fs/nfs/nfs2xdr.c

   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
  64 static 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  */
  70 static 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  */
  84 static 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  */
 106 static 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;
 118 out:
 119         result->eof = 0;        /* NFSv2 does not pass EOF flag on the wire. */
 120         result->count = count;
 121         return count;
 122 out_cheating:
 123         dprintk("NFS: server cheating in read result: "
 124                 "count %u > recvd %u\n", count, recvd);
 125         count = recvd;
 126         goto out;
 127 out_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  */
 154 static 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;
 163 out_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  */
 181 static __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  */
 194 static 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
 202 static 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;
 212 out_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  */
 225 static __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  */
 242 static __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
 250 static __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  */
 278 static 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;
 321 out_uid:
 322         dprintk("NFS: returned invalid uid\n");
 323         return -EINVAL;
 324 out_gid:
 325         dprintk("NFS: returned invalid gid\n");
 326         return -EINVAL;
 327 out_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
 347 static __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
 354 static 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  */
 396 static 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
 406 static 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;
 424 out_nametoolong:
 425         dprintk("NFS: returned filename too long: %u\n", count);
 426         return -ENAMETOOLONG;
 427 out_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  */
 437 static 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
 446 static 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;
 462 out_size:
 463         dprintk("NFS: returned pathname too long: %u\n", length);
 464         return -ENAMETOOLONG;
 465 out_cheating:
 466         dprintk("NFS: server cheating in pathname result: "
 467                 "length %u > received %u\n", length, recvd);
 468         return -EIO;
 469 out_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  */
 484 static 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);
 498 out:
 499         return error;
 500 out_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  */
 512 static 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  */
 532 static 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);
 540 out:
 541         return error;
 542 }
 543
 544 static 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);
 555 out:
 556         return error;
 557 out_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
 569 static void nfs2_xdr_enc_fhandle(struct rpc_rqst *req,
 570                                  struct xdr_stream *xdr,
 571                                  const void *data)
 572 {
 573         const struct nfs_fh *fh = data;
 574
 575         encode_fhandle(xdr, fh);
 576 }
 577
 578 /*
 579  * 2.2.3.  sattrargs
 580  *
 581  *      struct sattrargs {
 582  *              fhandle file;
 583  *              sattr attributes;
 584  *      };
 585  */
 586 static void nfs2_xdr_enc_sattrargs(struct rpc_rqst *req,
 587                                    struct xdr_stream *xdr,
 588                                    const void *data)
 589 {
 590         const struct nfs_sattrargs *args = data;
 591
 592         encode_fhandle(xdr, args->fh);
 593         encode_sattr(xdr, args->sattr);
 594 }
 595
 596 static void nfs2_xdr_enc_diropargs(struct rpc_rqst *req,
 597                                    struct xdr_stream *xdr,
 598                                    const void *data)
 599 {
 600         const struct nfs_diropargs *args = data;
 601
 602         encode_diropargs(xdr, args->fh, args->name, args->len);
 603 }
 604
 605 static void nfs2_xdr_enc_readlinkargs(struct rpc_rqst *req,
 606                                       struct xdr_stream *xdr,
 607                                       const void *data)
 608 {
 609         const struct nfs_readlinkargs *args = data;
 610
 611         encode_fhandle(xdr, args->fh);
 612         prepare_reply_buffer(req, args->pages, args->pgbase,
 613                                         args->pglen, NFS_readlinkres_sz);
 614 }
 615
 616 /*
 617  * 2.2.7.  readargs
 618  *
 619  *      struct readargs {
 620  *              fhandle file;
 621  *              unsigned offset;
 622  *              unsigned count;
 623  *              unsigned totalcount;
 624  *      };
 625  */
 626 static void encode_readargs(struct xdr_stream *xdr,
 627                             const struct nfs_pgio_args *args)
 628 {
 629         u32 offset = args->offset;
 630         u32 count = args->count;
 631         __be32 *p;
 632
 633         encode_fhandle(xdr, args->fh);
 634
 635         p = xdr_reserve_space(xdr, 4 + 4 + 4);
 636         *p++ = cpu_to_be32(offset);
 637         *p++ = cpu_to_be32(count);
 638         *p = cpu_to_be32(count);
 639 }
 640
 641 static void nfs2_xdr_enc_readargs(struct rpc_rqst *req,
 642                                   struct xdr_stream *xdr,
 643                                   const void *data)
 644 {
 645         const struct nfs_pgio_args *args = data;
 646
 647         encode_readargs(xdr, args);
 648         prepare_reply_buffer(req, args->pages, args->pgbase,
 649                                         args->count, NFS_readres_sz);
 650         req->rq_rcv_buf.flags |= XDRBUF_READ;
 651 }
 652
 653 /*
 654  * 2.2.9.  writeargs
 655  *
 656  *      struct writeargs {
 657  *              fhandle file;
 658  *              unsigned beginoffset;
 659  *              unsigned offset;
 660  *              unsigned totalcount;
 661  *              nfsdata data;
 662  *      };
 663  */
 664 static void encode_writeargs(struct xdr_stream *xdr,
 665                              const struct nfs_pgio_args *args)
 666 {
 667         u32 offset = args->offset;
 668         u32 count = args->count;
 669         __be32 *p;
 670
 671         encode_fhandle(xdr, args->fh);
 672
 673         p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
 674         *p++ = cpu_to_be32(offset);
 675         *p++ = cpu_to_be32(offset);
 676         *p++ = cpu_to_be32(count);
 677
 678         /* nfsdata */
 679         *p = cpu_to_be32(count);
 680         xdr_write_pages(xdr, args->pages, args->pgbase, count);
 681 }
 682
 683 static void nfs2_xdr_enc_writeargs(struct rpc_rqst *req,
 684                                    struct xdr_stream *xdr,
 685                                    const void *data)
 686 {
 687         const struct nfs_pgio_args *args = data;
 688
 689         encode_writeargs(xdr, args);
 690         xdr->buf->flags |= XDRBUF_WRITE;
 691 }
 692
 693 /*
 694  * 2.2.10.  createargs
 695  *
 696  *      struct createargs {
 697  *              diropargs where;
 698  *              sattr attributes;
 699  *      };
 700  */
 701 static void nfs2_xdr_enc_createargs(struct rpc_rqst *req,
 702                                     struct xdr_stream *xdr,
 703                                     const void *data)
 704 {
 705         const struct nfs_createargs *args = data;
 706
 707         encode_diropargs(xdr, args->fh, args->name, args->len);
 708         encode_sattr(xdr, args->sattr);
 709 }
 710
 711 static void nfs2_xdr_enc_removeargs(struct rpc_rqst *req,
 712                                     struct xdr_stream *xdr,
 713                                     const void *data)
 714 {
 715         const struct nfs_removeargs *args = data;
 716
 717         encode_diropargs(xdr, args->fh, args->name.name, args->name.len);
 718 }
 719
 720 /*
 721  * 2.2.12.  renameargs
 722  *
 723  *      struct renameargs {
 724  *              diropargs from;
 725  *              diropargs to;
 726  *      };
 727  */
 728 static void nfs2_xdr_enc_renameargs(struct rpc_rqst *req,
 729                                     struct xdr_stream *xdr,
 730                                     const void *data)
 731 {
 732         const struct nfs_renameargs *args = data;
 733         const struct qstr *old = args->old_name;
 734         const struct qstr *new = args->new_name;
 735
 736         encode_diropargs(xdr, args->old_dir, old->name, old->len);
 737         encode_diropargs(xdr, args->new_dir, new->name, new->len);
 738 }
 739
 740 /*
 741  * 2.2.13.  linkargs
 742  *
 743  *      struct linkargs {
 744  *              fhandle from;
 745  *              diropargs to;
 746  *      };
 747  */
 748 static void nfs2_xdr_enc_linkargs(struct rpc_rqst *req,
 749                                   struct xdr_stream *xdr,
 750                                   const void *data)
 751 {
 752         const struct nfs_linkargs *args = data;
 753
 754         encode_fhandle(xdr, args->fromfh);
 755         encode_diropargs(xdr, args->tofh, args->toname, args->tolen);
 756 }
 757
 758 /*
 759  * 2.2.14.  symlinkargs
 760  *
 761  *      struct symlinkargs {
 762  *              diropargs from;
 763  *              path to;
 764  *              sattr attributes;
 765  *      };
 766  */
 767 static void nfs2_xdr_enc_symlinkargs(struct rpc_rqst *req,
 768                                      struct xdr_stream *xdr,
 769                                      const void *data)
 770 {
 771         const struct nfs_symlinkargs *args = data;
 772
 773         encode_diropargs(xdr, args->fromfh, args->fromname, args->fromlen);
 774         encode_path(xdr, args->pages, args->pathlen);
 775         encode_sattr(xdr, args->sattr);
 776 }
 777
 778 /*
 779  * 2.2.17.  readdirargs
 780  *
 781  *      struct readdirargs {
 782  *              fhandle dir;
 783  *              nfscookie cookie;
 784  *              unsigned count;
 785  *      };
 786  */
 787 static void encode_readdirargs(struct xdr_stream *xdr,
 788                                const struct nfs_readdirargs *args)
 789 {
 790         __be32 *p;
 791
 792         encode_fhandle(xdr, args->fh);
 793
 794         p = xdr_reserve_space(xdr, 4 + 4);
 795         *p++ = cpu_to_be32(args->cookie);
 796         *p = cpu_to_be32(args->count);
 797 }
 798
 799 static void nfs2_xdr_enc_readdirargs(struct rpc_rqst *req,
 800                                      struct xdr_stream *xdr,
 801                                      const void *data)
 802 {
 803         const struct nfs_readdirargs *args = data;
 804
 805         encode_readdirargs(xdr, args);
 806         prepare_reply_buffer(req, args->pages, 0,
 807                                         args->count, NFS_readdirres_sz);
 808 }
 809
 810 /*
 811  * NFSv2 XDR decode functions
 812  *
 813  * NFSv2 result types are defined in section 2.2 of RFC 1094:
 814  * "NFS: Network File System Protocol Specification".
 815  */
 816
 817 static int nfs2_xdr_dec_stat(struct rpc_rqst *req, struct xdr_stream *xdr,
 818                              void *__unused)
 819 {
 820         enum nfs_stat status;
 821         int error;
 822
 823         error = decode_stat(xdr, &status);
 824         if (unlikely(error))
 825                 goto out;
 826         if (status != NFS_OK)
 827                 goto out_default;
 828 out:
 829         return error;
 830 out_default:
 831         return nfs_stat_to_errno(status);
 832 }
 833
 834 static int nfs2_xdr_dec_attrstat(struct rpc_rqst *req, struct xdr_stream *xdr,
 835                                  void *result)
 836 {
 837         return decode_attrstat(xdr, result, NULL);
 838 }
 839
 840 static int nfs2_xdr_dec_diropres(struct rpc_rqst *req, struct xdr_stream *xdr,
 841                                  void *result)
 842 {
 843         return decode_diropres(xdr, result);
 844 }
 845
 846 /*
 847  * 2.2.6.  readlinkres
 848  *
 849  *      union readlinkres switch (stat status) {
 850  *      case NFS_OK:
 851  *              path data;
 852  *      default:
 853  *              void;
 854  *      };
 855  */
 856 static int nfs2_xdr_dec_readlinkres(struct rpc_rqst *req,
 857                                     struct xdr_stream *xdr, void *__unused)
 858 {
 859         enum nfs_stat status;
 860         int error;
 861
 862         error = decode_stat(xdr, &status);
 863         if (unlikely(error))
 864                 goto out;
 865         if (status != NFS_OK)
 866                 goto out_default;
 867         error = decode_path(xdr);
 868 out:
 869         return error;
 870 out_default:
 871         return nfs_stat_to_errno(status);
 872 }
 873
 874 /*
 875  * 2.2.7.  readres
 876  *
 877  *      union readres switch (stat status) {
 878  *      case NFS_OK:
 879  *              fattr attributes;
 880  *              nfsdata data;
 881  *      default:
 882  *              void;
 883  *      };
 884  */
 885 static int nfs2_xdr_dec_readres(struct rpc_rqst *req, struct xdr_stream *xdr,
 886                                 void *data)
 887 {
 888         struct nfs_pgio_res *result = data;
 889         enum nfs_stat status;
 890         int error;
 891
 892         error = decode_stat(xdr, &status);
 893         if (unlikely(error))
 894                 goto out;
 895         result->op_status = status;
 896         if (status != NFS_OK)
 897                 goto out_default;
 898         error = decode_fattr(xdr, result->fattr);
 899         if (unlikely(error))
 900                 goto out;
 901         error = decode_nfsdata(xdr, result);
 902 out:
 903         return error;
 904 out_default:
 905         return nfs_stat_to_errno(status);
 906 }
 907
 908 static int nfs2_xdr_dec_writeres(struct rpc_rqst *req, struct xdr_stream *xdr,
 909                                  void *data)
 910 {
 911         struct nfs_pgio_res *result = data;
 912
 913         /* All NFSv2 writes are "file sync" writes */
 914         result->verf->committed = NFS_FILE_SYNC;
 915         return decode_attrstat(xdr, result->fattr, &result->op_status);
 916 }
 917
 918 /**
 919  * nfs2_decode_dirent - Decode a single NFSv2 directory entry stored in
 920  *                      the local page cache.
 921  * @xdr: XDR stream where entry resides
 922  * @entry: buffer to fill in with entry data
 923  * @plus: boolean indicating whether this should be a readdirplus entry
 924  *
 925  * Returns zero if successful, otherwise a negative errno value is
 926  * returned.
 927  *
 928  * This function is not invoked during READDIR reply decoding, but
 929  * rather whenever an application invokes the getdents(2) system call
 930  * on a directory already in our cache.
 931  *
 932  * 2.2.17.  entry
 933  *
 934  *      struct entry {
 935  *              unsigned        fileid;
 936  *              filename        name;
 937  *              nfscookie       cookie;
 938  *              entry           *nextentry;
 939  *      };
 940  */
 941 int nfs2_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
 942                        bool plus)
 943 {
 944         __be32 *p;
 945         int error;
 946
 947         p = xdr_inline_decode(xdr, 4);
 948         if (unlikely(p == NULL))
 949                 goto out_overflow;
 950         if (*p++ == xdr_zero) {
 951                 p = xdr_inline_decode(xdr, 4);
 952                 if (unlikely(p == NULL))
 953                         goto out_overflow;
 954                 if (*p++ == xdr_zero)
 955                         return -EAGAIN;
 956                 entry->eof = 1;
 957                 return -EBADCOOKIE;
 958         }
 959
 960         p = xdr_inline_decode(xdr, 4);
 961         if (unlikely(p == NULL))
 962                 goto out_overflow;
 963         entry->ino = be32_to_cpup(p);
 964
 965         error = decode_filename_inline(xdr, &entry->name, &entry->len);
 966         if (unlikely(error))
 967                 return error;
 968
 969         /*
 970          * The type (size and byte order) of nfscookie isn't defined in
 971          * RFC 1094.  This implementation assumes that it's an XDR uint32.
 972          */
 973         entry->prev_cookie = entry->cookie;
 974         p = xdr_inline_decode(xdr, 4);
 975         if (unlikely(p == NULL))
 976                 goto out_overflow;
 977         entry->cookie = be32_to_cpup(p);
 978
 979         entry->d_type = DT_UNKNOWN;
 980
 981         return 0;
 982
 983 out_overflow:
 984         print_overflow_msg(__func__, xdr);
 985         return -EAGAIN;
 986 }
 987
 988 /*
 989  * 2.2.17.  readdirres
 990  *
 991  *      union readdirres switch (stat status) {
 992  *      case NFS_OK:
 993  *              struct {
 994  *                      entry *entries;
 995  *                      bool eof;
 996  *              } readdirok;
 997  *      default:
 998  *              void;
 999  *      };
1000  *
1001  * Read the directory contents into the page cache, but don't
1002  * touch them.  The actual decoding is done by nfs2_decode_dirent()
1003  * during subsequent nfs_readdir() calls.
1004  */
1005 static int decode_readdirok(struct xdr_stream *xdr)
1006 {
1007         return xdr_read_pages(xdr, xdr->buf->page_len);
1008 }
1009
1010 static int nfs2_xdr_dec_readdirres(struct rpc_rqst *req,
1011                                    struct xdr_stream *xdr, void *__unused)
1012 {
1013         enum nfs_stat status;
1014         int error;
1015
1016         error = decode_stat(xdr, &status);
1017         if (unlikely(error))
1018                 goto out;
1019         if (status != NFS_OK)
1020                 goto out_default;
1021         error = decode_readdirok(xdr);
1022 out:
1023         return error;
1024 out_default:
1025         return nfs_stat_to_errno(status);
1026 }
1027
1028 /*
1029  * 2.2.18.  statfsres
1030  *
1031  *      union statfsres (stat status) {
1032  *      case NFS_OK:
1033  *              struct {
1034  *                      unsigned tsize;
1035  *                      unsigned bsize;
1036  *                      unsigned blocks;
1037  *                      unsigned bfree;
1038  *                      unsigned bavail;
1039  *              } info;
1040  *      default:
1041  *              void;
1042  *      };
1043  */
1044 static int decode_info(struct xdr_stream *xdr, struct nfs2_fsstat *result)
1045 {
1046         __be32 *p;
1047
1048         p = xdr_inline_decode(xdr, NFS_info_sz << 2);
1049         if (unlikely(p == NULL))
1050                 goto out_overflow;
1051         result->tsize  = be32_to_cpup(p++);
1052         result->bsize  = be32_to_cpup(p++);
1053         result->blocks = be32_to_cpup(p++);
1054         result->bfree  = be32_to_cpup(p++);
1055         result->bavail = be32_to_cpup(p);
1056         return 0;
1057 out_overflow:
1058         print_overflow_msg(__func__, xdr);
1059         return -EIO;
1060 }
1061
1062 static int nfs2_xdr_dec_statfsres(struct rpc_rqst *req, struct xdr_stream *xdr,
1063                                   void *result)
1064 {
1065         enum nfs_stat status;
1066         int error;
1067
1068         error = decode_stat(xdr, &status);
1069         if (unlikely(error))
1070                 goto out;
1071         if (status != NFS_OK)
1072                 goto out_default;
1073         error = decode_info(xdr, result);
1074 out:
1075         return error;
1076 out_default:
1077         return nfs_stat_to_errno(status);
1078 }
1079
1080
1081 /*
1082  * We need to translate between nfs status return values and
1083  * the local errno values which may not be the same.
1084  */
1085 static const struct {
1086         int stat;
1087         int errno;
1088 } nfs_errtbl[] = {
1089         { NFS_OK,               0               },
1090         { NFSERR_PERM,          -EPERM          },
1091         { NFSERR_NOENT,         -ENOENT         },
1092         { NFSERR_IO,            -errno_NFSERR_IO},
1093         { NFSERR_NXIO,          -ENXIO          },
1094 /*      { NFSERR_EAGAIN,        -EAGAIN         }, */
1095         { NFSERR_ACCES,         -EACCES         },
1096         { NFSERR_EXIST,         -EEXIST         },
1097         { NFSERR_XDEV,          -EXDEV          },
1098         { NFSERR_NODEV,         -ENODEV         },
1099         { NFSERR_NOTDIR,        -ENOTDIR        },
1100         { NFSERR_ISDIR,         -EISDIR         },
1101         { NFSERR_INVAL,         -EINVAL         },
1102         { NFSERR_FBIG,          -EFBIG          },
1103         { NFSERR_NOSPC,         -ENOSPC         },
1104         { NFSERR_ROFS,          -EROFS          },
1105         { NFSERR_MLINK,         -EMLINK         },
1106         { NFSERR_NAMETOOLONG,   -ENAMETOOLONG   },
1107         { NFSERR_NOTEMPTY,      -ENOTEMPTY      },
1108         { NFSERR_DQUOT,         -EDQUOT         },
1109         { NFSERR_STALE,         -ESTALE         },
1110         { NFSERR_REMOTE,        -EREMOTE        },
1111 #ifdef EWFLUSH
1112         { NFSERR_WFLUSH,        -EWFLUSH        },
1113 #endif
1114         { NFSERR_BADHANDLE,     -EBADHANDLE     },
1115         { NFSERR_NOT_SYNC,      -ENOTSYNC       },
1116         { NFSERR_BAD_COOKIE,    -EBADCOOKIE     },
1117         { NFSERR_NOTSUPP,       -ENOTSUPP       },
1118         { NFSERR_TOOSMALL,      -ETOOSMALL      },
1119         { NFSERR_SERVERFAULT,   -EREMOTEIO      },
1120         { NFSERR_BADTYPE,       -EBADTYPE       },
1121         { NFSERR_JUKEBOX,       -EJUKEBOX       },
1122         { -1,                   -EIO            }
1123 };
1124
1125 /**
1126  * nfs_stat_to_errno - convert an NFS status code to a local errno
1127  * @status: NFS status code to convert
1128  *
1129  * Returns a local errno value, or -EIO if the NFS status code is
1130  * not recognized.  This function is used jointly by NFSv2 and NFSv3.
1131  */
1132 static int nfs_stat_to_errno(enum nfs_stat status)
1133 {
1134         int i;
1135
1136         for (i = 0; nfs_errtbl[i].stat != -1; i++) {
1137                 if (nfs_errtbl[i].stat == (int)status)
1138                         return nfs_errtbl[i].errno;
1139         }
1140         dprintk("NFS: Unrecognized nfs status value: %u\n", status);
1141         return nfs_errtbl[i].errno;
1142 }
1143
1144 #define PROC(proc, argtype, restype, timer)                             \
1145 [NFSPROC_##proc] = {                                                    \
1146         .p_proc     =  NFSPROC_##proc,                                  \
1147         .p_encode   =  nfs2_xdr_enc_##argtype,                          \
1148         .p_decode   =  nfs2_xdr_dec_##restype,                          \
1149         .p_arglen   =  NFS_##argtype##_sz,                              \
1150         .p_replen   =  NFS_##restype##_sz,                              \
1151         .p_timer    =  timer,                                           \
1152         .p_statidx  =  NFSPROC_##proc,                                  \
1153         .p_name     =  #proc,                                           \
1154         }
1155 const struct rpc_procinfo nfs_procedures[] = {
1156         PROC(GETATTR,   fhandle,        attrstat,       1),
1157         PROC(SETATTR,   sattrargs,      attrstat,       0),
1158         PROC(LOOKUP,    diropargs,      diropres,       2),
1159         PROC(READLINK,  readlinkargs,   readlinkres,    3),
1160         PROC(READ,      readargs,       readres,        3),
1161         PROC(WRITE,     writeargs,      writeres,       4),
1162         PROC(CREATE,    createargs,     diropres,       0),
1163         PROC(REMOVE,    removeargs,     stat,           0),
1164         PROC(RENAME,    renameargs,     stat,           0),
1165         PROC(LINK,      linkargs,       stat,           0),
1166         PROC(SYMLINK,   symlinkargs,    stat,           0),
1167         PROC(MKDIR,     createargs,     diropres,       0),
1168         PROC(RMDIR,     diropargs,      stat,           0),
1169         PROC(READDIR,   readdirargs,    readdirres,     3),
1170         PROC(STATFS,    fhandle,        statfsres,      0),
1171 };
1172
1173 static unsigned int nfs_version2_counts[ARRAY_SIZE(nfs_procedures)];
1174 const struct rpc_version nfs_version2 = {
1175         .number                 = 2,
1176         .nrprocs                = ARRAY_SIZE(nfs_procedures),
1177         .procs                  = nfs_procedures,
1178         .counts                 = nfs_version2_counts,
1179 };