lib/util/util.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Samba utility functions
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Jeremy Allison 2001-2002
   6    Copyright (C) Simo Sorce 2001-2011
   7    Copyright (C) Jim McDonough (jmcd@us.ibm.com)  2003.
   8    Copyright (C) James J Myers 2003
   9    Copyright (C) Volker Lendecke 2010
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 3 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23 */
  24
  25 #include "includes.h"
  26 #include "system/network.h"
  27 #include "system/filesys.h"
  28 #include "system/locale.h"
  29 #include "system/shmem.h"
  30 #include "system/passwd.h"
  31
  32 #undef malloc
  33 #undef strcasecmp
  34 #undef strncasecmp
  35 #undef strdup
  36 #undef realloc
  37 #undef calloc
  38
  39 /**
  40  * @file
  41  * @brief Misc utility functions
  42  */
  43
  44 /**
  45  Find a suitable temporary directory. The result should be copied immediately
  46  as it may be overwritten by a subsequent call.
  47 **/
  48 _PUBLIC_ const char *tmpdir(void)
  49 {
  50         char *p;
  51         if ((p = getenv("TMPDIR")))
  52                 return p;
  53         return "/tmp";
  54 }
  55
  56
  57 /**
  58  Create a tmp file, open it and immediately unlink it.
  59  If dir is NULL uses tmpdir()
  60  Returns the file descriptor or -1 on error.
  61 **/
  62 int create_unlink_tmp(const char *dir)
  63 {
  64         char *fname;
  65         int fd;
  66
  67         if (!dir) {
  68                 dir = tmpdir();
  69         }
  70
  71         fname = talloc_asprintf(talloc_tos(), "%s/listenerlock_XXXXXX", dir);
  72         if (fname == NULL) {
  73                 errno = ENOMEM;
  74                 return -1;
  75         }
  76         fd = mkstemp(fname);
  77         if (fd == -1) {
  78                 TALLOC_FREE(fname);
  79                 return -1;
  80         }
  81         if (unlink(fname) == -1) {
  82                 int sys_errno = errno;
  83                 close(fd);
  84                 TALLOC_FREE(fname);
  85                 errno = sys_errno;
  86                 return -1;
  87         }
  88         TALLOC_FREE(fname);
  89         return fd;
  90 }
  91
  92
  93 /**
  94  Check if a file exists - call vfs_file_exist for samba files.
  95 **/
  96 _PUBLIC_ bool file_exist(const char *fname)
  97 {
  98         struct stat st;
  99
 100         if (stat(fname, &st) != 0) {
 101                 return false;
 102         }
 103
 104         return ((S_ISREG(st.st_mode)) || (S_ISFIFO(st.st_mode)));
 105 }
 106
 107 /**
 108  Check a files mod time.
 109 **/
 110
 111 _PUBLIC_ time_t file_modtime(const char *fname)
 112 {
 113         struct stat st;
 114
 115         if (stat(fname,&st) != 0)
 116                 return(0);
 117
 118         return(st.st_mtime);
 119 }
 120
 121 /**
 122  Check if a directory exists.
 123 **/
 124
 125 _PUBLIC_ bool directory_exist(const char *dname)
 126 {
 127         struct stat st;
 128         bool ret;
 129
 130         if (stat(dname,&st) != 0) {
 131                 return false;
 132         }
 133
 134         ret = S_ISDIR(st.st_mode);
 135         if(!ret)
 136                 errno = ENOTDIR;
 137         return ret;
 138 }
 139
 140 /**
 141  * Try to create the specified directory if it didn't exist.
 142  *
 143  * @retval true if the directory already existed and has the right permissions
 144  * or was successfully created.
 145  */
 146 _PUBLIC_ bool directory_create_or_exist(const char *dname,
 147                                         uid_t uid,
 148                                         mode_t dir_perms)
 149 {
 150         int ret;
 151         struct stat st;
 152
 153         ret = lstat(dname, &st);
 154         if (ret == -1) {
 155                 mode_t old_umask;
 156
 157                 if (errno != ENOENT) {
 158                         DEBUG(0, ("lstat failed on directory %s: %s\n",
 159                                   dname, strerror(errno)));
 160                         return false;
 161                 }
 162
 163                 /* Create directory */
 164                 old_umask = umask(0);
 165                 ret = mkdir(dname, dir_perms);
 166                 if (ret == -1 && errno != EEXIST) {
 167                         DEBUG(0, ("mkdir failed on directory "
 168                                   "%s: %s\n", dname,
 169                                   strerror(errno)));
 170                         umask(old_umask);
 171                         return false;
 172                 }
 173                 umask(old_umask);
 174
 175                 ret = lstat(dname, &st);
 176                 if (ret == -1) {
 177                         DEBUG(0, ("lstat failed on created directory %s: %s\n",
 178                                   dname, strerror(errno)));
 179                         return false;
 180                 }
 181         }
 182
 183         return true;
 184 }
 185
 186 /**
 187  * @brief Try to create a specified directory if it doesn't exist.
 188  *
 189  * The function creates a directory with the given uid and permissions if it
 190  * doesn't exixt. If it exists it makes sure the uid and permissions are
 191  * correct and it will fail if they are different.
 192  *
 193  * @param[in]  dname  The directory to create.
 194  *
 195  * @param[in]  uid    The uid the directory needs to belong too.
 196  *
 197  * @param[in]  dir_perms  The expected permissions of the directory.
 198  *
 199  * @return True on success, false on error.
 200  */
 201 _PUBLIC_ bool directory_create_or_exist_strict(const char *dname,
 202                                                uid_t uid,
 203                                                mode_t dir_perms)
 204 {
 205         struct stat st;
 206         bool ok;
 207         int rc;
 208
 209         ok = directory_create_or_exist(dname, uid, dir_perms);
 210         if (!ok) {
 211                 return false;
 212         }
 213
 214         rc = lstat(dname, &st);
 215         if (rc == -1) {
 216                 DEBUG(0, ("lstat failed on created directory %s: %s\n",
 217                           dname, strerror(errno)));
 218                 return false;
 219         }
 220
 221         /* Check ownership and permission on existing directory */
 222         if (!S_ISDIR(st.st_mode)) {
 223                 DEBUG(0, ("directory %s isn't a directory\n",
 224                         dname));
 225                 return false;
 226         }
 227         if (st.st_uid != uid && !uwrap_enabled()) {
 228                 DEBUG(0, ("invalid ownership on directory "
 229                           "%s\n", dname));
 230                 return false;
 231         }
 232         if ((st.st_mode & 0777) != dir_perms) {
 233                 DEBUG(0, ("invalid permissions on directory "
 234                           "'%s': has 0%o should be 0%o\n", dname,
 235                           (st.st_mode & 0777), dir_perms));
 236                 return false;
 237         }
 238
 239         return true;
 240 }
 241
 242
 243 /**
 244  Sleep for a specified number of milliseconds.
 245 **/
 246
 247 _PUBLIC_ void smb_msleep(unsigned int t)
 248 {
 249 #if defined(HAVE_NANOSLEEP)
 250         struct timespec ts;
 251         int ret;
 252
 253         ts.tv_sec = t/1000;
 254         ts.tv_nsec = 1000000*(t%1000);
 255
 256         do {
 257                 errno = 0;
 258                 ret = nanosleep(&ts, &ts);
 259         } while (ret < 0 && errno == EINTR && (ts.tv_sec > 0 || ts.tv_nsec > 0));
 260 #else
 261         unsigned int tdiff=0;
 262         struct timeval tval,t1,t2;
 263         fd_set fds;
 264
 265         GetTimeOfDay(&t1);
 266         t2 = t1;
 267
 268         while (tdiff < t) {
 269                 tval.tv_sec = (t-tdiff)/1000;
 270                 tval.tv_usec = 1000*((t-tdiff)%1000);
 271
 272                 /* Never wait for more than 1 sec. */
 273                 if (tval.tv_sec > 1) {
 274                         tval.tv_sec = 1;
 275                         tval.tv_usec = 0;
 276                 }
 277
 278                 FD_ZERO(&fds);
 279                 errno = 0;
 280                 select(0,&fds,NULL,NULL,&tval);
 281
 282                 GetTimeOfDay(&t2);
 283                 if (t2.tv_sec < t1.tv_sec) {
 284                         /* Someone adjusted time... */
 285                         t1 = t2;
 286                 }
 287
 288                 tdiff = usec_time_diff(&t2,&t1)/1000;
 289         }
 290 #endif
 291 }
 292
 293 /**
 294  Get my own name, return in talloc'ed storage.
 295 **/
 296
 297 _PUBLIC_ char *get_myname(TALLOC_CTX *ctx)
 298 {
 299         char *p;
 300         char hostname[HOST_NAME_MAX];
 301
 302         /* get my host name */
 303         if (gethostname(hostname, sizeof(hostname)) == -1) {
 304                 DEBUG(0,("gethostname failed\n"));
 305                 return NULL;
 306         }
 307
 308         /* Ensure null termination. */
 309         hostname[sizeof(hostname)-1] = '\0';
 310
 311         /* split off any parts after an initial . */
 312         p = strchr_m(hostname, '.');
 313         if (p) {
 314                 *p = 0;
 315         }
 316
 317         return talloc_strdup(ctx, hostname);
 318 }
 319
 320 /**
 321  Check if a process exists. Does this work on all unixes?
 322 **/
 323
 324 _PUBLIC_ bool process_exists_by_pid(pid_t pid)
 325 {
 326         /* Doing kill with a non-positive pid causes messages to be
 327          * sent to places we don't want. */
 328         if (pid <= 0) {
 329                 return false;
 330         }
 331         return(kill(pid,0) == 0 || errno != ESRCH);
 332 }
 333
 334 /**
 335  Simple routine to do POSIX file locking. Cruft in NFS and 64->32 bit mapping
 336  is dealt with in posix.c
 337 **/
 338
 339 _PUBLIC_ bool fcntl_lock(int fd, int op, off_t offset, off_t count, int type)
 340 {
 341         struct flock lock;
 342         int ret;
 343
 344         DEBUG(8,("fcntl_lock %d %d %.0f %.0f %d\n",fd,op,(double)offset,(double)count,type));
 345
 346         lock.l_type = type;
 347         lock.l_whence = SEEK_SET;
 348         lock.l_start = offset;
 349         lock.l_len = count;
 350         lock.l_pid = 0;
 351
 352         ret = fcntl(fd,op,&lock);
 353
 354         if (ret == -1 && errno != 0)
 355                 DEBUG(3,("fcntl_lock: fcntl lock gave errno %d (%s)\n",errno,strerror(errno)));
 356
 357         /* a lock query */
 358         if (op == F_GETLK) {
 359                 if ((ret != -1) &&
 360                                 (lock.l_type != F_UNLCK) &&
 361                                 (lock.l_pid != 0) &&
 362                                 (lock.l_pid != getpid())) {
 363                         DEBUG(3,("fcntl_lock: fd %d is locked by pid %d\n",fd,(int)lock.l_pid));
 364                         return true;
 365                 }
 366
 367                 /* it must be not locked or locked by me */
 368                 return false;
 369         }
 370
 371         /* a lock set or unset */
 372         if (ret == -1) {
 373                 DEBUG(3,("fcntl_lock: lock failed at offset %.0f count %.0f op %d type %d (%s)\n",
 374                         (double)offset,(double)count,op,type,strerror(errno)));
 375                 return false;
 376         }
 377
 378         /* everything went OK */
 379         DEBUG(8,("fcntl_lock: Lock call successful\n"));
 380
 381         return true;
 382 }
 383
 384 static void debugadd_cb(const char *buf, void *private_data)
 385 {
 386         int *plevel = (int *)private_data;
 387         DEBUGADD(*plevel, ("%s", buf));
 388 }
 389
 390 void print_asc_cb(const uint8_t *buf, int len,
 391                   void (*cb)(const char *buf, void *private_data),
 392                   void *private_data)
 393 {
 394         int i;
 395         char s[2];
 396         s[1] = 0;
 397
 398         for (i=0; i<len; i++) {
 399                 s[0] = isprint(buf[i]) ? buf[i] : '.';
 400                 cb(s, private_data);
 401         }
 402 }
 403
 404 void print_asc(int level, const uint8_t *buf,int len)
 405 {
 406         print_asc_cb(buf, len, debugadd_cb, &level);
 407 }
 408
 409 /**
 410  * Write dump of binary data to a callback
 411  */
 412 void dump_data_cb(const uint8_t *buf, int len,
 413                   bool omit_zero_bytes,
 414                   void (*cb)(const char *buf, void *private_data),
 415                   void *private_data)
 416 {
 417         int i=0;
 418         static const uint8_t empty[16] = { 0, };
 419         bool skipped = false;
 420         char tmp[16];
 421
 422         if (len<=0) return;
 423
 424         for (i=0;i<len;) {
 425
 426                 if (i%16 == 0) {
 427                         if ((omit_zero_bytes == true) &&
 428                             (i > 0) &&
 429                             (len > i+16) &&
 430                             (memcmp(&buf[i], &empty, 16) == 0))
 431                         {
 432                                 i +=16;
 433                                 continue;
 434                         }
 435
 436                         if (i<len)  {
 437                                 snprintf(tmp, sizeof(tmp), "[%04X] ", i);
 438                                 cb(tmp, private_data);
 439                         }
 440                 }
 441
 442                 snprintf(tmp, sizeof(tmp), "%02X ", (int)buf[i]);
 443                 cb(tmp, private_data);
 444                 i++;
 445                 if (i%8 == 0) {
 446                         cb("  ", private_data);
 447                 }
 448                 if (i%16 == 0) {
 449
 450                         print_asc_cb(&buf[i-16], 8, cb, private_data);
 451                         cb(" ", private_data);
 452                         print_asc_cb(&buf[i-8], 8, cb, private_data);
 453                         cb("\n", private_data);
 454
 455                         if ((omit_zero_bytes == true) &&
 456                             (len > i+16) &&
 457                             (memcmp(&buf[i], &empty, 16) == 0)) {
 458                                 if (!skipped) {
 459                                         cb("skipping zero buffer bytes\n",
 460                                            private_data);
 461                                         skipped = true;
 462                                 }
 463                         }
 464                 }
 465         }
 466
 467         if (i%16) {
 468                 int n;
 469                 n = 16 - (i%16);
 470                 cb(" ", private_data);
 471                 if (n>8) {
 472                         cb(" ", private_data);
 473                 }
 474                 while (n--) {
 475                         cb("   ", private_data);
 476                 }
 477                 n = MIN(8,i%16);
 478                 print_asc_cb(&buf[i-(i%16)], n, cb, private_data);
 479                 cb(" ", private_data);
 480                 n = (i%16) - n;
 481                 if (n>0) {
 482                         print_asc_cb(&buf[i-n], n, cb, private_data);
 483                 }
 484                 cb("\n", private_data);
 485         }
 486
 487 }
 488
 489 /**
 490  * Write dump of binary data to the log file.
 491  *
 492  * The data is only written if the log level is at least level.
 493  */
 494 _PUBLIC_ void dump_data(int level, const uint8_t *buf, int len)
 495 {
 496         if (!DEBUGLVL(level)) {
 497                 return;
 498         }
 499         dump_data_cb(buf, len, false, debugadd_cb, &level);
 500 }
 501
 502 /**
 503  * Write dump of binary data to the log file.
 504  *
 505  * The data is only written if the log level is at least level.
 506  * 16 zero bytes in a row are omitted
 507  */
 508 _PUBLIC_ void dump_data_skip_zeros(int level, const uint8_t *buf, int len)
 509 {
 510         if (!DEBUGLVL(level)) {
 511                 return;
 512         }
 513         dump_data_cb(buf, len, true, debugadd_cb, &level);
 514 }
 515
 516 static void fprintf_cb(const char *buf, void *private_data)
 517 {
 518         FILE *f = (FILE *)private_data;
 519         fprintf(f, "%s", buf);
 520 }
 521
 522 void dump_data_file(const uint8_t *buf, int len, bool omit_zero_bytes,
 523                     FILE *f)
 524 {
 525         dump_data_cb(buf, len, omit_zero_bytes, fprintf_cb, f);
 526 }
 527
 528 /**
 529  malloc that aborts with smb_panic on fail or zero size.
 530 **/
 531
 532 _PUBLIC_ void *smb_xmalloc(size_t size)
 533 {
 534         void *p;
 535         if (size == 0)
 536                 smb_panic("smb_xmalloc: called with zero size.\n");
 537         if ((p = malloc(size)) == NULL)
 538                 smb_panic("smb_xmalloc: malloc fail.\n");
 539         return p;
 540 }
 541
 542 /**
 543  Memdup with smb_panic on fail.
 544 **/
 545
 546 _PUBLIC_ void *smb_xmemdup(const void *p, size_t size)
 547 {
 548         void *p2;
 549         p2 = smb_xmalloc(size);
 550         memcpy(p2, p, size);
 551         return p2;
 552 }
 553
 554 /**
 555  strdup that aborts on malloc fail.
 556 **/
 557
 558 char *smb_xstrdup(const char *s)
 559 {
 560 #if defined(PARANOID_MALLOC_CHECKER)
 561 #ifdef strdup
 562 #undef strdup
 563 #endif
 564 #endif
 565
 566 #ifndef HAVE_STRDUP
 567 #define strdup rep_strdup
 568 #endif
 569
 570         char *s1 = strdup(s);
 571 #if defined(PARANOID_MALLOC_CHECKER)
 572 #ifdef strdup
 573 #undef strdup
 574 #endif
 575 #define strdup(s) __ERROR_DONT_USE_STRDUP_DIRECTLY
 576 #endif
 577         if (!s1) {
 578                 smb_panic("smb_xstrdup: malloc failed");
 579         }
 580         return s1;
 581
 582 }
 583
 584 /**
 585  strndup that aborts on malloc fail.
 586 **/
 587
 588 char *smb_xstrndup(const char *s, size_t n)
 589 {
 590 #if defined(PARANOID_MALLOC_CHECKER)
 591 #ifdef strndup
 592 #undef strndup
 593 #endif
 594 #endif
 595
 596 #if (defined(BROKEN_STRNDUP) || !defined(HAVE_STRNDUP))
 597 #undef HAVE_STRNDUP
 598 #define strndup rep_strndup
 599 #endif
 600
 601         char *s1 = strndup(s, n);
 602 #if defined(PARANOID_MALLOC_CHECKER)
 603 #ifdef strndup
 604 #undef strndup
 605 #endif
 606 #define strndup(s,n) __ERROR_DONT_USE_STRNDUP_DIRECTLY
 607 #endif
 608         if (!s1) {
 609                 smb_panic("smb_xstrndup: malloc failed");
 610         }
 611         return s1;
 612 }
 613
 614
 615
 616 /**
 617  Like strdup but for memory.
 618 **/
 619
 620 _PUBLIC_ void *memdup(const void *p, size_t size)
 621 {
 622         void *p2;
 623         if (size == 0)
 624                 return NULL;
 625         p2 = malloc(size);
 626         if (!p2)
 627                 return NULL;
 628         memcpy(p2, p, size);
 629         return p2;
 630 }
 631
 632 /**
 633  * Write a password to the log file.
 634  *
 635  * @note Only actually does something if DEBUG_PASSWORD was defined during
 636  * compile-time.
 637  */
 638 _PUBLIC_ void dump_data_pw(const char *msg, const uint8_t * data, size_t len)
 639 {
 640 #ifdef DEBUG_PASSWORD
 641         DEBUG(11, ("%s", msg));
 642         if (data != NULL && len > 0)
 643         {
 644                 dump_data(11, data, len);
 645         }
 646 #endif
 647 }
 648
 649
 650 /**
 651  * see if a range of memory is all zero. A NULL pointer is considered
 652  * to be all zero
 653  */
 654 _PUBLIC_ bool all_zero(const uint8_t *ptr, size_t size)
 655 {
 656         int i;
 657         if (!ptr) return true;
 658         for (i=0;i<size;i++) {
 659                 if (ptr[i]) return false;
 660         }
 661         return true;
 662 }
 663
 664 /**
 665   realloc an array, checking for integer overflow in the array size
 666 */
 667 _PUBLIC_ void *realloc_array(void *ptr, size_t el_size, unsigned count, bool free_on_fail)
 668 {
 669 #define MAX_MALLOC_SIZE 0x7fffffff
 670         if (count == 0 ||
 671             count >= MAX_MALLOC_SIZE/el_size) {
 672                 if (free_on_fail)
 673                         SAFE_FREE(ptr);
 674                 return NULL;
 675         }
 676         if (!ptr) {
 677                 return malloc(el_size * count);
 678         }
 679         return realloc(ptr, el_size * count);
 680 }
 681
 682 /****************************************************************************
 683  Type-safe malloc.
 684 ****************************************************************************/
 685
 686 void *malloc_array(size_t el_size, unsigned int count)
 687 {
 688         return realloc_array(NULL, el_size, count, false);
 689 }
 690
 691 /****************************************************************************
 692  Type-safe memalign
 693 ****************************************************************************/
 694
 695 void *memalign_array(size_t el_size, size_t align, unsigned int count)
 696 {
 697         if (count*el_size >= MAX_MALLOC_SIZE) {
 698                 return NULL;
 699         }
 700
 701         return memalign(align, el_size*count);
 702 }
 703
 704 /****************************************************************************
 705  Type-safe calloc.
 706 ****************************************************************************/
 707
 708 void *calloc_array(size_t size, size_t nmemb)
 709 {
 710         if (nmemb >= MAX_MALLOC_SIZE/size) {
 711                 return NULL;
 712         }
 713         if (size == 0 || nmemb == 0) {
 714                 return NULL;
 715         }
 716         return calloc(nmemb, size);
 717 }
 718
 719 /**
 720  Trim the specified elements off the front and back of a string.
 721 **/
 722 _PUBLIC_ bool trim_string(char *s, const char *front, const char *back)
 723 {
 724         bool ret = false;
 725         size_t front_len;
 726         size_t back_len;
 727         size_t len;
 728
 729         /* Ignore null or empty strings. */
 730         if (!s || (s[0] == '\0'))
 731                 return false;
 732
 733         front_len       = front? strlen(front) : 0;
 734         back_len        = back? strlen(back) : 0;
 735
 736         len = strlen(s);
 737
 738         if (front_len) {
 739                 while (len && strncmp(s, front, front_len)==0) {
 740                         /* Must use memmove here as src & dest can
 741                          * easily overlap. Found by valgrind. JRA. */
 742                         memmove(s, s+front_len, (len-front_len)+1);
 743                         len -= front_len;
 744                         ret=true;
 745                 }
 746         }
 747
 748         if (back_len) {
 749                 while ((len >= back_len) && strncmp(s+len-back_len,back,back_len)==0) {
 750                         s[len-back_len]='\0';
 751                         len -= back_len;
 752                         ret=true;
 753                 }
 754         }
 755         return ret;
 756 }
 757
 758 /**
 759  Find the number of 'c' chars in a string
 760 **/
 761 _PUBLIC_ _PURE_ size_t count_chars(const char *s, char c)
 762 {
 763         size_t count = 0;
 764
 765         while (*s) {
 766                 if (*s == c) count++;
 767                 s ++;
 768         }
 769
 770         return count;
 771 }
 772
 773 /**
 774  * Routine to get hex characters and turn them into a byte array.
 775  * the array can be variable length.
 776  * -  "0xnn" or "0Xnn" is specially catered for.
 777  * - The first non-hex-digit character (apart from possibly leading "0x"
 778  *   finishes the conversion and skips the rest of the input.
 779  * - A single hex-digit character at the end of the string is skipped.
 780  *
 781  * valid examples: "0A5D15"; "0x123456"
 782  */
 783 _PUBLIC_ size_t strhex_to_str(char *p, size_t p_len, const char *strhex, size_t strhex_len)
 784 {
 785         size_t i = 0;
 786         size_t num_chars = 0;
 787         uint8_t   lonybble, hinybble;
 788         const char     *hexchars = "0123456789ABCDEF";
 789         char           *p1 = NULL, *p2 = NULL;
 790
 791         /* skip leading 0x prefix */
 792         if (strncasecmp(strhex, "0x", 2) == 0) {
 793                 i += 2; /* skip two chars */
 794         }
 795
 796         for (; i+1 < strhex_len && strhex[i] != 0 && strhex[i+1] != 0; i++) {
 797                 p1 = strchr(hexchars, toupper((unsigned char)strhex[i]));
 798                 if (p1 == NULL) {
 799                         break;
 800                 }
 801
 802                 i++; /* next hex digit */
 803
 804                 p2 = strchr(hexchars, toupper((unsigned char)strhex[i]));
 805                 if (p2 == NULL) {
 806                         break;
 807                 }
 808
 809                 /* get the two nybbles */
 810                 hinybble = PTR_DIFF(p1, hexchars);
 811                 lonybble = PTR_DIFF(p2, hexchars);
 812
 813                 if (num_chars >= p_len) {
 814                         break;
 815                 }
 816
 817                 p[num_chars] = (hinybble << 4) | lonybble;
 818                 num_chars++;
 819
 820                 p1 = NULL;
 821                 p2 = NULL;
 822         }
 823         return num_chars;
 824 }
 825
 826 /**
 827  * Parse a hex string and return a data blob.
 828  */
 829 _PUBLIC_ _PURE_ DATA_BLOB strhex_to_data_blob(TALLOC_CTX *mem_ctx, const char *strhex)
 830 {
 831         DATA_BLOB ret_blob = data_blob_talloc(mem_ctx, NULL, strlen(strhex)/2+1);
 832
 833         ret_blob.length = strhex_to_str((char *)ret_blob.data, ret_blob.length,
 834                                         strhex,
 835                                         strlen(strhex));
 836
 837         return ret_blob;
 838 }
 839
 840 /**
 841  * Print a buf in hex. Assumes dst is at least (srclen*2)+1 large.
 842  */
 843 _PUBLIC_ void hex_encode_buf(char *dst, const uint8_t *src, size_t srclen)
 844 {
 845         size_t i;
 846         for (i=0; i<srclen; i++) {
 847                 snprintf(dst + i*2, 3, "%02X", src[i]);
 848         }
 849         /*
 850          * Ensure 0-termination for 0-length buffers
 851          */
 852         dst[srclen*2] = '\0';
 853 }
 854
 855 /**
 856  * Routine to print a buffer as HEX digits, into an allocated string.
 857  */
 858 _PUBLIC_ void hex_encode(const unsigned char *buff_in, size_t len, char **out_hex_buffer)
 859 {
 860         char *hex_buffer;
 861
 862         *out_hex_buffer = malloc_array_p(char, (len*2)+1);
 863         hex_buffer = *out_hex_buffer;
 864         hex_encode_buf(hex_buffer, buff_in, len);
 865 }
 866
 867 /**
 868  * talloc version of hex_encode()
 869  */
 870 _PUBLIC_ char *hex_encode_talloc(TALLOC_CTX *mem_ctx, const unsigned char *buff_in, size_t len)
 871 {
 872         char *hex_buffer;
 873
 874         hex_buffer = talloc_array(mem_ctx, char, (len*2)+1);
 875         if (!hex_buffer) {
 876                 return NULL;
 877         }
 878         hex_encode_buf(hex_buffer, buff_in, len);
 879         talloc_set_name_const(hex_buffer, hex_buffer);
 880         return hex_buffer;
 881 }
 882
 883 /**
 884   varient of strcmp() that handles NULL ptrs
 885 **/
 886 _PUBLIC_ int strcmp_safe(const char *s1, const char *s2)
 887 {
 888         if (s1 == s2) {
 889                 return 0;
 890         }
 891         if (s1 == NULL || s2 == NULL) {
 892                 return s1?-1:1;
 893         }
 894         return strcmp(s1, s2);
 895 }
 896
 897
 898 /**
 899 return the number of bytes occupied by a buffer in ASCII format
 900 the result includes the null termination
 901 limited by 'n' bytes
 902 **/
 903 _PUBLIC_ size_t ascii_len_n(const char *src, size_t n)
 904 {
 905         size_t len;
 906
 907         len = strnlen(src, n);
 908         if (len+1 <= n) {
 909                 len += 1;
 910         }
 911
 912         return len;
 913 }
 914
 915 /**
 916  Set a boolean variable from the text value stored in the passed string.
 917  Returns true in success, false if the passed string does not correctly
 918  represent a boolean.
 919 **/
 920
 921 _PUBLIC_ bool set_boolean(const char *boolean_string, bool *boolean)
 922 {
 923         if (strwicmp(boolean_string, "yes") == 0 ||
 924             strwicmp(boolean_string, "true") == 0 ||
 925             strwicmp(boolean_string, "on") == 0 ||
 926             strwicmp(boolean_string, "1") == 0) {
 927                 *boolean = true;
 928                 return true;
 929         } else if (strwicmp(boolean_string, "no") == 0 ||
 930                    strwicmp(boolean_string, "false") == 0 ||
 931                    strwicmp(boolean_string, "off") == 0 ||
 932                    strwicmp(boolean_string, "0") == 0) {
 933                 *boolean = false;
 934                 return true;
 935         }
 936         return false;
 937 }
 938
 939 /**
 940 return the number of bytes occupied by a buffer in CH_UTF16 format
 941 the result includes the null termination
 942 **/
 943 _PUBLIC_ size_t utf16_len(const void *buf)
 944 {
 945         size_t len;
 946
 947         for (len = 0; SVAL(buf,len); len += 2) ;
 948
 949         return len + 2;
 950 }
 951
 952 /**
 953 return the number of bytes occupied by a buffer in CH_UTF16 format
 954 the result includes the null termination
 955 limited by 'n' bytes
 956 **/
 957 _PUBLIC_ size_t utf16_len_n(const void *src, size_t n)
 958 {
 959         size_t len;
 960
 961         for (len = 0; (len+2 < n) && SVAL(src, len); len += 2) ;
 962
 963         if (len+2 <= n) {
 964                 len += 2;
 965         }
 966
 967         return len;
 968 }
 969
 970 /**
 971  * @file
 972  * @brief String utilities.
 973  **/
 974
 975 static bool next_token_internal_talloc(TALLOC_CTX *ctx,
 976                                 const char **ptr,
 977                                 char **pp_buff,
 978                                 const char *sep,
 979                                 bool ltrim)
 980 {
 981         const char *s;
 982         const char *saved_s;
 983         char *pbuf;
 984         bool quoted;
 985         size_t len=1;
 986
 987         *pp_buff = NULL;
 988         if (!ptr) {
 989                 return(false);
 990         }
 991
 992         s = *ptr;
 993
 994         /* default to simple separators */
 995         if (!sep) {
 996                 sep = " \t\n\r";
 997         }
 998
 999         /* find the first non sep char, if left-trimming is requested */
1000         if (ltrim) {
1001                 while (*s && strchr_m(sep,*s)) {
1002                         s++;
1003                 }
1004         }
1005
1006         /* nothing left? */
1007         if (!*s) {
1008                 return false;
1009         }
1010
1011         /* When restarting we need to go from here. */
1012         saved_s = s;
1013
1014         /* Work out the length needed. */
1015         for (quoted = false; *s &&
1016                         (quoted || !strchr_m(sep,*s)); s++) {
1017                 if (*s == '\"') {
1018                         quoted = !quoted;
1019                 } else {
1020                         len++;
1021                 }
1022         }
1023
1024         /* We started with len = 1 so we have space for the nul. */
1025         *pp_buff = talloc_array(ctx, char, len);
1026         if (!*pp_buff) {
1027                 return false;
1028         }
1029
1030         /* copy over the token */
1031         pbuf = *pp_buff;
1032         s = saved_s;
1033         for (quoted = false; *s &&
1034                         (quoted || !strchr_m(sep,*s)); s++) {
1035                 if ( *s == '\"' ) {
1036                         quoted = !quoted;
1037                 } else {
1038                         *pbuf++ = *s;
1039                 }
1040         }
1041
1042         *ptr = (*s) ? s+1 : s;
1043         *pbuf = 0;
1044
1045         return true;
1046 }
1047
1048 bool next_token_talloc(TALLOC_CTX *ctx,
1049                         const char **ptr,
1050                         char **pp_buff,
1051                         const char *sep)
1052 {
1053         return next_token_internal_talloc(ctx, ptr, pp_buff, sep, true);
1054 }
1055
1056 /*
1057  * Get the next token from a string, return false if none found.  Handles
1058  * double-quotes.  This version does not trim leading separator characters
1059  * before looking for a token.
1060  */
1061
1062 bool next_token_no_ltrim_talloc(TALLOC_CTX *ctx,
1063                         const char **ptr,
1064                         char **pp_buff,
1065                         const char *sep)
1066 {
1067         return next_token_internal_talloc(ctx, ptr, pp_buff, sep, false);
1068 }
1069
1070 /**
1071  * Get the next token from a string, return False if none found.
1072  * Handles double-quotes.
1073  *
1074  * Based on a routine by GJC@VILLAGE.COM.
1075  * Extensively modified by Andrew.Tridgell@anu.edu.au
1076  **/
1077 _PUBLIC_ bool next_token(const char **ptr,char *buff, const char *sep, size_t bufsize)
1078 {
1079         const char *s;
1080         bool quoted;
1081         size_t len=1;
1082
1083         if (!ptr)
1084                 return false;
1085
1086         s = *ptr;
1087
1088         /* default to simple separators */
1089         if (!sep)
1090                 sep = " \t\n\r";
1091
1092         /* find the first non sep char */
1093         while (*s && strchr_m(sep,*s))
1094                 s++;
1095
1096         /* nothing left? */
1097         if (!*s)
1098                 return false;
1099
1100         /* copy over the token */
1101         for (quoted = false; len < bufsize && *s && (quoted || !strchr_m(sep,*s)); s++) {
1102                 if (*s == '\"') {
1103                         quoted = !quoted;
1104                 } else {
1105                         len++;
1106                         *buff++ = *s;
1107                 }
1108         }
1109
1110         *ptr = (*s) ? s+1 : s;
1111         *buff = 0;
1112
1113         return true;
1114 }
1115
1116 struct anonymous_shared_header {
1117         union {
1118                 size_t length;
1119                 uint8_t pad[16];
1120         } u;
1121 };
1122
1123 /* Map a shared memory buffer of at least nelem counters. */
1124 void *anonymous_shared_allocate(size_t orig_bufsz)
1125 {
1126         void *ptr;
1127         void *buf;
1128         size_t pagesz = getpagesize();
1129         size_t pagecnt;
1130         size_t bufsz = orig_bufsz;
1131         struct anonymous_shared_header *hdr;
1132
1133         bufsz += sizeof(*hdr);
1134
1135         /* round up to full pages */
1136         pagecnt = bufsz / pagesz;
1137         if (bufsz % pagesz) {
1138                 pagecnt += 1;
1139         }
1140         bufsz = pagesz * pagecnt;
1141
1142         if (orig_bufsz >= bufsz) {
1143                 /* integer wrap */
1144                 errno = ENOMEM;
1145                 return NULL;
1146         }
1147
1148 #ifdef MAP_ANON
1149         /* BSD */
1150         buf = mmap(NULL, bufsz, PROT_READ|PROT_WRITE, MAP_ANON|MAP_SHARED,
1151                         -1 /* fd */, 0 /* offset */);
1152 #else
1153 {
1154         int saved_errno;
1155         int fd;
1156
1157         fd = open("/dev/zero", O_RDWR);
1158         if (fd == -1) {
1159                 return NULL;
1160         }
1161
1162         buf = mmap(NULL, bufsz, PROT_READ|PROT_WRITE, MAP_FILE|MAP_SHARED,
1163                    fd, 0 /* offset */);
1164         saved_errno = errno;
1165         close(fd);
1166         errno = saved_errno;
1167 }
1168 #endif
1169
1170         if (buf == MAP_FAILED) {
1171                 return NULL;
1172         }
1173
1174         hdr = (struct anonymous_shared_header *)buf;
1175         hdr->u.length = bufsz;
1176
1177         ptr = (void *)(&hdr[1]);
1178
1179         return ptr;
1180 }
1181
1182 void *anonymous_shared_resize(void *ptr, size_t new_size, bool maymove)
1183 {
1184 #ifdef HAVE_MREMAP
1185         void *buf;
1186         size_t pagesz = getpagesize();
1187         size_t pagecnt;
1188         size_t bufsz;
1189         struct anonymous_shared_header *hdr;
1190         int flags = 0;
1191
1192         if (ptr == NULL) {
1193                 errno = EINVAL;
1194                 return NULL;
1195         }
1196
1197         hdr = (struct anonymous_shared_header *)ptr;
1198         hdr--;
1199         if (hdr->u.length > (new_size + sizeof(*hdr))) {
1200                 errno = EINVAL;
1201                 return NULL;
1202         }
1203
1204         bufsz = new_size + sizeof(*hdr);
1205
1206         /* round up to full pages */
1207         pagecnt = bufsz / pagesz;
1208         if (bufsz % pagesz) {
1209                 pagecnt += 1;
1210         }
1211         bufsz = pagesz * pagecnt;
1212
1213         if (new_size >= bufsz) {
1214                 /* integer wrap */
1215                 errno = ENOSPC;
1216                 return NULL;
1217         }
1218
1219         if (bufsz <= hdr->u.length) {
1220                 return ptr;
1221         }
1222
1223         if (maymove) {
1224                 flags = MREMAP_MAYMOVE;
1225         }
1226
1227         buf = mremap(hdr, hdr->u.length, bufsz, flags);
1228
1229         if (buf == MAP_FAILED) {
1230                 errno = ENOSPC;
1231                 return NULL;
1232         }
1233
1234         hdr = (struct anonymous_shared_header *)buf;
1235         hdr->u.length = bufsz;
1236
1237         ptr = (void *)(&hdr[1]);
1238
1239         return ptr;
1240 #else
1241         errno = ENOSPC;
1242         return NULL;
1243 #endif
1244 }
1245
1246 void anonymous_shared_free(void *ptr)
1247 {
1248         struct anonymous_shared_header *hdr;
1249
1250         if (ptr == NULL) {
1251                 return;
1252         }
1253
1254         hdr = (struct anonymous_shared_header *)ptr;
1255
1256         hdr--;
1257
1258         munmap(hdr, hdr->u.length);
1259 }
1260
1261 #ifdef DEVELOPER
1262 /* used when you want a debugger started at a particular point in the
1263    code. Mostly useful in code that runs as a child process, where
1264    normal gdb attach is harder to organise.
1265 */
1266 void samba_start_debugger(void)
1267 {
1268         char *cmd = NULL;
1269         if (asprintf(&cmd, "xterm -e \"gdb --pid %u\"&", getpid()) == -1) {
1270                 return;
1271         }
1272         if (system(cmd) == -1) {
1273                 free(cmd);
1274                 return;
1275         }
1276         free(cmd);
1277         sleep(2);
1278 }
1279 #endif