fs/nfsd/nfs3xdr.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * XDR support for nfsd/protocol version 3.
   4  *
   5  * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
   6  *
   7  * 2003-08-09 Jamie Lokier: Use htonl() for nanoseconds, not htons()!
   8  */
   9
  10 #include <linux/namei.h>
  11 #include <linux/sunrpc/svc_xprt.h>
  12 #include "xdr3.h"
  13 #include "auth.h"
  14 #include "netns.h"
  15 #include "vfs.h"
  16
  17 #define NFSDDBG_FACILITY                NFSDDBG_XDR
  18
  19
  20 /*
  21  * Mapping of S_IF* types to NFS file types
  22  */
  23 static u32      nfs3_ftypes[] = {
  24         NF3NON,  NF3FIFO, NF3CHR, NF3BAD,
  25         NF3DIR,  NF3BAD,  NF3BLK, NF3BAD,
  26         NF3REG,  NF3BAD,  NF3LNK, NF3BAD,
  27         NF3SOCK, NF3BAD,  NF3LNK, NF3BAD,
  28 };
  29
  30 /*
  31  * XDR functions for basic NFS types
  32  */
  33 static __be32 *
  34 encode_time3(__be32 *p, struct timespec *time)
  35 {
  36         *p++ = htonl((u32) time->tv_sec); *p++ = htonl(time->tv_nsec);
  37         return p;
  38 }
  39
  40 static __be32 *
  41 decode_time3(__be32 *p, struct timespec *time)
  42 {
  43         time->tv_sec = ntohl(*p++);
  44         time->tv_nsec = ntohl(*p++);
  45         return p;
  46 }
  47
  48 static __be32 *
  49 decode_fh(__be32 *p, struct svc_fh *fhp)
  50 {
  51         unsigned int size;
  52         fh_init(fhp, NFS3_FHSIZE);
  53         size = ntohl(*p++);
  54         if (size > NFS3_FHSIZE)
  55                 return NULL;
  56
  57         memcpy(&fhp->fh_handle.fh_base, p, size);
  58         fhp->fh_handle.fh_size = size;
  59         return p + XDR_QUADLEN(size);
  60 }
  61
  62 /* Helper function for NFSv3 ACL code */
  63 __be32 *nfs3svc_decode_fh(__be32 *p, struct svc_fh *fhp)
  64 {
  65         return decode_fh(p, fhp);
  66 }
  67
  68 static __be32 *
  69 encode_fh(__be32 *p, struct svc_fh *fhp)
  70 {
  71         unsigned int size = fhp->fh_handle.fh_size;
  72         *p++ = htonl(size);
  73         if (size) p[XDR_QUADLEN(size)-1]=0;
  74         memcpy(p, &fhp->fh_handle.fh_base, size);
  75         return p + XDR_QUADLEN(size);
  76 }
  77
  78 /*
  79  * Decode a file name and make sure that the path contains
  80  * no slashes or null bytes.
  81  */
  82 static __be32 *
  83 decode_filename(__be32 *p, char **namp, unsigned int *lenp)
  84 {
  85         char            *name;
  86         unsigned int    i;
  87
  88         if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS3_MAXNAMLEN)) != NULL) {
  89                 for (i = 0, name = *namp; i < *lenp; i++, name++) {
  90                         if (*name == '\0' || *name == '/')
  91                                 return NULL;
  92                 }
  93         }
  94
  95         return p;
  96 }
  97
  98 static __be32 *
  99 decode_sattr3(__be32 *p, struct iattr *iap, struct user_namespace *userns)
 100 {
 101         u32     tmp;
 102
 103         iap->ia_valid = 0;
 104
 105         if (*p++) {
 106                 iap->ia_valid |= ATTR_MODE;
 107                 iap->ia_mode = ntohl(*p++);
 108         }
 109         if (*p++) {
 110                 iap->ia_uid = make_kuid(userns, ntohl(*p++));
 111                 if (uid_valid(iap->ia_uid))
 112                         iap->ia_valid |= ATTR_UID;
 113         }
 114         if (*p++) {
 115                 iap->ia_gid = make_kgid(userns, ntohl(*p++));
 116                 if (gid_valid(iap->ia_gid))
 117                         iap->ia_valid |= ATTR_GID;
 118         }
 119         if (*p++) {
 120                 u64     newsize;
 121
 122                 iap->ia_valid |= ATTR_SIZE;
 123                 p = xdr_decode_hyper(p, &newsize);
 124                 iap->ia_size = min_t(u64, newsize, NFS_OFFSET_MAX);
 125         }
 126         if ((tmp = ntohl(*p++)) == 1) { /* set to server time */
 127                 iap->ia_valid |= ATTR_ATIME;
 128         } else if (tmp == 2) {          /* set to client time */
 129                 iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
 130                 iap->ia_atime.tv_sec = ntohl(*p++);
 131                 iap->ia_atime.tv_nsec = ntohl(*p++);
 132         }
 133         if ((tmp = ntohl(*p++)) == 1) { /* set to server time */
 134                 iap->ia_valid |= ATTR_MTIME;
 135         } else if (tmp == 2) {          /* set to client time */
 136                 iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
 137                 iap->ia_mtime.tv_sec = ntohl(*p++);
 138                 iap->ia_mtime.tv_nsec = ntohl(*p++);
 139         }
 140         return p;
 141 }
 142
 143 static __be32 *encode_fsid(__be32 *p, struct svc_fh *fhp)
 144 {
 145         u64 f;
 146         switch(fsid_source(fhp)) {
 147         default:
 148         case FSIDSOURCE_DEV:
 149                 p = xdr_encode_hyper(p, (u64)huge_encode_dev
 150                                      (fhp->fh_dentry->d_sb->s_dev));
 151                 break;
 152         case FSIDSOURCE_FSID:
 153                 p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
 154                 break;
 155         case FSIDSOURCE_UUID:
 156                 f = ((u64*)fhp->fh_export->ex_uuid)[0];
 157                 f ^= ((u64*)fhp->fh_export->ex_uuid)[1];
 158                 p = xdr_encode_hyper(p, f);
 159                 break;
 160         }
 161         return p;
 162 }
 163
 164 static __be32 *
 165 encode_fattr3(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
 166               struct kstat *stat)
 167 {
 168         struct user_namespace *userns = nfsd_user_namespace(rqstp);
 169         struct timespec ts;
 170         *p++ = htonl(nfs3_ftypes[(stat->mode & S_IFMT) >> 12]);
 171         *p++ = htonl((u32) (stat->mode & S_IALLUGO));
 172         *p++ = htonl((u32) stat->nlink);
 173         *p++ = htonl((u32) from_kuid_munged(userns, stat->uid));
 174         *p++ = htonl((u32) from_kgid_munged(userns, stat->gid));
 175         if (S_ISLNK(stat->mode) && stat->size > NFS3_MAXPATHLEN) {
 176                 p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
 177         } else {
 178                 p = xdr_encode_hyper(p, (u64) stat->size);
 179         }
 180         p = xdr_encode_hyper(p, ((u64)stat->blocks) << 9);
 181         *p++ = htonl((u32) MAJOR(stat->rdev));
 182         *p++ = htonl((u32) MINOR(stat->rdev));
 183         p = encode_fsid(p, fhp);
 184         p = xdr_encode_hyper(p, stat->ino);
 185         ts = timespec64_to_timespec(stat->atime);
 186         p = encode_time3(p, &ts);
 187         ts = timespec64_to_timespec(stat->mtime);
 188         p = encode_time3(p, &ts);
 189         ts = timespec64_to_timespec(stat->ctime);
 190         p = encode_time3(p, &ts);
 191
 192         return p;
 193 }
 194
 195 static __be32 *
 196 encode_saved_post_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
 197 {
 198         /* Attributes to follow */
 199         *p++ = xdr_one;
 200         return encode_fattr3(rqstp, p, fhp, &fhp->fh_post_attr);
 201 }
 202
 203 /*
 204  * Encode post-operation attributes.
 205  * The inode may be NULL if the call failed because of a stale file
 206  * handle. In this case, no attributes are returned.
 207  */
 208 static __be32 *
 209 encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
 210 {
 211         struct dentry *dentry = fhp->fh_dentry;
 212         if (dentry && d_really_is_positive(dentry)) {
 213                 __be32 err;
 214                 struct kstat stat;
 215
 216                 err = fh_getattr(fhp, &stat);
 217                 if (!err) {
 218                         *p++ = xdr_one;         /* attributes follow */
 219                         lease_get_mtime(d_inode(dentry), &stat.mtime);
 220                         return encode_fattr3(rqstp, p, fhp, &stat);
 221                 }
 222         }
 223         *p++ = xdr_zero;
 224         return p;
 225 }
 226
 227 /* Helper for NFSv3 ACLs */
 228 __be32 *
 229 nfs3svc_encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
 230 {
 231         return encode_post_op_attr(rqstp, p, fhp);
 232 }
 233
 234 /*
 235  * Enocde weak cache consistency data
 236  */
 237 static __be32 *
 238 encode_wcc_data(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
 239 {
 240         struct dentry   *dentry = fhp->fh_dentry;
 241
 242         if (dentry && d_really_is_positive(dentry) && fhp->fh_post_saved) {
 243                 if (fhp->fh_pre_saved) {
 244                         *p++ = xdr_one;
 245                         p = xdr_encode_hyper(p, (u64) fhp->fh_pre_size);
 246                         p = encode_time3(p, &fhp->fh_pre_mtime);
 247                         p = encode_time3(p, &fhp->fh_pre_ctime);
 248                 } else {
 249                         *p++ = xdr_zero;
 250                 }
 251                 return encode_saved_post_attr(rqstp, p, fhp);
 252         }
 253         /* no pre- or post-attrs */
 254         *p++ = xdr_zero;
 255         return encode_post_op_attr(rqstp, p, fhp);
 256 }
 257
 258 /*
 259  * Fill in the pre_op attr for the wcc data
 260  */
 261 void fill_pre_wcc(struct svc_fh *fhp)
 262 {
 263         struct inode    *inode;
 264         struct kstat    stat;
 265         __be32 err;
 266
 267         if (fhp->fh_pre_saved)
 268                 return;
 269
 270         inode = d_inode(fhp->fh_dentry);
 271         err = fh_getattr(fhp, &stat);
 272         if (err) {
 273                 /* Grab the times from inode anyway */
 274                 stat.mtime = inode->i_mtime;
 275                 stat.ctime = inode->i_ctime;
 276                 stat.size  = inode->i_size;
 277         }
 278
 279         fhp->fh_pre_mtime = timespec64_to_timespec(stat.mtime);
 280         fhp->fh_pre_ctime = timespec64_to_timespec(stat.ctime);
 281         fhp->fh_pre_size  = stat.size;
 282         fhp->fh_pre_change = nfsd4_change_attribute(&stat, inode);
 283         fhp->fh_pre_saved = true;
 284 }
 285
 286 /*
 287  * Fill in the post_op attr for the wcc data
 288  */
 289 void fill_post_wcc(struct svc_fh *fhp)
 290 {
 291         __be32 err;
 292
 293         if (fhp->fh_post_saved)
 294                 printk("nfsd: inode locked twice during operation.\n");
 295
 296         err = fh_getattr(fhp, &fhp->fh_post_attr);
 297         fhp->fh_post_change = nfsd4_change_attribute(&fhp->fh_post_attr,
 298                                                      d_inode(fhp->fh_dentry));
 299         if (err) {
 300                 fhp->fh_post_saved = false;
 301                 /* Grab the ctime anyway - set_change_info might use it */
 302                 fhp->fh_post_attr.ctime = d_inode(fhp->fh_dentry)->i_ctime;
 303         } else
 304                 fhp->fh_post_saved = true;
 305 }
 306
 307 /*
 308  * XDR decode functions
 309  */
 310 int
 311 nfs3svc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p)
 312 {
 313         struct nfsd_fhandle *args = rqstp->rq_argp;
 314
 315         p = decode_fh(p, &args->fh);
 316         if (!p)
 317                 return 0;
 318         return xdr_argsize_check(rqstp, p);
 319 }
 320
 321 int
 322 nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p)
 323 {
 324         struct nfsd3_sattrargs *args = rqstp->rq_argp;
 325
 326         p = decode_fh(p, &args->fh);
 327         if (!p)
 328                 return 0;
 329         p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
 330
 331         if ((args->check_guard = ntohl(*p++)) != 0) {
 332                 struct timespec time;
 333                 p = decode_time3(p, &time);
 334                 args->guardtime = time.tv_sec;
 335         }
 336
 337         return xdr_argsize_check(rqstp, p);
 338 }
 339
 340 int
 341 nfs3svc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p)
 342 {
 343         struct nfsd3_diropargs *args = rqstp->rq_argp;
 344
 345         if (!(p = decode_fh(p, &args->fh))
 346          || !(p = decode_filename(p, &args->name, &args->len)))
 347                 return 0;
 348
 349         return xdr_argsize_check(rqstp, p);
 350 }
 351
 352 int
 353 nfs3svc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p)
 354 {
 355         struct nfsd3_accessargs *args = rqstp->rq_argp;
 356
 357         p = decode_fh(p, &args->fh);
 358         if (!p)
 359                 return 0;
 360         args->access = ntohl(*p++);
 361
 362         return xdr_argsize_check(rqstp, p);
 363 }
 364
 365 int
 366 nfs3svc_decode_readargs(struct svc_rqst *rqstp, __be32 *p)
 367 {
 368         struct nfsd3_readargs *args = rqstp->rq_argp;
 369         unsigned int len;
 370         int v;
 371         u32 max_blocksize = svc_max_payload(rqstp);
 372
 373         p = decode_fh(p, &args->fh);
 374         if (!p)
 375                 return 0;
 376         p = xdr_decode_hyper(p, &args->offset);
 377
 378         args->count = ntohl(*p++);
 379         len = min(args->count, max_blocksize);
 380
 381         /* set up the kvec */
 382         v=0;
 383         while (len > 0) {
 384                 struct page *p = *(rqstp->rq_next_page++);
 385
 386                 rqstp->rq_vec[v].iov_base = page_address(p);
 387                 rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
 388                 len -= rqstp->rq_vec[v].iov_len;
 389                 v++;
 390         }
 391         args->vlen = v;
 392         return xdr_argsize_check(rqstp, p);
 393 }
 394
 395 int
 396 nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p)
 397 {
 398         struct nfsd3_writeargs *args = rqstp->rq_argp;
 399         unsigned int len, hdr, dlen;
 400         u32 max_blocksize = svc_max_payload(rqstp);
 401         struct kvec *head = rqstp->rq_arg.head;
 402         struct kvec *tail = rqstp->rq_arg.tail;
 403
 404         p = decode_fh(p, &args->fh);
 405         if (!p)
 406                 return 0;
 407         p = xdr_decode_hyper(p, &args->offset);
 408
 409         args->count = ntohl(*p++);
 410         args->stable = ntohl(*p++);
 411         len = args->len = ntohl(*p++);
 412         if ((void *)p > head->iov_base + head->iov_len)
 413                 return 0;
 414         /*
 415          * The count must equal the amount of data passed.
 416          */
 417         if (args->count != args->len)
 418                 return 0;
 419
 420         /*
 421          * Check to make sure that we got the right number of
 422          * bytes.
 423          */
 424         hdr = (void*)p - head->iov_base;
 425         dlen = head->iov_len + rqstp->rq_arg.page_len + tail->iov_len - hdr;
 426         /*
 427          * Round the length of the data which was specified up to
 428          * the next multiple of XDR units and then compare that
 429          * against the length which was actually received.
 430          * Note that when RPCSEC/GSS (for example) is used, the
 431          * data buffer can be padded so dlen might be larger
 432          * than required.  It must never be smaller.
 433          */
 434         if (dlen < XDR_QUADLEN(len)*4)
 435                 return 0;
 436
 437         if (args->count > max_blocksize) {
 438                 args->count = max_blocksize;
 439                 len = args->len = max_blocksize;
 440         }
 441
 442         args->first.iov_base = (void *)p;
 443         args->first.iov_len = head->iov_len - hdr;
 444         return 1;
 445 }
 446
 447 int
 448 nfs3svc_decode_createargs(struct svc_rqst *rqstp, __be32 *p)
 449 {
 450         struct nfsd3_createargs *args = rqstp->rq_argp;
 451
 452         if (!(p = decode_fh(p, &args->fh))
 453          || !(p = decode_filename(p, &args->name, &args->len)))
 454                 return 0;
 455
 456         switch (args->createmode = ntohl(*p++)) {
 457         case NFS3_CREATE_UNCHECKED:
 458         case NFS3_CREATE_GUARDED:
 459                 p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
 460                 break;
 461         case NFS3_CREATE_EXCLUSIVE:
 462                 args->verf = p;
 463                 p += 2;
 464                 break;
 465         default:
 466                 return 0;
 467         }
 468
 469         return xdr_argsize_check(rqstp, p);
 470 }
 471
 472 int
 473 nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, __be32 *p)
 474 {
 475         struct nfsd3_createargs *args = rqstp->rq_argp;
 476
 477         if (!(p = decode_fh(p, &args->fh)) ||
 478             !(p = decode_filename(p, &args->name, &args->len)))
 479                 return 0;
 480         p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
 481
 482         return xdr_argsize_check(rqstp, p);
 483 }
 484
 485 int
 486 nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p)
 487 {
 488         struct nfsd3_symlinkargs *args = rqstp->rq_argp;
 489         char *base = (char *)p;
 490         size_t dlen;
 491
 492         if (!(p = decode_fh(p, &args->ffh)) ||
 493             !(p = decode_filename(p, &args->fname, &args->flen)))
 494                 return 0;
 495         p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
 496
 497         args->tlen = ntohl(*p++);
 498
 499         args->first.iov_base = p;
 500         args->first.iov_len = rqstp->rq_arg.head[0].iov_len;
 501         args->first.iov_len -= (char *)p - base;
 502
 503         dlen = args->first.iov_len + rqstp->rq_arg.page_len +
 504                rqstp->rq_arg.tail[0].iov_len;
 505         if (dlen < XDR_QUADLEN(args->tlen) << 2)
 506                 return 0;
 507         return 1;
 508 }
 509
 510 int
 511 nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, __be32 *p)
 512 {
 513         struct nfsd3_mknodargs *args = rqstp->rq_argp;
 514
 515         if (!(p = decode_fh(p, &args->fh))
 516          || !(p = decode_filename(p, &args->name, &args->len)))
 517                 return 0;
 518
 519         args->ftype = ntohl(*p++);
 520
 521         if (args->ftype == NF3BLK  || args->ftype == NF3CHR
 522          || args->ftype == NF3SOCK || args->ftype == NF3FIFO)
 523                 p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
 524
 525         if (args->ftype == NF3BLK || args->ftype == NF3CHR) {
 526                 args->major = ntohl(*p++);
 527                 args->minor = ntohl(*p++);
 528         }
 529
 530         return xdr_argsize_check(rqstp, p);
 531 }
 532
 533 int
 534 nfs3svc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p)
 535 {
 536         struct nfsd3_renameargs *args = rqstp->rq_argp;
 537
 538         if (!(p = decode_fh(p, &args->ffh))
 539          || !(p = decode_filename(p, &args->fname, &args->flen))
 540          || !(p = decode_fh(p, &args->tfh))
 541          || !(p = decode_filename(p, &args->tname, &args->tlen)))
 542                 return 0;
 543
 544         return xdr_argsize_check(rqstp, p);
 545 }
 546
 547 int
 548 nfs3svc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p)
 549 {
 550         struct nfsd3_readlinkargs *args = rqstp->rq_argp;
 551
 552         p = decode_fh(p, &args->fh);
 553         if (!p)
 554                 return 0;
 555         args->buffer = page_address(*(rqstp->rq_next_page++));
 556
 557         return xdr_argsize_check(rqstp, p);
 558 }
 559
 560 int
 561 nfs3svc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p)
 562 {
 563         struct nfsd3_linkargs *args = rqstp->rq_argp;
 564
 565         if (!(p = decode_fh(p, &args->ffh))
 566          || !(p = decode_fh(p, &args->tfh))
 567          || !(p = decode_filename(p, &args->tname, &args->tlen)))
 568                 return 0;
 569
 570         return xdr_argsize_check(rqstp, p);
 571 }
 572
 573 int
 574 nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
 575 {
 576         struct nfsd3_readdirargs *args = rqstp->rq_argp;
 577         int len;
 578         u32 max_blocksize = svc_max_payload(rqstp);
 579
 580         p = decode_fh(p, &args->fh);
 581         if (!p)
 582                 return 0;
 583         p = xdr_decode_hyper(p, &args->cookie);
 584         args->verf   = p; p += 2;
 585         args->dircount = ~0;
 586         args->count  = ntohl(*p++);
 587         len = args->count  = min_t(u32, args->count, max_blocksize);
 588
 589         while (len > 0) {
 590                 struct page *p = *(rqstp->rq_next_page++);
 591                 if (!args->buffer)
 592                         args->buffer = page_address(p);
 593                 len -= PAGE_SIZE;
 594         }
 595
 596         return xdr_argsize_check(rqstp, p);
 597 }
 598
 599 int
 600 nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p)
 601 {
 602         struct nfsd3_readdirargs *args = rqstp->rq_argp;
 603         int len;
 604         u32 max_blocksize = svc_max_payload(rqstp);
 605
 606         p = decode_fh(p, &args->fh);
 607         if (!p)
 608                 return 0;
 609         p = xdr_decode_hyper(p, &args->cookie);
 610         args->verf     = p; p += 2;
 611         args->dircount = ntohl(*p++);
 612         args->count    = ntohl(*p++);
 613
 614         len = args->count = min(args->count, max_blocksize);
 615         while (len > 0) {
 616                 struct page *p = *(rqstp->rq_next_page++);
 617                 if (!args->buffer)
 618                         args->buffer = page_address(p);
 619                 len -= PAGE_SIZE;
 620         }
 621
 622         return xdr_argsize_check(rqstp, p);
 623 }
 624
 625 int
 626 nfs3svc_decode_commitargs(struct svc_rqst *rqstp, __be32 *p)
 627 {
 628         struct nfsd3_commitargs *args = rqstp->rq_argp;
 629         p = decode_fh(p, &args->fh);
 630         if (!p)
 631                 return 0;
 632         p = xdr_decode_hyper(p, &args->offset);
 633         args->count = ntohl(*p++);
 634
 635         return xdr_argsize_check(rqstp, p);
 636 }
 637
 638 /*
 639  * XDR encode functions
 640  */
 641 /*
 642  * There must be an encoding function for void results so svc_process
 643  * will work properly.
 644  */
 645 int
 646 nfs3svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p)
 647 {
 648         return xdr_ressize_check(rqstp, p);
 649 }
 650
 651 /* GETATTR */
 652 int
 653 nfs3svc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p)
 654 {
 655         struct nfsd3_attrstat *resp = rqstp->rq_resp;
 656
 657         if (resp->status == 0) {
 658                 lease_get_mtime(d_inode(resp->fh.fh_dentry),
 659                                 &resp->stat.mtime);
 660                 p = encode_fattr3(rqstp, p, &resp->fh, &resp->stat);
 661         }
 662         return xdr_ressize_check(rqstp, p);
 663 }
 664
 665 /* SETATTR, REMOVE, RMDIR */
 666 int
 667 nfs3svc_encode_wccstat(struct svc_rqst *rqstp, __be32 *p)
 668 {
 669         struct nfsd3_attrstat *resp = rqstp->rq_resp;
 670
 671         p = encode_wcc_data(rqstp, p, &resp->fh);
 672         return xdr_ressize_check(rqstp, p);
 673 }
 674
 675 /* LOOKUP */
 676 int
 677 nfs3svc_encode_diropres(struct svc_rqst *rqstp, __be32 *p)
 678 {
 679         struct nfsd3_diropres *resp = rqstp->rq_resp;
 680
 681         if (resp->status == 0) {
 682                 p = encode_fh(p, &resp->fh);
 683                 p = encode_post_op_attr(rqstp, p, &resp->fh);
 684         }
 685         p = encode_post_op_attr(rqstp, p, &resp->dirfh);
 686         return xdr_ressize_check(rqstp, p);
 687 }
 688
 689 /* ACCESS */
 690 int
 691 nfs3svc_encode_accessres(struct svc_rqst *rqstp, __be32 *p)
 692 {
 693         struct nfsd3_accessres *resp = rqstp->rq_resp;
 694
 695         p = encode_post_op_attr(rqstp, p, &resp->fh);
 696         if (resp->status == 0)
 697                 *p++ = htonl(resp->access);
 698         return xdr_ressize_check(rqstp, p);
 699 }
 700
 701 /* READLINK */
 702 int
 703 nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p)
 704 {
 705         struct nfsd3_readlinkres *resp = rqstp->rq_resp;
 706
 707         p = encode_post_op_attr(rqstp, p, &resp->fh);
 708         if (resp->status == 0) {
 709                 *p++ = htonl(resp->len);
 710                 xdr_ressize_check(rqstp, p);
 711                 rqstp->rq_res.page_len = resp->len;
 712                 if (resp->len & 3) {
 713                         /* need to pad the tail */
 714                         rqstp->rq_res.tail[0].iov_base = p;
 715                         *p = 0;
 716                         rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
 717                 }
 718                 return 1;
 719         } else
 720                 return xdr_ressize_check(rqstp, p);
 721 }
 722
 723 /* READ */
 724 int
 725 nfs3svc_encode_readres(struct svc_rqst *rqstp, __be32 *p)
 726 {
 727         struct nfsd3_readres *resp = rqstp->rq_resp;
 728
 729         p = encode_post_op_attr(rqstp, p, &resp->fh);
 730         if (resp->status == 0) {
 731                 *p++ = htonl(resp->count);
 732                 *p++ = htonl(resp->eof);
 733                 *p++ = htonl(resp->count);      /* xdr opaque count */
 734                 xdr_ressize_check(rqstp, p);
 735                 /* now update rqstp->rq_res to reflect data as well */
 736                 rqstp->rq_res.page_len = resp->count;
 737                 if (resp->count & 3) {
 738                         /* need to pad the tail */
 739                         rqstp->rq_res.tail[0].iov_base = p;
 740                         *p = 0;
 741                         rqstp->rq_res.tail[0].iov_len = 4 - (resp->count & 3);
 742                 }
 743                 return 1;
 744         } else
 745                 return xdr_ressize_check(rqstp, p);
 746 }
 747
 748 /* WRITE */
 749 int
 750 nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p)
 751 {
 752         struct nfsd3_writeres *resp = rqstp->rq_resp;
 753         struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 754
 755         p = encode_wcc_data(rqstp, p, &resp->fh);
 756         if (resp->status == 0) {
 757                 *p++ = htonl(resp->count);
 758                 *p++ = htonl(resp->committed);
 759                 /* unique identifier, y2038 overflow can be ignored */
 760                 *p++ = htonl((u32)nn->nfssvc_boot.tv_sec);
 761                 *p++ = htonl(nn->nfssvc_boot.tv_nsec);
 762         }
 763         return xdr_ressize_check(rqstp, p);
 764 }
 765
 766 /* CREATE, MKDIR, SYMLINK, MKNOD */
 767 int
 768 nfs3svc_encode_createres(struct svc_rqst *rqstp, __be32 *p)
 769 {
 770         struct nfsd3_diropres *resp = rqstp->rq_resp;
 771
 772         if (resp->status == 0) {
 773                 *p++ = xdr_one;
 774                 p = encode_fh(p, &resp->fh);
 775                 p = encode_post_op_attr(rqstp, p, &resp->fh);
 776         }
 777         p = encode_wcc_data(rqstp, p, &resp->dirfh);
 778         return xdr_ressize_check(rqstp, p);
 779 }
 780
 781 /* RENAME */
 782 int
 783 nfs3svc_encode_renameres(struct svc_rqst *rqstp, __be32 *p)
 784 {
 785         struct nfsd3_renameres *resp = rqstp->rq_resp;
 786
 787         p = encode_wcc_data(rqstp, p, &resp->ffh);
 788         p = encode_wcc_data(rqstp, p, &resp->tfh);
 789         return xdr_ressize_check(rqstp, p);
 790 }
 791
 792 /* LINK */
 793 int
 794 nfs3svc_encode_linkres(struct svc_rqst *rqstp, __be32 *p)
 795 {
 796         struct nfsd3_linkres *resp = rqstp->rq_resp;
 797
 798         p = encode_post_op_attr(rqstp, p, &resp->fh);
 799         p = encode_wcc_data(rqstp, p, &resp->tfh);
 800         return xdr_ressize_check(rqstp, p);
 801 }
 802
 803 /* READDIR */
 804 int
 805 nfs3svc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p)
 806 {
 807         struct nfsd3_readdirres *resp = rqstp->rq_resp;
 808
 809         p = encode_post_op_attr(rqstp, p, &resp->fh);
 810
 811         if (resp->status == 0) {
 812                 /* stupid readdir cookie */
 813                 memcpy(p, resp->verf, 8); p += 2;
 814                 xdr_ressize_check(rqstp, p);
 815                 if (rqstp->rq_res.head[0].iov_len + (2<<2) > PAGE_SIZE)
 816                         return 1; /*No room for trailer */
 817                 rqstp->rq_res.page_len = (resp->count) << 2;
 818
 819                 /* add the 'tail' to the end of the 'head' page - page 0. */
 820                 rqstp->rq_res.tail[0].iov_base = p;
 821                 *p++ = 0;               /* no more entries */
 822                 *p++ = htonl(resp->common.err == nfserr_eof);
 823                 rqstp->rq_res.tail[0].iov_len = 2<<2;
 824                 return 1;
 825         } else
 826                 return xdr_ressize_check(rqstp, p);
 827 }
 828
 829 static __be32 *
 830 encode_entry_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name,
 831              int namlen, u64 ino)
 832 {
 833         *p++ = xdr_one;                          /* mark entry present */
 834         p    = xdr_encode_hyper(p, ino);         /* file id */
 835         p    = xdr_encode_array(p, name, namlen);/* name length & name */
 836
 837         cd->offset = p;                         /* remember pointer */
 838         p = xdr_encode_hyper(p, NFS_OFFSET_MAX);/* offset of next entry */
 839
 840         return p;
 841 }
 842
 843 static __be32
 844 compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
 845                  const char *name, int namlen, u64 ino)
 846 {
 847         struct svc_export       *exp;
 848         struct dentry           *dparent, *dchild;
 849         __be32 rv = nfserr_noent;
 850
 851         dparent = cd->fh.fh_dentry;
 852         exp  = cd->fh.fh_export;
 853
 854         if (isdotent(name, namlen)) {
 855                 if (namlen == 2) {
 856                         dchild = dget_parent(dparent);
 857                         /* filesystem root - cannot return filehandle for ".." */
 858                         if (dchild == dparent)
 859                                 goto out;
 860                 } else
 861                         dchild = dget(dparent);
 862         } else
 863                 dchild = lookup_one_len_unlocked(name, dparent, namlen);
 864         if (IS_ERR(dchild))
 865                 return rv;
 866         if (d_mountpoint(dchild))
 867                 goto out;
 868         if (d_really_is_negative(dchild))
 869                 goto out;
 870         if (dchild->d_inode->i_ino != ino)
 871                 goto out;
 872         rv = fh_compose(fhp, exp, dchild, &cd->fh);
 873 out:
 874         dput(dchild);
 875         return rv;
 876 }
 877
 878 static __be32 *encode_entryplus_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name, int namlen, u64 ino)
 879 {
 880         struct svc_fh   *fh = &cd->scratch;
 881         __be32 err;
 882
 883         fh_init(fh, NFS3_FHSIZE);
 884         err = compose_entry_fh(cd, fh, name, namlen, ino);
 885         if (err) {
 886                 *p++ = 0;
 887                 *p++ = 0;
 888                 goto out;
 889         }
 890         p = encode_post_op_attr(cd->rqstp, p, fh);
 891         *p++ = xdr_one;                 /* yes, a file handle follows */
 892         p = encode_fh(p, fh);
 893 out:
 894         fh_put(fh);
 895         return p;
 896 }
 897
 898 /*
 899  * Encode a directory entry. This one works for both normal readdir
 900  * and readdirplus.
 901  * The normal readdir reply requires 2 (fileid) + 1 (stringlen)
 902  * + string + 2 (cookie) + 1 (next) words, i.e. 6 + strlen.
 903  *
 904  * The readdirplus baggage is 1+21 words for post_op_attr, plus the
 905  * file handle.
 906  */
 907
 908 #define NFS3_ENTRY_BAGGAGE      (2 + 1 + 2 + 1)
 909 #define NFS3_ENTRYPLUS_BAGGAGE  (1 + 21 + 1 + (NFS3_FHSIZE >> 2))
 910 static int
 911 encode_entry(struct readdir_cd *ccd, const char *name, int namlen,
 912              loff_t offset, u64 ino, unsigned int d_type, int plus)
 913 {
 914         struct nfsd3_readdirres *cd = container_of(ccd, struct nfsd3_readdirres,
 915                                                         common);
 916         __be32          *p = cd->buffer;
 917         caddr_t         curr_page_addr = NULL;
 918         struct page **  page;
 919         int             slen;           /* string (name) length */
 920         int             elen;           /* estimated entry length in words */
 921         int             num_entry_words = 0;    /* actual number of words */
 922
 923         if (cd->offset) {
 924                 u64 offset64 = offset;
 925
 926                 if (unlikely(cd->offset1)) {
 927                         /* we ended up with offset on a page boundary */
 928                         *cd->offset = htonl(offset64 >> 32);
 929                         *cd->offset1 = htonl(offset64 & 0xffffffff);
 930                         cd->offset1 = NULL;
 931                 } else {
 932                         xdr_encode_hyper(cd->offset, offset64);
 933                 }
 934                 cd->offset = NULL;
 935         }
 936
 937         /*
 938         dprintk("encode_entry(%.*s @%ld%s)\n",
 939                 namlen, name, (long) offset, plus? " plus" : "");
 940          */
 941
 942         /* truncate filename if too long */
 943         namlen = min(namlen, NFS3_MAXNAMLEN);
 944
 945         slen = XDR_QUADLEN(namlen);
 946         elen = slen + NFS3_ENTRY_BAGGAGE
 947                 + (plus? NFS3_ENTRYPLUS_BAGGAGE : 0);
 948
 949         if (cd->buflen < elen) {
 950                 cd->common.err = nfserr_toosmall;
 951                 return -EINVAL;
 952         }
 953
 954         /* determine which page in rq_respages[] we are currently filling */
 955         for (page = cd->rqstp->rq_respages + 1;
 956                                 page < cd->rqstp->rq_next_page; page++) {
 957                 curr_page_addr = page_address(*page);
 958
 959                 if (((caddr_t)cd->buffer >= curr_page_addr) &&
 960                     ((caddr_t)cd->buffer <  curr_page_addr + PAGE_SIZE))
 961                         break;
 962         }
 963
 964         if ((caddr_t)(cd->buffer + elen) < (curr_page_addr + PAGE_SIZE)) {
 965                 /* encode entry in current page */
 966
 967                 p = encode_entry_baggage(cd, p, name, namlen, ino);
 968
 969                 if (plus)
 970                         p = encode_entryplus_baggage(cd, p, name, namlen, ino);
 971                 num_entry_words = p - cd->buffer;
 972         } else if (*(page+1) != NULL) {
 973                 /* temporarily encode entry into next page, then move back to
 974                  * current and next page in rq_respages[] */
 975                 __be32 *p1, *tmp;
 976                 int len1, len2;
 977
 978                 /* grab next page for temporary storage of entry */
 979                 p1 = tmp = page_address(*(page+1));
 980
 981                 p1 = encode_entry_baggage(cd, p1, name, namlen, ino);
 982
 983                 if (plus)
 984                         p1 = encode_entryplus_baggage(cd, p1, name, namlen, ino);
 985
 986                 /* determine entry word length and lengths to go in pages */
 987                 num_entry_words = p1 - tmp;
 988                 len1 = curr_page_addr + PAGE_SIZE - (caddr_t)cd->buffer;
 989                 if ((num_entry_words << 2) < len1) {
 990                         /* the actual number of words in the entry is less
 991                          * than elen and can still fit in the current page
 992                          */
 993                         memmove(p, tmp, num_entry_words << 2);
 994                         p += num_entry_words;
 995
 996                         /* update offset */
 997                         cd->offset = cd->buffer + (cd->offset - tmp);
 998                 } else {
 999                         unsigned int offset_r = (cd->offset - tmp) << 2;
1000
1001                         /* update pointer to offset location.
1002                          * This is a 64bit quantity, so we need to
1003                          * deal with 3 cases:
1004                          *  -   entirely in first page
1005                          *  -   entirely in second page
1006                          *  -   4 bytes in each page
1007                          */
1008                         if (offset_r + 8 <= len1) {
1009                                 cd->offset = p + (cd->offset - tmp);
1010                         } else if (offset_r >= len1) {
1011                                 cd->offset -= len1 >> 2;
1012                         } else {
1013                                 /* sitting on the fence */
1014                                 BUG_ON(offset_r != len1 - 4);
1015                                 cd->offset = p + (cd->offset - tmp);
1016                                 cd->offset1 = tmp;
1017                         }
1018
1019                         len2 = (num_entry_words << 2) - len1;
1020
1021                         /* move from temp page to current and next pages */
1022                         memmove(p, tmp, len1);
1023                         memmove(tmp, (caddr_t)tmp+len1, len2);
1024
1025                         p = tmp + (len2 >> 2);
1026                 }
1027         }
1028         else {
1029                 cd->common.err = nfserr_toosmall;
1030                 return -EINVAL;
1031         }
1032
1033         cd->buflen -= num_entry_words;
1034         cd->buffer = p;
1035         cd->common.err = nfs_ok;
1036         return 0;
1037
1038 }
1039
1040 int
1041 nfs3svc_encode_entry(void *cd, const char *name,
1042                      int namlen, loff_t offset, u64 ino, unsigned int d_type)
1043 {
1044         return encode_entry(cd, name, namlen, offset, ino, d_type, 0);
1045 }
1046
1047 int
1048 nfs3svc_encode_entry_plus(void *cd, const char *name,
1049                           int namlen, loff_t offset, u64 ino,
1050                           unsigned int d_type)
1051 {
1052         return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
1053 }
1054
1055 /* FSSTAT */
1056 int
1057 nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, __be32 *p)
1058 {
1059         struct nfsd3_fsstatres *resp = rqstp->rq_resp;
1060         struct kstatfs  *s = &resp->stats;
1061         u64             bs = s->f_bsize;
1062
1063         *p++ = xdr_zero;        /* no post_op_attr */
1064
1065         if (resp->status == 0) {
1066                 p = xdr_encode_hyper(p, bs * s->f_blocks);      /* total bytes */
1067                 p = xdr_encode_hyper(p, bs * s->f_bfree);       /* free bytes */
1068                 p = xdr_encode_hyper(p, bs * s->f_bavail);      /* user available bytes */
1069                 p = xdr_encode_hyper(p, s->f_files);    /* total inodes */
1070                 p = xdr_encode_hyper(p, s->f_ffree);    /* free inodes */
1071                 p = xdr_encode_hyper(p, s->f_ffree);    /* user available inodes */
1072                 *p++ = htonl(resp->invarsec);   /* mean unchanged time */
1073         }
1074         return xdr_ressize_check(rqstp, p);
1075 }
1076
1077 /* FSINFO */
1078 int
1079 nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, __be32 *p)
1080 {
1081         struct nfsd3_fsinfores *resp = rqstp->rq_resp;
1082
1083         *p++ = xdr_zero;        /* no post_op_attr */
1084
1085         if (resp->status == 0) {
1086                 *p++ = htonl(resp->f_rtmax);
1087                 *p++ = htonl(resp->f_rtpref);
1088                 *p++ = htonl(resp->f_rtmult);
1089                 *p++ = htonl(resp->f_wtmax);
1090                 *p++ = htonl(resp->f_wtpref);
1091                 *p++ = htonl(resp->f_wtmult);
1092                 *p++ = htonl(resp->f_dtpref);
1093                 p = xdr_encode_hyper(p, resp->f_maxfilesize);
1094                 *p++ = xdr_one;
1095                 *p++ = xdr_zero;
1096                 *p++ = htonl(resp->f_properties);
1097         }
1098
1099         return xdr_ressize_check(rqstp, p);
1100 }
1101
1102 /* PATHCONF */
1103 int
1104 nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, __be32 *p)
1105 {
1106         struct nfsd3_pathconfres *resp = rqstp->rq_resp;
1107
1108         *p++ = xdr_zero;        /* no post_op_attr */
1109
1110         if (resp->status == 0) {
1111                 *p++ = htonl(resp->p_link_max);
1112                 *p++ = htonl(resp->p_name_max);
1113                 *p++ = htonl(resp->p_no_trunc);
1114                 *p++ = htonl(resp->p_chown_restricted);
1115                 *p++ = htonl(resp->p_case_insensitive);
1116                 *p++ = htonl(resp->p_case_preserving);
1117         }
1118
1119         return xdr_ressize_check(rqstp, p);
1120 }
1121
1122 /* COMMIT */
1123 int
1124 nfs3svc_encode_commitres(struct svc_rqst *rqstp, __be32 *p)
1125 {
1126         struct nfsd3_commitres *resp = rqstp->rq_resp;
1127         struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1128
1129         p = encode_wcc_data(rqstp, p, &resp->fh);
1130         /* Write verifier */
1131         if (resp->status == 0) {
1132                 /* unique identifier, y2038 overflow can be ignored */
1133                 *p++ = htonl((u32)nn->nfssvc_boot.tv_sec);
1134                 *p++ = htonl(nn->nfssvc_boot.tv_nsec);
1135         }
1136         return xdr_ressize_check(rqstp, p);
1137 }
1138
1139 /*
1140  * XDR release functions
1141  */
1142 void
1143 nfs3svc_release_fhandle(struct svc_rqst *rqstp)
1144 {
1145         struct nfsd3_attrstat *resp = rqstp->rq_resp;
1146
1147         fh_put(&resp->fh);
1148 }
1149
1150 void
1151 nfs3svc_release_fhandle2(struct svc_rqst *rqstp)
1152 {
1153         struct nfsd3_fhandle_pair *resp = rqstp->rq_resp;
1154
1155         fh_put(&resp->fh1);
1156         fh_put(&resp->fh2);
1157 }