compat_fts.c

   1 #include "config.h"
   2
   3 #if HAVE_FTS
   4
   5 int dummy;
   6
   7 #else
   8
   9 /*      $Id: compat_fts.c,v 1.10 2016/08/02 11:09:46 schwarze Exp $     */
  10 /*      $OpenBSD: fts.c,v 1.50 2015/01/16 16:48:51 deraadt Exp $        */
  11
  12 /*-
  13  * Copyright (c) 1990, 1993, 1994
  14  *      The Regents of the University of California.  All rights reserved.
  15  *
  16  * Redistribution and use in source and binary forms, with or without
  17  * modification, are permitted provided that the following conditions
  18  * are met:
  19  * 1. Redistributions of source code must retain the above copyright
  20  *    notice, this list of conditions and the following disclaimer.
  21  * 2. Redistributions in binary form must reproduce the above copyright
  22  *    notice, this list of conditions and the following disclaimer in the
  23  *    documentation and/or other materials provided with the distribution.
  24  * 3. Neither the name of the University nor the names of its contributors
  25  *    may be used to endorse or promote products derived from this software
  26  *    without specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  38  * SUCH DAMAGE.
  39  */
  40
  41 #include <sys/stat.h>
  42 #include <sys/types.h>
  43
  44 #include <dirent.h>
  45 #include <errno.h>
  46 #include <fcntl.h>
  47 #include <limits.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50 #include <unistd.h>
  51 #include "compat_fts.h"
  52
  53 #define MAXIMUM(a, b)   (((a) > (b)) ? (a) : (b))
  54
  55 static FTSENT   *fts_alloc(FTS *, const char *, size_t);
  56 static FTSENT   *fts_build(FTS *);
  57 static void      fts_lfree(FTSENT *);
  58 static void      fts_load(FTS *, FTSENT *);
  59 static size_t    fts_maxarglen(char * const *);
  60 static void      fts_padjust(FTS *, FTSENT *);
  61 static int       fts_palloc(FTS *, size_t);
  62 static unsigned short    fts_stat(FTS *, FTSENT *);
  63
  64 #define ISDOT(a)        (a[0] == '.' && (!a[1] || (a[1] == '.' && !a[2])))
  65 #ifndef O_DIRECTORY
  66 #define O_DIRECTORY     0
  67 #endif
  68 #ifndef O_CLOEXEC
  69 #define O_CLOEXEC       0
  70 #endif
  71 #ifndef PATH_MAX
  72 #define PATH_MAX        4096
  73 #endif
  74
  75 #define CLR(opt)        (sp->fts_options &= ~(opt))
  76 #define ISSET(opt)      (sp->fts_options & (opt))
  77 #define SET(opt)        (sp->fts_options |= (opt))
  78
  79 FTS *
  80 fts_open(char * const *argv, int options, void *dummy)
  81 {
  82         FTS *sp;
  83         FTSENT *p, *root;
  84         int nitems;
  85         FTSENT *parent, *tmp;
  86         size_t len;
  87
  88         /* Options check. */
  89         if (options & ~FTS_OPTIONMASK) {
  90                 errno = EINVAL;
  91                 return (NULL);
  92         }
  93
  94         /* Allocate/initialize the stream */
  95         if ((sp = calloc(1, sizeof(FTS))) == NULL)
  96                 return (NULL);
  97         sp->fts_options = options;
  98
  99         /*
 100          * Start out with 1K of path space, and enough, in any case,
 101          * to hold the user's paths.
 102          */
 103         if (fts_palloc(sp, MAXIMUM(fts_maxarglen(argv), PATH_MAX)))
 104                 goto mem1;
 105
 106         /* Allocate/initialize root's parent. */
 107         if ((parent = fts_alloc(sp, "", 0)) == NULL)
 108                 goto mem2;
 109         parent->fts_level = FTS_ROOTPARENTLEVEL;
 110
 111         /* Allocate/initialize root(s). */
 112         for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) {
 113                 /* Don't allow zero-length paths. */
 114                 if ((len = strlen(*argv)) == 0) {
 115                         errno = ENOENT;
 116                         goto mem3;
 117                 }
 118
 119                 if ((p = fts_alloc(sp, *argv, len)) == NULL)
 120                         goto mem3;
 121                 p->fts_level = FTS_ROOTLEVEL;
 122                 p->fts_parent = parent;
 123                 p->fts_accpath = p->fts_name;
 124                 p->fts_info = fts_stat(sp, p);
 125
 126                 /* Command-line "." and ".." are real directories. */
 127                 if (p->fts_info == FTS_DOT)
 128                         p->fts_info = FTS_D;
 129
 130                 p->fts_link = NULL;
 131                 if (root == NULL)
 132                         tmp = root = p;
 133                 else {
 134                         tmp->fts_link = p;
 135                         tmp = p;
 136                 }
 137         }
 138
 139         /*
 140          * Allocate a dummy pointer and make fts_read think that we've just
 141          * finished the node before the root(s); set p->fts_info to FTS_INIT
 142          * so that everything about the "current" node is ignored.
 143          */
 144         if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
 145                 goto mem3;
 146         sp->fts_cur->fts_link = root;
 147         sp->fts_cur->fts_info = FTS_INIT;
 148
 149         if (nitems == 0)
 150                 free(parent);
 151
 152         return (sp);
 153
 154 mem3:   fts_lfree(root);
 155         free(parent);
 156 mem2:   free(sp->fts_path);
 157 mem1:   free(sp);
 158         return (NULL);
 159 }
 160
 161 static void
 162 fts_load(FTS *sp, FTSENT *p)
 163 {
 164         size_t len;
 165         char *cp;
 166
 167         /*
 168          * Load the stream structure for the next traversal.  Since we don't
 169          * actually enter the directory until after the preorder visit, set
 170          * the fts_accpath field specially so the chdir gets done to the right
 171          * place and the user can access the first node.  From fts_open it's
 172          * known that the path will fit.
 173          */
 174         len = p->fts_pathlen = p->fts_namelen;
 175         memmove(sp->fts_path, p->fts_name, len + 1);
 176         if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) {
 177                 len = strlen(++cp);
 178                 memmove(p->fts_name, cp, len + 1);
 179                 p->fts_namelen = len;
 180         }
 181         p->fts_accpath = p->fts_path = sp->fts_path;
 182         sp->fts_dev = p->fts_dev;
 183 }
 184
 185 int
 186 fts_close(FTS *sp)
 187 {
 188         FTSENT *freep, *p;
 189
 190         /*
 191          * This still works if we haven't read anything -- the dummy structure
 192          * points to the root list, so we step through to the end of the root
 193          * list which has a valid parent pointer.
 194          */
 195         if (sp->fts_cur) {
 196                 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
 197                         freep = p;
 198                         p = p->fts_link ? p->fts_link : p->fts_parent;
 199                         free(freep);
 200                 }
 201                 free(p);
 202         }
 203
 204         /* Free up child linked list, sort array, path buffer, stream ptr.*/
 205         if (sp->fts_child)
 206                 fts_lfree(sp->fts_child);
 207         free(sp->fts_path);
 208         free(sp);
 209
 210         return (0);
 211 }
 212
 213 /*
 214  * Special case of "/" at the end of the path so that slashes aren't
 215  * appended which would cause paths to be written as "....//foo".
 216  */
 217 #define NAPPEND(p)                                                      \
 218         (p->fts_path[p->fts_pathlen - 1] == '/'                         \
 219             ? p->fts_pathlen - 1 : p->fts_pathlen)
 220
 221 FTSENT *
 222 fts_read(FTS *sp)
 223 {
 224         FTSENT *p, *tmp;
 225         int instr;
 226         char *t;
 227
 228         /* If finished or unrecoverable error, return NULL. */
 229         if (sp->fts_cur == NULL || ISSET(FTS_STOP))
 230                 return (NULL);
 231
 232         /* Set current node pointer. */
 233         p = sp->fts_cur;
 234
 235         /* Save and zero out user instructions. */
 236         instr = p->fts_instr;
 237         p->fts_instr = FTS_NOINSTR;
 238
 239         /* Directory in pre-order. */
 240         if (p->fts_info == FTS_D) {
 241                 /* If skipped or crossed mount point, do post-order visit. */
 242                 if (instr == FTS_SKIP ||
 243                     (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) {
 244                         if (sp->fts_child) {
 245                                 fts_lfree(sp->fts_child);
 246                                 sp->fts_child = NULL;
 247                         }
 248                         p->fts_info = FTS_DP;
 249                         return (p);
 250                 }
 251
 252                 /*
 253                  * If haven't read do so.  If the read fails, fts_build sets
 254                  * FTS_STOP or the fts_info field of the node.
 255                  */
 256                 if (sp->fts_child) {
 257                         /* nothing */
 258                 } else if ((sp->fts_child = fts_build(sp)) == NULL) {
 259                         if (ISSET(FTS_STOP))
 260                                 return (NULL);
 261                         return (p);
 262                 }
 263                 p = sp->fts_child;
 264                 sp->fts_child = NULL;
 265                 goto name;
 266         }
 267
 268         /* Move to the next node on this level. */
 269 next:   tmp = p;
 270         if ((p = p->fts_link)) {
 271                 free(tmp);
 272
 273                 /*
 274                  * If reached the top, return to the original directory (or
 275                  * the root of the tree), and load the paths for the next root.
 276                  */
 277                 if (p->fts_level == FTS_ROOTLEVEL) {
 278                         fts_load(sp, p);
 279                         return (sp->fts_cur = p);
 280                 }
 281
 282                 /*
 283                  * User may have called fts_set on the node.  If skipped,
 284                  * ignore.  If followed, get a file descriptor so we can
 285                  * get back if necessary.
 286                  */
 287                 if (p->fts_instr == FTS_SKIP)
 288                         goto next;
 289
 290 name:           t = sp->fts_path + NAPPEND(p->fts_parent);
 291                 *t++ = '/';
 292                 memmove(t, p->fts_name, p->fts_namelen + 1);
 293                 return (sp->fts_cur = p);
 294         }
 295
 296         /* Move up to the parent node. */
 297         p = tmp->fts_parent;
 298         free(tmp);
 299
 300         if (p->fts_level == FTS_ROOTPARENTLEVEL) {
 301                 /*
 302                  * Done; free everything up and set errno to 0 so the user
 303                  * can distinguish between error and EOF.
 304                  */
 305                 free(p);
 306                 errno = 0;
 307                 return (sp->fts_cur = NULL);
 308         }
 309
 310         /* NUL terminate the pathname. */
 311         sp->fts_path[p->fts_pathlen] = '\0';
 312
 313         p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
 314         return (sp->fts_cur = p);
 315 }
 316
 317 /*
 318  * Fts_set takes the stream as an argument although it's not used in this
 319  * implementation; it would be necessary if anyone wanted to add global
 320  * semantics to fts using fts_set.  An error return is allowed for similar
 321  * reasons.
 322  */
 323 /* ARGSUSED */
 324 int
 325 fts_set(FTS *sp, FTSENT *p, int instr)
 326 {
 327         if (instr && instr != FTS_NOINSTR && instr != FTS_SKIP) {
 328                 errno = EINVAL;
 329                 return (1);
 330         }
 331         p->fts_instr = instr;
 332         return (0);
 333 }
 334
 335 /*
 336  * This is the tricky part -- do not casually change *anything* in here.  The
 337  * idea is to build the linked list of entries that are used by fts_children
 338  * and fts_read.  There are lots of special cases.
 339  *
 340  * The real slowdown in walking the tree is the stat calls.  If FTS_NOSTAT is
 341  * set and it's a physical walk (so that symbolic links can't be directories),
 342  * we can do things quickly.  First, if it's a 4.4BSD file system, the type
 343  * of the file is in the directory entry.  Otherwise, we assume that the number
 344  * of subdirectories in a node is equal to the number of links to the parent.
 345  * The former skips all stat calls.  The latter skips stat calls in any leaf
 346  * directories and for any files after the subdirectories in the directory have
 347  * been found, cutting the stat calls by about 2/3.
 348  */
 349 static FTSENT *
 350 fts_build(FTS *sp)
 351 {
 352         struct dirent *dp;
 353         FTSENT *p, *head;
 354         FTSENT *cur, *tail;
 355         DIR *dirp;
 356         void *oldaddr;
 357         size_t dlen, len, maxlen;
 358         int nitems, level, doadjust;
 359         int saved_errno;
 360         char *cp;
 361
 362         /* Set current node pointer. */
 363         cur = sp->fts_cur;
 364
 365         /*
 366          * Open the directory for reading.  If this fails, we're done.
 367          * If being called from fts_read, set the fts_info field.
 368          */
 369         if ((dirp = opendir(cur->fts_accpath)) == NULL) {
 370                 cur->fts_info = FTS_DNR;
 371                 cur->fts_errno = errno;
 372                 return (NULL);
 373         }
 374
 375         /*
 376          * Figure out the max file name length that can be stored in the
 377          * current path -- the inner loop allocates more path as necessary.
 378          * We really wouldn't have to do the maxlen calculations here, we
 379          * could do them in fts_read before returning the path, but it's a
 380          * lot easier here since the length is part of the dirent structure.
 381          *
 382          * If not changing directories set a pointer so that can just append
 383          * each new name into the path.
 384          */
 385         len = NAPPEND(cur);
 386         cp = sp->fts_path + len;
 387         *cp++ = '/';
 388         len++;
 389         maxlen = sp->fts_pathlen - len;
 390
 391         /*
 392          * fts_level is signed so we must prevent it from wrapping
 393          * around to FTS_ROOTLEVEL and FTS_ROOTPARENTLEVEL.
 394          */
 395         level = cur->fts_level;
 396         if (level < FTS_MAXLEVEL)
 397             level++;
 398
 399         /* Read the directory, attaching each entry to the `link' pointer. */
 400         doadjust = 0;
 401         for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) {
 402                 if (ISDOT(dp->d_name))
 403                         continue;
 404
 405 #if HAVE_DIRENT_NAMLEN
 406                 dlen = dp->d_namlen;
 407 #else
 408                 dlen = strlen(dp->d_name);
 409 #endif
 410
 411                 if (!(p = fts_alloc(sp, dp->d_name, dlen)))
 412                         goto mem1;
 413                 if (dlen >= maxlen) {   /* include space for NUL */
 414                         oldaddr = sp->fts_path;
 415                         if (fts_palloc(sp, dlen + len + 1)) {
 416                                 /*
 417                                  * No more memory for path or structures.  Save
 418                                  * errno, free up the current structure and the
 419                                  * structures already allocated.
 420                                  */
 421 mem1:                           saved_errno = errno;
 422                                 if (p)
 423                                         free(p);
 424                                 fts_lfree(head);
 425                                 (void)closedir(dirp);
 426                                 cur->fts_info = FTS_ERR;
 427                                 SET(FTS_STOP);
 428                                 errno = saved_errno;
 429                                 return (NULL);
 430                         }
 431                         /* Did realloc() change the pointer? */
 432                         if (oldaddr != sp->fts_path) {
 433                                 doadjust = 1;
 434                                 cp = sp->fts_path + len;
 435                         }
 436                         maxlen = sp->fts_pathlen - len;
 437                 }
 438
 439                 p->fts_level = level;
 440                 p->fts_parent = sp->fts_cur;
 441                 p->fts_pathlen = len + dlen;
 442                 if (p->fts_pathlen < len) {
 443                         /*
 444                          * If we wrap, free up the current structure and
 445                          * the structures already allocated, then error
 446                          * out with ENAMETOOLONG.
 447                          */
 448                         free(p);
 449                         fts_lfree(head);
 450                         (void)closedir(dirp);
 451                         cur->fts_info = FTS_ERR;
 452                         SET(FTS_STOP);
 453                         errno = ENAMETOOLONG;
 454                         return (NULL);
 455                 }
 456
 457                 /* Build a file name for fts_stat to stat. */
 458                 p->fts_accpath = p->fts_path;
 459                 memmove(cp, p->fts_name, p->fts_namelen + 1);
 460                 /* Stat it. */
 461                 p->fts_info = fts_stat(sp, p);
 462
 463                 /* We walk in directory order so "ls -f" doesn't get upset. */
 464                 p->fts_link = NULL;
 465                 if (head == NULL)
 466                         head = tail = p;
 467                 else {
 468                         tail->fts_link = p;
 469                         tail = p;
 470                 }
 471                 ++nitems;
 472         }
 473         if (dirp)
 474                 (void)closedir(dirp);
 475
 476         /*
 477          * If realloc() changed the address of the path, adjust the
 478          * addresses for the rest of the tree and the dir list.
 479          */
 480         if (doadjust)
 481                 fts_padjust(sp, head);
 482
 483         /*
 484          * If not changing directories, reset the path back to original
 485          * state.
 486          */
 487         if (len == sp->fts_pathlen || nitems == 0)
 488                 --cp;
 489         *cp = '\0';
 490
 491         /* If didn't find anything, return NULL. */
 492         if (!nitems) {
 493                 cur->fts_info = FTS_DP;
 494                 return (NULL);
 495         }
 496         return (head);
 497 }
 498
 499 static unsigned short
 500 fts_stat(FTS *sp, FTSENT *p)
 501 {
 502         FTSENT *t;
 503         dev_t dev;
 504         ino_t ino;
 505         struct stat *sbp;
 506
 507         /* If user needs stat info, stat buffer already allocated. */
 508         sbp = p->fts_statp;
 509
 510         if (lstat(p->fts_accpath, sbp)) {
 511                 p->fts_errno = errno;
 512                 memset(sbp, 0, sizeof(struct stat));
 513                 return (FTS_NS);
 514         }
 515
 516         if (S_ISDIR(sbp->st_mode)) {
 517                 /*
 518                  * Set the device/inode.  Used to find cycles and check for
 519                  * crossing mount points.  Also remember the link count, used
 520                  * in fts_build to limit the number of stat calls.  It is
 521                  * understood that these fields are only referenced if fts_info
 522                  * is set to FTS_D.
 523                  */
 524                 dev = p->fts_dev = sbp->st_dev;
 525                 ino = p->fts_ino = sbp->st_ino;
 526                 p->fts_nlink = sbp->st_nlink;
 527
 528                 if (ISDOT(p->fts_name))
 529                         return (FTS_DOT);
 530
 531                 /*
 532                  * Cycle detection is done by brute force when the directory
 533                  * is first encountered.  If the tree gets deep enough or the
 534                  * number of symbolic links to directories is high enough,
 535                  * something faster might be worthwhile.
 536                  */
 537                 for (t = p->fts_parent;
 538                     t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
 539                         if (ino == t->fts_ino && dev == t->fts_dev) {
 540                                 p->fts_cycle = t;
 541                                 return (FTS_DC);
 542                         }
 543                 return (FTS_D);
 544         }
 545         if (S_ISLNK(sbp->st_mode))
 546                 return (FTS_SL);
 547         if (S_ISREG(sbp->st_mode))
 548                 return (FTS_F);
 549         return (FTS_DEFAULT);
 550 }
 551
 552 static FTSENT *
 553 fts_alloc(FTS *sp, const char *name, size_t namelen)
 554 {
 555         FTSENT *p;
 556         size_t len;
 557
 558         len = sizeof(FTSENT) + namelen;
 559         if ((p = calloc(1, len)) == NULL)
 560                 return (NULL);
 561
 562         p->fts_path = sp->fts_path;
 563         p->fts_namelen = namelen;
 564         p->fts_instr = FTS_NOINSTR;
 565         p->fts_statp = malloc(sizeof(struct stat));
 566         if (p->fts_statp == NULL) {
 567                 free(p);
 568                 return (NULL);
 569         }
 570         memcpy(p->fts_name, name, namelen);
 571
 572         return (p);
 573 }
 574
 575 static void
 576 fts_lfree(FTSENT *head)
 577 {
 578         FTSENT *p;
 579
 580         /* Free a linked list of structures. */
 581         while ((p = head)) {
 582                 head = head->fts_link;
 583                 free(p);
 584         }
 585 }
 586
 587 /*
 588  * Allow essentially unlimited paths; find, rm, ls should all work on any tree.
 589  * Most systems will allow creation of paths much longer than PATH_MAX, even
 590  * though the kernel won't resolve them.  Add the size (not just what's needed)
 591  * plus 256 bytes so don't realloc the path 2 bytes at a time.
 592  */
 593 static int
 594 fts_palloc(FTS *sp, size_t more)
 595 {
 596         char *p;
 597
 598         /*
 599          * Check for possible wraparound.
 600          */
 601         more += 256;
 602         if (sp->fts_pathlen + more < sp->fts_pathlen) {
 603                 if (sp->fts_path)
 604                         free(sp->fts_path);
 605                 sp->fts_path = NULL;
 606                 errno = ENAMETOOLONG;
 607                 return (1);
 608         }
 609         sp->fts_pathlen += more;
 610         p = realloc(sp->fts_path, sp->fts_pathlen);
 611         if (p == NULL) {
 612                 if (sp->fts_path)
 613                         free(sp->fts_path);
 614                 sp->fts_path = NULL;
 615                 return (1);
 616         }
 617         sp->fts_path = p;
 618         return (0);
 619 }
 620
 621 /*
 622  * When the path is realloc'd, have to fix all of the pointers in structures
 623  * already returned.
 624  */
 625 static void
 626 fts_padjust(FTS *sp, FTSENT *head)
 627 {
 628         FTSENT *p;
 629         char *addr = sp->fts_path;
 630
 631 #define ADJUST(p) {                                                     \
 632         if ((p)->fts_accpath != (p)->fts_name) {                        \
 633                 (p)->fts_accpath =                                      \
 634                     (char *)addr + ((p)->fts_accpath - (p)->fts_path);  \
 635         }                                                               \
 636         (p)->fts_path = addr;                                           \
 637 }
 638         /* Adjust the current set of children. */
 639         for (p = sp->fts_child; p; p = p->fts_link)
 640                 ADJUST(p);
 641
 642         /* Adjust the rest of the tree, including the current level. */
 643         for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
 644                 ADJUST(p);
 645                 p = p->fts_link ? p->fts_link : p->fts_parent;
 646         }
 647 }
 648
 649 static size_t
 650 fts_maxarglen(char * const *argv)
 651 {
 652         size_t len, max;
 653
 654         for (max = 0; *argv; ++argv)
 655                 if ((len = strlen(*argv)) > max)
 656                         max = len;
 657         return (max + 1);
 658 }
 659
 660 #endif