fts.c revision 1.28
1/* $NetBSD: fts.c,v 1.28 2005/11/18 16:48:48 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 1.28 2005/11/18 16:48:48 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 1 60#endif 61 62static FTSENT *fts_alloc(FTS *, const char *, size_t); 63static FTSENT *fts_build(FTS *, int); 64static void fts_lfree(FTSENT *); 65static void fts_load(FTS *, FTSENT *); 66static size_t fts_maxarglen(char * const *); 67static size_t fts_pow2(size_t); 68static int fts_palloc(FTS *, size_t); 69static void fts_padjust(FTS *, FTSENT *); 70static FTSENT *fts_sort(FTS *, FTSENT *, size_t); 71static u_short fts_stat(FTS *, FTSENT *, int); 72static int fts_safe_changedir(const FTS *, const FTSENT *, int, 73 const char *); 74 75#define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2]))) 76 77#define CLR(opt) (sp->fts_options &= ~(opt)) 78#define ISSET(opt) (sp->fts_options & (opt)) 79#define SET(opt) (sp->fts_options |= (opt)) 80 81#define CHDIR(sp, path) (!ISSET(FTS_NOCHDIR) && chdir(path)) 82#define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 83 84/* fts_build flags */ 85#define BCHILD 1 /* fts_children */ 86#define BNAMES 2 /* fts_children, names only */ 87#define BREAD 3 /* fts_read */ 88 89#ifndef DTF_HIDEW 90#undef FTS_WHITEOUT 91#endif 92 93FTS * 94fts_open(char * const *argv, int options, 95 int (*compar)(const FTSENT **, const FTSENT **)) 96{ 97 FTS *sp; 98 FTSENT *p, *root; 99 size_t nitems; 100 FTSENT *parent, *tmp = NULL; /* pacify gcc */ 101 size_t len; 102 103 _DIAGASSERT(argv != NULL); 104 105 /* Options check. */ 106 if (options & ~FTS_OPTIONMASK) { 107 errno = EINVAL; 108 return (NULL); 109 } 110 111 /* Allocate/initialize the stream */ 112 if ((sp = malloc((u_int)sizeof(FTS))) == NULL) 113 return (NULL); 114 memset(sp, 0, sizeof(FTS)); 115 sp->fts_compar = compar; 116 sp->fts_options = options; 117 118 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 119 if (ISSET(FTS_LOGICAL)) 120 SET(FTS_NOCHDIR); 121 122 /* 123 * Start out with 1K of path space, and enough, in any case, 124 * to hold the user's paths. 125 */ 126 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN))) 127 goto mem1; 128 129 /* Allocate/initialize root's parent. */ 130 if ((parent = fts_alloc(sp, "", 0)) == NULL) 131 goto mem2; 132 parent->fts_level = FTS_ROOTPARENTLEVEL; 133 134 /* Allocate/initialize root(s). */ 135 for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) { 136 /* Don't allow zero-length paths. */ 137 if ((len = strlen(*argv)) == 0) { 138 errno = ENOENT; 139 goto mem3; 140 } 141 142 if ((p = fts_alloc(sp, *argv, len)) == NULL) 143 goto mem3; 144 p->fts_level = FTS_ROOTLEVEL; 145 p->fts_parent = parent; 146 p->fts_accpath = p->fts_name; 147 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW)); 148 149 /* Command-line "." and ".." are real directories. */ 150 if (p->fts_info == FTS_DOT) 151 p->fts_info = FTS_D; 152 153 /* 154 * If comparison routine supplied, traverse in sorted 155 * order; otherwise traverse in the order specified. 156 */ 157 if (compar) { 158 p->fts_link = root; 159 root = p; 160 } else { 161 p->fts_link = NULL; 162 if (root == NULL) 163 tmp = root = p; 164 else { 165 tmp->fts_link = p; 166 tmp = p; 167 } 168 } 169 } 170 if (compar && nitems > 1) 171 root = fts_sort(sp, root, nitems); 172 173 /* 174 * Allocate a dummy pointer and make fts_read think that we've just 175 * finished the node before the root(s); set p->fts_info to FTS_INIT 176 * so that everything about the "current" node is ignored. 177 */ 178 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 179 goto mem3; 180 sp->fts_cur->fts_link = root; 181 sp->fts_cur->fts_info = FTS_INIT; 182 183 /* 184 * If using chdir(2), grab a file descriptor pointing to dot to insure 185 * that we can get back here; this could be avoided for some paths, 186 * but almost certainly not worth the effort. Slashes, symbolic links, 187 * and ".." are all fairly nasty problems. Note, if we can't get the 188 * descriptor we run anyway, just more slowly. 189 */ 190 if (!ISSET(FTS_NOCHDIR)) { 191 if ((sp->fts_rfd = open(".", O_RDONLY, 0)) == -1) 192 SET(FTS_NOCHDIR); 193 else if (fcntl(sp->fts_rfd, F_SETFD, FD_CLOEXEC) == -1) { 194 close(sp->fts_rfd); 195 SET(FTS_NOCHDIR); 196 } 197 } 198 199 return (sp); 200 201mem3: fts_lfree(root); 202 free(parent); 203mem2: free(sp->fts_path); 204mem1: free(sp); 205 return (NULL); 206} 207 208static void 209fts_load(FTS *sp, FTSENT *p) 210{ 211 size_t len; 212 char *cp; 213 214 _DIAGASSERT(sp != NULL); 215 _DIAGASSERT(p != NULL); 216 217 /* 218 * Load the stream structure for the next traversal. Since we don't 219 * actually enter the directory until after the preorder visit, set 220 * the fts_accpath field specially so the chdir gets done to the right 221 * place and the user can access the first node. From fts_open it's 222 * known that the path will fit. 223 */ 224 len = p->fts_pathlen = p->fts_namelen; 225 memmove(sp->fts_path, p->fts_name, len + 1); 226 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 227 len = strlen(++cp); 228 memmove(p->fts_name, cp, len + 1); 229 p->fts_namelen = len; 230 } 231 p->fts_accpath = p->fts_path = sp->fts_path; 232 sp->fts_dev = p->fts_dev; 233} 234 235int 236fts_close(FTS *sp) 237{ 238 FTSENT *freep, *p; 239 int saved_errno; 240 241 _DIAGASSERT(sp != NULL); 242 243 /* 244 * This still works if we haven't read anything -- the dummy structure 245 * points to the root list, so we step through to the end of the root 246 * list which has a valid parent pointer. 247 */ 248 if (sp->fts_cur) { 249 if (ISSET(FTS_SYMFOLLOW)) 250 (void)close(sp->fts_cur->fts_symfd); 251 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 252 freep = p; 253 p = p->fts_link ? p->fts_link : p->fts_parent; 254 free(freep); 255 } 256 free(p); 257 } 258 259 /* Free up child linked list, sort array, path buffer. */ 260 if (sp->fts_child) 261 fts_lfree(sp->fts_child); 262 if (sp->fts_array) 263 free(sp->fts_array); 264 free(sp->fts_path); 265 266 /* Return to original directory, save errno if necessary. */ 267 if (!ISSET(FTS_NOCHDIR)) { 268 saved_errno = fchdir(sp->fts_rfd) ? errno : 0; 269 (void)close(sp->fts_rfd); 270 /* Set errno and return. */ 271 if (saved_errno) { 272 errno = saved_errno; 273 return (-1); 274 } 275 } 276 277 /* Free up the stream pointer. */ 278 free(sp); 279 /* ISSET() is illegal after this, since the macro touches sp */ 280 281 return (0); 282} 283 284/* 285 * Special case of "/" at the end of the path so that slashes aren't 286 * appended which would cause paths to be written as "....//foo". 287 */ 288#define NAPPEND(p) \ 289 (p->fts_path[p->fts_pathlen - 1] == '/' \ 290 ? p->fts_pathlen - 1 : p->fts_pathlen) 291 292FTSENT * 293fts_read(FTS *sp) 294{ 295 FTSENT *p, *tmp; 296 int instr; 297 char *t; 298 int saved_errno; 299 300 _DIAGASSERT(sp != NULL); 301 302 /* If finished or unrecoverable error, return NULL. */ 303 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 304 return (NULL); 305 306 /* Set current node pointer. */ 307 p = sp->fts_cur; 308 309 /* Save and zero out user instructions. */ 310 instr = p->fts_instr; 311 p->fts_instr = FTS_NOINSTR; 312 313 /* Any type of file may be re-visited; re-stat and re-turn. */ 314 if (instr == FTS_AGAIN) { 315 p->fts_info = fts_stat(sp, p, 0); 316 return (p); 317 } 318 319 /* 320 * Following a symlink -- SLNONE test allows application to see 321 * SLNONE and recover. If indirecting through a symlink, have 322 * keep a pointer to current location. If unable to get that 323 * pointer, follow fails. 324 */ 325 if (instr == FTS_FOLLOW && 326 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 327 p->fts_info = fts_stat(sp, p, 1); 328 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 329 if ((p->fts_symfd = open(".", O_RDONLY, 0)) == -1) { 330 p->fts_errno = errno; 331 p->fts_info = FTS_ERR; 332 } else if (fcntl(p->fts_symfd, F_SETFD, FD_CLOEXEC) == -1) { 333 p->fts_errno = errno; 334 p->fts_info = FTS_ERR; 335 close(p->fts_symfd); 336 } else 337 p->fts_flags |= FTS_SYMFOLLOW; 338 } 339 return (p); 340 } 341 342 /* Directory in pre-order. */ 343 if (p->fts_info == FTS_D) { 344 /* If skipped or crossed mount point, do post-order visit. */ 345 if (instr == FTS_SKIP || 346 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 347 if (p->fts_flags & FTS_SYMFOLLOW) 348 (void)close(p->fts_symfd); 349 if (sp->fts_child) { 350 fts_lfree(sp->fts_child); 351 sp->fts_child = NULL; 352 } 353 p->fts_info = FTS_DP; 354 return (p); 355 } 356 357 /* Rebuild if only read the names and now traversing. */ 358 if (sp->fts_child && ISSET(FTS_NAMEONLY)) { 359 CLR(FTS_NAMEONLY); 360 fts_lfree(sp->fts_child); 361 sp->fts_child = NULL; 362 } 363 364 /* 365 * Cd to the subdirectory. 366 * 367 * If have already read and now fail to chdir, whack the list 368 * to make the names come out right, and set the parent errno 369 * so the application will eventually get an error condition. 370 * Set the FTS_DONTCHDIR flag so that when we logically change 371 * directories back to the parent we don't do a chdir. 372 * 373 * If haven't read do so. If the read fails, fts_build sets 374 * FTS_STOP or the fts_info field of the node. 375 */ 376 if (sp->fts_child) { 377 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 378 p->fts_errno = errno; 379 p->fts_flags |= FTS_DONTCHDIR; 380 for (p = sp->fts_child; p; p = p->fts_link) 381 p->fts_accpath = 382 p->fts_parent->fts_accpath; 383 } 384 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 385 if (ISSET(FTS_STOP)) 386 return (NULL); 387 return (p); 388 } 389 p = sp->fts_child; 390 sp->fts_child = NULL; 391 goto name; 392 } 393 394 /* Move to the next node on this level. */ 395next: tmp = p; 396 if ((p = p->fts_link) != NULL) { 397 free(tmp); 398 399 /* 400 * If reached the top, return to the original directory, and 401 * load the paths for the next root. 402 */ 403 if (p->fts_level == FTS_ROOTLEVEL) { 404 if (FCHDIR(sp, sp->fts_rfd)) { 405 SET(FTS_STOP); 406 return (NULL); 407 } 408 fts_load(sp, p); 409 return (sp->fts_cur = p); 410 } 411 412 /* 413 * User may have called fts_set on the node. If skipped, 414 * ignore. If followed, get a file descriptor so we can 415 * get back if necessary. 416 */ 417 if (p->fts_instr == FTS_SKIP) 418 goto next; 419 if (p->fts_instr == FTS_FOLLOW) { 420 p->fts_info = fts_stat(sp, p, 1); 421 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 422 if ((p->fts_symfd = 423 open(".", O_RDONLY, 0)) == -1) { 424 p->fts_errno = errno; 425 p->fts_info = FTS_ERR; 426 } else if (fcntl(p->fts_symfd, F_SETFD, FD_CLOEXEC) == -1) { 427 p->fts_errno = errno; 428 p->fts_info = FTS_ERR; 429 close(p->fts_symfd); 430 } else 431 p->fts_flags |= FTS_SYMFOLLOW; 432 } 433 p->fts_instr = FTS_NOINSTR; 434 } 435 436name: t = sp->fts_path + NAPPEND(p->fts_parent); 437 *t++ = '/'; 438 memmove(t, p->fts_name, (size_t)(p->fts_namelen + 1)); 439 return (sp->fts_cur = p); 440 } 441 442 /* Move up to the parent node. */ 443 p = tmp->fts_parent; 444 free(tmp); 445 446 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 447 /* 448 * Done; free everything up and set errno to 0 so the user 449 * can distinguish between error and EOF. 450 */ 451 free(p); 452 errno = 0; 453 return (sp->fts_cur = NULL); 454 } 455 456 /* Nul terminate the pathname. */ 457 sp->fts_path[p->fts_pathlen] = '\0'; 458 459 /* 460 * Return to the parent directory. If at a root node or came through 461 * a symlink, go back through the file descriptor. Otherwise, cd up 462 * one directory. 463 */ 464 if (p->fts_level == FTS_ROOTLEVEL) { 465 if (FCHDIR(sp, sp->fts_rfd)) { 466 SET(FTS_STOP); 467 return (NULL); 468 } 469 } else if (p->fts_flags & FTS_SYMFOLLOW) { 470 if (FCHDIR(sp, p->fts_symfd)) { 471 saved_errno = errno; 472 (void)close(p->fts_symfd); 473 errno = saved_errno; 474 SET(FTS_STOP); 475 return (NULL); 476 } 477 (void)close(p->fts_symfd); 478 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 479 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 480 SET(FTS_STOP); 481 return (NULL); 482 } 483 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 484 return (sp->fts_cur = p); 485} 486 487/* 488 * Fts_set takes the stream as an argument although it's not used in this 489 * implementation; it would be necessary if anyone wanted to add global 490 * semantics to fts using fts_set. An error return is allowed for similar 491 * reasons. 492 */ 493/* ARGSUSED */ 494int 495fts_set(FTS *sp, FTSENT *p, int instr) 496{ 497 498 _DIAGASSERT(sp != NULL); 499 _DIAGASSERT(p != NULL); 500 501 if (instr && instr != FTS_AGAIN && instr != FTS_FOLLOW && 502 instr != FTS_NOINSTR && instr != FTS_SKIP) { 503 errno = EINVAL; 504 return (1); 505 } 506 p->fts_instr = instr; 507 return (0); 508} 509 510FTSENT * 511fts_children(FTS *sp, int instr) 512{ 513 FTSENT *p; 514 int fd; 515 516 _DIAGASSERT(sp != NULL); 517 518 if (instr && instr != FTS_NAMEONLY) { 519 errno = EINVAL; 520 return (NULL); 521 } 522 523 /* Set current node pointer. */ 524 p = sp->fts_cur; 525 526 /* 527 * Errno set to 0 so user can distinguish empty directory from 528 * an error. 529 */ 530 errno = 0; 531 532 /* Fatal errors stop here. */ 533 if (ISSET(FTS_STOP)) 534 return (NULL); 535 536 /* Return logical hierarchy of user's arguments. */ 537 if (p->fts_info == FTS_INIT) 538 return (p->fts_link); 539 540 /* 541 * If not a directory being visited in pre-order, stop here. Could 542 * allow FTS_DNR, assuming the user has fixed the problem, but the 543 * same effect is available with FTS_AGAIN. 544 */ 545 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 546 return (NULL); 547 548 /* Free up any previous child list. */ 549 if (sp->fts_child) 550 fts_lfree(sp->fts_child); 551 552 if (instr == FTS_NAMEONLY) { 553 SET(FTS_NAMEONLY); 554 instr = BNAMES; 555 } else 556 instr = BCHILD; 557 558 /* 559 * If using chdir on a relative path and called BEFORE fts_read does 560 * its chdir to the root of a traversal, we can lose -- we need to 561 * chdir into the subdirectory, and we don't know where the current 562 * directory is, so we can't get back so that the upcoming chdir by 563 * fts_read will work. 564 */ 565 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 566 ISSET(FTS_NOCHDIR)) 567 return (sp->fts_child = fts_build(sp, instr)); 568 569 if ((fd = open(".", O_RDONLY, 0)) == -1) 570 return (sp->fts_child = NULL); 571 sp->fts_child = fts_build(sp, instr); 572 if (fchdir(fd)) { 573 (void)close(fd); 574 return (NULL); 575 } 576 (void)close(fd); 577 return (sp->fts_child); 578} 579 580/* 581 * This is the tricky part -- do not casually change *anything* in here. The 582 * idea is to build the linked list of entries that are used by fts_children 583 * and fts_read. There are lots of special cases. 584 * 585 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 586 * set and it's a physical walk (so that symbolic links can't be directories), 587 * we can do things quickly. First, if it's a 4.4BSD file system, the type 588 * of the file is in the directory entry. Otherwise, we assume that the number 589 * of subdirectories in a node is equal to the number of links to the parent. 590 * The former skips all stat calls. The latter skips stat calls in any leaf 591 * directories and for any files after the subdirectories in the directory have 592 * been found, cutting the stat calls by about 2/3. 593 */ 594static FTSENT * 595fts_build(FTS *sp, int type) 596{ 597 struct dirent *dp; 598 FTSENT *p, *head; 599 size_t nitems; 600 FTSENT *cur, *tail; 601 DIR *dirp; 602 void *oldaddr; 603 size_t dnamlen; 604 int cderrno, descend, len, level, nlinks, saved_errno, nostat, doadjust; 605 size_t maxlen; 606#ifdef FTS_WHITEOUT 607 int oflag; 608#endif 609 char *cp = NULL; /* pacify gcc */ 610 611 _DIAGASSERT(sp != NULL); 612 613 /* Set current node pointer. */ 614 cur = sp->fts_cur; 615 616 /* 617 * Open the directory for reading. If this fails, we're done. 618 * If being called from fts_read, set the fts_info field. 619 */ 620#ifdef FTS_WHITEOUT 621 if (ISSET(FTS_WHITEOUT)) 622 oflag = DTF_NODUP|DTF_REWIND; 623 else 624 oflag = DTF_HIDEW|DTF_NODUP|DTF_REWIND; 625#else 626#define __opendir2(path, flag) opendir(path) 627#endif 628 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) { 629 if (type == BREAD) { 630 cur->fts_info = FTS_DNR; 631 cur->fts_errno = errno; 632 } 633 return (NULL); 634 } 635 636 /* 637 * Nlinks is the number of possible entries of type directory in the 638 * directory if we're cheating on stat calls, 0 if we're not doing 639 * any stat calls at all, -1 if we're doing stats on everything. 640 */ 641 if (type == BNAMES) { 642 nlinks = 0; 643 nostat = 1; 644 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 645 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 646 nostat = 1; 647 } else { 648 nlinks = -1; 649 nostat = 0; 650 } 651 652#ifdef notdef 653 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 654 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 655 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 656#endif 657 /* 658 * If we're going to need to stat anything or we want to descend 659 * and stay in the directory, chdir. If this fails we keep going, 660 * but set a flag so we don't chdir after the post-order visit. 661 * We won't be able to stat anything, but we can still return the 662 * names themselves. Note, that since fts_read won't be able to 663 * chdir into the directory, it will have to return different path 664 * names than before, i.e. "a/b" instead of "b". Since the node 665 * has already been visited in pre-order, have to wait until the 666 * post-order visit to return the error. There is a special case 667 * here, if there was nothing to stat then it's not an error to 668 * not be able to stat. This is all fairly nasty. If a program 669 * needed sorted entries or stat information, they had better be 670 * checking FTS_NS on the returned nodes. 671 */ 672 cderrno = 0; 673 if (nlinks || type == BREAD) { 674 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) { 675 if (nlinks && type == BREAD) 676 cur->fts_errno = errno; 677 cur->fts_flags |= FTS_DONTCHDIR; 678 descend = 0; 679 cderrno = errno; 680 } else 681 descend = 1; 682 } else 683 descend = 0; 684 685 /* 686 * Figure out the max file name length that can be stored in the 687 * current path -- the inner loop allocates more path as necessary. 688 * We really wouldn't have to do the maxlen calculations here, we 689 * could do them in fts_read before returning the path, but it's a 690 * lot easier here since the length is part of the dirent structure. 691 * 692 * If not changing directories set a pointer so that can just append 693 * each new name into the path. 694 */ 695 len = NAPPEND(cur); 696 if (ISSET(FTS_NOCHDIR)) { 697 cp = sp->fts_path + len; 698 *cp++ = '/'; 699 } 700 len++; 701 maxlen = sp->fts_pathlen - len; 702 703 level = cur->fts_level + 1; 704 705 /* Read the directory, attaching each entry to the `link' pointer. */ 706 doadjust = 0; 707 for (head = tail = NULL, nitems = 0; (dp = readdir(dirp)) != NULL;) { 708 709 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 710 continue; 711 712#if HAVE_STRUCT_DIRENT_D_NAMLEN 713 dnamlen = dp->d_namlen; 714#else 715 dnamlen = strlen(dp->d_name); 716#endif 717 if ((p = fts_alloc(sp, dp->d_name, dnamlen)) == NULL) 718 goto mem1; 719 if (dnamlen >= maxlen) { /* include space for NUL */ 720 oldaddr = sp->fts_path; 721 if (fts_palloc(sp, dnamlen + len + 1)) { 722 /* 723 * No more memory for path or structures. Save 724 * errno, free up the current structure and the 725 * structures already allocated. 726 */ 727mem1: saved_errno = errno; 728 if (p) 729 free(p); 730 fts_lfree(head); 731 (void)closedir(dirp); 732 errno = saved_errno; 733 cur->fts_info = FTS_ERR; 734 SET(FTS_STOP); 735 return (NULL); 736 } 737 /* Did realloc() change the pointer? */ 738 if (oldaddr != sp->fts_path) { 739 doadjust = 1; 740 if (ISSET(FTS_NOCHDIR)) 741 cp = sp->fts_path + len; 742 } 743 maxlen = sp->fts_pathlen - len; 744 } 745 746 if (len + dnamlen >= USHRT_MAX) { 747 /* 748 * In an FTSENT, fts_pathlen is a u_short so it is 749 * possible to wraparound here. If we do, free up 750 * the current structure and the structures already 751 * allocated, then error out with ENAMETOOLONG. 752 */ 753 free(p); 754 fts_lfree(head); 755 (void)closedir(dirp); 756 cur->fts_info = FTS_ERR; 757 SET(FTS_STOP); 758 errno = ENAMETOOLONG; 759 return (NULL); 760 } 761 p->fts_level = level; 762 p->fts_pathlen = len + dnamlen; 763 p->fts_parent = sp->fts_cur; 764 765#ifdef FTS_WHITEOUT 766 if (dp->d_type == DT_WHT) 767 p->fts_flags |= FTS_ISW; 768#endif 769 770 if (cderrno) { 771 if (nlinks) { 772 p->fts_info = FTS_NS; 773 p->fts_errno = cderrno; 774 } else 775 p->fts_info = FTS_NSOK; 776 p->fts_accpath = cur->fts_accpath; 777 } else if (nlinks == 0 778#ifdef DT_DIR 779 || (nostat && 780 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 781#endif 782 ) { 783 p->fts_accpath = 784 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 785 p->fts_info = FTS_NSOK; 786 } else { 787 /* Build a file name for fts_stat to stat. */ 788 if (ISSET(FTS_NOCHDIR)) { 789 p->fts_accpath = p->fts_path; 790 memmove(cp, p->fts_name, 791 (size_t)(p->fts_namelen + 1)); 792 } else 793 p->fts_accpath = p->fts_name; 794 /* Stat it. */ 795 p->fts_info = fts_stat(sp, p, 0); 796 797 /* Decrement link count if applicable. */ 798 if (nlinks > 0 && (p->fts_info == FTS_D || 799 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 800 --nlinks; 801 } 802 803 /* We walk in directory order so "ls -f" doesn't get upset. */ 804 p->fts_link = NULL; 805 if (head == NULL) 806 head = tail = p; 807 else { 808 tail->fts_link = p; 809 tail = p; 810 } 811 ++nitems; 812 } 813 (void)closedir(dirp); 814 815 /* 816 * If had to realloc the path, adjust the addresses for the rest 817 * of the tree. 818 */ 819 if (doadjust) 820 fts_padjust(sp, head); 821 822 /* 823 * If not changing directories, reset the path back to original 824 * state. 825 */ 826 if (ISSET(FTS_NOCHDIR)) { 827 if (len == sp->fts_pathlen || nitems == 0) 828 --cp; 829 *cp = '\0'; 830 } 831 832 /* 833 * If descended after called from fts_children or after called from 834 * fts_read and nothing found, get back. At the root level we use 835 * the saved fd; if one of fts_open()'s arguments is a relative path 836 * to an empty directory, we wind up here with no other way back. If 837 * can't get back, we're done. 838 */ 839 if (descend && (type == BCHILD || !nitems) && 840 (cur->fts_level == FTS_ROOTLEVEL ? 841 FCHDIR(sp, sp->fts_rfd) : 842 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 843 cur->fts_info = FTS_ERR; 844 SET(FTS_STOP); 845 return (NULL); 846 } 847 848 /* If didn't find anything, return NULL. */ 849 if (!nitems) { 850 if (type == BREAD) 851 cur->fts_info = FTS_DP; 852 return (NULL); 853 } 854 855 /* Sort the entries. */ 856 if (sp->fts_compar && nitems > 1) 857 head = fts_sort(sp, head, nitems); 858 return (head); 859} 860 861static u_short 862fts_stat(FTS *sp, FTSENT *p, int follow) 863{ 864 FTSENT *t; 865 dev_t dev; 866 __fts_ino_t ino; 867 __fts_stat_t *sbp, sb; 868 int saved_errno; 869 870 _DIAGASSERT(sp != NULL); 871 _DIAGASSERT(p != NULL); 872 873 /* If user needs stat info, stat buffer already allocated. */ 874 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 875 876#ifdef FTS_WHITEOUT 877 /* check for whiteout */ 878 if (p->fts_flags & FTS_ISW) { 879 if (sbp != &sb) { 880 memset(sbp, '\0', sizeof (*sbp)); 881 sbp->st_mode = S_IFWHT; 882 } 883 return (FTS_W); 884 } 885#endif 886 887 /* 888 * If doing a logical walk, or application requested FTS_FOLLOW, do 889 * a stat(2). If that fails, check for a non-existent symlink. If 890 * fail, set the errno from the stat call. 891 */ 892 if (ISSET(FTS_LOGICAL) || follow) { 893 if (stat(p->fts_accpath, sbp)) { 894 saved_errno = errno; 895 if (!lstat(p->fts_accpath, sbp)) { 896 errno = 0; 897 return (FTS_SLNONE); 898 } 899 p->fts_errno = saved_errno; 900 goto err; 901 } 902 } else if (lstat(p->fts_accpath, sbp)) { 903 p->fts_errno = errno; 904err: memset(sbp, 0, sizeof(*sbp)); 905 return (FTS_NS); 906 } 907 908 if (S_ISDIR(sbp->st_mode)) { 909 /* 910 * Set the device/inode. Used to find cycles and check for 911 * crossing mount points. Also remember the link count, used 912 * in fts_build to limit the number of stat calls. It is 913 * understood that these fields are only referenced if fts_info 914 * is set to FTS_D. 915 */ 916 dev = p->fts_dev = sbp->st_dev; 917 ino = p->fts_ino = sbp->st_ino; 918 p->fts_nlink = sbp->st_nlink; 919 920 if (ISDOT(p->fts_name)) 921 return (FTS_DOT); 922 923 /* 924 * Cycle detection is done by brute force when the directory 925 * is first encountered. If the tree gets deep enough or the 926 * number of symbolic links to directories is high enough, 927 * something faster might be worthwhile. 928 */ 929 for (t = p->fts_parent; 930 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 931 if (ino == t->fts_ino && dev == t->fts_dev) { 932 p->fts_cycle = t; 933 return (FTS_DC); 934 } 935 return (FTS_D); 936 } 937 if (S_ISLNK(sbp->st_mode)) 938 return (FTS_SL); 939 if (S_ISREG(sbp->st_mode)) 940 return (FTS_F); 941 return (FTS_DEFAULT); 942} 943 944static FTSENT * 945fts_sort(FTS *sp, FTSENT *head, size_t nitems) 946{ 947 FTSENT **ap, *p; 948 949 _DIAGASSERT(sp != NULL); 950 _DIAGASSERT(head != NULL); 951 952 /* 953 * Construct an array of pointers to the structures and call qsort(3). 954 * Reassemble the array in the order returned by qsort. If unable to 955 * sort for memory reasons, return the directory entries in their 956 * current order. Allocate enough space for the current needs plus 957 * 40 so don't realloc one entry at a time. 958 */ 959 if (nitems > sp->fts_nitems) { 960 FTSENT **new; 961 962 new = realloc(sp->fts_array, sizeof(FTSENT *) * (nitems + 40)); 963 if (new == 0) 964 return (head); 965 sp->fts_array = new; 966 sp->fts_nitems = nitems + 40; 967 } 968 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 969 *ap++ = p; 970 qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *), 971 (int (*)(const void *, const void *))sp->fts_compar); 972 for (head = *(ap = sp->fts_array); --nitems; ++ap) 973 ap[0]->fts_link = ap[1]; 974 ap[0]->fts_link = NULL; 975 return (head); 976} 977 978static FTSENT * 979fts_alloc(FTS *sp, const char *name, size_t namelen) 980{ 981 FTSENT *p; 982 size_t len; 983 984 _DIAGASSERT(sp != NULL); 985 _DIAGASSERT(name != NULL); 986 987#if defined(ALIGNBYTES) && defined(ALIGN) 988 /* 989 * The file name is a variable length array and no stat structure is 990 * necessary if the user has set the nostat bit. Allocate the FTSENT 991 * structure, the file name and the stat structure in one chunk, but 992 * be careful that the stat structure is reasonably aligned. Since the 993 * fts_name field is declared to be of size 1, the fts_name pointer is 994 * namelen + 2 before the first possible address of the stat structure. 995 */ 996 len = sizeof(FTSENT) + namelen; 997 if (!ISSET(FTS_NOSTAT)) 998 len += sizeof(*(p->fts_statp)) + ALIGNBYTES; 999 if ((p = malloc(len)) == NULL) 1000 return (NULL); 1001 1002 if (!ISSET(FTS_NOSTAT)) 1003 p->fts_statp = 1004 (__fts_stat_t *)ALIGN((u_long)(p->fts_name + namelen + 2)); 1005#else 1006 if ((p = malloc(sizeof(FTSENT) + namelen)) == NULL) 1007 return (NULL); 1008 1009 if (!ISSET(FTS_NOSTAT)) 1010 if ((p->fts_statp = malloc(sizeof(*(p->fts_statp)))) == NULL) { 1011 free(p); 1012 return (NULL); 1013 } 1014#endif 1015 1016 /* Copy the name plus the trailing NULL. */ 1017 memmove(p->fts_name, name, namelen + 1); 1018 1019 p->fts_namelen = namelen; 1020 p->fts_path = sp->fts_path; 1021 p->fts_errno = 0; 1022 p->fts_flags = 0; 1023 p->fts_instr = FTS_NOINSTR; 1024 p->fts_number = 0; 1025 p->fts_pointer = NULL; 1026 return (p); 1027} 1028 1029static void 1030fts_lfree(FTSENT *head) 1031{ 1032 FTSENT *p; 1033 1034 /* XXX: head may be NULL ? */ 1035 1036 /* Free a linked list of structures. */ 1037 while ((p = head) != NULL) { 1038 head = head->fts_link; 1039 1040#if !defined(ALIGNBYTES) || !defined(ALIGN) 1041 if (p->fts_statp) 1042 free(p->fts_statp); 1043#endif 1044 free(p); 1045 } 1046} 1047 1048static size_t 1049fts_pow2(size_t x) 1050{ 1051 1052 x--; 1053 x |= x>>1; 1054 x |= x>>2; 1055 x |= x>>4; 1056 x |= x>>8; 1057 x |= x>>16; 1058#if LONG_BIT > 32 1059 x |= x>>32; 1060#endif 1061#if LONG_BIT > 64 1062 x |= x>>64; 1063#endif 1064 x++; 1065 return (x); 1066} 1067 1068/* 1069 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 1070 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 1071 * though the kernel won't resolve them. Round up the new size to a power of 2, 1072 * so we don't realloc the path 2 bytes at a time. 1073 */ 1074static int 1075fts_palloc(FTS *sp, size_t size) 1076{ 1077 char *new; 1078 1079 _DIAGASSERT(sp != NULL); 1080 1081#if 1 1082 /* Protect against fts_pathlen overflow. */ 1083 if (size > USHRT_MAX + 1) { 1084 errno = ENAMETOOLONG; 1085 return (1); 1086 } 1087#endif 1088 size = fts_pow2(size); 1089 new = realloc(sp->fts_path, size); 1090 if (new == 0) 1091 return (1); 1092 sp->fts_path = new; 1093 sp->fts_pathlen = size; 1094 return (0); 1095} 1096 1097/* 1098 * When the path is realloc'd, have to fix all of the pointers in structures 1099 * already returned. 1100 */ 1101static void 1102fts_padjust(FTS *sp, FTSENT *head) 1103{ 1104 FTSENT *p; 1105 char *addr; 1106 1107 _DIAGASSERT(sp != NULL); 1108 1109#define ADJUST(p) do { \ 1110 if ((p)->fts_accpath != (p)->fts_name) \ 1111 (p)->fts_accpath = \ 1112 addr + ((p)->fts_accpath - (p)->fts_path); \ 1113 (p)->fts_path = addr; \ 1114} while (/*CONSTCOND*/0) 1115 1116 addr = sp->fts_path; 1117 1118 /* Adjust the current set of children. */ 1119 for (p = sp->fts_child; p; p = p->fts_link) 1120 ADJUST(p); 1121 1122 /* Adjust the rest of the tree, including the current level. */ 1123 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1124 ADJUST(p); 1125 p = p->fts_link ? p->fts_link : p->fts_parent; 1126 } 1127} 1128 1129static size_t 1130fts_maxarglen(char * const *argv) 1131{ 1132 size_t len, max; 1133 1134 _DIAGASSERT(argv != NULL); 1135 1136 for (max = 0; *argv; ++argv) 1137 if ((len = strlen(*argv)) > max) 1138 max = len; 1139 return (max + 1); 1140} 1141 1142/* 1143 * Change to dir specified by fd or p->fts_accpath without getting 1144 * tricked by someone changing the world out from underneath us. 1145 * Assumes p->fts_dev and p->fts_ino are filled in. 1146 */ 1147static int 1148fts_safe_changedir(const FTS *sp, const FTSENT *p, int fd, const char *path) 1149{ 1150 int oldfd = fd, ret = -1; 1151 __fts_stat_t sb; 1152 1153 if (ISSET(FTS_NOCHDIR)) 1154 return 0; 1155 1156 if (oldfd < 0 && (fd = open(path, O_RDONLY)) == -1) 1157 return -1; 1158 1159 if (fstat(fd, &sb) == -1) 1160 goto bail; 1161 1162 if (sb.st_ino != p->fts_ino || sb.st_dev != p->fts_dev) { 1163 errno = ENOENT; 1164 goto bail; 1165 } 1166 1167 ret = fchdir(fd); 1168 1169bail: 1170 if (oldfd < 0) { 1171 int save_errno = errno; 1172 (void)close(fd); 1173 errno = save_errno; 1174 } 1175 return ret; 1176} 1177