fs/nfsd/nfsxdr.c

   1 /*
   2  * linux/fs/nfsd/nfsxdr.c
   3  *
   4  * XDR support for nfsd
   5  *
   6  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   7  */
   8
   9 #include <linux/nfsd/xdr.h>
  10 #include "auth.h"
  11
  12 #define NFSDDBG_FACILITY                NFSDDBG_XDR
  13
  14 /*
  15  * Mapping of S_IF* types to NFS file types
  16  */
  17 static u32      nfs_ftypes[] = {
  18         NFNON,  NFCHR,  NFCHR, NFBAD,
  19         NFDIR,  NFBAD,  NFBLK, NFBAD,
  20         NFREG,  NFBAD,  NFLNK, NFBAD,
  21         NFSOCK, NFBAD,  NFLNK, NFBAD,
  22 };
  23
  24
  25 /*
  26  * XDR functions for basic NFS types
  27  */
  28 static __be32 *
  29 decode_fh(__be32 *p, struct svc_fh *fhp)
  30 {
  31         fh_init(fhp, NFS_FHSIZE);
  32         memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
  33         fhp->fh_handle.fh_size = NFS_FHSIZE;
  34
  35         /* FIXME: Look up export pointer here and verify
  36          * Sun Secure RPC if requested */
  37         return p + (NFS_FHSIZE >> 2);
  38 }
  39
  40 /* Helper function for NFSv2 ACL code */
  41 __be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
  42 {
  43         return decode_fh(p, fhp);
  44 }
  45
  46 static __be32 *
  47 encode_fh(__be32 *p, struct svc_fh *fhp)
  48 {
  49         memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
  50         return p + (NFS_FHSIZE>> 2);
  51 }
  52
  53 /*
  54  * Decode a file name and make sure that the path contains
  55  * no slashes or null bytes.
  56  */
  57 static __be32 *
  58 decode_filename(__be32 *p, char **namp, unsigned int *lenp)
  59 {
  60         char            *name;
  61         unsigned int    i;
  62
  63         if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
  64                 for (i = 0, name = *namp; i < *lenp; i++, name++) {
  65                         if (*name == '\0' || *name == '/')
  66                                 return NULL;
  67                 }
  68         }
  69
  70         return p;
  71 }
  72
  73 static __be32 *
  74 decode_pathname(__be32 *p, char **namp, unsigned int *lenp)
  75 {
  76         char            *name;
  77         unsigned int    i;
  78
  79         if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXPATHLEN)) != NULL) {
  80                 for (i = 0, name = *namp; i < *lenp; i++, name++) {
  81                         if (*name == '\0')
  82                                 return NULL;
  83                 }
  84         }
  85
  86         return p;
  87 }
  88
  89 static __be32 *
  90 decode_sattr(__be32 *p, struct iattr *iap)
  91 {
  92         u32     tmp, tmp1;
  93
  94         iap->ia_valid = 0;
  95
  96         /* Sun client bug compatibility check: some sun clients seem to
  97          * put 0xffff in the mode field when they mean 0xffffffff.
  98          * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
  99          */
 100         if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
 101                 iap->ia_valid |= ATTR_MODE;
 102                 iap->ia_mode = tmp;
 103         }
 104         if ((tmp = ntohl(*p++)) != (u32)-1) {
 105                 iap->ia_valid |= ATTR_UID;
 106                 iap->ia_uid = tmp;
 107         }
 108         if ((tmp = ntohl(*p++)) != (u32)-1) {
 109                 iap->ia_valid |= ATTR_GID;
 110                 iap->ia_gid = tmp;
 111         }
 112         if ((tmp = ntohl(*p++)) != (u32)-1) {
 113                 iap->ia_valid |= ATTR_SIZE;
 114                 iap->ia_size = tmp;
 115         }
 116         tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
 117         if (tmp != (u32)-1 && tmp1 != (u32)-1) {
 118                 iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
 119                 iap->ia_atime.tv_sec = tmp;
 120                 iap->ia_atime.tv_nsec = tmp1 * 1000;
 121         }
 122         tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
 123         if (tmp != (u32)-1 && tmp1 != (u32)-1) {
 124                 iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
 125                 iap->ia_mtime.tv_sec = tmp;
 126                 iap->ia_mtime.tv_nsec = tmp1 * 1000;
 127                 /*
 128                  * Passing the invalid value useconds=1000000 for mtime
 129                  * is a Sun convention for "set both mtime and atime to
 130                  * current server time".  It's needed to make permissions
 131                  * checks for the "touch" program across v2 mounts to
 132                  * Solaris and Irix boxes work correctly. See description of
 133                  * sattr in section 6.1 of "NFS Illustrated" by
 134                  * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
 135                  */
 136                 if (tmp1 == 1000000)
 137                         iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
 138         }
 139         return p;
 140 }
 141
 142 static __be32 *
 143 encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
 144              struct kstat *stat)
 145 {
 146         struct dentry   *dentry = fhp->fh_dentry;
 147         int type;
 148         struct timespec time;
 149         u32 f;
 150
 151         type = (stat->mode & S_IFMT);
 152
 153         *p++ = htonl(nfs_ftypes[type >> 12]);
 154         *p++ = htonl((u32) stat->mode);
 155         *p++ = htonl((u32) stat->nlink);
 156         *p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
 157         *p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
 158
 159         if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
 160                 *p++ = htonl(NFS_MAXPATHLEN);
 161         } else {
 162                 *p++ = htonl((u32) stat->size);
 163         }
 164         *p++ = htonl((u32) stat->blksize);
 165         if (S_ISCHR(type) || S_ISBLK(type))
 166                 *p++ = htonl(new_encode_dev(stat->rdev));
 167         else
 168                 *p++ = htonl(0xffffffff);
 169         *p++ = htonl((u32) stat->blocks);
 170         switch (fsid_source(fhp)) {
 171         default:
 172         case FSIDSOURCE_DEV:
 173                 *p++ = htonl(new_encode_dev(stat->dev));
 174                 break;
 175         case FSIDSOURCE_FSID:
 176                 *p++ = htonl((u32) fhp->fh_export->ex_fsid);
 177                 break;
 178         case FSIDSOURCE_UUID:
 179                 f = ((u32*)fhp->fh_export->ex_uuid)[0];
 180                 f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
 181                 f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
 182                 f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
 183                 *p++ = htonl(f);
 184                 break;
 185         }
 186         *p++ = htonl((u32) stat->ino);
 187         *p++ = htonl((u32) stat->atime.tv_sec);
 188         *p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
 189         lease_get_mtime(dentry->d_inode, &time);
 190         *p++ = htonl((u32) time.tv_sec);
 191         *p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0);
 192         *p++ = htonl((u32) stat->ctime.tv_sec);
 193         *p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
 194
 195         return p;
 196 }
 197
 198 /* Helper function for NFSv2 ACL code */
 199 __be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
 200 {
 201         struct kstat stat;
 202         vfs_getattr(fhp->fh_export->ex_path.mnt, fhp->fh_dentry, &stat);
 203         return encode_fattr(rqstp, p, fhp, &stat);
 204 }
 205
 206 /*
 207  * XDR decode functions
 208  */
 209 int
 210 nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
 211 {
 212         return xdr_argsize_check(rqstp, p);
 213 }
 214
 215 int
 216 nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
 217 {
 218         if (!(p = decode_fh(p, &args->fh)))
 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,pn;
 252         if (!(p = decode_fh(p, &args->fh)))
 253                 return 0;
 254
 255         args->offset    = ntohl(*p++);
 256         len = args->count     = ntohl(*p++);
 257         p++; /* totalcount - unused */
 258
 259         if (len > NFSSVC_MAXBLKSIZE_V2)
 260                 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                 pn = rqstp->rq_resused++;
 268                 rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
 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_respages[rqstp->rq_resused++]);
 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_respages[rqstp->rq_resused++]);
 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 aswell */
 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 }