1/*- 2 * Copyright (c) 1990, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $OpenBSD: fts.c,v 1.22 1999/10/03 19:22:22 millert Exp $ 30 */ 31 32#if 0 33#if defined(LIBC_SCCS) && !defined(lint) 34static char sccsid[] = "@(#)fts.c 8.6 (Berkeley) 8/14/94"; 35#endif /* LIBC_SCCS and not lint */ 36#endif 37 38#include <sys/cdefs.h> 39__FBSDID("$FreeBSD$"); 40 41#include "namespace.h" 42#include <sys/param.h> 43#include <sys/mount.h> 44#include <sys/stat.h> 45 46#include <dirent.h> 47#include <errno.h> 48#include <fcntl.h> 49#include <fts.h> 50#include <stdlib.h> 51#include <string.h> 52#include <unistd.h> 53#include "un-namespace.h" 54 55#include "gen-private.h" 56 57static FTSENT *fts_alloc(FTS *, char *, size_t); 58static FTSENT *fts_build(FTS *, int); 59static void fts_lfree(FTSENT *); 60static void fts_load(FTS *, FTSENT *); 61static size_t fts_maxarglen(char * const *); 62static void fts_padjust(FTS *, FTSENT *); 63static int fts_palloc(FTS *, size_t); 64static FTSENT *fts_sort(FTS *, FTSENT *, size_t); 65static int fts_stat(FTS *, FTSENT *, int); 66static int fts_safe_changedir(FTS *, FTSENT *, int, char *); 67static int fts_ufslinks(FTS *, const FTSENT *); 68 69#define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2]))) 70 71#define CLR(opt) (sp->fts_options &= ~(opt)) 72#define ISSET(opt) (sp->fts_options & (opt)) 73#define SET(opt) (sp->fts_options |= (opt)) 74 75#define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 76 77/* fts_build flags */ 78#define BCHILD 1 /* fts_children */ 79#define BNAMES 2 /* fts_children, names only */ 80#define BREAD 3 /* fts_read */ 81 82/* 83 * Internal representation of an FTS, including extra implementation 84 * details. The FTS returned from fts_open points to this structure's 85 * ftsp_fts member (and can be cast to an _fts_private as required) 86 */ 87struct _fts_private { 88 FTS ftsp_fts; 89 struct statfs ftsp_statfs; 90 dev_t ftsp_dev; 91 int ftsp_linksreliable; 92}; 93 94/* 95 * The "FTS_NOSTAT" option can avoid a lot of calls to stat(2) if it 96 * knows that a directory could not possibly have subdirectories. This 97 * is decided by looking at the link count: a subdirectory would 98 * increment its parent's link count by virtue of its own ".." entry. 99 * This assumption only holds for UFS-like filesystems that implement 100 * links and directories this way, so we must punt for others. 101 */ 102 103static const char *ufslike_filesystems[] = { 104 "ufs", 105 "zfs", 106 "nfs", 107 "nfs4", 108 "ext2fs", 109 0 110}; 111 112FTS * 113fts_open(argv, options, compar) 114 char * const *argv; 115 int options; 116 int (*compar)(const FTSENT * const *, const FTSENT * const *); 117{ 118 struct _fts_private *priv; 119 FTS *sp; 120 FTSENT *p, *root; 121 FTSENT *parent, *tmp; 122 size_t len, nitems; 123 124 /* Options check. */ 125 if (options & ~FTS_OPTIONMASK) { 126 errno = EINVAL; 127 return (NULL); 128 } 129 130 /* fts_open() requires at least one path */ 131 if (*argv == NULL) { 132 errno = EINVAL; 133 return (NULL); 134 } 135 136 /* Allocate/initialize the stream. */ 137 if ((priv = calloc(1, sizeof(*priv))) == NULL) 138 return (NULL); 139 sp = &priv->ftsp_fts; 140 sp->fts_compar = compar; 141 sp->fts_options = options; 142 143 /* Shush, GCC. */ 144 tmp = NULL; 145 146 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 147 if (ISSET(FTS_LOGICAL)) 148 SET(FTS_NOCHDIR); 149 150 /* 151 * Start out with 1K of path space, and enough, in any case, 152 * to hold the user's paths. 153 */ 154 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN))) 155 goto mem1; 156 157 /* Allocate/initialize root's parent. */ 158 if ((parent = fts_alloc(sp, "", 0)) == NULL) 159 goto mem2; 160 parent->fts_level = FTS_ROOTPARENTLEVEL; 161 162 /* Allocate/initialize root(s). */ 163 for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) { 164 /* Don't allow zero-length paths. */ 165 if ((len = strlen(*argv)) == 0) { 166 errno = ENOENT; 167 goto mem3; 168 } 169 170 p = fts_alloc(sp, *argv, len); 171 p->fts_level = FTS_ROOTLEVEL; 172 p->fts_parent = parent; 173 p->fts_accpath = p->fts_name; 174 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW)); 175 176 /* Command-line "." and ".." are real directories. */ 177 if (p->fts_info == FTS_DOT) 178 p->fts_info = FTS_D; 179 180 /* 181 * If comparison routine supplied, traverse in sorted 182 * order; otherwise traverse in the order specified. 183 */ 184 if (compar) { 185 p->fts_link = root; 186 root = p; 187 } else { 188 p->fts_link = NULL; 189 if (root == NULL) 190 tmp = root = p; 191 else { 192 tmp->fts_link = p; 193 tmp = p; 194 } 195 } 196 } 197 if (compar && nitems > 1) 198 root = fts_sort(sp, root, nitems); 199 200 /* 201 * Allocate a dummy pointer and make fts_read think that we've just 202 * finished the node before the root(s); set p->fts_info to FTS_INIT 203 * so that everything about the "current" node is ignored. 204 */ 205 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 206 goto mem3; 207 sp->fts_cur->fts_link = root; 208 sp->fts_cur->fts_info = FTS_INIT; 209 210 /* 211 * If using chdir(2), grab a file descriptor pointing to dot to ensure 212 * that we can get back here; this could be avoided for some paths, 213 * but almost certainly not worth the effort. Slashes, symbolic links, 214 * and ".." are all fairly nasty problems. Note, if we can't get the 215 * descriptor we run anyway, just more slowly. 216 */ 217 if (!ISSET(FTS_NOCHDIR) && 218 (sp->fts_rfd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) 219 SET(FTS_NOCHDIR); 220 221 return (sp); 222 223mem3: fts_lfree(root); 224 free(parent); 225mem2: free(sp->fts_path); 226mem1: free(sp); 227 return (NULL); 228} 229 230static void 231fts_load(FTS *sp, FTSENT *p) 232{ 233 size_t len; 234 char *cp; 235 236 /* 237 * Load the stream structure for the next traversal. Since we don't 238 * actually enter the directory until after the preorder visit, set 239 * the fts_accpath field specially so the chdir gets done to the right 240 * place and the user can access the first node. From fts_open it's 241 * known that the path will fit. 242 */ 243 len = p->fts_pathlen = p->fts_namelen; 244 memmove(sp->fts_path, p->fts_name, len + 1); 245 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 246 len = strlen(++cp); 247 memmove(p->fts_name, cp, len + 1); 248 p->fts_namelen = len; 249 } 250 p->fts_accpath = p->fts_path = sp->fts_path; 251 sp->fts_dev = p->fts_dev; 252} 253 254int 255fts_close(FTS *sp) 256{ 257 FTSENT *freep, *p; 258 int saved_errno; 259 260 /* 261 * This still works if we haven't read anything -- the dummy structure 262 * points to the root list, so we step through to the end of the root 263 * list which has a valid parent pointer. 264 */ 265 if (sp->fts_cur) { 266 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 267 freep = p; 268 p = p->fts_link != NULL ? p->fts_link : p->fts_parent; 269 free(freep); 270 } 271 free(p); 272 } 273 274 /* Free up child linked list, sort array, path buffer. */ 275 if (sp->fts_child) 276 fts_lfree(sp->fts_child); 277 if (sp->fts_array) 278 free(sp->fts_array); 279 free(sp->fts_path); 280 281 /* Return to original directory, save errno if necessary. */ 282 if (!ISSET(FTS_NOCHDIR)) { 283 saved_errno = fchdir(sp->fts_rfd) ? errno : 0; 284 (void)_close(sp->fts_rfd); 285 286 /* Set errno and return. */ 287 if (saved_errno != 0) { 288 /* Free up the stream pointer. */ 289 free(sp); 290 errno = saved_errno; 291 return (-1); 292 } 293 } 294 295 /* Free up the stream pointer. */ 296 free(sp); 297 return (0); 298} 299 300/* 301 * Special case of "/" at the end of the path so that slashes aren't 302 * appended which would cause paths to be written as "....//foo". 303 */ 304#define NAPPEND(p) \ 305 (p->fts_path[p->fts_pathlen - 1] == '/' \ 306 ? p->fts_pathlen - 1 : p->fts_pathlen) 307 308FTSENT * 309fts_read(FTS *sp) 310{ 311 FTSENT *p, *tmp; 312 int instr; 313 char *t; 314 int saved_errno; 315 316 /* If finished or unrecoverable error, return NULL. */ 317 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 318 return (NULL); 319 320 /* Set current node pointer. */ 321 p = sp->fts_cur; 322 323 /* Save and zero out user instructions. */ 324 instr = p->fts_instr; 325 p->fts_instr = FTS_NOINSTR; 326 327 /* Any type of file may be re-visited; re-stat and re-turn. */ 328 if (instr == FTS_AGAIN) { 329 p->fts_info = fts_stat(sp, p, 0); 330 return (p); 331 } 332 333 /* 334 * Following a symlink -- SLNONE test allows application to see 335 * SLNONE and recover. If indirecting through a symlink, have 336 * keep a pointer to current location. If unable to get that 337 * pointer, follow fails. 338 */ 339 if (instr == FTS_FOLLOW && 340 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 341 p->fts_info = fts_stat(sp, p, 1); 342 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 343 if ((p->fts_symfd = _open(".", O_RDONLY | O_CLOEXEC, 344 0)) < 0) { 345 p->fts_errno = errno; 346 p->fts_info = FTS_ERR; 347 } else 348 p->fts_flags |= FTS_SYMFOLLOW; 349 } 350 return (p); 351 } 352 353 /* Directory in pre-order. */ 354 if (p->fts_info == FTS_D) { 355 /* If skipped or crossed mount point, do post-order visit. */ 356 if (instr == FTS_SKIP || 357 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 358 if (p->fts_flags & FTS_SYMFOLLOW) 359 (void)_close(p->fts_symfd); 360 if (sp->fts_child) { 361 fts_lfree(sp->fts_child); 362 sp->fts_child = NULL; 363 } 364 p->fts_info = FTS_DP; 365 return (p); 366 } 367 368 /* Rebuild if only read the names and now traversing. */ 369 if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) { 370 CLR(FTS_NAMEONLY); 371 fts_lfree(sp->fts_child); 372 sp->fts_child = NULL; 373 } 374 375 /* 376 * Cd to the subdirectory. 377 * 378 * If have already read and now fail to chdir, whack the list 379 * to make the names come out right, and set the parent errno 380 * so the application will eventually get an error condition. 381 * Set the FTS_DONTCHDIR flag so that when we logically change 382 * directories back to the parent we don't do a chdir. 383 * 384 * If haven't read do so. If the read fails, fts_build sets 385 * FTS_STOP or the fts_info field of the node. 386 */ 387 if (sp->fts_child != NULL) { 388 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 389 p->fts_errno = errno; 390 p->fts_flags |= FTS_DONTCHDIR; 391 for (p = sp->fts_child; p != NULL; 392 p = p->fts_link) 393 p->fts_accpath = 394 p->fts_parent->fts_accpath; 395 } 396 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 397 if (ISSET(FTS_STOP)) 398 return (NULL); 399 return (p); 400 } 401 p = sp->fts_child; 402 sp->fts_child = NULL; 403 goto name; 404 } 405 406 /* Move to the next node on this level. */ 407next: tmp = p; 408 if ((p = p->fts_link) != NULL) { 409 free(tmp); 410 411 /* 412 * If reached the top, return to the original directory (or 413 * the root of the tree), and load the paths for the next root. 414 */ 415 if (p->fts_level == FTS_ROOTLEVEL) { 416 if (FCHDIR(sp, sp->fts_rfd)) { 417 SET(FTS_STOP); 418 return (NULL); 419 } 420 fts_load(sp, p); 421 return (sp->fts_cur = p); 422 } 423 424 /* 425 * User may have called fts_set on the node. If skipped, 426 * ignore. If followed, get a file descriptor so we can 427 * get back if necessary. 428 */ 429 if (p->fts_instr == FTS_SKIP) 430 goto next; 431 if (p->fts_instr == FTS_FOLLOW) { 432 p->fts_info = fts_stat(sp, p, 1); 433 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 434 if ((p->fts_symfd = 435 _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) { 436 p->fts_errno = errno; 437 p->fts_info = FTS_ERR; 438 } else 439 p->fts_flags |= FTS_SYMFOLLOW; 440 } 441 p->fts_instr = FTS_NOINSTR; 442 } 443 444name: t = sp->fts_path + NAPPEND(p->fts_parent); 445 *t++ = '/'; 446 memmove(t, p->fts_name, p->fts_namelen + 1); 447 return (sp->fts_cur = p); 448 } 449 450 /* Move up to the parent node. */ 451 p = tmp->fts_parent; 452 free(tmp); 453 454 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 455 /* 456 * Done; free everything up and set errno to 0 so the user 457 * can distinguish between error and EOF. 458 */ 459 free(p); 460 errno = 0; 461 return (sp->fts_cur = NULL); 462 } 463 464 /* NUL terminate the pathname. */ 465 sp->fts_path[p->fts_pathlen] = '\0'; 466 467 /* 468 * Return to the parent directory. If at a root node or came through 469 * a symlink, go back through the file descriptor. Otherwise, cd up 470 * one directory. 471 */ 472 if (p->fts_level == FTS_ROOTLEVEL) { 473 if (FCHDIR(sp, sp->fts_rfd)) { 474 SET(FTS_STOP); 475 return (NULL); 476 } 477 } else if (p->fts_flags & FTS_SYMFOLLOW) { 478 if (FCHDIR(sp, p->fts_symfd)) { 479 saved_errno = errno; 480 (void)_close(p->fts_symfd); 481 errno = saved_errno; 482 SET(FTS_STOP); 483 return (NULL); 484 } 485 (void)_close(p->fts_symfd); 486 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 487 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 488 SET(FTS_STOP); 489 return (NULL); 490 } 491 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 492 return (sp->fts_cur = p); 493} 494 495/* 496 * Fts_set takes the stream as an argument although it's not used in this 497 * implementation; it would be necessary if anyone wanted to add global 498 * semantics to fts using fts_set. An error return is allowed for similar 499 * reasons. 500 */ 501/* ARGSUSED */ 502int 503fts_set(FTS *sp, FTSENT *p, int instr) 504{ 505 if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW && 506 instr != FTS_NOINSTR && instr != FTS_SKIP) { 507 errno = EINVAL; 508 return (1); 509 } 510 p->fts_instr = instr; 511 return (0); 512} 513 514FTSENT * 515fts_children(FTS *sp, int instr) 516{ 517 FTSENT *p; 518 int fd; 519 520 if (instr != 0 && instr != FTS_NAMEONLY) { 521 errno = EINVAL; 522 return (NULL); 523 } 524 525 /* Set current node pointer. */ 526 p = sp->fts_cur; 527 528 /* 529 * Errno set to 0 so user can distinguish empty directory from 530 * an error. 531 */ 532 errno = 0; 533 534 /* Fatal errors stop here. */ 535 if (ISSET(FTS_STOP)) 536 return (NULL); 537 538 /* Return logical hierarchy of user's arguments. */ 539 if (p->fts_info == FTS_INIT) 540 return (p->fts_link); 541 542 /* 543 * If not a directory being visited in pre-order, stop here. Could 544 * allow FTS_DNR, assuming the user has fixed the problem, but the 545 * same effect is available with FTS_AGAIN. 546 */ 547 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 548 return (NULL); 549 550 /* Free up any previous child list. */ 551 if (sp->fts_child != NULL) 552 fts_lfree(sp->fts_child); 553 554 if (instr == FTS_NAMEONLY) { 555 SET(FTS_NAMEONLY); 556 instr = BNAMES; 557 } else 558 instr = BCHILD; 559 560 /* 561 * If using chdir on a relative path and called BEFORE fts_read does 562 * its chdir to the root of a traversal, we can lose -- we need to 563 * chdir into the subdirectory, and we don't know where the current 564 * directory is, so we can't get back so that the upcoming chdir by 565 * fts_read will work. 566 */ 567 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 568 ISSET(FTS_NOCHDIR)) 569 return (sp->fts_child = fts_build(sp, instr)); 570 571 if ((fd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) 572 return (NULL); 573 sp->fts_child = fts_build(sp, instr); 574 if (fchdir(fd)) { 575 (void)_close(fd); 576 return (NULL); 577 } 578 (void)_close(fd); 579 return (sp->fts_child); 580} 581 582#ifndef fts_get_clientptr 583#error "fts_get_clientptr not defined" 584#endif 585 586void * 587(fts_get_clientptr)(FTS *sp) 588{ 589 590 return (fts_get_clientptr(sp)); 591} 592 593#ifndef fts_get_stream 594#error "fts_get_stream not defined" 595#endif 596 597FTS * 598(fts_get_stream)(FTSENT *p) 599{ 600 return (fts_get_stream(p)); 601} 602 603void 604fts_set_clientptr(FTS *sp, void *clientptr) 605{ 606 607 sp->fts_clientptr = clientptr; 608} 609 610/* 611 * This is the tricky part -- do not casually change *anything* in here. The 612 * idea is to build the linked list of entries that are used by fts_children 613 * and fts_read. There are lots of special cases. 614 * 615 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 616 * set and it's a physical walk (so that symbolic links can't be directories), 617 * we can do things quickly. First, if it's a 4.4BSD file system, the type 618 * of the file is in the directory entry. Otherwise, we assume that the number 619 * of subdirectories in a node is equal to the number of links to the parent. 620 * The former skips all stat calls. The latter skips stat calls in any leaf 621 * directories and for any files after the subdirectories in the directory have 622 * been found, cutting the stat calls by about 2/3. 623 */ 624static FTSENT * 625fts_build(FTS *sp, int type) 626{ 627 struct dirent *dp; 628 FTSENT *p, *head; 629 FTSENT *cur, *tail; 630 DIR *dirp; 631 void *oldaddr; 632 char *cp; 633 int cderrno, descend, oflag, saved_errno, nostat, doadjust; 634 long level; 635 long nlinks; /* has to be signed because -1 is a magic value */ 636 size_t dnamlen, len, maxlen, nitems; 637 638 /* Set current node pointer. */ 639 cur = sp->fts_cur; 640 641 /* 642 * Open the directory for reading. If this fails, we're done. 643 * If being called from fts_read, set the fts_info field. 644 */ 645#ifdef FTS_WHITEOUT 646 if (ISSET(FTS_WHITEOUT)) 647 oflag = DTF_NODUP | DTF_REWIND; 648 else 649 oflag = DTF_HIDEW | DTF_NODUP | DTF_REWIND; 650#else 651#define __opendir2(path, flag) opendir(path) 652#endif 653 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) { 654 if (type == BREAD) { 655 cur->fts_info = FTS_DNR; 656 cur->fts_errno = errno; 657 } 658 return (NULL); 659 } 660 661 /* 662 * Nlinks is the number of possible entries of type directory in the 663 * directory if we're cheating on stat calls, 0 if we're not doing 664 * any stat calls at all, -1 if we're doing stats on everything. 665 */ 666 if (type == BNAMES) { 667 nlinks = 0; 668 /* Be quiet about nostat, GCC. */ 669 nostat = 0; 670 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 671 if (fts_ufslinks(sp, cur)) 672 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 673 else 674 nlinks = -1; 675 nostat = 1; 676 } else { 677 nlinks = -1; 678 nostat = 0; 679 } 680 681#ifdef notdef 682 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 683 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 684 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 685#endif 686 /* 687 * If we're going to need to stat anything or we want to descend 688 * and stay in the directory, chdir. If this fails we keep going, 689 * but set a flag so we don't chdir after the post-order visit. 690 * We won't be able to stat anything, but we can still return the 691 * names themselves. Note, that since fts_read won't be able to 692 * chdir into the directory, it will have to return different path 693 * names than before, i.e. "a/b" instead of "b". Since the node 694 * has already been visited in pre-order, have to wait until the 695 * post-order visit to return the error. There is a special case 696 * here, if there was nothing to stat then it's not an error to 697 * not be able to stat. This is all fairly nasty. If a program 698 * needed sorted entries or stat information, they had better be 699 * checking FTS_NS on the returned nodes. 700 */ 701 cderrno = 0; 702 if (nlinks || type == BREAD) { 703 if (fts_safe_changedir(sp, cur, _dirfd(dirp), NULL)) { 704 if (nlinks && type == BREAD) 705 cur->fts_errno = errno; 706 cur->fts_flags |= FTS_DONTCHDIR; 707 descend = 0; 708 cderrno = errno; 709 } else 710 descend = 1; 711 } else 712 descend = 0; 713 714 /* 715 * Figure out the max file name length that can be stored in the 716 * current path -- the inner loop allocates more path as necessary. 717 * We really wouldn't have to do the maxlen calculations here, we 718 * could do them in fts_read before returning the path, but it's a 719 * lot easier here since the length is part of the dirent structure. 720 * 721 * If not changing directories set a pointer so that can just append 722 * each new name into the path. 723 */ 724 len = NAPPEND(cur); 725 if (ISSET(FTS_NOCHDIR)) { 726 cp = sp->fts_path + len; 727 *cp++ = '/'; 728 } else { 729 /* GCC, you're too verbose. */ 730 cp = NULL; 731 } 732 len++; 733 maxlen = sp->fts_pathlen - len; 734 735 level = cur->fts_level + 1; 736 737 /* Read the directory, attaching each entry to the `link' pointer. */ 738 doadjust = 0; 739 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) { 740 dnamlen = dp->d_namlen; 741 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 742 continue; 743 744 if ((p = fts_alloc(sp, dp->d_name, dnamlen)) == NULL) 745 goto mem1; 746 if (dnamlen >= maxlen) { /* include space for NUL */ 747 oldaddr = sp->fts_path; 748 if (fts_palloc(sp, dnamlen + len + 1)) { 749 /* 750 * No more memory for path or structures. Save 751 * errno, free up the current structure and the 752 * structures already allocated. 753 */ 754mem1: saved_errno = errno; 755 if (p) 756 free(p); 757 fts_lfree(head); 758 (void)closedir(dirp); 759 cur->fts_info = FTS_ERR; 760 SET(FTS_STOP); 761 errno = saved_errno; 762 return (NULL); 763 } 764 /* Did realloc() change the pointer? */ 765 if (oldaddr != sp->fts_path) { 766 doadjust = 1; 767 if (ISSET(FTS_NOCHDIR)) 768 cp = sp->fts_path + len; 769 } 770 maxlen = sp->fts_pathlen - len; 771 } 772 773 p->fts_level = level; 774 p->fts_parent = sp->fts_cur; 775 p->fts_pathlen = len + dnamlen; 776 777#ifdef FTS_WHITEOUT 778 if (dp->d_type == DT_WHT) 779 p->fts_flags |= FTS_ISW; 780#endif 781 782 if (cderrno) { 783 if (nlinks) { 784 p->fts_info = FTS_NS; 785 p->fts_errno = cderrno; 786 } else 787 p->fts_info = FTS_NSOK; 788 p->fts_accpath = cur->fts_accpath; 789 } else if (nlinks == 0 790#ifdef DT_DIR 791 || (nostat && 792 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 793#endif 794 ) { 795 p->fts_accpath = 796 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 797 p->fts_info = FTS_NSOK; 798 } else { 799 /* Build a file name for fts_stat to stat. */ 800 if (ISSET(FTS_NOCHDIR)) { 801 p->fts_accpath = p->fts_path; 802 memmove(cp, p->fts_name, p->fts_namelen + 1); 803 } else 804 p->fts_accpath = p->fts_name; 805 /* Stat it. */ 806 p->fts_info = fts_stat(sp, p, 0); 807 808 /* Decrement link count if applicable. */ 809 if (nlinks > 0 && (p->fts_info == FTS_D || 810 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 811 --nlinks; 812 } 813 814 /* We walk in directory order so "ls -f" doesn't get upset. */ 815 p->fts_link = NULL; 816 if (head == NULL) 817 head = tail = p; 818 else { 819 tail->fts_link = p; 820 tail = p; 821 } 822 ++nitems; 823 } 824 if (dirp) 825 (void)closedir(dirp); 826 827 /* 828 * If realloc() changed the address of the path, adjust the 829 * addresses for the rest of the tree and the dir list. 830 */ 831 if (doadjust) 832 fts_padjust(sp, head); 833 834 /* 835 * If not changing directories, reset the path back to original 836 * state. 837 */ 838 if (ISSET(FTS_NOCHDIR)) 839 sp->fts_path[cur->fts_pathlen] = '\0'; 840 841 /* 842 * If descended after called from fts_children or after called from 843 * fts_read and nothing found, get back. At the root level we use 844 * the saved fd; if one of fts_open()'s arguments is a relative path 845 * to an empty directory, we wind up here with no other way back. If 846 * can't get back, we're done. 847 */ 848 if (descend && (type == BCHILD || !nitems) && 849 (cur->fts_level == FTS_ROOTLEVEL ? 850 FCHDIR(sp, sp->fts_rfd) : 851 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 852 cur->fts_info = FTS_ERR; 853 SET(FTS_STOP); 854 return (NULL); 855 } 856 857 /* If didn't find anything, return NULL. */ 858 if (!nitems) { 859 if (type == BREAD) 860 cur->fts_info = FTS_DP; 861 return (NULL); 862 } 863 864 /* Sort the entries. */ 865 if (sp->fts_compar && nitems > 1) 866 head = fts_sort(sp, head, nitems); 867 return (head); 868} 869 870static int 871fts_stat(FTS *sp, FTSENT *p, int follow) 872{ 873 FTSENT *t; 874 dev_t dev; 875 ino_t ino; 876 struct stat *sbp, sb; 877 int saved_errno; 878 879 /* If user needs stat info, stat buffer already allocated. */ 880 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 881 882#ifdef FTS_WHITEOUT 883 /* Check for whiteout. */ 884 if (p->fts_flags & FTS_ISW) { 885 if (sbp != &sb) { 886 memset(sbp, '\0', sizeof(*sbp)); 887 sbp->st_mode = S_IFWHT; 888 } 889 return (FTS_W); 890 } 891#endif 892 893 /* 894 * If doing a logical walk, or application requested FTS_FOLLOW, do 895 * a stat(2). If that fails, check for a non-existent symlink. If 896 * fail, set the errno from the stat call. 897 */ 898 if (ISSET(FTS_LOGICAL) || follow) { 899 if (stat(p->fts_accpath, sbp)) { 900 saved_errno = errno; 901 if (!lstat(p->fts_accpath, sbp)) { 902 errno = 0; 903 return (FTS_SLNONE); 904 } 905 p->fts_errno = saved_errno; 906 goto err; 907 } 908 } else if (lstat(p->fts_accpath, sbp)) { 909 p->fts_errno = errno; 910err: memset(sbp, 0, sizeof(struct stat)); 911 return (FTS_NS); 912 } 913 914 if (S_ISDIR(sbp->st_mode)) { 915 /* 916 * Set the device/inode. Used to find cycles and check for 917 * crossing mount points. Also remember the link count, used 918 * in fts_build to limit the number of stat calls. It is 919 * understood that these fields are only referenced if fts_info 920 * is set to FTS_D. 921 */ 922 dev = p->fts_dev = sbp->st_dev; 923 ino = p->fts_ino = sbp->st_ino; 924 p->fts_nlink = sbp->st_nlink; 925 926 if (ISDOT(p->fts_name)) 927 return (FTS_DOT); 928 929 /* 930 * Cycle detection is done by brute force when the directory 931 * is first encountered. If the tree gets deep enough or the 932 * number of symbolic links to directories is high enough, 933 * something faster might be worthwhile. 934 */ 935 for (t = p->fts_parent; 936 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 937 if (ino == t->fts_ino && dev == t->fts_dev) { 938 p->fts_cycle = t; 939 return (FTS_DC); 940 } 941 return (FTS_D); 942 } 943 if (S_ISLNK(sbp->st_mode)) 944 return (FTS_SL); 945 if (S_ISREG(sbp->st_mode)) 946 return (FTS_F); 947 return (FTS_DEFAULT); 948} 949 950/* 951 * The comparison function takes pointers to pointers to FTSENT structures. 952 * Qsort wants a comparison function that takes pointers to void. 953 * (Both with appropriate levels of const-poisoning, of course!) 954 * Use a trampoline function to deal with the difference. 955 */ 956static int 957fts_compar(const void *a, const void *b) 958{ 959 FTS *parent; 960 961 parent = (*(const FTSENT * const *)a)->fts_fts; 962 return (*parent->fts_compar)(a, b); 963} 964 965static FTSENT * 966fts_sort(FTS *sp, FTSENT *head, size_t nitems) 967{ 968 FTSENT **ap, *p; 969 970 /* 971 * Construct an array of pointers to the structures and call qsort(3). 972 * Reassemble the array in the order returned by qsort. If unable to 973 * sort for memory reasons, return the directory entries in their 974 * current order. Allocate enough space for the current needs plus 975 * 40 so don't realloc one entry at a time. 976 */ 977 if (nitems > sp->fts_nitems) { 978 sp->fts_nitems = nitems + 40; 979 if ((sp->fts_array = reallocf(sp->fts_array, 980 sp->fts_nitems * sizeof(FTSENT *))) == NULL) { 981 sp->fts_nitems = 0; 982 return (head); 983 } 984 } 985 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 986 *ap++ = p; 987 qsort(sp->fts_array, nitems, sizeof(FTSENT *), fts_compar); 988 for (head = *(ap = sp->fts_array); --nitems; ++ap) 989 ap[0]->fts_link = ap[1]; 990 ap[0]->fts_link = NULL; 991 return (head); 992} 993 994static FTSENT * 995fts_alloc(FTS *sp, char *name, size_t namelen) 996{ 997 FTSENT *p; 998 size_t len; 999 1000 struct ftsent_withstat { 1001 FTSENT ent; 1002 struct stat statbuf; 1003 }; 1004 1005 /* 1006 * The file name is a variable length array and no stat structure is 1007 * necessary if the user has set the nostat bit. Allocate the FTSENT 1008 * structure, the file name and the stat structure in one chunk, but 1009 * be careful that the stat structure is reasonably aligned. 1010 */ 1011 if (ISSET(FTS_NOSTAT)) 1012 len = sizeof(FTSENT) + namelen + 1; 1013 else 1014 len = sizeof(struct ftsent_withstat) + namelen + 1; 1015 1016 if ((p = malloc(len)) == NULL) 1017 return (NULL); 1018 1019 if (ISSET(FTS_NOSTAT)) { 1020 p->fts_name = (char *)(p + 1); 1021 p->fts_statp = NULL; 1022 } else { 1023 p->fts_name = (char *)((struct ftsent_withstat *)p + 1); 1024 p->fts_statp = &((struct ftsent_withstat *)p)->statbuf; 1025 } 1026 1027 /* Copy the name and guarantee NUL termination. */ 1028 memcpy(p->fts_name, name, namelen); 1029 p->fts_name[namelen] = '\0'; 1030 p->fts_namelen = namelen; 1031 p->fts_path = sp->fts_path; 1032 p->fts_errno = 0; 1033 p->fts_flags = 0; 1034 p->fts_instr = FTS_NOINSTR; 1035 p->fts_number = 0; 1036 p->fts_pointer = NULL; 1037 p->fts_fts = sp; 1038 return (p); 1039} 1040 1041static void 1042fts_lfree(FTSENT *head) 1043{ 1044 FTSENT *p; 1045 1046 /* Free a linked list of structures. */ 1047 while ((p = head)) { 1048 head = head->fts_link; 1049 free(p); 1050 } 1051} 1052 1053/* 1054 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 1055 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 1056 * though the kernel won't resolve them. Add the size (not just what's needed) 1057 * plus 256 bytes so don't realloc the path 2 bytes at a time. 1058 */ 1059static int 1060fts_palloc(FTS *sp, size_t more) 1061{ 1062 1063 sp->fts_pathlen += more + 256; 1064 sp->fts_path = reallocf(sp->fts_path, sp->fts_pathlen); 1065 return (sp->fts_path == NULL); 1066} 1067 1068/* 1069 * When the path is realloc'd, have to fix all of the pointers in structures 1070 * already returned. 1071 */ 1072static void 1073fts_padjust(FTS *sp, FTSENT *head) 1074{ 1075 FTSENT *p; 1076 char *addr = sp->fts_path; 1077 1078#define ADJUST(p) do { \ 1079 if ((p)->fts_accpath != (p)->fts_name) { \ 1080 (p)->fts_accpath = \ 1081 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \ 1082 } \ 1083 (p)->fts_path = addr; \ 1084} while (0) 1085 /* Adjust the current set of children. */ 1086 for (p = sp->fts_child; p; p = p->fts_link) 1087 ADJUST(p); 1088 1089 /* Adjust the rest of the tree, including the current level. */ 1090 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1091 ADJUST(p); 1092 p = p->fts_link ? p->fts_link : p->fts_parent; 1093 } 1094} 1095 1096static size_t 1097fts_maxarglen(argv) 1098 char * const *argv; 1099{ 1100 size_t len, max; 1101 1102 for (max = 0; *argv; ++argv) 1103 if ((len = strlen(*argv)) > max) 1104 max = len; 1105 return (max + 1); 1106} 1107 1108/* 1109 * Change to dir specified by fd or p->fts_accpath without getting 1110 * tricked by someone changing the world out from underneath us. 1111 * Assumes p->fts_dev and p->fts_ino are filled in. 1112 */ 1113static int 1114fts_safe_changedir(FTS *sp, FTSENT *p, int fd, char *path) 1115{ 1116 int ret, oerrno, newfd; 1117 struct stat sb; 1118 1119 newfd = fd; 1120 if (ISSET(FTS_NOCHDIR)) 1121 return (0); 1122 if (fd < 0 && (newfd = _open(path, O_RDONLY | O_DIRECTORY | 1123 O_CLOEXEC, 0)) < 0) 1124 return (-1); 1125 if (_fstat(newfd, &sb)) { 1126 ret = -1; 1127 goto bail; 1128 } 1129 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) { 1130 errno = ENOENT; /* disinformation */ 1131 ret = -1; 1132 goto bail; 1133 } 1134 ret = fchdir(newfd); 1135bail: 1136 oerrno = errno; 1137 if (fd < 0) 1138 (void)_close(newfd); 1139 errno = oerrno; 1140 return (ret); 1141} 1142 1143/* 1144 * Check if the filesystem for "ent" has UFS-style links. 1145 */ 1146static int 1147fts_ufslinks(FTS *sp, const FTSENT *ent) 1148{ 1149 struct _fts_private *priv; 1150 const char **cpp; 1151 1152 priv = (struct _fts_private *)sp; 1153 /* 1154 * If this node's device is different from the previous, grab 1155 * the filesystem information, and decide on the reliability 1156 * of the link information from this filesystem for stat(2) 1157 * avoidance. 1158 */ 1159 if (priv->ftsp_dev != ent->fts_dev) { 1160 if (statfs(ent->fts_path, &priv->ftsp_statfs) != -1) { 1161 priv->ftsp_dev = ent->fts_dev; 1162 priv->ftsp_linksreliable = 0; 1163 for (cpp = ufslike_filesystems; *cpp; cpp++) { 1164 if (strcmp(priv->ftsp_statfs.f_fstypename, 1165 *cpp) == 0) { 1166 priv->ftsp_linksreliable = 1; 1167 break; 1168 } 1169 } 1170 } else { 1171 priv->ftsp_linksreliable = 0; 1172 } 1173 } 1174 return (priv->ftsp_linksreliable); 1175} 1176