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v4.6
   1/*
   2 * linux/fs/nfs/nfs2xdr.c
   3 *
   4 * XDR functions to encode/decode NFS RPC arguments and results.
   5 *
   6 * Copyright (C) 1992, 1993, 1994  Rick Sladkey
   7 * Copyright (C) 1996 Olaf Kirch
   8 * 04 Aug 1998  Ion Badulescu <ionut@cs.columbia.edu>
   9 * 		FIFO's need special handling in NFSv2
  10 */
  11
  12#include <linux/param.h>
  13#include <linux/time.h>
  14#include <linux/mm.h>
  15#include <linux/errno.h>
  16#include <linux/string.h>
  17#include <linux/in.h>
  18#include <linux/pagemap.h>
  19#include <linux/proc_fs.h>
  20#include <linux/sunrpc/clnt.h>
  21#include <linux/nfs.h>
  22#include <linux/nfs2.h>
  23#include <linux/nfs_fs.h>
  24#include "internal.h"
  25
  26#define NFSDBG_FACILITY		NFSDBG_XDR
  27
  28/* Mapping from NFS error code to "errno" error code. */
  29#define errno_NFSERR_IO		EIO
  30
  31/*
  32 * Declare the space requirements for NFS arguments and replies as
  33 * number of 32bit-words
  34 */
  35#define NFS_fhandle_sz		(8)
  36#define NFS_sattr_sz		(8)
  37#define NFS_filename_sz		(1+(NFS2_MAXNAMLEN>>2))
  38#define NFS_path_sz		(1+(NFS2_MAXPATHLEN>>2))
  39#define NFS_fattr_sz		(17)
  40#define NFS_info_sz		(5)
  41#define NFS_entry_sz		(NFS_filename_sz+3)
  42
  43#define NFS_diropargs_sz	(NFS_fhandle_sz+NFS_filename_sz)
  44#define NFS_removeargs_sz	(NFS_fhandle_sz+NFS_filename_sz)
  45#define NFS_sattrargs_sz	(NFS_fhandle_sz+NFS_sattr_sz)
  46#define NFS_readlinkargs_sz	(NFS_fhandle_sz)
  47#define NFS_readargs_sz		(NFS_fhandle_sz+3)
  48#define NFS_writeargs_sz	(NFS_fhandle_sz+4)
  49#define NFS_createargs_sz	(NFS_diropargs_sz+NFS_sattr_sz)
  50#define NFS_renameargs_sz	(NFS_diropargs_sz+NFS_diropargs_sz)
  51#define NFS_linkargs_sz		(NFS_fhandle_sz+NFS_diropargs_sz)
  52#define NFS_symlinkargs_sz	(NFS_diropargs_sz+1+NFS_sattr_sz)
  53#define NFS_readdirargs_sz	(NFS_fhandle_sz+2)
  54
  55#define NFS_attrstat_sz		(1+NFS_fattr_sz)
  56#define NFS_diropres_sz		(1+NFS_fhandle_sz+NFS_fattr_sz)
  57#define NFS_readlinkres_sz	(2)
  58#define NFS_readres_sz		(1+NFS_fattr_sz+1)
  59#define NFS_writeres_sz         (NFS_attrstat_sz)
  60#define NFS_stat_sz		(1)
  61#define NFS_readdirres_sz	(1)
  62#define NFS_statfsres_sz	(1+NFS_info_sz)
  63
  64static int nfs_stat_to_errno(enum nfs_stat);
  65
  66/*
  67 * While encoding arguments, set up the reply buffer in advance to
  68 * receive reply data directly into the page cache.
  69 */
  70static void prepare_reply_buffer(struct rpc_rqst *req, struct page **pages,
  71				 unsigned int base, unsigned int len,
  72				 unsigned int bufsize)
  73{
  74	struct rpc_auth	*auth = req->rq_cred->cr_auth;
  75	unsigned int replen;
  76
  77	replen = RPC_REPHDRSIZE + auth->au_rslack + bufsize;
  78	xdr_inline_pages(&req->rq_rcv_buf, replen << 2, pages, base, len);
  79}
  80
  81/*
  82 * Handle decode buffer overflows out-of-line.
  83 */
  84static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
  85{
  86	dprintk("NFS: %s prematurely hit the end of our receive buffer. "
  87		"Remaining buffer length is %tu words.\n",
  88		func, xdr->end - xdr->p);
  89}
  90
  91
  92/*
  93 * Encode/decode NFSv2 basic data types
  94 *
  95 * Basic NFSv2 data types are defined in section 2.3 of RFC 1094:
  96 * "NFS: Network File System Protocol Specification".
  97 *
  98 * Not all basic data types have their own encoding and decoding
  99 * functions.  For run-time efficiency, some data types are encoded
 100 * or decoded inline.
 101 */
 102
 103/*
 104 *	typedef opaque	nfsdata<>;
 105 */
 106static int decode_nfsdata(struct xdr_stream *xdr, struct nfs_pgio_res *result)
 107{
 108	u32 recvd, count;
 109	__be32 *p;
 110
 111	p = xdr_inline_decode(xdr, 4);
 112	if (unlikely(p == NULL))
 113		goto out_overflow;
 114	count = be32_to_cpup(p);
 115	recvd = xdr_read_pages(xdr, count);
 116	if (unlikely(count > recvd))
 117		goto out_cheating;
 118out:
 119	result->eof = 0;	/* NFSv2 does not pass EOF flag on the wire. */
 120	result->count = count;
 121	return count;
 122out_cheating:
 123	dprintk("NFS: server cheating in read result: "
 124		"count %u > recvd %u\n", count, recvd);
 125	count = recvd;
 126	goto out;
 127out_overflow:
 128	print_overflow_msg(__func__, xdr);
 129	return -EIO;
 130}
 131
 132/*
 133 *	enum stat {
 134 *		NFS_OK = 0,
 135 *		NFSERR_PERM = 1,
 136 *		NFSERR_NOENT = 2,
 137 *		NFSERR_IO = 5,
 138 *		NFSERR_NXIO = 6,
 139 *		NFSERR_ACCES = 13,
 140 *		NFSERR_EXIST = 17,
 141 *		NFSERR_NODEV = 19,
 142 *		NFSERR_NOTDIR = 20,
 143 *		NFSERR_ISDIR = 21,
 144 *		NFSERR_FBIG = 27,
 145 *		NFSERR_NOSPC = 28,
 146 *		NFSERR_ROFS = 30,
 147 *		NFSERR_NAMETOOLONG = 63,
 148 *		NFSERR_NOTEMPTY = 66,
 149 *		NFSERR_DQUOT = 69,
 150 *		NFSERR_STALE = 70,
 151 *		NFSERR_WFLUSH = 99
 152 *	};
 153 */
 154static int decode_stat(struct xdr_stream *xdr, enum nfs_stat *status)
 155{
 156	__be32 *p;
 157
 158	p = xdr_inline_decode(xdr, 4);
 159	if (unlikely(p == NULL))
 160		goto out_overflow;
 161	*status = be32_to_cpup(p);
 162	return 0;
 163out_overflow:
 164	print_overflow_msg(__func__, xdr);
 165	return -EIO;
 166}
 167
 168/*
 169 * 2.3.2.  ftype
 170 *
 171 *	enum ftype {
 172 *		NFNON = 0,
 173 *		NFREG = 1,
 174 *		NFDIR = 2,
 175 *		NFBLK = 3,
 176 *		NFCHR = 4,
 177 *		NFLNK = 5
 178 *	};
 179 *
 180 */
 181static __be32 *xdr_decode_ftype(__be32 *p, u32 *type)
 182{
 183	*type = be32_to_cpup(p++);
 184	if (unlikely(*type > NF2FIFO))
 185		*type = NFBAD;
 186	return p;
 187}
 188
 189/*
 190 * 2.3.3.  fhandle
 191 *
 192 *	typedef opaque fhandle[FHSIZE];
 193 */
 194static void encode_fhandle(struct xdr_stream *xdr, const struct nfs_fh *fh)
 195{
 196	__be32 *p;
 197
 198	p = xdr_reserve_space(xdr, NFS2_FHSIZE);
 199	memcpy(p, fh->data, NFS2_FHSIZE);
 200}
 201
 202static int decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
 203{
 204	__be32 *p;
 205
 206	p = xdr_inline_decode(xdr, NFS2_FHSIZE);
 207	if (unlikely(p == NULL))
 208		goto out_overflow;
 209	fh->size = NFS2_FHSIZE;
 210	memcpy(fh->data, p, NFS2_FHSIZE);
 211	return 0;
 212out_overflow:
 213	print_overflow_msg(__func__, xdr);
 214	return -EIO;
 215}
 216
 217/*
 218 * 2.3.4.  timeval
 219 *
 220 *	struct timeval {
 221 *		unsigned int seconds;
 222 *		unsigned int useconds;
 223 *	};
 224 */
 225static __be32 *xdr_encode_time(__be32 *p, const struct timespec *timep)
 226{
 227	*p++ = cpu_to_be32(timep->tv_sec);
 228	if (timep->tv_nsec != 0)
 229		*p++ = cpu_to_be32(timep->tv_nsec / NSEC_PER_USEC);
 230	else
 231		*p++ = cpu_to_be32(0);
 232	return p;
 233}
 234
 235/*
 236 * Passing the invalid value useconds=1000000 is a Sun convention for
 237 * "set to current server time".  It's needed to make permissions checks
 238 * for the "touch" program across v2 mounts to Solaris and Irix servers
 239 * work correctly.  See description of sattr in section 6.1 of "NFS
 240 * Illustrated" by Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5.
 241 */
 242static __be32 *xdr_encode_current_server_time(__be32 *p,
 243					      const struct timespec *timep)
 244{
 245	*p++ = cpu_to_be32(timep->tv_sec);
 246	*p++ = cpu_to_be32(1000000);
 247	return p;
 248}
 249
 250static __be32 *xdr_decode_time(__be32 *p, struct timespec *timep)
 251{
 252	timep->tv_sec = be32_to_cpup(p++);
 253	timep->tv_nsec = be32_to_cpup(p++) * NSEC_PER_USEC;
 254	return p;
 255}
 256
 257/*
 258 * 2.3.5.  fattr
 259 *
 260 *	struct fattr {
 261 *		ftype		type;
 262 *		unsigned int	mode;
 263 *		unsigned int	nlink;
 264 *		unsigned int	uid;
 265 *		unsigned int	gid;
 266 *		unsigned int	size;
 267 *		unsigned int	blocksize;
 268 *		unsigned int	rdev;
 269 *		unsigned int	blocks;
 270 *		unsigned int	fsid;
 271 *		unsigned int	fileid;
 272 *		timeval		atime;
 273 *		timeval		mtime;
 274 *		timeval		ctime;
 275 *	};
 276 *
 277 */
 278static int decode_fattr(struct xdr_stream *xdr, struct nfs_fattr *fattr)
 279{
 280	u32 rdev, type;
 281	__be32 *p;
 282
 283	p = xdr_inline_decode(xdr, NFS_fattr_sz << 2);
 284	if (unlikely(p == NULL))
 285		goto out_overflow;
 286
 287	fattr->valid |= NFS_ATTR_FATTR_V2;
 288
 289	p = xdr_decode_ftype(p, &type);
 290
 291	fattr->mode = be32_to_cpup(p++);
 292	fattr->nlink = be32_to_cpup(p++);
 293	fattr->uid = make_kuid(&init_user_ns, be32_to_cpup(p++));
 294	if (!uid_valid(fattr->uid))
 295		goto out_uid;
 296	fattr->gid = make_kgid(&init_user_ns, be32_to_cpup(p++));
 297	if (!gid_valid(fattr->gid))
 298		goto out_gid;
 299		
 300	fattr->size = be32_to_cpup(p++);
 301	fattr->du.nfs2.blocksize = be32_to_cpup(p++);
 302
 303	rdev = be32_to_cpup(p++);
 304	fattr->rdev = new_decode_dev(rdev);
 305	if (type == (u32)NFCHR && rdev == (u32)NFS2_FIFO_DEV) {
 306		fattr->mode = (fattr->mode & ~S_IFMT) | S_IFIFO;
 307		fattr->rdev = 0;
 308	}
 309
 310	fattr->du.nfs2.blocks = be32_to_cpup(p++);
 311	fattr->fsid.major = be32_to_cpup(p++);
 312	fattr->fsid.minor = 0;
 313	fattr->fileid = be32_to_cpup(p++);
 314
 315	p = xdr_decode_time(p, &fattr->atime);
 316	p = xdr_decode_time(p, &fattr->mtime);
 317	xdr_decode_time(p, &fattr->ctime);
 318	fattr->change_attr = nfs_timespec_to_change_attr(&fattr->ctime);
 319
 320	return 0;
 321out_uid:
 322	dprintk("NFS: returned invalid uid\n");
 323	return -EINVAL;
 324out_gid:
 325	dprintk("NFS: returned invalid gid\n");
 326	return -EINVAL;
 327out_overflow:
 328	print_overflow_msg(__func__, xdr);
 329	return -EIO;
 330}
 331
 332/*
 333 * 2.3.6.  sattr
 334 *
 335 *	struct sattr {
 336 *		unsigned int	mode;
 337 *		unsigned int	uid;
 338 *		unsigned int	gid;
 339 *		unsigned int	size;
 340 *		timeval		atime;
 341 *		timeval		mtime;
 342 *	};
 343 */
 344
 345#define NFS2_SATTR_NOT_SET	(0xffffffff)
 346
 347static __be32 *xdr_time_not_set(__be32 *p)
 348{
 349	*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
 350	*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
 351	return p;
 352}
 353
 354static void encode_sattr(struct xdr_stream *xdr, const struct iattr *attr)
 355{
 356	__be32 *p;
 357
 358	p = xdr_reserve_space(xdr, NFS_sattr_sz << 2);
 359
 360	if (attr->ia_valid & ATTR_MODE)
 361		*p++ = cpu_to_be32(attr->ia_mode);
 362	else
 363		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
 364	if (attr->ia_valid & ATTR_UID)
 365		*p++ = cpu_to_be32(from_kuid(&init_user_ns, attr->ia_uid));
 366	else
 367		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
 368	if (attr->ia_valid & ATTR_GID)
 369		*p++ = cpu_to_be32(from_kgid(&init_user_ns, attr->ia_gid));
 370	else
 371		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
 372	if (attr->ia_valid & ATTR_SIZE)
 373		*p++ = cpu_to_be32((u32)attr->ia_size);
 374	else
 375		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
 376
 377	if (attr->ia_valid & ATTR_ATIME_SET)
 378		p = xdr_encode_time(p, &attr->ia_atime);
 379	else if (attr->ia_valid & ATTR_ATIME)
 380		p = xdr_encode_current_server_time(p, &attr->ia_atime);
 381	else
 382		p = xdr_time_not_set(p);
 383	if (attr->ia_valid & ATTR_MTIME_SET)
 384		xdr_encode_time(p, &attr->ia_mtime);
 385	else if (attr->ia_valid & ATTR_MTIME)
 386		xdr_encode_current_server_time(p, &attr->ia_mtime);
 387	else
 388		xdr_time_not_set(p);
 389}
 390
 391/*
 392 * 2.3.7.  filename
 393 *
 394 *	typedef string filename<MAXNAMLEN>;
 395 */
 396static void encode_filename(struct xdr_stream *xdr,
 397			    const char *name, u32 length)
 398{
 399	__be32 *p;
 400
 401	WARN_ON_ONCE(length > NFS2_MAXNAMLEN);
 402	p = xdr_reserve_space(xdr, 4 + length);
 403	xdr_encode_opaque(p, name, length);
 404}
 405
 406static int decode_filename_inline(struct xdr_stream *xdr,
 407				  const char **name, u32 *length)
 408{
 409	__be32 *p;
 410	u32 count;
 411
 412	p = xdr_inline_decode(xdr, 4);
 413	if (unlikely(p == NULL))
 414		goto out_overflow;
 415	count = be32_to_cpup(p);
 416	if (count > NFS3_MAXNAMLEN)
 417		goto out_nametoolong;
 418	p = xdr_inline_decode(xdr, count);
 419	if (unlikely(p == NULL))
 420		goto out_overflow;
 421	*name = (const char *)p;
 422	*length = count;
 423	return 0;
 424out_nametoolong:
 425	dprintk("NFS: returned filename too long: %u\n", count);
 426	return -ENAMETOOLONG;
 427out_overflow:
 428	print_overflow_msg(__func__, xdr);
 429	return -EIO;
 430}
 431
 432/*
 433 * 2.3.8.  path
 434 *
 435 *	typedef string path<MAXPATHLEN>;
 436 */
 437static void encode_path(struct xdr_stream *xdr, struct page **pages, u32 length)
 438{
 439	__be32 *p;
 440
 441	p = xdr_reserve_space(xdr, 4);
 442	*p = cpu_to_be32(length);
 443	xdr_write_pages(xdr, pages, 0, length);
 444}
 445
 446static int decode_path(struct xdr_stream *xdr)
 447{
 448	u32 length, recvd;
 449	__be32 *p;
 450
 451	p = xdr_inline_decode(xdr, 4);
 452	if (unlikely(p == NULL))
 453		goto out_overflow;
 454	length = be32_to_cpup(p);
 455	if (unlikely(length >= xdr->buf->page_len || length > NFS_MAXPATHLEN))
 456		goto out_size;
 457	recvd = xdr_read_pages(xdr, length);
 458	if (unlikely(length > recvd))
 459		goto out_cheating;
 460	xdr_terminate_string(xdr->buf, length);
 461	return 0;
 462out_size:
 463	dprintk("NFS: returned pathname too long: %u\n", length);
 464	return -ENAMETOOLONG;
 465out_cheating:
 466	dprintk("NFS: server cheating in pathname result: "
 467		"length %u > received %u\n", length, recvd);
 468	return -EIO;
 469out_overflow:
 470	print_overflow_msg(__func__, xdr);
 471	return -EIO;
 472}
 473
 474/*
 475 * 2.3.9.  attrstat
 476 *
 477 *	union attrstat switch (stat status) {
 478 *	case NFS_OK:
 479 *		fattr attributes;
 480 *	default:
 481 *		void;
 482 *	};
 483 */
 484static int decode_attrstat(struct xdr_stream *xdr, struct nfs_fattr *result,
 485			   __u32 *op_status)
 486{
 487	enum nfs_stat status;
 488	int error;
 489
 490	error = decode_stat(xdr, &status);
 491	if (unlikely(error))
 492		goto out;
 493	if (op_status)
 494		*op_status = status;
 495	if (status != NFS_OK)
 496		goto out_default;
 497	error = decode_fattr(xdr, result);
 498out:
 499	return error;
 500out_default:
 501	return nfs_stat_to_errno(status);
 502}
 503
 504/*
 505 * 2.3.10.  diropargs
 506 *
 507 *	struct diropargs {
 508 *		fhandle  dir;
 509 *		filename name;
 510 *	};
 511 */
 512static void encode_diropargs(struct xdr_stream *xdr, const struct nfs_fh *fh,
 513			     const char *name, u32 length)
 514{
 515	encode_fhandle(xdr, fh);
 516	encode_filename(xdr, name, length);
 517}
 518
 519/*
 520 * 2.3.11.  diropres
 521 *
 522 *	union diropres switch (stat status) {
 523 *	case NFS_OK:
 524 *		struct {
 525 *			fhandle file;
 526 *			fattr   attributes;
 527 *		} diropok;
 528 *	default:
 529 *		void;
 530 *	};
 531 */
 532static int decode_diropok(struct xdr_stream *xdr, struct nfs_diropok *result)
 533{
 534	int error;
 535
 536	error = decode_fhandle(xdr, result->fh);
 537	if (unlikely(error))
 538		goto out;
 539	error = decode_fattr(xdr, result->fattr);
 540out:
 541	return error;
 542}
 543
 544static int decode_diropres(struct xdr_stream *xdr, struct nfs_diropok *result)
 545{
 546	enum nfs_stat status;
 547	int error;
 548
 549	error = decode_stat(xdr, &status);
 550	if (unlikely(error))
 551		goto out;
 552	if (status != NFS_OK)
 553		goto out_default;
 554	error = decode_diropok(xdr, result);
 555out:
 556	return error;
 557out_default:
 558	return nfs_stat_to_errno(status);
 559}
 560
 561
 562/*
 563 * NFSv2 XDR encode functions
 564 *
 565 * NFSv2 argument types are defined in section 2.2 of RFC 1094:
 566 * "NFS: Network File System Protocol Specification".
 567 */
 568
 569static void nfs2_xdr_enc_fhandle(struct rpc_rqst *req,
 570				 struct xdr_stream *xdr,
 571				 const struct nfs_fh *fh)
 572{
 573	encode_fhandle(xdr, fh);
 574}
 575
 576/*
 577 * 2.2.3.  sattrargs
 578 *
 579 *	struct sattrargs {
 580 *		fhandle file;
 581 *		sattr attributes;
 582 *	};
 583 */
 584static void nfs2_xdr_enc_sattrargs(struct rpc_rqst *req,
 585				   struct xdr_stream *xdr,
 586				   const struct nfs_sattrargs *args)
 587{
 588	encode_fhandle(xdr, args->fh);
 589	encode_sattr(xdr, args->sattr);
 590}
 591
 592static void nfs2_xdr_enc_diropargs(struct rpc_rqst *req,
 593				   struct xdr_stream *xdr,
 594				   const struct nfs_diropargs *args)
 595{
 596	encode_diropargs(xdr, args->fh, args->name, args->len);
 597}
 598
 599static void nfs2_xdr_enc_readlinkargs(struct rpc_rqst *req,
 600				      struct xdr_stream *xdr,
 601				      const struct nfs_readlinkargs *args)
 602{
 603	encode_fhandle(xdr, args->fh);
 604	prepare_reply_buffer(req, args->pages, args->pgbase,
 605					args->pglen, NFS_readlinkres_sz);
 606}
 607
 608/*
 609 * 2.2.7.  readargs
 610 *
 611 *	struct readargs {
 612 *		fhandle file;
 613 *		unsigned offset;
 614 *		unsigned count;
 615 *		unsigned totalcount;
 616 *	};
 617 */
 618static void encode_readargs(struct xdr_stream *xdr,
 619			    const struct nfs_pgio_args *args)
 620{
 621	u32 offset = args->offset;
 622	u32 count = args->count;
 623	__be32 *p;
 624
 625	encode_fhandle(xdr, args->fh);
 626
 627	p = xdr_reserve_space(xdr, 4 + 4 + 4);
 628	*p++ = cpu_to_be32(offset);
 629	*p++ = cpu_to_be32(count);
 630	*p = cpu_to_be32(count);
 631}
 632
 633static void nfs2_xdr_enc_readargs(struct rpc_rqst *req,
 634				  struct xdr_stream *xdr,
 635				  const struct nfs_pgio_args *args)
 636{
 637	encode_readargs(xdr, args);
 638	prepare_reply_buffer(req, args->pages, args->pgbase,
 639					args->count, NFS_readres_sz);
 640	req->rq_rcv_buf.flags |= XDRBUF_READ;
 641}
 642
 643/*
 644 * 2.2.9.  writeargs
 645 *
 646 *	struct writeargs {
 647 *		fhandle file;
 648 *		unsigned beginoffset;
 649 *		unsigned offset;
 650 *		unsigned totalcount;
 651 *		nfsdata data;
 652 *	};
 653 */
 654static void encode_writeargs(struct xdr_stream *xdr,
 655			     const struct nfs_pgio_args *args)
 656{
 657	u32 offset = args->offset;
 658	u32 count = args->count;
 659	__be32 *p;
 660
 661	encode_fhandle(xdr, args->fh);
 662
 663	p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
 664	*p++ = cpu_to_be32(offset);
 665	*p++ = cpu_to_be32(offset);
 666	*p++ = cpu_to_be32(count);
 667
 668	/* nfsdata */
 669	*p = cpu_to_be32(count);
 670	xdr_write_pages(xdr, args->pages, args->pgbase, count);
 671}
 672
 673static void nfs2_xdr_enc_writeargs(struct rpc_rqst *req,
 674				   struct xdr_stream *xdr,
 675				   const struct nfs_pgio_args *args)
 676{
 677	encode_writeargs(xdr, args);
 678	xdr->buf->flags |= XDRBUF_WRITE;
 679}
 680
 681/*
 682 * 2.2.10.  createargs
 683 *
 684 *	struct createargs {
 685 *		diropargs where;
 686 *		sattr attributes;
 687 *	};
 688 */
 689static void nfs2_xdr_enc_createargs(struct rpc_rqst *req,
 690				    struct xdr_stream *xdr,
 691				    const struct nfs_createargs *args)
 692{
 693	encode_diropargs(xdr, args->fh, args->name, args->len);
 694	encode_sattr(xdr, args->sattr);
 695}
 696
 697static void nfs2_xdr_enc_removeargs(struct rpc_rqst *req,
 698				    struct xdr_stream *xdr,
 699				    const struct nfs_removeargs *args)
 700{
 701	encode_diropargs(xdr, args->fh, args->name.name, args->name.len);
 702}
 703
 704/*
 705 * 2.2.12.  renameargs
 706 *
 707 *	struct renameargs {
 708 *		diropargs from;
 709 *		diropargs to;
 710 *	};
 711 */
 712static void nfs2_xdr_enc_renameargs(struct rpc_rqst *req,
 713				    struct xdr_stream *xdr,
 714				    const struct nfs_renameargs *args)
 715{
 716	const struct qstr *old = args->old_name;
 717	const struct qstr *new = args->new_name;
 718
 719	encode_diropargs(xdr, args->old_dir, old->name, old->len);
 720	encode_diropargs(xdr, args->new_dir, new->name, new->len);
 721}
 722
 723/*
 724 * 2.2.13.  linkargs
 725 *
 726 *	struct linkargs {
 727 *		fhandle from;
 728 *		diropargs to;
 729 *	};
 730 */
 731static void nfs2_xdr_enc_linkargs(struct rpc_rqst *req,
 732				  struct xdr_stream *xdr,
 733				  const struct nfs_linkargs *args)
 734{
 735	encode_fhandle(xdr, args->fromfh);
 736	encode_diropargs(xdr, args->tofh, args->toname, args->tolen);
 737}
 738
 739/*
 740 * 2.2.14.  symlinkargs
 741 *
 742 *	struct symlinkargs {
 743 *		diropargs from;
 744 *		path to;
 745 *		sattr attributes;
 746 *	};
 747 */
 748static void nfs2_xdr_enc_symlinkargs(struct rpc_rqst *req,
 749				     struct xdr_stream *xdr,
 750				     const struct nfs_symlinkargs *args)
 751{
 752	encode_diropargs(xdr, args->fromfh, args->fromname, args->fromlen);
 753	encode_path(xdr, args->pages, args->pathlen);
 754	encode_sattr(xdr, args->sattr);
 755}
 756
 757/*
 758 * 2.2.17.  readdirargs
 759 *
 760 *	struct readdirargs {
 761 *		fhandle dir;
 762 *		nfscookie cookie;
 763 *		unsigned count;
 764 *	};
 765 */
 766static void encode_readdirargs(struct xdr_stream *xdr,
 767			       const struct nfs_readdirargs *args)
 768{
 769	__be32 *p;
 770
 771	encode_fhandle(xdr, args->fh);
 772
 773	p = xdr_reserve_space(xdr, 4 + 4);
 774	*p++ = cpu_to_be32(args->cookie);
 775	*p = cpu_to_be32(args->count);
 776}
 777
 778static void nfs2_xdr_enc_readdirargs(struct rpc_rqst *req,
 779				     struct xdr_stream *xdr,
 780				     const struct nfs_readdirargs *args)
 781{
 782	encode_readdirargs(xdr, args);
 783	prepare_reply_buffer(req, args->pages, 0,
 784					args->count, NFS_readdirres_sz);
 785}
 786
 787/*
 788 * NFSv2 XDR decode functions
 789 *
 790 * NFSv2 result types are defined in section 2.2 of RFC 1094:
 791 * "NFS: Network File System Protocol Specification".
 792 */
 793
 794static int nfs2_xdr_dec_stat(struct rpc_rqst *req, struct xdr_stream *xdr,
 795			     void *__unused)
 796{
 797	enum nfs_stat status;
 798	int error;
 799
 800	error = decode_stat(xdr, &status);
 801	if (unlikely(error))
 802		goto out;
 803	if (status != NFS_OK)
 804		goto out_default;
 805out:
 806	return error;
 807out_default:
 808	return nfs_stat_to_errno(status);
 809}
 810
 811static int nfs2_xdr_dec_attrstat(struct rpc_rqst *req, struct xdr_stream *xdr,
 812				 struct nfs_fattr *result)
 813{
 814	return decode_attrstat(xdr, result, NULL);
 815}
 816
 817static int nfs2_xdr_dec_diropres(struct rpc_rqst *req, struct xdr_stream *xdr,
 818				 struct nfs_diropok *result)
 819{
 820	return decode_diropres(xdr, result);
 821}
 822
 823/*
 824 * 2.2.6.  readlinkres
 825 *
 826 *	union readlinkres switch (stat status) {
 827 *	case NFS_OK:
 828 *		path data;
 829 *	default:
 830 *		void;
 831 *	};
 832 */
 833static int nfs2_xdr_dec_readlinkres(struct rpc_rqst *req,
 834				    struct xdr_stream *xdr, void *__unused)
 835{
 836	enum nfs_stat status;
 837	int error;
 838
 839	error = decode_stat(xdr, &status);
 840	if (unlikely(error))
 841		goto out;
 842	if (status != NFS_OK)
 843		goto out_default;
 844	error = decode_path(xdr);
 845out:
 846	return error;
 847out_default:
 848	return nfs_stat_to_errno(status);
 849}
 850
 851/*
 852 * 2.2.7.  readres
 853 *
 854 *	union readres switch (stat status) {
 855 *	case NFS_OK:
 856 *		fattr attributes;
 857 *		nfsdata data;
 858 *	default:
 859 *		void;
 860 *	};
 861 */
 862static int nfs2_xdr_dec_readres(struct rpc_rqst *req, struct xdr_stream *xdr,
 863				struct nfs_pgio_res *result)
 864{
 865	enum nfs_stat status;
 866	int error;
 867
 868	error = decode_stat(xdr, &status);
 869	if (unlikely(error))
 870		goto out;
 871	result->op_status = status;
 872	if (status != NFS_OK)
 873		goto out_default;
 874	error = decode_fattr(xdr, result->fattr);
 875	if (unlikely(error))
 876		goto out;
 877	error = decode_nfsdata(xdr, result);
 878out:
 879	return error;
 880out_default:
 881	return nfs_stat_to_errno(status);
 882}
 883
 884static int nfs2_xdr_dec_writeres(struct rpc_rqst *req, struct xdr_stream *xdr,
 885				 struct nfs_pgio_res *result)
 886{
 887	/* All NFSv2 writes are "file sync" writes */
 888	result->verf->committed = NFS_FILE_SYNC;
 889	return decode_attrstat(xdr, result->fattr, &result->op_status);
 890}
 891
 892/**
 893 * nfs2_decode_dirent - Decode a single NFSv2 directory entry stored in
 894 *                      the local page cache.
 895 * @xdr: XDR stream where entry resides
 896 * @entry: buffer to fill in with entry data
 897 * @plus: boolean indicating whether this should be a readdirplus entry
 898 *
 899 * Returns zero if successful, otherwise a negative errno value is
 900 * returned.
 901 *
 902 * This function is not invoked during READDIR reply decoding, but
 903 * rather whenever an application invokes the getdents(2) system call
 904 * on a directory already in our cache.
 905 *
 906 * 2.2.17.  entry
 907 *
 908 *	struct entry {
 909 *		unsigned	fileid;
 910 *		filename	name;
 911 *		nfscookie	cookie;
 912 *		entry		*nextentry;
 913 *	};
 914 */
 915int nfs2_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
 916		       int plus)
 917{
 918	__be32 *p;
 919	int error;
 920
 921	p = xdr_inline_decode(xdr, 4);
 922	if (unlikely(p == NULL))
 923		goto out_overflow;
 924	if (*p++ == xdr_zero) {
 925		p = xdr_inline_decode(xdr, 4);
 926		if (unlikely(p == NULL))
 927			goto out_overflow;
 928		if (*p++ == xdr_zero)
 929			return -EAGAIN;
 930		entry->eof = 1;
 931		return -EBADCOOKIE;
 932	}
 933
 934	p = xdr_inline_decode(xdr, 4);
 935	if (unlikely(p == NULL))
 936		goto out_overflow;
 937	entry->ino = be32_to_cpup(p);
 938
 939	error = decode_filename_inline(xdr, &entry->name, &entry->len);
 940	if (unlikely(error))
 941		return error;
 942
 943	/*
 944	 * The type (size and byte order) of nfscookie isn't defined in
 945	 * RFC 1094.  This implementation assumes that it's an XDR uint32.
 946	 */
 947	entry->prev_cookie = entry->cookie;
 948	p = xdr_inline_decode(xdr, 4);
 949	if (unlikely(p == NULL))
 950		goto out_overflow;
 951	entry->cookie = be32_to_cpup(p);
 952
 953	entry->d_type = DT_UNKNOWN;
 954
 955	return 0;
 956
 957out_overflow:
 958	print_overflow_msg(__func__, xdr);
 959	return -EAGAIN;
 960}
 961
 962/*
 963 * 2.2.17.  readdirres
 964 *
 965 *	union readdirres switch (stat status) {
 966 *	case NFS_OK:
 967 *		struct {
 968 *			entry *entries;
 969 *			bool eof;
 970 *		} readdirok;
 971 *	default:
 972 *		void;
 973 *	};
 974 *
 975 * Read the directory contents into the page cache, but don't
 976 * touch them.  The actual decoding is done by nfs2_decode_dirent()
 977 * during subsequent nfs_readdir() calls.
 978 */
 979static int decode_readdirok(struct xdr_stream *xdr)
 980{
 981	return xdr_read_pages(xdr, xdr->buf->page_len);
 982}
 983
 984static int nfs2_xdr_dec_readdirres(struct rpc_rqst *req,
 985				   struct xdr_stream *xdr, void *__unused)
 986{
 987	enum nfs_stat status;
 988	int error;
 989
 990	error = decode_stat(xdr, &status);
 991	if (unlikely(error))
 992		goto out;
 993	if (status != NFS_OK)
 994		goto out_default;
 995	error = decode_readdirok(xdr);
 996out:
 997	return error;
 998out_default:
 999	return nfs_stat_to_errno(status);
1000}
1001
1002/*
1003 * 2.2.18.  statfsres
1004 *
1005 *	union statfsres (stat status) {
1006 *	case NFS_OK:
1007 *		struct {
1008 *			unsigned tsize;
1009 *			unsigned bsize;
1010 *			unsigned blocks;
1011 *			unsigned bfree;
1012 *			unsigned bavail;
1013 *		} info;
1014 *	default:
1015 *		void;
1016 *	};
1017 */
1018static int decode_info(struct xdr_stream *xdr, struct nfs2_fsstat *result)
1019{
1020	__be32 *p;
1021
1022	p = xdr_inline_decode(xdr, NFS_info_sz << 2);
1023	if (unlikely(p == NULL))
1024		goto out_overflow;
1025	result->tsize  = be32_to_cpup(p++);
1026	result->bsize  = be32_to_cpup(p++);
1027	result->blocks = be32_to_cpup(p++);
1028	result->bfree  = be32_to_cpup(p++);
1029	result->bavail = be32_to_cpup(p);
1030	return 0;
1031out_overflow:
1032	print_overflow_msg(__func__, xdr);
1033	return -EIO;
1034}
1035
1036static int nfs2_xdr_dec_statfsres(struct rpc_rqst *req, struct xdr_stream *xdr,
1037				  struct nfs2_fsstat *result)
1038{
1039	enum nfs_stat status;
1040	int error;
1041
1042	error = decode_stat(xdr, &status);
1043	if (unlikely(error))
1044		goto out;
1045	if (status != NFS_OK)
1046		goto out_default;
1047	error = decode_info(xdr, result);
1048out:
1049	return error;
1050out_default:
1051	return nfs_stat_to_errno(status);
1052}
1053
1054
1055/*
1056 * We need to translate between nfs status return values and
1057 * the local errno values which may not be the same.
1058 */
1059static const struct {
1060	int stat;
1061	int errno;
1062} nfs_errtbl[] = {
1063	{ NFS_OK,		0		},
1064	{ NFSERR_PERM,		-EPERM		},
1065	{ NFSERR_NOENT,		-ENOENT		},
1066	{ NFSERR_IO,		-errno_NFSERR_IO},
1067	{ NFSERR_NXIO,		-ENXIO		},
1068/*	{ NFSERR_EAGAIN,	-EAGAIN		}, */
1069	{ NFSERR_ACCES,		-EACCES		},
1070	{ NFSERR_EXIST,		-EEXIST		},
1071	{ NFSERR_XDEV,		-EXDEV		},
1072	{ NFSERR_NODEV,		-ENODEV		},
1073	{ NFSERR_NOTDIR,	-ENOTDIR	},
1074	{ NFSERR_ISDIR,		-EISDIR		},
1075	{ NFSERR_INVAL,		-EINVAL		},
1076	{ NFSERR_FBIG,		-EFBIG		},
1077	{ NFSERR_NOSPC,		-ENOSPC		},
1078	{ NFSERR_ROFS,		-EROFS		},
1079	{ NFSERR_MLINK,		-EMLINK		},
1080	{ NFSERR_NAMETOOLONG,	-ENAMETOOLONG	},
1081	{ NFSERR_NOTEMPTY,	-ENOTEMPTY	},
1082	{ NFSERR_DQUOT,		-EDQUOT		},
1083	{ NFSERR_STALE,		-ESTALE		},
1084	{ NFSERR_REMOTE,	-EREMOTE	},
1085#ifdef EWFLUSH
1086	{ NFSERR_WFLUSH,	-EWFLUSH	},
1087#endif
1088	{ NFSERR_BADHANDLE,	-EBADHANDLE	},
1089	{ NFSERR_NOT_SYNC,	-ENOTSYNC	},
1090	{ NFSERR_BAD_COOKIE,	-EBADCOOKIE	},
1091	{ NFSERR_NOTSUPP,	-ENOTSUPP	},
1092	{ NFSERR_TOOSMALL,	-ETOOSMALL	},
1093	{ NFSERR_SERVERFAULT,	-EREMOTEIO	},
1094	{ NFSERR_BADTYPE,	-EBADTYPE	},
1095	{ NFSERR_JUKEBOX,	-EJUKEBOX	},
1096	{ -1,			-EIO		}
1097};
1098
1099/**
1100 * nfs_stat_to_errno - convert an NFS status code to a local errno
1101 * @status: NFS status code to convert
1102 *
1103 * Returns a local errno value, or -EIO if the NFS status code is
1104 * not recognized.  This function is used jointly by NFSv2 and NFSv3.
1105 */
1106static int nfs_stat_to_errno(enum nfs_stat status)
1107{
1108	int i;
1109
1110	for (i = 0; nfs_errtbl[i].stat != -1; i++) {
1111		if (nfs_errtbl[i].stat == (int)status)
1112			return nfs_errtbl[i].errno;
1113	}
1114	dprintk("NFS: Unrecognized nfs status value: %u\n", status);
1115	return nfs_errtbl[i].errno;
1116}
1117
1118#define PROC(proc, argtype, restype, timer)				\
1119[NFSPROC_##proc] = {							\
1120	.p_proc	    =  NFSPROC_##proc,					\
1121	.p_encode   =  (kxdreproc_t)nfs2_xdr_enc_##argtype,		\
1122	.p_decode   =  (kxdrdproc_t)nfs2_xdr_dec_##restype,		\
1123	.p_arglen   =  NFS_##argtype##_sz,				\
1124	.p_replen   =  NFS_##restype##_sz,				\
1125	.p_timer    =  timer,						\
1126	.p_statidx  =  NFSPROC_##proc,					\
1127	.p_name     =  #proc,						\
1128	}
1129struct rpc_procinfo	nfs_procedures[] = {
1130	PROC(GETATTR,	fhandle,	attrstat,	1),
1131	PROC(SETATTR,	sattrargs,	attrstat,	0),
1132	PROC(LOOKUP,	diropargs,	diropres,	2),
1133	PROC(READLINK,	readlinkargs,	readlinkres,	3),
1134	PROC(READ,	readargs,	readres,	3),
1135	PROC(WRITE,	writeargs,	writeres,	4),
1136	PROC(CREATE,	createargs,	diropres,	0),
1137	PROC(REMOVE,	removeargs,	stat,		0),
1138	PROC(RENAME,	renameargs,	stat,		0),
1139	PROC(LINK,	linkargs,	stat,		0),
1140	PROC(SYMLINK,	symlinkargs,	stat,		0),
1141	PROC(MKDIR,	createargs,	diropres,	0),
1142	PROC(RMDIR,	diropargs,	stat,		0),
1143	PROC(READDIR,	readdirargs,	readdirres,	3),
1144	PROC(STATFS,	fhandle,	statfsres,	0),
1145};
1146
1147const struct rpc_version nfs_version2 = {
1148	.number			= 2,
1149	.nrprocs		= ARRAY_SIZE(nfs_procedures),
1150	.procs			= nfs_procedures
1151};
v3.15
   1/*
   2 * linux/fs/nfs/nfs2xdr.c
   3 *
   4 * XDR functions to encode/decode NFS RPC arguments and results.
   5 *
   6 * Copyright (C) 1992, 1993, 1994  Rick Sladkey
   7 * Copyright (C) 1996 Olaf Kirch
   8 * 04 Aug 1998  Ion Badulescu <ionut@cs.columbia.edu>
   9 * 		FIFO's need special handling in NFSv2
  10 */
  11
  12#include <linux/param.h>
  13#include <linux/time.h>
  14#include <linux/mm.h>
  15#include <linux/errno.h>
  16#include <linux/string.h>
  17#include <linux/in.h>
  18#include <linux/pagemap.h>
  19#include <linux/proc_fs.h>
  20#include <linux/sunrpc/clnt.h>
  21#include <linux/nfs.h>
  22#include <linux/nfs2.h>
  23#include <linux/nfs_fs.h>
  24#include "internal.h"
  25
  26#define NFSDBG_FACILITY		NFSDBG_XDR
  27
  28/* Mapping from NFS error code to "errno" error code. */
  29#define errno_NFSERR_IO		EIO
  30
  31/*
  32 * Declare the space requirements for NFS arguments and replies as
  33 * number of 32bit-words
  34 */
  35#define NFS_fhandle_sz		(8)
  36#define NFS_sattr_sz		(8)
  37#define NFS_filename_sz		(1+(NFS2_MAXNAMLEN>>2))
  38#define NFS_path_sz		(1+(NFS2_MAXPATHLEN>>2))
  39#define NFS_fattr_sz		(17)
  40#define NFS_info_sz		(5)
  41#define NFS_entry_sz		(NFS_filename_sz+3)
  42
  43#define NFS_diropargs_sz	(NFS_fhandle_sz+NFS_filename_sz)
  44#define NFS_removeargs_sz	(NFS_fhandle_sz+NFS_filename_sz)
  45#define NFS_sattrargs_sz	(NFS_fhandle_sz+NFS_sattr_sz)
  46#define NFS_readlinkargs_sz	(NFS_fhandle_sz)
  47#define NFS_readargs_sz		(NFS_fhandle_sz+3)
  48#define NFS_writeargs_sz	(NFS_fhandle_sz+4)
  49#define NFS_createargs_sz	(NFS_diropargs_sz+NFS_sattr_sz)
  50#define NFS_renameargs_sz	(NFS_diropargs_sz+NFS_diropargs_sz)
  51#define NFS_linkargs_sz		(NFS_fhandle_sz+NFS_diropargs_sz)
  52#define NFS_symlinkargs_sz	(NFS_diropargs_sz+1+NFS_sattr_sz)
  53#define NFS_readdirargs_sz	(NFS_fhandle_sz+2)
  54
  55#define NFS_attrstat_sz		(1+NFS_fattr_sz)
  56#define NFS_diropres_sz		(1+NFS_fhandle_sz+NFS_fattr_sz)
  57#define NFS_readlinkres_sz	(2)
  58#define NFS_readres_sz		(1+NFS_fattr_sz+1)
  59#define NFS_writeres_sz         (NFS_attrstat_sz)
  60#define NFS_stat_sz		(1)
  61#define NFS_readdirres_sz	(1)
  62#define NFS_statfsres_sz	(1+NFS_info_sz)
  63
  64static int nfs_stat_to_errno(enum nfs_stat);
  65
  66/*
  67 * While encoding arguments, set up the reply buffer in advance to
  68 * receive reply data directly into the page cache.
  69 */
  70static void prepare_reply_buffer(struct rpc_rqst *req, struct page **pages,
  71				 unsigned int base, unsigned int len,
  72				 unsigned int bufsize)
  73{
  74	struct rpc_auth	*auth = req->rq_cred->cr_auth;
  75	unsigned int replen;
  76
  77	replen = RPC_REPHDRSIZE + auth->au_rslack + bufsize;
  78	xdr_inline_pages(&req->rq_rcv_buf, replen << 2, pages, base, len);
  79}
  80
  81/*
  82 * Handle decode buffer overflows out-of-line.
  83 */
  84static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
  85{
  86	dprintk("NFS: %s prematurely hit the end of our receive buffer. "
  87		"Remaining buffer length is %tu words.\n",
  88		func, xdr->end - xdr->p);
  89}
  90
  91
  92/*
  93 * Encode/decode NFSv2 basic data types
  94 *
  95 * Basic NFSv2 data types are defined in section 2.3 of RFC 1094:
  96 * "NFS: Network File System Protocol Specification".
  97 *
  98 * Not all basic data types have their own encoding and decoding
  99 * functions.  For run-time efficiency, some data types are encoded
 100 * or decoded inline.
 101 */
 102
 103/*
 104 *	typedef opaque	nfsdata<>;
 105 */
 106static int decode_nfsdata(struct xdr_stream *xdr, struct nfs_readres *result)
 107{
 108	u32 recvd, count;
 109	__be32 *p;
 110
 111	p = xdr_inline_decode(xdr, 4);
 112	if (unlikely(p == NULL))
 113		goto out_overflow;
 114	count = be32_to_cpup(p);
 115	recvd = xdr_read_pages(xdr, count);
 116	if (unlikely(count > recvd))
 117		goto out_cheating;
 118out:
 119	result->eof = 0;	/* NFSv2 does not pass EOF flag on the wire. */
 120	result->count = count;
 121	return count;
 122out_cheating:
 123	dprintk("NFS: server cheating in read result: "
 124		"count %u > recvd %u\n", count, recvd);
 125	count = recvd;
 126	goto out;
 127out_overflow:
 128	print_overflow_msg(__func__, xdr);
 129	return -EIO;
 130}
 131
 132/*
 133 *	enum stat {
 134 *		NFS_OK = 0,
 135 *		NFSERR_PERM = 1,
 136 *		NFSERR_NOENT = 2,
 137 *		NFSERR_IO = 5,
 138 *		NFSERR_NXIO = 6,
 139 *		NFSERR_ACCES = 13,
 140 *		NFSERR_EXIST = 17,
 141 *		NFSERR_NODEV = 19,
 142 *		NFSERR_NOTDIR = 20,
 143 *		NFSERR_ISDIR = 21,
 144 *		NFSERR_FBIG = 27,
 145 *		NFSERR_NOSPC = 28,
 146 *		NFSERR_ROFS = 30,
 147 *		NFSERR_NAMETOOLONG = 63,
 148 *		NFSERR_NOTEMPTY = 66,
 149 *		NFSERR_DQUOT = 69,
 150 *		NFSERR_STALE = 70,
 151 *		NFSERR_WFLUSH = 99
 152 *	};
 153 */
 154static int decode_stat(struct xdr_stream *xdr, enum nfs_stat *status)
 155{
 156	__be32 *p;
 157
 158	p = xdr_inline_decode(xdr, 4);
 159	if (unlikely(p == NULL))
 160		goto out_overflow;
 161	*status = be32_to_cpup(p);
 162	return 0;
 163out_overflow:
 164	print_overflow_msg(__func__, xdr);
 165	return -EIO;
 166}
 167
 168/*
 169 * 2.3.2.  ftype
 170 *
 171 *	enum ftype {
 172 *		NFNON = 0,
 173 *		NFREG = 1,
 174 *		NFDIR = 2,
 175 *		NFBLK = 3,
 176 *		NFCHR = 4,
 177 *		NFLNK = 5
 178 *	};
 179 *
 180 */
 181static __be32 *xdr_decode_ftype(__be32 *p, u32 *type)
 182{
 183	*type = be32_to_cpup(p++);
 184	if (unlikely(*type > NF2FIFO))
 185		*type = NFBAD;
 186	return p;
 187}
 188
 189/*
 190 * 2.3.3.  fhandle
 191 *
 192 *	typedef opaque fhandle[FHSIZE];
 193 */
 194static void encode_fhandle(struct xdr_stream *xdr, const struct nfs_fh *fh)
 195{
 196	__be32 *p;
 197
 198	p = xdr_reserve_space(xdr, NFS2_FHSIZE);
 199	memcpy(p, fh->data, NFS2_FHSIZE);
 200}
 201
 202static int decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
 203{
 204	__be32 *p;
 205
 206	p = xdr_inline_decode(xdr, NFS2_FHSIZE);
 207	if (unlikely(p == NULL))
 208		goto out_overflow;
 209	fh->size = NFS2_FHSIZE;
 210	memcpy(fh->data, p, NFS2_FHSIZE);
 211	return 0;
 212out_overflow:
 213	print_overflow_msg(__func__, xdr);
 214	return -EIO;
 215}
 216
 217/*
 218 * 2.3.4.  timeval
 219 *
 220 *	struct timeval {
 221 *		unsigned int seconds;
 222 *		unsigned int useconds;
 223 *	};
 224 */
 225static __be32 *xdr_encode_time(__be32 *p, const struct timespec *timep)
 226{
 227	*p++ = cpu_to_be32(timep->tv_sec);
 228	if (timep->tv_nsec != 0)
 229		*p++ = cpu_to_be32(timep->tv_nsec / NSEC_PER_USEC);
 230	else
 231		*p++ = cpu_to_be32(0);
 232	return p;
 233}
 234
 235/*
 236 * Passing the invalid value useconds=1000000 is a Sun convention for
 237 * "set to current server time".  It's needed to make permissions checks
 238 * for the "touch" program across v2 mounts to Solaris and Irix servers
 239 * work correctly.  See description of sattr in section 6.1 of "NFS
 240 * Illustrated" by Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5.
 241 */
 242static __be32 *xdr_encode_current_server_time(__be32 *p,
 243					      const struct timespec *timep)
 244{
 245	*p++ = cpu_to_be32(timep->tv_sec);
 246	*p++ = cpu_to_be32(1000000);
 247	return p;
 248}
 249
 250static __be32 *xdr_decode_time(__be32 *p, struct timespec *timep)
 251{
 252	timep->tv_sec = be32_to_cpup(p++);
 253	timep->tv_nsec = be32_to_cpup(p++) * NSEC_PER_USEC;
 254	return p;
 255}
 256
 257/*
 258 * 2.3.5.  fattr
 259 *
 260 *	struct fattr {
 261 *		ftype		type;
 262 *		unsigned int	mode;
 263 *		unsigned int	nlink;
 264 *		unsigned int	uid;
 265 *		unsigned int	gid;
 266 *		unsigned int	size;
 267 *		unsigned int	blocksize;
 268 *		unsigned int	rdev;
 269 *		unsigned int	blocks;
 270 *		unsigned int	fsid;
 271 *		unsigned int	fileid;
 272 *		timeval		atime;
 273 *		timeval		mtime;
 274 *		timeval		ctime;
 275 *	};
 276 *
 277 */
 278static int decode_fattr(struct xdr_stream *xdr, struct nfs_fattr *fattr)
 279{
 280	u32 rdev, type;
 281	__be32 *p;
 282
 283	p = xdr_inline_decode(xdr, NFS_fattr_sz << 2);
 284	if (unlikely(p == NULL))
 285		goto out_overflow;
 286
 287	fattr->valid |= NFS_ATTR_FATTR_V2;
 288
 289	p = xdr_decode_ftype(p, &type);
 290
 291	fattr->mode = be32_to_cpup(p++);
 292	fattr->nlink = be32_to_cpup(p++);
 293	fattr->uid = make_kuid(&init_user_ns, be32_to_cpup(p++));
 294	if (!uid_valid(fattr->uid))
 295		goto out_uid;
 296	fattr->gid = make_kgid(&init_user_ns, be32_to_cpup(p++));
 297	if (!gid_valid(fattr->gid))
 298		goto out_gid;
 299		
 300	fattr->size = be32_to_cpup(p++);
 301	fattr->du.nfs2.blocksize = be32_to_cpup(p++);
 302
 303	rdev = be32_to_cpup(p++);
 304	fattr->rdev = new_decode_dev(rdev);
 305	if (type == (u32)NFCHR && rdev == (u32)NFS2_FIFO_DEV) {
 306		fattr->mode = (fattr->mode & ~S_IFMT) | S_IFIFO;
 307		fattr->rdev = 0;
 308	}
 309
 310	fattr->du.nfs2.blocks = be32_to_cpup(p++);
 311	fattr->fsid.major = be32_to_cpup(p++);
 312	fattr->fsid.minor = 0;
 313	fattr->fileid = be32_to_cpup(p++);
 314
 315	p = xdr_decode_time(p, &fattr->atime);
 316	p = xdr_decode_time(p, &fattr->mtime);
 317	xdr_decode_time(p, &fattr->ctime);
 318	fattr->change_attr = nfs_timespec_to_change_attr(&fattr->ctime);
 319
 320	return 0;
 321out_uid:
 322	dprintk("NFS: returned invalid uid\n");
 323	return -EINVAL;
 324out_gid:
 325	dprintk("NFS: returned invalid gid\n");
 326	return -EINVAL;
 327out_overflow:
 328	print_overflow_msg(__func__, xdr);
 329	return -EIO;
 330}
 331
 332/*
 333 * 2.3.6.  sattr
 334 *
 335 *	struct sattr {
 336 *		unsigned int	mode;
 337 *		unsigned int	uid;
 338 *		unsigned int	gid;
 339 *		unsigned int	size;
 340 *		timeval		atime;
 341 *		timeval		mtime;
 342 *	};
 343 */
 344
 345#define NFS2_SATTR_NOT_SET	(0xffffffff)
 346
 347static __be32 *xdr_time_not_set(__be32 *p)
 348{
 349	*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
 350	*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
 351	return p;
 352}
 353
 354static void encode_sattr(struct xdr_stream *xdr, const struct iattr *attr)
 355{
 356	__be32 *p;
 357
 358	p = xdr_reserve_space(xdr, NFS_sattr_sz << 2);
 359
 360	if (attr->ia_valid & ATTR_MODE)
 361		*p++ = cpu_to_be32(attr->ia_mode);
 362	else
 363		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
 364	if (attr->ia_valid & ATTR_UID)
 365		*p++ = cpu_to_be32(from_kuid(&init_user_ns, attr->ia_uid));
 366	else
 367		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
 368	if (attr->ia_valid & ATTR_GID)
 369		*p++ = cpu_to_be32(from_kgid(&init_user_ns, attr->ia_gid));
 370	else
 371		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
 372	if (attr->ia_valid & ATTR_SIZE)
 373		*p++ = cpu_to_be32((u32)attr->ia_size);
 374	else
 375		*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
 376
 377	if (attr->ia_valid & ATTR_ATIME_SET)
 378		p = xdr_encode_time(p, &attr->ia_atime);
 379	else if (attr->ia_valid & ATTR_ATIME)
 380		p = xdr_encode_current_server_time(p, &attr->ia_atime);
 381	else
 382		p = xdr_time_not_set(p);
 383	if (attr->ia_valid & ATTR_MTIME_SET)
 384		xdr_encode_time(p, &attr->ia_mtime);
 385	else if (attr->ia_valid & ATTR_MTIME)
 386		xdr_encode_current_server_time(p, &attr->ia_mtime);
 387	else
 388		xdr_time_not_set(p);
 389}
 390
 391/*
 392 * 2.3.7.  filename
 393 *
 394 *	typedef string filename<MAXNAMLEN>;
 395 */
 396static void encode_filename(struct xdr_stream *xdr,
 397			    const char *name, u32 length)
 398{
 399	__be32 *p;
 400
 401	WARN_ON_ONCE(length > NFS2_MAXNAMLEN);
 402	p = xdr_reserve_space(xdr, 4 + length);
 403	xdr_encode_opaque(p, name, length);
 404}
 405
 406static int decode_filename_inline(struct xdr_stream *xdr,
 407				  const char **name, u32 *length)
 408{
 409	__be32 *p;
 410	u32 count;
 411
 412	p = xdr_inline_decode(xdr, 4);
 413	if (unlikely(p == NULL))
 414		goto out_overflow;
 415	count = be32_to_cpup(p);
 416	if (count > NFS3_MAXNAMLEN)
 417		goto out_nametoolong;
 418	p = xdr_inline_decode(xdr, count);
 419	if (unlikely(p == NULL))
 420		goto out_overflow;
 421	*name = (const char *)p;
 422	*length = count;
 423	return 0;
 424out_nametoolong:
 425	dprintk("NFS: returned filename too long: %u\n", count);
 426	return -ENAMETOOLONG;
 427out_overflow:
 428	print_overflow_msg(__func__, xdr);
 429	return -EIO;
 430}
 431
 432/*
 433 * 2.3.8.  path
 434 *
 435 *	typedef string path<MAXPATHLEN>;
 436 */
 437static void encode_path(struct xdr_stream *xdr, struct page **pages, u32 length)
 438{
 439	__be32 *p;
 440
 441	p = xdr_reserve_space(xdr, 4);
 442	*p = cpu_to_be32(length);
 443	xdr_write_pages(xdr, pages, 0, length);
 444}
 445
 446static int decode_path(struct xdr_stream *xdr)
 447{
 448	u32 length, recvd;
 449	__be32 *p;
 450
 451	p = xdr_inline_decode(xdr, 4);
 452	if (unlikely(p == NULL))
 453		goto out_overflow;
 454	length = be32_to_cpup(p);
 455	if (unlikely(length >= xdr->buf->page_len || length > NFS_MAXPATHLEN))
 456		goto out_size;
 457	recvd = xdr_read_pages(xdr, length);
 458	if (unlikely(length > recvd))
 459		goto out_cheating;
 460	xdr_terminate_string(xdr->buf, length);
 461	return 0;
 462out_size:
 463	dprintk("NFS: returned pathname too long: %u\n", length);
 464	return -ENAMETOOLONG;
 465out_cheating:
 466	dprintk("NFS: server cheating in pathname result: "
 467		"length %u > received %u\n", length, recvd);
 468	return -EIO;
 469out_overflow:
 470	print_overflow_msg(__func__, xdr);
 471	return -EIO;
 472}
 473
 474/*
 475 * 2.3.9.  attrstat
 476 *
 477 *	union attrstat switch (stat status) {
 478 *	case NFS_OK:
 479 *		fattr attributes;
 480 *	default:
 481 *		void;
 482 *	};
 483 */
 484static int decode_attrstat(struct xdr_stream *xdr, struct nfs_fattr *result)
 
 485{
 486	enum nfs_stat status;
 487	int error;
 488
 489	error = decode_stat(xdr, &status);
 490	if (unlikely(error))
 491		goto out;
 
 
 492	if (status != NFS_OK)
 493		goto out_default;
 494	error = decode_fattr(xdr, result);
 495out:
 496	return error;
 497out_default:
 498	return nfs_stat_to_errno(status);
 499}
 500
 501/*
 502 * 2.3.10.  diropargs
 503 *
 504 *	struct diropargs {
 505 *		fhandle  dir;
 506 *		filename name;
 507 *	};
 508 */
 509static void encode_diropargs(struct xdr_stream *xdr, const struct nfs_fh *fh,
 510			     const char *name, u32 length)
 511{
 512	encode_fhandle(xdr, fh);
 513	encode_filename(xdr, name, length);
 514}
 515
 516/*
 517 * 2.3.11.  diropres
 518 *
 519 *	union diropres switch (stat status) {
 520 *	case NFS_OK:
 521 *		struct {
 522 *			fhandle file;
 523 *			fattr   attributes;
 524 *		} diropok;
 525 *	default:
 526 *		void;
 527 *	};
 528 */
 529static int decode_diropok(struct xdr_stream *xdr, struct nfs_diropok *result)
 530{
 531	int error;
 532
 533	error = decode_fhandle(xdr, result->fh);
 534	if (unlikely(error))
 535		goto out;
 536	error = decode_fattr(xdr, result->fattr);
 537out:
 538	return error;
 539}
 540
 541static int decode_diropres(struct xdr_stream *xdr, struct nfs_diropok *result)
 542{
 543	enum nfs_stat status;
 544	int error;
 545
 546	error = decode_stat(xdr, &status);
 547	if (unlikely(error))
 548		goto out;
 549	if (status != NFS_OK)
 550		goto out_default;
 551	error = decode_diropok(xdr, result);
 552out:
 553	return error;
 554out_default:
 555	return nfs_stat_to_errno(status);
 556}
 557
 558
 559/*
 560 * NFSv2 XDR encode functions
 561 *
 562 * NFSv2 argument types are defined in section 2.2 of RFC 1094:
 563 * "NFS: Network File System Protocol Specification".
 564 */
 565
 566static void nfs2_xdr_enc_fhandle(struct rpc_rqst *req,
 567				 struct xdr_stream *xdr,
 568				 const struct nfs_fh *fh)
 569{
 570	encode_fhandle(xdr, fh);
 571}
 572
 573/*
 574 * 2.2.3.  sattrargs
 575 *
 576 *	struct sattrargs {
 577 *		fhandle file;
 578 *		sattr attributes;
 579 *	};
 580 */
 581static void nfs2_xdr_enc_sattrargs(struct rpc_rqst *req,
 582				   struct xdr_stream *xdr,
 583				   const struct nfs_sattrargs *args)
 584{
 585	encode_fhandle(xdr, args->fh);
 586	encode_sattr(xdr, args->sattr);
 587}
 588
 589static void nfs2_xdr_enc_diropargs(struct rpc_rqst *req,
 590				   struct xdr_stream *xdr,
 591				   const struct nfs_diropargs *args)
 592{
 593	encode_diropargs(xdr, args->fh, args->name, args->len);
 594}
 595
 596static void nfs2_xdr_enc_readlinkargs(struct rpc_rqst *req,
 597				      struct xdr_stream *xdr,
 598				      const struct nfs_readlinkargs *args)
 599{
 600	encode_fhandle(xdr, args->fh);
 601	prepare_reply_buffer(req, args->pages, args->pgbase,
 602					args->pglen, NFS_readlinkres_sz);
 603}
 604
 605/*
 606 * 2.2.7.  readargs
 607 *
 608 *	struct readargs {
 609 *		fhandle file;
 610 *		unsigned offset;
 611 *		unsigned count;
 612 *		unsigned totalcount;
 613 *	};
 614 */
 615static void encode_readargs(struct xdr_stream *xdr,
 616			    const struct nfs_readargs *args)
 617{
 618	u32 offset = args->offset;
 619	u32 count = args->count;
 620	__be32 *p;
 621
 622	encode_fhandle(xdr, args->fh);
 623
 624	p = xdr_reserve_space(xdr, 4 + 4 + 4);
 625	*p++ = cpu_to_be32(offset);
 626	*p++ = cpu_to_be32(count);
 627	*p = cpu_to_be32(count);
 628}
 629
 630static void nfs2_xdr_enc_readargs(struct rpc_rqst *req,
 631				  struct xdr_stream *xdr,
 632				  const struct nfs_readargs *args)
 633{
 634	encode_readargs(xdr, args);
 635	prepare_reply_buffer(req, args->pages, args->pgbase,
 636					args->count, NFS_readres_sz);
 637	req->rq_rcv_buf.flags |= XDRBUF_READ;
 638}
 639
 640/*
 641 * 2.2.9.  writeargs
 642 *
 643 *	struct writeargs {
 644 *		fhandle file;
 645 *		unsigned beginoffset;
 646 *		unsigned offset;
 647 *		unsigned totalcount;
 648 *		nfsdata data;
 649 *	};
 650 */
 651static void encode_writeargs(struct xdr_stream *xdr,
 652			     const struct nfs_writeargs *args)
 653{
 654	u32 offset = args->offset;
 655	u32 count = args->count;
 656	__be32 *p;
 657
 658	encode_fhandle(xdr, args->fh);
 659
 660	p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
 661	*p++ = cpu_to_be32(offset);
 662	*p++ = cpu_to_be32(offset);
 663	*p++ = cpu_to_be32(count);
 664
 665	/* nfsdata */
 666	*p = cpu_to_be32(count);
 667	xdr_write_pages(xdr, args->pages, args->pgbase, count);
 668}
 669
 670static void nfs2_xdr_enc_writeargs(struct rpc_rqst *req,
 671				   struct xdr_stream *xdr,
 672				   const struct nfs_writeargs *args)
 673{
 674	encode_writeargs(xdr, args);
 675	xdr->buf->flags |= XDRBUF_WRITE;
 676}
 677
 678/*
 679 * 2.2.10.  createargs
 680 *
 681 *	struct createargs {
 682 *		diropargs where;
 683 *		sattr attributes;
 684 *	};
 685 */
 686static void nfs2_xdr_enc_createargs(struct rpc_rqst *req,
 687				    struct xdr_stream *xdr,
 688				    const struct nfs_createargs *args)
 689{
 690	encode_diropargs(xdr, args->fh, args->name, args->len);
 691	encode_sattr(xdr, args->sattr);
 692}
 693
 694static void nfs2_xdr_enc_removeargs(struct rpc_rqst *req,
 695				    struct xdr_stream *xdr,
 696				    const struct nfs_removeargs *args)
 697{
 698	encode_diropargs(xdr, args->fh, args->name.name, args->name.len);
 699}
 700
 701/*
 702 * 2.2.12.  renameargs
 703 *
 704 *	struct renameargs {
 705 *		diropargs from;
 706 *		diropargs to;
 707 *	};
 708 */
 709static void nfs2_xdr_enc_renameargs(struct rpc_rqst *req,
 710				    struct xdr_stream *xdr,
 711				    const struct nfs_renameargs *args)
 712{
 713	const struct qstr *old = args->old_name;
 714	const struct qstr *new = args->new_name;
 715
 716	encode_diropargs(xdr, args->old_dir, old->name, old->len);
 717	encode_diropargs(xdr, args->new_dir, new->name, new->len);
 718}
 719
 720/*
 721 * 2.2.13.  linkargs
 722 *
 723 *	struct linkargs {
 724 *		fhandle from;
 725 *		diropargs to;
 726 *	};
 727 */
 728static void nfs2_xdr_enc_linkargs(struct rpc_rqst *req,
 729				  struct xdr_stream *xdr,
 730				  const struct nfs_linkargs *args)
 731{
 732	encode_fhandle(xdr, args->fromfh);
 733	encode_diropargs(xdr, args->tofh, args->toname, args->tolen);
 734}
 735
 736/*
 737 * 2.2.14.  symlinkargs
 738 *
 739 *	struct symlinkargs {
 740 *		diropargs from;
 741 *		path to;
 742 *		sattr attributes;
 743 *	};
 744 */
 745static void nfs2_xdr_enc_symlinkargs(struct rpc_rqst *req,
 746				     struct xdr_stream *xdr,
 747				     const struct nfs_symlinkargs *args)
 748{
 749	encode_diropargs(xdr, args->fromfh, args->fromname, args->fromlen);
 750	encode_path(xdr, args->pages, args->pathlen);
 751	encode_sattr(xdr, args->sattr);
 752}
 753
 754/*
 755 * 2.2.17.  readdirargs
 756 *
 757 *	struct readdirargs {
 758 *		fhandle dir;
 759 *		nfscookie cookie;
 760 *		unsigned count;
 761 *	};
 762 */
 763static void encode_readdirargs(struct xdr_stream *xdr,
 764			       const struct nfs_readdirargs *args)
 765{
 766	__be32 *p;
 767
 768	encode_fhandle(xdr, args->fh);
 769
 770	p = xdr_reserve_space(xdr, 4 + 4);
 771	*p++ = cpu_to_be32(args->cookie);
 772	*p = cpu_to_be32(args->count);
 773}
 774
 775static void nfs2_xdr_enc_readdirargs(struct rpc_rqst *req,
 776				     struct xdr_stream *xdr,
 777				     const struct nfs_readdirargs *args)
 778{
 779	encode_readdirargs(xdr, args);
 780	prepare_reply_buffer(req, args->pages, 0,
 781					args->count, NFS_readdirres_sz);
 782}
 783
 784/*
 785 * NFSv2 XDR decode functions
 786 *
 787 * NFSv2 result types are defined in section 2.2 of RFC 1094:
 788 * "NFS: Network File System Protocol Specification".
 789 */
 790
 791static int nfs2_xdr_dec_stat(struct rpc_rqst *req, struct xdr_stream *xdr,
 792			     void *__unused)
 793{
 794	enum nfs_stat status;
 795	int error;
 796
 797	error = decode_stat(xdr, &status);
 798	if (unlikely(error))
 799		goto out;
 800	if (status != NFS_OK)
 801		goto out_default;
 802out:
 803	return error;
 804out_default:
 805	return nfs_stat_to_errno(status);
 806}
 807
 808static int nfs2_xdr_dec_attrstat(struct rpc_rqst *req, struct xdr_stream *xdr,
 809				 struct nfs_fattr *result)
 810{
 811	return decode_attrstat(xdr, result);
 812}
 813
 814static int nfs2_xdr_dec_diropres(struct rpc_rqst *req, struct xdr_stream *xdr,
 815				 struct nfs_diropok *result)
 816{
 817	return decode_diropres(xdr, result);
 818}
 819
 820/*
 821 * 2.2.6.  readlinkres
 822 *
 823 *	union readlinkres switch (stat status) {
 824 *	case NFS_OK:
 825 *		path data;
 826 *	default:
 827 *		void;
 828 *	};
 829 */
 830static int nfs2_xdr_dec_readlinkres(struct rpc_rqst *req,
 831				    struct xdr_stream *xdr, void *__unused)
 832{
 833	enum nfs_stat status;
 834	int error;
 835
 836	error = decode_stat(xdr, &status);
 837	if (unlikely(error))
 838		goto out;
 839	if (status != NFS_OK)
 840		goto out_default;
 841	error = decode_path(xdr);
 842out:
 843	return error;
 844out_default:
 845	return nfs_stat_to_errno(status);
 846}
 847
 848/*
 849 * 2.2.7.  readres
 850 *
 851 *	union readres switch (stat status) {
 852 *	case NFS_OK:
 853 *		fattr attributes;
 854 *		nfsdata data;
 855 *	default:
 856 *		void;
 857 *	};
 858 */
 859static int nfs2_xdr_dec_readres(struct rpc_rqst *req, struct xdr_stream *xdr,
 860				struct nfs_readres *result)
 861{
 862	enum nfs_stat status;
 863	int error;
 864
 865	error = decode_stat(xdr, &status);
 866	if (unlikely(error))
 867		goto out;
 
 868	if (status != NFS_OK)
 869		goto out_default;
 870	error = decode_fattr(xdr, result->fattr);
 871	if (unlikely(error))
 872		goto out;
 873	error = decode_nfsdata(xdr, result);
 874out:
 875	return error;
 876out_default:
 877	return nfs_stat_to_errno(status);
 878}
 879
 880static int nfs2_xdr_dec_writeres(struct rpc_rqst *req, struct xdr_stream *xdr,
 881				 struct nfs_writeres *result)
 882{
 883	/* All NFSv2 writes are "file sync" writes */
 884	result->verf->committed = NFS_FILE_SYNC;
 885	return decode_attrstat(xdr, result->fattr);
 886}
 887
 888/**
 889 * nfs2_decode_dirent - Decode a single NFSv2 directory entry stored in
 890 *                      the local page cache.
 891 * @xdr: XDR stream where entry resides
 892 * @entry: buffer to fill in with entry data
 893 * @plus: boolean indicating whether this should be a readdirplus entry
 894 *
 895 * Returns zero if successful, otherwise a negative errno value is
 896 * returned.
 897 *
 898 * This function is not invoked during READDIR reply decoding, but
 899 * rather whenever an application invokes the getdents(2) system call
 900 * on a directory already in our cache.
 901 *
 902 * 2.2.17.  entry
 903 *
 904 *	struct entry {
 905 *		unsigned	fileid;
 906 *		filename	name;
 907 *		nfscookie	cookie;
 908 *		entry		*nextentry;
 909 *	};
 910 */
 911int nfs2_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
 912		       int plus)
 913{
 914	__be32 *p;
 915	int error;
 916
 917	p = xdr_inline_decode(xdr, 4);
 918	if (unlikely(p == NULL))
 919		goto out_overflow;
 920	if (*p++ == xdr_zero) {
 921		p = xdr_inline_decode(xdr, 4);
 922		if (unlikely(p == NULL))
 923			goto out_overflow;
 924		if (*p++ == xdr_zero)
 925			return -EAGAIN;
 926		entry->eof = 1;
 927		return -EBADCOOKIE;
 928	}
 929
 930	p = xdr_inline_decode(xdr, 4);
 931	if (unlikely(p == NULL))
 932		goto out_overflow;
 933	entry->ino = be32_to_cpup(p);
 934
 935	error = decode_filename_inline(xdr, &entry->name, &entry->len);
 936	if (unlikely(error))
 937		return error;
 938
 939	/*
 940	 * The type (size and byte order) of nfscookie isn't defined in
 941	 * RFC 1094.  This implementation assumes that it's an XDR uint32.
 942	 */
 943	entry->prev_cookie = entry->cookie;
 944	p = xdr_inline_decode(xdr, 4);
 945	if (unlikely(p == NULL))
 946		goto out_overflow;
 947	entry->cookie = be32_to_cpup(p);
 948
 949	entry->d_type = DT_UNKNOWN;
 950
 951	return 0;
 952
 953out_overflow:
 954	print_overflow_msg(__func__, xdr);
 955	return -EAGAIN;
 956}
 957
 958/*
 959 * 2.2.17.  readdirres
 960 *
 961 *	union readdirres switch (stat status) {
 962 *	case NFS_OK:
 963 *		struct {
 964 *			entry *entries;
 965 *			bool eof;
 966 *		} readdirok;
 967 *	default:
 968 *		void;
 969 *	};
 970 *
 971 * Read the directory contents into the page cache, but don't
 972 * touch them.  The actual decoding is done by nfs2_decode_dirent()
 973 * during subsequent nfs_readdir() calls.
 974 */
 975static int decode_readdirok(struct xdr_stream *xdr)
 976{
 977	return xdr_read_pages(xdr, xdr->buf->page_len);
 978}
 979
 980static int nfs2_xdr_dec_readdirres(struct rpc_rqst *req,
 981				   struct xdr_stream *xdr, void *__unused)
 982{
 983	enum nfs_stat status;
 984	int error;
 985
 986	error = decode_stat(xdr, &status);
 987	if (unlikely(error))
 988		goto out;
 989	if (status != NFS_OK)
 990		goto out_default;
 991	error = decode_readdirok(xdr);
 992out:
 993	return error;
 994out_default:
 995	return nfs_stat_to_errno(status);
 996}
 997
 998/*
 999 * 2.2.18.  statfsres
1000 *
1001 *	union statfsres (stat status) {
1002 *	case NFS_OK:
1003 *		struct {
1004 *			unsigned tsize;
1005 *			unsigned bsize;
1006 *			unsigned blocks;
1007 *			unsigned bfree;
1008 *			unsigned bavail;
1009 *		} info;
1010 *	default:
1011 *		void;
1012 *	};
1013 */
1014static int decode_info(struct xdr_stream *xdr, struct nfs2_fsstat *result)
1015{
1016	__be32 *p;
1017
1018	p = xdr_inline_decode(xdr, NFS_info_sz << 2);
1019	if (unlikely(p == NULL))
1020		goto out_overflow;
1021	result->tsize  = be32_to_cpup(p++);
1022	result->bsize  = be32_to_cpup(p++);
1023	result->blocks = be32_to_cpup(p++);
1024	result->bfree  = be32_to_cpup(p++);
1025	result->bavail = be32_to_cpup(p);
1026	return 0;
1027out_overflow:
1028	print_overflow_msg(__func__, xdr);
1029	return -EIO;
1030}
1031
1032static int nfs2_xdr_dec_statfsres(struct rpc_rqst *req, struct xdr_stream *xdr,
1033				  struct nfs2_fsstat *result)
1034{
1035	enum nfs_stat status;
1036	int error;
1037
1038	error = decode_stat(xdr, &status);
1039	if (unlikely(error))
1040		goto out;
1041	if (status != NFS_OK)
1042		goto out_default;
1043	error = decode_info(xdr, result);
1044out:
1045	return error;
1046out_default:
1047	return nfs_stat_to_errno(status);
1048}
1049
1050
1051/*
1052 * We need to translate between nfs status return values and
1053 * the local errno values which may not be the same.
1054 */
1055static const struct {
1056	int stat;
1057	int errno;
1058} nfs_errtbl[] = {
1059	{ NFS_OK,		0		},
1060	{ NFSERR_PERM,		-EPERM		},
1061	{ NFSERR_NOENT,		-ENOENT		},
1062	{ NFSERR_IO,		-errno_NFSERR_IO},
1063	{ NFSERR_NXIO,		-ENXIO		},
1064/*	{ NFSERR_EAGAIN,	-EAGAIN		}, */
1065	{ NFSERR_ACCES,		-EACCES		},
1066	{ NFSERR_EXIST,		-EEXIST		},
1067	{ NFSERR_XDEV,		-EXDEV		},
1068	{ NFSERR_NODEV,		-ENODEV		},
1069	{ NFSERR_NOTDIR,	-ENOTDIR	},
1070	{ NFSERR_ISDIR,		-EISDIR		},
1071	{ NFSERR_INVAL,		-EINVAL		},
1072	{ NFSERR_FBIG,		-EFBIG		},
1073	{ NFSERR_NOSPC,		-ENOSPC		},
1074	{ NFSERR_ROFS,		-EROFS		},
1075	{ NFSERR_MLINK,		-EMLINK		},
1076	{ NFSERR_NAMETOOLONG,	-ENAMETOOLONG	},
1077	{ NFSERR_NOTEMPTY,	-ENOTEMPTY	},
1078	{ NFSERR_DQUOT,		-EDQUOT		},
1079	{ NFSERR_STALE,		-ESTALE		},
1080	{ NFSERR_REMOTE,	-EREMOTE	},
1081#ifdef EWFLUSH
1082	{ NFSERR_WFLUSH,	-EWFLUSH	},
1083#endif
1084	{ NFSERR_BADHANDLE,	-EBADHANDLE	},
1085	{ NFSERR_NOT_SYNC,	-ENOTSYNC	},
1086	{ NFSERR_BAD_COOKIE,	-EBADCOOKIE	},
1087	{ NFSERR_NOTSUPP,	-ENOTSUPP	},
1088	{ NFSERR_TOOSMALL,	-ETOOSMALL	},
1089	{ NFSERR_SERVERFAULT,	-EREMOTEIO	},
1090	{ NFSERR_BADTYPE,	-EBADTYPE	},
1091	{ NFSERR_JUKEBOX,	-EJUKEBOX	},
1092	{ -1,			-EIO		}
1093};
1094
1095/**
1096 * nfs_stat_to_errno - convert an NFS status code to a local errno
1097 * @status: NFS status code to convert
1098 *
1099 * Returns a local errno value, or -EIO if the NFS status code is
1100 * not recognized.  This function is used jointly by NFSv2 and NFSv3.
1101 */
1102static int nfs_stat_to_errno(enum nfs_stat status)
1103{
1104	int i;
1105
1106	for (i = 0; nfs_errtbl[i].stat != -1; i++) {
1107		if (nfs_errtbl[i].stat == (int)status)
1108			return nfs_errtbl[i].errno;
1109	}
1110	dprintk("NFS: Unrecognized nfs status value: %u\n", status);
1111	return nfs_errtbl[i].errno;
1112}
1113
1114#define PROC(proc, argtype, restype, timer)				\
1115[NFSPROC_##proc] = {							\
1116	.p_proc	    =  NFSPROC_##proc,					\
1117	.p_encode   =  (kxdreproc_t)nfs2_xdr_enc_##argtype,		\
1118	.p_decode   =  (kxdrdproc_t)nfs2_xdr_dec_##restype,		\
1119	.p_arglen   =  NFS_##argtype##_sz,				\
1120	.p_replen   =  NFS_##restype##_sz,				\
1121	.p_timer    =  timer,						\
1122	.p_statidx  =  NFSPROC_##proc,					\
1123	.p_name     =  #proc,						\
1124	}
1125struct rpc_procinfo	nfs_procedures[] = {
1126	PROC(GETATTR,	fhandle,	attrstat,	1),
1127	PROC(SETATTR,	sattrargs,	attrstat,	0),
1128	PROC(LOOKUP,	diropargs,	diropres,	2),
1129	PROC(READLINK,	readlinkargs,	readlinkres,	3),
1130	PROC(READ,	readargs,	readres,	3),
1131	PROC(WRITE,	writeargs,	writeres,	4),
1132	PROC(CREATE,	createargs,	diropres,	0),
1133	PROC(REMOVE,	removeargs,	stat,		0),
1134	PROC(RENAME,	renameargs,	stat,		0),
1135	PROC(LINK,	linkargs,	stat,		0),
1136	PROC(SYMLINK,	symlinkargs,	stat,		0),
1137	PROC(MKDIR,	createargs,	diropres,	0),
1138	PROC(RMDIR,	diropargs,	stat,		0),
1139	PROC(READDIR,	readdirargs,	readdirres,	3),
1140	PROC(STATFS,	fhandle,	statfsres,	0),
1141};
1142
1143const struct rpc_version nfs_version2 = {
1144	.number			= 2,
1145	.nrprocs		= ARRAY_SIZE(nfs_procedures),
1146	.procs			= nfs_procedures
1147};