xref: /linux/fs/nfsd/nfs3xdr.c (revision cc04a46f11ea046ed53e2c832ae29e4790f7e35f)
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 				     (d_inode(fhp->fh_dentry)->i_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 = d_inode(fhp->fh_dentry)->i_version;
264 	if (err) {
265 		fhp->fh_post_saved = 0;
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 = 1;
270 }
271 
272 /*
273  * XDR decode functions
274  */
275 int
276 nfs3svc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
277 {
278 	p = decode_fh(p, &args->fh);
279 	if (!p)
280 		return 0;
281 	return xdr_argsize_check(rqstp, p);
282 }
283 
284 int
285 nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
286 					struct nfsd3_sattrargs *args)
287 {
288 	p = decode_fh(p, &args->fh);
289 	if (!p)
290 		return 0;
291 	p = decode_sattr3(p, &args->attrs);
292 
293 	if ((args->check_guard = ntohl(*p++)) != 0) {
294 		struct timespec time;
295 		p = decode_time3(p, &time);
296 		args->guardtime = time.tv_sec;
297 	}
298 
299 	return xdr_argsize_check(rqstp, p);
300 }
301 
302 int
303 nfs3svc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
304 					struct nfsd3_diropargs *args)
305 {
306 	if (!(p = decode_fh(p, &args->fh))
307 	 || !(p = decode_filename(p, &args->name, &args->len)))
308 		return 0;
309 
310 	return xdr_argsize_check(rqstp, p);
311 }
312 
313 int
314 nfs3svc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p,
315 					struct nfsd3_accessargs *args)
316 {
317 	p = decode_fh(p, &args->fh);
318 	if (!p)
319 		return 0;
320 	args->access = ntohl(*p++);
321 
322 	return xdr_argsize_check(rqstp, p);
323 }
324 
325 int
326 nfs3svc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
327 					struct nfsd3_readargs *args)
328 {
329 	unsigned int len;
330 	int v;
331 	u32 max_blocksize = svc_max_payload(rqstp);
332 
333 	p = decode_fh(p, &args->fh);
334 	if (!p)
335 		return 0;
336 	p = xdr_decode_hyper(p, &args->offset);
337 
338 	args->count = ntohl(*p++);
339 	len = min(args->count, max_blocksize);
340 
341 	/* set up the kvec */
342 	v=0;
343 	while (len > 0) {
344 		struct page *p = *(rqstp->rq_next_page++);
345 
346 		rqstp->rq_vec[v].iov_base = page_address(p);
347 		rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
348 		len -= rqstp->rq_vec[v].iov_len;
349 		v++;
350 	}
351 	args->vlen = v;
352 	return xdr_argsize_check(rqstp, p);
353 }
354 
355 int
356 nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
357 					struct nfsd3_writeargs *args)
358 {
359 	unsigned int len, v, hdr, dlen;
360 	u32 max_blocksize = svc_max_payload(rqstp);
361 
362 	p = decode_fh(p, &args->fh);
363 	if (!p)
364 		return 0;
365 	p = xdr_decode_hyper(p, &args->offset);
366 
367 	args->count = ntohl(*p++);
368 	args->stable = ntohl(*p++);
369 	len = args->len = ntohl(*p++);
370 	/*
371 	 * The count must equal the amount of data passed.
372 	 */
373 	if (args->count != args->len)
374 		return 0;
375 
376 	/*
377 	 * Check to make sure that we got the right number of
378 	 * bytes.
379 	 */
380 	hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
381 	dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
382 		- hdr;
383 	/*
384 	 * Round the length of the data which was specified up to
385 	 * the next multiple of XDR units and then compare that
386 	 * against the length which was actually received.
387 	 * Note that when RPCSEC/GSS (for example) is used, the
388 	 * data buffer can be padded so dlen might be larger
389 	 * than required.  It must never be smaller.
390 	 */
391 	if (dlen < XDR_QUADLEN(len)*4)
392 		return 0;
393 
394 	if (args->count > max_blocksize) {
395 		args->count = max_blocksize;
396 		len = args->len = max_blocksize;
397 	}
398 	rqstp->rq_vec[0].iov_base = (void*)p;
399 	rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
400 	v = 0;
401 	while (len > rqstp->rq_vec[v].iov_len) {
402 		len -= rqstp->rq_vec[v].iov_len;
403 		v++;
404 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
405 		rqstp->rq_vec[v].iov_len = PAGE_SIZE;
406 	}
407 	rqstp->rq_vec[v].iov_len = len;
408 	args->vlen = v + 1;
409 	return 1;
410 }
411 
412 int
413 nfs3svc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
414 					struct nfsd3_createargs *args)
415 {
416 	if (!(p = decode_fh(p, &args->fh))
417 	 || !(p = decode_filename(p, &args->name, &args->len)))
418 		return 0;
419 
420 	switch (args->createmode = ntohl(*p++)) {
421 	case NFS3_CREATE_UNCHECKED:
422 	case NFS3_CREATE_GUARDED:
423 		p = decode_sattr3(p, &args->attrs);
424 		break;
425 	case NFS3_CREATE_EXCLUSIVE:
426 		args->verf = p;
427 		p += 2;
428 		break;
429 	default:
430 		return 0;
431 	}
432 
433 	return xdr_argsize_check(rqstp, p);
434 }
435 int
436 nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, __be32 *p,
437 					struct nfsd3_createargs *args)
438 {
439 	if (!(p = decode_fh(p, &args->fh)) ||
440 	    !(p = decode_filename(p, &args->name, &args->len)))
441 		return 0;
442 	p = decode_sattr3(p, &args->attrs);
443 
444 	return xdr_argsize_check(rqstp, p);
445 }
446 
447 int
448 nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
449 					struct nfsd3_symlinkargs *args)
450 {
451 	unsigned int len, avail;
452 	char *old, *new;
453 	struct kvec *vec;
454 
455 	if (!(p = decode_fh(p, &args->ffh)) ||
456 	    !(p = decode_filename(p, &args->fname, &args->flen))
457 		)
458 		return 0;
459 	p = decode_sattr3(p, &args->attrs);
460 
461 	/* now decode the pathname, which might be larger than the first page.
462 	 * As we have to check for nul's anyway, we copy it into a new page
463 	 * This page appears in the rq_res.pages list, but as pages_len is always
464 	 * 0, it won't get in the way
465 	 */
466 	len = ntohl(*p++);
467 	if (len == 0 || len > NFS3_MAXPATHLEN || len >= PAGE_SIZE)
468 		return 0;
469 	args->tname = new = page_address(*(rqstp->rq_next_page++));
470 	args->tlen = len;
471 	/* first copy and check from the first page */
472 	old = (char*)p;
473 	vec = &rqstp->rq_arg.head[0];
474 	avail = vec->iov_len - (old - (char*)vec->iov_base);
475 	while (len && avail && *old) {
476 		*new++ = *old++;
477 		len--;
478 		avail--;
479 	}
480 	/* now copy next page if there is one */
481 	if (len && !avail && rqstp->rq_arg.page_len) {
482 		avail = min_t(unsigned int, rqstp->rq_arg.page_len, PAGE_SIZE);
483 		old = page_address(rqstp->rq_arg.pages[0]);
484 	}
485 	while (len && avail && *old) {
486 		*new++ = *old++;
487 		len--;
488 		avail--;
489 	}
490 	*new = '\0';
491 	if (len)
492 		return 0;
493 
494 	return 1;
495 }
496 
497 int
498 nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, __be32 *p,
499 					struct nfsd3_mknodargs *args)
500 {
501 	if (!(p = decode_fh(p, &args->fh))
502 	 || !(p = decode_filename(p, &args->name, &args->len)))
503 		return 0;
504 
505 	args->ftype = ntohl(*p++);
506 
507 	if (args->ftype == NF3BLK  || args->ftype == NF3CHR
508 	 || args->ftype == NF3SOCK || args->ftype == NF3FIFO)
509 		p = decode_sattr3(p, &args->attrs);
510 
511 	if (args->ftype == NF3BLK || args->ftype == NF3CHR) {
512 		args->major = ntohl(*p++);
513 		args->minor = ntohl(*p++);
514 	}
515 
516 	return xdr_argsize_check(rqstp, p);
517 }
518 
519 int
520 nfs3svc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
521 					struct nfsd3_renameargs *args)
522 {
523 	if (!(p = decode_fh(p, &args->ffh))
524 	 || !(p = decode_filename(p, &args->fname, &args->flen))
525 	 || !(p = decode_fh(p, &args->tfh))
526 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
527 		return 0;
528 
529 	return xdr_argsize_check(rqstp, p);
530 }
531 
532 int
533 nfs3svc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p,
534 					struct nfsd3_readlinkargs *args)
535 {
536 	p = decode_fh(p, &args->fh);
537 	if (!p)
538 		return 0;
539 	args->buffer = page_address(*(rqstp->rq_next_page++));
540 
541 	return xdr_argsize_check(rqstp, p);
542 }
543 
544 int
545 nfs3svc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
546 					struct nfsd3_linkargs *args)
547 {
548 	if (!(p = decode_fh(p, &args->ffh))
549 	 || !(p = decode_fh(p, &args->tfh))
550 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
551 		return 0;
552 
553 	return xdr_argsize_check(rqstp, p);
554 }
555 
556 int
557 nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
558 					struct nfsd3_readdirargs *args)
559 {
560 	p = decode_fh(p, &args->fh);
561 	if (!p)
562 		return 0;
563 	p = xdr_decode_hyper(p, &args->cookie);
564 	args->verf   = p; p += 2;
565 	args->dircount = ~0;
566 	args->count  = ntohl(*p++);
567 	args->count  = min_t(u32, args->count, PAGE_SIZE);
568 	args->buffer = page_address(*(rqstp->rq_next_page++));
569 
570 	return xdr_argsize_check(rqstp, p);
571 }
572 
573 int
574 nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p,
575 					struct nfsd3_readdirargs *args)
576 {
577 	int len;
578 	u32 max_blocksize = svc_max_payload(rqstp);
579 
580 	p = decode_fh(p, &args->fh);
581 	if (!p)
582 		return 0;
583 	p = xdr_decode_hyper(p, &args->cookie);
584 	args->verf     = p; p += 2;
585 	args->dircount = ntohl(*p++);
586 	args->count    = ntohl(*p++);
587 
588 	len = args->count = min(args->count, max_blocksize);
589 	while (len > 0) {
590 		struct page *p = *(rqstp->rq_next_page++);
591 		if (!args->buffer)
592 			args->buffer = page_address(p);
593 		len -= PAGE_SIZE;
594 	}
595 
596 	return xdr_argsize_check(rqstp, p);
597 }
598 
599 int
600 nfs3svc_decode_commitargs(struct svc_rqst *rqstp, __be32 *p,
601 					struct nfsd3_commitargs *args)
602 {
603 	p = decode_fh(p, &args->fh);
604 	if (!p)
605 		return 0;
606 	p = xdr_decode_hyper(p, &args->offset);
607 	args->count = ntohl(*p++);
608 
609 	return xdr_argsize_check(rqstp, p);
610 }
611 
612 /*
613  * XDR encode functions
614  */
615 /*
616  * There must be an encoding function for void results so svc_process
617  * will work properly.
618  */
619 int
620 nfs3svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p, void *dummy)
621 {
622 	return xdr_ressize_check(rqstp, p);
623 }
624 
625 /* GETATTR */
626 int
627 nfs3svc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
628 					struct nfsd3_attrstat *resp)
629 {
630 	if (resp->status == 0) {
631 		lease_get_mtime(d_inode(resp->fh.fh_dentry),
632 				&resp->stat.mtime);
633 		p = encode_fattr3(rqstp, p, &resp->fh, &resp->stat);
634 	}
635 	return xdr_ressize_check(rqstp, p);
636 }
637 
638 /* SETATTR, REMOVE, RMDIR */
639 int
640 nfs3svc_encode_wccstat(struct svc_rqst *rqstp, __be32 *p,
641 					struct nfsd3_attrstat *resp)
642 {
643 	p = encode_wcc_data(rqstp, p, &resp->fh);
644 	return xdr_ressize_check(rqstp, p);
645 }
646 
647 /* LOOKUP */
648 int
649 nfs3svc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
650 					struct nfsd3_diropres *resp)
651 {
652 	if (resp->status == 0) {
653 		p = encode_fh(p, &resp->fh);
654 		p = encode_post_op_attr(rqstp, p, &resp->fh);
655 	}
656 	p = encode_post_op_attr(rqstp, p, &resp->dirfh);
657 	return xdr_ressize_check(rqstp, p);
658 }
659 
660 /* ACCESS */
661 int
662 nfs3svc_encode_accessres(struct svc_rqst *rqstp, __be32 *p,
663 					struct nfsd3_accessres *resp)
664 {
665 	p = encode_post_op_attr(rqstp, p, &resp->fh);
666 	if (resp->status == 0)
667 		*p++ = htonl(resp->access);
668 	return xdr_ressize_check(rqstp, p);
669 }
670 
671 /* READLINK */
672 int
673 nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
674 					struct nfsd3_readlinkres *resp)
675 {
676 	p = encode_post_op_attr(rqstp, p, &resp->fh);
677 	if (resp->status == 0) {
678 		*p++ = htonl(resp->len);
679 		xdr_ressize_check(rqstp, p);
680 		rqstp->rq_res.page_len = resp->len;
681 		if (resp->len & 3) {
682 			/* need to pad the tail */
683 			rqstp->rq_res.tail[0].iov_base = p;
684 			*p = 0;
685 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
686 		}
687 		return 1;
688 	} else
689 		return xdr_ressize_check(rqstp, p);
690 }
691 
692 /* READ */
693 int
694 nfs3svc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
695 					struct nfsd3_readres *resp)
696 {
697 	p = encode_post_op_attr(rqstp, p, &resp->fh);
698 	if (resp->status == 0) {
699 		*p++ = htonl(resp->count);
700 		*p++ = htonl(resp->eof);
701 		*p++ = htonl(resp->count);	/* xdr opaque count */
702 		xdr_ressize_check(rqstp, p);
703 		/* now update rqstp->rq_res to reflect data as well */
704 		rqstp->rq_res.page_len = resp->count;
705 		if (resp->count & 3) {
706 			/* need to pad the tail */
707 			rqstp->rq_res.tail[0].iov_base = p;
708 			*p = 0;
709 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->count & 3);
710 		}
711 		return 1;
712 	} else
713 		return xdr_ressize_check(rqstp, p);
714 }
715 
716 /* WRITE */
717 int
718 nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p,
719 					struct nfsd3_writeres *resp)
720 {
721 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
722 
723 	p = encode_wcc_data(rqstp, p, &resp->fh);
724 	if (resp->status == 0) {
725 		*p++ = htonl(resp->count);
726 		*p++ = htonl(resp->committed);
727 		*p++ = htonl(nn->nfssvc_boot.tv_sec);
728 		*p++ = htonl(nn->nfssvc_boot.tv_usec);
729 	}
730 	return xdr_ressize_check(rqstp, p);
731 }
732 
733 /* CREATE, MKDIR, SYMLINK, MKNOD */
734 int
735 nfs3svc_encode_createres(struct svc_rqst *rqstp, __be32 *p,
736 					struct nfsd3_diropres *resp)
737 {
738 	if (resp->status == 0) {
739 		*p++ = xdr_one;
740 		p = encode_fh(p, &resp->fh);
741 		p = encode_post_op_attr(rqstp, p, &resp->fh);
742 	}
743 	p = encode_wcc_data(rqstp, p, &resp->dirfh);
744 	return xdr_ressize_check(rqstp, p);
745 }
746 
747 /* RENAME */
748 int
749 nfs3svc_encode_renameres(struct svc_rqst *rqstp, __be32 *p,
750 					struct nfsd3_renameres *resp)
751 {
752 	p = encode_wcc_data(rqstp, p, &resp->ffh);
753 	p = encode_wcc_data(rqstp, p, &resp->tfh);
754 	return xdr_ressize_check(rqstp, p);
755 }
756 
757 /* LINK */
758 int
759 nfs3svc_encode_linkres(struct svc_rqst *rqstp, __be32 *p,
760 					struct nfsd3_linkres *resp)
761 {
762 	p = encode_post_op_attr(rqstp, p, &resp->fh);
763 	p = encode_wcc_data(rqstp, p, &resp->tfh);
764 	return xdr_ressize_check(rqstp, p);
765 }
766 
767 /* READDIR */
768 int
769 nfs3svc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
770 					struct nfsd3_readdirres *resp)
771 {
772 	p = encode_post_op_attr(rqstp, p, &resp->fh);
773 
774 	if (resp->status == 0) {
775 		/* stupid readdir cookie */
776 		memcpy(p, resp->verf, 8); p += 2;
777 		xdr_ressize_check(rqstp, p);
778 		if (rqstp->rq_res.head[0].iov_len + (2<<2) > PAGE_SIZE)
779 			return 1; /*No room for trailer */
780 		rqstp->rq_res.page_len = (resp->count) << 2;
781 
782 		/* add the 'tail' to the end of the 'head' page - page 0. */
783 		rqstp->rq_res.tail[0].iov_base = p;
784 		*p++ = 0;		/* no more entries */
785 		*p++ = htonl(resp->common.err == nfserr_eof);
786 		rqstp->rq_res.tail[0].iov_len = 2<<2;
787 		return 1;
788 	} else
789 		return xdr_ressize_check(rqstp, p);
790 }
791 
792 static __be32 *
793 encode_entry_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name,
794 	     int namlen, u64 ino)
795 {
796 	*p++ = xdr_one;				 /* mark entry present */
797 	p    = xdr_encode_hyper(p, ino);	 /* file id */
798 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
799 
800 	cd->offset = p;				/* remember pointer */
801 	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);/* offset of next entry */
802 
803 	return p;
804 }
805 
806 static __be32
807 compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
808 		 const char *name, int namlen, u64 ino)
809 {
810 	struct svc_export	*exp;
811 	struct dentry		*dparent, *dchild;
812 	__be32 rv = nfserr_noent;
813 
814 	dparent = cd->fh.fh_dentry;
815 	exp  = cd->fh.fh_export;
816 
817 	if (isdotent(name, namlen)) {
818 		if (namlen == 2) {
819 			dchild = dget_parent(dparent);
820 			/* filesystem root - cannot return filehandle for ".." */
821 			if (dchild == dparent)
822 				goto out;
823 		} else
824 			dchild = dget(dparent);
825 	} else
826 		dchild = lookup_one_len(name, dparent, namlen);
827 	if (IS_ERR(dchild))
828 		return rv;
829 	if (d_mountpoint(dchild))
830 		goto out;
831 	if (d_really_is_negative(dchild))
832 		goto out;
833 	if (dchild->d_inode->i_ino != ino)
834 		goto out;
835 	rv = fh_compose(fhp, exp, dchild, &cd->fh);
836 out:
837 	dput(dchild);
838 	return rv;
839 }
840 
841 static __be32 *encode_entryplus_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name, int namlen, u64 ino)
842 {
843 	struct svc_fh	*fh = &cd->scratch;
844 	__be32 err;
845 
846 	fh_init(fh, NFS3_FHSIZE);
847 	err = compose_entry_fh(cd, fh, name, namlen, ino);
848 	if (err) {
849 		*p++ = 0;
850 		*p++ = 0;
851 		goto out;
852 	}
853 	p = encode_post_op_attr(cd->rqstp, p, fh);
854 	*p++ = xdr_one;			/* yes, a file handle follows */
855 	p = encode_fh(p, fh);
856 out:
857 	fh_put(fh);
858 	return p;
859 }
860 
861 /*
862  * Encode a directory entry. This one works for both normal readdir
863  * and readdirplus.
864  * The normal readdir reply requires 2 (fileid) + 1 (stringlen)
865  * + string + 2 (cookie) + 1 (next) words, i.e. 6 + strlen.
866  *
867  * The readdirplus baggage is 1+21 words for post_op_attr, plus the
868  * file handle.
869  */
870 
871 #define NFS3_ENTRY_BAGGAGE	(2 + 1 + 2 + 1)
872 #define NFS3_ENTRYPLUS_BAGGAGE	(1 + 21 + 1 + (NFS3_FHSIZE >> 2))
873 static int
874 encode_entry(struct readdir_cd *ccd, const char *name, int namlen,
875 	     loff_t offset, u64 ino, unsigned int d_type, int plus)
876 {
877 	struct nfsd3_readdirres *cd = container_of(ccd, struct nfsd3_readdirres,
878 		       					common);
879 	__be32		*p = cd->buffer;
880 	caddr_t		curr_page_addr = NULL;
881 	struct page **	page;
882 	int		slen;		/* string (name) length */
883 	int		elen;		/* estimated entry length in words */
884 	int		num_entry_words = 0;	/* actual number of words */
885 
886 	if (cd->offset) {
887 		u64 offset64 = offset;
888 
889 		if (unlikely(cd->offset1)) {
890 			/* we ended up with offset on a page boundary */
891 			*cd->offset = htonl(offset64 >> 32);
892 			*cd->offset1 = htonl(offset64 & 0xffffffff);
893 			cd->offset1 = NULL;
894 		} else {
895 			xdr_encode_hyper(cd->offset, offset64);
896 		}
897 	}
898 
899 	/*
900 	dprintk("encode_entry(%.*s @%ld%s)\n",
901 		namlen, name, (long) offset, plus? " plus" : "");
902 	 */
903 
904 	/* truncate filename if too long */
905 	namlen = min(namlen, NFS3_MAXNAMLEN);
906 
907 	slen = XDR_QUADLEN(namlen);
908 	elen = slen + NFS3_ENTRY_BAGGAGE
909 		+ (plus? NFS3_ENTRYPLUS_BAGGAGE : 0);
910 
911 	if (cd->buflen < elen) {
912 		cd->common.err = nfserr_toosmall;
913 		return -EINVAL;
914 	}
915 
916 	/* determine which page in rq_respages[] we are currently filling */
917 	for (page = cd->rqstp->rq_respages + 1;
918 				page < cd->rqstp->rq_next_page; page++) {
919 		curr_page_addr = page_address(*page);
920 
921 		if (((caddr_t)cd->buffer >= curr_page_addr) &&
922 		    ((caddr_t)cd->buffer <  curr_page_addr + PAGE_SIZE))
923 			break;
924 	}
925 
926 	if ((caddr_t)(cd->buffer + elen) < (curr_page_addr + PAGE_SIZE)) {
927 		/* encode entry in current page */
928 
929 		p = encode_entry_baggage(cd, p, name, namlen, ino);
930 
931 		if (plus)
932 			p = encode_entryplus_baggage(cd, p, name, namlen, ino);
933 		num_entry_words = p - cd->buffer;
934 	} else if (*(page+1) != NULL) {
935 		/* temporarily encode entry into next page, then move back to
936 		 * current and next page in rq_respages[] */
937 		__be32 *p1, *tmp;
938 		int len1, len2;
939 
940 		/* grab next page for temporary storage of entry */
941 		p1 = tmp = page_address(*(page+1));
942 
943 		p1 = encode_entry_baggage(cd, p1, name, namlen, ino);
944 
945 		if (plus)
946 			p1 = encode_entryplus_baggage(cd, p1, name, namlen, ino);
947 
948 		/* determine entry word length and lengths to go in pages */
949 		num_entry_words = p1 - tmp;
950 		len1 = curr_page_addr + PAGE_SIZE - (caddr_t)cd->buffer;
951 		if ((num_entry_words << 2) < len1) {
952 			/* the actual number of words in the entry is less
953 			 * than elen and can still fit in the current page
954 			 */
955 			memmove(p, tmp, num_entry_words << 2);
956 			p += num_entry_words;
957 
958 			/* update offset */
959 			cd->offset = cd->buffer + (cd->offset - tmp);
960 		} else {
961 			unsigned int offset_r = (cd->offset - tmp) << 2;
962 
963 			/* update pointer to offset location.
964 			 * This is a 64bit quantity, so we need to
965 			 * deal with 3 cases:
966 			 *  -	entirely in first page
967 			 *  -	entirely in second page
968 			 *  -	4 bytes in each page
969 			 */
970 			if (offset_r + 8 <= len1) {
971 				cd->offset = p + (cd->offset - tmp);
972 			} else if (offset_r >= len1) {
973 				cd->offset -= len1 >> 2;
974 			} else {
975 				/* sitting on the fence */
976 				BUG_ON(offset_r != len1 - 4);
977 				cd->offset = p + (cd->offset - tmp);
978 				cd->offset1 = tmp;
979 			}
980 
981 			len2 = (num_entry_words << 2) - len1;
982 
983 			/* move from temp page to current and next pages */
984 			memmove(p, tmp, len1);
985 			memmove(tmp, (caddr_t)tmp+len1, len2);
986 
987 			p = tmp + (len2 >> 2);
988 		}
989 	}
990 	else {
991 		cd->common.err = nfserr_toosmall;
992 		return -EINVAL;
993 	}
994 
995 	cd->buflen -= num_entry_words;
996 	cd->buffer = p;
997 	cd->common.err = nfs_ok;
998 	return 0;
999 
1000 }
1001 
1002 int
1003 nfs3svc_encode_entry(void *cd, const char *name,
1004 		     int namlen, loff_t offset, u64 ino, unsigned int d_type)
1005 {
1006 	return encode_entry(cd, name, namlen, offset, ino, d_type, 0);
1007 }
1008 
1009 int
1010 nfs3svc_encode_entry_plus(void *cd, const char *name,
1011 			  int namlen, loff_t offset, u64 ino,
1012 			  unsigned int d_type)
1013 {
1014 	return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
1015 }
1016 
1017 /* FSSTAT */
1018 int
1019 nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, __be32 *p,
1020 					struct nfsd3_fsstatres *resp)
1021 {
1022 	struct kstatfs	*s = &resp->stats;
1023 	u64		bs = s->f_bsize;
1024 
1025 	*p++ = xdr_zero;	/* no post_op_attr */
1026 
1027 	if (resp->status == 0) {
1028 		p = xdr_encode_hyper(p, bs * s->f_blocks);	/* total bytes */
1029 		p = xdr_encode_hyper(p, bs * s->f_bfree);	/* free bytes */
1030 		p = xdr_encode_hyper(p, bs * s->f_bavail);	/* user available bytes */
1031 		p = xdr_encode_hyper(p, s->f_files);	/* total inodes */
1032 		p = xdr_encode_hyper(p, s->f_ffree);	/* free inodes */
1033 		p = xdr_encode_hyper(p, s->f_ffree);	/* user available inodes */
1034 		*p++ = htonl(resp->invarsec);	/* mean unchanged time */
1035 	}
1036 	return xdr_ressize_check(rqstp, p);
1037 }
1038 
1039 /* FSINFO */
1040 int
1041 nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, __be32 *p,
1042 					struct nfsd3_fsinfores *resp)
1043 {
1044 	*p++ = xdr_zero;	/* no post_op_attr */
1045 
1046 	if (resp->status == 0) {
1047 		*p++ = htonl(resp->f_rtmax);
1048 		*p++ = htonl(resp->f_rtpref);
1049 		*p++ = htonl(resp->f_rtmult);
1050 		*p++ = htonl(resp->f_wtmax);
1051 		*p++ = htonl(resp->f_wtpref);
1052 		*p++ = htonl(resp->f_wtmult);
1053 		*p++ = htonl(resp->f_dtpref);
1054 		p = xdr_encode_hyper(p, resp->f_maxfilesize);
1055 		*p++ = xdr_one;
1056 		*p++ = xdr_zero;
1057 		*p++ = htonl(resp->f_properties);
1058 	}
1059 
1060 	return xdr_ressize_check(rqstp, p);
1061 }
1062 
1063 /* PATHCONF */
1064 int
1065 nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, __be32 *p,
1066 					struct nfsd3_pathconfres *resp)
1067 {
1068 	*p++ = xdr_zero;	/* no post_op_attr */
1069 
1070 	if (resp->status == 0) {
1071 		*p++ = htonl(resp->p_link_max);
1072 		*p++ = htonl(resp->p_name_max);
1073 		*p++ = htonl(resp->p_no_trunc);
1074 		*p++ = htonl(resp->p_chown_restricted);
1075 		*p++ = htonl(resp->p_case_insensitive);
1076 		*p++ = htonl(resp->p_case_preserving);
1077 	}
1078 
1079 	return xdr_ressize_check(rqstp, p);
1080 }
1081 
1082 /* COMMIT */
1083 int
1084 nfs3svc_encode_commitres(struct svc_rqst *rqstp, __be32 *p,
1085 					struct nfsd3_commitres *resp)
1086 {
1087 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1088 
1089 	p = encode_wcc_data(rqstp, p, &resp->fh);
1090 	/* Write verifier */
1091 	if (resp->status == 0) {
1092 		*p++ = htonl(nn->nfssvc_boot.tv_sec);
1093 		*p++ = htonl(nn->nfssvc_boot.tv_usec);
1094 	}
1095 	return xdr_ressize_check(rqstp, p);
1096 }
1097 
1098 /*
1099  * XDR release functions
1100  */
1101 int
1102 nfs3svc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
1103 					struct nfsd3_attrstat *resp)
1104 {
1105 	fh_put(&resp->fh);
1106 	return 1;
1107 }
1108 
1109 int
1110 nfs3svc_release_fhandle2(struct svc_rqst *rqstp, __be32 *p,
1111 					struct nfsd3_fhandle_pair *resp)
1112 {
1113 	fh_put(&resp->fh1);
1114 	fh_put(&resp->fh2);
1115 	return 1;
1116 }
1117