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 * @(#)fts.c 8.6 (Berkeley) 8/14/94 30 * $OpenBSD: fts.c,v 1.22 1999/10/03 19:22:22 millert Exp $ 31 * $FreeBSD: src/lib/libc/gen/fts.c,v 1.30 2009/03/04 03:30:21 das Exp $ 32 * $DragonFly: src/lib/libc/gen/fts.c,v 1.7 2005/11/13 00:07:42 swildner Exp $ 33 */ 34 35 #include "namespace.h" 36 #include <sys/param.h> 37 #include <sys/mount.h> 38 #include <sys/stat.h> 39 40 #include <dirent.h> 41 #include <errno.h> 42 #include <fcntl.h> 43 #include <fts.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <unistd.h> 47 #include "un-namespace.h" 48 49 static FTSENT *fts_alloc(FTS *, const char *, size_t); 50 static FTSENT *fts_build(FTS *, int); 51 static void fts_lfree(FTSENT *); 52 static void fts_load(FTS *, FTSENT *); 53 static size_t fts_maxarglen(char * const *); 54 static void fts_padjust(FTS *, FTSENT *); 55 static int fts_palloc(FTS *, size_t); 56 static FTSENT *fts_sort(FTS *, FTSENT *, size_t); 57 static int fts_stat(FTS *, FTSENT *, int); 58 static int fts_safe_changedir(FTS *, FTSENT *, int, const char *); 59 static int fts_ufslinks(FTS *, const FTSENT *); 60 61 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2]))) 62 63 #define CLR(opt) (sp->fts_options &= ~(opt)) 64 #define ISSET(opt) (sp->fts_options & (opt)) 65 #define SET(opt) (sp->fts_options |= (opt)) 66 67 #define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 68 69 /* fts_build flags */ 70 #define BCHILD 1 /* fts_children */ 71 #define BNAMES 2 /* fts_children, names only */ 72 #define BREAD 3 /* fts_read */ 73 74 /* 75 * Internal representation of an FTS, including extra implementation 76 * details. The FTS returned from fts_open points to this structure's 77 * ftsp_fts member (and can be cast to an _fts_private as required) 78 */ 79 struct _fts_private { 80 FTS ftsp_fts; 81 struct statfs ftsp_statfs; 82 dev_t ftsp_dev; 83 int ftsp_linksreliable; 84 }; 85 86 /* 87 * The "FTS_NOSTAT" option can avoid a lot of calls to stat(2) if it 88 * knows that a directory could not possibly have subdirectories. This 89 * is decided by looking at the link count: a subdirectory would 90 * increment its parent's link count by virtue of its own ".." entry. 91 * This assumption only holds for UFS-like filesystems that implement 92 * links and directories this way, so we must punt for others. 93 */ 94 95 static const char *ufslike_filesystems[] = { 96 "ufs", 97 "nfs", 98 "nfs4", 99 "ext2fs", 100 0 101 }; 102 103 FTS * 104 fts_open(char * const *argv, int options, 105 int (*compar)(const FTSENT * const *, const FTSENT * const *)) 106 { 107 struct _fts_private *priv; 108 FTS *sp; 109 FTSENT *p, *root; 110 FTSENT *parent, *tmp; 111 size_t len, nitems; 112 113 /* Options check. */ 114 if (options & ~FTS_OPTIONMASK) { 115 errno = EINVAL; 116 return (NULL); 117 } 118 119 /* Allocate/initialize the stream. */ 120 if ((priv = malloc(sizeof(*priv))) == NULL) 121 return (NULL); 122 memset(priv, 0, sizeof(*priv)); 123 sp = &priv->ftsp_fts; 124 sp->fts_compar = compar; 125 sp->fts_options = options; 126 127 /* Shush, GCC. */ 128 tmp = NULL; 129 130 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 131 if (ISSET(FTS_LOGICAL)) 132 SET(FTS_NOCHDIR); 133 134 /* 135 * Start out with 1K of path space, and enough, in any case, 136 * to hold the user's paths. 137 */ 138 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN))) 139 goto mem1; 140 141 /* Allocate/initialize root's parent. */ 142 if ((parent = fts_alloc(sp, "", 0)) == NULL) 143 goto mem2; 144 parent->fts_level = FTS_ROOTPARENTLEVEL; 145 146 /* Allocate/initialize root(s). */ 147 for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) { 148 /* Don't allow zero-length paths. */ 149 if ((len = strlen(*argv)) == 0) { 150 errno = ENOENT; 151 goto mem3; 152 } 153 154 p = fts_alloc(sp, *argv, len); 155 p->fts_level = FTS_ROOTLEVEL; 156 p->fts_parent = parent; 157 p->fts_accpath = p->fts_name; 158 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW)); 159 160 /* Command-line "." and ".." are real directories. */ 161 if (p->fts_info == FTS_DOT) 162 p->fts_info = FTS_D; 163 164 /* 165 * If comparison routine supplied, traverse in sorted 166 * order; otherwise traverse in the order specified. 167 */ 168 if (compar) { 169 p->fts_link = root; 170 root = p; 171 } else { 172 p->fts_link = NULL; 173 if (root == NULL) 174 tmp = root = p; 175 else { 176 tmp->fts_link = p; 177 tmp = p; 178 } 179 } 180 } 181 if (compar && nitems > 1) 182 root = fts_sort(sp, root, nitems); 183 184 /* 185 * Allocate a dummy pointer and make fts_read think that we've just 186 * finished the node before the root(s); set p->fts_info to FTS_INIT 187 * so that everything about the "current" node is ignored. 188 */ 189 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 190 goto mem3; 191 sp->fts_cur->fts_link = root; 192 sp->fts_cur->fts_info = FTS_INIT; 193 194 /* 195 * If using chdir(2), grab a file descriptor pointing to dot to ensure 196 * that we can get back here; this could be avoided for some paths, 197 * but almost certainly not worth the effort. Slashes, symbolic links, 198 * and ".." are all fairly nasty problems. Note, if we can't get the 199 * descriptor we run anyway, just more slowly. 200 */ 201 if (!ISSET(FTS_NOCHDIR) && (sp->fts_rfd = _open(".", O_RDONLY, 0)) < 0) 202 SET(FTS_NOCHDIR); 203 204 return (sp); 205 206 mem3: fts_lfree(root); 207 free(parent); 208 mem2: free(sp->fts_path); 209 mem1: free(sp); 210 return (NULL); 211 } 212 213 static void 214 fts_load(FTS *sp, FTSENT *p) 215 { 216 size_t len; 217 char *cp; 218 219 /* 220 * Load the stream structure for the next traversal. Since we don't 221 * actually enter the directory until after the preorder visit, set 222 * the fts_accpath field specially so the chdir gets done to the right 223 * place and the user can access the first node. From fts_open it's 224 * known that the path will fit. 225 */ 226 len = p->fts_pathlen = p->fts_namelen; 227 memmove(sp->fts_path, p->fts_name, len + 1); 228 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 229 len = strlen(++cp); 230 memmove(p->fts_name, cp, len + 1); 231 p->fts_namelen = len; 232 } 233 p->fts_accpath = p->fts_path = sp->fts_path; 234 sp->fts_dev = p->fts_dev; 235 } 236 237 int 238 fts_close(FTS *sp) 239 { 240 FTSENT *freep, *p; 241 int saved_errno; 242 243 /* 244 * This still works if we haven't read anything -- the dummy structure 245 * points to the root list, so we step through to the end of the root 246 * list which has a valid parent pointer. 247 */ 248 if (sp->fts_cur) { 249 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 250 freep = p; 251 p = p->fts_link != NULL ? p->fts_link : p->fts_parent; 252 free(freep); 253 } 254 free(p); 255 } 256 257 /* Free up child linked list, sort array, path buffer. */ 258 if (sp->fts_child) 259 fts_lfree(sp->fts_child); 260 if (sp->fts_array) 261 free(sp->fts_array); 262 free(sp->fts_path); 263 264 /* Return to original directory, save errno if necessary. */ 265 if (!ISSET(FTS_NOCHDIR)) { 266 saved_errno = fchdir(sp->fts_rfd) ? errno : 0; 267 _close(sp->fts_rfd); 268 269 /* Set errno and return. */ 270 if (saved_errno != 0) { 271 /* Free up the stream pointer. */ 272 free(sp); 273 errno = saved_errno; 274 return (-1); 275 } 276 } 277 278 /* Free up the stream pointer. */ 279 free(sp); 280 return (0); 281 } 282 283 /* 284 * Special case of "/" at the end of the path so that slashes aren't 285 * appended which would cause paths to be written as "....//foo". 286 */ 287 #define NAPPEND(p) \ 288 (p->fts_path[p->fts_pathlen - 1] == '/' \ 289 ? p->fts_pathlen - 1 : p->fts_pathlen) 290 291 FTSENT * 292 fts_read(FTS *sp) 293 { 294 FTSENT *p, *tmp; 295 int instr; 296 char *t; 297 int saved_errno; 298 299 /* If finished or unrecoverable error, return NULL. */ 300 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 301 return (NULL); 302 303 /* Set current node pointer. */ 304 p = sp->fts_cur; 305 306 /* Save and zero out user instructions. */ 307 instr = p->fts_instr; 308 p->fts_instr = FTS_NOINSTR; 309 310 /* Any type of file may be re-visited; re-stat and re-turn. */ 311 if (instr == FTS_AGAIN) { 312 p->fts_info = fts_stat(sp, p, 0); 313 return (p); 314 } 315 316 /* 317 * Following a symlink -- SLNONE test allows application to see 318 * SLNONE and recover. If indirecting through a symlink, have 319 * keep a pointer to current location. If unable to get that 320 * pointer, follow fails. 321 */ 322 if (instr == FTS_FOLLOW && 323 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 324 p->fts_info = fts_stat(sp, p, 1); 325 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 326 if ((p->fts_symfd = _open(".", O_RDONLY, 0)) < 0) { 327 p->fts_errno = errno; 328 p->fts_info = FTS_ERR; 329 } else 330 p->fts_flags |= FTS_SYMFOLLOW; 331 } 332 return (p); 333 } 334 335 /* Directory in pre-order. */ 336 if (p->fts_info == FTS_D) { 337 /* If skipped or crossed mount point, do post-order visit. */ 338 if (instr == FTS_SKIP || 339 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 340 if (p->fts_flags & FTS_SYMFOLLOW) 341 _close(p->fts_symfd); 342 if (sp->fts_child) { 343 fts_lfree(sp->fts_child); 344 sp->fts_child = NULL; 345 } 346 p->fts_info = FTS_DP; 347 return (p); 348 } 349 350 /* Rebuild if only read the names and now traversing. */ 351 if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) { 352 CLR(FTS_NAMEONLY); 353 fts_lfree(sp->fts_child); 354 sp->fts_child = NULL; 355 } 356 357 /* 358 * Cd to the subdirectory. 359 * 360 * If have already read and now fail to chdir, whack the list 361 * to make the names come out right, and set the parent errno 362 * so the application will eventually get an error condition. 363 * Set the FTS_DONTCHDIR flag so that when we logically change 364 * directories back to the parent we don't do a chdir. 365 * 366 * If haven't read do so. If the read fails, fts_build sets 367 * FTS_STOP or the fts_info field of the node. 368 */ 369 if (sp->fts_child != NULL) { 370 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 371 p->fts_errno = errno; 372 p->fts_flags |= FTS_DONTCHDIR; 373 for (p = sp->fts_child; p != NULL; 374 p = p->fts_link) 375 p->fts_accpath = 376 p->fts_parent->fts_accpath; 377 } 378 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 379 if (ISSET(FTS_STOP)) 380 return (NULL); 381 return (p); 382 } 383 p = sp->fts_child; 384 sp->fts_child = NULL; 385 goto name; 386 } 387 388 /* Move to the next node on this level. */ 389 next: tmp = p; 390 if ((p = p->fts_link) != NULL) { 391 free(tmp); 392 393 /* 394 * If reached the top, return to the original directory (or 395 * the root of the tree), and load the paths for the next root. 396 */ 397 if (p->fts_level == FTS_ROOTLEVEL) { 398 if (FCHDIR(sp, sp->fts_rfd)) { 399 SET(FTS_STOP); 400 return (NULL); 401 } 402 fts_load(sp, p); 403 return (sp->fts_cur = p); 404 } 405 406 /* 407 * User may have called fts_set on the node. If skipped, 408 * ignore. If followed, get a file descriptor so we can 409 * get back if necessary. 410 */ 411 if (p->fts_instr == FTS_SKIP) 412 goto next; 413 if (p->fts_instr == FTS_FOLLOW) { 414 p->fts_info = fts_stat(sp, p, 1); 415 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 416 if ((p->fts_symfd = 417 _open(".", O_RDONLY, 0)) < 0) { 418 p->fts_errno = errno; 419 p->fts_info = FTS_ERR; 420 } else 421 p->fts_flags |= FTS_SYMFOLLOW; 422 } 423 p->fts_instr = FTS_NOINSTR; 424 } 425 426 name: t = sp->fts_path + NAPPEND(p->fts_parent); 427 *t++ = '/'; 428 memmove(t, p->fts_name, p->fts_namelen + 1); 429 return (sp->fts_cur = p); 430 } 431 432 /* Move up to the parent node. */ 433 p = tmp->fts_parent; 434 free(tmp); 435 436 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 437 /* 438 * Done; free everything up and set errno to 0 so the user 439 * can distinguish between error and EOF. 440 */ 441 free(p); 442 errno = 0; 443 return (sp->fts_cur = NULL); 444 } 445 446 /* NUL terminate the pathname. */ 447 sp->fts_path[p->fts_pathlen] = '\0'; 448 449 /* 450 * Return to the parent directory. If at a root node or came through 451 * a symlink, go back through the file descriptor. Otherwise, cd up 452 * one directory. 453 */ 454 if (p->fts_level == FTS_ROOTLEVEL) { 455 if (FCHDIR(sp, sp->fts_rfd)) { 456 SET(FTS_STOP); 457 return (NULL); 458 } 459 } else if (p->fts_flags & FTS_SYMFOLLOW) { 460 if (FCHDIR(sp, p->fts_symfd)) { 461 saved_errno = errno; 462 _close(p->fts_symfd); 463 errno = saved_errno; 464 SET(FTS_STOP); 465 return (NULL); 466 } 467 _close(p->fts_symfd); 468 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 469 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 470 SET(FTS_STOP); 471 return (NULL); 472 } 473 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 474 return (sp->fts_cur = p); 475 } 476 477 /* 478 * Fts_set takes the stream as an argument although it's not used in this 479 * implementation; it would be necessary if anyone wanted to add global 480 * semantics to fts using fts_set. An error return is allowed for similar 481 * reasons. 482 */ 483 /* ARGSUSED */ 484 int 485 fts_set(FTS *sp __unused, FTSENT *p, int instr) 486 { 487 if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW && 488 instr != FTS_NOINSTR && instr != FTS_SKIP) { 489 errno = EINVAL; 490 return (1); 491 } 492 p->fts_instr = instr; 493 return (0); 494 } 495 496 FTSENT * 497 fts_children(FTS *sp, int instr) 498 { 499 FTSENT *p; 500 int fd; 501 502 if (instr != 0 && instr != FTS_NAMEONLY) { 503 errno = EINVAL; 504 return (NULL); 505 } 506 507 /* Set current node pointer. */ 508 p = sp->fts_cur; 509 510 /* 511 * Errno set to 0 so user can distinguish empty directory from 512 * an error. 513 */ 514 errno = 0; 515 516 /* Fatal errors stop here. */ 517 if (ISSET(FTS_STOP)) 518 return (NULL); 519 520 /* Return logical hierarchy of user's arguments. */ 521 if (p->fts_info == FTS_INIT) 522 return (p->fts_link); 523 524 /* 525 * If not a directory being visited in pre-order, stop here. Could 526 * allow FTS_DNR, assuming the user has fixed the problem, but the 527 * same effect is available with FTS_AGAIN. 528 */ 529 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 530 return (NULL); 531 532 /* Free up any previous child list. */ 533 if (sp->fts_child != NULL) 534 fts_lfree(sp->fts_child); 535 536 if (instr == FTS_NAMEONLY) { 537 SET(FTS_NAMEONLY); 538 instr = BNAMES; 539 } else 540 instr = BCHILD; 541 542 /* 543 * If using chdir on a relative path and called BEFORE fts_read does 544 * its chdir to the root of a traversal, we can lose -- we need to 545 * chdir into the subdirectory, and we don't know where the current 546 * directory is, so we can't get back so that the upcoming chdir by 547 * fts_read will work. 548 */ 549 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 550 ISSET(FTS_NOCHDIR)) 551 return (sp->fts_child = fts_build(sp, instr)); 552 553 if ((fd = _open(".", O_RDONLY, 0)) < 0) 554 return (NULL); 555 sp->fts_child = fts_build(sp, instr); 556 if (fchdir(fd)) { 557 _close(fd); 558 return (NULL); 559 } 560 _close(fd); 561 return (sp->fts_child); 562 } 563 564 #ifndef fts_get_clientptr 565 #error "fts_get_clientptr not defined" 566 #endif 567 568 void * 569 (fts_get_clientptr)(FTS *sp) 570 { 571 572 return (fts_get_clientptr(sp)); 573 } 574 575 #ifndef fts_get_stream 576 #error "fts_get_stream not defined" 577 #endif 578 579 FTS * 580 (fts_get_stream)(FTSENT *p) 581 { 582 return (fts_get_stream(p)); 583 } 584 585 void 586 fts_set_clientptr(FTS *sp, void *clientptr) 587 { 588 589 sp->fts_clientptr = clientptr; 590 } 591 592 /* 593 * This is the tricky part -- do not casually change *anything* in here. The 594 * idea is to build the linked list of entries that are used by fts_children 595 * and fts_read. There are lots of special cases. 596 * 597 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 598 * set and it's a physical walk (so that symbolic links can't be directories), 599 * we can do things quickly. First, if it's a 4.4BSD file system, the type 600 * of the file is in the directory entry. Otherwise, we assume that the number 601 * of subdirectories in a node is equal to the number of links to the parent. 602 * The former skips all stat calls. The latter skips stat calls in any leaf 603 * directories and for any files after the subdirectories in the directory have 604 * been found, cutting the stat calls by about 2/3. 605 */ 606 static FTSENT * 607 fts_build(FTS *sp, int type) 608 { 609 struct dirent *dp; 610 FTSENT *p, *head; 611 FTSENT *cur, *tail; 612 DIR *dirp; 613 void *oldaddr; 614 char *cp; 615 int cderrno, descend, oflag, saved_errno, nostat, doadjust; 616 long level; 617 long nlinks; /* has to be signed because -1 is a magic value */ 618 size_t dnamlen, len, maxlen, nitems; 619 620 /* Set current node pointer. */ 621 cur = sp->fts_cur; 622 623 /* 624 * Open the directory for reading. If this fails, we're done. 625 * If being called from fts_read, set the fts_info field. 626 */ 627 #ifdef FTS_WHITEOUT 628 if (ISSET(FTS_WHITEOUT)) 629 oflag = DTF_NODUP | DTF_REWIND; 630 else 631 oflag = DTF_HIDEW | DTF_NODUP | DTF_REWIND; 632 #else 633 #define __opendir2(path, flag) opendir(path) 634 #endif 635 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) { 636 if (type == BREAD) { 637 cur->fts_info = FTS_DNR; 638 cur->fts_errno = errno; 639 } 640 return (NULL); 641 } 642 643 /* 644 * Nlinks is the number of possible entries of type directory in the 645 * directory if we're cheating on stat calls, 0 if we're not doing 646 * any stat calls at all, -1 if we're doing stats on everything. 647 */ 648 if (type == BNAMES) { 649 nlinks = 0; 650 /* Be quiet about nostat, GCC. */ 651 nostat = 0; 652 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 653 if (fts_ufslinks(sp, cur)) 654 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 655 else 656 nlinks = -1; 657 nostat = 1; 658 } else { 659 nlinks = -1; 660 nostat = 0; 661 } 662 663 #ifdef notdef 664 printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 665 printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 666 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 667 #endif 668 /* 669 * If we're going to need to stat anything or we want to descend 670 * and stay in the directory, chdir. If this fails we keep going, 671 * but set a flag so we don't chdir after the post-order visit. 672 * We won't be able to stat anything, but we can still return the 673 * names themselves. Note, that since fts_read won't be able to 674 * chdir into the directory, it will have to return different path 675 * names than before, i.e. "a/b" instead of "b". Since the node 676 * has already been visited in pre-order, have to wait until the 677 * post-order visit to return the error. There is a special case 678 * here, if there was nothing to stat then it's not an error to 679 * not be able to stat. This is all fairly nasty. If a program 680 * needed sorted entries or stat information, they had better be 681 * checking FTS_NS on the returned nodes. 682 */ 683 cderrno = 0; 684 if (nlinks || type == BREAD) { 685 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) { 686 if (nlinks && type == BREAD) 687 cur->fts_errno = errno; 688 cur->fts_flags |= FTS_DONTCHDIR; 689 descend = 0; 690 cderrno = errno; 691 } else 692 descend = 1; 693 } else 694 descend = 0; 695 696 /* 697 * Figure out the max file name length that can be stored in the 698 * current path -- the inner loop allocates more path as necessary. 699 * We really wouldn't have to do the maxlen calculations here, we 700 * could do them in fts_read before returning the path, but it's a 701 * lot easier here since the length is part of the dirent structure. 702 * 703 * If not changing directories set a pointer so that can just append 704 * each new name into the path. 705 */ 706 len = NAPPEND(cur); 707 if (ISSET(FTS_NOCHDIR)) { 708 cp = sp->fts_path + len; 709 *cp++ = '/'; 710 } else { 711 /* GCC, you're too verbose. */ 712 cp = NULL; 713 } 714 len++; 715 maxlen = sp->fts_pathlen - len; 716 717 level = cur->fts_level + 1; 718 719 /* Read the directory, attaching each entry to the `link' pointer. */ 720 doadjust = 0; 721 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) { 722 dnamlen = dp->d_namlen; 723 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 724 continue; 725 726 if ((p = fts_alloc(sp, dp->d_name, dnamlen)) == NULL) 727 goto mem1; 728 if (dnamlen >= maxlen) { /* include space for NUL */ 729 oldaddr = sp->fts_path; 730 if (fts_palloc(sp, dnamlen + len + 1)) { 731 /* 732 * No more memory for path or structures. Save 733 * errno, free up the current structure and the 734 * structures already allocated. 735 */ 736 mem1: saved_errno = errno; 737 if (p) 738 free(p); 739 fts_lfree(head); 740 closedir(dirp); 741 cur->fts_info = FTS_ERR; 742 SET(FTS_STOP); 743 errno = saved_errno; 744 return (NULL); 745 } 746 /* Did realloc() change the pointer? */ 747 if (oldaddr != sp->fts_path) { 748 doadjust = 1; 749 if (ISSET(FTS_NOCHDIR)) 750 cp = sp->fts_path + len; 751 } 752 maxlen = sp->fts_pathlen - len; 753 } 754 755 p->fts_level = level; 756 p->fts_parent = sp->fts_cur; 757 p->fts_pathlen = len + dnamlen; 758 759 #ifdef FTS_WHITEOUT 760 if (dp->d_type == DT_WHT) 761 p->fts_flags |= FTS_ISW; 762 #endif 763 764 if (cderrno) { 765 if (nlinks) { 766 p->fts_info = FTS_NS; 767 p->fts_errno = cderrno; 768 } else 769 p->fts_info = FTS_NSOK; 770 p->fts_accpath = cur->fts_accpath; 771 } else if (nlinks == 0 772 #ifdef DT_DIR 773 || (nostat && 774 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 775 #endif 776 ) { 777 p->fts_accpath = 778 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 779 p->fts_info = FTS_NSOK; 780 } else { 781 /* Build a file name for fts_stat to stat. */ 782 if (ISSET(FTS_NOCHDIR)) { 783 p->fts_accpath = p->fts_path; 784 memmove(cp, p->fts_name, p->fts_namelen + 1); 785 } else 786 p->fts_accpath = p->fts_name; 787 /* Stat it. */ 788 p->fts_info = fts_stat(sp, p, 0); 789 790 /* Decrement link count if applicable. */ 791 if (nlinks > 0 && (p->fts_info == FTS_D || 792 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 793 --nlinks; 794 } 795 796 /* We walk in directory order so "ls -f" doesn't get upset. */ 797 p->fts_link = NULL; 798 if (head == NULL) 799 head = tail = p; 800 else { 801 tail->fts_link = p; 802 tail = p; 803 } 804 ++nitems; 805 } 806 if (dirp) 807 closedir(dirp); 808 809 /* 810 * If realloc() changed the address of the path, adjust the 811 * addresses for the rest of the tree and the dir list. 812 */ 813 if (doadjust) 814 fts_padjust(sp, head); 815 816 /* 817 * If not changing directories, reset the path back to original 818 * state. 819 */ 820 if (ISSET(FTS_NOCHDIR)) { 821 if (len == sp->fts_pathlen || nitems == 0) 822 --cp; 823 *cp = '\0'; 824 } 825 826 /* 827 * If descended after called from fts_children or after called from 828 * fts_read and nothing found, get back. At the root level we use 829 * the saved fd; if one of fts_open()'s arguments is a relative path 830 * to an empty directory, we wind up here with no other way back. If 831 * can't get back, we're done. 832 */ 833 if (descend && (type == BCHILD || !nitems) && 834 (cur->fts_level == FTS_ROOTLEVEL ? 835 FCHDIR(sp, sp->fts_rfd) : 836 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 837 cur->fts_info = FTS_ERR; 838 SET(FTS_STOP); 839 return (NULL); 840 } 841 842 /* If didn't find anything, return NULL. */ 843 if (!nitems) { 844 if (type == BREAD) 845 cur->fts_info = FTS_DP; 846 return (NULL); 847 } 848 849 /* Sort the entries. */ 850 if (sp->fts_compar && nitems > 1) 851 head = fts_sort(sp, head, nitems); 852 return (head); 853 } 854 855 static int 856 fts_stat(FTS *sp, FTSENT *p, int follow) 857 { 858 FTSENT *t; 859 dev_t dev; 860 ino_t ino; 861 struct stat *sbp, sb; 862 int saved_errno; 863 864 /* If user needs stat info, stat buffer already allocated. */ 865 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 866 867 #ifdef FTS_WHITEOUT 868 /* Check for whiteout. */ 869 if (p->fts_flags & FTS_ISW) { 870 if (sbp != &sb) { 871 memset(sbp, '\0', sizeof(*sbp)); 872 sbp->st_mode = S_IFWHT; 873 } 874 return (FTS_W); 875 } 876 #endif 877 878 /* 879 * If doing a logical walk, or application requested FTS_FOLLOW, do 880 * a stat(2). If that fails, check for a non-existent symlink. If 881 * fail, set the errno from the stat call. 882 */ 883 if (ISSET(FTS_LOGICAL) || follow) { 884 if (stat(p->fts_accpath, sbp)) { 885 saved_errno = errno; 886 if (!lstat(p->fts_accpath, sbp)) { 887 errno = 0; 888 return (FTS_SLNONE); 889 } 890 p->fts_errno = saved_errno; 891 goto err; 892 } 893 } else if (lstat(p->fts_accpath, sbp)) { 894 p->fts_errno = errno; 895 err: memset(sbp, 0, sizeof(struct stat)); 896 return (FTS_NS); 897 } 898 899 if (S_ISDIR(sbp->st_mode)) { 900 /* 901 * Set the device/inode. Used to find cycles and check for 902 * crossing mount points. Also remember the link count, used 903 * in fts_build to limit the number of stat calls. It is 904 * understood that these fields are only referenced if fts_info 905 * is set to FTS_D. 906 */ 907 dev = p->fts_dev = sbp->st_dev; 908 ino = p->fts_ino = sbp->st_ino; 909 p->fts_nlink = sbp->st_nlink; 910 911 if (ISDOT(p->fts_name)) 912 return (FTS_DOT); 913 914 /* 915 * Cycle detection is done by brute force when the directory 916 * is first encountered. If the tree gets deep enough or the 917 * number of symbolic links to directories is high enough, 918 * something faster might be worthwhile. 919 */ 920 for (t = p->fts_parent; 921 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 922 if (ino == t->fts_ino && dev == t->fts_dev) { 923 p->fts_cycle = t; 924 return (FTS_DC); 925 } 926 return (FTS_D); 927 } 928 if (S_ISLNK(sbp->st_mode)) 929 return (FTS_SL); 930 if (S_ISREG(sbp->st_mode)) 931 return (FTS_F); 932 return (FTS_DEFAULT); 933 } 934 935 /* 936 * The comparison function takes pointers to pointers to FTSENT structures. 937 * Qsort wants a comparison function that takes pointers to void. 938 * (Both with appropriate levels of const-poisoning, of course!) 939 * Use a trampoline function to deal with the difference. 940 */ 941 static int 942 fts_compar(const void *a, const void *b) 943 { 944 FTS *parent; 945 946 parent = (*(const FTSENT * const *)a)->fts_fts; 947 return (*parent->fts_compar)(a, b); 948 } 949 950 static FTSENT * 951 fts_sort(FTS *sp, FTSENT *head, size_t nitems) 952 { 953 FTSENT **ap, *p; 954 955 /* 956 * Construct an array of pointers to the structures and call qsort(3). 957 * Reassemble the array in the order returned by qsort. If unable to 958 * sort for memory reasons, return the directory entries in their 959 * current order. Allocate enough space for the current needs plus 960 * 40 so don't realloc one entry at a time. 961 */ 962 if (nitems > sp->fts_nitems) { 963 sp->fts_nitems = nitems + 40; 964 if ((sp->fts_array = reallocf(sp->fts_array, 965 sp->fts_nitems * sizeof(FTSENT *))) == NULL) { 966 sp->fts_nitems = 0; 967 return (head); 968 } 969 } 970 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 971 *ap++ = p; 972 qsort(sp->fts_array, nitems, sizeof(FTSENT *), fts_compar); 973 for (head = *(ap = sp->fts_array); --nitems; ++ap) 974 ap[0]->fts_link = ap[1]; 975 ap[0]->fts_link = NULL; 976 return (head); 977 } 978 979 static FTSENT * 980 fts_alloc(FTS *sp, const char *name, size_t namelen) 981 { 982 FTSENT *p; 983 size_t len; 984 985 struct ftsent_withstat { 986 FTSENT ent; 987 struct stat statbuf; 988 }; 989 990 /* 991 * The file name is a variable length array and no stat structure is 992 * necessary if the user has set the nostat bit. Allocate the FTSENT 993 * structure, the file name and the stat structure in one chunk, but 994 * be careful that the stat structure is reasonably aligned. 995 */ 996 if (ISSET(FTS_NOSTAT)) 997 len = sizeof(FTSENT) + namelen + 1; 998 else 999 len = sizeof(struct ftsent_withstat) + namelen + 1; 1000 1001 if ((p = malloc(len)) == NULL) 1002 return (NULL); 1003 1004 if (ISSET(FTS_NOSTAT)) { 1005 p->fts_name = (char *)(p + 1); 1006 p->fts_statp = NULL; 1007 } else { 1008 p->fts_name = (char *)((struct ftsent_withstat *)p + 1); 1009 p->fts_statp = &((struct ftsent_withstat *)p)->statbuf; 1010 } 1011 1012 /* Copy the name and guarantee NUL termination. */ 1013 memcpy(p->fts_name, name, namelen); 1014 p->fts_name[namelen] = '\0'; 1015 p->fts_namelen = namelen; 1016 p->fts_path = sp->fts_path; 1017 p->fts_errno = 0; 1018 p->fts_flags = 0; 1019 p->fts_instr = FTS_NOINSTR; 1020 p->fts_number = 0; 1021 p->fts_pointer = NULL; 1022 p->fts_fts = sp; 1023 return (p); 1024 } 1025 1026 static void 1027 fts_lfree(FTSENT *head) 1028 { 1029 FTSENT *p; 1030 1031 /* Free a linked list of structures. */ 1032 while ((p = head)) { 1033 head = head->fts_link; 1034 free(p); 1035 } 1036 } 1037 1038 /* 1039 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 1040 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 1041 * though the kernel won't resolve them. Add the size (not just what's needed) 1042 * plus 256 bytes so don't realloc the path 2 bytes at a time. 1043 */ 1044 static int 1045 fts_palloc(FTS *sp, size_t more) 1046 { 1047 1048 sp->fts_pathlen += more + 256; 1049 sp->fts_path = reallocf(sp->fts_path, sp->fts_pathlen); 1050 return (sp->fts_path == NULL); 1051 } 1052 1053 /* 1054 * When the path is realloc'd, have to fix all of the pointers in structures 1055 * already returned. 1056 */ 1057 static void 1058 fts_padjust(FTS *sp, FTSENT *head) 1059 { 1060 FTSENT *p; 1061 char *addr = sp->fts_path; 1062 1063 #define ADJUST(p) do { \ 1064 if ((p)->fts_accpath != (p)->fts_name) { \ 1065 (p)->fts_accpath = \ 1066 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \ 1067 } \ 1068 (p)->fts_path = addr; \ 1069 } while (0) 1070 /* Adjust the current set of children. */ 1071 for (p = sp->fts_child; p; p = p->fts_link) 1072 ADJUST(p); 1073 1074 /* Adjust the rest of the tree, including the current level. */ 1075 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1076 ADJUST(p); 1077 p = p->fts_link ? p->fts_link : p->fts_parent; 1078 } 1079 } 1080 1081 static size_t 1082 fts_maxarglen(char * const *argv) 1083 { 1084 size_t len, max; 1085 1086 for (max = 0; *argv; ++argv) 1087 if ((len = strlen(*argv)) > max) 1088 max = len; 1089 return (max + 1); 1090 } 1091 1092 /* 1093 * Change to dir specified by fd or p->fts_accpath without getting 1094 * tricked by someone changing the world out from underneath us. 1095 * Assumes p->fts_dev and p->fts_ino are filled in. 1096 */ 1097 static int 1098 fts_safe_changedir(FTS *sp, FTSENT *p, int fd, const char *path) 1099 { 1100 int ret, oerrno, newfd; 1101 struct stat sb; 1102 1103 newfd = fd; 1104 if (ISSET(FTS_NOCHDIR)) 1105 return (0); 1106 if (fd < 0 && (newfd = _open(path, O_RDONLY, 0)) < 0) 1107 return (-1); 1108 if (_fstat(newfd, &sb)) { 1109 ret = -1; 1110 goto bail; 1111 } 1112 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) { 1113 errno = ENOENT; /* disinformation */ 1114 ret = -1; 1115 goto bail; 1116 } 1117 ret = fchdir(newfd); 1118 bail: 1119 oerrno = errno; 1120 if (fd < 0) 1121 _close(newfd); 1122 errno = oerrno; 1123 return (ret); 1124 } 1125 1126 /* 1127 * Check if the filesystem for "ent" has UFS-style links. 1128 */ 1129 static int 1130 fts_ufslinks(FTS *sp, const FTSENT *ent) 1131 { 1132 struct _fts_private *priv; 1133 const char **cpp; 1134 1135 priv = (struct _fts_private *)sp; 1136 /* 1137 * If this node's device is different from the previous, grab 1138 * the filesystem information, and decide on the reliability 1139 * of the link information from this filesystem for stat(2) 1140 * avoidance. 1141 */ 1142 if (priv->ftsp_dev != ent->fts_dev) { 1143 if (statfs(ent->fts_path, &priv->ftsp_statfs) != -1) { 1144 priv->ftsp_dev = ent->fts_dev; 1145 priv->ftsp_linksreliable = 0; 1146 for (cpp = ufslike_filesystems; *cpp; cpp++) { 1147 if (strcmp(priv->ftsp_statfs.f_fstypename, 1148 *cpp) == 0) { 1149 priv->ftsp_linksreliable = 1; 1150 break; 1151 } 1152 } 1153 } else { 1154 priv->ftsp_linksreliable = 0; 1155 } 1156 } 1157 return (priv->ftsp_linksreliable); 1158 } 1159