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 daemon_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 #define ENSURE_MEMSPACE(buf, type, sz, req) \
 507         if ((req) > sz && !(buf = realloc_array(buf, type, sz = MAX(sz * 2, req)))) \
 508                 out_of_memory("glob_expand")
 509
 510 static inline void call_glob_match(const char *name, int len, int from_glob,
 511                                    char *arg, int abpos, int fbpos);
 512
 513 static struct glob_data {
 514         char *arg_buf, *filt_buf, **argv;
 515         int absize, fbsize, maxargs, argc;
 516 } glob;
 517
 518 static void glob_match(char *arg, int abpos, int fbpos)
 519 {
 520         int len;
 521         char *slash;
 522
 523         while (*arg == '.' && arg[1] == '/') {
 524                 if (fbpos < 0) {
 525                         ENSURE_MEMSPACE(glob.filt_buf, char, glob.fbsize, glob.absize);
 526                         memcpy(glob.filt_buf, glob.arg_buf, abpos + 1);
 527                         fbpos = abpos;
 528                 }
 529                 ENSURE_MEMSPACE(glob.arg_buf, char, glob.absize, abpos + 3);
 530                 glob.arg_buf[abpos++] = *arg++;
 531                 glob.arg_buf[abpos++] = *arg++;
 532                 glob.arg_buf[abpos] = '\0';
 533         }
 534         if ((slash = strchr(arg, '/')) != NULL) {
 535                 *slash = '\0';
 536                 len = slash - arg;
 537         } else
 538                 len = strlen(arg);
 539         if (strpbrk(arg, "*?[")) {
 540                 struct dirent *di;
 541                 DIR *d;
 542
 543                 if (!(d = opendir(abpos ? glob.arg_buf : ".")))
 544                         return;
 545                 while ((di = readdir(d)) != NULL) {
 546                         char *dname = d_name(di);
 547                         if (dname[0] == '.' && (dname[1] == '\0'
 548                           || (dname[1] == '.' && dname[2] == '\0')))
 549                                 continue;
 550                         if (!wildmatch(arg, dname))
 551                                 continue;
 552                         call_glob_match(dname, strlen(dname), 1,
 553                                         slash ? arg + len + 1 : NULL,
 554                                         abpos, fbpos);
 555                 }
 556                 closedir(d);
 557         } else {
 558                 call_glob_match(arg, len, 0,
 559                                 slash ? arg + len + 1 : NULL,
 560                                 abpos, fbpos);
 561         }
 562         if (slash)
 563                 *slash = '/';
 564 }
 565
 566 static inline void call_glob_match(const char *name, int len, int from_glob,
 567                                    char *arg, int abpos, int fbpos)
 568 {
 569         char *use_buf;
 570
 571         ENSURE_MEMSPACE(glob.arg_buf, char, glob.absize, abpos + len + 2);
 572         memcpy(glob.arg_buf + abpos, name, len);
 573         abpos += len;
 574         glob.arg_buf[abpos] = '\0';
 575
 576         if (fbpos >= 0) {
 577                 ENSURE_MEMSPACE(glob.filt_buf, char, glob.fbsize, fbpos + len + 2);
 578                 memcpy(glob.filt_buf + fbpos, name, len);
 579                 fbpos += len;
 580                 glob.filt_buf[fbpos] = '\0';
 581                 use_buf = glob.filt_buf;
 582         } else
 583                 use_buf = glob.arg_buf;
 584
 585         if (from_glob || (arg && len)) {
 586                 STRUCT_STAT st;
 587                 int is_dir;
 588
 589                 if (do_stat(glob.arg_buf, &st) != 0)
 590                         return;
 591                 is_dir = S_ISDIR(st.st_mode) != 0;
 592                 if (arg && !is_dir)
 593                         return;
 594
 595                 if (daemon_filter_list.head
 596                  && check_filter(&daemon_filter_list, FLOG, use_buf, is_dir) < 0)
 597                         return;
 598         }
 599
 600         if (arg) {
 601                 glob.arg_buf[abpos++] = '/';
 602                 glob.arg_buf[abpos] = '\0';
 603                 if (fbpos >= 0) {
 604                         glob.filt_buf[fbpos++] = '/';
 605                         glob.filt_buf[fbpos] = '\0';
 606                 }
 607                 glob_match(arg, abpos, fbpos);
 608         } else {
 609                 ENSURE_MEMSPACE(glob.argv, char *, glob.maxargs, glob.argc + 1);
 610                 if (!(glob.argv[glob.argc++] = strdup(glob.arg_buf)))
 611                         out_of_memory("glob_match");
 612         }
 613 }
 614
 615 /* This routine performs wild-card expansion of the pathname in "arg".  Any
 616  * daemon-excluded files/dirs will not be matched by the wildcards.  Returns 0
 617  * if a wild-card string is the only returned item (due to matching nothing). */
 618 int glob_expand(const char *arg, char ***argv_p, int *argc_p, int *maxargs_p)
 619 {
 620         int ret, save_argc;
 621         char *s;
 622
 623         if (!arg) {
 624                 if (glob.filt_buf)
 625                         free(glob.filt_buf);
 626                 free(glob.arg_buf);
 627                 memset(&glob, 0, sizeof glob);
 628                 return -1;
 629         }
 630
 631         if (sanitize_paths)
 632                 s = sanitize_path(NULL, arg, "", 0, SP_KEEP_DOT_DIRS);
 633         else {
 634                 s = strdup(arg);
 635                 if (!s)
 636                         out_of_memory("glob_expand");
 637                 clean_fname(s, CFN_KEEP_DOT_DIRS
 638                              | CFN_KEEP_TRAILING_SLASH
 639                              | CFN_COLLAPSE_DOT_DOT_DIRS);
 640         }
 641
 642         ENSURE_MEMSPACE(glob.arg_buf, char, glob.absize, MAXPATHLEN);
 643         *glob.arg_buf = '\0';
 644
 645         glob.argc = save_argc = *argc_p;
 646         glob.argv = *argv_p;
 647         glob.maxargs = *maxargs_p;
 648
 649         ENSURE_MEMSPACE(glob.argv, char *, glob.maxargs, 100);
 650
 651         glob_match(s, 0, -1);
 652
 653         /* The arg didn't match anything, so add the failed arg to the list. */
 654         if (glob.argc == save_argc) {
 655                 ENSURE_MEMSPACE(glob.argv, char *, glob.maxargs, glob.argc + 1);
 656                 glob.argv[glob.argc++] = s;
 657                 ret = 0;
 658         } else {
 659                 free(s);
 660                 ret = 1;
 661         }
 662
 663         *maxargs_p = glob.maxargs;
 664         *argv_p = glob.argv;
 665         *argc_p = glob.argc;
 666
 667         return ret;
 668 }
 669
 670 /* This routine is only used in daemon mode. */
 671 void glob_expand_module(char *base1, char *arg, char ***argv_p, int *argc_p, int *maxargs_p)
 672 {
 673         char *p, *s;
 674         char *base = base1;
 675         int base_len = strlen(base);
 676
 677         if (!arg || !*arg)
 678                 return;
 679
 680         if (strncmp(arg, base, base_len) == 0)
 681                 arg += base_len;
 682
 683         if (!(arg = strdup(arg)))
 684                 out_of_memory("glob_expand_module");
 685
 686         if (asprintf(&base," %s/", base1) <= 0)
 687                 out_of_memory("glob_expand_module");
 688         base_len++;
 689
 690         for (s = arg; *s; s = p + base_len) {
 691                 if ((p = strstr(s, base)) != NULL)
 692                         *p = '\0'; /* split it at this point */
 693                 glob_expand(s, argv_p, argc_p, maxargs_p);
 694                 if (!p)
 695                         break;
 696         }
 697
 698         free(arg);
 699         free(base);
 700 }
 701
 702 /**
 703  * Convert a string to lower case
 704  **/
 705 void strlower(char *s)
 706 {
 707         while (*s) {
 708                 if (isUpper(s))
 709                         *s = toLower(s);
 710                 s++;
 711         }
 712 }
 713
 714 /* Join strings p1 & p2 into "dest" with a guaranteed '/' between them.  (If
 715  * p1 ends with a '/', no extra '/' is inserted.)  Returns the length of both
 716  * strings + 1 (if '/' was inserted), regardless of whether the null-terminated
 717  * string fits into destsize. */
 718 size_t pathjoin(char *dest, size_t destsize, const char *p1, const char *p2)
 719 {
 720         size_t len = strlcpy(dest, p1, destsize);
 721         if (len < destsize - 1) {
 722                 if (!len || dest[len-1] != '/')
 723                         dest[len++] = '/';
 724                 if (len < destsize - 1)
 725                         len += strlcpy(dest + len, p2, destsize - len);
 726                 else {
 727                         dest[len] = '\0';
 728                         len += strlen(p2);
 729                 }
 730         }
 731         else
 732                 len += strlen(p2) + 1; /* Assume we'd insert a '/'. */
 733         return len;
 734 }
 735
 736 /* Join any number of strings together, putting them in "dest".  The return
 737  * value is the length of all the strings, regardless of whether the null-
 738  * terminated whole fits in destsize.  Your list of string pointers must end
 739  * with a NULL to indicate the end of the list. */
 740 size_t stringjoin(char *dest, size_t destsize, ...)
 741 {
 742         va_list ap;
 743         size_t len, ret = 0;
 744         const char *src;
 745
 746         va_start(ap, destsize);
 747         while (1) {
 748                 if (!(src = va_arg(ap, const char *)))
 749                         break;
 750                 len = strlen(src);
 751                 ret += len;
 752                 if (destsize > 1) {
 753                         if (len >= destsize)
 754                                 len = destsize - 1;
 755                         memcpy(dest, src, len);
 756                         destsize -= len;
 757                         dest += len;
 758                 }
 759         }
 760         *dest = '\0';
 761         va_end(ap);
 762
 763         return ret;
 764 }
 765
 766 int count_dir_elements(const char *p)
 767 {
 768         int cnt = 0, new_component = 1;
 769         while (*p) {
 770                 if (*p++ == '/')
 771                         new_component = (*p != '.' || (p[1] != '/' && p[1] != '\0'));
 772                 else if (new_component) {
 773                         new_component = 0;
 774                         cnt++;
 775                 }
 776         }
 777         return cnt;
 778 }
 779
 780 /* Turns multiple adjacent slashes into a single slash, drops all leading or
 781  * interior "." elements unless CFN_KEEP_DOT_DIRS is flagged.  Will also drop
 782  * a trailing '.' after a '/' if CFN_DROP_TRAILING_DOT_DIR is flagged, removes
 783  * a trailing slash (perhaps after removing the aforementioned dot) unless
 784  * CFN_KEEP_TRAILING_SLASH is flagged, and will also collapse ".." elements
 785  * (except at the start) if CFN_COLLAPSE_DOT_DOT_DIRS is flagged.  If the
 786  * resulting name would be empty, returns ".". */
 787 unsigned int clean_fname(char *name, int flags)
 788 {
 789         char *limit = name - 1, *t = name, *f = name;
 790         int anchored;
 791
 792         if (!name)
 793                 return 0;
 794
 795         if ((anchored = *f == '/') != 0)
 796                 *t++ = *f++;
 797         else if (flags & CFN_KEEP_DOT_DIRS && *f == '.' && f[1] == '/') {
 798                 *t++ = *f++;
 799                 *t++ = *f++;
 800         }
 801         while (*f) {
 802                 /* discard extra slashes */
 803                 if (*f == '/') {
 804                         f++;
 805                         continue;
 806                 }
 807                 if (*f == '.') {
 808                         /* discard interior "." dirs */
 809                         if (f[1] == '/' && !(flags & CFN_KEEP_DOT_DIRS)) {
 810                                 f += 2;
 811                                 continue;
 812                         }
 813                         if (f[1] == '\0' && flags & CFN_DROP_TRAILING_DOT_DIR)
 814                                 break;
 815                         /* collapse ".." dirs */
 816                         if (flags & CFN_COLLAPSE_DOT_DOT_DIRS
 817                          && f[1] == '.' && (f[2] == '/' || !f[2])) {
 818                                 char *s = t - 1;
 819                                 if (s == name && anchored) {
 820                                         f += 2;
 821                                         continue;
 822                                 }
 823                                 while (s > limit && *--s != '/') {}
 824                                 if (s != t - 1 && (s < name || *s == '/')) {
 825                                         t = s + 1;
 826                                         f += 2;
 827                                         continue;
 828                                 }
 829                                 limit = t + 2;
 830                         }
 831                 }
 832                 while (*f && (*t++ = *f++) != '/') {}
 833         }
 834
 835         if (t > name+anchored && t[-1] == '/' && !(flags & CFN_KEEP_TRAILING_SLASH))
 836                 t--;
 837         if (t == name)
 838                 *t++ = '.';
 839         *t = '\0';
 840
 841         return t - name;
 842 }
 843
 844 /* Make path appear as if a chroot had occurred.  This handles a leading
 845  * "/" (either removing it or expanding it) and any leading or embedded
 846  * ".." components that attempt to escape past the module's top dir.
 847  *
 848  * If dest is NULL, a buffer is allocated to hold the result.  It is legal
 849  * to call with the dest and the path (p) pointing to the same buffer, but
 850  * rootdir will be ignored to avoid expansion of the string.
 851  *
 852  * The rootdir string contains a value to use in place of a leading slash.
 853  * Specify NULL to get the default of "module_dir".
 854  *
 855  * The depth var is a count of how many '..'s to allow at the start of the
 856  * path.
 857  *
 858  * We also clean the path in a manner similar to clean_fname() but with a
 859  * few differences:
 860  *
 861  * Turns multiple adjacent slashes into a single slash, gets rid of "." dir
 862  * elements (INCLUDING a trailing dot dir), PRESERVES a trailing slash, and
 863  * ALWAYS collapses ".." elements (except for those at the start of the
 864  * string up to "depth" deep).  If the resulting name would be empty,
 865  * change it into a ".". */
 866 char *sanitize_path(char *dest, const char *p, const char *rootdir, int depth,
 867                     int flags)
 868 {
 869         char *start, *sanp;
 870         int rlen = 0, drop_dot_dirs = !relative_paths || !(flags & SP_KEEP_DOT_DIRS);
 871
 872         if (dest != p) {
 873                 int plen = strlen(p);
 874                 if (*p == '/') {
 875                         if (!rootdir)
 876                                 rootdir = module_dir;
 877                         rlen = strlen(rootdir);
 878                         depth = 0;
 879                         p++;
 880                 }
 881                 if (dest) {
 882                         if (rlen + plen + 1 >= MAXPATHLEN)
 883                                 return NULL;
 884                 } else if (!(dest = new_array(char, rlen + plen + 1)))
 885                         out_of_memory("sanitize_path");
 886                 if (rlen) {
 887                         memcpy(dest, rootdir, rlen);
 888                         if (rlen > 1)
 889                                 dest[rlen++] = '/';
 890                 }
 891         }
 892
 893         if (drop_dot_dirs) {
 894                 while (*p == '.' && p[1] == '/')
 895                         p += 2;
 896         }
 897
 898         start = sanp = dest + rlen;
 899         /* This loop iterates once per filename component in p, pointing at
 900          * the start of the name (past any prior slash) for each iteration. */
 901         while (*p) {
 902                 /* discard leading or extra slashes */
 903                 if (*p == '/') {
 904                         p++;
 905                         continue;
 906                 }
 907                 if (drop_dot_dirs) {
 908                         if (*p == '.' && (p[1] == '/' || p[1] == '\0')) {
 909                                 /* skip "." component */
 910                                 p++;
 911                                 continue;
 912                         }
 913                 }
 914                 if (*p == '.' && p[1] == '.' && (p[2] == '/' || p[2] == '\0')) {
 915                         /* ".." component followed by slash or end */
 916                         if (depth <= 0 || sanp != start) {
 917                                 p += 2;
 918                                 if (sanp != start) {
 919                                         /* back up sanp one level */
 920                                         --sanp; /* now pointing at slash */
 921                                         while (sanp > start && sanp[-1] != '/')
 922                                                 sanp--;
 923                                 }
 924                                 continue;
 925                         }
 926                         /* allow depth levels of .. at the beginning */
 927                         depth--;
 928                         /* move the virtual beginning to leave the .. alone */
 929                         start = sanp + 3;
 930                 }
 931                 /* copy one component through next slash */
 932                 while (*p && (*sanp++ = *p++) != '/') {}
 933         }
 934         if (sanp == dest) {
 935                 /* ended up with nothing, so put in "." component */
 936                 *sanp++ = '.';
 937         }
 938         *sanp = '\0';
 939
 940         return dest;
 941 }
 942
 943 /* Like chdir(), but it keeps track of the current directory (in the
 944  * global "curr_dir"), and ensures that the path size doesn't overflow.
 945  * Also cleans the path using the clean_fname() function. */
 946 int change_dir(const char *dir, int set_path_only)
 947 {
 948         static int initialised;
 949         unsigned int len;
 950
 951         if (!initialised) {
 952                 initialised = 1;
 953                 getcwd(curr_dir, sizeof curr_dir - 1);
 954                 curr_dir_len = strlen(curr_dir);
 955         }
 956
 957         if (!dir)       /* this call was probably just to initialize */
 958                 return 0;
 959
 960         len = strlen(dir);
 961         if (len == 1 && *dir == '.')
 962                 return 1;
 963
 964         if (*dir == '/') {
 965                 if (len >= sizeof curr_dir) {
 966                         errno = ENAMETOOLONG;
 967                         return 0;
 968                 }
 969                 if (!set_path_only && chdir(dir))
 970                         return 0;
 971                 memcpy(curr_dir, dir, len + 1);
 972         } else {
 973                 if (curr_dir_len + 1 + len >= sizeof curr_dir) {
 974                         errno = ENAMETOOLONG;
 975                         return 0;
 976                 }
 977                 curr_dir[curr_dir_len] = '/';
 978                 memcpy(curr_dir + curr_dir_len + 1, dir, len + 1);
 979
 980                 if (!set_path_only && chdir(curr_dir)) {
 981                         curr_dir[curr_dir_len] = '\0';
 982                         return 0;
 983                 }
 984         }
 985
 986         curr_dir_len = clean_fname(curr_dir, CFN_COLLAPSE_DOT_DOT_DIRS);
 987         if (sanitize_paths) {
 988                 if (module_dirlen > curr_dir_len)
 989                         module_dirlen = curr_dir_len;
 990                 curr_dir_depth = count_dir_elements(curr_dir + module_dirlen);
 991         }
 992
 993         if (verbose >= 5 && !set_path_only)
 994                 rprintf(FINFO, "[%s] change_dir(%s)\n", who_am_i(), curr_dir);
 995
 996         return 1;
 997 }
 998
 999 /**
1000  * Return a quoted string with the full pathname of the indicated filename.
1001  * The string " (in MODNAME)" may also be appended.  The returned pointer
1002  * remains valid until the next time full_fname() is called.
1003  **/
1004 char *full_fname(const char *fn)
1005 {
1006         static char *result = NULL;
1007         char *m1, *m2, *m3;
1008         char *p1, *p2;
1009
1010         if (result)
1011                 free(result);
1012
1013         if (*fn == '/')
1014                 p1 = p2 = "";
1015         else {
1016                 p1 = curr_dir + module_dirlen;
1017                 for (p2 = p1; *p2 == '/'; p2++) {}
1018                 if (*p2)
1019                         p2 = "/";
1020         }
1021         if (module_id >= 0) {
1022                 m1 = " (in ";
1023                 m2 = lp_name(module_id);
1024                 m3 = ")";
1025         } else
1026                 m1 = m2 = m3 = "";
1027
1028         if (asprintf(&result, "\"%s%s%s\"%s%s%s", p1, p2, fn, m1, m2, m3) <= 0)
1029                 out_of_memory("full_fname");
1030
1031         return result;
1032 }
1033
1034 static char partial_fname[MAXPATHLEN];
1035
1036 char *partial_dir_fname(const char *fname)
1037 {
1038         char *t = partial_fname;
1039         int sz = sizeof partial_fname;
1040         const char *fn;
1041
1042         if ((fn = strrchr(fname, '/')) != NULL) {
1043                 fn++;
1044                 if (*partial_dir != '/') {
1045                         int len = fn - fname;
1046                         strncpy(t, fname, len); /* safe */
1047                         t += len;
1048                         sz -= len;
1049                 }
1050         } else
1051                 fn = fname;
1052         if ((int)pathjoin(t, sz, partial_dir, fn) >= sz)
1053                 return NULL;
1054         if (daemon_filter_list.head) {
1055                 t = strrchr(partial_fname, '/');
1056                 *t = '\0';
1057                 if (check_filter(&daemon_filter_list, FLOG, partial_fname, 1) < 0)
1058                         return NULL;
1059                 *t = '/';
1060                 if (check_filter(&daemon_filter_list, FLOG, partial_fname, 0) < 0)
1061                         return NULL;
1062         }
1063
1064         return partial_fname;
1065 }
1066
1067 /* If no --partial-dir option was specified, we don't need to do anything
1068  * (the partial-dir is essentially '.'), so just return success. */
1069 int handle_partial_dir(const char *fname, int create)
1070 {
1071         char *fn, *dir;
1072
1073         if (fname != partial_fname)
1074                 return 1;
1075         if (!create && *partial_dir == '/')
1076                 return 1;
1077         if (!(fn = strrchr(partial_fname, '/')))
1078                 return 1;
1079
1080         *fn = '\0';
1081         dir = partial_fname;
1082         if (create) {
1083                 STRUCT_STAT st;
1084                 int statret = do_lstat(dir, &st);
1085                 if (statret == 0 && !S_ISDIR(st.st_mode)) {
1086                         if (do_unlink(dir) < 0)
1087                                 return 0;
1088                         statret = -1;
1089                 }
1090                 if (statret < 0 && do_mkdir(dir, 0700) < 0)
1091                         return 0;
1092         } else
1093                 do_rmdir(dir);
1094         *fn = '/';
1095
1096         return 1;
1097 }
1098
1099 /**
1100  * Determine if a symlink points outside the current directory tree.
1101  * This is considered "unsafe" because e.g. when mirroring somebody
1102  * else's machine it might allow them to establish a symlink to
1103  * /etc/passwd, and then read it through a web server.
1104  *
1105  * Null symlinks and absolute symlinks are always unsafe.
1106  *
1107  * Basically here we are concerned with symlinks whose target contains
1108  * "..", because this might cause us to walk back up out of the
1109  * transferred directory.  We are not allowed to go back up and
1110  * reenter.
1111  *
1112  * @param dest Target of the symlink in question.
1113  *
1114  * @param src Top source directory currently applicable.  Basically this
1115  * is the first parameter to rsync in a simple invocation, but it's
1116  * modified by flist.c in slightly complex ways.
1117  *
1118  * @retval True if unsafe
1119  * @retval False is unsafe
1120  *
1121  * @sa t_unsafe.c
1122  **/
1123 int unsafe_symlink(const char *dest, const char *src)
1124 {
1125         const char *name, *slash;
1126         int depth = 0;
1127
1128         /* all absolute and null symlinks are unsafe */
1129         if (!dest || !*dest || *dest == '/')
1130                 return 1;
1131
1132         /* find out what our safety margin is */
1133         for (name = src; (slash = strchr(name, '/')) != 0; name = slash+1) {
1134                 if (strncmp(name, "../", 3) == 0) {
1135                         depth = 0;
1136                 } else if (strncmp(name, "./", 2) == 0) {
1137                         /* nothing */
1138                 } else {
1139                         depth++;
1140                 }
1141         }
1142         if (strcmp(name, "..") == 0)
1143                 depth = 0;
1144
1145         for (name = dest; (slash = strchr(name, '/')) != 0; name = slash+1) {
1146                 if (strncmp(name, "../", 3) == 0) {
1147                         /* if at any point we go outside the current directory
1148                            then stop - it is unsafe */
1149                         if (--depth < 0)
1150                                 return 1;
1151                 } else if (strncmp(name, "./", 2) == 0) {
1152                         /* nothing */
1153                 } else {
1154                         depth++;
1155                 }
1156         }
1157         if (strcmp(name, "..") == 0)
1158                 depth--;
1159
1160         return (depth < 0);
1161 }
1162
1163 /* Return the int64 number as a string.  If the --human-readable option was
1164  * specified, we may output the number in K, M, or G units.  We can return
1165  * up to 4 buffers at a time. */
1166 char *human_num(int64 num)
1167 {
1168         static char bufs[4][128]; /* more than enough room */
1169         static unsigned int n;
1170         char *s;
1171
1172         n = (n + 1) % (sizeof bufs / sizeof bufs[0]);
1173
1174         if (human_readable) {
1175                 char units = '\0';
1176                 int mult = human_readable == 1 ? 1000 : 1024;
1177                 double dnum = 0;
1178                 if (num > mult*mult*mult) {
1179                         dnum = (double)num / (mult*mult*mult);
1180                         units = 'G';
1181                 } else if (num > mult*mult) {
1182                         dnum = (double)num / (mult*mult);
1183                         units = 'M';
1184                 } else if (num > mult) {
1185                         dnum = (double)num / mult;
1186                         units = 'K';
1187                 }
1188                 if (units) {
1189                         snprintf(bufs[n], sizeof bufs[0], "%.2f%c", dnum, units);
1190                         return bufs[n];
1191                 }
1192         }
1193
1194         s = bufs[n] + sizeof bufs[0] - 1;
1195         *s = '\0';
1196
1197         if (!num)
1198                 *--s = '0';
1199         while (num) {
1200                 *--s = (char)(num % 10) + '0';
1201                 num /= 10;
1202         }
1203         return s;
1204 }
1205
1206 /* Return the double number as a string.  If the --human-readable option was
1207  * specified, we may output the number in K, M, or G units.  We use a buffer
1208  * from human_num() to return our result. */
1209 char *human_dnum(double dnum, int decimal_digits)
1210 {
1211         char *buf = human_num(dnum);
1212         int len = strlen(buf);
1213         if (isDigit(buf + len - 1)) {
1214                 /* There's extra room in buf prior to the start of the num. */
1215                 buf -= decimal_digits + 1;
1216                 snprintf(buf, len + decimal_digits + 2, "%.*f", decimal_digits, dnum);
1217         }
1218         return buf;
1219 }
1220
1221 /* Return the date and time as a string.  Some callers tweak returned buf. */
1222 char *timestring(time_t t)
1223 {
1224         static char TimeBuf[200];
1225         struct tm *tm = localtime(&t);
1226         char *p;
1227
1228 #ifdef HAVE_STRFTIME
1229         strftime(TimeBuf, sizeof TimeBuf - 1, "%Y/%m/%d %H:%M:%S", tm);
1230 #else
1231         strlcpy(TimeBuf, asctime(tm), sizeof TimeBuf);
1232 #endif
1233
1234         if ((p = strchr(TimeBuf, '\n')) != NULL)
1235                 *p = '\0';
1236
1237         return TimeBuf;
1238 }
1239
1240 /**
1241  * Sleep for a specified number of milliseconds.
1242  *
1243  * Always returns TRUE.  (In the future it might return FALSE if
1244  * interrupted.)
1245  **/
1246 int msleep(int t)
1247 {
1248         int tdiff = 0;
1249         struct timeval tval, t1, t2;
1250
1251         gettimeofday(&t1, NULL);
1252
1253         while (tdiff < t) {
1254                 tval.tv_sec = (t-tdiff)/1000;
1255                 tval.tv_usec = 1000*((t-tdiff)%1000);
1256
1257                 errno = 0;
1258                 select(0,NULL,NULL, NULL, &tval);
1259
1260                 gettimeofday(&t2, NULL);
1261                 tdiff = (t2.tv_sec - t1.tv_sec)*1000 +
1262                         (t2.tv_usec - t1.tv_usec)/1000;
1263         }
1264
1265         return True;
1266 }
1267
1268 /* Determine if two time_t values are equivalent (either exact, or in
1269  * the modification timestamp window established by --modify-window).
1270  *
1271  * @retval 0 if the times should be treated as the same
1272  *
1273  * @retval +1 if the first is later
1274  *
1275  * @retval -1 if the 2nd is later
1276  **/
1277 int cmp_time(time_t file1, time_t file2)
1278 {
1279         if (file2 > file1) {
1280                 if (file2 - file1 <= modify_window)
1281                         return 0;
1282                 return -1;
1283         }
1284         if (file1 - file2 <= modify_window)
1285                 return 0;
1286         return 1;
1287 }
1288
1289
1290 #ifdef __INSURE__XX
1291 #include <dlfcn.h>
1292
1293 /**
1294    This routine is a trick to immediately catch errors when debugging
1295    with insure. A xterm with a gdb is popped up when insure catches
1296    a error. It is Linux specific.
1297 **/
1298 int _Insure_trap_error(int a1, int a2, int a3, int a4, int a5, int a6)
1299 {
1300         static int (*fn)();
1301         int ret;
1302         char *cmd;
1303
1304         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'",
1305                 getpid(), getpid(), getpid());
1306
1307         if (!fn) {
1308                 static void *h;
1309                 h = dlopen("/usr/local/parasoft/insure++lite/lib.linux2/libinsure.so", RTLD_LAZY);
1310                 fn = dlsym(h, "_Insure_trap_error");
1311         }
1312
1313         ret = fn(a1, a2, a3, a4, a5, a6);
1314
1315         system(cmd);
1316
1317         free(cmd);
1318
1319         return ret;
1320 }
1321 #endif
1322
1323 #define MALLOC_MAX 0x40000000
1324
1325 void *_new_array(unsigned long num, unsigned int size, int use_calloc)
1326 {
1327         if (num >= MALLOC_MAX/size)
1328                 return NULL;
1329         return use_calloc ? calloc(num, size) : malloc(num * size);
1330 }
1331
1332 void *_realloc_array(void *ptr, unsigned int size, size_t num)
1333 {
1334         if (num >= MALLOC_MAX/size)
1335                 return NULL;
1336         if (!ptr)
1337                 return malloc(size * num);
1338         return realloc(ptr, size * num);
1339 }
1340
1341 /* Take a filename and filename length and return the most significant
1342  * filename suffix we can find.  This ignores suffixes such as "~",
1343  * ".bak", ".orig", ".~1~", etc. */
1344 const char *find_filename_suffix(const char *fn, int fn_len, int *len_ptr)
1345 {
1346         const char *suf, *s;
1347         BOOL had_tilde;
1348         int s_len;
1349
1350         /* One or more dots at the start aren't a suffix. */
1351         while (fn_len && *fn == '.') fn++, fn_len--;
1352
1353         /* Ignore the ~ in a "foo~" filename. */
1354         if (fn_len > 1 && fn[fn_len-1] == '~')
1355                 fn_len--, had_tilde = True;
1356         else
1357                 had_tilde = False;
1358
1359         /* Assume we don't find an suffix. */
1360         suf = "";
1361         *len_ptr = 0;
1362
1363         /* Find the last significant suffix. */
1364         for (s = fn + fn_len; fn_len > 1; ) {
1365                 while (*--s != '.' && s != fn) {}
1366                 if (s == fn)
1367                         break;
1368                 s_len = fn_len - (s - fn);
1369                 fn_len = s - fn;
1370                 if (s_len == 4) {
1371                         if (strcmp(s+1, "bak") == 0
1372                          || strcmp(s+1, "old") == 0)
1373                                 continue;
1374                 } else if (s_len == 5) {
1375                         if (strcmp(s+1, "orig") == 0)
1376                                 continue;
1377                 } else if (s_len > 2 && had_tilde
1378                     && s[1] == '~' && isDigit(s + 2))
1379                         continue;
1380                 *len_ptr = s_len;
1381                 suf = s;
1382                 if (s_len == 1)
1383                         break;
1384                 /* Determine if the suffix is all digits. */
1385                 for (s++, s_len--; s_len > 0; s++, s_len--) {
1386                         if (!isDigit(s))
1387                                 return suf;
1388                 }
1389                 /* An all-digit suffix may not be that signficant. */
1390                 s = suf;
1391         }
1392
1393         return suf;
1394 }
1395
1396 /* This is an implementation of the Levenshtein distance algorithm.  It
1397  * was implemented to avoid needing a two-dimensional matrix (to save
1398  * memory).  It was also tweaked to try to factor in the ASCII distance
1399  * between changed characters as a minor distance quantity.  The normal
1400  * Levenshtein units of distance (each signifying a single change between
1401  * the two strings) are defined as a "UNIT". */
1402
1403 #define UNIT (1 << 16)
1404
1405 uint32 fuzzy_distance(const char *s1, int len1, const char *s2, int len2)
1406 {
1407         uint32 a[MAXPATHLEN], diag, above, left, diag_inc, above_inc, left_inc;
1408         int32 cost;
1409         int i1, i2;
1410
1411         if (!len1 || !len2) {
1412                 if (!len1) {
1413                         s1 = s2;
1414                         len1 = len2;
1415                 }
1416                 for (i1 = 0, cost = 0; i1 < len1; i1++)
1417                         cost += s1[i1];
1418                 return (int32)len1 * UNIT + cost;
1419         }
1420
1421         for (i2 = 0; i2 < len2; i2++)
1422                 a[i2] = (i2+1) * UNIT;
1423
1424         for (i1 = 0; i1 < len1; i1++) {
1425                 diag = i1 * UNIT;
1426                 above = (i1+1) * UNIT;
1427                 for (i2 = 0; i2 < len2; i2++) {
1428                         left = a[i2];
1429                         if ((cost = *((uchar*)s1+i1) - *((uchar*)s2+i2)) != 0) {
1430                                 if (cost < 0)
1431                                         cost = UNIT - cost;
1432                                 else
1433                                         cost = UNIT + cost;
1434                         }
1435                         diag_inc = diag + cost;
1436                         left_inc = left + UNIT + *((uchar*)s1+i1);
1437                         above_inc = above + UNIT + *((uchar*)s2+i2);
1438                         a[i2] = above = left < above
1439                               ? (left_inc < diag_inc ? left_inc : diag_inc)
1440                               : (above_inc < diag_inc ? above_inc : diag_inc);
1441                         diag = left;
1442                 }
1443         }
1444
1445         return a[len2-1];
1446 }
1447
1448 #define BB_SLOT_SIZE     (16*1024)          /* Desired size in bytes */
1449 #define BB_PER_SLOT_BITS (BB_SLOT_SIZE * 8) /* Number of bits per slot */
1450 #define BB_PER_SLOT_INTS (BB_SLOT_SIZE / 4) /* Number of int32s per slot */
1451
1452 struct bitbag {
1453     uint32 **bits;
1454     int slot_cnt;
1455 };
1456
1457 struct bitbag *bitbag_create(int max_ndx)
1458 {
1459         struct bitbag *bb = new(struct bitbag);
1460         bb->slot_cnt = (max_ndx + BB_PER_SLOT_BITS - 1) / BB_PER_SLOT_BITS;
1461
1462         if (!(bb->bits = (uint32**)calloc(bb->slot_cnt, sizeof (uint32*))))
1463                 out_of_memory("bitbag_create");
1464
1465         return bb;
1466 }
1467
1468 void bitbag_set_bit(struct bitbag *bb, int ndx)
1469 {
1470         int slot = ndx / BB_PER_SLOT_BITS;
1471         ndx %= BB_PER_SLOT_BITS;
1472
1473         if (!bb->bits[slot]) {
1474                 if (!(bb->bits[slot] = (uint32*)calloc(BB_PER_SLOT_INTS, 4)))
1475                         out_of_memory("bitbag_set_bit");
1476         }
1477
1478         bb->bits[slot][ndx/32] |= 1u << (ndx % 32);
1479 }
1480
1481 #if 0 /* not needed yet */
1482 void bitbag_clear_bit(struct bitbag *bb, int ndx)
1483 {
1484         int slot = ndx / BB_PER_SLOT_BITS;
1485         ndx %= BB_PER_SLOT_BITS;
1486
1487         if (!bb->bits[slot])
1488                 return;
1489
1490         bb->bits[slot][ndx/32] &= ~(1u << (ndx % 32));
1491 }
1492
1493 int bitbag_check_bit(struct bitbag *bb, int ndx)
1494 {
1495         int slot = ndx / BB_PER_SLOT_BITS;
1496         ndx %= BB_PER_SLOT_BITS;
1497
1498         if (!bb->bits[slot])
1499                 return 0;
1500
1501         return bb->bits[slot][ndx/32] & (1u << (ndx % 32)) ? 1 : 0;
1502 }
1503 #endif
1504
1505 /* Call this with -1 to start checking from 0.  Returns -1 at the end. */
1506 int bitbag_next_bit(struct bitbag *bb, int after)
1507 {
1508         uint32 bits, mask;
1509         int i, ndx = after + 1;
1510         int slot = ndx / BB_PER_SLOT_BITS;
1511         ndx %= BB_PER_SLOT_BITS;
1512
1513         mask = (1u << (ndx % 32)) - 1;
1514         for (i = ndx / 32; slot < bb->slot_cnt; slot++, i = mask = 0) {
1515                 if (!bb->bits[slot])
1516                         continue;
1517                 for ( ; i < BB_PER_SLOT_INTS; i++, mask = 0) {
1518                         if (!(bits = bb->bits[slot][i] & ~mask))
1519                                 continue;
1520                         /* The xor magic figures out the lowest enabled bit in
1521                          * bits, and the switch quickly computes log2(bit). */
1522                         switch (bits ^ (bits & (bits-1))) {
1523 #define LOG2(n) case 1u << n: return slot*BB_PER_SLOT_BITS + i*32 + n
1524                             LOG2(0);  LOG2(1);  LOG2(2);  LOG2(3);
1525                             LOG2(4);  LOG2(5);  LOG2(6);  LOG2(7);
1526                             LOG2(8);  LOG2(9);  LOG2(10); LOG2(11);
1527                             LOG2(12); LOG2(13); LOG2(14); LOG2(15);
1528                             LOG2(16); LOG2(17); LOG2(18); LOG2(19);
1529                             LOG2(20); LOG2(21); LOG2(22); LOG2(23);
1530                             LOG2(24); LOG2(25); LOG2(26); LOG2(27);
1531                             LOG2(28); LOG2(29); LOG2(30); LOG2(31);
1532                         }
1533                         return -1; /* impossible... */
1534                 }
1535         }
1536
1537         return -1;
1538 }
1539
1540 void *expand_item_list(item_list *lp, size_t item_size,
1541                        const char *desc, int incr)
1542 {
1543         /* First time through, 0 <= 0, so list is expanded. */
1544         if (lp->malloced <= lp->count) {
1545                 void *new_ptr;
1546                 size_t new_size = lp->malloced;
1547                 if (incr < 0)
1548                         new_size += -incr; /* increase slowly */
1549                 else if (new_size < (size_t)incr)
1550                         new_size += incr;
1551                 else
1552                         new_size *= 2;
1553                 if (new_size < lp->malloced)
1554                         overflow_exit("expand_item_list");
1555                 /* Using _realloc_array() lets us pass the size, not a type. */
1556                 new_ptr = _realloc_array(lp->items, item_size, new_size);
1557                 if (verbose >= 4) {
1558                         rprintf(FINFO, "[%s] expand %s to %.0f bytes, did%s move\n",
1559                                 who_am_i(), desc, (double)new_size * item_size,
1560                                 new_ptr == lp->items ? " not" : "");
1561                 }
1562                 if (!new_ptr)
1563                         out_of_memory("expand_item_list");
1564
1565                 lp->items = new_ptr;
1566                 lp->malloced = new_size;
1567         }
1568         return (char*)lp->items + (lp->count++ * item_size);
1569 }