util.c

   1 /*
   2  * Utility routines used in rsync.
   3  *
   4  * Copyright (C) 1996-2000 Andrew Tridgell
   5  * Copyright (C) 1996 Paul Mackerras
   6  * Copyright (C) 2001, 2002 Martin Pool <mbp@samba.org>
   7  * Copyright (C) 2003-2007 Wayne Davison
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 3 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, visit the http://fsf.org website.
  21  */
  22
  23 #include "rsync.h"
  24 #include "ifuncs.h"
  25
  26 extern int verbose;
  27 extern int dry_run;
  28 extern int module_id;
  29 extern int modify_window;
  30 extern int relative_paths;
  31 extern int human_readable;
  32 extern char *module_dir;
  33 extern unsigned int module_dirlen;
  34 extern mode_t orig_umask;
  35 extern char *partial_dir;
  36 extern struct filter_list_struct server_filter_list;
  37
  38 int sanitize_paths = 0;
  39
  40 char curr_dir[MAXPATHLEN];
  41 unsigned int curr_dir_len;
  42 int curr_dir_depth; /* This is only set for a sanitizing daemon. */
  43
  44 /* Set a fd into nonblocking mode. */
  45 void set_nonblocking(int fd)
  46 {
  47         int val;
  48
  49         if ((val = fcntl(fd, F_GETFL)) == -1)
  50                 return;
  51         if (!(val & NONBLOCK_FLAG)) {
  52                 val |= NONBLOCK_FLAG;
  53                 fcntl(fd, F_SETFL, val);
  54         }
  55 }
  56
  57 /* Set a fd into blocking mode. */
  58 void set_blocking(int fd)
  59 {
  60         int val;
  61
  62         if ((val = fcntl(fd, F_GETFL)) == -1)
  63                 return;
  64         if (val & NONBLOCK_FLAG) {
  65                 val &= ~NONBLOCK_FLAG;
  66                 fcntl(fd, F_SETFL, val);
  67         }
  68 }
  69
  70 /**
  71  * Create a file descriptor pair - like pipe() but use socketpair if
  72  * possible (because of blocking issues on pipes).
  73  *
  74  * Always set non-blocking.
  75  */
  76 int fd_pair(int fd[2])
  77 {
  78         int ret;
  79
  80 #ifdef HAVE_SOCKETPAIR
  81         ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fd);
  82 #else
  83         ret = pipe(fd);
  84 #endif
  85
  86         if (ret == 0) {
  87                 set_nonblocking(fd[0]);
  88                 set_nonblocking(fd[1]);
  89         }
  90
  91         return ret;
  92 }
  93
  94 void print_child_argv(const char *prefix, char **cmd)
  95 {
  96         rprintf(FCLIENT, "%s ", prefix);
  97         for (; *cmd; cmd++) {
  98                 /* Look for characters that ought to be quoted.  This
  99                 * is not a great quoting algorithm, but it's
 100                 * sufficient for a log message. */
 101                 if (strspn(*cmd, "abcdefghijklmnopqrstuvwxyz"
 102                            "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 103                            "0123456789"
 104                            ",.-_=+@/") != strlen(*cmd)) {
 105                         rprintf(FCLIENT, "\"%s\" ", *cmd);
 106                 } else {
 107                         rprintf(FCLIENT, "%s ", *cmd);
 108                 }
 109         }
 110         rprintf(FCLIENT, "\n");
 111 }
 112
 113 NORETURN void out_of_memory(const char *str)
 114 {
 115         rprintf(FERROR, "ERROR: out of memory in %s [%s]\n", str, who_am_i());
 116         exit_cleanup(RERR_MALLOC);
 117 }
 118
 119 NORETURN void overflow_exit(const char *str)
 120 {
 121         rprintf(FERROR, "ERROR: buffer overflow in %s [%s]\n", str, who_am_i());
 122         exit_cleanup(RERR_MALLOC);
 123 }
 124
 125 int set_modtime(const char *fname, time_t modtime, mode_t mode)
 126 {
 127 #if !defined HAVE_LUTIMES || !defined HAVE_UTIMES
 128         if (S_ISLNK(mode))
 129                 return 1;
 130 #endif
 131
 132         if (verbose > 2) {
 133                 rprintf(FINFO, "set modtime of %s to (%ld) %s",
 134                         fname, (long)modtime,
 135                         asctime(localtime(&modtime)));
 136         }
 137
 138         if (dry_run)
 139                 return 0;
 140
 141         {
 142 #ifdef HAVE_UTIMES
 143                 struct timeval t[2];
 144                 t[0].tv_sec = time(NULL);
 145                 t[0].tv_usec = 0;
 146                 t[1].tv_sec = modtime;
 147                 t[1].tv_usec = 0;
 148 # ifdef HAVE_LUTIMES
 149                 if (S_ISLNK(mode)) {
 150                         if (lutimes(fname, t) < 0 && errno != ENOSYS)
 151                                 return -1;
 152                         return 0;
 153                 }
 154 # endif
 155                 return utimes(fname, t);
 156 #elif defined HAVE_STRUCT_UTIMBUF
 157                 struct utimbuf tbuf;
 158                 tbuf.actime = time(NULL);
 159                 tbuf.modtime = modtime;
 160                 return utime(fname,&tbuf);
 161 #elif defined HAVE_UTIME
 162                 time_t t[2];
 163                 t[0] = time(NULL);
 164                 t[1] = modtime;
 165                 return utime(fname,t);
 166 #else
 167 #error No file-time-modification routine found!
 168 #endif
 169         }
 170 }
 171
 172 /* This creates a new directory with default permissions.  Since there
 173  * might be some directory-default permissions affecting this, we can't
 174  * force the permissions directly using the original umask and mkdir(). */
 175 int mkdir_defmode(char *fname)
 176 {
 177         int ret;
 178
 179         umask(orig_umask);
 180         ret = do_mkdir(fname, ACCESSPERMS);
 181         umask(0);
 182
 183         return ret;
 184 }
 185
 186 /* Create any necessary directories in fname.  Any missing directories are
 187  * created with default permissions. */
 188 int create_directory_path(char *fname)
 189 {
 190         char *p;
 191         int ret = 0;
 192
 193         while (*fname == '/')
 194                 fname++;
 195         while (strncmp(fname, "./", 2) == 0)
 196                 fname += 2;
 197
 198         umask(orig_umask);
 199         p = fname;
 200         while ((p = strchr(p,'/')) != NULL) {
 201                 *p = '\0';
 202                 if (do_mkdir(fname, ACCESSPERMS) < 0 && errno != EEXIST)
 203                     ret = -1;
 204                 *p++ = '/';
 205         }
 206         umask(0);
 207
 208         return ret;
 209 }
 210
 211 /**
 212  * Write @p len bytes at @p ptr to descriptor @p desc, retrying if
 213  * interrupted.
 214  *
 215  * @retval len upon success
 216  *
 217  * @retval <0 write's (negative) error code
 218  *
 219  * Derived from GNU C's cccp.c.
 220  */
 221 int full_write(int desc, const char *ptr, size_t len)
 222 {
 223         int total_written;
 224
 225         total_written = 0;
 226         while (len > 0) {
 227                 int written = write(desc, ptr, len);
 228                 if (written < 0)  {
 229                         if (errno == EINTR)
 230                                 continue;
 231                         return written;
 232                 }
 233                 total_written += written;
 234                 ptr += written;
 235                 len -= written;
 236         }
 237         return total_written;
 238 }
 239
 240 /**
 241  * Read @p len bytes at @p ptr from descriptor @p desc, retrying if
 242  * interrupted.
 243  *
 244  * @retval >0 the actual number of bytes read
 245  *
 246  * @retval 0 for EOF
 247  *
 248  * @retval <0 for an error.
 249  *
 250  * Derived from GNU C's cccp.c. */
 251 static int safe_read(int desc, char *ptr, size_t len)
 252 {
 253         int n_chars;
 254
 255         if (len == 0)
 256                 return len;
 257
 258         do {
 259                 n_chars = read(desc, ptr, len);
 260         } while (n_chars < 0 && errno == EINTR);
 261
 262         return n_chars;
 263 }
 264
 265 /* Copy a file.  If ofd < 0, copy_file unlinks and opens the "dest" file.
 266  * Otherwise, it just writes to and closes the provided file descriptor.
 267  *
 268  * This is used in conjunction with the --temp-dir, --backup, and
 269  * --copy-dest options. */
 270 int copy_file(const char *source, const char *dest, int ofd,
 271               mode_t mode, int create_bak_dir)
 272 {
 273         int ifd;
 274         char buf[1024 * 8];
 275         int len;   /* Number of bytes read into `buf'. */
 276
 277         if ((ifd = do_open(source, O_RDONLY, 0)) < 0) {
 278                 rsyserr(FERROR_XFER, errno, "open %s", full_fname(source));
 279                 return -1;
 280         }
 281
 282         if (ofd < 0) {
 283                 if (robust_unlink(dest) && errno != ENOENT) {
 284                         rsyserr(FERROR_XFER, errno, "unlink %s", full_fname(dest));
 285                         return -1;
 286                 }
 287
 288                 if ((ofd = do_open(dest, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, mode)) < 0
 289                  && (!create_bak_dir || errno != ENOENT || make_bak_dir(dest) < 0
 290                   || (ofd = do_open(dest, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, mode)) < 0)) {
 291                         rsyserr(FERROR_XFER, errno, "open %s", full_fname(dest));
 292                         close(ifd);
 293                         return -1;
 294                 }
 295         }
 296
 297         while ((len = safe_read(ifd, buf, sizeof buf)) > 0) {
 298                 if (full_write(ofd, buf, len) < 0) {
 299                         rsyserr(FERROR_XFER, errno, "write %s", full_fname(dest));
 300                         close(ifd);
 301                         close(ofd);
 302                         return -1;
 303                 }
 304         }
 305
 306         if (len < 0) {
 307                 rsyserr(FERROR_XFER, errno, "read %s", full_fname(source));
 308                 close(ifd);
 309                 close(ofd);
 310                 return -1;
 311         }
 312
 313         if (close(ifd) < 0) {
 314                 rsyserr(FWARNING, errno, "close failed on %s",
 315                         full_fname(source));
 316         }
 317
 318         if (close(ofd) < 0) {
 319                 rsyserr(FERROR_XFER, errno, "close failed on %s",
 320                         full_fname(dest));
 321                 return -1;
 322         }
 323
 324         return 0;
 325 }
 326
 327 /* MAX_RENAMES should be 10**MAX_RENAMES_DIGITS */
 328 #define MAX_RENAMES_DIGITS 3
 329 #define MAX_RENAMES 1000
 330
 331 /**
 332  * Robust unlink: some OS'es (HPUX) refuse to unlink busy files, so
 333  * rename to <path>/.rsyncNNN instead.
 334  *
 335  * Note that successive rsync runs will shuffle the filenames around a
 336  * bit as long as the file is still busy; this is because this function
 337  * does not know if the unlink call is due to a new file coming in, or
 338  * --delete trying to remove old .rsyncNNN files, hence it renames it
 339  * each time.
 340  **/
 341 int robust_unlink(const char *fname)
 342 {
 343 #ifndef ETXTBSY
 344         return do_unlink(fname);
 345 #else
 346         static int counter = 1;
 347         int rc, pos, start;
 348         char path[MAXPATHLEN];
 349
 350         rc = do_unlink(fname);
 351         if (rc == 0 || errno != ETXTBSY)
 352                 return rc;
 353
 354         if ((pos = strlcpy(path, fname, MAXPATHLEN)) >= MAXPATHLEN)
 355                 pos = MAXPATHLEN - 1;
 356
 357         while (pos > 0 && path[pos-1] != '/')
 358                 pos--;
 359         pos += strlcpy(path+pos, ".rsync", MAXPATHLEN-pos);
 360
 361         if (pos > (MAXPATHLEN-MAX_RENAMES_DIGITS-1)) {
 362                 errno = ETXTBSY;
 363                 return -1;
 364         }
 365
 366         /* start where the last one left off to reduce chance of clashes */
 367         start = counter;
 368         do {
 369                 snprintf(&path[pos], MAX_RENAMES_DIGITS+1, "%03d", counter);
 370                 if (++counter >= MAX_RENAMES)
 371                         counter = 1;
 372         } while ((rc = access(path, 0)) == 0 && counter != start);
 373
 374         if (verbose > 0) {
 375                 rprintf(FWARNING, "renaming %s to %s because of text busy\n",
 376                         fname, path);
 377         }
 378
 379         /* maybe we should return rename()'s exit status? Nah. */
 380         if (do_rename(fname, path) != 0) {
 381                 errno = ETXTBSY;
 382                 return -1;
 383         }
 384         return 0;
 385 #endif
 386 }
 387
 388 /* Returns 0 on successful rename, 1 if we successfully copied the file
 389  * across filesystems, -2 if copy_file() failed, and -1 on other errors.
 390  * If partialptr is not NULL and we need to do a copy, copy the file into
 391  * the active partial-dir instead of over the destination file. */
 392 int robust_rename(const char *from, const char *to, const char *partialptr,
 393                   int mode)
 394 {
 395         int tries = 4;
 396
 397         while (tries--) {
 398                 if (do_rename(from, to) == 0)
 399                         return 0;
 400
 401                 switch (errno) {
 402 #ifdef ETXTBSY
 403                 case ETXTBSY:
 404                         if (robust_unlink(to) != 0)
 405                                 return -1;
 406                         break;
 407 #endif
 408                 case EXDEV:
 409                         if (partialptr) {
 410                                 if (!handle_partial_dir(partialptr,PDIR_CREATE))
 411                                         return -1;
 412                                 to = partialptr;
 413                         }
 414                         if (copy_file(from, to, -1, mode, 0) != 0)
 415                                 return -2;
 416                         do_unlink(from);
 417                         return 1;
 418                 default:
 419                         return -1;
 420                 }
 421         }
 422         return -1;
 423 }
 424
 425 static pid_t all_pids[10];
 426 static int num_pids;
 427
 428 /** Fork and record the pid of the child. **/
 429 pid_t do_fork(void)
 430 {
 431         pid_t newpid = fork();
 432
 433         if (newpid != 0  &&  newpid != -1) {
 434                 all_pids[num_pids++] = newpid;
 435         }
 436         return newpid;
 437 }
 438
 439 /**
 440  * Kill all children.
 441  *
 442  * @todo It would be kind of nice to make sure that they are actually
 443  * all our children before we kill them, because their pids may have
 444  * been recycled by some other process.  Perhaps when we wait for a
 445  * child, we should remove it from this array.  Alternatively we could
 446  * perhaps use process groups, but I think that would not work on
 447  * ancient Unix versions that don't support them.
 448  **/
 449 void kill_all(int sig)
 450 {
 451         int i;
 452
 453         for (i = 0; i < num_pids; i++) {
 454                 /* Let's just be a little careful where we
 455                  * point that gun, hey?  See kill(2) for the
 456                  * magic caused by negative values. */
 457                 pid_t p = all_pids[i];
 458
 459                 if (p == getpid())
 460                         continue;
 461                 if (p <= 0)
 462                         continue;
 463
 464                 kill(p, sig);
 465         }
 466 }
 467
 468 /** Turn a user name into a uid */
 469 int name_to_uid(const char *name, uid_t *uid_p)
 470 {
 471         struct passwd *pass;
 472         if (!name || !*name)
 473                 return 0;
 474         if (!(pass = getpwnam(name)))
 475                 return 0;
 476         *uid_p = pass->pw_uid;
 477         return 1;
 478 }
 479
 480 /** Turn a group name into a gid */
 481 int name_to_gid(const char *name, gid_t *gid_p)
 482 {
 483         struct group *grp;
 484         if (!name || !*name)
 485                 return 0;
 486         if (!(grp = getgrnam(name)))
 487                 return 0;
 488         *gid_p = grp->gr_gid;
 489         return 1;
 490 }
 491
 492 /** Lock a byte range in a open file */
 493 int lock_range(int fd, int offset, int len)
 494 {
 495         struct flock lock;
 496
 497         lock.l_type = F_WRLCK;
 498         lock.l_whence = SEEK_SET;
 499         lock.l_start = offset;
 500         lock.l_len = len;
 501         lock.l_pid = 0;
 502
 503         return fcntl(fd,F_SETLK,&lock) == 0;
 504 }
 505
 506 static int filter_server_path(char *arg)
 507 {
 508         char *s;
 509
 510         if (server_filter_list.head) {
 511                 for (s = arg; (s = strchr(s, '/')) != NULL; ) {
 512                         *s = '\0';
 513                         if (check_filter(&server_filter_list, arg, 1) < 0) {
 514                                 /* We must leave arg truncated! */
 515                                 return 1;
 516                         }
 517                         *s++ = '/';
 518                 }
 519         }
 520         return 0;
 521 }
 522
 523 void glob_expand(char *s, char ***argv_ptr, int *argc_ptr, int *maxargs_ptr)
 524 {
 525         char **argv = *argv_ptr;
 526         int argc = *argc_ptr;
 527         int maxargs = *maxargs_ptr;
 528 #if !defined HAVE_GLOB || !defined HAVE_GLOB_H
 529         if (argc == maxargs) {
 530                 maxargs += MAX_ARGS;
 531                 if (!(argv = realloc_array(argv, char *, maxargs)))
 532                         out_of_memory("glob_expand");
 533                 *argv_ptr = argv;
 534                 *maxargs_ptr = maxargs;
 535         }
 536         if (!*s)
 537                 s = ".";
 538         s = argv[argc++] = strdup(s);
 539         filter_server_path(s);
 540 #else
 541         glob_t globbuf;
 542
 543         if (maxargs <= argc)
 544                 return;
 545         if (!*s)
 546                 s = ".";
 547
 548         if (sanitize_paths)
 549                 s = sanitize_path(NULL, s, "", 0);
 550         else
 551                 s = strdup(s);
 552         if (!s)
 553                 out_of_memory("glob_expand");
 554
 555         memset(&globbuf, 0, sizeof globbuf);
 556         if (!filter_server_path(s))
 557                 glob(s, 0, NULL, &globbuf);
 558         if (MAX((int)globbuf.gl_pathc, 1) > maxargs - argc) {
 559                 maxargs += globbuf.gl_pathc + MAX_ARGS;
 560                 if (!(argv = realloc_array(argv, char *, maxargs)))
 561                         out_of_memory("glob_expand");
 562                 *argv_ptr = argv;
 563                 *maxargs_ptr = maxargs;
 564         }
 565         if (globbuf.gl_pathc == 0)
 566                 argv[argc++] = s;
 567         else {
 568                 int i;
 569                 free(s);
 570                 for (i = 0; i < (int)globbuf.gl_pathc; i++) {
 571                         if (!(argv[argc++] = strdup(globbuf.gl_pathv[i])))
 572                                 out_of_memory("glob_expand");
 573                 }
 574         }
 575         globfree(&globbuf);
 576 #endif
 577         *argc_ptr = argc;
 578 }
 579
 580 /* This routine is only used in daemon mode. */
 581 void glob_expand_module(char *base1, char *arg, char ***argv_ptr, int *argc_ptr, int *maxargs_ptr)
 582 {
 583         char *p, *s;
 584         char *base = base1;
 585         int base_len = strlen(base);
 586
 587         if (!arg || !*arg)
 588                 return;
 589
 590         if (strncmp(arg, base, base_len) == 0)
 591                 arg += base_len;
 592
 593         if (!(arg = strdup(arg)))
 594                 out_of_memory("glob_expand_module");
 595
 596         if (asprintf(&base," %s/", base1) <= 0)
 597                 out_of_memory("glob_expand_module");
 598         base_len++;
 599
 600         for (s = arg; *s; s = p + base_len) {
 601                 if ((p = strstr(s, base)) != NULL)
 602                         *p = '\0'; /* split it at this point */
 603                 glob_expand(s, argv_ptr, argc_ptr, maxargs_ptr);
 604                 if (!p)
 605                         break;
 606         }
 607
 608         free(arg);
 609         free(base);
 610 }
 611
 612 /**
 613  * Convert a string to lower case
 614  **/
 615 void strlower(char *s)
 616 {
 617         while (*s) {
 618                 if (isUpper(s))
 619                         *s = toLower(s);
 620                 s++;
 621         }
 622 }
 623
 624 /* Join strings p1 & p2 into "dest" with a guaranteed '/' between them.  (If
 625  * p1 ends with a '/', no extra '/' is inserted.)  Returns the length of both
 626  * strings + 1 (if '/' was inserted), regardless of whether the null-terminated
 627  * string fits into destsize. */
 628 size_t pathjoin(char *dest, size_t destsize, const char *p1, const char *p2)
 629 {
 630         size_t len = strlcpy(dest, p1, destsize);
 631         if (len < destsize - 1) {
 632                 if (!len || dest[len-1] != '/')
 633                         dest[len++] = '/';
 634                 if (len < destsize - 1)
 635                         len += strlcpy(dest + len, p2, destsize - len);
 636                 else {
 637                         dest[len] = '\0';
 638                         len += strlen(p2);
 639                 }
 640         }
 641         else
 642                 len += strlen(p2) + 1; /* Assume we'd insert a '/'. */
 643         return len;
 644 }
 645
 646 /* Join any number of strings together, putting them in "dest".  The return
 647  * value is the length of all the strings, regardless of whether the null-
 648  * terminated whole fits in destsize.  Your list of string pointers must end
 649  * with a NULL to indicate the end of the list. */
 650 size_t stringjoin(char *dest, size_t destsize, ...)
 651 {
 652         va_list ap;
 653         size_t len, ret = 0;
 654         const char *src;
 655
 656         va_start(ap, destsize);
 657         while (1) {
 658                 if (!(src = va_arg(ap, const char *)))
 659                         break;
 660                 len = strlen(src);
 661                 ret += len;
 662                 if (destsize > 1) {
 663                         if (len >= destsize)
 664                                 len = destsize - 1;
 665                         memcpy(dest, src, len);
 666                         destsize -= len;
 667                         dest += len;
 668                 }
 669         }
 670         *dest = '\0';
 671         va_end(ap);
 672
 673         return ret;
 674 }
 675
 676 int count_dir_elements(const char *p)
 677 {
 678         int cnt = 0, new_component = 1;
 679         while (*p) {
 680                 if (*p++ == '/')
 681                         new_component = (*p != '.' || (p[1] != '/' && p[1] != '\0'));
 682                 else if (new_component) {
 683                         new_component = 0;
 684                         cnt++;
 685                 }
 686         }
 687         return cnt;
 688 }
 689
 690 /* Turns multiple adjacent slashes into a single slash, drops interior "."
 691  * elements, drops an intial "./" unless CFN_KEEP_LEADING_DOT_DIR is flagged,
 692  * will even drop a trailing '.' after a '/' if CFN_DROP_TRAILING_DOT_DIR is
 693  * flagged, removes a trailing slash (perhaps after removing the aforementioned
 694  * dot) unless CFN_KEEP_TRAILING_SLASH is flagged, will even collapse ".."
 695  * elements (except at the start of the string) if CFN_COLLAPSE_DOT_DOT_DIRS
 696  * is flagged.  If the resulting name would be empty, we return ".". */
 697 unsigned int clean_fname(char *name, int flags)
 698 {
 699         char *limit = name - 1, *t = name, *f = name;
 700         int anchored;
 701
 702         if (!name)
 703                 return 0;
 704
 705         if ((anchored = *f == '/') != 0)
 706                 *t++ = *f++;
 707         else if (flags & CFN_KEEP_LEADING_DOT_DIR && *f == '.' && f[1] == '/') {
 708                 *t++ = *f++;
 709                 *t++ = *f++;
 710         }
 711         while (*f) {
 712                 /* discard extra slashes */
 713                 if (*f == '/') {
 714                         f++;
 715                         continue;
 716                 }
 717                 if (*f == '.') {
 718                         /* discard interior "." dirs */
 719                         if (f[1] == '/') {
 720                                 f += 2;
 721                                 continue;
 722                         }
 723                         if (f[1] == '\0' && flags & CFN_DROP_TRAILING_DOT_DIR)
 724                                 break;
 725                         /* collapse ".." dirs */
 726                         if (flags & CFN_COLLAPSE_DOT_DOT_DIRS
 727                          && f[1] == '.' && (f[2] == '/' || !f[2])) {
 728                                 char *s = t - 1;
 729                                 if (s == name && anchored) {
 730                                         f += 2;
 731                                         continue;
 732                                 }
 733                                 while (s > limit && *--s != '/') {}
 734                                 if (s != t - 1 && (s < name || *s == '/')) {
 735                                         t = s + 1;
 736                                         f += 2;
 737                                         continue;
 738                                 }
 739                                 limit = t + 2;
 740                         }
 741                 }
 742                 while (*f && (*t++ = *f++) != '/') {}
 743         }
 744
 745         if (t > name+anchored && t[-1] == '/' && !(flags & CFN_KEEP_TRAILING_SLASH))
 746                 t--;
 747         if (t == name)
 748                 *t++ = '.';
 749         *t = '\0';
 750
 751         return t - name;
 752 }
 753
 754 /* Make path appear as if a chroot had occurred.  This handles a leading
 755  * "/" (either removing it or expanding it) and any leading or embedded
 756  * ".." components that attempt to escape past the module's top dir.
 757  *
 758  * If dest is NULL, a buffer is allocated to hold the result.  It is legal
 759  * to call with the dest and the path (p) pointing to the same buffer, but
 760  * rootdir will be ignored to avoid expansion of the string.
 761  *
 762  * The rootdir string contains a value to use in place of a leading slash.
 763  * Specify NULL to get the default of "module_dir".
 764  *
 765  * The depth var is a count of how many '..'s to allow at the start of the
 766  * path.
 767  *
 768  * We also clean the path in a manner similar to clean_fname() but with a
 769  * few differences:
 770  *
 771  * Turns multiple adjacent slashes into a single slash, gets rid of "." dir
 772  * elements (INCLUDING a trailing dot dir), PRESERVES a trailing slash, and
 773  * ALWAYS collapses ".." elements (except for those at the start of the
 774  * string up to "depth" deep).  If the resulting name would be empty,
 775  * change it into a ".". */
 776 char *sanitize_path(char *dest, const char *p, const char *rootdir, int depth)
 777 {
 778         char *start, *sanp;
 779         int rlen = 0, leave_one_dotdir = relative_paths;
 780
 781         if (dest != p) {
 782                 int plen = strlen(p);
 783                 if (*p == '/') {
 784                         if (!rootdir)
 785                                 rootdir = module_dir;
 786                         rlen = strlen(rootdir);
 787                         depth = 0;
 788                         p++;
 789                 }
 790                 if (dest) {
 791                         if (rlen + plen + 1 >= MAXPATHLEN)
 792                                 return NULL;
 793                 } else if (!(dest = new_array(char, rlen + plen + 1)))
 794                         out_of_memory("sanitize_path");
 795                 if (rlen) {
 796                         memcpy(dest, rootdir, rlen);
 797                         if (rlen > 1)
 798                                 dest[rlen++] = '/';
 799                 }
 800         }
 801
 802         start = sanp = dest + rlen;
 803         while (*p) {
 804                 /* discard leading or extra slashes */
 805                 if (*p == '/') {
 806                         p++;
 807                         continue;
 808                 }
 809                 /* this loop iterates once per filename component in p.
 810                  * both p (and sanp if the original had a slash) should
 811                  * always be left pointing after a slash
 812                  */
 813                 if (*p == '.' && (p[1] == '/' || p[1] == '\0')) {
 814                         if (leave_one_dotdir && p[1])
 815                                 leave_one_dotdir = 0;
 816                         else {
 817                                 /* skip "." component */
 818                                 p++;
 819                                 continue;
 820                         }
 821                 }
 822                 if (*p == '.' && p[1] == '.' && (p[2] == '/' || p[2] == '\0')) {
 823                         /* ".." component followed by slash or end */
 824                         if (depth <= 0 || sanp != start) {
 825                                 p += 2;
 826                                 if (sanp != start) {
 827                                         /* back up sanp one level */
 828                                         --sanp; /* now pointing at slash */
 829                                         while (sanp > start && sanp[-1] != '/') {
 830                                                 /* skip back up to slash */
 831                                                 sanp--;
 832                                         }
 833                                 }
 834                                 continue;
 835                         }
 836                         /* allow depth levels of .. at the beginning */
 837                         depth--;
 838                         /* move the virtual beginning to leave the .. alone */
 839                         start = sanp + 3;
 840                 }
 841                 /* copy one component through next slash */
 842                 while (*p && (*sanp++ = *p++) != '/') {}
 843         }
 844         if (sanp == dest) {
 845                 /* ended up with nothing, so put in "." component */
 846                 *sanp++ = '.';
 847         }
 848         *sanp = '\0';
 849
 850         return dest;
 851 }
 852
 853 /* Like chdir(), but it keeps track of the current directory (in the
 854  * global "curr_dir"), and ensures that the path size doesn't overflow.
 855  * Also cleans the path using the clean_fname() function. */
 856 int push_dir(const char *dir, int set_path_only)
 857 {
 858         static int initialised;
 859         unsigned int len;
 860
 861         if (!initialised) {
 862                 initialised = 1;
 863                 getcwd(curr_dir, sizeof curr_dir - 1);
 864                 curr_dir_len = strlen(curr_dir);
 865         }
 866
 867         if (!dir)       /* this call was probably just to initialize */
 868                 return 0;
 869
 870         len = strlen(dir);
 871         if (len == 1 && *dir == '.')
 872                 return 1;
 873
 874         if ((*dir == '/' ? len : curr_dir_len + 1 + len) >= sizeof curr_dir) {
 875                 errno = ENAMETOOLONG;
 876                 return 0;
 877         }
 878
 879         if (!set_path_only && chdir(dir))
 880                 return 0;
 881
 882         if (*dir == '/') {
 883                 memcpy(curr_dir, dir, len + 1);
 884                 curr_dir_len = len;
 885         } else {
 886                 curr_dir[curr_dir_len++] = '/';
 887                 memcpy(curr_dir + curr_dir_len, dir, len + 1);
 888                 curr_dir_len += len;
 889         }
 890
 891         curr_dir_len = clean_fname(curr_dir, CFN_COLLAPSE_DOT_DOT_DIRS);
 892         if (sanitize_paths) {
 893                 if (module_dirlen > curr_dir_len)
 894                         module_dirlen = curr_dir_len;
 895                 curr_dir_depth = count_dir_elements(curr_dir + module_dirlen);
 896         }
 897
 898         if (verbose >= 5)
 899                 rprintf(FINFO, "[%s] dir is now %s\n", who_am_i(), curr_dir);
 900
 901         return 1;
 902 }
 903
 904 /**
 905  * Reverse a push_dir() call.  You must pass in an absolute path
 906  * that was copied from a prior value of "curr_dir".
 907  **/
 908 int pop_dir(const char *dir)
 909 {
 910         if (chdir(dir))
 911                 return 0;
 912
 913         curr_dir_len = strlcpy(curr_dir, dir, sizeof curr_dir);
 914         if (curr_dir_len >= sizeof curr_dir)
 915                 curr_dir_len = sizeof curr_dir - 1;
 916         if (sanitize_paths)
 917                 curr_dir_depth = count_dir_elements(curr_dir + module_dirlen);
 918
 919         return 1;
 920 }
 921
 922 /**
 923  * Return a quoted string with the full pathname of the indicated filename.
 924  * The string " (in MODNAME)" may also be appended.  The returned pointer
 925  * remains valid until the next time full_fname() is called.
 926  **/
 927 char *full_fname(const char *fn)
 928 {
 929         static char *result = NULL;
 930         char *m1, *m2, *m3;
 931         char *p1, *p2;
 932
 933         if (result)
 934                 free(result);
 935
 936         if (*fn == '/')
 937                 p1 = p2 = "";
 938         else {
 939                 p1 = curr_dir + module_dirlen;
 940                 for (p2 = p1; *p2 == '/'; p2++) {}
 941                 if (*p2)
 942                         p2 = "/";
 943         }
 944         if (module_id >= 0) {
 945                 m1 = " (in ";
 946                 m2 = lp_name(module_id);
 947                 m3 = ")";
 948         } else
 949                 m1 = m2 = m3 = "";
 950
 951         if (asprintf(&result, "\"%s%s%s\"%s%s%s", p1, p2, fn, m1, m2, m3) <= 0)
 952                 out_of_memory("full_fname");
 953
 954         return result;
 955 }
 956
 957 static char partial_fname[MAXPATHLEN];
 958
 959 char *partial_dir_fname(const char *fname)
 960 {
 961         char *t = partial_fname;
 962         int sz = sizeof partial_fname;
 963         const char *fn;
 964
 965         if ((fn = strrchr(fname, '/')) != NULL) {
 966                 fn++;
 967                 if (*partial_dir != '/') {
 968                         int len = fn - fname;
 969                         strncpy(t, fname, len); /* safe */
 970                         t += len;
 971                         sz -= len;
 972                 }
 973         } else
 974                 fn = fname;
 975         if ((int)pathjoin(t, sz, partial_dir, fn) >= sz)
 976                 return NULL;
 977         if (server_filter_list.head) {
 978                 t = strrchr(partial_fname, '/');
 979                 *t = '\0';
 980                 if (check_filter(&server_filter_list, partial_fname, 1) < 0)
 981                         return NULL;
 982                 *t = '/';
 983                 if (check_filter(&server_filter_list, partial_fname, 0) < 0)
 984                         return NULL;
 985         }
 986
 987         return partial_fname;
 988 }
 989
 990 /* If no --partial-dir option was specified, we don't need to do anything
 991  * (the partial-dir is essentially '.'), so just return success. */
 992 int handle_partial_dir(const char *fname, int create)
 993 {
 994         char *fn, *dir;
 995
 996         if (fname != partial_fname)
 997                 return 1;
 998         if (!create && *partial_dir == '/')
 999                 return 1;
1000         if (!(fn = strrchr(partial_fname, '/')))
1001                 return 1;
1002
1003         *fn = '\0';
1004         dir = partial_fname;
1005         if (create) {
1006                 STRUCT_STAT st;
1007                 int statret = do_lstat(dir, &st);
1008                 if (statret == 0 && !S_ISDIR(st.st_mode)) {
1009                         if (do_unlink(dir) < 0)
1010                                 return 0;
1011                         statret = -1;
1012                 }
1013                 if (statret < 0 && do_mkdir(dir, 0700) < 0)
1014                         return 0;
1015         } else
1016                 do_rmdir(dir);
1017         *fn = '/';
1018
1019         return 1;
1020 }
1021
1022 /**
1023  * Determine if a symlink points outside the current directory tree.
1024  * This is considered "unsafe" because e.g. when mirroring somebody
1025  * else's machine it might allow them to establish a symlink to
1026  * /etc/passwd, and then read it through a web server.
1027  *
1028  * Null symlinks and absolute symlinks are always unsafe.
1029  *
1030  * Basically here we are concerned with symlinks whose target contains
1031  * "..", because this might cause us to walk back up out of the
1032  * transferred directory.  We are not allowed to go back up and
1033  * reenter.
1034  *
1035  * @param dest Target of the symlink in question.
1036  *
1037  * @param src Top source directory currently applicable.  Basically this
1038  * is the first parameter to rsync in a simple invocation, but it's
1039  * modified by flist.c in slightly complex ways.
1040  *
1041  * @retval True if unsafe
1042  * @retval False is unsafe
1043  *
1044  * @sa t_unsafe.c
1045  **/
1046 int unsafe_symlink(const char *dest, const char *src)
1047 {
1048         const char *name, *slash;
1049         int depth = 0;
1050
1051         /* all absolute and null symlinks are unsafe */
1052         if (!dest || !*dest || *dest == '/')
1053                 return 1;
1054
1055         /* find out what our safety margin is */
1056         for (name = src; (slash = strchr(name, '/')) != 0; name = slash+1) {
1057                 if (strncmp(name, "../", 3) == 0) {
1058                         depth = 0;
1059                 } else if (strncmp(name, "./", 2) == 0) {
1060                         /* nothing */
1061                 } else {
1062                         depth++;
1063                 }
1064         }
1065         if (strcmp(name, "..") == 0)
1066                 depth = 0;
1067
1068         for (name = dest; (slash = strchr(name, '/')) != 0; name = slash+1) {
1069                 if (strncmp(name, "../", 3) == 0) {
1070                         /* if at any point we go outside the current directory
1071                            then stop - it is unsafe */
1072                         if (--depth < 0)
1073                                 return 1;
1074                 } else if (strncmp(name, "./", 2) == 0) {
1075                         /* nothing */
1076                 } else {
1077                         depth++;
1078                 }
1079         }
1080         if (strcmp(name, "..") == 0)
1081                 depth--;
1082
1083         return (depth < 0);
1084 }
1085
1086 /* Return the int64 number as a string.  If the --human-readable option was
1087  * specified, we may output the number in K, M, or G units.  We can return
1088  * up to 4 buffers at a time. */
1089 char *human_num(int64 num)
1090 {
1091         static char bufs[4][128]; /* more than enough room */
1092         static unsigned int n;
1093         char *s;
1094
1095         n = (n + 1) % (sizeof bufs / sizeof bufs[0]);
1096
1097         if (human_readable) {
1098                 char units = '\0';
1099                 int mult = human_readable == 1 ? 1000 : 1024;
1100                 double dnum = 0;
1101                 if (num > mult*mult*mult) {
1102                         dnum = (double)num / (mult*mult*mult);
1103                         units = 'G';
1104                 } else if (num > mult*mult) {
1105                         dnum = (double)num / (mult*mult);
1106                         units = 'M';
1107                 } else if (num > mult) {
1108                         dnum = (double)num / mult;
1109                         units = 'K';
1110                 }
1111                 if (units) {
1112                         snprintf(bufs[n], sizeof bufs[0], "%.2f%c", dnum, units);
1113                         return bufs[n];
1114                 }
1115         }
1116
1117         s = bufs[n] + sizeof bufs[0] - 1;
1118         *s = '\0';
1119
1120         if (!num)
1121                 *--s = '0';
1122         while (num) {
1123                 *--s = (char)(num % 10) + '0';
1124                 num /= 10;
1125         }
1126         return s;
1127 }
1128
1129 /* Return the double number as a string.  If the --human-readable option was
1130  * specified, we may output the number in K, M, or G units.  We use a buffer
1131  * from human_num() to return our result. */
1132 char *human_dnum(double dnum, int decimal_digits)
1133 {
1134         char *buf = human_num(dnum);
1135         int len = strlen(buf);
1136         if (isDigit(buf + len - 1)) {
1137                 /* There's extra room in buf prior to the start of the num. */
1138                 buf -= decimal_digits + 1;
1139                 snprintf(buf, len + decimal_digits + 2, "%.*f", decimal_digits, dnum);
1140         }
1141         return buf;
1142 }
1143
1144 /* Return the date and time as a string.  Some callers tweak returned buf. */
1145 char *timestring(time_t t)
1146 {
1147         static char TimeBuf[200];
1148         struct tm *tm = localtime(&t);
1149         char *p;
1150
1151 #ifdef HAVE_STRFTIME
1152         strftime(TimeBuf, sizeof TimeBuf - 1, "%Y/%m/%d %H:%M:%S", tm);
1153 #else
1154         strlcpy(TimeBuf, asctime(tm), sizeof TimeBuf);
1155 #endif
1156
1157         if ((p = strchr(TimeBuf, '\n')) != NULL)
1158                 *p = '\0';
1159
1160         return TimeBuf;
1161 }
1162
1163 /**
1164  * Sleep for a specified number of milliseconds.
1165  *
1166  * Always returns TRUE.  (In the future it might return FALSE if
1167  * interrupted.)
1168  **/
1169 int msleep(int t)
1170 {
1171         int tdiff = 0;
1172         struct timeval tval, t1, t2;
1173
1174         gettimeofday(&t1, NULL);
1175
1176         while (tdiff < t) {
1177                 tval.tv_sec = (t-tdiff)/1000;
1178                 tval.tv_usec = 1000*((t-tdiff)%1000);
1179
1180                 errno = 0;
1181                 select(0,NULL,NULL, NULL, &tval);
1182
1183                 gettimeofday(&t2, NULL);
1184                 tdiff = (t2.tv_sec - t1.tv_sec)*1000 +
1185                         (t2.tv_usec - t1.tv_usec)/1000;
1186         }
1187
1188         return True;
1189 }
1190
1191 /* Determine if two time_t values are equivalent (either exact, or in
1192  * the modification timestamp window established by --modify-window).
1193  *
1194  * @retval 0 if the times should be treated as the same
1195  *
1196  * @retval +1 if the first is later
1197  *
1198  * @retval -1 if the 2nd is later
1199  **/
1200 int cmp_time(time_t file1, time_t file2)
1201 {
1202         if (file2 > file1) {
1203                 if (file2 - file1 <= modify_window)
1204                         return 0;
1205                 return -1;
1206         }
1207         if (file1 - file2 <= modify_window)
1208                 return 0;
1209         return 1;
1210 }
1211
1212
1213 #ifdef __INSURE__XX
1214 #include <dlfcn.h>
1215
1216 /**
1217    This routine is a trick to immediately catch errors when debugging
1218    with insure. A xterm with a gdb is popped up when insure catches
1219    a error. It is Linux specific.
1220 **/
1221 int _Insure_trap_error(int a1, int a2, int a3, int a4, int a5, int a6)
1222 {
1223         static int (*fn)();
1224         int ret;
1225         char *cmd;
1226
1227         asprintf(&cmd, "/usr/X11R6/bin/xterm -display :0 -T Panic -n Panic -e /bin/sh -c 'cat /tmp/ierrs.*.%d ; gdb /proc/%d/exe %d'",
1228                 getpid(), getpid(), getpid());
1229
1230         if (!fn) {
1231                 static void *h;
1232                 h = dlopen("/usr/local/parasoft/insure++lite/lib.linux2/libinsure.so", RTLD_LAZY);
1233                 fn = dlsym(h, "_Insure_trap_error");
1234         }
1235
1236         ret = fn(a1, a2, a3, a4, a5, a6);
1237
1238         system(cmd);
1239
1240         free(cmd);
1241
1242         return ret;
1243 }
1244 #endif
1245
1246 #define MALLOC_MAX 0x40000000
1247
1248 void *_new_array(unsigned long num, unsigned int size, int use_calloc)
1249 {
1250         if (num >= MALLOC_MAX/size)
1251                 return NULL;
1252         return use_calloc ? calloc(num, size) : malloc(num * size);
1253 }
1254
1255 void *_realloc_array(void *ptr, unsigned int size, unsigned long num)
1256 {
1257         if (num >= MALLOC_MAX/size)
1258                 return NULL;
1259         if (!ptr)
1260                 return malloc(size * num);
1261         return realloc(ptr, size * num);
1262 }
1263
1264 /* Take a filename and filename length and return the most significant
1265  * filename suffix we can find.  This ignores suffixes such as "~",
1266  * ".bak", ".orig", ".~1~", etc. */
1267 const char *find_filename_suffix(const char *fn, int fn_len, int *len_ptr)
1268 {
1269         const char *suf, *s;
1270         BOOL had_tilde;
1271         int s_len;
1272
1273         /* One or more dots at the start aren't a suffix. */
1274         while (fn_len && *fn == '.') fn++, fn_len--;
1275
1276         /* Ignore the ~ in a "foo~" filename. */
1277         if (fn_len > 1 && fn[fn_len-1] == '~')
1278                 fn_len--, had_tilde = True;
1279         else
1280                 had_tilde = False;
1281
1282         /* Assume we don't find an suffix. */
1283         suf = "";
1284         *len_ptr = 0;
1285
1286         /* Find the last significant suffix. */
1287         for (s = fn + fn_len; fn_len > 1; ) {
1288                 while (*--s != '.' && s != fn) {}
1289                 if (s == fn)
1290                         break;
1291                 s_len = fn_len - (s - fn);
1292                 fn_len = s - fn;
1293                 if (s_len == 4) {
1294                         if (strcmp(s+1, "bak") == 0
1295                          || strcmp(s+1, "old") == 0)
1296                                 continue;
1297                 } else if (s_len == 5) {
1298                         if (strcmp(s+1, "orig") == 0)
1299                                 continue;
1300                 } else if (s_len > 2 && had_tilde
1301                     && s[1] == '~' && isDigit(s + 2))
1302                         continue;
1303                 *len_ptr = s_len;
1304                 suf = s;
1305                 if (s_len == 1)
1306                         break;
1307                 /* Determine if the suffix is all digits. */
1308                 for (s++, s_len--; s_len > 0; s++, s_len--) {
1309                         if (!isDigit(s))
1310                                 return suf;
1311                 }
1312                 /* An all-digit suffix may not be that signficant. */
1313                 s = suf;
1314         }
1315
1316         return suf;
1317 }
1318
1319 /* This is an implementation of the Levenshtein distance algorithm.  It
1320  * was implemented to avoid needing a two-dimensional matrix (to save
1321  * memory).  It was also tweaked to try to factor in the ASCII distance
1322  * between changed characters as a minor distance quantity.  The normal
1323  * Levenshtein units of distance (each signifying a single change between
1324  * the two strings) are defined as a "UNIT". */
1325
1326 #define UNIT (1 << 16)
1327
1328 uint32 fuzzy_distance(const char *s1, int len1, const char *s2, int len2)
1329 {
1330         uint32 a[MAXPATHLEN], diag, above, left, diag_inc, above_inc, left_inc;
1331         int32 cost;
1332         int i1, i2;
1333
1334         if (!len1 || !len2) {
1335                 if (!len1) {
1336                         s1 = s2;
1337                         len1 = len2;
1338                 }
1339                 for (i1 = 0, cost = 0; i1 < len1; i1++)
1340                         cost += s1[i1];
1341                 return (int32)len1 * UNIT + cost;
1342         }
1343
1344         for (i2 = 0; i2 < len2; i2++)
1345                 a[i2] = (i2+1) * UNIT;
1346
1347         for (i1 = 0; i1 < len1; i1++) {
1348                 diag = i1 * UNIT;
1349                 above = (i1+1) * UNIT;
1350                 for (i2 = 0; i2 < len2; i2++) {
1351                         left = a[i2];
1352                         if ((cost = *((uchar*)s1+i1) - *((uchar*)s2+i2)) != 0) {
1353                                 if (cost < 0)
1354                                         cost = UNIT - cost;
1355                                 else
1356                                         cost = UNIT + cost;
1357                         }
1358                         diag_inc = diag + cost;
1359                         left_inc = left + UNIT + *((uchar*)s1+i1);
1360                         above_inc = above + UNIT + *((uchar*)s2+i2);
1361                         a[i2] = above = left < above
1362                               ? (left_inc < diag_inc ? left_inc : diag_inc)
1363                               : (above_inc < diag_inc ? above_inc : diag_inc);
1364                         diag = left;
1365                 }
1366         }
1367
1368         return a[len2-1];
1369 }
1370
1371 #define BB_SLOT_SIZE     (16*1024)          /* Desired size in bytes */
1372 #define BB_PER_SLOT_BITS (BB_SLOT_SIZE * 8) /* Number of bits per slot */
1373 #define BB_PER_SLOT_INTS (BB_SLOT_SIZE / 4) /* Number of int32s per slot */
1374
1375 struct bitbag {
1376     uint32 **bits;
1377     int slot_cnt;
1378 };
1379
1380 struct bitbag *bitbag_create(int max_ndx)
1381 {
1382         struct bitbag *bb = new(struct bitbag);
1383         bb->slot_cnt = (max_ndx + BB_PER_SLOT_BITS - 1) / BB_PER_SLOT_BITS;
1384
1385         if (!(bb->bits = (uint32**)calloc(bb->slot_cnt, sizeof (uint32*))))
1386                 out_of_memory("bitbag_create");
1387
1388         return bb;
1389 }
1390
1391 void bitbag_set_bit(struct bitbag *bb, int ndx)
1392 {
1393         int slot = ndx / BB_PER_SLOT_BITS;
1394         ndx %= BB_PER_SLOT_BITS;
1395
1396         if (!bb->bits[slot]) {
1397                 if (!(bb->bits[slot] = (uint32*)calloc(BB_PER_SLOT_INTS, 4)))
1398                         out_of_memory("bitbag_set_bit");
1399         }
1400
1401         bb->bits[slot][ndx/32] |= 1u << (ndx % 32);
1402 }
1403
1404 #if 0 /* not needed yet */
1405 void bitbag_clear_bit(struct bitbag *bb, int ndx)
1406 {
1407         int slot = ndx / BB_PER_SLOT_BITS;
1408         ndx %= BB_PER_SLOT_BITS;
1409
1410         if (!bb->bits[slot])
1411                 return;
1412
1413         bb->bits[slot][ndx/32] &= ~(1u << (ndx % 32));
1414 }
1415
1416 int bitbag_check_bit(struct bitbag *bb, int ndx)
1417 {
1418         int slot = ndx / BB_PER_SLOT_BITS;
1419         ndx %= BB_PER_SLOT_BITS;
1420
1421         if (!bb->bits[slot])
1422                 return 0;
1423
1424         return bb->bits[slot][ndx/32] & (1u << (ndx % 32)) ? 1 : 0;
1425 }
1426 #endif
1427
1428 /* Call this with -1 to start checking from 0.  Returns -1 at the end. */
1429 int bitbag_next_bit(struct bitbag *bb, int after)
1430 {
1431         uint32 bits, mask;
1432         int i, ndx = after + 1;
1433         int slot = ndx / BB_PER_SLOT_BITS;
1434         ndx %= BB_PER_SLOT_BITS;
1435
1436         mask = (1u << (ndx % 32)) - 1;
1437         for (i = ndx / 32; slot < bb->slot_cnt; slot++, i = mask = 0) {
1438                 if (!bb->bits[slot])
1439                         continue;
1440                 for ( ; i < BB_PER_SLOT_INTS; i++, mask = 0) {
1441                         if (!(bits = bb->bits[slot][i] & ~mask))
1442                                 continue;
1443                         /* The xor magic figures out the lowest enabled bit in
1444                          * bits, and the switch quickly computes log2(bit). */
1445                         switch (bits ^ (bits & (bits-1))) {
1446 #define LOG2(n) case 1u << n: return slot*BB_PER_SLOT_BITS + i*32 + n
1447                             LOG2(0);  LOG2(1);  LOG2(2);  LOG2(3);
1448                             LOG2(4);  LOG2(5);  LOG2(6);  LOG2(7);
1449                             LOG2(8);  LOG2(9);  LOG2(10); LOG2(11);
1450                             LOG2(12); LOG2(13); LOG2(14); LOG2(15);
1451                             LOG2(16); LOG2(17); LOG2(18); LOG2(19);
1452                             LOG2(20); LOG2(21); LOG2(22); LOG2(23);
1453                             LOG2(24); LOG2(25); LOG2(26); LOG2(27);
1454                             LOG2(28); LOG2(29); LOG2(30); LOG2(31);
1455                         }
1456                         return -1; /* impossible... */
1457                 }
1458         }
1459
1460         return -1;
1461 }
1462
1463 void *expand_item_list(item_list *lp, size_t item_size,
1464                        const char *desc, int incr)
1465 {
1466         /* First time through, 0 <= 0, so list is expanded. */
1467         if (lp->malloced <= lp->count) {
1468                 void *new_ptr;
1469                 size_t new_size = lp->malloced;
1470                 if (incr < 0)
1471                         new_size += -incr; /* increase slowly */
1472                 else if (new_size < (size_t)incr)
1473                         new_size += incr;
1474                 else
1475                         new_size *= 2;
1476                 new_ptr = realloc_array(lp->items, char, new_size * item_size);
1477                 if (verbose >= 4) {
1478                         rprintf(FINFO, "[%s] expand %s to %.0f bytes, did%s move\n",
1479                                 who_am_i(), desc, (double)new_size * item_size,
1480                                 new_ptr == lp->items ? " not" : "");
1481                 }
1482                 if (!new_ptr)
1483                         out_of_memory("expand_item_list");
1484
1485                 lp->items = new_ptr;
1486                 lp->malloced = new_size;
1487         }
1488         return (char*)lp->items + (lp->count++ * item_size);
1489 }