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 55static FTSENT *fts_alloc(FTS *, char *, size_t); 56static FTSENT *fts_build(FTS *, int); 57static void fts_lfree(FTSENT *); 58static void fts_load(FTS *, FTSENT *); 59static size_t fts_maxarglen(char * const *); 60static void fts_padjust(FTS *, FTSENT *); 61static int fts_palloc(FTS *, size_t); 62static FTSENT *fts_sort(FTS *, FTSENT *, size_t); 63static int fts_stat(FTS *, FTSENT *, int); 64static int fts_safe_changedir(FTS *, FTSENT *, int, char *); 65static int fts_ufslinks(FTS *, const FTSENT *); 66 67#define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2]))) 68 69#define CLR(opt) (sp->fts_options &= ~(opt)) 70#define ISSET(opt) (sp->fts_options & (opt)) 71#define SET(opt) (sp->fts_options |= (opt)) 72 73#define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 74 75/* fts_build flags */ 76#define BCHILD 1 /* fts_children */ 77#define BNAMES 2 /* fts_children, names only */ 78#define BREAD 3 /* fts_read */ 79 80/* 81 * Internal representation of an FTS, including extra implementation 82 * details. The FTS returned from fts_open points to this structure's 83 * ftsp_fts member (and can be cast to an _fts_private as required) 84 */ 85struct _fts_private { 86 FTS ftsp_fts; 87 struct statfs ftsp_statfs; 88 dev_t ftsp_dev; 89 int ftsp_linksreliable; 90}; 91 92/* 93 * The "FTS_NOSTAT" option can avoid a lot of calls to stat(2) if it 94 * knows that a directory could not possibly have subdirectories. This 95 * is decided by looking at the link count: a subdirectory would 96 * increment its parent's link count by virtue of its own ".." entry. 97 * This assumption only holds for UFS-like filesystems that implement 98 * links and directories this way, so we must punt for others. 99 */ 100 101static const char *ufslike_filesystems[] = { 102 "ufs", 103 "zfs", 104 "nfs", 105 "nfs4", 106 "ext2fs", 107 0 108}; 109 110FTS * 111fts_open(argv, options, compar) 112 char * const *argv; 113 int options; 114 int (*compar)(const FTSENT * const *, const FTSENT * const *); 115{ 116 struct _fts_private *priv; 117 FTS *sp; 118 FTSENT *p, *root; 119 FTSENT *parent, *tmp; 120 size_t len, nitems; 121 122 /* Options check. */ 123 if (options & ~FTS_OPTIONMASK) { 124 errno = EINVAL; 125 return (NULL); 126 } 127 128 /* fts_open() requires at least one path */ 129 if (*argv == NULL) { 130 errno = EINVAL; 131 return (NULL); 132 } 133 134 /* Allocate/initialize the stream. */ 135 if ((priv = malloc(sizeof(*priv))) == NULL) 136 return (NULL); 137 memset(priv, 0, sizeof(*priv)); 138 sp = &priv->ftsp_fts; 139 sp->fts_compar = compar; 140 sp->fts_options = options; 141 142 /* Shush, GCC. */ 143 tmp = NULL; 144 145 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 146 if (ISSET(FTS_LOGICAL)) 147 SET(FTS_NOCHDIR); 148 149 /* 150 * Start out with 1K of path space, and enough, in any case, 151 * to hold the user's paths. 152 */ 153 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN))) 154 goto mem1; 155 156 /* Allocate/initialize root's parent. */ 157 if ((parent = fts_alloc(sp, "", 0)) == NULL) 158 goto mem2; 159 parent->fts_level = FTS_ROOTPARENTLEVEL; 160 161 /* Allocate/initialize root(s). */ 162 for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) { 163 /* Don't allow zero-length paths. */ 164 if ((len = strlen(*argv)) == 0) { 165 errno = ENOENT; 166 goto mem3; 167 } 168 169 p = fts_alloc(sp, *argv, len); 170 p->fts_level = FTS_ROOTLEVEL; 171 p->fts_parent = parent; 172 p->fts_accpath = p->fts_name; 173 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW)); 174 175 /* Command-line "." and ".." are real directories. */ 176 if (p->fts_info == FTS_DOT) 177 p->fts_info = FTS_D; 178 179 /* 180 * If comparison routine supplied, traverse in sorted 181 * order; otherwise traverse in the order specified. 182 */ 183 if (compar) { 184 p->fts_link = root; 185 root = p; 186 } else { 187 p->fts_link = NULL; 188 if (root == NULL) 189 tmp = root = p; 190 else { 191 tmp->fts_link = p; 192 tmp = p; 193 } 194 } 195 } 196 if (compar && nitems > 1) 197 root = fts_sort(sp, root, nitems); 198 199 /* 200 * Allocate a dummy pointer and make fts_read think that we've just 201 * finished the node before the root(s); set p->fts_info to FTS_INIT 202 * so that everything about the "current" node is ignored. 203 */ 204 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 205 goto mem3; 206 sp->fts_cur->fts_link = root; 207 sp->fts_cur->fts_info = FTS_INIT; 208 209 /* 210 * If using chdir(2), grab a file descriptor pointing to dot to ensure 211 * that we can get back here; this could be avoided for some paths, 212 * but almost certainly not worth the effort. Slashes, symbolic links, 213 * and ".." are all fairly nasty problems. Note, if we can't get the 214 * descriptor we run anyway, just more slowly. 215 */ 216 if (!ISSET(FTS_NOCHDIR) && 217 (sp->fts_rfd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) 218 SET(FTS_NOCHDIR); 219 220 return (sp); 221 222mem3: fts_lfree(root); 223 free(parent); 224mem2: free(sp->fts_path); 225mem1: free(sp); 226 return (NULL); 227} 228 229static void 230fts_load(sp, p) 231 FTS *sp; 232 FTSENT *p; 233{ 234 size_t len; 235 char *cp; 236 237 /* 238 * Load the stream structure for the next traversal. Since we don't 239 * actually enter the directory until after the preorder visit, set 240 * the fts_accpath field specially so the chdir gets done to the right 241 * place and the user can access the first node. From fts_open it's 242 * known that the path will fit. 243 */ 244 len = p->fts_pathlen = p->fts_namelen; 245 memmove(sp->fts_path, p->fts_name, len + 1); 246 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 247 len = strlen(++cp); 248 memmove(p->fts_name, cp, len + 1); 249 p->fts_namelen = len; 250 } 251 p->fts_accpath = p->fts_path = sp->fts_path; 252 sp->fts_dev = p->fts_dev; 253} 254 255int 256fts_close(sp) 257 FTS *sp; 258{ 259 FTSENT *freep, *p; 260 int saved_errno; 261 262 /* 263 * This still works if we haven't read anything -- the dummy structure 264 * points to the root list, so we step through to the end of the root 265 * list which has a valid parent pointer. 266 */ 267 if (sp->fts_cur) { 268 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 269 freep = p; 270 p = p->fts_link != NULL ? p->fts_link : p->fts_parent; 271 free(freep); 272 } 273 free(p); 274 } 275 276 /* Free up child linked list, sort array, path buffer. */ 277 if (sp->fts_child) 278 fts_lfree(sp->fts_child); 279 if (sp->fts_array) 280 free(sp->fts_array); 281 free(sp->fts_path); 282 283 /* Return to original directory, save errno if necessary. */ 284 if (!ISSET(FTS_NOCHDIR)) { 285 saved_errno = fchdir(sp->fts_rfd) ? errno : 0; 286 (void)_close(sp->fts_rfd); 287 288 /* Set errno and return. */ 289 if (saved_errno != 0) { 290 /* Free up the stream pointer. */ 291 free(sp); 292 errno = saved_errno; 293 return (-1); 294 } 295 } 296 297 /* Free up the stream pointer. */ 298 free(sp); 299 return (0); 300} 301 302/* 303 * Special case of "/" at the end of the path so that slashes aren't 304 * appended which would cause paths to be written as "....//foo". 305 */ 306#define NAPPEND(p) \ 307 (p->fts_path[p->fts_pathlen - 1] == '/' \ 308 ? p->fts_pathlen - 1 : p->fts_pathlen) 309 310FTSENT * 311fts_read(sp) 312 FTS *sp; 313{ 314 FTSENT *p, *tmp; 315 int instr; 316 char *t; 317 int saved_errno; 318 319 /* If finished or unrecoverable error, return NULL. */ 320 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 321 return (NULL); 322 323 /* Set current node pointer. */ 324 p = sp->fts_cur; 325 326 /* Save and zero out user instructions. */ 327 instr = p->fts_instr; 328 p->fts_instr = FTS_NOINSTR; 329 330 /* Any type of file may be re-visited; re-stat and re-turn. */ 331 if (instr == FTS_AGAIN) { 332 p->fts_info = fts_stat(sp, p, 0); 333 return (p); 334 } 335 336 /* 337 * Following a symlink -- SLNONE test allows application to see 338 * SLNONE and recover. If indirecting through a symlink, have 339 * keep a pointer to current location. If unable to get that 340 * pointer, follow fails. 341 */ 342 if (instr == FTS_FOLLOW && 343 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 344 p->fts_info = fts_stat(sp, p, 1); 345 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 346 if ((p->fts_symfd = _open(".", O_RDONLY | O_CLOEXEC, 347 0)) < 0) { 348 p->fts_errno = errno; 349 p->fts_info = FTS_ERR; 350 } else 351 p->fts_flags |= FTS_SYMFOLLOW; 352 } 353 return (p); 354 } 355 356 /* Directory in pre-order. */ 357 if (p->fts_info == FTS_D) { 358 /* If skipped or crossed mount point, do post-order visit. */ 359 if (instr == FTS_SKIP || 360 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 361 if (p->fts_flags & FTS_SYMFOLLOW) 362 (void)_close(p->fts_symfd); 363 if (sp->fts_child) { 364 fts_lfree(sp->fts_child); 365 sp->fts_child = NULL; 366 } 367 p->fts_info = FTS_DP; 368 return (p); 369 } 370 371 /* Rebuild if only read the names and now traversing. */ 372 if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) { 373 CLR(FTS_NAMEONLY); 374 fts_lfree(sp->fts_child); 375 sp->fts_child = NULL; 376 } 377 378 /* 379 * Cd to the subdirectory. 380 * 381 * If have already read and now fail to chdir, whack the list 382 * to make the names come out right, and set the parent errno 383 * so the application will eventually get an error condition. 384 * Set the FTS_DONTCHDIR flag so that when we logically change 385 * directories back to the parent we don't do a chdir. 386 * 387 * If haven't read do so. If the read fails, fts_build sets 388 * FTS_STOP or the fts_info field of the node. 389 */ 390 if (sp->fts_child != NULL) { 391 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 392 p->fts_errno = errno; 393 p->fts_flags |= FTS_DONTCHDIR; 394 for (p = sp->fts_child; p != NULL; 395 p = p->fts_link) 396 p->fts_accpath = 397 p->fts_parent->fts_accpath; 398 } 399 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 400 if (ISSET(FTS_STOP)) 401 return (NULL); 402 return (p); 403 } 404 p = sp->fts_child; 405 sp->fts_child = NULL; 406 goto name; 407 } 408 409 /* Move to the next node on this level. */ 410next: tmp = p; 411 if ((p = p->fts_link) != NULL) { 412 free(tmp); 413 414 /* 415 * If reached the top, return to the original directory (or 416 * the root of the tree), and load the paths for the next root. 417 */ 418 if (p->fts_level == FTS_ROOTLEVEL) { 419 if (FCHDIR(sp, sp->fts_rfd)) { 420 SET(FTS_STOP); 421 return (NULL); 422 } 423 fts_load(sp, p); 424 return (sp->fts_cur = p); 425 } 426 427 /* 428 * User may have called fts_set on the node. If skipped, 429 * ignore. If followed, get a file descriptor so we can 430 * get back if necessary. 431 */ 432 if (p->fts_instr == FTS_SKIP) 433 goto next; 434 if (p->fts_instr == FTS_FOLLOW) { 435 p->fts_info = fts_stat(sp, p, 1); 436 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 437 if ((p->fts_symfd = 438 _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) { 439 p->fts_errno = errno; 440 p->fts_info = FTS_ERR; 441 } else 442 p->fts_flags |= FTS_SYMFOLLOW; 443 } 444 p->fts_instr = FTS_NOINSTR; 445 } 446 447name: t = sp->fts_path + NAPPEND(p->fts_parent); 448 *t++ = '/'; 449 memmove(t, p->fts_name, p->fts_namelen + 1); 450 return (sp->fts_cur = p); 451 } 452 453 /* Move up to the parent node. */ 454 p = tmp->fts_parent; 455 free(tmp); 456 457 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 458 /* 459 * Done; free everything up and set errno to 0 so the user 460 * can distinguish between error and EOF. 461 */ 462 free(p); 463 errno = 0; 464 return (sp->fts_cur = NULL); 465 } 466 467 /* NUL terminate the pathname. */ 468 sp->fts_path[p->fts_pathlen] = '\0'; 469 470 /* 471 * Return to the parent directory. If at a root node or came through 472 * a symlink, go back through the file descriptor. Otherwise, cd up 473 * one directory. 474 */ 475 if (p->fts_level == FTS_ROOTLEVEL) { 476 if (FCHDIR(sp, sp->fts_rfd)) { 477 SET(FTS_STOP); 478 return (NULL); 479 } 480 } else if (p->fts_flags & FTS_SYMFOLLOW) { 481 if (FCHDIR(sp, p->fts_symfd)) { 482 saved_errno = errno; 483 (void)_close(p->fts_symfd); 484 errno = saved_errno; 485 SET(FTS_STOP); 486 return (NULL); 487 } 488 (void)_close(p->fts_symfd); 489 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 490 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 491 SET(FTS_STOP); 492 return (NULL); 493 } 494 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 495 return (sp->fts_cur = p); 496} 497 498/* 499 * Fts_set takes the stream as an argument although it's not used in this 500 * implementation; it would be necessary if anyone wanted to add global 501 * semantics to fts using fts_set. An error return is allowed for similar 502 * reasons. 503 */ 504/* ARGSUSED */ 505int 506fts_set(sp, p, instr) 507 FTS *sp; 508 FTSENT *p; 509 int instr; 510{ 511 if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW && 512 instr != FTS_NOINSTR && instr != FTS_SKIP) { 513 errno = EINVAL; 514 return (1); 515 } 516 p->fts_instr = instr; 517 return (0); 518} 519 520FTSENT * 521fts_children(sp, instr) 522 FTS *sp; 523 int instr; 524{ 525 FTSENT *p; 526 int fd; 527 528 if (instr != 0 && instr != FTS_NAMEONLY) { 529 errno = EINVAL; 530 return (NULL); 531 } 532 533 /* Set current node pointer. */ 534 p = sp->fts_cur; 535 536 /* 537 * Errno set to 0 so user can distinguish empty directory from 538 * an error. 539 */ 540 errno = 0; 541 542 /* Fatal errors stop here. */ 543 if (ISSET(FTS_STOP)) 544 return (NULL); 545 546 /* Return logical hierarchy of user's arguments. */ 547 if (p->fts_info == FTS_INIT) 548 return (p->fts_link); 549 550 /* 551 * If not a directory being visited in pre-order, stop here. Could 552 * allow FTS_DNR, assuming the user has fixed the problem, but the 553 * same effect is available with FTS_AGAIN. 554 */ 555 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 556 return (NULL); 557 558 /* Free up any previous child list. */ 559 if (sp->fts_child != NULL) 560 fts_lfree(sp->fts_child); 561 562 if (instr == FTS_NAMEONLY) { 563 SET(FTS_NAMEONLY); 564 instr = BNAMES; 565 } else 566 instr = BCHILD; 567 568 /* 569 * If using chdir on a relative path and called BEFORE fts_read does 570 * its chdir to the root of a traversal, we can lose -- we need to 571 * chdir into the subdirectory, and we don't know where the current 572 * directory is, so we can't get back so that the upcoming chdir by 573 * fts_read will work. 574 */ 575 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 576 ISSET(FTS_NOCHDIR)) 577 return (sp->fts_child = fts_build(sp, instr)); 578 579 if ((fd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) 580 return (NULL); 581 sp->fts_child = fts_build(sp, instr); 582 if (fchdir(fd)) { 583 (void)_close(fd); 584 return (NULL); 585 } 586 (void)_close(fd); 587 return (sp->fts_child); 588} 589 590#ifndef fts_get_clientptr 591#error "fts_get_clientptr not defined" 592#endif 593 594void * 595(fts_get_clientptr)(FTS *sp) 596{ 597 598 return (fts_get_clientptr(sp)); 599} 600 601#ifndef fts_get_stream 602#error "fts_get_stream not defined" 603#endif 604 605FTS * 606(fts_get_stream)(FTSENT *p) 607{ 608 return (fts_get_stream(p)); 609} 610 611void 612fts_set_clientptr(FTS *sp, void *clientptr) 613{ 614 615 sp->fts_clientptr = clientptr; 616} 617 618/* 619 * This is the tricky part -- do not casually change *anything* in here. The 620 * idea is to build the linked list of entries that are used by fts_children 621 * and fts_read. There are lots of special cases. 622 * 623 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 624 * set and it's a physical walk (so that symbolic links can't be directories), 625 * we can do things quickly. First, if it's a 4.4BSD file system, the type 626 * of the file is in the directory entry. Otherwise, we assume that the number 627 * of subdirectories in a node is equal to the number of links to the parent. 628 * The former skips all stat calls. The latter skips stat calls in any leaf 629 * directories and for any files after the subdirectories in the directory have 630 * been found, cutting the stat calls by about 2/3. 631 */ 632static FTSENT * 633fts_build(sp, type) 634 FTS *sp; 635 int type; 636{ 637 struct dirent *dp; 638 FTSENT *p, *head; 639 FTSENT *cur, *tail; 640 DIR *dirp; 641 void *oldaddr; 642 char *cp; 643 int cderrno, descend, oflag, saved_errno, nostat, doadjust; 644 long level; 645 long nlinks; /* has to be signed because -1 is a magic value */ 646 size_t dnamlen, len, maxlen, nitems; 647 648 /* Set current node pointer. */ 649 cur = sp->fts_cur; 650 651 /* 652 * Open the directory for reading. If this fails, we're done. 653 * If being called from fts_read, set the fts_info field. 654 */ 655#ifdef FTS_WHITEOUT 656 if (ISSET(FTS_WHITEOUT)) 657 oflag = DTF_NODUP | DTF_REWIND; 658 else 659 oflag = DTF_HIDEW | DTF_NODUP | DTF_REWIND; 660#else 661#define __opendir2(path, flag) opendir(path) 662#endif 663 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) { 664 if (type == BREAD) { 665 cur->fts_info = FTS_DNR; 666 cur->fts_errno = errno; 667 } 668 return (NULL); 669 } 670 671 /* 672 * Nlinks is the number of possible entries of type directory in the 673 * directory if we're cheating on stat calls, 0 if we're not doing 674 * any stat calls at all, -1 if we're doing stats on everything. 675 */ 676 if (type == BNAMES) { 677 nlinks = 0; 678 /* Be quiet about nostat, GCC. */ 679 nostat = 0; 680 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 681 if (fts_ufslinks(sp, cur)) 682 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 683 else 684 nlinks = -1; 685 nostat = 1; 686 } else { 687 nlinks = -1; 688 nostat = 0; 689 } 690 691#ifdef notdef 692 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 693 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 694 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 695#endif 696 /* 697 * If we're going to need to stat anything or we want to descend 698 * and stay in the directory, chdir. If this fails we keep going, 699 * but set a flag so we don't chdir after the post-order visit. 700 * We won't be able to stat anything, but we can still return the 701 * names themselves. Note, that since fts_read won't be able to 702 * chdir into the directory, it will have to return different path 703 * names than before, i.e. "a/b" instead of "b". Since the node 704 * has already been visited in pre-order, have to wait until the 705 * post-order visit to return the error. There is a special case 706 * here, if there was nothing to stat then it's not an error to 707 * not be able to stat. This is all fairly nasty. If a program 708 * needed sorted entries or stat information, they had better be 709 * checking FTS_NS on the returned nodes. 710 */ 711 cderrno = 0; 712 if (nlinks || type == BREAD) { 713 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) { 714 if (nlinks && type == BREAD) 715 cur->fts_errno = errno; 716 cur->fts_flags |= FTS_DONTCHDIR; 717 descend = 0; 718 cderrno = errno; 719 } else 720 descend = 1; 721 } else 722 descend = 0; 723 724 /* 725 * Figure out the max file name length that can be stored in the 726 * current path -- the inner loop allocates more path as necessary. 727 * We really wouldn't have to do the maxlen calculations here, we 728 * could do them in fts_read before returning the path, but it's a 729 * lot easier here since the length is part of the dirent structure. 730 * 731 * If not changing directories set a pointer so that can just append 732 * each new name into the path. 733 */ 734 len = NAPPEND(cur); 735 if (ISSET(FTS_NOCHDIR)) { 736 cp = sp->fts_path + len; 737 *cp++ = '/'; 738 } else { 739 /* GCC, you're too verbose. */ 740 cp = NULL; 741 } 742 len++; 743 maxlen = sp->fts_pathlen - len; 744 745 level = cur->fts_level + 1; 746 747 /* Read the directory, attaching each entry to the `link' pointer. */ 748 doadjust = 0; 749 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) { 750 dnamlen = dp->d_namlen; 751 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 752 continue; 753 754 if ((p = fts_alloc(sp, dp->d_name, dnamlen)) == NULL) 755 goto mem1; 756 if (dnamlen >= maxlen) { /* include space for NUL */ 757 oldaddr = sp->fts_path; 758 if (fts_palloc(sp, dnamlen + len + 1)) { 759 /* 760 * No more memory for path or structures. Save 761 * errno, free up the current structure and the 762 * structures already allocated. 763 */ 764mem1: saved_errno = errno; 765 if (p) 766 free(p); 767 fts_lfree(head); 768 (void)closedir(dirp); 769 cur->fts_info = FTS_ERR; 770 SET(FTS_STOP); 771 errno = saved_errno; 772 return (NULL); 773 } 774 /* Did realloc() change the pointer? */ 775 if (oldaddr != sp->fts_path) { 776 doadjust = 1; 777 if (ISSET(FTS_NOCHDIR)) 778 cp = sp->fts_path + len; 779 } 780 maxlen = sp->fts_pathlen - len; 781 } 782 783 p->fts_level = level; 784 p->fts_parent = sp->fts_cur; 785 p->fts_pathlen = len + dnamlen; 786 787#ifdef FTS_WHITEOUT 788 if (dp->d_type == DT_WHT) 789 p->fts_flags |= FTS_ISW; 790#endif 791 792 if (cderrno) { 793 if (nlinks) { 794 p->fts_info = FTS_NS; 795 p->fts_errno = cderrno; 796 } else 797 p->fts_info = FTS_NSOK; 798 p->fts_accpath = cur->fts_accpath; 799 } else if (nlinks == 0 800#ifdef DT_DIR 801 || (nostat && 802 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 803#endif 804 ) { 805 p->fts_accpath = 806 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 807 p->fts_info = FTS_NSOK; 808 } else { 809 /* Build a file name for fts_stat to stat. */ 810 if (ISSET(FTS_NOCHDIR)) { 811 p->fts_accpath = p->fts_path; 812 memmove(cp, p->fts_name, p->fts_namelen + 1); 813 } else 814 p->fts_accpath = p->fts_name; 815 /* Stat it. */ 816 p->fts_info = fts_stat(sp, p, 0); 817 818 /* Decrement link count if applicable. */ 819 if (nlinks > 0 && (p->fts_info == FTS_D || 820 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 821 --nlinks; 822 } 823 824 /* We walk in directory order so "ls -f" doesn't get upset. */ 825 p->fts_link = NULL; 826 if (head == NULL) 827 head = tail = p; 828 else { 829 tail->fts_link = p; 830 tail = p; 831 } 832 ++nitems; 833 } 834 if (dirp) 835 (void)closedir(dirp); 836 837 /* 838 * If realloc() changed the address of the path, adjust the 839 * addresses for the rest of the tree and the dir list. 840 */ 841 if (doadjust) 842 fts_padjust(sp, head); 843 844 /* 845 * If not changing directories, reset the path back to original 846 * state. 847 */ 848 if (ISSET(FTS_NOCHDIR)) 849 sp->fts_path[cur->fts_pathlen] = '\0'; 850 851 /* 852 * If descended after called from fts_children or after called from 853 * fts_read and nothing found, get back. At the root level we use 854 * the saved fd; if one of fts_open()'s arguments is a relative path 855 * to an empty directory, we wind up here with no other way back. If 856 * can't get back, we're done. 857 */ 858 if (descend && (type == BCHILD || !nitems) && 859 (cur->fts_level == FTS_ROOTLEVEL ? 860 FCHDIR(sp, sp->fts_rfd) : 861 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 862 cur->fts_info = FTS_ERR; 863 SET(FTS_STOP); 864 return (NULL); 865 } 866 867 /* If didn't find anything, return NULL. */ 868 if (!nitems) { 869 if (type == BREAD) 870 cur->fts_info = FTS_DP; 871 return (NULL); 872 } 873 874 /* Sort the entries. */ 875 if (sp->fts_compar && nitems > 1) 876 head = fts_sort(sp, head, nitems); 877 return (head); 878} 879 880static int 881fts_stat(sp, p, follow) 882 FTS *sp; 883 FTSENT *p; 884 int follow; 885{ 886 FTSENT *t; 887 dev_t dev; 888 ino_t ino; 889 struct stat *sbp, sb; 890 int saved_errno; 891 892 /* If user needs stat info, stat buffer already allocated. */ 893 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 894 895#ifdef FTS_WHITEOUT 896 /* Check for whiteout. */ 897 if (p->fts_flags & FTS_ISW) { 898 if (sbp != &sb) { 899 memset(sbp, '\0', sizeof(*sbp)); 900 sbp->st_mode = S_IFWHT; 901 } 902 return (FTS_W); 903 } 904#endif 905 906 /* 907 * If doing a logical walk, or application requested FTS_FOLLOW, do 908 * a stat(2). If that fails, check for a non-existent symlink. If 909 * fail, set the errno from the stat call. 910 */ 911 if (ISSET(FTS_LOGICAL) || follow) { 912 if (stat(p->fts_accpath, sbp)) { 913 saved_errno = errno; 914 if (!lstat(p->fts_accpath, sbp)) { 915 errno = 0; 916 return (FTS_SLNONE); 917 } 918 p->fts_errno = saved_errno; 919 goto err; 920 } 921 } else if (lstat(p->fts_accpath, sbp)) { 922 p->fts_errno = errno; 923err: memset(sbp, 0, sizeof(struct stat)); 924 return (FTS_NS); 925 } 926 927 if (S_ISDIR(sbp->st_mode)) { 928 /* 929 * Set the device/inode. Used to find cycles and check for 930 * crossing mount points. Also remember the link count, used 931 * in fts_build to limit the number of stat calls. It is 932 * understood that these fields are only referenced if fts_info 933 * is set to FTS_D. 934 */ 935 dev = p->fts_dev = sbp->st_dev; 936 ino = p->fts_ino = sbp->st_ino; 937 p->fts_nlink = sbp->st_nlink; 938 939 if (ISDOT(p->fts_name)) 940 return (FTS_DOT); 941 942 /* 943 * Cycle detection is done by brute force when the directory 944 * is first encountered. If the tree gets deep enough or the 945 * number of symbolic links to directories is high enough, 946 * something faster might be worthwhile. 947 */ 948 for (t = p->fts_parent; 949 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 950 if (ino == t->fts_ino && dev == t->fts_dev) { 951 p->fts_cycle = t; 952 return (FTS_DC); 953 } 954 return (FTS_D); 955 } 956 if (S_ISLNK(sbp->st_mode)) 957 return (FTS_SL); 958 if (S_ISREG(sbp->st_mode)) 959 return (FTS_F); 960 return (FTS_DEFAULT); 961} 962 963/* 964 * The comparison function takes pointers to pointers to FTSENT structures. 965 * Qsort wants a comparison function that takes pointers to void. 966 * (Both with appropriate levels of const-poisoning, of course!) 967 * Use a trampoline function to deal with the difference. 968 */ 969static int 970fts_compar(const void *a, const void *b) 971{ 972 FTS *parent; 973 974 parent = (*(const FTSENT * const *)a)->fts_fts; 975 return (*parent->fts_compar)(a, b); 976} 977 978static FTSENT * 979fts_sort(sp, head, nitems) 980 FTS *sp; 981 FTSENT *head; 982 size_t nitems; 983{ 984 FTSENT **ap, *p; 985 986 /* 987 * Construct an array of pointers to the structures and call qsort(3). 988 * Reassemble the array in the order returned by qsort. If unable to 989 * sort for memory reasons, return the directory entries in their 990 * current order. Allocate enough space for the current needs plus 991 * 40 so don't realloc one entry at a time. 992 */ 993 if (nitems > sp->fts_nitems) { 994 sp->fts_nitems = nitems + 40; 995 if ((sp->fts_array = reallocf(sp->fts_array, 996 sp->fts_nitems * sizeof(FTSENT *))) == NULL) { 997 sp->fts_nitems = 0; 998 return (head); 999 } 1000 } 1001 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 1002 *ap++ = p; 1003 qsort(sp->fts_array, nitems, sizeof(FTSENT *), fts_compar); 1004 for (head = *(ap = sp->fts_array); --nitems; ++ap) 1005 ap[0]->fts_link = ap[1]; 1006 ap[0]->fts_link = NULL; 1007 return (head); 1008} 1009 1010static FTSENT * 1011fts_alloc(sp, name, namelen) 1012 FTS *sp; 1013 char *name; 1014 size_t namelen; 1015{ 1016 FTSENT *p; 1017 size_t len; 1018 1019 struct ftsent_withstat { 1020 FTSENT ent; 1021 struct stat statbuf; 1022 }; 1023 1024 /* 1025 * The file name is a variable length array and no stat structure is 1026 * necessary if the user has set the nostat bit. Allocate the FTSENT 1027 * structure, the file name and the stat structure in one chunk, but 1028 * be careful that the stat structure is reasonably aligned. 1029 */ 1030 if (ISSET(FTS_NOSTAT)) 1031 len = sizeof(FTSENT) + namelen + 1; 1032 else 1033 len = sizeof(struct ftsent_withstat) + namelen + 1; 1034 1035 if ((p = malloc(len)) == NULL) 1036 return (NULL); 1037 1038 if (ISSET(FTS_NOSTAT)) { 1039 p->fts_name = (char *)(p + 1); 1040 p->fts_statp = NULL; 1041 } else { 1042 p->fts_name = (char *)((struct ftsent_withstat *)p + 1); 1043 p->fts_statp = &((struct ftsent_withstat *)p)->statbuf; 1044 } 1045 1046 /* Copy the name and guarantee NUL termination. */ 1047 memcpy(p->fts_name, name, namelen); 1048 p->fts_name[namelen] = '\0'; 1049 p->fts_namelen = namelen; 1050 p->fts_path = sp->fts_path; 1051 p->fts_errno = 0; 1052 p->fts_flags = 0; 1053 p->fts_instr = FTS_NOINSTR; 1054 p->fts_number = 0; 1055 p->fts_pointer = NULL; 1056 p->fts_fts = sp; 1057 return (p); 1058} 1059 1060static void 1061fts_lfree(head) 1062 FTSENT *head; 1063{ 1064 FTSENT *p; 1065 1066 /* Free a linked list of structures. */ 1067 while ((p = head)) { 1068 head = head->fts_link; 1069 free(p); 1070 } 1071} 1072 1073/* 1074 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 1075 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 1076 * though the kernel won't resolve them. Add the size (not just what's needed) 1077 * plus 256 bytes so don't realloc the path 2 bytes at a time. 1078 */ 1079static int 1080fts_palloc(sp, more) 1081 FTS *sp; 1082 size_t more; 1083{ 1084 1085 sp->fts_pathlen += more + 256; 1086 sp->fts_path = reallocf(sp->fts_path, sp->fts_pathlen); 1087 return (sp->fts_path == NULL); 1088} 1089 1090/* 1091 * When the path is realloc'd, have to fix all of the pointers in structures 1092 * already returned. 1093 */ 1094static void 1095fts_padjust(sp, head) 1096 FTS *sp; 1097 FTSENT *head; 1098{ 1099 FTSENT *p; 1100 char *addr = sp->fts_path; 1101 1102#define ADJUST(p) do { \ 1103 if ((p)->fts_accpath != (p)->fts_name) { \ 1104 (p)->fts_accpath = \ 1105 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \ 1106 } \ 1107 (p)->fts_path = addr; \ 1108} while (0) 1109 /* Adjust the current set of children. */ 1110 for (p = sp->fts_child; p; p = p->fts_link) 1111 ADJUST(p); 1112 1113 /* Adjust the rest of the tree, including the current level. */ 1114 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1115 ADJUST(p); 1116 p = p->fts_link ? p->fts_link : p->fts_parent; 1117 } 1118} 1119 1120static size_t 1121fts_maxarglen(argv) 1122 char * const *argv; 1123{ 1124 size_t len, max; 1125 1126 for (max = 0; *argv; ++argv) 1127 if ((len = strlen(*argv)) > max) 1128 max = len; 1129 return (max + 1); 1130} 1131 1132/* 1133 * Change to dir specified by fd or p->fts_accpath without getting 1134 * tricked by someone changing the world out from underneath us. 1135 * Assumes p->fts_dev and p->fts_ino are filled in. 1136 */ 1137static int 1138fts_safe_changedir(sp, p, fd, path) 1139 FTS *sp; 1140 FTSENT *p; 1141 int fd; 1142 char *path; 1143{ 1144 int ret, oerrno, newfd; 1145 struct stat sb; 1146 1147 newfd = fd; 1148 if (ISSET(FTS_NOCHDIR)) 1149 return (0); 1150 if (fd < 0 && (newfd = _open(path, O_RDONLY | O_DIRECTORY | 1151 O_CLOEXEC, 0)) < 0) 1152 return (-1); 1153 if (_fstat(newfd, &sb)) { 1154 ret = -1; 1155 goto bail; 1156 } 1157 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) { 1158 errno = ENOENT; /* disinformation */ 1159 ret = -1; 1160 goto bail; 1161 } 1162 ret = fchdir(newfd); 1163bail: 1164 oerrno = errno; 1165 if (fd < 0) 1166 (void)_close(newfd); 1167 errno = oerrno; 1168 return (ret); 1169} 1170 1171/* 1172 * Check if the filesystem for "ent" has UFS-style links. 1173 */ 1174static int 1175fts_ufslinks(FTS *sp, const FTSENT *ent) 1176{ 1177 struct _fts_private *priv; 1178 const char **cpp; 1179 1180 priv = (struct _fts_private *)sp; 1181 /* 1182 * If this node's device is different from the previous, grab 1183 * the filesystem information, and decide on the reliability 1184 * of the link information from this filesystem for stat(2) 1185 * avoidance. 1186 */ 1187 if (priv->ftsp_dev != ent->fts_dev) { 1188 if (statfs(ent->fts_path, &priv->ftsp_statfs) != -1) { 1189 priv->ftsp_dev = ent->fts_dev; 1190 priv->ftsp_linksreliable = 0; 1191 for (cpp = ufslike_filesystems; *cpp; cpp++) { 1192 if (strcmp(priv->ftsp_statfs.f_fstypename, 1193 *cpp) == 0) { 1194 priv->ftsp_linksreliable = 1; 1195 break; 1196 } 1197 } 1198 } else { 1199 priv->ftsp_linksreliable = 0; 1200 } 1201 } 1202 return (priv->ftsp_linksreliable); 1203} 1204