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         mode_t mask;
  67
  68         if (!dir) {
  69                 dir = tmpdir();
  70         }
  71
  72         fname = talloc_asprintf(talloc_tos(), "%s/listenerlock_XXXXXX", dir);
  73         if (fname == NULL) {
  74                 errno = ENOMEM;
  75                 return -1;
  76         }
  77         mask = umask(S_IRWXO | S_IRWXG);
  78         fd = mkstemp(fname);
  79         umask(mask);
  80         if (fd == -1) {
  81                 TALLOC_FREE(fname);
  82                 return -1;
  83         }
  84         if (unlink(fname) == -1) {
  85                 int sys_errno = errno;
  86                 close(fd);
  87                 TALLOC_FREE(fname);
  88                 errno = sys_errno;
  89                 return -1;
  90         }
  91         TALLOC_FREE(fname);
  92         return fd;
  93 }
  94
  95
  96 /**
  97  Check if a file exists - call vfs_file_exist for samba files.
  98 **/
  99 _PUBLIC_ bool file_exist(const char *fname)
 100 {
 101         struct stat st;
 102
 103         if (stat(fname, &st) != 0) {
 104                 return false;
 105         }
 106
 107         return ((S_ISREG(st.st_mode)) || (S_ISFIFO(st.st_mode)));
 108 }
 109
 110 /**
 111  Check a files mod time.
 112 **/
 113
 114 _PUBLIC_ time_t file_modtime(const char *fname)
 115 {
 116         struct stat st;
 117
 118         if (stat(fname,&st) != 0)
 119                 return(0);
 120
 121         return(st.st_mtime);
 122 }
 123
 124 /**
 125  Check if a directory exists.
 126 **/
 127
 128 _PUBLIC_ bool directory_exist(const char *dname)
 129 {
 130         struct stat st;
 131         bool ret;
 132
 133         if (stat(dname,&st) != 0) {
 134                 return false;
 135         }
 136
 137         ret = S_ISDIR(st.st_mode);
 138         if(!ret)
 139                 errno = ENOTDIR;
 140         return ret;
 141 }
 142
 143 /**
 144  * Try to create the specified directory if it didn't exist.
 145  *
 146  * @retval true if the directory already existed and has the right permissions
 147  * or was successfully created.
 148  */
 149 _PUBLIC_ bool directory_create_or_exist(const char *dname,
 150                                         uid_t uid,
 151                                         mode_t dir_perms)
 152 {
 153         int ret;
 154         struct stat st;
 155
 156         ret = lstat(dname, &st);
 157         if (ret == -1) {
 158                 mode_t old_umask;
 159
 160                 if (errno != ENOENT) {
 161                         DEBUG(0, ("lstat failed on directory %s: %s\n",
 162                                   dname, strerror(errno)));
 163                         return false;
 164                 }
 165
 166                 /* Create directory */
 167                 old_umask = umask(0);
 168                 ret = mkdir(dname, dir_perms);
 169                 if (ret == -1 && errno != EEXIST) {
 170                         DEBUG(0, ("mkdir failed on directory "
 171                                   "%s: %s\n", dname,
 172                                   strerror(errno)));
 173                         umask(old_umask);
 174                         return false;
 175                 }
 176                 umask(old_umask);
 177
 178                 ret = lstat(dname, &st);
 179                 if (ret == -1) {
 180                         DEBUG(0, ("lstat failed on created directory %s: %s\n",
 181                                   dname, strerror(errno)));
 182                         return false;
 183                 }
 184         }
 185
 186         return true;
 187 }
 188
 189 /**
 190  * @brief Try to create a specified directory if it doesn't exist.
 191  *
 192  * The function creates a directory with the given uid and permissions if it
 193  * doesn't exixt. If it exists it makes sure the uid and permissions are
 194  * correct and it will fail if they are different.
 195  *
 196  * @param[in]  dname  The directory to create.
 197  *
 198  * @param[in]  uid    The uid the directory needs to belong too.
 199  *
 200  * @param[in]  dir_perms  The expected permissions of the directory.
 201  *
 202  * @return True on success, false on error.
 203  */
 204 _PUBLIC_ bool directory_create_or_exist_strict(const char *dname,
 205                                                uid_t uid,
 206                                                mode_t dir_perms)
 207 {
 208         struct stat st;
 209         bool ok;
 210         int rc;
 211
 212         ok = directory_create_or_exist(dname, uid, dir_perms);
 213         if (!ok) {
 214                 return false;
 215         }
 216
 217         rc = lstat(dname, &st);
 218         if (rc == -1) {
 219                 DEBUG(0, ("lstat failed on created directory %s: %s\n",
 220                           dname, strerror(errno)));
 221                 return false;
 222         }
 223
 224         /* Check ownership and permission on existing directory */
 225         if (!S_ISDIR(st.st_mode)) {
 226                 DEBUG(0, ("directory %s isn't a directory\n",
 227                         dname));
 228                 return false;
 229         }
 230         if (st.st_uid != uid && !uwrap_enabled()) {
 231                 DEBUG(0, ("invalid ownership on directory "
 232                           "%s\n", dname));
 233                 return false;
 234         }
 235         if ((st.st_mode & 0777) != dir_perms) {
 236                 DEBUG(0, ("invalid permissions on directory "
 237                           "'%s': has 0%o should be 0%o\n", dname,
 238                           (unsigned int)(st.st_mode & 0777), (unsigned int)dir_perms));
 239                 return false;
 240         }
 241
 242         return true;
 243 }
 244
 245
 246 /**
 247  Sleep for a specified number of milliseconds.
 248 **/
 249
 250 _PUBLIC_ void smb_msleep(unsigned int t)
 251 {
 252 #if defined(HAVE_NANOSLEEP)
 253         struct timespec ts;
 254         int ret;
 255
 256         ts.tv_sec = t/1000;
 257         ts.tv_nsec = 1000000*(t%1000);
 258
 259         do {
 260                 errno = 0;
 261                 ret = nanosleep(&ts, &ts);
 262         } while (ret < 0 && errno == EINTR && (ts.tv_sec > 0 || ts.tv_nsec > 0));
 263 #else
 264         unsigned int tdiff=0;
 265         struct timeval tval,t1,t2;
 266         fd_set fds;
 267
 268         GetTimeOfDay(&t1);
 269         t2 = t1;
 270
 271         while (tdiff < t) {
 272                 tval.tv_sec = (t-tdiff)/1000;
 273                 tval.tv_usec = 1000*((t-tdiff)%1000);
 274
 275                 /* Never wait for more than 1 sec. */
 276                 if (tval.tv_sec > 1) {
 277                         tval.tv_sec = 1;
 278                         tval.tv_usec = 0;
 279                 }
 280
 281                 FD_ZERO(&fds);
 282                 errno = 0;
 283                 select(0,&fds,NULL,NULL,&tval);
 284
 285                 GetTimeOfDay(&t2);
 286                 if (t2.tv_sec < t1.tv_sec) {
 287                         /* Someone adjusted time... */
 288                         t1 = t2;
 289                 }
 290
 291                 tdiff = usec_time_diff(&t2,&t1)/1000;
 292         }
 293 #endif
 294 }
 295
 296 /**
 297  Get my own name, return in talloc'ed storage.
 298 **/
 299
 300 _PUBLIC_ char *get_myname(TALLOC_CTX *ctx)
 301 {
 302         char *p;
 303         char hostname[HOST_NAME_MAX];
 304
 305         /* get my host name */
 306         if (gethostname(hostname, sizeof(hostname)) == -1) {
 307                 DEBUG(0,("gethostname failed\n"));
 308                 return NULL;
 309         }
 310
 311         /* Ensure null termination. */
 312         hostname[sizeof(hostname)-1] = '\0';
 313
 314         /* split off any parts after an initial . */
 315         p = strchr_m(hostname, '.');
 316         if (p) {
 317                 *p = 0;
 318         }
 319
 320         return talloc_strdup(ctx, hostname);
 321 }
 322
 323 /**
 324  Check if a process exists. Does this work on all unixes?
 325 **/
 326
 327 _PUBLIC_ bool process_exists_by_pid(pid_t pid)
 328 {
 329         /* Doing kill with a non-positive pid causes messages to be
 330          * sent to places we don't want. */
 331         if (pid <= 0) {
 332                 return false;
 333         }
 334         return(kill(pid,0) == 0 || errno != ESRCH);
 335 }
 336
 337 /**
 338  Simple routine to do POSIX file locking. Cruft in NFS and 64->32 bit mapping
 339  is dealt with in posix.c
 340 **/
 341
 342 _PUBLIC_ bool fcntl_lock(int fd, int op, off_t offset, off_t count, int type)
 343 {
 344         struct flock lock;
 345         int ret;
 346
 347         DEBUG(8,("fcntl_lock %d %d %.0f %.0f %d\n",fd,op,(double)offset,(double)count,type));
 348
 349         lock.l_type = type;
 350         lock.l_whence = SEEK_SET;
 351         lock.l_start = offset;
 352         lock.l_len = count;
 353         lock.l_pid = 0;
 354
 355         ret = fcntl(fd,op,&lock);
 356
 357         if (ret == -1 && errno != 0)
 358                 DEBUG(3,("fcntl_lock: fcntl lock gave errno %d (%s)\n",errno,strerror(errno)));
 359
 360         /* a lock query */
 361         if (op == F_GETLK) {
 362                 if ((ret != -1) &&
 363                                 (lock.l_type != F_UNLCK) &&
 364                                 (lock.l_pid != 0) &&
 365                                 (lock.l_pid != getpid())) {
 366                         DEBUG(3,("fcntl_lock: fd %d is locked by pid %d\n",fd,(int)lock.l_pid));
 367                         return true;
 368                 }
 369
 370                 /* it must be not locked or locked by me */
 371                 return false;
 372         }
 373
 374         /* a lock set or unset */
 375         if (ret == -1) {
 376                 DEBUG(3,("fcntl_lock: lock failed at offset %.0f count %.0f op %d type %d (%s)\n",
 377                         (double)offset,(double)count,op,type,strerror(errno)));
 378                 return false;
 379         }
 380
 381         /* everything went OK */
 382         DEBUG(8,("fcntl_lock: Lock call successful\n"));
 383
 384         return true;
 385 }
 386
 387 static void debugadd_cb(const char *buf, void *private_data)
 388 {
 389         int *plevel = (int *)private_data;
 390         DEBUGADD(*plevel, ("%s", buf));
 391 }
 392
 393 void print_asc_cb(const uint8_t *buf, int len,
 394                   void (*cb)(const char *buf, void *private_data),
 395                   void *private_data)
 396 {
 397         int i;
 398         char s[2];
 399         s[1] = 0;
 400
 401         for (i=0; i<len; i++) {
 402                 s[0] = isprint(buf[i]) ? buf[i] : '.';
 403                 cb(s, private_data);
 404         }
 405 }
 406
 407 void print_asc(int level, const uint8_t *buf,int len)
 408 {
 409         print_asc_cb(buf, len, debugadd_cb, &level);
 410 }
 411
 412 /**
 413  * Write dump of binary data to a callback
 414  */
 415 void dump_data_cb(const uint8_t *buf, int len,
 416                   bool omit_zero_bytes,
 417                   void (*cb)(const char *buf, void *private_data),
 418                   void *private_data)
 419 {
 420         int i=0;
 421         static const uint8_t empty[16] = { 0, };
 422         bool skipped = false;
 423         char tmp[16];
 424
 425         if (len<=0) return;
 426
 427         for (i=0;i<len;) {
 428
 429                 if (i%16 == 0) {
 430                         if ((omit_zero_bytes == true) &&
 431                             (i > 0) &&
 432                             (len > i+16) &&
 433                             (memcmp(&buf[i], &empty, 16) == 0))
 434                         {
 435                                 i +=16;
 436                                 continue;
 437                         }
 438
 439                         if (i<len)  {
 440                                 snprintf(tmp, sizeof(tmp), "[%04X] ", i);
 441                                 cb(tmp, private_data);
 442                         }
 443                 }
 444
 445                 snprintf(tmp, sizeof(tmp), "%02X ", (int)buf[i]);
 446                 cb(tmp, private_data);
 447                 i++;
 448                 if (i%8 == 0) {
 449                         cb("  ", private_data);
 450                 }
 451                 if (i%16 == 0) {
 452
 453                         print_asc_cb(&buf[i-16], 8, cb, private_data);
 454                         cb(" ", private_data);
 455                         print_asc_cb(&buf[i-8], 8, cb, private_data);
 456                         cb("\n", private_data);
 457
 458                         if ((omit_zero_bytes == true) &&
 459                             (len > i+16) &&
 460                             (memcmp(&buf[i], &empty, 16) == 0)) {
 461                                 if (!skipped) {
 462                                         cb("skipping zero buffer bytes\n",
 463                                            private_data);
 464                                         skipped = true;
 465                                 }
 466                         }
 467                 }
 468         }
 469
 470         if (i%16) {
 471                 int n;
 472                 n = 16 - (i%16);
 473                 cb(" ", private_data);
 474                 if (n>8) {
 475                         cb(" ", private_data);
 476                 }
 477                 while (n--) {
 478                         cb("   ", private_data);
 479                 }
 480                 n = MIN(8,i%16);
 481                 print_asc_cb(&buf[i-(i%16)], n, cb, private_data);
 482                 cb(" ", private_data);
 483                 n = (i%16) - n;
 484                 if (n>0) {
 485                         print_asc_cb(&buf[i-n], n, cb, private_data);
 486                 }
 487                 cb("\n", private_data);
 488         }
 489
 490 }
 491
 492 /**
 493  * Write dump of binary data to the log file.
 494  *
 495  * The data is only written if the log level is at least level.
 496  */
 497 _PUBLIC_ void dump_data(int level, const uint8_t *buf, int len)
 498 {
 499         if (!DEBUGLVL(level)) {
 500                 return;
 501         }
 502         dump_data_cb(buf, len, false, debugadd_cb, &level);
 503 }
 504
 505 /**
 506  * Write dump of binary data to the log file.
 507  *
 508  * The data is only written if the log level is at least level.
 509  * 16 zero bytes in a row are omitted
 510  */
 511 _PUBLIC_ void dump_data_skip_zeros(int level, const uint8_t *buf, int len)
 512 {
 513         if (!DEBUGLVL(level)) {
 514                 return;
 515         }
 516         dump_data_cb(buf, len, true, debugadd_cb, &level);
 517 }
 518
 519 static void fprintf_cb(const char *buf, void *private_data)
 520 {
 521         FILE *f = (FILE *)private_data;
 522         fprintf(f, "%s", buf);
 523 }
 524
 525 void dump_data_file(const uint8_t *buf, int len, bool omit_zero_bytes,
 526                     FILE *f)
 527 {
 528         dump_data_cb(buf, len, omit_zero_bytes, fprintf_cb, f);
 529 }
 530
 531 /**
 532  malloc that aborts with smb_panic on fail or zero size.
 533 **/
 534
 535 _PUBLIC_ void *smb_xmalloc(size_t size)
 536 {
 537         void *p;
 538         if (size == 0)
 539                 smb_panic("smb_xmalloc: called with zero size.\n");
 540         if ((p = malloc(size)) == NULL)
 541                 smb_panic("smb_xmalloc: malloc fail.\n");
 542         return p;
 543 }
 544
 545 /**
 546  Memdup with smb_panic on fail.
 547 **/
 548
 549 _PUBLIC_ void *smb_xmemdup(const void *p, size_t size)
 550 {
 551         void *p2;
 552         p2 = smb_xmalloc(size);
 553         memcpy(p2, p, size);
 554         return p2;
 555 }
 556
 557 /**
 558  strdup that aborts on malloc fail.
 559 **/
 560
 561 char *smb_xstrdup(const char *s)
 562 {
 563 #if defined(PARANOID_MALLOC_CHECKER)
 564 #ifdef strdup
 565 #undef strdup
 566 #endif
 567 #endif
 568
 569 #ifndef HAVE_STRDUP
 570 #define strdup rep_strdup
 571 #endif
 572
 573         char *s1 = strdup(s);
 574 #if defined(PARANOID_MALLOC_CHECKER)
 575 #ifdef strdup
 576 #undef strdup
 577 #endif
 578 #define strdup(s) __ERROR_DONT_USE_STRDUP_DIRECTLY
 579 #endif
 580         if (!s1) {
 581                 smb_panic("smb_xstrdup: malloc failed");
 582         }
 583         return s1;
 584
 585 }
 586
 587 /**
 588  strndup that aborts on malloc fail.
 589 **/
 590
 591 char *smb_xstrndup(const char *s, size_t n)
 592 {
 593 #if defined(PARANOID_MALLOC_CHECKER)
 594 #ifdef strndup
 595 #undef strndup
 596 #endif
 597 #endif
 598
 599 #if (defined(BROKEN_STRNDUP) || !defined(HAVE_STRNDUP))
 600 #undef HAVE_STRNDUP
 601 #define strndup rep_strndup
 602 #endif
 603
 604         char *s1 = strndup(s, n);
 605 #if defined(PARANOID_MALLOC_CHECKER)
 606 #ifdef strndup
 607 #undef strndup
 608 #endif
 609 #define strndup(s,n) __ERROR_DONT_USE_STRNDUP_DIRECTLY
 610 #endif
 611         if (!s1) {
 612                 smb_panic("smb_xstrndup: malloc failed");
 613         }
 614         return s1;
 615 }
 616
 617
 618
 619 /**
 620  Like strdup but for memory.
 621 **/
 622
 623 _PUBLIC_ void *memdup(const void *p, size_t size)
 624 {
 625         void *p2;
 626         if (size == 0)
 627                 return NULL;
 628         p2 = malloc(size);
 629         if (!p2)
 630                 return NULL;
 631         memcpy(p2, p, size);
 632         return p2;
 633 }
 634
 635 /**
 636  * Write a password to the log file.
 637  *
 638  * @note Only actually does something if DEBUG_PASSWORD was defined during
 639  * compile-time.
 640  */
 641 _PUBLIC_ void dump_data_pw(const char *msg, const uint8_t * data, size_t len)
 642 {
 643 #ifdef DEBUG_PASSWORD
 644         DEBUG(11, ("%s", msg));
 645         if (data != NULL && len > 0)
 646         {
 647                 dump_data(11, data, len);
 648         }
 649 #endif
 650 }
 651
 652
 653 /**
 654  * see if a range of memory is all zero. A NULL pointer is considered
 655  * to be all zero
 656  */
 657 _PUBLIC_ bool all_zero(const uint8_t *ptr, size_t size)
 658 {
 659         int i;
 660         if (!ptr) return true;
 661         for (i=0;i<size;i++) {
 662                 if (ptr[i]) return false;
 663         }
 664         return true;
 665 }
 666
 667 /**
 668   realloc an array, checking for integer overflow in the array size
 669 */
 670 _PUBLIC_ void *realloc_array(void *ptr, size_t el_size, unsigned count, bool free_on_fail)
 671 {
 672 #define MAX_MALLOC_SIZE 0x7fffffff
 673         if (count == 0 ||
 674             count >= MAX_MALLOC_SIZE/el_size) {
 675                 if (free_on_fail)
 676                         SAFE_FREE(ptr);
 677                 return NULL;
 678         }
 679         if (!ptr) {
 680                 return malloc(el_size * count);
 681         }
 682         return realloc(ptr, el_size * count);
 683 }
 684
 685 /****************************************************************************
 686  Type-safe malloc.
 687 ****************************************************************************/
 688
 689 void *malloc_array(size_t el_size, unsigned int count)
 690 {
 691         return realloc_array(NULL, el_size, count, false);
 692 }
 693
 694 /****************************************************************************
 695  Type-safe memalign
 696 ****************************************************************************/
 697
 698 void *memalign_array(size_t el_size, size_t align, unsigned int count)
 699 {
 700         if (count*el_size >= MAX_MALLOC_SIZE) {
 701                 return NULL;
 702         }
 703
 704         return memalign(align, el_size*count);
 705 }
 706
 707 /****************************************************************************
 708  Type-safe calloc.
 709 ****************************************************************************/
 710
 711 void *calloc_array(size_t size, size_t nmemb)
 712 {
 713         if (nmemb >= MAX_MALLOC_SIZE/size) {
 714                 return NULL;
 715         }
 716         if (size == 0 || nmemb == 0) {
 717                 return NULL;
 718         }
 719         return calloc(nmemb, size);
 720 }
 721
 722 /**
 723  Trim the specified elements off the front and back of a string.
 724 **/
 725 _PUBLIC_ bool trim_string(char *s, const char *front, const char *back)
 726 {
 727         bool ret = false;
 728         size_t front_len;
 729         size_t back_len;
 730         size_t len;
 731
 732         /* Ignore null or empty strings. */
 733         if (!s || (s[0] == '\0'))
 734                 return false;
 735
 736         front_len       = front? strlen(front) : 0;
 737         back_len        = back? strlen(back) : 0;
 738
 739         len = strlen(s);
 740
 741         if (front_len) {
 742                 while (len && strncmp(s, front, front_len)==0) {
 743                         /* Must use memmove here as src & dest can
 744                          * easily overlap. Found by valgrind. JRA. */
 745                         memmove(s, s+front_len, (len-front_len)+1);
 746                         len -= front_len;
 747                         ret=true;
 748                 }
 749         }
 750
 751         if (back_len) {
 752                 while ((len >= back_len) && strncmp(s+len-back_len,back,back_len)==0) {
 753                         s[len-back_len]='\0';
 754                         len -= back_len;
 755                         ret=true;
 756                 }
 757         }
 758         return ret;
 759 }
 760
 761 /**
 762  Find the number of 'c' chars in a string
 763 **/
 764 _PUBLIC_ _PURE_ size_t count_chars(const char *s, char c)
 765 {
 766         size_t count = 0;
 767
 768         while (*s) {
 769                 if (*s == c) count++;
 770                 s ++;
 771         }
 772
 773         return count;
 774 }
 775
 776 /**
 777  * Routine to get hex characters and turn them into a byte array.
 778  * the array can be variable length.
 779  * -  "0xnn" or "0Xnn" is specially catered for.
 780  * - The first non-hex-digit character (apart from possibly leading "0x"
 781  *   finishes the conversion and skips the rest of the input.
 782  * - A single hex-digit character at the end of the string is skipped.
 783  *
 784  * valid examples: "0A5D15"; "0x123456"
 785  */
 786 _PUBLIC_ size_t strhex_to_str(char *p, size_t p_len, const char *strhex, size_t strhex_len)
 787 {
 788         size_t i = 0;
 789         size_t num_chars = 0;
 790         uint8_t   lonybble, hinybble;
 791         const char     *hexchars = "0123456789ABCDEF";
 792         char           *p1 = NULL, *p2 = NULL;
 793
 794         /* skip leading 0x prefix */
 795         if (strncasecmp(strhex, "0x", 2) == 0) {
 796                 i += 2; /* skip two chars */
 797         }
 798
 799         for (; i+1 < strhex_len && strhex[i] != 0 && strhex[i+1] != 0; i++) {
 800                 p1 = strchr(hexchars, toupper((unsigned char)strhex[i]));
 801                 if (p1 == NULL) {
 802                         break;
 803                 }
 804
 805                 i++; /* next hex digit */
 806
 807                 p2 = strchr(hexchars, toupper((unsigned char)strhex[i]));
 808                 if (p2 == NULL) {
 809                         break;
 810                 }
 811
 812                 /* get the two nybbles */
 813                 hinybble = PTR_DIFF(p1, hexchars);
 814                 lonybble = PTR_DIFF(p2, hexchars);
 815
 816                 if (num_chars >= p_len) {
 817                         break;
 818                 }
 819
 820                 p[num_chars] = (hinybble << 4) | lonybble;
 821                 num_chars++;
 822
 823                 p1 = NULL;
 824                 p2 = NULL;
 825         }
 826         return num_chars;
 827 }
 828
 829 /**
 830  * Parse a hex string and return a data blob.
 831  */
 832 _PUBLIC_ _PURE_ DATA_BLOB strhex_to_data_blob(TALLOC_CTX *mem_ctx, const char *strhex)
 833 {
 834         DATA_BLOB ret_blob = data_blob_talloc(mem_ctx, NULL, strlen(strhex)/2+1);
 835
 836         ret_blob.length = strhex_to_str((char *)ret_blob.data, ret_blob.length,
 837                                         strhex,
 838                                         strlen(strhex));
 839
 840         return ret_blob;
 841 }
 842
 843 /**
 844  * Print a buf in hex. Assumes dst is at least (srclen*2)+1 large.
 845  */
 846 _PUBLIC_ void hex_encode_buf(char *dst, const uint8_t *src, size_t srclen)
 847 {
 848         size_t i;
 849         for (i=0; i<srclen; i++) {
 850                 snprintf(dst + i*2, 3, "%02X", src[i]);
 851         }
 852         /*
 853          * Ensure 0-termination for 0-length buffers
 854          */
 855         dst[srclen*2] = '\0';
 856 }
 857
 858 /**
 859  * Routine to print a buffer as HEX digits, into an allocated string.
 860  */
 861 _PUBLIC_ void hex_encode(const unsigned char *buff_in, size_t len, char **out_hex_buffer)
 862 {
 863         char *hex_buffer;
 864
 865         *out_hex_buffer = malloc_array_p(char, (len*2)+1);
 866         hex_buffer = *out_hex_buffer;
 867         hex_encode_buf(hex_buffer, buff_in, len);
 868 }
 869
 870 /**
 871  * talloc version of hex_encode()
 872  */
 873 _PUBLIC_ char *hex_encode_talloc(TALLOC_CTX *mem_ctx, const unsigned char *buff_in, size_t len)
 874 {
 875         char *hex_buffer;
 876
 877         hex_buffer = talloc_array(mem_ctx, char, (len*2)+1);
 878         if (!hex_buffer) {
 879                 return NULL;
 880         }
 881         hex_encode_buf(hex_buffer, buff_in, len);
 882         talloc_set_name_const(hex_buffer, hex_buffer);
 883         return hex_buffer;
 884 }
 885
 886 /**
 887   varient of strcmp() that handles NULL ptrs
 888 **/
 889 _PUBLIC_ int strcmp_safe(const char *s1, const char *s2)
 890 {
 891         if (s1 == s2) {
 892                 return 0;
 893         }
 894         if (s1 == NULL || s2 == NULL) {
 895                 return s1?-1:1;
 896         }
 897         return strcmp(s1, s2);
 898 }
 899
 900
 901 /**
 902 return the number of bytes occupied by a buffer in ASCII format
 903 the result includes the null termination
 904 limited by 'n' bytes
 905 **/
 906 _PUBLIC_ size_t ascii_len_n(const char *src, size_t n)
 907 {
 908         size_t len;
 909
 910         len = strnlen(src, n);
 911         if (len+1 <= n) {
 912                 len += 1;
 913         }
 914
 915         return len;
 916 }
 917
 918 /**
 919  Set a boolean variable from the text value stored in the passed string.
 920  Returns true in success, false if the passed string does not correctly
 921  represent a boolean.
 922 **/
 923
 924 _PUBLIC_ bool set_boolean(const char *boolean_string, bool *boolean)
 925 {
 926         if (strwicmp(boolean_string, "yes") == 0 ||
 927             strwicmp(boolean_string, "true") == 0 ||
 928             strwicmp(boolean_string, "on") == 0 ||
 929             strwicmp(boolean_string, "1") == 0) {
 930                 *boolean = true;
 931                 return true;
 932         } else if (strwicmp(boolean_string, "no") == 0 ||
 933                    strwicmp(boolean_string, "false") == 0 ||
 934                    strwicmp(boolean_string, "off") == 0 ||
 935                    strwicmp(boolean_string, "0") == 0) {
 936                 *boolean = false;
 937                 return true;
 938         }
 939         return false;
 940 }
 941
 942 /**
 943 return the number of bytes occupied by a buffer in CH_UTF16 format
 944 the result includes the null termination
 945 **/
 946 _PUBLIC_ size_t utf16_len(const void *buf)
 947 {
 948         size_t len;
 949
 950         for (len = 0; SVAL(buf,len); len += 2) ;
 951
 952         return len + 2;
 953 }
 954
 955 /**
 956 return the number of bytes occupied by a buffer in CH_UTF16 format
 957 the result includes the null termination
 958 limited by 'n' bytes
 959 **/
 960 _PUBLIC_ size_t utf16_len_n(const void *src, size_t n)
 961 {
 962         size_t len;
 963
 964         for (len = 0; (len+2 < n) && SVAL(src, len); len += 2) ;
 965
 966         if (len+2 <= n) {
 967                 len += 2;
 968         }
 969
 970         return len;
 971 }
 972
 973 /**
 974  * @file
 975  * @brief String utilities.
 976  **/
 977
 978 static bool next_token_internal_talloc(TALLOC_CTX *ctx,
 979                                 const char **ptr,
 980                                 char **pp_buff,
 981                                 const char *sep,
 982                                 bool ltrim)
 983 {
 984         const char *s;
 985         const char *saved_s;
 986         char *pbuf;
 987         bool quoted;
 988         size_t len=1;
 989
 990         *pp_buff = NULL;
 991         if (!ptr) {
 992                 return(false);
 993         }
 994
 995         s = *ptr;
 996
 997         /* default to simple separators */
 998         if (!sep) {
 999                 sep = " \t\n\r";
1000         }
1001
1002         /* find the first non sep char, if left-trimming is requested */
1003         if (ltrim) {
1004                 while (*s && strchr_m(sep,*s)) {
1005                         s++;
1006                 }
1007         }
1008
1009         /* nothing left? */
1010         if (!*s) {
1011                 return false;
1012         }
1013
1014         /* When restarting we need to go from here. */
1015         saved_s = s;
1016
1017         /* Work out the length needed. */
1018         for (quoted = false; *s &&
1019                         (quoted || !strchr_m(sep,*s)); s++) {
1020                 if (*s == '\"') {
1021                         quoted = !quoted;
1022                 } else {
1023                         len++;
1024                 }
1025         }
1026
1027         /* We started with len = 1 so we have space for the nul. */
1028         *pp_buff = talloc_array(ctx, char, len);
1029         if (!*pp_buff) {
1030                 return false;
1031         }
1032
1033         /* copy over the token */
1034         pbuf = *pp_buff;
1035         s = saved_s;
1036         for (quoted = false; *s &&
1037                         (quoted || !strchr_m(sep,*s)); s++) {
1038                 if ( *s == '\"' ) {
1039                         quoted = !quoted;
1040                 } else {
1041                         *pbuf++ = *s;
1042                 }
1043         }
1044
1045         *ptr = (*s) ? s+1 : s;
1046         *pbuf = 0;
1047
1048         return true;
1049 }
1050
1051 bool next_token_talloc(TALLOC_CTX *ctx,
1052                         const char **ptr,
1053                         char **pp_buff,
1054                         const char *sep)
1055 {
1056         return next_token_internal_talloc(ctx, ptr, pp_buff, sep, true);
1057 }
1058
1059 /*
1060  * Get the next token from a string, return false if none found.  Handles
1061  * double-quotes.  This version does not trim leading separator characters
1062  * before looking for a token.
1063  */
1064
1065 bool next_token_no_ltrim_talloc(TALLOC_CTX *ctx,
1066                         const char **ptr,
1067                         char **pp_buff,
1068                         const char *sep)
1069 {
1070         return next_token_internal_talloc(ctx, ptr, pp_buff, sep, false);
1071 }
1072
1073 /**
1074  * Get the next token from a string, return False if none found.
1075  * Handles double-quotes.
1076  *
1077  * Based on a routine by GJC@VILLAGE.COM.
1078  * Extensively modified by Andrew.Tridgell@anu.edu.au
1079  **/
1080 _PUBLIC_ bool next_token(const char **ptr,char *buff, const char *sep, size_t bufsize)
1081 {
1082         const char *s;
1083         bool quoted;
1084         size_t len=1;
1085
1086         if (!ptr)
1087                 return false;
1088
1089         s = *ptr;
1090
1091         /* default to simple separators */
1092         if (!sep)
1093                 sep = " \t\n\r";
1094
1095         /* find the first non sep char */
1096         while (*s && strchr_m(sep,*s))
1097                 s++;
1098
1099         /* nothing left? */
1100         if (!*s)
1101                 return false;
1102
1103         /* copy over the token */
1104         for (quoted = false; len < bufsize && *s && (quoted || !strchr_m(sep,*s)); s++) {
1105                 if (*s == '\"') {
1106                         quoted = !quoted;
1107                 } else {
1108                         len++;
1109                         *buff++ = *s;
1110                 }
1111         }
1112
1113         *ptr = (*s) ? s+1 : s;
1114         *buff = 0;
1115
1116         return true;
1117 }
1118
1119 struct anonymous_shared_header {
1120         union {
1121                 size_t length;
1122                 uint8_t pad[16];
1123         } u;
1124 };
1125
1126 /* Map a shared memory buffer of at least nelem counters. */
1127 void *anonymous_shared_allocate(size_t orig_bufsz)
1128 {
1129         void *ptr;
1130         void *buf;
1131         size_t pagesz = getpagesize();
1132         size_t pagecnt;
1133         size_t bufsz = orig_bufsz;
1134         struct anonymous_shared_header *hdr;
1135
1136         bufsz += sizeof(*hdr);
1137
1138         /* round up to full pages */
1139         pagecnt = bufsz / pagesz;
1140         if (bufsz % pagesz) {
1141                 pagecnt += 1;
1142         }
1143         bufsz = pagesz * pagecnt;
1144
1145         if (orig_bufsz >= bufsz) {
1146                 /* integer wrap */
1147                 errno = ENOMEM;
1148                 return NULL;
1149         }
1150
1151 #ifdef MAP_ANON
1152         /* BSD */
1153         buf = mmap(NULL, bufsz, PROT_READ|PROT_WRITE, MAP_ANON|MAP_SHARED,
1154                         -1 /* fd */, 0 /* offset */);
1155 #else
1156 {
1157         int saved_errno;
1158         int fd;
1159
1160         fd = open("/dev/zero", O_RDWR);
1161         if (fd == -1) {
1162                 return NULL;
1163         }
1164
1165         buf = mmap(NULL, bufsz, PROT_READ|PROT_WRITE, MAP_FILE|MAP_SHARED,
1166                    fd, 0 /* offset */);
1167         saved_errno = errno;
1168         close(fd);
1169         errno = saved_errno;
1170 }
1171 #endif
1172
1173         if (buf == MAP_FAILED) {
1174                 return NULL;
1175         }
1176
1177         hdr = (struct anonymous_shared_header *)buf;
1178         hdr->u.length = bufsz;
1179
1180         ptr = (void *)(&hdr[1]);
1181
1182         return ptr;
1183 }
1184
1185 void *anonymous_shared_resize(void *ptr, size_t new_size, bool maymove)
1186 {
1187 #ifdef HAVE_MREMAP
1188         void *buf;
1189         size_t pagesz = getpagesize();
1190         size_t pagecnt;
1191         size_t bufsz;
1192         struct anonymous_shared_header *hdr;
1193         int flags = 0;
1194
1195         if (ptr == NULL) {
1196                 errno = EINVAL;
1197                 return NULL;
1198         }
1199
1200         hdr = (struct anonymous_shared_header *)ptr;
1201         hdr--;
1202         if (hdr->u.length > (new_size + sizeof(*hdr))) {
1203                 errno = EINVAL;
1204                 return NULL;
1205         }
1206
1207         bufsz = new_size + sizeof(*hdr);
1208
1209         /* round up to full pages */
1210         pagecnt = bufsz / pagesz;
1211         if (bufsz % pagesz) {
1212                 pagecnt += 1;
1213         }
1214         bufsz = pagesz * pagecnt;
1215
1216         if (new_size >= bufsz) {
1217                 /* integer wrap */
1218                 errno = ENOSPC;
1219                 return NULL;
1220         }
1221
1222         if (bufsz <= hdr->u.length) {
1223                 return ptr;
1224         }
1225
1226         if (maymove) {
1227                 flags = MREMAP_MAYMOVE;
1228         }
1229
1230         buf = mremap(hdr, hdr->u.length, bufsz, flags);
1231
1232         if (buf == MAP_FAILED) {
1233                 errno = ENOSPC;
1234                 return NULL;
1235         }
1236
1237         hdr = (struct anonymous_shared_header *)buf;
1238         hdr->u.length = bufsz;
1239
1240         ptr = (void *)(&hdr[1]);
1241
1242         return ptr;
1243 #else
1244         errno = ENOSPC;
1245         return NULL;
1246 #endif
1247 }
1248
1249 void anonymous_shared_free(void *ptr)
1250 {
1251         struct anonymous_shared_header *hdr;
1252
1253         if (ptr == NULL) {
1254                 return;
1255         }
1256
1257         hdr = (struct anonymous_shared_header *)ptr;
1258
1259         hdr--;
1260
1261         munmap(hdr, hdr->u.length);
1262 }
1263
1264 #ifdef DEVELOPER
1265 /* used when you want a debugger started at a particular point in the
1266    code. Mostly useful in code that runs as a child process, where
1267    normal gdb attach is harder to organise.
1268 */
1269 void samba_start_debugger(void)
1270 {
1271         char *cmd = NULL;
1272         if (asprintf(&cmd, "xterm -e \"gdb --pid %u\"&", getpid()) == -1) {
1273                 return;
1274         }
1275         if (system(cmd) == -1) {
1276                 free(cmd);
1277                 return;
1278         }
1279         free(cmd);
1280         sleep(2);
1281 }
1282 #endif