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
 157         type = (stat->mode & S_IFMT);
 158
 159         *p++ = htonl(nfs_ftypes[type >> 12]);
 160         *p++ = htonl((u32) stat->mode);
 161         *p++ = htonl((u32) stat->nlink);
 162         *p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
 163         *p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
 164
 165         if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
 166                 *p++ = htonl(NFS_MAXPATHLEN);
 167         } else {
 168                 *p++ = htonl((u32) stat->size);
 169         }
 170         *p++ = htonl((u32) stat->blksize);
 171         if (S_ISCHR(type) || S_ISBLK(type))
 172                 *p++ = htonl(new_encode_dev(stat->rdev));
 173         else
 174                 *p++ = htonl(0xffffffff);
 175         *p++ = htonl((u32) stat->blocks);
 176         if (is_fsid(fhp, rqstp->rq_reffh))
 177                 *p++ = htonl((u32) fhp->fh_export->ex_fsid);
 178         else
 179                 *p++ = htonl(new_encode_dev(stat->dev));
 180         *p++ = htonl((u32) stat->ino);
 181         *p++ = htonl((u32) stat->atime.tv_sec);
 182         *p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
 183         lease_get_mtime(dentry->d_inode, &time);
 184         *p++ = htonl((u32) time.tv_sec);
 185         *p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0);
 186         *p++ = htonl((u32) stat->ctime.tv_sec);
 187         *p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
 188
 189         return p;
 190 }
 191
 192 /* Helper function for NFSv2 ACL code */
 193 __be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
 194 {
 195         struct kstat stat;
 196         vfs_getattr(fhp->fh_export->ex_mnt, fhp->fh_dentry, &stat);
 197         return encode_fattr(rqstp, p, fhp, &stat);
 198 }
 199
 200 /*
 201  * XDR decode functions
 202  */
 203 int
 204 nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
 205 {
 206         return xdr_argsize_check(rqstp, p);
 207 }
 208
 209 int
 210 nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
 211 {
 212         if (!(p = decode_fh(p, &args->fh)))
 213                 return 0;
 214         return xdr_argsize_check(rqstp, p);
 215 }
 216
 217 int
 218 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
 219                                         struct nfsd_sattrargs *args)
 220 {
 221         if (!(p = decode_fh(p, &args->fh))
 222          || !(p = decode_sattr(p, &args->attrs)))
 223                 return 0;
 224
 225         return xdr_argsize_check(rqstp, p);
 226 }
 227
 228 int
 229 nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
 230                                         struct nfsd_diropargs *args)
 231 {
 232         if (!(p = decode_fh(p, &args->fh))
 233          || !(p = decode_filename(p, &args->name, &args->len)))
 234                 return 0;
 235
 236          return xdr_argsize_check(rqstp, p);
 237 }
 238
 239 int
 240 nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
 241                                         struct nfsd_readargs *args)
 242 {
 243         unsigned int len;
 244         int v,pn;
 245         if (!(p = decode_fh(p, &args->fh)))
 246                 return 0;
 247
 248         args->offset    = ntohl(*p++);
 249         len = args->count     = ntohl(*p++);
 250         p++; /* totalcount - unused */
 251
 252         if (len > NFSSVC_MAXBLKSIZE_V2)
 253                 len = NFSSVC_MAXBLKSIZE_V2;
 254
 255         /* set up somewhere to store response.
 256          * We take pages, put them on reslist and include in iovec
 257          */
 258         v=0;
 259         while (len > 0) {
 260                 pn = rqstp->rq_resused++;
 261                 rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
 262                 rqstp->rq_vec[v].iov_len = len < PAGE_SIZE?len:PAGE_SIZE;
 263                 len -= rqstp->rq_vec[v].iov_len;
 264                 v++;
 265         }
 266         args->vlen = v;
 267         return xdr_argsize_check(rqstp, p);
 268 }
 269
 270 int
 271 nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
 272                                         struct nfsd_writeargs *args)
 273 {
 274         unsigned int len;
 275         int v;
 276         if (!(p = decode_fh(p, &args->fh)))
 277                 return 0;
 278
 279         p++;                            /* beginoffset */
 280         args->offset = ntohl(*p++);     /* offset */
 281         p++;                            /* totalcount */
 282         len = args->len = ntohl(*p++);
 283         rqstp->rq_vec[0].iov_base = (void*)p;
 284         rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len -
 285                                 (((void*)p) - rqstp->rq_arg.head[0].iov_base);
 286         if (len > NFSSVC_MAXBLKSIZE_V2)
 287                 len = NFSSVC_MAXBLKSIZE_V2;
 288         v = 0;
 289         while (len > rqstp->rq_vec[v].iov_len) {
 290                 len -= rqstp->rq_vec[v].iov_len;
 291                 v++;
 292                 rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
 293                 rqstp->rq_vec[v].iov_len = PAGE_SIZE;
 294         }
 295         rqstp->rq_vec[v].iov_len = len;
 296         args->vlen = v+1;
 297         return rqstp->rq_vec[0].iov_len > 0;
 298 }
 299
 300 int
 301 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
 302                                         struct nfsd_createargs *args)
 303 {
 304         if (!(p = decode_fh(p, &args->fh))
 305          || !(p = decode_filename(p, &args->name, &args->len))
 306          || !(p = decode_sattr(p, &args->attrs)))
 307                 return 0;
 308
 309         return xdr_argsize_check(rqstp, p);
 310 }
 311
 312 int
 313 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
 314                                         struct nfsd_renameargs *args)
 315 {
 316         if (!(p = decode_fh(p, &args->ffh))
 317          || !(p = decode_filename(p, &args->fname, &args->flen))
 318          || !(p = decode_fh(p, &args->tfh))
 319          || !(p = decode_filename(p, &args->tname, &args->tlen)))
 320                 return 0;
 321
 322         return xdr_argsize_check(rqstp, p);
 323 }
 324
 325 int
 326 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readlinkargs *args)
 327 {
 328         if (!(p = decode_fh(p, &args->fh)))
 329                 return 0;
 330         args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused++]);
 331
 332         return xdr_argsize_check(rqstp, p);
 333 }
 334
 335 int
 336 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
 337                                         struct nfsd_linkargs *args)
 338 {
 339         if (!(p = decode_fh(p, &args->ffh))
 340          || !(p = decode_fh(p, &args->tfh))
 341          || !(p = decode_filename(p, &args->tname, &args->tlen)))
 342                 return 0;
 343
 344         return xdr_argsize_check(rqstp, p);
 345 }
 346
 347 int
 348 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
 349                                         struct nfsd_symlinkargs *args)
 350 {
 351         if (!(p = decode_fh(p, &args->ffh))
 352          || !(p = decode_filename(p, &args->fname, &args->flen))
 353          || !(p = decode_pathname(p, &args->tname, &args->tlen))
 354          || !(p = decode_sattr(p, &args->attrs)))
 355                 return 0;
 356
 357         return xdr_argsize_check(rqstp, p);
 358 }
 359
 360 int
 361 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
 362                                         struct nfsd_readdirargs *args)
 363 {
 364         if (!(p = decode_fh(p, &args->fh)))
 365                 return 0;
 366         args->cookie = ntohl(*p++);
 367         args->count  = ntohl(*p++);
 368         if (args->count > PAGE_SIZE)
 369                 args->count = PAGE_SIZE;
 370
 371         args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused++]);
 372
 373         return xdr_argsize_check(rqstp, p);
 374 }
 375
 376 /*
 377  * XDR encode functions
 378  */
 379 int
 380 nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
 381 {
 382         return xdr_ressize_check(rqstp, p);
 383 }
 384
 385 int
 386 nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
 387                                         struct nfsd_attrstat *resp)
 388 {
 389         p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 390         return xdr_ressize_check(rqstp, p);
 391 }
 392
 393 int
 394 nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
 395                                         struct nfsd_diropres *resp)
 396 {
 397         p = encode_fh(p, &resp->fh);
 398         p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 399         return xdr_ressize_check(rqstp, p);
 400 }
 401
 402 int
 403 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
 404                                         struct nfsd_readlinkres *resp)
 405 {
 406         *p++ = htonl(resp->len);
 407         xdr_ressize_check(rqstp, p);
 408         rqstp->rq_res.page_len = resp->len;
 409         if (resp->len & 3) {
 410                 /* need to pad the tail */
 411                 rqstp->rq_res.tail[0].iov_base = p;
 412                 *p = 0;
 413                 rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
 414         }
 415         return 1;
 416 }
 417
 418 int
 419 nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
 420                                         struct nfsd_readres *resp)
 421 {
 422         p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 423         *p++ = htonl(resp->count);
 424         xdr_ressize_check(rqstp, p);
 425
 426         /* now update rqstp->rq_res to reflect data aswell */
 427         rqstp->rq_res.page_len = resp->count;
 428         if (resp->count & 3) {
 429                 /* need to pad the tail */
 430                 rqstp->rq_res.tail[0].iov_base = p;
 431                 *p = 0;
 432                 rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
 433         }
 434         return 1;
 435 }
 436
 437 int
 438 nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
 439                                         struct nfsd_readdirres *resp)
 440 {
 441         xdr_ressize_check(rqstp, p);
 442         p = resp->buffer;
 443         *p++ = 0;                       /* no more entries */
 444         *p++ = htonl((resp->common.err == nfserr_eof));
 445         rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
 446
 447         return 1;
 448 }
 449
 450 int
 451 nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,
 452                                         struct nfsd_statfsres *resp)
 453 {
 454         struct kstatfs  *stat = &resp->stats;
 455
 456         *p++ = htonl(NFSSVC_MAXBLKSIZE_V2);     /* max transfer size */
 457         *p++ = htonl(stat->f_bsize);
 458         *p++ = htonl(stat->f_blocks);
 459         *p++ = htonl(stat->f_bfree);
 460         *p++ = htonl(stat->f_bavail);
 461         return xdr_ressize_check(rqstp, p);
 462 }
 463
 464 int
 465 nfssvc_encode_entry(struct readdir_cd *ccd, const char *name,
 466                     int namlen, loff_t offset, ino_t ino, unsigned int d_type)
 467 {
 468         struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
 469         __be32  *p = cd->buffer;
 470         int     buflen, slen;
 471
 472         /*
 473         dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
 474                         namlen, name, offset, ino);
 475          */
 476
 477         if (offset > ~((u32) 0)) {
 478                 cd->common.err = nfserr_fbig;
 479                 return -EINVAL;
 480         }
 481         if (cd->offset)
 482                 *cd->offset = htonl(offset);
 483         if (namlen > NFS2_MAXNAMLEN)
 484                 namlen = NFS2_MAXNAMLEN;/* truncate filename */
 485
 486         slen = XDR_QUADLEN(namlen);
 487         if ((buflen = cd->buflen - slen - 4) < 0) {
 488                 cd->common.err = nfserr_toosmall;
 489                 return -EINVAL;
 490         }
 491         *p++ = xdr_one;                         /* mark entry present */
 492         *p++ = htonl((u32) ino);                /* file id */
 493         p    = xdr_encode_array(p, name, namlen);/* name length & name */
 494         cd->offset = p;                 /* remember pointer */
 495         *p++ = htonl(~0U);              /* offset of next entry */
 496
 497         cd->buflen = buflen;
 498         cd->buffer = p;
 499         cd->common.err = nfs_ok;
 500         return 0;
 501 }
 502
 503 /*
 504  * XDR release functions
 505  */
 506 int
 507 nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
 508                                         struct nfsd_fhandle *resp)
 509 {
 510         fh_put(&resp->fh);
 511         return 1;
 512 }