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 static struct dirent * 608 fts_safe_readdir(DIR *dirp, int *readdir_errno) 609 { 610 struct dirent *ret; 611 612 errno = 0; 613 if (!dirp) 614 return (NULL); 615 ret = readdir(dirp); 616 *readdir_errno = errno; 617 return (ret); 618 } 619 620 /* 621 * This is the tricky part -- do not casually change *anything* in here. The 622 * idea is to build the linked list of entries that are used by fts_children 623 * and fts_read. There are lots of special cases. 624 * 625 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 626 * set and it's a physical walk (so that symbolic links can't be directories), 627 * we can do things quickly. First, if it's a 4.4BSD file system, the type 628 * of the file is in the directory entry. Otherwise, we assume that the number 629 * of subdirectories in a node is equal to the number of links to the parent. 630 * The former skips all stat calls. The latter skips stat calls in any leaf 631 * directories and for any files after the subdirectories in the directory have 632 * been found, cutting the stat calls by about 2/3. 633 */ 634 static FTSENT * 635 fts_build(FTS *sp, 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 readdir_errno; 645 long level; 646 long nlinks; /* has to be signed because -1 is a magic value */ 647 size_t dnamlen, len, maxlen, nitems; 648 649 /* Set current node pointer. */ 650 cur = sp->fts_cur; 651 652 /* 653 * Open the directory for reading. If this fails, we're done. 654 * If being called from fts_read, set the fts_info field. 655 */ 656 #ifdef FTS_WHITEOUT 657 if (ISSET(FTS_WHITEOUT)) 658 oflag = DTF_NODUP; 659 else 660 oflag = DTF_HIDEW | DTF_NODUP; 661 #else 662 #define __opendir2(path, flag) opendir(path) 663 #endif 664 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) { 665 if (type == BREAD) { 666 cur->fts_info = FTS_DNR; 667 cur->fts_errno = errno; 668 } 669 return (NULL); 670 } 671 672 /* 673 * Nlinks is the number of possible entries of type directory in the 674 * directory if we're cheating on stat calls, 0 if we're not doing 675 * any stat calls at all, -1 if we're doing stats on everything. 676 */ 677 if (type == BNAMES) { 678 nlinks = 0; 679 /* Be quiet about nostat, GCC. */ 680 nostat = 0; 681 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 682 if (fts_ufslinks(sp, cur)) 683 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 684 else 685 nlinks = -1; 686 nostat = 1; 687 } else { 688 nlinks = -1; 689 nostat = 0; 690 } 691 692 #ifdef notdef 693 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 694 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 695 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 696 #endif 697 /* 698 * If we're going to need to stat anything or we want to descend 699 * and stay in the directory, chdir. If this fails we keep going, 700 * but set a flag so we don't chdir after the post-order visit. 701 * We won't be able to stat anything, but we can still return the 702 * names themselves. Note, that since fts_read won't be able to 703 * chdir into the directory, it will have to return different path 704 * names than before, i.e. "a/b" instead of "b". Since the node 705 * has already been visited in pre-order, have to wait until the 706 * post-order visit to return the error. There is a special case 707 * here, if there was nothing to stat then it's not an error to 708 * not be able to stat. This is all fairly nasty. If a program 709 * needed sorted entries or stat information, they had better be 710 * checking FTS_NS on the returned nodes. 711 */ 712 cderrno = 0; 713 if (nlinks || type == BREAD) { 714 if (fts_safe_changedir(sp, cur, _dirfd(dirp), NULL)) { 715 if (nlinks && type == BREAD) 716 cur->fts_errno = errno; 717 cur->fts_flags |= FTS_DONTCHDIR; 718 descend = 0; 719 cderrno = errno; 720 } else 721 descend = 1; 722 } else 723 descend = 0; 724 725 /* 726 * Figure out the max file name length that can be stored in the 727 * current path -- the inner loop allocates more path as necessary. 728 * We really wouldn't have to do the maxlen calculations here, we 729 * could do them in fts_read before returning the path, but it's a 730 * lot easier here since the length is part of the dirent structure. 731 * 732 * If not changing directories set a pointer so that can just append 733 * each new name into the path. 734 */ 735 len = NAPPEND(cur); 736 if (ISSET(FTS_NOCHDIR)) { 737 cp = sp->fts_path + len; 738 *cp++ = '/'; 739 } else { 740 /* GCC, you're too verbose. */ 741 cp = NULL; 742 } 743 len++; 744 maxlen = sp->fts_pathlen - len; 745 746 level = cur->fts_level + 1; 747 748 /* Read the directory, attaching each entry to the `link' pointer. */ 749 doadjust = 0; 750 readdir_errno = 0; 751 for (head = tail = NULL, nitems = 0; 752 (dp = fts_safe_readdir(dirp, &readdir_errno));) { 753 dnamlen = dp->d_namlen; 754 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 755 continue; 756 757 if ((p = fts_alloc(sp, dp->d_name, dnamlen)) == NULL) 758 goto mem1; 759 if (dnamlen >= maxlen) { /* include space for NUL */ 760 oldaddr = sp->fts_path; 761 if (fts_palloc(sp, dnamlen + len + 1)) { 762 /* 763 * No more memory for path or structures. Save 764 * errno, free up the current structure and the 765 * structures already allocated. 766 */ 767 mem1: saved_errno = errno; 768 if (p) 769 free(p); 770 fts_lfree(head); 771 (void)closedir(dirp); 772 cur->fts_info = FTS_ERR; 773 SET(FTS_STOP); 774 errno = saved_errno; 775 return (NULL); 776 } 777 /* Did realloc() change the pointer? */ 778 if (oldaddr != sp->fts_path) { 779 doadjust = 1; 780 if (ISSET(FTS_NOCHDIR)) 781 cp = sp->fts_path + len; 782 } 783 maxlen = sp->fts_pathlen - len; 784 } 785 786 p->fts_level = level; 787 p->fts_parent = sp->fts_cur; 788 p->fts_pathlen = len + dnamlen; 789 790 #ifdef FTS_WHITEOUT 791 if (dp->d_type == DT_WHT) 792 p->fts_flags |= FTS_ISW; 793 #endif 794 795 if (cderrno) { 796 if (nlinks) { 797 p->fts_info = FTS_NS; 798 p->fts_errno = cderrno; 799 } else 800 p->fts_info = FTS_NSOK; 801 p->fts_accpath = cur->fts_accpath; 802 } else if (nlinks == 0 803 #ifdef DT_DIR 804 || (nostat && 805 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 806 #endif 807 ) { 808 p->fts_accpath = 809 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 810 p->fts_info = FTS_NSOK; 811 } else { 812 /* Build a file name for fts_stat to stat. */ 813 if (ISSET(FTS_NOCHDIR)) { 814 p->fts_accpath = p->fts_path; 815 memmove(cp, p->fts_name, p->fts_namelen + 1); 816 p->fts_info = fts_stat(sp, p, 0, _dirfd(dirp)); 817 } else { 818 p->fts_accpath = p->fts_name; 819 p->fts_info = fts_stat(sp, p, 0, -1); 820 } 821 822 /* Decrement link count if applicable. */ 823 if (nlinks > 0 && (p->fts_info == FTS_D || 824 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 825 --nlinks; 826 } 827 828 /* We walk in directory order so "ls -f" doesn't get upset. */ 829 p->fts_link = NULL; 830 if (head == NULL) 831 head = tail = p; 832 else { 833 tail->fts_link = p; 834 tail = p; 835 } 836 ++nitems; 837 } 838 839 if (readdir_errno) { 840 cur->fts_errno = readdir_errno; 841 /* 842 * If we've not read any items yet, treat 843 * the error as if we can't access the dir. 844 */ 845 cur->fts_info = nitems ? FTS_ERR : FTS_DNR; 846 } 847 848 if (dirp) 849 (void)closedir(dirp); 850 851 /* 852 * If realloc() changed the address of the path, adjust the 853 * addresses for the rest of the tree and the dir list. 854 */ 855 if (doadjust) 856 fts_padjust(sp, head); 857 858 /* 859 * If not changing directories, reset the path back to original 860 * state. 861 */ 862 if (ISSET(FTS_NOCHDIR)) 863 sp->fts_path[cur->fts_pathlen] = '\0'; 864 865 /* 866 * If descended after called from fts_children or after called from 867 * fts_read and nothing found, get back. At the root level we use 868 * the saved fd; if one of fts_open()'s arguments is a relative path 869 * to an empty directory, we wind up here with no other way back. If 870 * can't get back, we're done. 871 */ 872 if (descend && (type == BCHILD || !nitems) && 873 (cur->fts_level == FTS_ROOTLEVEL ? 874 FCHDIR(sp, sp->fts_rfd) : 875 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 876 fts_lfree(head); 877 cur->fts_info = FTS_ERR; 878 SET(FTS_STOP); 879 return (NULL); 880 } 881 882 /* If didn't find anything, return NULL. */ 883 if (!nitems) { 884 if (type == BREAD && 885 cur->fts_info != FTS_DNR && cur->fts_info != FTS_ERR) 886 cur->fts_info = FTS_DP; 887 return (NULL); 888 } 889 890 /* Sort the entries. */ 891 if (sp->fts_compar && nitems > 1) 892 head = fts_sort(sp, head, nitems); 893 return (head); 894 } 895 896 static int 897 fts_stat(FTS *sp, FTSENT *p, int follow, int dfd) 898 { 899 FTSENT *t; 900 dev_t dev; 901 ino_t ino; 902 struct stat *sbp, sb; 903 int saved_errno; 904 const char *path; 905 906 if (dfd == -1) 907 path = p->fts_accpath, dfd = AT_FDCWD; 908 else 909 path = p->fts_name; 910 911 /* If user needs stat info, stat buffer already allocated. */ 912 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 913 914 #ifdef FTS_WHITEOUT 915 /* Check for whiteout. */ 916 if (p->fts_flags & FTS_ISW) { 917 if (sbp != &sb) { 918 memset(sbp, '\0', sizeof(*sbp)); 919 sbp->st_mode = S_IFWHT; 920 } 921 return (FTS_W); 922 } 923 #endif 924 925 /* 926 * If doing a logical walk, or application requested FTS_FOLLOW, do 927 * a stat(2). If that fails, check for a non-existent symlink. If 928 * fail, set the errno from the stat call. 929 */ 930 if (ISSET(FTS_LOGICAL) || follow) { 931 if (fstatat(dfd, path, sbp, 0)) { 932 saved_errno = errno; 933 if (fstatat(dfd, path, sbp, AT_SYMLINK_NOFOLLOW)) { 934 p->fts_errno = saved_errno; 935 goto err; 936 } 937 errno = 0; 938 if (S_ISLNK(sbp->st_mode)) 939 return (FTS_SLNONE); 940 } 941 } else if (fstatat(dfd, path, sbp, AT_SYMLINK_NOFOLLOW)) { 942 p->fts_errno = errno; 943 err: memset(sbp, 0, sizeof(struct stat)); 944 return (FTS_NS); 945 } 946 947 if (S_ISDIR(sbp->st_mode)) { 948 /* 949 * Set the device/inode. Used to find cycles and check for 950 * crossing mount points. Also remember the link count, used 951 * in fts_build to limit the number of stat calls. It is 952 * understood that these fields are only referenced if fts_info 953 * is set to FTS_D. 954 */ 955 dev = p->fts_dev = sbp->st_dev; 956 ino = p->fts_ino = sbp->st_ino; 957 p->fts_nlink = sbp->st_nlink; 958 959 if (ISDOT(p->fts_name)) 960 return (FTS_DOT); 961 962 /* 963 * Cycle detection is done by brute force when the directory 964 * is first encountered. If the tree gets deep enough or the 965 * number of symbolic links to directories is high enough, 966 * something faster might be worthwhile. 967 */ 968 for (t = p->fts_parent; 969 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 970 if (ino == t->fts_ino && dev == t->fts_dev) { 971 p->fts_cycle = t; 972 return (FTS_DC); 973 } 974 return (FTS_D); 975 } 976 if (S_ISLNK(sbp->st_mode)) 977 return (FTS_SL); 978 if (S_ISREG(sbp->st_mode)) 979 return (FTS_F); 980 return (FTS_DEFAULT); 981 } 982 983 /* 984 * The comparison function takes pointers to pointers to FTSENT structures. 985 * Qsort wants a comparison function that takes pointers to void. 986 * (Both with appropriate levels of const-poisoning, of course!) 987 * Use a trampoline function to deal with the difference. 988 */ 989 static int 990 fts_compar(const void *a, const void *b) 991 { 992 FTS *parent; 993 994 parent = (*(const FTSENT * const *)a)->fts_fts; 995 return (*parent->fts_compar)(a, b); 996 } 997 998 static FTSENT * 999 fts_sort(FTS *sp, FTSENT *head, size_t nitems) 1000 { 1001 FTSENT **ap, *p; 1002 1003 /* 1004 * Construct an array of pointers to the structures and call qsort(3). 1005 * Reassemble the array in the order returned by qsort. If unable to 1006 * sort for memory reasons, return the directory entries in their 1007 * current order. Allocate enough space for the current needs plus 1008 * 40 so don't realloc one entry at a time. 1009 */ 1010 if (nitems > sp->fts_nitems) { 1011 sp->fts_nitems = nitems + 40; 1012 if ((sp->fts_array = reallocf(sp->fts_array, 1013 sp->fts_nitems * sizeof(FTSENT *))) == NULL) { 1014 sp->fts_nitems = 0; 1015 return (head); 1016 } 1017 } 1018 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 1019 *ap++ = p; 1020 qsort(sp->fts_array, nitems, sizeof(FTSENT *), fts_compar); 1021 for (head = *(ap = sp->fts_array); --nitems; ++ap) 1022 ap[0]->fts_link = ap[1]; 1023 ap[0]->fts_link = NULL; 1024 return (head); 1025 } 1026 1027 static FTSENT * 1028 fts_alloc(FTS *sp, char *name, size_t namelen) 1029 { 1030 FTSENT *p; 1031 size_t len; 1032 1033 struct ftsent_withstat { 1034 FTSENT ent; 1035 struct stat statbuf; 1036 }; 1037 1038 /* 1039 * The file name is a variable length array and no stat structure is 1040 * necessary if the user has set the nostat bit. Allocate the FTSENT 1041 * structure, the file name and the stat structure in one chunk, but 1042 * be careful that the stat structure is reasonably aligned. 1043 */ 1044 if (ISSET(FTS_NOSTAT)) 1045 len = sizeof(FTSENT) + namelen + 1; 1046 else 1047 len = sizeof(struct ftsent_withstat) + namelen + 1; 1048 1049 if ((p = malloc(len)) == NULL) 1050 return (NULL); 1051 1052 if (ISSET(FTS_NOSTAT)) { 1053 p->fts_name = (char *)(p + 1); 1054 p->fts_statp = NULL; 1055 } else { 1056 p->fts_name = (char *)((struct ftsent_withstat *)p + 1); 1057 p->fts_statp = &((struct ftsent_withstat *)p)->statbuf; 1058 } 1059 1060 /* Copy the name and guarantee NUL termination. */ 1061 memcpy(p->fts_name, name, namelen); 1062 p->fts_name[namelen] = '\0'; 1063 p->fts_namelen = namelen; 1064 p->fts_path = sp->fts_path; 1065 p->fts_errno = 0; 1066 p->fts_flags = 0; 1067 p->fts_instr = FTS_NOINSTR; 1068 p->fts_number = 0; 1069 p->fts_pointer = NULL; 1070 p->fts_fts = sp; 1071 return (p); 1072 } 1073 1074 static void 1075 fts_lfree(FTSENT *head) 1076 { 1077 FTSENT *p; 1078 1079 /* Free a linked list of structures. */ 1080 while ((p = head)) { 1081 head = head->fts_link; 1082 free(p); 1083 } 1084 } 1085 1086 /* 1087 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 1088 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 1089 * though the kernel won't resolve them. Add the size (not just what's needed) 1090 * plus 256 bytes so don't realloc the path 2 bytes at a time. 1091 */ 1092 static int 1093 fts_palloc(FTS *sp, size_t more) 1094 { 1095 1096 sp->fts_pathlen += more + 256; 1097 sp->fts_path = reallocf(sp->fts_path, sp->fts_pathlen); 1098 return (sp->fts_path == NULL); 1099 } 1100 1101 /* 1102 * When the path is realloc'd, have to fix all of the pointers in structures 1103 * already returned. 1104 */ 1105 static void 1106 fts_padjust(FTS *sp, FTSENT *head) 1107 { 1108 FTSENT *p; 1109 char *addr = sp->fts_path; 1110 1111 #define ADJUST(p) do { \ 1112 if ((p)->fts_accpath != (p)->fts_name) { \ 1113 (p)->fts_accpath = \ 1114 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \ 1115 } \ 1116 (p)->fts_path = addr; \ 1117 } while (0) 1118 /* Adjust the current set of children. */ 1119 for (p = sp->fts_child; p; p = p->fts_link) 1120 ADJUST(p); 1121 1122 /* Adjust the rest of the tree, including the current level. */ 1123 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1124 ADJUST(p); 1125 p = p->fts_link ? p->fts_link : p->fts_parent; 1126 } 1127 } 1128 1129 static size_t 1130 fts_maxarglen(char * const *argv) 1131 { 1132 size_t len, max; 1133 1134 for (max = 0; *argv; ++argv) 1135 if ((len = strlen(*argv)) > max) 1136 max = len; 1137 return (max + 1); 1138 } 1139 1140 /* 1141 * Change to dir specified by fd or p->fts_accpath without getting 1142 * tricked by someone changing the world out from underneath us. 1143 * Assumes p->fts_dev and p->fts_ino are filled in. 1144 */ 1145 static int 1146 fts_safe_changedir(FTS *sp, FTSENT *p, int fd, char *path) 1147 { 1148 int ret, oerrno, newfd; 1149 struct stat sb; 1150 1151 newfd = fd; 1152 if (ISSET(FTS_NOCHDIR)) 1153 return (0); 1154 if (fd < 0 && (newfd = _open(path, O_RDONLY | O_DIRECTORY | 1155 O_CLOEXEC, 0)) < 0) 1156 return (-1); 1157 if (_fstat(newfd, &sb)) { 1158 ret = -1; 1159 goto bail; 1160 } 1161 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) { 1162 errno = ENOENT; /* disinformation */ 1163 ret = -1; 1164 goto bail; 1165 } 1166 ret = fchdir(newfd); 1167 bail: 1168 oerrno = errno; 1169 if (fd < 0) 1170 (void)_close(newfd); 1171 errno = oerrno; 1172 return (ret); 1173 } 1174 1175 /* 1176 * Check if the filesystem for "ent" has UFS-style links. 1177 */ 1178 static int 1179 fts_ufslinks(FTS *sp, const FTSENT *ent) 1180 { 1181 struct _fts_private *priv; 1182 const char **cpp; 1183 1184 priv = (struct _fts_private *)sp; 1185 /* 1186 * If this node's device is different from the previous, grab 1187 * the filesystem information, and decide on the reliability 1188 * of the link information from this filesystem for stat(2) 1189 * avoidance. 1190 */ 1191 if (priv->ftsp_dev != ent->fts_dev) { 1192 if (statfs(ent->fts_path, &priv->ftsp_statfs) != -1) { 1193 priv->ftsp_dev = ent->fts_dev; 1194 priv->ftsp_linksreliable = 0; 1195 for (cpp = ufslike_filesystems; *cpp; cpp++) { 1196 if (strcmp(priv->ftsp_statfs.f_fstypename, 1197 *cpp) == 0) { 1198 priv->ftsp_linksreliable = 1; 1199 break; 1200 } 1201 } 1202 } else { 1203 priv->ftsp_linksreliable = 0; 1204 } 1205 } 1206 return (priv->ftsp_linksreliable); 1207 } 1208