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         len = min_t(unsigned int, len, NFSSVC_MAXBLKSIZE_V2);
 261
 262         /* set up somewhere to store response.
 263          * We take pages, put them on reslist and include in iovec
 264          */
 265         v=0;
 266         while (len > 0) {
 267                 struct page *p = *(rqstp->rq_next_page++);
 268
 269                 rqstp->rq_vec[v].iov_base = page_address(p);
 270                 rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
 271                 len -= rqstp->rq_vec[v].iov_len;
 272                 v++;
 273         }
 274         args->vlen = v;
 275         return xdr_argsize_check(rqstp, p);
 276 }
 277
 278 int
 279 nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
 280                                         struct nfsd_writeargs *args)
 281 {
 282         unsigned int len, hdr, dlen;
 283         struct kvec *head = rqstp->rq_arg.head;
 284         int v;
 285
 286         p = decode_fh(p, &args->fh);
 287         if (!p)
 288                 return 0;
 289
 290         p++;                            /* beginoffset */
 291         args->offset = ntohl(*p++);     /* offset */
 292         p++;                            /* totalcount */
 293         len = args->len = ntohl(*p++);
 294         /*
 295          * The protocol specifies a maximum of 8192 bytes.
 296          */
 297         if (len > NFSSVC_MAXBLKSIZE_V2)
 298                 return 0;
 299
 300         /*
 301          * Check to make sure that we got the right number of
 302          * bytes.
 303          */
 304         hdr = (void*)p - head->iov_base;
 305         if (hdr > head->iov_len)
 306                 return 0;
 307         dlen = head->iov_len + rqstp->rq_arg.page_len - hdr;
 308
 309         /*
 310          * Round the length of the data which was specified up to
 311          * the next multiple of XDR units and then compare that
 312          * against the length which was actually received.
 313          * Note that when RPCSEC/GSS (for example) is used, the
 314          * data buffer can be padded so dlen might be larger
 315          * than required.  It must never be smaller.
 316          */
 317         if (dlen < XDR_QUADLEN(len)*4)
 318                 return 0;
 319
 320         rqstp->rq_vec[0].iov_base = (void*)p;
 321         rqstp->rq_vec[0].iov_len = head->iov_len - hdr;
 322         v = 0;
 323         while (len > rqstp->rq_vec[v].iov_len) {
 324                 len -= rqstp->rq_vec[v].iov_len;
 325                 v++;
 326                 rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
 327                 rqstp->rq_vec[v].iov_len = PAGE_SIZE;
 328         }
 329         rqstp->rq_vec[v].iov_len = len;
 330         args->vlen = v + 1;
 331         return 1;
 332 }
 333
 334 int
 335 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
 336                                         struct nfsd_createargs *args)
 337 {
 338         if (   !(p = decode_fh(p, &args->fh))
 339             || !(p = decode_filename(p, &args->name, &args->len)))
 340                 return 0;
 341         p = decode_sattr(p, &args->attrs);
 342
 343         return xdr_argsize_check(rqstp, p);
 344 }
 345
 346 int
 347 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
 348                                         struct nfsd_renameargs *args)
 349 {
 350         if (!(p = decode_fh(p, &args->ffh))
 351          || !(p = decode_filename(p, &args->fname, &args->flen))
 352          || !(p = decode_fh(p, &args->tfh))
 353          || !(p = decode_filename(p, &args->tname, &args->tlen)))
 354                 return 0;
 355
 356         return xdr_argsize_check(rqstp, p);
 357 }
 358
 359 int
 360 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readlinkargs *args)
 361 {
 362         p = decode_fh(p, &args->fh);
 363         if (!p)
 364                 return 0;
 365         args->buffer = page_address(*(rqstp->rq_next_page++));
 366
 367         return xdr_argsize_check(rqstp, p);
 368 }
 369
 370 int
 371 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
 372                                         struct nfsd_linkargs *args)
 373 {
 374         if (!(p = decode_fh(p, &args->ffh))
 375          || !(p = decode_fh(p, &args->tfh))
 376          || !(p = decode_filename(p, &args->tname, &args->tlen)))
 377                 return 0;
 378
 379         return xdr_argsize_check(rqstp, p);
 380 }
 381
 382 int
 383 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
 384                                         struct nfsd_symlinkargs *args)
 385 {
 386         if (   !(p = decode_fh(p, &args->ffh))
 387             || !(p = decode_filename(p, &args->fname, &args->flen))
 388             || !(p = decode_pathname(p, &args->tname, &args->tlen)))
 389                 return 0;
 390         p = decode_sattr(p, &args->attrs);
 391
 392         return xdr_argsize_check(rqstp, p);
 393 }
 394
 395 int
 396 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
 397                                         struct nfsd_readdirargs *args)
 398 {
 399         p = decode_fh(p, &args->fh);
 400         if (!p)
 401                 return 0;
 402         args->cookie = ntohl(*p++);
 403         args->count  = ntohl(*p++);
 404         args->count  = min_t(u32, args->count, PAGE_SIZE);
 405         args->buffer = page_address(*(rqstp->rq_next_page++));
 406
 407         return xdr_argsize_check(rqstp, p);
 408 }
 409
 410 /*
 411  * XDR encode functions
 412  */
 413 int
 414 nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
 415 {
 416         return xdr_ressize_check(rqstp, p);
 417 }
 418
 419 int
 420 nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
 421                                         struct nfsd_attrstat *resp)
 422 {
 423         p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 424         return xdr_ressize_check(rqstp, p);
 425 }
 426
 427 int
 428 nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
 429                                         struct nfsd_diropres *resp)
 430 {
 431         p = encode_fh(p, &resp->fh);
 432         p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 433         return xdr_ressize_check(rqstp, p);
 434 }
 435
 436 int
 437 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
 438                                         struct nfsd_readlinkres *resp)
 439 {
 440         *p++ = htonl(resp->len);
 441         xdr_ressize_check(rqstp, p);
 442         rqstp->rq_res.page_len = resp->len;
 443         if (resp->len & 3) {
 444                 /* need to pad the tail */
 445                 rqstp->rq_res.tail[0].iov_base = p;
 446                 *p = 0;
 447                 rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
 448         }
 449         return 1;
 450 }
 451
 452 int
 453 nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
 454                                         struct nfsd_readres *resp)
 455 {
 456         p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 457         *p++ = htonl(resp->count);
 458         xdr_ressize_check(rqstp, p);
 459
 460         /* now update rqstp->rq_res to reflect data as well */
 461         rqstp->rq_res.page_len = resp->count;
 462         if (resp->count & 3) {
 463                 /* need to pad the tail */
 464                 rqstp->rq_res.tail[0].iov_base = p;
 465                 *p = 0;
 466                 rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
 467         }
 468         return 1;
 469 }
 470
 471 int
 472 nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
 473                                         struct nfsd_readdirres *resp)
 474 {
 475         xdr_ressize_check(rqstp, p);
 476         p = resp->buffer;
 477         *p++ = 0;                       /* no more entries */
 478         *p++ = htonl((resp->common.err == nfserr_eof));
 479         rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
 480
 481         return 1;
 482 }
 483
 484 int
 485 nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,
 486                                         struct nfsd_statfsres *resp)
 487 {
 488         struct kstatfs  *stat = &resp->stats;
 489
 490         *p++ = htonl(NFSSVC_MAXBLKSIZE_V2);     /* max transfer size */
 491         *p++ = htonl(stat->f_bsize);
 492         *p++ = htonl(stat->f_blocks);
 493         *p++ = htonl(stat->f_bfree);
 494         *p++ = htonl(stat->f_bavail);
 495         return xdr_ressize_check(rqstp, p);
 496 }
 497
 498 int
 499 nfssvc_encode_entry(void *ccdv, const char *name,
 500                     int namlen, loff_t offset, u64 ino, unsigned int d_type)
 501 {
 502         struct readdir_cd *ccd = ccdv;
 503         struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
 504         __be32  *p = cd->buffer;
 505         int     buflen, slen;
 506
 507         /*
 508         dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
 509                         namlen, name, offset, ino);
 510          */
 511
 512         if (offset > ~((u32) 0)) {
 513                 cd->common.err = nfserr_fbig;
 514                 return -EINVAL;
 515         }
 516         if (cd->offset)
 517                 *cd->offset = htonl(offset);
 518
 519         /* truncate filename */
 520         namlen = min(namlen, NFS2_MAXNAMLEN);
 521         slen = XDR_QUADLEN(namlen);
 522
 523         if ((buflen = cd->buflen - slen - 4) < 0) {
 524                 cd->common.err = nfserr_toosmall;
 525                 return -EINVAL;
 526         }
 527         if (ino > ~((u32) 0)) {
 528                 cd->common.err = nfserr_fbig;
 529                 return -EINVAL;
 530         }
 531         *p++ = xdr_one;                         /* mark entry present */
 532         *p++ = htonl((u32) ino);                /* file id */
 533         p    = xdr_encode_array(p, name, namlen);/* name length & name */
 534         cd->offset = p;                 /* remember pointer */
 535         *p++ = htonl(~0U);              /* offset of next entry */
 536
 537         cd->buflen = buflen;
 538         cd->buffer = p;
 539         cd->common.err = nfs_ok;
 540         return 0;
 541 }
 542
 543 /*
 544  * XDR release functions
 545  */
 546 int
 547 nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
 548                                         struct nfsd_fhandle *resp)
 549 {
 550         fh_put(&resp->fh);
 551         return 1;
 552 }