usr.sbin/makefs/walk.c

   1 /*      $NetBSD: walk.c,v 1.24 2008/12/28 21:51:46 christos Exp $       */
   2
   3 /*
   4  * Copyright (c) 2001 Wasabi Systems, Inc.
   5  * All rights reserved.
   6  *
   7  * Written by Luke Mewburn for Wasabi Systems, Inc.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed for the NetBSD Project by
  20  *      Wasabi Systems, Inc.
  21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
  22  *    or promote products derived from this software without specific prior
  23  *    written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
  29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35  * POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38
  39 #include <sys/cdefs.h>
  40 __FBSDID("$FreeBSD$");
  41
  42 #include <sys/param.h>
  43
  44 #include <assert.h>
  45 #include <errno.h>
  46 #include <fcntl.h>
  47 #include <stdio.h>
  48 #include <dirent.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <unistd.h>
  52 #include <sys/stat.h>
  53
  54 #include "makefs.h"
  55 #include "mtree.h"
  56 #include "extern.h"
  57
  58 static  void     apply_specdir(const char *, NODE *, fsnode *, int);
  59 static  void     apply_specentry(const char *, NODE *, fsnode *);
  60 static  fsnode  *create_fsnode(const char *, const char *, const char *,
  61                                struct stat *);
  62
  63
  64 /*
  65  * walk_dir --
  66  *      build a tree of fsnodes from `root' and `dir', with a parent
  67  *      fsnode of `parent' (which may be NULL for the root of the tree).
  68  *      append the tree to a fsnode of `join' if it is not NULL.
  69  *      each "level" is a directory, with the "." entry guaranteed to be
  70  *      at the start of the list, and without ".." entries.
  71  */
  72 fsnode *
  73 walk_dir(const char *root, const char *dir, fsnode *parent, fsnode *join)
  74 {
  75         fsnode          *first, *cur, *prev, *last;
  76         DIR             *dirp;
  77         struct dirent   *dent;
  78         char            path[MAXPATHLEN + 1];
  79         struct stat     stbuf;
  80         char            *name, *rp;
  81         int             dot, len;
  82
  83         assert(root != NULL);
  84         assert(dir != NULL);
  85
  86         len = snprintf(path, sizeof(path), "%s/%s", root, dir);
  87         if (len >= (int)sizeof(path))
  88                 errx(1, "Pathname too long.");
  89         if (debug & DEBUG_WALK_DIR)
  90                 printf("walk_dir: %s %p\n", path, parent);
  91         if ((dirp = opendir(path)) == NULL)
  92                 err(1, "Can't opendir `%s'", path);
  93         rp = path + strlen(root) + 1;
  94         if (join != NULL) {
  95                 first = cur = join;
  96                 while (cur->next != NULL)
  97                         cur = cur->next;
  98                 prev = cur;
  99         } else
 100                 first = prev = NULL;
 101         last = prev;
 102         while ((dent = readdir(dirp)) != NULL) {
 103                 name = dent->d_name;
 104                 dot = 0;
 105                 if (name[0] == '.')
 106                         switch (name[1]) {
 107                         case '\0':      /* "." */
 108                                 if (join != NULL)
 109                                         continue;
 110                                 dot = 1;
 111                                 break;
 112                         case '.':       /* ".." */
 113                                 if (name[2] == '\0')
 114                                         continue;
 115                                 /* FALLTHROUGH */
 116                         default:
 117                                 dot = 0;
 118                         }
 119                 if (debug & DEBUG_WALK_DIR_NODE)
 120                         printf("scanning %s/%s/%s\n", root, dir, name);
 121                 if (snprintf(path + len, sizeof(path) - len, "/%s", name) >=
 122                     (int)sizeof(path) - len)
 123                         errx(1, "Pathname too long.");
 124                 if (lstat(path, &stbuf) == -1)
 125                         err(1, "Can't lstat `%s'", path);
 126 #ifdef S_ISSOCK
 127                 if (S_ISSOCK(stbuf.st_mode & S_IFMT)) {
 128                         if (debug & DEBUG_WALK_DIR_NODE)
 129                                 printf("  skipping socket %s\n", path);
 130                         continue;
 131                 }
 132 #endif
 133
 134                 if (join != NULL) {
 135                         cur = join->next;
 136                         for (;;) {
 137                                 if (cur == NULL || strcmp(cur->name, name) == 0)
 138                                         break;
 139                                 if (cur == last) {
 140                                         cur = NULL;
 141                                         break;
 142                                 }
 143                                 cur = cur->next;
 144                         }
 145                         if (cur != NULL) {
 146                                 if (S_ISDIR(cur->type) &&
 147                                     S_ISDIR(stbuf.st_mode)) {
 148                                         if (debug & DEBUG_WALK_DIR_NODE)
 149                                                 printf("merging %s with %p\n",
 150                                                     path, cur->child);
 151                                         cur->child = walk_dir(root, rp, cur,
 152                                             cur->child);
 153                                         continue;
 154                                 }
 155                                 errx(1, "Can't merge %s `%s' with existing %s",
 156                                     inode_type(stbuf.st_mode), path,
 157                                     inode_type(cur->type));
 158                         }
 159                 }
 160
 161                 cur = create_fsnode(root, dir, name, &stbuf);
 162                 cur->parent = parent;
 163                 if (dot) {
 164                                 /* ensure "." is at the start of the list */
 165                         cur->next = first;
 166                         first = cur;
 167                         if (! prev)
 168                                 prev = cur;
 169                         cur->first = first;
 170                 } else {                        /* not "." */
 171                         if (prev)
 172                                 prev->next = cur;
 173                         prev = cur;
 174                         if (!first)
 175                                 first = cur;
 176                         cur->first = first;
 177                         if (S_ISDIR(cur->type)) {
 178                                 cur->child = walk_dir(root, rp, cur, NULL);
 179                                 continue;
 180                         }
 181                 }
 182                 if (stbuf.st_nlink > 1) {
 183                         fsinode *curino;
 184
 185                         curino = link_check(cur->inode);
 186                         if (curino != NULL) {
 187                                 free(cur->inode);
 188                                 cur->inode = curino;
 189                                 cur->inode->nlink++;
 190                                 if (debug & DEBUG_WALK_DIR_LINKCHECK)
 191                                         printf("link_check: found [%llu, %llu]\n",
 192                                             (unsigned long long)curino->st.st_dev,
 193                                             (unsigned long long)curino->st.st_ino);
 194                         }
 195                 }
 196                 if (S_ISLNK(cur->type)) {
 197                         char    slink[PATH_MAX+1];
 198                         int     llen;
 199
 200                         llen = readlink(path, slink, sizeof(slink) - 1);
 201                         if (llen == -1)
 202                                 err(1, "Readlink `%s'", path);
 203                         slink[llen] = '\0';
 204                         if ((cur->symlink = strdup(slink)) == NULL)
 205                                 err(1, "Memory allocation error");
 206                 }
 207         }
 208         assert(first != NULL);
 209         if (join == NULL)
 210                 for (cur = first->next; cur != NULL; cur = cur->next)
 211                         cur->first = first;
 212         if (closedir(dirp) == -1)
 213                 err(1, "Can't closedir `%s/%s'", root, dir);
 214         return (first);
 215 }
 216
 217 static fsnode *
 218 create_fsnode(const char *root, const char *path, const char *name,
 219     struct stat *stbuf)
 220 {
 221         fsnode *cur;
 222
 223         if ((cur = calloc(1, sizeof(fsnode))) == NULL ||
 224             (cur->path = strdup(path)) == NULL ||
 225             (cur->name = strdup(name)) == NULL ||
 226             (cur->inode = calloc(1, sizeof(fsinode))) == NULL)
 227                 err(1, "Memory allocation error");
 228         cur->root = root;
 229         cur->type = stbuf->st_mode & S_IFMT;
 230         cur->inode->nlink = 1;
 231         cur->inode->st = *stbuf;
 232         return (cur);
 233 }
 234
 235 /*
 236  * free_fsnodes --
 237  *      Removes node from tree and frees it and all of
 238  *   its descendants.
 239  */
 240 void
 241 free_fsnodes(fsnode *node)
 242 {
 243         fsnode  *cur, *next;
 244
 245         assert(node != NULL);
 246
 247         /* for ".", start with actual parent node */
 248         if (node->first == node) {
 249                 assert(node->name[0] == '.' && node->name[1] == '\0');
 250                 if (node->parent) {
 251                         assert(node->parent->child == node);
 252                         node = node->parent;
 253                 }
 254         }
 255
 256         /* Find ourselves in our sibling list and unlink */
 257         if (node->first != node) {
 258                 for (cur = node->first; cur->next; cur = cur->next) {
 259                         if (cur->next == node) {
 260                                 cur->next = node->next;
 261                                 node->next = NULL;
 262                                 break;
 263                         }
 264                 }
 265         }
 266
 267         for (cur = node; cur != NULL; cur = next) {
 268                 next = cur->next;
 269                 if (cur->child) {
 270                         cur->child->parent = NULL;
 271                         free_fsnodes(cur->child);
 272                 }
 273                 if (cur->inode->nlink-- == 1)
 274                         free(cur->inode);
 275                 if (cur->symlink)
 276                         free(cur->symlink);
 277                 free(cur->path);
 278                 free(cur->name);
 279                 free(cur);
 280         }
 281 }
 282
 283 /*
 284  * apply_specfile --
 285  *      read in the mtree(8) specfile, and apply it to the tree
 286  *      at dir,parent. parameters in parent on equivalent types
 287  *      will be changed to those found in specfile, and missing
 288  *      entries will be added.
 289  */
 290 void
 291 apply_specfile(const char *specfile, const char *dir, fsnode *parent, int speconly)
 292 {
 293         struct timeval   start;
 294         FILE    *fp;
 295         NODE    *root;
 296
 297         assert(specfile != NULL);
 298         assert(parent != NULL);
 299
 300         if (debug & DEBUG_APPLY_SPECFILE)
 301                 printf("apply_specfile: %s, %s %p\n", specfile, dir, parent);
 302
 303                                 /* read in the specfile */
 304         if ((fp = fopen(specfile, "r")) == NULL)
 305                 err(1, "Can't open `%s'", specfile);
 306         TIMER_START(start);
 307         root = spec(fp);
 308         TIMER_RESULTS(start, "spec");
 309         if (fclose(fp) == EOF)
 310                 err(1, "Can't close `%s'", specfile);
 311
 312                                 /* perform some sanity checks */
 313         if (root == NULL)
 314                 errx(1, "Specfile `%s' did not contain a tree", specfile);
 315         assert(strcmp(root->name, ".") == 0);
 316         assert(root->type == F_DIR);
 317
 318                                 /* merge in the changes */
 319         apply_specdir(dir, root, parent, speconly);
 320
 321 }
 322
 323 static void
 324 apply_specdir(const char *dir, NODE *specnode, fsnode *dirnode, int speconly)
 325 {
 326         char     path[MAXPATHLEN + 1];
 327         NODE    *curnode;
 328         fsnode  *curfsnode;
 329
 330         assert(specnode != NULL);
 331         assert(dirnode != NULL);
 332
 333         if (debug & DEBUG_APPLY_SPECFILE)
 334                 printf("apply_specdir: %s %p %p\n", dir, specnode, dirnode);
 335
 336         if (specnode->type != F_DIR)
 337                 errx(1, "Specfile node `%s/%s' is not a directory",
 338                     dir, specnode->name);
 339         if (dirnode->type != S_IFDIR)
 340                 errx(1, "Directory node `%s/%s' is not a directory",
 341                     dir, dirnode->name);
 342
 343         apply_specentry(dir, specnode, dirnode);
 344
 345         /* Remove any filesystem nodes not found in specfile */
 346         /* XXX inefficient.  This is O^2 in each dir and it would
 347          * have been better never to have walked this part of the tree
 348          * to begin with
 349          */
 350         if (speconly) {
 351                 fsnode *next;
 352                 assert(dirnode->name[0] == '.' && dirnode->name[1] == '\0');
 353                 for (curfsnode = dirnode->next; curfsnode != NULL; curfsnode = next) {
 354                         next = curfsnode->next;
 355                         for (curnode = specnode->child; curnode != NULL;
 356                              curnode = curnode->next) {
 357                                 if (strcmp(curnode->name, curfsnode->name) == 0)
 358                                         break;
 359                         }
 360                         if (curnode == NULL) {
 361                                 if (debug & DEBUG_APPLY_SPECONLY) {
 362                                         printf("apply_specdir: trimming %s/%s %p\n", dir, curfsnode->name, curfsnode);
 363                                 }
 364                                 free_fsnodes(curfsnode);
 365                         }
 366                 }
 367         }
 368
 369                         /* now walk specnode->child matching up with dirnode */
 370         for (curnode = specnode->child; curnode != NULL;
 371             curnode = curnode->next) {
 372                 if (debug & DEBUG_APPLY_SPECENTRY)
 373                         printf("apply_specdir:  spec %s\n",
 374                             curnode->name);
 375                 for (curfsnode = dirnode->next; curfsnode != NULL;
 376                     curfsnode = curfsnode->next) {
 377 #if 0   /* too verbose for now */
 378                         if (debug & DEBUG_APPLY_SPECENTRY)
 379                                 printf("apply_specdir:  dirent %s\n",
 380                                     curfsnode->name);
 381 #endif
 382                         if (strcmp(curnode->name, curfsnode->name) == 0)
 383                                 break;
 384                 }
 385                 if (snprintf(path, sizeof(path), "%s/%s",
 386                     dir, curnode->name) >= sizeof(path))
 387                         errx(1, "Pathname too long.");
 388                 if (curfsnode == NULL) {        /* need new entry */
 389                         struct stat     stbuf;
 390
 391                                             /*
 392                                              * don't add optional spec entries
 393                                              * that lack an existing fs entry
 394                                              */
 395                         if ((curnode->flags & F_OPT) &&
 396                             lstat(path, &stbuf) == -1)
 397                                         continue;
 398
 399                                         /* check that enough info is provided */
 400 #define NODETEST(t, m)                                                  \
 401                         if (!(t))                                       \
 402                                 errx(1, "`%s': %s not provided", path, m)
 403                         NODETEST(curnode->flags & F_TYPE, "type");
 404                         NODETEST(curnode->flags & F_MODE, "mode");
 405                                 /* XXX: require F_TIME ? */
 406                         NODETEST(curnode->flags & F_GID ||
 407                             curnode->flags & F_GNAME, "group");
 408                         NODETEST(curnode->flags & F_UID ||
 409                             curnode->flags & F_UNAME, "user");
 410 /*                      if (curnode->type == F_BLOCK || curnode->type == F_CHAR)
 411                                 NODETEST(curnode->flags & F_DEV,
 412                                     "device number");*/
 413 #undef NODETEST
 414
 415                         if (debug & DEBUG_APPLY_SPECFILE)
 416                                 printf("apply_specdir: adding %s\n",
 417                                     curnode->name);
 418                                         /* build minimal fsnode */
 419                         memset(&stbuf, 0, sizeof(stbuf));
 420                         stbuf.st_mode = nodetoino(curnode->type);
 421                         stbuf.st_nlink = 1;
 422                         stbuf.st_mtime = stbuf.st_atime =
 423                             stbuf.st_ctime = start_time.tv_sec;
 424 #if HAVE_STRUCT_STAT_ST_MTIMENSEC
 425                         stbuf.st_mtimensec = stbuf.st_atimensec =
 426                             stbuf.st_ctimensec = start_time.tv_nsec;
 427 #endif
 428                         curfsnode = create_fsnode(".", ".", curnode->name,
 429                             &stbuf);
 430                         curfsnode->parent = dirnode->parent;
 431                         curfsnode->first = dirnode;
 432                         curfsnode->next = dirnode->next;
 433                         dirnode->next = curfsnode;
 434                         if (curfsnode->type == S_IFDIR) {
 435                                         /* for dirs, make "." entry as well */
 436                                 curfsnode->child = create_fsnode(".", ".", ".",
 437                                     &stbuf);
 438                                 curfsnode->child->parent = curfsnode;
 439                                 curfsnode->child->first = curfsnode->child;
 440                         }
 441                         if (curfsnode->type == S_IFLNK) {
 442                                 assert(curnode->slink != NULL);
 443                                         /* for symlinks, copy the target */
 444                                 if ((curfsnode->symlink =
 445                                     strdup(curnode->slink)) == NULL)
 446                                         err(1, "Memory allocation error");
 447                         }
 448                 }
 449                 apply_specentry(dir, curnode, curfsnode);
 450                 if (curnode->type == F_DIR) {
 451                         if (curfsnode->type != S_IFDIR)
 452                                 errx(1, "`%s' is not a directory", path);
 453                         assert (curfsnode->child != NULL);
 454                         apply_specdir(path, curnode, curfsnode->child, speconly);
 455                 }
 456         }
 457 }
 458
 459 static void
 460 apply_specentry(const char *dir, NODE *specnode, fsnode *dirnode)
 461 {
 462
 463         assert(specnode != NULL);
 464         assert(dirnode != NULL);
 465
 466         if (nodetoino(specnode->type) != dirnode->type)
 467                 errx(1, "`%s/%s' type mismatch: specfile %s, tree %s",
 468                     dir, specnode->name, inode_type(nodetoino(specnode->type)),
 469                     inode_type(dirnode->type));
 470
 471         if (debug & DEBUG_APPLY_SPECENTRY)
 472                 printf("apply_specentry: %s/%s\n", dir, dirnode->name);
 473
 474 #define ASEPRINT(t, b, o, n) \
 475                 if (debug & DEBUG_APPLY_SPECENTRY) \
 476                         printf("\t\t\tchanging %s from " b " to " b "\n", \
 477                             t, o, n)
 478
 479         if (specnode->flags & (F_GID | F_GNAME)) {
 480                 ASEPRINT("gid", "%d",
 481                     dirnode->inode->st.st_gid, specnode->st_gid);
 482                 dirnode->inode->st.st_gid = specnode->st_gid;
 483         }
 484         if (specnode->flags & F_MODE) {
 485                 ASEPRINT("mode", "%#o",
 486                     dirnode->inode->st.st_mode & ALLPERMS, specnode->st_mode);
 487                 dirnode->inode->st.st_mode &= ~ALLPERMS;
 488                 dirnode->inode->st.st_mode |= (specnode->st_mode & ALLPERMS);
 489         }
 490                 /* XXX: ignoring F_NLINK for now */
 491         if (specnode->flags & F_SIZE) {
 492                 ASEPRINT("size", "%lld",
 493                     (long long)dirnode->inode->st.st_size,
 494                     (long long)specnode->st_size);
 495                 dirnode->inode->st.st_size = specnode->st_size;
 496         }
 497         if (specnode->flags & F_SLINK) {
 498                 assert(dirnode->symlink != NULL);
 499                 assert(specnode->slink != NULL);
 500                 ASEPRINT("symlink", "%s", dirnode->symlink, specnode->slink);
 501                 free(dirnode->symlink);
 502                 if ((dirnode->symlink = strdup(specnode->slink)) == NULL)
 503                         err(1, "Memory allocation error");
 504         }
 505         if (specnode->flags & F_TIME) {
 506                 ASEPRINT("time", "%ld",
 507                     (long)dirnode->inode->st.st_mtime,
 508                     (long)specnode->st_mtimespec.tv_sec);
 509                 dirnode->inode->st.st_mtime =           specnode->st_mtimespec.tv_sec;
 510                 dirnode->inode->st.st_atime =           specnode->st_mtimespec.tv_sec;
 511                 dirnode->inode->st.st_ctime =           start_time.tv_sec;
 512 #if HAVE_STRUCT_STAT_ST_MTIMENSEC
 513                 dirnode->inode->st.st_mtimensec =       specnode->st_mtimespec.tv_nsec;
 514                 dirnode->inode->st.st_atimensec =       specnode->st_mtimespec.tv_nsec;
 515                 dirnode->inode->st.st_ctimensec =       start_time.tv_nsec;
 516 #endif
 517         }
 518         if (specnode->flags & (F_UID | F_UNAME)) {
 519                 ASEPRINT("uid", "%d",
 520                     dirnode->inode->st.st_uid, specnode->st_uid);
 521                 dirnode->inode->st.st_uid = specnode->st_uid;
 522         }
 523 #if HAVE_STRUCT_STAT_ST_FLAGS
 524         if (specnode->flags & F_FLAGS) {
 525                 ASEPRINT("flags", "%#lX",
 526                     (unsigned long)dirnode->inode->st.st_flags,
 527                     (unsigned long)specnode->st_flags);
 528                 dirnode->inode->st.st_flags = specnode->st_flags;
 529         }
 530 #endif
 531 /*      if (specnode->flags & F_DEV) {
 532                 ASEPRINT("rdev", "%#llx",
 533                     (unsigned long long)dirnode->inode->st.st_rdev,
 534                     (unsigned long long)specnode->st_rdev);
 535                 dirnode->inode->st.st_rdev = specnode->st_rdev;
 536         }*/
 537 #undef ASEPRINT
 538
 539         dirnode->flags |= FSNODE_F_HASSPEC;
 540 }
 541
 542
 543 /*
 544  * dump_fsnodes --
 545  *      dump the fsnodes from `cur'
 546  */
 547 void
 548 dump_fsnodes(fsnode *root)
 549 {
 550         fsnode  *cur;
 551         char    path[MAXPATHLEN + 1];
 552
 553         printf("dump_fsnodes: %s %p\n", root->path, root);
 554         for (cur = root; cur != NULL; cur = cur->next) {
 555                 if (snprintf(path, sizeof(path), "%s/%s", cur->path,
 556                     cur->name) >= (int)sizeof(path))
 557                         errx(1, "Pathname too long.");
 558
 559                 if (debug & DEBUG_DUMP_FSNODES_VERBOSE)
 560                         printf("cur=%8p parent=%8p first=%8p ",
 561                             cur, cur->parent, cur->first);
 562                 printf("%7s: %s", inode_type(cur->type), path);
 563                 if (S_ISLNK(cur->type)) {
 564                         assert(cur->symlink != NULL);
 565                         printf(" -> %s", cur->symlink);
 566                 } else {
 567                         assert (cur->symlink == NULL);
 568                 }
 569                 if (cur->inode->nlink > 1)
 570                         printf(", nlinks=%d", cur->inode->nlink);
 571                 putchar('\n');
 572
 573                 if (cur->child) {
 574                         assert (cur->type == S_IFDIR);
 575                         dump_fsnodes(cur->child);
 576                 }
 577         }
 578         printf("dump_fsnodes: finished %s/%s\n", root->path, root->name);
 579 }
 580
 581
 582 /*
 583  * inode_type --
 584  *      for a given inode type `mode', return a descriptive string.
 585  *      for most cases, uses inotype() from mtree/misc.c
 586  */
 587 const char *
 588 inode_type(mode_t mode)
 589 {
 590         if (S_ISREG(mode))
 591                 return ("file");
 592         if (S_ISLNK(mode))
 593                 return ("symlink");
 594         if (S_ISDIR(mode))
 595                 return ("dir");
 596         if (S_ISLNK(mode))
 597                 return ("link");
 598         if (S_ISFIFO(mode))
 599                 return ("fifo");
 600         if (S_ISSOCK(mode))
 601                 return ("socket");
 602         /* XXX should not happen but handle them */
 603         if (S_ISCHR(mode))
 604                 return ("char");
 605         if (S_ISBLK(mode))
 606                 return ("block");
 607         return ("unknown");
 608 }
 609
 610
 611 /*
 612  * link_check --
 613  *      return pointer to fsinode matching `entry's st_ino & st_dev if it exists,
 614  *      otherwise add `entry' to table and return NULL
 615  */
 616 /* This was borrowed from du.c and tweaked to keep an fsnode
 617  * pointer instead. -- dbj@netbsd.org
 618  */
 619 fsinode *
 620 link_check(fsinode *entry)
 621 {
 622         static struct entry {
 623                 fsinode *data;
 624         } *htable;
 625         static int htshift;  /* log(allocated size) */
 626         static int htmask;   /* allocated size - 1 */
 627         static int htused;   /* 2*number of insertions */
 628         int h, h2;
 629         uint64_t tmp;
 630         /* this constant is (1<<64)/((1+sqrt(5))/2)
 631          * aka (word size)/(golden ratio)
 632          */
 633         const uint64_t HTCONST = 11400714819323198485ULL;
 634         const int HTBITS = 64;
 635
 636         /* Never store zero in hashtable */
 637         assert(entry);
 638
 639         /* Extend hash table if necessary, keep load under 0.5 */
 640         if (htused<<1 >= htmask) {
 641                 struct entry *ohtable;
 642
 643                 if (!htable)
 644                         htshift = 10;   /* starting hashtable size */
 645                 else
 646                         htshift++;   /* exponential hashtable growth */
 647
 648                 htmask  = (1 << htshift) - 1;
 649                 htused = 0;
 650
 651                 ohtable = htable;
 652                 htable = calloc(htmask+1, sizeof(*htable));
 653                 if (!htable)
 654                         err(1, "Memory allocation error");
 655
 656                 /* populate newly allocated hashtable */
 657                 if (ohtable) {
 658                         int i;
 659                         for (i = 0; i <= htmask>>1; i++)
 660                                 if (ohtable[i].data)
 661                                         link_check(ohtable[i].data);
 662                         free(ohtable);
 663                 }
 664         }
 665
 666         /* multiplicative hashing */
 667         tmp = entry->st.st_dev;
 668         tmp <<= HTBITS>>1;
 669         tmp |=  entry->st.st_ino;
 670         tmp *= HTCONST;
 671         h  = tmp >> (HTBITS - htshift);
 672         h2 = 1 | ( tmp >> (HTBITS - (htshift<<1) - 1)); /* must be odd */
 673
 674         /* open address hashtable search with double hash probing */
 675         while (htable[h].data) {
 676                 if ((htable[h].data->st.st_ino == entry->st.st_ino) &&
 677                     (htable[h].data->st.st_dev == entry->st.st_dev)) {
 678                         return htable[h].data;
 679                 }
 680                 h = (h + h2) & htmask;
 681         }
 682
 683         /* Insert the current entry into hashtable */
 684         htable[h].data = entry;
 685         htused++;
 686         return NULL;
 687 }