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