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 "replace.h"
  26 #include <talloc.h>
  27 #include "system/network.h"
  28 #include "system/filesys.h"
  29 #include "system/locale.h"
  30 #include "system/shmem.h"
  31 #include "system/passwd.h"
  32 #include "system/time.h"
  33 #include "system/wait.h"
  34 #include "debug.h"
  35 #include "samba_util.h"
  36 #include "lib/util/select.h"
  37
  38 #undef malloc
  39 #undef strcasecmp
  40 #undef strncasecmp
  41 #undef strdup
  42 #undef realloc
  43 #undef calloc
  44
  45 /**
  46  * @file
  47  * @brief Misc utility functions
  48  */
  49
  50 /**
  51  Find a suitable temporary directory. The result should be copied immediately
  52  as it may be overwritten by a subsequent call.
  53 **/
  54 _PUBLIC_ const char *tmpdir(void)
  55 {
  56         char *p;
  57         if ((p = getenv("TMPDIR")))
  58                 return p;
  59         return "/tmp";
  60 }
  61
  62
  63 /**
  64  Create a tmp file, open it and immediately unlink it.
  65  If dir is NULL uses tmpdir()
  66  Returns the file descriptor or -1 on error.
  67 **/
  68 int create_unlink_tmp(const char *dir)
  69 {
  70         size_t len = strlen(dir ? dir : (dir = tmpdir()));
  71         char fname[len+25];
  72         int fd;
  73         mode_t mask;
  74
  75         len = snprintf(fname, sizeof(fname), "%s/listenerlock_XXXXXX", dir);
  76         if (len >= sizeof(fname)) {
  77                 errno = ENOMEM;
  78                 return -1;
  79         }
  80         mask = umask(S_IRWXO | S_IRWXG);
  81         fd = mkstemp(fname);
  82         umask(mask);
  83         if (fd == -1) {
  84                 return -1;
  85         }
  86         if (unlink(fname) == -1) {
  87                 int sys_errno = errno;
  88                 close(fd);
  89                 errno = sys_errno;
  90                 return -1;
  91         }
  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 file permissions.
 126 **/
 127
 128 _PUBLIC_ bool file_check_permissions(const char *fname,
 129                                      uid_t uid,
 130                                      mode_t file_perms,
 131                                      struct stat *pst)
 132 {
 133         int ret;
 134         struct stat st;
 135
 136         if (pst == NULL) {
 137                 pst = &st;
 138         }
 139
 140         ZERO_STRUCTP(pst);
 141
 142         ret = stat(fname, pst);
 143         if (ret != 0) {
 144                 DEBUG(0, ("stat failed on file '%s': %s\n",
 145                          fname, strerror(errno)));
 146                 return false;
 147         }
 148
 149         if (pst->st_uid != uid && !uid_wrapper_enabled()) {
 150                 DEBUG(0, ("invalid ownership of file '%s': "
 151                          "owned by uid %u, should be %u\n",
 152                          fname, (unsigned int)pst->st_uid,
 153                          (unsigned int)uid));
 154                 return false;
 155         }
 156
 157         if ((pst->st_mode & 0777) != file_perms) {
 158                 DEBUG(0, ("invalid permissions on file "
 159                          "'%s': has 0%o should be 0%o\n", fname,
 160                          (unsigned int)(pst->st_mode & 0777),
 161                          (unsigned int)file_perms));
 162                 return false;
 163         }
 164
 165         return true;
 166 }
 167
 168 /**
 169  Check if a directory exists.
 170 **/
 171
 172 _PUBLIC_ bool directory_exist(const char *dname)
 173 {
 174         struct stat st;
 175         bool ret;
 176
 177         if (stat(dname,&st) != 0) {
 178                 return false;
 179         }
 180
 181         ret = S_ISDIR(st.st_mode);
 182         if(!ret)
 183                 errno = ENOTDIR;
 184         return ret;
 185 }
 186
 187 /**
 188  * Try to create the specified directory if it didn't exist.
 189  *
 190  * @retval true if the directory already existed
 191  * or was successfully created.
 192  */
 193 _PUBLIC_ bool directory_create_or_exist(const char *dname,
 194                                         mode_t dir_perms)
 195 {
 196         int ret;
 197         mode_t old_umask;
 198
 199         /* Create directory */
 200         old_umask = umask(0);
 201         ret = mkdir(dname, dir_perms);
 202         if (ret == -1 && errno != EEXIST) {
 203                 DEBUG(0, ("mkdir failed on directory "
 204                           "%s: %s\n", dname,
 205                           strerror(errno)));
 206                 umask(old_umask);
 207                 return false;
 208         }
 209         umask(old_umask);
 210
 211         if (ret != 0 && errno == EEXIST) {
 212                 struct stat sbuf;
 213
 214                 ret = lstat(dname, &sbuf);
 215                 if (ret != 0) {
 216                         return false;
 217                 }
 218
 219                 if (!S_ISDIR(sbuf.st_mode)) {
 220                         return false;
 221                 }
 222         }
 223
 224         return true;
 225 }
 226
 227 /**
 228  * @brief Try to create a specified directory if it doesn't exist.
 229  *
 230  * The function creates a directory with the given uid and permissions if it
 231  * doesn't exist. If it exists it makes sure the uid and permissions are
 232  * correct and it will fail if they are different.
 233  *
 234  * @param[in]  dname  The directory to create.
 235  *
 236  * @param[in]  uid    The uid the directory needs to belong too.
 237  *
 238  * @param[in]  dir_perms  The expected permissions of the directory.
 239  *
 240  * @return True on success, false on error.
 241  */
 242 _PUBLIC_ bool directory_create_or_exist_strict(const char *dname,
 243                                                uid_t uid,
 244                                                mode_t dir_perms)
 245 {
 246         struct stat st;
 247         bool ok;
 248         int rc;
 249
 250         ok = directory_create_or_exist(dname, dir_perms);
 251         if (!ok) {
 252                 return false;
 253         }
 254
 255         rc = lstat(dname, &st);
 256         if (rc == -1) {
 257                 DEBUG(0, ("lstat failed on created directory %s: %s\n",
 258                           dname, strerror(errno)));
 259                 return false;
 260         }
 261
 262         /* Check ownership and permission on existing directory */
 263         if (!S_ISDIR(st.st_mode)) {
 264                 DEBUG(0, ("directory %s isn't a directory\n",
 265                         dname));
 266                 return false;
 267         }
 268         if (st.st_uid != uid && !uid_wrapper_enabled()) {
 269                 DBG_NOTICE("invalid ownership on directory "
 270                           "%s\n", dname);
 271                 return false;
 272         }
 273         if ((st.st_mode & 0777) != dir_perms) {
 274                 DEBUG(0, ("invalid permissions on directory "
 275                           "'%s': has 0%o should be 0%o\n", dname,
 276                           (unsigned int)(st.st_mode & 0777), (unsigned int)dir_perms));
 277                 return false;
 278         }
 279
 280         return true;
 281 }
 282
 283
 284 /**
 285  Sleep for a specified number of milliseconds.
 286 **/
 287
 288 _PUBLIC_ void smb_msleep(unsigned int t)
 289 {
 290         sys_poll_intr(NULL, 0, t);
 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 struct debug_channel_level {
 385         int channel;
 386         int level;
 387 };
 388
 389 static void debugadd_channel_cb(const char *buf, void *private_data)
 390 {
 391         struct debug_channel_level *dcl =
 392                 (struct debug_channel_level *)private_data;
 393
 394         DEBUGADDC(dcl->channel, dcl->level,("%s", buf));
 395 }
 396
 397 static void debugadd_cb(const char *buf, void *private_data)
 398 {
 399         int *plevel = (int *)private_data;
 400         DEBUGADD(*plevel, ("%s", buf));
 401 }
 402
 403 void print_asc_cb(const uint8_t *buf, int len,
 404                   void (*cb)(const char *buf, void *private_data),
 405                   void *private_data)
 406 {
 407         int i;
 408         char s[2];
 409         s[1] = 0;
 410
 411         for (i=0; i<len; i++) {
 412                 s[0] = isprint(buf[i]) ? buf[i] : '.';
 413                 cb(s, private_data);
 414         }
 415 }
 416
 417 void print_asc(int level, const uint8_t *buf,int len)
 418 {
 419         print_asc_cb(buf, len, debugadd_cb, &level);
 420 }
 421
 422 /**
 423  * Write dump of binary data to a callback
 424  */
 425 void dump_data_cb(const uint8_t *buf, int len,
 426                   bool omit_zero_bytes,
 427                   void (*cb)(const char *buf, void *private_data),
 428                   void *private_data)
 429 {
 430         int i=0;
 431         bool skipped = false;
 432         char tmp[16];
 433
 434         if (len<=0) return;
 435
 436         for (i=0;i<len;) {
 437
 438                 if (i%16 == 0) {
 439                         if ((omit_zero_bytes == true) &&
 440                             (i > 0) &&
 441                             (len > i+16) &&
 442                             all_zero(&buf[i], 16))
 443                         {
 444                                 i +=16;
 445                                 continue;
 446                         }
 447
 448                         if (i<len)  {
 449                                 snprintf(tmp, sizeof(tmp), "[%04X] ", i);
 450                                 cb(tmp, private_data);
 451                         }
 452                 }
 453
 454                 snprintf(tmp, sizeof(tmp), "%02X ", (int)buf[i]);
 455                 cb(tmp, private_data);
 456                 i++;
 457                 if (i%8 == 0) {
 458                         cb("  ", private_data);
 459                 }
 460                 if (i%16 == 0) {
 461
 462                         print_asc_cb(&buf[i-16], 8, cb, private_data);
 463                         cb(" ", private_data);
 464                         print_asc_cb(&buf[i-8], 8, cb, private_data);
 465                         cb("\n", private_data);
 466
 467                         if ((omit_zero_bytes == true) &&
 468                             (len > i+16) &&
 469                             all_zero(&buf[i], 16)) {
 470                                 if (!skipped) {
 471                                         cb("skipping zero buffer bytes\n",
 472                                            private_data);
 473                                         skipped = true;
 474                                 }
 475                         }
 476                 }
 477         }
 478
 479         if (i%16) {
 480                 int n;
 481                 n = 16 - (i%16);
 482                 cb("  ", private_data);
 483                 if (n>8) {
 484                         cb(" ", private_data);
 485                 }
 486                 while (n--) {
 487                         cb("   ", private_data);
 488                 }
 489                 n = MIN(8,i%16);
 490                 print_asc_cb(&buf[i-(i%16)], n, cb, private_data);
 491                 cb(" ", private_data);
 492                 n = (i%16) - n;
 493                 if (n>0) {
 494                         print_asc_cb(&buf[i-n], n, cb, private_data);
 495                 }
 496                 cb("\n", private_data);
 497         }
 498
 499 }
 500
 501 /**
 502  * Write dump of binary data to the log file.
 503  *
 504  * The data is only written if the log level is at least level.
 505  */
 506 _PUBLIC_ void dump_data(int level, const uint8_t *buf, int len)
 507 {
 508         if (!DEBUGLVL(level)) {
 509                 return;
 510         }
 511         dump_data_cb(buf, len, false, debugadd_cb, &level);
 512 }
 513
 514 /**
 515  * Write dump of binary data to the log file.
 516  *
 517  * The data is only written if the log level is at least level for
 518  * debug class dbgc_class.
 519  */
 520 _PUBLIC_ void dump_data_dbgc(int dbgc_class, int level, const uint8_t *buf, int len)
 521 {
 522         struct debug_channel_level dcl = { dbgc_class, level };
 523
 524         if (!DEBUGLVLC(dbgc_class, level)) {
 525                 return;
 526         }
 527         dump_data_cb(buf, len, false, debugadd_channel_cb, &dcl);
 528 }
 529
 530 /**
 531  * Write dump of binary data to the log file.
 532  *
 533  * The data is only written if the log level is at least level.
 534  * 16 zero bytes in a row are omitted
 535  */
 536 _PUBLIC_ void dump_data_skip_zeros(int level, const uint8_t *buf, int len)
 537 {
 538         if (!DEBUGLVL(level)) {
 539                 return;
 540         }
 541         dump_data_cb(buf, len, true, debugadd_cb, &level);
 542 }
 543
 544 static void fprintf_cb(const char *buf, void *private_data)
 545 {
 546         FILE *f = (FILE *)private_data;
 547         fprintf(f, "%s", buf);
 548 }
 549
 550 void dump_data_file(const uint8_t *buf, int len, bool omit_zero_bytes,
 551                     FILE *f)
 552 {
 553         dump_data_cb(buf, len, omit_zero_bytes, fprintf_cb, f);
 554 }
 555
 556 /**
 557  malloc that aborts with smb_panic on fail or zero size.
 558 **/
 559
 560 _PUBLIC_ void *smb_xmalloc(size_t size)
 561 {
 562         void *p;
 563         if (size == 0)
 564                 smb_panic("smb_xmalloc: called with zero size.\n");
 565         if ((p = malloc(size)) == NULL)
 566                 smb_panic("smb_xmalloc: malloc fail.\n");
 567         return p;
 568 }
 569
 570 /**
 571  Memdup with smb_panic on fail.
 572 **/
 573
 574 _PUBLIC_ void *smb_xmemdup(const void *p, size_t size)
 575 {
 576         void *p2;
 577         p2 = smb_xmalloc(size);
 578         memcpy(p2, p, size);
 579         return p2;
 580 }
 581
 582 /**
 583  strdup that aborts on malloc fail.
 584 **/
 585
 586 char *smb_xstrdup(const char *s)
 587 {
 588 #if defined(PARANOID_MALLOC_CHECKER)
 589 #ifdef strdup
 590 #undef strdup
 591 #endif
 592 #endif
 593
 594 #ifndef HAVE_STRDUP
 595 #define strdup rep_strdup
 596 #endif
 597
 598         char *s1 = strdup(s);
 599 #if defined(PARANOID_MALLOC_CHECKER)
 600 #ifdef strdup
 601 #undef strdup
 602 #endif
 603 #define strdup(s) __ERROR_DONT_USE_STRDUP_DIRECTLY
 604 #endif
 605         if (!s1) {
 606                 smb_panic("smb_xstrdup: malloc failed");
 607         }
 608         return s1;
 609
 610 }
 611
 612 /**
 613  strndup that aborts on malloc fail.
 614 **/
 615
 616 char *smb_xstrndup(const char *s, size_t n)
 617 {
 618 #if defined(PARANOID_MALLOC_CHECKER)
 619 #ifdef strndup
 620 #undef strndup
 621 #endif
 622 #endif
 623
 624 #if (defined(BROKEN_STRNDUP) || !defined(HAVE_STRNDUP))
 625 #undef HAVE_STRNDUP
 626 #define strndup rep_strndup
 627 #endif
 628
 629         char *s1 = strndup(s, n);
 630 #if defined(PARANOID_MALLOC_CHECKER)
 631 #ifdef strndup
 632 #undef strndup
 633 #endif
 634 #define strndup(s,n) __ERROR_DONT_USE_STRNDUP_DIRECTLY
 635 #endif
 636         if (!s1) {
 637                 smb_panic("smb_xstrndup: malloc failed");
 638         }
 639         return s1;
 640 }
 641
 642
 643
 644 /**
 645  Like strdup but for memory.
 646 **/
 647
 648 _PUBLIC_ void *smb_memdup(const void *p, size_t size)
 649 {
 650         void *p2;
 651         if (size == 0)
 652                 return NULL;
 653         p2 = malloc(size);
 654         if (!p2)
 655                 return NULL;
 656         memcpy(p2, p, size);
 657         return p2;
 658 }
 659
 660 /**
 661  * Write a password to the log file.
 662  *
 663  * @note Only actually does something if DEBUG_PASSWORD was defined during
 664  * compile-time.
 665  */
 666 _PUBLIC_ void dump_data_pw(const char *msg, const uint8_t * data, size_t len)
 667 {
 668 #ifdef DEBUG_PASSWORD
 669         DEBUG(11, ("%s", msg));
 670         if (data != NULL && len > 0)
 671         {
 672                 dump_data(11, data, len);
 673         }
 674 #endif
 675 }
 676
 677
 678 /**
 679  * see if a range of memory is all zero. A NULL pointer is considered
 680  * to be all zero
 681  */
 682 _PUBLIC_ bool all_zero(const uint8_t *ptr, size_t size)
 683 {
 684         size_t i;
 685         if (!ptr) return true;
 686         for (i=0;i<size;i++) {
 687                 if (ptr[i]) return false;
 688         }
 689         return true;
 690 }
 691
 692 /**
 693   realloc an array, checking for integer overflow in the array size
 694 */
 695 _PUBLIC_ void *realloc_array(void *ptr, size_t el_size, unsigned count, bool free_on_fail)
 696 {
 697 #define MAX_MALLOC_SIZE 0x7fffffff
 698         if (count == 0 ||
 699             count >= MAX_MALLOC_SIZE/el_size) {
 700                 if (free_on_fail)
 701                         SAFE_FREE(ptr);
 702                 return NULL;
 703         }
 704         if (!ptr) {
 705                 return malloc(el_size * count);
 706         }
 707         return realloc(ptr, el_size * count);
 708 }
 709
 710 /****************************************************************************
 711  Type-safe malloc.
 712 ****************************************************************************/
 713
 714 void *malloc_array(size_t el_size, unsigned int count)
 715 {
 716         return realloc_array(NULL, el_size, count, false);
 717 }
 718
 719 /****************************************************************************
 720  Type-safe memalign
 721 ****************************************************************************/
 722
 723 void *memalign_array(size_t el_size, size_t align, unsigned int count)
 724 {
 725         if (el_size == 0 || count >= MAX_MALLOC_SIZE/el_size) {
 726                 return NULL;
 727         }
 728
 729         return memalign(align, el_size*count);
 730 }
 731
 732 /****************************************************************************
 733  Type-safe calloc.
 734 ****************************************************************************/
 735
 736 void *calloc_array(size_t size, size_t nmemb)
 737 {
 738         if (nmemb >= MAX_MALLOC_SIZE/size) {
 739                 return NULL;
 740         }
 741         if (size == 0 || nmemb == 0) {
 742                 return NULL;
 743         }
 744         return calloc(nmemb, size);
 745 }
 746
 747 /**
 748  Trim the specified elements off the front and back of a string.
 749 **/
 750 _PUBLIC_ bool trim_string(char *s, const char *front, const char *back)
 751 {
 752         bool ret = false;
 753         size_t front_len;
 754         size_t back_len;
 755         size_t len;
 756
 757         /* Ignore null or empty strings. */
 758         if (!s || (s[0] == '\0')) {
 759                 return false;
 760         }
 761         len = strlen(s);
 762
 763         front_len       = front? strlen(front) : 0;
 764         back_len        = back? strlen(back) : 0;
 765
 766         if (front_len) {
 767                 size_t front_trim = 0;
 768
 769                 while (strncmp(s+front_trim, front, front_len)==0) {
 770                         front_trim += front_len;
 771                 }
 772                 if (front_trim > 0) {
 773                         /* Must use memmove here as src & dest can
 774                          * easily overlap. Found by valgrind. JRA. */
 775                         memmove(s, s+front_trim, (len-front_trim)+1);
 776                         len -= front_trim;
 777                         ret=true;
 778                 }
 779         }
 780
 781         if (back_len) {
 782                 while ((len >= back_len) && strncmp(s+len-back_len,back,back_len)==0) {
 783                         s[len-back_len]='\0';
 784                         len -= back_len;
 785                         ret=true;
 786                 }
 787         }
 788         return ret;
 789 }
 790
 791 /**
 792  Find the number of 'c' chars in a string
 793 **/
 794 _PUBLIC_ _PURE_ size_t count_chars(const char *s, char c)
 795 {
 796         size_t count = 0;
 797
 798         while (*s) {
 799                 if (*s == c) count++;
 800                 s ++;
 801         }
 802
 803         return count;
 804 }
 805
 806 /**
 807  * Routine to get hex characters and turn them into a byte array.
 808  * the array can be variable length.
 809  * -  "0xnn" or "0Xnn" is specially catered for.
 810  * - The first non-hex-digit character (apart from possibly leading "0x"
 811  *   finishes the conversion and skips the rest of the input.
 812  * - A single hex-digit character at the end of the string is skipped.
 813  *
 814  * valid examples: "0A5D15"; "0x123456"
 815  */
 816 _PUBLIC_ size_t strhex_to_str(char *p, size_t p_len, const char *strhex, size_t strhex_len)
 817 {
 818         size_t i = 0;
 819         size_t num_chars = 0;
 820         uint8_t   lonybble, hinybble;
 821         const char     *hexchars = "0123456789ABCDEF";
 822         char           *p1 = NULL, *p2 = NULL;
 823
 824         /* skip leading 0x prefix */
 825         if (strncasecmp(strhex, "0x", 2) == 0) {
 826                 i += 2; /* skip two chars */
 827         }
 828
 829         for (; i+1 < strhex_len && strhex[i] != 0 && strhex[i+1] != 0; i++) {
 830                 p1 = strchr(hexchars, toupper((unsigned char)strhex[i]));
 831                 if (p1 == NULL) {
 832                         break;
 833                 }
 834
 835                 i++; /* next hex digit */
 836
 837                 p2 = strchr(hexchars, toupper((unsigned char)strhex[i]));
 838                 if (p2 == NULL) {
 839                         break;
 840                 }
 841
 842                 /* get the two nybbles */
 843                 hinybble = PTR_DIFF(p1, hexchars);
 844                 lonybble = PTR_DIFF(p2, hexchars);
 845
 846                 if (num_chars >= p_len) {
 847                         break;
 848                 }
 849
 850                 p[num_chars] = (hinybble << 4) | lonybble;
 851                 num_chars++;
 852
 853                 p1 = NULL;
 854                 p2 = NULL;
 855         }
 856         return num_chars;
 857 }
 858
 859 /**
 860  * Parse a hex string and return a data blob.
 861  */
 862 _PUBLIC_ _PURE_ DATA_BLOB strhex_to_data_blob(TALLOC_CTX *mem_ctx, const char *strhex)
 863 {
 864         DATA_BLOB ret_blob = data_blob_talloc(mem_ctx, NULL, strlen(strhex)/2+1);
 865
 866         ret_blob.length = strhex_to_str((char *)ret_blob.data, ret_blob.length,
 867                                         strhex,
 868                                         strlen(strhex));
 869
 870         return ret_blob;
 871 }
 872
 873 /**
 874  * Parse a hex dump and return a data blob. Hex dump is structured as
 875  * is generated from dump_data_cb() elsewhere in this file
 876  *
 877  */
 878 _PUBLIC_ _PURE_ DATA_BLOB hexdump_to_data_blob(TALLOC_CTX *mem_ctx, const char *hexdump, size_t hexdump_len)
 879 {
 880         DATA_BLOB ret_blob = { 0 };
 881         size_t i = 0;
 882         size_t char_count = 0;
 883         /* hexdump line length is 77 chars long. We then use the ASCII representation of the bytes
 884          * at the end of the final line to calculate how many are in that line, minus the extra space
 885          * and newline. */
 886         size_t hexdump_byte_count = (16 * (hexdump_len / 77));
 887         if (hexdump_len % 77) {
 888                 hexdump_byte_count += ((hexdump_len % 77) - 59 - 2);
 889         }
 890
 891         ret_blob = data_blob_talloc(mem_ctx, NULL, hexdump_byte_count+1);
 892         for (; i+1 < hexdump_len && hexdump[i] != 0 && hexdump[i+1] != 0; i++) {
 893                 if ((i%77) == 0)
 894                         i += 7; /* Skip the offset at the start of the line */
 895                 if ((i%77) < 56) { /* position 56 is after both hex chunks */
 896                         if (hexdump[i] != ' ') {
 897                                 char_count += strhex_to_str((char *)&ret_blob.data[char_count],
 898                                                             hexdump_byte_count - char_count,
 899                                                             &hexdump[i], 2);
 900                                 i += 2;
 901                         } else {
 902                                 i++;
 903                         }
 904                 } else {
 905                         i++;
 906                 }
 907         }
 908         ret_blob.length = char_count;
 909
 910         return ret_blob;
 911 }
 912
 913 /**
 914  * Print a buf in hex. Assumes dst is at least (srclen*2)+1 large.
 915  */
 916 _PUBLIC_ void hex_encode_buf(char *dst, const uint8_t *src, size_t srclen)
 917 {
 918         size_t i;
 919         for (i=0; i<srclen; i++) {
 920                 snprintf(dst + i*2, 3, "%02X", src[i]);
 921         }
 922         /*
 923          * Ensure 0-termination for 0-length buffers
 924          */
 925         dst[srclen*2] = '\0';
 926 }
 927
 928 /**
 929  * talloc version of hex_encode_buf()
 930  */
 931 _PUBLIC_ char *hex_encode_talloc(TALLOC_CTX *mem_ctx, const unsigned char *buff_in, size_t len)
 932 {
 933         char *hex_buffer;
 934
 935         hex_buffer = talloc_array(mem_ctx, char, (len*2)+1);
 936         if (!hex_buffer) {
 937                 return NULL;
 938         }
 939         hex_encode_buf(hex_buffer, buff_in, len);
 940         talloc_set_name_const(hex_buffer, hex_buffer);
 941         return hex_buffer;
 942 }
 943
 944 /**
 945   varient of strcmp() that handles NULL ptrs
 946 **/
 947 _PUBLIC_ int strcmp_safe(const char *s1, const char *s2)
 948 {
 949         if (s1 == s2) {
 950                 return 0;
 951         }
 952         if (s1 == NULL || s2 == NULL) {
 953                 return s1?-1:1;
 954         }
 955         return strcmp(s1, s2);
 956 }
 957
 958
 959 /**
 960 return the number of bytes occupied by a buffer in ASCII format
 961 the result includes the null termination
 962 limited by 'n' bytes
 963 **/
 964 _PUBLIC_ size_t ascii_len_n(const char *src, size_t n)
 965 {
 966         size_t len;
 967
 968         len = strnlen(src, n);
 969         if (len+1 <= n) {
 970                 len += 1;
 971         }
 972
 973         return len;
 974 }
 975
 976 struct anonymous_shared_header {
 977         union {
 978                 size_t length;
 979                 uint8_t pad[16];
 980         } u;
 981 };
 982
 983 /* Map a shared memory buffer of at least nelem counters. */
 984 void *anonymous_shared_allocate(size_t orig_bufsz)
 985 {
 986         void *ptr;
 987         void *buf;
 988         size_t pagesz = getpagesize();
 989         size_t pagecnt;
 990         size_t bufsz = orig_bufsz;
 991         struct anonymous_shared_header *hdr;
 992
 993         bufsz += sizeof(*hdr);
 994
 995         /* round up to full pages */
 996         pagecnt = bufsz / pagesz;
 997         if (bufsz % pagesz) {
 998                 pagecnt += 1;
 999         }
1000         bufsz = pagesz * pagecnt;
1001
1002         if (orig_bufsz >= bufsz) {
1003                 /* integer wrap */
1004                 errno = ENOMEM;
1005                 return NULL;
1006         }
1007
1008 #ifdef MAP_ANON
1009         /* BSD */
1010         buf = mmap(NULL, bufsz, PROT_READ|PROT_WRITE, MAP_ANON|MAP_SHARED,
1011                         -1 /* fd */, 0 /* offset */);
1012 #else
1013 {
1014         int saved_errno;
1015         int fd;
1016
1017         fd = open("/dev/zero", O_RDWR);
1018         if (fd == -1) {
1019                 return NULL;
1020         }
1021
1022         buf = mmap(NULL, bufsz, PROT_READ|PROT_WRITE, MAP_FILE|MAP_SHARED,
1023                    fd, 0 /* offset */);
1024         saved_errno = errno;
1025         close(fd);
1026         errno = saved_errno;
1027 }
1028 #endif
1029
1030         if (buf == MAP_FAILED) {
1031                 return NULL;
1032         }
1033
1034         hdr = (struct anonymous_shared_header *)buf;
1035         hdr->u.length = bufsz;
1036
1037         ptr = (void *)(&hdr[1]);
1038
1039         return ptr;
1040 }
1041
1042 void *anonymous_shared_resize(void *ptr, size_t new_size, bool maymove)
1043 {
1044 #ifdef HAVE_MREMAP
1045         void *buf;
1046         size_t pagesz = getpagesize();
1047         size_t pagecnt;
1048         size_t bufsz;
1049         struct anonymous_shared_header *hdr;
1050         int flags = 0;
1051
1052         if (ptr == NULL) {
1053                 errno = EINVAL;
1054                 return NULL;
1055         }
1056
1057         hdr = (struct anonymous_shared_header *)ptr;
1058         hdr--;
1059         if (hdr->u.length > (new_size + sizeof(*hdr))) {
1060                 errno = EINVAL;
1061                 return NULL;
1062         }
1063
1064         bufsz = new_size + sizeof(*hdr);
1065
1066         /* round up to full pages */
1067         pagecnt = bufsz / pagesz;
1068         if (bufsz % pagesz) {
1069                 pagecnt += 1;
1070         }
1071         bufsz = pagesz * pagecnt;
1072
1073         if (new_size >= bufsz) {
1074                 /* integer wrap */
1075                 errno = ENOSPC;
1076                 return NULL;
1077         }
1078
1079         if (bufsz <= hdr->u.length) {
1080                 return ptr;
1081         }
1082
1083         if (maymove) {
1084                 flags = MREMAP_MAYMOVE;
1085         }
1086
1087         buf = mremap(hdr, hdr->u.length, bufsz, flags);
1088
1089         if (buf == MAP_FAILED) {
1090                 errno = ENOSPC;
1091                 return NULL;
1092         }
1093
1094         hdr = (struct anonymous_shared_header *)buf;
1095         hdr->u.length = bufsz;
1096
1097         ptr = (void *)(&hdr[1]);
1098
1099         return ptr;
1100 #else
1101         errno = ENOSPC;
1102         return NULL;
1103 #endif
1104 }
1105
1106 void anonymous_shared_free(void *ptr)
1107 {
1108         struct anonymous_shared_header *hdr;
1109
1110         if (ptr == NULL) {
1111                 return;
1112         }
1113
1114         hdr = (struct anonymous_shared_header *)ptr;
1115
1116         hdr--;
1117
1118         munmap(hdr, hdr->u.length);
1119 }
1120
1121 #ifdef DEVELOPER
1122 /* used when you want a debugger started at a particular point in the
1123    code. Mostly useful in code that runs as a child process, where
1124    normal gdb attach is harder to organise.
1125 */
1126 void samba_start_debugger(void)
1127 {
1128         char *cmd = NULL;
1129         if (asprintf(&cmd, "xterm -e \"gdb --pid %u\"&", getpid()) == -1) {
1130                 return;
1131         }
1132         if (system(cmd) == -1) {
1133                 free(cmd);
1134                 return;
1135         }
1136         free(cmd);
1137         sleep(2);
1138 }
1139 #endif