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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * $OpenBSD: fts.c,v 1.22 1999/10/03 19:22:22 millert Exp $ 34 */ 35 36 #if 0 37 #if defined(LIBC_SCCS) && !defined(lint) 38 static char sccsid[] = "@(#)fts.c 8.6 (Berkeley) 8/14/94"; 39 #endif /* LIBC_SCCS and not lint */ 40 #endif 41 42 #include <sys/cdefs.h> 43 __FBSDID("$FreeBSD$"); 44 45 #include "namespace.h" 46 #include <sys/param.h> 47 #include <sys/mount.h> 48 #include <sys/stat.h> 49 50 #include <dirent.h> 51 #include <errno.h> 52 #include <fcntl.h> 53 #include <fts.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #include <unistd.h> 57 #include "un-namespace.h" 58 59 static FTSENT *fts_alloc(FTS *, char *, int); 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 *, int); 67 static u_short fts_stat(FTS *, FTSENT *, 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 "nfs", 108 "nfs4", 109 "ext2fs", 110 0 111 }; 112 113 FTS * 114 fts_open(argv, options, compar) 115 char * const *argv; 116 int options; 117 int (*compar)(const FTSENT * const *, const FTSENT * const *); 118 { 119 struct _fts_private *priv; 120 FTS *sp; 121 FTSENT *p, *root; 122 int nitems; 123 FTSENT *parent, *tmp; 124 int len; 125 126 /* Options check. */ 127 if (options & ~FTS_OPTIONMASK) { 128 errno = EINVAL; 129 return (NULL); 130 } 131 132 /* Allocate/initialize the stream. */ 133 if ((priv = malloc(sizeof(*priv))) == NULL) 134 return (NULL); 135 memset(priv, 0, sizeof(*priv)); 136 sp = &priv->ftsp_fts; 137 sp->fts_compar = compar; 138 sp->fts_options = options; 139 140 /* Shush, GCC. */ 141 tmp = NULL; 142 143 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 144 if (ISSET(FTS_LOGICAL)) 145 SET(FTS_NOCHDIR); 146 147 /* 148 * Start out with 1K of path space, and enough, in any case, 149 * to hold the user's paths. 150 */ 151 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN))) 152 goto mem1; 153 154 /* Allocate/initialize root's parent. */ 155 if ((parent = fts_alloc(sp, "", 0)) == NULL) 156 goto mem2; 157 parent->fts_level = FTS_ROOTPARENTLEVEL; 158 159 /* Allocate/initialize root(s). */ 160 for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) { 161 /* Don't allow zero-length paths. */ 162 if ((len = strlen(*argv)) == 0) { 163 errno = ENOENT; 164 goto mem3; 165 } 166 167 p = fts_alloc(sp, *argv, len); 168 p->fts_level = FTS_ROOTLEVEL; 169 p->fts_parent = parent; 170 p->fts_accpath = p->fts_name; 171 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW)); 172 173 /* Command-line "." and ".." are real directories. */ 174 if (p->fts_info == FTS_DOT) 175 p->fts_info = FTS_D; 176 177 /* 178 * If comparison routine supplied, traverse in sorted 179 * order; otherwise traverse in the order specified. 180 */ 181 if (compar) { 182 p->fts_link = root; 183 root = p; 184 } else { 185 p->fts_link = NULL; 186 if (root == NULL) 187 tmp = root = p; 188 else { 189 tmp->fts_link = p; 190 tmp = p; 191 } 192 } 193 } 194 if (compar && nitems > 1) 195 root = fts_sort(sp, root, nitems); 196 197 /* 198 * Allocate a dummy pointer and make fts_read think that we've just 199 * finished the node before the root(s); set p->fts_info to FTS_INIT 200 * so that everything about the "current" node is ignored. 201 */ 202 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 203 goto mem3; 204 sp->fts_cur->fts_link = root; 205 sp->fts_cur->fts_info = FTS_INIT; 206 207 /* 208 * If using chdir(2), grab a file descriptor pointing to dot to ensure 209 * that we can get back here; this could be avoided for some paths, 210 * but almost certainly not worth the effort. Slashes, symbolic links, 211 * and ".." are all fairly nasty problems. Note, if we can't get the 212 * descriptor we run anyway, just more slowly. 213 */ 214 if (!ISSET(FTS_NOCHDIR) && (sp->fts_rfd = _open(".", O_RDONLY, 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(sp, p) 228 FTS *sp; 229 FTSENT *p; 230 { 231 int len; 232 char *cp; 233 234 /* 235 * Load the stream structure for the next traversal. Since we don't 236 * actually enter the directory until after the preorder visit, set 237 * the fts_accpath field specially so the chdir gets done to the right 238 * place and the user can access the first node. From fts_open it's 239 * known that the path will fit. 240 */ 241 len = p->fts_pathlen = p->fts_namelen; 242 memmove(sp->fts_path, p->fts_name, len + 1); 243 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 244 len = strlen(++cp); 245 memmove(p->fts_name, cp, len + 1); 246 p->fts_namelen = len; 247 } 248 p->fts_accpath = p->fts_path = sp->fts_path; 249 sp->fts_dev = p->fts_dev; 250 } 251 252 int 253 fts_close(sp) 254 FTS *sp; 255 { 256 FTSENT *freep, *p; 257 int saved_errno; 258 259 /* 260 * This still works if we haven't read anything -- the dummy structure 261 * points to the root list, so we step through to the end of the root 262 * list which has a valid parent pointer. 263 */ 264 if (sp->fts_cur) { 265 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 266 freep = p; 267 p = p->fts_link != NULL ? p->fts_link : p->fts_parent; 268 free(freep); 269 } 270 free(p); 271 } 272 273 /* Free up child linked list, sort array, path buffer. */ 274 if (sp->fts_child) 275 fts_lfree(sp->fts_child); 276 if (sp->fts_array) 277 free(sp->fts_array); 278 free(sp->fts_path); 279 280 /* Return to original directory, save errno if necessary. */ 281 if (!ISSET(FTS_NOCHDIR)) { 282 saved_errno = fchdir(sp->fts_rfd) ? errno : 0; 283 (void)_close(sp->fts_rfd); 284 285 /* Set errno and return. */ 286 if (saved_errno != 0) { 287 /* Free up the stream pointer. */ 288 free(sp); 289 errno = saved_errno; 290 return (-1); 291 } 292 } 293 294 /* Free up the stream pointer. */ 295 free(sp); 296 return (0); 297 } 298 299 /* 300 * Special case of "/" at the end of the path so that slashes aren't 301 * appended which would cause paths to be written as "....//foo". 302 */ 303 #define NAPPEND(p) \ 304 (p->fts_path[p->fts_pathlen - 1] == '/' \ 305 ? p->fts_pathlen - 1 : p->fts_pathlen) 306 307 FTSENT * 308 fts_read(sp) 309 FTS *sp; 310 { 311 FTSENT *p, *tmp; 312 int instr; 313 char *t; 314 int saved_errno; 315 316 /* If finished or unrecoverable error, return NULL. */ 317 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 318 return (NULL); 319 320 /* Set current node pointer. */ 321 p = sp->fts_cur; 322 323 /* Save and zero out user instructions. */ 324 instr = p->fts_instr; 325 p->fts_instr = FTS_NOINSTR; 326 327 /* Any type of file may be re-visited; re-stat and re-turn. */ 328 if (instr == FTS_AGAIN) { 329 p->fts_info = fts_stat(sp, p, 0); 330 return (p); 331 } 332 333 /* 334 * Following a symlink -- SLNONE test allows application to see 335 * SLNONE and recover. If indirecting through a symlink, have 336 * keep a pointer to current location. If unable to get that 337 * pointer, follow fails. 338 */ 339 if (instr == FTS_FOLLOW && 340 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 341 p->fts_info = fts_stat(sp, p, 1); 342 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 343 if ((p->fts_symfd = _open(".", O_RDONLY, 0)) < 0) { 344 p->fts_errno = errno; 345 p->fts_info = FTS_ERR; 346 } else 347 p->fts_flags |= FTS_SYMFOLLOW; 348 } 349 return (p); 350 } 351 352 /* Directory in pre-order. */ 353 if (p->fts_info == FTS_D) { 354 /* If skipped or crossed mount point, do post-order visit. */ 355 if (instr == FTS_SKIP || 356 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 357 if (p->fts_flags & FTS_SYMFOLLOW) 358 (void)_close(p->fts_symfd); 359 if (sp->fts_child) { 360 fts_lfree(sp->fts_child); 361 sp->fts_child = NULL; 362 } 363 p->fts_info = FTS_DP; 364 return (p); 365 } 366 367 /* Rebuild if only read the names and now traversing. */ 368 if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) { 369 CLR(FTS_NAMEONLY); 370 fts_lfree(sp->fts_child); 371 sp->fts_child = NULL; 372 } 373 374 /* 375 * Cd to the subdirectory. 376 * 377 * If have already read and now fail to chdir, whack the list 378 * to make the names come out right, and set the parent errno 379 * so the application will eventually get an error condition. 380 * Set the FTS_DONTCHDIR flag so that when we logically change 381 * directories back to the parent we don't do a chdir. 382 * 383 * If haven't read do so. If the read fails, fts_build sets 384 * FTS_STOP or the fts_info field of the node. 385 */ 386 if (sp->fts_child != NULL) { 387 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 388 p->fts_errno = errno; 389 p->fts_flags |= FTS_DONTCHDIR; 390 for (p = sp->fts_child; p != NULL; 391 p = p->fts_link) 392 p->fts_accpath = 393 p->fts_parent->fts_accpath; 394 } 395 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 396 if (ISSET(FTS_STOP)) 397 return (NULL); 398 return (p); 399 } 400 p = sp->fts_child; 401 sp->fts_child = NULL; 402 goto name; 403 } 404 405 /* Move to the next node on this level. */ 406 next: tmp = p; 407 if ((p = p->fts_link) != NULL) { 408 free(tmp); 409 410 /* 411 * If reached the top, return to the original directory (or 412 * the root of the tree), and load the paths for the next root. 413 */ 414 if (p->fts_level == FTS_ROOTLEVEL) { 415 if (FCHDIR(sp, sp->fts_rfd)) { 416 SET(FTS_STOP); 417 return (NULL); 418 } 419 fts_load(sp, p); 420 return (sp->fts_cur = p); 421 } 422 423 /* 424 * User may have called fts_set on the node. If skipped, 425 * ignore. If followed, get a file descriptor so we can 426 * get back if necessary. 427 */ 428 if (p->fts_instr == FTS_SKIP) 429 goto next; 430 if (p->fts_instr == FTS_FOLLOW) { 431 p->fts_info = fts_stat(sp, p, 1); 432 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 433 if ((p->fts_symfd = 434 _open(".", O_RDONLY, 0)) < 0) { 435 p->fts_errno = errno; 436 p->fts_info = FTS_ERR; 437 } else 438 p->fts_flags |= FTS_SYMFOLLOW; 439 } 440 p->fts_instr = FTS_NOINSTR; 441 } 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 free(tmp); 452 453 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 454 /* 455 * Done; free everything up and set errno to 0 so the user 456 * can distinguish between error and EOF. 457 */ 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 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(sp, p, instr) 503 FTS *sp; 504 FTSENT *p; 505 int instr; 506 { 507 if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW && 508 instr != FTS_NOINSTR && instr != FTS_SKIP) { 509 errno = EINVAL; 510 return (1); 511 } 512 p->fts_instr = instr; 513 return (0); 514 } 515 516 FTSENT * 517 fts_children(sp, instr) 518 FTS *sp; 519 int instr; 520 { 521 FTSENT *p; 522 int fd; 523 524 if (instr != 0 && instr != FTS_NAMEONLY) { 525 errno = EINVAL; 526 return (NULL); 527 } 528 529 /* Set current node pointer. */ 530 p = sp->fts_cur; 531 532 /* 533 * Errno set to 0 so user can distinguish empty directory from 534 * an error. 535 */ 536 errno = 0; 537 538 /* Fatal errors stop here. */ 539 if (ISSET(FTS_STOP)) 540 return (NULL); 541 542 /* Return logical hierarchy of user's arguments. */ 543 if (p->fts_info == FTS_INIT) 544 return (p->fts_link); 545 546 /* 547 * If not a directory being visited in pre-order, stop here. Could 548 * allow FTS_DNR, assuming the user has fixed the problem, but the 549 * same effect is available with FTS_AGAIN. 550 */ 551 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 552 return (NULL); 553 554 /* Free up any previous child list. */ 555 if (sp->fts_child != NULL) 556 fts_lfree(sp->fts_child); 557 558 if (instr == FTS_NAMEONLY) { 559 SET(FTS_NAMEONLY); 560 instr = BNAMES; 561 } else 562 instr = BCHILD; 563 564 /* 565 * If using chdir on a relative path and called BEFORE fts_read does 566 * its chdir to the root of a traversal, we can lose -- we need to 567 * chdir into the subdirectory, and we don't know where the current 568 * directory is, so we can't get back so that the upcoming chdir by 569 * fts_read will work. 570 */ 571 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 572 ISSET(FTS_NOCHDIR)) 573 return (sp->fts_child = fts_build(sp, instr)); 574 575 if ((fd = _open(".", O_RDONLY, 0)) < 0) 576 return (NULL); 577 sp->fts_child = fts_build(sp, instr); 578 if (fchdir(fd)) 579 return (NULL); 580 (void)_close(fd); 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(sp, type) 628 FTS *sp; 629 int type; 630 { 631 struct dirent *dp; 632 FTSENT *p, *head; 633 int nitems; 634 FTSENT *cur, *tail; 635 DIR *dirp; 636 void *oldaddr; 637 size_t dnamlen; 638 int cderrno, descend, len, level, maxlen, nlinks, oflag, saved_errno, 639 nostat, doadjust; 640 char *cp; 641 642 /* Set current node pointer. */ 643 cur = sp->fts_cur; 644 645 /* 646 * Open the directory for reading. If this fails, we're done. 647 * If being called from fts_read, set the fts_info field. 648 */ 649 #ifdef FTS_WHITEOUT 650 if (ISSET(FTS_WHITEOUT)) 651 oflag = DTF_NODUP | DTF_REWIND; 652 else 653 oflag = DTF_HIDEW | DTF_NODUP | DTF_REWIND; 654 #else 655 #define __opendir2(path, flag) opendir(path) 656 #endif 657 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) { 658 if (type == BREAD) { 659 cur->fts_info = FTS_DNR; 660 cur->fts_errno = errno; 661 } 662 return (NULL); 663 } 664 665 /* 666 * Nlinks is the number of possible entries of type directory in the 667 * directory if we're cheating on stat calls, 0 if we're not doing 668 * any stat calls at all, -1 if we're doing stats on everything. 669 */ 670 if (type == BNAMES) { 671 nlinks = 0; 672 /* Be quiet about nostat, GCC. */ 673 nostat = 0; 674 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 675 if (fts_ufslinks(sp, cur)) 676 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 677 else 678 nlinks = -1; 679 nostat = 1; 680 } else { 681 nlinks = -1; 682 nostat = 0; 683 } 684 685 #ifdef notdef 686 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 687 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 688 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 689 #endif 690 /* 691 * If we're going to need to stat anything or we want to descend 692 * and stay in the directory, chdir. If this fails we keep going, 693 * but set a flag so we don't chdir after the post-order visit. 694 * We won't be able to stat anything, but we can still return the 695 * names themselves. Note, that since fts_read won't be able to 696 * chdir into the directory, it will have to return different path 697 * names than before, i.e. "a/b" instead of "b". Since the node 698 * has already been visited in pre-order, have to wait until the 699 * post-order visit to return the error. There is a special case 700 * here, if there was nothing to stat then it's not an error to 701 * not be able to stat. This is all fairly nasty. If a program 702 * needed sorted entries or stat information, they had better be 703 * checking FTS_NS on the returned nodes. 704 */ 705 cderrno = 0; 706 if (nlinks || type == BREAD) { 707 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) { 708 if (nlinks && type == BREAD) 709 cur->fts_errno = errno; 710 cur->fts_flags |= FTS_DONTCHDIR; 711 descend = 0; 712 cderrno = errno; 713 (void)closedir(dirp); 714 dirp = NULL; 715 } else 716 descend = 1; 717 } else 718 descend = 0; 719 720 /* 721 * Figure out the max file name length that can be stored in the 722 * current path -- the inner loop allocates more path as necessary. 723 * We really wouldn't have to do the maxlen calculations here, we 724 * could do them in fts_read before returning the path, but it's a 725 * lot easier here since the length is part of the dirent structure. 726 * 727 * If not changing directories set a pointer so that can just append 728 * each new name into the path. 729 */ 730 len = NAPPEND(cur); 731 if (ISSET(FTS_NOCHDIR)) { 732 cp = sp->fts_path + len; 733 *cp++ = '/'; 734 } else { 735 /* GCC, you're too verbose. */ 736 cp = NULL; 737 } 738 len++; 739 maxlen = sp->fts_pathlen - len; 740 741 level = cur->fts_level + 1; 742 743 /* Read the directory, attaching each entry to the `link' pointer. */ 744 doadjust = 0; 745 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) { 746 dnamlen = dp->d_namlen; 747 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 748 continue; 749 750 if ((p = fts_alloc(sp, dp->d_name, (int)dnamlen)) == NULL) 751 goto mem1; 752 if (dnamlen >= maxlen) { /* include space for NUL */ 753 oldaddr = sp->fts_path; 754 if (fts_palloc(sp, dnamlen + len + 1)) { 755 /* 756 * No more memory for path or structures. Save 757 * errno, free up the current structure and the 758 * structures already allocated. 759 */ 760 mem1: saved_errno = errno; 761 if (p) 762 free(p); 763 fts_lfree(head); 764 (void)closedir(dirp); 765 cur->fts_info = FTS_ERR; 766 SET(FTS_STOP); 767 errno = saved_errno; 768 return (NULL); 769 } 770 /* Did realloc() change the pointer? */ 771 if (oldaddr != sp->fts_path) { 772 doadjust = 1; 773 if (ISSET(FTS_NOCHDIR)) 774 cp = sp->fts_path + len; 775 } 776 maxlen = sp->fts_pathlen - len; 777 } 778 779 if (len + dnamlen >= USHRT_MAX) { 780 /* 781 * In an FTSENT, fts_pathlen is a u_short so it is 782 * possible to wraparound here. If we do, free up 783 * the current structure and the structures already 784 * allocated, then error out with ENAMETOOLONG. 785 */ 786 free(p); 787 fts_lfree(head); 788 (void)closedir(dirp); 789 cur->fts_info = FTS_ERR; 790 SET(FTS_STOP); 791 errno = ENAMETOOLONG; 792 return (NULL); 793 } 794 p->fts_level = level; 795 p->fts_parent = sp->fts_cur; 796 p->fts_pathlen = len + dnamlen; 797 798 #ifdef FTS_WHITEOUT 799 if (dp->d_type == DT_WHT) 800 p->fts_flags |= FTS_ISW; 801 #endif 802 803 if (cderrno) { 804 if (nlinks) { 805 p->fts_info = FTS_NS; 806 p->fts_errno = cderrno; 807 } else 808 p->fts_info = FTS_NSOK; 809 p->fts_accpath = cur->fts_accpath; 810 } else if (nlinks == 0 811 #ifdef DT_DIR 812 || (nostat && 813 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 814 #endif 815 ) { 816 p->fts_accpath = 817 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 818 p->fts_info = FTS_NSOK; 819 } else { 820 /* Build a file name for fts_stat to stat. */ 821 if (ISSET(FTS_NOCHDIR)) { 822 p->fts_accpath = p->fts_path; 823 memmove(cp, p->fts_name, p->fts_namelen + 1); 824 } else 825 p->fts_accpath = p->fts_name; 826 /* Stat it. */ 827 p->fts_info = fts_stat(sp, p, 0); 828 829 /* Decrement link count if applicable. */ 830 if (nlinks > 0 && (p->fts_info == FTS_D || 831 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 832 --nlinks; 833 } 834 835 /* We walk in directory order so "ls -f" doesn't get upset. */ 836 p->fts_link = NULL; 837 if (head == NULL) 838 head = tail = p; 839 else { 840 tail->fts_link = p; 841 tail = p; 842 } 843 ++nitems; 844 } 845 if (dirp) 846 (void)closedir(dirp); 847 848 /* 849 * If realloc() changed the address of the path, adjust the 850 * addresses for the rest of the tree and the dir list. 851 */ 852 if (doadjust) 853 fts_padjust(sp, head); 854 855 /* 856 * If not changing directories, reset the path back to original 857 * state. 858 */ 859 if (ISSET(FTS_NOCHDIR)) { 860 if (len == sp->fts_pathlen || nitems == 0) 861 --cp; 862 *cp = '\0'; 863 } 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 cur->fts_info = FTS_ERR; 877 SET(FTS_STOP); 878 return (NULL); 879 } 880 881 /* If didn't find anything, return NULL. */ 882 if (!nitems) { 883 if (type == BREAD) 884 cur->fts_info = FTS_DP; 885 return (NULL); 886 } 887 888 /* Sort the entries. */ 889 if (sp->fts_compar && nitems > 1) 890 head = fts_sort(sp, head, nitems); 891 return (head); 892 } 893 894 static u_short 895 fts_stat(sp, p, follow) 896 FTS *sp; 897 FTSENT *p; 898 int follow; 899 { 900 FTSENT *t; 901 dev_t dev; 902 ino_t ino; 903 struct stat *sbp, sb; 904 int saved_errno; 905 906 /* If user needs stat info, stat buffer already allocated. */ 907 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 908 909 #ifdef FTS_WHITEOUT 910 /* Check for whiteout. */ 911 if (p->fts_flags & FTS_ISW) { 912 if (sbp != &sb) { 913 memset(sbp, '\0', sizeof(*sbp)); 914 sbp->st_mode = S_IFWHT; 915 } 916 return (FTS_W); 917 } 918 #endif 919 920 /* 921 * If doing a logical walk, or application requested FTS_FOLLOW, do 922 * a stat(2). If that fails, check for a non-existent symlink. If 923 * fail, set the errno from the stat call. 924 */ 925 if (ISSET(FTS_LOGICAL) || follow) { 926 if (stat(p->fts_accpath, sbp)) { 927 saved_errno = errno; 928 if (!lstat(p->fts_accpath, sbp)) { 929 errno = 0; 930 return (FTS_SLNONE); 931 } 932 p->fts_errno = saved_errno; 933 goto err; 934 } 935 } else if (lstat(p->fts_accpath, sbp)) { 936 p->fts_errno = errno; 937 err: memset(sbp, 0, sizeof(struct stat)); 938 return (FTS_NS); 939 } 940 941 if (S_ISDIR(sbp->st_mode)) { 942 /* 943 * Set the device/inode. Used to find cycles and check for 944 * crossing mount points. Also remember the link count, used 945 * in fts_build to limit the number of stat calls. It is 946 * understood that these fields are only referenced if fts_info 947 * is set to FTS_D. 948 */ 949 dev = p->fts_dev = sbp->st_dev; 950 ino = p->fts_ino = sbp->st_ino; 951 p->fts_nlink = sbp->st_nlink; 952 953 if (ISDOT(p->fts_name)) 954 return (FTS_DOT); 955 956 /* 957 * Cycle detection is done by brute force when the directory 958 * is first encountered. If the tree gets deep enough or the 959 * number of symbolic links to directories is high enough, 960 * something faster might be worthwhile. 961 */ 962 for (t = p->fts_parent; 963 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 964 if (ino == t->fts_ino && dev == t->fts_dev) { 965 p->fts_cycle = t; 966 return (FTS_DC); 967 } 968 return (FTS_D); 969 } 970 if (S_ISLNK(sbp->st_mode)) 971 return (FTS_SL); 972 if (S_ISREG(sbp->st_mode)) 973 return (FTS_F); 974 return (FTS_DEFAULT); 975 } 976 977 /* 978 * The comparison function takes pointers to pointers to FTSENT structures. 979 * Qsort wants a comparison function that takes pointers to void. 980 * (Both with appropriate levels of const-poisoning, of course!) 981 * Use a trampoline function to deal with the difference. 982 */ 983 static int 984 fts_compar(const void *a, const void *b) 985 { 986 FTS *parent; 987 988 parent = (*(const FTSENT * const *)a)->fts_fts; 989 return (*parent->fts_compar)(a, b); 990 } 991 992 static FTSENT * 993 fts_sort(sp, head, nitems) 994 FTS *sp; 995 FTSENT *head; 996 int nitems; 997 { 998 FTSENT **ap, *p; 999 1000 /* 1001 * Construct an array of pointers to the structures and call qsort(3). 1002 * Reassemble the array in the order returned by qsort. If unable to 1003 * sort for memory reasons, return the directory entries in their 1004 * current order. Allocate enough space for the current needs plus 1005 * 40 so don't realloc one entry at a time. 1006 */ 1007 if (nitems > sp->fts_nitems) { 1008 sp->fts_nitems = nitems + 40; 1009 if ((sp->fts_array = reallocf(sp->fts_array, 1010 sp->fts_nitems * sizeof(FTSENT *))) == NULL) { 1011 sp->fts_nitems = 0; 1012 return (head); 1013 } 1014 } 1015 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 1016 *ap++ = p; 1017 qsort(sp->fts_array, nitems, sizeof(FTSENT *), fts_compar); 1018 for (head = *(ap = sp->fts_array); --nitems; ++ap) 1019 ap[0]->fts_link = ap[1]; 1020 ap[0]->fts_link = NULL; 1021 return (head); 1022 } 1023 1024 static FTSENT * 1025 fts_alloc(sp, name, namelen) 1026 FTS *sp; 1027 char *name; 1028 int 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(head) 1076 FTSENT *head; 1077 { 1078 FTSENT *p; 1079 1080 /* Free a linked list of structures. */ 1081 while ((p = head)) { 1082 head = head->fts_link; 1083 free(p); 1084 } 1085 } 1086 1087 /* 1088 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 1089 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 1090 * though the kernel won't resolve them. Add the size (not just what's needed) 1091 * plus 256 bytes so don't realloc the path 2 bytes at a time. 1092 */ 1093 static int 1094 fts_palloc(sp, more) 1095 FTS *sp; 1096 size_t more; 1097 { 1098 1099 sp->fts_pathlen += more + 256; 1100 /* 1101 * Check for possible wraparound. In an FTS, fts_pathlen is 1102 * a signed int but in an FTSENT it is an unsigned short. 1103 * We limit fts_pathlen to USHRT_MAX to be safe in both cases. 1104 */ 1105 if (sp->fts_pathlen < 0 || sp->fts_pathlen >= USHRT_MAX) { 1106 if (sp->fts_path) 1107 free(sp->fts_path); 1108 sp->fts_path = NULL; 1109 errno = ENAMETOOLONG; 1110 return (1); 1111 } 1112 sp->fts_path = reallocf(sp->fts_path, sp->fts_pathlen); 1113 return (sp->fts_path == NULL); 1114 } 1115 1116 /* 1117 * When the path is realloc'd, have to fix all of the pointers in structures 1118 * already returned. 1119 */ 1120 static void 1121 fts_padjust(sp, head) 1122 FTS *sp; 1123 FTSENT *head; 1124 { 1125 FTSENT *p; 1126 char *addr = sp->fts_path; 1127 1128 #define ADJUST(p) do { \ 1129 if ((p)->fts_accpath != (p)->fts_name) { \ 1130 (p)->fts_accpath = \ 1131 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \ 1132 } \ 1133 (p)->fts_path = addr; \ 1134 } while (0) 1135 /* Adjust the current set of children. */ 1136 for (p = sp->fts_child; p; p = p->fts_link) 1137 ADJUST(p); 1138 1139 /* Adjust the rest of the tree, including the current level. */ 1140 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1141 ADJUST(p); 1142 p = p->fts_link ? p->fts_link : p->fts_parent; 1143 } 1144 } 1145 1146 static size_t 1147 fts_maxarglen(argv) 1148 char * const *argv; 1149 { 1150 size_t len, max; 1151 1152 for (max = 0; *argv; ++argv) 1153 if ((len = strlen(*argv)) > max) 1154 max = len; 1155 return (max + 1); 1156 } 1157 1158 /* 1159 * Change to dir specified by fd or p->fts_accpath without getting 1160 * tricked by someone changing the world out from underneath us. 1161 * Assumes p->fts_dev and p->fts_ino are filled in. 1162 */ 1163 static int 1164 fts_safe_changedir(sp, p, fd, path) 1165 FTS *sp; 1166 FTSENT *p; 1167 int fd; 1168 char *path; 1169 { 1170 int ret, oerrno, newfd; 1171 struct stat sb; 1172 1173 newfd = fd; 1174 if (ISSET(FTS_NOCHDIR)) 1175 return (0); 1176 if (fd < 0 && (newfd = _open(path, O_RDONLY, 0)) < 0) 1177 return (-1); 1178 if (_fstat(newfd, &sb)) { 1179 ret = -1; 1180 goto bail; 1181 } 1182 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) { 1183 errno = ENOENT; /* disinformation */ 1184 ret = -1; 1185 goto bail; 1186 } 1187 ret = fchdir(newfd); 1188 bail: 1189 oerrno = errno; 1190 if (fd < 0) 1191 (void)_close(newfd); 1192 errno = oerrno; 1193 return (ret); 1194 } 1195 1196 /* 1197 * Check if the filesystem for "ent" has UFS-style links. 1198 */ 1199 static int 1200 fts_ufslinks(FTS *sp, const FTSENT *ent) 1201 { 1202 struct _fts_private *priv; 1203 const char **cpp; 1204 1205 priv = (struct _fts_private *)sp; 1206 /* 1207 * If this node's device is different from the previous, grab 1208 * the filesystem information, and decide on the reliability 1209 * of the link information from this filesystem for stat(2) 1210 * avoidance. 1211 */ 1212 if (priv->ftsp_dev != ent->fts_dev) { 1213 if (statfs(ent->fts_path, &priv->ftsp_statfs) != -1) { 1214 priv->ftsp_dev = ent->fts_dev; 1215 priv->ftsp_linksreliable = 0; 1216 for (cpp = ufslike_filesystems; *cpp; cpp++) { 1217 if (strcmp(priv->ftsp_statfs.f_fstypename, 1218 *cpp) == 0) { 1219 priv->ftsp_linksreliable = 1; 1220 break; 1221 } 1222 } 1223 } else { 1224 priv->ftsp_linksreliable = 0; 1225 } 1226 } 1227 return (priv->ftsp_linksreliable); 1228 } 1229