1 /* $OpenBSD: fts.c,v 1.48 2014/11/20 04:14:15 guenther Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/param.h> 33 #include <sys/stat.h> 34 35 #include <dirent.h> 36 #include <errno.h> 37 #include <fcntl.h> 38 #include <fts.h> 39 #include <limits.h> 40 #include <stdlib.h> 41 #include <string.h> 42 #include <unistd.h> 43 44 static FTSENT *fts_alloc(FTS *, char *, size_t); 45 static FTSENT *fts_build(FTS *, int); 46 static void fts_lfree(FTSENT *); 47 static void fts_load(FTS *, FTSENT *); 48 static size_t fts_maxarglen(char * const *); 49 static void fts_padjust(FTS *, FTSENT *); 50 static int fts_palloc(FTS *, size_t); 51 static FTSENT *fts_sort(FTS *, FTSENT *, int); 52 static u_short fts_stat(FTS *, FTSENT *, int, int); 53 static int fts_safe_changedir(FTS *, FTSENT *, int, char *); 54 55 #define ALIGNBYTES (sizeof(uintptr_t) - 1) 56 #define ALIGN(p) (((uintptr_t)(p) + ALIGNBYTES) &~ ALIGNBYTES) 57 void* reallocarray(void*, size_t, size_t); 58 59 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2]))) 60 61 #define CLR(opt) (sp->fts_options &= ~(opt)) 62 #define ISSET(opt) (sp->fts_options & (opt)) 63 #define SET(opt) (sp->fts_options |= (opt)) 64 65 #define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 66 67 /* fts_build flags */ 68 #define BCHILD 1 /* fts_children */ 69 #define BNAMES 2 /* fts_children, names only */ 70 #define BREAD 3 /* fts_read */ 71 72 FTS * 73 fts_open(char * const *argv, int options, 74 int (*compar)(const FTSENT **, const FTSENT **)) 75 { 76 FTS *sp; 77 FTSENT *p, *root; 78 int nitems; 79 FTSENT *parent, *tmp; 80 size_t len; 81 82 /* Options check. */ 83 if (options & ~FTS_OPTIONMASK) { 84 errno = EINVAL; 85 return (NULL); 86 } 87 88 /* Allocate/initialize the stream */ 89 if ((sp = calloc(1, sizeof(FTS))) == NULL) 90 return (NULL); 91 sp->fts_compar = compar; 92 sp->fts_options = options; 93 94 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 95 if (ISSET(FTS_LOGICAL)) 96 SET(FTS_NOCHDIR); 97 98 /* 99 * Start out with 1K of path space, and enough, in any case, 100 * to hold the user's paths. 101 */ 102 if (fts_palloc(sp, MAX(fts_maxarglen(argv), PATH_MAX))) 103 goto mem1; 104 105 /* Allocate/initialize root's parent. */ 106 if ((parent = fts_alloc(sp, "", 0)) == NULL) 107 goto mem2; 108 parent->fts_level = FTS_ROOTPARENTLEVEL; 109 110 /* Allocate/initialize root(s). */ 111 for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) { 112 /* Don't allow zero-length paths. */ 113 if ((len = strlen(*argv)) == 0) { 114 errno = ENOENT; 115 goto mem3; 116 } 117 118 if ((p = fts_alloc(sp, *argv, len)) == NULL) 119 goto mem3; 120 p->fts_level = FTS_ROOTLEVEL; 121 p->fts_parent = parent; 122 p->fts_accpath = p->fts_name; 123 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW), -1); 124 125 /* Command-line "." and ".." are real directories. */ 126 if (p->fts_info == FTS_DOT) 127 p->fts_info = FTS_D; 128 129 /* 130 * If comparison routine supplied, traverse in sorted 131 * order; otherwise traverse in the order specified. 132 */ 133 if (compar) { 134 p->fts_link = root; 135 root = p; 136 } else { 137 p->fts_link = NULL; 138 if (root == NULL) 139 tmp = root = p; 140 else { 141 tmp->fts_link = p; 142 tmp = p; 143 } 144 } 145 } 146 if (compar && nitems > 1) 147 root = fts_sort(sp, root, nitems); 148 149 /* 150 * Allocate a dummy pointer and make fts_read think that we've just 151 * finished the node before the root(s); set p->fts_info to FTS_INIT 152 * so that everything about the "current" node is ignored. 153 */ 154 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 155 goto mem3; 156 sp->fts_cur->fts_link = root; 157 sp->fts_cur->fts_info = FTS_INIT; 158 159 /* 160 * If using chdir(2), grab a file descriptor pointing to dot to ensure 161 * that we can get back here; this could be avoided for some paths, 162 * but almost certainly not worth the effort. Slashes, symbolic links, 163 * and ".." are all fairly nasty problems. Note, if we can't get the 164 * descriptor we run anyway, just more slowly. 165 */ 166 if (!ISSET(FTS_NOCHDIR) && (sp->fts_rfd = open(".", O_RDONLY, 0)) < 0) 167 SET(FTS_NOCHDIR); 168 169 if (nitems == 0) 170 free(parent); 171 172 return (sp); 173 174 mem3: fts_lfree(root); 175 free(parent); 176 mem2: free(sp->fts_path); 177 mem1: free(sp); 178 return (NULL); 179 } 180 181 static void 182 fts_load(FTS *sp, FTSENT *p) 183 { 184 size_t len; 185 char *cp; 186 187 /* 188 * Load the stream structure for the next traversal. Since we don't 189 * actually enter the directory until after the preorder visit, set 190 * the fts_accpath field specially so the chdir gets done to the right 191 * place and the user can access the first node. From fts_open it's 192 * known that the path will fit. 193 */ 194 len = p->fts_pathlen = p->fts_namelen; 195 memmove(sp->fts_path, p->fts_name, len + 1); 196 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 197 len = strlen(++cp); 198 memmove(p->fts_name, cp, len + 1); 199 p->fts_namelen = len; 200 } 201 p->fts_accpath = p->fts_path = sp->fts_path; 202 sp->fts_dev = p->fts_dev; 203 } 204 205 int 206 fts_close(FTS *sp) 207 { 208 FTSENT *freep, *p; 209 int rfd, error = 0; 210 211 /* 212 * This still works if we haven't read anything -- the dummy structure 213 * points to the root list, so we step through to the end of the root 214 * list which has a valid parent pointer. 215 */ 216 if (sp->fts_cur) { 217 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 218 freep = p; 219 p = p->fts_link ? p->fts_link : p->fts_parent; 220 free(freep); 221 } 222 free(p); 223 } 224 225 /* Stash the original directory fd if needed. */ 226 rfd = ISSET(FTS_NOCHDIR) ? -1 : sp->fts_rfd; 227 228 /* Free up child linked list, sort array, path buffer, stream ptr.*/ 229 if (sp->fts_child) 230 fts_lfree(sp->fts_child); 231 if (sp->fts_array) 232 free(sp->fts_array); 233 free(sp->fts_path); 234 free(sp); 235 236 /* Return to original directory, checking for error. */ 237 if (rfd != -1) { 238 int saved_errno; 239 error = fchdir(rfd); 240 saved_errno = errno; 241 (void)close(rfd); 242 errno = saved_errno; 243 } 244 245 return (error); 246 } 247 248 /* 249 * Special case of "/" at the end of the path so that slashes aren't 250 * appended which would cause paths to be written as "....//foo". 251 */ 252 #define NAPPEND(p) \ 253 (p->fts_path[p->fts_pathlen - 1] == '/' \ 254 ? p->fts_pathlen - 1 : p->fts_pathlen) 255 256 FTSENT * 257 fts_read(FTS *sp) 258 { 259 FTSENT *p, *tmp; 260 int instr; 261 char *t; 262 int saved_errno; 263 264 /* If finished or unrecoverable error, return NULL. */ 265 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 266 return (NULL); 267 268 /* Set current node pointer. */ 269 p = sp->fts_cur; 270 271 /* Save and zero out user instructions. */ 272 instr = p->fts_instr; 273 p->fts_instr = FTS_NOINSTR; 274 275 /* Any type of file may be re-visited; re-stat and re-turn. */ 276 if (instr == FTS_AGAIN) { 277 p->fts_info = fts_stat(sp, p, 0, -1); 278 return (p); 279 } 280 281 /* 282 * Following a symlink -- SLNONE test allows application to see 283 * SLNONE and recover. If indirecting through a symlink, have 284 * keep a pointer to current location. If unable to get that 285 * pointer, follow fails. 286 */ 287 if (instr == FTS_FOLLOW && 288 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 289 p->fts_info = fts_stat(sp, p, 1, -1); 290 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 291 if ((p->fts_symfd = open(".", O_RDONLY, 0)) < 0) { 292 p->fts_errno = errno; 293 p->fts_info = FTS_ERR; 294 } else 295 p->fts_flags |= FTS_SYMFOLLOW; 296 } 297 return (p); 298 } 299 300 /* Directory in pre-order. */ 301 if (p->fts_info == FTS_D) { 302 /* If skipped or crossed mount point, do post-order visit. */ 303 if (instr == FTS_SKIP || 304 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 305 if (p->fts_flags & FTS_SYMFOLLOW) 306 (void)close(p->fts_symfd); 307 if (sp->fts_child) { 308 fts_lfree(sp->fts_child); 309 sp->fts_child = NULL; 310 } 311 p->fts_info = FTS_DP; 312 return (p); 313 } 314 315 /* Rebuild if only read the names and now traversing. */ 316 if (sp->fts_child && ISSET(FTS_NAMEONLY)) { 317 CLR(FTS_NAMEONLY); 318 fts_lfree(sp->fts_child); 319 sp->fts_child = NULL; 320 } 321 322 /* 323 * Cd to the subdirectory. 324 * 325 * If have already read and now fail to chdir, whack the list 326 * to make the names come out right, and set the parent errno 327 * so the application will eventually get an error condition. 328 * Set the FTS_DONTCHDIR flag so that when we logically change 329 * directories back to the parent we don't do a chdir. 330 * 331 * If haven't read do so. If the read fails, fts_build sets 332 * FTS_STOP or the fts_info field of the node. 333 */ 334 if (sp->fts_child) { 335 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 336 p->fts_errno = errno; 337 p->fts_flags |= FTS_DONTCHDIR; 338 for (p = sp->fts_child; p; p = p->fts_link) 339 p->fts_accpath = 340 p->fts_parent->fts_accpath; 341 } 342 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 343 if (ISSET(FTS_STOP)) 344 return (NULL); 345 return (p); 346 } 347 p = sp->fts_child; 348 sp->fts_child = NULL; 349 goto name; 350 } 351 352 /* Move to the next node on this level. */ 353 next: tmp = p; 354 if ((p = p->fts_link)) { 355 free(tmp); 356 357 /* 358 * If reached the top, return to the original directory (or 359 * the root of the tree), and load the paths for the next root. 360 */ 361 if (p->fts_level == FTS_ROOTLEVEL) { 362 if (FCHDIR(sp, sp->fts_rfd)) { 363 SET(FTS_STOP); 364 return (NULL); 365 } 366 fts_load(sp, p); 367 return (sp->fts_cur = p); 368 } 369 370 /* 371 * User may have called fts_set on the node. If skipped, 372 * ignore. If followed, get a file descriptor so we can 373 * get back if necessary. 374 */ 375 if (p->fts_instr == FTS_SKIP) 376 goto next; 377 if (p->fts_instr == FTS_FOLLOW) { 378 p->fts_info = fts_stat(sp, p, 1, -1); 379 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 380 if ((p->fts_symfd = 381 open(".", O_RDONLY, 0)) < 0) { 382 p->fts_errno = errno; 383 p->fts_info = FTS_ERR; 384 } else 385 p->fts_flags |= FTS_SYMFOLLOW; 386 } 387 p->fts_instr = FTS_NOINSTR; 388 } 389 390 name: t = sp->fts_path + NAPPEND(p->fts_parent); 391 *t++ = '/'; 392 memmove(t, p->fts_name, p->fts_namelen + 1); 393 return (sp->fts_cur = p); 394 } 395 396 /* Move up to the parent node. */ 397 p = tmp->fts_parent; 398 free(tmp); 399 400 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 401 /* 402 * Done; free everything up and set errno to 0 so the user 403 * can distinguish between error and EOF. 404 */ 405 free(p); 406 errno = 0; 407 return (sp->fts_cur = NULL); 408 } 409 410 /* NUL terminate the pathname. */ 411 sp->fts_path[p->fts_pathlen] = '\0'; 412 413 /* 414 * Return to the parent directory. If at a root node or came through 415 * a symlink, go back through the file descriptor. Otherwise, cd up 416 * one directory. 417 */ 418 if (p->fts_level == FTS_ROOTLEVEL) { 419 if (FCHDIR(sp, sp->fts_rfd)) { 420 SET(FTS_STOP); 421 sp->fts_cur = p; 422 return (NULL); 423 } 424 } else if (p->fts_flags & FTS_SYMFOLLOW) { 425 if (FCHDIR(sp, p->fts_symfd)) { 426 saved_errno = errno; 427 (void)close(p->fts_symfd); 428 errno = saved_errno; 429 SET(FTS_STOP); 430 sp->fts_cur = p; 431 return (NULL); 432 } 433 (void)close(p->fts_symfd); 434 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 435 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 436 SET(FTS_STOP); 437 sp->fts_cur = p; 438 return (NULL); 439 } 440 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 441 return (sp->fts_cur = p); 442 } 443 444 /* 445 * Fts_set takes the stream as an argument although it's not used in this 446 * implementation; it would be necessary if anyone wanted to add global 447 * semantics to fts using fts_set. An error return is allowed for similar 448 * reasons. 449 */ 450 /* ARGSUSED */ 451 int 452 fts_set(FTS *sp __unused, FTSENT *p, int instr) 453 { 454 if (instr && instr != FTS_AGAIN && instr != FTS_FOLLOW && 455 instr != FTS_NOINSTR && instr != FTS_SKIP) { 456 errno = EINVAL; 457 return (1); 458 } 459 p->fts_instr = instr; 460 return (0); 461 } 462 463 FTSENT * 464 fts_children(FTS *sp, int instr) 465 { 466 FTSENT *p; 467 int fd; 468 469 if (instr && instr != FTS_NAMEONLY) { 470 errno = EINVAL; 471 return (NULL); 472 } 473 474 /* Set current node pointer. */ 475 p = sp->fts_cur; 476 477 /* 478 * Errno set to 0 so user can distinguish empty directory from 479 * an error. 480 */ 481 errno = 0; 482 483 /* Fatal errors stop here. */ 484 if (ISSET(FTS_STOP)) 485 return (NULL); 486 487 /* Return logical hierarchy of user's arguments. */ 488 if (p->fts_info == FTS_INIT) 489 return (p->fts_link); 490 491 /* 492 * If not a directory being visited in pre-order, stop here. Could 493 * allow FTS_DNR, assuming the user has fixed the problem, but the 494 * same effect is available with FTS_AGAIN. 495 */ 496 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 497 return (NULL); 498 499 /* Free up any previous child list. */ 500 if (sp->fts_child) 501 fts_lfree(sp->fts_child); 502 503 if (instr == FTS_NAMEONLY) { 504 SET(FTS_NAMEONLY); 505 instr = BNAMES; 506 } else 507 instr = BCHILD; 508 509 /* 510 * If using chdir on a relative path and called BEFORE fts_read does 511 * its chdir to the root of a traversal, we can lose -- we need to 512 * chdir into the subdirectory, and we don't know where the current 513 * directory is, so we can't get back so that the upcoming chdir by 514 * fts_read will work. 515 */ 516 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 517 ISSET(FTS_NOCHDIR)) 518 return (sp->fts_child = fts_build(sp, instr)); 519 520 if ((fd = open(".", O_RDONLY, 0)) < 0) 521 return (NULL); 522 sp->fts_child = fts_build(sp, instr); 523 if (fchdir(fd)) { 524 (void)close(fd); 525 return (NULL); 526 } 527 (void)close(fd); 528 return (sp->fts_child); 529 } 530 531 /* 532 * This is the tricky part -- do not casually change *anything* in here. The 533 * idea is to build the linked list of entries that are used by fts_children 534 * and fts_read. There are lots of special cases. 535 * 536 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 537 * set and it's a physical walk (so that symbolic links can't be directories), 538 * we can do things quickly. First, if it's a 4.4BSD file system, the type 539 * of the file is in the directory entry. Otherwise, we assume that the number 540 * of subdirectories in a node is equal to the number of links to the parent. 541 * The former skips all stat calls. The latter skips stat calls in any leaf 542 * directories and for any files after the subdirectories in the directory have 543 * been found, cutting the stat calls by about 2/3. 544 */ 545 static FTSENT * 546 fts_build(FTS *sp, int type) 547 { 548 struct dirent *dp; 549 FTSENT *p, *head; 550 FTSENT *cur, *tail; 551 DIR *dirp; 552 void *oldaddr; 553 size_t len, maxlen; 554 int nitems, cderrno, descend, level, nlinks, nostat = 0, doadjust; 555 int saved_errno; 556 char *cp = NULL; 557 558 /* Set current node pointer. */ 559 cur = sp->fts_cur; 560 561 /* 562 * Open the directory for reading. If this fails, we're done. 563 * If being called from fts_read, set the fts_info field. 564 */ 565 if ((dirp = opendir(cur->fts_accpath)) == NULL) { 566 if (type == BREAD) { 567 cur->fts_info = FTS_DNR; 568 cur->fts_errno = errno; 569 } 570 return (NULL); 571 } 572 573 /* 574 * Nlinks is the number of possible entries of type directory in the 575 * directory if we're cheating on stat calls, 0 if we're not doing 576 * any stat calls at all, -1 if we're doing stats on everything. 577 */ 578 if (type == BNAMES) 579 nlinks = 0; 580 else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 581 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 582 nostat = 1; 583 } else { 584 nlinks = -1; 585 nostat = 0; 586 } 587 588 #ifdef notdef 589 (void)printf("nlinks == %d (cur: %u)\n", nlinks, cur->fts_nlink); 590 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 591 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 592 #endif 593 /* 594 * If we're going to need to stat anything or we want to descend 595 * and stay in the directory, chdir. If this fails we keep going, 596 * but set a flag so we don't chdir after the post-order visit. 597 * We won't be able to stat anything, but we can still return the 598 * names themselves. Note, that since fts_read won't be able to 599 * chdir into the directory, it will have to return different path 600 * names than before, i.e. "a/b" instead of "b". Since the node 601 * has already been visited in pre-order, have to wait until the 602 * post-order visit to return the error. There is a special case 603 * here, if there was nothing to stat then it's not an error to 604 * not be able to stat. This is all fairly nasty. If a program 605 * needed sorted entries or stat information, they had better be 606 * checking FTS_NS on the returned nodes. 607 */ 608 cderrno = 0; 609 if (nlinks || type == BREAD) { 610 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) { 611 if (nlinks && type == BREAD) 612 cur->fts_errno = errno; 613 cur->fts_flags |= FTS_DONTCHDIR; 614 descend = 0; 615 cderrno = errno; 616 (void)closedir(dirp); 617 dirp = NULL; 618 } else 619 descend = 1; 620 } else 621 descend = 0; 622 623 /* 624 * Figure out the max file name length that can be stored in the 625 * current path -- the inner loop allocates more path as necessary. 626 * We really wouldn't have to do the maxlen calculations here, we 627 * could do them in fts_read before returning the path, but it's a 628 * lot easier here since the length is part of the dirent structure. 629 * 630 * If not changing directories set a pointer so that can just append 631 * each new name into the path. 632 */ 633 len = NAPPEND(cur); 634 if (ISSET(FTS_NOCHDIR)) { 635 cp = sp->fts_path + len; 636 *cp++ = '/'; 637 } 638 len++; 639 maxlen = sp->fts_pathlen - len; 640 641 /* 642 * fts_level is signed so we must prevent it from wrapping 643 * around to FTS_ROOTLEVEL and FTS_ROOTPARENTLEVEL. 644 */ 645 level = cur->fts_level; 646 if (level < FTS_MAXLEVEL) 647 level++; 648 649 /* Read the directory, attaching each entry to the `link' pointer. */ 650 doadjust = 0; 651 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) { 652 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 653 continue; 654 655 if (!(p = fts_alloc(sp, dp->d_name, strlen(dp->d_name)))) 656 goto mem1; 657 if (strlen(dp->d_name) >= maxlen) { /* include space for NUL */ 658 oldaddr = sp->fts_path; 659 if (fts_palloc(sp, strlen(dp->d_name) +len + 1)) { 660 /* 661 * No more memory for path or structures. Save 662 * errno, free up the current structure and the 663 * structures already allocated. 664 */ 665 mem1: saved_errno = errno; 666 if (p) 667 free(p); 668 fts_lfree(head); 669 (void)closedir(dirp); 670 cur->fts_info = FTS_ERR; 671 SET(FTS_STOP); 672 errno = saved_errno; 673 return (NULL); 674 } 675 /* Did realloc() change the pointer? */ 676 if (oldaddr != sp->fts_path) { 677 doadjust = 1; 678 if (ISSET(FTS_NOCHDIR)) 679 cp = sp->fts_path + len; 680 } 681 maxlen = sp->fts_pathlen - len; 682 } 683 684 p->fts_level = level; 685 p->fts_parent = sp->fts_cur; 686 p->fts_pathlen = len + strlen(dp->d_name); 687 if (p->fts_pathlen < len) { 688 /* 689 * If we wrap, free up the current structure and 690 * the structures already allocated, then error 691 * out with ENAMETOOLONG. 692 */ 693 free(p); 694 fts_lfree(head); 695 (void)closedir(dirp); 696 cur->fts_info = FTS_ERR; 697 SET(FTS_STOP); 698 errno = ENAMETOOLONG; 699 return (NULL); 700 } 701 702 if (cderrno) { 703 if (nlinks) { 704 p->fts_info = FTS_NS; 705 p->fts_errno = cderrno; 706 } else 707 p->fts_info = FTS_NSOK; 708 p->fts_accpath = cur->fts_accpath; 709 } else if (nlinks == 0 710 #ifdef DT_DIR 711 || (nostat && 712 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 713 #endif 714 ) { 715 p->fts_accpath = 716 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 717 p->fts_info = FTS_NSOK; 718 } else { 719 /* Build a file name for fts_stat to stat. */ 720 if (ISSET(FTS_NOCHDIR)) { 721 p->fts_accpath = p->fts_path; 722 memmove(cp, p->fts_name, p->fts_namelen + 1); 723 p->fts_info = fts_stat(sp, p, 0, dirfd(dirp)); 724 } else { 725 p->fts_accpath = p->fts_name; 726 p->fts_info = fts_stat(sp, p, 0, -1); 727 } 728 729 /* Decrement link count if applicable. */ 730 if (nlinks > 0 && (p->fts_info == FTS_D || 731 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 732 --nlinks; 733 } 734 735 /* We walk in directory order so "ls -f" doesn't get upset. */ 736 p->fts_link = NULL; 737 if (head == NULL) 738 head = tail = p; 739 else { 740 tail->fts_link = p; 741 tail = p; 742 } 743 ++nitems; 744 } 745 if (dirp) 746 (void)closedir(dirp); 747 748 /* 749 * If realloc() changed the address of the path, adjust the 750 * addresses for the rest of the tree and the dir list. 751 */ 752 if (doadjust) 753 fts_padjust(sp, head); 754 755 /* 756 * If not changing directories, reset the path back to original 757 * state. 758 */ 759 if (ISSET(FTS_NOCHDIR)) { 760 if (len == sp->fts_pathlen || nitems == 0) 761 --cp; 762 *cp = '\0'; 763 } 764 765 /* 766 * If descended after called from fts_children or after called from 767 * fts_read and nothing found, get back. At the root level we use 768 * the saved fd; if one of fts_open()'s arguments is a relative path 769 * to an empty directory, we wind up here with no other way back. If 770 * can't get back, we're done. 771 */ 772 if (descend && (type == BCHILD || !nitems) && 773 (cur->fts_level == FTS_ROOTLEVEL ? FCHDIR(sp, sp->fts_rfd) : 774 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 775 cur->fts_info = FTS_ERR; 776 SET(FTS_STOP); 777 return (NULL); 778 } 779 780 /* If didn't find anything, return NULL. */ 781 if (!nitems) { 782 if (type == BREAD) 783 cur->fts_info = FTS_DP; 784 return (NULL); 785 } 786 787 /* Sort the entries. */ 788 if (sp->fts_compar && nitems > 1) 789 head = fts_sort(sp, head, nitems); 790 return (head); 791 } 792 793 static u_short 794 fts_stat(FTS *sp, FTSENT *p, int follow, int dfd) 795 { 796 FTSENT *t; 797 dev_t dev; 798 ino_t ino; 799 struct stat *sbp, sb; 800 int saved_errno; 801 const char *path; 802 803 if (dfd == -1) { 804 path = p->fts_accpath; 805 dfd = AT_FDCWD; 806 } else 807 path = p->fts_name; 808 809 /* If user needs stat info, stat buffer already allocated. */ 810 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 811 812 /* 813 * If doing a logical walk, or application requested FTS_FOLLOW, do 814 * a stat(2). If that fails, check for a non-existent symlink. If 815 * fail, set the errno from the stat call. 816 */ 817 if (ISSET(FTS_LOGICAL) || follow) { 818 if (fstatat(dfd, path, sbp, 0)) { 819 saved_errno = errno; 820 if (!fstatat(dfd, path, sbp, AT_SYMLINK_NOFOLLOW)) { 821 errno = 0; 822 return (FTS_SLNONE); 823 } 824 p->fts_errno = saved_errno; 825 goto err; 826 } 827 } else if (fstatat(dfd, path, sbp, AT_SYMLINK_NOFOLLOW)) { 828 p->fts_errno = errno; 829 err: memset(sbp, 0, sizeof(struct stat)); 830 return (FTS_NS); 831 } 832 833 if (S_ISDIR(sbp->st_mode)) { 834 /* 835 * Set the device/inode. Used to find cycles and check for 836 * crossing mount points. Also remember the link count, used 837 * in fts_build to limit the number of stat calls. It is 838 * understood that these fields are only referenced if fts_info 839 * is set to FTS_D. 840 */ 841 dev = p->fts_dev = sbp->st_dev; 842 ino = p->fts_ino = sbp->st_ino; 843 p->fts_nlink = sbp->st_nlink; 844 845 if (ISDOT(p->fts_name)) 846 return (FTS_DOT); 847 848 /* 849 * Cycle detection is done by brute force when the directory 850 * is first encountered. If the tree gets deep enough or the 851 * number of symbolic links to directories is high enough, 852 * something faster might be worthwhile. 853 */ 854 for (t = p->fts_parent; 855 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 856 if (ino == t->fts_ino && dev == t->fts_dev) { 857 p->fts_cycle = t; 858 return (FTS_DC); 859 } 860 return (FTS_D); 861 } 862 if (S_ISLNK(sbp->st_mode)) 863 return (FTS_SL); 864 if (S_ISREG(sbp->st_mode)) 865 return (FTS_F); 866 return (FTS_DEFAULT); 867 } 868 869 static FTSENT * 870 fts_sort(FTS *sp, FTSENT *head, int nitems) 871 { 872 FTSENT **ap, *p; 873 874 /* 875 * Construct an array of pointers to the structures and call qsort(3). 876 * Reassemble the array in the order returned by qsort. If unable to 877 * sort for memory reasons, return the directory entries in their 878 * current order. Allocate enough space for the current needs plus 879 * 40 so don't realloc one entry at a time. 880 */ 881 if (nitems > sp->fts_nitems) { 882 struct _ftsent **a; 883 884 sp->fts_nitems = nitems + 40; 885 if ((a = reallocarray(sp->fts_array, 886 sp->fts_nitems, sizeof(FTSENT *))) == NULL) { 887 if (sp->fts_array) 888 free(sp->fts_array); 889 sp->fts_array = NULL; 890 sp->fts_nitems = 0; 891 return (head); 892 } 893 sp->fts_array = a; 894 } 895 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 896 *ap++ = p; 897 qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *), sp->fts_compar); 898 for (head = *(ap = sp->fts_array); --nitems; ++ap) 899 ap[0]->fts_link = ap[1]; 900 ap[0]->fts_link = NULL; 901 return (head); 902 } 903 904 static FTSENT * 905 fts_alloc(FTS *sp, char *name, size_t namelen) 906 { 907 FTSENT *p; 908 size_t len; 909 910 /* 911 * The file name is a variable length array and no stat structure is 912 * necessary if the user has set the nostat bit. Allocate the FTSENT 913 * structure, the file name and the stat structure in one chunk, but 914 * be careful that the stat structure is reasonably aligned. Since the 915 * fts_name field is declared to be of size 1, the fts_name pointer is 916 * namelen + 2 before the first possible address of the stat structure. 917 */ 918 len = sizeof(FTSENT) + namelen; 919 if (!ISSET(FTS_NOSTAT)) 920 len += sizeof(struct stat) + ALIGNBYTES; 921 if ((p = calloc(1, len)) == NULL) 922 return (NULL); 923 924 p->fts_path = sp->fts_path; 925 p->fts_namelen = namelen; 926 p->fts_instr = FTS_NOINSTR; 927 if (!ISSET(FTS_NOSTAT)) 928 p->fts_statp = (struct stat *)ALIGN(p->fts_name + namelen + 2); 929 memcpy(p->fts_name, name, namelen); 930 931 return (p); 932 } 933 934 static void 935 fts_lfree(FTSENT *head) 936 { 937 FTSENT *p; 938 939 /* Free a linked list of structures. */ 940 while ((p = head)) { 941 head = head->fts_link; 942 free(p); 943 } 944 } 945 946 /* 947 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 948 * Most systems will allow creation of paths much longer than PATH_MAX, even 949 * though the kernel won't resolve them. Add the size (not just what's needed) 950 * plus 256 bytes so don't realloc the path 2 bytes at a time. 951 */ 952 static int 953 fts_palloc(FTS *sp, size_t more) 954 { 955 char *p; 956 957 /* 958 * Check for possible wraparound. 959 */ 960 more += 256; 961 if (sp->fts_pathlen + more < sp->fts_pathlen) { 962 if (sp->fts_path) 963 free(sp->fts_path); 964 sp->fts_path = NULL; 965 errno = ENAMETOOLONG; 966 return (1); 967 } 968 sp->fts_pathlen += more; 969 p = realloc(sp->fts_path, sp->fts_pathlen); 970 if (p == NULL) { 971 if (sp->fts_path) 972 free(sp->fts_path); 973 sp->fts_path = NULL; 974 return (1); 975 } 976 sp->fts_path = p; 977 return (0); 978 } 979 980 /* 981 * When the path is realloc'd, have to fix all of the pointers in structures 982 * already returned. 983 */ 984 static void 985 fts_padjust(FTS *sp, FTSENT *head) 986 { 987 FTSENT *p; 988 char *addr = sp->fts_path; 989 990 #define ADJUST(p) { \ 991 if ((p)->fts_accpath != (p)->fts_name) { \ 992 (p)->fts_accpath = \ 993 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \ 994 } \ 995 (p)->fts_path = addr; \ 996 } 997 /* Adjust the current set of children. */ 998 for (p = sp->fts_child; p; p = p->fts_link) 999 ADJUST(p); 1000 1001 /* Adjust the rest of the tree, including the current level. */ 1002 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1003 ADJUST(p); 1004 p = p->fts_link ? p->fts_link : p->fts_parent; 1005 } 1006 } 1007 1008 static size_t 1009 fts_maxarglen(char * const *argv) 1010 { 1011 size_t len, max; 1012 1013 for (max = 0; *argv; ++argv) 1014 if ((len = strlen(*argv)) > max) 1015 max = len; 1016 return (max + 1); 1017 } 1018 1019 /* 1020 * Change to dir specified by fd or p->fts_accpath without getting 1021 * tricked by someone changing the world out from underneath us. 1022 * Assumes p->fts_dev and p->fts_ino are filled in. 1023 */ 1024 static int 1025 fts_safe_changedir(FTS *sp, FTSENT *p, int fd, char *path) 1026 { 1027 int ret, oerrno, newfd; 1028 struct stat sb; 1029 1030 newfd = fd; 1031 if (ISSET(FTS_NOCHDIR)) 1032 return (0); 1033 if (fd < 0 && (newfd = open(path, O_RDONLY, 0)) < 0) 1034 return (-1); 1035 if (fstat(newfd, &sb)) { 1036 ret = -1; 1037 goto bail; 1038 } 1039 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) { 1040 errno = ENOENT; /* disinformation */ 1041 ret = -1; 1042 goto bail; 1043 } 1044 ret = fchdir(newfd); 1045 bail: 1046 oerrno = errno; 1047 if (fd < 0) 1048 (void)close(newfd); 1049 errno = oerrno; 1050 return (ret); 1051 } 1052
