fts.c revision 165903
1/*- 2 * Copyright (c) 1990, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $OpenBSD: fts.c,v 1.22 1999/10/03 19:22:22 millert Exp $ 30 */ 31 32#if 0 33#if defined(LIBC_SCCS) && !defined(lint) 34static char sccsid[] = "@(#)fts.c 8.6 (Berkeley) 8/14/94"; 35#endif /* LIBC_SCCS and not lint */ 36#endif 37 38#include <sys/cdefs.h> 39__FBSDID("$FreeBSD: head/lib/libc/gen/fts.c 165903 2007-01-09 00:28:16Z imp $"); 40 41#include "namespace.h" 42#include <sys/param.h> 43#include <sys/mount.h> 44#include <sys/stat.h> 45 46#include <dirent.h> 47#include <errno.h> 48#include <fcntl.h> 49#include <fts.h> 50#include <stdlib.h> 51#include <string.h> 52#include <unistd.h> 53#include "un-namespace.h" 54 55static FTSENT *fts_alloc(FTS *, char *, int); 56static FTSENT *fts_build(FTS *, int); 57static void fts_lfree(FTSENT *); 58static void fts_load(FTS *, FTSENT *); 59static size_t fts_maxarglen(char * const *); 60static void fts_padjust(FTS *, FTSENT *); 61static int fts_palloc(FTS *, size_t); 62static FTSENT *fts_sort(FTS *, FTSENT *, int); 63static u_short fts_stat(FTS *, FTSENT *, int); 64static int fts_safe_changedir(FTS *, FTSENT *, int, char *); 65static int fts_ufslinks(FTS *, const FTSENT *); 66 67#define ISDOT(a) (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2]))) 68 69#define CLR(opt) (sp->fts_options &= ~(opt)) 70#define ISSET(opt) (sp->fts_options & (opt)) 71#define SET(opt) (sp->fts_options |= (opt)) 72 73#define FCHDIR(sp, fd) (!ISSET(FTS_NOCHDIR) && fchdir(fd)) 74 75/* fts_build flags */ 76#define BCHILD 1 /* fts_children */ 77#define BNAMES 2 /* fts_children, names only */ 78#define BREAD 3 /* fts_read */ 79 80/* 81 * Internal representation of an FTS, including extra implementation 82 * details. The FTS returned from fts_open points to this structure's 83 * ftsp_fts member (and can be cast to an _fts_private as required) 84 */ 85struct _fts_private { 86 FTS ftsp_fts; 87 struct statfs ftsp_statfs; 88 dev_t ftsp_dev; 89 int ftsp_linksreliable; 90}; 91 92/* 93 * The "FTS_NOSTAT" option can avoid a lot of calls to stat(2) if it 94 * knows that a directory could not possibly have subdirectories. This 95 * is decided by looking at the link count: a subdirectory would 96 * increment its parent's link count by virtue of its own ".." entry. 97 * This assumption only holds for UFS-like filesystems that implement 98 * links and directories this way, so we must punt for others. 99 */ 100 101static const char *ufslike_filesystems[] = { 102 "ufs", 103 "nfs", 104 "nfs4", 105 "ext2fs", 106 0 107}; 108 109FTS * 110fts_open(argv, options, compar) 111 char * const *argv; 112 int options; 113 int (*compar)(const FTSENT * const *, const FTSENT * const *); 114{ 115 struct _fts_private *priv; 116 FTS *sp; 117 FTSENT *p, *root; 118 int nitems; 119 FTSENT *parent, *tmp; 120 int len; 121 122 /* Options check. */ 123 if (options & ~FTS_OPTIONMASK) { 124 errno = EINVAL; 125 return (NULL); 126 } 127 128 /* Allocate/initialize the stream. */ 129 if ((priv = malloc(sizeof(*priv))) == NULL) 130 return (NULL); 131 memset(priv, 0, sizeof(*priv)); 132 sp = &priv->ftsp_fts; 133 sp->fts_compar = compar; 134 sp->fts_options = options; 135 136 /* Shush, GCC. */ 137 tmp = NULL; 138 139 /* Logical walks turn on NOCHDIR; symbolic links are too hard. */ 140 if (ISSET(FTS_LOGICAL)) 141 SET(FTS_NOCHDIR); 142 143 /* 144 * Start out with 1K of path space, and enough, in any case, 145 * to hold the user's paths. 146 */ 147 if (fts_palloc(sp, MAX(fts_maxarglen(argv), MAXPATHLEN))) 148 goto mem1; 149 150 /* Allocate/initialize root's parent. */ 151 if ((parent = fts_alloc(sp, "", 0)) == NULL) 152 goto mem2; 153 parent->fts_level = FTS_ROOTPARENTLEVEL; 154 155 /* Allocate/initialize root(s). */ 156 for (root = NULL, nitems = 0; *argv != NULL; ++argv, ++nitems) { 157 /* Don't allow zero-length paths. */ 158 if ((len = strlen(*argv)) == 0) { 159 errno = ENOENT; 160 goto mem3; 161 } 162 163 p = fts_alloc(sp, *argv, len); 164 p->fts_level = FTS_ROOTLEVEL; 165 p->fts_parent = parent; 166 p->fts_accpath = p->fts_name; 167 p->fts_info = fts_stat(sp, p, ISSET(FTS_COMFOLLOW)); 168 169 /* Command-line "." and ".." are real directories. */ 170 if (p->fts_info == FTS_DOT) 171 p->fts_info = FTS_D; 172 173 /* 174 * If comparison routine supplied, traverse in sorted 175 * order; otherwise traverse in the order specified. 176 */ 177 if (compar) { 178 p->fts_link = root; 179 root = p; 180 } else { 181 p->fts_link = NULL; 182 if (root == NULL) 183 tmp = root = p; 184 else { 185 tmp->fts_link = p; 186 tmp = p; 187 } 188 } 189 } 190 if (compar && nitems > 1) 191 root = fts_sort(sp, root, nitems); 192 193 /* 194 * Allocate a dummy pointer and make fts_read think that we've just 195 * finished the node before the root(s); set p->fts_info to FTS_INIT 196 * so that everything about the "current" node is ignored. 197 */ 198 if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL) 199 goto mem3; 200 sp->fts_cur->fts_link = root; 201 sp->fts_cur->fts_info = FTS_INIT; 202 203 /* 204 * If using chdir(2), grab a file descriptor pointing to dot to ensure 205 * that we can get back here; this could be avoided for some paths, 206 * but almost certainly not worth the effort. Slashes, symbolic links, 207 * and ".." are all fairly nasty problems. Note, if we can't get the 208 * descriptor we run anyway, just more slowly. 209 */ 210 if (!ISSET(FTS_NOCHDIR) && (sp->fts_rfd = _open(".", O_RDONLY, 0)) < 0) 211 SET(FTS_NOCHDIR); 212 213 return (sp); 214 215mem3: fts_lfree(root); 216 free(parent); 217mem2: free(sp->fts_path); 218mem1: free(sp); 219 return (NULL); 220} 221 222static void 223fts_load(sp, p) 224 FTS *sp; 225 FTSENT *p; 226{ 227 int len; 228 char *cp; 229 230 /* 231 * Load the stream structure for the next traversal. Since we don't 232 * actually enter the directory until after the preorder visit, set 233 * the fts_accpath field specially so the chdir gets done to the right 234 * place and the user can access the first node. From fts_open it's 235 * known that the path will fit. 236 */ 237 len = p->fts_pathlen = p->fts_namelen; 238 memmove(sp->fts_path, p->fts_name, len + 1); 239 if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) { 240 len = strlen(++cp); 241 memmove(p->fts_name, cp, len + 1); 242 p->fts_namelen = len; 243 } 244 p->fts_accpath = p->fts_path = sp->fts_path; 245 sp->fts_dev = p->fts_dev; 246} 247 248int 249fts_close(sp) 250 FTS *sp; 251{ 252 FTSENT *freep, *p; 253 int saved_errno; 254 255 /* 256 * This still works if we haven't read anything -- the dummy structure 257 * points to the root list, so we step through to the end of the root 258 * list which has a valid parent pointer. 259 */ 260 if (sp->fts_cur) { 261 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) { 262 freep = p; 263 p = p->fts_link != NULL ? p->fts_link : p->fts_parent; 264 free(freep); 265 } 266 free(p); 267 } 268 269 /* Free up child linked list, sort array, path buffer. */ 270 if (sp->fts_child) 271 fts_lfree(sp->fts_child); 272 if (sp->fts_array) 273 free(sp->fts_array); 274 free(sp->fts_path); 275 276 /* Return to original directory, save errno if necessary. */ 277 if (!ISSET(FTS_NOCHDIR)) { 278 saved_errno = fchdir(sp->fts_rfd) ? errno : 0; 279 (void)_close(sp->fts_rfd); 280 281 /* Set errno and return. */ 282 if (saved_errno != 0) { 283 /* Free up the stream pointer. */ 284 free(sp); 285 errno = saved_errno; 286 return (-1); 287 } 288 } 289 290 /* Free up the stream pointer. */ 291 free(sp); 292 return (0); 293} 294 295/* 296 * Special case of "/" at the end of the path so that slashes aren't 297 * appended which would cause paths to be written as "....//foo". 298 */ 299#define NAPPEND(p) \ 300 (p->fts_path[p->fts_pathlen - 1] == '/' \ 301 ? p->fts_pathlen - 1 : p->fts_pathlen) 302 303FTSENT * 304fts_read(sp) 305 FTS *sp; 306{ 307 FTSENT *p, *tmp; 308 int instr; 309 char *t; 310 int saved_errno; 311 312 /* If finished or unrecoverable error, return NULL. */ 313 if (sp->fts_cur == NULL || ISSET(FTS_STOP)) 314 return (NULL); 315 316 /* Set current node pointer. */ 317 p = sp->fts_cur; 318 319 /* Save and zero out user instructions. */ 320 instr = p->fts_instr; 321 p->fts_instr = FTS_NOINSTR; 322 323 /* Any type of file may be re-visited; re-stat and re-turn. */ 324 if (instr == FTS_AGAIN) { 325 p->fts_info = fts_stat(sp, p, 0); 326 return (p); 327 } 328 329 /* 330 * Following a symlink -- SLNONE test allows application to see 331 * SLNONE and recover. If indirecting through a symlink, have 332 * keep a pointer to current location. If unable to get that 333 * pointer, follow fails. 334 */ 335 if (instr == FTS_FOLLOW && 336 (p->fts_info == FTS_SL || p->fts_info == FTS_SLNONE)) { 337 p->fts_info = fts_stat(sp, p, 1); 338 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 339 if ((p->fts_symfd = _open(".", O_RDONLY, 0)) < 0) { 340 p->fts_errno = errno; 341 p->fts_info = FTS_ERR; 342 } else 343 p->fts_flags |= FTS_SYMFOLLOW; 344 } 345 return (p); 346 } 347 348 /* Directory in pre-order. */ 349 if (p->fts_info == FTS_D) { 350 /* If skipped or crossed mount point, do post-order visit. */ 351 if (instr == FTS_SKIP || 352 (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) { 353 if (p->fts_flags & FTS_SYMFOLLOW) 354 (void)_close(p->fts_symfd); 355 if (sp->fts_child) { 356 fts_lfree(sp->fts_child); 357 sp->fts_child = NULL; 358 } 359 p->fts_info = FTS_DP; 360 return (p); 361 } 362 363 /* Rebuild if only read the names and now traversing. */ 364 if (sp->fts_child != NULL && ISSET(FTS_NAMEONLY)) { 365 CLR(FTS_NAMEONLY); 366 fts_lfree(sp->fts_child); 367 sp->fts_child = NULL; 368 } 369 370 /* 371 * Cd to the subdirectory. 372 * 373 * If have already read and now fail to chdir, whack the list 374 * to make the names come out right, and set the parent errno 375 * so the application will eventually get an error condition. 376 * Set the FTS_DONTCHDIR flag so that when we logically change 377 * directories back to the parent we don't do a chdir. 378 * 379 * If haven't read do so. If the read fails, fts_build sets 380 * FTS_STOP or the fts_info field of the node. 381 */ 382 if (sp->fts_child != NULL) { 383 if (fts_safe_changedir(sp, p, -1, p->fts_accpath)) { 384 p->fts_errno = errno; 385 p->fts_flags |= FTS_DONTCHDIR; 386 for (p = sp->fts_child; p != NULL; 387 p = p->fts_link) 388 p->fts_accpath = 389 p->fts_parent->fts_accpath; 390 } 391 } else if ((sp->fts_child = fts_build(sp, BREAD)) == NULL) { 392 if (ISSET(FTS_STOP)) 393 return (NULL); 394 return (p); 395 } 396 p = sp->fts_child; 397 sp->fts_child = NULL; 398 goto name; 399 } 400 401 /* Move to the next node on this level. */ 402next: tmp = p; 403 if ((p = p->fts_link) != NULL) { 404 free(tmp); 405 406 /* 407 * If reached the top, return to the original directory (or 408 * the root of the tree), and load the paths for the next root. 409 */ 410 if (p->fts_level == FTS_ROOTLEVEL) { 411 if (FCHDIR(sp, sp->fts_rfd)) { 412 SET(FTS_STOP); 413 return (NULL); 414 } 415 fts_load(sp, p); 416 return (sp->fts_cur = p); 417 } 418 419 /* 420 * User may have called fts_set on the node. If skipped, 421 * ignore. If followed, get a file descriptor so we can 422 * get back if necessary. 423 */ 424 if (p->fts_instr == FTS_SKIP) 425 goto next; 426 if (p->fts_instr == FTS_FOLLOW) { 427 p->fts_info = fts_stat(sp, p, 1); 428 if (p->fts_info == FTS_D && !ISSET(FTS_NOCHDIR)) { 429 if ((p->fts_symfd = 430 _open(".", O_RDONLY, 0)) < 0) { 431 p->fts_errno = errno; 432 p->fts_info = FTS_ERR; 433 } else 434 p->fts_flags |= FTS_SYMFOLLOW; 435 } 436 p->fts_instr = FTS_NOINSTR; 437 } 438 439name: t = sp->fts_path + NAPPEND(p->fts_parent); 440 *t++ = '/'; 441 memmove(t, p->fts_name, p->fts_namelen + 1); 442 return (sp->fts_cur = p); 443 } 444 445 /* Move up to the parent node. */ 446 p = tmp->fts_parent; 447 free(tmp); 448 449 if (p->fts_level == FTS_ROOTPARENTLEVEL) { 450 /* 451 * Done; free everything up and set errno to 0 so the user 452 * can distinguish between error and EOF. 453 */ 454 free(p); 455 errno = 0; 456 return (sp->fts_cur = NULL); 457 } 458 459 /* NUL terminate the pathname. */ 460 sp->fts_path[p->fts_pathlen] = '\0'; 461 462 /* 463 * Return to the parent directory. If at a root node or came through 464 * a symlink, go back through the file descriptor. Otherwise, cd up 465 * one directory. 466 */ 467 if (p->fts_level == FTS_ROOTLEVEL) { 468 if (FCHDIR(sp, sp->fts_rfd)) { 469 SET(FTS_STOP); 470 return (NULL); 471 } 472 } else if (p->fts_flags & FTS_SYMFOLLOW) { 473 if (FCHDIR(sp, p->fts_symfd)) { 474 saved_errno = errno; 475 (void)_close(p->fts_symfd); 476 errno = saved_errno; 477 SET(FTS_STOP); 478 return (NULL); 479 } 480 (void)_close(p->fts_symfd); 481 } else if (!(p->fts_flags & FTS_DONTCHDIR) && 482 fts_safe_changedir(sp, p->fts_parent, -1, "..")) { 483 SET(FTS_STOP); 484 return (NULL); 485 } 486 p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP; 487 return (sp->fts_cur = p); 488} 489 490/* 491 * Fts_set takes the stream as an argument although it's not used in this 492 * implementation; it would be necessary if anyone wanted to add global 493 * semantics to fts using fts_set. An error return is allowed for similar 494 * reasons. 495 */ 496/* ARGSUSED */ 497int 498fts_set(sp, p, instr) 499 FTS *sp; 500 FTSENT *p; 501 int instr; 502{ 503 if (instr != 0 && instr != FTS_AGAIN && instr != FTS_FOLLOW && 504 instr != FTS_NOINSTR && instr != FTS_SKIP) { 505 errno = EINVAL; 506 return (1); 507 } 508 p->fts_instr = instr; 509 return (0); 510} 511 512FTSENT * 513fts_children(sp, instr) 514 FTS *sp; 515 int instr; 516{ 517 FTSENT *p; 518 int fd; 519 520 if (instr != 0 && instr != FTS_NAMEONLY) { 521 errno = EINVAL; 522 return (NULL); 523 } 524 525 /* Set current node pointer. */ 526 p = sp->fts_cur; 527 528 /* 529 * Errno set to 0 so user can distinguish empty directory from 530 * an error. 531 */ 532 errno = 0; 533 534 /* Fatal errors stop here. */ 535 if (ISSET(FTS_STOP)) 536 return (NULL); 537 538 /* Return logical hierarchy of user's arguments. */ 539 if (p->fts_info == FTS_INIT) 540 return (p->fts_link); 541 542 /* 543 * If not a directory being visited in pre-order, stop here. Could 544 * allow FTS_DNR, assuming the user has fixed the problem, but the 545 * same effect is available with FTS_AGAIN. 546 */ 547 if (p->fts_info != FTS_D /* && p->fts_info != FTS_DNR */) 548 return (NULL); 549 550 /* Free up any previous child list. */ 551 if (sp->fts_child != NULL) 552 fts_lfree(sp->fts_child); 553 554 if (instr == FTS_NAMEONLY) { 555 SET(FTS_NAMEONLY); 556 instr = BNAMES; 557 } else 558 instr = BCHILD; 559 560 /* 561 * If using chdir on a relative path and called BEFORE fts_read does 562 * its chdir to the root of a traversal, we can lose -- we need to 563 * chdir into the subdirectory, and we don't know where the current 564 * directory is, so we can't get back so that the upcoming chdir by 565 * fts_read will work. 566 */ 567 if (p->fts_level != FTS_ROOTLEVEL || p->fts_accpath[0] == '/' || 568 ISSET(FTS_NOCHDIR)) 569 return (sp->fts_child = fts_build(sp, instr)); 570 571 if ((fd = _open(".", O_RDONLY, 0)) < 0) 572 return (NULL); 573 sp->fts_child = fts_build(sp, instr); 574 if (fchdir(fd)) 575 return (NULL); 576 (void)_close(fd); 577 return (sp->fts_child); 578} 579 580#ifndef fts_get_clientptr 581#error "fts_get_clientptr not defined" 582#endif 583 584void * 585(fts_get_clientptr)(FTS *sp) 586{ 587 588 return (fts_get_clientptr(sp)); 589} 590 591#ifndef fts_get_stream 592#error "fts_get_stream not defined" 593#endif 594 595FTS * 596(fts_get_stream)(FTSENT *p) 597{ 598 return (fts_get_stream(p)); 599} 600 601void 602fts_set_clientptr(FTS *sp, void *clientptr) 603{ 604 605 sp->fts_clientptr = clientptr; 606} 607 608/* 609 * This is the tricky part -- do not casually change *anything* in here. The 610 * idea is to build the linked list of entries that are used by fts_children 611 * and fts_read. There are lots of special cases. 612 * 613 * The real slowdown in walking the tree is the stat calls. If FTS_NOSTAT is 614 * set and it's a physical walk (so that symbolic links can't be directories), 615 * we can do things quickly. First, if it's a 4.4BSD file system, the type 616 * of the file is in the directory entry. Otherwise, we assume that the number 617 * of subdirectories in a node is equal to the number of links to the parent. 618 * The former skips all stat calls. The latter skips stat calls in any leaf 619 * directories and for any files after the subdirectories in the directory have 620 * been found, cutting the stat calls by about 2/3. 621 */ 622static FTSENT * 623fts_build(sp, type) 624 FTS *sp; 625 int type; 626{ 627 struct dirent *dp; 628 FTSENT *p, *head; 629 int nitems; 630 FTSENT *cur, *tail; 631 DIR *dirp; 632 void *oldaddr; 633 size_t dnamlen; 634 int cderrno, descend, len, level, maxlen, nlinks, oflag, saved_errno, 635 nostat, doadjust; 636 char *cp; 637 638 /* Set current node pointer. */ 639 cur = sp->fts_cur; 640 641 /* 642 * Open the directory for reading. If this fails, we're done. 643 * If being called from fts_read, set the fts_info field. 644 */ 645#ifdef FTS_WHITEOUT 646 if (ISSET(FTS_WHITEOUT)) 647 oflag = DTF_NODUP | DTF_REWIND; 648 else 649 oflag = DTF_HIDEW | DTF_NODUP | DTF_REWIND; 650#else 651#define __opendir2(path, flag) opendir(path) 652#endif 653 if ((dirp = __opendir2(cur->fts_accpath, oflag)) == NULL) { 654 if (type == BREAD) { 655 cur->fts_info = FTS_DNR; 656 cur->fts_errno = errno; 657 } 658 return (NULL); 659 } 660 661 /* 662 * Nlinks is the number of possible entries of type directory in the 663 * directory if we're cheating on stat calls, 0 if we're not doing 664 * any stat calls at all, -1 if we're doing stats on everything. 665 */ 666 if (type == BNAMES) { 667 nlinks = 0; 668 /* Be quiet about nostat, GCC. */ 669 nostat = 0; 670 } else if (ISSET(FTS_NOSTAT) && ISSET(FTS_PHYSICAL)) { 671 if (fts_ufslinks(sp, cur)) 672 nlinks = cur->fts_nlink - (ISSET(FTS_SEEDOT) ? 0 : 2); 673 else 674 nlinks = -1; 675 nostat = 1; 676 } else { 677 nlinks = -1; 678 nostat = 0; 679 } 680 681#ifdef notdef 682 (void)printf("nlinks == %d (cur: %d)\n", nlinks, cur->fts_nlink); 683 (void)printf("NOSTAT %d PHYSICAL %d SEEDOT %d\n", 684 ISSET(FTS_NOSTAT), ISSET(FTS_PHYSICAL), ISSET(FTS_SEEDOT)); 685#endif 686 /* 687 * If we're going to need to stat anything or we want to descend 688 * and stay in the directory, chdir. If this fails we keep going, 689 * but set a flag so we don't chdir after the post-order visit. 690 * We won't be able to stat anything, but we can still return the 691 * names themselves. Note, that since fts_read won't be able to 692 * chdir into the directory, it will have to return different path 693 * names than before, i.e. "a/b" instead of "b". Since the node 694 * has already been visited in pre-order, have to wait until the 695 * post-order visit to return the error. There is a special case 696 * here, if there was nothing to stat then it's not an error to 697 * not be able to stat. This is all fairly nasty. If a program 698 * needed sorted entries or stat information, they had better be 699 * checking FTS_NS on the returned nodes. 700 */ 701 cderrno = 0; 702 if (nlinks || type == BREAD) { 703 if (fts_safe_changedir(sp, cur, dirfd(dirp), NULL)) { 704 if (nlinks && type == BREAD) 705 cur->fts_errno = errno; 706 cur->fts_flags |= FTS_DONTCHDIR; 707 descend = 0; 708 cderrno = errno; 709 } else 710 descend = 1; 711 } else 712 descend = 0; 713 714 /* 715 * Figure out the max file name length that can be stored in the 716 * current path -- the inner loop allocates more path as necessary. 717 * We really wouldn't have to do the maxlen calculations here, we 718 * could do them in fts_read before returning the path, but it's a 719 * lot easier here since the length is part of the dirent structure. 720 * 721 * If not changing directories set a pointer so that can just append 722 * each new name into the path. 723 */ 724 len = NAPPEND(cur); 725 if (ISSET(FTS_NOCHDIR)) { 726 cp = sp->fts_path + len; 727 *cp++ = '/'; 728 } else { 729 /* GCC, you're too verbose. */ 730 cp = NULL; 731 } 732 len++; 733 maxlen = sp->fts_pathlen - len; 734 735 level = cur->fts_level + 1; 736 737 /* Read the directory, attaching each entry to the `link' pointer. */ 738 doadjust = 0; 739 for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) { 740 dnamlen = dp->d_namlen; 741 if (!ISSET(FTS_SEEDOT) && ISDOT(dp->d_name)) 742 continue; 743 744 if ((p = fts_alloc(sp, dp->d_name, (int)dnamlen)) == NULL) 745 goto mem1; 746 if (dnamlen >= maxlen) { /* include space for NUL */ 747 oldaddr = sp->fts_path; 748 if (fts_palloc(sp, dnamlen + len + 1)) { 749 /* 750 * No more memory for path or structures. Save 751 * errno, free up the current structure and the 752 * structures already allocated. 753 */ 754mem1: saved_errno = errno; 755 if (p) 756 free(p); 757 fts_lfree(head); 758 (void)closedir(dirp); 759 cur->fts_info = FTS_ERR; 760 SET(FTS_STOP); 761 errno = saved_errno; 762 return (NULL); 763 } 764 /* Did realloc() change the pointer? */ 765 if (oldaddr != sp->fts_path) { 766 doadjust = 1; 767 if (ISSET(FTS_NOCHDIR)) 768 cp = sp->fts_path + len; 769 } 770 maxlen = sp->fts_pathlen - len; 771 } 772 773 if (len + dnamlen >= USHRT_MAX) { 774 /* 775 * In an FTSENT, fts_pathlen is a u_short so it is 776 * possible to wraparound here. If we do, free up 777 * the current structure and the structures already 778 * allocated, then error out with ENAMETOOLONG. 779 */ 780 free(p); 781 fts_lfree(head); 782 (void)closedir(dirp); 783 cur->fts_info = FTS_ERR; 784 SET(FTS_STOP); 785 errno = ENAMETOOLONG; 786 return (NULL); 787 } 788 p->fts_level = level; 789 p->fts_parent = sp->fts_cur; 790 p->fts_pathlen = len + dnamlen; 791 792#ifdef FTS_WHITEOUT 793 if (dp->d_type == DT_WHT) 794 p->fts_flags |= FTS_ISW; 795#endif 796 797 if (cderrno) { 798 if (nlinks) { 799 p->fts_info = FTS_NS; 800 p->fts_errno = cderrno; 801 } else 802 p->fts_info = FTS_NSOK; 803 p->fts_accpath = cur->fts_accpath; 804 } else if (nlinks == 0 805#ifdef DT_DIR 806 || (nostat && 807 dp->d_type != DT_DIR && dp->d_type != DT_UNKNOWN) 808#endif 809 ) { 810 p->fts_accpath = 811 ISSET(FTS_NOCHDIR) ? p->fts_path : p->fts_name; 812 p->fts_info = FTS_NSOK; 813 } else { 814 /* Build a file name for fts_stat to stat. */ 815 if (ISSET(FTS_NOCHDIR)) { 816 p->fts_accpath = p->fts_path; 817 memmove(cp, p->fts_name, p->fts_namelen + 1); 818 } else 819 p->fts_accpath = p->fts_name; 820 /* Stat it. */ 821 p->fts_info = fts_stat(sp, p, 0); 822 823 /* Decrement link count if applicable. */ 824 if (nlinks > 0 && (p->fts_info == FTS_D || 825 p->fts_info == FTS_DC || p->fts_info == FTS_DOT)) 826 --nlinks; 827 } 828 829 /* We walk in directory order so "ls -f" doesn't get upset. */ 830 p->fts_link = NULL; 831 if (head == NULL) 832 head = tail = p; 833 else { 834 tail->fts_link = p; 835 tail = p; 836 } 837 ++nitems; 838 } 839 if (dirp) 840 (void)closedir(dirp); 841 842 /* 843 * If realloc() changed the address of the path, adjust the 844 * addresses for the rest of the tree and the dir list. 845 */ 846 if (doadjust) 847 fts_padjust(sp, head); 848 849 /* 850 * If not changing directories, reset the path back to original 851 * state. 852 */ 853 if (ISSET(FTS_NOCHDIR)) { 854 if (len == sp->fts_pathlen || nitems == 0) 855 --cp; 856 *cp = '\0'; 857 } 858 859 /* 860 * If descended after called from fts_children or after called from 861 * fts_read and nothing found, get back. At the root level we use 862 * the saved fd; if one of fts_open()'s arguments is a relative path 863 * to an empty directory, we wind up here with no other way back. If 864 * can't get back, we're done. 865 */ 866 if (descend && (type == BCHILD || !nitems) && 867 (cur->fts_level == FTS_ROOTLEVEL ? 868 FCHDIR(sp, sp->fts_rfd) : 869 fts_safe_changedir(sp, cur->fts_parent, -1, ".."))) { 870 cur->fts_info = FTS_ERR; 871 SET(FTS_STOP); 872 return (NULL); 873 } 874 875 /* If didn't find anything, return NULL. */ 876 if (!nitems) { 877 if (type == BREAD) 878 cur->fts_info = FTS_DP; 879 return (NULL); 880 } 881 882 /* Sort the entries. */ 883 if (sp->fts_compar && nitems > 1) 884 head = fts_sort(sp, head, nitems); 885 return (head); 886} 887 888static u_short 889fts_stat(sp, p, follow) 890 FTS *sp; 891 FTSENT *p; 892 int follow; 893{ 894 FTSENT *t; 895 dev_t dev; 896 ino_t ino; 897 struct stat *sbp, sb; 898 int saved_errno; 899 900 /* If user needs stat info, stat buffer already allocated. */ 901 sbp = ISSET(FTS_NOSTAT) ? &sb : p->fts_statp; 902 903#ifdef FTS_WHITEOUT 904 /* Check for whiteout. */ 905 if (p->fts_flags & FTS_ISW) { 906 if (sbp != &sb) { 907 memset(sbp, '\0', sizeof(*sbp)); 908 sbp->st_mode = S_IFWHT; 909 } 910 return (FTS_W); 911 } 912#endif 913 914 /* 915 * If doing a logical walk, or application requested FTS_FOLLOW, do 916 * a stat(2). If that fails, check for a non-existent symlink. If 917 * fail, set the errno from the stat call. 918 */ 919 if (ISSET(FTS_LOGICAL) || follow) { 920 if (stat(p->fts_accpath, sbp)) { 921 saved_errno = errno; 922 if (!lstat(p->fts_accpath, sbp)) { 923 errno = 0; 924 return (FTS_SLNONE); 925 } 926 p->fts_errno = saved_errno; 927 goto err; 928 } 929 } else if (lstat(p->fts_accpath, sbp)) { 930 p->fts_errno = errno; 931err: memset(sbp, 0, sizeof(struct stat)); 932 return (FTS_NS); 933 } 934 935 if (S_ISDIR(sbp->st_mode)) { 936 /* 937 * Set the device/inode. Used to find cycles and check for 938 * crossing mount points. Also remember the link count, used 939 * in fts_build to limit the number of stat calls. It is 940 * understood that these fields are only referenced if fts_info 941 * is set to FTS_D. 942 */ 943 dev = p->fts_dev = sbp->st_dev; 944 ino = p->fts_ino = sbp->st_ino; 945 p->fts_nlink = sbp->st_nlink; 946 947 if (ISDOT(p->fts_name)) 948 return (FTS_DOT); 949 950 /* 951 * Cycle detection is done by brute force when the directory 952 * is first encountered. If the tree gets deep enough or the 953 * number of symbolic links to directories is high enough, 954 * something faster might be worthwhile. 955 */ 956 for (t = p->fts_parent; 957 t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent) 958 if (ino == t->fts_ino && dev == t->fts_dev) { 959 p->fts_cycle = t; 960 return (FTS_DC); 961 } 962 return (FTS_D); 963 } 964 if (S_ISLNK(sbp->st_mode)) 965 return (FTS_SL); 966 if (S_ISREG(sbp->st_mode)) 967 return (FTS_F); 968 return (FTS_DEFAULT); 969} 970 971/* 972 * The comparison function takes pointers to pointers to FTSENT structures. 973 * Qsort wants a comparison function that takes pointers to void. 974 * (Both with appropriate levels of const-poisoning, of course!) 975 * Use a trampoline function to deal with the difference. 976 */ 977static int 978fts_compar(const void *a, const void *b) 979{ 980 FTS *parent; 981 982 parent = (*(const FTSENT * const *)a)->fts_fts; 983 return (*parent->fts_compar)(a, b); 984} 985 986static FTSENT * 987fts_sort(sp, head, nitems) 988 FTS *sp; 989 FTSENT *head; 990 int nitems; 991{ 992 FTSENT **ap, *p; 993 994 /* 995 * Construct an array of pointers to the structures and call qsort(3). 996 * Reassemble the array in the order returned by qsort. If unable to 997 * sort for memory reasons, return the directory entries in their 998 * current order. Allocate enough space for the current needs plus 999 * 40 so don't realloc one entry at a time. 1000 */ 1001 if (nitems > sp->fts_nitems) { 1002 sp->fts_nitems = nitems + 40; 1003 if ((sp->fts_array = reallocf(sp->fts_array, 1004 sp->fts_nitems * sizeof(FTSENT *))) == NULL) { 1005 sp->fts_nitems = 0; 1006 return (head); 1007 } 1008 } 1009 for (ap = sp->fts_array, p = head; p; p = p->fts_link) 1010 *ap++ = p; 1011 qsort(sp->fts_array, nitems, sizeof(FTSENT *), fts_compar); 1012 for (head = *(ap = sp->fts_array); --nitems; ++ap) 1013 ap[0]->fts_link = ap[1]; 1014 ap[0]->fts_link = NULL; 1015 return (head); 1016} 1017 1018static FTSENT * 1019fts_alloc(sp, name, namelen) 1020 FTS *sp; 1021 char *name; 1022 int namelen; 1023{ 1024 FTSENT *p; 1025 size_t len; 1026 1027 struct ftsent_withstat { 1028 FTSENT ent; 1029 struct stat statbuf; 1030 }; 1031 1032 /* 1033 * The file name is a variable length array and no stat structure is 1034 * necessary if the user has set the nostat bit. Allocate the FTSENT 1035 * structure, the file name and the stat structure in one chunk, but 1036 * be careful that the stat structure is reasonably aligned. 1037 */ 1038 if (ISSET(FTS_NOSTAT)) 1039 len = sizeof(FTSENT) + namelen + 1; 1040 else 1041 len = sizeof(struct ftsent_withstat) + namelen + 1; 1042 1043 if ((p = malloc(len)) == NULL) 1044 return (NULL); 1045 1046 if (ISSET(FTS_NOSTAT)) { 1047 p->fts_name = (char *)(p + 1); 1048 p->fts_statp = NULL; 1049 } else { 1050 p->fts_name = (char *)((struct ftsent_withstat *)p + 1); 1051 p->fts_statp = &((struct ftsent_withstat *)p)->statbuf; 1052 } 1053 1054 /* Copy the name and guarantee NUL termination. */ 1055 memcpy(p->fts_name, name, namelen); 1056 p->fts_name[namelen] = '\0'; 1057 p->fts_namelen = namelen; 1058 p->fts_path = sp->fts_path; 1059 p->fts_errno = 0; 1060 p->fts_flags = 0; 1061 p->fts_instr = FTS_NOINSTR; 1062 p->fts_number = 0; 1063 p->fts_pointer = NULL; 1064 p->fts_fts = sp; 1065 return (p); 1066} 1067 1068static void 1069fts_lfree(head) 1070 FTSENT *head; 1071{ 1072 FTSENT *p; 1073 1074 /* Free a linked list of structures. */ 1075 while ((p = head)) { 1076 head = head->fts_link; 1077 free(p); 1078 } 1079} 1080 1081/* 1082 * Allow essentially unlimited paths; find, rm, ls should all work on any tree. 1083 * Most systems will allow creation of paths much longer than MAXPATHLEN, even 1084 * though the kernel won't resolve them. Add the size (not just what's needed) 1085 * plus 256 bytes so don't realloc the path 2 bytes at a time. 1086 */ 1087static int 1088fts_palloc(sp, more) 1089 FTS *sp; 1090 size_t more; 1091{ 1092 1093 sp->fts_pathlen += more + 256; 1094 /* 1095 * Check for possible wraparound. In an FTS, fts_pathlen is 1096 * a signed int but in an FTSENT it is an unsigned short. 1097 * We limit fts_pathlen to USHRT_MAX to be safe in both cases. 1098 */ 1099 if (sp->fts_pathlen < 0 || sp->fts_pathlen >= USHRT_MAX) { 1100 if (sp->fts_path) 1101 free(sp->fts_path); 1102 sp->fts_path = NULL; 1103 errno = ENAMETOOLONG; 1104 return (1); 1105 } 1106 sp->fts_path = reallocf(sp->fts_path, sp->fts_pathlen); 1107 return (sp->fts_path == NULL); 1108} 1109 1110/* 1111 * When the path is realloc'd, have to fix all of the pointers in structures 1112 * already returned. 1113 */ 1114static void 1115fts_padjust(sp, head) 1116 FTS *sp; 1117 FTSENT *head; 1118{ 1119 FTSENT *p; 1120 char *addr = sp->fts_path; 1121 1122#define ADJUST(p) do { \ 1123 if ((p)->fts_accpath != (p)->fts_name) { \ 1124 (p)->fts_accpath = \ 1125 (char *)addr + ((p)->fts_accpath - (p)->fts_path); \ 1126 } \ 1127 (p)->fts_path = addr; \ 1128} while (0) 1129 /* Adjust the current set of children. */ 1130 for (p = sp->fts_child; p; p = p->fts_link) 1131 ADJUST(p); 1132 1133 /* Adjust the rest of the tree, including the current level. */ 1134 for (p = head; p->fts_level >= FTS_ROOTLEVEL;) { 1135 ADJUST(p); 1136 p = p->fts_link ? p->fts_link : p->fts_parent; 1137 } 1138} 1139 1140static size_t 1141fts_maxarglen(argv) 1142 char * const *argv; 1143{ 1144 size_t len, max; 1145 1146 for (max = 0; *argv; ++argv) 1147 if ((len = strlen(*argv)) > max) 1148 max = len; 1149 return (max + 1); 1150} 1151 1152/* 1153 * Change to dir specified by fd or p->fts_accpath without getting 1154 * tricked by someone changing the world out from underneath us. 1155 * Assumes p->fts_dev and p->fts_ino are filled in. 1156 */ 1157static int 1158fts_safe_changedir(sp, p, fd, path) 1159 FTS *sp; 1160 FTSENT *p; 1161 int fd; 1162 char *path; 1163{ 1164 int ret, oerrno, newfd; 1165 struct stat sb; 1166 1167 newfd = fd; 1168 if (ISSET(FTS_NOCHDIR)) 1169 return (0); 1170 if (fd < 0 && (newfd = _open(path, O_RDONLY, 0)) < 0) 1171 return (-1); 1172 if (_fstat(newfd, &sb)) { 1173 ret = -1; 1174 goto bail; 1175 } 1176 if (p->fts_dev != sb.st_dev || p->fts_ino != sb.st_ino) { 1177 errno = ENOENT; /* disinformation */ 1178 ret = -1; 1179 goto bail; 1180 } 1181 ret = fchdir(newfd); 1182bail: 1183 oerrno = errno; 1184 if (fd < 0) 1185 (void)_close(newfd); 1186 errno = oerrno; 1187 return (ret); 1188} 1189 1190/* 1191 * Check if the filesystem for "ent" has UFS-style links. 1192 */ 1193static int 1194fts_ufslinks(FTS *sp, const FTSENT *ent) 1195{ 1196 struct _fts_private *priv; 1197 const char **cpp; 1198 1199 priv = (struct _fts_private *)sp; 1200 /* 1201 * If this node's device is different from the previous, grab 1202 * the filesystem information, and decide on the reliability 1203 * of the link information from this filesystem for stat(2) 1204 * avoidance. 1205 */ 1206 if (priv->ftsp_dev != ent->fts_dev) { 1207 if (statfs(ent->fts_path, &priv->ftsp_statfs) != -1) { 1208 priv->ftsp_dev = ent->fts_dev; 1209 priv->ftsp_linksreliable = 0; 1210 for (cpp = ufslike_filesystems; *cpp; cpp++) { 1211 if (strcmp(priv->ftsp_statfs.f_fstypename, 1212 *cpp) == 0) { 1213 priv->ftsp_linksreliable = 1; 1214 break; 1215 } 1216 } 1217 } else { 1218 priv->ftsp_linksreliable = 0; 1219 } 1220 } 1221 return (priv->ftsp_linksreliable); 1222} 1223