1 /* $OpenBSD: fts.c,v 1.46 2014/05/25 17:47:04 tedu 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); 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 58 #define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2]))) 59 60 #define CLR(opt) (sp->fts_options &= ~(opt)) 61 #define ISSET(opt) (sp->fts_options & (opt)) 62 #define SET(opt) (sp->fts_options |= (opt)) 63 64 #define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 65 66 /* fts_build flags */ 67 #define BCHILD 1 /* fts_children */ 68 #define BNAMES 2 /* fts_children, names only */ 69 #define BREAD 3 /* fts_read */ 70 71 FTS * 72 fts_open(char * const *argv, int options, 73 int (*compar)(const FTSENT **, const FTSENT **)) 74 { 75 FTS *sp; 76 FTSENT *p, *root; 77 int nitems; 78 FTSENT *parent, *tmp; 79 size_t len; 80 81 /* Options check. */ 82 if (options & ~FTS_OPTIONMASK) { 83 errno = EINVAL; 84 return (NULL); 85 } 86 87 /* Allocate/initialize the stream */ 88 if ((sp = calloc(1, sizeof(FTS))) == NULL) 89 return (NULL); 90 sp->fts_compar = compar; 91 sp->fts_options = options; 92 93 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 94 if (ISSET(FTS_LOGICAL)) 95 SET(FTS_NOCHDIR); 96 97 /* 98 * Start out with 1K of path space, and enough, in any case, 99 * to hold the user's paths. 100 */ 101 if (fts_palloc(sp, MAX(fts_maxarglen(argv), PATH_MAX))) 102 goto mem1; 103 104 /* Allocate/initialize root's parent. */ 105 if ((parent = fts_alloc(sp, "", 0)) == NULL) 106 goto mem2; 107 parent->fts_level = FTS_ROOTPARENTLEVEL; 108 109 /* Allocate/initialize root(s). */ 110 for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) { 111 /* Don't allow zero-length paths. */ 112 if ((len = strlen(*argv)) == 0) { 113 errno = ENOENT; 114 goto mem3; 115 } 116 117 if ((p = fts_alloc(sp, *argv, len)) == NULL) 118 goto mem3; 119 p->fts_level = FTS_ROOTLEVEL; 120 p->fts_parent = parent; 121 p->fts_accpath = p->fts_name; 122 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW)); 123 124 /* Command-line "." and ".." are real directories. */ 125 if (p->fts_info == FTS_DOT) 126 p->fts_info = FTS_D; 127 128 /* 129 * If comparison routine supplied, traverse in sorted 130 * order; otherwise traverse in the order specified. 131 */ 132 if (compar) { 133 p->fts_link = root; 134 root = p; 135 } else { 136 p->fts_link = NULL; 137 if (root == NULL) 138 tmp = root = p; 139 else { 140 tmp->fts_link = p; 141 tmp = p; 142 } 143 } 144 } 145 if (compar && nitems > 1) 146 root = fts_sort(sp, root, nitems); 147 148 /* 149 * Allocate a dummy pointer and make fts_read think that we've just 150 * finished the node before the root(s); set p->fts_info to FTS_INIT 151 * so that everything about the "current" node is ignored. 152 */ 153 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 154 goto mem3; 155 sp->fts_cur->fts_link = root; 156 sp->fts_cur->fts_info = FTS_INIT; 157 158 /* 159 * If using chdir(2), grab a file descriptor pointing to dot to ensure 160 * that we can get back here; this could be avoided for some paths, 161 * but almost certainly not worth the effort. Slashes, symbolic links, 162 * and ".." are all fairly nasty problems. Note, if we can't get the 163 * descriptor we run anyway, just more slowly. 164 */ 165 if (!ISSET(FTS_NOCHDIR) && (sp->fts_rfd = open(".", O_RDONLY, 0)) < 0) 166 SET(FTS_NOCHDIR); 167 168 if (nitems == 0) 169 free(parent); 170 171 return (sp); 172 173 mem3: fts_lfree(root); 174 free(parent); 175 mem2: free(sp->fts_path); 176 mem1: free(sp); 177 return (NULL); 178 } 179 180 static void 181 fts_load(FTS *sp, FTSENT *p) 182 { 183 size_t len; 184 char *cp; 185 186 /* 187 * Load the stream structure for the next traversal. Since we don't 188 * actually enter the directory until after the preorder visit, set 189 * the fts_accpath field specially so the chdir gets done to the right 190 * place and the user can access the first node. From fts_open it's 191 * known that the path will fit. 192 */ 193 len = p->fts_pathlen = p->fts_namelen; 194 memmove(sp->fts_path, p->fts_name, len + 1); 195 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 196 len = strlen(++cp); 197 memmove(p->fts_name, cp, len + 1); 198 p->fts_namelen = len; 199 } 200 p->fts_accpath = p->fts_path = sp->fts_path; 201 sp->fts_dev = p->fts_dev; 202 } 203 204 int 205 fts_close(FTS *sp) 206 { 207 FTSENT *freep, *p; 208 int rfd, error = 0; 209 210 /* 211 * This still works if we haven't read anything -- the dummy structure 212 * points to the root list, so we step through to the end of the root 213 * list which has a valid parent pointer. 214 */ 215 if (sp->fts_cur) { 216 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 217 freep = p; 218 p = p->fts_link ? p->fts_link : p->fts_parent; 219 free(freep); 220 } 221 free(p); 222 } 223 224 /* Stash the original directory fd if needed. */ 225 rfd = ISSET(FTS_NOCHDIR) ? -1 : sp->fts_rfd; 226 227 /* Free up child linked list, sort array, path buffer, stream ptr.*/ 228 if (sp->fts_child) 229 fts_lfree(sp->fts_child); 230 if (sp->fts_array) 231 free(sp->fts_array); 232 free(sp->fts_path); 233 free(sp); 234 235 /* Return to original directory, checking for error. */ 236 if (rfd != -1) { 237 int saved_errno; 238 error = fchdir(rfd); 239 saved_errno = errno; 240 (void)close(rfd); 241 errno = saved_errno; 242 } 243 244 return (error); 245 } 246 247 /* 248 * Special case of "/" at the end of the path so that slashes aren't 249 * appended which would cause paths to be written as "....//foo". 250 */ 251 #define NAPPEND(p) \ 252 (p->fts_path[p->fts_pathlen - 1] == '/' \ 253 ? p->fts_pathlen - 1 : p->fts_pathlen) 254 255 FTSENT * 256 fts_read(FTS *sp) 257 { 258 FTSENT *p, *tmp; 259 int instr; 260 char *t; 261 int saved_errno; 262 263 /* If finished or unrecoverable error, return NULL. */ 264 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 265 return (NULL); 266 267 /* Set current node pointer. */ 268 p = sp->fts_cur; 269 270 /* Save and zero out user instructions. */ 271 instr = p->fts_instr; 272 p->fts_instr = FTS_NOINSTR; 273 274 /* Any type of file may be re-visited; re-stat and re-turn. */ 275 if (instr == FTS_AGAIN) { 276 p->fts_info = fts_stat(sp, p, 0); 277 return (p); 278 } 279 280 /* 281 * Following a symlink -- SLNONE test allows application to see 282 * SLNONE and recover. If indirecting through a symlink, have 283 * keep a pointer to current location. If unable to get that 284 * pointer, follow fails. 285 */ 286 if (instr == FTS_FOLLOW && 287 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 288 p->fts_info = fts_stat(sp, p, 1); 289 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 290 if ((p->fts_symfd = open(".", O_RDONLY, 0)) < 0) { 291 p->fts_errno = errno; 292 p->fts_info = FTS_ERR; 293 } else 294 p->fts_flags |= FTS_SYMFOLLOW; 295 } 296 return (p); 297 } 298 299 /* Directory in pre-order. */ 300 if (p->fts_info == FTS_D) { 301 /* If skipped or crossed mount point, do post-order visit. */ 302 if (instr == FTS_SKIP || 303 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 304 if (p->fts_flags & FTS_SYMFOLLOW) 305 (void)close(p->fts_symfd); 306 if (sp->fts_child) { 307 fts_lfree(sp->fts_child); 308 sp->fts_child = NULL; 309 } 310 p->fts_info = FTS_DP; 311 return (p); 312 } 313 314 /* Rebuild if only read the names and now traversing. */ 315 if (sp->fts_child && ISSET(FTS_NAMEONLY)) { 316 CLR(FTS_NAMEONLY); 317 fts_lfree(sp->fts_child); 318 sp->fts_child = NULL; 319 } 320 321 /* 322 * Cd to the subdirectory. 323 * 324 * If have already read and now fail to chdir, whack the list 325 * to make the names come out right, and set the parent errno 326 * so the application will eventually get an error condition. 327 * Set the FTS_DONTCHDIR flag so that when we logically change 328 * directories back to the parent we don't do a chdir. 329 * 330 * If haven't read do so. If the read fails, fts_build sets 331 * FTS_STOP or the fts_info field of the node. 332 */ 333 if (sp->fts_child) { 334 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 335 p->fts_errno = errno; 336 p->fts_flags |= FTS_DONTCHDIR; 337 for (p = sp->fts_child; p; p = p->fts_link) 338 p->fts_accpath = 339 p->fts_parent->fts_accpath; 340 } 341 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 342 if (ISSET(FTS_STOP)) 343 return (NULL); 344 return (p); 345 } 346 p = sp->fts_child; 347 sp->fts_child = NULL; 348 goto name; 349 } 350 351 /* Move to the next node on this level. */ 352 next: tmp = p; 353 if ((p = p->fts_link)) { 354 free(tmp); 355 356 /* 357 * If reached the top, return to the original directory (or 358 * the root of the tree), and load the paths for the next root. 359 */ 360 if (p->fts_level == FTS_ROOTLEVEL) { 361 if (FCHDIR(sp, sp->fts_rfd)) { 362 SET(FTS_STOP); 363 return (NULL); 364 } 365 fts_load(sp, p); 366 return (sp->fts_cur = p); 367 } 368 369 /* 370 * User may have called fts_set on the node. If skipped, 371 * ignore. If followed, get a file descriptor so we can 372 * get back if necessary. 373 */ 374 if (p->fts_instr == FTS_SKIP) 375 goto next; 376 if (p->fts_instr == FTS_FOLLOW) { 377 p->fts_info = fts_stat(sp, p, 1); 378 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 379 if ((p->fts_symfd = 380 open(".", O_RDONLY, 0)) < 0) { 381 p->fts_errno = errno; 382 p->fts_info = FTS_ERR; 383 } else 384 p->fts_flags |= FTS_SYMFOLLOW; 385 } 386 p->fts_instr = FTS_NOINSTR; 387 } 388 389 name: t = sp->fts_path + NAPPEND(p->fts_parent); 390 *t++ = '/'; 391 memmove(t, p->fts_name, p->fts_namelen + 1); 392 return (sp->fts_cur = p); 393 } 394 395 /* Move up to the parent node. */ 396 p = tmp->fts_parent; 397 free(tmp); 398 399 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 400 /* 401 * Done; free everything up and set errno to 0 so the user 402 * can distinguish between error and EOF. 403 */ 404 free(p); 405 errno = 0; 406 return (sp->fts_cur = NULL); 407 } 408 409 /* NUL terminate the pathname. */ 410 sp->fts_path[p->fts_pathlen] = '\0'; 411 412 /* 413 * Return to the parent directory. If at a root node or came through 414 * a symlink, go back through the file descriptor. Otherwise, cd up 415 * one directory. 416 */ 417 if (p->fts_level == FTS_ROOTLEVEL) { 418 if (FCHDIR(sp, sp->fts_rfd)) { 419 SET(FTS_STOP); 420 sp->fts_cur = p; 421 return (NULL); 422 } 423 } else if (p->fts_flags & FTS_SYMFOLLOW) { 424 if (FCHDIR(sp, p->fts_symfd)) { 425 saved_errno = errno; 426 (void)close(p->fts_symfd); 427 errno = saved_errno; 428 SET(FTS_STOP); 429 sp->fts_cur = p; 430 return (NULL); 431 } 432 (void)close(p->fts_symfd); 433 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 434 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 435 SET(FTS_STOP); 436 sp->fts_cur = p; 437 return (NULL); 438 } 439 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 440 return (sp->fts_cur = p); 441 } 442 443 /* 444 * Fts_set takes the stream as an argument although it's not used in this 445 * implementation; it would be necessary if anyone wanted to add global 446 * semantics to fts using fts_set. An error return is allowed for similar 447 * reasons. 448 */ 449 /* ARGSUSED */ 450 int 451 fts_set(FTS *sp __unused, FTSENT *p, int instr) 452 { 453 if (instr && instr != FTS_AGAIN && instr != FTS_FOLLOW && 454 instr != FTS_NOINSTR && instr != FTS_SKIP) { 455 errno = EINVAL; 456 return (1); 457 } 458 p->fts_instr = instr; 459 return (0); 460 } 461 462 FTSENT * 463 fts_children(FTS *sp, int instr) 464 { 465 FTSENT *p; 466 int fd; 467 468 if (instr && instr != FTS_NAMEONLY) { 469 errno = EINVAL; 470 return (NULL); 471 } 472 473 /* Set current node pointer. */ 474 p = sp->fts_cur; 475 476 /* 477 * Errno set to 0 so user can distinguish empty directory from 478 * an error. 479 */ 480 errno = 0; 481 482 /* Fatal errors stop here. */ 483 if (ISSET(FTS_STOP)) 484 return (NULL); 485 486 /* Return logical hierarchy of user's arguments. */ 487 if (p->fts_info == FTS_INIT) 488 return (p->fts_link); 489 490 /* 491 * If not a directory being visited in pre-order, stop here. Could 492 * allow FTS_DNR, assuming the user has fixed the problem, but the 493 * same effect is available with FTS_AGAIN. 494 */ 495 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 496 return (NULL); 497 498 /* Free up any previous child list. */ 499 if (sp->fts_child) 500 fts_lfree(sp->fts_child); 501 502 if (instr == FTS_NAMEONLY) { 503 SET(FTS_NAMEONLY); 504 instr = BNAMES; 505 } else 506 instr = BCHILD; 507 508 /* 509 * If using chdir on a relative path and called BEFORE fts_read does 510 * its chdir to the root of a traversal, we can lose -- we need to 511 * chdir into the subdirectory, and we don't know where the current 512 * directory is, so we can't get back so that the upcoming chdir by 513 * fts_read will work. 514 */ 515 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 516 ISSET(FTS_NOCHDIR)) 517 return (sp->fts_child = fts_build(sp, instr)); 518 519 if ((fd = open(".", O_RDONLY, 0)) < 0) 520 return (NULL); 521 sp->fts_child = fts_build(sp, instr); 522 if (fchdir(fd)) { 523 (void)close(fd); 524 return (NULL); 525 } 526 (void)close(fd); 527 return (sp->fts_child); 528 } 529 530 /* 531 * This is the tricky part -- do not casually change *anything* in here. The 532 * idea is to build the linked list of entries that are used by fts_children 533 * and fts_read. There are lots of special cases. 534 * 535 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 536 * set and it's a physical walk (so that symbolic links can't be directories), 537 * we can do things quickly. First, if it's a 4.4BSD file system, the type 538 * of the file is in the directory entry. Otherwise, we assume that the number 539 * of subdirectories in a node is equal to the number of links to the parent. 540 * The former skips all stat calls. The latter skips stat calls in any leaf 541 * directories and for any files after the subdirectories in the directory have 542 * been found, cutting the stat calls by about 2/3. 543 */ 544 static FTSENT * 545 fts_build(FTS *sp, int type) 546 { 547 struct dirent *dp; 548 FTSENT *p, *head; 549 FTSENT *cur, *tail; 550 DIR *dirp; 551 void *oldaddr; 552 size_t len, maxlen; 553 int nitems, cderrno, descend, level, nlinks, nostat = 0, doadjust; 554 int saved_errno; 555 char *cp = NULL; 556 557 /* Set current node pointer. */ 558 cur = sp->fts_cur; 559 560 /* 561 * Open the directory for reading. If this fails, we're done. 562 * If being called from fts_read, set the fts_info field. 563 */ 564 if ((dirp = opendir(cur->fts_accpath)) == NULL) { 565 if (type == BREAD) { 566 cur->fts_info = FTS_DNR; 567 cur->fts_errno = errno; 568 } 569 return (NULL); 570 } 571 572 /* 573 * Nlinks is the number of possible entries of type directory in the 574 * directory if we're cheating on stat calls, 0 if we're not doing 575 * any stat calls at all, -1 if we're doing stats on everything. 576 */ 577 if (type == BNAMES) 578 nlinks = 0; 579 else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 580 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 581 nostat = 1; 582 } else { 583 nlinks = -1; 584 nostat = 0; 585 } 586 587 #ifdef notdef 588 (void)printf("nlinks == %d (cur: %u)\n", nlinks, cur->fts_nlink); 589 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 590 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 591 #endif 592 /* 593 * If we're going to need to stat anything or we want to descend 594 * and stay in the directory, chdir. If this fails we keep going, 595 * but set a flag so we don't chdir after the post-order visit. 596 * We won't be able to stat anything, but we can still return the 597 * names themselves. Note, that since fts_read won't be able to 598 * chdir into the directory, it will have to return different path 599 * names than before, i.e. "a/b" instead of "b". Since the node 600 * has already been visited in pre-order, have to wait until the 601 * post-order visit to return the error. There is a special case 602 * here, if there was nothing to stat then it's not an error to 603 * not be able to stat. This is all fairly nasty. If a program 604 * needed sorted entries or stat information, they had better be 605 * checking FTS_NS on the returned nodes. 606 */ 607 cderrno = 0; 608 if (nlinks || type == BREAD) { 609 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) { 610 if (nlinks && type == BREAD) 611 cur->fts_errno = errno; 612 cur->fts_flags |= FTS_DONTCHDIR; 613 descend = 0; 614 cderrno = errno; 615 (void)closedir(dirp); 616 dirp = NULL; 617 } else 618 descend = 1; 619 } else 620 descend = 0; 621 622 /* 623 * Figure out the max file name length that can be stored in the 624 * current path -- the inner loop allocates more path as necessary. 625 * We really wouldn't have to do the maxlen calculations here, we 626 * could do them in fts_read before returning the path, but it's a 627 * lot easier here since the length is part of the dirent structure. 628 * 629 * If not changing directories set a pointer so that can just append 630 * each new name into the path. 631 */ 632 len = NAPPEND(cur); 633 if (ISSET(FTS_NOCHDIR)) { 634 cp = sp->fts_path + len; 635 *cp++ = '/'; 636 } 637 len++; 638 maxlen = sp->fts_pathlen - len; 639 640 /* 641 * fts_level is signed so we must prevent it from wrapping 642 * around to FTS_ROOTLEVEL and FTS_ROOTPARENTLEVEL. 643 */ 644 level = cur->fts_level; 645 if (level < FTS_MAXLEVEL) 646 level++; 647 648 /* Read the directory, attaching each entry to the `link' pointer. */ 649 doadjust = 0; 650 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) { 651 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 652 continue; 653 654 if (!(p = fts_alloc(sp, dp->d_name, strlen(dp->d_name)))) 655 goto mem1; 656 if (strlen(dp->d_name) >= maxlen) { /* include space for NUL */ 657 oldaddr = sp->fts_path; 658 if (fts_palloc(sp, strlen(dp->d_name) +len + 1)) { 659 /* 660 * No more memory for path or structures. Save 661 * errno, free up the current structure and the 662 * structures already allocated. 663 */ 664 mem1: saved_errno = errno; 665 if (p) 666 free(p); 667 fts_lfree(head); 668 (void)closedir(dirp); 669 cur->fts_info = FTS_ERR; 670 SET(FTS_STOP); 671 errno = saved_errno; 672 return (NULL); 673 } 674 /* Did realloc() change the pointer? */ 675 if (oldaddr != sp->fts_path) { 676 doadjust = 1; 677 if (ISSET(FTS_NOCHDIR)) 678 cp = sp->fts_path + len; 679 } 680 maxlen = sp->fts_pathlen - len; 681 } 682 683 p->fts_level = level; 684 p->fts_parent = sp->fts_cur; 685 p->fts_pathlen = len + strlen(dp->d_name); 686 if (p->fts_pathlen < len) { 687 /* 688 * If we wrap, free up the current structure and 689 * the structures already allocated, then error 690 * out with ENAMETOOLONG. 691 */ 692 free(p); 693 fts_lfree(head); 694 (void)closedir(dirp); 695 cur->fts_info = FTS_ERR; 696 SET(FTS_STOP); 697 errno = ENAMETOOLONG; 698 return (NULL); 699 } 700 701 if (cderrno) { 702 if (nlinks) { 703 p->fts_info = FTS_NS; 704 p->fts_errno = cderrno; 705 } else 706 p->fts_info = FTS_NSOK; 707 p->fts_accpath = cur->fts_accpath; 708 } else if (nlinks == 0 709 #ifdef DT_DIR 710 || (nostat && 711 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 712 #endif 713 ) { 714 p->fts_accpath = 715 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 716 p->fts_info = FTS_NSOK; 717 } else { 718 /* Build a file name for fts_stat to stat. */ 719 if (ISSET(FTS_NOCHDIR)) { 720 p->fts_accpath = p->fts_path; 721 memmove(cp, p->fts_name, p->fts_namelen + 1); 722 } else 723 p->fts_accpath = p->fts_name; 724 /* Stat it. */ 725 p->fts_info = fts_stat(sp, p, 0); 726 727 /* Decrement link count if applicable. */ 728 if (nlinks > 0 && (p->fts_info == FTS_D || 729 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 730 --nlinks; 731 } 732 733 /* We walk in directory order so "ls -f" doesn't get upset. */ 734 p->fts_link = NULL; 735 if (head == NULL) 736 head = tail = p; 737 else { 738 tail->fts_link = p; 739 tail = p; 740 } 741 ++nitems; 742 } 743 if (dirp) 744 (void)closedir(dirp); 745 746 /* 747 * If realloc() changed the address of the path, adjust the 748 * addresses for the rest of the tree and the dir list. 749 */ 750 if (doadjust) 751 fts_padjust(sp, head); 752 753 /* 754 * If not changing directories, reset the path back to original 755 * state. 756 */ 757 if (ISSET(FTS_NOCHDIR)) { 758 if (len == sp->fts_pathlen || nitems == 0) 759 --cp; 760 *cp = '\0'; 761 } 762 763 /* 764 * If descended after called from fts_children or after called from 765 * fts_read and nothing found, get back. At the root level we use 766 * the saved fd; if one of fts_open()'s arguments is a relative path 767 * to an empty directory, we wind up here with no other way back. If 768 * can't get back, we're done. 769 */ 770 if (descend && (type == BCHILD || !nitems) && 771 (cur->fts_level == FTS_ROOTLEVEL ? FCHDIR(sp, sp->fts_rfd) : 772 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 773 cur->fts_info = FTS_ERR; 774 SET(FTS_STOP); 775 return (NULL); 776 } 777 778 /* If didn't find anything, return NULL. */ 779 if (!nitems) { 780 if (type == BREAD) 781 cur->fts_info = FTS_DP; 782 return (NULL); 783 } 784 785 /* Sort the entries. */ 786 if (sp->fts_compar && nitems > 1) 787 head = fts_sort(sp, head, nitems); 788 return (head); 789 } 790 791 static u_short 792 fts_stat(FTS *sp, FTSENT *p, int follow) 793 { 794 FTSENT *t; 795 dev_t dev; 796 ino_t ino; 797 struct stat *sbp, sb; 798 int saved_errno; 799 800 /* If user needs stat info, stat buffer already allocated. */ 801 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 802 803 /* 804 * If doing a logical walk, or application requested FTS_FOLLOW, do 805 * a stat(2). If that fails, check for a non-existent symlink. If 806 * fail, set the errno from the stat call. 807 */ 808 if (ISSET(FTS_LOGICAL) || follow) { 809 if (stat(p->fts_accpath, sbp)) { 810 saved_errno = errno; 811 if (!lstat(p->fts_accpath, sbp)) { 812 errno = 0; 813 return (FTS_SLNONE); 814 } 815 p->fts_errno = saved_errno; 816 goto err; 817 } 818 } else if (lstat(p->fts_accpath, sbp)) { 819 p->fts_errno = errno; 820 err: memset(sbp, 0, sizeof(struct stat)); 821 return (FTS_NS); 822 } 823 824 if (S_ISDIR(sbp->st_mode)) { 825 /* 826 * Set the device/inode. Used to find cycles and check for 827 * crossing mount points. Also remember the link count, used 828 * in fts_build to limit the number of stat calls. It is 829 * understood that these fields are only referenced if fts_info 830 * is set to FTS_D. 831 */ 832 dev = p->fts_dev = sbp->st_dev; 833 ino = p->fts_ino = sbp->st_ino; 834 p->fts_nlink = sbp->st_nlink; 835 836 if (ISDOT(p->fts_name)) 837 return (FTS_DOT); 838 839 /* 840 * Cycle detection is done by brute force when the directory 841 * is first encountered. If the tree gets deep enough or the 842 * number of symbolic links to directories is high enough, 843 * something faster might be worthwhile. 844 */ 845 for (t = p->fts_parent; 846 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 847 if (ino == t->fts_ino && dev == t->fts_dev) { 848 p->fts_cycle = t; 849 return (FTS_DC); 850 } 851 return (FTS_D); 852 } 853 if (S_ISLNK(sbp->st_mode)) 854 return (FTS_SL); 855 if (S_ISREG(sbp->st_mode)) 856 return (FTS_F); 857 return (FTS_DEFAULT); 858 } 859 860 static FTSENT * 861 fts_sort(FTS *sp, FTSENT *head, int nitems) 862 { 863 FTSENT **ap, *p; 864 865 /* 866 * Construct an array of pointers to the structures and call qsort(3). 867 * Reassemble the array in the order returned by qsort. If unable to 868 * sort for memory reasons, return the directory entries in their 869 * current order. Allocate enough space for the current needs plus 870 * 40 so don't realloc one entry at a time. 871 */ 872 if (nitems > sp->fts_nitems) { 873 struct _ftsent **a; 874 875 sp->fts_nitems = nitems + 40; 876 if ((a = realloc(sp->fts_array, 877 sp->fts_nitems * sizeof(FTSENT *))) == NULL) { 878 if (sp->fts_array) 879 free(sp->fts_array); 880 sp->fts_array = NULL; 881 sp->fts_nitems = 0; 882 return (head); 883 } 884 sp->fts_array = a; 885 } 886 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 887 *ap++ = p; 888 qsort((void *)sp->fts_array, nitems, sizeof(FTSENT *), sp->fts_compar); 889 for (head = *(ap = sp->fts_array); --nitems; ++ap) 890 ap[0]->fts_link = ap[1]; 891 ap[0]->fts_link = NULL; 892 return (head); 893 } 894 895 static FTSENT * 896 fts_alloc(FTS *sp, char *name, size_t namelen) 897 { 898 FTSENT *p; 899 size_t len; 900 901 /* 902 * The file name is a variable length array and no stat structure is 903 * necessary if the user has set the nostat bit. Allocate the FTSENT 904 * structure, the file name and the stat structure in one chunk, but 905 * be careful that the stat structure is reasonably aligned. Since the 906 * fts_name field is declared to be of size 1, the fts_name pointer is 907 * namelen + 2 before the first possible address of the stat structure. 908 */ 909 len = sizeof(FTSENT) + namelen; 910 if (!ISSET(FTS_NOSTAT)) 911 len += sizeof(struct stat) + ALIGNBYTES; 912 if ((p = calloc(1, len)) == NULL) 913 return (NULL); 914 915 p->fts_path = sp->fts_path; 916 p->fts_namelen = namelen; 917 p->fts_instr = FTS_NOINSTR; 918 if (!ISSET(FTS_NOSTAT)) 919 p->fts_statp = (struct stat *)ALIGN(p->fts_name + namelen + 2); 920 memcpy(p->fts_name, name, namelen); 921 922 return (p); 923 } 924 925 static void 926 fts_lfree(FTSENT *head) 927 { 928 FTSENT *p; 929 930 /* Free a linked list of structures. */ 931 while ((p = head)) { 932 head = head->fts_link; 933 free(p); 934 } 935 } 936 937 /* 938 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 939 * Most systems will allow creation of paths much longer than PATH_MAX, even 940 * though the kernel won't resolve them. Add the size (not just what's needed) 941 * plus 256 bytes so don't realloc the path 2 bytes at a time. 942 */ 943 static int 944 fts_palloc(FTS *sp, size_t more) 945 { 946 char *p; 947 948 /* 949 * Check for possible wraparound. 950 */ 951 more += 256; 952 if (sp->fts_pathlen + more < sp->fts_pathlen) { 953 if (sp->fts_path) 954 free(sp->fts_path); 955 sp->fts_path = NULL; 956 errno = ENAMETOOLONG; 957 return (1); 958 } 959 sp->fts_pathlen += more; 960 p = realloc(sp->fts_path, sp->fts_pathlen); 961 if (p == NULL) { 962 if (sp->fts_path) 963 free(sp->fts_path); 964 sp->fts_path = NULL; 965 return (1); 966 } 967 sp->fts_path = p; 968 return (0); 969 } 970 971 /* 972 * When the path is realloc'd, have to fix all of the pointers in structures 973 * already returned. 974 */ 975 static void 976 fts_padjust(FTS *sp, FTSENT *head) 977 { 978 FTSENT *p; 979 char *addr = sp->fts_path; 980 981 #define ADJUST(p) { \ 982 if ((p)->fts_accpath != (p)->fts_name) { \ 983 (p)->fts_accpath = \ 984 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \ 985 } \ 986 (p)->fts_path = addr; \ 987 } 988 /* Adjust the current set of children. */ 989 for (p = sp->fts_child; p; p = p->fts_link) 990 ADJUST(p); 991 992 /* Adjust the rest of the tree, including the current level. */ 993 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 994 ADJUST(p); 995 p = p->fts_link ? p->fts_link : p->fts_parent; 996 } 997 } 998 999 static size_t 1000 fts_maxarglen(char * const *argv) 1001 { 1002 size_t len, max; 1003 1004 for (max = 0; *argv; ++argv) 1005 if ((len = strlen(*argv)) > max) 1006 max = len; 1007 return (max + 1); 1008 } 1009 1010 /* 1011 * Change to dir specified by fd or p->fts_accpath without getting 1012 * tricked by someone changing the world out from underneath us. 1013 * Assumes p->fts_dev and p->fts_ino are filled in. 1014 */ 1015 static int 1016 fts_safe_changedir(FTS *sp, FTSENT *p, int fd, char *path) 1017 { 1018 int ret, oerrno, newfd; 1019 struct stat sb; 1020 1021 newfd = fd; 1022 if (ISSET(FTS_NOCHDIR)) 1023 return (0); 1024 if (fd < 0 && (newfd = open(path, O_RDONLY, 0)) < 0) 1025 return (-1); 1026 if (fstat(newfd, &sb)) { 1027 ret = -1; 1028 goto bail; 1029 } 1030 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) { 1031 errno = ENOENT; /* disinformation */ 1032 ret = -1; 1033 goto bail; 1034 } 1035 ret = fchdir(newfd); 1036 bail: 1037 oerrno = errno; 1038 if (fd < 0) 1039 (void)close(newfd); 1040 errno = oerrno; 1041 return (ret); 1042 } 1043
