aboutsummaryrefslogtreecommitdiff
path: root/fs/nfsd/nfsxdr.c
blob: caf6355b18fa99769850d41ab88db0f8330848fb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
// SPDX-License-Identifier: GPL-2.0
/*
 * XDR support for nfsd
 *
 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
 */

#include "vfs.h"
#include "xdr.h"
#include "auth.h"

/*
 * Mapping of S_IF* types to NFS file types
 */
static const u32 nfs_ftypes[] = {
	NFNON,  NFCHR,  NFCHR, NFBAD,
	NFDIR,  NFBAD,  NFBLK, NFBAD,
	NFREG,  NFBAD,  NFLNK, NFBAD,
	NFSOCK, NFBAD,  NFLNK, NFBAD,
};


/*
 * Basic NFSv2 data types (RFC 1094 Section 2.3)
 */

/**
 * svcxdr_encode_stat - Encode an NFSv2 status code
 * @xdr: XDR stream
 * @status: status value to encode
 *
 * Return values:
 *   %false: Send buffer space was exhausted
 *   %true: Success
 */
bool
svcxdr_encode_stat(struct xdr_stream *xdr, __be32 status)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, sizeof(status));
	if (!p)
		return false;
	*p = status;

	return true;
}

/**
 * svcxdr_decode_fhandle - Decode an NFSv2 file handle
 * @xdr: XDR stream positioned at an encoded NFSv2 FH
 * @fhp: OUT: filled-in server file handle
 *
 * Return values:
 *  %false: The encoded file handle was not valid
 *  %true: @fhp has been initialized
 */
bool
svcxdr_decode_fhandle(struct xdr_stream *xdr, struct svc_fh *fhp)
{
	__be32 *p;

	p = xdr_inline_decode(xdr, NFS_FHSIZE);
	if (!p)
		return false;
	fh_init(fhp, NFS_FHSIZE);
	memcpy(&fhp->fh_handle.fh_raw, p, NFS_FHSIZE);
	fhp->fh_handle.fh_size = NFS_FHSIZE;

	return true;
}

static bool
svcxdr_encode_fhandle(struct xdr_stream *xdr, const struct svc_fh *fhp)
{
	__be32 *p;

	p = xdr_reserve_space(xdr, NFS_FHSIZE);
	if (!p)
		return false;
	memcpy(p, &fhp->fh_handle.fh_raw, NFS_FHSIZE);

	return true;
}

static __be32 *
encode_timeval(__be32 *p, const struct timespec64 *time)
{
	*p++ = cpu_to_be32((u32)time->tv_sec);
	if (time->tv_nsec)
		*p++ = cpu_to_be32(time->tv_nsec / NSEC_PER_USEC);
	else
		*p++ = xdr_zero;
	return p;
}

static bool
svcxdr_decode_filename(struct xdr_stream *xdr, char **name, unsigned int *len)
{
	u32 size, i;
	__be32 *p;
	char *c;

	if (xdr_stream_decode_u32(xdr, &size) < 0)
		return false;
	if (size == 0 || size > NFS_MAXNAMLEN)
		return false;
	p = xdr_inline_decode(xdr, size);
	if (!p)
		return false;

	*len = size;
	*name = (char *)p;
	for (i = 0, c = *name; i < size; i++, c++)
		if (*c == '\0' || *c == '/')
			return false;

	return true;
}

static bool
svcxdr_decode_diropargs(struct xdr_stream *xdr, struct svc_fh *fhp,
			char **name, unsigned int *len)
{
	return svcxdr_decode_fhandle(xdr, fhp) &&
		svcxdr_decode_filename(xdr, name, len);
}

static bool
svcxdr_decode_sattr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
		    struct iattr *iap)
{
	u32 tmp1, tmp2;
	__be32 *p;

	p = xdr_inline_decode(xdr, XDR_UNIT * 8);
	if (!p)
		return false;

	iap->ia_valid = 0;

	/*
	 * Some Sun clients put 0xffff in the mode field when they
	 * mean 0xffffffff.
	 */
	tmp1 = be32_to_cpup(p++);
	if (tmp1 != (u32)-1 && tmp1 != 0xffff) {
		iap->ia_valid |= ATTR_MODE;
		iap->ia_mode = tmp1;
	}

	tmp1 = be32_to_cpup(p++);
	if (tmp1 != (u32)-1) {
		iap->ia_uid = make_kuid(nfsd_user_namespace(rqstp), tmp1);
		if (uid_valid(iap->ia_uid))
			iap->ia_valid |= ATTR_UID;
	}

	tmp1 = be32_to_cpup(p++);
	if (tmp1 != (u32)-1) {
		iap->ia_gid = make_kgid(nfsd_user_namespace(rqstp), tmp1);
		if (gid_valid(iap->ia_gid))
			iap->ia_valid |= ATTR_GID;
	}

	tmp1 = be32_to_cpup(p++);
	if (tmp1 != (u32)-1) {
		iap->ia_valid |= ATTR_SIZE;
		iap->ia_size = tmp1;
	}

	tmp1 = be32_to_cpup(p++);
	tmp2 = be32_to_cpup(p++);
	if (tmp1 != (u32)-1 && tmp2 != (u32)-1) {
		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
		iap->ia_atime.tv_sec = tmp1;
		iap->ia_atime.tv_nsec = tmp2 * NSEC_PER_USEC;
	}

	tmp1 = be32_to_cpup(p++);
	tmp2 = be32_to_cpup(p++);
	if (tmp1 != (u32)-1 && tmp2 != (u32)-1) {
		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
		iap->ia_mtime.tv_sec = tmp1;
		iap->ia_mtime.tv_nsec = tmp2 * NSEC_PER_USEC;
		/*
		 * Passing the invalid value useconds=1000000 for mtime
		 * is a Sun convention for "set both mtime and atime to
		 * current server time".  It's needed to make permissions
		 * checks for the "touch" program across v2 mounts to
		 * Solaris and Irix boxes work correctly. See description of
		 * sattr in section 6.1 of "NFS Illustrated" by
		 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
		 */
		if (tmp2 == 1000000)
			iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
	}

	return true;
}

/**
 * svcxdr_encode_fattr - Encode NFSv2 file attributes
 * @rqstp: Context of a completed RPC transaction
 * @xdr: XDR stream
 * @fhp: File handle to encode
 * @stat: Attributes to encode
 *
 * Return values:
 *   %false: Send buffer space was exhausted
 *   %true: Success
 */
bool
svcxdr_encode_fattr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
		    const struct svc_fh *fhp, const struct kstat *stat)
{
	struct user_namespace *userns = nfsd_user_namespace(rqstp);
	struct dentry *dentry = fhp->fh_dentry;
	int type = stat->mode & S_IFMT;
	struct timespec64 time;
	__be32 *p;
	u32 fsid;

	p = xdr_reserve_space(xdr, XDR_UNIT * 17);
	if (!p)
		return false;

	*p++ = cpu_to_be32(nfs_ftypes[type >> 12]);
	*p++ = cpu_to_be32((u32)stat->mode);
	*p++ = cpu_to_be32((u32)stat->nlink);
	*p++ = cpu_to_be32((u32)from_kuid_munged(userns, stat->uid));
	*p++ = cpu_to_be32((u32)from_kgid_munged(userns, stat->gid));

	if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN)
		*p++ = cpu_to_be32(NFS_MAXPATHLEN);
	else
		*p++ = cpu_to_be32((u32) stat->size);
	*p++ = cpu_to_be32((u32) stat->blksize);
	if (S_ISCHR(type) || S_ISBLK(type))
		*p++ = cpu_to_be32(new_encode_dev(stat->rdev));
	else
		*p++ = cpu_to_be32(0xffffffff);
	*p++ = cpu_to_be32((u32)stat->blocks);

	switch (fsid_source(fhp)) {
	case FSIDSOURCE_FSID:
		fsid = (u32)fhp->fh_export->ex_fsid;
		break;
	case FSIDSOURCE_UUID:
		fsid = ((u32 *)fhp->fh_export->ex_uuid)[0];
		fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[1];
		fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[2];
		fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[3];
		break;
	default:
		fsid = new_encode_dev(stat->dev);
		break;
	}
	*p++ = cpu_to_be32(fsid);

	*p++ = cpu_to_be32((u32)stat->ino);
	p = encode_timeval(p, &stat->atime);
	time = stat->mtime;
	lease_get_mtime(d_inode(dentry), &time);
	p = encode_timeval(p, &time);
	encode_timeval(p, &stat->ctime);

	return true;
}

/*
 * XDR decode functions
 */

bool
nfssvc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_fhandle *args = rqstp->rq_argp;

	return svcxdr_decode_fhandle(xdr, &args->fh);
}

bool
nfssvc_decode_sattrargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_sattrargs *args = rqstp->rq_argp;

	return svcxdr_decode_fhandle(xdr, &args->fh) &&
		svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
}

bool
nfssvc_decode_diropargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_diropargs *args = rqstp->rq_argp;

	return svcxdr_decode_diropargs(xdr, &args->fh, &args->name, &args->len);
}

bool
nfssvc_decode_readargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_readargs *args = rqstp->rq_argp;
	u32 totalcount;

	if (!svcxdr_decode_fhandle(xdr, &args->fh))
		return false;
	if (xdr_stream_decode_u32(xdr, &args->offset) < 0)
		return false;
	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
		return false;
	/* totalcount is ignored */
	if (xdr_stream_decode_u32(xdr, &totalcount) < 0)
		return false;

	return true;
}

bool
nfssvc_decode_writeargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_writeargs *args = rqstp->rq_argp;
	u32 beginoffset, totalcount;

	if (!svcxdr_decode_fhandle(xdr, &args->fh))
		return false;
	/* beginoffset is ignored */
	if (xdr_stream_decode_u32(xdr, &beginoffset) < 0)
		return false;
	if (xdr_stream_decode_u32(xdr, &args->offset) < 0)
		return false;
	/* totalcount is ignored */
	if (xdr_stream_decode_u32(xdr, &totalcount) < 0)
		return false;

	/* opaque data */
	if (xdr_stream_decode_u32(xdr, &args->len) < 0)
		return false;
	if (args->len > NFSSVC_MAXBLKSIZE_V2)
		return false;

	return xdr_stream_subsegment(xdr, &args->payload, args->len);
}

bool
nfssvc_decode_createargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_createargs *args = rqstp->rq_argp;

	return svcxdr_decode_diropargs(xdr, &args->fh,
				       &args->name, &args->len) &&
		svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
}

bool
nfssvc_decode_renameargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_renameargs *args = rqstp->rq_argp;

	return svcxdr_decode_diropargs(xdr, &args->ffh,
				       &args->fname, &args->flen) &&
		svcxdr_decode_diropargs(xdr, &args->tfh,
					&args->tname, &args->tlen);
}

bool
nfssvc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_linkargs *args = rqstp->rq_argp;

	return svcxdr_decode_fhandle(xdr, &args->ffh) &&
		svcxdr_decode_diropargs(xdr, &args->tfh,
					&args->tname, &args->tlen);
}

bool
nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_symlinkargs *args = rqstp->rq_argp;
	struct kvec *head = rqstp->rq_arg.head;

	if (!svcxdr_decode_diropargs(xdr, &args->ffh, &args->fname, &args->flen))
		return false;
	if (xdr_stream_decode_u32(xdr, &args->tlen) < 0)
		return false;
	if (args->tlen == 0)
		return false;

	args->first.iov_len = head->iov_len - xdr_stream_pos(xdr);
	args->first.iov_base = xdr_inline_decode(xdr, args->tlen);
	if (!args->first.iov_base)
		return false;
	return svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
}

bool
nfssvc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_readdirargs *args = rqstp->rq_argp;

	if (!svcxdr_decode_fhandle(xdr, &args->fh))
		return false;
	if (xdr_stream_decode_u32(xdr, &args->cookie) < 0)
		return false;
	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
		return false;

	return true;
}

/*
 * XDR encode functions
 */

bool
nfssvc_encode_statres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_stat *resp = rqstp->rq_resp;

	return svcxdr_encode_stat(xdr, resp->status);
}

bool
nfssvc_encode_attrstatres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_attrstat *resp = rqstp->rq_resp;

	if (!svcxdr_encode_stat(xdr, resp->status))
		return false;
	switch (resp->status) {
	case nfs_ok:
		if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
			return false;
		break;
	}

	return true;
}

bool
nfssvc_encode_diropres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_diropres *resp = rqstp->rq_resp;

	if (!svcxdr_encode_stat(xdr, resp->status))
		return false;
	switch (resp->status) {
	case nfs_ok:
		if (!svcxdr_encode_fhandle(xdr, &resp->fh))
			return false;
		if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
			return false;
		break;
	}

	return true;
}

bool
nfssvc_encode_readlinkres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_readlinkres *resp = rqstp->rq_resp;
	struct kvec *head = rqstp->rq_res.head;

	if (!svcxdr_encode_stat(xdr, resp->status))
		return false;
	switch (resp->status) {
	case nfs_ok:
		if (xdr_stream_encode_u32(xdr, resp->len) < 0)
			return false;
		xdr_write_pages(xdr, &resp->page, 0, resp->len);
		if (svc_encode_result_payload(rqstp, head->iov_len, resp->len) < 0)
			return false;
		break;
	}

	return true;
}

bool
nfssvc_encode_readres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_readres *resp = rqstp->rq_resp;
	struct kvec *head = rqstp->rq_res.head;

	if (!svcxdr_encode_stat(xdr, resp->status))
		return false;
	switch (resp->status) {
	case nfs_ok:
		if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat))
			return false;
		if (xdr_stream_encode_u32(xdr, resp->count) < 0)
			return false;
		xdr_write_pages(xdr, resp->pages, rqstp->rq_res.page_base,
				resp->count);
		if (svc_encode_result_payload(rqstp, head->iov_len, resp->count) < 0)
			return false;
		break;
	}

	return true;
}

bool
nfssvc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_readdirres *resp = rqstp->rq_resp;
	struct xdr_buf *dirlist = &resp->dirlist;

	if (!svcxdr_encode_stat(xdr, resp->status))
		return false;
	switch (resp->status) {
	case nfs_ok:
		xdr_write_pages(xdr, dirlist->pages, 0, dirlist->len);
		/* no more entries */
		if (xdr_stream_encode_item_absent(xdr) < 0)
			return false;
		if (xdr_stream_encode_bool(xdr, resp->common.err == nfserr_eof) < 0)
			return false;
		break;
	}

	return true;
}

bool
nfssvc_encode_statfsres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
{
	struct nfsd_statfsres *resp = rqstp->rq_resp;
	struct kstatfs	*stat = &resp->stats;
	__be32 *p;

	if (!svcxdr_encode_stat(xdr, resp->status))
		return false;
	switch (resp->status) {
	case nfs_ok:
		p = xdr_reserve_space(xdr, XDR_UNIT * 5);
		if (!p)
			return false;
		*p++ = cpu_to_be32(NFSSVC_MAXBLKSIZE_V2);
		*p++ = cpu_to_be32(stat->f_bsize);
		*p++ = cpu_to_be32(stat->f_blocks);
		*p++ = cpu_to_be32(stat->f_bfree);
		*p = cpu_to_be32(stat->f_bavail);
		break;
	}

	return true;
}

/**
 * nfssvc_encode_nfscookie - Encode a directory offset cookie
 * @resp: readdir result context
 * @offset: offset cookie to encode
 *
 * The buffer space for the offset cookie has already been reserved
 * by svcxdr_encode_entry_common().
 */
void nfssvc_encode_nfscookie(struct nfsd_readdirres *resp, u32 offset)
{
	__be32 cookie = cpu_to_be32(offset);

	if (!resp->cookie_offset)
		return;

	write_bytes_to_xdr_buf(&resp->dirlist, resp->cookie_offset, &cookie,
			       sizeof(cookie));
	resp->cookie_offset = 0;
}

static bool
svcxdr_encode_entry_common(struct nfsd_readdirres *resp, const char *name,
			   int namlen, loff_t offset, u64 ino)
{
	struct xdr_buf *dirlist = &resp->dirlist;
	struct xdr_stream *xdr = &resp->xdr;

	if (xdr_stream_encode_item_present(xdr) < 0)
		return false;
	/* fileid */
	if (xdr_stream_encode_u32(xdr, (u32)ino) < 0)
		return false;
	/* name */
	if (xdr_stream_encode_opaque(xdr, name, min(namlen, NFS2_MAXNAMLEN)) < 0)
		return false;
	/* cookie */
	resp->cookie_offset = dirlist->len;
	if (xdr_stream_encode_u32(xdr, ~0U) < 0)
		return false;

	return true;
}

/**
 * nfssvc_encode_entry - encode one NFSv2 READDIR entry
 * @data: directory context
 * @name: name of the object to be encoded
 * @namlen: length of that name, in bytes
 * @offset: the offset of the previous entry
 * @ino: the fileid of this entry
 * @d_type: unused
 *
 * Return values:
 *   %0: Entry was successfully encoded.
 *   %-EINVAL: An encoding problem occured, secondary status code in resp->common.err
 *
 * On exit, the following fields are updated:
 *   - resp->xdr
 *   - resp->common.err
 *   - resp->cookie_offset
 */
int nfssvc_encode_entry(void *data, const char *name, int namlen,
			loff_t offset, u64 ino, unsigned int d_type)
{
	struct readdir_cd *ccd = data;
	struct nfsd_readdirres *resp = container_of(ccd,
						    struct nfsd_readdirres,
						    common);
	unsigned int starting_length = resp->dirlist.len;

	/* The offset cookie for the previous entry */
	nfssvc_encode_nfscookie(resp, offset);

	if (!svcxdr_encode_entry_common(resp, name, namlen, offset, ino))
		goto out_toosmall;

	xdr_commit_encode(&resp->xdr);
	resp->common.err = nfs_ok;
	return 0;

out_toosmall:
	resp->cookie_offset = 0;
	resp->common.err = nfserr_toosmall;
	resp->dirlist.len = starting_length;
	return -EINVAL;
}

/*
 * XDR release functions
 */
void nfssvc_release_attrstat(struct svc_rqst *rqstp)
{
	struct nfsd_attrstat *resp = rqstp->rq_resp;

	fh_put(&resp->fh);
}

void nfssvc_release_diropres(struct svc_rqst *rqstp)
{
	struct nfsd_diropres *resp = rqstp->rq_resp;

	fh_put(&resp->fh);
}

void nfssvc_release_readres(struct svc_rqst *rqstp)
{
	struct nfsd_readres *resp = rqstp->rq_resp;

	fh_put(&resp->fh);
}