1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 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 * $OpenBSD: fts.c,v 1.22 1999/10/03 19:22:22 millert Exp $ 32 */ 33 34 #include <sys/cdefs.h> 35 __SCCSID("@(#)fts.c 8.6 (Berkeley) 8/14/94"); 36 __FBSDID("$FreeBSD$"); 37 38 #include "namespace.h" 39 #include <sys/param.h> 40 #include <sys/mount.h> 41 #include <sys/stat.h> 42 43 #include <dirent.h> 44 #include <errno.h> 45 #include <fcntl.h> 46 #include <fts.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <unistd.h> 50 #include "un-namespace.h" 51 52 #include "gen-private.h" 53 54 static FTSENT *fts_alloc(FTS *, char *, size_t); 55 static FTSENT *fts_build(FTS *, int); 56 static void fts_lfree(FTSENT *); 57 static void fts_load(FTS *, FTSENT *); 58 static size_t fts_maxarglen(char * const *); 59 static void fts_padjust(FTS *, FTSENT *); 60 static int fts_palloc(FTS *, size_t); 61 static FTSENT *fts_sort(FTS *, FTSENT *, size_t); 62 static int fts_stat(FTS *, FTSENT *, int, int); 63 static int fts_safe_changedir(FTS *, FTSENT *, int, char *); 64 static int fts_ufslinks(FTS *, const FTSENT *); 65 66 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2]))) 67 68 #define CLR(opt) (sp->fts_options &= ~(opt)) 69 #define ISSET(opt) (sp->fts_options & (opt)) 70 #define SET(opt) (sp->fts_options |= (opt)) 71 72 #define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 73 74 /* fts_build flags */ 75 #define BCHILD 1 /* fts_children */ 76 #define BNAMES 2 /* fts_children, names only */ 77 #define BREAD 3 /* fts_read */ 78 79 /* 80 * Internal representation of an FTS, including extra implementation 81 * details. The FTS returned from fts_open points to this structure's 82 * ftsp_fts member (and can be cast to an _fts_private as required) 83 */ 84 struct _fts_private { 85 FTS ftsp_fts; 86 struct statfs ftsp_statfs; 87 dev_t ftsp_dev; 88 int ftsp_linksreliable; 89 }; 90 91 /* 92 * The "FTS_NOSTAT" option can avoid a lot of calls to stat(2) if it 93 * knows that a directory could not possibly have subdirectories. This 94 * is decided by looking at the link count: a subdirectory would 95 * increment its parent's link count by virtue of its own ".." entry. 96 * This assumption only holds for UFS-like filesystems that implement 97 * links and directories this way, so we must punt for others. 98 */ 99 100 static const char *ufslike_filesystems[] = { 101 "ufs", 102 "zfs", 103 "nfs", 104 "ext2fs", 105 0 106 }; 107 108 FTS * 109 fts_open(char * const *argv, int options, 110 int (*compar)(const FTSENT * const *, const FTSENT * const *)) 111 { 112 struct _fts_private *priv; 113 FTS *sp; 114 FTSENT *p, *root; 115 FTSENT *parent, *tmp; 116 size_t len, nitems; 117 118 /* Options check. */ 119 if (options & ~FTS_OPTIONMASK) { 120 errno = EINVAL; 121 return (NULL); 122 } 123 124 /* fts_open() requires at least one path */ 125 if (*argv == NULL) { 126 errno = EINVAL; 127 return (NULL); 128 } 129 130 /* Allocate/initialize the stream. */ 131 if ((priv = calloc(1, sizeof(*priv))) == NULL) 132 return (NULL); 133 sp = &priv->ftsp_fts; 134 sp->fts_compar = compar; 135 sp->fts_options = options; 136 137 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 138 if (ISSET(FTS_LOGICAL)) 139 SET(FTS_NOCHDIR); 140 141 /* 142 * Start out with 1K of path space, and enough, in any case, 143 * to hold the user's paths. 144 */ 145 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN))) 146 goto mem1; 147 148 /* Allocate/initialize root's parent. */ 149 if ((parent = fts_alloc(sp, "", 0)) == NULL) 150 goto mem2; 151 parent->fts_level = FTS_ROOTPARENTLEVEL; 152 153 /* Shush, GCC. */ 154 tmp = NULL; 155 156 /* Allocate/initialize root(s). */ 157 for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) { 158 len = strlen(*argv); 159 160 p = fts_alloc(sp, *argv, len); 161 p->fts_level = FTS_ROOTLEVEL; 162 p->fts_parent = parent; 163 p->fts_accpath = p->fts_name; 164 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW), -1); 165 166 /* Command-line "." and ".." are real directories. */ 167 if (p->fts_info == FTS_DOT) 168 p->fts_info = FTS_D; 169 170 /* 171 * If comparison routine supplied, traverse in sorted 172 * order; otherwise traverse in the order specified. 173 */ 174 if (compar) { 175 p->fts_link = root; 176 root = p; 177 } else { 178 p->fts_link = NULL; 179 if (root == NULL) 180 tmp = root = p; 181 else { 182 tmp->fts_link = p; 183 tmp = p; 184 } 185 } 186 } 187 if (compar && nitems > 1) 188 root = fts_sort(sp, root, nitems); 189 190 /* 191 * Allocate a dummy pointer and make fts_read think that we've just 192 * finished the node before the root(s); set p->fts_info to FTS_INIT 193 * so that everything about the "current" node is ignored. 194 */ 195 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 196 goto mem3; 197 sp->fts_cur->fts_link = root; 198 sp->fts_cur->fts_info = FTS_INIT; 199 200 /* 201 * If using chdir(2), grab a file descriptor pointing to dot to ensure 202 * that we can get back here; this could be avoided for some paths, 203 * but almost certainly not worth the effort. Slashes, symbolic links, 204 * and ".." are all fairly nasty problems. Note, if we can't get the 205 * descriptor we run anyway, just more slowly. 206 */ 207 if (!ISSET(FTS_NOCHDIR) && 208 (sp->fts_rfd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) 209 SET(FTS_NOCHDIR); 210 211 return (sp); 212 213 mem3: fts_lfree(root); 214 free(parent); 215 mem2: free(sp->fts_path); 216 mem1: free(sp); 217 return (NULL); 218 } 219 220 static void 221 fts_load(FTS *sp, FTSENT *p) 222 { 223 size_t len; 224 char *cp; 225 226 /* 227 * Load the stream structure for the next traversal. Since we don't 228 * actually enter the directory until after the preorder visit, set 229 * the fts_accpath field specially so the chdir gets done to the right 230 * place and the user can access the first node. From fts_open it's 231 * known that the path will fit. 232 */ 233 len = p->fts_pathlen = p->fts_namelen; 234 memmove(sp->fts_path, p->fts_name, len + 1); 235 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 236 len = strlen(++cp); 237 memmove(p->fts_name, cp, len + 1); 238 p->fts_namelen = len; 239 } 240 p->fts_accpath = p->fts_path = sp->fts_path; 241 sp->fts_dev = p->fts_dev; 242 } 243 244 int 245 fts_close(FTS *sp) 246 { 247 FTSENT *freep, *p; 248 int saved_errno; 249 250 /* 251 * This still works if we haven't read anything -- the dummy structure 252 * points to the root list, so we step through to the end of the root 253 * list which has a valid parent pointer. 254 */ 255 if (sp->fts_cur) { 256 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 257 freep = p; 258 p = p->fts_link != NULL ? p->fts_link : p->fts_parent; 259 free(freep); 260 } 261 free(p); 262 } 263 264 /* Free up child linked list, sort array, path buffer. */ 265 if (sp->fts_child) 266 fts_lfree(sp->fts_child); 267 if (sp->fts_array) 268 free(sp->fts_array); 269 free(sp->fts_path); 270 271 /* Return to original directory, save errno if necessary. */ 272 if (!ISSET(FTS_NOCHDIR)) { 273 saved_errno = fchdir(sp->fts_rfd) ? errno : 0; 274 (void)_close(sp->fts_rfd); 275 276 /* Set errno and return. */ 277 if (saved_errno != 0) { 278 /* Free up the stream pointer. */ 279 free(sp); 280 errno = saved_errno; 281 return (-1); 282 } 283 } 284 285 /* Free up the stream pointer. */ 286 free(sp); 287 return (0); 288 } 289 290 /* 291 * Special case of "/" at the end of the path so that slashes aren't 292 * appended which would cause paths to be written as "....//foo". 293 */ 294 #define NAPPEND(p) \ 295 (p->fts_path[p->fts_pathlen - 1] == '/' \ 296 ? p->fts_pathlen - 1 : p->fts_pathlen) 297 298 FTSENT * 299 fts_read(FTS *sp) 300 { 301 FTSENT *p, *tmp; 302 int instr; 303 char *t; 304 int saved_errno; 305 306 /* If finished or unrecoverable error, return NULL. */ 307 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 308 return (NULL); 309 310 /* Set current node pointer. */ 311 p = sp->fts_cur; 312 313 /* Save and zero out user instructions. */ 314 instr = p->fts_instr; 315 p->fts_instr = FTS_NOINSTR; 316 317 /* Any type of file may be re-visited; re-stat and re-turn. */ 318 if (instr == FTS_AGAIN) { 319 p->fts_info = fts_stat(sp, p, 0, -1); 320 return (p); 321 } 322 323 /* 324 * Following a symlink -- SLNONE test allows application to see 325 * SLNONE and recover. If indirecting through a symlink, have 326 * keep a pointer to current location. If unable to get that 327 * pointer, follow fails. 328 */ 329 if (instr == FTS_FOLLOW && 330 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 331 p->fts_info = fts_stat(sp, p, 1, -1); 332 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 333 if ((p->fts_symfd = _open(".", O_RDONLY | O_CLOEXEC, 334 0)) < 0) { 335 p->fts_errno = errno; 336 p->fts_info = FTS_ERR; 337 } else 338 p->fts_flags |= FTS_SYMFOLLOW; 339 } 340 return (p); 341 } 342 343 /* Directory in pre-order. */ 344 if (p->fts_info == FTS_D) { 345 /* If skipped or crossed mount point, do post-order visit. */ 346 if (instr == FTS_SKIP || 347 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 348 if (p->fts_flags & FTS_SYMFOLLOW) 349 (void)_close(p->fts_symfd); 350 if (sp->fts_child) { 351 fts_lfree(sp->fts_child); 352 sp->fts_child = NULL; 353 } 354 p->fts_info = FTS_DP; 355 return (p); 356 } 357 358 /* Rebuild if only read the names and now traversing. */ 359 if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) { 360 CLR(FTS_NAMEONLY); 361 fts_lfree(sp->fts_child); 362 sp->fts_child = NULL; 363 } 364 365 /* 366 * Cd to the subdirectory. 367 * 368 * If have already read and now fail to chdir, whack the list 369 * to make the names come out right, and set the parent errno 370 * so the application will eventually get an error condition. 371 * Set the FTS_DONTCHDIR flag so that when we logically change 372 * directories back to the parent we don't do a chdir. 373 * 374 * If haven't read do so. If the read fails, fts_build sets 375 * FTS_STOP or the fts_info field of the node. 376 */ 377 if (sp->fts_child != NULL) { 378 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 379 p->fts_errno = errno; 380 p->fts_flags |= FTS_DONTCHDIR; 381 for (p = sp->fts_child; p != NULL; 382 p = p->fts_link) 383 p->fts_accpath = 384 p->fts_parent->fts_accpath; 385 } 386 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 387 if (ISSET(FTS_STOP)) 388 return (NULL); 389 return (p); 390 } 391 p = sp->fts_child; 392 sp->fts_child = NULL; 393 goto name; 394 } 395 396 /* Move to the next node on this level. */ 397 next: tmp = p; 398 if ((p = p->fts_link) != NULL) { 399 /* 400 * If reached the top, return to the original directory (or 401 * the root of the tree), and load the paths for the next root. 402 */ 403 if (p->fts_level == FTS_ROOTLEVEL) { 404 if (FCHDIR(sp, sp->fts_rfd)) { 405 SET(FTS_STOP); 406 return (NULL); 407 } 408 free(tmp); 409 fts_load(sp, p); 410 return (sp->fts_cur = p); 411 } 412 413 /* 414 * User may have called fts_set on the node. If skipped, 415 * ignore. If followed, get a file descriptor so we can 416 * get back if necessary. 417 */ 418 if (p->fts_instr == FTS_SKIP) { 419 free(tmp); 420 goto next; 421 } 422 if (p->fts_instr == FTS_FOLLOW) { 423 p->fts_info = fts_stat(sp, p, 1, -1); 424 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 425 if ((p->fts_symfd = 426 _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) { 427 p->fts_errno = errno; 428 p->fts_info = FTS_ERR; 429 } else 430 p->fts_flags |= FTS_SYMFOLLOW; 431 } 432 p->fts_instr = FTS_NOINSTR; 433 } 434 435 free(tmp); 436 437 name: t = sp->fts_path + NAPPEND(p->fts_parent); 438 *t++ = '/'; 439 memmove(t, p->fts_name, p->fts_namelen + 1); 440 return (sp->fts_cur = p); 441 } 442 443 /* Move up to the parent node. */ 444 p = tmp->fts_parent; 445 446 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 447 /* 448 * Done; free everything up and set errno to 0 so the user 449 * can distinguish between error and EOF. 450 */ 451 free(tmp); 452 free(p); 453 errno = 0; 454 return (sp->fts_cur = NULL); 455 } 456 457 /* NUL terminate the pathname. */ 458 sp->fts_path[p->fts_pathlen] = '\0'; 459 460 /* 461 * Return to the parent directory. If at a root node or came through 462 * a symlink, go back through the file descriptor. Otherwise, cd up 463 * one directory. 464 */ 465 if (p->fts_level == FTS_ROOTLEVEL) { 466 if (FCHDIR(sp, sp->fts_rfd)) { 467 SET(FTS_STOP); 468 return (NULL); 469 } 470 } else if (p->fts_flags & FTS_SYMFOLLOW) { 471 if (FCHDIR(sp, p->fts_symfd)) { 472 saved_errno = errno; 473 (void)_close(p->fts_symfd); 474 errno = saved_errno; 475 SET(FTS_STOP); 476 return (NULL); 477 } 478 (void)_close(p->fts_symfd); 479 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 480 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 481 SET(FTS_STOP); 482 return (NULL); 483 } 484 free(tmp); 485 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 486 return (sp->fts_cur = p); 487 } 488 489 /* 490 * Fts_set takes the stream as an argument although it's not used in this 491 * implementation; it would be necessary if anyone wanted to add global 492 * semantics to fts using fts_set. An error return is allowed for similar 493 * reasons. 494 */ 495 /* ARGSUSED */ 496 int 497 fts_set(FTS *sp, FTSENT *p, int instr) 498 { 499 if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW && 500 instr != FTS_NOINSTR && instr != FTS_SKIP) { 501 errno = EINVAL; 502 return (1); 503 } 504 p->fts_instr = instr; 505 return (0); 506 } 507 508 FTSENT * 509 fts_children(FTS *sp, int instr) 510 { 511 FTSENT *p; 512 int fd, rc, serrno; 513 514 if (instr != 0 && instr != FTS_NAMEONLY) { 515 errno = EINVAL; 516 return (NULL); 517 } 518 519 /* Set current node pointer. */ 520 p = sp->fts_cur; 521 522 /* 523 * Errno set to 0 so user can distinguish empty directory from 524 * an error. 525 */ 526 errno = 0; 527 528 /* Fatal errors stop here. */ 529 if (ISSET(FTS_STOP)) 530 return (NULL); 531 532 /* Return logical hierarchy of user's arguments. */ 533 if (p->fts_info == FTS_INIT) 534 return (p->fts_link); 535 536 /* 537 * If not a directory being visited in pre-order, stop here. Could 538 * allow FTS_DNR, assuming the user has fixed the problem, but the 539 * same effect is available with FTS_AGAIN. 540 */ 541 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 542 return (NULL); 543 544 /* Free up any previous child list. */ 545 if (sp->fts_child != NULL) 546 fts_lfree(sp->fts_child); 547 548 if (instr == FTS_NAMEONLY) { 549 SET(FTS_NAMEONLY); 550 instr = BNAMES; 551 } else 552 instr = BCHILD; 553 554 /* 555 * If using chdir on a relative path and called BEFORE fts_read does 556 * its chdir to the root of a traversal, we can lose -- we need to 557 * chdir into the subdirectory, and we don't know where the current 558 * directory is, so we can't get back so that the upcoming chdir by 559 * fts_read will work. 560 */ 561 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 562 ISSET(FTS_NOCHDIR)) 563 return (sp->fts_child = fts_build(sp, instr)); 564 565 if ((fd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) 566 return (NULL); 567 sp->fts_child = fts_build(sp, instr); 568 serrno = (sp->fts_child == NULL) ? errno : 0; 569 rc = fchdir(fd); 570 if (rc < 0 && serrno == 0) 571 serrno = errno; 572 (void)_close(fd); 573 errno = serrno; 574 if (rc < 0) 575 return (NULL); 576 return (sp->fts_child); 577 } 578 579 #ifndef fts_get_clientptr 580 #error "fts_get_clientptr not defined" 581 #endif 582 583 void * 584 (fts_get_clientptr)(FTS *sp) 585 { 586 587 return (fts_get_clientptr(sp)); 588 } 589 590 #ifndef fts_get_stream 591 #error "fts_get_stream not defined" 592 #endif 593 594 FTS * 595 (fts_get_stream)(FTSENT *p) 596 { 597 return (fts_get_stream(p)); 598 } 599 600 void 601 fts_set_clientptr(FTS *sp, void *clientptr) 602 { 603 604 sp->fts_clientptr = clientptr; 605 } 606 607 /* 608 * This is the tricky part -- do not casually change *anything* in here. The 609 * idea is to build the linked list of entries that are used by fts_children 610 * and fts_read. There are lots of special cases. 611 * 612 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 613 * set and it's a physical walk (so that symbolic links can't be directories), 614 * we can do things quickly. First, if it's a 4.4BSD file system, the type 615 * of the file is in the directory entry. Otherwise, we assume that the number 616 * of subdirectories in a node is equal to the number of links to the parent. 617 * The former skips all stat calls. The latter skips stat calls in any leaf 618 * directories and for any files after the subdirectories in the directory have 619 * been found, cutting the stat calls by about 2/3. 620 */ 621 static FTSENT * 622 fts_build(FTS *sp, int type) 623 { 624 struct dirent *dp; 625 FTSENT *p, *head; 626 FTSENT *cur, *tail; 627 DIR *dirp; 628 void *oldaddr; 629 char *cp; 630 int cderrno, descend, oflag, saved_errno, nostat, doadjust; 631 long level; 632 long nlinks; /* has to be signed because -1 is a magic value */ 633 size_t dnamlen, len, maxlen, nitems; 634 635 /* Set current node pointer. */ 636 cur = sp->fts_cur; 637 638 /* 639 * Open the directory for reading. If this fails, we're done. 640 * If being called from fts_read, set the fts_info field. 641 */ 642 #ifdef FTS_WHITEOUT 643 if (ISSET(FTS_WHITEOUT)) 644 oflag = DTF_NODUP | DTF_REWIND; 645 else 646 oflag = DTF_HIDEW | DTF_NODUP | DTF_REWIND; 647 #else 648 #define __opendir2(path, flag) opendir(path) 649 #endif 650 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) { 651 if (type == BREAD) { 652 cur->fts_info = FTS_DNR; 653 cur->fts_errno = errno; 654 } 655 return (NULL); 656 } 657 658 /* 659 * Nlinks is the number of possible entries of type directory in the 660 * directory if we're cheating on stat calls, 0 if we're not doing 661 * any stat calls at all, -1 if we're doing stats on everything. 662 */ 663 if (type == BNAMES) { 664 nlinks = 0; 665 /* Be quiet about nostat, GCC. */ 666 nostat = 0; 667 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 668 if (fts_ufslinks(sp, cur)) 669 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 670 else 671 nlinks = -1; 672 nostat = 1; 673 } else { 674 nlinks = -1; 675 nostat = 0; 676 } 677 678 #ifdef notdef 679 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 680 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 681 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 682 #endif 683 /* 684 * If we're going to need to stat anything or we want to descend 685 * and stay in the directory, chdir. If this fails we keep going, 686 * but set a flag so we don't chdir after the post-order visit. 687 * We won't be able to stat anything, but we can still return the 688 * names themselves. Note, that since fts_read won't be able to 689 * chdir into the directory, it will have to return different path 690 * names than before, i.e. "a/b" instead of "b". Since the node 691 * has already been visited in pre-order, have to wait until the 692 * post-order visit to return the error. There is a special case 693 * here, if there was nothing to stat then it's not an error to 694 * not be able to stat. This is all fairly nasty. If a program 695 * needed sorted entries or stat information, they had better be 696 * checking FTS_NS on the returned nodes. 697 */ 698 cderrno = 0; 699 if (nlinks || type == BREAD) { 700 if (fts_safe_changedir(sp, cur, _dirfd(dirp), NULL)) { 701 if (nlinks && type == BREAD) 702 cur->fts_errno = errno; 703 cur->fts_flags |= FTS_DONTCHDIR; 704 descend = 0; 705 cderrno = errno; 706 } else 707 descend = 1; 708 } else 709 descend = 0; 710 711 /* 712 * Figure out the max file name length that can be stored in the 713 * current path -- the inner loop allocates more path as necessary. 714 * We really wouldn't have to do the maxlen calculations here, we 715 * could do them in fts_read before returning the path, but it's a 716 * lot easier here since the length is part of the dirent structure. 717 * 718 * If not changing directories set a pointer so that can just append 719 * each new name into the path. 720 */ 721 len = NAPPEND(cur); 722 if (ISSET(FTS_NOCHDIR)) { 723 cp = sp->fts_path + len; 724 *cp++ = '/'; 725 } else { 726 /* GCC, you're too verbose. */ 727 cp = NULL; 728 } 729 len++; 730 maxlen = sp->fts_pathlen - len; 731 732 level = cur->fts_level + 1; 733 734 /* Read the directory, attaching each entry to the `link' pointer. */ 735 doadjust = 0; 736 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) { 737 dnamlen = dp->d_namlen; 738 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 739 continue; 740 741 if ((p = fts_alloc(sp, dp->d_name, dnamlen)) == NULL) 742 goto mem1; 743 if (dnamlen >= maxlen) { /* include space for NUL */ 744 oldaddr = sp->fts_path; 745 if (fts_palloc(sp, dnamlen + len + 1)) { 746 /* 747 * No more memory for path or structures. Save 748 * errno, free up the current structure and the 749 * structures already allocated. 750 */ 751 mem1: saved_errno = errno; 752 if (p) 753 free(p); 754 fts_lfree(head); 755 (void)closedir(dirp); 756 cur->fts_info = FTS_ERR; 757 SET(FTS_STOP); 758 errno = saved_errno; 759 return (NULL); 760 } 761 /* Did realloc() change the pointer? */ 762 if (oldaddr != sp->fts_path) { 763 doadjust = 1; 764 if (ISSET(FTS_NOCHDIR)) 765 cp = sp->fts_path + len; 766 } 767 maxlen = sp->fts_pathlen - len; 768 } 769 770 p->fts_level = level; 771 p->fts_parent = sp->fts_cur; 772 p->fts_pathlen = len + dnamlen; 773 774 #ifdef FTS_WHITEOUT 775 if (dp->d_type == DT_WHT) 776 p->fts_flags |= FTS_ISW; 777 #endif 778 779 if (cderrno) { 780 if (nlinks) { 781 p->fts_info = FTS_NS; 782 p->fts_errno = cderrno; 783 } else 784 p->fts_info = FTS_NSOK; 785 p->fts_accpath = cur->fts_accpath; 786 } else if (nlinks == 0 787 #ifdef DT_DIR 788 || (nostat && 789 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 790 #endif 791 ) { 792 p->fts_accpath = 793 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 794 p->fts_info = FTS_NSOK; 795 } else { 796 /* Build a file name for fts_stat to stat. */ 797 if (ISSET(FTS_NOCHDIR)) { 798 p->fts_accpath = p->fts_path; 799 memmove(cp, p->fts_name, p->fts_namelen + 1); 800 p->fts_info = fts_stat(sp, p, 0, _dirfd(dirp)); 801 } else { 802 p->fts_accpath = p->fts_name; 803 p->fts_info = fts_stat(sp, p, 0, -1); 804 } 805 806 /* Decrement link count if applicable. */ 807 if (nlinks > 0 && (p->fts_info == FTS_D || 808 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 809 --nlinks; 810 } 811 812 /* We walk in directory order so "ls -f" doesn't get upset. */ 813 p->fts_link = NULL; 814 if (head == NULL) 815 head = tail = p; 816 else { 817 tail->fts_link = p; 818 tail = p; 819 } 820 ++nitems; 821 } 822 if (dirp) 823 (void)closedir(dirp); 824 825 /* 826 * If realloc() changed the address of the path, adjust the 827 * addresses for the rest of the tree and the dir list. 828 */ 829 if (doadjust) 830 fts_padjust(sp, head); 831 832 /* 833 * If not changing directories, reset the path back to original 834 * state. 835 */ 836 if (ISSET(FTS_NOCHDIR)) 837 sp->fts_path[cur->fts_pathlen] = '\0'; 838 839 /* 840 * If descended after called from fts_children or after called from 841 * fts_read and nothing found, get back. At the root level we use 842 * the saved fd; if one of fts_open()'s arguments is a relative path 843 * to an empty directory, we wind up here with no other way back. If 844 * can't get back, we're done. 845 */ 846 if (descend && (type == BCHILD || !nitems) && 847 (cur->fts_level == FTS_ROOTLEVEL ? 848 FCHDIR(sp, sp->fts_rfd) : 849 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 850 fts_lfree(head); 851 cur->fts_info = FTS_ERR; 852 SET(FTS_STOP); 853 return (NULL); 854 } 855 856 /* If didn't find anything, return NULL. */ 857 if (!nitems) { 858 if (type == BREAD) 859 cur->fts_info = FTS_DP; 860 return (NULL); 861 } 862 863 /* Sort the entries. */ 864 if (sp->fts_compar && nitems > 1) 865 head = fts_sort(sp, head, nitems); 866 return (head); 867 } 868 869 static int 870 fts_stat(FTS *sp, FTSENT *p, int follow, int dfd) 871 { 872 FTSENT *t; 873 dev_t dev; 874 ino_t ino; 875 struct stat *sbp, sb; 876 int saved_errno; 877 const char *path; 878 879 if (dfd == -1) 880 path = p->fts_accpath, dfd = AT_FDCWD; 881 else 882 path = p->fts_name; 883 884 /* If user needs stat info, stat buffer already allocated. */ 885 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 886 887 #ifdef FTS_WHITEOUT 888 /* Check for whiteout. */ 889 if (p->fts_flags & FTS_ISW) { 890 if (sbp != &sb) { 891 memset(sbp, '\0', sizeof(*sbp)); 892 sbp->st_mode = S_IFWHT; 893 } 894 return (FTS_W); 895 } 896 #endif 897 898 /* 899 * If doing a logical walk, or application requested FTS_FOLLOW, do 900 * a stat(2). If that fails, check for a non-existent symlink. If 901 * fail, set the errno from the stat call. 902 */ 903 if (ISSET(FTS_LOGICAL) || follow) { 904 if (fstatat(dfd, path, sbp, 0)) { 905 saved_errno = errno; 906 if (fstatat(dfd, path, sbp, AT_SYMLINK_NOFOLLOW)) { 907 p->fts_errno = saved_errno; 908 goto err; 909 } 910 errno = 0; 911 if (S_ISLNK(sbp->st_mode)) 912 return (FTS_SLNONE); 913 } 914 } else if (fstatat(dfd, path, sbp, AT_SYMLINK_NOFOLLOW)) { 915 p->fts_errno = errno; 916 err: memset(sbp, 0, sizeof(struct stat)); 917 return (FTS_NS); 918 } 919 920 if (S_ISDIR(sbp->st_mode)) { 921 /* 922 * Set the device/inode. Used to find cycles and check for 923 * crossing mount points. Also remember the link count, used 924 * in fts_build to limit the number of stat calls. It is 925 * understood that these fields are only referenced if fts_info 926 * is set to FTS_D. 927 */ 928 dev = p->fts_dev = sbp->st_dev; 929 ino = p->fts_ino = sbp->st_ino; 930 p->fts_nlink = sbp->st_nlink; 931 932 if (ISDOT(p->fts_name)) 933 return (FTS_DOT); 934 935 /* 936 * Cycle detection is done by brute force when the directory 937 * is first encountered. If the tree gets deep enough or the 938 * number of symbolic links to directories is high enough, 939 * something faster might be worthwhile. 940 */ 941 for (t = p->fts_parent; 942 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 943 if (ino == t->fts_ino && dev == t->fts_dev) { 944 p->fts_cycle = t; 945 return (FTS_DC); 946 } 947 return (FTS_D); 948 } 949 if (S_ISLNK(sbp->st_mode)) 950 return (FTS_SL); 951 if (S_ISREG(sbp->st_mode)) 952 return (FTS_F); 953 return (FTS_DEFAULT); 954 } 955 956 /* 957 * The comparison function takes pointers to pointers to FTSENT structures. 958 * Qsort wants a comparison function that takes pointers to void. 959 * (Both with appropriate levels of const-poisoning, of course!) 960 * Use a trampoline function to deal with the difference. 961 */ 962 static int 963 fts_compar(const void *a, const void *b) 964 { 965 FTS *parent; 966 967 parent = (*(const FTSENT * const *)a)->fts_fts; 968 return (*parent->fts_compar)(a, b); 969 } 970 971 static FTSENT * 972 fts_sort(FTS *sp, FTSENT *head, size_t nitems) 973 { 974 FTSENT **ap, *p; 975 976 /* 977 * Construct an array of pointers to the structures and call qsort(3). 978 * Reassemble the array in the order returned by qsort. If unable to 979 * sort for memory reasons, return the directory entries in their 980 * current order. Allocate enough space for the current needs plus 981 * 40 so don't realloc one entry at a time. 982 */ 983 if (nitems > sp->fts_nitems) { 984 sp->fts_nitems = nitems + 40; 985 if ((sp->fts_array = reallocf(sp->fts_array, 986 sp->fts_nitems * sizeof(FTSENT *))) == NULL) { 987 sp->fts_nitems = 0; 988 return (head); 989 } 990 } 991 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 992 *ap++ = p; 993 qsort(sp->fts_array, nitems, sizeof(FTSENT *), fts_compar); 994 for (head = *(ap = sp->fts_array); --nitems; ++ap) 995 ap[0]->fts_link = ap[1]; 996 ap[0]->fts_link = NULL; 997 return (head); 998 } 999 1000 static FTSENT * 1001 fts_alloc(FTS *sp, char *name, size_t namelen) 1002 { 1003 FTSENT *p; 1004 size_t len; 1005 1006 struct ftsent_withstat { 1007 FTSENT ent; 1008 struct stat statbuf; 1009 }; 1010 1011 /* 1012 * The file name is a variable length array and no stat structure is 1013 * necessary if the user has set the nostat bit. Allocate the FTSENT 1014 * structure, the file name and the stat structure in one chunk, but 1015 * be careful that the stat structure is reasonably aligned. 1016 */ 1017 if (ISSET(FTS_NOSTAT)) 1018 len = sizeof(FTSENT) + namelen + 1; 1019 else 1020 len = sizeof(struct ftsent_withstat) + namelen + 1; 1021 1022 if ((p = malloc(len)) == NULL) 1023 return (NULL); 1024 1025 if (ISSET(FTS_NOSTAT)) { 1026 p->fts_name = (char *)(p + 1); 1027 p->fts_statp = NULL; 1028 } else { 1029 p->fts_name = (char *)((struct ftsent_withstat *)p + 1); 1030 p->fts_statp = &((struct ftsent_withstat *)p)->statbuf; 1031 } 1032 1033 /* Copy the name and guarantee NUL termination. */ 1034 memcpy(p->fts_name, name, namelen); 1035 p->fts_name[namelen] = '\0'; 1036 p->fts_namelen = namelen; 1037 p->fts_path = sp->fts_path; 1038 p->fts_errno = 0; 1039 p->fts_flags = 0; 1040 p->fts_instr = FTS_NOINSTR; 1041 p->fts_number = 0; 1042 p->fts_pointer = NULL; 1043 p->fts_fts = sp; 1044 return (p); 1045 } 1046 1047 static void 1048 fts_lfree(FTSENT *head) 1049 { 1050 FTSENT *p; 1051 1052 /* Free a linked list of structures. */ 1053 while ((p = head)) { 1054 head = head->fts_link; 1055 free(p); 1056 } 1057 } 1058 1059 /* 1060 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 1061 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 1062 * though the kernel won't resolve them. Add the size (not just what's needed) 1063 * plus 256 bytes so don't realloc the path 2 bytes at a time. 1064 */ 1065 static int 1066 fts_palloc(FTS *sp, size_t more) 1067 { 1068 1069 sp->fts_pathlen += more + 256; 1070 sp->fts_path = reallocf(sp->fts_path, sp->fts_pathlen); 1071 return (sp->fts_path == NULL); 1072 } 1073 1074 /* 1075 * When the path is realloc'd, have to fix all of the pointers in structures 1076 * already returned. 1077 */ 1078 static void 1079 fts_padjust(FTS *sp, FTSENT *head) 1080 { 1081 FTSENT *p; 1082 char *addr = sp->fts_path; 1083 1084 #define ADJUST(p) do { \ 1085 if ((p)->fts_accpath != (p)->fts_name) { \ 1086 (p)->fts_accpath = \ 1087 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \ 1088 } \ 1089 (p)->fts_path = addr; \ 1090 } while (0) 1091 /* Adjust the current set of children. */ 1092 for (p = sp->fts_child; p; p = p->fts_link) 1093 ADJUST(p); 1094 1095 /* Adjust the rest of the tree, including the current level. */ 1096 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1097 ADJUST(p); 1098 p = p->fts_link ? p->fts_link : p->fts_parent; 1099 } 1100 } 1101 1102 static size_t 1103 fts_maxarglen(char * const *argv) 1104 { 1105 size_t len, max; 1106 1107 for (max = 0; *argv; ++argv) 1108 if ((len = strlen(*argv)) > max) 1109 max = len; 1110 return (max + 1); 1111 } 1112 1113 /* 1114 * Change to dir specified by fd or p->fts_accpath without getting 1115 * tricked by someone changing the world out from underneath us. 1116 * Assumes p->fts_dev and p->fts_ino are filled in. 1117 */ 1118 static int 1119 fts_safe_changedir(FTS *sp, FTSENT *p, int fd, char *path) 1120 { 1121 int ret, oerrno, newfd; 1122 struct stat sb; 1123 1124 newfd = fd; 1125 if (ISSET(FTS_NOCHDIR)) 1126 return (0); 1127 if (fd < 0 && (newfd = _open(path, O_RDONLY | O_DIRECTORY | 1128 O_CLOEXEC, 0)) < 0) 1129 return (-1); 1130 if (_fstat(newfd, &sb)) { 1131 ret = -1; 1132 goto bail; 1133 } 1134 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) { 1135 errno = ENOENT; /* disinformation */ 1136 ret = -1; 1137 goto bail; 1138 } 1139 ret = fchdir(newfd); 1140 bail: 1141 oerrno = errno; 1142 if (fd < 0) 1143 (void)_close(newfd); 1144 errno = oerrno; 1145 return (ret); 1146 } 1147 1148 /* 1149 * Check if the filesystem for "ent" has UFS-style links. 1150 */ 1151 static int 1152 fts_ufslinks(FTS *sp, const FTSENT *ent) 1153 { 1154 struct _fts_private *priv; 1155 const char **cpp; 1156 1157 priv = (struct _fts_private *)sp; 1158 /* 1159 * If this node's device is different from the previous, grab 1160 * the filesystem information, and decide on the reliability 1161 * of the link information from this filesystem for stat(2) 1162 * avoidance. 1163 */ 1164 if (priv->ftsp_dev != ent->fts_dev) { 1165 if (statfs(ent->fts_path, &priv->ftsp_statfs) != -1) { 1166 priv->ftsp_dev = ent->fts_dev; 1167 priv->ftsp_linksreliable = 0; 1168 for (cpp = ufslike_filesystems; *cpp; cpp++) { 1169 if (strcmp(priv->ftsp_statfs.f_fstypename, 1170 *cpp) == 0) { 1171 priv->ftsp_linksreliable = 1; 1172 break; 1173 } 1174 } 1175 } else { 1176 priv->ftsp_linksreliable = 0; 1177 } 1178 } 1179 return (priv->ftsp_linksreliable); 1180 } 1181