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_pathname(__be32 *p, char **namp, unsigned int *lenp) 75 { 76 char *name; 77 unsigned int i; 78 79 if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXPATHLEN)) != NULL) { 80 for (i = 0, name = *namp; i < *lenp; i++, name++) { 81 if (*name == '\0') 82 return NULL; 83 } 84 } 85 86 return p; 87 } 88 89 static __be32 * 90 decode_sattr(__be32 *p, struct iattr *iap) 91 { 92 u32 tmp, tmp1; 93 94 iap->ia_valid = 0; 95 96 /* Sun client bug compatibility check: some sun clients seem to 97 * put 0xffff in the mode field when they mean 0xffffffff. 98 * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah. 99 */ 100 if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) { 101 iap->ia_valid |= ATTR_MODE; 102 iap->ia_mode = tmp; 103 } 104 if ((tmp = ntohl(*p++)) != (u32)-1) { 105 iap->ia_uid = make_kuid(&init_user_ns, tmp); 106 if (uid_valid(iap->ia_uid)) 107 iap->ia_valid |= ATTR_UID; 108 } 109 if ((tmp = ntohl(*p++)) != (u32)-1) { 110 iap->ia_gid = make_kgid(&init_user_ns, tmp); 111 if (gid_valid(iap->ia_gid)) 112 iap->ia_valid |= ATTR_GID; 113 } 114 if ((tmp = ntohl(*p++)) != (u32)-1) { 115 iap->ia_valid |= ATTR_SIZE; 116 iap->ia_size = tmp; 117 } 118 tmp = ntohl(*p++); tmp1 = ntohl(*p++); 119 if (tmp != (u32)-1 && tmp1 != (u32)-1) { 120 iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET; 121 iap->ia_atime.tv_sec = tmp; 122 iap->ia_atime.tv_nsec = tmp1 * 1000; 123 } 124 tmp = ntohl(*p++); tmp1 = ntohl(*p++); 125 if (tmp != (u32)-1 && tmp1 != (u32)-1) { 126 iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET; 127 iap->ia_mtime.tv_sec = tmp; 128 iap->ia_mtime.tv_nsec = tmp1 * 1000; 129 /* 130 * Passing the invalid value useconds=1000000 for mtime 131 * is a Sun convention for "set both mtime and atime to 132 * current server time". It's needed to make permissions 133 * checks for the "touch" program across v2 mounts to 134 * Solaris and Irix boxes work correctly. See description of 135 * sattr in section 6.1 of "NFS Illustrated" by 136 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5 137 */ 138 if (tmp1 == 1000000) 139 iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET); 140 } 141 return p; 142 } 143 144 static __be32 * 145 encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp, 146 struct kstat *stat) 147 { 148 struct dentry *dentry = fhp->fh_dentry; 149 int type; 150 struct timespec time; 151 u32 f; 152 153 type = (stat->mode & S_IFMT); 154 155 *p++ = htonl(nfs_ftypes[type >> 12]); 156 *p++ = htonl((u32) stat->mode); 157 *p++ = htonl((u32) stat->nlink); 158 *p++ = htonl((u32) from_kuid(&init_user_ns, stat->uid)); 159 *p++ = htonl((u32) from_kgid(&init_user_ns, stat->gid)); 160 161 if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) { 162 *p++ = htonl(NFS_MAXPATHLEN); 163 } else { 164 *p++ = htonl((u32) stat->size); 165 } 166 *p++ = htonl((u32) stat->blksize); 167 if (S_ISCHR(type) || S_ISBLK(type)) 168 *p++ = htonl(new_encode_dev(stat->rdev)); 169 else 170 *p++ = htonl(0xffffffff); 171 *p++ = htonl((u32) stat->blocks); 172 switch (fsid_source(fhp)) { 173 default: 174 case FSIDSOURCE_DEV: 175 *p++ = htonl(new_encode_dev(stat->dev)); 176 break; 177 case FSIDSOURCE_FSID: 178 *p++ = htonl((u32) fhp->fh_export->ex_fsid); 179 break; 180 case FSIDSOURCE_UUID: 181 f = ((u32*)fhp->fh_export->ex_uuid)[0]; 182 f ^= ((u32*)fhp->fh_export->ex_uuid)[1]; 183 f ^= ((u32*)fhp->fh_export->ex_uuid)[2]; 184 f ^= ((u32*)fhp->fh_export->ex_uuid)[3]; 185 *p++ = htonl(f); 186 break; 187 } 188 *p++ = htonl((u32) stat->ino); 189 *p++ = htonl((u32) stat->atime.tv_sec); 190 *p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0); 191 lease_get_mtime(d_inode(dentry), &time); 192 *p++ = htonl((u32) time.tv_sec); 193 *p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0); 194 *p++ = htonl((u32) stat->ctime.tv_sec); 195 *p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0); 196 197 return p; 198 } 199 200 /* Helper function for NFSv2 ACL code */ 201 __be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp, struct kstat *stat) 202 { 203 return encode_fattr(rqstp, p, fhp, stat); 204 } 205 206 /* 207 * XDR decode functions 208 */ 209 int 210 nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p) 211 { 212 return xdr_argsize_check(rqstp, p); 213 } 214 215 int 216 nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p) 217 { 218 struct nfsd_fhandle *args = rqstp->rq_argp; 219 220 p = decode_fh(p, &args->fh); 221 if (!p) 222 return 0; 223 return xdr_argsize_check(rqstp, p); 224 } 225 226 int 227 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p) 228 { 229 struct nfsd_sattrargs *args = rqstp->rq_argp; 230 231 p = decode_fh(p, &args->fh); 232 if (!p) 233 return 0; 234 p = decode_sattr(p, &args->attrs); 235 236 return xdr_argsize_check(rqstp, p); 237 } 238 239 int 240 nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p) 241 { 242 struct nfsd_diropargs *args = rqstp->rq_argp; 243 244 if (!(p = decode_fh(p, &args->fh)) 245 || !(p = decode_filename(p, &args->name, &args->len))) 246 return 0; 247 248 return xdr_argsize_check(rqstp, p); 249 } 250 251 int 252 nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p) 253 { 254 struct nfsd_readargs *args = rqstp->rq_argp; 255 unsigned int len; 256 int v; 257 p = decode_fh(p, &args->fh); 258 if (!p) 259 return 0; 260 261 args->offset = ntohl(*p++); 262 len = args->count = ntohl(*p++); 263 p++; /* totalcount - unused */ 264 265 len = min_t(unsigned int, len, NFSSVC_MAXBLKSIZE_V2); 266 267 /* set up somewhere to store response. 268 * We take pages, put them on reslist and include in iovec 269 */ 270 v=0; 271 while (len > 0) { 272 struct page *p = *(rqstp->rq_next_page++); 273 274 rqstp->rq_vec[v].iov_base = page_address(p); 275 rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE); 276 len -= rqstp->rq_vec[v].iov_len; 277 v++; 278 } 279 args->vlen = v; 280 return xdr_argsize_check(rqstp, p); 281 } 282 283 int 284 nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p) 285 { 286 struct nfsd_writeargs *args = rqstp->rq_argp; 287 unsigned int len, hdr, dlen; 288 struct kvec *head = rqstp->rq_arg.head; 289 int v; 290 291 p = decode_fh(p, &args->fh); 292 if (!p) 293 return 0; 294 295 p++; /* beginoffset */ 296 args->offset = ntohl(*p++); /* offset */ 297 p++; /* totalcount */ 298 len = args->len = ntohl(*p++); 299 /* 300 * The protocol specifies a maximum of 8192 bytes. 301 */ 302 if (len > NFSSVC_MAXBLKSIZE_V2) 303 return 0; 304 305 /* 306 * Check to make sure that we got the right number of 307 * bytes. 308 */ 309 hdr = (void*)p - head->iov_base; 310 if (hdr > head->iov_len) 311 return 0; 312 dlen = head->iov_len + rqstp->rq_arg.page_len - hdr; 313 314 /* 315 * Round the length of the data which was specified up to 316 * the next multiple of XDR units and then compare that 317 * against the length which was actually received. 318 * Note that when RPCSEC/GSS (for example) is used, the 319 * data buffer can be padded so dlen might be larger 320 * than required. It must never be smaller. 321 */ 322 if (dlen < XDR_QUADLEN(len)*4) 323 return 0; 324 325 rqstp->rq_vec[0].iov_base = (void*)p; 326 rqstp->rq_vec[0].iov_len = head->iov_len - hdr; 327 v = 0; 328 while (len > rqstp->rq_vec[v].iov_len) { 329 len -= rqstp->rq_vec[v].iov_len; 330 v++; 331 rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]); 332 rqstp->rq_vec[v].iov_len = PAGE_SIZE; 333 } 334 rqstp->rq_vec[v].iov_len = len; 335 args->vlen = v + 1; 336 return 1; 337 } 338 339 int 340 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p) 341 { 342 struct nfsd_createargs *args = rqstp->rq_argp; 343 344 if ( !(p = decode_fh(p, &args->fh)) 345 || !(p = decode_filename(p, &args->name, &args->len))) 346 return 0; 347 p = decode_sattr(p, &args->attrs); 348 349 return xdr_argsize_check(rqstp, p); 350 } 351 352 int 353 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p) 354 { 355 struct nfsd_renameargs *args = rqstp->rq_argp; 356 357 if (!(p = decode_fh(p, &args->ffh)) 358 || !(p = decode_filename(p, &args->fname, &args->flen)) 359 || !(p = decode_fh(p, &args->tfh)) 360 || !(p = decode_filename(p, &args->tname, &args->tlen))) 361 return 0; 362 363 return xdr_argsize_check(rqstp, p); 364 } 365 366 int 367 nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p) 368 { 369 struct nfsd_readlinkargs *args = rqstp->rq_argp; 370 371 p = decode_fh(p, &args->fh); 372 if (!p) 373 return 0; 374 args->buffer = page_address(*(rqstp->rq_next_page++)); 375 376 return xdr_argsize_check(rqstp, p); 377 } 378 379 int 380 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p) 381 { 382 struct nfsd_linkargs *args = rqstp->rq_argp; 383 384 if (!(p = decode_fh(p, &args->ffh)) 385 || !(p = decode_fh(p, &args->tfh)) 386 || !(p = decode_filename(p, &args->tname, &args->tlen))) 387 return 0; 388 389 return xdr_argsize_check(rqstp, p); 390 } 391 392 int 393 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p) 394 { 395 struct nfsd_symlinkargs *args = rqstp->rq_argp; 396 397 if ( !(p = decode_fh(p, &args->ffh)) 398 || !(p = decode_filename(p, &args->fname, &args->flen)) 399 || !(p = decode_pathname(p, &args->tname, &args->tlen))) 400 return 0; 401 p = decode_sattr(p, &args->attrs); 402 403 return xdr_argsize_check(rqstp, p); 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