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 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 && !uwrap_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 and has the right permissions
 191  * or was successfully created.
 192  */
 193 _PUBLIC_ bool directory_create_or_exist(const char *dname,
 194                                         uid_t uid,
 195                                         mode_t dir_perms)
 196 {
 197         int ret;
 198         struct stat st;
 199
 200         ret = lstat(dname, &st);
 201         if (ret == -1) {
 202                 mode_t old_umask;
 203
 204                 if (errno != ENOENT) {
 205                         DEBUG(0, ("lstat failed on directory %s: %s\n",
 206                                   dname, strerror(errno)));
 207                         return false;
 208                 }
 209
 210                 /* Create directory */
 211                 old_umask = umask(0);
 212                 ret = mkdir(dname, dir_perms);
 213                 if (ret == -1 && errno != EEXIST) {
 214                         DEBUG(0, ("mkdir failed on directory "
 215                                   "%s: %s\n", dname,
 216                                   strerror(errno)));
 217                         umask(old_umask);
 218                         return false;
 219                 }
 220                 umask(old_umask);
 221
 222                 ret = lstat(dname, &st);
 223                 if (ret == -1) {
 224                         DEBUG(0, ("lstat failed on created directory %s: %s\n",
 225                                   dname, strerror(errno)));
 226                         return false;
 227                 }
 228         }
 229
 230         return true;
 231 }
 232
 233 /**
 234  * @brief Try to create a specified directory if it doesn't exist.
 235  *
 236  * The function creates a directory with the given uid and permissions if it
 237  * doesn't exist. If it exists it makes sure the uid and permissions are
 238  * correct and it will fail if they are different.
 239  *
 240  * @param[in]  dname  The directory to create.
 241  *
 242  * @param[in]  uid    The uid the directory needs to belong too.
 243  *
 244  * @param[in]  dir_perms  The expected permissions of the directory.
 245  *
 246  * @return True on success, false on error.
 247  */
 248 _PUBLIC_ bool directory_create_or_exist_strict(const char *dname,
 249                                                uid_t uid,
 250                                                mode_t dir_perms)
 251 {
 252         struct stat st;
 253         bool ok;
 254         int rc;
 255
 256         ok = directory_create_or_exist(dname, uid, dir_perms);
 257         if (!ok) {
 258                 return false;
 259         }
 260
 261         rc = lstat(dname, &st);
 262         if (rc == -1) {
 263                 DEBUG(0, ("lstat failed on created directory %s: %s\n",
 264                           dname, strerror(errno)));
 265                 return false;
 266         }
 267
 268         /* Check ownership and permission on existing directory */
 269         if (!S_ISDIR(st.st_mode)) {
 270                 DEBUG(0, ("directory %s isn't a directory\n",
 271                         dname));
 272                 return false;
 273         }
 274         if (st.st_uid != uid && !uwrap_enabled()) {
 275                 DEBUG(0, ("invalid ownership on directory "
 276                           "%s\n", dname));
 277                 return false;
 278         }
 279         if ((st.st_mode & 0777) != dir_perms) {
 280                 DEBUG(0, ("invalid permissions on directory "
 281                           "'%s': has 0%o should be 0%o\n", dname,
 282                           (unsigned int)(st.st_mode & 0777), (unsigned int)dir_perms));
 283                 return false;
 284         }
 285
 286         return true;
 287 }
 288
 289
 290 /**
 291  Sleep for a specified number of milliseconds.
 292 **/
 293
 294 _PUBLIC_ void smb_msleep(unsigned int t)
 295 {
 296 #if defined(HAVE_NANOSLEEP)
 297         struct timespec ts;
 298         int ret;
 299
 300         ts.tv_sec = t/1000;
 301         ts.tv_nsec = 1000000*(t%1000);
 302
 303         do {
 304                 errno = 0;
 305                 ret = nanosleep(&ts, &ts);
 306         } while (ret < 0 && errno == EINTR && (ts.tv_sec > 0 || ts.tv_nsec > 0));
 307 #else
 308         unsigned int tdiff=0;
 309         struct timeval tval,t1,t2;
 310         fd_set fds;
 311
 312         GetTimeOfDay(&t1);
 313         t2 = t1;
 314
 315         while (tdiff < t) {
 316                 tval.tv_sec = (t-tdiff)/1000;
 317                 tval.tv_usec = 1000*((t-tdiff)%1000);
 318
 319                 /* Never wait for more than 1 sec. */
 320                 if (tval.tv_sec > 1) {
 321                         tval.tv_sec = 1;
 322                         tval.tv_usec = 0;
 323                 }
 324
 325                 FD_ZERO(&fds);
 326                 errno = 0;
 327                 select(0,&fds,NULL,NULL,&tval);
 328
 329                 GetTimeOfDay(&t2);
 330                 if (t2.tv_sec < t1.tv_sec) {
 331                         /* Someone adjusted time... */
 332                         t1 = t2;
 333                 }
 334
 335                 tdiff = usec_time_diff(&t2,&t1)/1000;
 336         }
 337 #endif
 338 }
 339
 340 /**
 341  Get my own name, return in talloc'ed storage.
 342 **/
 343
 344 _PUBLIC_ char *get_myname(TALLOC_CTX *ctx)
 345 {
 346         char *p;
 347         char hostname[HOST_NAME_MAX];
 348
 349         /* get my host name */
 350         if (gethostname(hostname, sizeof(hostname)) == -1) {
 351                 DEBUG(0,("gethostname failed\n"));
 352                 return NULL;
 353         }
 354
 355         /* Ensure null termination. */
 356         hostname[sizeof(hostname)-1] = '\0';
 357
 358         /* split off any parts after an initial . */
 359         p = strchr_m(hostname, '.');
 360         if (p) {
 361                 *p = 0;
 362         }
 363
 364         return talloc_strdup(ctx, hostname);
 365 }
 366
 367 /**
 368  Check if a process exists. Does this work on all unixes?
 369 **/
 370
 371 _PUBLIC_ bool process_exists_by_pid(pid_t pid)
 372 {
 373         /* Doing kill with a non-positive pid causes messages to be
 374          * sent to places we don't want. */
 375         if (pid <= 0) {
 376                 return false;
 377         }
 378         return(kill(pid,0) == 0 || errno != ESRCH);
 379 }
 380
 381 /**
 382  Simple routine to do POSIX file locking. Cruft in NFS and 64->32 bit mapping
 383  is dealt with in posix.c
 384 **/
 385
 386 _PUBLIC_ bool fcntl_lock(int fd, int op, off_t offset, off_t count, int type)
 387 {
 388         struct flock lock;
 389         int ret;
 390
 391         DEBUG(8,("fcntl_lock %d %d %.0f %.0f %d\n",fd,op,(double)offset,(double)count,type));
 392
 393         lock.l_type = type;
 394         lock.l_whence = SEEK_SET;
 395         lock.l_start = offset;
 396         lock.l_len = count;
 397         lock.l_pid = 0;
 398
 399         ret = fcntl(fd,op,&lock);
 400
 401         if (ret == -1 && errno != 0)
 402                 DEBUG(3,("fcntl_lock: fcntl lock gave errno %d (%s)\n",errno,strerror(errno)));
 403
 404         /* a lock query */
 405         if (op == F_GETLK) {
 406                 if ((ret != -1) &&
 407                                 (lock.l_type != F_UNLCK) &&
 408                                 (lock.l_pid != 0) &&
 409                                 (lock.l_pid != getpid())) {
 410                         DEBUG(3,("fcntl_lock: fd %d is locked by pid %d\n",fd,(int)lock.l_pid));
 411                         return true;
 412                 }
 413
 414                 /* it must be not locked or locked by me */
 415                 return false;
 416         }
 417
 418         /* a lock set or unset */
 419         if (ret == -1) {
 420                 DEBUG(3,("fcntl_lock: lock failed at offset %.0f count %.0f op %d type %d (%s)\n",
 421                         (double)offset,(double)count,op,type,strerror(errno)));
 422                 return false;
 423         }
 424
 425         /* everything went OK */
 426         DEBUG(8,("fcntl_lock: Lock call successful\n"));
 427
 428         return true;
 429 }
 430
 431 struct debug_channel_level {
 432         int channel;
 433         int level;
 434 };
 435
 436 static void debugadd_channel_cb(const char *buf, void *private_data)
 437 {
 438         struct debug_channel_level *dcl =
 439                 (struct debug_channel_level *)private_data;
 440
 441         DEBUGADDC(dcl->channel, dcl->level,("%s", buf));
 442 }
 443
 444 static void debugadd_cb(const char *buf, void *private_data)
 445 {
 446         int *plevel = (int *)private_data;
 447         DEBUGADD(*plevel, ("%s", buf));
 448 }
 449
 450 void print_asc_cb(const uint8_t *buf, int len,
 451                   void (*cb)(const char *buf, void *private_data),
 452                   void *private_data)
 453 {
 454         int i;
 455         char s[2];
 456         s[1] = 0;
 457
 458         for (i=0; i<len; i++) {
 459                 s[0] = isprint(buf[i]) ? buf[i] : '.';
 460                 cb(s, private_data);
 461         }
 462 }
 463
 464 void print_asc(int level, const uint8_t *buf,int len)
 465 {
 466         print_asc_cb(buf, len, debugadd_cb, &level);
 467 }
 468
 469 /**
 470  * Write dump of binary data to a callback
 471  */
 472 void dump_data_cb(const uint8_t *buf, int len,
 473                   bool omit_zero_bytes,
 474                   void (*cb)(const char *buf, void *private_data),
 475                   void *private_data)
 476 {
 477         int i=0;
 478         static const uint8_t empty[16] = { 0, };
 479         bool skipped = false;
 480         char tmp[16];
 481
 482         if (len<=0) return;
 483
 484         for (i=0;i<len;) {
 485
 486                 if (i%16 == 0) {
 487                         if ((omit_zero_bytes == true) &&
 488                             (i > 0) &&
 489                             (len > i+16) &&
 490                             (memcmp(&buf[i], &empty, 16) == 0))
 491                         {
 492                                 i +=16;
 493                                 continue;
 494                         }
 495
 496                         if (i<len)  {
 497                                 snprintf(tmp, sizeof(tmp), "[%04X] ", i);
 498                                 cb(tmp, private_data);
 499                         }
 500                 }
 501
 502                 snprintf(tmp, sizeof(tmp), "%02X ", (int)buf[i]);
 503                 cb(tmp, private_data);
 504                 i++;
 505                 if (i%8 == 0) {
 506                         cb("  ", private_data);
 507                 }
 508                 if (i%16 == 0) {
 509
 510                         print_asc_cb(&buf[i-16], 8, cb, private_data);
 511                         cb(" ", private_data);
 512                         print_asc_cb(&buf[i-8], 8, cb, private_data);
 513                         cb("\n", private_data);
 514
 515                         if ((omit_zero_bytes == true) &&
 516                             (len > i+16) &&
 517                             (memcmp(&buf[i], &empty, 16) == 0)) {
 518                                 if (!skipped) {
 519                                         cb("skipping zero buffer bytes\n",
 520                                            private_data);
 521                                         skipped = true;
 522                                 }
 523                         }
 524                 }
 525         }
 526
 527         if (i%16) {
 528                 int n;
 529                 n = 16 - (i%16);
 530                 cb(" ", private_data);
 531                 if (n>8) {
 532                         cb(" ", private_data);
 533                 }
 534                 while (n--) {
 535                         cb("   ", private_data);
 536                 }
 537                 n = MIN(8,i%16);
 538                 print_asc_cb(&buf[i-(i%16)], n, cb, private_data);
 539                 cb(" ", private_data);
 540                 n = (i%16) - n;
 541                 if (n>0) {
 542                         print_asc_cb(&buf[i-n], n, cb, private_data);
 543                 }
 544                 cb("\n", private_data);
 545         }
 546
 547 }
 548
 549 /**
 550  * Write dump of binary data to the log file.
 551  *
 552  * The data is only written if the log level is at least level.
 553  */
 554 _PUBLIC_ void dump_data(int level, const uint8_t *buf, int len)
 555 {
 556         if (!DEBUGLVL(level)) {
 557                 return;
 558         }
 559         dump_data_cb(buf, len, false, debugadd_cb, &level);
 560 }
 561
 562 /**
 563  * Write dump of binary data to the log file.
 564  *
 565  * The data is only written if the log level is at least level for
 566  * debug class dbgc_class.
 567  */
 568 _PUBLIC_ void dump_data_dbgc(int dbgc_class, int level, const uint8_t *buf, int len)
 569 {
 570         struct debug_channel_level dcl = { dbgc_class, level };
 571
 572         if (!DEBUGLVLC(dbgc_class, level)) {
 573                 return;
 574         }
 575         dump_data_cb(buf, len, false, debugadd_channel_cb, &dcl);
 576 }
 577
 578 /**
 579  * Write dump of binary data to the log file.
 580  *
 581  * The data is only written if the log level is at least level.
 582  * 16 zero bytes in a row are omitted
 583  */
 584 _PUBLIC_ void dump_data_skip_zeros(int level, const uint8_t *buf, int len)
 585 {
 586         if (!DEBUGLVL(level)) {
 587                 return;
 588         }
 589         dump_data_cb(buf, len, true, debugadd_cb, &level);
 590 }
 591
 592 static void fprintf_cb(const char *buf, void *private_data)
 593 {
 594         FILE *f = (FILE *)private_data;
 595         fprintf(f, "%s", buf);
 596 }
 597
 598 void dump_data_file(const uint8_t *buf, int len, bool omit_zero_bytes,
 599                     FILE *f)
 600 {
 601         dump_data_cb(buf, len, omit_zero_bytes, fprintf_cb, f);
 602 }
 603
 604 /**
 605  malloc that aborts with smb_panic on fail or zero size.
 606 **/
 607
 608 _PUBLIC_ void *smb_xmalloc(size_t size)
 609 {
 610         void *p;
 611         if (size == 0)
 612                 smb_panic("smb_xmalloc: called with zero size.\n");
 613         if ((p = malloc(size)) == NULL)
 614                 smb_panic("smb_xmalloc: malloc fail.\n");
 615         return p;
 616 }
 617
 618 /**
 619  Memdup with smb_panic on fail.
 620 **/
 621
 622 _PUBLIC_ void *smb_xmemdup(const void *p, size_t size)
 623 {
 624         void *p2;
 625         p2 = smb_xmalloc(size);
 626         memcpy(p2, p, size);
 627         return p2;
 628 }
 629
 630 /**
 631  strdup that aborts on malloc fail.
 632 **/
 633
 634 char *smb_xstrdup(const char *s)
 635 {
 636 #if defined(PARANOID_MALLOC_CHECKER)
 637 #ifdef strdup
 638 #undef strdup
 639 #endif
 640 #endif
 641
 642 #ifndef HAVE_STRDUP
 643 #define strdup rep_strdup
 644 #endif
 645
 646         char *s1 = strdup(s);
 647 #if defined(PARANOID_MALLOC_CHECKER)
 648 #ifdef strdup
 649 #undef strdup
 650 #endif
 651 #define strdup(s) __ERROR_DONT_USE_STRDUP_DIRECTLY
 652 #endif
 653         if (!s1) {
 654                 smb_panic("smb_xstrdup: malloc failed");
 655         }
 656         return s1;
 657
 658 }
 659
 660 /**
 661  strndup that aborts on malloc fail.
 662 **/
 663
 664 char *smb_xstrndup(const char *s, size_t n)
 665 {
 666 #if defined(PARANOID_MALLOC_CHECKER)
 667 #ifdef strndup
 668 #undef strndup
 669 #endif
 670 #endif
 671
 672 #if (defined(BROKEN_STRNDUP) || !defined(HAVE_STRNDUP))
 673 #undef HAVE_STRNDUP
 674 #define strndup rep_strndup
 675 #endif
 676
 677         char *s1 = strndup(s, n);
 678 #if defined(PARANOID_MALLOC_CHECKER)
 679 #ifdef strndup
 680 #undef strndup
 681 #endif
 682 #define strndup(s,n) __ERROR_DONT_USE_STRNDUP_DIRECTLY
 683 #endif
 684         if (!s1) {
 685                 smb_panic("smb_xstrndup: malloc failed");
 686         }
 687         return s1;
 688 }
 689
 690
 691
 692 /**
 693  Like strdup but for memory.
 694 **/
 695
 696 _PUBLIC_ void *memdup(const void *p, size_t size)
 697 {
 698         void *p2;
 699         if (size == 0)
 700                 return NULL;
 701         p2 = malloc(size);
 702         if (!p2)
 703                 return NULL;
 704         memcpy(p2, p, size);
 705         return p2;
 706 }
 707
 708 /**
 709  * Write a password to the log file.
 710  *
 711  * @note Only actually does something if DEBUG_PASSWORD was defined during
 712  * compile-time.
 713  */
 714 _PUBLIC_ void dump_data_pw(const char *msg, const uint8_t * data, size_t len)
 715 {
 716 #ifdef DEBUG_PASSWORD
 717         DEBUG(11, ("%s", msg));
 718         if (data != NULL && len > 0)
 719         {
 720                 dump_data(11, data, len);
 721         }
 722 #endif
 723 }
 724
 725
 726 /**
 727  * see if a range of memory is all zero. A NULL pointer is considered
 728  * to be all zero
 729  */
 730 _PUBLIC_ bool all_zero(const uint8_t *ptr, size_t size)
 731 {
 732         int i;
 733         if (!ptr) return true;
 734         for (i=0;i<size;i++) {
 735                 if (ptr[i]) return false;
 736         }
 737         return true;
 738 }
 739
 740 /**
 741   realloc an array, checking for integer overflow in the array size
 742 */
 743 _PUBLIC_ void *realloc_array(void *ptr, size_t el_size, unsigned count, bool free_on_fail)
 744 {
 745 #define MAX_MALLOC_SIZE 0x7fffffff
 746         if (count == 0 ||
 747             count >= MAX_MALLOC_SIZE/el_size) {
 748                 if (free_on_fail)
 749                         SAFE_FREE(ptr);
 750                 return NULL;
 751         }
 752         if (!ptr) {
 753                 return malloc(el_size * count);
 754         }
 755         return realloc(ptr, el_size * count);
 756 }
 757
 758 /****************************************************************************
 759  Type-safe malloc.
 760 ****************************************************************************/
 761
 762 void *malloc_array(size_t el_size, unsigned int count)
 763 {
 764         return realloc_array(NULL, el_size, count, false);
 765 }
 766
 767 /****************************************************************************
 768  Type-safe memalign
 769 ****************************************************************************/
 770
 771 void *memalign_array(size_t el_size, size_t align, unsigned int count)
 772 {
 773         if (count*el_size >= MAX_MALLOC_SIZE) {
 774                 return NULL;
 775         }
 776
 777         return memalign(align, el_size*count);
 778 }
 779
 780 /****************************************************************************
 781  Type-safe calloc.
 782 ****************************************************************************/
 783
 784 void *calloc_array(size_t size, size_t nmemb)
 785 {
 786         if (nmemb >= MAX_MALLOC_SIZE/size) {
 787                 return NULL;
 788         }
 789         if (size == 0 || nmemb == 0) {
 790                 return NULL;
 791         }
 792         return calloc(nmemb, size);
 793 }
 794
 795 /**
 796  Trim the specified elements off the front and back of a string.
 797 **/
 798 _PUBLIC_ bool trim_string(char *s, const char *front, const char *back)
 799 {
 800         bool ret = false;
 801         size_t front_len;
 802         size_t back_len;
 803         size_t len;
 804
 805         /* Ignore null or empty strings. */
 806         if (!s || (s[0] == '\0'))
 807                 return false;
 808
 809         front_len       = front? strlen(front) : 0;
 810         back_len        = back? strlen(back) : 0;
 811
 812         len = strlen(s);
 813
 814         if (front_len) {
 815                 while (len && strncmp(s, front, front_len)==0) {
 816                         /* Must use memmove here as src & dest can
 817                          * easily overlap. Found by valgrind. JRA. */
 818                         memmove(s, s+front_len, (len-front_len)+1);
 819                         len -= front_len;
 820                         ret=true;
 821                 }
 822         }
 823
 824         if (back_len) {
 825                 while ((len >= back_len) && strncmp(s+len-back_len,back,back_len)==0) {
 826                         s[len-back_len]='\0';
 827                         len -= back_len;
 828                         ret=true;
 829                 }
 830         }
 831         return ret;
 832 }
 833
 834 /**
 835  Find the number of 'c' chars in a string
 836 **/
 837 _PUBLIC_ _PURE_ size_t count_chars(const char *s, char c)
 838 {
 839         size_t count = 0;
 840
 841         while (*s) {
 842                 if (*s == c) count++;
 843                 s ++;
 844         }
 845
 846         return count;
 847 }
 848
 849 /**
 850  * Routine to get hex characters and turn them into a byte array.
 851  * the array can be variable length.
 852  * -  "0xnn" or "0Xnn" is specially catered for.
 853  * - The first non-hex-digit character (apart from possibly leading "0x"
 854  *   finishes the conversion and skips the rest of the input.
 855  * - A single hex-digit character at the end of the string is skipped.
 856  *
 857  * valid examples: "0A5D15"; "0x123456"
 858  */
 859 _PUBLIC_ size_t strhex_to_str(char *p, size_t p_len, const char *strhex, size_t strhex_len)
 860 {
 861         size_t i = 0;
 862         size_t num_chars = 0;
 863         uint8_t   lonybble, hinybble;
 864         const char     *hexchars = "0123456789ABCDEF";
 865         char           *p1 = NULL, *p2 = NULL;
 866
 867         /* skip leading 0x prefix */
 868         if (strncasecmp(strhex, "0x", 2) == 0) {
 869                 i += 2; /* skip two chars */
 870         }
 871
 872         for (; i+1 < strhex_len && strhex[i] != 0 && strhex[i+1] != 0; i++) {
 873                 p1 = strchr(hexchars, toupper((unsigned char)strhex[i]));
 874                 if (p1 == NULL) {
 875                         break;
 876                 }
 877
 878                 i++; /* next hex digit */
 879
 880                 p2 = strchr(hexchars, toupper((unsigned char)strhex[i]));
 881                 if (p2 == NULL) {
 882                         break;
 883                 }
 884
 885                 /* get the two nybbles */
 886                 hinybble = PTR_DIFF(p1, hexchars);
 887                 lonybble = PTR_DIFF(p2, hexchars);
 888
 889                 if (num_chars >= p_len) {
 890                         break;
 891                 }
 892
 893                 p[num_chars] = (hinybble << 4) | lonybble;
 894                 num_chars++;
 895
 896                 p1 = NULL;
 897                 p2 = NULL;
 898         }
 899         return num_chars;
 900 }
 901
 902 /**
 903  * Parse a hex string and return a data blob.
 904  */
 905 _PUBLIC_ _PURE_ DATA_BLOB strhex_to_data_blob(TALLOC_CTX *mem_ctx, const char *strhex)
 906 {
 907         DATA_BLOB ret_blob = data_blob_talloc(mem_ctx, NULL, strlen(strhex)/2+1);
 908
 909         ret_blob.length = strhex_to_str((char *)ret_blob.data, ret_blob.length,
 910                                         strhex,
 911                                         strlen(strhex));
 912
 913         return ret_blob;
 914 }
 915
 916 /**
 917  * Print a buf in hex. Assumes dst is at least (srclen*2)+1 large.
 918  */
 919 _PUBLIC_ void hex_encode_buf(char *dst, const uint8_t *src, size_t srclen)
 920 {
 921         size_t i;
 922         for (i=0; i<srclen; i++) {
 923                 snprintf(dst + i*2, 3, "%02X", src[i]);
 924         }
 925         /*
 926          * Ensure 0-termination for 0-length buffers
 927          */
 928         dst[srclen*2] = '\0';
 929 }
 930
 931 /**
 932  * Routine to print a buffer as HEX digits, into an allocated string.
 933  */
 934 _PUBLIC_ void hex_encode(const unsigned char *buff_in, size_t len, char **out_hex_buffer)
 935 {
 936         char *hex_buffer;
 937
 938         *out_hex_buffer = malloc_array_p(char, (len*2)+1);
 939         hex_buffer = *out_hex_buffer;
 940         hex_encode_buf(hex_buffer, buff_in, len);
 941 }
 942
 943 /**
 944  * talloc version of hex_encode()
 945  */
 946 _PUBLIC_ char *hex_encode_talloc(TALLOC_CTX *mem_ctx, const unsigned char *buff_in, size_t len)
 947 {
 948         char *hex_buffer;
 949
 950         hex_buffer = talloc_array(mem_ctx, char, (len*2)+1);
 951         if (!hex_buffer) {
 952                 return NULL;
 953         }
 954         hex_encode_buf(hex_buffer, buff_in, len);
 955         talloc_set_name_const(hex_buffer, hex_buffer);
 956         return hex_buffer;
 957 }
 958
 959 /**
 960   varient of strcmp() that handles NULL ptrs
 961 **/
 962 _PUBLIC_ int strcmp_safe(const char *s1, const char *s2)
 963 {
 964         if (s1 == s2) {
 965                 return 0;
 966         }
 967         if (s1 == NULL || s2 == NULL) {
 968                 return s1?-1:1;
 969         }
 970         return strcmp(s1, s2);
 971 }
 972
 973
 974 /**
 975 return the number of bytes occupied by a buffer in ASCII format
 976 the result includes the null termination
 977 limited by 'n' bytes
 978 **/
 979 _PUBLIC_ size_t ascii_len_n(const char *src, size_t n)
 980 {
 981         size_t len;
 982
 983         len = strnlen(src, n);
 984         if (len+1 <= n) {
 985                 len += 1;
 986         }
 987
 988         return len;
 989 }
 990
 991 /**
 992  Set a boolean variable from the text value stored in the passed string.
 993  Returns true in success, false if the passed string does not correctly
 994  represent a boolean.
 995 **/
 996
 997 _PUBLIC_ bool set_boolean(const char *boolean_string, bool *boolean)
 998 {
 999         if (strwicmp(boolean_string, "yes") == 0 ||
1000             strwicmp(boolean_string, "true") == 0 ||
1001             strwicmp(boolean_string, "on") == 0 ||
1002             strwicmp(boolean_string, "1") == 0) {
1003                 *boolean = true;
1004                 return true;
1005         } else if (strwicmp(boolean_string, "no") == 0 ||
1006                    strwicmp(boolean_string, "false") == 0 ||
1007                    strwicmp(boolean_string, "off") == 0 ||
1008                    strwicmp(boolean_string, "0") == 0) {
1009                 *boolean = false;
1010                 return true;
1011         }
1012         return false;
1013 }
1014
1015 /**
1016 return the number of bytes occupied by a buffer in CH_UTF16 format
1017 the result includes the null termination
1018 **/
1019 _PUBLIC_ size_t utf16_len(const void *buf)
1020 {
1021         size_t len;
1022
1023         for (len = 0; SVAL(buf,len); len += 2) ;
1024
1025         return len + 2;
1026 }
1027
1028 /**
1029 return the number of bytes occupied by a buffer in CH_UTF16 format
1030 the result includes the null termination
1031 limited by 'n' bytes
1032 **/
1033 _PUBLIC_ size_t utf16_len_n(const void *src, size_t n)
1034 {
1035         size_t len;
1036
1037         for (len = 0; (len+2 < n) && SVAL(src, len); len += 2) ;
1038
1039         if (len+2 <= n) {
1040                 len += 2;
1041         }
1042
1043         return len;
1044 }
1045
1046 /**
1047  * @file
1048  * @brief String utilities.
1049  **/
1050
1051 static bool next_token_internal_talloc(TALLOC_CTX *ctx,
1052                                 const char **ptr,
1053                                 char **pp_buff,
1054                                 const char *sep,
1055                                 bool ltrim)
1056 {
1057         const char *s;
1058         const char *saved_s;
1059         char *pbuf;
1060         bool quoted;
1061         size_t len=1;
1062
1063         *pp_buff = NULL;
1064         if (!ptr) {
1065                 return(false);
1066         }
1067
1068         s = *ptr;
1069
1070         /* default to simple separators */
1071         if (!sep) {
1072                 sep = " \t\n\r";
1073         }
1074
1075         /* find the first non sep char, if left-trimming is requested */
1076         if (ltrim) {
1077                 while (*s && strchr_m(sep,*s)) {
1078                         s++;
1079                 }
1080         }
1081
1082         /* nothing left? */
1083         if (!*s) {
1084                 return false;
1085         }
1086
1087         /* When restarting we need to go from here. */
1088         saved_s = s;
1089
1090         /* Work out the length needed. */
1091         for (quoted = false; *s &&
1092                         (quoted || !strchr_m(sep,*s)); s++) {
1093                 if (*s == '\"') {
1094                         quoted = !quoted;
1095                 } else {
1096                         len++;
1097                 }
1098         }
1099
1100         /* We started with len = 1 so we have space for the nul. */
1101         *pp_buff = talloc_array(ctx, char, len);
1102         if (!*pp_buff) {
1103                 return false;
1104         }
1105
1106         /* copy over the token */
1107         pbuf = *pp_buff;
1108         s = saved_s;
1109         for (quoted = false; *s &&
1110                         (quoted || !strchr_m(sep,*s)); s++) {
1111                 if ( *s == '\"' ) {
1112                         quoted = !quoted;
1113                 } else {
1114                         *pbuf++ = *s;
1115                 }
1116         }
1117
1118         *ptr = (*s) ? s+1 : s;
1119         *pbuf = 0;
1120
1121         return true;
1122 }
1123
1124 bool next_token_talloc(TALLOC_CTX *ctx,
1125                         const char **ptr,
1126                         char **pp_buff,
1127                         const char *sep)
1128 {
1129         return next_token_internal_talloc(ctx, ptr, pp_buff, sep, true);
1130 }
1131
1132 /*
1133  * Get the next token from a string, return false if none found.  Handles
1134  * double-quotes.  This version does not trim leading separator characters
1135  * before looking for a token.
1136  */
1137
1138 bool next_token_no_ltrim_talloc(TALLOC_CTX *ctx,
1139                         const char **ptr,
1140                         char **pp_buff,
1141                         const char *sep)
1142 {
1143         return next_token_internal_talloc(ctx, ptr, pp_buff, sep, false);
1144 }
1145
1146 /**
1147  * Get the next token from a string, return False if none found.
1148  * Handles double-quotes.
1149  *
1150  * Based on a routine by GJC@VILLAGE.COM.
1151  * Extensively modified by Andrew.Tridgell@anu.edu.au
1152  **/
1153 _PUBLIC_ bool next_token(const char **ptr,char *buff, const char *sep, size_t bufsize)
1154 {
1155         const char *s;
1156         bool quoted;
1157         size_t len=1;
1158
1159         if (!ptr)
1160                 return false;
1161
1162         s = *ptr;
1163
1164         /* default to simple separators */
1165         if (!sep)
1166                 sep = " \t\n\r";
1167
1168         /* find the first non sep char */
1169         while (*s && strchr_m(sep,*s))
1170                 s++;
1171
1172         /* nothing left? */
1173         if (!*s)
1174                 return false;
1175
1176         /* copy over the token */
1177         for (quoted = false; len < bufsize && *s && (quoted || !strchr_m(sep,*s)); s++) {
1178                 if (*s == '\"') {
1179                         quoted = !quoted;
1180                 } else {
1181                         len++;
1182                         *buff++ = *s;
1183                 }
1184         }
1185
1186         *ptr = (*s) ? s+1 : s;
1187         *buff = 0;
1188
1189         return true;
1190 }
1191
1192 struct anonymous_shared_header {
1193         union {
1194                 size_t length;
1195                 uint8_t pad[16];
1196         } u;
1197 };
1198
1199 /* Map a shared memory buffer of at least nelem counters. */
1200 void *anonymous_shared_allocate(size_t orig_bufsz)
1201 {
1202         void *ptr;
1203         void *buf;
1204         size_t pagesz = getpagesize();
1205         size_t pagecnt;
1206         size_t bufsz = orig_bufsz;
1207         struct anonymous_shared_header *hdr;
1208
1209         bufsz += 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 (orig_bufsz >= bufsz) {
1219                 /* integer wrap */
1220                 errno = ENOMEM;
1221                 return NULL;
1222         }
1223
1224 #ifdef MAP_ANON
1225         /* BSD */
1226         buf = mmap(NULL, bufsz, PROT_READ|PROT_WRITE, MAP_ANON|MAP_SHARED,
1227                         -1 /* fd */, 0 /* offset */);
1228 #else
1229 {
1230         int saved_errno;
1231         int fd;
1232
1233         fd = open("/dev/zero", O_RDWR);
1234         if (fd == -1) {
1235                 return NULL;
1236         }
1237
1238         buf = mmap(NULL, bufsz, PROT_READ|PROT_WRITE, MAP_FILE|MAP_SHARED,
1239                    fd, 0 /* offset */);
1240         saved_errno = errno;
1241         close(fd);
1242         errno = saved_errno;
1243 }
1244 #endif
1245
1246         if (buf == MAP_FAILED) {
1247                 return NULL;
1248         }
1249
1250         hdr = (struct anonymous_shared_header *)buf;
1251         hdr->u.length = bufsz;
1252
1253         ptr = (void *)(&hdr[1]);
1254
1255         return ptr;
1256 }
1257
1258 void *anonymous_shared_resize(void *ptr, size_t new_size, bool maymove)
1259 {
1260 #ifdef HAVE_MREMAP
1261         void *buf;
1262         size_t pagesz = getpagesize();
1263         size_t pagecnt;
1264         size_t bufsz;
1265         struct anonymous_shared_header *hdr;
1266         int flags = 0;
1267
1268         if (ptr == NULL) {
1269                 errno = EINVAL;
1270                 return NULL;
1271         }
1272
1273         hdr = (struct anonymous_shared_header *)ptr;
1274         hdr--;
1275         if (hdr->u.length > (new_size + sizeof(*hdr))) {
1276                 errno = EINVAL;
1277                 return NULL;
1278         }
1279
1280         bufsz = new_size + sizeof(*hdr);
1281
1282         /* round up to full pages */
1283         pagecnt = bufsz / pagesz;
1284         if (bufsz % pagesz) {
1285                 pagecnt += 1;
1286         }
1287         bufsz = pagesz * pagecnt;
1288
1289         if (new_size >= bufsz) {
1290                 /* integer wrap */
1291                 errno = ENOSPC;
1292                 return NULL;
1293         }
1294
1295         if (bufsz <= hdr->u.length) {
1296                 return ptr;
1297         }
1298
1299         if (maymove) {
1300                 flags = MREMAP_MAYMOVE;
1301         }
1302
1303         buf = mremap(hdr, hdr->u.length, bufsz, flags);
1304
1305         if (buf == MAP_FAILED) {
1306                 errno = ENOSPC;
1307                 return NULL;
1308         }
1309
1310         hdr = (struct anonymous_shared_header *)buf;
1311         hdr->u.length = bufsz;
1312
1313         ptr = (void *)(&hdr[1]);
1314
1315         return ptr;
1316 #else
1317         errno = ENOSPC;
1318         return NULL;
1319 #endif
1320 }
1321
1322 void anonymous_shared_free(void *ptr)
1323 {
1324         struct anonymous_shared_header *hdr;
1325
1326         if (ptr == NULL) {
1327                 return;
1328         }
1329
1330         hdr = (struct anonymous_shared_header *)ptr;
1331
1332         hdr--;
1333
1334         munmap(hdr, hdr->u.length);
1335 }
1336
1337 #ifdef DEVELOPER
1338 /* used when you want a debugger started at a particular point in the
1339    code. Mostly useful in code that runs as a child process, where
1340    normal gdb attach is harder to organise.
1341 */
1342 void samba_start_debugger(void)
1343 {
1344         char *cmd = NULL;
1345         if (asprintf(&cmd, "xterm -e \"gdb --pid %u\"&", getpid()) == -1) {
1346                 return;
1347         }
1348         if (system(cmd) == -1) {
1349                 free(cmd);
1350                 return;
1351         }
1352         free(cmd);
1353         sleep(2);
1354 }
1355 #endif