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 #define NFSDDBG_FACILITY NFSDDBG_XDR 13 14 /* 15 * Mapping of S_IF* types to NFS file types 16 */ 17 static u32 nfs_ftypes[] = { 18 NFNON, NFCHR, NFCHR, NFBAD, 19 NFDIR, NFBAD, NFBLK, NFBAD, 20 NFREG, NFBAD, NFLNK, NFBAD, 21 NFSOCK, NFBAD, NFLNK, NFBAD, 22 }; 23 24 25 /* 26 * XDR functions for basic NFS types 27 */ 28 static __be32 * 29 decode_fh(__be32 *p, struct svc_fh *fhp) 30 { 31 fh_init(fhp, NFS_FHSIZE); 32 memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE); 33 fhp->fh_handle.fh_size = NFS_FHSIZE; 34 35 /* FIXME: Look up export pointer here and verify 36 * Sun Secure RPC if requested */ 37 return p + (NFS_FHSIZE >> 2); 38 } 39 40 /* Helper function for NFSv2 ACL code */ 41 __be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp) 42 { 43 return decode_fh(p, fhp); 44 } 45 46 static __be32 * 47 encode_fh(__be32 *p, struct svc_fh *fhp) 48 { 49 memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE); 50 return p + (NFS_FHSIZE>> 2); 51 } 52 53 /* 54 * Decode a file name and make sure that the path contains 55 * no slashes or null bytes. 56 */ 57 static __be32 * 58 decode_filename(__be32 *p, char **namp, unsigned int *lenp) 59 { 60 char *name; 61 unsigned int i; 62 63 if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) { 64 for (i = 0, name = *namp; i < *lenp; i++, name++) { 65 if (*name == '\0' || *name == '/') 66 return NULL; 67 } 68 } 69 70 return p; 71 } 72 73 static __be32 * 74 decode_sattr(__be32 *p, struct iattr *iap, struct user_namespace *userns) 75 { 76 u32 tmp, tmp1; 77 78 iap->ia_valid = 0; 79 80 /* Sun client bug compatibility check: some sun clients seem to 81 * put 0xffff in the mode field when they mean 0xffffffff. 82 * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah. 83 */ 84 if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) { 85 iap->ia_valid |= ATTR_MODE; 86 iap->ia_mode = tmp; 87 } 88 if ((tmp = ntohl(*p++)) != (u32)-1) { 89 iap->ia_uid = make_kuid(userns, tmp); 90 if (uid_valid(iap->ia_uid)) 91 iap->ia_valid |= ATTR_UID; 92 } 93 if ((tmp = ntohl(*p++)) != (u32)-1) { 94 iap->ia_gid = make_kgid(userns, tmp); 95 if (gid_valid(iap->ia_gid)) 96 iap->ia_valid |= ATTR_GID; 97 } 98 if ((tmp = ntohl(*p++)) != (u32)-1) { 99 iap->ia_valid |= ATTR_SIZE; 100 iap->ia_size = tmp; 101 } 102 tmp = ntohl(*p++); tmp1 = ntohl(*p++); 103 if (tmp != (u32)-1 && tmp1 != (u32)-1) { 104 iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET; 105 iap->ia_atime.tv_sec = tmp; 106 iap->ia_atime.tv_nsec = tmp1 * 1000; 107 } 108 tmp = ntohl(*p++); tmp1 = ntohl(*p++); 109 if (tmp != (u32)-1 && tmp1 != (u32)-1) { 110 iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET; 111 iap->ia_mtime.tv_sec = tmp; 112 iap->ia_mtime.tv_nsec = tmp1 * 1000; 113 /* 114 * Passing the invalid value useconds=1000000 for mtime 115 * is a Sun convention for "set both mtime and atime to 116 * current server time". It's needed to make permissions 117 * checks for the "touch" program across v2 mounts to 118 * Solaris and Irix boxes work correctly. See description of 119 * sattr in section 6.1 of "NFS Illustrated" by 120 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5 121 */ 122 if (tmp1 == 1000000) 123 iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET); 124 } 125 return p; 126 } 127 128 static __be32 * 129 encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp, 130 struct kstat *stat) 131 { 132 struct user_namespace *userns = nfsd_user_namespace(rqstp); 133 struct dentry *dentry = fhp->fh_dentry; 134 int type; 135 struct timespec64 time; 136 u32 f; 137 138 type = (stat->mode & S_IFMT); 139 140 *p++ = htonl(nfs_ftypes[type >> 12]); 141 *p++ = htonl((u32) stat->mode); 142 *p++ = htonl((u32) stat->nlink); 143 *p++ = htonl((u32) from_kuid_munged(userns, stat->uid)); 144 *p++ = htonl((u32) from_kgid_munged(userns, stat->gid)); 145 146 if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) { 147 *p++ = htonl(NFS_MAXPATHLEN); 148 } else { 149 *p++ = htonl((u32) stat->size); 150 } 151 *p++ = htonl((u32) stat->blksize); 152 if (S_ISCHR(type) || S_ISBLK(type)) 153 *p++ = htonl(new_encode_dev(stat->rdev)); 154 else 155 *p++ = htonl(0xffffffff); 156 *p++ = htonl((u32) stat->blocks); 157 switch (fsid_source(fhp)) { 158 default: 159 case FSIDSOURCE_DEV: 160 *p++ = htonl(new_encode_dev(stat->dev)); 161 break; 162 case FSIDSOURCE_FSID: 163 *p++ = htonl((u32) fhp->fh_export->ex_fsid); 164 break; 165 case FSIDSOURCE_UUID: 166 f = ((u32*)fhp->fh_export->ex_uuid)[0]; 167 f ^= ((u32*)fhp->fh_export->ex_uuid)[1]; 168 f ^= ((u32*)fhp->fh_export->ex_uuid)[2]; 169 f ^= ((u32*)fhp->fh_export->ex_uuid)[3]; 170 *p++ = htonl(f); 171 break; 172 } 173 *p++ = htonl((u32) stat->ino); 174 *p++ = htonl((u32) stat->atime.tv_sec); 175 *p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0); 176 time = stat->mtime; 177 lease_get_mtime(d_inode(dentry), &time); 178 *p++ = htonl((u32) time.tv_sec); 179 *p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0); 180 *p++ = htonl((u32) stat->ctime.tv_sec); 181 *p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0); 182 183 return p; 184 } 185 186 /* Helper function for NFSv2 ACL code */ 187 __be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp, struct kstat *stat) 188 { 189 return encode_fattr(rqstp, p, fhp, stat); 190 } 191 192 /* 193 * XDR decode functions 194 */ 195 int 196 nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p) 197 { 198 return xdr_argsize_check(rqstp, p); 199 } 200 201 int 202 nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p) 203 { 204 struct nfsd_fhandle *args = rqstp->rq_argp; 205 206 p = decode_fh(p, &args->fh); 207 if (!p) 208 return 0; 209 return xdr_argsize_check(rqstp, p); 210 } 211 212 int 213 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p) 214 { 215 struct nfsd_sattrargs *args = rqstp->rq_argp; 216 217 p = decode_fh(p, &args->fh); 218 if (!p) 219 return 0; 220 p = decode_sattr(p, &args->attrs, nfsd_user_namespace(rqstp)); 221 222 return xdr_argsize_check(rqstp, p); 223 } 224 225 int 226 nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p) 227 { 228 struct nfsd_diropargs *args = rqstp->rq_argp; 229 230 if (!(p = decode_fh(p, &args->fh)) 231 || !(p = decode_filename(p, &args->name, &args->len))) 232 return 0; 233 234 return xdr_argsize_check(rqstp, p); 235 } 236 237 int 238 nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p) 239 { 240 struct nfsd_readargs *args = rqstp->rq_argp; 241 unsigned int len; 242 int v; 243 p = decode_fh(p, &args->fh); 244 if (!p) 245 return 0; 246 247 args->offset = ntohl(*p++); 248 len = args->count = ntohl(*p++); 249 p++; /* totalcount - unused */ 250 251 len = min_t(unsigned int, len, NFSSVC_MAXBLKSIZE_V2); 252 253 /* set up somewhere to store response. 254 * We take pages, put them on reslist and include in iovec 255 */ 256 v=0; 257 while (len > 0) { 258 struct page *p = *(rqstp->rq_next_page++); 259 260 rqstp->rq_vec[v].iov_base = page_address(p); 261 rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE); 262 len -= rqstp->rq_vec[v].iov_len; 263 v++; 264 } 265 args->vlen = v; 266 return xdr_argsize_check(rqstp, p); 267 } 268 269 int 270 nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p) 271 { 272 struct nfsd_writeargs *args = rqstp->rq_argp; 273 unsigned int len, hdr, dlen; 274 struct kvec *head = rqstp->rq_arg.head; 275 276 p = decode_fh(p, &args->fh); 277 if (!p) 278 return 0; 279 280 p++; /* beginoffset */ 281 args->offset = ntohl(*p++); /* offset */ 282 p++; /* totalcount */ 283 len = args->len = ntohl(*p++); 284 /* 285 * The protocol specifies a maximum of 8192 bytes. 286 */ 287 if (len > NFSSVC_MAXBLKSIZE_V2) 288 return 0; 289 290 /* 291 * Check to make sure that we got the right number of 292 * bytes. 293 */ 294 hdr = (void*)p - head->iov_base; 295 if (hdr > head->iov_len) 296 return 0; 297 dlen = head->iov_len + rqstp->rq_arg.page_len - hdr; 298 299 /* 300 * Round the length of the data which was specified up to 301 * the next multiple of XDR units and then compare that 302 * against the length which was actually received. 303 * Note that when RPCSEC/GSS (for example) is used, the 304 * data buffer can be padded so dlen might be larger 305 * than required. It must never be smaller. 306 */ 307 if (dlen < XDR_QUADLEN(len)*4) 308 return 0; 309 310 args->first.iov_base = (void *)p; 311 args->first.iov_len = head->iov_len - hdr; 312 return 1; 313 } 314 315 int 316 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p) 317 { 318 struct nfsd_createargs *args = rqstp->rq_argp; 319 320 if ( !(p = decode_fh(p, &args->fh)) 321 || !(p = decode_filename(p, &args->name, &args->len))) 322 return 0; 323 p = decode_sattr(p, &args->attrs, nfsd_user_namespace(rqstp)); 324 325 return xdr_argsize_check(rqstp, p); 326 } 327 328 int 329 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p) 330 { 331 struct nfsd_renameargs *args = rqstp->rq_argp; 332 333 if (!(p = decode_fh(p, &args->ffh)) 334 || !(p = decode_filename(p, &args->fname, &args->flen)) 335 || !(p = decode_fh(p, &args->tfh)) 336 || !(p = decode_filename(p, &args->tname, &args->tlen))) 337 return 0; 338 339 return xdr_argsize_check(rqstp, p); 340 } 341 342 int 343 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p) 344 { 345 struct nfsd_readlinkargs *args = rqstp->rq_argp; 346 347 p = decode_fh(p, &args->fh); 348 if (!p) 349 return 0; 350 args->buffer = page_address(*(rqstp->rq_next_page++)); 351 352 return xdr_argsize_check(rqstp, p); 353 } 354 355 int 356 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p) 357 { 358 struct nfsd_linkargs *args = rqstp->rq_argp; 359 360 if (!(p = decode_fh(p, &args->ffh)) 361 || !(p = decode_fh(p, &args->tfh)) 362 || !(p = decode_filename(p, &args->tname, &args->tlen))) 363 return 0; 364 365 return xdr_argsize_check(rqstp, p); 366 } 367 368 int 369 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p) 370 { 371 struct nfsd_symlinkargs *args = rqstp->rq_argp; 372 char *base = (char *)p; 373 size_t xdrlen; 374 375 if ( !(p = decode_fh(p, &args->ffh)) 376 || !(p = decode_filename(p, &args->fname, &args->flen))) 377 return 0; 378 379 args->tlen = ntohl(*p++); 380 if (args->tlen == 0) 381 return 0; 382 383 args->first.iov_base = p; 384 args->first.iov_len = rqstp->rq_arg.head[0].iov_len; 385 args->first.iov_len -= (char *)p - base; 386 387 /* This request is never larger than a page. Therefore, 388 * transport will deliver either: 389 * 1. pathname in the pagelist -> sattr is in the tail. 390 * 2. everything in the head buffer -> sattr is in the head. 391 */ 392 if (rqstp->rq_arg.page_len) { 393 if (args->tlen != rqstp->rq_arg.page_len) 394 return 0; 395 p = rqstp->rq_arg.tail[0].iov_base; 396 } else { 397 xdrlen = XDR_QUADLEN(args->tlen); 398 if (xdrlen > args->first.iov_len - (8 * sizeof(__be32))) 399 return 0; 400 p += xdrlen; 401 } 402 decode_sattr(p, &args->attrs, nfsd_user_namespace(rqstp)); 403 404 return 1; 405 } 406 407 int 408 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p) 409 { 410 struct nfsd_readdirargs *args = rqstp->rq_argp; 411 412 p = decode_fh(p, &args->fh); 413 if (!p) 414 return 0; 415 args->cookie = ntohl(*p++); 416 args->count = ntohl(*p++); 417 args->count = min_t(u32, args->count, PAGE_SIZE); 418 args->buffer = page_address(*(rqstp->rq_next_page++)); 419 420 return xdr_argsize_check(rqstp, p); 421 } 422 423 /* 424 * XDR encode functions 425 */ 426 int 427 nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p) 428 { 429 return xdr_ressize_check(rqstp, p); 430 } 431 432 int 433 nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p) 434 { 435 struct nfsd_attrstat *resp = rqstp->rq_resp; 436 437 p = encode_fattr(rqstp, p, &resp->fh, &resp->stat); 438 return xdr_ressize_check(rqstp, p); 439 } 440 441 int 442 nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p) 443 { 444 struct nfsd_diropres *resp = rqstp->rq_resp; 445 446 p = encode_fh(p, &resp->fh); 447 p = encode_fattr(rqstp, p, &resp->fh, &resp->stat); 448 return xdr_ressize_check(rqstp, p); 449 } 450 451 int 452 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p) 453 { 454 struct nfsd_readlinkres *resp = rqstp->rq_resp; 455 456 *p++ = htonl(resp->len); 457 xdr_ressize_check(rqstp, p); 458 rqstp->rq_res.page_len = resp->len; 459 if (resp->len & 3) { 460 /* need to pad the tail */ 461 rqstp->rq_res.tail[0].iov_base = p; 462 *p = 0; 463 rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3); 464 } 465 return 1; 466 } 467 468 int 469 nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p) 470 { 471 struct nfsd_readres *resp = rqstp->rq_resp; 472 473 p = encode_fattr(rqstp, p, &resp->fh, &resp->stat); 474 *p++ = htonl(resp->count); 475 xdr_ressize_check(rqstp, p); 476 477 /* now update rqstp->rq_res to reflect data as well */ 478 rqstp->rq_res.page_len = resp->count; 479 if (resp->count & 3) { 480 /* need to pad the tail */ 481 rqstp->rq_res.tail[0].iov_base = p; 482 *p = 0; 483 rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3); 484 } 485 return 1; 486 } 487 488 int 489 nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p) 490 { 491 struct nfsd_readdirres *resp = rqstp->rq_resp; 492 493 xdr_ressize_check(rqstp, p); 494 p = resp->buffer; 495 *p++ = 0; /* no more entries */ 496 *p++ = htonl((resp->common.err == nfserr_eof)); 497 rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1; 498 499 return 1; 500 } 501 502 int 503 nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p) 504 { 505 struct nfsd_statfsres *resp = rqstp->rq_resp; 506 struct kstatfs *stat = &resp->stats; 507 508 *p++ = htonl(NFSSVC_MAXBLKSIZE_V2); /* max transfer size */ 509 *p++ = htonl(stat->f_bsize); 510 *p++ = htonl(stat->f_blocks); 511 *p++ = htonl(stat->f_bfree); 512 *p++ = htonl(stat->f_bavail); 513 return xdr_ressize_check(rqstp, p); 514 } 515 516 int 517 nfssvc_encode_entry(void *ccdv, const char *name, 518 int namlen, loff_t offset, u64 ino, unsigned int d_type) 519 { 520 struct readdir_cd *ccd = ccdv; 521 struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common); 522 __be32 *p = cd->buffer; 523 int buflen, slen; 524 525 /* 526 dprintk("nfsd: entry(%.*s off %ld ino %ld)\n", 527 namlen, name, offset, ino); 528 */ 529 530 if (offset > ~((u32) 0)) { 531 cd->common.err = nfserr_fbig; 532 return -EINVAL; 533 } 534 if (cd->offset) 535 *cd->offset = htonl(offset); 536 537 /* truncate filename */ 538 namlen = min(namlen, NFS2_MAXNAMLEN); 539 slen = XDR_QUADLEN(namlen); 540 541 if ((buflen = cd->buflen - slen - 4) < 0) { 542 cd->common.err = nfserr_toosmall; 543 return -EINVAL; 544 } 545 if (ino > ~((u32) 0)) { 546 cd->common.err = nfserr_fbig; 547 return -EINVAL; 548 } 549 *p++ = xdr_one; /* mark entry present */ 550 *p++ = htonl((u32) ino); /* file id */ 551 p = xdr_encode_array(p, name, namlen);/* name length & name */ 552 cd->offset = p; /* remember pointer */ 553 *p++ = htonl(~0U); /* offset of next entry */ 554 555 cd->buflen = buflen; 556 cd->buffer = p; 557 cd->common.err = nfs_ok; 558 return 0; 559 } 560 561 /* 562 * XDR release functions 563 */ 564 void 565 nfssvc_release_fhandle(struct svc_rqst *rqstp) 566 { 567 struct nfsd_fhandle *resp = rqstp->rq_resp; 568 569 fh_put(&resp->fh); 570 } 571