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(dentry->d_inode, &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         if (!(p = decode_fh(p, &args->fh)))
 218                 return 0;
 219         return xdr_argsize_check(rqstp, p);
 220 }
 221
 222 int
 223 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
 224                                         struct nfsd_sattrargs *args)
 225 {
 226         p = decode_fh(p, &args->fh);
 227         if (!p)
 228                 return 0;
 229         p = decode_sattr(p, &args->attrs);
 230
 231         return xdr_argsize_check(rqstp, p);
 232 }
 233
 234 int
 235 nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
 236                                         struct nfsd_diropargs *args)
 237 {
 238         if (!(p = decode_fh(p, &args->fh))
 239          || !(p = decode_filename(p, &args->name, &args->len)))
 240                 return 0;
 241
 242          return xdr_argsize_check(rqstp, p);
 243 }
 244
 245 int
 246 nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
 247                                         struct nfsd_readargs *args)
 248 {
 249         unsigned int len;
 250         int v;
 251         if (!(p = decode_fh(p, &args->fh)))
 252                 return 0;
 253
 254         args->offset    = ntohl(*p++);
 255         len = args->count     = ntohl(*p++);
 256         p++; /* totalcount - unused */
 257
 258         if (len > NFSSVC_MAXBLKSIZE_V2)
 259                 len = NFSSVC_MAXBLKSIZE_V2;
 260
 261         /* set up somewhere to store response.
 262          * We take pages, put them on reslist and include in iovec
 263          */
 264         v=0;
 265         while (len > 0) {
 266                 struct page *p = *(rqstp->rq_next_page++);
 267
 268                 rqstp->rq_vec[v].iov_base = page_address(p);
 269                 rqstp->rq_vec[v].iov_len = len < PAGE_SIZE?len:PAGE_SIZE;
 270                 len -= rqstp->rq_vec[v].iov_len;
 271                 v++;
 272         }
 273         args->vlen = v;
 274         return xdr_argsize_check(rqstp, p);
 275 }
 276
 277 int
 278 nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
 279                                         struct nfsd_writeargs *args)
 280 {
 281         unsigned int len, hdr, dlen;
 282         int v;
 283
 284         if (!(p = decode_fh(p, &args->fh)))
 285                 return 0;
 286
 287         p++;                            /* beginoffset */
 288         args->offset = ntohl(*p++);     /* offset */
 289         p++;                            /* totalcount */
 290         len = args->len = ntohl(*p++);
 291         /*
 292          * The protocol specifies a maximum of 8192 bytes.
 293          */
 294         if (len > NFSSVC_MAXBLKSIZE_V2)
 295                 return 0;
 296
 297         /*
 298          * Check to make sure that we got the right number of
 299          * bytes.
 300          */
 301         hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
 302         dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
 303                 - hdr;
 304
 305         /*
 306          * Round the length of the data which was specified up to
 307          * the next multiple of XDR units and then compare that
 308          * against the length which was actually received.
 309          * Note that when RPCSEC/GSS (for example) is used, the
 310          * data buffer can be padded so dlen might be larger
 311          * than required.  It must never be smaller.
 312          */
 313         if (dlen < XDR_QUADLEN(len)*4)
 314                 return 0;
 315
 316         rqstp->rq_vec[0].iov_base = (void*)p;
 317         rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
 318         v = 0;
 319         while (len > rqstp->rq_vec[v].iov_len) {
 320                 len -= rqstp->rq_vec[v].iov_len;
 321                 v++;
 322                 rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
 323                 rqstp->rq_vec[v].iov_len = PAGE_SIZE;
 324         }
 325         rqstp->rq_vec[v].iov_len = len;
 326         args->vlen = v + 1;
 327         return 1;
 328 }
 329
 330 int
 331 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
 332                                         struct nfsd_createargs *args)
 333 {
 334         if (   !(p = decode_fh(p, &args->fh))
 335             || !(p = decode_filename(p, &args->name, &args->len)))
 336                 return 0;
 337         p = decode_sattr(p, &args->attrs);
 338
 339         return xdr_argsize_check(rqstp, p);
 340 }
 341
 342 int
 343 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
 344                                         struct nfsd_renameargs *args)
 345 {
 346         if (!(p = decode_fh(p, &args->ffh))
 347          || !(p = decode_filename(p, &args->fname, &args->flen))
 348          || !(p = decode_fh(p, &args->tfh))
 349          || !(p = decode_filename(p, &args->tname, &args->tlen)))
 350                 return 0;
 351
 352         return xdr_argsize_check(rqstp, p);
 353 }
 354
 355 int
 356 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readlinkargs *args)
 357 {
 358         if (!(p = decode_fh(p, &args->fh)))
 359                 return 0;
 360         args->buffer = page_address(*(rqstp->rq_next_page++));
 361
 362         return xdr_argsize_check(rqstp, p);
 363 }
 364
 365 int
 366 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
 367                                         struct nfsd_linkargs *args)
 368 {
 369         if (!(p = decode_fh(p, &args->ffh))
 370          || !(p = decode_fh(p, &args->tfh))
 371          || !(p = decode_filename(p, &args->tname, &args->tlen)))
 372                 return 0;
 373
 374         return xdr_argsize_check(rqstp, p);
 375 }
 376
 377 int
 378 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
 379                                         struct nfsd_symlinkargs *args)
 380 {
 381         if (   !(p = decode_fh(p, &args->ffh))
 382             || !(p = decode_filename(p, &args->fname, &args->flen))
 383             || !(p = decode_pathname(p, &args->tname, &args->tlen)))
 384                 return 0;
 385         p = decode_sattr(p, &args->attrs);
 386
 387         return xdr_argsize_check(rqstp, p);
 388 }
 389
 390 int
 391 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
 392                                         struct nfsd_readdirargs *args)
 393 {
 394         if (!(p = decode_fh(p, &args->fh)))
 395                 return 0;
 396         args->cookie = ntohl(*p++);
 397         args->count  = ntohl(*p++);
 398         if (args->count > PAGE_SIZE)
 399                 args->count = PAGE_SIZE;
 400
 401         args->buffer = page_address(*(rqstp->rq_next_page++));
 402
 403         return xdr_argsize_check(rqstp, p);
 404 }
 405
 406 /*
 407  * XDR encode functions
 408  */
 409 int
 410 nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
 411 {
 412         return xdr_ressize_check(rqstp, p);
 413 }
 414
 415 int
 416 nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
 417                                         struct nfsd_attrstat *resp)
 418 {
 419         p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 420         return xdr_ressize_check(rqstp, p);
 421 }
 422
 423 int
 424 nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
 425                                         struct nfsd_diropres *resp)
 426 {
 427         p = encode_fh(p, &resp->fh);
 428         p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 429         return xdr_ressize_check(rqstp, p);
 430 }
 431
 432 int
 433 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
 434                                         struct nfsd_readlinkres *resp)
 435 {
 436         *p++ = htonl(resp->len);
 437         xdr_ressize_check(rqstp, p);
 438         rqstp->rq_res.page_len = resp->len;
 439         if (resp->len & 3) {
 440                 /* need to pad the tail */
 441                 rqstp->rq_res.tail[0].iov_base = p;
 442                 *p = 0;
 443                 rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
 444         }
 445         return 1;
 446 }
 447
 448 int
 449 nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
 450                                         struct nfsd_readres *resp)
 451 {
 452         p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 453         *p++ = htonl(resp->count);
 454         xdr_ressize_check(rqstp, p);
 455
 456         /* now update rqstp->rq_res to reflect data as well */
 457         rqstp->rq_res.page_len = resp->count;
 458         if (resp->count & 3) {
 459                 /* need to pad the tail */
 460                 rqstp->rq_res.tail[0].iov_base = p;
 461                 *p = 0;
 462                 rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
 463         }
 464         return 1;
 465 }
 466
 467 int
 468 nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
 469                                         struct nfsd_readdirres *resp)
 470 {
 471         xdr_ressize_check(rqstp, p);
 472         p = resp->buffer;
 473         *p++ = 0;                       /* no more entries */
 474         *p++ = htonl((resp->common.err == nfserr_eof));
 475         rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
 476
 477         return 1;
 478 }
 479
 480 int
 481 nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,
 482                                         struct nfsd_statfsres *resp)
 483 {
 484         struct kstatfs  *stat = &resp->stats;
 485
 486         *p++ = htonl(NFSSVC_MAXBLKSIZE_V2);     /* max transfer size */
 487         *p++ = htonl(stat->f_bsize);
 488         *p++ = htonl(stat->f_blocks);
 489         *p++ = htonl(stat->f_bfree);
 490         *p++ = htonl(stat->f_bavail);
 491         return xdr_ressize_check(rqstp, p);
 492 }
 493
 494 int
 495 nfssvc_encode_entry(void *ccdv, const char *name,
 496                     int namlen, loff_t offset, u64 ino, unsigned int d_type)
 497 {
 498         struct readdir_cd *ccd = ccdv;
 499         struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
 500         __be32  *p = cd->buffer;
 501         int     buflen, slen;
 502
 503         /*
 504         dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
 505                         namlen, name, offset, ino);
 506          */
 507
 508         if (offset > ~((u32) 0)) {
 509                 cd->common.err = nfserr_fbig;
 510                 return -EINVAL;
 511         }
 512         if (cd->offset)
 513                 *cd->offset = htonl(offset);
 514         if (namlen > NFS2_MAXNAMLEN)
 515                 namlen = NFS2_MAXNAMLEN;/* truncate filename */
 516
 517         slen = XDR_QUADLEN(namlen);
 518         if ((buflen = cd->buflen - slen - 4) < 0) {
 519                 cd->common.err = nfserr_toosmall;
 520                 return -EINVAL;
 521         }
 522         if (ino > ~((u32) 0)) {
 523                 cd->common.err = nfserr_fbig;
 524                 return -EINVAL;
 525         }
 526         *p++ = xdr_one;                         /* mark entry present */
 527         *p++ = htonl((u32) ino);                /* file id */
 528         p    = xdr_encode_array(p, name, namlen);/* name length & name */
 529         cd->offset = p;                 /* remember pointer */
 530         *p++ = htonl(~0U);              /* offset of next entry */
 531
 532         cd->buflen = buflen;
 533         cd->buffer = p;
 534         cd->common.err = nfs_ok;
 535         return 0;
 536 }
 537
 538 /*
 539  * XDR release functions
 540  */
 541 int
 542 nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
 543                                         struct nfsd_fhandle *resp)
 544 {
 545         fh_put(&resp->fh);
 546         return 1;
 547 }