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 "vfs.h"
   8 #include "xdr.h"
   9 #include "auth.h"
  10
  11 #define NFSDDBG_FACILITY                NFSDDBG_XDR
  12
  13 /*
  14  * Mapping of S_IF* types to NFS file types
  15  */
  16 static u32      nfs_ftypes[] = {
  17         NFNON,  NFCHR,  NFCHR, NFBAD,
  18         NFDIR,  NFBAD,  NFBLK, NFBAD,
  19         NFREG,  NFBAD,  NFLNK, NFBAD,
  20         NFSOCK, NFBAD,  NFLNK, NFBAD,
  21 };
  22
  23
  24 /*
  25  * XDR functions for basic NFS types
  26  */
  27 static __be32 *
  28 decode_fh(__be32 *p, struct svc_fh *fhp)
  29 {
  30         fh_init(fhp, NFS_FHSIZE);
  31         memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
  32         fhp->fh_handle.fh_size = NFS_FHSIZE;
  33
  34         /* FIXME: Look up export pointer here and verify
  35          * Sun Secure RPC if requested */
  36         return p + (NFS_FHSIZE >> 2);
  37 }
  38
  39 /* Helper function for NFSv2 ACL code */
  40 __be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
  41 {
  42         return decode_fh(p, fhp);
  43 }
  44
  45 static __be32 *
  46 encode_fh(__be32 *p, struct svc_fh *fhp)
  47 {
  48         memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
  49         return p + (NFS_FHSIZE>> 2);
  50 }
  51
  52 /*
  53  * Decode a file name and make sure that the path contains
  54  * no slashes or null bytes.
  55  */
  56 static __be32 *
  57 decode_filename(__be32 *p, char **namp, unsigned int *lenp)
  58 {
  59         char            *name;
  60         unsigned int    i;
  61
  62         if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
  63                 for (i = 0, name = *namp; i < *lenp; i++, name++) {
  64                         if (*name == '\0' || *name == '/')
  65                                 return NULL;
  66                 }
  67         }
  68
  69         return p;
  70 }
  71
  72 static __be32 *
  73 decode_pathname(__be32 *p, char **namp, unsigned int *lenp)
  74 {
  75         char            *name;
  76         unsigned int    i;
  77
  78         if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXPATHLEN)) != NULL) {
  79                 for (i = 0, name = *namp; i < *lenp; i++, name++) {
  80                         if (*name == '\0')
  81                                 return NULL;
  82                 }
  83         }
  84
  85         return p;
  86 }
  87
  88 static __be32 *
  89 decode_sattr(__be32 *p, struct iattr *iap)
  90 {
  91         u32     tmp, tmp1;
  92
  93         iap->ia_valid = 0;
  94
  95         /* Sun client bug compatibility check: some sun clients seem to
  96          * put 0xffff in the mode field when they mean 0xffffffff.
  97          * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
  98          */
  99         if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
 100                 iap->ia_valid |= ATTR_MODE;
 101                 iap->ia_mode = tmp;
 102         }
 103         if ((tmp = ntohl(*p++)) != (u32)-1) {
 104                 iap->ia_uid = make_kuid(&init_user_ns, tmp);
 105                 if (uid_valid(iap->ia_uid))
 106                         iap->ia_valid |= ATTR_UID;
 107         }
 108         if ((tmp = ntohl(*p++)) != (u32)-1) {
 109                 iap->ia_gid = make_kgid(&init_user_ns, tmp);
 110                 if (gid_valid(iap->ia_gid))
 111                         iap->ia_valid |= ATTR_GID;
 112         }
 113         if ((tmp = ntohl(*p++)) != (u32)-1) {
 114                 iap->ia_valid |= ATTR_SIZE;
 115                 iap->ia_size = tmp;
 116         }
 117         tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
 118         if (tmp != (u32)-1 && tmp1 != (u32)-1) {
 119                 iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
 120                 iap->ia_atime.tv_sec = tmp;
 121                 iap->ia_atime.tv_nsec = tmp1 * 1000;
 122         }
 123         tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
 124         if (tmp != (u32)-1 && tmp1 != (u32)-1) {
 125                 iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
 126                 iap->ia_mtime.tv_sec = tmp;
 127                 iap->ia_mtime.tv_nsec = tmp1 * 1000;
 128                 /*
 129                  * Passing the invalid value useconds=1000000 for mtime
 130                  * is a Sun convention for "set both mtime and atime to
 131                  * current server time".  It's needed to make permissions
 132                  * checks for the "touch" program across v2 mounts to
 133                  * Solaris and Irix boxes work correctly. See description of
 134                  * sattr in section 6.1 of "NFS Illustrated" by
 135                  * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
 136                  */
 137                 if (tmp1 == 1000000)
 138                         iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
 139         }
 140         return p;
 141 }
 142
 143 static __be32 *
 144 encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
 145              struct kstat *stat)
 146 {
 147         struct dentry   *dentry = fhp->fh_dentry;
 148         int type;
 149         struct timespec time;
 150         u32 f;
 151
 152         type = (stat->mode & S_IFMT);
 153
 154         *p++ = htonl(nfs_ftypes[type >> 12]);
 155         *p++ = htonl((u32) stat->mode);
 156         *p++ = htonl((u32) stat->nlink);
 157         *p++ = htonl((u32) from_kuid(&init_user_ns, stat->uid));
 158         *p++ = htonl((u32) from_kgid(&init_user_ns, stat->gid));
 159
 160         if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
 161                 *p++ = htonl(NFS_MAXPATHLEN);
 162         } else {
 163                 *p++ = htonl((u32) stat->size);
 164         }
 165         *p++ = htonl((u32) stat->blksize);
 166         if (S_ISCHR(type) || S_ISBLK(type))
 167                 *p++ = htonl(new_encode_dev(stat->rdev));
 168         else
 169                 *p++ = htonl(0xffffffff);
 170         *p++ = htonl((u32) stat->blocks);
 171         switch (fsid_source(fhp)) {
 172         default:
 173         case FSIDSOURCE_DEV:
 174                 *p++ = htonl(new_encode_dev(stat->dev));
 175                 break;
 176         case FSIDSOURCE_FSID:
 177                 *p++ = htonl((u32) fhp->fh_export->ex_fsid);
 178                 break;
 179         case FSIDSOURCE_UUID:
 180                 f = ((u32*)fhp->fh_export->ex_uuid)[0];
 181                 f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
 182                 f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
 183                 f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
 184                 *p++ = htonl(f);
 185                 break;
 186         }
 187         *p++ = htonl((u32) stat->ino);
 188         *p++ = htonl((u32) stat->atime.tv_sec);
 189         *p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
 190         lease_get_mtime(d_inode(dentry), &time);
 191         *p++ = htonl((u32) time.tv_sec);
 192         *p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0);
 193         *p++ = htonl((u32) stat->ctime.tv_sec);
 194         *p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
 195
 196         return p;
 197 }
 198
 199 /* Helper function for NFSv2 ACL code */
 200 __be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp, struct kstat *stat)
 201 {
 202         return encode_fattr(rqstp, p, fhp, stat);
 203 }
 204
 205 /*
 206  * XDR decode functions
 207  */
 208 int
 209 nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
 210 {
 211         return xdr_argsize_check(rqstp, p);
 212 }
 213
 214 int
 215 nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
 216 {
 217         p = decode_fh(p, &args->fh);
 218         if (!p)
 219                 return 0;
 220         return xdr_argsize_check(rqstp, p);
 221 }
 222
 223 int
 224 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
 225                                         struct nfsd_sattrargs *args)
 226 {
 227         p = decode_fh(p, &args->fh);
 228         if (!p)
 229                 return 0;
 230         p = decode_sattr(p, &args->attrs);
 231
 232         return xdr_argsize_check(rqstp, p);
 233 }
 234
 235 int
 236 nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
 237                                         struct nfsd_diropargs *args)
 238 {
 239         if (!(p = decode_fh(p, &args->fh))
 240          || !(p = decode_filename(p, &args->name, &args->len)))
 241                 return 0;
 242
 243         return xdr_argsize_check(rqstp, p);
 244 }
 245
 246 int
 247 nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
 248                                         struct nfsd_readargs *args)
 249 {
 250         unsigned int len;
 251         int v;
 252         p = decode_fh(p, &args->fh);
 253         if (!p)
 254                 return 0;
 255
 256         args->offset    = ntohl(*p++);
 257         len = args->count     = ntohl(*p++);
 258         p++; /* totalcount - unused */
 259
 260         if (!xdr_argsize_check(rqstp, p))
 261                 return 0;
 262
 263         len = min_t(unsigned int, len, NFSSVC_MAXBLKSIZE_V2);
 264
 265         /* set up somewhere to store response.
 266          * We take pages, put them on reslist and include in iovec
 267          */
 268         v=0;
 269         while (len > 0) {
 270                 struct page *p = *(rqstp->rq_next_page++);
 271
 272                 rqstp->rq_vec[v].iov_base = page_address(p);
 273                 rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
 274                 len -= rqstp->rq_vec[v].iov_len;
 275                 v++;
 276         }
 277         args->vlen = v;
 278         return 1;
 279 }
 280
 281 int
 282 nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
 283                                         struct nfsd_writeargs *args)
 284 {
 285         unsigned int len, hdr, dlen;
 286         struct kvec *head = rqstp->rq_arg.head;
 287         int v;
 288
 289         p = decode_fh(p, &args->fh);
 290         if (!p)
 291                 return 0;
 292
 293         p++;                            /* beginoffset */
 294         args->offset = ntohl(*p++);     /* offset */
 295         p++;                            /* totalcount */
 296         len = args->len = ntohl(*p++);
 297         /*
 298          * The protocol specifies a maximum of 8192 bytes.
 299          */
 300         if (len > NFSSVC_MAXBLKSIZE_V2)
 301                 return 0;
 302
 303         /*
 304          * Check to make sure that we got the right number of
 305          * bytes.
 306          */
 307         hdr = (void*)p - head->iov_base;
 308         if (hdr > head->iov_len)
 309                 return 0;
 310         dlen = head->iov_len + rqstp->rq_arg.page_len - hdr;
 311
 312         /*
 313          * Round the length of the data which was specified up to
 314          * the next multiple of XDR units and then compare that
 315          * against the length which was actually received.
 316          * Note that when RPCSEC/GSS (for example) is used, the
 317          * data buffer can be padded so dlen might be larger
 318          * than required.  It must never be smaller.
 319          */
 320         if (dlen < XDR_QUADLEN(len)*4)
 321                 return 0;
 322
 323         rqstp->rq_vec[0].iov_base = (void*)p;
 324         rqstp->rq_vec[0].iov_len = head->iov_len - hdr;
 325         v = 0;
 326         while (len > rqstp->rq_vec[v].iov_len) {
 327                 len -= rqstp->rq_vec[v].iov_len;
 328                 v++;
 329                 rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
 330                 rqstp->rq_vec[v].iov_len = PAGE_SIZE;
 331         }
 332         rqstp->rq_vec[v].iov_len = len;
 333         args->vlen = v + 1;
 334         return 1;
 335 }
 336
 337 int
 338 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
 339                                         struct nfsd_createargs *args)
 340 {
 341         if (   !(p = decode_fh(p, &args->fh))
 342             || !(p = decode_filename(p, &args->name, &args->len)))
 343                 return 0;
 344         p = decode_sattr(p, &args->attrs);
 345
 346         return xdr_argsize_check(rqstp, p);
 347 }
 348
 349 int
 350 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
 351                                         struct nfsd_renameargs *args)
 352 {
 353         if (!(p = decode_fh(p, &args->ffh))
 354          || !(p = decode_filename(p, &args->fname, &args->flen))
 355          || !(p = decode_fh(p, &args->tfh))
 356          || !(p = decode_filename(p, &args->tname, &args->tlen)))
 357                 return 0;
 358
 359         return xdr_argsize_check(rqstp, p);
 360 }
 361
 362 int
 363 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readlinkargs *args)
 364 {
 365         p = decode_fh(p, &args->fh);
 366         if (!p)
 367                 return 0;
 368         if (!xdr_argsize_check(rqstp, p))
 369                 return 0;
 370         args->buffer = page_address(*(rqstp->rq_next_page++));
 371
 372         return 1;
 373 }
 374
 375 int
 376 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
 377                                         struct nfsd_linkargs *args)
 378 {
 379         if (!(p = decode_fh(p, &args->ffh))
 380          || !(p = decode_fh(p, &args->tfh))
 381          || !(p = decode_filename(p, &args->tname, &args->tlen)))
 382                 return 0;
 383
 384         return xdr_argsize_check(rqstp, p);
 385 }
 386
 387 int
 388 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
 389                                         struct nfsd_symlinkargs *args)
 390 {
 391         if (   !(p = decode_fh(p, &args->ffh))
 392             || !(p = decode_filename(p, &args->fname, &args->flen))
 393             || !(p = decode_pathname(p, &args->tname, &args->tlen)))
 394                 return 0;
 395         p = decode_sattr(p, &args->attrs);
 396
 397         return xdr_argsize_check(rqstp, p);
 398 }
 399
 400 int
 401 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
 402                                         struct nfsd_readdirargs *args)
 403 {
 404         p = decode_fh(p, &args->fh);
 405         if (!p)
 406                 return 0;
 407         args->cookie = ntohl(*p++);
 408         args->count  = ntohl(*p++);
 409         args->count  = min_t(u32, args->count, PAGE_SIZE);
 410         if (!xdr_argsize_check(rqstp, p))
 411                 return 0;
 412         args->buffer = page_address(*(rqstp->rq_next_page++));
 413
 414         return 1;
 415 }
 416
 417 /*
 418  * XDR encode functions
 419  */
 420 int
 421 nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
 422 {
 423         return xdr_ressize_check(rqstp, p);
 424 }
 425
 426 int
 427 nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
 428                                         struct nfsd_attrstat *resp)
 429 {
 430         p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 431         return xdr_ressize_check(rqstp, p);
 432 }
 433
 434 int
 435 nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
 436                                         struct nfsd_diropres *resp)
 437 {
 438         p = encode_fh(p, &resp->fh);
 439         p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 440         return xdr_ressize_check(rqstp, p);
 441 }
 442
 443 int
 444 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
 445                                         struct nfsd_readlinkres *resp)
 446 {
 447         *p++ = htonl(resp->len);
 448         xdr_ressize_check(rqstp, p);
 449         rqstp->rq_res.page_len = resp->len;
 450         if (resp->len & 3) {
 451                 /* need to pad the tail */
 452                 rqstp->rq_res.tail[0].iov_base = p;
 453                 *p = 0;
 454                 rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
 455         }
 456         return 1;
 457 }
 458
 459 int
 460 nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
 461                                         struct nfsd_readres *resp)
 462 {
 463         p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 464         *p++ = htonl(resp->count);
 465         xdr_ressize_check(rqstp, p);
 466
 467         /* now update rqstp->rq_res to reflect data as well */
 468         rqstp->rq_res.page_len = resp->count;
 469         if (resp->count & 3) {
 470                 /* need to pad the tail */
 471                 rqstp->rq_res.tail[0].iov_base = p;
 472                 *p = 0;
 473                 rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
 474         }
 475         return 1;
 476 }
 477
 478 int
 479 nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
 480                                         struct nfsd_readdirres *resp)
 481 {
 482         xdr_ressize_check(rqstp, p);
 483         p = resp->buffer;
 484         *p++ = 0;                       /* no more entries */
 485         *p++ = htonl((resp->common.err == nfserr_eof));
 486         rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
 487
 488         return 1;
 489 }
 490
 491 int
 492 nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,
 493                                         struct nfsd_statfsres *resp)
 494 {
 495         struct kstatfs  *stat = &resp->stats;
 496
 497         *p++ = htonl(NFSSVC_MAXBLKSIZE_V2);     /* max transfer size */
 498         *p++ = htonl(stat->f_bsize);
 499         *p++ = htonl(stat->f_blocks);
 500         *p++ = htonl(stat->f_bfree);
 501         *p++ = htonl(stat->f_bavail);
 502         return xdr_ressize_check(rqstp, p);
 503 }
 504
 505 int
 506 nfssvc_encode_entry(void *ccdv, const char *name,
 507                     int namlen, loff_t offset, u64 ino, unsigned int d_type)
 508 {
 509         struct readdir_cd *ccd = ccdv;
 510         struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
 511         __be32  *p = cd->buffer;
 512         int     buflen, slen;
 513
 514         /*
 515         dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
 516                         namlen, name, offset, ino);
 517          */
 518
 519         if (offset > ~((u32) 0)) {
 520                 cd->common.err = nfserr_fbig;
 521                 return -EINVAL;
 522         }
 523         if (cd->offset)
 524                 *cd->offset = htonl(offset);
 525
 526         /* truncate filename */
 527         namlen = min(namlen, NFS2_MAXNAMLEN);
 528         slen = XDR_QUADLEN(namlen);
 529
 530         if ((buflen = cd->buflen - slen - 4) < 0) {
 531                 cd->common.err = nfserr_toosmall;
 532                 return -EINVAL;
 533         }
 534         if (ino > ~((u32) 0)) {
 535                 cd->common.err = nfserr_fbig;
 536                 return -EINVAL;
 537         }
 538         *p++ = xdr_one;                         /* mark entry present */
 539         *p++ = htonl((u32) ino);                /* file id */
 540         p    = xdr_encode_array(p, name, namlen);/* name length & name */
 541         cd->offset = p;                 /* remember pointer */
 542         *p++ = htonl(~0U);              /* offset of next entry */
 543
 544         cd->buflen = buflen;
 545         cd->buffer = p;
 546         cd->common.err = nfs_ok;
 547         return 0;
 548 }
 549
 550 /*
 551  * XDR release functions
 552  */
 553 int
 554 nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
 555                                         struct nfsd_fhandle *resp)
 556 {
 557         fh_put(&resp->fh);
 558         return 1;
 559 }