fts.c revision 1.41
1/* $NetBSD: fts.c,v 1.41 2011/10/15 23:00:01 christos Exp $ */ 2 3/*- 4 * Copyright (c) 1990, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 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 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32#if HAVE_NBTOOL_CONFIG_H 33#include "nbtool_config.h" 34#endif 35 36#include <sys/cdefs.h> 37#if defined(LIBC_SCCS) && !defined(lint) 38#if 0 39static char sccsid[] = "@(#)fts.c 8.6 (Berkeley) 8/14/94"; 40#else 41__RCSID("$NetBSD: fts.c,v 1.41 2011/10/15 23:00:01 christos Exp $"); 42#endif 43#endif /* LIBC_SCCS and not lint */ 44 45#include "namespace.h" 46#include <sys/param.h> 47#include <sys/stat.h> 48 49#include <assert.h> 50#include <dirent.h> 51#include <errno.h> 52#include <fcntl.h> 53#include <fts.h> 54#include <stdlib.h> 55#include <string.h> 56#include <unistd.h> 57 58#if ! HAVE_NBTOOL_CONFIG_H 59#define HAVE_STRUCT_DIRENT_D_NAMLEN 60#endif 61 62static FTSENT *fts_alloc(FTS *, const char *, size_t); 63static FTSENT *fts_build(FTS *, int); 64static void fts_free(FTSENT *); 65static void fts_lfree(FTSENT *); 66static void fts_load(FTS *, FTSENT *); 67static size_t fts_maxarglen(char * const *); 68static size_t fts_pow2(size_t); 69static int fts_palloc(FTS *, size_t); 70static void fts_padjust(FTS *, FTSENT *); 71static FTSENT *fts_sort(FTS *, FTSENT *, size_t); 72static unsigned short fts_stat(FTS *, FTSENT *, int); 73static int fts_safe_changedir(const FTS *, const FTSENT *, int, 74 const char *); 75 76#if defined(ALIGNBYTES) && defined(ALIGN) 77#define FTS_ALLOC_ALIGNED 1 78#else 79#undef FTS_ALLOC_ALIGNED 80#endif 81 82#define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2]))) 83 84#define CLR(opt) (sp->fts_options &= ~(opt)) 85#define ISSET(opt) (sp->fts_options & (opt)) 86#define SET(opt) (sp->fts_options |= (opt)) 87 88#define CHDIR(sp, path) (!ISSET(FTS_NOCHDIR) && chdir(path)) 89#define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 90 91/* fts_build flags */ 92#define BCHILD 1 /* fts_children */ 93#define BNAMES 2 /* fts_children, names only */ 94#define BREAD 3 /* fts_read */ 95 96#ifndef DTF_HIDEW 97#undef FTS_WHITEOUT 98#endif 99 100FTS * 101fts_open(char * const *argv, int options, 102 int (*compar)(const FTSENT **, const FTSENT **)) 103{ 104 FTS *sp; 105 FTSENT *p, *root; 106 size_t nitems; 107 FTSENT *parent, *tmp = NULL; /* pacify gcc */ 108 size_t len; 109 110 _DIAGASSERT(argv != NULL); 111 112 /* Options check. */ 113 if (options & ~FTS_OPTIONMASK) { 114 errno = EINVAL; 115 return (NULL); 116 } 117 118 /* Allocate/initialize the stream */ 119 if ((sp = malloc((unsigned int)sizeof(FTS))) == NULL) 120 return (NULL); 121 memset(sp, 0, sizeof(FTS)); 122 sp->fts_compar = compar; 123 sp->fts_options = options; 124 125 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 126 if (ISSET(FTS_LOGICAL)) 127 SET(FTS_NOCHDIR); 128 129 /* 130 * Start out with 1K of path space, and enough, in any case, 131 * to hold the user's paths. 132 */ 133 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN))) 134 goto mem1; 135 136 /* Allocate/initialize root's parent. */ 137 if ((parent = fts_alloc(sp, "", 0)) == NULL) 138 goto mem2; 139 parent->fts_level = FTS_ROOTPARENTLEVEL; 140 141 /* Allocate/initialize root(s). */ 142 for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) { 143 /* Don't allow zero-length paths. */ 144 if ((len = strlen(*argv)) == 0) { 145 errno = ENOENT; 146 goto mem3; 147 } 148 149 if ((p = fts_alloc(sp, *argv, len)) == NULL) 150 goto mem3; 151 p->fts_level = FTS_ROOTLEVEL; 152 p->fts_parent = parent; 153 p->fts_accpath = p->fts_name; 154 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW)); 155 156 /* Command-line "." and ".." are real directories. */ 157 if (p->fts_info == FTS_DOT) 158 p->fts_info = FTS_D; 159 160 /* 161 * If comparison routine supplied, traverse in sorted 162 * order; otherwise traverse in the order specified. 163 */ 164 if (compar) { 165 p->fts_link = root; 166 root = p; 167 } else { 168 p->fts_link = NULL; 169 if (root == NULL) 170 tmp = root = p; 171 else { 172 tmp->fts_link = p; 173 tmp = p; 174 } 175 } 176 } 177 if (compar && nitems > 1) 178 root = fts_sort(sp, root, nitems); 179 180 /* 181 * Allocate a dummy pointer and make fts_read think that we've just 182 * finished the node before the root(s); set p->fts_info to FTS_INIT 183 * so that everything about the "current" node is ignored. 184 */ 185 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 186 goto mem3; 187 sp->fts_cur->fts_link = root; 188 sp->fts_cur->fts_info = FTS_INIT; 189 190 /* 191 * If using chdir(2), grab a file descriptor pointing to dot to insure 192 * that we can get back here; this could be avoided for some paths, 193 * but almost certainly not worth the effort. Slashes, symbolic links, 194 * and ".." are all fairly nasty problems. Note, if we can't get the 195 * descriptor we run anyway, just more slowly. 196 */ 197 if (!ISSET(FTS_NOCHDIR)) { 198 if ((sp->fts_rfd = open(".", O_RDONLY | O_CLOEXEC, 0)) == -1) 199 SET(FTS_NOCHDIR); 200 } 201 202 if (nitems == 0) 203 fts_free(parent); 204 205 return (sp); 206 207mem3: fts_lfree(root); 208 fts_free(parent); 209mem2: free(sp->fts_path); 210mem1: free(sp); 211 return (NULL); 212} 213 214static void 215fts_load(FTS *sp, FTSENT *p) 216{ 217 size_t len; 218 char *cp; 219 220 _DIAGASSERT(sp != NULL); 221 _DIAGASSERT(p != NULL); 222 223 /* 224 * Load the stream structure for the next traversal. Since we don't 225 * actually enter the directory until after the preorder visit, set 226 * the fts_accpath field specially so the chdir gets done to the right 227 * place and the user can access the first node. From fts_open it's 228 * known that the path will fit. 229 */ 230 len = p->fts_pathlen = p->fts_namelen; 231 memmove(sp->fts_path, p->fts_name, len + 1); 232 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 233 len = strlen(++cp); 234 memmove(p->fts_name, cp, len + 1); 235 p->fts_namelen = len; 236 } 237 p->fts_accpath = p->fts_path = sp->fts_path; 238 sp->fts_dev = p->fts_dev; 239} 240 241int 242fts_close(FTS *sp) 243{ 244 FTSENT *freep, *p; 245 int saved_errno = 0; 246 247 _DIAGASSERT(sp != NULL); 248 249 /* 250 * This still works if we haven't read anything -- the dummy structure 251 * points to the root list, so we step through to the end of the root 252 * list which has a valid parent pointer. 253 */ 254 if (sp->fts_cur) { 255 if (sp->fts_cur->fts_flags & FTS_SYMFOLLOW) 256 (void)close(sp->fts_cur->fts_symfd); 257 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 258 freep = p; 259 p = p->fts_link ? p->fts_link : p->fts_parent; 260 fts_free(freep); 261 } 262 fts_free(p); 263 } 264 265 /* Free up child linked list, sort array, path buffer. */ 266 if (sp->fts_child) 267 fts_lfree(sp->fts_child); 268 if (sp->fts_array) 269 free(sp->fts_array); 270 free(sp->fts_path); 271 272 /* Return to original directory, save errno if necessary. */ 273 if (!ISSET(FTS_NOCHDIR)) { 274 if (fchdir(sp->fts_rfd) == -1) 275 saved_errno = errno; 276 (void)close(sp->fts_rfd); 277 } 278 279 /* Free up the stream pointer. */ 280 free(sp); 281 if (saved_errno) { 282 errno = saved_errno; 283 return -1; 284 } 285 286 return 0; 287} 288 289#if !defined(__FTS_COMPAT_TAILINGSLASH) 290 291/* 292 * Special case of "/" at the end of the path so that slashes aren't 293 * appended which would cause paths to be written as "....//foo". 294 */ 295#define NAPPEND(p) \ 296 (p->fts_path[p->fts_pathlen - 1] == '/' \ 297 ? p->fts_pathlen - 1 : p->fts_pathlen) 298 299#else /* !defined(__FTS_COMPAT_TAILINGSLASH) */ 300 301/* 302 * compatibility with the old behaviour. 303 * 304 * Special case a root of "/" so that slashes aren't appended which would 305 * cause paths to be written as "//foo". 306 */ 307 308#define NAPPEND(p) \ 309 (p->fts_level == FTS_ROOTLEVEL && p->fts_pathlen == 1 && \ 310 p->fts_path[0] == '/' ? 0 : p->fts_pathlen) 311 312#endif /* !defined(__FTS_COMPAT_TAILINGSLASH) */ 313 314FTSENT * 315fts_read(FTS *sp) 316{ 317 FTSENT *p, *tmp; 318 int instr; 319 char *t; 320 int saved_errno; 321 322 _DIAGASSERT(sp != NULL); 323 324 /* If finished or unrecoverable error, return NULL. */ 325 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 326 return (NULL); 327 328 /* Set current node pointer. */ 329 p = sp->fts_cur; 330 331 /* Save and zero out user instructions. */ 332 instr = p->fts_instr; 333 p->fts_instr = FTS_NOINSTR; 334 335 /* Any type of file may be re-visited; re-stat and re-turn. */ 336 if (instr == FTS_AGAIN) { 337 p->fts_info = fts_stat(sp, p, 0); 338 return (p); 339 } 340 341 /* 342 * Following a symlink -- SLNONE test allows application to see 343 * SLNONE and recover. If indirecting through a symlink, have 344 * keep a pointer to current location. If unable to get that 345 * pointer, follow fails. 346 */ 347 if (instr == FTS_FOLLOW && 348 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 349 p->fts_info = fts_stat(sp, p, 1); 350 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 351 if ((p->fts_symfd = open(".", O_RDONLY | O_CLOEXEC, 0)) 352 == -1) { 353 p->fts_errno = errno; 354 p->fts_info = FTS_ERR; 355 } else 356 p->fts_flags |= FTS_SYMFOLLOW; 357 } 358 return (p); 359 } 360 361 /* Directory in pre-order. */ 362 if (p->fts_info == FTS_D) { 363 /* If skipped or crossed mount point, do post-order visit. */ 364 if (instr == FTS_SKIP || 365 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 366 if (p->fts_flags & FTS_SYMFOLLOW) 367 (void)close(p->fts_symfd); 368 if (sp->fts_child) { 369 fts_lfree(sp->fts_child); 370 sp->fts_child = NULL; 371 } 372 p->fts_info = FTS_DP; 373 return (p); 374 } 375 376 /* Rebuild if only read the names and now traversing. */ 377 if (sp->fts_child && ISSET(FTS_NAMEONLY)) { 378 CLR(FTS_NAMEONLY); 379 fts_lfree(sp->fts_child); 380 sp->fts_child = NULL; 381 } 382 383 /* 384 * Cd to the subdirectory. 385 * 386 * If have already read and now fail to chdir, whack the list 387 * to make the names come out right, and set the parent errno 388 * so the application will eventually get an error condition. 389 * Set the FTS_DONTCHDIR flag so that when we logically change 390 * directories back to the parent we don't do a chdir. 391 * 392 * If haven't read do so. If the read fails, fts_build sets 393 * FTS_STOP or the fts_info field of the node. 394 */ 395 if (sp->fts_child) { 396 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 397 p->fts_errno = errno; 398 p->fts_flags |= FTS_DONTCHDIR; 399 for (p = sp->fts_child; p; p = p->fts_link) 400 p->fts_accpath = 401 p->fts_parent->fts_accpath; 402 } 403 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 404 if (ISSET(FTS_STOP)) 405 return (NULL); 406 return (p); 407 } 408 p = sp->fts_child; 409 sp->fts_child = NULL; 410 goto name; 411 } 412 413 /* Move to the next node on this level. */ 414next: tmp = p; 415 if ((p = p->fts_link) != NULL) { 416 fts_free(tmp); 417 418 /* 419 * If reached the top, return to the original directory, and 420 * load the paths for the next root. 421 */ 422 if (p->fts_level == FTS_ROOTLEVEL) { 423 if (FCHDIR(sp, sp->fts_rfd)) { 424 SET(FTS_STOP); 425 return (NULL); 426 } 427 fts_load(sp, p); 428 return (sp->fts_cur = p); 429 } 430 431 /* 432 * User may have called fts_set on the node. If skipped, 433 * ignore. If followed, get a file descriptor so we can 434 * get back if necessary. 435 */ 436 if (p->fts_instr == FTS_SKIP) 437 goto next; 438 if (p->fts_instr == FTS_FOLLOW) { 439 p->fts_info = fts_stat(sp, p, 1); 440 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 441 if ((p->fts_symfd = 442 open(".", O_RDONLY | O_CLOEXEC, 0)) == -1) { 443 p->fts_errno = errno; 444 p->fts_info = FTS_ERR; 445 } else 446 p->fts_flags |= FTS_SYMFOLLOW; 447 } 448 p->fts_instr = FTS_NOINSTR; 449 } 450 451name: t = sp->fts_path + NAPPEND(p->fts_parent); 452 *t++ = '/'; 453 memmove(t, p->fts_name, (size_t)(p->fts_namelen + 1)); 454 return (sp->fts_cur = p); 455 } 456 457 /* Move up to the parent node. */ 458 p = tmp->fts_parent; 459 fts_free(tmp); 460 461 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 462 /* 463 * Done; free everything up and set errno to 0 so the user 464 * can distinguish between error and EOF. 465 */ 466 fts_free(p); 467 errno = 0; 468 return (sp->fts_cur = NULL); 469 } 470 471 /* Nul terminate the pathname. */ 472 sp->fts_path[p->fts_pathlen] = '\0'; 473 474 /* 475 * Return to the parent directory. If at a root node or came through 476 * a symlink, go back through the file descriptor. Otherwise, cd up 477 * one directory. 478 */ 479 if (p->fts_level == FTS_ROOTLEVEL) { 480 if (FCHDIR(sp, sp->fts_rfd)) { 481 SET(FTS_STOP); 482 return (NULL); 483 } 484 } else if (p->fts_flags & FTS_SYMFOLLOW) { 485 if (FCHDIR(sp, p->fts_symfd)) { 486 saved_errno = errno; 487 (void)close(p->fts_symfd); 488 errno = saved_errno; 489 SET(FTS_STOP); 490 return (NULL); 491 } 492 (void)close(p->fts_symfd); 493 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 494 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 495 SET(FTS_STOP); 496 return (NULL); 497 } 498 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 499 return (sp->fts_cur = p); 500} 501 502/* 503 * Fts_set takes the stream as an argument although it's not used in this 504 * implementation; it would be necessary if anyone wanted to add global 505 * semantics to fts using fts_set. An error return is allowed for similar 506 * reasons. 507 */ 508/* ARGSUSED */ 509int 510fts_set(FTS *sp, FTSENT *p, int instr) 511{ 512 513 _DIAGASSERT(sp != NULL); 514 _DIAGASSERT(p != NULL); 515 516 if (instr && instr != FTS_AGAIN && instr != FTS_FOLLOW && 517 instr != FTS_NOINSTR && instr != FTS_SKIP) { 518 errno = EINVAL; 519 return (1); 520 } 521 p->fts_instr = instr; 522 return (0); 523} 524 525FTSENT * 526fts_children(FTS *sp, int instr) 527{ 528 FTSENT *p; 529 int fd; 530 531 _DIAGASSERT(sp != NULL); 532 533 if (instr && instr != FTS_NAMEONLY) { 534 errno = EINVAL; 535 return (NULL); 536 } 537 538 /* Set current node pointer. */ 539 p = sp->fts_cur; 540 541 /* 542 * Errno set to 0 so user can distinguish empty directory from 543 * an error. 544 */ 545 errno = 0; 546 547 /* Fatal errors stop here. */ 548 if (ISSET(FTS_STOP)) 549 return (NULL); 550 551 /* Return logical hierarchy of user's arguments. */ 552 if (p->fts_info == FTS_INIT) 553 return (p->fts_link); 554 555 /* 556 * If not a directory being visited in pre-order, stop here. Could 557 * allow FTS_DNR, assuming the user has fixed the problem, but the 558 * same effect is available with FTS_AGAIN. 559 */ 560 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 561 return (NULL); 562 563 /* Free up any previous child list. */ 564 if (sp->fts_child) 565 fts_lfree(sp->fts_child); 566 567 if (instr == FTS_NAMEONLY) { 568 SET(FTS_NAMEONLY); 569 instr = BNAMES; 570 } else 571 instr = BCHILD; 572 573 /* 574 * If using chdir on a relative path and called BEFORE fts_read does 575 * its chdir to the root of a traversal, we can lose -- we need to 576 * chdir into the subdirectory, and we don't know where the current 577 * directory is, so we can't get back so that the upcoming chdir by 578 * fts_read will work. 579 */ 580 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 581 ISSET(FTS_NOCHDIR)) 582 return (sp->fts_child = fts_build(sp, instr)); 583 584 if ((fd = open(".", O_RDONLY, 0)) == -1) 585 return (sp->fts_child = NULL); 586 sp->fts_child = fts_build(sp, instr); 587 if (fchdir(fd)) { 588 (void)close(fd); 589 return (NULL); 590 } 591 (void)close(fd); 592 return (sp->fts_child); 593} 594 595/* 596 * This is the tricky part -- do not casually change *anything* in here. The 597 * idea is to build the linked list of entries that are used by fts_children 598 * and fts_read. There are lots of special cases. 599 * 600 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 601 * set and it's a physical walk (so that symbolic links can't be directories), 602 * we can do things quickly. First, if it's a 4.4BSD file system, the type 603 * of the file is in the directory entry. Otherwise, we assume that the number 604 * of subdirectories in a node is equal to the number of links to the parent. 605 * The former skips all stat calls. The latter skips stat calls in any leaf 606 * directories and for any files after the subdirectories in the directory have 607 * been found, cutting the stat calls by about 2/3. 608 */ 609static FTSENT * 610fts_build(FTS *sp, int type) 611{ 612 struct dirent *dp; 613 FTSENT *p, *head; 614 size_t nitems; 615 FTSENT *cur, *tail; 616 DIR *dirp; 617 void *oldaddr; 618 size_t dnamlen; 619 int cderrno, descend, level, nlinks, saved_errno, nostat, doadjust; 620 size_t len, maxlen; 621#ifdef FTS_WHITEOUT 622 int oflag; 623#endif 624 char *cp = NULL; /* pacify gcc */ 625 626 _DIAGASSERT(sp != NULL); 627 628 /* Set current node pointer. */ 629 cur = sp->fts_cur; 630 631 /* 632 * Open the directory for reading. If this fails, we're done. 633 * If being called from fts_read, set the fts_info field. 634 */ 635#ifdef FTS_WHITEOUT 636 if (ISSET(FTS_WHITEOUT)) 637 oflag = DTF_NODUP|DTF_REWIND; 638 else 639 oflag = DTF_HIDEW|DTF_NODUP|DTF_REWIND; 640#else 641#define __opendir2(path, flag) opendir(path) 642#endif 643 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) { 644 if (type == BREAD) { 645 cur->fts_info = FTS_DNR; 646 cur->fts_errno = errno; 647 } 648 return (NULL); 649 } 650 651 /* 652 * Nlinks is the number of possible entries of type directory in the 653 * directory if we're cheating on stat calls, 0 if we're not doing 654 * any stat calls at all, -1 if we're doing stats on everything. 655 */ 656 if (type == BNAMES) { 657 nlinks = 0; 658 nostat = 1; 659 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 660 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 661 nostat = 1; 662 } else { 663 nlinks = -1; 664 nostat = 0; 665 } 666 667#ifdef notdef 668 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 669 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 670 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 671#endif 672 /* 673 * If we're going to need to stat anything or we want to descend 674 * and stay in the directory, chdir. If this fails we keep going, 675 * but set a flag so we don't chdir after the post-order visit. 676 * We won't be able to stat anything, but we can still return the 677 * names themselves. Note, that since fts_read won't be able to 678 * chdir into the directory, it will have to return different path 679 * names than before, i.e. "a/b" instead of "b". Since the node 680 * has already been visited in pre-order, have to wait until the 681 * post-order visit to return the error. There is a special case 682 * here, if there was nothing to stat then it's not an error to 683 * not be able to stat. This is all fairly nasty. If a program 684 * needed sorted entries or stat information, they had better be 685 * checking FTS_NS on the returned nodes. 686 */ 687 cderrno = 0; 688 if (nlinks || type == BREAD) { 689 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) { 690 if (nlinks && type == BREAD) 691 cur->fts_errno = errno; 692 cur->fts_flags |= FTS_DONTCHDIR; 693 descend = 0; 694 cderrno = errno; 695 } else 696 descend = 1; 697 } else 698 descend = 0; 699 700 /* 701 * Figure out the max file name length that can be stored in the 702 * current path -- the inner loop allocates more path as necessary. 703 * We really wouldn't have to do the maxlen calculations here, we 704 * could do them in fts_read before returning the path, but it's a 705 * lot easier here since the length is part of the dirent structure. 706 * 707 * If not changing directories set a pointer so that can just append 708 * each new name into the path. 709 */ 710 len = NAPPEND(cur); 711 if (ISSET(FTS_NOCHDIR)) { 712 cp = sp->fts_path + len; 713 *cp++ = '/'; 714 } 715 len++; 716 maxlen = sp->fts_pathlen - len; 717 718#if defined(__FTS_COMPAT_LEVEL) 719 if (cur->fts_level == SHRT_MAX) { 720 (void)closedir(dirp); 721 cur->fts_info = FTS_ERR; 722 SET(FTS_STOP); 723 errno = ENAMETOOLONG; 724 return (NULL); 725 } 726#endif 727 728 level = cur->fts_level + 1; 729 730 /* Read the directory, attaching each entry to the `link' pointer. */ 731 doadjust = 0; 732 for (head = tail = NULL, nitems = 0; (dp = readdir(dirp)) != NULL;) { 733 734 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 735 continue; 736 737#if defined(HAVE_STRUCT_DIRENT_D_NAMLEN) 738 dnamlen = dp->d_namlen; 739#else 740 dnamlen = strlen(dp->d_name); 741#endif 742 if ((p = fts_alloc(sp, dp->d_name, dnamlen)) == NULL) 743 goto mem1; 744 if (dnamlen >= maxlen) { /* include space for NUL */ 745 oldaddr = sp->fts_path; 746 if (fts_palloc(sp, dnamlen + len + 1)) { 747 /* 748 * No more memory for path or structures. Save 749 * errno, free up the current structure and the 750 * structures already allocated. 751 */ 752mem1: saved_errno = errno; 753 if (p) 754 fts_free(p); 755 fts_lfree(head); 756 (void)closedir(dirp); 757 errno = saved_errno; 758 cur->fts_info = FTS_ERR; 759 SET(FTS_STOP); 760 return (NULL); 761 } 762 /* Did realloc() change the pointer? */ 763 if (oldaddr != sp->fts_path) { 764 doadjust = 1; 765 if (ISSET(FTS_NOCHDIR)) 766 cp = sp->fts_path + len; 767 } 768 maxlen = sp->fts_pathlen - len; 769 } 770 771#if defined(__FTS_COMPAT_LENGTH) 772 if (len + dnamlen >= USHRT_MAX) { 773 /* 774 * In an FTSENT, fts_pathlen is an unsigned short 775 * so it is possible to wraparound here. 776 * If we do, free up the current structure and the 777 * structures already allocated, then error out 778 * with ENAMETOOLONG. 779 */ 780 fts_free(p); 781 fts_lfree(head); 782 (void)closedir(dirp); 783 cur->fts_info = FTS_ERR; 784 SET(FTS_STOP); 785 errno = ENAMETOOLONG; 786 return (NULL); 787 } 788#endif 789 p->fts_level = level; 790 p->fts_pathlen = len + dnamlen; 791 p->fts_parent = sp->fts_cur; 792 793#ifdef FTS_WHITEOUT 794 if (dp->d_type == DT_WHT) 795 p->fts_flags |= FTS_ISW; 796#endif 797 798 if (cderrno) { 799 if (nlinks) { 800 p->fts_info = FTS_NS; 801 p->fts_errno = cderrno; 802 } else 803 p->fts_info = FTS_NSOK; 804 p->fts_accpath = cur->fts_accpath; 805 } else if (nlinks == 0 806#ifdef DT_DIR 807 || (nostat && 808 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 809#endif 810 ) { 811 p->fts_accpath = 812 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 813 p->fts_info = FTS_NSOK; 814 } else { 815 /* Build a file name for fts_stat to stat. */ 816 if (ISSET(FTS_NOCHDIR)) { 817 p->fts_accpath = p->fts_path; 818 memmove(cp, p->fts_name, 819 (size_t)(p->fts_namelen + 1)); 820 } else 821 p->fts_accpath = p->fts_name; 822 /* Stat it. */ 823 p->fts_info = fts_stat(sp, p, 0); 824 825 /* Decrement link count if applicable. */ 826 if (nlinks > 0 && (p->fts_info == FTS_D || 827 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 828 --nlinks; 829 } 830 831 /* We walk in directory order so "ls -f" doesn't get upset. */ 832 p->fts_link = NULL; 833 if (head == NULL) 834 head = tail = p; 835 else { 836 tail->fts_link = p; 837 tail = p; 838 } 839 ++nitems; 840 } 841 (void)closedir(dirp); 842 843 /* 844 * If had to realloc the path, adjust the addresses for the rest 845 * of the tree. 846 */ 847 if (doadjust) 848 fts_padjust(sp, head); 849 850 /* 851 * If not changing directories, reset the path back to original 852 * state. 853 */ 854 if (ISSET(FTS_NOCHDIR)) { 855 if (len == sp->fts_pathlen || nitems == 0) 856 --cp; 857 *cp = '\0'; 858 } 859 860 /* 861 * If descended after called from fts_children or after called from 862 * fts_read and nothing found, get back. At the root level we use 863 * the saved fd; if one of fts_open()'s arguments is a relative path 864 * to an empty directory, we wind up here with no other way back. If 865 * can't get back, we're done. 866 */ 867 if (descend && (type == BCHILD || !nitems) && 868 (cur->fts_level == FTS_ROOTLEVEL ? 869 FCHDIR(sp, sp->fts_rfd) : 870 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 871 cur->fts_info = FTS_ERR; 872 SET(FTS_STOP); 873 return (NULL); 874 } 875 876 /* If didn't find anything, return NULL. */ 877 if (!nitems) { 878 if (type == BREAD) 879 cur->fts_info = FTS_DP; 880 return (NULL); 881 } 882 883 /* Sort the entries. */ 884 if (sp->fts_compar && nitems > 1) 885 head = fts_sort(sp, head, nitems); 886 return (head); 887} 888 889static unsigned short 890fts_stat(FTS *sp, FTSENT *p, int follow) 891{ 892 FTSENT *t; 893 dev_t dev; 894 __fts_ino_t ino; 895 __fts_stat_t *sbp, sb; 896 int saved_errno; 897 898 _DIAGASSERT(sp != NULL); 899 _DIAGASSERT(p != NULL); 900 901 /* If user needs stat info, stat buffer already allocated. */ 902 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 903 904#ifdef FTS_WHITEOUT 905 /* check for whiteout */ 906 if (p->fts_flags & FTS_ISW) { 907 if (sbp != &sb) { 908 memset(sbp, '\0', sizeof (*sbp)); 909 sbp->st_mode = S_IFWHT; 910 } 911 return (FTS_W); 912 } 913#endif 914 915 /* 916 * If doing a logical walk, or application requested FTS_FOLLOW, do 917 * a stat(2). If that fails, check for a non-existent symlink. If 918 * fail, set the errno from the stat call. 919 */ 920 if (ISSET(FTS_LOGICAL) || follow) { 921 if (stat(p->fts_accpath, sbp)) { 922 saved_errno = errno; 923 if (!lstat(p->fts_accpath, sbp)) { 924 errno = 0; 925 return (FTS_SLNONE); 926 } 927 p->fts_errno = saved_errno; 928 goto err; 929 } 930 } else if (lstat(p->fts_accpath, sbp)) { 931 p->fts_errno = errno; 932err: memset(sbp, 0, sizeof(*sbp)); 933 return (FTS_NS); 934 } 935 936 if (S_ISDIR(sbp->st_mode)) { 937 /* 938 * Set the device/inode. Used to find cycles and check for 939 * crossing mount points. Also remember the link count, used 940 * in fts_build to limit the number of stat calls. It is 941 * understood that these fields are only referenced if fts_info 942 * is set to FTS_D. 943 */ 944 dev = p->fts_dev = sbp->st_dev; 945 ino = p->fts_ino = sbp->st_ino; 946 p->fts_nlink = sbp->st_nlink; 947 948 if (ISDOT(p->fts_name)) 949 return (FTS_DOT); 950 951 /* 952 * Cycle detection is done by brute force when the directory 953 * is first encountered. If the tree gets deep enough or the 954 * number of symbolic links to directories is high enough, 955 * something faster might be worthwhile. 956 */ 957 for (t = p->fts_parent; 958 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 959 if (ino == t->fts_ino && dev == t->fts_dev) { 960 p->fts_cycle = t; 961 return (FTS_DC); 962 } 963 return (FTS_D); 964 } 965 if (S_ISLNK(sbp->st_mode)) 966 return (FTS_SL); 967 if (S_ISREG(sbp->st_mode)) 968 return (FTS_F); 969 return (FTS_DEFAULT); 970} 971 972static FTSENT * 973fts_sort(FTS *sp, FTSENT *head, size_t nitems) 974{ 975 FTSENT **ap, *p; 976 977 _DIAGASSERT(sp != NULL); 978 _DIAGASSERT(head != NULL); 979 980 /* 981 * Construct an array of pointers to the structures and call qsort(3). 982 * Reassemble the array in the order returned by qsort. If unable to 983 * sort for memory reasons, return the directory entries in their 984 * current order. Allocate enough space for the current needs plus 985 * 40 so don't realloc one entry at a time. 986 */ 987 if (nitems > sp->fts_nitems) { 988 FTSENT **new; 989 990 new = realloc(sp->fts_array, sizeof(FTSENT *) * (nitems + 40)); 991 if (new == 0) 992 return (head); 993 sp->fts_array = new; 994 sp->fts_nitems = nitems + 40; 995 } 996 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 997 *ap++ = p; 998 qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *), 999 (int (*)(const void *, const void *))sp->fts_compar); 1000 for (head = *(ap = sp->fts_array); --nitems; ++ap) 1001 ap[0]->fts_link = ap[1]; 1002 ap[0]->fts_link = NULL; 1003 return (head); 1004} 1005 1006static FTSENT * 1007fts_alloc(FTS *sp, const char *name, size_t namelen) 1008{ 1009 FTSENT *p; 1010#if defined(FTS_ALLOC_ALIGNED) 1011 size_t len; 1012#endif 1013 1014 _DIAGASSERT(sp != NULL); 1015 _DIAGASSERT(name != NULL); 1016 1017#if defined(FTS_ALLOC_ALIGNED) 1018 /* 1019 * The file name is a variable length array and no stat structure is 1020 * necessary if the user has set the nostat bit. Allocate the FTSENT 1021 * structure, the file name and the stat structure in one chunk, but 1022 * be careful that the stat structure is reasonably aligned. Since the 1023 * fts_name field is declared to be of size 1, the fts_name pointer is 1024 * namelen + 2 before the first possible address of the stat structure. 1025 */ 1026 len = sizeof(FTSENT) + namelen; 1027 if (!ISSET(FTS_NOSTAT)) 1028 len += sizeof(*(p->fts_statp)) + ALIGNBYTES; 1029 if ((p = malloc(len)) == NULL) 1030 return (NULL); 1031 1032 if (!ISSET(FTS_NOSTAT)) 1033 p->fts_statp = (__fts_stat_t *)ALIGN( 1034 (unsigned long)(p->fts_name + namelen + 2)); 1035#else 1036 if ((p = malloc(sizeof(FTSENT) + namelen)) == NULL) 1037 return (NULL); 1038 1039 if (!ISSET(FTS_NOSTAT)) 1040 if ((p->fts_statp = malloc(sizeof(*(p->fts_statp)))) == NULL) { 1041 free(p); 1042 return (NULL); 1043 } 1044#endif 1045 1046 if (ISSET(FTS_NOSTAT)) 1047 p->fts_statp = NULL; 1048 1049 /* Copy the name plus the trailing NULL. */ 1050 memmove(p->fts_name, name, namelen + 1); 1051 1052 p->fts_namelen = namelen; 1053 p->fts_path = sp->fts_path; 1054 p->fts_errno = 0; 1055 p->fts_flags = 0; 1056 p->fts_instr = FTS_NOINSTR; 1057 p->fts_number = 0; 1058 p->fts_pointer = NULL; 1059 return (p); 1060} 1061 1062static void 1063fts_free(FTSENT *p) 1064{ 1065#if !defined(FTS_ALLOC_ALIGNED) 1066 if (p->fts_statp) 1067 free(p->fts_statp); 1068#endif 1069 free(p); 1070} 1071 1072static void 1073fts_lfree(FTSENT *head) 1074{ 1075 FTSENT *p; 1076 1077 /* XXX: head may be NULL ? */ 1078 1079 /* Free a linked list of structures. */ 1080 while ((p = head) != NULL) { 1081 head = head->fts_link; 1082 fts_free(p); 1083 } 1084} 1085 1086static size_t 1087fts_pow2(size_t x) 1088{ 1089 1090 x--; 1091 x |= x>>1; 1092 x |= x>>2; 1093 x |= x>>4; 1094 x |= x>>8; 1095 x |= x>>16; 1096#if LONG_BIT > 32 1097 x |= x>>32; 1098#endif 1099#if LONG_BIT > 64 1100 x |= x>>64; 1101#endif 1102 x++; 1103 return (x); 1104} 1105 1106/* 1107 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 1108 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 1109 * though the kernel won't resolve them. Round up the new size to a power of 2, 1110 * so we don't realloc the path 2 bytes at a time. 1111 */ 1112static int 1113fts_palloc(FTS *sp, size_t size) 1114{ 1115 char *new; 1116 1117 _DIAGASSERT(sp != NULL); 1118 1119#ifdef __FTS_COMPAT_LENGTH 1120 /* Protect against fts_pathlen overflow. */ 1121 if (size > USHRT_MAX + 1) { 1122 errno = ENAMETOOLONG; 1123 return (1); 1124 } 1125#endif 1126 size = fts_pow2(size); 1127 new = realloc(sp->fts_path, size); 1128 if (new == 0) 1129 return (1); 1130 sp->fts_path = new; 1131 sp->fts_pathlen = size; 1132 return (0); 1133} 1134 1135/* 1136 * When the path is realloc'd, have to fix all of the pointers in structures 1137 * already returned. 1138 */ 1139static void 1140fts_padjust(FTS *sp, FTSENT *head) 1141{ 1142 FTSENT *p; 1143 char *addr; 1144 1145 _DIAGASSERT(sp != NULL); 1146 1147#define ADJUST(p) do { \ 1148 if ((p)->fts_accpath != (p)->fts_name) \ 1149 (p)->fts_accpath = \ 1150 addr + ((p)->fts_accpath - (p)->fts_path); \ 1151 (p)->fts_path = addr; \ 1152} while (/*CONSTCOND*/0) 1153 1154 addr = sp->fts_path; 1155 1156 /* Adjust the current set of children. */ 1157 for (p = sp->fts_child; p; p = p->fts_link) 1158 ADJUST(p); 1159 1160 /* Adjust the rest of the tree, including the current level. */ 1161 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1162 ADJUST(p); 1163 p = p->fts_link ? p->fts_link : p->fts_parent; 1164 } 1165} 1166 1167static size_t 1168fts_maxarglen(char * const *argv) 1169{ 1170 size_t len, max; 1171 1172 _DIAGASSERT(argv != NULL); 1173 1174 for (max = 0; *argv; ++argv) 1175 if ((len = strlen(*argv)) > max) 1176 max = len; 1177 return (max + 1); 1178} 1179 1180/* 1181 * Change to dir specified by fd or p->fts_accpath without getting 1182 * tricked by someone changing the world out from underneath us. 1183 * Assumes p->fts_dev and p->fts_ino are filled in. 1184 */ 1185static int 1186fts_safe_changedir(const FTS *sp, const FTSENT *p, int fd, const char *path) 1187{ 1188 int oldfd = fd, ret = -1; 1189 __fts_stat_t sb; 1190 1191 if (ISSET(FTS_NOCHDIR)) 1192 return 0; 1193 1194 if (oldfd < 0 && (fd = open(path, O_RDONLY)) == -1) 1195 return -1; 1196 1197 if (fstat(fd, &sb) == -1) 1198 goto bail; 1199 1200 if (sb.st_ino != p->fts_ino || sb.st_dev != p->fts_dev) { 1201 errno = ENOENT; 1202 goto bail; 1203 } 1204 1205 ret = fchdir(fd); 1206 1207bail: 1208 if (oldfd < 0) { 1209 int save_errno = errno; 1210 (void)close(fd); 1211 errno = save_errno; 1212 } 1213 return ret; 1214} 1215