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 file permissions.
 123 **/
 124
 125 _PUBLIC_ bool file_check_permissions(const char *fname,
 126                                      uid_t uid,
 127                                      mode_t file_perms,
 128                                      struct stat *pst)
 129 {
 130         int ret;
 131         struct stat st;
 132
 133         if (pst == NULL) {
 134                 pst = &st;
 135         }
 136
 137         ZERO_STRUCTP(pst);
 138
 139         ret = stat(fname, pst);
 140         if (ret != 0) {
 141                 DEBUG(0, ("stat failed on file '%s': %s\n",
 142                          fname, strerror(errno)));
 143                 return false;
 144         }
 145
 146         if (pst->st_uid != uid && !uwrap_enabled()) {
 147                 DEBUG(0, ("invalid ownership of file '%s': "
 148                          "owned by uid %u, should be %u\n",
 149                          fname, (unsigned int)pst->st_uid,
 150                          (unsigned int)uid));
 151                 return false;
 152         }
 153
 154         if ((pst->st_mode & 0777) != file_perms) {
 155                 DEBUG(0, ("invalid permissions on file "
 156                          "'%s': has 0%o should be 0%o\n", fname,
 157                          (unsigned int)(pst->st_mode & 0777),
 158                          (unsigned int)file_perms));
 159                 return false;
 160         }
 161
 162         return true;
 163 }
 164
 165 /**
 166  Check if a directory exists.
 167 **/
 168
 169 _PUBLIC_ bool directory_exist(const char *dname)
 170 {
 171         struct stat st;
 172         bool ret;
 173
 174         if (stat(dname,&st) != 0) {
 175                 return false;
 176         }
 177
 178         ret = S_ISDIR(st.st_mode);
 179         if(!ret)
 180                 errno = ENOTDIR;
 181         return ret;
 182 }
 183
 184 /**
 185  * Try to create the specified directory if it didn't exist.
 186  *
 187  * @retval true if the directory already existed and has the right permissions
 188  * or was successfully created.
 189  */
 190 _PUBLIC_ bool directory_create_or_exist(const char *dname, uid_t uid,
 191                                mode_t dir_perms)
 192 {
 193         int ret;
 194         struct stat st;
 195
 196         ret = lstat(dname, &st);
 197         if (ret == -1) {
 198                 mode_t old_umask;
 199
 200                 if (errno != ENOENT) {
 201                         DEBUG(0, ("lstat failed on directory %s: %s\n",
 202                                   dname, strerror(errno)));
 203                         return false;
 204                 }
 205
 206                 /* Create directory */
 207                 old_umask = umask(0);
 208                 ret = mkdir(dname, dir_perms);
 209                 if (ret == -1 && errno != EEXIST) {
 210                         DEBUG(0, ("mkdir failed on directory "
 211                                   "%s: %s\n", dname,
 212                                   strerror(errno)));
 213                         umask(old_umask);
 214                         return false;
 215                 }
 216                 umask(old_umask);
 217
 218                 ret = lstat(dname, &st);
 219                 if (ret == -1) {
 220                         DEBUG(0, ("lstat failed on created directory %s: %s\n",
 221                                   dname, strerror(errno)));
 222                         return false;
 223                 }
 224         }
 225
 226         /* Check ownership and permission on existing directory */
 227         if (!S_ISDIR(st.st_mode)) {
 228                 DEBUG(0, ("directory %s isn't a directory\n",
 229                         dname));
 230                 return false;
 231         }
 232         if (st.st_uid != uid && !uwrap_enabled()) {
 233                 DEBUG(0, ("invalid ownership on directory "
 234                           "%s\n", dname));
 235                 return false;
 236         }
 237         if ((st.st_mode & 0777) != dir_perms) {
 238                 DEBUG(0, ("invalid permissions on directory "
 239                           "'%s': has 0%o should be 0%o\n", dname,
 240                           (st.st_mode & 0777), dir_perms));
 241                 return false;
 242         }
 243
 244         return true;
 245 }
 246
 247
 248 /**
 249  Sleep for a specified number of milliseconds.
 250 **/
 251
 252 _PUBLIC_ void smb_msleep(unsigned int t)
 253 {
 254 #if defined(HAVE_NANOSLEEP)
 255         struct timespec ts;
 256         int ret;
 257
 258         ts.tv_sec = t/1000;
 259         ts.tv_nsec = 1000000*(t%1000);
 260
 261         do {
 262                 errno = 0;
 263                 ret = nanosleep(&ts, &ts);
 264         } while (ret < 0 && errno == EINTR && (ts.tv_sec > 0 || ts.tv_nsec > 0));
 265 #else
 266         unsigned int tdiff=0;
 267         struct timeval tval,t1,t2;
 268         fd_set fds;
 269
 270         GetTimeOfDay(&t1);
 271         t2 = t1;
 272
 273         while (tdiff < t) {
 274                 tval.tv_sec = (t-tdiff)/1000;
 275                 tval.tv_usec = 1000*((t-tdiff)%1000);
 276
 277                 /* Never wait for more than 1 sec. */
 278                 if (tval.tv_sec > 1) {
 279                         tval.tv_sec = 1;
 280                         tval.tv_usec = 0;
 281                 }
 282
 283                 FD_ZERO(&fds);
 284                 errno = 0;
 285                 select(0,&fds,NULL,NULL,&tval);
 286
 287                 GetTimeOfDay(&t2);
 288                 if (t2.tv_sec < t1.tv_sec) {
 289                         /* Someone adjusted time... */
 290                         t1 = t2;
 291                 }
 292
 293                 tdiff = usec_time_diff(&t2,&t1)/1000;
 294         }
 295 #endif
 296 }
 297
 298 /**
 299  Get my own name, return in talloc'ed storage.
 300 **/
 301
 302 _PUBLIC_ char *get_myname(TALLOC_CTX *ctx)
 303 {
 304         char *p;
 305         char hostname[HOST_NAME_MAX];
 306
 307         /* get my host name */
 308         if (gethostname(hostname, sizeof(hostname)) == -1) {
 309                 DEBUG(0,("gethostname failed\n"));
 310                 return NULL;
 311         }
 312
 313         /* Ensure null termination. */
 314         hostname[sizeof(hostname)-1] = '\0';
 315
 316         /* split off any parts after an initial . */
 317         p = strchr_m(hostname, '.');
 318         if (p) {
 319                 *p = 0;
 320         }
 321
 322         return talloc_strdup(ctx, hostname);
 323 }
 324
 325 /**
 326  Check if a process exists. Does this work on all unixes?
 327 **/
 328
 329 _PUBLIC_ bool process_exists_by_pid(pid_t pid)
 330 {
 331         /* Doing kill with a non-positive pid causes messages to be
 332          * sent to places we don't want. */
 333         if (pid <= 0) {
 334                 return false;
 335         }
 336         return(kill(pid,0) == 0 || errno != ESRCH);
 337 }
 338
 339 /**
 340  Simple routine to do POSIX file locking. Cruft in NFS and 64->32 bit mapping
 341  is dealt with in posix.c
 342 **/
 343
 344 _PUBLIC_ bool fcntl_lock(int fd, int op, off_t offset, off_t count, int type)
 345 {
 346         struct flock lock;
 347         int ret;
 348
 349         DEBUG(8,("fcntl_lock %d %d %.0f %.0f %d\n",fd,op,(double)offset,(double)count,type));
 350
 351         lock.l_type = type;
 352         lock.l_whence = SEEK_SET;
 353         lock.l_start = offset;
 354         lock.l_len = count;
 355         lock.l_pid = 0;
 356
 357         ret = fcntl(fd,op,&lock);
 358
 359         if (ret == -1 && errno != 0)
 360                 DEBUG(3,("fcntl_lock: fcntl lock gave errno %d (%s)\n",errno,strerror(errno)));
 361
 362         /* a lock query */
 363         if (op == F_GETLK) {
 364                 if ((ret != -1) &&
 365                                 (lock.l_type != F_UNLCK) &&
 366                                 (lock.l_pid != 0) &&
 367                                 (lock.l_pid != getpid())) {
 368                         DEBUG(3,("fcntl_lock: fd %d is locked by pid %d\n",fd,(int)lock.l_pid));
 369                         return true;
 370                 }
 371
 372                 /* it must be not locked or locked by me */
 373                 return false;
 374         }
 375
 376         /* a lock set or unset */
 377         if (ret == -1) {
 378                 DEBUG(3,("fcntl_lock: lock failed at offset %.0f count %.0f op %d type %d (%s)\n",
 379                         (double)offset,(double)count,op,type,strerror(errno)));
 380                 return false;
 381         }
 382
 383         /* everything went OK */
 384         DEBUG(8,("fcntl_lock: Lock call successful\n"));
 385
 386         return true;
 387 }
 388
 389 static void debugadd_cb(const char *buf, void *private_data)
 390 {
 391         int *plevel = (int *)private_data;
 392         DEBUGADD(*plevel, ("%s", buf));
 393 }
 394
 395 void print_asc_cb(const uint8_t *buf, int len,
 396                   void (*cb)(const char *buf, void *private_data),
 397                   void *private_data)
 398 {
 399         int i;
 400         char s[2];
 401         s[1] = 0;
 402
 403         for (i=0; i<len; i++) {
 404                 s[0] = isprint(buf[i]) ? buf[i] : '.';
 405                 cb(s, private_data);
 406         }
 407 }
 408
 409 void print_asc(int level, const uint8_t *buf,int len)
 410 {
 411         print_asc_cb(buf, len, debugadd_cb, &level);
 412 }
 413
 414 /**
 415  * Write dump of binary data to a callback
 416  */
 417 void dump_data_cb(const uint8_t *buf, int len,
 418                   bool omit_zero_bytes,
 419                   void (*cb)(const char *buf, void *private_data),
 420                   void *private_data)
 421 {
 422         int i=0;
 423         static const uint8_t empty[16] = { 0, };
 424         bool skipped = false;
 425         char tmp[16];
 426
 427         if (len<=0) return;
 428
 429         for (i=0;i<len;) {
 430
 431                 if (i%16 == 0) {
 432                         if ((omit_zero_bytes == true) &&
 433                             (i > 0) &&
 434                             (len > i+16) &&
 435                             (memcmp(&buf[i], &empty, 16) == 0))
 436                         {
 437                                 i +=16;
 438                                 continue;
 439                         }
 440
 441                         if (i<len)  {
 442                                 snprintf(tmp, sizeof(tmp), "[%04X] ", i);
 443                                 cb(tmp, private_data);
 444                         }
 445                 }
 446
 447                 snprintf(tmp, sizeof(tmp), "%02X ", (int)buf[i]);
 448                 cb(tmp, private_data);
 449                 i++;
 450                 if (i%8 == 0) {
 451                         cb("  ", private_data);
 452                 }
 453                 if (i%16 == 0) {
 454
 455                         print_asc_cb(&buf[i-16], 8, cb, private_data);
 456                         cb(" ", private_data);
 457                         print_asc_cb(&buf[i-8], 8, cb, private_data);
 458                         cb("\n", private_data);
 459
 460                         if ((omit_zero_bytes == true) &&
 461                             (len > i+16) &&
 462                             (memcmp(&buf[i], &empty, 16) == 0)) {
 463                                 if (!skipped) {
 464                                         cb("skipping zero buffer bytes\n",
 465                                            private_data);
 466                                         skipped = true;
 467                                 }
 468                         }
 469                 }
 470         }
 471
 472         if (i%16) {
 473                 int n;
 474                 n = 16 - (i%16);
 475                 cb(" ", private_data);
 476                 if (n>8) {
 477                         cb(" ", private_data);
 478                 }
 479                 while (n--) {
 480                         cb("   ", private_data);
 481                 }
 482                 n = MIN(8,i%16);
 483                 print_asc_cb(&buf[i-(i%16)], n, cb, private_data);
 484                 cb(" ", private_data);
 485                 n = (i%16) - n;
 486                 if (n>0) {
 487                         print_asc_cb(&buf[i-n], n, cb, private_data);
 488                 }
 489                 cb("\n", private_data);
 490         }
 491
 492 }
 493
 494 /**
 495  * Write dump of binary data to the log file.
 496  *
 497  * The data is only written if the log level is at least level.
 498  */
 499 _PUBLIC_ void dump_data(int level, const uint8_t *buf, int len)
 500 {
 501         if (!DEBUGLVL(level)) {
 502                 return;
 503         }
 504         dump_data_cb(buf, len, false, debugadd_cb, &level);
 505 }
 506
 507 /**
 508  * Write dump of binary data to the log file.
 509  *
 510  * The data is only written if the log level is at least level.
 511  * 16 zero bytes in a row are omitted
 512  */
 513 _PUBLIC_ void dump_data_skip_zeros(int level, const uint8_t *buf, int len)
 514 {
 515         if (!DEBUGLVL(level)) {
 516                 return;
 517         }
 518         dump_data_cb(buf, len, true, debugadd_cb, &level);
 519 }
 520
 521 static void fprintf_cb(const char *buf, void *private_data)
 522 {
 523         FILE *f = (FILE *)private_data;
 524         fprintf(f, "%s", buf);
 525 }
 526
 527 void dump_data_file(const uint8_t *buf, int len, bool omit_zero_bytes,
 528                     FILE *f)
 529 {
 530         dump_data_cb(buf, len, omit_zero_bytes, fprintf_cb, f);
 531 }
 532
 533 /**
 534  malloc that aborts with smb_panic on fail or zero size.
 535 **/
 536
 537 _PUBLIC_ void *smb_xmalloc(size_t size)
 538 {
 539         void *p;
 540         if (size == 0)
 541                 smb_panic("smb_xmalloc: called with zero size.\n");
 542         if ((p = malloc(size)) == NULL)
 543                 smb_panic("smb_xmalloc: malloc fail.\n");
 544         return p;
 545 }
 546
 547 /**
 548  Memdup with smb_panic on fail.
 549 **/
 550
 551 _PUBLIC_ void *smb_xmemdup(const void *p, size_t size)
 552 {
 553         void *p2;
 554         p2 = smb_xmalloc(size);
 555         memcpy(p2, p, size);
 556         return p2;
 557 }
 558
 559 /**
 560  strdup that aborts on malloc fail.
 561 **/
 562
 563 char *smb_xstrdup(const char *s)
 564 {
 565 #if defined(PARANOID_MALLOC_CHECKER)
 566 #ifdef strdup
 567 #undef strdup
 568 #endif
 569 #endif
 570
 571 #ifndef HAVE_STRDUP
 572 #define strdup rep_strdup
 573 #endif
 574
 575         char *s1 = strdup(s);
 576 #if defined(PARANOID_MALLOC_CHECKER)
 577 #ifdef strdup
 578 #undef strdup
 579 #endif
 580 #define strdup(s) __ERROR_DONT_USE_STRDUP_DIRECTLY
 581 #endif
 582         if (!s1) {
 583                 smb_panic("smb_xstrdup: malloc failed");
 584         }
 585         return s1;
 586
 587 }
 588
 589 /**
 590  strndup that aborts on malloc fail.
 591 **/
 592
 593 char *smb_xstrndup(const char *s, size_t n)
 594 {
 595 #if defined(PARANOID_MALLOC_CHECKER)
 596 #ifdef strndup
 597 #undef strndup
 598 #endif
 599 #endif
 600
 601 #if (defined(BROKEN_STRNDUP) || !defined(HAVE_STRNDUP))
 602 #undef HAVE_STRNDUP
 603 #define strndup rep_strndup
 604 #endif
 605
 606         char *s1 = strndup(s, n);
 607 #if defined(PARANOID_MALLOC_CHECKER)
 608 #ifdef strndup
 609 #undef strndup
 610 #endif
 611 #define strndup(s,n) __ERROR_DONT_USE_STRNDUP_DIRECTLY
 612 #endif
 613         if (!s1) {
 614                 smb_panic("smb_xstrndup: malloc failed");
 615         }
 616         return s1;
 617 }
 618
 619
 620
 621 /**
 622  Like strdup but for memory.
 623 **/
 624
 625 _PUBLIC_ void *memdup(const void *p, size_t size)
 626 {
 627         void *p2;
 628         if (size == 0)
 629                 return NULL;
 630         p2 = malloc(size);
 631         if (!p2)
 632                 return NULL;
 633         memcpy(p2, p, size);
 634         return p2;
 635 }
 636
 637 /**
 638  * Write a password to the log file.
 639  *
 640  * @note Only actually does something if DEBUG_PASSWORD was defined during
 641  * compile-time.
 642  */
 643 _PUBLIC_ void dump_data_pw(const char *msg, const uint8_t * data, size_t len)
 644 {
 645 #ifdef DEBUG_PASSWORD
 646         DEBUG(11, ("%s", msg));
 647         if (data != NULL && len > 0)
 648         {
 649                 dump_data(11, data, len);
 650         }
 651 #endif
 652 }
 653
 654
 655 /**
 656  * see if a range of memory is all zero. A NULL pointer is considered
 657  * to be all zero
 658  */
 659 _PUBLIC_ bool all_zero(const uint8_t *ptr, size_t size)
 660 {
 661         int i;
 662         if (!ptr) return true;
 663         for (i=0;i<size;i++) {
 664                 if (ptr[i]) return false;
 665         }
 666         return true;
 667 }
 668
 669 /**
 670   realloc an array, checking for integer overflow in the array size
 671 */
 672 _PUBLIC_ void *realloc_array(void *ptr, size_t el_size, unsigned count, bool free_on_fail)
 673 {
 674 #define MAX_MALLOC_SIZE 0x7fffffff
 675         if (count == 0 ||
 676             count >= MAX_MALLOC_SIZE/el_size) {
 677                 if (free_on_fail)
 678                         SAFE_FREE(ptr);
 679                 return NULL;
 680         }
 681         if (!ptr) {
 682                 return malloc(el_size * count);
 683         }
 684         return realloc(ptr, el_size * count);
 685 }
 686
 687 /****************************************************************************
 688  Type-safe malloc.
 689 ****************************************************************************/
 690
 691 void *malloc_array(size_t el_size, unsigned int count)
 692 {
 693         return realloc_array(NULL, el_size, count, false);
 694 }
 695
 696 /****************************************************************************
 697  Type-safe memalign
 698 ****************************************************************************/
 699
 700 void *memalign_array(size_t el_size, size_t align, unsigned int count)
 701 {
 702         if (count*el_size >= MAX_MALLOC_SIZE) {
 703                 return NULL;
 704         }
 705
 706         return memalign(align, el_size*count);
 707 }
 708
 709 /****************************************************************************
 710  Type-safe calloc.
 711 ****************************************************************************/
 712
 713 void *calloc_array(size_t size, size_t nmemb)
 714 {
 715         if (nmemb >= MAX_MALLOC_SIZE/size) {
 716                 return NULL;
 717         }
 718         if (size == 0 || nmemb == 0) {
 719                 return NULL;
 720         }
 721         return calloc(nmemb, size);
 722 }
 723
 724 /**
 725  Trim the specified elements off the front and back of a string.
 726 **/
 727 _PUBLIC_ bool trim_string(char *s, const char *front, const char *back)
 728 {
 729         bool ret = false;
 730         size_t front_len;
 731         size_t back_len;
 732         size_t len;
 733
 734         /* Ignore null or empty strings. */
 735         if (!s || (s[0] == '\0'))
 736                 return false;
 737
 738         front_len       = front? strlen(front) : 0;
 739         back_len        = back? strlen(back) : 0;
 740
 741         len = strlen(s);
 742
 743         if (front_len) {
 744                 while (len && strncmp(s, front, front_len)==0) {
 745                         /* Must use memmove here as src & dest can
 746                          * easily overlap. Found by valgrind. JRA. */
 747                         memmove(s, s+front_len, (len-front_len)+1);
 748                         len -= front_len;
 749                         ret=true;
 750                 }
 751         }
 752
 753         if (back_len) {
 754                 while ((len >= back_len) && strncmp(s+len-back_len,back,back_len)==0) {
 755                         s[len-back_len]='\0';
 756                         len -= back_len;
 757                         ret=true;
 758                 }
 759         }
 760         return ret;
 761 }
 762
 763 /**
 764  Find the number of 'c' chars in a string
 765 **/
 766 _PUBLIC_ _PURE_ size_t count_chars(const char *s, char c)
 767 {
 768         size_t count = 0;
 769
 770         while (*s) {
 771                 if (*s == c) count++;
 772                 s ++;
 773         }
 774
 775         return count;
 776 }
 777
 778 /**
 779  * Routine to get hex characters and turn them into a byte array.
 780  * the array can be variable length.
 781  * -  "0xnn" or "0Xnn" is specially catered for.
 782  * - The first non-hex-digit character (apart from possibly leading "0x"
 783  *   finishes the conversion and skips the rest of the input.
 784  * - A single hex-digit character at the end of the string is skipped.
 785  *
 786  * valid examples: "0A5D15"; "0x123456"
 787  */
 788 _PUBLIC_ size_t strhex_to_str(char *p, size_t p_len, const char *strhex, size_t strhex_len)
 789 {
 790         size_t i = 0;
 791         size_t num_chars = 0;
 792         uint8_t   lonybble, hinybble;
 793         const char     *hexchars = "0123456789ABCDEF";
 794         char           *p1 = NULL, *p2 = NULL;
 795
 796         /* skip leading 0x prefix */
 797         if (strncasecmp(strhex, "0x", 2) == 0) {
 798                 i += 2; /* skip two chars */
 799         }
 800
 801         for (; i+1 < strhex_len && strhex[i] != 0 && strhex[i+1] != 0; i++) {
 802                 p1 = strchr(hexchars, toupper((unsigned char)strhex[i]));
 803                 if (p1 == NULL) {
 804                         break;
 805                 }
 806
 807                 i++; /* next hex digit */
 808
 809                 p2 = strchr(hexchars, toupper((unsigned char)strhex[i]));
 810                 if (p2 == NULL) {
 811                         break;
 812                 }
 813
 814                 /* get the two nybbles */
 815                 hinybble = PTR_DIFF(p1, hexchars);
 816                 lonybble = PTR_DIFF(p2, hexchars);
 817
 818                 if (num_chars >= p_len) {
 819                         break;
 820                 }
 821
 822                 p[num_chars] = (hinybble << 4) | lonybble;
 823                 num_chars++;
 824
 825                 p1 = NULL;
 826                 p2 = NULL;
 827         }
 828         return num_chars;
 829 }
 830
 831 /**
 832  * Parse a hex string and return a data blob.
 833  */
 834 _PUBLIC_ _PURE_ DATA_BLOB strhex_to_data_blob(TALLOC_CTX *mem_ctx, const char *strhex)
 835 {
 836         DATA_BLOB ret_blob = data_blob_talloc(mem_ctx, NULL, strlen(strhex)/2+1);
 837
 838         ret_blob.length = strhex_to_str((char *)ret_blob.data, ret_blob.length,
 839                                         strhex,
 840                                         strlen(strhex));
 841
 842         return ret_blob;
 843 }
 844
 845 /**
 846  * Print a buf in hex. Assumes dst is at least (srclen*2)+1 large.
 847  */
 848 _PUBLIC_ void hex_encode_buf(char *dst, const uint8_t *src, size_t srclen)
 849 {
 850         size_t i;
 851         for (i=0; i<srclen; i++) {
 852                 snprintf(dst + i*2, 3, "%02X", src[i]);
 853         }
 854         /*
 855          * Ensure 0-termination for 0-length buffers
 856          */
 857         dst[srclen*2] = '\0';
 858 }
 859
 860 /**
 861  * Routine to print a buffer as HEX digits, into an allocated string.
 862  */
 863 _PUBLIC_ void hex_encode(const unsigned char *buff_in, size_t len, char **out_hex_buffer)
 864 {
 865         char *hex_buffer;
 866
 867         *out_hex_buffer = malloc_array_p(char, (len*2)+1);
 868         hex_buffer = *out_hex_buffer;
 869         hex_encode_buf(hex_buffer, buff_in, len);
 870 }
 871
 872 /**
 873  * talloc version of hex_encode()
 874  */
 875 _PUBLIC_ char *hex_encode_talloc(TALLOC_CTX *mem_ctx, const unsigned char *buff_in, size_t len)
 876 {
 877         char *hex_buffer;
 878
 879         hex_buffer = talloc_array(mem_ctx, char, (len*2)+1);
 880         if (!hex_buffer) {
 881                 return NULL;
 882         }
 883         hex_encode_buf(hex_buffer, buff_in, len);
 884         talloc_set_name_const(hex_buffer, hex_buffer);
 885         return hex_buffer;
 886 }
 887
 888 /**
 889   varient of strcmp() that handles NULL ptrs
 890 **/
 891 _PUBLIC_ int strcmp_safe(const char *s1, const char *s2)
 892 {
 893         if (s1 == s2) {
 894                 return 0;
 895         }
 896         if (s1 == NULL || s2 == NULL) {
 897                 return s1?-1:1;
 898         }
 899         return strcmp(s1, s2);
 900 }
 901
 902
 903 /**
 904 return the number of bytes occupied by a buffer in ASCII format
 905 the result includes the null termination
 906 limited by 'n' bytes
 907 **/
 908 _PUBLIC_ size_t ascii_len_n(const char *src, size_t n)
 909 {
 910         size_t len;
 911
 912         len = strnlen(src, n);
 913         if (len+1 <= n) {
 914                 len += 1;
 915         }
 916
 917         return len;
 918 }
 919
 920 /**
 921  Set a boolean variable from the text value stored in the passed string.
 922  Returns true in success, false if the passed string does not correctly
 923  represent a boolean.
 924 **/
 925
 926 _PUBLIC_ bool set_boolean(const char *boolean_string, bool *boolean)
 927 {
 928         if (strwicmp(boolean_string, "yes") == 0 ||
 929             strwicmp(boolean_string, "true") == 0 ||
 930             strwicmp(boolean_string, "on") == 0 ||
 931             strwicmp(boolean_string, "1") == 0) {
 932                 *boolean = true;
 933                 return true;
 934         } else if (strwicmp(boolean_string, "no") == 0 ||
 935                    strwicmp(boolean_string, "false") == 0 ||
 936                    strwicmp(boolean_string, "off") == 0 ||
 937                    strwicmp(boolean_string, "0") == 0) {
 938                 *boolean = false;
 939                 return true;
 940         }
 941         return false;
 942 }
 943
 944 /**
 945 return the number of bytes occupied by a buffer in CH_UTF16 format
 946 the result includes the null termination
 947 **/
 948 _PUBLIC_ size_t utf16_len(const void *buf)
 949 {
 950         size_t len;
 951
 952         for (len = 0; SVAL(buf,len); len += 2) ;
 953
 954         return len + 2;
 955 }
 956
 957 /**
 958 return the number of bytes occupied by a buffer in CH_UTF16 format
 959 the result includes the null termination
 960 limited by 'n' bytes
 961 **/
 962 _PUBLIC_ size_t utf16_len_n(const void *src, size_t n)
 963 {
 964         size_t len;
 965
 966         for (len = 0; (len+2 < n) && SVAL(src, len); len += 2) ;
 967
 968         if (len+2 <= n) {
 969                 len += 2;
 970         }
 971
 972         return len;
 973 }
 974
 975 /**
 976  * @file
 977  * @brief String utilities.
 978  **/
 979
 980 static bool next_token_internal_talloc(TALLOC_CTX *ctx,
 981                                 const char **ptr,
 982                                 char **pp_buff,
 983                                 const char *sep,
 984                                 bool ltrim)
 985 {
 986         const char *s;
 987         const char *saved_s;
 988         char *pbuf;
 989         bool quoted;
 990         size_t len=1;
 991
 992         *pp_buff = NULL;
 993         if (!ptr) {
 994                 return(false);
 995         }
 996
 997         s = *ptr;
 998
 999         /* default to simple separators */
1000         if (!sep) {
1001                 sep = " \t\n\r";
1002         }
1003
1004         /* find the first non sep char, if left-trimming is requested */
1005         if (ltrim) {
1006                 while (*s && strchr_m(sep,*s)) {
1007                         s++;
1008                 }
1009         }
1010
1011         /* nothing left? */
1012         if (!*s) {
1013                 return false;
1014         }
1015
1016         /* When restarting we need to go from here. */
1017         saved_s = s;
1018
1019         /* Work out the length needed. */
1020         for (quoted = false; *s &&
1021                         (quoted || !strchr_m(sep,*s)); s++) {
1022                 if (*s == '\"') {
1023                         quoted = !quoted;
1024                 } else {
1025                         len++;
1026                 }
1027         }
1028
1029         /* We started with len = 1 so we have space for the nul. */
1030         *pp_buff = talloc_array(ctx, char, len);
1031         if (!*pp_buff) {
1032                 return false;
1033         }
1034
1035         /* copy over the token */
1036         pbuf = *pp_buff;
1037         s = saved_s;
1038         for (quoted = false; *s &&
1039                         (quoted || !strchr_m(sep,*s)); s++) {
1040                 if ( *s == '\"' ) {
1041                         quoted = !quoted;
1042                 } else {
1043                         *pbuf++ = *s;
1044                 }
1045         }
1046
1047         *ptr = (*s) ? s+1 : s;
1048         *pbuf = 0;
1049
1050         return true;
1051 }
1052
1053 bool next_token_talloc(TALLOC_CTX *ctx,
1054                         const char **ptr,
1055                         char **pp_buff,
1056                         const char *sep)
1057 {
1058         return next_token_internal_talloc(ctx, ptr, pp_buff, sep, true);
1059 }
1060
1061 /*
1062  * Get the next token from a string, return false if none found.  Handles
1063  * double-quotes.  This version does not trim leading separator characters
1064  * before looking for a token.
1065  */
1066
1067 bool next_token_no_ltrim_talloc(TALLOC_CTX *ctx,
1068                         const char **ptr,
1069                         char **pp_buff,
1070                         const char *sep)
1071 {
1072         return next_token_internal_talloc(ctx, ptr, pp_buff, sep, false);
1073 }
1074
1075 /**
1076  * Get the next token from a string, return False if none found.
1077  * Handles double-quotes.
1078  *
1079  * Based on a routine by GJC@VILLAGE.COM.
1080  * Extensively modified by Andrew.Tridgell@anu.edu.au
1081  **/
1082 _PUBLIC_ bool next_token(const char **ptr,char *buff, const char *sep, size_t bufsize)
1083 {
1084         const char *s;
1085         bool quoted;
1086         size_t len=1;
1087
1088         if (!ptr)
1089                 return false;
1090
1091         s = *ptr;
1092
1093         /* default to simple separators */
1094         if (!sep)
1095                 sep = " \t\n\r";
1096
1097         /* find the first non sep char */
1098         while (*s && strchr_m(sep,*s))
1099                 s++;
1100
1101         /* nothing left? */
1102         if (!*s)
1103                 return false;
1104
1105         /* copy over the token */
1106         for (quoted = false; len < bufsize && *s && (quoted || !strchr_m(sep,*s)); s++) {
1107                 if (*s == '\"') {
1108                         quoted = !quoted;
1109                 } else {
1110                         len++;
1111                         *buff++ = *s;
1112                 }
1113         }
1114
1115         *ptr = (*s) ? s+1 : s;
1116         *buff = 0;
1117
1118         return true;
1119 }
1120
1121 struct anonymous_shared_header {
1122         union {
1123                 size_t length;
1124                 uint8_t pad[16];
1125         } u;
1126 };
1127
1128 /* Map a shared memory buffer of at least nelem counters. */
1129 void *anonymous_shared_allocate(size_t orig_bufsz)
1130 {
1131         void *ptr;
1132         void *buf;
1133         size_t pagesz = getpagesize();
1134         size_t pagecnt;
1135         size_t bufsz = orig_bufsz;
1136         struct anonymous_shared_header *hdr;
1137
1138         bufsz += sizeof(*hdr);
1139
1140         /* round up to full pages */
1141         pagecnt = bufsz / pagesz;
1142         if (bufsz % pagesz) {
1143                 pagecnt += 1;
1144         }
1145         bufsz = pagesz * pagecnt;
1146
1147         if (orig_bufsz >= bufsz) {
1148                 /* integer wrap */
1149                 errno = ENOMEM;
1150                 return NULL;
1151         }
1152
1153 #ifdef MAP_ANON
1154         /* BSD */
1155         buf = mmap(NULL, bufsz, PROT_READ|PROT_WRITE, MAP_ANON|MAP_SHARED,
1156                         -1 /* fd */, 0 /* offset */);
1157 #else
1158 {
1159         int saved_errno;
1160         int fd;
1161
1162         fd = open("/dev/zero", O_RDWR);
1163         if (fd == -1) {
1164                 return NULL;
1165         }
1166
1167         buf = mmap(NULL, bufsz, PROT_READ|PROT_WRITE, MAP_FILE|MAP_SHARED,
1168                    fd, 0 /* offset */);
1169         saved_errno = errno;
1170         close(fd);
1171         errno = saved_errno;
1172 }
1173 #endif
1174
1175         if (buf == MAP_FAILED) {
1176                 return NULL;
1177         }
1178
1179         hdr = (struct anonymous_shared_header *)buf;
1180         hdr->u.length = bufsz;
1181
1182         ptr = (void *)(&hdr[1]);
1183
1184         return ptr;
1185 }
1186
1187 void *anonymous_shared_resize(void *ptr, size_t new_size, bool maymove)
1188 {
1189 #ifdef HAVE_MREMAP
1190         void *buf;
1191         size_t pagesz = getpagesize();
1192         size_t pagecnt;
1193         size_t bufsz;
1194         struct anonymous_shared_header *hdr;
1195         int flags = 0;
1196
1197         if (ptr == NULL) {
1198                 errno = EINVAL;
1199                 return NULL;
1200         }
1201
1202         hdr = (struct anonymous_shared_header *)ptr;
1203         hdr--;
1204         if (hdr->u.length > (new_size + sizeof(*hdr))) {
1205                 errno = EINVAL;
1206                 return NULL;
1207         }
1208
1209         bufsz = new_size + sizeof(*hdr);
1210
1211         /* round up to full pages */
1212         pagecnt = bufsz / pagesz;
1213         if (bufsz % pagesz) {
1214                 pagecnt += 1;
1215         }
1216         bufsz = pagesz * pagecnt;
1217
1218         if (new_size >= bufsz) {
1219                 /* integer wrap */
1220                 errno = ENOSPC;
1221                 return NULL;
1222         }
1223
1224         if (bufsz <= hdr->u.length) {
1225                 return ptr;
1226         }
1227
1228         if (maymove) {
1229                 flags = MREMAP_MAYMOVE;
1230         }
1231
1232         buf = mremap(hdr, hdr->u.length, bufsz, flags);
1233
1234         if (buf == MAP_FAILED) {
1235                 errno = ENOSPC;
1236                 return NULL;
1237         }
1238
1239         hdr = (struct anonymous_shared_header *)buf;
1240         hdr->u.length = bufsz;
1241
1242         ptr = (void *)(&hdr[1]);
1243
1244         return ptr;
1245 #else
1246         errno = ENOSPC;
1247         return NULL;
1248 #endif
1249 }
1250
1251 void anonymous_shared_free(void *ptr)
1252 {
1253         struct anonymous_shared_header *hdr;
1254
1255         if (ptr == NULL) {
1256                 return;
1257         }
1258
1259         hdr = (struct anonymous_shared_header *)ptr;
1260
1261         hdr--;
1262
1263         munmap(hdr, hdr->u.length);
1264 }
1265
1266 #ifdef DEVELOPER
1267 /* used when you want a debugger started at a particular point in the
1268    code. Mostly useful in code that runs as a child process, where
1269    normal gdb attach is harder to organise.
1270 */
1271 void samba_start_debugger(void)
1272 {
1273         char *cmd = NULL;
1274         if (asprintf(&cmd, "xterm -e \"gdb --pid %u\"&", getpid()) == -1) {
1275                 return;
1276         }
1277         if (system(cmd) == -1) {
1278                 free(cmd);
1279                 return;
1280         }
1281         free(cmd);
1282         sleep(2);
1283 }
1284 #endif