *req,
585 struct xdr_stream *xdr,
586 const struct nfs_sattrargs *args)
587{
588 encode_fhandle(xdr, args->fh);
589 encode_sattr(xdr, args->sattr);
590}
591
592static void nfs2_xdr_enc_diropargs(struct rpc_rqst *req,
593 struct xdr_stream *xdr,
594 const struct nfs_diropargs *args)
595{
596 encode_diropargs(xdr, args->fh, args->name, args->len);
597}
598
599static void nfs2_xdr_enc_readlinkargs(struct rpc_rqst *req,
600 struct xdr_stream *xdr,
601 const struct nfs_readlinkargs *args)
602{
603 encode_fhandle(xdr, args->fh);
604 prepare_reply_buffer(req, args->pages, args->pgbase,
605 args->pglen, NFS_readlinkres_sz);
606}
607
608/*
609 * 2.2.7. readargs
610 *
611 * struct readargs {
612 * fhandle file;
613 * unsigned offset;
614 * unsigned count;
615 * unsigned totalcount;
616 * };
617 */
618static void encode_readargs(struct xdr_stream *xdr,
619 const struct nfs_pgio_args *args)
620{
621 u32 offset = args->offset;
622 u32 count = args->count;
623 __be32 *p;
624
625 encode_fhandle(xdr, args->fh);
626
627 p = xdr_reserve_space(xdr, 4 + 4 + 4);
628 *p++ = cpu_to_be32(offset);
629 *p++ = cpu_to_be32(count);
630 *p = cpu_to_be32(count);
631}
632
633static void nfs2_xdr_enc_readargs(struct rpc_rqst *req,
634 struct xdr_stream *xdr,
635 const struct nfs_pgio_args *args)
636{
637 encode_readargs(xdr, args);
638 prepare_reply_buffer(req, args->pages, args->pgbase,
639 args->count, NFS_readres_sz);
640 req->rq_rcv_buf.flags |= XDRBUF_READ;
641}
642
643/*
644 * 2.2.9. writeargs
645 *
646 * struct writeargs {
647 * fhandle file;
648 * unsigned beginoffset;
649 * unsigned offset;
650 * unsigned totalcount;
651 * nfsdata data;
652 * };
653 */
654static void encode_writeargs(struct xdr_stream *xdr,
655 const struct nfs_pgio_args *args)
656{
657 u32 offset = args->offset;
658 u32 count = args->count;
659 __be32 *p;
660
661 encode_fhandle(xdr, args->fh);
662
663 p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
664 *p++ = cpu_to_be32(offset);
665 *p++ = cpu_to_be32(offset);
666 *p++ = cpu_to_be32(count);
667
668 /* nfsdata */
669 *p = cpu_to_be32(count);
670 xdr_write_pages(xdr, args->pages, args->pgbase, count);
671}
672
673static void nfs2_xdr_enc_writeargs(struct rpc_rqst *req,
674 struct xdr_stream *xdr,
675 const struct nfs_pgio_args *args)
676{
677 encode_writeargs(xdr, args);
678 xdr->buf->flags |= XDRBUF_WRITE;
679}
680
681/*
682 * 2.2.10. createargs
683 *
684 * struct createargs {
685 * diropargs where;
686 * sattr attributes;
687 * };
688 */
689static void nfs2_xdr_enc_createargs(struct rpc_rqst *req,
690 struct xdr_stream *xdr,
691 const struct nfs_createargs *args)
692{
693 encode_diropargs(xdr, args->fh, args->name, args->len);
694 encode_sattr(xdr, args->sattr);
695}
696
697static void nfs2_xdr_enc_removeargs(struct rpc_rqst *req,
698 struct xdr_stream *xdr,
699 const struct nfs_removeargs *args)
700{
701 encode_diropargs(xdr, args->fh, args->name.name, args->name.len);
702}
703
704/*
705 * 2.2.12. renameargs
706 *
707 * struct renameargs {
708 * diropargs from;
709 * diropargs to;
710 * };
711 */
712static void nfs2_xdr_enc_renameargs(struct rpc_rqst *req,
713 struct xdr_stream *xdr,
714 const struct nfs_renameargs *args)
715{
716 const struct qstr *old = args->old_name;
717 const struct qstr *new = args->new_name;
718
719 encode_diropargs(xdr, args->old_dir, old->name, old->len);
720 encode_diropargs(xdr, args->new_dir, new->name, new->len);
721}
722
723/*
724 * 2.2.13. linkargs
725 *
726 * struct linkargs {
727 * fhandle from;
728 * diropargs to;
729 * };
730 */
731static void nfs2_xdr_enc_linkargs(struct rpc_rqst *req,
732 struct xdr_stream *xdr,
733 const struct nfs_linkargs *args)
734{
735 encode_fhandle(xdr, args->fromfh);
736 encode_diropargs(xdr, args->tofh, args->toname, args->tolen);
737}
738
739/*
740 * 2.2.14. symlinkargs
741 *
742 * struct symlinkargs {
743 * diropargs from;
744 * path to;
745 * sattr attributes;
746 * };
747 */
748static void nfs2_xdr_enc_symlinkargs(struct rpc_rqst *req,
749 struct xdr_stream *xdr,
750 const struct nfs_symlinkargs *args)
751{
752 encode_diropargs(xdr, args->fromfh, args->fromname, args->fromlen);
753 encode_path(xdr, args->pages, args->pathlen);
754 encode_sattr(xdr, args->sattr);
755}
756
757/*
758 * 2.2.17. readdirargs
759 *
760 * struct readdirargs {
761 * fhandle dir;
762 * nfscookie cookie;
763 * unsigned count;
764 * };
765 */
766static void encode_readdirargs(struct xdr_stream *xdr,
767 const struct nfs_readdirargs *args)
768{
769 __be32 *p;
770
771 encode_fhandle(xdr, args->fh);
772
773 p = xdr_reserve_space(xdr, 4 + 4);
774 *p++ = cpu_to_be32(args->cookie);
775 *p = cpu_to_be32(args->count);
776}
777
778static void nfs2_xdr_enc_readdirargs(struct rpc_rqst *req,
779 struct xdr_stream *xdr,
780 const struct nfs_readdirargs *args)
781{
782 encode_readdirargs(xdr, args);
783 prepare_reply_buffer(req, args->pages, 0,
784 args->count, NFS_readdirres_sz);
785}
786
787/*
788 * NFSv2 XDR decode functions
789 *
790 * NFSv2 result types are defined in section 2.2 of RFC 1094:
791 * "NFS: Network File System Protocol Specification".
792 */
793
794static int nfs2_xdr_dec_stat(struct rpc_rqst *req, struct xdr_stream *xdr,
795 void *__unused)
796{
797 enum nfs_stat status;
798 int error;
799
800 error = decode_stat(xdr, &status);
801 if (unlikely(error))
802 goto out;
803 if (status != NFS_OK)
804 goto out_default;
805out:
806 return error;
807out_default:
808 return nfs_stat_to_errno(status);
809}
810
811static int nfs2_xdr_dec_attrstat(struct rpc_rqst *req, struct xdr_stream *xdr,
812 struct nfs_fattr *result)
813{
814 return decode_attrstat(xdr, result, NULL);
815}
816
817static int nfs2_xdr_dec_diropres(struct rpc_rqst *req, struct xdr_stream *xdr,
818 struct nfs_diropok *result)
819{
820 return decode_diropres(xdr, result);
821}
822
823/*
824 * 2.2.6. readlinkres
825 *
826 * union readlinkres switch (stat status) {
827 * case NFS_OK:
828 * path data;
829 * default:
830 * void;
831 * };
832 */
833static int nfs2_xdr_dec_readlinkres(struct rpc_rqst *req,
834 struct xdr_stream *xdr, void *__unused)
835{
836 enum nfs_stat status;
837 int error;
838
839 error = decode_stat(xdr, &status);
840 if (unlikely(error))
841 goto out;
842 if (status != NFS_OK)
843 goto out_default;
844 error = decode_path(xdr);
845out:
846 return error;
847out_default:
848 return nfs_stat_to_errno(status);
849}
850
851/*
852 * 2.2.7. readres
853 *
854 * union readres switch (stat status) {
855 * case NFS_OK:
856 * fattr attributes;
857 * nfsdata data;
858 * default:
859 * void;
860 * };
861 */
862static int nfs2_xdr_dec_readres(struct rpc_rqst *req, struct xdr_stream *xdr,
863 struct nfs_pgio_res *result)
864{
865 enum nfs_stat status;
866 int error;
867
868 error = decode_stat(xdr, &status);
869 if (unlikely(error))
870 goto out;
871 result->op_status = status;
872 if (status != NFS_OK)
873 goto out_default;
874 error = decode_fattr(xdr, result->fattr);
875 if (unlikely(error))
876 goto out;
877 error = decode_nfsdata(xdr, result);
878out:
879 return error;
880out_default:
881 return nfs_stat_to_errno(status);
882}
883
884static int nfs2_xdr_dec_writeres(struct rpc_rqst *req, struct xdr_stream *xdr,
885 struct nfs_pgio_res *result)
886{
887 /* All NFSv2 writes are "file sync" writes */
888 result->verf->committed = NFS_FILE_SYNC;
889 return decode_attrstat(xdr, result->fattr, &result->op_status);
890}
891
892/**
893 * nfs2_decode_dirent - Decode a single NFSv2 directory entry stored in
894 * the local page cache.
895 * @xdr: XDR stream where entry resides
896 * @entry: buffer to fill in with entry data
897 * @plus: boolean indicating whether this should be a readdirplus entry
898 *
899 * Returns zero if successful, otherwise a negative errno value is
900 * returned.
901 *
902 * This function is not invoked during READDIR reply decoding, but
903 * rather whenever an application invokes the getdents(2) system call
904 * on a directory already in our cache.
905 *
906 * 2.2.17. entry
907 *
908 * struct entry {
909 * unsigned fileid;
910 * filename name;
911 * nfscookie cookie;
912 * entry *nextentry;
913 * };
914 */
915int nfs2_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
916 int plus)
917{
918 __be32 *p;
919 int error;
920
921 p = xdr_inline_decode(xdr, 4);
922 if (unlikely(p == NULL))
923 goto out_overflow;
924 if (*p++ == xdr_zero) {
925 p = xdr_inline_decode(xdr, 4);
926 if (unlikely(p == NULL))
927 goto out_overflow;
928 if (*p++ == xdr_zero)
929 return -EAGAIN;
930 entry->eof = 1;
931 return -EBADCOOKIE;
932 }
933
934 p = xdr_inline_decode(xdr, 4);
935 if (unlikely(p == NULL))
936 goto out_overflow;
937 entry->ino = be32_to_cpup(p);
938
939 error = decode_filename_inline(xdr, &entry->name, &entry->len);
940 if (unlikely(error))
941 return error;
942
943 /*
944 * The type (size and byte order) of nfscookie isn't defined in
945 * RFC 1094. This implementation assumes that it's an XDR uint32.
946 */
947 entry->prev_cookie = entry->cookie;
948 p = xdr_inline_decode(xdr, 4);
949 if (unlikely(p == NULL))
950 goto out_overflow;
951 entry->cookie = be32_to_cpup(p);
952
953 entry->d_type = DT_UNKNOWN;
954
955 return 0;
956
957out_overflow:
958 print_overflow_msg(__func__, xdr);
959 return -EAGAIN;
960}
961
962/*
963 * 2.2.17. readdirres
964 *
965 * union readdirres switch (stat status) {
966 * case NFS_OK:
967 * struct {
968 * entry *entries;
969 * bool eof;
970 * } readdirok;
971 * default:
972 * void;
973 * };
974 *
975 * Read the directory contents into the page cache, but don't
976 * touch them. The actual decoding is done by nfs2_decode_dirent()
977 * during subsequent nfs_readdir() calls.
978 */
979static int decode_readdirok(struct xdr_stream *xdr)
980{
981 return xdr_read_pages(xdr, xdr->buf->page_len);
982}
983
984static int nfs2_xdr_dec_readdirres(struct rpc_rqst *req,
985 struct xdr_stream *xdr, void *__unused)
986{
987 enum nfs_stat status;
988 int error;
989
990 error = decode_stat(xdr, &status);
991 if (unlikely(error))
992 goto out;
993 if (status != NFS_OK)
994 goto out_default;
995 error = decode_readdirok(xdr);
996out:
997 return error;
998out_default:
999 return nfs_stat_to_errno(status);
1000}
1001
1002/*
1003 * 2.2.18. statfsres
1004 *
1005 * union statfsres (stat status) {
1006 * case NFS_OK:
1007 * struct {
1008 * unsigned tsize;
1009 * unsigned bsize;
1010 * unsigned blocks;
1011 * unsigned bfree;
1012 * unsigned bavail;
1013 * } info;
1014 * default:
1015 * void;
1016 * };
1017 */
1018static int decode_info(struct xdr_stream *xdr, struct nfs2_fsstat *result)
1019{
1020 __be32 *p;
1021
1022 p = xdr_inline_decode(xdr, NFS_info_sz << 2);
1023 if (unlikely(p == NULL))
1024 goto out_overflow;
1025 result->tsize = be32_to_cpup(p++);
1026 result->bsize = be32_to_cpup(p++);
1027 result->blocks = be32_to_cpup(p++);
1028 result->bfree = be32_to_cpup(p++);
1029 result->bavail = be32_to_cpup(p);
1030 return 0;
1031out_overflow:
1032 print_overflow_msg(__func__, xdr);
1033 return -EIO;
1034}
1035
1036static int nfs2_xdr_dec_statfsres(struct rpc_rqst *req, struct xdr_stream *xdr,
1037 struct nfs2_fsstat *result)
1038{
1039 enum nfs_stat status;
1040 int error;
1041
1042 error = decode_stat(xdr, &status);
1043 if (unlikely(error))
1044 goto out;
1045 if (status != NFS_OK)
1046 goto out_default;
1047 error = decode_info(xdr, result);
1048out:
1049 return error;
1050out_default:
1051 return nfs_stat_to_errno(status);
1052}
1053
1054
1055/*
1056 * We need to translate between nfs status return values and
1057 * the local errno values which may not be the same.
1058 */
1059static const struct {
1060 int stat;
1061 int errno;
1062} nfs_errtbl[] = {
1063 { NFS_OK, 0 },
1064 { NFSERR_PERM, -EPERM },
1065 { NFSERR_NOENT, -ENOENT },
1066 { NFSERR_IO, -errno_NFSERR_IO},
1067 { NFSERR_NXIO, -ENXIO },
1068/* { NFSERR_EAGAIN, -EAGAIN }, */
1069 { NFSERR_ACCES, -EACCES },
1070 { NFSERR_EXIST, -EEXIST },
1071 { NFSERR_XDEV, -EXDEV },
1072 { NFSERR_NODEV, -ENODEV },
1073 { NFSERR_NOTDIR, -ENOTDIR },
1074 { NFSERR_ISDIR, -EISDIR },
1075 { NFSERR_INVAL, -EINVAL },
1076 { NFSERR_FBIG, -EFBIG },
1077 { NFSERR_NOSPC, -ENOSPC },
1078 { NFSERR_ROFS, -EROFS },
1079 { NFSERR_MLINK, -EMLINK },
1080 { NFSERR_NAMETOOLONG, -ENAMETOOLONG },
1081 { NFSERR_NOTEMPTY, -ENOTEMPTY },
1082 { NFSERR_DQUOT, -EDQUOT },
1083 { NFSERR_STALE, -ESTALE },
1084 { NFSERR_REMOTE, -EREMOTE },
1085#ifdef EWFLUSH
1086 { NFSERR_WFLUSH, -EWFLUSH },
1087#endif
1088 { NFSERR_BADHANDLE, -EBADHANDLE },
1089 { NFSERR_NOT_SYNC, -ENOTSYNC },
1090 { NFSERR_BAD_COOKIE, -EBADCOOKIE },
1091 { NFSERR_NOTSUPP, -ENOTSUPP },
1092 { NFSERR_TOOSMALL, -ETOOSMALL },
1093 { NFSERR_SERVERFAULT, -EREMOTEIO },
1094 { NFSERR_BADTYPE, -EBADTYPE },
1095 { NFSERR_JUKEBOX, -EJUKEBOX },
1096 { -1, -EIO }
1097};
1098
1099/**
1100 * nfs_stat_to_errno - convert an NFS status code to a local errno
1101 * @status: NFS status code to convert
1102 *
1103 * Returns a local errno value, or -EIO if the NFS status code is
1104 * not recognized. This function is used jointly by NFSv2 and NFSv3.
1105 */
1106static int nfs_stat_to_errno(enum nfs_stat status)
1107{
1108 int i;
1109
1110 for (i = 0; nfs_errtbl[i].stat != -1; i++) {
1111 if (nfs_errtbl[i].stat == (int)status)
1112 return nfs_errtbl[i].errno;
1113 }
1114 dprintk("NFS: Unrecognized nfs status value: %u\n", status);
1115 return nfs_errtbl[i].errno;
1116}
1117
1118#define PROC(proc, argtype, restype, timer) \
1119[NFSPROC_##proc] = { \
1120 .p_proc = NFSPROC_##proc, \
1121 .p_encode = (kxdreproc_t)nfs2_xdr_enc_##argtype, \
1122 .p_decode = (kxdrdproc_t)nfs2_xdr_dec_##restype, \
1123 .p_arglen = NFS_##argtype##_sz, \
1124 .p_replen = NFS_##restype##_sz, \
1125 .p_timer = timer, \
1126 .p_statidx = NFSPROC_##proc, \
1127 .p_name = #proc, \
1128 }
1129struct rpc_procinfo nfs_procedures[] = {
1130 PROC(GETATTR, fhandle, attrstat, 1),
1131 PROC(SETATTR, sattrargs, attrstat, 0),
1132 PROC(LOOKUP, diropargs, diropres, 2),
1133 PROC(READLINK, readlinkargs, readlinkres, 3),
1134 PROC(READ, readargs, readres, 3),
1135 PROC(WRITE, writeargs, writeres, 4),
1136 PROC(CREATE, createargs, diropres, 0),
1137 PROC(REMOVE, removeargs, stat, 0),
1138 PROC(RENAME, renameargs, stat, 0),
1139 PROC(LINK, linkargs, stat, 0),
1140 PROC(SYMLINK, symlinkargs, stat, 0),
1141 PROC(MKDIR, createargs, diropres, 0),
1142 PROC(RMDIR, diropargs, stat, 0),
1143 PROC(READDIR, readdirargs, readdirres, 3),
1144 PROC(STATFS, fhandle, statfsres, 0),
1145};
1146
1147const struct rpc_version nfs_version2 = {
1148 .number = 2,
1149 .nrprocs = ARRAY_SIZE(nfs_procedures),
1150 .procs = nfs_procedures
1151};