xref: /linux/fs/nfsd/nfs3xdr.c (revision bb1c928df78ee6e3665a0d013e74108cc9abf34b)
1 /*
2  * XDR support for nfsd/protocol version 3.
3  *
4  * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
5  *
6  * 2003-08-09 Jamie Lokier: Use htonl() for nanoseconds, not htons()!
7  */
8 
9 #include <linux/namei.h>
10 #include <linux/sunrpc/svc_xprt.h>
11 #include "xdr3.h"
12 #include "auth.h"
13 #include "netns.h"
14 #include "vfs.h"
15 
16 #define NFSDDBG_FACILITY		NFSDDBG_XDR
17 
18 
19 /*
20  * Mapping of S_IF* types to NFS file types
21  */
22 static u32	nfs3_ftypes[] = {
23 	NF3NON,  NF3FIFO, NF3CHR, NF3BAD,
24 	NF3DIR,  NF3BAD,  NF3BLK, NF3BAD,
25 	NF3REG,  NF3BAD,  NF3LNK, NF3BAD,
26 	NF3SOCK, NF3BAD,  NF3LNK, NF3BAD,
27 };
28 
29 /*
30  * XDR functions for basic NFS types
31  */
32 static __be32 *
33 encode_time3(__be32 *p, struct timespec *time)
34 {
35 	*p++ = htonl((u32) time->tv_sec); *p++ = htonl(time->tv_nsec);
36 	return p;
37 }
38 
39 static __be32 *
40 decode_time3(__be32 *p, struct timespec *time)
41 {
42 	time->tv_sec = ntohl(*p++);
43 	time->tv_nsec = ntohl(*p++);
44 	return p;
45 }
46 
47 static __be32 *
48 decode_fh(__be32 *p, struct svc_fh *fhp)
49 {
50 	unsigned int size;
51 	fh_init(fhp, NFS3_FHSIZE);
52 	size = ntohl(*p++);
53 	if (size > NFS3_FHSIZE)
54 		return NULL;
55 
56 	memcpy(&fhp->fh_handle.fh_base, p, size);
57 	fhp->fh_handle.fh_size = size;
58 	return p + XDR_QUADLEN(size);
59 }
60 
61 /* Helper function for NFSv3 ACL code */
62 __be32 *nfs3svc_decode_fh(__be32 *p, struct svc_fh *fhp)
63 {
64 	return decode_fh(p, fhp);
65 }
66 
67 static __be32 *
68 encode_fh(__be32 *p, struct svc_fh *fhp)
69 {
70 	unsigned int size = fhp->fh_handle.fh_size;
71 	*p++ = htonl(size);
72 	if (size) p[XDR_QUADLEN(size)-1]=0;
73 	memcpy(p, &fhp->fh_handle.fh_base, size);
74 	return p + XDR_QUADLEN(size);
75 }
76 
77 /*
78  * Decode a file name and make sure that the path contains
79  * no slashes or null bytes.
80  */
81 static __be32 *
82 decode_filename(__be32 *p, char **namp, unsigned int *lenp)
83 {
84 	char		*name;
85 	unsigned int	i;
86 
87 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS3_MAXNAMLEN)) != NULL) {
88 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
89 			if (*name == '\0' || *name == '/')
90 				return NULL;
91 		}
92 	}
93 
94 	return p;
95 }
96 
97 static __be32 *
98 decode_sattr3(__be32 *p, struct iattr *iap)
99 {
100 	u32	tmp;
101 
102 	iap->ia_valid = 0;
103 
104 	if (*p++) {
105 		iap->ia_valid |= ATTR_MODE;
106 		iap->ia_mode = ntohl(*p++);
107 	}
108 	if (*p++) {
109 		iap->ia_uid = make_kuid(&init_user_ns, ntohl(*p++));
110 		if (uid_valid(iap->ia_uid))
111 			iap->ia_valid |= ATTR_UID;
112 	}
113 	if (*p++) {
114 		iap->ia_gid = make_kgid(&init_user_ns, ntohl(*p++));
115 		if (gid_valid(iap->ia_gid))
116 			iap->ia_valid |= ATTR_GID;
117 	}
118 	if (*p++) {
119 		u64	newsize;
120 
121 		iap->ia_valid |= ATTR_SIZE;
122 		p = xdr_decode_hyper(p, &newsize);
123 		iap->ia_size = min_t(u64, newsize, NFS_OFFSET_MAX);
124 	}
125 	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
126 		iap->ia_valid |= ATTR_ATIME;
127 	} else if (tmp == 2) {		/* set to client time */
128 		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
129 		iap->ia_atime.tv_sec = ntohl(*p++);
130 		iap->ia_atime.tv_nsec = ntohl(*p++);
131 	}
132 	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
133 		iap->ia_valid |= ATTR_MTIME;
134 	} else if (tmp == 2) {		/* set to client time */
135 		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
136 		iap->ia_mtime.tv_sec = ntohl(*p++);
137 		iap->ia_mtime.tv_nsec = ntohl(*p++);
138 	}
139 	return p;
140 }
141 
142 static __be32 *encode_fsid(__be32 *p, struct svc_fh *fhp)
143 {
144 	u64 f;
145 	switch(fsid_source(fhp)) {
146 	default:
147 	case FSIDSOURCE_DEV:
148 		p = xdr_encode_hyper(p, (u64)huge_encode_dev
149 				     (fhp->fh_dentry->d_sb->s_dev));
150 		break;
151 	case FSIDSOURCE_FSID:
152 		p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
153 		break;
154 	case FSIDSOURCE_UUID:
155 		f = ((u64*)fhp->fh_export->ex_uuid)[0];
156 		f ^= ((u64*)fhp->fh_export->ex_uuid)[1];
157 		p = xdr_encode_hyper(p, f);
158 		break;
159 	}
160 	return p;
161 }
162 
163 static __be32 *
164 encode_fattr3(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
165 	      struct kstat *stat)
166 {
167 	*p++ = htonl(nfs3_ftypes[(stat->mode & S_IFMT) >> 12]);
168 	*p++ = htonl((u32) (stat->mode & S_IALLUGO));
169 	*p++ = htonl((u32) stat->nlink);
170 	*p++ = htonl((u32) from_kuid(&init_user_ns, stat->uid));
171 	*p++ = htonl((u32) from_kgid(&init_user_ns, stat->gid));
172 	if (S_ISLNK(stat->mode) && stat->size > NFS3_MAXPATHLEN) {
173 		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
174 	} else {
175 		p = xdr_encode_hyper(p, (u64) stat->size);
176 	}
177 	p = xdr_encode_hyper(p, ((u64)stat->blocks) << 9);
178 	*p++ = htonl((u32) MAJOR(stat->rdev));
179 	*p++ = htonl((u32) MINOR(stat->rdev));
180 	p = encode_fsid(p, fhp);
181 	p = xdr_encode_hyper(p, stat->ino);
182 	p = encode_time3(p, &stat->atime);
183 	p = encode_time3(p, &stat->mtime);
184 	p = encode_time3(p, &stat->ctime);
185 
186 	return p;
187 }
188 
189 static __be32 *
190 encode_saved_post_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
191 {
192 	/* Attributes to follow */
193 	*p++ = xdr_one;
194 	return encode_fattr3(rqstp, p, fhp, &fhp->fh_post_attr);
195 }
196 
197 /*
198  * Encode post-operation attributes.
199  * The inode may be NULL if the call failed because of a stale file
200  * handle. In this case, no attributes are returned.
201  */
202 static __be32 *
203 encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
204 {
205 	struct dentry *dentry = fhp->fh_dentry;
206 	if (dentry && d_really_is_positive(dentry)) {
207 	        __be32 err;
208 		struct kstat stat;
209 
210 		err = fh_getattr(fhp, &stat);
211 		if (!err) {
212 			*p++ = xdr_one;		/* attributes follow */
213 			lease_get_mtime(d_inode(dentry), &stat.mtime);
214 			return encode_fattr3(rqstp, p, fhp, &stat);
215 		}
216 	}
217 	*p++ = xdr_zero;
218 	return p;
219 }
220 
221 /* Helper for NFSv3 ACLs */
222 __be32 *
223 nfs3svc_encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
224 {
225 	return encode_post_op_attr(rqstp, p, fhp);
226 }
227 
228 /*
229  * Enocde weak cache consistency data
230  */
231 static __be32 *
232 encode_wcc_data(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
233 {
234 	struct dentry	*dentry = fhp->fh_dentry;
235 
236 	if (dentry && d_really_is_positive(dentry) && fhp->fh_post_saved) {
237 		if (fhp->fh_pre_saved) {
238 			*p++ = xdr_one;
239 			p = xdr_encode_hyper(p, (u64) fhp->fh_pre_size);
240 			p = encode_time3(p, &fhp->fh_pre_mtime);
241 			p = encode_time3(p, &fhp->fh_pre_ctime);
242 		} else {
243 			*p++ = xdr_zero;
244 		}
245 		return encode_saved_post_attr(rqstp, p, fhp);
246 	}
247 	/* no pre- or post-attrs */
248 	*p++ = xdr_zero;
249 	return encode_post_op_attr(rqstp, p, fhp);
250 }
251 
252 /*
253  * Fill in the post_op attr for the wcc data
254  */
255 void fill_post_wcc(struct svc_fh *fhp)
256 {
257 	__be32 err;
258 
259 	if (fhp->fh_post_saved)
260 		printk("nfsd: inode locked twice during operation.\n");
261 
262 	err = fh_getattr(fhp, &fhp->fh_post_attr);
263 	fhp->fh_post_change = nfsd4_change_attribute(d_inode(fhp->fh_dentry));
264 	if (err) {
265 		fhp->fh_post_saved = false;
266 		/* Grab the ctime anyway - set_change_info might use it */
267 		fhp->fh_post_attr.ctime = d_inode(fhp->fh_dentry)->i_ctime;
268 	} else
269 		fhp->fh_post_saved = true;
270 }
271 
272 /*
273  * XDR decode functions
274  */
275 int
276 nfs3svc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p)
277 {
278 	struct nfsd_fhandle *args = rqstp->rq_argp;
279 
280 	p = decode_fh(p, &args->fh);
281 	if (!p)
282 		return 0;
283 	return xdr_argsize_check(rqstp, p);
284 }
285 
286 int
287 nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p)
288 {
289 	struct nfsd3_sattrargs *args = rqstp->rq_argp;
290 
291 	p = decode_fh(p, &args->fh);
292 	if (!p)
293 		return 0;
294 	p = decode_sattr3(p, &args->attrs);
295 
296 	if ((args->check_guard = ntohl(*p++)) != 0) {
297 		struct timespec time;
298 		p = decode_time3(p, &time);
299 		args->guardtime = time.tv_sec;
300 	}
301 
302 	return xdr_argsize_check(rqstp, p);
303 }
304 
305 int
306 nfs3svc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p)
307 {
308 	struct nfsd3_diropargs *args = rqstp->rq_argp;
309 
310 	if (!(p = decode_fh(p, &args->fh))
311 	 || !(p = decode_filename(p, &args->name, &args->len)))
312 		return 0;
313 
314 	return xdr_argsize_check(rqstp, p);
315 }
316 
317 int
318 nfs3svc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p)
319 {
320 	struct nfsd3_accessargs *args = rqstp->rq_argp;
321 
322 	p = decode_fh(p, &args->fh);
323 	if (!p)
324 		return 0;
325 	args->access = ntohl(*p++);
326 
327 	return xdr_argsize_check(rqstp, p);
328 }
329 
330 int
331 nfs3svc_decode_readargs(struct svc_rqst *rqstp, __be32 *p)
332 {
333 	struct nfsd3_readargs *args = rqstp->rq_argp;
334 	unsigned int len;
335 	int v;
336 	u32 max_blocksize = svc_max_payload(rqstp);
337 
338 	p = decode_fh(p, &args->fh);
339 	if (!p)
340 		return 0;
341 	p = xdr_decode_hyper(p, &args->offset);
342 
343 	args->count = ntohl(*p++);
344 	len = min(args->count, max_blocksize);
345 
346 	/* set up the kvec */
347 	v=0;
348 	while (len > 0) {
349 		struct page *p = *(rqstp->rq_next_page++);
350 
351 		rqstp->rq_vec[v].iov_base = page_address(p);
352 		rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
353 		len -= rqstp->rq_vec[v].iov_len;
354 		v++;
355 	}
356 	args->vlen = v;
357 	return xdr_argsize_check(rqstp, p);
358 }
359 
360 int
361 nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p)
362 {
363 	struct nfsd3_writeargs *args = rqstp->rq_argp;
364 	unsigned int len, v, hdr, dlen;
365 	u32 max_blocksize = svc_max_payload(rqstp);
366 	struct kvec *head = rqstp->rq_arg.head;
367 	struct kvec *tail = rqstp->rq_arg.tail;
368 
369 	p = decode_fh(p, &args->fh);
370 	if (!p)
371 		return 0;
372 	p = xdr_decode_hyper(p, &args->offset);
373 
374 	args->count = ntohl(*p++);
375 	args->stable = ntohl(*p++);
376 	len = args->len = ntohl(*p++);
377 	if ((void *)p > head->iov_base + head->iov_len)
378 		return 0;
379 	/*
380 	 * The count must equal the amount of data passed.
381 	 */
382 	if (args->count != args->len)
383 		return 0;
384 
385 	/*
386 	 * Check to make sure that we got the right number of
387 	 * bytes.
388 	 */
389 	hdr = (void*)p - head->iov_base;
390 	dlen = head->iov_len + rqstp->rq_arg.page_len + tail->iov_len - hdr;
391 	/*
392 	 * Round the length of the data which was specified up to
393 	 * the next multiple of XDR units and then compare that
394 	 * against the length which was actually received.
395 	 * Note that when RPCSEC/GSS (for example) is used, the
396 	 * data buffer can be padded so dlen might be larger
397 	 * than required.  It must never be smaller.
398 	 */
399 	if (dlen < XDR_QUADLEN(len)*4)
400 		return 0;
401 
402 	if (args->count > max_blocksize) {
403 		args->count = max_blocksize;
404 		len = args->len = max_blocksize;
405 	}
406 	rqstp->rq_vec[0].iov_base = (void*)p;
407 	rqstp->rq_vec[0].iov_len = head->iov_len - hdr;
408 	v = 0;
409 	while (len > rqstp->rq_vec[v].iov_len) {
410 		len -= rqstp->rq_vec[v].iov_len;
411 		v++;
412 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
413 		rqstp->rq_vec[v].iov_len = PAGE_SIZE;
414 	}
415 	rqstp->rq_vec[v].iov_len = len;
416 	args->vlen = v + 1;
417 	return 1;
418 }
419 
420 int
421 nfs3svc_decode_createargs(struct svc_rqst *rqstp, __be32 *p)
422 {
423 	struct nfsd3_createargs *args = rqstp->rq_argp;
424 
425 	if (!(p = decode_fh(p, &args->fh))
426 	 || !(p = decode_filename(p, &args->name, &args->len)))
427 		return 0;
428 
429 	switch (args->createmode = ntohl(*p++)) {
430 	case NFS3_CREATE_UNCHECKED:
431 	case NFS3_CREATE_GUARDED:
432 		p = decode_sattr3(p, &args->attrs);
433 		break;
434 	case NFS3_CREATE_EXCLUSIVE:
435 		args->verf = p;
436 		p += 2;
437 		break;
438 	default:
439 		return 0;
440 	}
441 
442 	return xdr_argsize_check(rqstp, p);
443 }
444 
445 int
446 nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, __be32 *p)
447 {
448 	struct nfsd3_createargs *args = rqstp->rq_argp;
449 
450 	if (!(p = decode_fh(p, &args->fh)) ||
451 	    !(p = decode_filename(p, &args->name, &args->len)))
452 		return 0;
453 	p = decode_sattr3(p, &args->attrs);
454 
455 	return xdr_argsize_check(rqstp, p);
456 }
457 
458 int
459 nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p)
460 {
461 	struct nfsd3_symlinkargs *args = rqstp->rq_argp;
462 	unsigned int len, avail;
463 	char *old, *new;
464 	struct kvec *vec;
465 
466 	if (!(p = decode_fh(p, &args->ffh)) ||
467 	    !(p = decode_filename(p, &args->fname, &args->flen))
468 		)
469 		return 0;
470 	p = decode_sattr3(p, &args->attrs);
471 
472 	/* now decode the pathname, which might be larger than the first page.
473 	 * As we have to check for nul's anyway, we copy it into a new page
474 	 * This page appears in the rq_res.pages list, but as pages_len is always
475 	 * 0, it won't get in the way
476 	 */
477 	len = ntohl(*p++);
478 	if (len == 0 || len > NFS3_MAXPATHLEN || len >= PAGE_SIZE)
479 		return 0;
480 	args->tname = new = page_address(*(rqstp->rq_next_page++));
481 	args->tlen = len;
482 	/* first copy and check from the first page */
483 	old = (char*)p;
484 	vec = &rqstp->rq_arg.head[0];
485 	if ((void *)old > vec->iov_base + vec->iov_len)
486 		return 0;
487 	avail = vec->iov_len - (old - (char*)vec->iov_base);
488 	while (len && avail && *old) {
489 		*new++ = *old++;
490 		len--;
491 		avail--;
492 	}
493 	/* now copy next page if there is one */
494 	if (len && !avail && rqstp->rq_arg.page_len) {
495 		avail = min_t(unsigned int, rqstp->rq_arg.page_len, PAGE_SIZE);
496 		old = page_address(rqstp->rq_arg.pages[0]);
497 	}
498 	while (len && avail && *old) {
499 		*new++ = *old++;
500 		len--;
501 		avail--;
502 	}
503 	*new = '\0';
504 	if (len)
505 		return 0;
506 
507 	return 1;
508 }
509 
510 int
511 nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, __be32 *p)
512 {
513 	struct nfsd3_mknodargs *args = rqstp->rq_argp;
514 
515 	if (!(p = decode_fh(p, &args->fh))
516 	 || !(p = decode_filename(p, &args->name, &args->len)))
517 		return 0;
518 
519 	args->ftype = ntohl(*p++);
520 
521 	if (args->ftype == NF3BLK  || args->ftype == NF3CHR
522 	 || args->ftype == NF3SOCK || args->ftype == NF3FIFO)
523 		p = decode_sattr3(p, &args->attrs);
524 
525 	if (args->ftype == NF3BLK || args->ftype == NF3CHR) {
526 		args->major = ntohl(*p++);
527 		args->minor = ntohl(*p++);
528 	}
529 
530 	return xdr_argsize_check(rqstp, p);
531 }
532 
533 int
534 nfs3svc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p)
535 {
536 	struct nfsd3_renameargs *args = rqstp->rq_argp;
537 
538 	if (!(p = decode_fh(p, &args->ffh))
539 	 || !(p = decode_filename(p, &args->fname, &args->flen))
540 	 || !(p = decode_fh(p, &args->tfh))
541 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
542 		return 0;
543 
544 	return xdr_argsize_check(rqstp, p);
545 }
546 
547 int
548 nfs3svc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p)
549 {
550 	struct nfsd3_readlinkargs *args = rqstp->rq_argp;
551 
552 	p = decode_fh(p, &args->fh);
553 	if (!p)
554 		return 0;
555 	args->buffer = page_address(*(rqstp->rq_next_page++));
556 
557 	return xdr_argsize_check(rqstp, p);
558 }
559 
560 int
561 nfs3svc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p)
562 {
563 	struct nfsd3_linkargs *args = rqstp->rq_argp;
564 
565 	if (!(p = decode_fh(p, &args->ffh))
566 	 || !(p = decode_fh(p, &args->tfh))
567 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
568 		return 0;
569 
570 	return xdr_argsize_check(rqstp, p);
571 }
572 
573 int
574 nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
575 {
576 	struct nfsd3_readdirargs *args = rqstp->rq_argp;
577 	p = decode_fh(p, &args->fh);
578 	if (!p)
579 		return 0;
580 	p = xdr_decode_hyper(p, &args->cookie);
581 	args->verf   = p; p += 2;
582 	args->dircount = ~0;
583 	args->count  = ntohl(*p++);
584 	args->count  = min_t(u32, args->count, PAGE_SIZE);
585 	args->buffer = page_address(*(rqstp->rq_next_page++));
586 
587 	return xdr_argsize_check(rqstp, p);
588 }
589 
590 int
591 nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p)
592 {
593 	struct nfsd3_readdirargs *args = rqstp->rq_argp;
594 	int len;
595 	u32 max_blocksize = svc_max_payload(rqstp);
596 
597 	p = decode_fh(p, &args->fh);
598 	if (!p)
599 		return 0;
600 	p = xdr_decode_hyper(p, &args->cookie);
601 	args->verf     = p; p += 2;
602 	args->dircount = ntohl(*p++);
603 	args->count    = ntohl(*p++);
604 
605 	len = args->count = min(args->count, max_blocksize);
606 	while (len > 0) {
607 		struct page *p = *(rqstp->rq_next_page++);
608 		if (!args->buffer)
609 			args->buffer = page_address(p);
610 		len -= PAGE_SIZE;
611 	}
612 
613 	return xdr_argsize_check(rqstp, p);
614 }
615 
616 int
617 nfs3svc_decode_commitargs(struct svc_rqst *rqstp, __be32 *p)
618 {
619 	struct nfsd3_commitargs *args = rqstp->rq_argp;
620 	p = decode_fh(p, &args->fh);
621 	if (!p)
622 		return 0;
623 	p = xdr_decode_hyper(p, &args->offset);
624 	args->count = ntohl(*p++);
625 
626 	return xdr_argsize_check(rqstp, p);
627 }
628 
629 /*
630  * XDR encode functions
631  */
632 /*
633  * There must be an encoding function for void results so svc_process
634  * will work properly.
635  */
636 int
637 nfs3svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p)
638 {
639 	return xdr_ressize_check(rqstp, p);
640 }
641 
642 /* GETATTR */
643 int
644 nfs3svc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p)
645 {
646 	struct nfsd3_attrstat *resp = rqstp->rq_resp;
647 
648 	if (resp->status == 0) {
649 		lease_get_mtime(d_inode(resp->fh.fh_dentry),
650 				&resp->stat.mtime);
651 		p = encode_fattr3(rqstp, p, &resp->fh, &resp->stat);
652 	}
653 	return xdr_ressize_check(rqstp, p);
654 }
655 
656 /* SETATTR, REMOVE, RMDIR */
657 int
658 nfs3svc_encode_wccstat(struct svc_rqst *rqstp, __be32 *p)
659 {
660 	struct nfsd3_attrstat *resp = rqstp->rq_resp;
661 
662 	p = encode_wcc_data(rqstp, p, &resp->fh);
663 	return xdr_ressize_check(rqstp, p);
664 }
665 
666 /* LOOKUP */
667 int
668 nfs3svc_encode_diropres(struct svc_rqst *rqstp, __be32 *p)
669 {
670 	struct nfsd3_diropres *resp = rqstp->rq_resp;
671 
672 	if (resp->status == 0) {
673 		p = encode_fh(p, &resp->fh);
674 		p = encode_post_op_attr(rqstp, p, &resp->fh);
675 	}
676 	p = encode_post_op_attr(rqstp, p, &resp->dirfh);
677 	return xdr_ressize_check(rqstp, p);
678 }
679 
680 /* ACCESS */
681 int
682 nfs3svc_encode_accessres(struct svc_rqst *rqstp, __be32 *p)
683 {
684 	struct nfsd3_accessres *resp = rqstp->rq_resp;
685 
686 	p = encode_post_op_attr(rqstp, p, &resp->fh);
687 	if (resp->status == 0)
688 		*p++ = htonl(resp->access);
689 	return xdr_ressize_check(rqstp, p);
690 }
691 
692 /* READLINK */
693 int
694 nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p)
695 {
696 	struct nfsd3_readlinkres *resp = rqstp->rq_resp;
697 
698 	p = encode_post_op_attr(rqstp, p, &resp->fh);
699 	if (resp->status == 0) {
700 		*p++ = htonl(resp->len);
701 		xdr_ressize_check(rqstp, p);
702 		rqstp->rq_res.page_len = resp->len;
703 		if (resp->len & 3) {
704 			/* need to pad the tail */
705 			rqstp->rq_res.tail[0].iov_base = p;
706 			*p = 0;
707 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
708 		}
709 		return 1;
710 	} else
711 		return xdr_ressize_check(rqstp, p);
712 }
713 
714 /* READ */
715 int
716 nfs3svc_encode_readres(struct svc_rqst *rqstp, __be32 *p)
717 {
718 	struct nfsd3_readres *resp = rqstp->rq_resp;
719 
720 	p = encode_post_op_attr(rqstp, p, &resp->fh);
721 	if (resp->status == 0) {
722 		*p++ = htonl(resp->count);
723 		*p++ = htonl(resp->eof);
724 		*p++ = htonl(resp->count);	/* xdr opaque count */
725 		xdr_ressize_check(rqstp, p);
726 		/* now update rqstp->rq_res to reflect data as well */
727 		rqstp->rq_res.page_len = resp->count;
728 		if (resp->count & 3) {
729 			/* need to pad the tail */
730 			rqstp->rq_res.tail[0].iov_base = p;
731 			*p = 0;
732 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->count & 3);
733 		}
734 		return 1;
735 	} else
736 		return xdr_ressize_check(rqstp, p);
737 }
738 
739 /* WRITE */
740 int
741 nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p)
742 {
743 	struct nfsd3_writeres *resp = rqstp->rq_resp;
744 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
745 
746 	p = encode_wcc_data(rqstp, p, &resp->fh);
747 	if (resp->status == 0) {
748 		*p++ = htonl(resp->count);
749 		*p++ = htonl(resp->committed);
750 		*p++ = htonl(nn->nfssvc_boot.tv_sec);
751 		*p++ = htonl(nn->nfssvc_boot.tv_usec);
752 	}
753 	return xdr_ressize_check(rqstp, p);
754 }
755 
756 /* CREATE, MKDIR, SYMLINK, MKNOD */
757 int
758 nfs3svc_encode_createres(struct svc_rqst *rqstp, __be32 *p)
759 {
760 	struct nfsd3_diropres *resp = rqstp->rq_resp;
761 
762 	if (resp->status == 0) {
763 		*p++ = xdr_one;
764 		p = encode_fh(p, &resp->fh);
765 		p = encode_post_op_attr(rqstp, p, &resp->fh);
766 	}
767 	p = encode_wcc_data(rqstp, p, &resp->dirfh);
768 	return xdr_ressize_check(rqstp, p);
769 }
770 
771 /* RENAME */
772 int
773 nfs3svc_encode_renameres(struct svc_rqst *rqstp, __be32 *p)
774 {
775 	struct nfsd3_renameres *resp = rqstp->rq_resp;
776 
777 	p = encode_wcc_data(rqstp, p, &resp->ffh);
778 	p = encode_wcc_data(rqstp, p, &resp->tfh);
779 	return xdr_ressize_check(rqstp, p);
780 }
781 
782 /* LINK */
783 int
784 nfs3svc_encode_linkres(struct svc_rqst *rqstp, __be32 *p)
785 {
786 	struct nfsd3_linkres *resp = rqstp->rq_resp;
787 
788 	p = encode_post_op_attr(rqstp, p, &resp->fh);
789 	p = encode_wcc_data(rqstp, p, &resp->tfh);
790 	return xdr_ressize_check(rqstp, p);
791 }
792 
793 /* READDIR */
794 int
795 nfs3svc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p)
796 {
797 	struct nfsd3_readdirres *resp = rqstp->rq_resp;
798 
799 	p = encode_post_op_attr(rqstp, p, &resp->fh);
800 
801 	if (resp->status == 0) {
802 		/* stupid readdir cookie */
803 		memcpy(p, resp->verf, 8); p += 2;
804 		xdr_ressize_check(rqstp, p);
805 		if (rqstp->rq_res.head[0].iov_len + (2<<2) > PAGE_SIZE)
806 			return 1; /*No room for trailer */
807 		rqstp->rq_res.page_len = (resp->count) << 2;
808 
809 		/* add the 'tail' to the end of the 'head' page - page 0. */
810 		rqstp->rq_res.tail[0].iov_base = p;
811 		*p++ = 0;		/* no more entries */
812 		*p++ = htonl(resp->common.err == nfserr_eof);
813 		rqstp->rq_res.tail[0].iov_len = 2<<2;
814 		return 1;
815 	} else
816 		return xdr_ressize_check(rqstp, p);
817 }
818 
819 static __be32 *
820 encode_entry_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name,
821 	     int namlen, u64 ino)
822 {
823 	*p++ = xdr_one;				 /* mark entry present */
824 	p    = xdr_encode_hyper(p, ino);	 /* file id */
825 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
826 
827 	cd->offset = p;				/* remember pointer */
828 	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);/* offset of next entry */
829 
830 	return p;
831 }
832 
833 static __be32
834 compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
835 		 const char *name, int namlen, u64 ino)
836 {
837 	struct svc_export	*exp;
838 	struct dentry		*dparent, *dchild;
839 	__be32 rv = nfserr_noent;
840 
841 	dparent = cd->fh.fh_dentry;
842 	exp  = cd->fh.fh_export;
843 
844 	if (isdotent(name, namlen)) {
845 		if (namlen == 2) {
846 			dchild = dget_parent(dparent);
847 			/* filesystem root - cannot return filehandle for ".." */
848 			if (dchild == dparent)
849 				goto out;
850 		} else
851 			dchild = dget(dparent);
852 	} else
853 		dchild = lookup_one_len_unlocked(name, dparent, namlen);
854 	if (IS_ERR(dchild))
855 		return rv;
856 	if (d_mountpoint(dchild))
857 		goto out;
858 	if (d_really_is_negative(dchild))
859 		goto out;
860 	if (dchild->d_inode->i_ino != ino)
861 		goto out;
862 	rv = fh_compose(fhp, exp, dchild, &cd->fh);
863 out:
864 	dput(dchild);
865 	return rv;
866 }
867 
868 static __be32 *encode_entryplus_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name, int namlen, u64 ino)
869 {
870 	struct svc_fh	*fh = &cd->scratch;
871 	__be32 err;
872 
873 	fh_init(fh, NFS3_FHSIZE);
874 	err = compose_entry_fh(cd, fh, name, namlen, ino);
875 	if (err) {
876 		*p++ = 0;
877 		*p++ = 0;
878 		goto out;
879 	}
880 	p = encode_post_op_attr(cd->rqstp, p, fh);
881 	*p++ = xdr_one;			/* yes, a file handle follows */
882 	p = encode_fh(p, fh);
883 out:
884 	fh_put(fh);
885 	return p;
886 }
887 
888 /*
889  * Encode a directory entry. This one works for both normal readdir
890  * and readdirplus.
891  * The normal readdir reply requires 2 (fileid) + 1 (stringlen)
892  * + string + 2 (cookie) + 1 (next) words, i.e. 6 + strlen.
893  *
894  * The readdirplus baggage is 1+21 words for post_op_attr, plus the
895  * file handle.
896  */
897 
898 #define NFS3_ENTRY_BAGGAGE	(2 + 1 + 2 + 1)
899 #define NFS3_ENTRYPLUS_BAGGAGE	(1 + 21 + 1 + (NFS3_FHSIZE >> 2))
900 static int
901 encode_entry(struct readdir_cd *ccd, const char *name, int namlen,
902 	     loff_t offset, u64 ino, unsigned int d_type, int plus)
903 {
904 	struct nfsd3_readdirres *cd = container_of(ccd, struct nfsd3_readdirres,
905 		       					common);
906 	__be32		*p = cd->buffer;
907 	caddr_t		curr_page_addr = NULL;
908 	struct page **	page;
909 	int		slen;		/* string (name) length */
910 	int		elen;		/* estimated entry length in words */
911 	int		num_entry_words = 0;	/* actual number of words */
912 
913 	if (cd->offset) {
914 		u64 offset64 = offset;
915 
916 		if (unlikely(cd->offset1)) {
917 			/* we ended up with offset on a page boundary */
918 			*cd->offset = htonl(offset64 >> 32);
919 			*cd->offset1 = htonl(offset64 & 0xffffffff);
920 			cd->offset1 = NULL;
921 		} else {
922 			xdr_encode_hyper(cd->offset, offset64);
923 		}
924 	}
925 
926 	/*
927 	dprintk("encode_entry(%.*s @%ld%s)\n",
928 		namlen, name, (long) offset, plus? " plus" : "");
929 	 */
930 
931 	/* truncate filename if too long */
932 	namlen = min(namlen, NFS3_MAXNAMLEN);
933 
934 	slen = XDR_QUADLEN(namlen);
935 	elen = slen + NFS3_ENTRY_BAGGAGE
936 		+ (plus? NFS3_ENTRYPLUS_BAGGAGE : 0);
937 
938 	if (cd->buflen < elen) {
939 		cd->common.err = nfserr_toosmall;
940 		return -EINVAL;
941 	}
942 
943 	/* determine which page in rq_respages[] we are currently filling */
944 	for (page = cd->rqstp->rq_respages + 1;
945 				page < cd->rqstp->rq_next_page; page++) {
946 		curr_page_addr = page_address(*page);
947 
948 		if (((caddr_t)cd->buffer >= curr_page_addr) &&
949 		    ((caddr_t)cd->buffer <  curr_page_addr + PAGE_SIZE))
950 			break;
951 	}
952 
953 	if ((caddr_t)(cd->buffer + elen) < (curr_page_addr + PAGE_SIZE)) {
954 		/* encode entry in current page */
955 
956 		p = encode_entry_baggage(cd, p, name, namlen, ino);
957 
958 		if (plus)
959 			p = encode_entryplus_baggage(cd, p, name, namlen, ino);
960 		num_entry_words = p - cd->buffer;
961 	} else if (*(page+1) != NULL) {
962 		/* temporarily encode entry into next page, then move back to
963 		 * current and next page in rq_respages[] */
964 		__be32 *p1, *tmp;
965 		int len1, len2;
966 
967 		/* grab next page for temporary storage of entry */
968 		p1 = tmp = page_address(*(page+1));
969 
970 		p1 = encode_entry_baggage(cd, p1, name, namlen, ino);
971 
972 		if (plus)
973 			p1 = encode_entryplus_baggage(cd, p1, name, namlen, ino);
974 
975 		/* determine entry word length and lengths to go in pages */
976 		num_entry_words = p1 - tmp;
977 		len1 = curr_page_addr + PAGE_SIZE - (caddr_t)cd->buffer;
978 		if ((num_entry_words << 2) < len1) {
979 			/* the actual number of words in the entry is less
980 			 * than elen and can still fit in the current page
981 			 */
982 			memmove(p, tmp, num_entry_words << 2);
983 			p += num_entry_words;
984 
985 			/* update offset */
986 			cd->offset = cd->buffer + (cd->offset - tmp);
987 		} else {
988 			unsigned int offset_r = (cd->offset - tmp) << 2;
989 
990 			/* update pointer to offset location.
991 			 * This is a 64bit quantity, so we need to
992 			 * deal with 3 cases:
993 			 *  -	entirely in first page
994 			 *  -	entirely in second page
995 			 *  -	4 bytes in each page
996 			 */
997 			if (offset_r + 8 <= len1) {
998 				cd->offset = p + (cd->offset - tmp);
999 			} else if (offset_r >= len1) {
1000 				cd->offset -= len1 >> 2;
1001 			} else {
1002 				/* sitting on the fence */
1003 				BUG_ON(offset_r != len1 - 4);
1004 				cd->offset = p + (cd->offset - tmp);
1005 				cd->offset1 = tmp;
1006 			}
1007 
1008 			len2 = (num_entry_words << 2) - len1;
1009 
1010 			/* move from temp page to current and next pages */
1011 			memmove(p, tmp, len1);
1012 			memmove(tmp, (caddr_t)tmp+len1, len2);
1013 
1014 			p = tmp + (len2 >> 2);
1015 		}
1016 	}
1017 	else {
1018 		cd->common.err = nfserr_toosmall;
1019 		return -EINVAL;
1020 	}
1021 
1022 	cd->buflen -= num_entry_words;
1023 	cd->buffer = p;
1024 	cd->common.err = nfs_ok;
1025 	return 0;
1026 
1027 }
1028 
1029 int
1030 nfs3svc_encode_entry(void *cd, const char *name,
1031 		     int namlen, loff_t offset, u64 ino, unsigned int d_type)
1032 {
1033 	return encode_entry(cd, name, namlen, offset, ino, d_type, 0);
1034 }
1035 
1036 int
1037 nfs3svc_encode_entry_plus(void *cd, const char *name,
1038 			  int namlen, loff_t offset, u64 ino,
1039 			  unsigned int d_type)
1040 {
1041 	return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
1042 }
1043 
1044 /* FSSTAT */
1045 int
1046 nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, __be32 *p)
1047 {
1048 	struct nfsd3_fsstatres *resp = rqstp->rq_resp;
1049 	struct kstatfs	*s = &resp->stats;
1050 	u64		bs = s->f_bsize;
1051 
1052 	*p++ = xdr_zero;	/* no post_op_attr */
1053 
1054 	if (resp->status == 0) {
1055 		p = xdr_encode_hyper(p, bs * s->f_blocks);	/* total bytes */
1056 		p = xdr_encode_hyper(p, bs * s->f_bfree);	/* free bytes */
1057 		p = xdr_encode_hyper(p, bs * s->f_bavail);	/* user available bytes */
1058 		p = xdr_encode_hyper(p, s->f_files);	/* total inodes */
1059 		p = xdr_encode_hyper(p, s->f_ffree);	/* free inodes */
1060 		p = xdr_encode_hyper(p, s->f_ffree);	/* user available inodes */
1061 		*p++ = htonl(resp->invarsec);	/* mean unchanged time */
1062 	}
1063 	return xdr_ressize_check(rqstp, p);
1064 }
1065 
1066 /* FSINFO */
1067 int
1068 nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, __be32 *p)
1069 {
1070 	struct nfsd3_fsinfores *resp = rqstp->rq_resp;
1071 
1072 	*p++ = xdr_zero;	/* no post_op_attr */
1073 
1074 	if (resp->status == 0) {
1075 		*p++ = htonl(resp->f_rtmax);
1076 		*p++ = htonl(resp->f_rtpref);
1077 		*p++ = htonl(resp->f_rtmult);
1078 		*p++ = htonl(resp->f_wtmax);
1079 		*p++ = htonl(resp->f_wtpref);
1080 		*p++ = htonl(resp->f_wtmult);
1081 		*p++ = htonl(resp->f_dtpref);
1082 		p = xdr_encode_hyper(p, resp->f_maxfilesize);
1083 		*p++ = xdr_one;
1084 		*p++ = xdr_zero;
1085 		*p++ = htonl(resp->f_properties);
1086 	}
1087 
1088 	return xdr_ressize_check(rqstp, p);
1089 }
1090 
1091 /* PATHCONF */
1092 int
1093 nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, __be32 *p)
1094 {
1095 	struct nfsd3_pathconfres *resp = rqstp->rq_resp;
1096 
1097 	*p++ = xdr_zero;	/* no post_op_attr */
1098 
1099 	if (resp->status == 0) {
1100 		*p++ = htonl(resp->p_link_max);
1101 		*p++ = htonl(resp->p_name_max);
1102 		*p++ = htonl(resp->p_no_trunc);
1103 		*p++ = htonl(resp->p_chown_restricted);
1104 		*p++ = htonl(resp->p_case_insensitive);
1105 		*p++ = htonl(resp->p_case_preserving);
1106 	}
1107 
1108 	return xdr_ressize_check(rqstp, p);
1109 }
1110 
1111 /* COMMIT */
1112 int
1113 nfs3svc_encode_commitres(struct svc_rqst *rqstp, __be32 *p)
1114 {
1115 	struct nfsd3_commitres *resp = rqstp->rq_resp;
1116 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1117 
1118 	p = encode_wcc_data(rqstp, p, &resp->fh);
1119 	/* Write verifier */
1120 	if (resp->status == 0) {
1121 		*p++ = htonl(nn->nfssvc_boot.tv_sec);
1122 		*p++ = htonl(nn->nfssvc_boot.tv_usec);
1123 	}
1124 	return xdr_ressize_check(rqstp, p);
1125 }
1126 
1127 /*
1128  * XDR release functions
1129  */
1130 void
1131 nfs3svc_release_fhandle(struct svc_rqst *rqstp)
1132 {
1133 	struct nfsd3_attrstat *resp = rqstp->rq_resp;
1134 
1135 	fh_put(&resp->fh);
1136 }
1137 
1138 void
1139 nfs3svc_release_fhandle2(struct svc_rqst *rqstp)
1140 {
1141 	struct nfsd3_fhandle_pair *resp = rqstp->rq_resp;
1142 
1143 	fh_put(&resp->fh1);
1144 	fh_put(&resp->fh2);
1145 }
1146