fs/nfsd/nfsxdr.c

   1 /*
   2  * XDR support for nfsd
   3  *
   4  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   5  */
   6
   7 #include "xdr.h"
   8 #include "auth.h"
   9
  10 #define NFSDDBG_FACILITY                NFSDDBG_XDR
  11
  12 /*
  13  * Mapping of S_IF* types to NFS file types
  14  */
  15 static u32      nfs_ftypes[] = {
  16         NFNON,  NFCHR,  NFCHR, NFBAD,
  17         NFDIR,  NFBAD,  NFBLK, NFBAD,
  18         NFREG,  NFBAD,  NFLNK, NFBAD,
  19         NFSOCK, NFBAD,  NFLNK, NFBAD,
  20 };
  21
  22
  23 /*
  24  * XDR functions for basic NFS types
  25  */
  26 static __be32 *
  27 decode_fh(__be32 *p, struct svc_fh *fhp)
  28 {
  29         fh_init(fhp, NFS_FHSIZE);
  30         memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
  31         fhp->fh_handle.fh_size = NFS_FHSIZE;
  32
  33         /* FIXME: Look up export pointer here and verify
  34          * Sun Secure RPC if requested */
  35         return p + (NFS_FHSIZE >> 2);
  36 }
  37
  38 /* Helper function for NFSv2 ACL code */
  39 __be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
  40 {
  41         return decode_fh(p, fhp);
  42 }
  43
  44 static __be32 *
  45 encode_fh(__be32 *p, struct svc_fh *fhp)
  46 {
  47         memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
  48         return p + (NFS_FHSIZE>> 2);
  49 }
  50
  51 /*
  52  * Decode a file name and make sure that the path contains
  53  * no slashes or null bytes.
  54  */
  55 static __be32 *
  56 decode_filename(__be32 *p, char **namp, unsigned int *lenp)
  57 {
  58         char            *name;
  59         unsigned int    i;
  60
  61         if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
  62                 for (i = 0, name = *namp; i < *lenp; i++, name++) {
  63                         if (*name == '\0' || *name == '/')
  64                                 return NULL;
  65                 }
  66         }
  67
  68         return p;
  69 }
  70
  71 static __be32 *
  72 decode_pathname(__be32 *p, char **namp, unsigned int *lenp)
  73 {
  74         char            *name;
  75         unsigned int    i;
  76
  77         if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXPATHLEN)) != NULL) {
  78                 for (i = 0, name = *namp; i < *lenp; i++, name++) {
  79                         if (*name == '\0')
  80                                 return NULL;
  81                 }
  82         }
  83
  84         return p;
  85 }
  86
  87 static __be32 *
  88 decode_sattr(__be32 *p, struct iattr *iap)
  89 {
  90         u32     tmp, tmp1;
  91
  92         iap->ia_valid = 0;
  93
  94         /* Sun client bug compatibility check: some sun clients seem to
  95          * put 0xffff in the mode field when they mean 0xffffffff.
  96          * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
  97          */
  98         if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
  99                 iap->ia_valid |= ATTR_MODE;
 100                 iap->ia_mode = tmp;
 101         }
 102         if ((tmp = ntohl(*p++)) != (u32)-1) {
 103                 iap->ia_valid |= ATTR_UID;
 104                 iap->ia_uid = tmp;
 105         }
 106         if ((tmp = ntohl(*p++)) != (u32)-1) {
 107                 iap->ia_valid |= ATTR_GID;
 108                 iap->ia_gid = tmp;
 109         }
 110         if ((tmp = ntohl(*p++)) != (u32)-1) {
 111                 iap->ia_valid |= ATTR_SIZE;
 112                 iap->ia_size = tmp;
 113         }
 114         tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
 115         if (tmp != (u32)-1 && tmp1 != (u32)-1) {
 116                 iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
 117                 iap->ia_atime.tv_sec = tmp;
 118                 iap->ia_atime.tv_nsec = tmp1 * 1000;
 119         }
 120         tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
 121         if (tmp != (u32)-1 && tmp1 != (u32)-1) {
 122                 iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
 123                 iap->ia_mtime.tv_sec = tmp;
 124                 iap->ia_mtime.tv_nsec = tmp1 * 1000;
 125                 /*
 126                  * Passing the invalid value useconds=1000000 for mtime
 127                  * is a Sun convention for "set both mtime and atime to
 128                  * current server time".  It's needed to make permissions
 129                  * checks for the "touch" program across v2 mounts to
 130                  * Solaris and Irix boxes work correctly. See description of
 131                  * sattr in section 6.1 of "NFS Illustrated" by
 132                  * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
 133                  */
 134                 if (tmp1 == 1000000)
 135                         iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
 136         }
 137         return p;
 138 }
 139
 140 static __be32 *
 141 encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
 142              struct kstat *stat)
 143 {
 144         struct dentry   *dentry = fhp->fh_dentry;
 145         int type;
 146         struct timespec time;
 147         u32 f;
 148
 149         type = (stat->mode & S_IFMT);
 150
 151         *p++ = htonl(nfs_ftypes[type >> 12]);
 152         *p++ = htonl((u32) stat->mode);
 153         *p++ = htonl((u32) stat->nlink);
 154         *p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
 155         *p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
 156
 157         if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
 158                 *p++ = htonl(NFS_MAXPATHLEN);
 159         } else {
 160                 *p++ = htonl((u32) stat->size);
 161         }
 162         *p++ = htonl((u32) stat->blksize);
 163         if (S_ISCHR(type) || S_ISBLK(type))
 164                 *p++ = htonl(new_encode_dev(stat->rdev));
 165         else
 166                 *p++ = htonl(0xffffffff);
 167         *p++ = htonl((u32) stat->blocks);
 168         switch (fsid_source(fhp)) {
 169         default:
 170         case FSIDSOURCE_DEV:
 171                 *p++ = htonl(new_encode_dev(stat->dev));
 172                 break;
 173         case FSIDSOURCE_FSID:
 174                 *p++ = htonl((u32) fhp->fh_export->ex_fsid);
 175                 break;
 176         case FSIDSOURCE_UUID:
 177                 f = ((u32*)fhp->fh_export->ex_uuid)[0];
 178                 f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
 179                 f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
 180                 f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
 181                 *p++ = htonl(f);
 182                 break;
 183         }
 184         *p++ = htonl((u32) stat->ino);
 185         *p++ = htonl((u32) stat->atime.tv_sec);
 186         *p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
 187         lease_get_mtime(dentry->d_inode, &time);
 188         *p++ = htonl((u32) time.tv_sec);
 189         *p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0);
 190         *p++ = htonl((u32) stat->ctime.tv_sec);
 191         *p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
 192
 193         return p;
 194 }
 195
 196 /* Helper function for NFSv2 ACL code */
 197 __be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
 198 {
 199         struct kstat stat;
 200         vfs_getattr(fhp->fh_export->ex_path.mnt, fhp->fh_dentry, &stat);
 201         return encode_fattr(rqstp, p, fhp, &stat);
 202 }
 203
 204 /*
 205  * XDR decode functions
 206  */
 207 int
 208 nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
 209 {
 210         return xdr_argsize_check(rqstp, p);
 211 }
 212
 213 int
 214 nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
 215 {
 216         if (!(p = decode_fh(p, &args->fh)))
 217                 return 0;
 218         return xdr_argsize_check(rqstp, p);
 219 }
 220
 221 int
 222 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
 223                                         struct nfsd_sattrargs *args)
 224 {
 225         p = decode_fh(p, &args->fh);
 226         if (!p)
 227                 return 0;
 228         p = decode_sattr(p, &args->attrs);
 229
 230         return xdr_argsize_check(rqstp, p);
 231 }
 232
 233 int
 234 nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
 235                                         struct nfsd_diropargs *args)
 236 {
 237         if (!(p = decode_fh(p, &args->fh))
 238          || !(p = decode_filename(p, &args->name, &args->len)))
 239                 return 0;
 240
 241          return xdr_argsize_check(rqstp, p);
 242 }
 243
 244 int
 245 nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
 246                                         struct nfsd_readargs *args)
 247 {
 248         unsigned int len;
 249         int v;
 250         if (!(p = decode_fh(p, &args->fh)))
 251                 return 0;
 252
 253         args->offset    = ntohl(*p++);
 254         len = args->count     = ntohl(*p++);
 255         p++; /* totalcount - unused */
 256
 257         if (len > NFSSVC_MAXBLKSIZE_V2)
 258                 len = NFSSVC_MAXBLKSIZE_V2;
 259
 260         /* set up somewhere to store response.
 261          * We take pages, put them on reslist and include in iovec
 262          */
 263         v=0;
 264         while (len > 0) {
 265                 struct page *p = *(rqstp->rq_next_page++);
 266
 267                 rqstp->rq_vec[v].iov_base = page_address(p);
 268                 rqstp->rq_vec[v].iov_len = len < PAGE_SIZE?len:PAGE_SIZE;
 269                 len -= rqstp->rq_vec[v].iov_len;
 270                 v++;
 271         }
 272         args->vlen = v;
 273         return xdr_argsize_check(rqstp, p);
 274 }
 275
 276 int
 277 nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
 278                                         struct nfsd_writeargs *args)
 279 {
 280         unsigned int len, hdr, dlen;
 281         int v;
 282
 283         if (!(p = decode_fh(p, &args->fh)))
 284                 return 0;
 285
 286         p++;                            /* beginoffset */
 287         args->offset = ntohl(*p++);     /* offset */
 288         p++;                            /* totalcount */
 289         len = args->len = ntohl(*p++);
 290         /*
 291          * The protocol specifies a maximum of 8192 bytes.
 292          */
 293         if (len > NFSSVC_MAXBLKSIZE_V2)
 294                 return 0;
 295
 296         /*
 297          * Check to make sure that we got the right number of
 298          * bytes.
 299          */
 300         hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
 301         dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
 302                 - hdr;
 303
 304         /*
 305          * Round the length of the data which was specified up to
 306          * the next multiple of XDR units and then compare that
 307          * against the length which was actually received.
 308          * Note that when RPCSEC/GSS (for example) is used, the
 309          * data buffer can be padded so dlen might be larger
 310          * than required.  It must never be smaller.
 311          */
 312         if (dlen < XDR_QUADLEN(len)*4)
 313                 return 0;
 314
 315         rqstp->rq_vec[0].iov_base = (void*)p;
 316         rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
 317         v = 0;
 318         while (len > rqstp->rq_vec[v].iov_len) {
 319                 len -= rqstp->rq_vec[v].iov_len;
 320                 v++;
 321                 rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
 322                 rqstp->rq_vec[v].iov_len = PAGE_SIZE;
 323         }
 324         rqstp->rq_vec[v].iov_len = len;
 325         args->vlen = v + 1;
 326         return 1;
 327 }
 328
 329 int
 330 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
 331                                         struct nfsd_createargs *args)
 332 {
 333         if (   !(p = decode_fh(p, &args->fh))
 334             || !(p = decode_filename(p, &args->name, &args->len)))
 335                 return 0;
 336         p = decode_sattr(p, &args->attrs);
 337
 338         return xdr_argsize_check(rqstp, p);
 339 }
 340
 341 int
 342 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
 343                                         struct nfsd_renameargs *args)
 344 {
 345         if (!(p = decode_fh(p, &args->ffh))
 346          || !(p = decode_filename(p, &args->fname, &args->flen))
 347          || !(p = decode_fh(p, &args->tfh))
 348          || !(p = decode_filename(p, &args->tname, &args->tlen)))
 349                 return 0;
 350
 351         return xdr_argsize_check(rqstp, p);
 352 }
 353
 354 int
 355 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readlinkargs *args)
 356 {
 357         if (!(p = decode_fh(p, &args->fh)))
 358                 return 0;
 359         args->buffer = page_address(*(rqstp->rq_next_page++));
 360
 361         return xdr_argsize_check(rqstp, p);
 362 }
 363
 364 int
 365 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
 366                                         struct nfsd_linkargs *args)
 367 {
 368         if (!(p = decode_fh(p, &args->ffh))
 369          || !(p = decode_fh(p, &args->tfh))
 370          || !(p = decode_filename(p, &args->tname, &args->tlen)))
 371                 return 0;
 372
 373         return xdr_argsize_check(rqstp, p);
 374 }
 375
 376 int
 377 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
 378                                         struct nfsd_symlinkargs *args)
 379 {
 380         if (   !(p = decode_fh(p, &args->ffh))
 381             || !(p = decode_filename(p, &args->fname, &args->flen))
 382             || !(p = decode_pathname(p, &args->tname, &args->tlen)))
 383                 return 0;
 384         p = decode_sattr(p, &args->attrs);
 385
 386         return xdr_argsize_check(rqstp, p);
 387 }
 388
 389 int
 390 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
 391                                         struct nfsd_readdirargs *args)
 392 {
 393         if (!(p = decode_fh(p, &args->fh)))
 394                 return 0;
 395         args->cookie = ntohl(*p++);
 396         args->count  = ntohl(*p++);
 397         if (args->count > PAGE_SIZE)
 398                 args->count = PAGE_SIZE;
 399
 400         args->buffer = page_address(*(rqstp->rq_next_page++));
 401
 402         return xdr_argsize_check(rqstp, p);
 403 }
 404
 405 /*
 406  * XDR encode functions
 407  */
 408 int
 409 nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
 410 {
 411         return xdr_ressize_check(rqstp, p);
 412 }
 413
 414 int
 415 nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
 416                                         struct nfsd_attrstat *resp)
 417 {
 418         p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 419         return xdr_ressize_check(rqstp, p);
 420 }
 421
 422 int
 423 nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
 424                                         struct nfsd_diropres *resp)
 425 {
 426         p = encode_fh(p, &resp->fh);
 427         p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 428         return xdr_ressize_check(rqstp, p);
 429 }
 430
 431 int
 432 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
 433                                         struct nfsd_readlinkres *resp)
 434 {
 435         *p++ = htonl(resp->len);
 436         xdr_ressize_check(rqstp, p);
 437         rqstp->rq_res.page_len = resp->len;
 438         if (resp->len & 3) {
 439                 /* need to pad the tail */
 440                 rqstp->rq_res.tail[0].iov_base = p;
 441                 *p = 0;
 442                 rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
 443         }
 444         return 1;
 445 }
 446
 447 int
 448 nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
 449                                         struct nfsd_readres *resp)
 450 {
 451         p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 452         *p++ = htonl(resp->count);
 453         xdr_ressize_check(rqstp, p);
 454
 455         /* now update rqstp->rq_res to reflect data as well */
 456         rqstp->rq_res.page_len = resp->count;
 457         if (resp->count & 3) {
 458                 /* need to pad the tail */
 459                 rqstp->rq_res.tail[0].iov_base = p;
 460                 *p = 0;
 461                 rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
 462         }
 463         return 1;
 464 }
 465
 466 int
 467 nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
 468                                         struct nfsd_readdirres *resp)
 469 {
 470         xdr_ressize_check(rqstp, p);
 471         p = resp->buffer;
 472         *p++ = 0;                       /* no more entries */
 473         *p++ = htonl((resp->common.err == nfserr_eof));
 474         rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
 475
 476         return 1;
 477 }
 478
 479 int
 480 nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,
 481                                         struct nfsd_statfsres *resp)
 482 {
 483         struct kstatfs  *stat = &resp->stats;
 484
 485         *p++ = htonl(NFSSVC_MAXBLKSIZE_V2);     /* max transfer size */
 486         *p++ = htonl(stat->f_bsize);
 487         *p++ = htonl(stat->f_blocks);
 488         *p++ = htonl(stat->f_bfree);
 489         *p++ = htonl(stat->f_bavail);
 490         return xdr_ressize_check(rqstp, p);
 491 }
 492
 493 int
 494 nfssvc_encode_entry(void *ccdv, const char *name,
 495                     int namlen, loff_t offset, u64 ino, unsigned int d_type)
 496 {
 497         struct readdir_cd *ccd = ccdv;
 498         struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
 499         __be32  *p = cd->buffer;
 500         int     buflen, slen;
 501
 502         /*
 503         dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
 504                         namlen, name, offset, ino);
 505          */
 506
 507         if (offset > ~((u32) 0)) {
 508                 cd->common.err = nfserr_fbig;
 509                 return -EINVAL;
 510         }
 511         if (cd->offset)
 512                 *cd->offset = htonl(offset);
 513         if (namlen > NFS2_MAXNAMLEN)
 514                 namlen = NFS2_MAXNAMLEN;/* truncate filename */
 515
 516         slen = XDR_QUADLEN(namlen);
 517         if ((buflen = cd->buflen - slen - 4) < 0) {
 518                 cd->common.err = nfserr_toosmall;
 519                 return -EINVAL;
 520         }
 521         if (ino > ~((u32) 0)) {
 522                 cd->common.err = nfserr_fbig;
 523                 return -EINVAL;
 524         }
 525         *p++ = xdr_one;                         /* mark entry present */
 526         *p++ = htonl((u32) ino);                /* file id */
 527         p    = xdr_encode_array(p, name, namlen);/* name length & name */
 528         cd->offset = p;                 /* remember pointer */
 529         *p++ = htonl(~0U);              /* offset of next entry */
 530
 531         cd->buflen = buflen;
 532         cd->buffer = p;
 533         cd->common.err = nfs_ok;
 534         return 0;
 535 }
 536
 537 /*
 538  * XDR release functions
 539  */
 540 int
 541 nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
 542                                         struct nfsd_fhandle *resp)
 543 {
 544         fh_put(&resp->fh);
 545         return 1;
 546 }