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 */ 15static 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 */ 36bool 37svcxdr_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 */ 58bool 59svcxdr_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 73static bool 74svcxdr_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 86static __be32 * 87encode_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 97static bool 98svcxdr_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 121static bool 122svcxdr_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 129static bool 130svcxdr_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 */ 213bool 214svcxdr_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 275bool 276nfssvc_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 283bool 284nfssvc_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 292bool 293nfssvc_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 300bool 301nfssvc_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 319bool 320nfssvc_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 345bool 346nfssvc_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 355bool 356nfssvc_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 366bool 367nfssvc_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 376bool 377nfssvc_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 396bool 397nfssvc_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 415bool 416nfssvc_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 423bool 424nfssvc_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 440bool 441nfssvc_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 459bool 460nfssvc_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 svcxdr_encode_opaque_pages(rqstp, xdr, &resp->page, 0, 472 resp->len); 473 if (svc_encode_result_payload(rqstp, head->iov_len, resp->len) < 0) 474 return false; 475 break; 476 } 477 478 return true; 479} 480 481bool 482nfssvc_encode_readres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 483{ 484 struct nfsd_readres *resp = rqstp->rq_resp; 485 struct kvec *head = rqstp->rq_res.head; 486 487 if (!svcxdr_encode_stat(xdr, resp->status)) 488 return false; 489 switch (resp->status) { 490 case nfs_ok: 491 if (!svcxdr_encode_fattr(rqstp, xdr, &resp->fh, &resp->stat)) 492 return false; 493 if (xdr_stream_encode_u32(xdr, resp->count) < 0) 494 return false; 495 svcxdr_encode_opaque_pages(rqstp, xdr, resp->pages, 496 rqstp->rq_res.page_base, 497 resp->count); 498 if (svc_encode_result_payload(rqstp, head->iov_len, resp->count) < 0) 499 return false; 500 break; 501 } 502 503 return true; 504} 505 506bool 507nfssvc_encode_readdirres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 508{ 509 struct nfsd_readdirres *resp = rqstp->rq_resp; 510 struct xdr_buf *dirlist = &resp->dirlist; 511 512 if (!svcxdr_encode_stat(xdr, resp->status)) 513 return false; 514 switch (resp->status) { 515 case nfs_ok: 516 svcxdr_encode_opaque_pages(rqstp, xdr, dirlist->pages, 0, 517 dirlist->len); 518 /* no more entries */ 519 if (xdr_stream_encode_item_absent(xdr) < 0) 520 return false; 521 if (xdr_stream_encode_bool(xdr, resp->common.err == nfserr_eof) < 0) 522 return false; 523 break; 524 } 525 526 return true; 527} 528 529bool 530nfssvc_encode_statfsres(struct svc_rqst *rqstp, struct xdr_stream *xdr) 531{ 532 struct nfsd_statfsres *resp = rqstp->rq_resp; 533 struct kstatfs *stat = &resp->stats; 534 __be32 *p; 535 536 if (!svcxdr_encode_stat(xdr, resp->status)) 537 return false; 538 switch (resp->status) { 539 case nfs_ok: 540 p = xdr_reserve_space(xdr, XDR_UNIT * 5); 541 if (!p) 542 return false; 543 *p++ = cpu_to_be32(NFSSVC_MAXBLKSIZE_V2); 544 *p++ = cpu_to_be32(stat->f_bsize); 545 *p++ = cpu_to_be32(stat->f_blocks); 546 *p++ = cpu_to_be32(stat->f_bfree); 547 *p = cpu_to_be32(stat->f_bavail); 548 break; 549 } 550 551 return true; 552} 553 554/** 555 * nfssvc_encode_nfscookie - Encode a directory offset cookie 556 * @resp: readdir result context 557 * @offset: offset cookie to encode 558 * 559 * The buffer space for the offset cookie has already been reserved 560 * by svcxdr_encode_entry_common(). 561 */ 562void nfssvc_encode_nfscookie(struct nfsd_readdirres *resp, u32 offset) 563{ 564 __be32 cookie = cpu_to_be32(offset); 565 566 if (!resp->cookie_offset) 567 return; 568 569 write_bytes_to_xdr_buf(&resp->dirlist, resp->cookie_offset, &cookie, 570 sizeof(cookie)); 571 resp->cookie_offset = 0; 572} 573 574static bool 575svcxdr_encode_entry_common(struct nfsd_readdirres *resp, const char *name, 576 int namlen, loff_t offset, u64 ino) 577{ 578 struct xdr_buf *dirlist = &resp->dirlist; 579 struct xdr_stream *xdr = &resp->xdr; 580 581 if (xdr_stream_encode_item_present(xdr) < 0) 582 return false; 583 /* fileid */ 584 if (xdr_stream_encode_u32(xdr, (u32)ino) < 0) 585 return false; 586 /* name */ 587 if (xdr_stream_encode_opaque(xdr, name, min(namlen, NFS2_MAXNAMLEN)) < 0) 588 return false; 589 /* cookie */ 590 resp->cookie_offset = dirlist->len; 591 if (xdr_stream_encode_u32(xdr, ~0U) < 0) 592 return false; 593 594 return true; 595} 596 597/** 598 * nfssvc_encode_entry - encode one NFSv2 READDIR entry 599 * @data: directory context 600 * @name: name of the object to be encoded 601 * @namlen: length of that name, in bytes 602 * @offset: the offset of the previous entry 603 * @ino: the fileid of this entry 604 * @d_type: unused 605 * 606 * Return values: 607 * %0: Entry was successfully encoded. 608 * %-EINVAL: An encoding problem occured, secondary status code in resp->common.err 609 * 610 * On exit, the following fields are updated: 611 * - resp->xdr 612 * - resp->common.err 613 * - resp->cookie_offset 614 */ 615int nfssvc_encode_entry(void *data, const char *name, int namlen, 616 loff_t offset, u64 ino, unsigned int d_type) 617{ 618 struct readdir_cd *ccd = data; 619 struct nfsd_readdirres *resp = container_of(ccd, 620 struct nfsd_readdirres, 621 common); 622 unsigned int starting_length = resp->dirlist.len; 623 624 /* The offset cookie for the previous entry */ 625 nfssvc_encode_nfscookie(resp, offset); 626 627 if (!svcxdr_encode_entry_common(resp, name, namlen, offset, ino)) 628 goto out_toosmall; 629 630 xdr_commit_encode(&resp->xdr); 631 resp->common.err = nfs_ok; 632 return 0; 633 634out_toosmall: 635 resp->cookie_offset = 0; 636 resp->common.err = nfserr_toosmall; 637 resp->dirlist.len = starting_length; 638 return -EINVAL; 639} 640 641/* 642 * XDR release functions 643 */ 644void nfssvc_release_attrstat(struct svc_rqst *rqstp) 645{ 646 struct nfsd_attrstat *resp = rqstp->rq_resp; 647 648 fh_put(&resp->fh); 649} 650 651void nfssvc_release_diropres(struct svc_rqst *rqstp) 652{ 653 struct nfsd_diropres *resp = rqstp->rq_resp; 654 655 fh_put(&resp->fh); 656} 657 658void nfssvc_release_readres(struct svc_rqst *rqstp) 659{ 660 struct nfsd_readres *resp = rqstp->rq_resp; 661 662 fh_put(&resp->fh); 663} 664