linux/fs/nfsd/nfsxdr.c
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   1/*
   2 * XDR support for nfsd
   3 *
   4 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   5 */
   6
   7#include "xdr.h"
   8#include "auth.h"
   9
  10#define NFSDDBG_FACILITY                NFSDDBG_XDR
  11
  12/*
  13 * Mapping of S_IF* types to NFS file types
  14 */
  15static u32      nfs_ftypes[] = {
  16        NFNON,  NFCHR,  NFCHR, NFBAD,
  17        NFDIR,  NFBAD,  NFBLK, NFBAD,
  18        NFREG,  NFBAD,  NFLNK, NFBAD,
  19        NFSOCK, NFBAD,  NFLNK, NFBAD,
  20};
  21
  22
  23/*
  24 * XDR functions for basic NFS types
  25 */
  26static __be32 *
  27decode_fh(__be32 *p, struct svc_fh *fhp)
  28{
  29        fh_init(fhp, NFS_FHSIZE);
  30        memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
  31        fhp->fh_handle.fh_size = NFS_FHSIZE;
  32
  33        /* FIXME: Look up export pointer here and verify
  34         * Sun Secure RPC if requested */
  35        return p + (NFS_FHSIZE >> 2);
  36}
  37
  38/* Helper function for NFSv2 ACL code */
  39__be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
  40{
  41        return decode_fh(p, fhp);
  42}
  43
  44static __be32 *
  45encode_fh(__be32 *p, struct svc_fh *fhp)
  46{
  47        memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
  48        return p + (NFS_FHSIZE>> 2);
  49}
  50
  51/*
  52 * Decode a file name and make sure that the path contains
  53 * no slashes or null bytes.
  54 */
  55static __be32 *
  56decode_filename(__be32 *p, char **namp, unsigned int *lenp)
  57{
  58        char            *name;
  59        unsigned int    i;
  60
  61        if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
  62                for (i = 0, name = *namp; i < *lenp; i++, name++) {
  63                        if (*name == '\0' || *name == '/')
  64                                return NULL;
  65                }
  66        }
  67
  68        return p;
  69}
  70
  71static __be32 *
  72decode_pathname(__be32 *p, char **namp, unsigned int *lenp)
  73{
  74        char            *name;
  75        unsigned int    i;
  76
  77        if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXPATHLEN)) != NULL) {
  78                for (i = 0, name = *namp; i < *lenp; i++, name++) {
  79                        if (*name == '\0')
  80                                return NULL;
  81                }
  82        }
  83
  84        return p;
  85}
  86
  87static __be32 *
  88decode_sattr(__be32 *p, struct iattr *iap)
  89{
  90        u32     tmp, tmp1;
  91
  92        iap->ia_valid = 0;
  93
  94        /* Sun client bug compatibility check: some sun clients seem to
  95         * put 0xffff in the mode field when they mean 0xffffffff.
  96         * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
  97         */
  98        if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
  99                iap->ia_valid |= ATTR_MODE;
 100                iap->ia_mode = tmp;
 101        }
 102        if ((tmp = ntohl(*p++)) != (u32)-1) {
 103                iap->ia_valid |= ATTR_UID;
 104                iap->ia_uid = tmp;
 105        }
 106        if ((tmp = ntohl(*p++)) != (u32)-1) {
 107                iap->ia_valid |= ATTR_GID;
 108                iap->ia_gid = tmp;
 109        }
 110        if ((tmp = ntohl(*p++)) != (u32)-1) {
 111                iap->ia_valid |= ATTR_SIZE;
 112                iap->ia_size = tmp;
 113        }
 114        tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
 115        if (tmp != (u32)-1 && tmp1 != (u32)-1) {
 116                iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
 117                iap->ia_atime.tv_sec = tmp;
 118                iap->ia_atime.tv_nsec = tmp1 * 1000; 
 119        }
 120        tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
 121        if (tmp != (u32)-1 && tmp1 != (u32)-1) {
 122                iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
 123                iap->ia_mtime.tv_sec = tmp;
 124                iap->ia_mtime.tv_nsec = tmp1 * 1000; 
 125                /*
 126                 * Passing the invalid value useconds=1000000 for mtime
 127                 * is a Sun convention for "set both mtime and atime to
 128                 * current server time".  It's needed to make permissions
 129                 * checks for the "touch" program across v2 mounts to
 130                 * Solaris and Irix boxes work correctly. See description of
 131                 * sattr in section 6.1 of "NFS Illustrated" by
 132                 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
 133                 */
 134                if (tmp1 == 1000000)
 135                        iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
 136        }
 137        return p;
 138}
 139
 140static __be32 *
 141encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
 142             struct kstat *stat)
 143{
 144        struct dentry   *dentry = fhp->fh_dentry;
 145        int type;
 146        struct timespec time;
 147        u32 f;
 148
 149        type = (stat->mode & S_IFMT);
 150
 151        *p++ = htonl(nfs_ftypes[type >> 12]);
 152        *p++ = htonl((u32) stat->mode);
 153        *p++ = htonl((u32) stat->nlink);
 154        *p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
 155        *p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
 156
 157        if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
 158                *p++ = htonl(NFS_MAXPATHLEN);
 159        } else {
 160                *p++ = htonl((u32) stat->size);
 161        }
 162        *p++ = htonl((u32) stat->blksize);
 163        if (S_ISCHR(type) || S_ISBLK(type))
 164                *p++ = htonl(new_encode_dev(stat->rdev));
 165        else
 166                *p++ = htonl(0xffffffff);
 167        *p++ = htonl((u32) stat->blocks);
 168        switch (fsid_source(fhp)) {
 169        default:
 170        case FSIDSOURCE_DEV:
 171                *p++ = htonl(new_encode_dev(stat->dev));
 172                break;
 173        case FSIDSOURCE_FSID:
 174                *p++ = htonl((u32) fhp->fh_export->ex_fsid);
 175                break;
 176        case FSIDSOURCE_UUID:
 177                f = ((u32*)fhp->fh_export->ex_uuid)[0];
 178                f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
 179                f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
 180                f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
 181                *p++ = htonl(f);
 182                break;
 183        }
 184        *p++ = htonl((u32) stat->ino);
 185        *p++ = htonl((u32) stat->atime.tv_sec);
 186        *p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
 187        lease_get_mtime(dentry->d_inode, &time); 
 188        *p++ = htonl((u32) time.tv_sec);
 189        *p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0); 
 190        *p++ = htonl((u32) stat->ctime.tv_sec);
 191        *p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
 192
 193        return p;
 194}
 195
 196/* Helper function for NFSv2 ACL code */
 197__be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
 198{
 199        struct kstat stat;
 200        vfs_getattr(fhp->fh_export->ex_path.mnt, fhp->fh_dentry, &stat);
 201        return encode_fattr(rqstp, p, fhp, &stat);
 202}
 203
 204/*
 205 * XDR decode functions
 206 */
 207int
 208nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
 209{
 210        return xdr_argsize_check(rqstp, p);
 211}
 212
 213int
 214nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
 215{
 216        if (!(p = decode_fh(p, &args->fh)))
 217                return 0;
 218        return xdr_argsize_check(rqstp, p);
 219}
 220
 221int
 222nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
 223                                        struct nfsd_sattrargs *args)
 224{
 225        p = decode_fh(p, &args->fh);
 226        if (!p)
 227                return 0;
 228        p = decode_sattr(p, &args->attrs);
 229
 230        return xdr_argsize_check(rqstp, p);
 231}
 232
 233int
 234nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *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
 244int
 245nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *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_V2)
 258                len = NFSSVC_MAXBLKSIZE_V2;
 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                rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
 267                rqstp->rq_vec[v].iov_len = len < PAGE_SIZE?len:PAGE_SIZE;
 268                len -= rqstp->rq_vec[v].iov_len;
 269                v++;
 270        }
 271        args->vlen = v;
 272        return xdr_argsize_check(rqstp, p);
 273}
 274
 275int
 276nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
 277                                        struct nfsd_writeargs *args)
 278{
 279        unsigned int len, hdr, dlen;
 280        int v;
 281
 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        /*
 290         * The protocol specifies a maximum of 8192 bytes.
 291         */
 292        if (len > NFSSVC_MAXBLKSIZE_V2)
 293                return 0;
 294
 295        /*
 296         * Check to make sure that we got the right number of
 297         * bytes.
 298         */
 299        hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
 300        dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
 301                - hdr;
 302
 303        /*
 304         * Round the length of the data which was specified up to
 305         * the next multiple of XDR units and then compare that
 306         * against the length which was actually received.
 307         * Note that when RPCSEC/GSS (for example) is used, the
 308         * data buffer can be padded so dlen might be larger
 309         * than required.  It must never be smaller.
 310         */
 311        if (dlen < XDR_QUADLEN(len)*4)
 312                return 0;
 313
 314        rqstp->rq_vec[0].iov_base = (void*)p;
 315        rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
 316        v = 0;
 317        while (len > rqstp->rq_vec[v].iov_len) {
 318                len -= rqstp->rq_vec[v].iov_len;
 319                v++;
 320                rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
 321                rqstp->rq_vec[v].iov_len = PAGE_SIZE;
 322        }
 323        rqstp->rq_vec[v].iov_len = len;
 324        args->vlen = v + 1;
 325        return 1;
 326}
 327
 328int
 329nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
 330                                        struct nfsd_createargs *args)
 331{
 332        if (   !(p = decode_fh(p, &args->fh))
 333            || !(p = decode_filename(p, &args->name, &args->len)))
 334                return 0;
 335        p = decode_sattr(p, &args->attrs);
 336
 337        return xdr_argsize_check(rqstp, p);
 338}
 339
 340int
 341nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
 342                                        struct nfsd_renameargs *args)
 343{
 344        if (!(p = decode_fh(p, &args->ffh))
 345         || !(p = decode_filename(p, &args->fname, &args->flen))
 346         || !(p = decode_fh(p, &args->tfh))
 347         || !(p = decode_filename(p, &args->tname, &args->tlen)))
 348                return 0;
 349
 350        return xdr_argsize_check(rqstp, p);
 351}
 352
 353int
 354nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readlinkargs *args)
 355{
 356        if (!(p = decode_fh(p, &args->fh)))
 357                return 0;
 358        args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused++]);
 359
 360        return xdr_argsize_check(rqstp, p);
 361}
 362
 363int
 364nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
 365                                        struct nfsd_linkargs *args)
 366{
 367        if (!(p = decode_fh(p, &args->ffh))
 368         || !(p = decode_fh(p, &args->tfh))
 369         || !(p = decode_filename(p, &args->tname, &args->tlen)))
 370                return 0;
 371
 372        return xdr_argsize_check(rqstp, p);
 373}
 374
 375int
 376nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
 377                                        struct nfsd_symlinkargs *args)
 378{
 379        if (   !(p = decode_fh(p, &args->ffh))
 380            || !(p = decode_filename(p, &args->fname, &args->flen))
 381            || !(p = decode_pathname(p, &args->tname, &args->tlen)))
 382                return 0;
 383        p = decode_sattr(p, &args->attrs);
 384
 385        return xdr_argsize_check(rqstp, p);
 386}
 387
 388int
 389nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
 390                                        struct nfsd_readdirargs *args)
 391{
 392        if (!(p = decode_fh(p, &args->fh)))
 393                return 0;
 394        args->cookie = ntohl(*p++);
 395        args->count  = ntohl(*p++);
 396        if (args->count > PAGE_SIZE)
 397                args->count = PAGE_SIZE;
 398
 399        args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused++]);
 400
 401        return xdr_argsize_check(rqstp, p);
 402}
 403
 404/*
 405 * XDR encode functions
 406 */
 407int
 408nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
 409{
 410        return xdr_ressize_check(rqstp, p);
 411}
 412
 413int
 414nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
 415                                        struct nfsd_attrstat *resp)
 416{
 417        p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 418        return xdr_ressize_check(rqstp, p);
 419}
 420
 421int
 422nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
 423                                        struct nfsd_diropres *resp)
 424{
 425        p = encode_fh(p, &resp->fh);
 426        p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 427        return xdr_ressize_check(rqstp, p);
 428}
 429
 430int
 431nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
 432                                        struct nfsd_readlinkres *resp)
 433{
 434        *p++ = htonl(resp->len);
 435        xdr_ressize_check(rqstp, p);
 436        rqstp->rq_res.page_len = resp->len;
 437        if (resp->len & 3) {
 438                /* need to pad the tail */
 439                rqstp->rq_res.tail[0].iov_base = p;
 440                *p = 0;
 441                rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
 442        }
 443        return 1;
 444}
 445
 446int
 447nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
 448                                        struct nfsd_readres *resp)
 449{
 450        p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 451        *p++ = htonl(resp->count);
 452        xdr_ressize_check(rqstp, p);
 453
 454        /* now update rqstp->rq_res to reflect data as well */
 455        rqstp->rq_res.page_len = resp->count;
 456        if (resp->count & 3) {
 457                /* need to pad the tail */
 458                rqstp->rq_res.tail[0].iov_base = p;
 459                *p = 0;
 460                rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
 461        }
 462        return 1;
 463}
 464
 465int
 466nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
 467                                        struct nfsd_readdirres *resp)
 468{
 469        xdr_ressize_check(rqstp, p);
 470        p = resp->buffer;
 471        *p++ = 0;                       /* no more entries */
 472        *p++ = htonl((resp->common.err == nfserr_eof));
 473        rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
 474
 475        return 1;
 476}
 477
 478int
 479nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,
 480                                        struct nfsd_statfsres *resp)
 481{
 482        struct kstatfs  *stat = &resp->stats;
 483
 484        *p++ = htonl(NFSSVC_MAXBLKSIZE_V2);     /* max transfer size */
 485        *p++ = htonl(stat->f_bsize);
 486        *p++ = htonl(stat->f_blocks);
 487        *p++ = htonl(stat->f_bfree);
 488        *p++ = htonl(stat->f_bavail);
 489        return xdr_ressize_check(rqstp, p);
 490}
 491
 492int
 493nfssvc_encode_entry(void *ccdv, const char *name,
 494                    int namlen, loff_t offset, u64 ino, unsigned int d_type)
 495{
 496        struct readdir_cd *ccd = ccdv;
 497        struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
 498        __be32  *p = cd->buffer;
 499        int     buflen, slen;
 500
 501        /*
 502        dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
 503                        namlen, name, offset, ino);
 504         */
 505
 506        if (offset > ~((u32) 0)) {
 507                cd->common.err = nfserr_fbig;
 508                return -EINVAL;
 509        }
 510        if (cd->offset)
 511                *cd->offset = htonl(offset);
 512        if (namlen > NFS2_MAXNAMLEN)
 513                namlen = NFS2_MAXNAMLEN;/* truncate filename */
 514
 515        slen = XDR_QUADLEN(namlen);
 516        if ((buflen = cd->buflen - slen - 4) < 0) {
 517                cd->common.err = nfserr_toosmall;
 518                return -EINVAL;
 519        }
 520        if (ino > ~((u32) 0)) {
 521                cd->common.err = nfserr_fbig;
 522                return -EINVAL;
 523        }
 524        *p++ = xdr_one;                         /* mark entry present */
 525        *p++ = htonl((u32) ino);                /* file id */
 526        p    = xdr_encode_array(p, name, namlen);/* name length & name */
 527        cd->offset = p;                 /* remember pointer */
 528        *p++ = htonl(~0U);              /* offset of next entry */
 529
 530        cd->buflen = buflen;
 531        cd->buffer = p;
 532        cd->common.err = nfs_ok;
 533        return 0;
 534}
 535
 536/*
 537 * XDR release functions
 538 */
 539int
 540nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
 541                                        struct nfsd_fhandle *resp)
 542{
 543        fh_put(&resp->fh);
 544        return 1;
 545}
 546
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