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 <linux/filelock.h> 9 10 #include "vfs.h" 11 #include "xdr.h" 12 #include "auth.h" 13 14 /* 15 * Sun convention: a sattr time-useconds field of one full second (an 16 * otherwise out-of-range value) means "set this time to the current 17 * server time." It's needed to make permissions checks for the "touch" 18 * program across NFSv2 mounts work correctly. See description of 19 * sattr in section 6.1 of "NFS Illustrated" by Brent Callaghan, 20 * Addison-Wesley, ISBN 0-201-32750-5 21 */ 22 #define NFS2_SATTR_SET_TO_SERVER_TIME (1000000) 23 24 /* 25 * Mapping of S_IF* types to NFS file types 26 */ 27 static const u32 nfs_ftypes[] = { 28 NFNON, NFCHR, NFCHR, NFBAD, 29 NFDIR, NFBAD, NFBLK, NFBAD, 30 NFREG, NFBAD, NFLNK, NFBAD, 31 NFSOCK, NFBAD, NFLNK, NFBAD, 32 }; 33 34 35 /* 36 * Basic NFSv2 data types (RFC 1094 Section 2.3) 37 */ 38 39 /** 40 * svcxdr_encode_stat - Encode an NFSv2 status code 41 * @xdr: XDR stream 42 * @status: status value to encode 43 * 44 * Return values: 45 * %false: Send buffer space was exhausted 46 * %true: Success 47 */ 48 bool 49 svcxdr_encode_stat(struct xdr_stream *xdr, __be32 status) 50 { 51 __be32 *p; 52 53 p = xdr_reserve_space(xdr, sizeof(status)); 54 if (!p) 55 return false; 56 *p = status; 57 58 return true; 59 } 60 61 /** 62 * svcxdr_decode_fhandle - Decode an NFSv2 file handle 63 * @xdr: XDR stream positioned at an encoded NFSv2 FH 64 * @fhp: OUT: filled-in server file handle 65 * 66 * Return values: 67 * %false: The encoded file handle was not valid 68 * %true: @fhp has been initialized 69 */ 70 bool 71 svcxdr_decode_fhandle(struct xdr_stream *xdr, struct svc_fh *fhp) 72 { 73 __be32 *p; 74 75 p = xdr_inline_decode(xdr, NFS_FHSIZE); 76 if (!p) 77 return false; 78 fh_init(fhp, NFS_FHSIZE); 79 memcpy(&fhp->fh_handle.fh_raw, p, NFS_FHSIZE); 80 fhp->fh_handle.fh_size = NFS_FHSIZE; 81 82 return true; 83 } 84 85 static bool 86 svcxdr_encode_fhandle(struct xdr_stream *xdr, const struct svc_fh *fhp) 87 { 88 __be32 *p; 89 90 p = xdr_reserve_space(xdr, NFS_FHSIZE); 91 if (!p) 92 return false; 93 memcpy(p, &fhp->fh_handle.fh_raw, NFS_FHSIZE); 94 95 return true; 96 } 97 98 static __be32 * 99 encode_timeval(__be32 *p, const struct timespec64 *time) 100 { 101 *p++ = cpu_to_be32((u32)time->tv_sec); 102 if (time->tv_nsec) 103 *p++ = cpu_to_be32(time->tv_nsec / NSEC_PER_USEC); 104 else 105 *p++ = xdr_zero; 106 return p; 107 } 108 109 static bool 110 svcxdr_decode_filename(struct xdr_stream *xdr, char **name, unsigned int *len) 111 { 112 u32 size, i; 113 __be32 *p; 114 char *c; 115 116 if (xdr_stream_decode_u32(xdr, &size) < 0) 117 return false; 118 if (size == 0 || size > NFS_MAXNAMLEN) 119 return false; 120 p = xdr_inline_decode(xdr, size); 121 if (!p) 122 return false; 123 124 *len = size; 125 *name = (char *)p; 126 for (i = 0, c = *name; i < size; i++, c++) 127 if (*c == '\0' || *c == '/') 128 return false; 129 130 return true; 131 } 132 133 static bool 134 svcxdr_decode_diropargs(struct xdr_stream *xdr, struct svc_fh *fhp, 135 char **name, unsigned int *len) 136 { 137 return svcxdr_decode_fhandle(xdr, fhp) && 138 svcxdr_decode_filename(xdr, name, len); 139 } 140 141 static bool 142 svcxdr_decode_sattr(struct svc_rqst *rqstp, struct xdr_stream *xdr, 143 struct iattr *iap) 144 { 145 u32 tmp1, tmp2; 146 __be32 *p; 147 148 p = xdr_inline_decode(xdr, XDR_UNIT * 8); 149 if (!p) 150 return false; 151 152 iap->ia_valid = 0; 153 154 /* 155 * Some Sun clients put 0xffff in the mode field when they 156 * mean 0xffffffff. 157 */ 158 tmp1 = be32_to_cpup(p++); 159 if (tmp1 != (u32)-1 && tmp1 != 0xffff) { 160 iap->ia_valid |= ATTR_MODE; 161 iap->ia_mode = tmp1; 162 } 163 164 tmp1 = be32_to_cpup(p++); 165 if (tmp1 != (u32)-1) { 166 iap->ia_uid = make_kuid(nfsd_user_namespace(rqstp), tmp1); 167 if (uid_valid(iap->ia_uid)) 168 iap->ia_valid |= ATTR_UID; 169 } 170 171 tmp1 = be32_to_cpup(p++); 172 if (tmp1 != (u32)-1) { 173 iap->ia_gid = make_kgid(nfsd_user_namespace(rqstp), tmp1); 174 if (gid_valid(iap->ia_gid)) 175 iap->ia_valid |= ATTR_GID; 176 } 177 178 tmp1 = be32_to_cpup(p++); 179 if (tmp1 != (u32)-1) { 180 iap->ia_valid |= ATTR_SIZE; 181 iap->ia_size = tmp1; 182 } 183 184 tmp1 = be32_to_cpup(p++); 185 tmp2 = be32_to_cpup(p++); 186 if (tmp1 != (u32)-1 && tmp2 != (u32)-1) { 187 /* 188 * Range test here to prevent the multiplication from 189 * wrapping to a valid (but incorrect) value on 32-bit 190 * platforms. 191 */ 192 if (tmp2 > NFS2_SATTR_SET_TO_SERVER_TIME) 193 return false; 194 iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET; 195 iap->ia_atime.tv_sec = tmp1; 196 iap->ia_atime.tv_nsec = tmp2 * NSEC_PER_USEC; 197 if (tmp2 == NFS2_SATTR_SET_TO_SERVER_TIME) 198 iap->ia_valid &= ~ATTR_ATIME_SET; 199 } 200 201 tmp1 = be32_to_cpup(p++); 202 tmp2 = be32_to_cpup(p++); 203 if (tmp1 != (u32)-1 && tmp2 != (u32)-1) { 204 if (tmp2 > NFS2_SATTR_SET_TO_SERVER_TIME) 205 return false; 206 iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET; 207 iap->ia_mtime.tv_sec = tmp1; 208 iap->ia_mtime.tv_nsec = tmp2 * NSEC_PER_USEC; 209 if (tmp2 == NFS2_SATTR_SET_TO_SERVER_TIME) 210 iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET); 211 } 212 213 return true; 214 } 215 216 /** 217 * svcxdr_encode_fattr - Encode NFSv2 file attributes 218 * @rqstp: Context of a completed RPC transaction 219 * @xdr: XDR stream 220 * @fhp: File handle to encode 221 * @stat: Attributes to encode 222 * 223 * Return values: 224 * %false: Send buffer space was exhausted 225 * %true: Success 226 */ 227 bool 228 svcxdr_encode_fattr(struct svc_rqst *rqstp, struct xdr_stream *xdr, 229 const struct svc_fh *fhp, const struct kstat *stat) 230 { 231 struct user_namespace *userns = nfsd_user_namespace(rqstp); 232 struct dentry *dentry = fhp->fh_dentry; 233 int type = stat->mode & S_IFMT; 234 struct timespec64 time; 235 __be32 *p; 236 u32 fsid; 237 238 p = xdr_reserve_space(xdr, XDR_UNIT * 17); 239 if (!p) 240 return false; 241 242 *p++ = cpu_to_be32(nfs_ftypes[type >> 12]); 243 *p++ = cpu_to_be32((u32)stat->mode); 244 *p++ = cpu_to_be32((u32)stat->nlink); 245 *p++ = cpu_to_be32((u32)from_kuid_munged(userns, stat->uid)); 246 *p++ = cpu_to_be32((u32)from_kgid_munged(userns, stat->gid)); 247 248 if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) 249 *p++ = cpu_to_be32(NFS_MAXPATHLEN); 250 else 251 *p++ = cpu_to_be32((u32) stat->size); 252 *p++ = cpu_to_be32((u32) stat->blksize); 253 if (S_ISCHR(type) || S_ISBLK(type)) 254 *p++ = cpu_to_be32(new_encode_dev(stat->rdev)); 255 else 256 *p++ = cpu_to_be32(0xffffffff); 257 *p++ = cpu_to_be32((u32)stat->blocks); 258 259 switch (fsid_source(fhp)) { 260 case FSIDSOURCE_FSID: 261 fsid = (u32)fhp->fh_export->ex_fsid; 262 break; 263 case FSIDSOURCE_UUID: 264 fsid = ((u32 *)fhp->fh_export->ex_uuid)[0]; 265 fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[1]; 266 fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[2]; 267 fsid ^= ((u32 *)fhp->fh_export->ex_uuid)[3]; 268 break; 269 default: 270 fsid = new_encode_dev(stat->dev); 271 break; 272 } 273 *p++ = cpu_to_be32(fsid); 274 275 *p++ = cpu_to_be32((u32)stat->ino); 276 p = encode_timeval(p, &stat->atime); 277 time = stat->mtime; 278 lease_get_mtime(d_inode(dentry), &time); 279 p = encode_timeval(p, &time); 280 encode_timeval(p, &stat->ctime); 281 282 return true; 283 } 284 285 /* 286 * XDR decode functions 287 */ 288 289 bool 290 nfssvc_decode_fhandleargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 291 { 292 struct nfsd_fhandle *args = rqstp->rq_argp; 293 294 return svcxdr_decode_fhandle(xdr, &args->fh); 295 } 296 297 bool 298 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 299 { 300 struct nfsd_sattrargs *args = rqstp->rq_argp; 301 302 return svcxdr_decode_fhandle(xdr, &args->fh) && 303 svcxdr_decode_sattr(rqstp, xdr, &args->attrs); 304 } 305 306 bool 307 nfssvc_decode_diropargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 308 { 309 struct nfsd_diropargs *args = rqstp->rq_argp; 310 311 return svcxdr_decode_diropargs(xdr, &args->fh, &args->name, &args->len); 312 } 313 314 bool 315 nfssvc_decode_readargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 316 { 317 struct nfsd_readargs *args = rqstp->rq_argp; 318 u32 totalcount; 319 320 if (!svcxdr_decode_fhandle(xdr, &args->fh)) 321 return false; 322 if (xdr_stream_decode_u32(xdr, &args->offset) < 0) 323 return false; 324 if (xdr_stream_decode_u32(xdr, &args->count) < 0) 325 return false; 326 /* totalcount is ignored */ 327 if (xdr_stream_decode_u32(xdr, &totalcount) < 0) 328 return false; 329 330 return true; 331 } 332 333 bool 334 nfssvc_decode_writeargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 335 { 336 struct nfsd_writeargs *args = rqstp->rq_argp; 337 u32 beginoffset, totalcount; 338 339 if (!svcxdr_decode_fhandle(xdr, &args->fh)) 340 return false; 341 /* beginoffset is ignored */ 342 if (xdr_stream_decode_u32(xdr, &beginoffset) < 0) 343 return false; 344 if (xdr_stream_decode_u32(xdr, &args->offset) < 0) 345 return false; 346 /* totalcount is ignored */ 347 if (xdr_stream_decode_u32(xdr, &totalcount) < 0) 348 return false; 349 350 /* opaque data */ 351 if (xdr_stream_decode_u32(xdr, &args->len) < 0) 352 return false; 353 if (args->len > NFS_MAXDATA) 354 return false; 355 356 return xdr_stream_subsegment(xdr, &args->payload, args->len); 357 } 358 359 bool 360 nfssvc_decode_createargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 361 { 362 struct nfsd_createargs *args = rqstp->rq_argp; 363 364 return svcxdr_decode_diropargs(xdr, &args->fh, 365 &args->name, &args->len) && 366 svcxdr_decode_sattr(rqstp, xdr, &args->attrs); 367 } 368 369 bool 370 nfssvc_decode_renameargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 371 { 372 struct nfsd_renameargs *args = rqstp->rq_argp; 373 374 return svcxdr_decode_diropargs(xdr, &args->ffh, 375 &args->fname, &args->flen) && 376 svcxdr_decode_diropargs(xdr, &args->tfh, 377 &args->tname, &args->tlen); 378 } 379 380 bool 381 nfssvc_decode_linkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 382 { 383 struct nfsd_linkargs *args = rqstp->rq_argp; 384 385 return svcxdr_decode_fhandle(xdr, &args->ffh) && 386 svcxdr_decode_diropargs(xdr, &args->tfh, 387 &args->tname, &args->tlen); 388 } 389 390 bool 391 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 392 { 393 struct nfsd_symlinkargs *args = rqstp->rq_argp; 394 struct kvec *head = rqstp->rq_arg.head; 395 396 if (!svcxdr_decode_diropargs(xdr, &args->ffh, &args->fname, &args->flen)) 397 return false; 398 if (xdr_stream_decode_u32(xdr, &args->tlen) < 0) 399 return false; 400 if (args->tlen == 0) 401 return false; 402 403 args->first.iov_len = head->iov_len - xdr_stream_pos(xdr); 404 args->first.iov_base = xdr_inline_decode(xdr, args->tlen); 405 if (!args->first.iov_base) 406 return false; 407 return svcxdr_decode_sattr(rqstp, xdr, &args->attrs); 408 } 409 410 bool 411 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, struct xdr_stream *xdr) 412 { 413 struct nfsd_readdirargs *args = rqstp->rq_argp; 414 415 if (!svcxdr_decode_fhandle(xdr, &args->fh)) 416 return false; 417 if (xdr_stream_decode_u32(xdr, &args->cookie) < 0) 418 return false; 419 if (xdr_stream_decode_u32(xdr, &args->count) < 0) 420 return false; 421 422 return true; 423 } 424 425 /* 426 * XDR encode functions 427 */ 428 429 bool 430 nfssvc_encode_statres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 431 { 432 struct nfsd_stat *resp = rqstp->rq_resp; 433 434 return svcxdr_encode_stat(xdr, resp->status); 435 } 436 437 bool 438 nfssvc_encode_attrstatres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 439 { 440 struct nfsd_attrstat *resp = rqstp->rq_resp; 441 442 if (!svcxdr_encode_stat(xdr, resp->status)) 443 return false; 444 switch (resp->status) { 445 case nfs_ok: 446 if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat)) 447 return false; 448 break; 449 } 450 451 return true; 452 } 453 454 bool 455 nfssvc_encode_diropres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 456 { 457 struct nfsd_diropres *resp = rqstp->rq_resp; 458 459 if (!svcxdr_encode_stat(xdr, resp->status)) 460 return false; 461 switch (resp->status) { 462 case nfs_ok: 463 if (!svcxdr_encode_fhandle(xdr, &resp->fh)) 464 return false; 465 if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat)) 466 return false; 467 break; 468 } 469 470 return true; 471 } 472 473 bool 474 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 475 { 476 struct nfsd_readlinkres *resp = rqstp->rq_resp; 477 struct kvec *head = rqstp->rq_res.head; 478 479 if (!svcxdr_encode_stat(xdr, resp->status)) 480 return false; 481 switch (resp->status) { 482 case nfs_ok: 483 if (xdr_stream_encode_u32(xdr, resp->len) < 0) 484 return false; 485 svcxdr_encode_opaque_pages(rqstp, xdr, &resp->page, 0, 486 resp->len); 487 if (svc_encode_result_payload(rqstp, head->iov_len, resp->len) < 0) 488 return false; 489 break; 490 } 491 492 return true; 493 } 494 495 bool 496 nfssvc_encode_readres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 497 { 498 struct nfsd_readres *resp = rqstp->rq_resp; 499 struct kvec *head = rqstp->rq_res.head; 500 501 if (!svcxdr_encode_stat(xdr, resp->status)) 502 return false; 503 switch (resp->status) { 504 case nfs_ok: 505 if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat)) 506 return false; 507 if (xdr_stream_encode_u32(xdr, resp->count) < 0) 508 return false; 509 svcxdr_encode_opaque_pages(rqstp, xdr, resp->pages, 510 rqstp->rq_res.page_base, 511 resp->count); 512 if (svc_encode_result_payload(rqstp, head->iov_len, resp->count) < 0) 513 return false; 514 break; 515 } 516 517 return true; 518 } 519 520 bool 521 nfssvc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 522 { 523 struct nfsd_readdirres *resp = rqstp->rq_resp; 524 struct xdr_buf *dirlist = &resp->dirlist; 525 526 if (!svcxdr_encode_stat(xdr, resp->status)) 527 return false; 528 switch (resp->status) { 529 case nfs_ok: 530 svcxdr_encode_opaque_pages(rqstp, xdr, dirlist->pages, 0, 531 dirlist->len); 532 /* no more entries */ 533 if (xdr_stream_encode_item_absent(xdr) < 0) 534 return false; 535 if (xdr_stream_encode_bool(xdr, resp->common.err == nfserr_eof) < 0) 536 return false; 537 break; 538 } 539 540 return true; 541 } 542 543 bool 544 nfssvc_encode_statfsres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 545 { 546 struct nfsd_statfsres *resp = rqstp->rq_resp; 547 struct kstatfs *stat = &resp->stats; 548 __be32 *p; 549 550 if (!svcxdr_encode_stat(xdr, resp->status)) 551 return false; 552 switch (resp->status) { 553 case nfs_ok: 554 p = xdr_reserve_space(xdr, XDR_UNIT * 5); 555 if (!p) 556 return false; 557 *p++ = cpu_to_be32(NFS_MAXDATA); 558 *p++ = cpu_to_be32(stat->f_bsize); 559 *p++ = cpu_to_be32(stat->f_blocks); 560 *p++ = cpu_to_be32(stat->f_bfree); 561 *p = cpu_to_be32(stat->f_bavail); 562 break; 563 } 564 565 return true; 566 } 567 568 /** 569 * nfssvc_encode_nfscookie - Encode a directory offset cookie 570 * @resp: readdir result context 571 * @offset: offset cookie to encode 572 * 573 * The buffer space for the offset cookie has already been reserved 574 * by svcxdr_encode_entry_common(). 575 */ 576 void nfssvc_encode_nfscookie(struct nfsd_readdirres *resp, u32 offset) 577 { 578 __be32 cookie = cpu_to_be32(offset); 579 580 if (!resp->cookie_offset) 581 return; 582 583 write_bytes_to_xdr_buf(&resp->dirlist, resp->cookie_offset, &cookie, 584 sizeof(cookie)); 585 resp->cookie_offset = 0; 586 } 587 588 static bool 589 svcxdr_encode_entry_common(struct nfsd_readdirres *resp, const char *name, 590 int namlen, loff_t offset, u64 ino) 591 { 592 struct xdr_buf *dirlist = &resp->dirlist; 593 struct xdr_stream *xdr = &resp->xdr; 594 595 if (xdr_stream_encode_item_present(xdr) < 0) 596 return false; 597 /* fileid */ 598 if (xdr_stream_encode_u32(xdr, (u32)ino) < 0) 599 return false; 600 /* name */ 601 if (xdr_stream_encode_opaque(xdr, name, min(namlen, NFS2_MAXNAMLEN)) < 0) 602 return false; 603 /* cookie */ 604 resp->cookie_offset = dirlist->len; 605 if (xdr_stream_encode_u32(xdr, ~0U) < 0) 606 return false; 607 608 return true; 609 } 610 611 /** 612 * nfssvc_encode_entry - encode one NFSv2 READDIR entry 613 * @data: directory context 614 * @name: name of the object to be encoded 615 * @namlen: length of that name, in bytes 616 * @offset: the offset of the previous entry 617 * @ino: the fileid of this entry 618 * @d_type: unused 619 * 620 * Return values: 621 * %0: Entry was successfully encoded. 622 * %-EINVAL: An encoding problem occurred, secondary status code in resp->common.err 623 * 624 * On exit, the following fields are updated: 625 * - resp->xdr 626 * - resp->common.err 627 * - resp->cookie_offset 628 */ 629 int nfssvc_encode_entry(void *data, const char *name, int namlen, 630 loff_t offset, u64 ino, unsigned int d_type) 631 { 632 struct readdir_cd *ccd = data; 633 struct nfsd_readdirres *resp = container_of(ccd, 634 struct nfsd_readdirres, 635 common); 636 unsigned int starting_length = resp->dirlist.len; 637 638 /* The offset cookie for the previous entry */ 639 nfssvc_encode_nfscookie(resp, offset); 640 641 if (!svcxdr_encode_entry_common(resp, name, namlen, offset, ino)) 642 goto out_toosmall; 643 644 xdr_commit_encode(&resp->xdr); 645 resp->common.err = nfs_ok; 646 return 0; 647 648 out_toosmall: 649 resp->cookie_offset = 0; 650 resp->common.err = nfserr_toosmall; 651 resp->dirlist.len = starting_length; 652 return -EINVAL; 653 } 654 655 /* 656 * XDR release functions 657 */ 658 void nfssvc_release_attrstat(struct svc_rqst *rqstp) 659 { 660 struct nfsd_attrstat *resp = rqstp->rq_resp; 661 662 fh_put(&resp->fh); 663 } 664 665 void nfssvc_release_diropres(struct svc_rqst *rqstp) 666 { 667 struct nfsd_diropres *resp = rqstp->rq_resp; 668 669 fh_put(&resp->fh); 670 } 671 672 void nfssvc_release_readres(struct svc_rqst *rqstp) 673 { 674 struct nfsd_readres *resp = rqstp->rq_resp; 675 676 fh_put(&resp->fh); 677 } 678