xref: /linux/fs/nfs/nfs3xdr.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 /*
2  * linux/fs/nfs/nfs3xdr.c
3  *
4  * XDR functions to encode/decode NFSv3 RPC arguments and results.
5  *
6  * Copyright (C) 1996, 1997 Olaf Kirch
7  */
8 
9 #include <linux/param.h>
10 #include <linux/time.h>
11 #include <linux/mm.h>
12 #include <linux/slab.h>
13 #include <linux/utsname.h>
14 #include <linux/errno.h>
15 #include <linux/string.h>
16 #include <linux/in.h>
17 #include <linux/pagemap.h>
18 #include <linux/proc_fs.h>
19 #include <linux/kdev_t.h>
20 #include <linux/sunrpc/clnt.h>
21 #include <linux/nfs.h>
22 #include <linux/nfs3.h>
23 #include <linux/nfs_fs.h>
24 #include <linux/nfsacl.h>
25 #include "internal.h"
26 
27 #define NFSDBG_FACILITY		NFSDBG_XDR
28 
29 /* Mapping from NFS error code to "errno" error code. */
30 #define errno_NFSERR_IO		EIO
31 
32 /*
33  * Declare the space requirements for NFS arguments and replies as
34  * number of 32bit-words
35  */
36 #define NFS3_fhandle_sz		(1+16)
37 #define NFS3_fh_sz		(NFS3_fhandle_sz)	/* shorthand */
38 #define NFS3_sattr_sz		(15)
39 #define NFS3_filename_sz	(1+(NFS3_MAXNAMLEN>>2))
40 #define NFS3_path_sz		(1+(NFS3_MAXPATHLEN>>2))
41 #define NFS3_fattr_sz		(21)
42 #define NFS3_wcc_attr_sz		(6)
43 #define NFS3_pre_op_attr_sz	(1+NFS3_wcc_attr_sz)
44 #define NFS3_post_op_attr_sz	(1+NFS3_fattr_sz)
45 #define NFS3_wcc_data_sz		(NFS3_pre_op_attr_sz+NFS3_post_op_attr_sz)
46 #define NFS3_fsstat_sz
47 #define NFS3_fsinfo_sz
48 #define NFS3_pathconf_sz
49 #define NFS3_entry_sz		(NFS3_filename_sz+3)
50 
51 #define NFS3_sattrargs_sz	(NFS3_fh_sz+NFS3_sattr_sz+3)
52 #define NFS3_diropargs_sz	(NFS3_fh_sz+NFS3_filename_sz)
53 #define NFS3_removeargs_sz	(NFS3_fh_sz+NFS3_filename_sz)
54 #define NFS3_accessargs_sz	(NFS3_fh_sz+1)
55 #define NFS3_readlinkargs_sz	(NFS3_fh_sz)
56 #define NFS3_readargs_sz	(NFS3_fh_sz+3)
57 #define NFS3_writeargs_sz	(NFS3_fh_sz+5)
58 #define NFS3_createargs_sz	(NFS3_diropargs_sz+NFS3_sattr_sz)
59 #define NFS3_mkdirargs_sz	(NFS3_diropargs_sz+NFS3_sattr_sz)
60 #define NFS3_symlinkargs_sz	(NFS3_diropargs_sz+1+NFS3_sattr_sz)
61 #define NFS3_mknodargs_sz	(NFS3_diropargs_sz+2+NFS3_sattr_sz)
62 #define NFS3_renameargs_sz	(NFS3_diropargs_sz+NFS3_diropargs_sz)
63 #define NFS3_linkargs_sz		(NFS3_fh_sz+NFS3_diropargs_sz)
64 #define NFS3_readdirargs_sz	(NFS3_fh_sz+2)
65 #define NFS3_commitargs_sz	(NFS3_fh_sz+3)
66 
67 #define NFS3_attrstat_sz	(1+NFS3_fattr_sz)
68 #define NFS3_wccstat_sz		(1+NFS3_wcc_data_sz)
69 #define NFS3_removeres_sz	(NFS3_wccstat_sz)
70 #define NFS3_lookupres_sz	(1+NFS3_fh_sz+(2 * NFS3_post_op_attr_sz))
71 #define NFS3_accessres_sz	(1+NFS3_post_op_attr_sz+1)
72 #define NFS3_readlinkres_sz	(1+NFS3_post_op_attr_sz+1)
73 #define NFS3_readres_sz		(1+NFS3_post_op_attr_sz+3)
74 #define NFS3_writeres_sz	(1+NFS3_wcc_data_sz+4)
75 #define NFS3_createres_sz	(1+NFS3_fh_sz+NFS3_post_op_attr_sz+NFS3_wcc_data_sz)
76 #define NFS3_renameres_sz	(1+(2 * NFS3_wcc_data_sz))
77 #define NFS3_linkres_sz		(1+NFS3_post_op_attr_sz+NFS3_wcc_data_sz)
78 #define NFS3_readdirres_sz	(1+NFS3_post_op_attr_sz+2)
79 #define NFS3_fsstatres_sz	(1+NFS3_post_op_attr_sz+13)
80 #define NFS3_fsinfores_sz	(1+NFS3_post_op_attr_sz+12)
81 #define NFS3_pathconfres_sz	(1+NFS3_post_op_attr_sz+6)
82 #define NFS3_commitres_sz	(1+NFS3_wcc_data_sz+2)
83 
84 #define ACL3_getaclargs_sz	(NFS3_fh_sz+1)
85 #define ACL3_setaclargs_sz	(NFS3_fh_sz+1+ \
86 				XDR_QUADLEN(NFS_ACL_INLINE_BUFSIZE))
87 #define ACL3_getaclres_sz	(1+NFS3_post_op_attr_sz+1+ \
88 				XDR_QUADLEN(NFS_ACL_INLINE_BUFSIZE))
89 #define ACL3_setaclres_sz	(1+NFS3_post_op_attr_sz)
90 
91 /*
92  * Map file type to S_IFMT bits
93  */
94 static const umode_t nfs_type2fmt[] = {
95 	[NF3BAD] = 0,
96 	[NF3REG] = S_IFREG,
97 	[NF3DIR] = S_IFDIR,
98 	[NF3BLK] = S_IFBLK,
99 	[NF3CHR] = S_IFCHR,
100 	[NF3LNK] = S_IFLNK,
101 	[NF3SOCK] = S_IFSOCK,
102 	[NF3FIFO] = S_IFIFO,
103 };
104 
105 /*
106  * Common NFS XDR functions as inlines
107  */
108 static inline __be32 *
109 xdr_encode_fhandle(__be32 *p, const struct nfs_fh *fh)
110 {
111 	return xdr_encode_array(p, fh->data, fh->size);
112 }
113 
114 static inline __be32 *
115 xdr_decode_fhandle(__be32 *p, struct nfs_fh *fh)
116 {
117 	if ((fh->size = ntohl(*p++)) <= NFS3_FHSIZE) {
118 		memcpy(fh->data, p, fh->size);
119 		return p + XDR_QUADLEN(fh->size);
120 	}
121 	return NULL;
122 }
123 
124 /*
125  * Encode/decode time.
126  */
127 static inline __be32 *
128 xdr_encode_time3(__be32 *p, struct timespec *timep)
129 {
130 	*p++ = htonl(timep->tv_sec);
131 	*p++ = htonl(timep->tv_nsec);
132 	return p;
133 }
134 
135 static inline __be32 *
136 xdr_decode_time3(__be32 *p, struct timespec *timep)
137 {
138 	timep->tv_sec = ntohl(*p++);
139 	timep->tv_nsec = ntohl(*p++);
140 	return p;
141 }
142 
143 static __be32 *
144 xdr_decode_fattr(__be32 *p, struct nfs_fattr *fattr)
145 {
146 	unsigned int	type, major, minor;
147 	umode_t		fmode;
148 
149 	type = ntohl(*p++);
150 	if (type > NF3FIFO)
151 		type = NF3NON;
152 	fmode = nfs_type2fmt[type];
153 	fattr->mode = (ntohl(*p++) & ~S_IFMT) | fmode;
154 	fattr->nlink = ntohl(*p++);
155 	fattr->uid = ntohl(*p++);
156 	fattr->gid = ntohl(*p++);
157 	p = xdr_decode_hyper(p, &fattr->size);
158 	p = xdr_decode_hyper(p, &fattr->du.nfs3.used);
159 
160 	/* Turn remote device info into Linux-specific dev_t */
161 	major = ntohl(*p++);
162 	minor = ntohl(*p++);
163 	fattr->rdev = MKDEV(major, minor);
164 	if (MAJOR(fattr->rdev) != major || MINOR(fattr->rdev) != minor)
165 		fattr->rdev = 0;
166 
167 	p = xdr_decode_hyper(p, &fattr->fsid.major);
168 	fattr->fsid.minor = 0;
169 	p = xdr_decode_hyper(p, &fattr->fileid);
170 	p = xdr_decode_time3(p, &fattr->atime);
171 	p = xdr_decode_time3(p, &fattr->mtime);
172 	p = xdr_decode_time3(p, &fattr->ctime);
173 
174 	/* Update the mode bits */
175 	fattr->valid |= NFS_ATTR_FATTR_V3;
176 	return p;
177 }
178 
179 static inline __be32 *
180 xdr_encode_sattr(__be32 *p, struct iattr *attr)
181 {
182 	if (attr->ia_valid & ATTR_MODE) {
183 		*p++ = xdr_one;
184 		*p++ = htonl(attr->ia_mode & S_IALLUGO);
185 	} else {
186 		*p++ = xdr_zero;
187 	}
188 	if (attr->ia_valid & ATTR_UID) {
189 		*p++ = xdr_one;
190 		*p++ = htonl(attr->ia_uid);
191 	} else {
192 		*p++ = xdr_zero;
193 	}
194 	if (attr->ia_valid & ATTR_GID) {
195 		*p++ = xdr_one;
196 		*p++ = htonl(attr->ia_gid);
197 	} else {
198 		*p++ = xdr_zero;
199 	}
200 	if (attr->ia_valid & ATTR_SIZE) {
201 		*p++ = xdr_one;
202 		p = xdr_encode_hyper(p, (__u64) attr->ia_size);
203 	} else {
204 		*p++ = xdr_zero;
205 	}
206 	if (attr->ia_valid & ATTR_ATIME_SET) {
207 		*p++ = xdr_two;
208 		p = xdr_encode_time3(p, &attr->ia_atime);
209 	} else if (attr->ia_valid & ATTR_ATIME) {
210 		*p++ = xdr_one;
211 	} else {
212 		*p++ = xdr_zero;
213 	}
214 	if (attr->ia_valid & ATTR_MTIME_SET) {
215 		*p++ = xdr_two;
216 		p = xdr_encode_time3(p, &attr->ia_mtime);
217 	} else if (attr->ia_valid & ATTR_MTIME) {
218 		*p++ = xdr_one;
219 	} else {
220 		*p++ = xdr_zero;
221 	}
222 	return p;
223 }
224 
225 static inline __be32 *
226 xdr_decode_wcc_attr(__be32 *p, struct nfs_fattr *fattr)
227 {
228 	p = xdr_decode_hyper(p, &fattr->pre_size);
229 	p = xdr_decode_time3(p, &fattr->pre_mtime);
230 	p = xdr_decode_time3(p, &fattr->pre_ctime);
231 	fattr->valid |= NFS_ATTR_FATTR_PRESIZE
232 		| NFS_ATTR_FATTR_PREMTIME
233 		| NFS_ATTR_FATTR_PRECTIME;
234 	return p;
235 }
236 
237 static inline __be32 *
238 xdr_decode_post_op_attr(__be32 *p, struct nfs_fattr *fattr)
239 {
240 	if (*p++)
241 		p = xdr_decode_fattr(p, fattr);
242 	return p;
243 }
244 
245 static inline __be32 *
246 xdr_decode_pre_op_attr(__be32 *p, struct nfs_fattr *fattr)
247 {
248 	if (*p++)
249 		return xdr_decode_wcc_attr(p, fattr);
250 	return p;
251 }
252 
253 
254 static inline __be32 *
255 xdr_decode_wcc_data(__be32 *p, struct nfs_fattr *fattr)
256 {
257 	p = xdr_decode_pre_op_attr(p, fattr);
258 	return xdr_decode_post_op_attr(p, fattr);
259 }
260 
261 /*
262  * NFS encode functions
263  */
264 
265 /*
266  * Encode file handle argument
267  */
268 static int
269 nfs3_xdr_fhandle(struct rpc_rqst *req, __be32 *p, struct nfs_fh *fh)
270 {
271 	p = xdr_encode_fhandle(p, fh);
272 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
273 	return 0;
274 }
275 
276 /*
277  * Encode SETATTR arguments
278  */
279 static int
280 nfs3_xdr_sattrargs(struct rpc_rqst *req, __be32 *p, struct nfs3_sattrargs *args)
281 {
282 	p = xdr_encode_fhandle(p, args->fh);
283 	p = xdr_encode_sattr(p, args->sattr);
284 	*p++ = htonl(args->guard);
285 	if (args->guard)
286 		p = xdr_encode_time3(p, &args->guardtime);
287 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
288 	return 0;
289 }
290 
291 /*
292  * Encode directory ops argument
293  */
294 static int
295 nfs3_xdr_diropargs(struct rpc_rqst *req, __be32 *p, struct nfs3_diropargs *args)
296 {
297 	p = xdr_encode_fhandle(p, args->fh);
298 	p = xdr_encode_array(p, args->name, args->len);
299 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
300 	return 0;
301 }
302 
303 /*
304  * Encode REMOVE argument
305  */
306 static int
307 nfs3_xdr_removeargs(struct rpc_rqst *req, __be32 *p, const struct nfs_removeargs *args)
308 {
309 	p = xdr_encode_fhandle(p, args->fh);
310 	p = xdr_encode_array(p, args->name.name, args->name.len);
311 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
312 	return 0;
313 }
314 
315 /*
316  * Encode access() argument
317  */
318 static int
319 nfs3_xdr_accessargs(struct rpc_rqst *req, __be32 *p, struct nfs3_accessargs *args)
320 {
321 	p = xdr_encode_fhandle(p, args->fh);
322 	*p++ = htonl(args->access);
323 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
324 	return 0;
325 }
326 
327 /*
328  * Arguments to a READ call. Since we read data directly into the page
329  * cache, we also set up the reply iovec here so that iov[1] points
330  * exactly to the page we want to fetch.
331  */
332 static int
333 nfs3_xdr_readargs(struct rpc_rqst *req, __be32 *p, struct nfs_readargs *args)
334 {
335 	struct rpc_auth	*auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
336 	unsigned int replen;
337 	u32 count = args->count;
338 
339 	p = xdr_encode_fhandle(p, args->fh);
340 	p = xdr_encode_hyper(p, args->offset);
341 	*p++ = htonl(count);
342 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
343 
344 	/* Inline the page array */
345 	replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS3_readres_sz) << 2;
346 	xdr_inline_pages(&req->rq_rcv_buf, replen,
347 			 args->pages, args->pgbase, count);
348 	req->rq_rcv_buf.flags |= XDRBUF_READ;
349 	return 0;
350 }
351 
352 /*
353  * Write arguments. Splice the buffer to be written into the iovec.
354  */
355 static int
356 nfs3_xdr_writeargs(struct rpc_rqst *req, __be32 *p, struct nfs_writeargs *args)
357 {
358 	struct xdr_buf *sndbuf = &req->rq_snd_buf;
359 	u32 count = args->count;
360 
361 	p = xdr_encode_fhandle(p, args->fh);
362 	p = xdr_encode_hyper(p, args->offset);
363 	*p++ = htonl(count);
364 	*p++ = htonl(args->stable);
365 	*p++ = htonl(count);
366 	sndbuf->len = xdr_adjust_iovec(sndbuf->head, p);
367 
368 	/* Copy the page array */
369 	xdr_encode_pages(sndbuf, args->pages, args->pgbase, count);
370 	sndbuf->flags |= XDRBUF_WRITE;
371 	return 0;
372 }
373 
374 /*
375  * Encode CREATE arguments
376  */
377 static int
378 nfs3_xdr_createargs(struct rpc_rqst *req, __be32 *p, struct nfs3_createargs *args)
379 {
380 	p = xdr_encode_fhandle(p, args->fh);
381 	p = xdr_encode_array(p, args->name, args->len);
382 
383 	*p++ = htonl(args->createmode);
384 	if (args->createmode == NFS3_CREATE_EXCLUSIVE) {
385 		*p++ = args->verifier[0];
386 		*p++ = args->verifier[1];
387 	} else
388 		p = xdr_encode_sattr(p, args->sattr);
389 
390 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
391 	return 0;
392 }
393 
394 /*
395  * Encode MKDIR arguments
396  */
397 static int
398 nfs3_xdr_mkdirargs(struct rpc_rqst *req, __be32 *p, struct nfs3_mkdirargs *args)
399 {
400 	p = xdr_encode_fhandle(p, args->fh);
401 	p = xdr_encode_array(p, args->name, args->len);
402 	p = xdr_encode_sattr(p, args->sattr);
403 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
404 	return 0;
405 }
406 
407 /*
408  * Encode SYMLINK arguments
409  */
410 static int
411 nfs3_xdr_symlinkargs(struct rpc_rqst *req, __be32 *p, struct nfs3_symlinkargs *args)
412 {
413 	p = xdr_encode_fhandle(p, args->fromfh);
414 	p = xdr_encode_array(p, args->fromname, args->fromlen);
415 	p = xdr_encode_sattr(p, args->sattr);
416 	*p++ = htonl(args->pathlen);
417 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
418 
419 	/* Copy the page */
420 	xdr_encode_pages(&req->rq_snd_buf, args->pages, 0, args->pathlen);
421 	return 0;
422 }
423 
424 /*
425  * Encode MKNOD arguments
426  */
427 static int
428 nfs3_xdr_mknodargs(struct rpc_rqst *req, __be32 *p, struct nfs3_mknodargs *args)
429 {
430 	p = xdr_encode_fhandle(p, args->fh);
431 	p = xdr_encode_array(p, args->name, args->len);
432 	*p++ = htonl(args->type);
433 	p = xdr_encode_sattr(p, args->sattr);
434 	if (args->type == NF3CHR || args->type == NF3BLK) {
435 		*p++ = htonl(MAJOR(args->rdev));
436 		*p++ = htonl(MINOR(args->rdev));
437 	}
438 
439 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
440 	return 0;
441 }
442 
443 /*
444  * Encode RENAME arguments
445  */
446 static int
447 nfs3_xdr_renameargs(struct rpc_rqst *req, __be32 *p, struct nfs3_renameargs *args)
448 {
449 	p = xdr_encode_fhandle(p, args->fromfh);
450 	p = xdr_encode_array(p, args->fromname, args->fromlen);
451 	p = xdr_encode_fhandle(p, args->tofh);
452 	p = xdr_encode_array(p, args->toname, args->tolen);
453 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
454 	return 0;
455 }
456 
457 /*
458  * Encode LINK arguments
459  */
460 static int
461 nfs3_xdr_linkargs(struct rpc_rqst *req, __be32 *p, struct nfs3_linkargs *args)
462 {
463 	p = xdr_encode_fhandle(p, args->fromfh);
464 	p = xdr_encode_fhandle(p, args->tofh);
465 	p = xdr_encode_array(p, args->toname, args->tolen);
466 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
467 	return 0;
468 }
469 
470 /*
471  * Encode arguments to readdir call
472  */
473 static int
474 nfs3_xdr_readdirargs(struct rpc_rqst *req, __be32 *p, struct nfs3_readdirargs *args)
475 {
476 	struct rpc_auth	*auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
477 	unsigned int replen;
478 	u32 count = args->count;
479 
480 	p = xdr_encode_fhandle(p, args->fh);
481 	p = xdr_encode_hyper(p, args->cookie);
482 	*p++ = args->verf[0];
483 	*p++ = args->verf[1];
484 	if (args->plus) {
485 		/* readdirplus: need dircount + buffer size.
486 		 * We just make sure we make dircount big enough */
487 		*p++ = htonl(count >> 3);
488 	}
489 	*p++ = htonl(count);
490 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
491 
492 	/* Inline the page array */
493 	replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS3_readdirres_sz) << 2;
494 	xdr_inline_pages(&req->rq_rcv_buf, replen, args->pages, 0, count);
495 	return 0;
496 }
497 
498 /*
499  * Decode the result of a readdir call.
500  * We just check for syntactical correctness.
501  */
502 static int
503 nfs3_xdr_readdirres(struct rpc_rqst *req, __be32 *p, struct nfs3_readdirres *res)
504 {
505 	struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
506 	struct kvec *iov = rcvbuf->head;
507 	struct page **page;
508 	size_t hdrlen;
509 	u32 len, recvd, pglen;
510 	int status, nr = 0;
511 	__be32 *entry, *end, *kaddr;
512 
513 	status = ntohl(*p++);
514 	/* Decode post_op_attrs */
515 	p = xdr_decode_post_op_attr(p, res->dir_attr);
516 	if (status)
517 		return nfs_stat_to_errno(status);
518 	/* Decode verifier cookie */
519 	if (res->verf) {
520 		res->verf[0] = *p++;
521 		res->verf[1] = *p++;
522 	} else {
523 		p += 2;
524 	}
525 
526 	hdrlen = (u8 *) p - (u8 *) iov->iov_base;
527 	if (iov->iov_len < hdrlen) {
528 		dprintk("NFS: READDIR reply header overflowed:"
529 				"length %Zu > %Zu\n", hdrlen, iov->iov_len);
530 		return -errno_NFSERR_IO;
531 	} else if (iov->iov_len != hdrlen) {
532 		dprintk("NFS: READDIR header is short. iovec will be shifted.\n");
533 		xdr_shift_buf(rcvbuf, iov->iov_len - hdrlen);
534 	}
535 
536 	pglen = rcvbuf->page_len;
537 	recvd = rcvbuf->len - hdrlen;
538 	if (pglen > recvd)
539 		pglen = recvd;
540 	page = rcvbuf->pages;
541 	kaddr = p = kmap_atomic(*page, KM_USER0);
542 	end = (__be32 *)((char *)p + pglen);
543 	entry = p;
544 
545 	/* Make sure the packet actually has a value_follows and EOF entry */
546 	if ((entry + 1) > end)
547 		goto short_pkt;
548 
549 	for (; *p++; nr++) {
550 		if (p + 3 > end)
551 			goto short_pkt;
552 		p += 2;				/* inode # */
553 		len = ntohl(*p++);		/* string length */
554 		p += XDR_QUADLEN(len) + 2;	/* name + cookie */
555 		if (len > NFS3_MAXNAMLEN) {
556 			dprintk("NFS: giant filename in readdir (len 0x%x)!\n",
557 						len);
558 			goto err_unmap;
559 		}
560 
561 		if (res->plus) {
562 			/* post_op_attr */
563 			if (p + 2 > end)
564 				goto short_pkt;
565 			if (*p++) {
566 				p += 21;
567 				if (p + 1 > end)
568 					goto short_pkt;
569 			}
570 			/* post_op_fh3 */
571 			if (*p++) {
572 				if (p + 1 > end)
573 					goto short_pkt;
574 				len = ntohl(*p++);
575 				if (len > NFS3_FHSIZE) {
576 					dprintk("NFS: giant filehandle in "
577 						"readdir (len 0x%x)!\n", len);
578 					goto err_unmap;
579 				}
580 				p += XDR_QUADLEN(len);
581 			}
582 		}
583 
584 		if (p + 2 > end)
585 			goto short_pkt;
586 		entry = p;
587 	}
588 
589 	/*
590 	 * Apparently some server sends responses that are a valid size, but
591 	 * contain no entries, and have value_follows==0 and EOF==0. For
592 	 * those, just set the EOF marker.
593 	 */
594 	if (!nr && entry[1] == 0) {
595 		dprintk("NFS: readdir reply truncated!\n");
596 		entry[1] = 1;
597 	}
598  out:
599 	kunmap_atomic(kaddr, KM_USER0);
600 	return nr;
601  short_pkt:
602 	/*
603 	 * When we get a short packet there are 2 possibilities. We can
604 	 * return an error, or fix up the response to look like a valid
605 	 * response and return what we have so far. If there are no
606 	 * entries and the packet was short, then return -EIO. If there
607 	 * are valid entries in the response, return them and pretend that
608 	 * the call was successful, but incomplete. The caller can retry the
609 	 * readdir starting at the last cookie.
610 	 */
611 	entry[0] = entry[1] = 0;
612 	if (!nr)
613 		nr = -errno_NFSERR_IO;
614 	goto out;
615 err_unmap:
616 	nr = -errno_NFSERR_IO;
617 	goto out;
618 }
619 
620 __be32 *
621 nfs3_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
622 {
623 	struct nfs_entry old = *entry;
624 
625 	if (!*p++) {
626 		if (!*p)
627 			return ERR_PTR(-EAGAIN);
628 		entry->eof = 1;
629 		return ERR_PTR(-EBADCOOKIE);
630 	}
631 
632 	p = xdr_decode_hyper(p, &entry->ino);
633 	entry->len  = ntohl(*p++);
634 	entry->name = (const char *) p;
635 	p += XDR_QUADLEN(entry->len);
636 	entry->prev_cookie = entry->cookie;
637 	p = xdr_decode_hyper(p, &entry->cookie);
638 
639 	if (plus) {
640 		entry->fattr->valid = 0;
641 		p = xdr_decode_post_op_attr(p, entry->fattr);
642 		/* In fact, a post_op_fh3: */
643 		if (*p++) {
644 			p = xdr_decode_fhandle(p, entry->fh);
645 			/* Ugh -- server reply was truncated */
646 			if (p == NULL) {
647 				dprintk("NFS: FH truncated\n");
648 				*entry = old;
649 				return ERR_PTR(-EAGAIN);
650 			}
651 		} else
652 			memset((u8*)(entry->fh), 0, sizeof(*entry->fh));
653 	}
654 
655 	entry->eof = !p[0] && p[1];
656 	return p;
657 }
658 
659 /*
660  * Encode COMMIT arguments
661  */
662 static int
663 nfs3_xdr_commitargs(struct rpc_rqst *req, __be32 *p, struct nfs_writeargs *args)
664 {
665 	p = xdr_encode_fhandle(p, args->fh);
666 	p = xdr_encode_hyper(p, args->offset);
667 	*p++ = htonl(args->count);
668 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
669 	return 0;
670 }
671 
672 #ifdef CONFIG_NFS_V3_ACL
673 /*
674  * Encode GETACL arguments
675  */
676 static int
677 nfs3_xdr_getaclargs(struct rpc_rqst *req, __be32 *p,
678 		    struct nfs3_getaclargs *args)
679 {
680 	struct rpc_auth	*auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
681 	unsigned int replen;
682 
683 	p = xdr_encode_fhandle(p, args->fh);
684 	*p++ = htonl(args->mask);
685 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
686 
687 	if (args->mask & (NFS_ACL | NFS_DFACL)) {
688 		/* Inline the page array */
689 		replen = (RPC_REPHDRSIZE + auth->au_rslack +
690 			  ACL3_getaclres_sz) << 2;
691 		xdr_inline_pages(&req->rq_rcv_buf, replen, args->pages, 0,
692 				 NFSACL_MAXPAGES << PAGE_SHIFT);
693 	}
694 	return 0;
695 }
696 
697 /*
698  * Encode SETACL arguments
699  */
700 static int
701 nfs3_xdr_setaclargs(struct rpc_rqst *req, __be32 *p,
702                    struct nfs3_setaclargs *args)
703 {
704 	struct xdr_buf *buf = &req->rq_snd_buf;
705 	unsigned int base;
706 	int err;
707 
708 	p = xdr_encode_fhandle(p, NFS_FH(args->inode));
709 	*p++ = htonl(args->mask);
710 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
711 	base = req->rq_slen;
712 
713 	if (args->npages != 0)
714 		xdr_encode_pages(buf, args->pages, 0, args->len);
715 	else
716 		req->rq_slen += args->len;
717 
718 	err = nfsacl_encode(buf, base, args->inode,
719 			    (args->mask & NFS_ACL) ?
720 			    args->acl_access : NULL, 1, 0);
721 	if (err > 0)
722 		err = nfsacl_encode(buf, base + err, args->inode,
723 				    (args->mask & NFS_DFACL) ?
724 				    args->acl_default : NULL, 1,
725 				    NFS_ACL_DEFAULT);
726 	return (err > 0) ? 0 : err;
727 }
728 #endif  /* CONFIG_NFS_V3_ACL */
729 
730 /*
731  * NFS XDR decode functions
732  */
733 
734 /*
735  * Decode attrstat reply.
736  */
737 static int
738 nfs3_xdr_attrstat(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)
739 {
740 	int	status;
741 
742 	if ((status = ntohl(*p++)))
743 		return nfs_stat_to_errno(status);
744 	xdr_decode_fattr(p, fattr);
745 	return 0;
746 }
747 
748 /*
749  * Decode status+wcc_data reply
750  * SATTR, REMOVE, RMDIR
751  */
752 static int
753 nfs3_xdr_wccstat(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)
754 {
755 	int	status;
756 
757 	if ((status = ntohl(*p++)))
758 		status = nfs_stat_to_errno(status);
759 	xdr_decode_wcc_data(p, fattr);
760 	return status;
761 }
762 
763 static int
764 nfs3_xdr_removeres(struct rpc_rqst *req, __be32 *p, struct nfs_removeres *res)
765 {
766 	return nfs3_xdr_wccstat(req, p, &res->dir_attr);
767 }
768 
769 /*
770  * Decode LOOKUP reply
771  */
772 static int
773 nfs3_xdr_lookupres(struct rpc_rqst *req, __be32 *p, struct nfs3_diropres *res)
774 {
775 	int	status;
776 
777 	if ((status = ntohl(*p++))) {
778 		status = nfs_stat_to_errno(status);
779 	} else {
780 		if (!(p = xdr_decode_fhandle(p, res->fh)))
781 			return -errno_NFSERR_IO;
782 		p = xdr_decode_post_op_attr(p, res->fattr);
783 	}
784 	xdr_decode_post_op_attr(p, res->dir_attr);
785 	return status;
786 }
787 
788 /*
789  * Decode ACCESS reply
790  */
791 static int
792 nfs3_xdr_accessres(struct rpc_rqst *req, __be32 *p, struct nfs3_accessres *res)
793 {
794 	int	status = ntohl(*p++);
795 
796 	p = xdr_decode_post_op_attr(p, res->fattr);
797 	if (status)
798 		return nfs_stat_to_errno(status);
799 	res->access = ntohl(*p++);
800 	return 0;
801 }
802 
803 static int
804 nfs3_xdr_readlinkargs(struct rpc_rqst *req, __be32 *p, struct nfs3_readlinkargs *args)
805 {
806 	struct rpc_auth	*auth = req->rq_task->tk_msg.rpc_cred->cr_auth;
807 	unsigned int replen;
808 
809 	p = xdr_encode_fhandle(p, args->fh);
810 	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
811 
812 	/* Inline the page array */
813 	replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS3_readlinkres_sz) << 2;
814 	xdr_inline_pages(&req->rq_rcv_buf, replen, args->pages, args->pgbase, args->pglen);
815 	return 0;
816 }
817 
818 /*
819  * Decode READLINK reply
820  */
821 static int
822 nfs3_xdr_readlinkres(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)
823 {
824 	struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
825 	struct kvec *iov = rcvbuf->head;
826 	size_t hdrlen;
827 	u32 len, recvd;
828 	char	*kaddr;
829 	int	status;
830 
831 	status = ntohl(*p++);
832 	p = xdr_decode_post_op_attr(p, fattr);
833 
834 	if (status != 0)
835 		return nfs_stat_to_errno(status);
836 
837 	/* Convert length of symlink */
838 	len = ntohl(*p++);
839 	if (len >= rcvbuf->page_len) {
840 		dprintk("nfs: server returned giant symlink!\n");
841 		return -ENAMETOOLONG;
842 	}
843 
844 	hdrlen = (u8 *) p - (u8 *) iov->iov_base;
845 	if (iov->iov_len < hdrlen) {
846 		dprintk("NFS: READLINK reply header overflowed:"
847 				"length %Zu > %Zu\n", hdrlen, iov->iov_len);
848 		return -errno_NFSERR_IO;
849 	} else if (iov->iov_len != hdrlen) {
850 		dprintk("NFS: READLINK header is short. "
851 			"iovec will be shifted.\n");
852 		xdr_shift_buf(rcvbuf, iov->iov_len - hdrlen);
853 	}
854 	recvd = req->rq_rcv_buf.len - hdrlen;
855 	if (recvd < len) {
856 		dprintk("NFS: server cheating in readlink reply: "
857 				"count %u > recvd %u\n", len, recvd);
858 		return -EIO;
859 	}
860 
861 	/* NULL terminate the string we got */
862 	kaddr = (char*)kmap_atomic(rcvbuf->pages[0], KM_USER0);
863 	kaddr[len+rcvbuf->page_base] = '\0';
864 	kunmap_atomic(kaddr, KM_USER0);
865 	return 0;
866 }
867 
868 /*
869  * Decode READ reply
870  */
871 static int
872 nfs3_xdr_readres(struct rpc_rqst *req, __be32 *p, struct nfs_readres *res)
873 {
874 	struct kvec *iov = req->rq_rcv_buf.head;
875 	size_t hdrlen;
876 	u32 count, ocount, recvd;
877 	int status;
878 
879 	status = ntohl(*p++);
880 	p = xdr_decode_post_op_attr(p, res->fattr);
881 
882 	if (status != 0)
883 		return nfs_stat_to_errno(status);
884 
885 	/* Decode reply count and EOF flag. NFSv3 is somewhat redundant
886 	 * in that it puts the count both in the res struct and in the
887 	 * opaque data count. */
888 	count    = ntohl(*p++);
889 	res->eof = ntohl(*p++);
890 	ocount   = ntohl(*p++);
891 
892 	if (ocount != count) {
893 		dprintk("NFS: READ count doesn't match RPC opaque count.\n");
894 		return -errno_NFSERR_IO;
895 	}
896 
897 	hdrlen = (u8 *) p - (u8 *) iov->iov_base;
898 	if (iov->iov_len < hdrlen) {
899 		dprintk("NFS: READ reply header overflowed:"
900 				"length %Zu > %Zu\n", hdrlen, iov->iov_len);
901        		return -errno_NFSERR_IO;
902 	} else if (iov->iov_len != hdrlen) {
903 		dprintk("NFS: READ header is short. iovec will be shifted.\n");
904 		xdr_shift_buf(&req->rq_rcv_buf, iov->iov_len - hdrlen);
905 	}
906 
907 	recvd = req->rq_rcv_buf.len - hdrlen;
908 	if (count > recvd) {
909 		dprintk("NFS: server cheating in read reply: "
910 			"count %u > recvd %u\n", count, recvd);
911 		count = recvd;
912 		res->eof = 0;
913 	}
914 
915 	if (count < res->count)
916 		res->count = count;
917 
918 	return count;
919 }
920 
921 /*
922  * Decode WRITE response
923  */
924 static int
925 nfs3_xdr_writeres(struct rpc_rqst *req, __be32 *p, struct nfs_writeres *res)
926 {
927 	int	status;
928 
929 	status = ntohl(*p++);
930 	p = xdr_decode_wcc_data(p, res->fattr);
931 
932 	if (status != 0)
933 		return nfs_stat_to_errno(status);
934 
935 	res->count = ntohl(*p++);
936 	res->verf->committed = (enum nfs3_stable_how)ntohl(*p++);
937 	res->verf->verifier[0] = *p++;
938 	res->verf->verifier[1] = *p++;
939 
940 	return res->count;
941 }
942 
943 /*
944  * Decode a CREATE response
945  */
946 static int
947 nfs3_xdr_createres(struct rpc_rqst *req, __be32 *p, struct nfs3_diropres *res)
948 {
949 	int	status;
950 
951 	status = ntohl(*p++);
952 	if (status == 0) {
953 		if (*p++) {
954 			if (!(p = xdr_decode_fhandle(p, res->fh)))
955 				return -errno_NFSERR_IO;
956 			p = xdr_decode_post_op_attr(p, res->fattr);
957 		} else {
958 			memset(res->fh, 0, sizeof(*res->fh));
959 			/* Do decode post_op_attr but set it to NULL */
960 			p = xdr_decode_post_op_attr(p, res->fattr);
961 			res->fattr->valid = 0;
962 		}
963 	} else {
964 		status = nfs_stat_to_errno(status);
965 	}
966 	p = xdr_decode_wcc_data(p, res->dir_attr);
967 	return status;
968 }
969 
970 /*
971  * Decode RENAME reply
972  */
973 static int
974 nfs3_xdr_renameres(struct rpc_rqst *req, __be32 *p, struct nfs3_renameres *res)
975 {
976 	int	status;
977 
978 	if ((status = ntohl(*p++)) != 0)
979 		status = nfs_stat_to_errno(status);
980 	p = xdr_decode_wcc_data(p, res->fromattr);
981 	p = xdr_decode_wcc_data(p, res->toattr);
982 	return status;
983 }
984 
985 /*
986  * Decode LINK reply
987  */
988 static int
989 nfs3_xdr_linkres(struct rpc_rqst *req, __be32 *p, struct nfs3_linkres *res)
990 {
991 	int	status;
992 
993 	if ((status = ntohl(*p++)) != 0)
994 		status = nfs_stat_to_errno(status);
995 	p = xdr_decode_post_op_attr(p, res->fattr);
996 	p = xdr_decode_wcc_data(p, res->dir_attr);
997 	return status;
998 }
999 
1000 /*
1001  * Decode FSSTAT reply
1002  */
1003 static int
1004 nfs3_xdr_fsstatres(struct rpc_rqst *req, __be32 *p, struct nfs_fsstat *res)
1005 {
1006 	int		status;
1007 
1008 	status = ntohl(*p++);
1009 
1010 	p = xdr_decode_post_op_attr(p, res->fattr);
1011 	if (status != 0)
1012 		return nfs_stat_to_errno(status);
1013 
1014 	p = xdr_decode_hyper(p, &res->tbytes);
1015 	p = xdr_decode_hyper(p, &res->fbytes);
1016 	p = xdr_decode_hyper(p, &res->abytes);
1017 	p = xdr_decode_hyper(p, &res->tfiles);
1018 	p = xdr_decode_hyper(p, &res->ffiles);
1019 	p = xdr_decode_hyper(p, &res->afiles);
1020 
1021 	/* ignore invarsec */
1022 	return 0;
1023 }
1024 
1025 /*
1026  * Decode FSINFO reply
1027  */
1028 static int
1029 nfs3_xdr_fsinfores(struct rpc_rqst *req, __be32 *p, struct nfs_fsinfo *res)
1030 {
1031 	int		status;
1032 
1033 	status = ntohl(*p++);
1034 
1035 	p = xdr_decode_post_op_attr(p, res->fattr);
1036 	if (status != 0)
1037 		return nfs_stat_to_errno(status);
1038 
1039 	res->rtmax  = ntohl(*p++);
1040 	res->rtpref = ntohl(*p++);
1041 	res->rtmult = ntohl(*p++);
1042 	res->wtmax  = ntohl(*p++);
1043 	res->wtpref = ntohl(*p++);
1044 	res->wtmult = ntohl(*p++);
1045 	res->dtpref = ntohl(*p++);
1046 	p = xdr_decode_hyper(p, &res->maxfilesize);
1047 
1048 	/* ignore time_delta and properties */
1049 	res->lease_time = 0;
1050 	return 0;
1051 }
1052 
1053 /*
1054  * Decode PATHCONF reply
1055  */
1056 static int
1057 nfs3_xdr_pathconfres(struct rpc_rqst *req, __be32 *p, struct nfs_pathconf *res)
1058 {
1059 	int		status;
1060 
1061 	status = ntohl(*p++);
1062 
1063 	p = xdr_decode_post_op_attr(p, res->fattr);
1064 	if (status != 0)
1065 		return nfs_stat_to_errno(status);
1066 	res->max_link = ntohl(*p++);
1067 	res->max_namelen = ntohl(*p++);
1068 
1069 	/* ignore remaining fields */
1070 	return 0;
1071 }
1072 
1073 /*
1074  * Decode COMMIT reply
1075  */
1076 static int
1077 nfs3_xdr_commitres(struct rpc_rqst *req, __be32 *p, struct nfs_writeres *res)
1078 {
1079 	int		status;
1080 
1081 	status = ntohl(*p++);
1082 	p = xdr_decode_wcc_data(p, res->fattr);
1083 	if (status != 0)
1084 		return nfs_stat_to_errno(status);
1085 
1086 	res->verf->verifier[0] = *p++;
1087 	res->verf->verifier[1] = *p++;
1088 	return 0;
1089 }
1090 
1091 #ifdef CONFIG_NFS_V3_ACL
1092 /*
1093  * Decode GETACL reply
1094  */
1095 static int
1096 nfs3_xdr_getaclres(struct rpc_rqst *req, __be32 *p,
1097 		   struct nfs3_getaclres *res)
1098 {
1099 	struct xdr_buf *buf = &req->rq_rcv_buf;
1100 	int status = ntohl(*p++);
1101 	struct posix_acl **acl;
1102 	unsigned int *aclcnt;
1103 	int err, base;
1104 
1105 	if (status != 0)
1106 		return nfs_stat_to_errno(status);
1107 	p = xdr_decode_post_op_attr(p, res->fattr);
1108 	res->mask = ntohl(*p++);
1109 	if (res->mask & ~(NFS_ACL|NFS_ACLCNT|NFS_DFACL|NFS_DFACLCNT))
1110 		return -EINVAL;
1111 	base = (char *)p - (char *)req->rq_rcv_buf.head->iov_base;
1112 
1113 	acl = (res->mask & NFS_ACL) ? &res->acl_access : NULL;
1114 	aclcnt = (res->mask & NFS_ACLCNT) ? &res->acl_access_count : NULL;
1115 	err = nfsacl_decode(buf, base, aclcnt, acl);
1116 
1117 	acl = (res->mask & NFS_DFACL) ? &res->acl_default : NULL;
1118 	aclcnt = (res->mask & NFS_DFACLCNT) ? &res->acl_default_count : NULL;
1119 	if (err > 0)
1120 		err = nfsacl_decode(buf, base + err, aclcnt, acl);
1121 	return (err > 0) ? 0 : err;
1122 }
1123 
1124 /*
1125  * Decode setacl reply.
1126  */
1127 static int
1128 nfs3_xdr_setaclres(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)
1129 {
1130 	int status = ntohl(*p++);
1131 
1132 	if (status)
1133 		return nfs_stat_to_errno(status);
1134 	xdr_decode_post_op_attr(p, fattr);
1135 	return 0;
1136 }
1137 #endif  /* CONFIG_NFS_V3_ACL */
1138 
1139 #define PROC(proc, argtype, restype, timer)				\
1140 [NFS3PROC_##proc] = {							\
1141 	.p_proc      = NFS3PROC_##proc,					\
1142 	.p_encode    = (kxdrproc_t) nfs3_xdr_##argtype,			\
1143 	.p_decode    = (kxdrproc_t) nfs3_xdr_##restype,			\
1144 	.p_arglen    = NFS3_##argtype##_sz,				\
1145 	.p_replen    = NFS3_##restype##_sz,				\
1146 	.p_timer     = timer,						\
1147 	.p_statidx   = NFS3PROC_##proc,					\
1148 	.p_name      = #proc,						\
1149 	}
1150 
1151 struct rpc_procinfo	nfs3_procedures[] = {
1152   PROC(GETATTR,		fhandle,	attrstat, 1),
1153   PROC(SETATTR, 	sattrargs,	wccstat, 0),
1154   PROC(LOOKUP,		diropargs,	lookupres, 2),
1155   PROC(ACCESS,		accessargs,	accessres, 1),
1156   PROC(READLINK,	readlinkargs,	readlinkres, 3),
1157   PROC(READ,		readargs,	readres, 3),
1158   PROC(WRITE,		writeargs,	writeres, 4),
1159   PROC(CREATE,		createargs,	createres, 0),
1160   PROC(MKDIR,		mkdirargs,	createres, 0),
1161   PROC(SYMLINK,		symlinkargs,	createres, 0),
1162   PROC(MKNOD,		mknodargs,	createres, 0),
1163   PROC(REMOVE,		removeargs,	removeres, 0),
1164   PROC(RMDIR,		diropargs,	wccstat, 0),
1165   PROC(RENAME,		renameargs,	renameres, 0),
1166   PROC(LINK,		linkargs,	linkres, 0),
1167   PROC(READDIR,		readdirargs,	readdirres, 3),
1168   PROC(READDIRPLUS,	readdirargs,	readdirres, 3),
1169   PROC(FSSTAT,		fhandle,	fsstatres, 0),
1170   PROC(FSINFO,  	fhandle,	fsinfores, 0),
1171   PROC(PATHCONF,	fhandle,	pathconfres, 0),
1172   PROC(COMMIT,		commitargs,	commitres, 5),
1173 };
1174 
1175 struct rpc_version		nfs_version3 = {
1176 	.number			= 3,
1177 	.nrprocs		= ARRAY_SIZE(nfs3_procedures),
1178 	.procs			= nfs3_procedures
1179 };
1180 
1181 #ifdef CONFIG_NFS_V3_ACL
1182 static struct rpc_procinfo	nfs3_acl_procedures[] = {
1183 	[ACLPROC3_GETACL] = {
1184 		.p_proc = ACLPROC3_GETACL,
1185 		.p_encode = (kxdrproc_t) nfs3_xdr_getaclargs,
1186 		.p_decode = (kxdrproc_t) nfs3_xdr_getaclres,
1187 		.p_arglen = ACL3_getaclargs_sz,
1188 		.p_replen = ACL3_getaclres_sz,
1189 		.p_timer = 1,
1190 		.p_name = "GETACL",
1191 	},
1192 	[ACLPROC3_SETACL] = {
1193 		.p_proc = ACLPROC3_SETACL,
1194 		.p_encode = (kxdrproc_t) nfs3_xdr_setaclargs,
1195 		.p_decode = (kxdrproc_t) nfs3_xdr_setaclres,
1196 		.p_arglen = ACL3_setaclargs_sz,
1197 		.p_replen = ACL3_setaclres_sz,
1198 		.p_timer = 0,
1199 		.p_name = "SETACL",
1200 	},
1201 };
1202 
1203 struct rpc_version		nfsacl_version3 = {
1204 	.number			= 3,
1205 	.nrprocs		= sizeof(nfs3_acl_procedures)/
1206 				  sizeof(nfs3_acl_procedures[0]),
1207 	.procs			= nfs3_acl_procedures,
1208 };
1209 #endif  /* CONFIG_NFS_V3_ACL */
1210