fts.c revision 129161
1/*- 2 * Copyright (c) 1990, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * $OpenBSD: fts.c,v 1.22 1999/10/03 19:22:22 millert Exp $ 34 */ 35 36#if defined(LIBC_SCCS) && !defined(lint) 37static char sccsid[] = "@(#)fts.c 8.6 (Berkeley) 8/14/94"; 38#endif /* LIBC_SCCS and not lint */ 39#include <sys/cdefs.h> 40__FBSDID("$FreeBSD: head/lib/libc/gen/fts.c 129161 2004-05-12 21:38:39Z peadar $"); 41 42#include "namespace.h" 43#include <sys/param.h> 44#include <sys/mount.h> 45#include <sys/stat.h> 46 47#include <dirent.h> 48#include <errno.h> 49#include <fcntl.h> 50#include <fts.h> 51#include <stdlib.h> 52#include <string.h> 53#include <unistd.h> 54#include "un-namespace.h" 55 56static FTSENT *fts_alloc(FTS *, char *, int); 57static FTSENT *fts_build(FTS *, int); 58static void fts_lfree(FTSENT *); 59static void fts_load(FTS *, FTSENT *); 60static size_t fts_maxarglen(char * const *); 61static void fts_padjust(FTS *, FTSENT *); 62static int fts_palloc(FTS *, size_t); 63static FTSENT *fts_sort(FTS *, FTSENT *, int); 64static u_short fts_stat(FTS *, FTSENT *, int); 65static int fts_safe_changedir(FTS *, FTSENT *, int, char *); 66static int fts_ufslinks(FTS *, const FTSENT *); 67 68#define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2]))) 69 70#define CLR(opt) (sp->fts_options &= ~(opt)) 71#define ISSET(opt) (sp->fts_options & (opt)) 72#define SET(opt) (sp->fts_options |= (opt)) 73 74#define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 75 76/* fts_build flags */ 77#define BCHILD 1 /* fts_children */ 78#define BNAMES 2 /* fts_children, names only */ 79#define BREAD 3 /* fts_read */ 80 81/* 82 * Internal representation of an FTS, including extra implementation 83 * details. The FTS returned from fts_open points to this structure's 84 * ftsp_fts member (and can be cast to an _fts_private as required) 85 */ 86struct _fts_private { 87 FTS ftsp_fts; 88 struct statfs ftsp_statfs; 89 dev_t ftsp_dev; 90 int ftsp_linksreliable; 91}; 92 93/* 94 * The "FTS_NOSTAT" option can avoid a lot of calls to stat(2) if it 95 * knows that a directory could not possibly have subdirectories. This 96 * is decided by looking at the link count: a subdirectory would 97 * increment its parent's link count by virtue of its own ".." entry. 98 * This assumption only holds for UFS-like filesystems that implement 99 * links and directories this way, so we must punt for others. 100 */ 101 102static const char *ufslike_filesystems[] = { 103 "ufs", 104 "nfs", 105 "nfs4", 106 "ext2fs", 107 0 108}; 109 110FTS * 111fts_open(argv, options, compar) 112 char * const *argv; 113 int options; 114 int (*compar)(const FTSENT * const *, const FTSENT * const *); 115{ 116 struct _fts_private *priv; 117 FTS *sp; 118 FTSENT *p, *root; 119 int nitems; 120 FTSENT *parent, *tmp; 121 int len; 122 123 /* Options check. */ 124 if (options & ~FTS_OPTIONMASK) { 125 errno = EINVAL; 126 return (NULL); 127 } 128 129 /* Allocate/initialize the stream */ 130 if ((priv = malloc(sizeof(*priv))) == NULL) 131 return (NULL); 132 memset(priv, 0, sizeof(*priv)); 133 sp = &priv->ftsp_fts; 134 sp->fts_compar = compar; 135 sp->fts_options = options; 136 137 /* Shush, GCC. */ 138 tmp = NULL; 139 140 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 141 if (ISSET(FTS_LOGICAL)) 142 SET(FTS_NOCHDIR); 143 144 /* 145 * Start out with 1K of path space, and enough, in any case, 146 * to hold the user's paths. 147 */ 148 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN))) 149 goto mem1; 150 151 /* Allocate/initialize root's parent. */ 152 if ((parent = fts_alloc(sp, "", 0)) == NULL) 153 goto mem2; 154 parent->fts_level = FTS_ROOTPARENTLEVEL; 155 156 /* Allocate/initialize root(s). */ 157 for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) { 158 /* Don't allow zero-length paths. */ 159 if ((len = strlen(*argv)) == 0) { 160 errno = ENOENT; 161 goto mem3; 162 } 163 164 p = fts_alloc(sp, *argv, len); 165 p->fts_level = FTS_ROOTLEVEL; 166 p->fts_parent = parent; 167 p->fts_accpath = p->fts_name; 168 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW)); 169 170 /* Command-line "." and ".." are real directories. */ 171 if (p->fts_info == FTS_DOT) 172 p->fts_info = FTS_D; 173 174 /* 175 * If comparison routine supplied, traverse in sorted 176 * order; otherwise traverse in the order specified. 177 */ 178 if (compar) { 179 p->fts_link = root; 180 root = p; 181 } else { 182 p->fts_link = NULL; 183 if (root == NULL) 184 tmp = root = p; 185 else { 186 tmp->fts_link = p; 187 tmp = p; 188 } 189 } 190 } 191 if (compar && nitems > 1) 192 root = fts_sort(sp, root, nitems); 193 194 /* 195 * Allocate a dummy pointer and make fts_read think that we've just 196 * finished the node before the root(s); set p->fts_info to FTS_INIT 197 * so that everything about the "current" node is ignored. 198 */ 199 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 200 goto mem3; 201 sp->fts_cur->fts_link = root; 202 sp->fts_cur->fts_info = FTS_INIT; 203 204 /* 205 * If using chdir(2), grab a file descriptor pointing to dot to ensure 206 * that we can get back here; this could be avoided for some paths, 207 * but almost certainly not worth the effort. Slashes, symbolic links, 208 * and ".." are all fairly nasty problems. Note, if we can't get the 209 * descriptor we run anyway, just more slowly. 210 */ 211 if (!ISSET(FTS_NOCHDIR) && (sp->fts_rfd = _open(".", O_RDONLY, 0)) < 0) 212 SET(FTS_NOCHDIR); 213 214 return (sp); 215 216mem3: fts_lfree(root); 217 free(parent); 218mem2: free(sp->fts_path); 219mem1: free(sp); 220 return (NULL); 221} 222 223static void 224fts_load(sp, p) 225 FTS *sp; 226 FTSENT *p; 227{ 228 int len; 229 char *cp; 230 231 /* 232 * Load the stream structure for the next traversal. Since we don't 233 * actually enter the directory until after the preorder visit, set 234 * the fts_accpath field specially so the chdir gets done to the right 235 * place and the user can access the first node. From fts_open it's 236 * known that the path will fit. 237 */ 238 len = p->fts_pathlen = p->fts_namelen; 239 memmove(sp->fts_path, p->fts_name, len + 1); 240 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 241 len = strlen(++cp); 242 memmove(p->fts_name, cp, len + 1); 243 p->fts_namelen = len; 244 } 245 p->fts_accpath = p->fts_path = sp->fts_path; 246 sp->fts_dev = p->fts_dev; 247} 248 249int 250fts_close(sp) 251 FTS *sp; 252{ 253 FTSENT *freep, *p; 254 int saved_errno; 255 256 /* 257 * This still works if we haven't read anything -- the dummy structure 258 * points to the root list, so we step through to the end of the root 259 * list which has a valid parent pointer. 260 */ 261 if (sp->fts_cur) { 262 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 263 freep = p; 264 p = p->fts_link != NULL ? p->fts_link : p->fts_parent; 265 free(freep); 266 } 267 free(p); 268 } 269 270 /* Free up child linked list, sort array, path buffer. */ 271 if (sp->fts_child) 272 fts_lfree(sp->fts_child); 273 if (sp->fts_array) 274 free(sp->fts_array); 275 free(sp->fts_path); 276 277 /* Return to original directory, save errno if necessary. */ 278 if (!ISSET(FTS_NOCHDIR)) { 279 saved_errno = fchdir(sp->fts_rfd) ? errno : 0; 280 (void)_close(sp->fts_rfd); 281 282 /* Set errno and return. */ 283 if (saved_errno != 0) { 284 /* Free up the stream pointer. */ 285 free(sp); 286 errno = saved_errno; 287 return (-1); 288 } 289 } 290 291 /* Free up the stream pointer. */ 292 free(sp); 293 return (0); 294} 295 296/* 297 * Special case of "/" at the end of the path so that slashes aren't 298 * appended which would cause paths to be written as "....//foo". 299 */ 300#define NAPPEND(p) \ 301 (p->fts_path[p->fts_pathlen - 1] == '/' \ 302 ? p->fts_pathlen - 1 : p->fts_pathlen) 303 304FTSENT * 305fts_read(sp) 306 FTS *sp; 307{ 308 FTSENT *p, *tmp; 309 int instr; 310 char *t; 311 int saved_errno; 312 313 /* If finished or unrecoverable error, return NULL. */ 314 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 315 return (NULL); 316 317 /* Set current node pointer. */ 318 p = sp->fts_cur; 319 320 /* Save and zero out user instructions. */ 321 instr = p->fts_instr; 322 p->fts_instr = FTS_NOINSTR; 323 324 /* Any type of file may be re-visited; re-stat and re-turn. */ 325 if (instr == FTS_AGAIN) { 326 p->fts_info = fts_stat(sp, p, 0); 327 return (p); 328 } 329 330 /* 331 * Following a symlink -- SLNONE test allows application to see 332 * SLNONE and recover. If indirecting through a symlink, have 333 * keep a pointer to current location. If unable to get that 334 * pointer, follow fails. 335 */ 336 if (instr == FTS_FOLLOW && 337 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 338 p->fts_info = fts_stat(sp, p, 1); 339 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 340 if ((p->fts_symfd = _open(".", O_RDONLY, 0)) < 0) { 341 p->fts_errno = errno; 342 p->fts_info = FTS_ERR; 343 } else 344 p->fts_flags |= FTS_SYMFOLLOW; 345 } 346 return (p); 347 } 348 349 /* Directory in pre-order. */ 350 if (p->fts_info == FTS_D) { 351 /* If skipped or crossed mount point, do post-order visit. */ 352 if (instr == FTS_SKIP || 353 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 354 if (p->fts_flags & FTS_SYMFOLLOW) 355 (void)_close(p->fts_symfd); 356 if (sp->fts_child) { 357 fts_lfree(sp->fts_child); 358 sp->fts_child = NULL; 359 } 360 p->fts_info = FTS_DP; 361 return (p); 362 } 363 364 /* Rebuild if only read the names and now traversing. */ 365 if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) { 366 CLR(FTS_NAMEONLY); 367 fts_lfree(sp->fts_child); 368 sp->fts_child = NULL; 369 } 370 371 /* 372 * Cd to the subdirectory. 373 * 374 * If have already read and now fail to chdir, whack the list 375 * to make the names come out right, and set the parent errno 376 * so the application will eventually get an error condition. 377 * Set the FTS_DONTCHDIR flag so that when we logically change 378 * directories back to the parent we don't do a chdir. 379 * 380 * If haven't read do so. If the read fails, fts_build sets 381 * FTS_STOP or the fts_info field of the node. 382 */ 383 if (sp->fts_child != NULL) { 384 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 385 p->fts_errno = errno; 386 p->fts_flags |= FTS_DONTCHDIR; 387 for (p = sp->fts_child; p != NULL; 388 p = p->fts_link) 389 p->fts_accpath = 390 p->fts_parent->fts_accpath; 391 } 392 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 393 if (ISSET(FTS_STOP)) 394 return (NULL); 395 return (p); 396 } 397 p = sp->fts_child; 398 sp->fts_child = NULL; 399 goto name; 400 } 401 402 /* Move to the next node on this level. */ 403next: tmp = p; 404 if ((p = p->fts_link) != NULL) { 405 free(tmp); 406 407 /* 408 * If reached the top, return to the original directory (or 409 * the root of the tree), and load the paths for the next root. 410 */ 411 if (p->fts_level == FTS_ROOTLEVEL) { 412 if (FCHDIR(sp, sp->fts_rfd)) { 413 SET(FTS_STOP); 414 return (NULL); 415 } 416 fts_load(sp, p); 417 return (sp->fts_cur = p); 418 } 419 420 /* 421 * User may have called fts_set on the node. If skipped, 422 * ignore. If followed, get a file descriptor so we can 423 * get back if necessary. 424 */ 425 if (p->fts_instr == FTS_SKIP) 426 goto next; 427 if (p->fts_instr == FTS_FOLLOW) { 428 p->fts_info = fts_stat(sp, p, 1); 429 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 430 if ((p->fts_symfd = 431 _open(".", O_RDONLY, 0)) < 0) { 432 p->fts_errno = errno; 433 p->fts_info = FTS_ERR; 434 } else 435 p->fts_flags |= FTS_SYMFOLLOW; 436 } 437 p->fts_instr = FTS_NOINSTR; 438 } 439 440name: t = sp->fts_path + NAPPEND(p->fts_parent); 441 *t++ = '/'; 442 memmove(t, p->fts_name, p->fts_namelen + 1); 443 return (sp->fts_cur = p); 444 } 445 446 /* Move up to the parent node. */ 447 p = tmp->fts_parent; 448 free(tmp); 449 450 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 451 /* 452 * Done; free everything up and set errno to 0 so the user 453 * can distinguish between error and EOF. 454 */ 455 free(p); 456 errno = 0; 457 return (sp->fts_cur = NULL); 458 } 459 460 /* NUL terminate the pathname. */ 461 sp->fts_path[p->fts_pathlen] = '\0'; 462 463 /* 464 * Return to the parent directory. If at a root node or came through 465 * a symlink, go back through the file descriptor. Otherwise, cd up 466 * one directory. 467 */ 468 if (p->fts_level == FTS_ROOTLEVEL) { 469 if (FCHDIR(sp, sp->fts_rfd)) { 470 SET(FTS_STOP); 471 return (NULL); 472 } 473 } else if (p->fts_flags & FTS_SYMFOLLOW) { 474 if (FCHDIR(sp, p->fts_symfd)) { 475 saved_errno = errno; 476 (void)_close(p->fts_symfd); 477 errno = saved_errno; 478 SET(FTS_STOP); 479 return (NULL); 480 } 481 (void)_close(p->fts_symfd); 482 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 483 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 484 SET(FTS_STOP); 485 return (NULL); 486 } 487 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 488 return (sp->fts_cur = p); 489} 490 491/* 492 * Fts_set takes the stream as an argument although it's not used in this 493 * implementation; it would be necessary if anyone wanted to add global 494 * semantics to fts using fts_set. An error return is allowed for similar 495 * reasons. 496 */ 497/* ARGSUSED */ 498int 499fts_set(sp, p, instr) 500 FTS *sp; 501 FTSENT *p; 502 int instr; 503{ 504 if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW && 505 instr != FTS_NOINSTR && instr != FTS_SKIP) { 506 errno = EINVAL; 507 return (1); 508 } 509 p->fts_instr = instr; 510 return (0); 511} 512 513FTSENT * 514fts_children(sp, instr) 515 FTS *sp; 516 int instr; 517{ 518 FTSENT *p; 519 int fd; 520 521 if (instr != 0 && instr != FTS_NAMEONLY) { 522 errno = EINVAL; 523 return (NULL); 524 } 525 526 /* Set current node pointer. */ 527 p = sp->fts_cur; 528 529 /* 530 * Errno set to 0 so user can distinguish empty directory from 531 * an error. 532 */ 533 errno = 0; 534 535 /* Fatal errors stop here. */ 536 if (ISSET(FTS_STOP)) 537 return (NULL); 538 539 /* Return logical hierarchy of user's arguments. */ 540 if (p->fts_info == FTS_INIT) 541 return (p->fts_link); 542 543 /* 544 * If not a directory being visited in pre-order, stop here. Could 545 * allow FTS_DNR, assuming the user has fixed the problem, but the 546 * same effect is available with FTS_AGAIN. 547 */ 548 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 549 return (NULL); 550 551 /* Free up any previous child list. */ 552 if (sp->fts_child != NULL) 553 fts_lfree(sp->fts_child); 554 555 if (instr == FTS_NAMEONLY) { 556 SET(FTS_NAMEONLY); 557 instr = BNAMES; 558 } else 559 instr = BCHILD; 560 561 /* 562 * If using chdir on a relative path and called BEFORE fts_read does 563 * its chdir to the root of a traversal, we can lose -- we need to 564 * chdir into the subdirectory, and we don't know where the current 565 * directory is, so we can't get back so that the upcoming chdir by 566 * fts_read will work. 567 */ 568 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 569 ISSET(FTS_NOCHDIR)) 570 return (sp->fts_child = fts_build(sp, instr)); 571 572 if ((fd = _open(".", O_RDONLY, 0)) < 0) 573 return (NULL); 574 sp->fts_child = fts_build(sp, instr); 575 if (fchdir(fd)) 576 return (NULL); 577 (void)_close(fd); 578 return (sp->fts_child); 579} 580 581#ifndef fts_get_clientptr 582#error "fts_get_clientptr not defined" 583#endif 584 585void * 586(fts_get_clientptr)(FTS *sp) 587{ 588 589 return (fts_get_clientptr(sp)); 590} 591 592#ifndef fts_get_stream 593#error "fts_get_stream not defined" 594#endif 595 596FTS * 597(fts_get_stream)(FTSENT *p) 598{ 599 return (fts_get_stream(p)); 600} 601 602void 603fts_set_clientptr(FTS *sp, void *clientptr) 604{ 605 606 sp->fts_clientptr = clientptr; 607} 608 609/* 610 * This is the tricky part -- do not casually change *anything* in here. The 611 * idea is to build the linked list of entries that are used by fts_children 612 * and fts_read. There are lots of special cases. 613 * 614 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 615 * set and it's a physical walk (so that symbolic links can't be directories), 616 * we can do things quickly. First, if it's a 4.4BSD file system, the type 617 * of the file is in the directory entry. Otherwise, we assume that the number 618 * of subdirectories in a node is equal to the number of links to the parent. 619 * The former skips all stat calls. The latter skips stat calls in any leaf 620 * directories and for any files after the subdirectories in the directory have 621 * been found, cutting the stat calls by about 2/3. 622 */ 623static FTSENT * 624fts_build(sp, type) 625 FTS *sp; 626 int type; 627{ 628 struct dirent *dp; 629 FTSENT *p, *head; 630 int nitems; 631 FTSENT *cur, *tail; 632 DIR *dirp; 633 void *oldaddr; 634 size_t dnamlen; 635 int cderrno, descend, len, level, maxlen, nlinks, oflag, saved_errno, 636 nostat, doadjust; 637 char *cp; 638 639 /* Set current node pointer. */ 640 cur = sp->fts_cur; 641 642 /* 643 * Open the directory for reading. If this fails, we're done. 644 * If being called from fts_read, set the fts_info field. 645 */ 646#ifdef FTS_WHITEOUT 647 if (ISSET(FTS_WHITEOUT)) 648 oflag = DTF_NODUP|DTF_REWIND; 649 else 650 oflag = DTF_HIDEW|DTF_NODUP|DTF_REWIND; 651#else 652#define __opendir2(path, flag) opendir(path) 653#endif 654 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) { 655 if (type == BREAD) { 656 cur->fts_info = FTS_DNR; 657 cur->fts_errno = errno; 658 } 659 return (NULL); 660 } 661 662 /* 663 * Nlinks is the number of possible entries of type directory in the 664 * directory if we're cheating on stat calls, 0 if we're not doing 665 * any stat calls at all, -1 if we're doing stats on everything. 666 */ 667 if (type == BNAMES) { 668 nlinks = 0; 669 /* Be quiet about nostat, GCC. */ 670 nostat = 0; 671 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 672 if (fts_ufslinks(sp, cur)) 673 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 674 else 675 nlinks = -1; 676 nostat = 1; 677 } else { 678 nlinks = -1; 679 nostat = 0; 680 } 681 682#ifdef notdef 683 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 684 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 685 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 686#endif 687 /* 688 * If we're going to need to stat anything or we want to descend 689 * and stay in the directory, chdir. If this fails we keep going, 690 * but set a flag so we don't chdir after the post-order visit. 691 * We won't be able to stat anything, but we can still return the 692 * names themselves. Note, that since fts_read won't be able to 693 * chdir into the directory, it will have to return different path 694 * names than before, i.e. "a/b" instead of "b". Since the node 695 * has already been visited in pre-order, have to wait until the 696 * post-order visit to return the error. There is a special case 697 * here, if there was nothing to stat then it's not an error to 698 * not be able to stat. This is all fairly nasty. If a program 699 * needed sorted entries or stat information, they had better be 700 * checking FTS_NS on the returned nodes. 701 */ 702 cderrno = 0; 703 if (nlinks || type == BREAD) { 704 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) { 705 if (nlinks && type == BREAD) 706 cur->fts_errno = errno; 707 cur->fts_flags |= FTS_DONTCHDIR; 708 descend = 0; 709 cderrno = errno; 710 (void)closedir(dirp); 711 dirp = NULL; 712 } else 713 descend = 1; 714 } else 715 descend = 0; 716 717 /* 718 * Figure out the max file name length that can be stored in the 719 * current path -- the inner loop allocates more path as necessary. 720 * We really wouldn't have to do the maxlen calculations here, we 721 * could do them in fts_read before returning the path, but it's a 722 * lot easier here since the length is part of the dirent structure. 723 * 724 * If not changing directories set a pointer so that can just append 725 * each new name into the path. 726 */ 727 len = NAPPEND(cur); 728 if (ISSET(FTS_NOCHDIR)) { 729 cp = sp->fts_path + len; 730 *cp++ = '/'; 731 } else { 732 /* GCC, you're too verbose. */ 733 cp = NULL; 734 } 735 len++; 736 maxlen = sp->fts_pathlen - len; 737 738 level = cur->fts_level + 1; 739 740 /* Read the directory, attaching each entry to the `link' pointer. */ 741 doadjust = 0; 742 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) { 743 dnamlen = dp->d_namlen; 744 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 745 continue; 746 747 if ((p = fts_alloc(sp, dp->d_name, (int)dnamlen)) == NULL) 748 goto mem1; 749 if (dnamlen >= maxlen) { /* include space for NUL */ 750 oldaddr = sp->fts_path; 751 if (fts_palloc(sp, dnamlen + len + 1)) { 752 /* 753 * No more memory for path or structures. Save 754 * errno, free up the current structure and the 755 * structures already allocated. 756 */ 757mem1: saved_errno = errno; 758 if (p) 759 free(p); 760 fts_lfree(head); 761 (void)closedir(dirp); 762 cur->fts_info = FTS_ERR; 763 SET(FTS_STOP); 764 errno = saved_errno; 765 return (NULL); 766 } 767 /* Did realloc() change the pointer? */ 768 if (oldaddr != sp->fts_path) { 769 doadjust = 1; 770 if (ISSET(FTS_NOCHDIR)) 771 cp = sp->fts_path + len; 772 } 773 maxlen = sp->fts_pathlen - len; 774 } 775 776 if (len + dnamlen >= USHRT_MAX) { 777 /* 778 * In an FTSENT, fts_pathlen is a u_short so it is 779 * possible to wraparound here. If we do, free up 780 * the current structure and the structures already 781 * allocated, then error out with ENAMETOOLONG. 782 */ 783 free(p); 784 fts_lfree(head); 785 (void)closedir(dirp); 786 cur->fts_info = FTS_ERR; 787 SET(FTS_STOP); 788 errno = ENAMETOOLONG; 789 return (NULL); 790 } 791 p->fts_level = level; 792 p->fts_parent = sp->fts_cur; 793 p->fts_pathlen = len + dnamlen; 794 795#ifdef FTS_WHITEOUT 796 if (dp->d_type == DT_WHT) 797 p->fts_flags |= FTS_ISW; 798#endif 799 800 if (cderrno) { 801 if (nlinks) { 802 p->fts_info = FTS_NS; 803 p->fts_errno = cderrno; 804 } else 805 p->fts_info = FTS_NSOK; 806 p->fts_accpath = cur->fts_accpath; 807 } else if (nlinks == 0 808#ifdef DT_DIR 809 || (nostat && 810 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 811#endif 812 ) { 813 p->fts_accpath = 814 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 815 p->fts_info = FTS_NSOK; 816 } else { 817 /* Build a file name for fts_stat to stat. */ 818 if (ISSET(FTS_NOCHDIR)) { 819 p->fts_accpath = p->fts_path; 820 memmove(cp, p->fts_name, p->fts_namelen + 1); 821 } else 822 p->fts_accpath = p->fts_name; 823 /* Stat it. */ 824 p->fts_info = fts_stat(sp, p, 0); 825 826 /* Decrement link count if applicable. */ 827 if (nlinks > 0 && (p->fts_info == FTS_D || 828 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 829 --nlinks; 830 } 831 832 /* We walk in directory order so "ls -f" doesn't get upset. */ 833 p->fts_link = NULL; 834 if (head == NULL) 835 head = tail = p; 836 else { 837 tail->fts_link = p; 838 tail = p; 839 } 840 ++nitems; 841 } 842 if (dirp) 843 (void)closedir(dirp); 844 845 /* 846 * If realloc() changed the address of the path, adjust the 847 * addresses for the rest of the tree and the dir list. 848 */ 849 if (doadjust) 850 fts_padjust(sp, head); 851 852 /* 853 * If not changing directories, reset the path back to original 854 * state. 855 */ 856 if (ISSET(FTS_NOCHDIR)) { 857 if (len == sp->fts_pathlen || nitems == 0) 858 --cp; 859 *cp = '\0'; 860 } 861 862 /* 863 * If descended after called from fts_children or after called from 864 * fts_read and nothing found, get back. At the root level we use 865 * the saved fd; if one of fts_open()'s arguments is a relative path 866 * to an empty directory, we wind up here with no other way back. If 867 * can't get back, we're done. 868 */ 869 if (descend && (type == BCHILD || !nitems) && 870 (cur->fts_level == FTS_ROOTLEVEL ? 871 FCHDIR(sp, sp->fts_rfd) : 872 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 873 cur->fts_info = FTS_ERR; 874 SET(FTS_STOP); 875 return (NULL); 876 } 877 878 /* If didn't find anything, return NULL. */ 879 if (!nitems) { 880 if (type == BREAD) 881 cur->fts_info = FTS_DP; 882 return (NULL); 883 } 884 885 /* Sort the entries. */ 886 if (sp->fts_compar && nitems > 1) 887 head = fts_sort(sp, head, nitems); 888 return (head); 889} 890 891static u_short 892fts_stat(sp, p, follow) 893 FTS *sp; 894 FTSENT *p; 895 int follow; 896{ 897 FTSENT *t; 898 dev_t dev; 899 ino_t ino; 900 struct stat *sbp, sb; 901 int saved_errno; 902 903 /* If user needs stat info, stat buffer already allocated. */ 904 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 905 906#ifdef FTS_WHITEOUT 907 /* check for whiteout */ 908 if (p->fts_flags & FTS_ISW) { 909 if (sbp != &sb) { 910 memset(sbp, '\0', sizeof (*sbp)); 911 sbp->st_mode = S_IFWHT; 912 } 913 return (FTS_W); 914 } 915#endif 916 917 /* 918 * If doing a logical walk, or application requested FTS_FOLLOW, do 919 * a stat(2). If that fails, check for a non-existent symlink. If 920 * fail, set the errno from the stat call. 921 */ 922 if (ISSET(FTS_LOGICAL) || follow) { 923 if (stat(p->fts_accpath, sbp)) { 924 saved_errno = errno; 925 if (!lstat(p->fts_accpath, sbp)) { 926 errno = 0; 927 return (FTS_SLNONE); 928 } 929 p->fts_errno = saved_errno; 930 goto err; 931 } 932 } else if (lstat(p->fts_accpath, sbp)) { 933 p->fts_errno = errno; 934err: memset(sbp, 0, sizeof(struct stat)); 935 return (FTS_NS); 936 } 937 938 if (S_ISDIR(sbp->st_mode)) { 939 /* 940 * Set the device/inode. Used to find cycles and check for 941 * crossing mount points. Also remember the link count, used 942 * in fts_build to limit the number of stat calls. It is 943 * understood that these fields are only referenced if fts_info 944 * is set to FTS_D. 945 */ 946 dev = p->fts_dev = sbp->st_dev; 947 ino = p->fts_ino = sbp->st_ino; 948 p->fts_nlink = sbp->st_nlink; 949 950 if (ISDOT(p->fts_name)) 951 return (FTS_DOT); 952 953 /* 954 * Cycle detection is done by brute force when the directory 955 * is first encountered. If the tree gets deep enough or the 956 * number of symbolic links to directories is high enough, 957 * something faster might be worthwhile. 958 */ 959 for (t = p->fts_parent; 960 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 961 if (ino == t->fts_ino && dev == t->fts_dev) { 962 p->fts_cycle = t; 963 return (FTS_DC); 964 } 965 return (FTS_D); 966 } 967 if (S_ISLNK(sbp->st_mode)) 968 return (FTS_SL); 969 if (S_ISREG(sbp->st_mode)) 970 return (FTS_F); 971 return (FTS_DEFAULT); 972} 973 974/* 975 * The comparison function takes pointers to pointers to FTSENT structures. 976 * Qsort wants a comparison function that takes pointers to void. 977 * (Both with appropriate levels of const-poisoning, of course!) 978 * Use a trampoline function to deal with the difference. 979 */ 980static int 981fts_compar(const void *a, const void *b) 982{ 983 FTS *parent; 984 985 parent = (*(const FTSENT * const *)a)->fts_fts; 986 return (*parent->fts_compar)(a, b); 987} 988 989static FTSENT * 990fts_sort(sp, head, nitems) 991 FTS *sp; 992 FTSENT *head; 993 int nitems; 994{ 995 FTSENT **ap, *p; 996 997 /* 998 * Construct an array of pointers to the structures and call qsort(3). 999 * Reassemble the array in the order returned by qsort. If unable to 1000 * sort for memory reasons, return the directory entries in their 1001 * current order. Allocate enough space for the current needs plus 1002 * 40 so don't realloc one entry at a time. 1003 */ 1004 if (nitems > sp->fts_nitems) { 1005 sp->fts_nitems = nitems + 40; 1006 if ((sp->fts_array = reallocf(sp->fts_array, 1007 sp->fts_nitems * sizeof(FTSENT *))) == NULL) { 1008 sp->fts_nitems = 0; 1009 return (head); 1010 } 1011 } 1012 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 1013 *ap++ = p; 1014 qsort(sp->fts_array, nitems, sizeof(FTSENT *), fts_compar); 1015 for (head = *(ap = sp->fts_array); --nitems; ++ap) 1016 ap[0]->fts_link = ap[1]; 1017 ap[0]->fts_link = NULL; 1018 return (head); 1019} 1020 1021static FTSENT * 1022fts_alloc(sp, name, namelen) 1023 FTS *sp; 1024 char *name; 1025 int namelen; 1026{ 1027 FTSENT *p; 1028 size_t len; 1029 1030 struct ftsent_withstat { 1031 FTSENT ent; 1032 struct stat statbuf; 1033 }; 1034 1035 /* 1036 * The file name is a variable length array and no stat structure is 1037 * necessary if the user has set the nostat bit. Allocate the FTSENT 1038 * structure, the file name and the stat structure in one chunk, but 1039 * be careful that the stat structure is reasonably aligned. 1040 */ 1041 if (ISSET(FTS_NOSTAT)) 1042 len = sizeof(FTSENT) + namelen + 1; 1043 else 1044 len = sizeof(struct ftsent_withstat) + namelen + 1; 1045 1046 if ((p = malloc(len)) == NULL) 1047 return (NULL); 1048 1049 if (ISSET(FTS_NOSTAT)) { 1050 p->fts_name = (char *)(p + 1); 1051 p->fts_statp = NULL; 1052 } else { 1053 p->fts_name = (char *)((struct ftsent_withstat *)p + 1); 1054 p->fts_statp = &((struct ftsent_withstat *)p)->statbuf; 1055 } 1056 1057 /* Copy the name and guarantee NUL termination. */ 1058 memcpy(p->fts_name, name, namelen); 1059 p->fts_name[namelen] = '\0'; 1060 p->fts_namelen = namelen; 1061 p->fts_path = sp->fts_path; 1062 p->fts_errno = 0; 1063 p->fts_flags = 0; 1064 p->fts_instr = FTS_NOINSTR; 1065 p->fts_number = 0; 1066 p->fts_pointer = NULL; 1067 p->fts_fts = sp; 1068 return (p); 1069} 1070 1071static void 1072fts_lfree(head) 1073 FTSENT *head; 1074{ 1075 FTSENT *p; 1076 1077 /* Free a linked list of structures. */ 1078 while ((p = head)) { 1079 head = head->fts_link; 1080 free(p); 1081 } 1082} 1083 1084/* 1085 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 1086 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 1087 * though the kernel won't resolve them. Add the size (not just what's needed) 1088 * plus 256 bytes so don't realloc the path 2 bytes at a time. 1089 */ 1090static int 1091fts_palloc(sp, more) 1092 FTS *sp; 1093 size_t more; 1094{ 1095 1096 sp->fts_pathlen += more + 256; 1097 /* 1098 * Check for possible wraparound. In an FTS, fts_pathlen is 1099 * a signed int but in an FTSENT it is an unsigned short. 1100 * We limit fts_pathlen to USHRT_MAX to be safe in both cases. 1101 */ 1102 if (sp->fts_pathlen < 0 || sp->fts_pathlen >= USHRT_MAX) { 1103 if (sp->fts_path) 1104 free(sp->fts_path); 1105 sp->fts_path = NULL; 1106 errno = ENAMETOOLONG; 1107 return (1); 1108 } 1109 sp->fts_path = reallocf(sp->fts_path, sp->fts_pathlen); 1110 return (sp->fts_path == NULL); 1111} 1112 1113/* 1114 * When the path is realloc'd, have to fix all of the pointers in structures 1115 * already returned. 1116 */ 1117static void 1118fts_padjust(sp, head) 1119 FTS *sp; 1120 FTSENT *head; 1121{ 1122 FTSENT *p; 1123 char *addr = sp->fts_path; 1124 1125#define ADJUST(p) do { \ 1126 if ((p)->fts_accpath != (p)->fts_name) { \ 1127 (p)->fts_accpath = \ 1128 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \ 1129 } \ 1130 (p)->fts_path = addr; \ 1131} while (0) 1132 /* Adjust the current set of children. */ 1133 for (p = sp->fts_child; p; p = p->fts_link) 1134 ADJUST(p); 1135 1136 /* Adjust the rest of the tree, including the current level. */ 1137 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1138 ADJUST(p); 1139 p = p->fts_link ? p->fts_link : p->fts_parent; 1140 } 1141} 1142 1143static size_t 1144fts_maxarglen(argv) 1145 char * const *argv; 1146{ 1147 size_t len, max; 1148 1149 for (max = 0; *argv; ++argv) 1150 if ((len = strlen(*argv)) > max) 1151 max = len; 1152 return (max + 1); 1153} 1154 1155/* 1156 * Change to dir specified by fd or p->fts_accpath without getting 1157 * tricked by someone changing the world out from underneath us. 1158 * Assumes p->fts_dev and p->fts_ino are filled in. 1159 */ 1160static int 1161fts_safe_changedir(sp, p, fd, path) 1162 FTS *sp; 1163 FTSENT *p; 1164 int fd; 1165 char *path; 1166{ 1167 int ret, oerrno, newfd; 1168 struct stat sb; 1169 1170 newfd = fd; 1171 if (ISSET(FTS_NOCHDIR)) 1172 return (0); 1173 if (fd < 0 && (newfd = _open(path, O_RDONLY, 0)) < 0) 1174 return (-1); 1175 if (_fstat(newfd, &sb)) { 1176 ret = -1; 1177 goto bail; 1178 } 1179 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) { 1180 errno = ENOENT; /* disinformation */ 1181 ret = -1; 1182 goto bail; 1183 } 1184 ret = fchdir(newfd); 1185bail: 1186 oerrno = errno; 1187 if (fd < 0) 1188 (void)_close(newfd); 1189 errno = oerrno; 1190 return (ret); 1191} 1192 1193/* 1194 * Check if the filesystem for "ent" has UFS-style links. 1195 */ 1196static int 1197fts_ufslinks(FTS *sp, const FTSENT *ent) 1198{ 1199 struct _fts_private *priv; 1200 const char **cpp; 1201 1202 priv = (struct _fts_private *)sp; 1203 /* 1204 * If this node's device is different from the previous, grab 1205 * the filesystem information, and decide on the reliability 1206 * of the link information from this filesystem for stat(2) 1207 * avoidance. 1208 */ 1209 if (priv->ftsp_dev != ent->fts_dev) { 1210 if (statfs(ent->fts_path, &priv->ftsp_statfs) != -1) { 1211 priv->ftsp_dev = ent->fts_dev; 1212 priv->ftsp_linksreliable = 0; 1213 for (cpp = ufslike_filesystems; *cpp; cpp++) { 1214 if (strcmp(priv->ftsp_statfs.f_fstypename, 1215 *cpp) == 0) { 1216 priv->ftsp_linksreliable = 1; 1217 break; 1218 } 1219 } 1220 } else { 1221 priv->ftsp_linksreliable = 0; 1222 } 1223 } 1224 return (priv->ftsp_linksreliable); 1225} 1226