1/* $NetBSD: fts.c,v 1.52 2022/04/19 20:32:15 rillig 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 1.52 2022/04/19 20:32:15 rillig 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#ifndef ftsent_namelen_truncate 83#define ftsent_namelen_truncate(a) \ 84 ((a) > UINT_MAX ? UINT_MAX : (unsigned int)(a)) 85#endif 86#ifndef ftsent_pathlen_truncate 87#define ftsent_pathlen_truncate(a) \ 88 ((a) > UINT_MAX ? UINT_MAX : (unsigned int)(a)) 89#endif 90#ifndef fts_pathlen_truncate 91#define fts_pathlen_truncate(a) \ 92 ((a) > UINT_MAX ? UINT_MAX : (unsigned int)(a)) 93#endif 94#ifndef fts_nitems_truncate 95#define fts_nitems_truncate(a) \ 96 ((a) > UINT_MAX ? UINT_MAX : (unsigned int)(a)) 97#endif 98 99#define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2]))) 100 101#define CLR(opt) (sp->fts_options &= ~(opt)) 102#define ISSET(opt) (sp->fts_options & (opt)) 103#define SET(opt) (sp->fts_options |= (opt)) 104 105#define CHDIR(sp, path) (!ISSET(FTS_NOCHDIR) && chdir(path)) 106#define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 107 108/* fts_build flags */ 109#define BCHILD 1 /* fts_children */ 110#define BNAMES 2 /* fts_children, names only */ 111#define BREAD 3 /* fts_read */ 112 113#ifndef DTF_HIDEW 114#undef FTS_WHITEOUT 115#endif 116 117FTS * 118fts_open(char * const *argv, int options, 119 int (*compar)(const FTSENT **, const FTSENT **)) 120{ 121 FTS *sp; 122 FTSENT *p, *root; 123 size_t nitems; 124 FTSENT *parent, *tmp = NULL; /* pacify gcc */ 125 size_t len; 126 127 _DIAGASSERT(argv != NULL); 128 129 /* Options check. */ 130 if (options & ~FTS_OPTIONMASK) { 131 errno = EINVAL; 132 return (NULL); 133 } 134 135 /* Allocate/initialize the stream */ 136 if ((sp = calloc(1, sizeof(FTS))) == NULL) 137 return (NULL); 138 sp->fts_compar = compar; 139 sp->fts_options = options; 140 141 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 142 if (ISSET(FTS_LOGICAL)) 143 SET(FTS_NOCHDIR); 144 145 /* 146 * Start out with 1K of path space, and enough, in any case, 147 * to hold the user's paths. 148 */ 149 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN))) 150 goto mem1; 151 152 /* Allocate/initialize root's parent. */ 153 if ((parent = fts_alloc(sp, "", 0)) == NULL) 154 goto mem2; 155 parent->fts_level = FTS_ROOTPARENTLEVEL; 156 157 /* Allocate/initialize root(s). */ 158 for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) { 159 /* Don't allow zero-length paths. */ 160 if ((len = strlen(*argv)) == 0) { 161 errno = ENOENT; 162 goto mem3; 163 } 164 165 if ((p = fts_alloc(sp, *argv, len)) == NULL) 166 goto mem3; 167 p->fts_level = FTS_ROOTLEVEL; 168 p->fts_parent = parent; 169 p->fts_accpath = p->fts_name; 170 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW)); 171 172 /* Command-line "." and ".." are real directories. */ 173 if (p->fts_info == FTS_DOT) 174 p->fts_info = FTS_D; 175 176 /* 177 * If comparison routine supplied, traverse in sorted 178 * order; otherwise traverse in the order specified. 179 */ 180 if (compar) { 181 p->fts_link = root; 182 root = p; 183 } else { 184 p->fts_link = NULL; 185 if (root == NULL) 186 tmp = root = p; 187 else { 188 tmp->fts_link = p; 189 tmp = p; 190 } 191 } 192 } 193 if (compar && nitems > 1) 194 root = fts_sort(sp, root, nitems); 195 196 /* 197 * Allocate a dummy pointer and make fts_read think that we've just 198 * finished the node before the root(s); set p->fts_info to FTS_INIT 199 * so that everything about the "current" node is ignored. 200 */ 201 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 202 goto mem3; 203 sp->fts_cur->fts_link = root; 204 sp->fts_cur->fts_info = FTS_INIT; 205 206 /* 207 * If using chdir(2), grab a file descriptor pointing to dot to ensure 208 * that we can get back here; this could be avoided for some paths, 209 * but almost certainly not worth the effort. Slashes, symbolic links, 210 * and ".." are all fairly nasty problems. Note, if we can't get the 211 * descriptor we run anyway, just more slowly. 212 */ 213#ifndef O_CLOEXEC 214#define O_CLOEXEC 0 215#endif 216 if (!ISSET(FTS_NOCHDIR)) { 217 if ((sp->fts_rfd = open(".", O_RDONLY | O_CLOEXEC, 0)) == -1) 218 SET(FTS_NOCHDIR); 219 } 220 221 if (nitems == 0) 222 fts_free(parent); 223 224 return (sp); 225 226mem3: fts_lfree(root); 227 fts_free(parent); 228mem2: free(sp->fts_path); 229mem1: free(sp); 230 return (NULL); 231} 232 233static void 234fts_load(FTS *sp, FTSENT *p) 235{ 236 size_t len; 237 char *cp; 238 239 _DIAGASSERT(sp != NULL); 240 _DIAGASSERT(p != NULL); 241 242 /* 243 * Load the stream structure for the next traversal. Since we don't 244 * actually enter the directory until after the preorder visit, set 245 * the fts_accpath field specially so the chdir gets done to the right 246 * place and the user can access the first node. From fts_open it's 247 * known that the path will fit. 248 */ 249 len = p->fts_pathlen = p->fts_namelen; 250 memmove(sp->fts_path, p->fts_name, len + 1); 251 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 252 len = strlen(++cp); 253 memmove(p->fts_name, cp, len + 1); 254 p->fts_namelen = ftsent_namelen_truncate(len); 255 } 256 p->fts_accpath = p->fts_path = sp->fts_path; 257 sp->fts_dev = p->fts_dev; 258} 259 260int 261fts_close(FTS *sp) 262{ 263 FTSENT *freep, *p; 264 int saved_errno = 0; 265 266 _DIAGASSERT(sp != NULL); 267 268 /* 269 * This still works if we haven't read anything -- the dummy structure 270 * points to the root list, so we step through to the end of the root 271 * list which has a valid parent pointer. 272 */ 273 if (sp->fts_cur) { 274 if (sp->fts_cur->fts_flags & FTS_SYMFOLLOW) 275 (void)close(sp->fts_cur->fts_symfd); 276 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 277 freep = p; 278 p = p->fts_link ? p->fts_link : p->fts_parent; 279 fts_free(freep); 280 } 281 fts_free(p); 282 } 283 284 /* Free up child linked list, sort array, path buffer. */ 285 if (sp->fts_child) 286 fts_lfree(sp->fts_child); 287 if (sp->fts_array) 288 free(sp->fts_array); 289 free(sp->fts_path); 290 291 /* Return to original directory, save errno if necessary. */ 292 if (!ISSET(FTS_NOCHDIR)) { 293 if (fchdir(sp->fts_rfd) == -1) 294 saved_errno = errno; 295 (void)close(sp->fts_rfd); 296 } 297 298 /* Free up the stream pointer. */ 299 free(sp); 300 if (saved_errno) { 301 errno = saved_errno; 302 return -1; 303 } 304 305 return 0; 306} 307 308#if !defined(__FTS_COMPAT_TAILINGSLASH) 309 310/* 311 * Special case of "/" at the end of the path so that slashes aren't 312 * appended which would cause paths to be written as "....//foo". 313 */ 314#define NAPPEND(p) \ 315 (p->fts_path[p->fts_pathlen - 1] == '/' \ 316 ? p->fts_pathlen - 1 : p->fts_pathlen) 317 318#else /* !defined(__FTS_COMPAT_TAILINGSLASH) */ 319 320/* 321 * compatibility with the old behaviour. 322 * 323 * Special case a root of "/" so that slashes aren't appended which would 324 * cause paths to be written as "//foo". 325 */ 326 327#define NAPPEND(p) \ 328 (p->fts_level == FTS_ROOTLEVEL && p->fts_pathlen == 1 && \ 329 p->fts_path[0] == '/' ? 0 : p->fts_pathlen) 330 331#endif /* !defined(__FTS_COMPAT_TAILINGSLASH) */ 332 333FTSENT * 334fts_read(FTS *sp) 335{ 336 FTSENT *p, *tmp; 337 int instr; 338 char *t; 339 int saved_errno; 340 341 _DIAGASSERT(sp != NULL); 342 343 /* If finished or unrecoverable error, return NULL. */ 344 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 345 return (NULL); 346 347 /* Set current node pointer. */ 348 p = sp->fts_cur; 349 350 /* Save and zero out user instructions. */ 351 instr = p->fts_instr; 352 p->fts_instr = FTS_NOINSTR; 353 354 /* Any type of file may be re-visited; re-stat and re-turn. */ 355 if (instr == FTS_AGAIN) { 356 p->fts_info = fts_stat(sp, p, 0); 357 return (p); 358 } 359 360 /* 361 * Following a symlink -- SLNONE test allows application to see 362 * SLNONE and recover. If indirecting through a symlink, have 363 * keep a pointer to current location. If unable to get that 364 * pointer, follow fails. 365 */ 366 if (instr == FTS_FOLLOW && 367 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 368 p->fts_info = fts_stat(sp, p, 1); 369 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 370 if ((p->fts_symfd = open(".", O_RDONLY | O_CLOEXEC, 0)) 371 == -1) { 372 p->fts_errno = errno; 373 p->fts_info = FTS_ERR; 374 } else 375 p->fts_flags |= FTS_SYMFOLLOW; 376 } 377 return (p); 378 } 379 380 /* Directory in pre-order. */ 381 if (p->fts_info == FTS_D) { 382 /* If skipped or crossed mount point, do post-order visit. */ 383 if (instr == FTS_SKIP || 384 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 385 if (p->fts_flags & FTS_SYMFOLLOW) 386 (void)close(p->fts_symfd); 387 if (sp->fts_child) { 388 fts_lfree(sp->fts_child); 389 sp->fts_child = NULL; 390 } 391 p->fts_info = FTS_DP; 392 return (p); 393 } 394 395 /* Rebuild if only read the names and now traversing. */ 396 if (sp->fts_child && ISSET(FTS_NAMEONLY)) { 397 CLR(FTS_NAMEONLY); 398 fts_lfree(sp->fts_child); 399 sp->fts_child = NULL; 400 } 401 402 /* 403 * Cd to the subdirectory. 404 * 405 * If have already read and now fail to chdir, whack the list 406 * to make the names come out right, and set the parent errno 407 * so the application will eventually get an error condition. 408 * Set the FTS_DONTCHDIR flag so that when we logically change 409 * directories back to the parent we don't do a chdir. 410 * 411 * If haven't read do so. If the read fails, fts_build sets 412 * FTS_STOP or the fts_info field of the node. 413 */ 414 if (sp->fts_child) { 415 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 416 p->fts_errno = errno; 417 p->fts_flags |= FTS_DONTCHDIR; 418 for (p = sp->fts_child; p; p = p->fts_link) 419 p->fts_accpath = 420 p->fts_parent->fts_accpath; 421 } 422 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 423 if (ISSET(FTS_STOP)) 424 return (NULL); 425 return (p); 426 } 427 p = sp->fts_child; 428 sp->fts_child = NULL; 429 goto name; 430 } 431 432next: 433 /* Move to the next node on this level. */ 434 tmp = p; 435 436 /* 437 * We are going to free sp->fts_cur, set it to NULL so 438 * that fts_close() does not attempt to free it again 439 * if we exit without setting it to a new value because 440 * FCHDIR() failed below. 441 */ 442 assert(tmp == sp->fts_cur); 443 sp->fts_cur = NULL; 444 445 if ((p = p->fts_link) != NULL) { 446 fts_free(tmp); 447 448 /* 449 * If reached the top, return to the original directory, and 450 * load the paths for the next root. 451 */ 452 if (p->fts_level == FTS_ROOTLEVEL) { 453 if (FCHDIR(sp, sp->fts_rfd)) { 454 SET(FTS_STOP); 455 return (NULL); 456 } 457 fts_load(sp, p); 458 return (sp->fts_cur = p); 459 } 460 461 /* 462 * User may have called fts_set on the node. If skipped, 463 * ignore. If followed, get a file descriptor so we can 464 * get back if necessary. 465 */ 466 if (p->fts_instr == FTS_SKIP) 467 goto next; 468 if (p->fts_instr == FTS_FOLLOW) { 469 p->fts_info = fts_stat(sp, p, 1); 470 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 471 if ((p->fts_symfd = 472 open(".", O_RDONLY | O_CLOEXEC, 0)) == -1) { 473 p->fts_errno = errno; 474 p->fts_info = FTS_ERR; 475 } else 476 p->fts_flags |= FTS_SYMFOLLOW; 477 } 478 p->fts_instr = FTS_NOINSTR; 479 } 480 481name: t = sp->fts_path + NAPPEND(p->fts_parent); 482 *t++ = '/'; 483 memmove(t, p->fts_name, (size_t)(p->fts_namelen + 1)); 484 return (sp->fts_cur = p); 485 } 486 487 /* Move up to the parent node. */ 488 p = tmp->fts_parent; 489 fts_free(tmp); 490 491 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 492 /* 493 * Done; free everything up and set errno to 0 so the user 494 * can distinguish between error and EOF. 495 */ 496 fts_free(p); 497 errno = 0; 498 return (sp->fts_cur = NULL); 499 } 500 501 /* NUL terminate the pathname. */ 502 sp->fts_path[p->fts_pathlen] = '\0'; 503 504 /* 505 * Return to the parent directory. If at a root node or came through 506 * a symlink, go back through the file descriptor. Otherwise, cd up 507 * one directory. 508 */ 509 if (p->fts_level == FTS_ROOTLEVEL) { 510 if (FCHDIR(sp, sp->fts_rfd)) { 511 SET(FTS_STOP); 512 return (NULL); 513 } 514 } else if (p->fts_flags & FTS_SYMFOLLOW) { 515 if (FCHDIR(sp, p->fts_symfd)) { 516 saved_errno = errno; 517 (void)close(p->fts_symfd); 518 errno = saved_errno; 519 SET(FTS_STOP); 520 return (NULL); 521 } 522 (void)close(p->fts_symfd); 523 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 524 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 525 SET(FTS_STOP); 526 return (NULL); 527 } 528 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 529 return (sp->fts_cur = p); 530} 531 532/* 533 * Fts_set takes the stream as an argument although it's not used in this 534 * implementation; it would be necessary if anyone wanted to add global 535 * semantics to fts using fts_set. An error return is allowed for similar 536 * reasons. 537 */ 538/* ARGSUSED */ 539int 540fts_set(FTS *sp, FTSENT *p, int instr) 541{ 542 543 _DIAGASSERT(sp != NULL); 544 _DIAGASSERT(p != NULL); 545 546 if (instr && instr != FTS_AGAIN && instr != FTS_FOLLOW && 547 instr != FTS_NOINSTR && instr != FTS_SKIP) { 548 errno = EINVAL; 549 return (1); 550 } 551 p->fts_instr = instr; 552 return (0); 553} 554 555FTSENT * 556fts_children(FTS *sp, int instr) 557{ 558 FTSENT *p; 559 int fd; 560 561 _DIAGASSERT(sp != NULL); 562 563 if (instr && instr != FTS_NAMEONLY) { 564 errno = EINVAL; 565 return (NULL); 566 } 567 568 /* Set current node pointer. */ 569 p = sp->fts_cur; 570 571 /* 572 * Errno set to 0 so user can distinguish empty directory from 573 * an error. 574 */ 575 errno = 0; 576 577 /* Fatal errors stop here. */ 578 if (ISSET(FTS_STOP)) 579 return (NULL); 580 581 /* Return logical hierarchy of user's arguments. */ 582 if (p->fts_info == FTS_INIT) 583 return (p->fts_link); 584 585 /* 586 * If not a directory being visited in pre-order, stop here. Could 587 * allow FTS_DNR, assuming the user has fixed the problem, but the 588 * same effect is available with FTS_AGAIN. 589 */ 590 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 591 return (NULL); 592 593 /* Free up any previous child list. */ 594 if (sp->fts_child) 595 fts_lfree(sp->fts_child); 596 597 if (instr == FTS_NAMEONLY) { 598 SET(FTS_NAMEONLY); 599 instr = BNAMES; 600 } else 601 instr = BCHILD; 602 603 /* 604 * If using chdir on a relative path and called BEFORE fts_read does 605 * its chdir to the root of a traversal, we can lose -- we need to 606 * chdir into the subdirectory, and we don't know where the current 607 * directory is, so we can't get back so that the upcoming chdir by 608 * fts_read will work. 609 */ 610 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 611 ISSET(FTS_NOCHDIR)) 612 return (sp->fts_child = fts_build(sp, instr)); 613 614 if ((fd = open(".", O_RDONLY | O_CLOEXEC, 0)) == -1) 615 return (sp->fts_child = NULL); 616 sp->fts_child = fts_build(sp, instr); 617 if (fchdir(fd)) { 618 (void)close(fd); 619 return (NULL); 620 } 621 (void)close(fd); 622 return (sp->fts_child); 623} 624 625/* 626 * This is the tricky part -- do not casually change *anything* in here. The 627 * idea is to build the linked list of entries that are used by fts_children 628 * and fts_read. There are lots of special cases. 629 * 630 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 631 * set and it's a physical walk (so that symbolic links can't be directories), 632 * we can do things quickly. First, if it's a 4.4BSD file system, the type 633 * of the file is in the directory entry. Otherwise, we assume that the number 634 * of subdirectories in a node is equal to the number of links to the parent. 635 * The former skips all stat calls. The latter skips stat calls in any leaf 636 * directories and for any files after the subdirectories in the directory have 637 * been found, cutting the stat calls by about 2/3. 638 */ 639static FTSENT * 640fts_build(FTS *sp, int type) 641{ 642 struct dirent *dp; 643 FTSENT *p, *head; 644 size_t nitems; 645 FTSENT *cur, *tail; 646 DIR *dirp; 647 void *oldaddr; 648 size_t dnamlen; 649 int cderrno, descend, level, nlinks, saved_errno, nostat, doadjust; 650 size_t len, maxlen; 651#ifdef FTS_WHITEOUT 652 int oflag; 653#endif 654 char *cp = NULL; /* pacify gcc */ 655 656 _DIAGASSERT(sp != NULL); 657 658 /* Set current node pointer. */ 659 cur = sp->fts_cur; 660 661 /* 662 * Open the directory for reading. If this fails, we're done. 663 * If being called from fts_read, set the fts_info field. 664 */ 665#ifdef FTS_WHITEOUT 666 if (ISSET(FTS_WHITEOUT)) 667 oflag = DTF_NODUP|DTF_REWIND; 668 else 669 oflag = DTF_HIDEW|DTF_NODUP|DTF_REWIND; 670#else 671#define __opendir2(path, flag) opendir(path) 672#endif 673 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) { 674 if (type == BREAD) { 675 cur->fts_info = FTS_DNR; 676 cur->fts_errno = errno; 677 } 678 return (NULL); 679 } 680 681 /* 682 * Nlinks is the number of possible entries of type directory in the 683 * directory if we're cheating on stat calls, 0 if we're not doing 684 * any stat calls at all, -1 if we're doing stats on everything. 685 */ 686 if (type == BNAMES) { 687 nlinks = 0; 688 nostat = 1; 689 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 690 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 691 nostat = 1; 692 } else { 693 nlinks = -1; 694 nostat = 0; 695 } 696 697#ifdef notdef 698 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 699 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 700 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 701#endif 702 /* 703 * If we're going to need to stat anything or we want to descend 704 * and stay in the directory, chdir. If this fails we keep going, 705 * but set a flag so we don't chdir after the post-order visit. 706 * We won't be able to stat anything, but we can still return the 707 * names themselves. Note, that since fts_read won't be able to 708 * chdir into the directory, it will have to return different path 709 * names than before, i.e. "a/b" instead of "b". Since the node 710 * has already been visited in pre-order, have to wait until the 711 * post-order visit to return the error. There is a special case 712 * here, if there was nothing to stat then it's not an error to 713 * not be able to stat. This is all fairly nasty. If a program 714 * needed sorted entries or stat information, they had better be 715 * checking FTS_NS on the returned nodes. 716 */ 717 cderrno = 0; 718 if (nlinks || type == BREAD) { 719 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) { 720 if (nlinks && type == BREAD) 721 cur->fts_errno = errno; 722 cur->fts_flags |= FTS_DONTCHDIR; 723 descend = 0; 724 cderrno = errno; 725 } else 726 descend = 1; 727 } else 728 descend = 0; 729 730 /* 731 * Figure out the max file name length that can be stored in the 732 * current path -- the inner loop allocates more path as necessary. 733 * We really wouldn't have to do the maxlen calculations here, we 734 * could do them in fts_read before returning the path, but it's a 735 * lot easier here since the length is part of the dirent structure. 736 * 737 * If not changing directories set a pointer so that can just append 738 * each new name into the path. 739 */ 740 len = NAPPEND(cur); 741 if (ISSET(FTS_NOCHDIR)) { 742 cp = sp->fts_path + len; 743 *cp++ = '/'; 744 } 745 len++; 746 maxlen = sp->fts_pathlen - len; 747 748#if defined(__FTS_COMPAT_LEVEL) 749 if (cur->fts_level == SHRT_MAX) { 750 (void)closedir(dirp); 751 cur->fts_info = FTS_ERR; 752 SET(FTS_STOP); 753 errno = ENAMETOOLONG; 754 return (NULL); 755 } 756#endif 757 758 level = cur->fts_level + 1; 759 760 /* Read the directory, attaching each entry to the `link' pointer. */ 761 doadjust = 0; 762 for (head = tail = NULL, nitems = 0; (dp = readdir(dirp)) != NULL;) { 763 764 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 765 continue; 766 767#if defined(HAVE_STRUCT_DIRENT_D_NAMLEN) 768 dnamlen = dp->d_namlen; 769#else 770 dnamlen = strlen(dp->d_name); 771#endif 772 if ((p = fts_alloc(sp, dp->d_name, dnamlen)) == NULL) 773 goto mem1; 774 if (dnamlen >= maxlen) { /* include space for NUL */ 775 oldaddr = sp->fts_path; 776 if (fts_palloc(sp, dnamlen + len + 1)) { 777 /* 778 * No more memory for path or structures. Save 779 * errno, free up the current structure and the 780 * structures already allocated. 781 */ 782mem1: saved_errno = errno; 783 if (p) 784 fts_free(p); 785 fts_lfree(head); 786 (void)closedir(dirp); 787 errno = saved_errno; 788 cur->fts_info = FTS_ERR; 789 SET(FTS_STOP); 790 return (NULL); 791 } 792 /* Did realloc() change the pointer? */ 793 if (oldaddr != sp->fts_path) { 794 doadjust = 1; 795 if (ISSET(FTS_NOCHDIR)) 796 cp = sp->fts_path + len; 797 } 798 maxlen = sp->fts_pathlen - len; 799 } 800 801#if defined(__FTS_COMPAT_LENGTH) 802 if (len + dnamlen >= USHRT_MAX) { 803 /* 804 * In an FTSENT, fts_pathlen is an unsigned short 805 * so it is possible to wraparound here. 806 * If we do, free up the current structure and the 807 * structures already allocated, then error out 808 * with ENAMETOOLONG. 809 */ 810 fts_free(p); 811 fts_lfree(head); 812 (void)closedir(dirp); 813 cur->fts_info = FTS_ERR; 814 SET(FTS_STOP); 815 errno = ENAMETOOLONG; 816 return (NULL); 817 } 818#endif 819 p->fts_level = level; 820 p->fts_pathlen = ftsent_pathlen_truncate(len + dnamlen); 821 p->fts_parent = sp->fts_cur; 822 823#ifdef FTS_WHITEOUT 824 if (dp->d_type == DT_WHT) 825 p->fts_flags |= FTS_ISW; 826#endif 827 828 if (cderrno) { 829 if (nlinks) { 830 p->fts_info = FTS_NS; 831 p->fts_errno = cderrno; 832 } else 833 p->fts_info = FTS_NSOK; 834 p->fts_accpath = cur->fts_accpath; 835 } else if (nlinks == 0 836#ifdef DT_DIR 837 || (nostat && 838 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 839#endif 840 ) { 841 p->fts_accpath = 842 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 843 p->fts_info = FTS_NSOK; 844 } else { 845 /* Build a file name for fts_stat to stat. */ 846 if (ISSET(FTS_NOCHDIR)) { 847 p->fts_accpath = p->fts_path; 848 memmove(cp, p->fts_name, 849 (size_t)(p->fts_namelen + 1)); 850 } else 851 p->fts_accpath = p->fts_name; 852 /* Stat it. */ 853 p->fts_info = fts_stat(sp, p, 0); 854 855 /* Decrement link count if applicable. */ 856 if (nlinks > 0 && (p->fts_info == FTS_D || 857 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 858 --nlinks; 859 } 860 861 /* We walk in directory order so "ls -f" doesn't get upset. */ 862 p->fts_link = NULL; 863 if (head == NULL) 864 head = tail = p; 865 else { 866 tail->fts_link = p; 867 tail = p; 868 } 869 ++nitems; 870 } 871 (void)closedir(dirp); 872 873 /* 874 * If had to realloc the path, adjust the addresses for the rest 875 * of the tree. 876 */ 877 if (doadjust) 878 fts_padjust(sp, head); 879 880 /* 881 * If not changing directories, reset the path back to original 882 * state. 883 */ 884 if (ISSET(FTS_NOCHDIR)) { 885 if (len == sp->fts_pathlen || nitems == 0) 886 --cp; 887 *cp = '\0'; 888 } 889 890 /* 891 * If descended after called from fts_children or after called from 892 * fts_read and nothing found, get back. At the root level we use 893 * the saved fd; if one of fts_open()'s arguments is a relative path 894 * to an empty directory, we wind up here with no other way back. If 895 * can't get back, we're done. 896 */ 897 if (descend && (type == BCHILD || !nitems) && 898 (cur->fts_level == FTS_ROOTLEVEL ? 899 FCHDIR(sp, sp->fts_rfd) : 900 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 901 cur->fts_info = FTS_ERR; 902 SET(FTS_STOP); 903 return (NULL); 904 } 905 906 /* If didn't find anything, return NULL. */ 907 if (!nitems) { 908 if (type == BREAD) 909 cur->fts_info = FTS_DP; 910 return (NULL); 911 } 912 913 /* Sort the entries. */ 914 if (sp->fts_compar && nitems > 1) 915 head = fts_sort(sp, head, nitems); 916 return (head); 917} 918 919static unsigned short 920fts_stat(FTS *sp, FTSENT *p, int follow) 921{ 922 FTSENT *t; 923 dev_t dev; 924 __fts_ino_t ino; 925 __fts_stat_t *sbp, sb; 926 int saved_errno; 927 928 _DIAGASSERT(sp != NULL); 929 _DIAGASSERT(p != NULL); 930 931 /* If user needs stat info, stat buffer already allocated. */ 932 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 933 934#ifdef FTS_WHITEOUT 935 /* check for whiteout */ 936 if (p->fts_flags & FTS_ISW) { 937 if (sbp != &sb) { 938 memset(sbp, '\0', sizeof (*sbp)); 939 sbp->st_mode = S_IFWHT; 940 } 941 return (FTS_W); 942 } 943#endif 944 945 /* 946 * If doing a logical walk, or application requested FTS_FOLLOW, do 947 * a stat(2). If that fails, check for a non-existent symlink. If 948 * fail, set the errno from the stat call. 949 */ 950 if (ISSET(FTS_LOGICAL) || follow) { 951 if (stat(p->fts_accpath, sbp)) { 952 saved_errno = errno; 953 if (!lstat(p->fts_accpath, sbp)) { 954 errno = 0; 955 return (FTS_SLNONE); 956 } 957 p->fts_errno = saved_errno; 958 goto err; 959 } 960 } else if (lstat(p->fts_accpath, sbp)) { 961 p->fts_errno = errno; 962err: memset(sbp, 0, sizeof(*sbp)); 963 return (FTS_NS); 964 } 965 966 if (S_ISDIR(sbp->st_mode)) { 967 /* 968 * Set the device/inode. Used to find cycles and check for 969 * crossing mount points. Also remember the link count, used 970 * in fts_build to limit the number of stat calls. It is 971 * understood that these fields are only referenced if fts_info 972 * is set to FTS_D. 973 */ 974 dev = p->fts_dev = sbp->st_dev; 975 ino = p->fts_ino = sbp->st_ino; 976 p->fts_nlink = sbp->st_nlink; 977 978 if (ISDOT(p->fts_name)) 979 return (FTS_DOT); 980 981 /* 982 * Cycle detection is done by brute force when the directory 983 * is first encountered. If the tree gets deep enough or the 984 * number of symbolic links to directories is high enough, 985 * something faster might be worthwhile. 986 */ 987 for (t = p->fts_parent; 988 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 989 if (ino == t->fts_ino && dev == t->fts_dev) { 990 p->fts_cycle = t; 991 return (FTS_DC); 992 } 993 return (FTS_D); 994 } 995 if (S_ISLNK(sbp->st_mode)) 996 return (FTS_SL); 997 if (S_ISREG(sbp->st_mode)) 998 return (FTS_F); 999 return (FTS_DEFAULT); 1000} 1001 1002static FTSENT * 1003fts_sort(FTS *sp, FTSENT *head, size_t nitems) 1004{ 1005 FTSENT **ap, *p; 1006 1007 _DIAGASSERT(sp != NULL); 1008 _DIAGASSERT(head != NULL); 1009 1010 /* 1011 * Construct an array of pointers to the structures and call qsort(3). 1012 * Reassemble the array in the order returned by qsort. If unable to 1013 * sort for memory reasons, return the directory entries in their 1014 * current order. Allocate enough space for the current needs plus 1015 * 40 so don't realloc one entry at a time. 1016 */ 1017 if (nitems > sp->fts_nitems) { 1018 errno = reallocarr(&sp->fts_array, 1019 nitems + 40, sizeof(*sp->fts_array)); 1020 if (errno) 1021 return head; 1022 sp->fts_nitems = fts_nitems_truncate(nitems + 40); 1023 } 1024 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 1025 *ap++ = p; 1026 qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *), 1027 (int (*)(const void *, const void *))sp->fts_compar); 1028 for (head = *(ap = sp->fts_array); --nitems; ++ap) 1029 ap[0]->fts_link = ap[1]; 1030 ap[0]->fts_link = NULL; 1031 return (head); 1032} 1033 1034static FTSENT * 1035fts_alloc(FTS *sp, const char *name, size_t namelen) 1036{ 1037 FTSENT *p; 1038#if defined(FTS_ALLOC_ALIGNED) 1039 size_t len; 1040#endif 1041 1042 _DIAGASSERT(sp != NULL); 1043 _DIAGASSERT(name != NULL); 1044 1045#if defined(FTS_ALLOC_ALIGNED) 1046 /* 1047 * The file name is a variable length array and no stat structure is 1048 * necessary if the user has set the nostat bit. Allocate the FTSENT 1049 * structure, the file name and the stat structure in one chunk, but 1050 * be careful that the stat structure is reasonably aligned. Since the 1051 * fts_name field is declared to be of size 1, the fts_name pointer is 1052 * namelen + 2 before the first possible address of the stat structure. 1053 */ 1054 len = sizeof(FTSENT) + namelen; 1055 if (!ISSET(FTS_NOSTAT)) 1056 len += sizeof(*(p->fts_statp)) + ALIGNBYTES; 1057 if ((p = malloc(len)) == NULL) 1058 return (NULL); 1059 1060 if (!ISSET(FTS_NOSTAT)) 1061 p->fts_statp = (__fts_stat_t *)ALIGN( 1062 (unsigned long)(p->fts_name + namelen + 2)); 1063#else 1064 if ((p = malloc(sizeof(FTSENT) + namelen)) == NULL) 1065 return (NULL); 1066 1067 if (!ISSET(FTS_NOSTAT)) 1068 if ((p->fts_statp = malloc(sizeof(*(p->fts_statp)))) == NULL) { 1069 free(p); 1070 return (NULL); 1071 } 1072#endif 1073 1074 if (ISSET(FTS_NOSTAT)) 1075 p->fts_statp = NULL; 1076 1077 /* Copy the name plus the trailing NULL. */ 1078 memmove(p->fts_name, name, namelen + 1); 1079 1080 p->fts_namelen = ftsent_namelen_truncate(namelen); 1081 p->fts_path = sp->fts_path; 1082 p->fts_errno = 0; 1083 p->fts_flags = 0; 1084 p->fts_instr = FTS_NOINSTR; 1085 p->fts_number = 0; 1086 p->fts_pointer = NULL; 1087 return (p); 1088} 1089 1090static void 1091fts_free(FTSENT *p) 1092{ 1093#if !defined(FTS_ALLOC_ALIGNED) 1094 if (p->fts_statp) 1095 free(p->fts_statp); 1096#endif 1097 free(p); 1098} 1099 1100static void 1101fts_lfree(FTSENT *head) 1102{ 1103 FTSENT *p; 1104 1105 /* XXX: head may be NULL ? */ 1106 1107 /* Free a linked list of structures. */ 1108 while ((p = head) != NULL) { 1109 head = head->fts_link; 1110 fts_free(p); 1111 } 1112} 1113 1114static size_t 1115fts_pow2(size_t x) 1116{ 1117 1118 x--; 1119 x |= x>>1; 1120 x |= x>>2; 1121 x |= x>>4; 1122 x |= x>>8; 1123 x |= x>>16; 1124#if LONG_BIT > 32 1125 x |= x>>32; 1126#endif 1127#if LONG_BIT > 64 1128 x |= x>>64; 1129#endif 1130 x++; 1131 return (x); 1132} 1133 1134/* 1135 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 1136 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 1137 * though the kernel won't resolve them. Round up the new size to a power of 2, 1138 * so we don't realloc the path 2 bytes at a time. 1139 */ 1140static int 1141fts_palloc(FTS *sp, size_t size) 1142{ 1143 char *new; 1144 1145 _DIAGASSERT(sp != NULL); 1146 1147#ifdef __FTS_COMPAT_LENGTH 1148 /* Protect against fts_pathlen overflow. */ 1149 if (size > USHRT_MAX + 1) { 1150 errno = ENAMETOOLONG; 1151 return (1); 1152 } 1153#endif 1154 size = fts_pow2(size); 1155 new = realloc(sp->fts_path, size); 1156 if (new == 0) 1157 return (1); 1158 sp->fts_path = new; 1159 sp->fts_pathlen = fts_pathlen_truncate(size); 1160 return (0); 1161} 1162 1163/* 1164 * When the path is realloc'd, have to fix all of the pointers in structures 1165 * already returned. 1166 */ 1167static void 1168fts_padjust(FTS *sp, FTSENT *head) 1169{ 1170 FTSENT *p; 1171 char *addr; 1172 1173 _DIAGASSERT(sp != NULL); 1174 1175#define ADJUST(p) do { \ 1176 if ((p)->fts_accpath != (p)->fts_name) \ 1177 (p)->fts_accpath = \ 1178 addr + ((p)->fts_accpath - (p)->fts_path); \ 1179 (p)->fts_path = addr; \ 1180} while (0) 1181 1182 addr = sp->fts_path; 1183 1184 /* Adjust the current set of children. */ 1185 for (p = sp->fts_child; p; p = p->fts_link) 1186 ADJUST(p); 1187 1188 /* Adjust the rest of the tree, including the current level. */ 1189 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1190 ADJUST(p); 1191 p = p->fts_link ? p->fts_link : p->fts_parent; 1192 } 1193} 1194 1195static size_t 1196fts_maxarglen(char * const *argv) 1197{ 1198 size_t len, max; 1199 1200 _DIAGASSERT(argv != NULL); 1201 1202 for (max = 0; *argv; ++argv) 1203 if ((len = strlen(*argv)) > max) 1204 max = len; 1205 return (max + 1); 1206} 1207 1208/* 1209 * Change to dir specified by fd or p->fts_accpath without getting 1210 * tricked by someone changing the world out from underneath us. 1211 * Assumes p->fts_dev and p->fts_ino are filled in. 1212 */ 1213static int 1214fts_safe_changedir(const FTS *sp, const FTSENT *p, int fd, const char *path) 1215{ 1216 int oldfd = fd, ret = -1; 1217 __fts_stat_t sb; 1218 1219 if (ISSET(FTS_NOCHDIR)) 1220 return 0; 1221 1222 if (oldfd < 0 && (fd = open(path, O_RDONLY | O_CLOEXEC)) == -1) 1223 return -1; 1224 1225 if (fstat(fd, &sb) == -1) 1226 goto bail; 1227 1228 if (sb.st_ino != p->fts_ino || sb.st_dev != p->fts_dev) { 1229 errno = ENOENT; 1230 goto bail; 1231 } 1232 1233 ret = fchdir(fd); 1234 1235bail: 1236 if (oldfd < 0) { 1237 int save_errno = errno; 1238 (void)close(fd); 1239 errno = save_errno; 1240 } 1241 return ret; 1242} 1243