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 1.9 2015/03/18 19:29:48 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
  72 #define CLR(opt)        (sp->fts_options &= ~(opt))
  73 #define ISSET(opt)      (sp->fts_options & (opt))
  74 #define SET(opt)        (sp->fts_options |= (opt))
  75
  76 FTS *
  77 fts_open(char * const *argv, int options, void *dummy)
  78 {
  79         FTS *sp;
  80         FTSENT *p, *root;
  81         int nitems;
  82         FTSENT *parent, *tmp;
  83         size_t len;
  84
  85         /* Options check. */
  86         if (options & ~FTS_OPTIONMASK) {
  87                 errno = EINVAL;
  88                 return (NULL);
  89         }
  90
  91         /* Allocate/initialize the stream */
  92         if ((sp = calloc(1, sizeof(FTS))) == NULL)
  93                 return (NULL);
  94         sp->fts_options = options;
  95
  96         /*
  97          * Start out with 1K of path space, and enough, in any case,
  98          * to hold the user's paths.
  99          */
 100         if (fts_palloc(sp, MAXIMUM(fts_maxarglen(argv), PATH_MAX)))
 101                 goto mem1;
 102
 103         /* Allocate/initialize root's parent. */
 104         if ((parent = fts_alloc(sp, "", 0)) == NULL)
 105                 goto mem2;
 106         parent->fts_level = FTS_ROOTPARENTLEVEL;
 107
 108         /* Allocate/initialize root(s). */
 109         for (root = NULL, nitems = 0; *argv; ++argv, ++nitems) {
 110                 /* Don't allow zero-length paths. */
 111                 if ((len = strlen(*argv)) == 0) {
 112                         errno = ENOENT;
 113                         goto mem3;
 114                 }
 115
 116                 if ((p = fts_alloc(sp, *argv, len)) == NULL)
 117                         goto mem3;
 118                 p->fts_level = FTS_ROOTLEVEL;
 119                 p->fts_parent = parent;
 120                 p->fts_accpath = p->fts_name;
 121                 p->fts_info = fts_stat(sp, p);
 122
 123                 /* Command-line "." and ".." are real directories. */
 124                 if (p->fts_info == FTS_DOT)
 125                         p->fts_info = FTS_D;
 126
 127                 p->fts_link = NULL;
 128                 if (root == NULL)
 129                         tmp = root = p;
 130                 else {
 131                         tmp->fts_link = p;
 132                         tmp = p;
 133                 }
 134         }
 135
 136         /*
 137          * Allocate a dummy pointer and make fts_read think that we've just
 138          * finished the node before the root(s); set p->fts_info to FTS_INIT
 139          * so that everything about the "current" node is ignored.
 140          */
 141         if ((sp->fts_cur = fts_alloc(sp, "", 0)) == NULL)
 142                 goto mem3;
 143         sp->fts_cur->fts_link = root;
 144         sp->fts_cur->fts_info = FTS_INIT;
 145
 146         if (nitems == 0)
 147                 free(parent);
 148
 149         return (sp);
 150
 151 mem3:   fts_lfree(root);
 152         free(parent);
 153 mem2:   free(sp->fts_path);
 154 mem1:   free(sp);
 155         return (NULL);
 156 }
 157
 158 static void
 159 fts_load(FTS *sp, FTSENT *p)
 160 {
 161         size_t len;
 162         char *cp;
 163
 164         /*
 165          * Load the stream structure for the next traversal.  Since we don't
 166          * actually enter the directory until after the preorder visit, set
 167          * the fts_accpath field specially so the chdir gets done to the right
 168          * place and the user can access the first node.  From fts_open it's
 169          * known that the path will fit.
 170          */
 171         len = p->fts_pathlen = p->fts_namelen;
 172         memmove(sp->fts_path, p->fts_name, len + 1);
 173         if ((cp = strrchr(p->fts_name, '/')) && (cp != p->fts_name || cp[1])) {
 174                 len = strlen(++cp);
 175                 memmove(p->fts_name, cp, len + 1);
 176                 p->fts_namelen = len;
 177         }
 178         p->fts_accpath = p->fts_path = sp->fts_path;
 179         sp->fts_dev = p->fts_dev;
 180 }
 181
 182 int
 183 fts_close(FTS *sp)
 184 {
 185         FTSENT *freep, *p;
 186
 187         /*
 188          * This still works if we haven't read anything -- the dummy structure
 189          * points to the root list, so we step through to the end of the root
 190          * list which has a valid parent pointer.
 191          */
 192         if (sp->fts_cur) {
 193                 for (p = sp->fts_cur; p->fts_level >= FTS_ROOTLEVEL;) {
 194                         freep = p;
 195                         p = p->fts_link ? p->fts_link : p->fts_parent;
 196                         free(freep);
 197                 }
 198                 free(p);
 199         }
 200
 201         /* Free up child linked list, sort array, path buffer, stream ptr.*/
 202         if (sp->fts_child)
 203                 fts_lfree(sp->fts_child);
 204         free(sp->fts_path);
 205         free(sp);
 206
 207         return (0);
 208 }
 209
 210 /*
 211  * Special case of "/" at the end of the path so that slashes aren't
 212  * appended which would cause paths to be written as "....//foo".
 213  */
 214 #define NAPPEND(p)                                                      \
 215         (p->fts_path[p->fts_pathlen - 1] == '/'                         \
 216             ? p->fts_pathlen - 1 : p->fts_pathlen)
 217
 218 FTSENT *
 219 fts_read(FTS *sp)
 220 {
 221         FTSENT *p, *tmp;
 222         int instr;
 223         char *t;
 224
 225         /* If finished or unrecoverable error, return NULL. */
 226         if (sp->fts_cur == NULL || ISSET(FTS_STOP))
 227                 return (NULL);
 228
 229         /* Set current node pointer. */
 230         p = sp->fts_cur;
 231
 232         /* Save and zero out user instructions. */
 233         instr = p->fts_instr;
 234         p->fts_instr = FTS_NOINSTR;
 235
 236         /* Directory in pre-order. */
 237         if (p->fts_info == FTS_D) {
 238                 /* If skipped or crossed mount point, do post-order visit. */
 239                 if (instr == FTS_SKIP ||
 240                     (ISSET(FTS_XDEV) && p->fts_dev != sp->fts_dev)) {
 241                         if (sp->fts_child) {
 242                                 fts_lfree(sp->fts_child);
 243                                 sp->fts_child = NULL;
 244                         }
 245                         p->fts_info = FTS_DP;
 246                         return (p);
 247                 }
 248
 249                 /*
 250                  * If haven't read do so.  If the read fails, fts_build sets
 251                  * FTS_STOP or the fts_info field of the node.
 252                  */
 253                 if (sp->fts_child) {
 254                         /* nothing */
 255                 } else if ((sp->fts_child = fts_build(sp)) == NULL) {
 256                         if (ISSET(FTS_STOP))
 257                                 return (NULL);
 258                         return (p);
 259                 }
 260                 p = sp->fts_child;
 261                 sp->fts_child = NULL;
 262                 goto name;
 263         }
 264
 265         /* Move to the next node on this level. */
 266 next:   tmp = p;
 267         if ((p = p->fts_link)) {
 268                 free(tmp);
 269
 270                 /*
 271                  * If reached the top, return to the original directory (or
 272                  * the root of the tree), and load the paths for the next root.
 273                  */
 274                 if (p->fts_level == FTS_ROOTLEVEL) {
 275                         fts_load(sp, p);
 276                         return (sp->fts_cur = p);
 277                 }
 278
 279                 /*
 280                  * User may have called fts_set on the node.  If skipped,
 281                  * ignore.  If followed, get a file descriptor so we can
 282                  * get back if necessary.
 283                  */
 284                 if (p->fts_instr == FTS_SKIP)
 285                         goto next;
 286
 287 name:           t = sp->fts_path + NAPPEND(p->fts_parent);
 288                 *t++ = '/';
 289                 memmove(t, p->fts_name, p->fts_namelen + 1);
 290                 return (sp->fts_cur = p);
 291         }
 292
 293         /* Move up to the parent node. */
 294         p = tmp->fts_parent;
 295         free(tmp);
 296
 297         if (p->fts_level == FTS_ROOTPARENTLEVEL) {
 298                 /*
 299                  * Done; free everything up and set errno to 0 so the user
 300                  * can distinguish between error and EOF.
 301                  */
 302                 free(p);
 303                 errno = 0;
 304                 return (sp->fts_cur = NULL);
 305         }
 306
 307         /* NUL terminate the pathname. */
 308         sp->fts_path[p->fts_pathlen] = '\0';
 309
 310         p->fts_info = p->fts_errno ? FTS_ERR : FTS_DP;
 311         return (sp->fts_cur = p);
 312 }
 313
 314 /*
 315  * Fts_set takes the stream as an argument although it's not used in this
 316  * implementation; it would be necessary if anyone wanted to add global
 317  * semantics to fts using fts_set.  An error return is allowed for similar
 318  * reasons.
 319  */
 320 /* ARGSUSED */
 321 int
 322 fts_set(FTS *sp, FTSENT *p, int instr)
 323 {
 324         if (instr && instr != FTS_NOINSTR && instr != FTS_SKIP) {
 325                 errno = EINVAL;
 326                 return (1);
 327         }
 328         p->fts_instr = instr;
 329         return (0);
 330 }
 331
 332 /*
 333  * This is the tricky part -- do not casually change *anything* in here.  The
 334  * idea is to build the linked list of entries that are used by fts_children
 335  * and fts_read.  There are lots of special cases.
 336  *
 337  * The real slowdown in walking the tree is the stat calls.  If FTS_NOSTAT is
 338  * set and it's a physical walk (so that symbolic links can't be directories),
 339  * we can do things quickly.  First, if it's a 4.4BSD file system, the type
 340  * of the file is in the directory entry.  Otherwise, we assume that the number
 341  * of subdirectories in a node is equal to the number of links to the parent.
 342  * The former skips all stat calls.  The latter skips stat calls in any leaf
 343  * directories and for any files after the subdirectories in the directory have
 344  * been found, cutting the stat calls by about 2/3.
 345  */
 346 static FTSENT *
 347 fts_build(FTS *sp)
 348 {
 349         struct dirent *dp;
 350         FTSENT *p, *head;
 351         FTSENT *cur, *tail;
 352         DIR *dirp;
 353         void *oldaddr;
 354         size_t dlen, len, maxlen;
 355         int nitems, level, doadjust;
 356         int saved_errno;
 357         char *cp;
 358
 359         /* Set current node pointer. */
 360         cur = sp->fts_cur;
 361
 362         /*
 363          * Open the directory for reading.  If this fails, we're done.
 364          * If being called from fts_read, set the fts_info field.
 365          */
 366         if ((dirp = opendir(cur->fts_accpath)) == NULL) {
 367                 cur->fts_info = FTS_DNR;
 368                 cur->fts_errno = errno;
 369                 return (NULL);
 370         }
 371
 372         /*
 373          * Figure out the max file name length that can be stored in the
 374          * current path -- the inner loop allocates more path as necessary.
 375          * We really wouldn't have to do the maxlen calculations here, we
 376          * could do them in fts_read before returning the path, but it's a
 377          * lot easier here since the length is part of the dirent structure.
 378          *
 379          * If not changing directories set a pointer so that can just append
 380          * each new name into the path.
 381          */
 382         len = NAPPEND(cur);
 383         cp = sp->fts_path + len;
 384         *cp++ = '/';
 385         len++;
 386         maxlen = sp->fts_pathlen - len;
 387
 388         /*
 389          * fts_level is signed so we must prevent it from wrapping
 390          * around to FTS_ROOTLEVEL and FTS_ROOTPARENTLEVEL.
 391          */
 392         level = cur->fts_level;
 393         if (level < FTS_MAXLEVEL)
 394             level++;
 395
 396         /* Read the directory, attaching each entry to the `link' pointer. */
 397         doadjust = 0;
 398         for (head = tail = NULL, nitems = 0; dirp && (dp = readdir(dirp));) {
 399                 if (ISDOT(dp->d_name))
 400                         continue;
 401
 402 #if HAVE_DIRENT_NAMLEN
 403                 dlen = dp->d_namlen;
 404 #else
 405                 dlen = strlen(dp->d_name);
 406 #endif
 407
 408                 if (!(p = fts_alloc(sp, dp->d_name, dlen)))
 409                         goto mem1;
 410                 if (dlen >= maxlen) {   /* include space for NUL */
 411                         oldaddr = sp->fts_path;
 412                         if (fts_palloc(sp, dlen + len + 1)) {
 413                                 /*
 414                                  * No more memory for path or structures.  Save
 415                                  * errno, free up the current structure and the
 416                                  * structures already allocated.
 417                                  */
 418 mem1:                           saved_errno = errno;
 419                                 if (p)
 420                                         free(p);
 421                                 fts_lfree(head);
 422                                 (void)closedir(dirp);
 423                                 cur->fts_info = FTS_ERR;
 424                                 SET(FTS_STOP);
 425                                 errno = saved_errno;
 426                                 return (NULL);
 427                         }
 428                         /* Did realloc() change the pointer? */
 429                         if (oldaddr != sp->fts_path) {
 430                                 doadjust = 1;
 431                                 cp = sp->fts_path + len;
 432                         }
 433                         maxlen = sp->fts_pathlen - len;
 434                 }
 435
 436                 p->fts_level = level;
 437                 p->fts_parent = sp->fts_cur;
 438                 p->fts_pathlen = len + dlen;
 439                 if (p->fts_pathlen < len) {
 440                         /*
 441                          * If we wrap, free up the current structure and
 442                          * the structures already allocated, then error
 443                          * out with ENAMETOOLONG.
 444                          */
 445                         free(p);
 446                         fts_lfree(head);
 447                         (void)closedir(dirp);
 448                         cur->fts_info = FTS_ERR;
 449                         SET(FTS_STOP);
 450                         errno = ENAMETOOLONG;
 451                         return (NULL);
 452                 }
 453
 454                 /* Build a file name for fts_stat to stat. */
 455                 p->fts_accpath = p->fts_path;
 456                 memmove(cp, p->fts_name, p->fts_namelen + 1);
 457                 /* Stat it. */
 458                 p->fts_info = fts_stat(sp, p);
 459
 460                 /* We walk in directory order so "ls -f" doesn't get upset. */
 461                 p->fts_link = NULL;
 462                 if (head == NULL)
 463                         head = tail = p;
 464                 else {
 465                         tail->fts_link = p;
 466                         tail = p;
 467                 }
 468                 ++nitems;
 469         }
 470         if (dirp)
 471                 (void)closedir(dirp);
 472
 473         /*
 474          * If realloc() changed the address of the path, adjust the
 475          * addresses for the rest of the tree and the dir list.
 476          */
 477         if (doadjust)
 478                 fts_padjust(sp, head);
 479
 480         /*
 481          * If not changing directories, reset the path back to original
 482          * state.
 483          */
 484         if (len == sp->fts_pathlen || nitems == 0)
 485                 --cp;
 486         *cp = '\0';
 487
 488         /* If didn't find anything, return NULL. */
 489         if (!nitems) {
 490                 cur->fts_info = FTS_DP;
 491                 return (NULL);
 492         }
 493         return (head);
 494 }
 495
 496 static unsigned short
 497 fts_stat(FTS *sp, FTSENT *p)
 498 {
 499         FTSENT *t;
 500         dev_t dev;
 501         ino_t ino;
 502         struct stat *sbp;
 503
 504         /* If user needs stat info, stat buffer already allocated. */
 505         sbp = p->fts_statp;
 506
 507         if (lstat(p->fts_accpath, sbp)) {
 508                 p->fts_errno = errno;
 509                 memset(sbp, 0, sizeof(struct stat));
 510                 return (FTS_NS);
 511         }
 512
 513         if (S_ISDIR(sbp->st_mode)) {
 514                 /*
 515                  * Set the device/inode.  Used to find cycles and check for
 516                  * crossing mount points.  Also remember the link count, used
 517                  * in fts_build to limit the number of stat calls.  It is
 518                  * understood that these fields are only referenced if fts_info
 519                  * is set to FTS_D.
 520                  */
 521                 dev = p->fts_dev = sbp->st_dev;
 522                 ino = p->fts_ino = sbp->st_ino;
 523                 p->fts_nlink = sbp->st_nlink;
 524
 525                 if (ISDOT(p->fts_name))
 526                         return (FTS_DOT);
 527
 528                 /*
 529                  * Cycle detection is done by brute force when the directory
 530                  * is first encountered.  If the tree gets deep enough or the
 531                  * number of symbolic links to directories is high enough,
 532                  * something faster might be worthwhile.
 533                  */
 534                 for (t = p->fts_parent;
 535                     t->fts_level >= FTS_ROOTLEVEL; t = t->fts_parent)
 536                         if (ino == t->fts_ino && dev == t->fts_dev) {
 537                                 p->fts_cycle = t;
 538                                 return (FTS_DC);
 539                         }
 540                 return (FTS_D);
 541         }
 542         if (S_ISLNK(sbp->st_mode))
 543                 return (FTS_SL);
 544         if (S_ISREG(sbp->st_mode))
 545                 return (FTS_F);
 546         return (FTS_DEFAULT);
 547 }
 548
 549 static FTSENT *
 550 fts_alloc(FTS *sp, const char *name, size_t namelen)
 551 {
 552         FTSENT *p;
 553         size_t len;
 554
 555         len = sizeof(FTSENT) + namelen;
 556         if ((p = calloc(1, len)) == NULL)
 557                 return (NULL);
 558
 559         p->fts_path = sp->fts_path;
 560         p->fts_namelen = namelen;
 561         p->fts_instr = FTS_NOINSTR;
 562         p->fts_statp = malloc(sizeof(struct stat));
 563         if (p->fts_statp == NULL) {
 564                 free(p);
 565                 return (NULL);
 566         }
 567         memcpy(p->fts_name, name, namelen);
 568
 569         return (p);
 570 }
 571
 572 static void
 573 fts_lfree(FTSENT *head)
 574 {
 575         FTSENT *p;
 576
 577         /* Free a linked list of structures. */
 578         while ((p = head)) {
 579                 head = head->fts_link;
 580                 free(p);
 581         }
 582 }
 583
 584 /*
 585  * Allow essentially unlimited paths; find, rm, ls should all work on any tree.
 586  * Most systems will allow creation of paths much longer than PATH_MAX, even
 587  * though the kernel won't resolve them.  Add the size (not just what's needed)
 588  * plus 256 bytes so don't realloc the path 2 bytes at a time.
 589  */
 590 static int
 591 fts_palloc(FTS *sp, size_t more)
 592 {
 593         char *p;
 594
 595         /*
 596          * Check for possible wraparound.
 597          */
 598         more += 256;
 599         if (sp->fts_pathlen + more < sp->fts_pathlen) {
 600                 if (sp->fts_path)
 601                         free(sp->fts_path);
 602                 sp->fts_path = NULL;
 603                 errno = ENAMETOOLONG;
 604                 return (1);
 605         }
 606         sp->fts_pathlen += more;
 607         p = realloc(sp->fts_path, sp->fts_pathlen);
 608         if (p == NULL) {
 609                 if (sp->fts_path)
 610                         free(sp->fts_path);
 611                 sp->fts_path = NULL;
 612                 return (1);
 613         }
 614         sp->fts_path = p;
 615         return (0);
 616 }
 617
 618 /*
 619  * When the path is realloc'd, have to fix all of the pointers in structures
 620  * already returned.
 621  */
 622 static void
 623 fts_padjust(FTS *sp, FTSENT *head)
 624 {
 625         FTSENT *p;
 626         char *addr = sp->fts_path;
 627
 628 #define ADJUST(p) {                                                     \
 629         if ((p)->fts_accpath != (p)->fts_name) {                        \
 630                 (p)->fts_accpath =                                      \
 631                     (char *)addr + ((p)->fts_accpath - (p)->fts_path);  \
 632         }                                                               \
 633         (p)->fts_path = addr;                                           \
 634 }
 635         /* Adjust the current set of children. */
 636         for (p = sp->fts_child; p; p = p->fts_link)
 637                 ADJUST(p);
 638
 639         /* Adjust the rest of the tree, including the current level. */
 640         for (p = head; p->fts_level >= FTS_ROOTLEVEL;) {
 641                 ADJUST(p);
 642                 p = p->fts_link ? p->fts_link : p->fts_parent;
 643         }
 644 }
 645
 646 static size_t
 647 fts_maxarglen(char * const *argv)
 648 {
 649         size_t len, max;
 650
 651         for (max = 0; *argv; ++argv)
 652                 if ((len = strlen(*argv)) > max)
 653                         max = len;
 654         return (max + 1);
 655 }
 656
 657 #endif