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 #if 0 35 #if defined(LIBC_SCCS) && !defined(lint) 36 static char sccsid[] = "@(#)fts.c 8.6 (Berkeley) 8/14/94"; 37 #endif /* LIBC_SCCS and not lint */ 38 #endif 39 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD$"); 42 43 #include "namespace.h" 44 #include <sys/param.h> 45 #include <sys/mount.h> 46 #include <sys/stat.h> 47 48 #include <dirent.h> 49 #include <errno.h> 50 #include <fcntl.h> 51 #include <fts.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <unistd.h> 55 #include "un-namespace.h" 56 57 #include "gen-private.h" 58 59 static FTSENT *fts_alloc(FTS *, char *, size_t); 60 static FTSENT *fts_build(FTS *, int); 61 static void fts_lfree(FTSENT *); 62 static void fts_load(FTS *, FTSENT *); 63 static size_t fts_maxarglen(char * const *); 64 static void fts_padjust(FTS *, FTSENT *); 65 static int fts_palloc(FTS *, size_t); 66 static FTSENT *fts_sort(FTS *, FTSENT *, size_t); 67 static int fts_stat(FTS *, FTSENT *, int, int); 68 static int fts_safe_changedir(FTS *, FTSENT *, int, char *); 69 static int fts_ufslinks(FTS *, const FTSENT *); 70 71 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2]))) 72 73 #define CLR(opt) (sp->fts_options &= ~(opt)) 74 #define ISSET(opt) (sp->fts_options & (opt)) 75 #define SET(opt) (sp->fts_options |= (opt)) 76 77 #define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 78 79 /* fts_build flags */ 80 #define BCHILD 1 /* fts_children */ 81 #define BNAMES 2 /* fts_children, names only */ 82 #define BREAD 3 /* fts_read */ 83 84 /* 85 * Internal representation of an FTS, including extra implementation 86 * details. The FTS returned from fts_open points to this structure's 87 * ftsp_fts member (and can be cast to an _fts_private as required) 88 */ 89 struct _fts_private { 90 FTS ftsp_fts; 91 struct statfs ftsp_statfs; 92 dev_t ftsp_dev; 93 int ftsp_linksreliable; 94 }; 95 96 /* 97 * The "FTS_NOSTAT" option can avoid a lot of calls to stat(2) if it 98 * knows that a directory could not possibly have subdirectories. This 99 * is decided by looking at the link count: a subdirectory would 100 * increment its parent's link count by virtue of its own ".." entry. 101 * This assumption only holds for UFS-like filesystems that implement 102 * links and directories this way, so we must punt for others. 103 */ 104 105 static const char *ufslike_filesystems[] = { 106 "ufs", 107 "zfs", 108 "nfs", 109 "ext2fs", 110 0 111 }; 112 113 FTS * 114 fts_open(char * const *argv, int options, 115 int (*compar)(const FTSENT * const *, const FTSENT * const *)) 116 { 117 struct _fts_private *priv; 118 FTS *sp; 119 FTSENT *p, *root; 120 FTSENT *parent, *tmp; 121 size_t len, nitems; 122 123 /* Options check. */ 124 if (options & ~FTS_OPTIONMASK) { 125 errno = EINVAL; 126 return (NULL); 127 } 128 129 /* fts_open() requires at least one path */ 130 if (*argv == NULL) { 131 errno = EINVAL; 132 return (NULL); 133 } 134 135 /* Allocate/initialize the stream. */ 136 if ((priv = calloc(1, sizeof(*priv))) == NULL) 137 return (NULL); 138 sp = &priv->ftsp_fts; 139 sp->fts_compar = compar; 140 sp->fts_options = options; 141 142 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 143 if (ISSET(FTS_LOGICAL)) 144 SET(FTS_NOCHDIR); 145 146 /* 147 * Start out with 1K of path space, and enough, in any case, 148 * to hold the user's paths. 149 */ 150 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN))) 151 goto mem1; 152 153 /* Allocate/initialize root's parent. */ 154 if ((parent = fts_alloc(sp, "", 0)) == NULL) 155 goto mem2; 156 parent->fts_level = FTS_ROOTPARENTLEVEL; 157 158 /* Shush, GCC. */ 159 tmp = NULL; 160 161 /* Allocate/initialize root(s). */ 162 for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) { 163 len = strlen(*argv); 164 165 p = fts_alloc(sp, *argv, len); 166 p->fts_level = FTS_ROOTLEVEL; 167 p->fts_parent = parent; 168 p->fts_accpath = p->fts_name; 169 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW), -1); 170 171 /* Command-line "." and ".." are real directories. */ 172 if (p->fts_info == FTS_DOT) 173 p->fts_info = FTS_D; 174 175 /* 176 * If comparison routine supplied, traverse in sorted 177 * order; otherwise traverse in the order specified. 178 */ 179 if (compar) { 180 p->fts_link = root; 181 root = p; 182 } else { 183 p->fts_link = NULL; 184 if (root == NULL) 185 tmp = root = p; 186 else { 187 tmp->fts_link = p; 188 tmp = p; 189 } 190 } 191 } 192 if (compar && nitems > 1) 193 root = fts_sort(sp, root, nitems); 194 195 /* 196 * Allocate a dummy pointer and make fts_read think that we've just 197 * finished the node before the root(s); set p->fts_info to FTS_INIT 198 * so that everything about the "current" node is ignored. 199 */ 200 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 201 goto mem3; 202 sp->fts_cur->fts_link = root; 203 sp->fts_cur->fts_info = FTS_INIT; 204 205 /* 206 * If using chdir(2), grab a file descriptor pointing to dot to ensure 207 * that we can get back here; this could be avoided for some paths, 208 * but almost certainly not worth the effort. Slashes, symbolic links, 209 * and ".." are all fairly nasty problems. Note, if we can't get the 210 * descriptor we run anyway, just more slowly. 211 */ 212 if (!ISSET(FTS_NOCHDIR) && 213 (sp->fts_rfd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) 214 SET(FTS_NOCHDIR); 215 216 return (sp); 217 218 mem3: fts_lfree(root); 219 free(parent); 220 mem2: free(sp->fts_path); 221 mem1: free(sp); 222 return (NULL); 223 } 224 225 static void 226 fts_load(FTS *sp, FTSENT *p) 227 { 228 size_t len; 229 char *cp; 230 231 /* 232 * Load the stream structure for the next traversal. Since we don't 233 * actually enter the directory until after the preorder visit, set 234 * the fts_accpath field specially so the chdir gets done to the right 235 * place and the user can access the first node. From fts_open it's 236 * known that the path will fit. 237 */ 238 len = p->fts_pathlen = p->fts_namelen; 239 memmove(sp->fts_path, p->fts_name, len + 1); 240 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 241 len = strlen(++cp); 242 memmove(p->fts_name, cp, len + 1); 243 p->fts_namelen = len; 244 } 245 p->fts_accpath = p->fts_path = sp->fts_path; 246 sp->fts_dev = p->fts_dev; 247 } 248 249 int 250 fts_close(FTS *sp) 251 { 252 FTSENT *freep, *p; 253 int saved_errno; 254 255 /* 256 * This still works if we haven't read anything -- the dummy structure 257 * points to the root list, so we step through to the end of the root 258 * list which has a valid parent pointer. 259 */ 260 if (sp->fts_cur) { 261 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 262 freep = p; 263 p = p->fts_link != NULL ? p->fts_link : p->fts_parent; 264 free(freep); 265 } 266 free(p); 267 } 268 269 /* Free up child linked list, sort array, path buffer. */ 270 if (sp->fts_child) 271 fts_lfree(sp->fts_child); 272 if (sp->fts_array) 273 free(sp->fts_array); 274 free(sp->fts_path); 275 276 /* Return to original directory, save errno if necessary. */ 277 if (!ISSET(FTS_NOCHDIR)) { 278 saved_errno = fchdir(sp->fts_rfd) ? errno : 0; 279 (void)_close(sp->fts_rfd); 280 281 /* Set errno and return. */ 282 if (saved_errno != 0) { 283 /* Free up the stream pointer. */ 284 free(sp); 285 errno = saved_errno; 286 return (-1); 287 } 288 } 289 290 /* Free up the stream pointer. */ 291 free(sp); 292 return (0); 293 } 294 295 /* 296 * Special case of "/" at the end of the path so that slashes aren't 297 * appended which would cause paths to be written as "....//foo". 298 */ 299 #define NAPPEND(p) \ 300 (p->fts_path[p->fts_pathlen - 1] == '/' \ 301 ? p->fts_pathlen - 1 : p->fts_pathlen) 302 303 FTSENT * 304 fts_read(FTS *sp) 305 { 306 FTSENT *p, *tmp; 307 int instr; 308 char *t; 309 int saved_errno; 310 311 /* If finished or unrecoverable error, return NULL. */ 312 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 313 return (NULL); 314 315 /* Set current node pointer. */ 316 p = sp->fts_cur; 317 318 /* Save and zero out user instructions. */ 319 instr = p->fts_instr; 320 p->fts_instr = FTS_NOINSTR; 321 322 /* Any type of file may be re-visited; re-stat and re-turn. */ 323 if (instr == FTS_AGAIN) { 324 p->fts_info = fts_stat(sp, p, 0, -1); 325 return (p); 326 } 327 328 /* 329 * Following a symlink -- SLNONE test allows application to see 330 * SLNONE and recover. If indirecting through a symlink, have 331 * keep a pointer to current location. If unable to get that 332 * pointer, follow fails. 333 */ 334 if (instr == FTS_FOLLOW && 335 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 336 p->fts_info = fts_stat(sp, p, 1, -1); 337 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 338 if ((p->fts_symfd = _open(".", O_RDONLY | O_CLOEXEC, 339 0)) < 0) { 340 p->fts_errno = errno; 341 p->fts_info = FTS_ERR; 342 } else 343 p->fts_flags |= FTS_SYMFOLLOW; 344 } 345 return (p); 346 } 347 348 /* Directory in pre-order. */ 349 if (p->fts_info == FTS_D) { 350 /* If skipped or crossed mount point, do post-order visit. */ 351 if (instr == FTS_SKIP || 352 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 353 if (p->fts_flags & FTS_SYMFOLLOW) 354 (void)_close(p->fts_symfd); 355 if (sp->fts_child) { 356 fts_lfree(sp->fts_child); 357 sp->fts_child = NULL; 358 } 359 p->fts_info = FTS_DP; 360 return (p); 361 } 362 363 /* Rebuild if only read the names and now traversing. */ 364 if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) { 365 CLR(FTS_NAMEONLY); 366 fts_lfree(sp->fts_child); 367 sp->fts_child = NULL; 368 } 369 370 /* 371 * Cd to the subdirectory. 372 * 373 * If have already read and now fail to chdir, whack the list 374 * to make the names come out right, and set the parent errno 375 * so the application will eventually get an error condition. 376 * Set the FTS_DONTCHDIR flag so that when we logically change 377 * directories back to the parent we don't do a chdir. 378 * 379 * If haven't read do so. If the read fails, fts_build sets 380 * FTS_STOP or the fts_info field of the node. 381 */ 382 if (sp->fts_child != NULL) { 383 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 384 p->fts_errno = errno; 385 p->fts_flags |= FTS_DONTCHDIR; 386 for (p = sp->fts_child; p != NULL; 387 p = p->fts_link) 388 p->fts_accpath = 389 p->fts_parent->fts_accpath; 390 } 391 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 392 if (ISSET(FTS_STOP)) 393 return (NULL); 394 return (p); 395 } 396 p = sp->fts_child; 397 sp->fts_child = NULL; 398 goto name; 399 } 400 401 /* Move to the next node on this level. */ 402 next: tmp = p; 403 if ((p = p->fts_link) != NULL) { 404 /* 405 * If reached the top, return to the original directory (or 406 * the root of the tree), and load the paths for the next root. 407 */ 408 if (p->fts_level == FTS_ROOTLEVEL) { 409 if (FCHDIR(sp, sp->fts_rfd)) { 410 SET(FTS_STOP); 411 return (NULL); 412 } 413 free(tmp); 414 fts_load(sp, p); 415 return (sp->fts_cur = p); 416 } 417 418 /* 419 * User may have called fts_set on the node. If skipped, 420 * ignore. If followed, get a file descriptor so we can 421 * get back if necessary. 422 */ 423 if (p->fts_instr == FTS_SKIP) { 424 free(tmp); 425 goto next; 426 } 427 if (p->fts_instr == FTS_FOLLOW) { 428 p->fts_info = fts_stat(sp, p, 1, -1); 429 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 430 if ((p->fts_symfd = 431 _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) { 432 p->fts_errno = errno; 433 p->fts_info = FTS_ERR; 434 } else 435 p->fts_flags |= FTS_SYMFOLLOW; 436 } 437 p->fts_instr = FTS_NOINSTR; 438 } 439 440 free(tmp); 441 442 name: t = sp->fts_path + NAPPEND(p->fts_parent); 443 *t++ = '/'; 444 memmove(t, p->fts_name, p->fts_namelen + 1); 445 return (sp->fts_cur = p); 446 } 447 448 /* Move up to the parent node. */ 449 p = tmp->fts_parent; 450 451 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 452 /* 453 * Done; free everything up and set errno to 0 so the user 454 * can distinguish between error and EOF. 455 */ 456 free(tmp); 457 free(p); 458 errno = 0; 459 return (sp->fts_cur = NULL); 460 } 461 462 /* NUL terminate the pathname. */ 463 sp->fts_path[p->fts_pathlen] = '\0'; 464 465 /* 466 * Return to the parent directory. If at a root node or came through 467 * a symlink, go back through the file descriptor. Otherwise, cd up 468 * one directory. 469 */ 470 if (p->fts_level == FTS_ROOTLEVEL) { 471 if (FCHDIR(sp, sp->fts_rfd)) { 472 SET(FTS_STOP); 473 return (NULL); 474 } 475 } else if (p->fts_flags & FTS_SYMFOLLOW) { 476 if (FCHDIR(sp, p->fts_symfd)) { 477 saved_errno = errno; 478 (void)_close(p->fts_symfd); 479 errno = saved_errno; 480 SET(FTS_STOP); 481 return (NULL); 482 } 483 (void)_close(p->fts_symfd); 484 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 485 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 486 SET(FTS_STOP); 487 return (NULL); 488 } 489 free(tmp); 490 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 491 return (sp->fts_cur = p); 492 } 493 494 /* 495 * Fts_set takes the stream as an argument although it's not used in this 496 * implementation; it would be necessary if anyone wanted to add global 497 * semantics to fts using fts_set. An error return is allowed for similar 498 * reasons. 499 */ 500 /* ARGSUSED */ 501 int 502 fts_set(FTS *sp, FTSENT *p, int instr) 503 { 504 if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW && 505 instr != FTS_NOINSTR && instr != FTS_SKIP) { 506 errno = EINVAL; 507 return (1); 508 } 509 p->fts_instr = instr; 510 return (0); 511 } 512 513 FTSENT * 514 fts_children(FTS *sp, int instr) 515 { 516 FTSENT *p; 517 int fd, rc, serrno; 518 519 if (instr != 0 && instr != FTS_NAMEONLY) { 520 errno = EINVAL; 521 return (NULL); 522 } 523 524 /* Set current node pointer. */ 525 p = sp->fts_cur; 526 527 /* 528 * Errno set to 0 so user can distinguish empty directory from 529 * an error. 530 */ 531 errno = 0; 532 533 /* Fatal errors stop here. */ 534 if (ISSET(FTS_STOP)) 535 return (NULL); 536 537 /* Return logical hierarchy of user's arguments. */ 538 if (p->fts_info == FTS_INIT) 539 return (p->fts_link); 540 541 /* 542 * If not a directory being visited in pre-order, stop here. Could 543 * allow FTS_DNR, assuming the user has fixed the problem, but the 544 * same effect is available with FTS_AGAIN. 545 */ 546 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 547 return (NULL); 548 549 /* Free up any previous child list. */ 550 if (sp->fts_child != NULL) 551 fts_lfree(sp->fts_child); 552 553 if (instr == FTS_NAMEONLY) { 554 SET(FTS_NAMEONLY); 555 instr = BNAMES; 556 } else 557 instr = BCHILD; 558 559 /* 560 * If using chdir on a relative path and called BEFORE fts_read does 561 * its chdir to the root of a traversal, we can lose -- we need to 562 * chdir into the subdirectory, and we don't know where the current 563 * directory is, so we can't get back so that the upcoming chdir by 564 * fts_read will work. 565 */ 566 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 567 ISSET(FTS_NOCHDIR)) 568 return (sp->fts_child = fts_build(sp, instr)); 569 570 if ((fd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) 571 return (NULL); 572 sp->fts_child = fts_build(sp, instr); 573 serrno = (sp->fts_child == NULL) ? errno : 0; 574 rc = fchdir(fd); 575 if (rc < 0 && serrno == 0) 576 serrno = errno; 577 (void)_close(fd); 578 errno = serrno; 579 if (rc < 0) 580 return (NULL); 581 return (sp->fts_child); 582 } 583 584 #ifndef fts_get_clientptr 585 #error "fts_get_clientptr not defined" 586 #endif 587 588 void * 589 (fts_get_clientptr)(FTS *sp) 590 { 591 592 return (fts_get_clientptr(sp)); 593 } 594 595 #ifndef fts_get_stream 596 #error "fts_get_stream not defined" 597 #endif 598 599 FTS * 600 (fts_get_stream)(FTSENT *p) 601 { 602 return (fts_get_stream(p)); 603 } 604 605 void 606 fts_set_clientptr(FTS *sp, void *clientptr) 607 { 608 609 sp->fts_clientptr = clientptr; 610 } 611 612 /* 613 * This is the tricky part -- do not casually change *anything* in here. The 614 * idea is to build the linked list of entries that are used by fts_children 615 * and fts_read. There are lots of special cases. 616 * 617 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 618 * set and it's a physical walk (so that symbolic links can't be directories), 619 * we can do things quickly. First, if it's a 4.4BSD file system, the type 620 * of the file is in the directory entry. Otherwise, we assume that the number 621 * of subdirectories in a node is equal to the number of links to the parent. 622 * The former skips all stat calls. The latter skips stat calls in any leaf 623 * directories and for any files after the subdirectories in the directory have 624 * been found, cutting the stat calls by about 2/3. 625 */ 626 static FTSENT * 627 fts_build(FTS *sp, int type) 628 { 629 struct dirent *dp; 630 FTSENT *p, *head; 631 FTSENT *cur, *tail; 632 DIR *dirp; 633 void *oldaddr; 634 char *cp; 635 int cderrno, descend, oflag, saved_errno, nostat, doadjust; 636 long level; 637 long nlinks; /* has to be signed because -1 is a magic value */ 638 size_t dnamlen, len, maxlen, nitems; 639 640 /* Set current node pointer. */ 641 cur = sp->fts_cur; 642 643 /* 644 * Open the directory for reading. If this fails, we're done. 645 * If being called from fts_read, set the fts_info field. 646 */ 647 #ifdef FTS_WHITEOUT 648 if (ISSET(FTS_WHITEOUT)) 649 oflag = DTF_NODUP | DTF_REWIND; 650 else 651 oflag = DTF_HIDEW | DTF_NODUP | DTF_REWIND; 652 #else 653 #define __opendir2(path, flag) opendir(path) 654 #endif 655 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) { 656 if (type == BREAD) { 657 cur->fts_info = FTS_DNR; 658 cur->fts_errno = errno; 659 } 660 return (NULL); 661 } 662 663 /* 664 * Nlinks is the number of possible entries of type directory in the 665 * directory if we're cheating on stat calls, 0 if we're not doing 666 * any stat calls at all, -1 if we're doing stats on everything. 667 */ 668 if (type == BNAMES) { 669 nlinks = 0; 670 /* Be quiet about nostat, GCC. */ 671 nostat = 0; 672 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 673 if (fts_ufslinks(sp, cur)) 674 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 675 else 676 nlinks = -1; 677 nostat = 1; 678 } else { 679 nlinks = -1; 680 nostat = 0; 681 } 682 683 #ifdef notdef 684 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 685 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 686 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 687 #endif 688 /* 689 * If we're going to need to stat anything or we want to descend 690 * and stay in the directory, chdir. If this fails we keep going, 691 * but set a flag so we don't chdir after the post-order visit. 692 * We won't be able to stat anything, but we can still return the 693 * names themselves. Note, that since fts_read won't be able to 694 * chdir into the directory, it will have to return different path 695 * names than before, i.e. "a/b" instead of "b". Since the node 696 * has already been visited in pre-order, have to wait until the 697 * post-order visit to return the error. There is a special case 698 * here, if there was nothing to stat then it's not an error to 699 * not be able to stat. This is all fairly nasty. If a program 700 * needed sorted entries or stat information, they had better be 701 * checking FTS_NS on the returned nodes. 702 */ 703 cderrno = 0; 704 if (nlinks || type == BREAD) { 705 if (fts_safe_changedir(sp, cur, _dirfd(dirp), NULL)) { 706 if (nlinks && type == BREAD) 707 cur->fts_errno = errno; 708 cur->fts_flags |= FTS_DONTCHDIR; 709 descend = 0; 710 cderrno = errno; 711 } else 712 descend = 1; 713 } else 714 descend = 0; 715 716 /* 717 * Figure out the max file name length that can be stored in the 718 * current path -- the inner loop allocates more path as necessary. 719 * We really wouldn't have to do the maxlen calculations here, we 720 * could do them in fts_read before returning the path, but it's a 721 * lot easier here since the length is part of the dirent structure. 722 * 723 * If not changing directories set a pointer so that can just append 724 * each new name into the path. 725 */ 726 len = NAPPEND(cur); 727 if (ISSET(FTS_NOCHDIR)) { 728 cp = sp->fts_path + len; 729 *cp++ = '/'; 730 } else { 731 /* GCC, you're too verbose. */ 732 cp = NULL; 733 } 734 len++; 735 maxlen = sp->fts_pathlen - len; 736 737 level = cur->fts_level + 1; 738 739 /* Read the directory, attaching each entry to the `link' pointer. */ 740 doadjust = 0; 741 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) { 742 dnamlen = dp->d_namlen; 743 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 744 continue; 745 746 if ((p = fts_alloc(sp, dp->d_name, dnamlen)) == NULL) 747 goto mem1; 748 if (dnamlen >= maxlen) { /* include space for NUL */ 749 oldaddr = sp->fts_path; 750 if (fts_palloc(sp, dnamlen + len + 1)) { 751 /* 752 * No more memory for path or structures. Save 753 * errno, free up the current structure and the 754 * structures already allocated. 755 */ 756 mem1: saved_errno = errno; 757 if (p) 758 free(p); 759 fts_lfree(head); 760 (void)closedir(dirp); 761 cur->fts_info = FTS_ERR; 762 SET(FTS_STOP); 763 errno = saved_errno; 764 return (NULL); 765 } 766 /* Did realloc() change the pointer? */ 767 if (oldaddr != sp->fts_path) { 768 doadjust = 1; 769 if (ISSET(FTS_NOCHDIR)) 770 cp = sp->fts_path + len; 771 } 772 maxlen = sp->fts_pathlen - len; 773 } 774 775 p->fts_level = level; 776 p->fts_parent = sp->fts_cur; 777 p->fts_pathlen = len + dnamlen; 778 779 #ifdef FTS_WHITEOUT 780 if (dp->d_type == DT_WHT) 781 p->fts_flags |= FTS_ISW; 782 #endif 783 784 if (cderrno) { 785 if (nlinks) { 786 p->fts_info = FTS_NS; 787 p->fts_errno = cderrno; 788 } else 789 p->fts_info = FTS_NSOK; 790 p->fts_accpath = cur->fts_accpath; 791 } else if (nlinks == 0 792 #ifdef DT_DIR 793 || (nostat && 794 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 795 #endif 796 ) { 797 p->fts_accpath = 798 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 799 p->fts_info = FTS_NSOK; 800 } else { 801 /* Build a file name for fts_stat to stat. */ 802 if (ISSET(FTS_NOCHDIR)) { 803 p->fts_accpath = p->fts_path; 804 memmove(cp, p->fts_name, p->fts_namelen + 1); 805 p->fts_info = fts_stat(sp, p, 0, _dirfd(dirp)); 806 } else { 807 p->fts_accpath = p->fts_name; 808 p->fts_info = fts_stat(sp, p, 0, -1); 809 } 810 811 /* Decrement link count if applicable. */ 812 if (nlinks > 0 && (p->fts_info == FTS_D || 813 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 814 --nlinks; 815 } 816 817 /* We walk in directory order so "ls -f" doesn't get upset. */ 818 p->fts_link = NULL; 819 if (head == NULL) 820 head = tail = p; 821 else { 822 tail->fts_link = p; 823 tail = p; 824 } 825 ++nitems; 826 } 827 if (dirp) 828 (void)closedir(dirp); 829 830 /* 831 * If realloc() changed the address of the path, adjust the 832 * addresses for the rest of the tree and the dir list. 833 */ 834 if (doadjust) 835 fts_padjust(sp, head); 836 837 /* 838 * If not changing directories, reset the path back to original 839 * state. 840 */ 841 if (ISSET(FTS_NOCHDIR)) 842 sp->fts_path[cur->fts_pathlen] = '\0'; 843 844 /* 845 * If descended after called from fts_children or after called from 846 * fts_read and nothing found, get back. At the root level we use 847 * the saved fd; if one of fts_open()'s arguments is a relative path 848 * to an empty directory, we wind up here with no other way back. If 849 * can't get back, we're done. 850 */ 851 if (descend && (type == BCHILD || !nitems) && 852 (cur->fts_level == FTS_ROOTLEVEL ? 853 FCHDIR(sp, sp->fts_rfd) : 854 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 855 fts_lfree(head); 856 cur->fts_info = FTS_ERR; 857 SET(FTS_STOP); 858 return (NULL); 859 } 860 861 /* If didn't find anything, return NULL. */ 862 if (!nitems) { 863 if (type == BREAD) 864 cur->fts_info = FTS_DP; 865 return (NULL); 866 } 867 868 /* Sort the entries. */ 869 if (sp->fts_compar && nitems > 1) 870 head = fts_sort(sp, head, nitems); 871 return (head); 872 } 873 874 static int 875 fts_stat(FTS *sp, FTSENT *p, int follow, int dfd) 876 { 877 FTSENT *t; 878 dev_t dev; 879 ino_t ino; 880 struct stat *sbp, sb; 881 int saved_errno; 882 const char *path; 883 884 if (dfd == -1) 885 path = p->fts_accpath, dfd = AT_FDCWD; 886 else 887 path = p->fts_name; 888 889 /* If user needs stat info, stat buffer already allocated. */ 890 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 891 892 #ifdef FTS_WHITEOUT 893 /* Check for whiteout. */ 894 if (p->fts_flags & FTS_ISW) { 895 if (sbp != &sb) { 896 memset(sbp, '\0', sizeof(*sbp)); 897 sbp->st_mode = S_IFWHT; 898 } 899 return (FTS_W); 900 } 901 #endif 902 903 /* 904 * If doing a logical walk, or application requested FTS_FOLLOW, do 905 * a stat(2). If that fails, check for a non-existent symlink. If 906 * fail, set the errno from the stat call. 907 */ 908 if (ISSET(FTS_LOGICAL) || follow) { 909 if (fstatat(dfd, path, sbp, 0)) { 910 saved_errno = errno; 911 if (fstatat(dfd, path, sbp, AT_SYMLINK_NOFOLLOW)) { 912 p->fts_errno = saved_errno; 913 goto err; 914 } 915 errno = 0; 916 if (S_ISLNK(sbp->st_mode)) 917 return (FTS_SLNONE); 918 } 919 } else if (fstatat(dfd, path, sbp, AT_SYMLINK_NOFOLLOW)) { 920 p->fts_errno = errno; 921 err: memset(sbp, 0, sizeof(struct stat)); 922 return (FTS_NS); 923 } 924 925 if (S_ISDIR(sbp->st_mode)) { 926 /* 927 * Set the device/inode. Used to find cycles and check for 928 * crossing mount points. Also remember the link count, used 929 * in fts_build to limit the number of stat calls. It is 930 * understood that these fields are only referenced if fts_info 931 * is set to FTS_D. 932 */ 933 dev = p->fts_dev = sbp->st_dev; 934 ino = p->fts_ino = sbp->st_ino; 935 p->fts_nlink = sbp->st_nlink; 936 937 if (ISDOT(p->fts_name)) 938 return (FTS_DOT); 939 940 /* 941 * Cycle detection is done by brute force when the directory 942 * is first encountered. If the tree gets deep enough or the 943 * number of symbolic links to directories is high enough, 944 * something faster might be worthwhile. 945 */ 946 for (t = p->fts_parent; 947 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 948 if (ino == t->fts_ino && dev == t->fts_dev) { 949 p->fts_cycle = t; 950 return (FTS_DC); 951 } 952 return (FTS_D); 953 } 954 if (S_ISLNK(sbp->st_mode)) 955 return (FTS_SL); 956 if (S_ISREG(sbp->st_mode)) 957 return (FTS_F); 958 return (FTS_DEFAULT); 959 } 960 961 /* 962 * The comparison function takes pointers to pointers to FTSENT structures. 963 * Qsort wants a comparison function that takes pointers to void. 964 * (Both with appropriate levels of const-poisoning, of course!) 965 * Use a trampoline function to deal with the difference. 966 */ 967 static int 968 fts_compar(const void *a, const void *b) 969 { 970 FTS *parent; 971 972 parent = (*(const FTSENT * const *)a)->fts_fts; 973 return (*parent->fts_compar)(a, b); 974 } 975 976 static FTSENT * 977 fts_sort(FTS *sp, FTSENT *head, size_t nitems) 978 { 979 FTSENT **ap, *p; 980 981 /* 982 * Construct an array of pointers to the structures and call qsort(3). 983 * Reassemble the array in the order returned by qsort. If unable to 984 * sort for memory reasons, return the directory entries in their 985 * current order. Allocate enough space for the current needs plus 986 * 40 so don't realloc one entry at a time. 987 */ 988 if (nitems > sp->fts_nitems) { 989 sp->fts_nitems = nitems + 40; 990 if ((sp->fts_array = reallocf(sp->fts_array, 991 sp->fts_nitems * sizeof(FTSENT *))) == NULL) { 992 sp->fts_nitems = 0; 993 return (head); 994 } 995 } 996 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 997 *ap++ = p; 998 qsort(sp->fts_array, nitems, sizeof(FTSENT *), fts_compar); 999 for (head = *(ap = sp->fts_array); --nitems; ++ap) 1000 ap[0]->fts_link = ap[1]; 1001 ap[0]->fts_link = NULL; 1002 return (head); 1003 } 1004 1005 static FTSENT * 1006 fts_alloc(FTS *sp, char *name, size_t namelen) 1007 { 1008 FTSENT *p; 1009 size_t len; 1010 1011 struct ftsent_withstat { 1012 FTSENT ent; 1013 struct stat statbuf; 1014 }; 1015 1016 /* 1017 * The file name is a variable length array and no stat structure is 1018 * necessary if the user has set the nostat bit. Allocate the FTSENT 1019 * structure, the file name and the stat structure in one chunk, but 1020 * be careful that the stat structure is reasonably aligned. 1021 */ 1022 if (ISSET(FTS_NOSTAT)) 1023 len = sizeof(FTSENT) + namelen + 1; 1024 else 1025 len = sizeof(struct ftsent_withstat) + namelen + 1; 1026 1027 if ((p = malloc(len)) == NULL) 1028 return (NULL); 1029 1030 if (ISSET(FTS_NOSTAT)) { 1031 p->fts_name = (char *)(p + 1); 1032 p->fts_statp = NULL; 1033 } else { 1034 p->fts_name = (char *)((struct ftsent_withstat *)p + 1); 1035 p->fts_statp = &((struct ftsent_withstat *)p)->statbuf; 1036 } 1037 1038 /* Copy the name and guarantee NUL termination. */ 1039 memcpy(p->fts_name, name, namelen); 1040 p->fts_name[namelen] = '\0'; 1041 p->fts_namelen = namelen; 1042 p->fts_path = sp->fts_path; 1043 p->fts_errno = 0; 1044 p->fts_flags = 0; 1045 p->fts_instr = FTS_NOINSTR; 1046 p->fts_number = 0; 1047 p->fts_pointer = NULL; 1048 p->fts_fts = sp; 1049 return (p); 1050 } 1051 1052 static void 1053 fts_lfree(FTSENT *head) 1054 { 1055 FTSENT *p; 1056 1057 /* Free a linked list of structures. */ 1058 while ((p = head)) { 1059 head = head->fts_link; 1060 free(p); 1061 } 1062 } 1063 1064 /* 1065 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 1066 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 1067 * though the kernel won't resolve them. Add the size (not just what's needed) 1068 * plus 256 bytes so don't realloc the path 2 bytes at a time. 1069 */ 1070 static int 1071 fts_palloc(FTS *sp, size_t more) 1072 { 1073 1074 sp->fts_pathlen += more + 256; 1075 sp->fts_path = reallocf(sp->fts_path, sp->fts_pathlen); 1076 return (sp->fts_path == NULL); 1077 } 1078 1079 /* 1080 * When the path is realloc'd, have to fix all of the pointers in structures 1081 * already returned. 1082 */ 1083 static void 1084 fts_padjust(FTS *sp, FTSENT *head) 1085 { 1086 FTSENT *p; 1087 char *addr = sp->fts_path; 1088 1089 #define ADJUST(p) do { \ 1090 if ((p)->fts_accpath != (p)->fts_name) { \ 1091 (p)->fts_accpath = \ 1092 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \ 1093 } \ 1094 (p)->fts_path = addr; \ 1095 } while (0) 1096 /* Adjust the current set of children. */ 1097 for (p = sp->fts_child; p; p = p->fts_link) 1098 ADJUST(p); 1099 1100 /* Adjust the rest of the tree, including the current level. */ 1101 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1102 ADJUST(p); 1103 p = p->fts_link ? p->fts_link : p->fts_parent; 1104 } 1105 } 1106 1107 static size_t 1108 fts_maxarglen(char * const *argv) 1109 { 1110 size_t len, max; 1111 1112 for (max = 0; *argv; ++argv) 1113 if ((len = strlen(*argv)) > max) 1114 max = len; 1115 return (max + 1); 1116 } 1117 1118 /* 1119 * Change to dir specified by fd or p->fts_accpath without getting 1120 * tricked by someone changing the world out from underneath us. 1121 * Assumes p->fts_dev and p->fts_ino are filled in. 1122 */ 1123 static int 1124 fts_safe_changedir(FTS *sp, FTSENT *p, int fd, char *path) 1125 { 1126 int ret, oerrno, newfd; 1127 struct stat sb; 1128 1129 newfd = fd; 1130 if (ISSET(FTS_NOCHDIR)) 1131 return (0); 1132 if (fd < 0 && (newfd = _open(path, O_RDONLY | O_DIRECTORY | 1133 O_CLOEXEC, 0)) < 0) 1134 return (-1); 1135 if (_fstat(newfd, &sb)) { 1136 ret = -1; 1137 goto bail; 1138 } 1139 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) { 1140 errno = ENOENT; /* disinformation */ 1141 ret = -1; 1142 goto bail; 1143 } 1144 ret = fchdir(newfd); 1145 bail: 1146 oerrno = errno; 1147 if (fd < 0) 1148 (void)_close(newfd); 1149 errno = oerrno; 1150 return (ret); 1151 } 1152 1153 /* 1154 * Check if the filesystem for "ent" has UFS-style links. 1155 */ 1156 static int 1157 fts_ufslinks(FTS *sp, const FTSENT *ent) 1158 { 1159 struct _fts_private *priv; 1160 const char **cpp; 1161 1162 priv = (struct _fts_private *)sp; 1163 /* 1164 * If this node's device is different from the previous, grab 1165 * the filesystem information, and decide on the reliability 1166 * of the link information from this filesystem for stat(2) 1167 * avoidance. 1168 */ 1169 if (priv->ftsp_dev != ent->fts_dev) { 1170 if (statfs(ent->fts_path, &priv->ftsp_statfs) != -1) { 1171 priv->ftsp_dev = ent->fts_dev; 1172 priv->ftsp_linksreliable = 0; 1173 for (cpp = ufslike_filesystems; *cpp; cpp++) { 1174 if (strcmp(priv->ftsp_statfs.f_fstypename, 1175 *cpp) == 0) { 1176 priv->ftsp_linksreliable = 1; 1177 break; 1178 } 1179 } 1180 } else { 1181 priv->ftsp_linksreliable = 0; 1182 } 1183 } 1184 return (priv->ftsp_linksreliable); 1185 } 1186