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