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 * $FreeBSD: src/lib/libc/gen/fts.c,v 1.14.2.4 2001/06/01 22:00:34 kris Exp $ 36 * $DragonFly: src/lib/libc/gen/fts.c,v 1.7 2005/11/13 00:07:42 swildner Exp $ 37 * 38 * @(#)fts.c 8.6 (Berkeley) 8/14/94 39 * $FreeBSD: src/lib/libc/gen/fts.c,v 1.14.2.4 2001/06/01 22:00:34 kris Exp $ 40 */ 41 42 #include "namespace.h" 43 #include <sys/param.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 static FTSENT *fts_alloc(FTS *, const char *, int); 56 static FTSENT *fts_build(FTS *, int); 57 static void fts_lfree(FTSENT *); 58 static void fts_load(FTS *, FTSENT *); 59 static size_t fts_maxarglen(char * const *); 60 static void fts_padjust(FTS *, FTSENT *); 61 static int fts_palloc(FTS *, size_t); 62 static FTSENT *fts_sort(FTS *, FTSENT *, int); 63 static u_short fts_stat(FTS *, FTSENT *, int); 64 static int fts_safe_changedir(FTS *, FTSENT *, int, const char *); 65 66 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2]))) 67 68 #define CLR(opt) (sp->fts_options &= ~(opt)) 69 #define ISSET(opt) (sp->fts_options & (opt)) 70 #define SET(opt) (sp->fts_options |= (opt)) 71 72 #define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 73 74 /* fts_build flags */ 75 #define BCHILD 1 /* fts_children */ 76 #define BNAMES 2 /* fts_children, names only */ 77 #define BREAD 3 /* fts_read */ 78 79 FTS * 80 fts_open(char * const *argv, int options, 81 int (*compar)(const FTSENT **, const FTSENT **)) 82 { 83 FTS *sp; 84 FTSENT *p, *root; 85 FTSENT *parent, *tmp; 86 size_t len, nitems; 87 88 /* Options check. */ 89 if (options & ~FTS_OPTIONMASK) { 90 errno = EINVAL; 91 return (NULL); 92 } 93 94 /* Allocate/initialize the stream */ 95 if ((sp = malloc((u_int)sizeof(FTS))) == NULL) 96 return (NULL); 97 memset(sp, 0, sizeof(FTS)); 98 sp->fts_compar = compar; 99 sp->fts_options = options; 100 101 /* Shush, GCC. */ 102 tmp = NULL; 103 104 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 105 if (ISSET(FTS_LOGICAL)) 106 SET(FTS_NOCHDIR); 107 108 /* 109 * Start out with 1K of path space, and enough, in any case, 110 * to hold the user's paths. 111 */ 112 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN))) 113 goto mem1; 114 115 /* Allocate/initialize root's parent. */ 116 if ((parent = fts_alloc(sp, "", 0)) == NULL) 117 goto mem2; 118 parent->fts_level = FTS_ROOTPARENTLEVEL; 119 120 /* Allocate/initialize root(s). */ 121 for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) { 122 /* Don't allow zero-length paths. */ 123 if ((len = strlen(*argv)) == 0) { 124 errno = ENOENT; 125 goto mem3; 126 } 127 128 p = fts_alloc(sp, *argv, len); 129 p->fts_level = FTS_ROOTLEVEL; 130 p->fts_parent = parent; 131 p->fts_accpath = p->fts_name; 132 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW)); 133 134 /* Command-line "." and ".." are real directories. */ 135 if (p->fts_info == FTS_DOT) 136 p->fts_info = FTS_D; 137 138 /* 139 * If comparison routine supplied, traverse in sorted 140 * order; otherwise traverse in the order specified. 141 */ 142 if (compar) { 143 p->fts_link = root; 144 root = p; 145 } else { 146 p->fts_link = NULL; 147 if (root == NULL) 148 tmp = root = p; 149 else { 150 tmp->fts_link = p; 151 tmp = p; 152 } 153 } 154 } 155 if (compar && nitems > 1) 156 root = fts_sort(sp, root, nitems); 157 158 /* 159 * Allocate a dummy pointer and make fts_read think that we've just 160 * finished the node before the root(s); set p->fts_info to FTS_INIT 161 * so that everything about the "current" node is ignored. 162 */ 163 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 164 goto mem3; 165 sp->fts_cur->fts_link = root; 166 sp->fts_cur->fts_info = FTS_INIT; 167 168 /* 169 * If using chdir(2), grab a file descriptor pointing to dot to ensure 170 * that we can get back here; this could be avoided for some paths, 171 * but almost certainly not worth the effort. Slashes, symbolic links, 172 * and ".." are all fairly nasty problems. Note, if we can't get the 173 * descriptor we run anyway, just more slowly. 174 */ 175 if (!ISSET(FTS_NOCHDIR) && (sp->fts_rfd = _open(".", O_RDONLY, 0)) < 0) 176 SET(FTS_NOCHDIR); 177 178 return (sp); 179 180 mem3: fts_lfree(root); 181 free(parent); 182 mem2: free(sp->fts_path); 183 mem1: free(sp); 184 return (NULL); 185 } 186 187 static void 188 fts_load(FTS *sp, FTSENT *p) 189 { 190 size_t len; 191 char *cp; 192 193 /* 194 * Load the stream structure for the next traversal. Since we don't 195 * actually enter the directory until after the preorder visit, set 196 * the fts_accpath field specially so the chdir gets done to the right 197 * place and the user can access the first node. From fts_open it's 198 * known that the path will fit. 199 */ 200 len = p->fts_pathlen = p->fts_namelen; 201 memmove(sp->fts_path, p->fts_name, len + 1); 202 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 203 len = strlen(++cp); 204 memmove(p->fts_name, cp, len + 1); 205 p->fts_namelen = len; 206 } 207 p->fts_accpath = p->fts_path = sp->fts_path; 208 sp->fts_dev = p->fts_dev; 209 } 210 211 int 212 fts_close(FTS *sp) 213 { 214 FTSENT *freep, *p; 215 int saved_errno; 216 217 /* 218 * This still works if we haven't read anything -- the dummy structure 219 * points to the root list, so we step through to the end of the root 220 * list which has a valid parent pointer. 221 */ 222 if (sp->fts_cur) { 223 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 224 freep = p; 225 p = p->fts_link != NULL ? p->fts_link : p->fts_parent; 226 free(freep); 227 } 228 free(p); 229 } 230 231 /* Free up child linked list, sort array, path buffer. */ 232 if (sp->fts_child) 233 fts_lfree(sp->fts_child); 234 if (sp->fts_array) 235 free(sp->fts_array); 236 free(sp->fts_path); 237 238 /* Return to original directory, save errno if necessary. */ 239 if (!ISSET(FTS_NOCHDIR)) { 240 saved_errno = fchdir(sp->fts_rfd) ? errno : 0; 241 _close(sp->fts_rfd); 242 243 /* Set errno and return. */ 244 if (saved_errno != 0) { 245 /* Free up the stream pointer. */ 246 free(sp); 247 errno = saved_errno; 248 return (-1); 249 } 250 } 251 252 /* Free up the stream pointer. */ 253 free(sp); 254 return (0); 255 } 256 257 /* 258 * Special case of "/" at the end of the path so that slashes aren't 259 * appended which would cause paths to be written as "....//foo". 260 */ 261 #define NAPPEND(p) \ 262 (p->fts_path[p->fts_pathlen - 1] == '/' \ 263 ? p->fts_pathlen - 1 : p->fts_pathlen) 264 265 FTSENT * 266 fts_read(FTS *sp) 267 { 268 FTSENT *p, *tmp; 269 int instr; 270 char *t; 271 int saved_errno; 272 273 /* If finished or unrecoverable error, return NULL. */ 274 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 275 return (NULL); 276 277 /* Set current node pointer. */ 278 p = sp->fts_cur; 279 280 /* Save and zero out user instructions. */ 281 instr = p->fts_instr; 282 p->fts_instr = FTS_NOINSTR; 283 284 /* Any type of file may be re-visited; re-stat and re-turn. */ 285 if (instr == FTS_AGAIN) { 286 p->fts_info = fts_stat(sp, p, 0); 287 return (p); 288 } 289 290 /* 291 * Following a symlink -- SLNONE test allows application to see 292 * SLNONE and recover. If indirecting through a symlink, have 293 * keep a pointer to current location. If unable to get that 294 * pointer, follow fails. 295 */ 296 if (instr == FTS_FOLLOW && 297 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 298 p->fts_info = fts_stat(sp, p, 1); 299 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 300 if ((p->fts_symfd = _open(".", O_RDONLY, 0)) < 0) { 301 p->fts_errno = errno; 302 p->fts_info = FTS_ERR; 303 } else 304 p->fts_flags |= FTS_SYMFOLLOW; 305 } 306 return (p); 307 } 308 309 /* Directory in pre-order. */ 310 if (p->fts_info == FTS_D) { 311 /* If skipped or crossed mount point, do post-order visit. */ 312 if (instr == FTS_SKIP || 313 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 314 if (p->fts_flags & FTS_SYMFOLLOW) 315 _close(p->fts_symfd); 316 if (sp->fts_child) { 317 fts_lfree(sp->fts_child); 318 sp->fts_child = NULL; 319 } 320 p->fts_info = FTS_DP; 321 return (p); 322 } 323 324 /* Rebuild if only read the names and now traversing. */ 325 if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) { 326 CLR(FTS_NAMEONLY); 327 fts_lfree(sp->fts_child); 328 sp->fts_child = NULL; 329 } 330 331 /* 332 * Cd to the subdirectory. 333 * 334 * If have already read and now fail to chdir, whack the list 335 * to make the names come out right, and set the parent errno 336 * so the application will eventually get an error condition. 337 * Set the FTS_DONTCHDIR flag so that when we logically change 338 * directories back to the parent we don't do a chdir. 339 * 340 * If haven't read do so. If the read fails, fts_build sets 341 * FTS_STOP or the fts_info field of the node. 342 */ 343 if (sp->fts_child != NULL) { 344 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 345 p->fts_errno = errno; 346 p->fts_flags |= FTS_DONTCHDIR; 347 for (p = sp->fts_child; p != NULL; 348 p = p->fts_link) 349 p->fts_accpath = 350 p->fts_parent->fts_accpath; 351 } 352 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 353 if (ISSET(FTS_STOP)) 354 return (NULL); 355 return (p); 356 } 357 p = sp->fts_child; 358 sp->fts_child = NULL; 359 goto name; 360 } 361 362 /* Move to the next node on this level. */ 363 next: tmp = p; 364 if ((p = p->fts_link) != NULL) { 365 free(tmp); 366 367 /* 368 * If reached the top, return to the original directory (or 369 * the root of the tree), and load the paths for the next root. 370 */ 371 if (p->fts_level == FTS_ROOTLEVEL) { 372 if (FCHDIR(sp, sp->fts_rfd)) { 373 SET(FTS_STOP); 374 return (NULL); 375 } 376 fts_load(sp, p); 377 return (sp->fts_cur = p); 378 } 379 380 /* 381 * User may have called fts_set on the node. If skipped, 382 * ignore. If followed, get a file descriptor so we can 383 * get back if necessary. 384 */ 385 if (p->fts_instr == FTS_SKIP) 386 goto next; 387 if (p->fts_instr == FTS_FOLLOW) { 388 p->fts_info = fts_stat(sp, p, 1); 389 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 390 if ((p->fts_symfd = 391 _open(".", O_RDONLY, 0)) < 0) { 392 p->fts_errno = errno; 393 p->fts_info = FTS_ERR; 394 } else 395 p->fts_flags |= FTS_SYMFOLLOW; 396 } 397 p->fts_instr = FTS_NOINSTR; 398 } 399 400 name: t = sp->fts_path + NAPPEND(p->fts_parent); 401 *t++ = '/'; 402 memmove(t, p->fts_name, p->fts_namelen + 1); 403 return (sp->fts_cur = p); 404 } 405 406 /* Move up to the parent node. */ 407 p = tmp->fts_parent; 408 free(tmp); 409 410 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 411 /* 412 * Done; free everything up and set errno to 0 so the user 413 * can distinguish between error and EOF. 414 */ 415 free(p); 416 errno = 0; 417 return (sp->fts_cur = NULL); 418 } 419 420 /* NUL terminate the pathname. */ 421 sp->fts_path[p->fts_pathlen] = '\0'; 422 423 /* 424 * Return to the parent directory. If at a root node or came through 425 * a symlink, go back through the file descriptor. Otherwise, cd up 426 * one directory. 427 */ 428 if (p->fts_level == FTS_ROOTLEVEL) { 429 if (FCHDIR(sp, sp->fts_rfd)) { 430 SET(FTS_STOP); 431 return (NULL); 432 } 433 } else if (p->fts_flags & FTS_SYMFOLLOW) { 434 if (FCHDIR(sp, p->fts_symfd)) { 435 saved_errno = errno; 436 _close(p->fts_symfd); 437 errno = saved_errno; 438 SET(FTS_STOP); 439 return (NULL); 440 } 441 _close(p->fts_symfd); 442 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 443 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 444 SET(FTS_STOP); 445 return (NULL); 446 } 447 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 448 return (sp->fts_cur = p); 449 } 450 451 /* 452 * Fts_set takes the stream as an argument although it's not used in this 453 * implementation; it would be necessary if anyone wanted to add global 454 * semantics to fts using fts_set. An error return is allowed for similar 455 * reasons. 456 */ 457 /* ARGSUSED */ 458 int 459 fts_set(FTS *sp __unused, FTSENT *p, int instr) 460 { 461 if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW && 462 instr != FTS_NOINSTR && instr != FTS_SKIP) { 463 errno = EINVAL; 464 return (1); 465 } 466 p->fts_instr = instr; 467 return (0); 468 } 469 470 FTSENT * 471 fts_children(FTS *sp, int instr) 472 { 473 FTSENT *p; 474 int fd; 475 476 if (instr != 0 && instr != FTS_NAMEONLY) { 477 errno = EINVAL; 478 return (NULL); 479 } 480 481 /* Set current node pointer. */ 482 p = sp->fts_cur; 483 484 /* 485 * Errno set to 0 so user can distinguish empty directory from 486 * an error. 487 */ 488 errno = 0; 489 490 /* Fatal errors stop here. */ 491 if (ISSET(FTS_STOP)) 492 return (NULL); 493 494 /* Return logical hierarchy of user's arguments. */ 495 if (p->fts_info == FTS_INIT) 496 return (p->fts_link); 497 498 /* 499 * If not a directory being visited in pre-order, stop here. Could 500 * allow FTS_DNR, assuming the user has fixed the problem, but the 501 * same effect is available with FTS_AGAIN. 502 */ 503 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 504 return (NULL); 505 506 /* Free up any previous child list. */ 507 if (sp->fts_child != NULL) 508 fts_lfree(sp->fts_child); 509 510 if (instr == FTS_NAMEONLY) { 511 SET(FTS_NAMEONLY); 512 instr = BNAMES; 513 } else 514 instr = BCHILD; 515 516 /* 517 * If using chdir on a relative path and called BEFORE fts_read does 518 * its chdir to the root of a traversal, we can lose -- we need to 519 * chdir into the subdirectory, and we don't know where the current 520 * directory is, so we can't get back so that the upcoming chdir by 521 * fts_read will work. 522 */ 523 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 524 ISSET(FTS_NOCHDIR)) 525 return (sp->fts_child = fts_build(sp, instr)); 526 527 if ((fd = _open(".", O_RDONLY, 0)) < 0) 528 return (NULL); 529 sp->fts_child = fts_build(sp, instr); 530 if (fchdir(fd)) 531 return (NULL); 532 _close(fd); 533 return (sp->fts_child); 534 } 535 536 /* 537 * This is the tricky part -- do not casually change *anything* in here. The 538 * idea is to build the linked list of entries that are used by fts_children 539 * and fts_read. There are lots of special cases. 540 * 541 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 542 * set and it's a physical walk (so that symbolic links can't be directories), 543 * we can do things quickly. First, if it's a 4.4BSD file system, the type 544 * of the file is in the directory entry. Otherwise, we assume that the number 545 * of subdirectories in a node is equal to the number of links to the parent. 546 * The former skips all stat calls. The latter skips stat calls in any leaf 547 * directories and for any files after the subdirectories in the directory have 548 * been found, cutting the stat calls by about 2/3. 549 */ 550 static FTSENT * 551 fts_build(FTS *sp, int type) 552 { 553 struct dirent *dp; 554 FTSENT *p, *head; 555 int nitems; 556 FTSENT *cur, *tail; 557 DIR *dirp; 558 void *oldaddr; 559 int cderrno, descend, len, level, maxlen, nlinks, oflag, saved_errno, 560 nostat, doadjust; 561 char *cp; 562 563 /* Set current node pointer. */ 564 cur = sp->fts_cur; 565 566 /* 567 * Open the directory for reading. If this fails, we're done. 568 * If being called from fts_read, set the fts_info field. 569 */ 570 #ifdef FTS_WHITEOUT 571 if (ISSET(FTS_WHITEOUT)) 572 oflag = DTF_NODUP|DTF_REWIND; 573 else 574 oflag = DTF_HIDEW|DTF_NODUP|DTF_REWIND; 575 #else 576 #define __opendir2(path, flag) opendir(path) 577 #endif 578 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) { 579 if (type == BREAD) { 580 cur->fts_info = FTS_DNR; 581 cur->fts_errno = errno; 582 } 583 return (NULL); 584 } 585 586 /* 587 * Nlinks is the number of possible entries of type directory in the 588 * directory if we're cheating on stat calls, 0 if we're not doing 589 * any stat calls at all, -1 if we're doing stats on everything. 590 */ 591 if (type == BNAMES) { 592 nlinks = 0; 593 /* Be quiet about nostat, GCC. */ 594 nostat = 0; 595 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 596 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 597 nostat = 1; 598 } else { 599 nlinks = -1; 600 nostat = 0; 601 } 602 603 #ifdef notdef 604 printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 605 printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 606 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 607 #endif 608 /* 609 * If we're going to need to stat anything or we want to descend 610 * and stay in the directory, chdir. If this fails we keep going, 611 * but set a flag so we don't chdir after the post-order visit. 612 * We won't be able to stat anything, but we can still return the 613 * names themselves. Note, that since fts_read won't be able to 614 * chdir into the directory, it will have to return different path 615 * names than before, i.e. "a/b" instead of "b". Since the node 616 * has already been visited in pre-order, have to wait until the 617 * post-order visit to return the error. There is a special case 618 * here, if there was nothing to stat then it's not an error to 619 * not be able to stat. This is all fairly nasty. If a program 620 * needed sorted entries or stat information, they had better be 621 * checking FTS_NS on the returned nodes. 622 */ 623 cderrno = 0; 624 if (nlinks || type == BREAD) { 625 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) { 626 if (nlinks && type == BREAD) 627 cur->fts_errno = errno; 628 cur->fts_flags |= FTS_DONTCHDIR; 629 descend = 0; 630 cderrno = errno; 631 closedir(dirp); 632 dirp = NULL; 633 } else 634 descend = 1; 635 } else 636 descend = 0; 637 638 /* 639 * Figure out the max file name length that can be stored in the 640 * current path -- the inner loop allocates more path as necessary. 641 * We really wouldn't have to do the maxlen calculations here, we 642 * could do them in fts_read before returning the path, but it's a 643 * lot easier here since the length is part of the dirent structure. 644 * 645 * If not changing directories set a pointer so that can just append 646 * each new name into the path. 647 */ 648 len = NAPPEND(cur); 649 if (ISSET(FTS_NOCHDIR)) { 650 cp = sp->fts_path + len; 651 *cp++ = '/'; 652 } else { 653 /* GCC, you're too verbose. */ 654 cp = NULL; 655 } 656 len++; 657 maxlen = sp->fts_pathlen - len; 658 659 level = cur->fts_level + 1; 660 661 /* Read the directory, attaching each entry to the `link' pointer. */ 662 doadjust = 0; 663 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) { 664 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 665 continue; 666 667 if ((p = fts_alloc(sp, dp->d_name, (int)dp->d_namlen)) == NULL) 668 goto mem1; 669 if (dp->d_namlen >= maxlen) { /* include space for NUL */ 670 oldaddr = sp->fts_path; 671 if (fts_palloc(sp, dp->d_namlen + len + 1)) { 672 /* 673 * No more memory for path or structures. Save 674 * errno, free up the current structure and the 675 * structures already allocated. 676 */ 677 mem1: saved_errno = errno; 678 if (p) 679 free(p); 680 fts_lfree(head); 681 closedir(dirp); 682 cur->fts_info = FTS_ERR; 683 SET(FTS_STOP); 684 errno = saved_errno; 685 return (NULL); 686 } 687 /* Did realloc() change the pointer? */ 688 if (oldaddr != sp->fts_path) { 689 doadjust = 1; 690 if (ISSET(FTS_NOCHDIR)) 691 cp = sp->fts_path + len; 692 } 693 maxlen = sp->fts_pathlen - len; 694 } 695 696 if (len + dp->d_namlen >= USHRT_MAX) { 697 /* 698 * In an FTSENT, fts_pathlen is a u_short so it is 699 * possible to wraparound here. If we do, free up 700 * the current structure and the structures already 701 * allocated, then error out with ENAMETOOLONG. 702 */ 703 free(p); 704 fts_lfree(head); 705 closedir(dirp); 706 cur->fts_info = FTS_ERR; 707 SET(FTS_STOP); 708 errno = ENAMETOOLONG; 709 return (NULL); 710 } 711 p->fts_level = level; 712 p->fts_parent = sp->fts_cur; 713 p->fts_pathlen = len + dp->d_namlen; 714 715 #ifdef FTS_WHITEOUT 716 if (dp->d_type == DT_WHT) 717 p->fts_flags |= FTS_ISW; 718 #endif 719 720 if (cderrno) { 721 if (nlinks) { 722 p->fts_info = FTS_NS; 723 p->fts_errno = cderrno; 724 } else 725 p->fts_info = FTS_NSOK; 726 p->fts_accpath = cur->fts_accpath; 727 } else if (nlinks == 0 728 #ifdef DT_DIR 729 || (nostat && 730 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 731 #endif 732 ) { 733 p->fts_accpath = 734 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 735 p->fts_info = FTS_NSOK; 736 } else { 737 /* Build a file name for fts_stat to stat. */ 738 if (ISSET(FTS_NOCHDIR)) { 739 p->fts_accpath = p->fts_path; 740 memmove(cp, p->fts_name, p->fts_namelen + 1); 741 } else 742 p->fts_accpath = p->fts_name; 743 /* Stat it. */ 744 p->fts_info = fts_stat(sp, p, 0); 745 746 /* Decrement link count if applicable. */ 747 if (nlinks > 0 && (p->fts_info == FTS_D || 748 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 749 --nlinks; 750 } 751 752 /* We walk in directory order so "ls -f" doesn't get upset. */ 753 p->fts_link = NULL; 754 if (head == NULL) 755 head = tail = p; 756 else { 757 tail->fts_link = p; 758 tail = p; 759 } 760 ++nitems; 761 } 762 if (dirp) 763 closedir(dirp); 764 765 /* 766 * If realloc() changed the address of the path, adjust the 767 * addresses for the rest of the tree and the dir list. 768 */ 769 if (doadjust) 770 fts_padjust(sp, head); 771 772 /* 773 * If not changing directories, reset the path back to original 774 * state. 775 */ 776 if (ISSET(FTS_NOCHDIR)) { 777 if (len == sp->fts_pathlen || nitems == 0) 778 --cp; 779 *cp = '\0'; 780 } 781 782 /* 783 * If descended after called from fts_children or after called from 784 * fts_read and nothing found, get back. At the root level we use 785 * the saved fd; if one of fts_open()'s arguments is a relative path 786 * to an empty directory, we wind up here with no other way back. If 787 * can't get back, we're done. 788 */ 789 if (descend && (type == BCHILD || !nitems) && 790 (cur->fts_level == FTS_ROOTLEVEL ? 791 FCHDIR(sp, sp->fts_rfd) : 792 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 793 cur->fts_info = FTS_ERR; 794 SET(FTS_STOP); 795 return (NULL); 796 } 797 798 /* If didn't find anything, return NULL. */ 799 if (!nitems) { 800 if (type == BREAD) 801 cur->fts_info = FTS_DP; 802 return (NULL); 803 } 804 805 /* Sort the entries. */ 806 if (sp->fts_compar && nitems > 1) 807 head = fts_sort(sp, head, nitems); 808 return (head); 809 } 810 811 static u_short 812 fts_stat(FTS *sp, FTSENT *p, int follow) 813 { 814 FTSENT *t; 815 dev_t dev; 816 ino_t ino; 817 struct stat *sbp, sb; 818 int saved_errno; 819 820 /* If user needs stat info, stat buffer already allocated. */ 821 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 822 823 #ifdef FTS_WHITEOUT 824 /* check for whiteout */ 825 if (p->fts_flags & FTS_ISW) { 826 if (sbp != &sb) { 827 memset(sbp, '\0', sizeof (*sbp)); 828 sbp->st_mode = S_IFWHT; 829 } 830 return (FTS_W); 831 } 832 #endif 833 834 /* 835 * If doing a logical walk, or application requested FTS_FOLLOW, do 836 * a stat(2). If that fails, check for a non-existent symlink. If 837 * fail, set the errno from the stat call. 838 */ 839 if (ISSET(FTS_LOGICAL) || follow) { 840 if (stat(p->fts_accpath, sbp)) { 841 saved_errno = errno; 842 if (!lstat(p->fts_accpath, sbp)) { 843 errno = 0; 844 return (FTS_SLNONE); 845 } 846 p->fts_errno = saved_errno; 847 goto err; 848 } 849 } else if (lstat(p->fts_accpath, sbp)) { 850 p->fts_errno = errno; 851 err: memset(sbp, 0, sizeof(struct stat)); 852 return (FTS_NS); 853 } 854 855 if (S_ISDIR(sbp->st_mode)) { 856 /* 857 * Set the device/inode. Used to find cycles and check for 858 * crossing mount points. Also remember the link count, used 859 * in fts_build to limit the number of stat calls. It is 860 * understood that these fields are only referenced if fts_info 861 * is set to FTS_D. 862 */ 863 dev = p->fts_dev = sbp->st_dev; 864 ino = p->fts_ino = sbp->st_ino; 865 p->fts_nlink = sbp->st_nlink; 866 867 if (ISDOT(p->fts_name)) 868 return (FTS_DOT); 869 870 /* 871 * Cycle detection is done by brute force when the directory 872 * is first encountered. If the tree gets deep enough or the 873 * number of symbolic links to directories is high enough, 874 * something faster might be worthwhile. 875 */ 876 for (t = p->fts_parent; 877 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 878 if (ino == t->fts_ino && dev == t->fts_dev) { 879 p->fts_cycle = t; 880 return (FTS_DC); 881 } 882 return (FTS_D); 883 } 884 if (S_ISLNK(sbp->st_mode)) 885 return (FTS_SL); 886 if (S_ISREG(sbp->st_mode)) 887 return (FTS_F); 888 return (FTS_DEFAULT); 889 } 890 891 static FTSENT * 892 fts_sort(FTS *sp, FTSENT *head, int nitems) 893 { 894 FTSENT **ap, *p; 895 896 /* 897 * Construct an array of pointers to the structures and call qsort(3). 898 * Reassemble the array in the order returned by qsort. If unable to 899 * sort for memory reasons, return the directory entries in their 900 * current order. Allocate enough space for the current needs plus 901 * 40 so don't realloc one entry at a time. 902 */ 903 if (nitems > sp->fts_nitems) { 904 sp->fts_nitems = nitems + 40; 905 if ((sp->fts_array = reallocf(sp->fts_array, 906 sp->fts_nitems * sizeof(FTSENT *))) == NULL) { 907 sp->fts_nitems = 0; 908 return (head); 909 } 910 } 911 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 912 *ap++ = p; 913 qsort(sp->fts_array, nitems, sizeof(FTSENT *), 914 (int (*)(const void *, const void *))sp->fts_compar); 915 for (head = *(ap = sp->fts_array); --nitems; ++ap) 916 ap[0]->fts_link = ap[1]; 917 ap[0]->fts_link = NULL; 918 return (head); 919 } 920 921 static FTSENT * 922 fts_alloc(FTS *sp, const char *name, int namelen) 923 { 924 FTSENT *p; 925 size_t len; 926 927 /* 928 * The file name is a variable length array and no stat structure is 929 * necessary if the user has set the nostat bit. Allocate the FTSENT 930 * structure, the file name and the stat structure in one chunk, but 931 * be careful that the stat structure is reasonably aligned. Since the 932 * fts_name field is declared to be of size 1, the fts_name pointer is 933 * namelen + 2 before the first possible address of the stat structure. 934 */ 935 len = sizeof(FTSENT) + namelen; 936 if (!ISSET(FTS_NOSTAT)) 937 len += sizeof(struct stat) + ALIGNBYTES; 938 if ((p = malloc(len)) == NULL) 939 return (NULL); 940 941 /* Copy the name and guarantee NUL termination. */ 942 memmove(p->fts_name, name, namelen); 943 p->fts_name[namelen] = '\0'; 944 945 if (!ISSET(FTS_NOSTAT)) 946 p->fts_statp = (struct stat *)ALIGN(p->fts_name + namelen + 2); 947 p->fts_namelen = namelen; 948 p->fts_path = sp->fts_path; 949 p->fts_errno = 0; 950 p->fts_flags = 0; 951 p->fts_instr = FTS_NOINSTR; 952 p->fts_number = 0; 953 p->fts_pointer = NULL; 954 return (p); 955 } 956 957 static void 958 fts_lfree(FTSENT *head) 959 { 960 FTSENT *p; 961 962 /* Free a linked list of structures. */ 963 while ((p = head)) { 964 head = head->fts_link; 965 free(p); 966 } 967 } 968 969 /* 970 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 971 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 972 * though the kernel won't resolve them. Add the size (not just what's needed) 973 * plus 256 bytes so don't realloc the path 2 bytes at a time. 974 */ 975 static int 976 fts_palloc(FTS *sp, size_t more) 977 { 978 979 sp->fts_pathlen += more + 256; 980 /* 981 * Check for possible wraparound. In an FTS, fts_pathlen is 982 * a signed int but in an FTSENT it is an unsigned short. 983 * We limit fts_pathlen to USHRT_MAX to be safe in both cases. 984 */ 985 if (sp->fts_pathlen < 0 || sp->fts_pathlen >= USHRT_MAX) { 986 if (sp->fts_path) 987 free(sp->fts_path); 988 sp->fts_path = NULL; 989 errno = ENAMETOOLONG; 990 return (1); 991 } 992 sp->fts_path = reallocf(sp->fts_path, sp->fts_pathlen); 993 return (sp->fts_path == NULL); 994 } 995 996 /* 997 * When the path is realloc'd, have to fix all of the pointers in structures 998 * already returned. 999 */ 1000 static void 1001 fts_padjust(FTS *sp, FTSENT *head) 1002 { 1003 FTSENT *p; 1004 char *addr = sp->fts_path; 1005 1006 #define ADJUST(p) do { \ 1007 if ((p)->fts_accpath != (p)->fts_name) { \ 1008 (p)->fts_accpath = \ 1009 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \ 1010 } \ 1011 (p)->fts_path = addr; \ 1012 } while (0) 1013 /* Adjust the current set of children. */ 1014 for (p = sp->fts_child; p; p = p->fts_link) 1015 ADJUST(p); 1016 1017 /* Adjust the rest of the tree, including the current level. */ 1018 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1019 ADJUST(p); 1020 p = p->fts_link ? p->fts_link : p->fts_parent; 1021 } 1022 } 1023 1024 static size_t 1025 fts_maxarglen(char * const *argv) 1026 { 1027 size_t len, max; 1028 1029 for (max = 0; *argv; ++argv) 1030 if ((len = strlen(*argv)) > max) 1031 max = len; 1032 return (max + 1); 1033 } 1034 1035 /* 1036 * Change to dir specified by fd or p->fts_accpath without getting 1037 * tricked by someone changing the world out from underneath us. 1038 * Assumes p->fts_dev and p->fts_ino are filled in. 1039 */ 1040 static int 1041 fts_safe_changedir(FTS *sp, FTSENT *p, int fd, const char *path) 1042 { 1043 int ret, oerrno, newfd; 1044 struct stat sb; 1045 1046 newfd = fd; 1047 if (ISSET(FTS_NOCHDIR)) 1048 return (0); 1049 if (fd < 0 && (newfd = _open(path, O_RDONLY, 0)) < 0) 1050 return (-1); 1051 if (_fstat(newfd, &sb)) { 1052 ret = -1; 1053 goto bail; 1054 } 1055 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) { 1056 errno = ENOENT; /* disinformation */ 1057 ret = -1; 1058 goto bail; 1059 } 1060 ret = fchdir(newfd); 1061 bail: 1062 oerrno = errno; 1063 if (fd < 0) 1064 _close(newfd); 1065 errno = oerrno; 1066 return (ret); 1067 } 1068