1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * XDR support for nfsd 4 * 5 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> 6 */ 7 8 #include "vfs.h" 9 #include "xdr.h" 10 #include "auth.h" 11 12 /* 13 * Mapping of S_IF* types to NFS file types 14 */ 15 static const 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 * Basic NFSv2 data types (RFC 1094 Section 2.3) 25 */ 26 27 /** 28 * svcxdr_encode_stat - Encode an NFSv2 status code 29 * @xdr: XDR stream 30 * @status: status value to encode 31 * 32 * Return values: 33 * %false: Send buffer space was exhausted 34 * %true: Success 35 */ 36 bool 37 svcxdr_encode_stat(struct xdr_stream *xdr, __be32 status) 38 { 39 __be32 *p; 40 41 p = xdr_reserve_space(xdr, sizeof(status)); 42 if (!p) 43 return false; 44 *p = status; 45 46 return true; 47 } 48 49 /** 50 * svcxdr_decode_fhandle - Decode an NFSv2 file handle 51 * @xdr: XDR stream positioned at an encoded NFSv2 FH 52 * @fhp: OUT: filled-in server file handle 53 * 54 * Return values: 55 * %false: The encoded file handle was not valid 56 * %true: @fhp has been initialized 57 */ 58 bool 59 svcxdr_decode_fhandle(struct xdr_stream *xdr, struct svc_fh *fhp) 60 { 61 __be32 *p; 62 63 p = xdr_inline_decode(xdr, NFS_FHSIZE); 64 if (!p) 65 return false; 66 fh_init(fhp, NFS_FHSIZE); 67 memcpy(&fhp->fh_handle.fh_raw, p, NFS_FHSIZE); 68 fhp->fh_handle.fh_size = NFS_FHSIZE; 69 70 return true; 71 } 72 73 static bool 74 svcxdr_encode_fhandle(struct xdr_stream *xdr, const struct svc_fh *fhp) 75 { 76 __be32 *p; 77 78 p = xdr_reserve_space(xdr, NFS_FHSIZE); 79 if (!p) 80 return false; 81 memcpy(p, &fhp->fh_handle.fh_raw, NFS_FHSIZE); 82 83 return true; 84 } 85 86 static __be32 * 87 encode_timeval(__be32 *p, const struct timespec64 *time) 88 { 89 *p++ = cpu_to_be32((u32)time->tv_sec); 90 if (time->tv_nsec) 91 *p++ = cpu_to_be32(time->tv_nsec / NSEC_PER_USEC); 92 else 93 *p++ = xdr_zero; 94 return p; 95 } 96 97 static bool 98 svcxdr_decode_filename(struct xdr_stream *xdr, char **name, unsigned int *len) 99 { 100 u32 size, i; 101 __be32 *p; 102 char *c; 103 104 if (xdr_stream_decode_u32(xdr, &size) < 0) 105 return false; 106 if (size == 0 || size > NFS_MAXNAMLEN) 107 return false; 108 p = xdr_inline_decode(xdr, size); 109 if (!p) 110 return false; 111 112 *len = size; 113 *name = (char *)p; 114 for (i = 0, c = *name; i < size; i++, c++) 115 if (*c == '\0' || *c == '/') 116 return false; 117 118 return true; 119 } 120 121 static bool 122 svcxdr_decode_diropargs(struct xdr_stream *xdr, struct svc_fh *fhp, 123 char **name, unsigned int *len) 124 { 125 return svcxdr_decode_fhandle(xdr, fhp) && 126 svcxdr_decode_filename(xdr, name, len); 127 } 128 129 static bool 130 svcxdr_decode_sattr(struct svc_rqst *rqstp, struct xdr_stream *xdr, 131 struct iattr *iap) 132 { 133 u32 tmp1, tmp2; 134 __be32 *p; 135 136 p = xdr_inline_decode(xdr, XDR_UNIT * 8); 137 if (!p) 138 return false; 139 140 iap->ia_valid = 0; 141 142 /* 143 * Some Sun clients put 0xffff in the mode field when they 144 * mean 0xffffffff. 145 */ 146 tmp1 = be32_to_cpup(p++); 147 if (tmp1 != (u32)-1 && tmp1 != 0xffff) { 148 iap->ia_valid |= ATTR_MODE; 149 iap->ia_mode = tmp1; 150 } 151 152 tmp1 = be32_to_cpup(p++); 153 if (tmp1 != (u32)-1) { 154 iap->ia_uid = make_kuid(nfsd_user_namespace(rqstp), tmp1); 155 if (uid_valid(iap->ia_uid)) 156 iap->ia_valid |= ATTR_UID; 157 } 158 159 tmp1 = be32_to_cpup(p++); 160 if (tmp1 != (u32)-1) { 161 iap->ia_gid = make_kgid(nfsd_user_namespace(rqstp), tmp1); 162 if (gid_valid(iap->ia_gid)) 163 iap->ia_valid |= ATTR_GID; 164 } 165 166 tmp1 = be32_to_cpup(p++); 167 if (tmp1 != (u32)-1) { 168 iap->ia_valid |= ATTR_SIZE; 169 iap->ia_size = tmp1; 170 } 171 172 tmp1 = be32_to_cpup(p++); 173 tmp2 = be32_to_cpup(p++); 174 if (tmp1 != (u32)-1 && tmp2 != (u32)-1) { 175 iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET; 176 iap->ia_atime.tv_sec = tmp1; 177 iap->ia_atime.tv_nsec = tmp2 * NSEC_PER_USEC; 178 } 179 180 tmp1 = be32_to_cpup(p++); 181 tmp2 = be32_to_cpup(p++); 182 if (tmp1 != (u32)-1 && tmp2 != (u32)-1) { 183 iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET; 184 iap->ia_mtime.tv_sec = tmp1; 185 iap->ia_mtime.tv_nsec = tmp2 * NSEC_PER_USEC; 186 /* 187 * Passing the invalid value useconds=1000000 for mtime 188 * is a Sun convention for "set both mtime and atime to 189 * current server time". It's needed to make permissions 190 * checks for the "touch" program across v2 mounts to 191 * Solaris and Irix boxes work correctly. See description of 192 * sattr in section 6.1 of "NFS Illustrated" by 193 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5 194 */ 195 if (tmp2 == 1000000) 196 iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET); 197 } 198 199 return true; 200 } 201 202 /** 203 * svcxdr_encode_fattr - Encode NFSv2 file attributes 204 * @rqstp: Context of a completed RPC transaction 205 * @xdr: XDR stream 206 * @fhp: File handle to encode 207 * @stat: Attributes to encode 208 * 209 * Return values: 210 * %false: Send buffer space was exhausted 211 * %true: Success 212 */ 213 bool 214 svcxdr_encode_fattr(struct svc_rqst *rqstp, struct xdr_stream *xdr, 215 const struct svc_fh *fhp, const struct kstat *stat) 216 { 217 struct user_namespace *userns = nfsd_user_namespace(rqstp); 218 struct dentry *dentry = fhp->fh_dentry; 219 int type = stat->mode & S_IFMT; 220 struct timespec64 time; 221 __be32 *p; 222 u32 fsid; 223 224 p = xdr_reserve_space(xdr, XDR_UNIT * 17); 225 if (!p) 226 return false; 227 228 *p++ = cpu_to_be32(nfs_ftypes[type >> 12]); 229 *p++ = cpu_to_be32((u32)stat->mode); 230 *p++ = cpu_to_be32((u32)stat->nlink); 231 *p++ = cpu_to_be32((u32)from_kuid_munged(userns, stat->uid)); 232 *p++ = cpu_to_be32((u32)from_kgid_munged(userns, stat->gid)); 233 234 if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) 235 *p++ = cpu_to_be32(NFS_MAXPATHLEN); 236 else 237 *p++ = cpu_to_be32((u32) stat->size); 238 *p++ = cpu_to_be32((u32) stat->blksize); 239 if (S_ISCHR(type) || S_ISBLK(type)) 240 *p++ = cpu_to_be32(new_encode_dev(stat->rdev)); 241 else 242 *p++ = cpu_to_be32(0xffffffff); 243 *p++ = cpu_to_be32((u32)stat->blocks); 244 245 switch (fsid_source(fhp)) { 246 case FSIDSOURCE_FSID: 247 fsid = (u32)fhp->fh_export->ex_fsid; 248 break; 249 case FSIDSOURCE_UUID: 250 fsid = ((u32 *)fhp->fh_export->ex_uuid)[0]; 251 fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[1]; 252 fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[2]; 253 fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[3]; 254 break; 255 default: 256 fsid = new_encode_dev(stat->dev); 257 break; 258 } 259 *p++ = cpu_to_be32(fsid); 260 261 *p++ = cpu_to_be32((u32)stat->ino); 262 p = encode_timeval(p, &stat->atime); 263 time = stat->mtime; 264 lease_get_mtime(d_inode(dentry), &time); 265 p = encode_timeval(p, &time); 266 encode_timeval(p, &stat->ctime); 267 268 return true; 269 } 270 271 /* 272 * XDR decode functions 273 */ 274 275 bool 276 nfssvc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 277 { 278 struct nfsd_fhandle *args = rqstp->rq_argp; 279 280 return svcxdr_decode_fhandle(xdr, &args->fh); 281 } 282 283 bool 284 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 285 { 286 struct nfsd_sattrargs *args = rqstp->rq_argp; 287 288 return svcxdr_decode_fhandle(xdr, &args->fh) && 289 svcxdr_decode_sattr(rqstp, xdr, &args->attrs); 290 } 291 292 bool 293 nfssvc_decode_diropargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 294 { 295 struct nfsd_diropargs *args = rqstp->rq_argp; 296 297 return svcxdr_decode_diropargs(xdr, &args->fh, &args->name, &args->len); 298 } 299 300 bool 301 nfssvc_decode_readargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 302 { 303 struct nfsd_readargs *args = rqstp->rq_argp; 304 u32 totalcount; 305 306 if (!svcxdr_decode_fhandle(xdr, &args->fh)) 307 return false; 308 if (xdr_stream_decode_u32(xdr, &args->offset) < 0) 309 return false; 310 if (xdr_stream_decode_u32(xdr, &args->count) < 0) 311 return false; 312 /* totalcount is ignored */ 313 if (xdr_stream_decode_u32(xdr, &totalcount) < 0) 314 return false; 315 316 return true; 317 } 318 319 bool 320 nfssvc_decode_writeargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 321 { 322 struct nfsd_writeargs *args = rqstp->rq_argp; 323 u32 beginoffset, totalcount; 324 325 if (!svcxdr_decode_fhandle(xdr, &args->fh)) 326 return false; 327 /* beginoffset is ignored */ 328 if (xdr_stream_decode_u32(xdr, &beginoffset) < 0) 329 return false; 330 if (xdr_stream_decode_u32(xdr, &args->offset) < 0) 331 return false; 332 /* totalcount is ignored */ 333 if (xdr_stream_decode_u32(xdr, &totalcount) < 0) 334 return false; 335 336 /* opaque data */ 337 if (xdr_stream_decode_u32(xdr, &args->len) < 0) 338 return false; 339 if (args->len > NFSSVC_MAXBLKSIZE_V2) 340 return false; 341 342 return xdr_stream_subsegment(xdr, &args->payload, args->len); 343 } 344 345 bool 346 nfssvc_decode_createargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 347 { 348 struct nfsd_createargs *args = rqstp->rq_argp; 349 350 return svcxdr_decode_diropargs(xdr, &args->fh, 351 &args->name, &args->len) && 352 svcxdr_decode_sattr(rqstp, xdr, &args->attrs); 353 } 354 355 bool 356 nfssvc_decode_renameargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 357 { 358 struct nfsd_renameargs *args = rqstp->rq_argp; 359 360 return svcxdr_decode_diropargs(xdr, &args->ffh, 361 &args->fname, &args->flen) && 362 svcxdr_decode_diropargs(xdr, &args->tfh, 363 &args->tname, &args->tlen); 364 } 365 366 bool 367 nfssvc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 368 { 369 struct nfsd_linkargs *args = rqstp->rq_argp; 370 371 return svcxdr_decode_fhandle(xdr, &args->ffh) && 372 svcxdr_decode_diropargs(xdr, &args->tfh, 373 &args->tname, &args->tlen); 374 } 375 376 bool 377 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 378 { 379 struct nfsd_symlinkargs *args = rqstp->rq_argp; 380 struct kvec *head = rqstp->rq_arg.head; 381 382 if (!svcxdr_decode_diropargs(xdr, &args->ffh, &args->fname, &args->flen)) 383 return false; 384 if (xdr_stream_decode_u32(xdr, &args->tlen) < 0) 385 return false; 386 if (args->tlen == 0) 387 return false; 388 389 args->first.iov_len = head->iov_len - xdr_stream_pos(xdr); 390 args->first.iov_base = xdr_inline_decode(xdr, args->tlen); 391 if (!args->first.iov_base) 392 return false; 393 return svcxdr_decode_sattr(rqstp, xdr, &args->attrs); 394 } 395 396 bool 397 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 398 { 399 struct nfsd_readdirargs *args = rqstp->rq_argp; 400 401 if (!svcxdr_decode_fhandle(xdr, &args->fh)) 402 return false; 403 if (xdr_stream_decode_u32(xdr, &args->cookie) < 0) 404 return false; 405 if (xdr_stream_decode_u32(xdr, &args->count) < 0) 406 return false; 407 408 return true; 409 } 410 411 /* 412 * XDR encode functions 413 */ 414 415 bool 416 nfssvc_encode_statres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 417 { 418 struct nfsd_stat *resp = rqstp->rq_resp; 419 420 return svcxdr_encode_stat(xdr, resp->status); 421 } 422 423 bool 424 nfssvc_encode_attrstatres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 425 { 426 struct nfsd_attrstat *resp = rqstp->rq_resp; 427 428 if (!svcxdr_encode_stat(xdr, resp->status)) 429 return false; 430 switch (resp->status) { 431 case nfs_ok: 432 if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat)) 433 return false; 434 break; 435 } 436 437 return true; 438 } 439 440 bool 441 nfssvc_encode_diropres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 442 { 443 struct nfsd_diropres *resp = rqstp->rq_resp; 444 445 if (!svcxdr_encode_stat(xdr, resp->status)) 446 return false; 447 switch (resp->status) { 448 case nfs_ok: 449 if (!svcxdr_encode_fhandle(xdr, &resp->fh)) 450 return false; 451 if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat)) 452 return false; 453 break; 454 } 455 456 return true; 457 } 458 459 bool 460 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 461 { 462 struct nfsd_readlinkres *resp = rqstp->rq_resp; 463 struct kvec *head = rqstp->rq_res.head; 464 465 if (!svcxdr_encode_stat(xdr, resp->status)) 466 return false; 467 switch (resp->status) { 468 case nfs_ok: 469 if (xdr_stream_encode_u32(xdr, resp->len) < 0) 470 return false; 471 xdr_write_pages(xdr, &resp->page, 0, resp->len); 472 if (svc_encode_result_payload(rqstp, head->iov_len, resp->len) < 0) 473 return false; 474 break; 475 } 476 477 return true; 478 } 479 480 bool 481 nfssvc_encode_readres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 482 { 483 struct nfsd_readres *resp = rqstp->rq_resp; 484 struct kvec *head = rqstp->rq_res.head; 485 486 if (!svcxdr_encode_stat(xdr, resp->status)) 487 return false; 488 switch (resp->status) { 489 case nfs_ok: 490 if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat)) 491 return false; 492 if (xdr_stream_encode_u32(xdr, resp->count) < 0) 493 return false; 494 xdr_write_pages(xdr, resp->pages, rqstp->rq_res.page_base, 495 resp->count); 496 if (svc_encode_result_payload(rqstp, head->iov_len, resp->count) < 0) 497 return false; 498 break; 499 } 500 501 return true; 502 } 503 504 bool 505 nfssvc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 506 { 507 struct nfsd_readdirres *resp = rqstp->rq_resp; 508 struct xdr_buf *dirlist = &resp->dirlist; 509 510 if (!svcxdr_encode_stat(xdr, resp->status)) 511 return false; 512 switch (resp->status) { 513 case nfs_ok: 514 xdr_write_pages(xdr, dirlist->pages, 0, dirlist->len); 515 /* no more entries */ 516 if (xdr_stream_encode_item_absent(xdr) < 0) 517 return false; 518 if (xdr_stream_encode_bool(xdr, resp->common.err == nfserr_eof) < 0) 519 return false; 520 break; 521 } 522 523 return true; 524 } 525 526 bool 527 nfssvc_encode_statfsres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 528 { 529 struct nfsd_statfsres *resp = rqstp->rq_resp; 530 struct kstatfs *stat = &resp->stats; 531 __be32 *p; 532 533 if (!svcxdr_encode_stat(xdr, resp->status)) 534 return false; 535 switch (resp->status) { 536 case nfs_ok: 537 p = xdr_reserve_space(xdr, XDR_UNIT * 5); 538 if (!p) 539 return false; 540 *p++ = cpu_to_be32(NFSSVC_MAXBLKSIZE_V2); 541 *p++ = cpu_to_be32(stat->f_bsize); 542 *p++ = cpu_to_be32(stat->f_blocks); 543 *p++ = cpu_to_be32(stat->f_bfree); 544 *p = cpu_to_be32(stat->f_bavail); 545 break; 546 } 547 548 return true; 549 } 550 551 /** 552 * nfssvc_encode_nfscookie - Encode a directory offset cookie 553 * @resp: readdir result context 554 * @offset: offset cookie to encode 555 * 556 * The buffer space for the offset cookie has already been reserved 557 * by svcxdr_encode_entry_common(). 558 */ 559 void nfssvc_encode_nfscookie(struct nfsd_readdirres *resp, u32 offset) 560 { 561 __be32 cookie = cpu_to_be32(offset); 562 563 if (!resp->cookie_offset) 564 return; 565 566 write_bytes_to_xdr_buf(&resp->dirlist, resp->cookie_offset, &cookie, 567 sizeof(cookie)); 568 resp->cookie_offset = 0; 569 } 570 571 static bool 572 svcxdr_encode_entry_common(struct nfsd_readdirres *resp, const char *name, 573 int namlen, loff_t offset, u64 ino) 574 { 575 struct xdr_buf *dirlist = &resp->dirlist; 576 struct xdr_stream *xdr = &resp->xdr; 577 578 if (xdr_stream_encode_item_present(xdr) < 0) 579 return false; 580 /* fileid */ 581 if (xdr_stream_encode_u32(xdr, (u32)ino) < 0) 582 return false; 583 /* name */ 584 if (xdr_stream_encode_opaque(xdr, name, min(namlen, NFS2_MAXNAMLEN)) < 0) 585 return false; 586 /* cookie */ 587 resp->cookie_offset = dirlist->len; 588 if (xdr_stream_encode_u32(xdr, ~0U) < 0) 589 return false; 590 591 return true; 592 } 593 594 /** 595 * nfssvc_encode_entry - encode one NFSv2 READDIR entry 596 * @data: directory context 597 * @name: name of the object to be encoded 598 * @namlen: length of that name, in bytes 599 * @offset: the offset of the previous entry 600 * @ino: the fileid of this entry 601 * @d_type: unused 602 * 603 * Return values: 604 * %0: Entry was successfully encoded. 605 * %-EINVAL: An encoding problem occured, secondary status code in resp->common.err 606 * 607 * On exit, the following fields are updated: 608 * - resp->xdr 609 * - resp->common.err 610 * - resp->cookie_offset 611 */ 612 int nfssvc_encode_entry(void *data, const char *name, int namlen, 613 loff_t offset, u64 ino, unsigned int d_type) 614 { 615 struct readdir_cd *ccd = data; 616 struct nfsd_readdirres *resp = container_of(ccd, 617 struct nfsd_readdirres, 618 common); 619 unsigned int starting_length = resp->dirlist.len; 620 621 /* The offset cookie for the previous entry */ 622 nfssvc_encode_nfscookie(resp, offset); 623 624 if (!svcxdr_encode_entry_common(resp, name, namlen, offset, ino)) 625 goto out_toosmall; 626 627 xdr_commit_encode(&resp->xdr); 628 resp->common.err = nfs_ok; 629 return 0; 630 631 out_toosmall: 632 resp->cookie_offset = 0; 633 resp->common.err = nfserr_toosmall; 634 resp->dirlist.len = starting_length; 635 return -EINVAL; 636 } 637 638 /* 639 * XDR release functions 640 */ 641 void nfssvc_release_attrstat(struct svc_rqst *rqstp) 642 { 643 struct nfsd_attrstat *resp = rqstp->rq_resp; 644 645 fh_put(&resp->fh); 646 } 647 648 void nfssvc_release_diropres(struct svc_rqst *rqstp) 649 { 650 struct nfsd_diropres *resp = rqstp->rq_resp; 651 652 fh_put(&resp->fh); 653 } 654 655 void nfssvc_release_readres(struct svc_rqst *rqstp) 656 { 657 struct nfsd_readres *resp = rqstp->rq_resp; 658 659 fh_put(&resp->fh); 660 } 661