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) 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(&init_user_ns, 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(&init_user_ns, 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 dentry *dentry = fhp->fh_dentry; 133 int type; 134 struct timespec64 time; 135 u32 f; 136 137 type = (stat->mode & S_IFMT); 138 139 *p++ = htonl(nfs_ftypes[type >> 12]); 140 *p++ = htonl((u32) stat->mode); 141 *p++ = htonl((u32) stat->nlink); 142 *p++ = htonl((u32) from_kuid(&init_user_ns, stat->uid)); 143 *p++ = htonl((u32) from_kgid(&init_user_ns, stat->gid)); 144 145 if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) { 146 *p++ = htonl(NFS_MAXPATHLEN); 147 } else { 148 *p++ = htonl((u32) stat->size); 149 } 150 *p++ = htonl((u32) stat->blksize); 151 if (S_ISCHR(type) || S_ISBLK(type)) 152 *p++ = htonl(new_encode_dev(stat->rdev)); 153 else 154 *p++ = htonl(0xffffffff); 155 *p++ = htonl((u32) stat->blocks); 156 switch (fsid_source(fhp)) { 157 default: 158 case FSIDSOURCE_DEV: 159 *p++ = htonl(new_encode_dev(stat->dev)); 160 break; 161 case FSIDSOURCE_FSID: 162 *p++ = htonl((u32) fhp->fh_export->ex_fsid); 163 break; 164 case FSIDSOURCE_UUID: 165 f = ((u32*)fhp->fh_export->ex_uuid)[0]; 166 f ^= ((u32*)fhp->fh_export->ex_uuid)[1]; 167 f ^= ((u32*)fhp->fh_export->ex_uuid)[2]; 168 f ^= ((u32*)fhp->fh_export->ex_uuid)[3]; 169 *p++ = htonl(f); 170 break; 171 } 172 *p++ = htonl((u32) stat->ino); 173 *p++ = htonl((u32) stat->atime.tv_sec); 174 *p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0); 175 time = stat->mtime; 176 lease_get_mtime(d_inode(dentry), &time); 177 *p++ = htonl((u32) time.tv_sec); 178 *p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0); 179 *p++ = htonl((u32) stat->ctime.tv_sec); 180 *p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0); 181 182 return p; 183 } 184 185 /* Helper function for NFSv2 ACL code */ 186 __be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp, struct kstat *stat) 187 { 188 return encode_fattr(rqstp, p, fhp, stat); 189 } 190 191 /* 192 * XDR decode functions 193 */ 194 int 195 nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p) 196 { 197 return xdr_argsize_check(rqstp, p); 198 } 199 200 int 201 nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p) 202 { 203 struct nfsd_fhandle *args = rqstp->rq_argp; 204 205 p = decode_fh(p, &args->fh); 206 if (!p) 207 return 0; 208 return xdr_argsize_check(rqstp, p); 209 } 210 211 int 212 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p) 213 { 214 struct nfsd_sattrargs *args = rqstp->rq_argp; 215 216 p = decode_fh(p, &args->fh); 217 if (!p) 218 return 0; 219 p = decode_sattr(p, &args->attrs); 220 221 return xdr_argsize_check(rqstp, p); 222 } 223 224 int 225 nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p) 226 { 227 struct nfsd_diropargs *args = rqstp->rq_argp; 228 229 if (!(p = decode_fh(p, &args->fh)) 230 || !(p = decode_filename(p, &args->name, &args->len))) 231 return 0; 232 233 return xdr_argsize_check(rqstp, p); 234 } 235 236 int 237 nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p) 238 { 239 struct nfsd_readargs *args = rqstp->rq_argp; 240 unsigned int len; 241 int v; 242 p = decode_fh(p, &args->fh); 243 if (!p) 244 return 0; 245 246 args->offset = ntohl(*p++); 247 len = args->count = ntohl(*p++); 248 p++; /* totalcount - unused */ 249 250 len = min_t(unsigned int, len, NFSSVC_MAXBLKSIZE_V2); 251 252 /* set up somewhere to store response. 253 * We take pages, put them on reslist and include in iovec 254 */ 255 v=0; 256 while (len > 0) { 257 struct page *p = *(rqstp->rq_next_page++); 258 259 rqstp->rq_vec[v].iov_base = page_address(p); 260 rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE); 261 len -= rqstp->rq_vec[v].iov_len; 262 v++; 263 } 264 args->vlen = v; 265 return xdr_argsize_check(rqstp, p); 266 } 267 268 int 269 nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p) 270 { 271 struct nfsd_writeargs *args = rqstp->rq_argp; 272 unsigned int len, hdr, dlen; 273 struct kvec *head = rqstp->rq_arg.head; 274 275 p = decode_fh(p, &args->fh); 276 if (!p) 277 return 0; 278 279 p++; /* beginoffset */ 280 args->offset = ntohl(*p++); /* offset */ 281 p++; /* totalcount */ 282 len = args->len = ntohl(*p++); 283 /* 284 * The protocol specifies a maximum of 8192 bytes. 285 */ 286 if (len > NFSSVC_MAXBLKSIZE_V2) 287 return 0; 288 289 /* 290 * Check to make sure that we got the right number of 291 * bytes. 292 */ 293 hdr = (void*)p - head->iov_base; 294 if (hdr > head->iov_len) 295 return 0; 296 dlen = head->iov_len + rqstp->rq_arg.page_len - hdr; 297 298 /* 299 * Round the length of the data which was specified up to 300 * the next multiple of XDR units and then compare that 301 * against the length which was actually received. 302 * Note that when RPCSEC/GSS (for example) is used, the 303 * data buffer can be padded so dlen might be larger 304 * than required. It must never be smaller. 305 */ 306 if (dlen < XDR_QUADLEN(len)*4) 307 return 0; 308 309 args->first.iov_base = (void *)p; 310 args->first.iov_len = head->iov_len - hdr; 311 return 1; 312 } 313 314 int 315 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p) 316 { 317 struct nfsd_createargs *args = rqstp->rq_argp; 318 319 if ( !(p = decode_fh(p, &args->fh)) 320 || !(p = decode_filename(p, &args->name, &args->len))) 321 return 0; 322 p = decode_sattr(p, &args->attrs); 323 324 return xdr_argsize_check(rqstp, p); 325 } 326 327 int 328 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p) 329 { 330 struct nfsd_renameargs *args = rqstp->rq_argp; 331 332 if (!(p = decode_fh(p, &args->ffh)) 333 || !(p = decode_filename(p, &args->fname, &args->flen)) 334 || !(p = decode_fh(p, &args->tfh)) 335 || !(p = decode_filename(p, &args->tname, &args->tlen))) 336 return 0; 337 338 return xdr_argsize_check(rqstp, p); 339 } 340 341 int 342 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p) 343 { 344 struct nfsd_readlinkargs *args = rqstp->rq_argp; 345 346 p = decode_fh(p, &args->fh); 347 if (!p) 348 return 0; 349 args->buffer = page_address(*(rqstp->rq_next_page++)); 350 351 return xdr_argsize_check(rqstp, p); 352 } 353 354 int 355 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p) 356 { 357 struct nfsd_linkargs *args = rqstp->rq_argp; 358 359 if (!(p = decode_fh(p, &args->ffh)) 360 || !(p = decode_fh(p, &args->tfh)) 361 || !(p = decode_filename(p, &args->tname, &args->tlen))) 362 return 0; 363 364 return xdr_argsize_check(rqstp, p); 365 } 366 367 int 368 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p) 369 { 370 struct nfsd_symlinkargs *args = rqstp->rq_argp; 371 char *base = (char *)p; 372 size_t xdrlen; 373 374 if ( !(p = decode_fh(p, &args->ffh)) 375 || !(p = decode_filename(p, &args->fname, &args->flen))) 376 return 0; 377 378 args->tlen = ntohl(*p++); 379 if (args->tlen == 0) 380 return 0; 381 382 args->first.iov_base = p; 383 args->first.iov_len = rqstp->rq_arg.head[0].iov_len; 384 args->first.iov_len -= (char *)p - base; 385 386 /* This request is never larger than a page. Therefore, 387 * transport will deliver either: 388 * 1. pathname in the pagelist -> sattr is in the tail. 389 * 2. everything in the head buffer -> sattr is in the head. 390 */ 391 if (rqstp->rq_arg.page_len) { 392 if (args->tlen != rqstp->rq_arg.page_len) 393 return 0; 394 p = rqstp->rq_arg.tail[0].iov_base; 395 } else { 396 xdrlen = XDR_QUADLEN(args->tlen); 397 if (xdrlen > args->first.iov_len - (8 * sizeof(__be32))) 398 return 0; 399 p += xdrlen; 400 } 401 decode_sattr(p, &args->attrs); 402 403 return 1; 404 } 405 406 int 407 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p) 408 { 409 struct nfsd_readdirargs *args = rqstp->rq_argp; 410 411 p = decode_fh(p, &args->fh); 412 if (!p) 413 return 0; 414 args->cookie = ntohl(*p++); 415 args->count = ntohl(*p++); 416 args->count = min_t(u32, args->count, PAGE_SIZE); 417 args->buffer = page_address(*(rqstp->rq_next_page++)); 418 419 return xdr_argsize_check(rqstp, p); 420 } 421 422 /* 423 * XDR encode functions 424 */ 425 int 426 nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p) 427 { 428 return xdr_ressize_check(rqstp, p); 429 } 430 431 int 432 nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p) 433 { 434 struct nfsd_attrstat *resp = rqstp->rq_resp; 435 436 p = encode_fattr(rqstp, p, &resp->fh, &resp->stat); 437 return xdr_ressize_check(rqstp, p); 438 } 439 440 int 441 nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p) 442 { 443 struct nfsd_diropres *resp = rqstp->rq_resp; 444 445 p = encode_fh(p, &resp->fh); 446 p = encode_fattr(rqstp, p, &resp->fh, &resp->stat); 447 return xdr_ressize_check(rqstp, p); 448 } 449 450 int 451 nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p) 452 { 453 struct nfsd_readlinkres *resp = rqstp->rq_resp; 454 455 *p++ = htonl(resp->len); 456 xdr_ressize_check(rqstp, p); 457 rqstp->rq_res.page_len = resp->len; 458 if (resp->len & 3) { 459 /* need to pad the tail */ 460 rqstp->rq_res.tail[0].iov_base = p; 461 *p = 0; 462 rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3); 463 } 464 return 1; 465 } 466 467 int 468 nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p) 469 { 470 struct nfsd_readres *resp = rqstp->rq_resp; 471 472 p = encode_fattr(rqstp, p, &resp->fh, &resp->stat); 473 *p++ = htonl(resp->count); 474 xdr_ressize_check(rqstp, p); 475 476 /* now update rqstp->rq_res to reflect data as well */ 477 rqstp->rq_res.page_len = resp->count; 478 if (resp->count & 3) { 479 /* need to pad the tail */ 480 rqstp->rq_res.tail[0].iov_base = p; 481 *p = 0; 482 rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3); 483 } 484 return 1; 485 } 486 487 int 488 nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p) 489 { 490 struct nfsd_readdirres *resp = rqstp->rq_resp; 491 492 xdr_ressize_check(rqstp, p); 493 p = resp->buffer; 494 *p++ = 0; /* no more entries */ 495 *p++ = htonl((resp->common.err == nfserr_eof)); 496 rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1; 497 498 return 1; 499 } 500 501 int 502 nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p) 503 { 504 struct nfsd_statfsres *resp = rqstp->rq_resp; 505 struct kstatfs *stat = &resp->stats; 506 507 *p++ = htonl(NFSSVC_MAXBLKSIZE_V2); /* max transfer size */ 508 *p++ = htonl(stat->f_bsize); 509 *p++ = htonl(stat->f_blocks); 510 *p++ = htonl(stat->f_bfree); 511 *p++ = htonl(stat->f_bavail); 512 return xdr_ressize_check(rqstp, p); 513 } 514 515 int 516 nfssvc_encode_entry(void *ccdv, const char *name, 517 int namlen, loff_t offset, u64 ino, unsigned int d_type) 518 { 519 struct readdir_cd *ccd = ccdv; 520 struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common); 521 __be32 *p = cd->buffer; 522 int buflen, slen; 523 524 /* 525 dprintk("nfsd: entry(%.*s off %ld ino %ld)\n", 526 namlen, name, offset, ino); 527 */ 528 529 if (offset > ~((u32) 0)) { 530 cd->common.err = nfserr_fbig; 531 return -EINVAL; 532 } 533 if (cd->offset) 534 *cd->offset = htonl(offset); 535 536 /* truncate filename */ 537 namlen = min(namlen, NFS2_MAXNAMLEN); 538 slen = XDR_QUADLEN(namlen); 539 540 if ((buflen = cd->buflen - slen - 4) < 0) { 541 cd->common.err = nfserr_toosmall; 542 return -EINVAL; 543 } 544 if (ino > ~((u32) 0)) { 545 cd->common.err = nfserr_fbig; 546 return -EINVAL; 547 } 548 *p++ = xdr_one; /* mark entry present */ 549 *p++ = htonl((u32) ino); /* file id */ 550 p = xdr_encode_array(p, name, namlen);/* name length & name */ 551 cd->offset = p; /* remember pointer */ 552 *p++ = htonl(~0U); /* offset of next entry */ 553 554 cd->buflen = buflen; 555 cd->buffer = p; 556 cd->common.err = nfs_ok; 557 return 0; 558 } 559 560 /* 561 * XDR release functions 562 */ 563 void 564 nfssvc_release_fhandle(struct svc_rqst *rqstp) 565 { 566 struct nfsd_fhandle *resp = rqstp->rq_resp; 567 568 fh_put(&resp->fh); 569 } 570