1 /* 2 * Copyright (c) 2004 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 /* 35 * nlookup() is the 'new' namei interface. Rather then return directory and 36 * leaf vnodes (in various lock states) the new interface instead deals in 37 * namecache records. Namecache records may represent both a positive or 38 * a negative hit. The namespace is locked via the namecache record instead 39 * of via the vnode, and only the leaf namecache record (representing the 40 * filename) needs to be locked. 41 * 42 * This greatly improves filesystem parallelism and is a huge simplification 43 * of the API verses the old vnode locking / namei scheme. 44 * 45 * Filesystems must actively control the caching aspects of the namecache, 46 * and since namecache pointers are used as handles they are non-optional 47 * even for filesystems which do not generally wish to cache things. It is 48 * intended that a separate cache coherency API will be constructed to handle 49 * these issues. 50 */ 51 52 #include "opt_ktrace.h" 53 54 #include <sys/param.h> 55 #include <sys/systm.h> 56 #include <sys/kernel.h> 57 #include <sys/vnode.h> 58 #include <sys/mount.h> 59 #include <sys/filedesc.h> 60 #include <sys/proc.h> 61 #include <sys/namei.h> 62 #include <sys/nlookup.h> 63 #include <sys/malloc.h> 64 #include <sys/stat.h> 65 #include <sys/objcache.h> 66 #include <sys/file.h> 67 68 #ifdef KTRACE 69 #include <sys/ktrace.h> 70 #endif 71 72 static int naccess(struct nchandle *nch, int vmode, struct ucred *cred, 73 int *stickyp); 74 75 /* 76 * Initialize a nlookup() structure, early error return for copyin faults 77 * or a degenerate empty string (which is not allowed). 78 * 79 * The first process proc0's credentials are used if the calling thread 80 * is not associated with a process context. 81 * 82 * MPSAFE 83 */ 84 int 85 nlookup_init(struct nlookupdata *nd, 86 const char *path, enum uio_seg seg, int flags) 87 { 88 size_t pathlen; 89 struct proc *p; 90 thread_t td; 91 int error; 92 93 td = curthread; 94 p = td->td_proc; 95 96 /* 97 * note: the pathlen set by copy*str() includes the terminating \0. 98 */ 99 bzero(nd, sizeof(struct nlookupdata)); 100 nd->nl_path = objcache_get(namei_oc, M_WAITOK); 101 nd->nl_flags |= NLC_HASBUF; 102 if (seg == UIO_SYSSPACE) 103 error = copystr(path, nd->nl_path, MAXPATHLEN, &pathlen); 104 else 105 error = copyinstr(path, nd->nl_path, MAXPATHLEN, &pathlen); 106 107 /* 108 * Don't allow empty pathnames. 109 * POSIX.1 requirement: "" is not a vaild file name. 110 */ 111 if (error == 0 && pathlen <= 1) 112 error = ENOENT; 113 114 if (error == 0) { 115 if (p && p->p_fd) { 116 cache_copy(&p->p_fd->fd_ncdir, &nd->nl_nch); 117 cache_copy(&p->p_fd->fd_nrdir, &nd->nl_rootnch); 118 if (p->p_fd->fd_njdir.ncp) 119 cache_copy(&p->p_fd->fd_njdir, &nd->nl_jailnch); 120 nd->nl_cred = crhold(p->p_ucred); 121 } else { 122 cache_copy(&rootnch, &nd->nl_nch); 123 cache_copy(&nd->nl_nch, &nd->nl_rootnch); 124 cache_copy(&nd->nl_nch, &nd->nl_jailnch); 125 nd->nl_cred = crhold(proc0.p_ucred); 126 } 127 nd->nl_td = td; 128 nd->nl_flags |= flags; 129 } else { 130 nlookup_done(nd); 131 } 132 return(error); 133 } 134 135 136 /* 137 * nlookup_init() for "at" family of syscalls. 138 * 139 * Works similarly to nlookup_init() but if path is relative and fd is not 140 * AT_FDCWD, path is interpreted relative to the directory pointed to by fd. 141 * In this case, the file entry pointed to by fd is ref'ed and returned in 142 * *fpp. 143 * 144 * If the call succeeds, nlookup_done_at() must be called to clean-up the nd 145 * and release the ref to the file entry. 146 */ 147 int 148 nlookup_init_at(struct nlookupdata *nd, struct file **fpp, int fd, 149 const char *path, enum uio_seg seg, int flags) 150 { 151 struct thread *td = curthread; 152 struct proc *p = td->td_proc; 153 struct file* fp; 154 struct vnode *vp; 155 int error; 156 157 *fpp = NULL; 158 159 if ((error = nlookup_init(nd, path, seg, flags)) != 0) { 160 return (error); 161 } 162 163 if (nd->nl_path[0] != '/' && fd != AT_FDCWD) { 164 if ((error = holdvnode(p->p_fd, fd, &fp)) != 0) 165 goto done; 166 vp = (struct vnode*)fp->f_data; 167 if (vp->v_type != VDIR || fp->f_nchandle.ncp == NULL) { 168 fdrop(fp); 169 fp = NULL; 170 error = ENOTDIR; 171 goto done; 172 } 173 cache_drop(&nd->nl_nch); 174 cache_copy(&fp->f_nchandle, &nd->nl_nch); 175 *fpp = fp; 176 } 177 178 179 done: 180 if (error) 181 nlookup_done(nd); 182 return (error); 183 184 } 185 186 /* 187 * This works similarly to nlookup_init() but does not assume a process 188 * context. rootnch is always chosen for the root directory and the cred 189 * and starting directory are supplied in arguments. 190 */ 191 int 192 nlookup_init_raw(struct nlookupdata *nd, 193 const char *path, enum uio_seg seg, int flags, 194 struct ucred *cred, struct nchandle *ncstart) 195 { 196 size_t pathlen; 197 thread_t td; 198 int error; 199 200 td = curthread; 201 202 bzero(nd, sizeof(struct nlookupdata)); 203 nd->nl_path = objcache_get(namei_oc, M_WAITOK); 204 nd->nl_flags |= NLC_HASBUF; 205 if (seg == UIO_SYSSPACE) 206 error = copystr(path, nd->nl_path, MAXPATHLEN, &pathlen); 207 else 208 error = copyinstr(path, nd->nl_path, MAXPATHLEN, &pathlen); 209 210 /* 211 * Don't allow empty pathnames. 212 * POSIX.1 requirement: "" is not a vaild file name. 213 */ 214 if (error == 0 && pathlen <= 1) 215 error = ENOENT; 216 217 if (error == 0) { 218 cache_copy(ncstart, &nd->nl_nch); 219 cache_copy(&rootnch, &nd->nl_rootnch); 220 cache_copy(&rootnch, &nd->nl_jailnch); 221 nd->nl_cred = crhold(cred); 222 nd->nl_td = td; 223 nd->nl_flags |= flags; 224 } else { 225 nlookup_done(nd); 226 } 227 return(error); 228 } 229 230 /* 231 * This works similarly to nlookup_init_raw() but does not rely 232 * on rootnch being initialized yet. 233 */ 234 int 235 nlookup_init_root(struct nlookupdata *nd, 236 const char *path, enum uio_seg seg, int flags, 237 struct ucred *cred, struct nchandle *ncstart, 238 struct nchandle *ncroot) 239 { 240 size_t pathlen; 241 thread_t td; 242 int error; 243 244 td = curthread; 245 246 bzero(nd, sizeof(struct nlookupdata)); 247 nd->nl_path = objcache_get(namei_oc, M_WAITOK); 248 nd->nl_flags |= NLC_HASBUF; 249 if (seg == UIO_SYSSPACE) 250 error = copystr(path, nd->nl_path, MAXPATHLEN, &pathlen); 251 else 252 error = copyinstr(path, nd->nl_path, MAXPATHLEN, &pathlen); 253 254 /* 255 * Don't allow empty pathnames. 256 * POSIX.1 requirement: "" is not a vaild file name. 257 */ 258 if (error == 0 && pathlen <= 1) 259 error = ENOENT; 260 261 if (error == 0) { 262 cache_copy(ncstart, &nd->nl_nch); 263 cache_copy(ncroot, &nd->nl_rootnch); 264 cache_copy(ncroot, &nd->nl_jailnch); 265 nd->nl_cred = crhold(cred); 266 nd->nl_td = td; 267 nd->nl_flags |= flags; 268 } else { 269 nlookup_done(nd); 270 } 271 return(error); 272 } 273 274 /* 275 * Set a different credential; this credential will be used by future 276 * operations performed on nd.nl_open_vp and nlookupdata structure. 277 */ 278 void 279 nlookup_set_cred(struct nlookupdata *nd, struct ucred *cred) 280 { 281 KKASSERT(nd->nl_cred != NULL); 282 283 if (nd->nl_cred != cred) { 284 cred = crhold(cred); 285 crfree(nd->nl_cred); 286 nd->nl_cred = cred; 287 } 288 } 289 290 /* 291 * Cleanup a nlookupdata structure after we are through with it. This may 292 * be called on any nlookupdata structure initialized with nlookup_init(). 293 * Calling nlookup_done() is mandatory in all cases except where nlookup_init() 294 * returns an error, even if as a consumer you believe you have taken all 295 * dynamic elements out of the nlookupdata structure. 296 */ 297 void 298 nlookup_done(struct nlookupdata *nd) 299 { 300 if (nd->nl_nch.ncp) { 301 if (nd->nl_flags & NLC_NCPISLOCKED) { 302 nd->nl_flags &= ~NLC_NCPISLOCKED; 303 cache_unlock(&nd->nl_nch); 304 } 305 cache_drop(&nd->nl_nch); /* NULL's out the nch */ 306 } 307 if (nd->nl_rootnch.ncp) 308 cache_drop(&nd->nl_rootnch); 309 if (nd->nl_jailnch.ncp) 310 cache_drop(&nd->nl_jailnch); 311 if ((nd->nl_flags & NLC_HASBUF) && nd->nl_path) { 312 objcache_put(namei_oc, nd->nl_path); 313 nd->nl_path = NULL; 314 } 315 if (nd->nl_cred) { 316 crfree(nd->nl_cred); 317 nd->nl_cred = NULL; 318 } 319 if (nd->nl_open_vp) { 320 if (nd->nl_flags & NLC_LOCKVP) { 321 vn_unlock(nd->nl_open_vp); 322 nd->nl_flags &= ~NLC_LOCKVP; 323 } 324 vn_close(nd->nl_open_vp, nd->nl_vp_fmode, NULL); 325 nd->nl_open_vp = NULL; 326 } 327 if (nd->nl_dvp) { 328 vrele(nd->nl_dvp); 329 nd->nl_dvp = NULL; 330 } 331 nd->nl_flags = 0; /* clear remaining flags (just clear everything) */ 332 } 333 334 /* 335 * Works similarly to nlookup_done() when nd initialized with 336 * nlookup_init_at(). 337 */ 338 void 339 nlookup_done_at(struct nlookupdata *nd, struct file *fp) 340 { 341 nlookup_done(nd); 342 if (fp != NULL) 343 fdrop(fp); 344 } 345 346 void 347 nlookup_zero(struct nlookupdata *nd) 348 { 349 bzero(nd, sizeof(struct nlookupdata)); 350 } 351 352 /* 353 * Simple all-in-one nlookup. Returns a locked namecache structure or NULL 354 * if an error occured. 355 * 356 * Note that the returned ncp is not checked for permissions, though VEXEC 357 * is checked on the directory path leading up to the result. The caller 358 * must call naccess() to check the permissions of the returned leaf. 359 */ 360 struct nchandle 361 nlookup_simple(const char *str, enum uio_seg seg, 362 int niflags, int *error) 363 { 364 struct nlookupdata nd; 365 struct nchandle nch; 366 367 *error = nlookup_init(&nd, str, seg, niflags); 368 if (*error == 0) { 369 if ((*error = nlookup(&nd)) == 0) { 370 nch = nd.nl_nch; /* keep hold ref from structure */ 371 cache_zero(&nd.nl_nch); /* and NULL out */ 372 } else { 373 cache_zero(&nch); 374 } 375 nlookup_done(&nd); 376 } else { 377 cache_zero(&nch); 378 } 379 return(nch); 380 } 381 382 /* 383 * Returns non-zero if the path element is the last element 384 */ 385 static 386 int 387 islastelement(const char *ptr) 388 { 389 while (*ptr == '/') 390 ++ptr; 391 return (*ptr == 0); 392 } 393 394 /* 395 * Returns non-zero if we need to lock the namecache element 396 * exclusively. Unless otherwise requested by NLC_SHAREDLOCK, 397 * the last element of the namecache lookup will be locked 398 * exclusively. 399 * 400 * NOTE: Even if we return on-zero, an unresolved namecache record 401 * will always be locked exclusively. 402 */ 403 static __inline 404 int 405 wantsexcllock(struct nlookupdata *nd, const char *ptr) 406 { 407 if ((nd->nl_flags & NLC_SHAREDLOCK) == 0) 408 return(islastelement(ptr)); 409 return(0); 410 } 411 412 413 /* 414 * Do a generic nlookup. Note that the passed nd is not nlookup_done()'d 415 * on return, even if an error occurs. If no error occurs or NLC_CREATE 416 * is flagged and ENOENT is returned, then the returned nl_nch is always 417 * referenced and locked exclusively. 418 * 419 * WARNING: For any general error other than ENOENT w/NLC_CREATE, the 420 * the resulting nl_nch may or may not be locked and if locked 421 * might be locked either shared or exclusive. 422 * 423 * Intermediate directory elements, including the current directory, require 424 * execute (search) permission. nlookup does not examine the access 425 * permissions on the returned element. 426 * 427 * If NLC_CREATE is set the last directory must allow node creation, 428 * and an error code of 0 will be returned for a non-existant 429 * target (not ENOENT). 430 * 431 * If NLC_RENAME_DST is set the last directory mut allow node deletion, 432 * plus the sticky check is made, and an error code of 0 will be returned 433 * for a non-existant target (not ENOENT). 434 * 435 * If NLC_DELETE is set the last directory mut allow node deletion, 436 * plus the sticky check is made. 437 * 438 * If NLC_REFDVP is set nd->nl_dvp will be set to the directory vnode 439 * of the returned entry. The vnode will be referenced, but not locked, 440 * and will be released by nlookup_done() along with everything else. 441 * 442 * NOTE: As an optimization we attempt to obtain a shared namecache lock 443 * on any intermediate elements. On success, the returned element 444 * is ALWAYS locked exclusively. 445 */ 446 int 447 nlookup(struct nlookupdata *nd) 448 { 449 globaldata_t gd = mycpu; 450 struct nlcomponent nlc; 451 struct nchandle nch; 452 struct nchandle par; 453 struct nchandle nctmp; 454 struct mount *mp; 455 struct vnode *hvp; /* hold to prevent recyclement */ 456 int wasdotordotdot; 457 char *ptr; 458 int error; 459 int len; 460 int dflags; 461 int hit = 1; 462 463 #ifdef KTRACE 464 if (KTRPOINT(nd->nl_td, KTR_NAMEI)) 465 ktrnamei(nd->nl_td->td_lwp, nd->nl_path); 466 #endif 467 bzero(&nlc, sizeof(nlc)); 468 469 /* 470 * Setup for the loop. The current working namecache element is 471 * always at least referenced. We lock it as required, but always 472 * return a locked, resolved namecache entry. 473 */ 474 nd->nl_loopcnt = 0; 475 if (nd->nl_dvp) { 476 vrele(nd->nl_dvp); 477 nd->nl_dvp = NULL; 478 } 479 ptr = nd->nl_path; 480 481 /* 482 * Loop on the path components. At the top of the loop nd->nl_nch 483 * is ref'd and unlocked and represents our current position. 484 */ 485 for (;;) { 486 /* 487 * Make sure nl_nch is locked so we can access the vnode, resolution 488 * state, etc. 489 */ 490 if ((nd->nl_flags & NLC_NCPISLOCKED) == 0) { 491 nd->nl_flags |= NLC_NCPISLOCKED; 492 cache_lock_maybe_shared(&nd->nl_nch, wantsexcllock(nd, ptr)); 493 } 494 495 /* 496 * Check if the root directory should replace the current 497 * directory. This is done at the start of a translation 498 * or after a symbolic link has been found. In other cases 499 * ptr will never be pointing at a '/'. 500 */ 501 if (*ptr == '/') { 502 do { 503 ++ptr; 504 } while (*ptr == '/'); 505 cache_unlock(&nd->nl_nch); 506 cache_get_maybe_shared(&nd->nl_rootnch, &nch, 507 wantsexcllock(nd, ptr)); 508 cache_drop(&nd->nl_nch); 509 nd->nl_nch = nch; /* remains locked */ 510 511 /* 512 * Fast-track termination. There is no parent directory of 513 * the root in the same mount from the point of view of 514 * the caller so return EACCES if NLC_REFDVP is specified, 515 * and EEXIST if NLC_CREATE is also specified. 516 * e.g. 'rmdir /' or 'mkdir /' are not allowed. 517 */ 518 if (*ptr == 0) { 519 if (nd->nl_flags & NLC_REFDVP) 520 error = (nd->nl_flags & NLC_CREATE) ? EEXIST : EACCES; 521 else 522 error = 0; 523 break; 524 } 525 continue; 526 } 527 528 /* 529 * Check directory search permissions (nd->nl_nch is locked & refd) 530 */ 531 dflags = 0; 532 error = naccess(&nd->nl_nch, NLC_EXEC, nd->nl_cred, &dflags); 533 if (error) 534 break; 535 536 /* 537 * Extract the path component. Path components are limited to 538 * 255 characters. 539 */ 540 nlc.nlc_nameptr = ptr; 541 while (*ptr && *ptr != '/') 542 ++ptr; 543 nlc.nlc_namelen = ptr - nlc.nlc_nameptr; 544 if (nlc.nlc_namelen >= 256) { 545 error = ENAMETOOLONG; 546 break; 547 } 548 549 /* 550 * Lookup the path component in the cache, creating an unresolved 551 * entry if necessary. We have to handle "." and ".." as special 552 * cases. 553 * 554 * When handling ".." we have to detect a traversal back through a 555 * mount point. If we are at the root, ".." just returns the root. 556 * 557 * When handling "." or ".." we also have to recalculate dflags 558 * since our dflags will be for some sub-directory instead of the 559 * parent dir. 560 * 561 * This subsection returns a locked, refd 'nch' unless it errors out, 562 * and an unlocked but still ref'd nd->nl_nch. 563 * 564 * The namecache topology is not allowed to be disconnected, so 565 * encountering a NULL parent will generate EINVAL. This typically 566 * occurs when a directory is removed out from under a process. 567 * 568 * WARNING! The unlocking of nd->nl_nch is sensitive code. 569 */ 570 KKASSERT(nd->nl_flags & NLC_NCPISLOCKED); 571 572 if (nlc.nlc_namelen == 1 && nlc.nlc_nameptr[0] == '.') { 573 cache_unlock(&nd->nl_nch); 574 nd->nl_flags &= ~NLC_NCPISLOCKED; 575 cache_get_maybe_shared(&nd->nl_nch, &nch, wantsexcllock(nd, ptr)); 576 wasdotordotdot = 1; 577 } else if (nlc.nlc_namelen == 2 && 578 nlc.nlc_nameptr[0] == '.' && nlc.nlc_nameptr[1] == '.') { 579 if (nd->nl_nch.mount == nd->nl_rootnch.mount && 580 nd->nl_nch.ncp == nd->nl_rootnch.ncp 581 ) { 582 /* 583 * ".." at the root returns the root 584 */ 585 cache_unlock(&nd->nl_nch); 586 nd->nl_flags &= ~NLC_NCPISLOCKED; 587 cache_get_maybe_shared(&nd->nl_nch, &nch, 588 wantsexcllock(nd, ptr)); 589 } else { 590 /* 591 * Locate the parent ncp. If we are at the root of a 592 * filesystem mount we have to skip to the mounted-on 593 * point in the underlying filesystem. 594 * 595 * Expect the parent to always be good since the 596 * mountpoint doesn't go away. XXX hack. cache_get() 597 * requires the ncp to already have a ref as a safety. 598 */ 599 nctmp = nd->nl_nch; 600 while (nctmp.ncp == nctmp.mount->mnt_ncmountpt.ncp) 601 nctmp = nctmp.mount->mnt_ncmounton; 602 nctmp.ncp = nctmp.ncp->nc_parent; 603 KKASSERT(nctmp.ncp != NULL); 604 cache_hold(&nctmp); 605 cache_unlock(&nd->nl_nch); 606 nd->nl_flags &= ~NLC_NCPISLOCKED; 607 cache_get_maybe_shared(&nctmp, &nch, wantsexcllock(nd, ptr)); 608 cache_drop(&nctmp); /* NOTE: zero's nctmp */ 609 } 610 wasdotordotdot = 2; 611 } else { 612 /* 613 * Must unlock nl_nch when traversing down the path. However, 614 * the child ncp has not yet been found/created and the parent's 615 * child list might be empty. Thus releasing the lock can 616 * allow a race whereby the parent ncp's vnode is recycled. 617 * This case can occur especially when maxvnodes is set very low. 618 * 619 * We need the parent's ncp to remain resolved for all normal 620 * filesystem activities, so we vhold() the vp during the lookup 621 * to prevent recyclement due to vnlru / maxvnodes. 622 * 623 * If we race an unlink or rename the ncp might be marked 624 * DESTROYED after resolution, requiring a retry. 625 */ 626 if ((hvp = nd->nl_nch.ncp->nc_vp) != NULL) 627 vhold(hvp); 628 cache_unlock(&nd->nl_nch); 629 nd->nl_flags &= ~NLC_NCPISLOCKED; 630 error = cache_nlookup_maybe_shared(&nd->nl_nch, &nlc, 631 wantsexcllock(nd, ptr), &nch); 632 if (error == EWOULDBLOCK) { 633 nch = cache_nlookup(&nd->nl_nch, &nlc); 634 if (nch.ncp->nc_flag & NCF_UNRESOLVED) 635 hit = 0; 636 for (;;) { 637 error = cache_resolve(&nch, nd->nl_cred); 638 if (error != EAGAIN && 639 (nch.ncp->nc_flag & NCF_DESTROYED) == 0) { 640 break; 641 } 642 kprintf("[diagnostic] nlookup: relookup %*.*s\n", 643 nch.ncp->nc_nlen, nch.ncp->nc_nlen, 644 nch.ncp->nc_name); 645 cache_put(&nch); 646 nch = cache_nlookup(&nd->nl_nch, &nlc); 647 } 648 } 649 if (hvp) 650 vdrop(hvp); 651 wasdotordotdot = 0; 652 } 653 654 /* 655 * If the last component was "." or ".." our dflags no longer 656 * represents the parent directory and we have to explicitly 657 * look it up. 658 * 659 * Expect the parent to be good since nch is locked. 660 */ 661 if (wasdotordotdot && error == 0) { 662 dflags = 0; 663 if ((par.ncp = nch.ncp->nc_parent) != NULL) { 664 par.mount = nch.mount; 665 cache_hold(&par); 666 cache_lock_maybe_shared(&par, wantsexcllock(nd, ptr)); 667 error = naccess(&par, 0, nd->nl_cred, &dflags); 668 cache_put(&par); 669 } 670 } 671 672 /* 673 * [end of subsection] 674 * 675 * nch is locked and referenced. 676 * nd->nl_nch is unlocked and referenced. 677 * 678 * nl_nch must be unlocked or we could chain lock to the root 679 * if a resolve gets stuck (e.g. in NFS). 680 */ 681 KKASSERT((nd->nl_flags & NLC_NCPISLOCKED) == 0); 682 683 /* 684 * Resolve the namespace if necessary. The ncp returned by 685 * cache_nlookup() is referenced and locked. 686 * 687 * XXX neither '.' nor '..' should return EAGAIN since they were 688 * previously resolved and thus cannot be newly created ncp's. 689 */ 690 if (nch.ncp->nc_flag & NCF_UNRESOLVED) { 691 hit = 0; 692 error = cache_resolve(&nch, nd->nl_cred); 693 KKASSERT(error != EAGAIN); 694 } else { 695 error = nch.ncp->nc_error; 696 } 697 698 /* 699 * Early completion. ENOENT is not an error if this is the last 700 * component and NLC_CREATE or NLC_RENAME (rename target) was 701 * requested. Note that ncp->nc_error is left as ENOENT in that 702 * case, which we check later on. 703 * 704 * Also handle invalid '.' or '..' components terminating a path 705 * for a create/rename/delete. The standard requires this and pax 706 * pretty stupidly depends on it. 707 */ 708 if (islastelement(ptr)) { 709 if (error == ENOENT && 710 (nd->nl_flags & (NLC_CREATE | NLC_RENAME_DST)) 711 ) { 712 if (nd->nl_flags & NLC_NFS_RDONLY) { 713 error = EROFS; 714 } else { 715 error = naccess(&nch, nd->nl_flags | dflags, 716 nd->nl_cred, NULL); 717 } 718 } 719 if (error == 0 && wasdotordotdot && 720 (nd->nl_flags & (NLC_CREATE | NLC_DELETE | 721 NLC_RENAME_SRC | NLC_RENAME_DST))) { 722 /* 723 * POSIX junk 724 */ 725 if (nd->nl_flags & NLC_CREATE) 726 error = EEXIST; 727 else if (nd->nl_flags & NLC_DELETE) 728 error = (wasdotordotdot == 1) ? EINVAL : ENOTEMPTY; 729 else 730 error = EINVAL; 731 } 732 } 733 734 /* 735 * Early completion on error. 736 */ 737 if (error) { 738 cache_put(&nch); 739 break; 740 } 741 742 /* 743 * If the element is a symlink and it is either not the last 744 * element or it is the last element and we are allowed to 745 * follow symlinks, resolve the symlink. 746 */ 747 if ((nch.ncp->nc_flag & NCF_ISSYMLINK) && 748 (*ptr || (nd->nl_flags & NLC_FOLLOW)) 749 ) { 750 if (nd->nl_loopcnt++ >= MAXSYMLINKS) { 751 error = ELOOP; 752 cache_put(&nch); 753 break; 754 } 755 error = nreadsymlink(nd, &nch, &nlc); 756 cache_put(&nch); 757 if (error) 758 break; 759 760 /* 761 * Concatenate trailing path elements onto the returned symlink. 762 * Note that if the path component (ptr) is not exhausted, it 763 * will being with a '/', so we do not have to add another one. 764 * 765 * The symlink may not be empty. 766 */ 767 len = strlen(ptr); 768 if (nlc.nlc_namelen == 0 || nlc.nlc_namelen + len >= MAXPATHLEN) { 769 error = nlc.nlc_namelen ? ENAMETOOLONG : ENOENT; 770 objcache_put(namei_oc, nlc.nlc_nameptr); 771 break; 772 } 773 bcopy(ptr, nlc.nlc_nameptr + nlc.nlc_namelen, len + 1); 774 if (nd->nl_flags & NLC_HASBUF) 775 objcache_put(namei_oc, nd->nl_path); 776 nd->nl_path = nlc.nlc_nameptr; 777 nd->nl_flags |= NLC_HASBUF; 778 ptr = nd->nl_path; 779 780 /* 781 * Go back up to the top to resolve any initial '/'s in the 782 * symlink. 783 */ 784 continue; 785 } 786 787 /* 788 * If the element is a directory and we are crossing a mount point, 789 * Locate the mount. 790 */ 791 while ((nch.ncp->nc_flag & NCF_ISMOUNTPT) && 792 (nd->nl_flags & NLC_NOCROSSMOUNT) == 0 && 793 (mp = cache_findmount(&nch)) != NULL 794 ) { 795 struct vnode *tdp; 796 int vfs_do_busy = 0; 797 798 /* 799 * VFS must be busied before the namecache entry is locked, 800 * but we don't want to waste time calling vfs_busy() if the 801 * mount point is already resolved. 802 */ 803 again: 804 cache_put(&nch); 805 if (vfs_do_busy) { 806 while (vfs_busy(mp, 0)) { 807 if (mp->mnt_kern_flag & MNTK_UNMOUNT) { 808 kprintf("nlookup: warning umount race avoided\n"); 809 cache_dropmount(mp); 810 error = EBUSY; 811 vfs_do_busy = 0; 812 goto double_break; 813 } 814 } 815 } 816 cache_get_maybe_shared(&mp->mnt_ncmountpt, &nch, 817 wantsexcllock(nd, ptr)); 818 819 if (nch.ncp->nc_flag & NCF_UNRESOLVED) { 820 if (vfs_do_busy == 0) { 821 vfs_do_busy = 1; 822 goto again; 823 } 824 error = VFS_ROOT(mp, &tdp); 825 vfs_unbusy(mp); 826 vfs_do_busy = 0; 827 if (error) { 828 cache_dropmount(mp); 829 break; 830 } 831 cache_setvp(&nch, tdp); 832 vput(tdp); 833 } 834 if (vfs_do_busy) 835 vfs_unbusy(mp); 836 cache_dropmount(mp); 837 } 838 839 if (error) { 840 cache_put(&nch); 841 double_break: 842 break; 843 } 844 845 /* 846 * Skip any slashes to get to the next element. If there 847 * are any slashes at all the current element must be a 848 * directory or, in the create case, intended to become a directory. 849 * If it isn't we break without incrementing ptr and fall through 850 * to the failure case below. 851 */ 852 while (*ptr == '/') { 853 if ((nch.ncp->nc_flag & NCF_ISDIR) == 0 && 854 !(nd->nl_flags & NLC_WILLBEDIR) 855 ) { 856 break; 857 } 858 ++ptr; 859 } 860 861 /* 862 * Continuation case: additional elements and the current 863 * element is a directory. 864 */ 865 if (*ptr && (nch.ncp->nc_flag & NCF_ISDIR)) { 866 cache_drop(&nd->nl_nch); 867 cache_unlock(&nch); 868 KKASSERT((nd->nl_flags & NLC_NCPISLOCKED) == 0); 869 nd->nl_nch = nch; 870 continue; 871 } 872 873 /* 874 * Failure case: additional elements and the current element 875 * is not a directory 876 */ 877 if (*ptr) { 878 cache_put(&nch); 879 error = ENOTDIR; 880 break; 881 } 882 883 /* 884 * Successful lookup of last element. 885 * 886 * Check permissions if the target exists. If the target does not 887 * exist directory permissions were already tested in the early 888 * completion code above. 889 * 890 * nd->nl_flags will be adjusted on return with NLC_APPENDONLY 891 * if the file is marked append-only, and NLC_STICKY if the directory 892 * containing the file is sticky. 893 */ 894 if (nch.ncp->nc_vp && (nd->nl_flags & NLC_ALLCHKS)) { 895 error = naccess(&nch, nd->nl_flags | dflags, 896 nd->nl_cred, NULL); 897 if (error) { 898 cache_put(&nch); 899 break; 900 } 901 } 902 903 /* 904 * Termination: no more elements. 905 * 906 * If NLC_REFDVP is set acquire a referenced parent dvp. 907 */ 908 if (nd->nl_flags & NLC_REFDVP) { 909 cache_lock(&nd->nl_nch); 910 error = cache_vref(&nd->nl_nch, nd->nl_cred, &nd->nl_dvp); 911 cache_unlock(&nd->nl_nch); 912 if (error) { 913 kprintf("NLC_REFDVP: Cannot ref dvp of %p\n", nch.ncp); 914 cache_put(&nch); 915 break; 916 } 917 } 918 cache_drop(&nd->nl_nch); 919 nd->nl_nch = nch; 920 nd->nl_flags |= NLC_NCPISLOCKED; 921 error = 0; 922 break; 923 } 924 925 if (hit) 926 ++gd->gd_nchstats->ncs_longhits; 927 else 928 ++gd->gd_nchstats->ncs_longmiss; 929 930 if (nd->nl_flags & NLC_NCPISLOCKED) 931 KKASSERT(cache_lockstatus(&nd->nl_nch) > 0); 932 933 /* 934 * NOTE: If NLC_CREATE was set the ncp may represent a negative hit 935 * (ncp->nc_error will be ENOENT), but we will still return an error 936 * code of 0. 937 */ 938 return(error); 939 } 940 941 /* 942 * Resolve a mount point's glue ncp. This ncp connects creates the illusion 943 * of continuity in the namecache tree by connecting the ncp related to the 944 * vnode under the mount to the ncp related to the mount's root vnode. 945 * 946 * If no error occured a locked, ref'd ncp is stored in *ncpp. 947 */ 948 int 949 nlookup_mp(struct mount *mp, struct nchandle *nch) 950 { 951 struct vnode *vp; 952 int error; 953 954 error = 0; 955 cache_get(&mp->mnt_ncmountpt, nch); 956 if (nch->ncp->nc_flag & NCF_UNRESOLVED) { 957 while (vfs_busy(mp, 0)) 958 ; 959 error = VFS_ROOT(mp, &vp); 960 vfs_unbusy(mp); 961 if (error) { 962 cache_put(nch); 963 } else { 964 cache_setvp(nch, vp); 965 vput(vp); 966 } 967 } 968 return(error); 969 } 970 971 /* 972 * Read the contents of a symlink, allocate a path buffer out of the 973 * namei_oc and initialize the supplied nlcomponent with the result. 974 * 975 * If an error occurs no buffer will be allocated or returned in the nlc. 976 */ 977 int 978 nreadsymlink(struct nlookupdata *nd, struct nchandle *nch, 979 struct nlcomponent *nlc) 980 { 981 struct vnode *vp; 982 struct iovec aiov; 983 struct uio auio; 984 int linklen; 985 int error; 986 char *cp; 987 988 nlc->nlc_nameptr = NULL; 989 nlc->nlc_namelen = 0; 990 if (nch->ncp->nc_vp == NULL) 991 return(ENOENT); 992 if ((error = cache_vget(nch, nd->nl_cred, LK_SHARED, &vp)) != 0) 993 return(error); 994 cp = objcache_get(namei_oc, M_WAITOK); 995 aiov.iov_base = cp; 996 aiov.iov_len = MAXPATHLEN; 997 auio.uio_iov = &aiov; 998 auio.uio_iovcnt = 1; 999 auio.uio_offset = 0; 1000 auio.uio_rw = UIO_READ; 1001 auio.uio_segflg = UIO_SYSSPACE; 1002 auio.uio_td = nd->nl_td; 1003 auio.uio_resid = MAXPATHLEN - 1; 1004 error = VOP_READLINK(vp, &auio, nd->nl_cred); 1005 if (error) 1006 goto fail; 1007 linklen = MAXPATHLEN - 1 - auio.uio_resid; 1008 if (varsym_enable) { 1009 linklen = varsymreplace(cp, linklen, MAXPATHLEN - 1); 1010 if (linklen < 0) { 1011 error = ENAMETOOLONG; 1012 goto fail; 1013 } 1014 } 1015 cp[linklen] = 0; 1016 nlc->nlc_nameptr = cp; 1017 nlc->nlc_namelen = linklen; 1018 vput(vp); 1019 return(0); 1020 fail: 1021 objcache_put(namei_oc, cp); 1022 vput(vp); 1023 return(error); 1024 } 1025 1026 /* 1027 * Check access [XXX cache vattr!] [XXX quota] 1028 * 1029 * Generally check the NLC_* access bits. All specified bits must pass 1030 * for this function to return 0. 1031 * 1032 * The file does not have to exist when checking NLC_CREATE or NLC_RENAME_DST 1033 * access, otherwise it must exist. No error is returned in this case. 1034 * 1035 * The file must not exist if NLC_EXCL is specified. 1036 * 1037 * Directory permissions in general are tested for NLC_CREATE if the file 1038 * does not exist, NLC_DELETE if the file does exist, and NLC_RENAME_DST 1039 * whether the file exists or not. 1040 * 1041 * The directory sticky bit is tested for NLC_DELETE and NLC_RENAME_DST, 1042 * the latter is only tested if the target exists. 1043 * 1044 * The passed ncp must be referenced and locked. If it is already resolved 1045 * it may be locked shared but otherwise should be locked exclusively. 1046 */ 1047 static int 1048 naccess(struct nchandle *nch, int nflags, struct ucred *cred, int *nflagsp) 1049 { 1050 struct vnode *vp; 1051 struct vattr va; 1052 struct namecache *ncp; 1053 int error; 1054 int cflags; 1055 1056 KKASSERT(cache_lockstatus(nch) > 0); 1057 1058 ncp = nch->ncp; 1059 if (ncp->nc_flag & NCF_UNRESOLVED) { 1060 cache_resolve(nch, cred); 1061 ncp = nch->ncp; 1062 } 1063 error = ncp->nc_error; 1064 1065 /* 1066 * Directory permissions checks. Silently ignore ENOENT if these 1067 * tests pass. It isn't an error. 1068 * 1069 * We can safely resolve ncp->nc_parent because ncp is currently 1070 * locked. 1071 */ 1072 if (nflags & (NLC_CREATE | NLC_DELETE | NLC_RENAME_SRC | NLC_RENAME_DST)) { 1073 if (((nflags & NLC_CREATE) && ncp->nc_vp == NULL) || 1074 ((nflags & NLC_DELETE) && ncp->nc_vp != NULL) || 1075 ((nflags & NLC_RENAME_SRC) && ncp->nc_vp != NULL) || 1076 (nflags & NLC_RENAME_DST) 1077 ) { 1078 struct nchandle par; 1079 1080 if ((par.ncp = ncp->nc_parent) == NULL) { 1081 if (error != EAGAIN) 1082 error = EINVAL; 1083 } else if (error == 0 || error == ENOENT) { 1084 par.mount = nch->mount; 1085 cache_hold(&par); 1086 cache_lock_maybe_shared(&par, 0); 1087 error = naccess(&par, NLC_WRITE, cred, NULL); 1088 cache_put(&par); 1089 } 1090 } 1091 } 1092 1093 /* 1094 * NLC_EXCL check. Target file must not exist. 1095 */ 1096 if (error == 0 && (nflags & NLC_EXCL) && ncp->nc_vp != NULL) 1097 error = EEXIST; 1098 1099 /* 1100 * Get the vnode attributes so we can do the rest of our checks. 1101 * 1102 * NOTE: We only call naccess_va() if the target exists. 1103 */ 1104 if (error == 0) { 1105 error = cache_vget(nch, cred, LK_SHARED, &vp); 1106 if (error == ENOENT) { 1107 /* 1108 * Silently zero-out ENOENT if creating or renaming 1109 * (rename target). It isn't an error. 1110 */ 1111 if (nflags & (NLC_CREATE | NLC_RENAME_DST)) 1112 error = 0; 1113 } else if (error == 0) { 1114 /* 1115 * Get the vnode attributes and check for illegal O_TRUNC 1116 * requests and read-only mounts. 1117 * 1118 * NOTE: You can still open devices on read-only mounts for 1119 * writing. 1120 * 1121 * NOTE: creates/deletes/renames are handled by the NLC_WRITE 1122 * check on the parent directory above. 1123 * 1124 * XXX cache the va in the namecache or in the vnode 1125 */ 1126 error = VOP_GETATTR(vp, &va); 1127 if (error == 0 && (nflags & NLC_TRUNCATE)) { 1128 switch(va.va_type) { 1129 case VREG: 1130 case VDATABASE: 1131 case VCHR: 1132 case VBLK: 1133 case VFIFO: 1134 break; 1135 case VDIR: 1136 error = EISDIR; 1137 break; 1138 default: 1139 error = EINVAL; 1140 break; 1141 } 1142 } 1143 if (error == 0 && (nflags & NLC_WRITE) && vp->v_mount && 1144 (vp->v_mount->mnt_flag & MNT_RDONLY) 1145 ) { 1146 switch(va.va_type) { 1147 case VDIR: 1148 case VLNK: 1149 case VREG: 1150 case VDATABASE: 1151 error = EROFS; 1152 break; 1153 default: 1154 break; 1155 } 1156 } 1157 vput(vp); 1158 1159 /* 1160 * Check permissions based on file attributes. The passed 1161 * flags (*nflagsp) are modified with feedback based on 1162 * special attributes and requirements. 1163 */ 1164 if (error == 0) { 1165 /* 1166 * Adjust the returned (*nflagsp) if non-NULL. 1167 */ 1168 if (nflagsp) { 1169 if ((va.va_mode & VSVTX) && va.va_uid != cred->cr_uid) 1170 *nflagsp |= NLC_STICKY; 1171 if (va.va_flags & APPEND) 1172 *nflagsp |= NLC_APPENDONLY; 1173 if (va.va_flags & IMMUTABLE) 1174 *nflagsp |= NLC_IMMUTABLE; 1175 } 1176 1177 /* 1178 * Track swapcache management flags in the namecache. 1179 * 1180 * Calculate the flags based on the current vattr info 1181 * and recalculate the inherited flags from the parent 1182 * (the original cache linkage may have occurred without 1183 * getattrs and thus have stale flags). 1184 */ 1185 cflags = 0; 1186 if (va.va_flags & SF_NOCACHE) 1187 cflags |= NCF_SF_NOCACHE; 1188 if (va.va_flags & UF_CACHE) 1189 cflags |= NCF_UF_CACHE; 1190 if (ncp->nc_parent) { 1191 if (ncp->nc_parent->nc_flag & 1192 (NCF_SF_NOCACHE | NCF_SF_PNOCACHE)) { 1193 cflags |= NCF_SF_PNOCACHE; 1194 } 1195 if (ncp->nc_parent->nc_flag & 1196 (NCF_UF_CACHE | NCF_UF_PCACHE)) { 1197 cflags |= NCF_UF_PCACHE; 1198 } 1199 } 1200 1201 /* 1202 * XXX we're not supposed to update nc_flag when holding 1203 * a shared lock. 1204 */ 1205 atomic_clear_short(&ncp->nc_flag, 1206 (NCF_SF_NOCACHE | NCF_UF_CACHE | 1207 NCF_SF_PNOCACHE | NCF_UF_PCACHE) & ~cflags); 1208 atomic_set_short(&ncp->nc_flag, cflags); 1209 1210 /* 1211 * Process general access. 1212 */ 1213 error = naccess_va(&va, nflags, cred); 1214 } 1215 } 1216 } 1217 return(error); 1218 } 1219 1220 /* 1221 * Check the requested access against the given vattr using cred. 1222 */ 1223 int 1224 naccess_va(struct vattr *va, int nflags, struct ucred *cred) 1225 { 1226 int i; 1227 int vmode; 1228 1229 /* 1230 * Test the immutable bit. Creations, deletions, renames (source 1231 * or destination) are not allowed. chown/chmod/other is also not 1232 * allowed but is handled by SETATTR. Hardlinks to the immutable 1233 * file are allowed. 1234 * 1235 * If the directory is set to immutable then creations, deletions, 1236 * renames (source or dest) and hardlinks to files within the directory 1237 * are not allowed, and regular files opened through the directory may 1238 * not be written to or truncated (unless a special device). 1239 * 1240 * NOTE! New hardlinks to immutable files work but new hardlinks to 1241 * files, immutable or not, sitting inside an immutable directory are 1242 * not allowed. As always if the file is hardlinked via some other 1243 * path additional hardlinks may be possible even if the file is marked 1244 * immutable. The sysop needs to create a closure by checking the hard 1245 * link count. Once closure is achieved you are good, and security 1246 * scripts should check link counts anyway. 1247 * 1248 * Writes and truncations are only allowed on special devices. 1249 */ 1250 if ((va->va_flags & IMMUTABLE) || (nflags & NLC_IMMUTABLE)) { 1251 if ((nflags & NLC_IMMUTABLE) && (nflags & NLC_HLINK)) 1252 return (EPERM); 1253 if (nflags & (NLC_CREATE | NLC_DELETE | 1254 NLC_RENAME_SRC | NLC_RENAME_DST)) { 1255 return (EPERM); 1256 } 1257 if (nflags & (NLC_WRITE | NLC_TRUNCATE)) { 1258 switch(va->va_type) { 1259 case VDIR: 1260 return (EISDIR); 1261 case VLNK: 1262 case VREG: 1263 case VDATABASE: 1264 return (EPERM); 1265 default: 1266 break; 1267 } 1268 } 1269 } 1270 1271 /* 1272 * Test the no-unlink and append-only bits for opens, rename targets, 1273 * and deletions. These bits are not tested for creations or 1274 * rename sources. 1275 * 1276 * Unlike FreeBSD we allow a file with APPEND set to be renamed. 1277 * If you do not wish this you must also set NOUNLINK. 1278 * 1279 * If the governing directory is marked APPEND-only it implies 1280 * NOUNLINK for all entries in the directory. 1281 */ 1282 if (((va->va_flags & NOUNLINK) || (nflags & NLC_APPENDONLY)) && 1283 (nflags & (NLC_DELETE | NLC_RENAME_SRC | NLC_RENAME_DST)) 1284 ) { 1285 return (EPERM); 1286 } 1287 1288 /* 1289 * A file marked append-only may not be deleted but can be renamed. 1290 */ 1291 if ((va->va_flags & APPEND) && 1292 (nflags & (NLC_DELETE | NLC_RENAME_DST)) 1293 ) { 1294 return (EPERM); 1295 } 1296 1297 /* 1298 * A file marked append-only which is opened for writing must also 1299 * be opened O_APPEND. 1300 */ 1301 if ((va->va_flags & APPEND) && (nflags & (NLC_OPEN | NLC_TRUNCATE))) { 1302 if (nflags & NLC_TRUNCATE) 1303 return (EPERM); 1304 if ((nflags & (NLC_OPEN | NLC_WRITE)) == (NLC_OPEN | NLC_WRITE)) { 1305 if ((nflags & NLC_APPEND) == 0) 1306 return (EPERM); 1307 } 1308 } 1309 1310 /* 1311 * root gets universal access 1312 */ 1313 if (cred->cr_uid == 0) 1314 return(0); 1315 1316 /* 1317 * Check owner perms. 1318 * 1319 * If NLC_OWN is set the owner of the file is allowed no matter when 1320 * the owner-mode bits say (utimes). 1321 */ 1322 vmode = 0; 1323 if (nflags & NLC_READ) 1324 vmode |= S_IRUSR; 1325 if (nflags & NLC_WRITE) 1326 vmode |= S_IWUSR; 1327 if (nflags & NLC_EXEC) 1328 vmode |= S_IXUSR; 1329 1330 if (cred->cr_uid == va->va_uid) { 1331 if ((nflags & NLC_OWN) == 0) { 1332 if ((vmode & va->va_mode) != vmode) 1333 return(EACCES); 1334 } 1335 return(0); 1336 } 1337 1338 /* 1339 * If NLC_STICKY is set only the owner may delete or rename a file. 1340 * This bit is typically set on /tmp. 1341 * 1342 * Note that the NLC_READ/WRITE/EXEC bits are not typically set in 1343 * the specific delete or rename case. For deletions and renames we 1344 * usually just care about directory permissions, not file permissions. 1345 */ 1346 if ((nflags & NLC_STICKY) && 1347 (nflags & (NLC_RENAME_SRC | NLC_RENAME_DST | NLC_DELETE))) { 1348 return(EACCES); 1349 } 1350 1351 /* 1352 * Check group perms 1353 */ 1354 vmode >>= 3; 1355 for (i = 0; i < cred->cr_ngroups; ++i) { 1356 if (va->va_gid == cred->cr_groups[i]) { 1357 if ((vmode & va->va_mode) != vmode) 1358 return(EACCES); 1359 return(0); 1360 } 1361 } 1362 1363 /* 1364 * Check world perms 1365 */ 1366 vmode >>= 3; 1367 if ((vmode & va->va_mode) != vmode) 1368 return(EACCES); 1369 return(0); 1370 } 1371 1372