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) 2003-2008 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)
 151                                 return errno == ENOSYS ? 1 : -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         int count, have_glob_results;
 529
 530 #if !defined HAVE_GLOB || !defined HAVE_GLOB_H
 531         if (argc == maxargs) {
 532                 maxargs += MAX_ARGS;
 533                 if (!(argv = realloc_array(argv, char *, maxargs)))
 534                         out_of_memory("glob_expand");
 535                 *argv_ptr = argv;
 536                 *maxargs_ptr = maxargs;
 537         }
 538         if (!*s)
 539                 s = ".";
 540         s = argv[argc++] = strdup(s);
 541         filter_server_path(s);
 542 #else
 543         glob_t globbuf;
 544
 545         if (maxargs <= argc)
 546                 return;
 547         if (!*s)
 548                 s = ".";
 549
 550         if (sanitize_paths)
 551                 s = sanitize_path(NULL, s, "", 0);
 552         else
 553                 s = strdup(s);
 554         if (!s)
 555                 out_of_memory("glob_expand");
 556
 557         memset(&globbuf, 0, sizeof globbuf);
 558         glob(s, 0, NULL, &globbuf);
 559         /* Note: we check the first match against the filter list,
 560          * just in case the user specified a wildcard in the path. */
 561         if ((count = globbuf.gl_pathc) > 0) {
 562                 if (filter_server_path(globbuf.gl_pathv[0])) {
 563                         int slashes = 0;
 564                         char *cp;
 565                         /* Truncate original arg at glob's truncation point. */
 566                         for (cp = globbuf.gl_pathv[0]; *cp; cp++) {
 567                                 if (*cp == '/')
 568                                         slashes++;
 569                         }
 570                         for (cp = s; *cp; cp++) {
 571                                 if (*cp == '/') {
 572                                         if (slashes-- <= 0) {
 573                                                 *cp = '\0';
 574                                                 break;
 575                                         }
 576                                 }
 577                         }
 578                         have_glob_results = 0;
 579                         count = 1;
 580                 } else
 581                         have_glob_results = 1;
 582         } else {
 583                 /* This truncates "s" at a filtered element, if present. */
 584                 filter_server_path(s);
 585                 have_glob_results = 0;
 586                 count = 1;
 587         }
 588         if (count + argc > maxargs) {
 589                 maxargs += count + MAX_ARGS;
 590                 if (!(argv = realloc_array(argv, char *, maxargs)))
 591                         out_of_memory("glob_expand");
 592                 *argv_ptr = argv;
 593                 *maxargs_ptr = maxargs;
 594         }
 595         if (have_glob_results) {
 596                 int i;
 597                 free(s);
 598                 for (i = 0; i < count; i++) {
 599                         if (!(argv[argc++] = strdup(globbuf.gl_pathv[i])))
 600                                 out_of_memory("glob_expand");
 601                 }
 602         } else
 603                 argv[argc++] = s;
 604         globfree(&globbuf);
 605 #endif
 606         *argc_ptr = argc;
 607 }
 608
 609 /* This routine is only used in daemon mode. */
 610 void glob_expand_module(char *base1, char *arg, char ***argv_ptr, int *argc_ptr, int *maxargs_ptr)
 611 {
 612         char *p, *s;
 613         char *base = base1;
 614         int base_len = strlen(base);
 615
 616         if (!arg || !*arg)
 617                 return;
 618
 619         if (strncmp(arg, base, base_len) == 0)
 620                 arg += base_len;
 621
 622         if (!(arg = strdup(arg)))
 623                 out_of_memory("glob_expand_module");
 624
 625         if (asprintf(&base," %s/", base1) <= 0)
 626                 out_of_memory("glob_expand_module");
 627         base_len++;
 628
 629         for (s = arg; *s; s = p + base_len) {
 630                 if ((p = strstr(s, base)) != NULL)
 631                         *p = '\0'; /* split it at this point */
 632                 glob_expand(s, argv_ptr, argc_ptr, maxargs_ptr);
 633                 if (!p)
 634                         break;
 635         }
 636
 637         free(arg);
 638         free(base);
 639 }
 640
 641 /**
 642  * Convert a string to lower case
 643  **/
 644 void strlower(char *s)
 645 {
 646         while (*s) {
 647                 if (isUpper(s))
 648                         *s = toLower(s);
 649                 s++;
 650         }
 651 }
 652
 653 /* Join strings p1 & p2 into "dest" with a guaranteed '/' between them.  (If
 654  * p1 ends with a '/', no extra '/' is inserted.)  Returns the length of both
 655  * strings + 1 (if '/' was inserted), regardless of whether the null-terminated
 656  * string fits into destsize. */
 657 size_t pathjoin(char *dest, size_t destsize, const char *p1, const char *p2)
 658 {
 659         size_t len = strlcpy(dest, p1, destsize);
 660         if (len < destsize - 1) {
 661                 if (!len || dest[len-1] != '/')
 662                         dest[len++] = '/';
 663                 if (len < destsize - 1)
 664                         len += strlcpy(dest + len, p2, destsize - len);
 665                 else {
 666                         dest[len] = '\0';
 667                         len += strlen(p2);
 668                 }
 669         }
 670         else
 671                 len += strlen(p2) + 1; /* Assume we'd insert a '/'. */
 672         return len;
 673 }
 674
 675 /* Join any number of strings together, putting them in "dest".  The return
 676  * value is the length of all the strings, regardless of whether the null-
 677  * terminated whole fits in destsize.  Your list of string pointers must end
 678  * with a NULL to indicate the end of the list. */
 679 size_t stringjoin(char *dest, size_t destsize, ...)
 680 {
 681         va_list ap;
 682         size_t len, ret = 0;
 683         const char *src;
 684
 685         va_start(ap, destsize);
 686         while (1) {
 687                 if (!(src = va_arg(ap, const char *)))
 688                         break;
 689                 len = strlen(src);
 690                 ret += len;
 691                 if (destsize > 1) {
 692                         if (len >= destsize)
 693                                 len = destsize - 1;
 694                         memcpy(dest, src, len);
 695                         destsize -= len;
 696                         dest += len;
 697                 }
 698         }
 699         *dest = '\0';
 700         va_end(ap);
 701
 702         return ret;
 703 }
 704
 705 int count_dir_elements(const char *p)
 706 {
 707         int cnt = 0, new_component = 1;
 708         while (*p) {
 709                 if (*p++ == '/')
 710                         new_component = (*p != '.' || (p[1] != '/' && p[1] != '\0'));
 711                 else if (new_component) {
 712                         new_component = 0;
 713                         cnt++;
 714                 }
 715         }
 716         return cnt;
 717 }
 718
 719 /* Turns multiple adjacent slashes into a single slash, drops interior "."
 720  * elements, drops an intial "./" unless CFN_KEEP_LEADING_DOT_DIR is flagged,
 721  * will even drop a trailing '.' after a '/' if CFN_DROP_TRAILING_DOT_DIR is
 722  * flagged, removes a trailing slash (perhaps after removing the aforementioned
 723  * dot) unless CFN_KEEP_TRAILING_SLASH is flagged, will even collapse ".."
 724  * elements (except at the start of the string) if CFN_COLLAPSE_DOT_DOT_DIRS
 725  * is flagged.  If the resulting name would be empty, we return ".". */
 726 unsigned int clean_fname(char *name, int flags)
 727 {
 728         char *limit = name - 1, *t = name, *f = name;
 729         int anchored;
 730
 731         if (!name)
 732                 return 0;
 733
 734         if ((anchored = *f == '/') != 0)
 735                 *t++ = *f++;
 736         else if (flags & CFN_KEEP_LEADING_DOT_DIR && *f == '.' && f[1] == '/') {
 737                 *t++ = *f++;
 738                 *t++ = *f++;
 739         }
 740         while (*f) {
 741                 /* discard extra slashes */
 742                 if (*f == '/') {
 743                         f++;
 744                         continue;
 745                 }
 746                 if (*f == '.') {
 747                         /* discard interior "." dirs */
 748                         if (f[1] == '/') {
 749                                 f += 2;
 750                                 continue;
 751                         }
 752                         if (f[1] == '\0' && flags & CFN_DROP_TRAILING_DOT_DIR)
 753                                 break;
 754                         /* collapse ".." dirs */
 755                         if (flags & CFN_COLLAPSE_DOT_DOT_DIRS
 756                          && f[1] == '.' && (f[2] == '/' || !f[2])) {
 757                                 char *s = t - 1;
 758                                 if (s == name && anchored) {
 759                                         f += 2;
 760                                         continue;
 761                                 }
 762                                 while (s > limit && *--s != '/') {}
 763                                 if (s != t - 1 && (s < name || *s == '/')) {
 764                                         t = s + 1;
 765                                         f += 2;
 766                                         continue;
 767                                 }
 768                                 limit = t + 2;
 769                         }
 770                 }
 771                 while (*f && (*t++ = *f++) != '/') {}
 772         }
 773
 774         if (t > name+anchored && t[-1] == '/' && !(flags & CFN_KEEP_TRAILING_SLASH))
 775                 t--;
 776         if (t == name)
 777                 *t++ = '.';
 778         *t = '\0';
 779
 780         return t - name;
 781 }
 782
 783 /* Make path appear as if a chroot had occurred.  This handles a leading
 784  * "/" (either removing it or expanding it) and any leading or embedded
 785  * ".." components that attempt to escape past the module's top dir.
 786  *
 787  * If dest is NULL, a buffer is allocated to hold the result.  It is legal
 788  * to call with the dest and the path (p) pointing to the same buffer, but
 789  * rootdir will be ignored to avoid expansion of the string.
 790  *
 791  * The rootdir string contains a value to use in place of a leading slash.
 792  * Specify NULL to get the default of "module_dir".
 793  *
 794  * The depth var is a count of how many '..'s to allow at the start of the
 795  * path.
 796  *
 797  * We also clean the path in a manner similar to clean_fname() but with a
 798  * few differences:
 799  *
 800  * Turns multiple adjacent slashes into a single slash, gets rid of "." dir
 801  * elements (INCLUDING a trailing dot dir), PRESERVES a trailing slash, and
 802  * ALWAYS collapses ".." elements (except for those at the start of the
 803  * string up to "depth" deep).  If the resulting name would be empty,
 804  * change it into a ".". */
 805 char *sanitize_path(char *dest, const char *p, const char *rootdir, int depth)
 806 {
 807         char *start, *sanp;
 808         int rlen = 0, leave_one_dotdir = relative_paths;
 809
 810         if (dest != p) {
 811                 int plen = strlen(p);
 812                 if (*p == '/') {
 813                         if (!rootdir)
 814                                 rootdir = module_dir;
 815                         rlen = strlen(rootdir);
 816                         depth = 0;
 817                         p++;
 818                 }
 819                 if (dest) {
 820                         if (rlen + plen + 1 >= MAXPATHLEN)
 821                                 return NULL;
 822                 } else if (!(dest = new_array(char, rlen + plen + 1)))
 823                         out_of_memory("sanitize_path");
 824                 if (rlen) {
 825                         memcpy(dest, rootdir, rlen);
 826                         if (rlen > 1)
 827                                 dest[rlen++] = '/';
 828                 }
 829         }
 830
 831         start = sanp = dest + rlen;
 832         /* This loop iterates once per filename component in p, pointing at
 833          * the start of the name (past any prior slash) for each iteration. */
 834         while (*p) {
 835                 /* discard leading or extra slashes */
 836                 if (*p == '/') {
 837                         p++;
 838                         continue;
 839                 }
 840                 if (*p == '.' && (p[1] == '/' || p[1] == '\0')) {
 841                         if (leave_one_dotdir && p[1])
 842                                 leave_one_dotdir = 0;
 843                         else {
 844                                 /* skip "." component */
 845                                 p++;
 846                                 continue;
 847                         }
 848                 }
 849                 if (*p == '.' && p[1] == '.' && (p[2] == '/' || p[2] == '\0')) {
 850                         /* ".." component followed by slash or end */
 851                         if (depth <= 0 || sanp != start) {
 852                                 p += 2;
 853                                 if (sanp != start) {
 854                                         /* back up sanp one level */
 855                                         --sanp; /* now pointing at slash */
 856                                         while (sanp > start && sanp[-1] != '/') {
 857                                                 /* skip back up to slash */
 858                                                 sanp--;
 859                                         }
 860                                 }
 861                                 continue;
 862                         }
 863                         /* allow depth levels of .. at the beginning */
 864                         depth--;
 865                         /* move the virtual beginning to leave the .. alone */
 866                         start = sanp + 3;
 867                 }
 868                 /* copy one component through next slash */
 869                 while (*p && (*sanp++ = *p++) != '/') {}
 870         }
 871         if (sanp == dest) {
 872                 /* ended up with nothing, so put in "." component */
 873                 *sanp++ = '.';
 874         }
 875         *sanp = '\0';
 876
 877         return dest;
 878 }
 879
 880 /* Like chdir(), but it keeps track of the current directory (in the
 881  * global "curr_dir"), and ensures that the path size doesn't overflow.
 882  * Also cleans the path using the clean_fname() function. */
 883 int push_dir(const char *dir, int set_path_only)
 884 {
 885         static int initialised;
 886         unsigned int len;
 887
 888         if (!initialised) {
 889                 initialised = 1;
 890                 getcwd(curr_dir, sizeof curr_dir - 1);
 891                 curr_dir_len = strlen(curr_dir);
 892         }
 893
 894         if (!dir)       /* this call was probably just to initialize */
 895                 return 0;
 896
 897         len = strlen(dir);
 898         if (len == 1 && *dir == '.')
 899                 return 1;
 900
 901         if ((*dir == '/' ? len : curr_dir_len + 1 + len) >= sizeof curr_dir) {
 902                 errno = ENAMETOOLONG;
 903                 return 0;
 904         }
 905
 906         if (!set_path_only && chdir(dir))
 907                 return 0;
 908
 909         if (*dir == '/') {
 910                 memcpy(curr_dir, dir, len + 1);
 911                 curr_dir_len = len;
 912         } else {
 913                 curr_dir[curr_dir_len++] = '/';
 914                 memcpy(curr_dir + curr_dir_len, dir, len + 1);
 915                 curr_dir_len += len;
 916         }
 917
 918         curr_dir_len = clean_fname(curr_dir, CFN_COLLAPSE_DOT_DOT_DIRS);
 919         if (sanitize_paths) {
 920                 if (module_dirlen > curr_dir_len)
 921                         module_dirlen = curr_dir_len;
 922                 curr_dir_depth = count_dir_elements(curr_dir + module_dirlen);
 923         }
 924
 925         if (verbose >= 5 && !set_path_only)
 926                 rprintf(FINFO, "[%s] push_dir(%s)\n", who_am_i(), curr_dir);
 927
 928         return 1;
 929 }
 930
 931 /**
 932  * Reverse a push_dir() call.  You must pass in an absolute path
 933  * that was copied from a prior value of "curr_dir".
 934  **/
 935 int pop_dir(const char *dir)
 936 {
 937         if (chdir(dir))
 938                 return 0;
 939
 940         curr_dir_len = strlcpy(curr_dir, dir, sizeof curr_dir);
 941         if (curr_dir_len >= sizeof curr_dir)
 942                 curr_dir_len = sizeof curr_dir - 1;
 943         if (sanitize_paths)
 944                 curr_dir_depth = count_dir_elements(curr_dir + module_dirlen);
 945
 946         if (verbose >= 5)
 947                 rprintf(FINFO, "[%s] pop_dir(%s)\n", who_am_i(), curr_dir);
 948
 949         return 1;
 950 }
 951
 952 /**
 953  * Return a quoted string with the full pathname of the indicated filename.
 954  * The string " (in MODNAME)" may also be appended.  The returned pointer
 955  * remains valid until the next time full_fname() is called.
 956  **/
 957 char *full_fname(const char *fn)
 958 {
 959         static char *result = NULL;
 960         char *m1, *m2, *m3;
 961         char *p1, *p2;
 962
 963         if (result)
 964                 free(result);
 965
 966         if (*fn == '/')
 967                 p1 = p2 = "";
 968         else {
 969                 p1 = curr_dir + module_dirlen;
 970                 for (p2 = p1; *p2 == '/'; p2++) {}
 971                 if (*p2)
 972                         p2 = "/";
 973         }
 974         if (module_id >= 0) {
 975                 m1 = " (in ";
 976                 m2 = lp_name(module_id);
 977                 m3 = ")";
 978         } else
 979                 m1 = m2 = m3 = "";
 980
 981         if (asprintf(&result, "\"%s%s%s\"%s%s%s", p1, p2, fn, m1, m2, m3) <= 0)
 982                 out_of_memory("full_fname");
 983
 984         return result;
 985 }
 986
 987 static char partial_fname[MAXPATHLEN];
 988
 989 char *partial_dir_fname(const char *fname)
 990 {
 991         char *t = partial_fname;
 992         int sz = sizeof partial_fname;
 993         const char *fn;
 994
 995         if ((fn = strrchr(fname, '/')) != NULL) {
 996                 fn++;
 997                 if (*partial_dir != '/') {
 998                         int len = fn - fname;
 999                         strncpy(t, fname, len); /* safe */
1000                         t += len;
1001                         sz -= len;
1002                 }
1003         } else
1004                 fn = fname;
1005         if ((int)pathjoin(t, sz, partial_dir, fn) >= sz)
1006                 return NULL;
1007         if (server_filter_list.head) {
1008                 t = strrchr(partial_fname, '/');
1009                 *t = '\0';
1010                 if (check_filter(&server_filter_list, partial_fname, 1) < 0)
1011                         return NULL;
1012                 *t = '/';
1013                 if (check_filter(&server_filter_list, partial_fname, 0) < 0)
1014                         return NULL;
1015         }
1016
1017         return partial_fname;
1018 }
1019
1020 /* If no --partial-dir option was specified, we don't need to do anything
1021  * (the partial-dir is essentially '.'), so just return success. */
1022 int handle_partial_dir(const char *fname, int create)
1023 {
1024         char *fn, *dir;
1025
1026         if (fname != partial_fname)
1027                 return 1;
1028         if (!create && *partial_dir == '/')
1029                 return 1;
1030         if (!(fn = strrchr(partial_fname, '/')))
1031                 return 1;
1032
1033         *fn = '\0';
1034         dir = partial_fname;
1035         if (create) {
1036                 STRUCT_STAT st;
1037                 int statret = do_lstat(dir, &st);
1038                 if (statret == 0 && !S_ISDIR(st.st_mode)) {
1039                         if (do_unlink(dir) < 0)
1040                                 return 0;
1041                         statret = -1;
1042                 }
1043                 if (statret < 0 && do_mkdir(dir, 0700) < 0)
1044                         return 0;
1045         } else
1046                 do_rmdir(dir);
1047         *fn = '/';
1048
1049         return 1;
1050 }
1051
1052 /**
1053  * Determine if a symlink points outside the current directory tree.
1054  * This is considered "unsafe" because e.g. when mirroring somebody
1055  * else's machine it might allow them to establish a symlink to
1056  * /etc/passwd, and then read it through a web server.
1057  *
1058  * Null symlinks and absolute symlinks are always unsafe.
1059  *
1060  * Basically here we are concerned with symlinks whose target contains
1061  * "..", because this might cause us to walk back up out of the
1062  * transferred directory.  We are not allowed to go back up and
1063  * reenter.
1064  *
1065  * @param dest Target of the symlink in question.
1066  *
1067  * @param src Top source directory currently applicable.  Basically this
1068  * is the first parameter to rsync in a simple invocation, but it's
1069  * modified by flist.c in slightly complex ways.
1070  *
1071  * @retval True if unsafe
1072  * @retval False is unsafe
1073  *
1074  * @sa t_unsafe.c
1075  **/
1076 int unsafe_symlink(const char *dest, const char *src)
1077 {
1078         const char *name, *slash;
1079         int depth = 0;
1080
1081         /* all absolute and null symlinks are unsafe */
1082         if (!dest || !*dest || *dest == '/')
1083                 return 1;
1084
1085         /* find out what our safety margin is */
1086         for (name = src; (slash = strchr(name, '/')) != 0; name = slash+1) {
1087                 if (strncmp(name, "../", 3) == 0) {
1088                         depth = 0;
1089                 } else if (strncmp(name, "./", 2) == 0) {
1090                         /* nothing */
1091                 } else {
1092                         depth++;
1093                 }
1094         }
1095         if (strcmp(name, "..") == 0)
1096                 depth = 0;
1097
1098         for (name = dest; (slash = strchr(name, '/')) != 0; name = slash+1) {
1099                 if (strncmp(name, "../", 3) == 0) {
1100                         /* if at any point we go outside the current directory
1101                            then stop - it is unsafe */
1102                         if (--depth < 0)
1103                                 return 1;
1104                 } else if (strncmp(name, "./", 2) == 0) {
1105                         /* nothing */
1106                 } else {
1107                         depth++;
1108                 }
1109         }
1110         if (strcmp(name, "..") == 0)
1111                 depth--;
1112
1113         return (depth < 0);
1114 }
1115
1116 /* Return the int64 number as a string.  If the --human-readable option was
1117  * specified, we may output the number in K, M, or G units.  We can return
1118  * up to 4 buffers at a time. */
1119 char *human_num(int64 num)
1120 {
1121         static char bufs[4][128]; /* more than enough room */
1122         static unsigned int n;
1123         char *s;
1124
1125         n = (n + 1) % (sizeof bufs / sizeof bufs[0]);
1126
1127         if (human_readable) {
1128                 char units = '\0';
1129                 int mult = human_readable == 1 ? 1000 : 1024;
1130                 double dnum = 0;
1131                 if (num > mult*mult*mult) {
1132                         dnum = (double)num / (mult*mult*mult);
1133                         units = 'G';
1134                 } else if (num > mult*mult) {
1135                         dnum = (double)num / (mult*mult);
1136                         units = 'M';
1137                 } else if (num > mult) {
1138                         dnum = (double)num / mult;
1139                         units = 'K';
1140                 }
1141                 if (units) {
1142                         snprintf(bufs[n], sizeof bufs[0], "%.2f%c", dnum, units);
1143                         return bufs[n];
1144                 }
1145         }
1146
1147         s = bufs[n] + sizeof bufs[0] - 1;
1148         *s = '\0';
1149
1150         if (!num)
1151                 *--s = '0';
1152         while (num) {
1153                 *--s = (char)(num % 10) + '0';
1154                 num /= 10;
1155         }
1156         return s;
1157 }
1158
1159 /* Return the double number as a string.  If the --human-readable option was
1160  * specified, we may output the number in K, M, or G units.  We use a buffer
1161  * from human_num() to return our result. */
1162 char *human_dnum(double dnum, int decimal_digits)
1163 {
1164         char *buf = human_num(dnum);
1165         int len = strlen(buf);
1166         if (isDigit(buf + len - 1)) {
1167                 /* There's extra room in buf prior to the start of the num. */
1168                 buf -= decimal_digits + 1;
1169                 snprintf(buf, len + decimal_digits + 2, "%.*f", decimal_digits, dnum);
1170         }
1171         return buf;
1172 }
1173
1174 /* Return the date and time as a string.  Some callers tweak returned buf. */
1175 char *timestring(time_t t)
1176 {
1177         static char TimeBuf[200];
1178         struct tm *tm = localtime(&t);
1179         char *p;
1180
1181 #ifdef HAVE_STRFTIME
1182         strftime(TimeBuf, sizeof TimeBuf - 1, "%Y/%m/%d %H:%M:%S", tm);
1183 #else
1184         strlcpy(TimeBuf, asctime(tm), sizeof TimeBuf);
1185 #endif
1186
1187         if ((p = strchr(TimeBuf, '\n')) != NULL)
1188                 *p = '\0';
1189
1190         return TimeBuf;
1191 }
1192
1193 /**
1194  * Sleep for a specified number of milliseconds.
1195  *
1196  * Always returns TRUE.  (In the future it might return FALSE if
1197  * interrupted.)
1198  **/
1199 int msleep(int t)
1200 {
1201         int tdiff = 0;
1202         struct timeval tval, t1, t2;
1203
1204         gettimeofday(&t1, NULL);
1205
1206         while (tdiff < t) {
1207                 tval.tv_sec = (t-tdiff)/1000;
1208                 tval.tv_usec = 1000*((t-tdiff)%1000);
1209
1210                 errno = 0;
1211                 select(0,NULL,NULL, NULL, &tval);
1212
1213                 gettimeofday(&t2, NULL);
1214                 tdiff = (t2.tv_sec - t1.tv_sec)*1000 +
1215                         (t2.tv_usec - t1.tv_usec)/1000;
1216         }
1217
1218         return True;
1219 }
1220
1221 /* Determine if two time_t values are equivalent (either exact, or in
1222  * the modification timestamp window established by --modify-window).
1223  *
1224  * @retval 0 if the times should be treated as the same
1225  *
1226  * @retval +1 if the first is later
1227  *
1228  * @retval -1 if the 2nd is later
1229  **/
1230 int cmp_time(time_t file1, time_t file2)
1231 {
1232         if (file2 > file1) {
1233                 if (file2 - file1 <= modify_window)
1234                         return 0;
1235                 return -1;
1236         }
1237         if (file1 - file2 <= modify_window)
1238                 return 0;
1239         return 1;
1240 }
1241
1242
1243 #ifdef __INSURE__XX
1244 #include <dlfcn.h>
1245
1246 /**
1247    This routine is a trick to immediately catch errors when debugging
1248    with insure. A xterm with a gdb is popped up when insure catches
1249    a error. It is Linux specific.
1250 **/
1251 int _Insure_trap_error(int a1, int a2, int a3, int a4, int a5, int a6)
1252 {
1253         static int (*fn)();
1254         int ret;
1255         char *cmd;
1256
1257         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'",
1258                 getpid(), getpid(), getpid());
1259
1260         if (!fn) {
1261                 static void *h;
1262                 h = dlopen("/usr/local/parasoft/insure++lite/lib.linux2/libinsure.so", RTLD_LAZY);
1263                 fn = dlsym(h, "_Insure_trap_error");
1264         }
1265
1266         ret = fn(a1, a2, a3, a4, a5, a6);
1267
1268         system(cmd);
1269
1270         free(cmd);
1271
1272         return ret;
1273 }
1274 #endif
1275
1276 #define MALLOC_MAX 0x40000000
1277
1278 void *_new_array(unsigned long num, unsigned int size, int use_calloc)
1279 {
1280         if (num >= MALLOC_MAX/size)
1281                 return NULL;
1282         return use_calloc ? calloc(num, size) : malloc(num * size);
1283 }
1284
1285 void *_realloc_array(void *ptr, unsigned int size, unsigned long num)
1286 {
1287         if (num >= MALLOC_MAX/size)
1288                 return NULL;
1289         if (!ptr)
1290                 return malloc(size * num);
1291         return realloc(ptr, size * num);
1292 }
1293
1294 /* Take a filename and filename length and return the most significant
1295  * filename suffix we can find.  This ignores suffixes such as "~",
1296  * ".bak", ".orig", ".~1~", etc. */
1297 const char *find_filename_suffix(const char *fn, int fn_len, int *len_ptr)
1298 {
1299         const char *suf, *s;
1300         BOOL had_tilde;
1301         int s_len;
1302
1303         /* One or more dots at the start aren't a suffix. */
1304         while (fn_len && *fn == '.') fn++, fn_len--;
1305
1306         /* Ignore the ~ in a "foo~" filename. */
1307         if (fn_len > 1 && fn[fn_len-1] == '~')
1308                 fn_len--, had_tilde = True;
1309         else
1310                 had_tilde = False;
1311
1312         /* Assume we don't find an suffix. */
1313         suf = "";
1314         *len_ptr = 0;
1315
1316         /* Find the last significant suffix. */
1317         for (s = fn + fn_len; fn_len > 1; ) {
1318                 while (*--s != '.' && s != fn) {}
1319                 if (s == fn)
1320                         break;
1321                 s_len = fn_len - (s - fn);
1322                 fn_len = s - fn;
1323                 if (s_len == 4) {
1324                         if (strcmp(s+1, "bak") == 0
1325                          || strcmp(s+1, "old") == 0)
1326                                 continue;
1327                 } else if (s_len == 5) {
1328                         if (strcmp(s+1, "orig") == 0)
1329                                 continue;
1330                 } else if (s_len > 2 && had_tilde
1331                     && s[1] == '~' && isDigit(s + 2))
1332                         continue;
1333                 *len_ptr = s_len;
1334                 suf = s;
1335                 if (s_len == 1)
1336                         break;
1337                 /* Determine if the suffix is all digits. */
1338                 for (s++, s_len--; s_len > 0; s++, s_len--) {
1339                         if (!isDigit(s))
1340                                 return suf;
1341                 }
1342                 /* An all-digit suffix may not be that signficant. */
1343                 s = suf;
1344         }
1345
1346         return suf;
1347 }
1348
1349 /* This is an implementation of the Levenshtein distance algorithm.  It
1350  * was implemented to avoid needing a two-dimensional matrix (to save
1351  * memory).  It was also tweaked to try to factor in the ASCII distance
1352  * between changed characters as a minor distance quantity.  The normal
1353  * Levenshtein units of distance (each signifying a single change between
1354  * the two strings) are defined as a "UNIT". */
1355
1356 #define UNIT (1 << 16)
1357
1358 uint32 fuzzy_distance(const char *s1, int len1, const char *s2, int len2)
1359 {
1360         uint32 a[MAXPATHLEN], diag, above, left, diag_inc, above_inc, left_inc;
1361         int32 cost;
1362         int i1, i2;
1363
1364         if (!len1 || !len2) {
1365                 if (!len1) {
1366                         s1 = s2;
1367                         len1 = len2;
1368                 }
1369                 for (i1 = 0, cost = 0; i1 < len1; i1++)
1370                         cost += s1[i1];
1371                 return (int32)len1 * UNIT + cost;
1372         }
1373
1374         for (i2 = 0; i2 < len2; i2++)
1375                 a[i2] = (i2+1) * UNIT;
1376
1377         for (i1 = 0; i1 < len1; i1++) {
1378                 diag = i1 * UNIT;
1379                 above = (i1+1) * UNIT;
1380                 for (i2 = 0; i2 < len2; i2++) {
1381                         left = a[i2];
1382                         if ((cost = *((uchar*)s1+i1) - *((uchar*)s2+i2)) != 0) {
1383                                 if (cost < 0)
1384                                         cost = UNIT - cost;
1385                                 else
1386                                         cost = UNIT + cost;
1387                         }
1388                         diag_inc = diag + cost;
1389                         left_inc = left + UNIT + *((uchar*)s1+i1);
1390                         above_inc = above + UNIT + *((uchar*)s2+i2);
1391                         a[i2] = above = left < above
1392                               ? (left_inc < diag_inc ? left_inc : diag_inc)
1393                               : (above_inc < diag_inc ? above_inc : diag_inc);
1394                         diag = left;
1395                 }
1396         }
1397
1398         return a[len2-1];
1399 }
1400
1401 #define BB_SLOT_SIZE     (16*1024)          /* Desired size in bytes */
1402 #define BB_PER_SLOT_BITS (BB_SLOT_SIZE * 8) /* Number of bits per slot */
1403 #define BB_PER_SLOT_INTS (BB_SLOT_SIZE / 4) /* Number of int32s per slot */
1404
1405 struct bitbag {
1406     uint32 **bits;
1407     int slot_cnt;
1408 };
1409
1410 struct bitbag *bitbag_create(int max_ndx)
1411 {
1412         struct bitbag *bb = new(struct bitbag);
1413         bb->slot_cnt = (max_ndx + BB_PER_SLOT_BITS - 1) / BB_PER_SLOT_BITS;
1414
1415         if (!(bb->bits = (uint32**)calloc(bb->slot_cnt, sizeof (uint32*))))
1416                 out_of_memory("bitbag_create");
1417
1418         return bb;
1419 }
1420
1421 void bitbag_set_bit(struct bitbag *bb, int ndx)
1422 {
1423         int slot = ndx / BB_PER_SLOT_BITS;
1424         ndx %= BB_PER_SLOT_BITS;
1425
1426         if (!bb->bits[slot]) {
1427                 if (!(bb->bits[slot] = (uint32*)calloc(BB_PER_SLOT_INTS, 4)))
1428                         out_of_memory("bitbag_set_bit");
1429         }
1430
1431         bb->bits[slot][ndx/32] |= 1u << (ndx % 32);
1432 }
1433
1434 #if 0 /* not needed yet */
1435 void bitbag_clear_bit(struct bitbag *bb, int ndx)
1436 {
1437         int slot = ndx / BB_PER_SLOT_BITS;
1438         ndx %= BB_PER_SLOT_BITS;
1439
1440         if (!bb->bits[slot])
1441                 return;
1442
1443         bb->bits[slot][ndx/32] &= ~(1u << (ndx % 32));
1444 }
1445
1446 int bitbag_check_bit(struct bitbag *bb, int ndx)
1447 {
1448         int slot = ndx / BB_PER_SLOT_BITS;
1449         ndx %= BB_PER_SLOT_BITS;
1450
1451         if (!bb->bits[slot])
1452                 return 0;
1453
1454         return bb->bits[slot][ndx/32] & (1u << (ndx % 32)) ? 1 : 0;
1455 }
1456 #endif
1457
1458 /* Call this with -1 to start checking from 0.  Returns -1 at the end. */
1459 int bitbag_next_bit(struct bitbag *bb, int after)
1460 {
1461         uint32 bits, mask;
1462         int i, ndx = after + 1;
1463         int slot = ndx / BB_PER_SLOT_BITS;
1464         ndx %= BB_PER_SLOT_BITS;
1465
1466         mask = (1u << (ndx % 32)) - 1;
1467         for (i = ndx / 32; slot < bb->slot_cnt; slot++, i = mask = 0) {
1468                 if (!bb->bits[slot])
1469                         continue;
1470                 for ( ; i < BB_PER_SLOT_INTS; i++, mask = 0) {
1471                         if (!(bits = bb->bits[slot][i] & ~mask))
1472                                 continue;
1473                         /* The xor magic figures out the lowest enabled bit in
1474                          * bits, and the switch quickly computes log2(bit). */
1475                         switch (bits ^ (bits & (bits-1))) {
1476 #define LOG2(n) case 1u << n: return slot*BB_PER_SLOT_BITS + i*32 + n
1477                             LOG2(0);  LOG2(1);  LOG2(2);  LOG2(3);
1478                             LOG2(4);  LOG2(5);  LOG2(6);  LOG2(7);
1479                             LOG2(8);  LOG2(9);  LOG2(10); LOG2(11);
1480                             LOG2(12); LOG2(13); LOG2(14); LOG2(15);
1481                             LOG2(16); LOG2(17); LOG2(18); LOG2(19);
1482                             LOG2(20); LOG2(21); LOG2(22); LOG2(23);
1483                             LOG2(24); LOG2(25); LOG2(26); LOG2(27);
1484                             LOG2(28); LOG2(29); LOG2(30); LOG2(31);
1485                         }
1486                         return -1; /* impossible... */
1487                 }
1488         }
1489
1490         return -1;
1491 }
1492
1493 void *expand_item_list(item_list *lp, size_t item_size,
1494                        const char *desc, int incr)
1495 {
1496         /* First time through, 0 <= 0, so list is expanded. */
1497         if (lp->malloced <= lp->count) {
1498                 void *new_ptr;
1499                 size_t new_size = lp->malloced;
1500                 if (incr < 0)
1501                         new_size += -incr; /* increase slowly */
1502                 else if (new_size < (size_t)incr)
1503                         new_size += incr;
1504                 else
1505                         new_size *= 2;
1506                 new_ptr = realloc_array(lp->items, char, new_size * item_size);
1507                 if (verbose >= 4) {
1508                         rprintf(FINFO, "[%s] expand %s to %.0f bytes, did%s move\n",
1509                                 who_am_i(), desc, (double)new_size * item_size,
1510                                 new_ptr == lp->items ? " not" : "");
1511                 }
1512                 if (!new_ptr)
1513                         out_of_memory("expand_item_list");
1514
1515                 lp->items = new_ptr;
1516                 lp->malloced = new_size;
1517         }
1518         return (char*)lp->items + (lp->count++ * item_size);
1519 }