fs/nfsd/nfsxdr.c

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