1 /*- 2 * Copyright (c) 1990, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $OpenBSD: fts.c,v 1.22 1999/10/03 19:22:22 millert Exp $ 30 */ 31 32 #if 0 33 #if defined(LIBC_SCCS) && !defined(lint) 34 static char sccsid[] = "@(#)fts.c 8.6 (Berkeley) 8/14/94"; 35 #endif /* LIBC_SCCS and not lint */ 36 #endif 37 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include "namespace.h" 42 #include <sys/param.h> 43 #include <sys/mount.h> 44 #include <sys/stat.h> 45 46 #include <dirent.h> 47 #include <errno.h> 48 #include <fcntl.h> 49 #include <fts.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 #include "un-namespace.h" 54 55 #include "gen-private.h" 56 57 static FTSENT *fts_alloc(FTS *, char *, size_t); 58 static FTSENT *fts_build(FTS *, int); 59 static void fts_lfree(FTSENT *); 60 static void fts_load(FTS *, FTSENT *); 61 static size_t fts_maxarglen(char * const *); 62 static void fts_padjust(FTS *, FTSENT *); 63 static int fts_palloc(FTS *, size_t); 64 static FTSENT *fts_sort(FTS *, FTSENT *, size_t); 65 static int fts_stat(FTS *, FTSENT *, int, int); 66 static int fts_safe_changedir(FTS *, FTSENT *, int, char *); 67 static int fts_ufslinks(FTS *, const FTSENT *); 68 69 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2]))) 70 71 #define CLR(opt) (sp->fts_options &= ~(opt)) 72 #define ISSET(opt) (sp->fts_options & (opt)) 73 #define SET(opt) (sp->fts_options |= (opt)) 74 75 #define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 76 77 /* fts_build flags */ 78 #define BCHILD 1 /* fts_children */ 79 #define BNAMES 2 /* fts_children, names only */ 80 #define BREAD 3 /* fts_read */ 81 82 /* 83 * Internal representation of an FTS, including extra implementation 84 * details. The FTS returned from fts_open points to this structure's 85 * ftsp_fts member (and can be cast to an _fts_private as required) 86 */ 87 struct _fts_private { 88 FTS ftsp_fts; 89 struct statfs ftsp_statfs; 90 dev_t ftsp_dev; 91 int ftsp_linksreliable; 92 }; 93 94 /* 95 * The "FTS_NOSTAT" option can avoid a lot of calls to stat(2) if it 96 * knows that a directory could not possibly have subdirectories. This 97 * is decided by looking at the link count: a subdirectory would 98 * increment its parent's link count by virtue of its own ".." entry. 99 * This assumption only holds for UFS-like filesystems that implement 100 * links and directories this way, so we must punt for others. 101 */ 102 103 static const char *ufslike_filesystems[] = { 104 "ufs", 105 "zfs", 106 "nfs", 107 "nfs4", 108 "ext2fs", 109 0 110 }; 111 112 FTS * 113 fts_open(argv, options, compar) 114 char * const *argv; 115 int options; 116 int (*compar)(const FTSENT * const *, const FTSENT * const *); 117 { 118 struct _fts_private *priv; 119 FTS *sp; 120 FTSENT *p, *root; 121 FTSENT *parent, *tmp; 122 size_t len, nitems; 123 124 /* Options check. */ 125 if (options & ~FTS_OPTIONMASK) { 126 errno = EINVAL; 127 return (NULL); 128 } 129 130 /* fts_open() requires at least one path */ 131 if (*argv == NULL) { 132 errno = EINVAL; 133 return (NULL); 134 } 135 136 /* Allocate/initialize the stream. */ 137 if ((priv = calloc(1, sizeof(*priv))) == NULL) 138 return (NULL); 139 sp = &priv->ftsp_fts; 140 sp->fts_compar = compar; 141 sp->fts_options = options; 142 143 /* Shush, GCC. */ 144 tmp = NULL; 145 146 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 147 if (ISSET(FTS_LOGICAL)) 148 SET(FTS_NOCHDIR); 149 150 /* 151 * Start out with 1K of path space, and enough, in any case, 152 * to hold the user's paths. 153 */ 154 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN))) 155 goto mem1; 156 157 /* Allocate/initialize root's parent. */ 158 if ((parent = fts_alloc(sp, "", 0)) == NULL) 159 goto mem2; 160 parent->fts_level = FTS_ROOTPARENTLEVEL; 161 162 /* Allocate/initialize root(s). */ 163 for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) { 164 len = strlen(*argv); 165 166 p = fts_alloc(sp, *argv, len); 167 p->fts_level = FTS_ROOTLEVEL; 168 p->fts_parent = parent; 169 p->fts_accpath = p->fts_name; 170 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW), -1); 171 172 /* Command-line "." and ".." are real directories. */ 173 if (p->fts_info == FTS_DOT) 174 p->fts_info = FTS_D; 175 176 /* 177 * If comparison routine supplied, traverse in sorted 178 * order; otherwise traverse in the order specified. 179 */ 180 if (compar) { 181 p->fts_link = root; 182 root = p; 183 } else { 184 p->fts_link = NULL; 185 if (root == NULL) 186 tmp = root = p; 187 else { 188 tmp->fts_link = p; 189 tmp = p; 190 } 191 } 192 } 193 if (compar && nitems > 1) 194 root = fts_sort(sp, root, nitems); 195 196 /* 197 * Allocate a dummy pointer and make fts_read think that we've just 198 * finished the node before the root(s); set p->fts_info to FTS_INIT 199 * so that everything about the "current" node is ignored. 200 */ 201 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 202 goto mem3; 203 sp->fts_cur->fts_link = root; 204 sp->fts_cur->fts_info = FTS_INIT; 205 206 /* 207 * If using chdir(2), grab a file descriptor pointing to dot to ensure 208 * that we can get back here; this could be avoided for some paths, 209 * but almost certainly not worth the effort. Slashes, symbolic links, 210 * and ".." are all fairly nasty problems. Note, if we can't get the 211 * descriptor we run anyway, just more slowly. 212 */ 213 if (!ISSET(FTS_NOCHDIR) && 214 (sp->fts_rfd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) 215 SET(FTS_NOCHDIR); 216 217 return (sp); 218 219 mem3: fts_lfree(root); 220 free(parent); 221 mem2: free(sp->fts_path); 222 mem1: free(sp); 223 return (NULL); 224 } 225 226 static void 227 fts_load(FTS *sp, FTSENT *p) 228 { 229 size_t len; 230 char *cp; 231 232 /* 233 * Load the stream structure for the next traversal. Since we don't 234 * actually enter the directory until after the preorder visit, set 235 * the fts_accpath field specially so the chdir gets done to the right 236 * place and the user can access the first node. From fts_open it's 237 * known that the path will fit. 238 */ 239 len = p->fts_pathlen = p->fts_namelen; 240 memmove(sp->fts_path, p->fts_name, len + 1); 241 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 242 len = strlen(++cp); 243 memmove(p->fts_name, cp, len + 1); 244 p->fts_namelen = len; 245 } 246 p->fts_accpath = p->fts_path = sp->fts_path; 247 sp->fts_dev = p->fts_dev; 248 } 249 250 int 251 fts_close(FTS *sp) 252 { 253 FTSENT *freep, *p; 254 int saved_errno; 255 256 /* 257 * This still works if we haven't read anything -- the dummy structure 258 * points to the root list, so we step through to the end of the root 259 * list which has a valid parent pointer. 260 */ 261 if (sp->fts_cur) { 262 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 263 freep = p; 264 p = p->fts_link != NULL ? p->fts_link : p->fts_parent; 265 free(freep); 266 } 267 free(p); 268 } 269 270 /* Free up child linked list, sort array, path buffer. */ 271 if (sp->fts_child) 272 fts_lfree(sp->fts_child); 273 if (sp->fts_array) 274 free(sp->fts_array); 275 free(sp->fts_path); 276 277 /* Return to original directory, save errno if necessary. */ 278 if (!ISSET(FTS_NOCHDIR)) { 279 saved_errno = fchdir(sp->fts_rfd) ? errno : 0; 280 (void)_close(sp->fts_rfd); 281 282 /* Set errno and return. */ 283 if (saved_errno != 0) { 284 /* Free up the stream pointer. */ 285 free(sp); 286 errno = saved_errno; 287 return (-1); 288 } 289 } 290 291 /* Free up the stream pointer. */ 292 free(sp); 293 return (0); 294 } 295 296 /* 297 * Special case of "/" at the end of the path so that slashes aren't 298 * appended which would cause paths to be written as "....//foo". 299 */ 300 #define NAPPEND(p) \ 301 (p->fts_path[p->fts_pathlen - 1] == '/' \ 302 ? p->fts_pathlen - 1 : p->fts_pathlen) 303 304 FTSENT * 305 fts_read(FTS *sp) 306 { 307 FTSENT *p, *tmp; 308 int instr; 309 char *t; 310 int saved_errno; 311 312 /* If finished or unrecoverable error, return NULL. */ 313 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 314 return (NULL); 315 316 /* Set current node pointer. */ 317 p = sp->fts_cur; 318 319 /* Save and zero out user instructions. */ 320 instr = p->fts_instr; 321 p->fts_instr = FTS_NOINSTR; 322 323 /* Any type of file may be re-visited; re-stat and re-turn. */ 324 if (instr == FTS_AGAIN) { 325 p->fts_info = fts_stat(sp, p, 0, -1); 326 return (p); 327 } 328 329 /* 330 * Following a symlink -- SLNONE test allows application to see 331 * SLNONE and recover. If indirecting through a symlink, have 332 * keep a pointer to current location. If unable to get that 333 * pointer, follow fails. 334 */ 335 if (instr == FTS_FOLLOW && 336 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 337 p->fts_info = fts_stat(sp, p, 1, -1); 338 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 339 if ((p->fts_symfd = _open(".", O_RDONLY | O_CLOEXEC, 340 0)) < 0) { 341 p->fts_errno = errno; 342 p->fts_info = FTS_ERR; 343 } else 344 p->fts_flags |= FTS_SYMFOLLOW; 345 } 346 return (p); 347 } 348 349 /* Directory in pre-order. */ 350 if (p->fts_info == FTS_D) { 351 /* If skipped or crossed mount point, do post-order visit. */ 352 if (instr == FTS_SKIP || 353 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 354 if (p->fts_flags & FTS_SYMFOLLOW) 355 (void)_close(p->fts_symfd); 356 if (sp->fts_child) { 357 fts_lfree(sp->fts_child); 358 sp->fts_child = NULL; 359 } 360 p->fts_info = FTS_DP; 361 return (p); 362 } 363 364 /* Rebuild if only read the names and now traversing. */ 365 if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) { 366 CLR(FTS_NAMEONLY); 367 fts_lfree(sp->fts_child); 368 sp->fts_child = NULL; 369 } 370 371 /* 372 * Cd to the subdirectory. 373 * 374 * If have already read and now fail to chdir, whack the list 375 * to make the names come out right, and set the parent errno 376 * so the application will eventually get an error condition. 377 * Set the FTS_DONTCHDIR flag so that when we logically change 378 * directories back to the parent we don't do a chdir. 379 * 380 * If haven't read do so. If the read fails, fts_build sets 381 * FTS_STOP or the fts_info field of the node. 382 */ 383 if (sp->fts_child != NULL) { 384 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 385 p->fts_errno = errno; 386 p->fts_flags |= FTS_DONTCHDIR; 387 for (p = sp->fts_child; p != NULL; 388 p = p->fts_link) 389 p->fts_accpath = 390 p->fts_parent->fts_accpath; 391 } 392 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 393 if (ISSET(FTS_STOP)) 394 return (NULL); 395 return (p); 396 } 397 p = sp->fts_child; 398 sp->fts_child = NULL; 399 goto name; 400 } 401 402 /* Move to the next node on this level. */ 403 next: tmp = p; 404 if ((p = p->fts_link) != NULL) { 405 /* 406 * If reached the top, return to the original directory (or 407 * the root of the tree), and load the paths for the next root. 408 */ 409 if (p->fts_level == FTS_ROOTLEVEL) { 410 if (FCHDIR(sp, sp->fts_rfd)) { 411 SET(FTS_STOP); 412 return (NULL); 413 } 414 free(tmp); 415 fts_load(sp, p); 416 return (sp->fts_cur = p); 417 } 418 419 /* 420 * User may have called fts_set on the node. If skipped, 421 * ignore. If followed, get a file descriptor so we can 422 * get back if necessary. 423 */ 424 if (p->fts_instr == FTS_SKIP) { 425 free(tmp); 426 goto next; 427 } 428 if (p->fts_instr == FTS_FOLLOW) { 429 p->fts_info = fts_stat(sp, p, 1, -1); 430 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 431 if ((p->fts_symfd = 432 _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) { 433 p->fts_errno = errno; 434 p->fts_info = FTS_ERR; 435 } else 436 p->fts_flags |= FTS_SYMFOLLOW; 437 } 438 p->fts_instr = FTS_NOINSTR; 439 } 440 441 free(tmp); 442 443 name: t = sp->fts_path + NAPPEND(p->fts_parent); 444 *t++ = '/'; 445 memmove(t, p->fts_name, p->fts_namelen + 1); 446 return (sp->fts_cur = p); 447 } 448 449 /* Move up to the parent node. */ 450 p = tmp->fts_parent; 451 452 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 453 /* 454 * Done; free everything up and set errno to 0 so the user 455 * can distinguish between error and EOF. 456 */ 457 free(tmp); 458 free(p); 459 errno = 0; 460 return (sp->fts_cur = NULL); 461 } 462 463 /* NUL terminate the pathname. */ 464 sp->fts_path[p->fts_pathlen] = '\0'; 465 466 /* 467 * Return to the parent directory. If at a root node or came through 468 * a symlink, go back through the file descriptor. Otherwise, cd up 469 * one directory. 470 */ 471 if (p->fts_level == FTS_ROOTLEVEL) { 472 if (FCHDIR(sp, sp->fts_rfd)) { 473 SET(FTS_STOP); 474 return (NULL); 475 } 476 } else if (p->fts_flags & FTS_SYMFOLLOW) { 477 if (FCHDIR(sp, p->fts_symfd)) { 478 saved_errno = errno; 479 (void)_close(p->fts_symfd); 480 errno = saved_errno; 481 SET(FTS_STOP); 482 return (NULL); 483 } 484 (void)_close(p->fts_symfd); 485 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 486 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 487 SET(FTS_STOP); 488 return (NULL); 489 } 490 free(tmp); 491 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 492 return (sp->fts_cur = p); 493 } 494 495 /* 496 * Fts_set takes the stream as an argument although it's not used in this 497 * implementation; it would be necessary if anyone wanted to add global 498 * semantics to fts using fts_set. An error return is allowed for similar 499 * reasons. 500 */ 501 /* ARGSUSED */ 502 int 503 fts_set(FTS *sp, FTSENT *p, int instr) 504 { 505 if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW && 506 instr != FTS_NOINSTR && instr != FTS_SKIP) { 507 errno = EINVAL; 508 return (1); 509 } 510 p->fts_instr = instr; 511 return (0); 512 } 513 514 FTSENT * 515 fts_children(FTS *sp, int instr) 516 { 517 FTSENT *p; 518 int fd; 519 520 if (instr != 0 && instr != FTS_NAMEONLY) { 521 errno = EINVAL; 522 return (NULL); 523 } 524 525 /* Set current node pointer. */ 526 p = sp->fts_cur; 527 528 /* 529 * Errno set to 0 so user can distinguish empty directory from 530 * an error. 531 */ 532 errno = 0; 533 534 /* Fatal errors stop here. */ 535 if (ISSET(FTS_STOP)) 536 return (NULL); 537 538 /* Return logical hierarchy of user's arguments. */ 539 if (p->fts_info == FTS_INIT) 540 return (p->fts_link); 541 542 /* 543 * If not a directory being visited in pre-order, stop here. Could 544 * allow FTS_DNR, assuming the user has fixed the problem, but the 545 * same effect is available with FTS_AGAIN. 546 */ 547 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 548 return (NULL); 549 550 /* Free up any previous child list. */ 551 if (sp->fts_child != NULL) 552 fts_lfree(sp->fts_child); 553 554 if (instr == FTS_NAMEONLY) { 555 SET(FTS_NAMEONLY); 556 instr = BNAMES; 557 } else 558 instr = BCHILD; 559 560 /* 561 * If using chdir on a relative path and called BEFORE fts_read does 562 * its chdir to the root of a traversal, we can lose -- we need to 563 * chdir into the subdirectory, and we don't know where the current 564 * directory is, so we can't get back so that the upcoming chdir by 565 * fts_read will work. 566 */ 567 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 568 ISSET(FTS_NOCHDIR)) 569 return (sp->fts_child = fts_build(sp, instr)); 570 571 if ((fd = _open(".", O_RDONLY | O_CLOEXEC, 0)) < 0) 572 return (NULL); 573 sp->fts_child = fts_build(sp, instr); 574 if (fchdir(fd)) { 575 (void)_close(fd); 576 return (NULL); 577 } 578 (void)_close(fd); 579 return (sp->fts_child); 580 } 581 582 #ifndef fts_get_clientptr 583 #error "fts_get_clientptr not defined" 584 #endif 585 586 void * 587 (fts_get_clientptr)(FTS *sp) 588 { 589 590 return (fts_get_clientptr(sp)); 591 } 592 593 #ifndef fts_get_stream 594 #error "fts_get_stream not defined" 595 #endif 596 597 FTS * 598 (fts_get_stream)(FTSENT *p) 599 { 600 return (fts_get_stream(p)); 601 } 602 603 void 604 fts_set_clientptr(FTS *sp, void *clientptr) 605 { 606 607 sp->fts_clientptr = clientptr; 608 } 609 610 /* 611 * This is the tricky part -- do not casually change *anything* in here. The 612 * idea is to build the linked list of entries that are used by fts_children 613 * and fts_read. There are lots of special cases. 614 * 615 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 616 * set and it's a physical walk (so that symbolic links can't be directories), 617 * we can do things quickly. First, if it's a 4.4BSD file system, the type 618 * of the file is in the directory entry. Otherwise, we assume that the number 619 * of subdirectories in a node is equal to the number of links to the parent. 620 * The former skips all stat calls. The latter skips stat calls in any leaf 621 * directories and for any files after the subdirectories in the directory have 622 * been found, cutting the stat calls by about 2/3. 623 */ 624 static FTSENT * 625 fts_build(FTS *sp, int type) 626 { 627 struct dirent *dp; 628 FTSENT *p, *head; 629 FTSENT *cur, *tail; 630 DIR *dirp; 631 void *oldaddr; 632 char *cp; 633 int cderrno, descend, oflag, saved_errno, nostat, doadjust; 634 long level; 635 long nlinks; /* has to be signed because -1 is a magic value */ 636 size_t dnamlen, len, maxlen, nitems; 637 638 /* Set current node pointer. */ 639 cur = sp->fts_cur; 640 641 /* 642 * Open the directory for reading. If this fails, we're done. 643 * If being called from fts_read, set the fts_info field. 644 */ 645 #ifdef FTS_WHITEOUT 646 if (ISSET(FTS_WHITEOUT)) 647 oflag = DTF_NODUP | DTF_REWIND; 648 else 649 oflag = DTF_HIDEW | DTF_NODUP | DTF_REWIND; 650 #else 651 #define __opendir2(path, flag) opendir(path) 652 #endif 653 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) { 654 if (type == BREAD) { 655 cur->fts_info = FTS_DNR; 656 cur->fts_errno = errno; 657 } 658 return (NULL); 659 } 660 661 /* 662 * Nlinks is the number of possible entries of type directory in the 663 * directory if we're cheating on stat calls, 0 if we're not doing 664 * any stat calls at all, -1 if we're doing stats on everything. 665 */ 666 if (type == BNAMES) { 667 nlinks = 0; 668 /* Be quiet about nostat, GCC. */ 669 nostat = 0; 670 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 671 if (fts_ufslinks(sp, cur)) 672 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 673 else 674 nlinks = -1; 675 nostat = 1; 676 } else { 677 nlinks = -1; 678 nostat = 0; 679 } 680 681 #ifdef notdef 682 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 683 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 684 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 685 #endif 686 /* 687 * If we're going to need to stat anything or we want to descend 688 * and stay in the directory, chdir. If this fails we keep going, 689 * but set a flag so we don't chdir after the post-order visit. 690 * We won't be able to stat anything, but we can still return the 691 * names themselves. Note, that since fts_read won't be able to 692 * chdir into the directory, it will have to return different path 693 * names than before, i.e. "a/b" instead of "b". Since the node 694 * has already been visited in pre-order, have to wait until the 695 * post-order visit to return the error. There is a special case 696 * here, if there was nothing to stat then it's not an error to 697 * not be able to stat. This is all fairly nasty. If a program 698 * needed sorted entries or stat information, they had better be 699 * checking FTS_NS on the returned nodes. 700 */ 701 cderrno = 0; 702 if (nlinks || type == BREAD) { 703 if (fts_safe_changedir(sp, cur, _dirfd(dirp), NULL)) { 704 if (nlinks && type == BREAD) 705 cur->fts_errno = errno; 706 cur->fts_flags |= FTS_DONTCHDIR; 707 descend = 0; 708 cderrno = errno; 709 } else 710 descend = 1; 711 } else 712 descend = 0; 713 714 /* 715 * Figure out the max file name length that can be stored in the 716 * current path -- the inner loop allocates more path as necessary. 717 * We really wouldn't have to do the maxlen calculations here, we 718 * could do them in fts_read before returning the path, but it's a 719 * lot easier here since the length is part of the dirent structure. 720 * 721 * If not changing directories set a pointer so that can just append 722 * each new name into the path. 723 */ 724 len = NAPPEND(cur); 725 if (ISSET(FTS_NOCHDIR)) { 726 cp = sp->fts_path + len; 727 *cp++ = '/'; 728 } else { 729 /* GCC, you're too verbose. */ 730 cp = NULL; 731 } 732 len++; 733 maxlen = sp->fts_pathlen - len; 734 735 level = cur->fts_level + 1; 736 737 /* Read the directory, attaching each entry to the `link' pointer. */ 738 doadjust = 0; 739 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) { 740 dnamlen = dp->d_namlen; 741 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 742 continue; 743 744 if ((p = fts_alloc(sp, dp->d_name, dnamlen)) == NULL) 745 goto mem1; 746 if (dnamlen >= maxlen) { /* include space for NUL */ 747 oldaddr = sp->fts_path; 748 if (fts_palloc(sp, dnamlen + len + 1)) { 749 /* 750 * No more memory for path or structures. Save 751 * errno, free up the current structure and the 752 * structures already allocated. 753 */ 754 mem1: saved_errno = errno; 755 if (p) 756 free(p); 757 fts_lfree(head); 758 (void)closedir(dirp); 759 cur->fts_info = FTS_ERR; 760 SET(FTS_STOP); 761 errno = saved_errno; 762 return (NULL); 763 } 764 /* Did realloc() change the pointer? */ 765 if (oldaddr != sp->fts_path) { 766 doadjust = 1; 767 if (ISSET(FTS_NOCHDIR)) 768 cp = sp->fts_path + len; 769 } 770 maxlen = sp->fts_pathlen - len; 771 } 772 773 p->fts_level = level; 774 p->fts_parent = sp->fts_cur; 775 p->fts_pathlen = len + dnamlen; 776 777 #ifdef FTS_WHITEOUT 778 if (dp->d_type == DT_WHT) 779 p->fts_flags |= FTS_ISW; 780 #endif 781 782 if (cderrno) { 783 if (nlinks) { 784 p->fts_info = FTS_NS; 785 p->fts_errno = cderrno; 786 } else 787 p->fts_info = FTS_NSOK; 788 p->fts_accpath = cur->fts_accpath; 789 } else if (nlinks == 0 790 #ifdef DT_DIR 791 || (nostat && 792 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 793 #endif 794 ) { 795 p->fts_accpath = 796 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 797 p->fts_info = FTS_NSOK; 798 } else { 799 /* Build a file name for fts_stat to stat. */ 800 if (ISSET(FTS_NOCHDIR)) { 801 p->fts_accpath = p->fts_path; 802 memmove(cp, p->fts_name, p->fts_namelen + 1); 803 p->fts_info = fts_stat(sp, p, 0, _dirfd(dirp)); 804 } else { 805 p->fts_accpath = p->fts_name; 806 p->fts_info = fts_stat(sp, p, 0, -1); 807 } 808 809 /* Decrement link count if applicable. */ 810 if (nlinks > 0 && (p->fts_info == FTS_D || 811 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 812 --nlinks; 813 } 814 815 /* We walk in directory order so "ls -f" doesn't get upset. */ 816 p->fts_link = NULL; 817 if (head == NULL) 818 head = tail = p; 819 else { 820 tail->fts_link = p; 821 tail = p; 822 } 823 ++nitems; 824 } 825 if (dirp) 826 (void)closedir(dirp); 827 828 /* 829 * If realloc() changed the address of the path, adjust the 830 * addresses for the rest of the tree and the dir list. 831 */ 832 if (doadjust) 833 fts_padjust(sp, head); 834 835 /* 836 * If not changing directories, reset the path back to original 837 * state. 838 */ 839 if (ISSET(FTS_NOCHDIR)) 840 sp->fts_path[cur->fts_pathlen] = '\0'; 841 842 /* 843 * If descended after called from fts_children or after called from 844 * fts_read and nothing found, get back. At the root level we use 845 * the saved fd; if one of fts_open()'s arguments is a relative path 846 * to an empty directory, we wind up here with no other way back. If 847 * can't get back, we're done. 848 */ 849 if (descend && (type == BCHILD || !nitems) && 850 (cur->fts_level == FTS_ROOTLEVEL ? 851 FCHDIR(sp, sp->fts_rfd) : 852 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 853 cur->fts_info = FTS_ERR; 854 SET(FTS_STOP); 855 return (NULL); 856 } 857 858 /* If didn't find anything, return NULL. */ 859 if (!nitems) { 860 if (type == BREAD) 861 cur->fts_info = FTS_DP; 862 return (NULL); 863 } 864 865 /* Sort the entries. */ 866 if (sp->fts_compar && nitems > 1) 867 head = fts_sort(sp, head, nitems); 868 return (head); 869 } 870 871 static int 872 fts_stat(FTS *sp, FTSENT *p, int follow, int dfd) 873 { 874 FTSENT *t; 875 dev_t dev; 876 ino_t ino; 877 struct stat *sbp, sb; 878 int saved_errno; 879 const char *path; 880 881 if (dfd == -1) 882 path = p->fts_accpath, dfd = AT_FDCWD; 883 else 884 path = p->fts_name; 885 886 /* If user needs stat info, stat buffer already allocated. */ 887 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 888 889 #ifdef FTS_WHITEOUT 890 /* Check for whiteout. */ 891 if (p->fts_flags & FTS_ISW) { 892 if (sbp != &sb) { 893 memset(sbp, '\0', sizeof(*sbp)); 894 sbp->st_mode = S_IFWHT; 895 } 896 return (FTS_W); 897 } 898 #endif 899 900 /* 901 * If doing a logical walk, or application requested FTS_FOLLOW, do 902 * a stat(2). If that fails, check for a non-existent symlink. If 903 * fail, set the errno from the stat call. 904 */ 905 if (ISSET(FTS_LOGICAL) || follow) { 906 if (fstatat(dfd, path, sbp, 0)) { 907 saved_errno = errno; 908 if (fstatat(dfd, path, sbp, AT_SYMLINK_NOFOLLOW)) { 909 p->fts_errno = saved_errno; 910 goto err; 911 } 912 errno = 0; 913 if (S_ISLNK(sbp->st_mode)) 914 return (FTS_SLNONE); 915 } 916 } else if (fstatat(dfd, path, sbp, AT_SYMLINK_NOFOLLOW)) { 917 p->fts_errno = errno; 918 err: memset(sbp, 0, sizeof(struct stat)); 919 return (FTS_NS); 920 } 921 922 if (S_ISDIR(sbp->st_mode)) { 923 /* 924 * Set the device/inode. Used to find cycles and check for 925 * crossing mount points. Also remember the link count, used 926 * in fts_build to limit the number of stat calls. It is 927 * understood that these fields are only referenced if fts_info 928 * is set to FTS_D. 929 */ 930 dev = p->fts_dev = sbp->st_dev; 931 ino = p->fts_ino = sbp->st_ino; 932 p->fts_nlink = sbp->st_nlink; 933 934 if (ISDOT(p->fts_name)) 935 return (FTS_DOT); 936 937 /* 938 * Cycle detection is done by brute force when the directory 939 * is first encountered. If the tree gets deep enough or the 940 * number of symbolic links to directories is high enough, 941 * something faster might be worthwhile. 942 */ 943 for (t = p->fts_parent; 944 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 945 if (ino == t->fts_ino && dev == t->fts_dev) { 946 p->fts_cycle = t; 947 return (FTS_DC); 948 } 949 return (FTS_D); 950 } 951 if (S_ISLNK(sbp->st_mode)) 952 return (FTS_SL); 953 if (S_ISREG(sbp->st_mode)) 954 return (FTS_F); 955 return (FTS_DEFAULT); 956 } 957 958 /* 959 * The comparison function takes pointers to pointers to FTSENT structures. 960 * Qsort wants a comparison function that takes pointers to void. 961 * (Both with appropriate levels of const-poisoning, of course!) 962 * Use a trampoline function to deal with the difference. 963 */ 964 static int 965 fts_compar(const void *a, const void *b) 966 { 967 FTS *parent; 968 969 parent = (*(const FTSENT * const *)a)->fts_fts; 970 return (*parent->fts_compar)(a, b); 971 } 972 973 static FTSENT * 974 fts_sort(FTS *sp, FTSENT *head, size_t nitems) 975 { 976 FTSENT **ap, *p; 977 978 /* 979 * Construct an array of pointers to the structures and call qsort(3). 980 * Reassemble the array in the order returned by qsort. If unable to 981 * sort for memory reasons, return the directory entries in their 982 * current order. Allocate enough space for the current needs plus 983 * 40 so don't realloc one entry at a time. 984 */ 985 if (nitems > sp->fts_nitems) { 986 sp->fts_nitems = nitems + 40; 987 if ((sp->fts_array = reallocf(sp->fts_array, 988 sp->fts_nitems * sizeof(FTSENT *))) == NULL) { 989 sp->fts_nitems = 0; 990 return (head); 991 } 992 } 993 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 994 *ap++ = p; 995 qsort(sp->fts_array, nitems, sizeof(FTSENT *), fts_compar); 996 for (head = *(ap = sp->fts_array); --nitems; ++ap) 997 ap[0]->fts_link = ap[1]; 998 ap[0]->fts_link = NULL; 999 return (head); 1000 } 1001 1002 static FTSENT * 1003 fts_alloc(FTS *sp, char *name, size_t namelen) 1004 { 1005 FTSENT *p; 1006 size_t len; 1007 1008 struct ftsent_withstat { 1009 FTSENT ent; 1010 struct stat statbuf; 1011 }; 1012 1013 /* 1014 * The file name is a variable length array and no stat structure is 1015 * necessary if the user has set the nostat bit. Allocate the FTSENT 1016 * structure, the file name and the stat structure in one chunk, but 1017 * be careful that the stat structure is reasonably aligned. 1018 */ 1019 if (ISSET(FTS_NOSTAT)) 1020 len = sizeof(FTSENT) + namelen + 1; 1021 else 1022 len = sizeof(struct ftsent_withstat) + namelen + 1; 1023 1024 if ((p = malloc(len)) == NULL) 1025 return (NULL); 1026 1027 if (ISSET(FTS_NOSTAT)) { 1028 p->fts_name = (char *)(p + 1); 1029 p->fts_statp = NULL; 1030 } else { 1031 p->fts_name = (char *)((struct ftsent_withstat *)p + 1); 1032 p->fts_statp = &((struct ftsent_withstat *)p)->statbuf; 1033 } 1034 1035 /* Copy the name and guarantee NUL termination. */ 1036 memcpy(p->fts_name, name, namelen); 1037 p->fts_name[namelen] = '\0'; 1038 p->fts_namelen = namelen; 1039 p->fts_path = sp->fts_path; 1040 p->fts_errno = 0; 1041 p->fts_flags = 0; 1042 p->fts_instr = FTS_NOINSTR; 1043 p->fts_number = 0; 1044 p->fts_pointer = NULL; 1045 p->fts_fts = sp; 1046 return (p); 1047 } 1048 1049 static void 1050 fts_lfree(FTSENT *head) 1051 { 1052 FTSENT *p; 1053 1054 /* Free a linked list of structures. */ 1055 while ((p = head)) { 1056 head = head->fts_link; 1057 free(p); 1058 } 1059 } 1060 1061 /* 1062 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 1063 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 1064 * though the kernel won't resolve them. Add the size (not just what's needed) 1065 * plus 256 bytes so don't realloc the path 2 bytes at a time. 1066 */ 1067 static int 1068 fts_palloc(FTS *sp, size_t more) 1069 { 1070 1071 sp->fts_pathlen += more + 256; 1072 sp->fts_path = reallocf(sp->fts_path, sp->fts_pathlen); 1073 return (sp->fts_path == NULL); 1074 } 1075 1076 /* 1077 * When the path is realloc'd, have to fix all of the pointers in structures 1078 * already returned. 1079 */ 1080 static void 1081 fts_padjust(FTS *sp, FTSENT *head) 1082 { 1083 FTSENT *p; 1084 char *addr = sp->fts_path; 1085 1086 #define ADJUST(p) do { \ 1087 if ((p)->fts_accpath != (p)->fts_name) { \ 1088 (p)->fts_accpath = \ 1089 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \ 1090 } \ 1091 (p)->fts_path = addr; \ 1092 } while (0) 1093 /* Adjust the current set of children. */ 1094 for (p = sp->fts_child; p; p = p->fts_link) 1095 ADJUST(p); 1096 1097 /* Adjust the rest of the tree, including the current level. */ 1098 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1099 ADJUST(p); 1100 p = p->fts_link ? p->fts_link : p->fts_parent; 1101 } 1102 } 1103 1104 static size_t 1105 fts_maxarglen(argv) 1106 char * const *argv; 1107 { 1108 size_t len, max; 1109 1110 for (max = 0; *argv; ++argv) 1111 if ((len = strlen(*argv)) > max) 1112 max = len; 1113 return (max + 1); 1114 } 1115 1116 /* 1117 * Change to dir specified by fd or p->fts_accpath without getting 1118 * tricked by someone changing the world out from underneath us. 1119 * Assumes p->fts_dev and p->fts_ino are filled in. 1120 */ 1121 static int 1122 fts_safe_changedir(FTS *sp, FTSENT *p, int fd, char *path) 1123 { 1124 int ret, oerrno, newfd; 1125 struct stat sb; 1126 1127 newfd = fd; 1128 if (ISSET(FTS_NOCHDIR)) 1129 return (0); 1130 if (fd < 0 && (newfd = _open(path, O_RDONLY | O_DIRECTORY | 1131 O_CLOEXEC, 0)) < 0) 1132 return (-1); 1133 if (_fstat(newfd, &sb)) { 1134 ret = -1; 1135 goto bail; 1136 } 1137 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) { 1138 errno = ENOENT; /* disinformation */ 1139 ret = -1; 1140 goto bail; 1141 } 1142 ret = fchdir(newfd); 1143 bail: 1144 oerrno = errno; 1145 if (fd < 0) 1146 (void)_close(newfd); 1147 errno = oerrno; 1148 return (ret); 1149 } 1150 1151 /* 1152 * Check if the filesystem for "ent" has UFS-style links. 1153 */ 1154 static int 1155 fts_ufslinks(FTS *sp, const FTSENT *ent) 1156 { 1157 struct _fts_private *priv; 1158 const char **cpp; 1159 1160 priv = (struct _fts_private *)sp; 1161 /* 1162 * If this node's device is different from the previous, grab 1163 * the filesystem information, and decide on the reliability 1164 * of the link information from this filesystem for stat(2) 1165 * avoidance. 1166 */ 1167 if (priv->ftsp_dev != ent->fts_dev) { 1168 if (statfs(ent->fts_path, &priv->ftsp_statfs) != -1) { 1169 priv->ftsp_dev = ent->fts_dev; 1170 priv->ftsp_linksreliable = 0; 1171 for (cpp = ufslike_filesystems; *cpp; cpp++) { 1172 if (strcmp(priv->ftsp_statfs.f_fstypename, 1173 *cpp) == 0) { 1174 priv->ftsp_linksreliable = 1; 1175 break; 1176 } 1177 } 1178 } else { 1179 priv->ftsp_linksreliable = 0; 1180 } 1181 } 1182 return (priv->ftsp_linksreliable); 1183 } 1184