fts.c revision 1.25
1/* $NetBSD: fts.c,v 1.25 2005/09/13 01:44:09 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 1.25 2005/09/13 01:44:09 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 __P((FTS *, const char *, size_t)); 63static FTSENT *fts_build __P((FTS *, int)); 64static void fts_lfree __P((FTSENT *)); 65static void fts_load __P((FTS *, FTSENT *)); 66static size_t fts_maxarglen __P((char * const *)); 67static size_t fts_pow2 __P((size_t)); 68static int fts_palloc __P((FTS *, size_t)); 69static void fts_padjust __P((FTS *, FTSENT *)); 70static FTSENT *fts_sort __P((FTS *, FTSENT *, size_t)); 71static u_short fts_stat __P((FTS *, FTSENT *, int)); 72static int fts_safe_changedir __P((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(argv, options, compar) 95 char * const *argv; 96 int options; 97 int (*compar) __P((const FTSENT **, const FTSENT **)); 98{ 99 FTS *sp; 100 FTSENT *p, *root; 101 size_t nitems; 102 FTSENT *parent, *tmp = NULL; /* pacify gcc */ 103 size_t len; 104 105 _DIAGASSERT(argv != NULL); 106 107 /* Options check. */ 108 if (options & ~FTS_OPTIONMASK) { 109 errno = EINVAL; 110 return (NULL); 111 } 112 113 /* Allocate/initialize the stream */ 114 if ((sp = malloc((u_int)sizeof(FTS))) == NULL) 115 return (NULL); 116 memset(sp, 0, sizeof(FTS)); 117 sp->fts_compar = compar; 118 sp->fts_options = options; 119 120 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 121 if (ISSET(FTS_LOGICAL)) 122 SET(FTS_NOCHDIR); 123 124 /* 125 * Start out with 1K of path space, and enough, in any case, 126 * to hold the user's paths. 127 */ 128 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN))) 129 goto mem1; 130 131 /* Allocate/initialize root's parent. */ 132 if ((parent = fts_alloc(sp, "", 0)) == NULL) 133 goto mem2; 134 parent->fts_level = FTS_ROOTPARENTLEVEL; 135 136 /* Allocate/initialize root(s). */ 137 for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) { 138 /* Don't allow zero-length paths. */ 139 if ((len = strlen(*argv)) == 0) { 140 errno = ENOENT; 141 goto mem3; 142 } 143 144 if ((p = fts_alloc(sp, *argv, len)) == NULL) 145 goto mem3; 146 p->fts_level = FTS_ROOTLEVEL; 147 p->fts_parent = parent; 148 p->fts_accpath = p->fts_name; 149 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW)); 150 151 /* Command-line "." and ".." are real directories. */ 152 if (p->fts_info == FTS_DOT) 153 p->fts_info = FTS_D; 154 155 /* 156 * If comparison routine supplied, traverse in sorted 157 * order; otherwise traverse in the order specified. 158 */ 159 if (compar) { 160 p->fts_link = root; 161 root = p; 162 } else { 163 p->fts_link = NULL; 164 if (root == NULL) 165 tmp = root = p; 166 else { 167 tmp->fts_link = p; 168 tmp = p; 169 } 170 } 171 } 172 if (compar && nitems > 1) 173 root = fts_sort(sp, root, nitems); 174 175 /* 176 * Allocate a dummy pointer and make fts_read think that we've just 177 * finished the node before the root(s); set p->fts_info to FTS_INIT 178 * so that everything about the "current" node is ignored. 179 */ 180 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 181 goto mem3; 182 sp->fts_cur->fts_link = root; 183 sp->fts_cur->fts_info = FTS_INIT; 184 185 /* 186 * If using chdir(2), grab a file descriptor pointing to dot to insure 187 * that we can get back here; this could be avoided for some paths, 188 * but almost certainly not worth the effort. Slashes, symbolic links, 189 * and ".." are all fairly nasty problems. Note, if we can't get the 190 * descriptor we run anyway, just more slowly. 191 */ 192 if (!ISSET(FTS_NOCHDIR)) { 193 if ((sp->fts_rfd = open(".", O_RDONLY, 0)) == -1) 194 SET(FTS_NOCHDIR); 195 else if (fcntl(sp->fts_rfd, F_SETFD, FD_CLOEXEC) == -1) { 196 close(sp->fts_rfd); 197 SET(FTS_NOCHDIR); 198 } 199 } 200 201 return (sp); 202 203mem3: fts_lfree(root); 204 free(parent); 205mem2: free(sp->fts_path); 206mem1: free(sp); 207 return (NULL); 208} 209 210static void 211fts_load(sp, p) 212 FTS *sp; 213 FTSENT *p; 214{ 215 size_t len; 216 char *cp; 217 218 _DIAGASSERT(sp != NULL); 219 _DIAGASSERT(p != NULL); 220 221 /* 222 * Load the stream structure for the next traversal. Since we don't 223 * actually enter the directory until after the preorder visit, set 224 * the fts_accpath field specially so the chdir gets done to the right 225 * place and the user can access the first node. From fts_open it's 226 * known that the path will fit. 227 */ 228 len = p->fts_pathlen = p->fts_namelen; 229 memmove(sp->fts_path, p->fts_name, len + 1); 230 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 231 len = strlen(++cp); 232 memmove(p->fts_name, cp, len + 1); 233 p->fts_namelen = len; 234 } 235 p->fts_accpath = p->fts_path = sp->fts_path; 236 sp->fts_dev = p->fts_dev; 237} 238 239int 240fts_close(sp) 241 FTS *sp; 242{ 243 FTSENT *freep, *p; 244 int saved_errno = 0; 245 246 _DIAGASSERT(sp != NULL); 247 248 /* 249 * This still works if we haven't read anything -- the dummy structure 250 * points to the root list, so we step through to the end of the root 251 * list which has a valid parent pointer. 252 */ 253 if (sp->fts_cur) { 254 if (ISSET(FTS_SYMFOLLOW)) 255 (void)close(sp->fts_cur->fts_symfd); 256 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 257 freep = p; 258 p = p->fts_link ? p->fts_link : p->fts_parent; 259 free(freep); 260 } 261 free(p); 262 } 263 264 /* Free up child linked list, sort array, path buffer. */ 265 if (sp->fts_child) 266 fts_lfree(sp->fts_child); 267 if (sp->fts_array) 268 free(sp->fts_array); 269 free(sp->fts_path); 270 271 /* Return to original directory, save errno if necessary. */ 272 if (!ISSET(FTS_NOCHDIR)) { 273 if (fchdir(sp->fts_rfd)) 274 saved_errno = errno; 275 (void)close(sp->fts_rfd); 276 } 277 278 /* Free up the stream pointer. */ 279 free(sp); 280 /* ISSET() is illegal after this, since the macro touches sp */ 281 282 /* Set errno and return. */ 283 if (saved_errno) { 284 errno = saved_errno; 285 return (-1); 286 } 287 return (0); 288} 289 290/* 291 * Special case a root of "/" so that slashes aren't appended which would 292 * cause paths to be written as "//foo". 293 */ 294#define NAPPEND(p) \ 295 (p->fts_level == FTS_ROOTLEVEL && p->fts_pathlen == 1 && \ 296 p->fts_path[0] == '/' ? 0 : p->fts_pathlen) 297 298FTSENT * 299fts_read(sp) 300 FTS *sp; 301{ 302 FTSENT *p, *tmp; 303 int instr; 304 char *t; 305 int saved_errno; 306 307 _DIAGASSERT(sp != NULL); 308 309 /* If finished or unrecoverable error, return NULL. */ 310 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 311 return (NULL); 312 313 /* Set current node pointer. */ 314 p = sp->fts_cur; 315 316 /* Save and zero out user instructions. */ 317 instr = p->fts_instr; 318 p->fts_instr = FTS_NOINSTR; 319 320 /* Any type of file may be re-visited; re-stat and re-turn. */ 321 if (instr == FTS_AGAIN) { 322 p->fts_info = fts_stat(sp, p, 0); 323 return (p); 324 } 325 326 /* 327 * Following a symlink -- SLNONE test allows application to see 328 * SLNONE and recover. If indirecting through a symlink, have 329 * keep a pointer to current location. If unable to get that 330 * pointer, follow fails. 331 */ 332 if (instr == FTS_FOLLOW && 333 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 334 p->fts_info = fts_stat(sp, p, 1); 335 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 336 if ((p->fts_symfd = open(".", O_RDONLY, 0)) == -1) { 337 p->fts_errno = errno; 338 p->fts_info = FTS_ERR; 339 } else if (fcntl(p->fts_symfd, F_SETFD, FD_CLOEXEC) == -1) { 340 p->fts_errno = errno; 341 p->fts_info = FTS_ERR; 342 close(p->fts_symfd); 343 } else 344 p->fts_flags |= FTS_SYMFOLLOW; 345 } 346 return (p); 347 } 348 349 /* Directory in pre-order. */ 350 if (p->fts_info == FTS_D) { 351 /* If skipped or crossed mount point, do post-order visit. */ 352 if (instr == FTS_SKIP || 353 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 354 if (p->fts_flags & FTS_SYMFOLLOW) 355 (void)close(p->fts_symfd); 356 if (sp->fts_child) { 357 fts_lfree(sp->fts_child); 358 sp->fts_child = NULL; 359 } 360 p->fts_info = FTS_DP; 361 return (p); 362 } 363 364 /* Rebuild if only read the names and now traversing. */ 365 if (sp->fts_child && ISSET(FTS_NAMEONLY)) { 366 CLR(FTS_NAMEONLY); 367 fts_lfree(sp->fts_child); 368 sp->fts_child = NULL; 369 } 370 371 /* 372 * Cd to the subdirectory. 373 * 374 * If have already read and now fail to chdir, whack the list 375 * to make the names come out right, and set the parent errno 376 * so the application will eventually get an error condition. 377 * Set the FTS_DONTCHDIR flag so that when we logically change 378 * directories back to the parent we don't do a chdir. 379 * 380 * If haven't read do so. If the read fails, fts_build sets 381 * FTS_STOP or the fts_info field of the node. 382 */ 383 if (sp->fts_child) { 384 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 385 p->fts_errno = errno; 386 p->fts_flags |= FTS_DONTCHDIR; 387 for (p = sp->fts_child; p; p = p->fts_link) 388 p->fts_accpath = 389 p->fts_parent->fts_accpath; 390 } 391 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 392 if (ISSET(FTS_STOP)) 393 return (NULL); 394 return (p); 395 } 396 p = sp->fts_child; 397 sp->fts_child = NULL; 398 goto name; 399 } 400 401 /* Move to the next node on this level. */ 402next: tmp = p; 403 if ((p = p->fts_link) != NULL) { 404 free(tmp); 405 406 /* 407 * If reached the top, return to the original directory, and 408 * load the paths for the next root. 409 */ 410 if (p->fts_level == FTS_ROOTLEVEL) { 411 if (FCHDIR(sp, sp->fts_rfd)) { 412 SET(FTS_STOP); 413 return (NULL); 414 } 415 fts_load(sp, p); 416 return (sp->fts_cur = p); 417 } 418 419 /* 420 * User may have called fts_set on the node. If skipped, 421 * ignore. If followed, get a file descriptor so we can 422 * get back if necessary. 423 */ 424 if (p->fts_instr == FTS_SKIP) 425 goto next; 426 if (p->fts_instr == FTS_FOLLOW) { 427 p->fts_info = fts_stat(sp, p, 1); 428 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 429 if ((p->fts_symfd = 430 open(".", O_RDONLY, 0)) == -1) { 431 p->fts_errno = errno; 432 p->fts_info = FTS_ERR; 433 } else if (fcntl(p->fts_symfd, F_SETFD, FD_CLOEXEC) == -1) { 434 p->fts_errno = errno; 435 p->fts_info = FTS_ERR; 436 close(p->fts_symfd); 437 } else 438 p->fts_flags |= FTS_SYMFOLLOW; 439 } 440 p->fts_instr = FTS_NOINSTR; 441 } 442 443name: t = sp->fts_path + NAPPEND(p->fts_parent); 444 *t++ = '/'; 445 memmove(t, p->fts_name, (size_t)(p->fts_namelen + 1)); 446 return (sp->fts_cur = p); 447 } 448 449 /* Move up to the parent node. */ 450 p = tmp->fts_parent; 451 free(tmp); 452 453 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 454 /* 455 * Done; free everything up and set errno to 0 so the user 456 * can distinguish between error and EOF. 457 */ 458 free(p); 459 errno = 0; 460 return (sp->fts_cur = NULL); 461 } 462 463 /* Nul terminate the pathname. */ 464 sp->fts_path[p->fts_pathlen] = '\0'; 465 466 /* 467 * Return to the parent directory. If at a root node or came through 468 * a symlink, go back through the file descriptor. Otherwise, cd up 469 * one directory. 470 */ 471 if (p->fts_level == FTS_ROOTLEVEL) { 472 if (FCHDIR(sp, sp->fts_rfd)) { 473 SET(FTS_STOP); 474 return (NULL); 475 } 476 } else if (p->fts_flags & FTS_SYMFOLLOW) { 477 if (FCHDIR(sp, p->fts_symfd)) { 478 saved_errno = errno; 479 (void)close(p->fts_symfd); 480 errno = saved_errno; 481 SET(FTS_STOP); 482 return (NULL); 483 } 484 (void)close(p->fts_symfd); 485 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 486 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 487 SET(FTS_STOP); 488 return (NULL); 489 } 490 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 491 return (sp->fts_cur = p); 492} 493 494/* 495 * Fts_set takes the stream as an argument although it's not used in this 496 * implementation; it would be necessary if anyone wanted to add global 497 * semantics to fts using fts_set. An error return is allowed for similar 498 * reasons. 499 */ 500/* ARGSUSED */ 501int 502fts_set(sp, p, instr) 503 FTS *sp; 504 FTSENT *p; 505 int instr; 506{ 507 508 _DIAGASSERT(sp != NULL); 509 _DIAGASSERT(p != NULL); 510 511 if (instr && instr != FTS_AGAIN && instr != FTS_FOLLOW && 512 instr != FTS_NOINSTR && instr != FTS_SKIP) { 513 errno = EINVAL; 514 return (1); 515 } 516 p->fts_instr = instr; 517 return (0); 518} 519 520FTSENT * 521fts_children(sp, instr) 522 FTS *sp; 523 int instr; 524{ 525 FTSENT *p; 526 int fd; 527 528 _DIAGASSERT(sp != NULL); 529 530 if (instr && instr != FTS_NAMEONLY) { 531 errno = EINVAL; 532 return (NULL); 533 } 534 535 /* Set current node pointer. */ 536 p = sp->fts_cur; 537 538 /* 539 * Errno set to 0 so user can distinguish empty directory from 540 * an error. 541 */ 542 errno = 0; 543 544 /* Fatal errors stop here. */ 545 if (ISSET(FTS_STOP)) 546 return (NULL); 547 548 /* Return logical hierarchy of user's arguments. */ 549 if (p->fts_info == FTS_INIT) 550 return (p->fts_link); 551 552 /* 553 * If not a directory being visited in pre-order, stop here. Could 554 * allow FTS_DNR, assuming the user has fixed the problem, but the 555 * same effect is available with FTS_AGAIN. 556 */ 557 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 558 return (NULL); 559 560 /* Free up any previous child list. */ 561 if (sp->fts_child) 562 fts_lfree(sp->fts_child); 563 564 if (instr == FTS_NAMEONLY) { 565 SET(FTS_NAMEONLY); 566 instr = BNAMES; 567 } else 568 instr = BCHILD; 569 570 /* 571 * If using chdir on a relative path and called BEFORE fts_read does 572 * its chdir to the root of a traversal, we can lose -- we need to 573 * chdir into the subdirectory, and we don't know where the current 574 * directory is, so we can't get back so that the upcoming chdir by 575 * fts_read will work. 576 */ 577 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 578 ISSET(FTS_NOCHDIR)) 579 return (sp->fts_child = fts_build(sp, instr)); 580 581 if ((fd = open(".", O_RDONLY, 0)) == -1) 582 return (sp->fts_child = NULL); 583 sp->fts_child = fts_build(sp, instr); 584 if (fchdir(fd)) { 585 (void)close(fd); 586 return (NULL); 587 } 588 (void)close(fd); 589 return (sp->fts_child); 590} 591 592/* 593 * This is the tricky part -- do not casually change *anything* in here. The 594 * idea is to build the linked list of entries that are used by fts_children 595 * and fts_read. There are lots of special cases. 596 * 597 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 598 * set and it's a physical walk (so that symbolic links can't be directories), 599 * we can do things quickly. First, if it's a 4.4BSD file system, the type 600 * of the file is in the directory entry. Otherwise, we assume that the number 601 * of subdirectories in a node is equal to the number of links to the parent. 602 * The former skips all stat calls. The latter skips stat calls in any leaf 603 * directories and for any files after the subdirectories in the directory have 604 * been found, cutting the stat calls by about 2/3. 605 */ 606static FTSENT * 607fts_build(sp, type) 608 FTS *sp; 609 int type; 610{ 611 struct dirent *dp; 612 FTSENT *p, *head; 613 size_t nitems; 614 FTSENT *cur, *tail; 615 DIR *dirp; 616 int adjust, cderrno, descend, len, level, nlinks, saved_errno, nostat; 617 size_t maxlen; 618#ifdef FTS_WHITEOUT 619 int oflag; 620#endif 621 char *cp = NULL; /* pacify gcc */ 622 623 _DIAGASSERT(sp != NULL); 624 625 /* Set current node pointer. */ 626 cur = sp->fts_cur; 627 628 /* 629 * Open the directory for reading. If this fails, we're done. 630 * If being called from fts_read, set the fts_info field. 631 */ 632#ifdef FTS_WHITEOUT 633 if (ISSET(FTS_WHITEOUT)) 634 oflag = DTF_NODUP|DTF_REWIND; 635 else 636 oflag = DTF_HIDEW|DTF_NODUP|DTF_REWIND; 637#else 638#define __opendir2(path, flag) opendir(path) 639#endif 640 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) { 641 if (type == BREAD) { 642 cur->fts_info = FTS_DNR; 643 cur->fts_errno = errno; 644 } 645 return (NULL); 646 } 647 648 /* 649 * Nlinks is the number of possible entries of type directory in the 650 * directory if we're cheating on stat calls, 0 if we're not doing 651 * any stat calls at all, -1 if we're doing stats on everything. 652 */ 653 if (type == BNAMES) { 654 nlinks = 0; 655 nostat = 1; 656 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 657 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 658 nostat = 1; 659 } else { 660 nlinks = -1; 661 nostat = 0; 662 } 663 664#ifdef notdef 665 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 666 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 667 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 668#endif 669 /* 670 * If we're going to need to stat anything or we want to descend 671 * and stay in the directory, chdir. If this fails we keep going, 672 * but set a flag so we don't chdir after the post-order visit. 673 * We won't be able to stat anything, but we can still return the 674 * names themselves. Note, that since fts_read won't be able to 675 * chdir into the directory, it will have to return different path 676 * names than before, i.e. "a/b" instead of "b". Since the node 677 * has already been visited in pre-order, have to wait until the 678 * post-order visit to return the error. There is a special case 679 * here, if there was nothing to stat then it's not an error to 680 * not be able to stat. This is all fairly nasty. If a program 681 * needed sorted entries or stat information, they had better be 682 * checking FTS_NS on the returned nodes. 683 */ 684 cderrno = 0; 685 if (nlinks || type == BREAD) { 686 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) { 687 if (nlinks && type == BREAD) 688 cur->fts_errno = errno; 689 cur->fts_flags |= FTS_DONTCHDIR; 690 descend = 0; 691 cderrno = errno; 692 } else 693 descend = 1; 694 } else 695 descend = 0; 696 697 /* 698 * Figure out the max file name length that can be stored in the 699 * current path -- the inner loop allocates more path as necessary. 700 * We really wouldn't have to do the maxlen calculations here, we 701 * could do them in fts_read before returning the path, but it's a 702 * lot easier here since the length is part of the dirent structure. 703 * 704 * If not changing directories set a pointer so that can just append 705 * each new name into the path. 706 */ 707 len = NAPPEND(cur); 708 if (ISSET(FTS_NOCHDIR)) { 709 cp = sp->fts_path + len; 710 *cp++ = '/'; 711 } 712 len++; 713 maxlen = sp->fts_pathlen - len; 714 715 level = cur->fts_level + 1; 716 717 /* Read the directory, attaching each entry to the `link' pointer. */ 718 adjust = 0; 719 for (head = tail = NULL, nitems = 0; (dp = readdir(dirp)) != NULL;) { 720 size_t dlen; 721 722 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 723 continue; 724 725#if HAVE_STRUCT_DIRENT_D_NAMLEN 726 dlen = dp->d_namlen; 727#else 728 dlen = strlen(dp->d_name); 729#endif 730 if ((p = fts_alloc(sp, dp->d_name, dlen)) == NULL) 731 goto mem1; 732 if (dlen >= maxlen) { /* include space for NUL */ 733 if (fts_palloc(sp, len + dlen + 1)) { 734 /* 735 * No more memory for path or structures. Save 736 * errno, free up the current structure and the 737 * structures already allocated. 738 */ 739mem1: saved_errno = errno; 740 if (p) 741 free(p); 742 fts_lfree(head); 743 (void)closedir(dirp); 744 errno = saved_errno; 745 cur->fts_info = FTS_ERR; 746 SET(FTS_STOP); 747 return (NULL); 748 } 749 adjust = 1; 750 if (ISSET(FTS_NOCHDIR)) 751 cp = sp->fts_path + len; 752 maxlen = sp->fts_pathlen - len; 753 } 754 755 p->fts_pathlen = len + dlen; 756 p->fts_parent = sp->fts_cur; 757 p->fts_level = level; 758 759#ifdef FTS_WHITEOUT 760 if (dp->d_type == DT_WHT) 761 p->fts_flags |= FTS_ISW; 762#endif 763 764 if (cderrno) { 765 if (nlinks) { 766 p->fts_info = FTS_NS; 767 p->fts_errno = cderrno; 768 } else 769 p->fts_info = FTS_NSOK; 770 p->fts_accpath = cur->fts_accpath; 771 } else if (nlinks == 0 772#ifdef DT_DIR 773 || (nostat && 774 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 775#endif 776 ) { 777 p->fts_accpath = 778 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 779 p->fts_info = FTS_NSOK; 780 } else { 781 /* Build a file name for fts_stat to stat. */ 782 if (ISSET(FTS_NOCHDIR)) { 783 p->fts_accpath = p->fts_path; 784 memmove(cp, p->fts_name, 785 (size_t)(p->fts_namelen + 1)); 786 } else 787 p->fts_accpath = p->fts_name; 788 /* Stat it. */ 789 p->fts_info = fts_stat(sp, p, 0); 790 791 /* Decrement link count if applicable. */ 792 if (nlinks > 0 && (p->fts_info == FTS_D || 793 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 794 --nlinks; 795 } 796 797 /* We walk in directory order so "ls -f" doesn't get upset. */ 798 p->fts_link = NULL; 799 if (head == NULL) 800 head = tail = p; 801 else { 802 tail->fts_link = p; 803 tail = p; 804 } 805 ++nitems; 806 } 807 (void)closedir(dirp); 808 809 /* 810 * If had to realloc the path, adjust the addresses for the rest 811 * of the tree. 812 */ 813 if (adjust) 814 fts_padjust(sp, head); 815 816 /* 817 * If not changing directories, reset the path back to original 818 * state. 819 */ 820 if (ISSET(FTS_NOCHDIR)) { 821 if (cp - 1 > sp->fts_path) 822 --cp; 823 *cp = '\0'; 824 } 825 826 /* 827 * If descended after called from fts_children or after called from 828 * fts_read and nothing found, get back. At the root level we use 829 * the saved fd; if one of fts_open()'s arguments is a relative path 830 * to an empty directory, we wind up here with no other way back. If 831 * can't get back, we're done. 832 */ 833 if (descend && (type == BCHILD || !nitems) && 834 (cur->fts_level == FTS_ROOTLEVEL ? 835 FCHDIR(sp, sp->fts_rfd) : 836 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 837 cur->fts_info = FTS_ERR; 838 SET(FTS_STOP); 839 return (NULL); 840 } 841 842 /* If didn't find anything, return NULL. */ 843 if (!nitems) { 844 if (type == BREAD) 845 cur->fts_info = FTS_DP; 846 return (NULL); 847 } 848 849 /* Sort the entries. */ 850 if (sp->fts_compar && nitems > 1) 851 head = fts_sort(sp, head, nitems); 852 return (head); 853} 854 855static u_short 856fts_stat(sp, p, follow) 857 FTS *sp; 858 FTSENT *p; 859 int follow; 860{ 861 FTSENT *t; 862 dev_t dev; 863 __fts_ino_t ino; 864 __fts_stat_t *sbp, sb; 865 int saved_errno; 866 867 _DIAGASSERT(sp != NULL); 868 _DIAGASSERT(p != NULL); 869 870 /* If user needs stat info, stat buffer already allocated. */ 871 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 872 873#ifdef FTS_WHITEOUT 874 /* check for whiteout */ 875 if (p->fts_flags & FTS_ISW) { 876 if (sbp != &sb) { 877 memset(sbp, '\0', sizeof (*sbp)); 878 sbp->st_mode = S_IFWHT; 879 } 880 return (FTS_W); 881 } 882#endif 883 884 /* 885 * If doing a logical walk, or application requested FTS_FOLLOW, do 886 * a stat(2). If that fails, check for a non-existent symlink. If 887 * fail, set the errno from the stat call. 888 */ 889 if (ISSET(FTS_LOGICAL) || follow) { 890 if (stat(p->fts_accpath, sbp)) { 891 saved_errno = errno; 892 if (!lstat(p->fts_accpath, sbp)) { 893 errno = 0; 894 return (FTS_SLNONE); 895 } 896 p->fts_errno = saved_errno; 897 goto err; 898 } 899 } else if (lstat(p->fts_accpath, sbp)) { 900 p->fts_errno = errno; 901err: memset(sbp, 0, sizeof(*sbp)); 902 return (FTS_NS); 903 } 904 905 if (S_ISDIR(sbp->st_mode)) { 906 /* 907 * Set the device/inode. Used to find cycles and check for 908 * crossing mount points. Also remember the link count, used 909 * in fts_build to limit the number of stat calls. It is 910 * understood that these fields are only referenced if fts_info 911 * is set to FTS_D. 912 */ 913 dev = p->fts_dev = sbp->st_dev; 914 ino = p->fts_ino = sbp->st_ino; 915 p->fts_nlink = sbp->st_nlink; 916 917 if (ISDOT(p->fts_name)) 918 return (FTS_DOT); 919 920 /* 921 * Cycle detection is done by brute force when the directory 922 * is first encountered. If the tree gets deep enough or the 923 * number of symbolic links to directories is high enough, 924 * something faster might be worthwhile. 925 */ 926 for (t = p->fts_parent; 927 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 928 if (ino == t->fts_ino && dev == t->fts_dev) { 929 p->fts_cycle = t; 930 return (FTS_DC); 931 } 932 return (FTS_D); 933 } 934 if (S_ISLNK(sbp->st_mode)) 935 return (FTS_SL); 936 if (S_ISREG(sbp->st_mode)) 937 return (FTS_F); 938 return (FTS_DEFAULT); 939} 940 941static FTSENT * 942fts_sort(sp, head, nitems) 943 FTS *sp; 944 FTSENT *head; 945 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 (*) __P((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(sp, name, namelen) 980 FTS *sp; 981 const char *name; 982 size_t namelen; 983{ 984 FTSENT *p; 985 size_t len; 986 987 _DIAGASSERT(sp != NULL); 988 _DIAGASSERT(name != NULL); 989 990#if defined(ALIGNBYTES) && defined(ALIGN) 991 /* 992 * The file name is a variable length array and no stat structure is 993 * necessary if the user has set the nostat bit. Allocate the FTSENT 994 * structure, the file name and the stat structure in one chunk, but 995 * be careful that the stat structure is reasonably aligned. Since the 996 * fts_name field is declared to be of size 1, the fts_name pointer is 997 * namelen + 2 before the first possible address of the stat structure. 998 */ 999 len = sizeof(FTSENT) + namelen; 1000 if (!ISSET(FTS_NOSTAT)) 1001 len += sizeof(*(p->fts_statp)) + ALIGNBYTES; 1002 if ((p = malloc(len)) == NULL) 1003 return (NULL); 1004 1005 if (!ISSET(FTS_NOSTAT)) 1006 p->fts_statp = 1007 (__fts_stat_t *)ALIGN((u_long)(p->fts_name + namelen + 2)); 1008#else 1009 if ((p = malloc(sizeof(FTSENT) + namelen)) == NULL) 1010 return (NULL); 1011 1012 if (!ISSET(FTS_NOSTAT)) 1013 if ((p->fts_statp = malloc(sizeof(*(p->fts_statp)))) == NULL) { 1014 free(p); 1015 return (NULL); 1016 } 1017#endif 1018 1019 /* Copy the name plus the trailing NULL. */ 1020 memmove(p->fts_name, name, namelen + 1); 1021 1022 p->fts_namelen = namelen; 1023 p->fts_path = sp->fts_path; 1024 p->fts_errno = 0; 1025 p->fts_flags = 0; 1026 p->fts_instr = FTS_NOINSTR; 1027 p->fts_number = 0; 1028 p->fts_pointer = NULL; 1029 return (p); 1030} 1031 1032static void 1033fts_lfree(head) 1034 FTSENT *head; 1035{ 1036 FTSENT *p; 1037 1038 /* XXX: head may be NULL ? */ 1039 1040 /* Free a linked list of structures. */ 1041 while ((p = head) != NULL) { 1042 head = head->fts_link; 1043 1044#if !defined(ALIGNBYTES) || !defined(ALIGN) 1045 if (p->fts_statp) 1046 free(p->fts_statp); 1047#endif 1048 free(p); 1049 } 1050} 1051 1052static size_t 1053fts_pow2(x) 1054 size_t x; 1055{ 1056 1057 x--; 1058 x |= x>>1; 1059 x |= x>>2; 1060 x |= x>>4; 1061 x |= x>>8; 1062 x |= x>>16; 1063#if LONG_BIT > 32 1064 x |= x>>32; 1065#endif 1066#if LONG_BIT > 64 1067 x |= x>>64; 1068#endif 1069 x++; 1070 return (x); 1071} 1072 1073/* 1074 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 1075 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 1076 * though the kernel won't resolve them. Round up the new size to a power of 2, 1077 * so we don't realloc the path 2 bytes at a time. 1078 */ 1079static int 1080fts_palloc(sp, size) 1081 FTS *sp; 1082 size_t size; 1083{ 1084 char *new; 1085 1086 _DIAGASSERT(sp != NULL); 1087 1088#if 1 1089 /* Protect against fts_pathlen overflow. */ 1090 if (size > USHRT_MAX + 1) { 1091 errno = ENOMEM; 1092 return (1); 1093 } 1094#endif 1095 size = fts_pow2(size); 1096 new = realloc(sp->fts_path, size); 1097 if (new == 0) 1098 return (1); 1099 sp->fts_path = new; 1100 sp->fts_pathlen = size; 1101 return (0); 1102} 1103 1104/* 1105 * When the path is realloc'd, have to fix all of the pointers in structures 1106 * already returned. 1107 */ 1108static void 1109fts_padjust(sp, head) 1110 FTS *sp; 1111 FTSENT *head; 1112{ 1113 FTSENT *p; 1114 char *addr; 1115 1116 _DIAGASSERT(sp != NULL); 1117 1118#define ADJUST(p) do { \ 1119 if ((p)->fts_accpath != (p)->fts_name) \ 1120 (p)->fts_accpath = \ 1121 addr + ((p)->fts_accpath - (p)->fts_path); \ 1122 (p)->fts_path = addr; \ 1123} while (/*CONSTCOND*/0) 1124 1125 addr = sp->fts_path; 1126 1127 /* Adjust the current set of children. */ 1128 for (p = sp->fts_child; p; p = p->fts_link) 1129 ADJUST(p); 1130 1131 /* Adjust the rest of the tree, including the current level. */ 1132 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1133 ADJUST(p); 1134 p = p->fts_link ? p->fts_link : p->fts_parent; 1135 } 1136} 1137 1138static size_t 1139fts_maxarglen(argv) 1140 char * const *argv; 1141{ 1142 size_t len, max; 1143 1144 _DIAGASSERT(argv != NULL); 1145 1146 for (max = 0; *argv; ++argv) 1147 if ((len = strlen(*argv)) > max) 1148 max = len; 1149 return (max + 1); 1150} 1151 1152/* 1153 * Change to dir specified by fd or p->fts_accpath without getting 1154 * tricked by someone changing the world out from underneath us. 1155 * Assumes p->fts_dev and p->fts_ino are filled in. 1156 */ 1157static int 1158fts_safe_changedir(sp, p, fd, path) 1159 const FTS *sp; 1160 const FTSENT *p; 1161 int fd; 1162 const char *path; 1163{ 1164 int oldfd = fd, ret = -1; 1165 __fts_stat_t sb; 1166 1167 if (ISSET(FTS_NOCHDIR)) 1168 return 0; 1169 1170 if (oldfd < 0 && (fd = open(path, O_RDONLY)) == -1) 1171 return -1; 1172 1173 if (fstat(fd, &sb) == -1) 1174 goto bail; 1175 1176 if (sb.st_ino != p->fts_ino || sb.st_dev != p->fts_dev) { 1177 errno = ENOENT; 1178 goto bail; 1179 } 1180 1181 ret = fchdir(fd); 1182 1183bail: 1184 if (oldfd < 0) { 1185 int save_errno = errno; 1186 (void)close(fd); 1187 errno = save_errno; 1188 } 1189 return ret; 1190} 1191