1/* $OpenBSD: fts.c,v 1.61 2021/11/29 03:20:37 deraadt 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#include <sys/param.h> /* ALIGN ALIGNBYTES */ 33#include <sys/stat.h> 34 35#include <dirent.h> 36#include <errno.h> 37#include <fcntl.h> 38#include <fts.h> 39#include <limits.h> 40#include <stdlib.h> 41#include <string.h> 42#include <unistd.h> 43 44#define MAXIMUM(a, b) (((a) > (b)) ? (a) : (b)) 45 46static FTSENT *fts_alloc(FTS *, const char *, size_t); 47static FTSENT *fts_build(FTS *, int); 48static void fts_lfree(FTSENT *); 49static void fts_load(FTS *, FTSENT *); 50static size_t fts_maxarglen(char * const *); 51static void fts_padjust(FTS *, FTSENT *); 52static int fts_palloc(FTS *, size_t); 53static FTSENT *fts_sort(FTS *, FTSENT *, int); 54static u_short fts_stat(FTS *, FTSENT *, int, int); 55static int fts_safe_changedir(FTS *, FTSENT *, int, const char *); 56 57#define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2]))) 58 59#define CLR(opt) (sp->fts_options &= ~(opt)) 60#define ISSET(opt) (sp->fts_options & (opt)) 61#define SET(opt) (sp->fts_options |= (opt)) 62 63#define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 64 65/* fts_build flags */ 66#define BCHILD 1 /* fts_children */ 67#define BNAMES 2 /* fts_children, names only */ 68#define BREAD 3 /* fts_read */ 69 70FTS * 71fts_open(char * const *argv, int options, 72 int (*compar)(const FTSENT **, const FTSENT **)) 73{ 74 FTS *sp; 75 FTSENT *p, *root; 76 int nitems; 77 FTSENT *parent, *prev; 78 79 /* Options check. */ 80 if (options & ~FTS_OPTIONMASK) { 81 errno = EINVAL; 82 return (NULL); 83 } 84 85 /* At least one path must be specified. */ 86 if (*argv == NULL) { 87 errno = EINVAL; 88 return (NULL); 89 } 90 91 /* Allocate/initialize the stream */ 92 if ((sp = calloc(1, sizeof(FTS))) == NULL) 93 return (NULL); 94 sp->fts_compar = compar; 95 sp->fts_options = options; 96 97 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 98 if (ISSET(FTS_LOGICAL)) 99 SET(FTS_NOCHDIR); 100 101 /* 102 * Start out with 1K of path space, and enough, in any case, 103 * to hold the user's paths. 104 */ 105 if (fts_palloc(sp, MAXIMUM(fts_maxarglen(argv), PATH_MAX))) 106 goto mem1; 107 108 /* Allocate/initialize root's parent. */ 109 if ((parent = fts_alloc(sp, "", 0)) == NULL) 110 goto mem2; 111 parent->fts_level = FTS_ROOTPARENTLEVEL; 112 113 /* Allocate/initialize root(s). */ 114 for (root = prev = NULL, nitems = 0; *argv; ++argv, ++nitems) { 115 if ((p = fts_alloc(sp, *argv, strlen(*argv))) == NULL) 116 goto mem3; 117 p->fts_level = FTS_ROOTLEVEL; 118 p->fts_parent = parent; 119 p->fts_accpath = p->fts_name; 120 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW), -1); 121 122 /* Command-line "." and ".." are real directories. */ 123 if (p->fts_info == FTS_DOT) 124 p->fts_info = FTS_D; 125 126 /* 127 * If comparison routine supplied, traverse in sorted 128 * order; otherwise traverse in the order specified. 129 */ 130 if (compar) { 131 p->fts_link = root; 132 root = p; 133 } else { 134 p->fts_link = NULL; 135 if (root == NULL) 136 root = p; 137 else 138 prev->fts_link = p; 139 prev = p; 140 } 141 } 142 if (compar && nitems > 1) 143 root = fts_sort(sp, root, nitems); 144 145 /* 146 * Allocate a dummy pointer and make fts_read think that we've just 147 * finished the node before the root(s); set p->fts_info to FTS_INIT 148 * so that everything about the "current" node is ignored. 149 */ 150 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 151 goto mem3; 152 sp->fts_cur->fts_link = root; 153 sp->fts_cur->fts_info = FTS_INIT; 154 155 /* 156 * If using chdir(2), grab a file descriptor pointing to dot to ensure 157 * that we can get back here; this could be avoided for some paths, 158 * but almost certainly not worth the effort. Slashes, symbolic links, 159 * and ".." are all fairly nasty problems. Note, if we can't get the 160 * descriptor we run anyway, just more slowly. 161 */ 162 if (!ISSET(FTS_NOCHDIR) && 163 (sp->fts_rfd = open(".", O_RDONLY | O_CLOEXEC)) == -1) 164 SET(FTS_NOCHDIR); 165 166 if (nitems == 0) 167 free(parent); 168 169 return (sp); 170 171mem3: fts_lfree(root); 172 free(parent); 173mem2: free(sp->fts_path); 174mem1: free(sp); 175 return (NULL); 176} 177DEF_WEAK(fts_open); 178 179static void 180fts_load(FTS *sp, FTSENT *p) 181{ 182 size_t len; 183 char *cp; 184 185 /* 186 * Load the stream structure for the next traversal. Since we don't 187 * actually enter the directory until after the preorder visit, set 188 * the fts_accpath field specially so the chdir gets done to the right 189 * place and the user can access the first node. From fts_open it's 190 * known that the path will fit. 191 */ 192 len = p->fts_pathlen = p->fts_namelen; 193 memmove(sp->fts_path, p->fts_name, len + 1); 194 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 195 len = strlen(++cp); 196 memmove(p->fts_name, cp, len + 1); 197 p->fts_namelen = len; 198 } 199 p->fts_accpath = p->fts_path = sp->fts_path; 200 sp->fts_dev = p->fts_dev; 201} 202 203int 204fts_close(FTS *sp) 205{ 206 FTSENT *freep, *p; 207 int rfd, error = 0; 208 209 /* 210 * This still works if we haven't read anything -- the dummy structure 211 * points to the root list, so we step through to the end of the root 212 * list which has a valid parent pointer. 213 */ 214 if (sp->fts_cur) { 215 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 216 freep = p; 217 p = p->fts_link ? p->fts_link : p->fts_parent; 218 free(freep); 219 } 220 free(p); 221 } 222 223 /* Stash the original directory fd if needed. */ 224 rfd = ISSET(FTS_NOCHDIR) ? -1 : sp->fts_rfd; 225 226 /* Free up child linked list, sort array, path buffer, stream ptr.*/ 227 if (sp->fts_child) 228 fts_lfree(sp->fts_child); 229 free(sp->fts_array); 230 free(sp->fts_path); 231 free(sp); 232 233 /* Return to original directory, checking for error. */ 234 if (rfd != -1) { 235 int saved_errno; 236 error = fchdir(rfd); 237 saved_errno = errno; 238 (void)close(rfd); 239 errno = saved_errno; 240 } 241 242 return (error); 243} 244DEF_WEAK(fts_close); 245 246/* 247 * Special case of "/" at the end of the path so that slashes aren't 248 * appended which would cause paths to be written as "....//foo". 249 */ 250#define NAPPEND(p) \ 251 (p->fts_path[p->fts_pathlen - 1] == '/' \ 252 ? p->fts_pathlen - 1 : p->fts_pathlen) 253 254FTSENT * 255fts_read(FTS *sp) 256{ 257 FTSENT *p, *tmp; 258 int instr; 259 char *t; 260 int saved_errno; 261 262 /* If finished or unrecoverable error, return NULL. */ 263 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 264 return (NULL); 265 266 /* Set current node pointer. */ 267 p = sp->fts_cur; 268 269 /* Save and zero out user instructions. */ 270 instr = p->fts_instr; 271 p->fts_instr = FTS_NOINSTR; 272 273 /* Any type of file may be re-visited; re-stat and re-turn. */ 274 if (instr == FTS_AGAIN) { 275 p->fts_info = fts_stat(sp, p, 0, -1); 276 return (p); 277 } 278 279 /* 280 * Following a symlink -- SLNONE test allows application to see 281 * SLNONE and recover. If indirecting through a symlink, have 282 * keep a pointer to current location. If unable to get that 283 * pointer, follow fails. 284 */ 285 if (instr == FTS_FOLLOW && 286 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 287 p->fts_info = fts_stat(sp, p, 1, -1); 288 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 289 if ((p->fts_symfd = 290 open(".", O_RDONLY | O_CLOEXEC)) == -1) { 291 p->fts_errno = errno; 292 p->fts_info = FTS_ERR; 293 } else 294 p->fts_flags |= FTS_SYMFOLLOW; 295 } 296 return (p); 297 } 298 299 /* Directory in pre-order. */ 300 if (p->fts_info == FTS_D) { 301 /* If skipped or crossed mount point, do post-order visit. */ 302 if (instr == FTS_SKIP || 303 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 304 if (p->fts_flags & FTS_SYMFOLLOW) 305 (void)close(p->fts_symfd); 306 if (sp->fts_child) { 307 fts_lfree(sp->fts_child); 308 sp->fts_child = NULL; 309 } 310 p->fts_info = FTS_DP; 311 return (p); 312 } 313 314 /* Rebuild if only read the names and now traversing. */ 315 if (sp->fts_child && ISSET(FTS_NAMEONLY)) { 316 CLR(FTS_NAMEONLY); 317 fts_lfree(sp->fts_child); 318 sp->fts_child = NULL; 319 } 320 321 /* 322 * Cd to the subdirectory. 323 * 324 * If have already read and now fail to chdir, whack the list 325 * to make the names come out right, and set the parent errno 326 * so the application will eventually get an error condition. 327 * Set the FTS_DONTCHDIR flag so that when we logically change 328 * directories back to the parent we don't do a chdir. 329 * 330 * If haven't read do so. If the read fails, fts_build sets 331 * FTS_STOP or the fts_info field of the node. 332 */ 333 if (sp->fts_child) { 334 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 335 p->fts_errno = errno; 336 p->fts_flags |= FTS_DONTCHDIR; 337 for (p = sp->fts_child; p; p = p->fts_link) 338 p->fts_accpath = 339 p->fts_parent->fts_accpath; 340 } 341 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 342 if (ISSET(FTS_STOP)) 343 return (NULL); 344 return (p); 345 } 346 p = sp->fts_child; 347 sp->fts_child = NULL; 348 goto name; 349 } 350 351 /* Move to the next node on this level. */ 352next: tmp = p; 353 if ((p = p->fts_link)) { 354 free(tmp); 355 356 /* 357 * If reached the top, return to the original directory (or 358 * the root of the tree), and load the paths for the next root. 359 */ 360 if (p->fts_level == FTS_ROOTLEVEL) { 361 if (FCHDIR(sp, sp->fts_rfd)) { 362 SET(FTS_STOP); 363 return (NULL); 364 } 365 fts_load(sp, p); 366 return (sp->fts_cur = p); 367 } 368 369 /* 370 * User may have called fts_set on the node. If skipped, 371 * ignore. If followed, get a file descriptor so we can 372 * get back if necessary. 373 */ 374 if (p->fts_instr == FTS_SKIP) 375 goto next; 376 if (p->fts_instr == FTS_FOLLOW) { 377 p->fts_info = fts_stat(sp, p, 1, -1); 378 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 379 if ((p->fts_symfd = 380 open(".", O_RDONLY | O_CLOEXEC)) == -1) { 381 p->fts_errno = errno; 382 p->fts_info = FTS_ERR; 383 } else 384 p->fts_flags |= FTS_SYMFOLLOW; 385 } 386 p->fts_instr = FTS_NOINSTR; 387 } 388 389name: t = sp->fts_path + NAPPEND(p->fts_parent); 390 *t++ = '/'; 391 memmove(t, p->fts_name, p->fts_namelen + 1); 392 return (sp->fts_cur = p); 393 } 394 395 /* Move up to the parent node. */ 396 p = tmp->fts_parent; 397 free(tmp); 398 399 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 400 /* 401 * Done; free everything up and set errno to 0 so the user 402 * can distinguish between error and EOF. 403 */ 404 free(p); 405 errno = 0; 406 return (sp->fts_cur = NULL); 407 } 408 409 /* NUL terminate the pathname. */ 410 sp->fts_path[p->fts_pathlen] = '\0'; 411 412 /* 413 * Return to the parent directory. If at a root node or came through 414 * a symlink, go back through the file descriptor. Otherwise, cd up 415 * one directory. 416 */ 417 if (p->fts_level == FTS_ROOTLEVEL) { 418 if (FCHDIR(sp, sp->fts_rfd)) { 419 SET(FTS_STOP); 420 sp->fts_cur = p; 421 return (NULL); 422 } 423 } else if (p->fts_flags & FTS_SYMFOLLOW) { 424 if (FCHDIR(sp, p->fts_symfd)) { 425 saved_errno = errno; 426 (void)close(p->fts_symfd); 427 errno = saved_errno; 428 SET(FTS_STOP); 429 sp->fts_cur = p; 430 return (NULL); 431 } 432 (void)close(p->fts_symfd); 433 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 434 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 435 SET(FTS_STOP); 436 sp->fts_cur = p; 437 return (NULL); 438 } 439 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 440 return (sp->fts_cur = p); 441} 442DEF_WEAK(fts_read); 443 444/* 445 * Fts_set takes the stream as an argument although it's not used in this 446 * implementation; it would be necessary if anyone wanted to add global 447 * semantics to fts using fts_set. An error return is allowed for similar 448 * reasons. 449 */ 450int 451fts_set(FTS *sp, FTSENT *p, int instr) 452{ 453 if (instr && instr != FTS_AGAIN && instr != FTS_FOLLOW && 454 instr != FTS_NOINSTR && instr != FTS_SKIP) { 455 errno = EINVAL; 456 return (1); 457 } 458 p->fts_instr = instr; 459 return (0); 460} 461DEF_WEAK(fts_set); 462 463FTSENT * 464fts_children(FTS *sp, int instr) 465{ 466 FTSENT *p; 467 int fd; 468 469 if (instr && instr != FTS_NAMEONLY) { 470 errno = EINVAL; 471 return (NULL); 472 } 473 474 /* Set current node pointer. */ 475 p = sp->fts_cur; 476 477 /* 478 * Errno set to 0 so user can distinguish empty directory from 479 * an error. 480 */ 481 errno = 0; 482 483 /* Fatal errors stop here. */ 484 if (ISSET(FTS_STOP)) 485 return (NULL); 486 487 /* Return logical hierarchy of user's arguments. */ 488 if (p->fts_info == FTS_INIT) 489 return (p->fts_link); 490 491 /* 492 * If not a directory being visited in pre-order, stop here. Could 493 * allow FTS_DNR, assuming the user has fixed the problem, but the 494 * same effect is available with FTS_AGAIN. 495 */ 496 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 497 return (NULL); 498 499 /* Free up any previous child list. */ 500 if (sp->fts_child) 501 fts_lfree(sp->fts_child); 502 503 if (instr == FTS_NAMEONLY) { 504 SET(FTS_NAMEONLY); 505 instr = BNAMES; 506 } else 507 instr = BCHILD; 508 509 /* 510 * If using chdir on a relative path and called BEFORE fts_read does 511 * its chdir to the root of a traversal, we can lose -- we need to 512 * chdir into the subdirectory, and we don't know where the current 513 * directory is, so we can't get back so that the upcoming chdir by 514 * fts_read will work. 515 */ 516 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 517 ISSET(FTS_NOCHDIR)) 518 return (sp->fts_child = fts_build(sp, instr)); 519 520 if ((fd = open(".", O_RDONLY | O_CLOEXEC)) == -1) 521 return (NULL); 522 sp->fts_child = fts_build(sp, instr); 523 if (fchdir(fd)) { 524 (void)close(fd); 525 return (NULL); 526 } 527 (void)close(fd); 528 return (sp->fts_child); 529} 530DEF_WEAK(fts_children); 531 532/* 533 * This is the tricky part -- do not casually change *anything* in here. The 534 * idea is to build the linked list of entries that are used by fts_children 535 * and fts_read. There are lots of special cases. 536 * 537 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 538 * set and it's a physical walk (so that symbolic links can't be directories), 539 * we can do things quickly. First, if it's a 4.4BSD file system, the type 540 * of the file is in the directory entry. Otherwise, we assume that the number 541 * of subdirectories in a node is equal to the number of links to the parent. 542 * The former skips all stat calls. The latter skips stat calls in any leaf 543 * directories and for any files after the subdirectories in the directory have 544 * been found, cutting the stat calls by about 2/3. 545 */ 546static FTSENT * 547fts_build(FTS *sp, int type) 548{ 549 struct dirent *dp; 550 FTSENT *p, *head; 551 FTSENT *cur, *tail; 552 DIR *dirp; 553 void *oldaddr; 554 size_t len, maxlen; 555 int nitems, cderrno, descend, level, nlinks, nostat, doadjust; 556 int saved_errno; 557 char *cp; 558 559 /* Set current node pointer. */ 560 cur = sp->fts_cur; 561 562 /* 563 * Open the directory for reading. If this fails, we're done. 564 * If being called from fts_read, set the fts_info field. 565 */ 566 if ((dirp = opendir(cur->fts_accpath)) == NULL) { 567 if (type == BREAD) { 568 cur->fts_info = FTS_DNR; 569 cur->fts_errno = errno; 570 } 571 return (NULL); 572 } 573 574 /* 575 * Nlinks is the number of possible entries of type directory in the 576 * directory if we're cheating on stat calls, 0 if we're not doing 577 * any stat calls at all, -1 if we're doing stats on everything. 578 */ 579 if (type == BNAMES) 580 nlinks = 0; 581 else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 582 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 583 nostat = 1; 584 } else { 585 nlinks = -1; 586 nostat = 0; 587 } 588 589#ifdef notdef 590 (void)printf("nlinks == %d (cur: %u)\n", nlinks, cur->fts_nlink); 591 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 592 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 593#endif 594 /* 595 * If we're going to need to stat anything or we want to descend 596 * and stay in the directory, chdir. If this fails we keep going, 597 * but set a flag so we don't chdir after the post-order visit. 598 * We won't be able to stat anything, but we can still return the 599 * names themselves. Note, that since fts_read won't be able to 600 * chdir into the directory, it will have to return different path 601 * names than before, i.e. "a/b" instead of "b". Since the node 602 * has already been visited in pre-order, have to wait until the 603 * post-order visit to return the error. There is a special case 604 * here, if there was nothing to stat then it's not an error to 605 * not be able to stat. This is all fairly nasty. If a program 606 * needed sorted entries or stat information, they had better be 607 * checking FTS_NS on the returned nodes. 608 */ 609 cderrno = 0; 610 if (nlinks || type == BREAD) { 611 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) { 612 if (nlinks && type == BREAD) 613 cur->fts_errno = errno; 614 cur->fts_flags |= FTS_DONTCHDIR; 615 descend = 0; 616 cderrno = errno; 617 (void)closedir(dirp); 618 dirp = NULL; 619 } else 620 descend = 1; 621 } else 622 descend = 0; 623 624 /* 625 * Figure out the max file name length that can be stored in the 626 * current path -- the inner loop allocates more path as necessary. 627 * We really wouldn't have to do the maxlen calculations here, we 628 * could do them in fts_read before returning the path, but it's a 629 * lot easier here since the length is part of the dirent structure. 630 * 631 * If not changing directories set a pointer so that can just append 632 * each new name into the path. 633 */ 634 len = NAPPEND(cur); 635 if (ISSET(FTS_NOCHDIR)) { 636 cp = sp->fts_path + len; 637 *cp++ = '/'; 638 } 639 len++; 640 maxlen = sp->fts_pathlen - len; 641 642 /* 643 * fts_level is signed so we must prevent it from wrapping 644 * around to FTS_ROOTLEVEL and FTS_ROOTPARENTLEVEL. 645 */ 646 level = cur->fts_level; 647 if (level < FTS_MAXLEVEL) 648 level++; 649 650 /* Read the directory, attaching each entry to the `link' pointer. */ 651 doadjust = 0; 652 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) { 653 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 654 continue; 655 656 if (!(p = fts_alloc(sp, dp->d_name, dp->d_namlen))) 657 goto mem1; 658 if (dp->d_namlen >= maxlen) { /* include space for NUL */ 659 oldaddr = sp->fts_path; 660 if (fts_palloc(sp, dp->d_namlen +len + 1)) { 661 /* 662 * No more memory for path or structures. Save 663 * errno, free up the current structure and the 664 * structures already allocated. 665 */ 666mem1: saved_errno = errno; 667 free(p); 668 fts_lfree(head); 669 (void)closedir(dirp); 670 cur->fts_info = FTS_ERR; 671 SET(FTS_STOP); 672 errno = saved_errno; 673 return (NULL); 674 } 675 /* Did realloc() change the pointer? */ 676 if (oldaddr != sp->fts_path) { 677 doadjust = 1; 678 if (ISSET(FTS_NOCHDIR)) 679 cp = sp->fts_path + len; 680 } 681 maxlen = sp->fts_pathlen - len; 682 } 683 684 p->fts_level = level; 685 p->fts_parent = sp->fts_cur; 686 p->fts_pathlen = len + dp->d_namlen; 687 if (p->fts_pathlen < len) { 688 /* 689 * If we wrap, free up the current structure and 690 * the structures already allocated, then error 691 * out with ENAMETOOLONG. 692 */ 693 free(p); 694 fts_lfree(head); 695 (void)closedir(dirp); 696 cur->fts_info = FTS_ERR; 697 SET(FTS_STOP); 698 errno = ENAMETOOLONG; 699 return (NULL); 700 } 701 702 if (cderrno) { 703 if (nlinks) { 704 p->fts_info = FTS_NS; 705 p->fts_errno = cderrno; 706 } else 707 p->fts_info = FTS_NSOK; 708 p->fts_accpath = cur->fts_accpath; 709 } else if (nlinks == 0 710#ifdef DT_DIR 711 || (nostat && 712 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 713#endif 714 ) { 715 p->fts_accpath = 716 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 717 p->fts_info = FTS_NSOK; 718 } else { 719 /* Build a file name for fts_stat to stat. */ 720 if (ISSET(FTS_NOCHDIR)) { 721 p->fts_accpath = p->fts_path; 722 memmove(cp, p->fts_name, p->fts_namelen + 1); 723 p->fts_info = fts_stat(sp, p, 0, dirfd(dirp)); 724 } else { 725 p->fts_accpath = p->fts_name; 726 p->fts_info = fts_stat(sp, p, 0, -1); 727 } 728 729 /* Decrement link count if applicable. */ 730 if (nlinks > 0 && (p->fts_info == FTS_D || 731 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 732 --nlinks; 733 } 734 735 /* We walk in directory order so "ls -f" doesn't get upset. */ 736 p->fts_link = NULL; 737 if (head == NULL) 738 head = tail = p; 739 else { 740 tail->fts_link = p; 741 tail = p; 742 } 743 ++nitems; 744 } 745 if (dirp) 746 (void)closedir(dirp); 747 748 /* 749 * If realloc() changed the address of the path, adjust the 750 * addresses for the rest of the tree and the dir list. 751 */ 752 if (doadjust) 753 fts_padjust(sp, head); 754 755 /* 756 * If not changing directories, reset the path back to original 757 * state. 758 */ 759 if (ISSET(FTS_NOCHDIR)) { 760 if (len == sp->fts_pathlen || nitems == 0) 761 --cp; 762 *cp = '\0'; 763 } 764 765 /* 766 * If descended after called from fts_children or after called from 767 * fts_read and nothing found, get back. At the root level we use 768 * the saved fd; if one of fts_open()'s arguments is a relative path 769 * to an empty directory, we wind up here with no other way back. If 770 * can't get back, we're done. 771 */ 772 if (descend && (type == BCHILD || !nitems) && 773 (cur->fts_level == FTS_ROOTLEVEL ? FCHDIR(sp, sp->fts_rfd) : 774 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 775 cur->fts_info = FTS_ERR; 776 SET(FTS_STOP); 777 return (NULL); 778 } 779 780 /* If didn't find anything, return NULL. */ 781 if (!nitems) { 782 if (type == BREAD) 783 cur->fts_info = FTS_DP; 784 return (NULL); 785 } 786 787 /* Sort the entries. */ 788 if (sp->fts_compar && nitems > 1) 789 head = fts_sort(sp, head, nitems); 790 return (head); 791} 792 793static u_short 794fts_stat(FTS *sp, FTSENT *p, int follow, int dfd) 795{ 796 FTSENT *t; 797 dev_t dev; 798 ino_t ino; 799 struct stat *sbp, sb; 800 int saved_errno; 801 const char *path; 802 803 if (dfd == -1) { 804 path = p->fts_accpath; 805 dfd = AT_FDCWD; 806 } else 807 path = p->fts_name; 808 809 /* If user needs stat info, stat buffer already allocated. */ 810 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 811 812 /* 813 * If doing a logical walk, or application requested FTS_FOLLOW, do 814 * a stat(2). If that fails, check for a non-existent symlink. If 815 * fail, set the errno from the stat call. 816 */ 817 if (ISSET(FTS_LOGICAL) || follow) { 818 if (fstatat(dfd, path, sbp, 0)) { 819 saved_errno = errno; 820 if (!fstatat(dfd, path, sbp, AT_SYMLINK_NOFOLLOW)) { 821 errno = 0; 822 return (FTS_SLNONE); 823 } 824 p->fts_errno = saved_errno; 825 goto err; 826 } 827 } else if (fstatat(dfd, path, sbp, AT_SYMLINK_NOFOLLOW)) { 828 p->fts_errno = errno; 829err: memset(sbp, 0, sizeof(struct stat)); 830 return (FTS_NS); 831 } 832 833 if (S_ISDIR(sbp->st_mode)) { 834 /* 835 * Set the device/inode. Used to find cycles and check for 836 * crossing mount points. Also remember the link count, used 837 * in fts_build to limit the number of stat calls. It is 838 * understood that these fields are only referenced if fts_info 839 * is set to FTS_D. 840 */ 841 dev = p->fts_dev = sbp->st_dev; 842 ino = p->fts_ino = sbp->st_ino; 843 p->fts_nlink = sbp->st_nlink; 844 845 if (ISDOT(p->fts_name)) 846 return (FTS_DOT); 847 848 /* 849 * Cycle detection is done by brute force when the directory 850 * is first encountered. If the tree gets deep enough or the 851 * number of symbolic links to directories is high enough, 852 * something faster might be worthwhile. 853 */ 854 for (t = p->fts_parent; 855 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 856 if (ino == t->fts_ino && dev == t->fts_dev) { 857 p->fts_cycle = t; 858 return (FTS_DC); 859 } 860 return (FTS_D); 861 } 862 if (S_ISLNK(sbp->st_mode)) 863 return (FTS_SL); 864 if (S_ISREG(sbp->st_mode)) 865 return (FTS_F); 866 return (FTS_DEFAULT); 867} 868 869static FTSENT * 870fts_sort(FTS *sp, FTSENT *head, int nitems) 871{ 872 FTSENT **ap, *p; 873 874 /* 875 * Construct an array of pointers to the structures and call qsort(3). 876 * Reassemble the array in the order returned by qsort. If unable to 877 * sort for memory reasons, return the directory entries in their 878 * current order. Allocate enough space for the current needs plus 879 * 40 so don't realloc one entry at a time. 880 */ 881 if (nitems > sp->fts_nitems) { 882 struct _ftsent **a; 883 884 if ((a = reallocarray(sp->fts_array, 885 nitems + 40, sizeof(FTSENT *))) == NULL) { 886 free(sp->fts_array); 887 sp->fts_array = NULL; 888 sp->fts_nitems = 0; 889 return (head); 890 } 891 sp->fts_nitems = nitems + 40; 892 sp->fts_array = a; 893 } 894 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 895 *ap++ = p; 896 qsort(sp->fts_array, nitems, sizeof(FTSENT *), sp->fts_compar); 897 for (head = *(ap = sp->fts_array); --nitems; ++ap) 898 ap[0]->fts_link = ap[1]; 899 ap[0]->fts_link = NULL; 900 return (head); 901} 902 903static FTSENT * 904fts_alloc(FTS *sp, const char *name, size_t namelen) 905{ 906 FTSENT *p; 907 size_t len; 908 909 /* 910 * The file name is a variable length array and no stat structure is 911 * necessary if the user has set the nostat bit. Allocate the FTSENT 912 * structure, the file name and the stat structure in one chunk, but 913 * be careful that the stat structure is reasonably aligned. Since the 914 * fts_name field is declared to be of size 1, the fts_name pointer is 915 * namelen + 2 before the first possible address of the stat structure. 916 */ 917 len = sizeof(FTSENT) + namelen; 918 if (!ISSET(FTS_NOSTAT)) 919 len += sizeof(struct stat) + ALIGNBYTES; 920 if ((p = calloc(1, len)) == NULL) 921 return (NULL); 922 923 p->fts_path = sp->fts_path; 924 p->fts_namelen = namelen; 925 p->fts_instr = FTS_NOINSTR; 926 if (!ISSET(FTS_NOSTAT)) 927 p->fts_statp = (struct stat *)ALIGN(p->fts_name + namelen + 2); 928 memcpy(p->fts_name, name, namelen); 929 930 return (p); 931} 932 933static void 934fts_lfree(FTSENT *head) 935{ 936 FTSENT *p; 937 938 /* Free a linked list of structures. */ 939 while ((p = head)) { 940 head = head->fts_link; 941 free(p); 942 } 943} 944 945/* 946 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 947 * Most systems will allow creation of paths much longer than PATH_MAX, even 948 * though the kernel won't resolve them. Add the size (not just what's needed) 949 * plus 256 bytes so don't realloc the path 2 bytes at a time. 950 */ 951static int 952fts_palloc(FTS *sp, size_t more) 953{ 954 char *p; 955 956 /* 957 * Check for possible wraparound. 958 */ 959 more += 256; 960 if (sp->fts_pathlen + more < sp->fts_pathlen) { 961 free(sp->fts_path); 962 sp->fts_path = NULL; 963 errno = ENAMETOOLONG; 964 return (1); 965 } 966 p = recallocarray(sp->fts_path, sp->fts_pathlen, 967 sp->fts_pathlen + more, 1); 968 if (p == NULL) { 969 free(sp->fts_path); 970 sp->fts_path = NULL; 971 return (1); 972 } 973 sp->fts_pathlen += more; 974 sp->fts_path = p; 975 return (0); 976} 977 978/* 979 * When the path is realloc'd, have to fix all of the pointers in structures 980 * already returned. 981 */ 982static void 983fts_padjust(FTS *sp, FTSENT *head) 984{ 985 FTSENT *p; 986 char *addr = sp->fts_path; 987 988#define ADJUST(p) { \ 989 if ((p)->fts_accpath != (p)->fts_name) { \ 990 (p)->fts_accpath = \ 991 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \ 992 } \ 993 (p)->fts_path = addr; \ 994} 995 /* Adjust the current set of children. */ 996 for (p = sp->fts_child; p; p = p->fts_link) 997 ADJUST(p); 998 999 /* Adjust the rest of the tree, including the current level. */ 1000 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1001 ADJUST(p); 1002 p = p->fts_link ? p->fts_link : p->fts_parent; 1003 } 1004} 1005 1006static size_t 1007fts_maxarglen(char * const *argv) 1008{ 1009 size_t len, max; 1010 1011 for (max = 0; *argv; ++argv) 1012 if ((len = strlen(*argv)) > max) 1013 max = len; 1014 return (max + 1); 1015} 1016 1017/* 1018 * Change to dir specified by fd or p->fts_accpath without getting 1019 * tricked by someone changing the world out from underneath us. 1020 * Assumes p->fts_dev and p->fts_ino are filled in. 1021 */ 1022static int 1023fts_safe_changedir(FTS *sp, FTSENT *p, int fd, const char *path) 1024{ 1025 int ret, oerrno, newfd; 1026 struct stat sb; 1027 1028 newfd = fd; 1029 if (ISSET(FTS_NOCHDIR)) 1030 return (0); 1031 if (fd == -1 && (newfd = open(path, O_RDONLY|O_DIRECTORY|O_CLOEXEC)) == -1) 1032 return (-1); 1033 if (fstat(newfd, &sb) == -1) { 1034 ret = -1; 1035 goto bail; 1036 } 1037 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) { 1038 errno = ENOENT; /* disinformation */ 1039 ret = -1; 1040 goto bail; 1041 } 1042 ret = fchdir(newfd); 1043bail: 1044 oerrno = errno; 1045 if (fd == -1) 1046 (void)close(newfd); 1047 errno = oerrno; 1048 return (ret); 1049} 1050