lib/util/samba_util.h

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Utility functions for Samba
   4    Copyright (C) Andrew Tridgell 1992-1999
   5    Copyright (C) Jelmer Vernooij 2005
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #ifndef _SAMBA_UTIL_H_
  22 #define _SAMBA_UTIL_H_
  23
  24 #ifndef SAMBA_UTIL_CORE_ONLY
  25 #include "lib/util/charset/charset.h"
  26 #else
  27 #include "charset_compat.h"
  28 #endif
  29
  30 #include "lib/util/attr.h"
  31
  32 /* for TALLOC_CTX */
  33 #include <talloc.h>
  34
  35 /* for struct stat */
  36 #include <sys/stat.h>
  37
  38 /**
  39  * @file
  40  * @brief Helpful macros
  41  */
  42
  43 struct smbsrv_tcon;
  44
  45 extern const char *panic_action;
  46
  47 #include "lib/util/time.h"
  48 #include "lib/util/data_blob.h"
  49 #include "lib/util/byteorder.h"
  50 #include "lib/util/talloc_stack.h"
  51 #include "lib/util/talloc_keep_secret.h"
  52
  53 #ifndef ABS
  54 #define ABS(a) ((a)>0?(a):(-(a)))
  55 #endif
  56
  57 #include "lib/util/memory.h"
  58 #include "lib/util/discard.h"
  59
  60 #include "fault.h"
  61
  62 #include "lib/util/util.h"
  63
  64 /**
  65  * Write backtrace to debug log
  66  */
  67 _PUBLIC_ void dump_core_setup(const char *progname, const char *logfile);
  68
  69 /**
  70   register a fault handler.
  71   Should only be called once in the execution of smbd.
  72 */
  73 _PUBLIC_ bool register_fault_handler(const char *name, void (*fault_handler)(int sig));
  74
  75 #include "lib/util/signal.h" /* Avoid /usr/include/signal.h */
  76
  77 struct sockaddr;
  78
  79 _PUBLIC_ int sys_getnameinfo(const struct sockaddr *psa,
  80                              int salen,
  81                              char *host,
  82                              size_t hostlen,
  83                              char *service,
  84                              size_t servlen,
  85                              int flags);
  86
  87 /* The following definitions come from lib/util/genrand.c  */
  88
  89 #include "lib/util/genrand.h"
  90
  91 /**
  92   generate a single random uint32_t
  93 **/
  94 _PUBLIC_ uint32_t generate_random(void);
  95
  96 /**
  97  * generate a single random uint64_t
  98  * @see generate_unique_u64
  99 **/
 100 _PUBLIC_ uint64_t generate_random_u64(void);
 101
 102 _PUBLIC_ uint64_t generate_random_u64_range(uint64_t lower, uint64_t upper);
 103
 104 /**
 105  * @brief Generate random nonces usable for re-use detection.
 106  *
 107  * We have a lot of places which require a unique id that can
 108  * be used as a unique identitier for caching states.
 109  *
 110  * Always using generate_nonce_buffer() has it's performance costs,
 111  * it's typically much better than generate_random_buffer(), but
 112  * still it's overhead we want to avoid in performance critical
 113  * workloads.
 114  *
 115  * We call generate_nonce_buffer() just once per given state
 116  * and process.
 117  *
 118  * This is much lighter than generate_random_u64() and it's
 119  * designed for performance critical code paths.
 120  *
 121  * @veto_value It is guaranteed that the return value is different from
 122  *             the veto_value.
 123  *
 124  * @return a unique value per given state and process
 125  *
 126  * @see generate_random_u64
 127  */
 128 uint64_t generate_unique_u64(uint64_t veto_value);
 129
 130 /**
 131   very basic password quality checker
 132 **/
 133 _PUBLIC_ bool check_password_quality(const char *s);
 134
 135 /**
 136  * Generate a random text password (based on printable ascii characters).
 137  * This function is designed to provide a password that
 138  * meats the complexity requirements of UF_NORMAL_ACCOUNT objects
 139  * and they should be human readable and writeable on any keyboard layout.
 140  *
 141  * Characters used are:
 142  * ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+_-#.,@$%&!?:;<=>()[]~
 143  */
 144 _PUBLIC_ char *generate_random_password(TALLOC_CTX *mem_ctx, size_t min, size_t max);
 145
 146 /**
 147  * Generate a random machine password
 148  *
 149  * min and max are the number of utf16 characters used
 150  * to generate on utf8 compatible password.
 151  *
 152  * Note: if 'unix charset' is not 'utf8' (the default)
 153  * then each utf16 character is only filled with
 154  * values from 0x01 to 0x7f (ascii values without 0x00).
 155  * This is important as the password neets to be
 156  * a valid value as utf8 string and at the same time
 157  * a valid value in the 'unix charset'.
 158  *
 159  * If 'unix charset' is 'utf8' (the default) then
 160  * each utf16 character is a random value from 0x0000
 161  * 0xFFFF (excluding the surrogate ranges from 0xD800-0xDFFF)
 162  * while the translation from CH_UTF16MUNGED
 163  * to CH_UTF8 replaces invalid values (see utf16_munged_pull()).
 164  *
 165  * Note: these passwords may not pass the complexity requirements
 166  * for UF_NORMAL_ACCOUNT objects (except krbtgt accounts).
 167  */
 168 _PUBLIC_ char *generate_random_machine_password(TALLOC_CTX *mem_ctx, size_t min, size_t max);
 169
 170 /**
 171  Use the random number generator to generate a random string.
 172 **/
 173 _PUBLIC_ char *generate_random_str_list(TALLOC_CTX *mem_ctx, size_t len, const char *list);
 174
 175 /**
 176  * Generate a random text string consisting of the specified length.
 177  * The returned string will be allocated.
 178  *
 179  * Characters used are: ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+_-#.,
 180  */
 181 _PUBLIC_ char *generate_random_str(TALLOC_CTX *mem_ctx, size_t len);
 182
 183 /**
 184  * Generate an array of unique text strings all of the same length.
 185  * The returned strings will be allocated.
 186  * Returns NULL if the number of unique combinations cannot be created.
 187  *
 188  * Characters used are: ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+_-#.,
 189  */
 190 _PUBLIC_ char** generate_unique_strs(TALLOC_CTX *mem_ctx, size_t len,
 191                                          uint32_t num);
 192
 193 /* The following definitions come from lib/util/dprintf.c  */
 194
 195 _PUBLIC_ int d_fprintf(FILE *f, const char *format, ...) PRINTF_ATTRIBUTE(2,3);
 196 _PUBLIC_ int d_printf(const char *format, ...) PRINTF_ATTRIBUTE(1,2);
 197 _PUBLIC_ void display_set_stderr(void);
 198
 199 /* The following definitions come from lib/util/util_str.c  */
 200
 201 bool next_token_talloc(TALLOC_CTX *ctx,
 202                         const char **ptr,
 203                         char **pp_buff,
 204                         const char *sep);
 205
 206 /**
 207  * Get the next token from a string, return false if none found.  Handles
 208  * double-quotes.  This version does not trim leading separator characters
 209  * before looking for a token.
 210  */
 211 bool next_token_no_ltrim_talloc(TALLOC_CTX *ctx,
 212                         const char **ptr,
 213                         char **pp_buff,
 214                         const char *sep);
 215
 216
 217 /**
 218  Trim the specified elements off the front and back of a string.
 219 **/
 220 _PUBLIC_ bool trim_string(char *s, const char *front, const char *back);
 221
 222 /**
 223  Find the number of 'c' chars in a string
 224 **/
 225 _PUBLIC_ _PURE_ size_t count_chars(const char *s, char c);
 226
 227 /**
 228  Routine to get hex characters and turn them into a 16 byte array.
 229  the array can be variable length, and any non-hex-numeric
 230  characters are skipped.  "0xnn" or "0Xnn" is specially catered
 231  for.
 232
 233  valid examples: "0A5D15"; "0x15, 0x49, 0xa2"; "59\ta9\te3\n"
 234
 235
 236 **/
 237 _PUBLIC_ size_t strhex_to_str(char *p, size_t p_len, const char *strhex, size_t strhex_len);
 238
 239 /**
 240  * Parse a hex string and return a data blob.
 241  */
 242 _PUBLIC_ DATA_BLOB strhex_to_data_blob(TALLOC_CTX *mem_ctx, const char *strhex) ;
 243
 244 /**
 245  * Parse a hex dump and return a data blob
 246  */
 247 _PUBLIC_ DATA_BLOB hexdump_to_data_blob(TALLOC_CTX *mem_ctx, const char *hexdump, size_t len);
 248
 249 /**
 250  * Print a buf in hex. Assumes dst is at least (srclen*2)+1 large.
 251  */
 252 _PUBLIC_ void hex_encode_buf(char *dst, const uint8_t *src, size_t srclen);
 253
 254 /**
 255  * talloc version of hex_encode_buf()
 256  */
 257 _PUBLIC_ char *hex_encode_talloc(TALLOC_CTX *mem_ctx, const unsigned char *buff_in, size_t len);
 258
 259 #include "substitute.h"
 260
 261 /**
 262  Unescape a URL encoded string, in place.
 263 **/
 264 _PUBLIC_ char *rfc1738_unescape(char *buf);
 265
 266 /**
 267  * rfc1738_escape_part
 268  * Returns a static buffer that contains the RFC
 269  * 1738 compliant, escaped version of the given url segment. (escapes
 270  * unsafe, reserved and % chars) It would mangle the :// in http://,
 271  * and mangle paths (because of /).
 272  **/
 273 _PUBLIC_ char *rfc1738_escape_part(TALLOC_CTX *mem_ctx, const char *url);
 274
 275 /**
 276   variant of strcmp() that handles NULL ptrs
 277 **/
 278 _PUBLIC_ int strcmp_safe(const char *s1, const char *s2);
 279
 280 /**
 281 return the number of bytes occupied by a buffer in ASCII format
 282 the result includes the null termination
 283 limited by 'n' bytes
 284 **/
 285 _PUBLIC_ size_t ascii_len_n(const char *src, size_t n);
 286
 287 /**
 288  Set a boolean variable from the text value stored in the passed string.
 289  Returns true in success, false if the passed string does not correctly
 290  represent a boolean.
 291 **/
 292 _PUBLIC_ bool set_boolean(const char *boolean_string, bool *boolean);
 293
 294 /**
 295  * Parse a string containing a boolean value.
 296  *
 297  * val will be set to the read value.
 298  *
 299  * @retval true if a boolean value was parsed, false otherwise.
 300  */
 301 _PUBLIC_ bool conv_str_bool(const char * str, bool * val);
 302
 303 /**
 304  * Convert a size specification like 16K into an integral number of bytes.
 305  **/
 306 _PUBLIC_ bool conv_str_size_error(const char * str, uint64_t * val);
 307
 308 /**
 309  * Parse a uint64_t value from a string
 310  *
 311  * val will be set to the value read.
 312  *
 313  * @retval true if parsing was successful, false otherwise
 314  */
 315 _PUBLIC_ bool conv_str_u64(const char * str, uint64_t * val);
 316
 317 /**
 318  * @brief Constant time compare to memory regions.
 319  *
 320  * @param[in]  s1  The first memory region to compare.
 321  *
 322  * @param[in]  s2  The second memory region to compare.
 323  *
 324  * @param[in]  n   The length of the memory to compare.
 325  *
 326  * @return true when the memory regions are equal, false if not.
 327  */
 328 _PUBLIC_ bool mem_equal_const_time(const void *s1, const void *s2, size_t n);
 329
 330 /**
 331 Do a case-insensitive, whitespace-ignoring string compare.
 332 **/
 333 _PUBLIC_ int strwicmp(const char *psz1, const char *psz2);
 334
 335 /**
 336  String replace.
 337 **/
 338 _PUBLIC_ void string_replace(char *s, char oldc, char newc);
 339
 340 /**
 341  * Compare 2 strings.
 342  *
 343  * @note The comparison is case-insensitive.
 344  **/
 345 _PUBLIC_ bool strequal(const char *s1, const char *s2);
 346
 347 #include "util_strlist.h"
 348
 349 /* The following definitions come from lib/util/util_strlist_v3.c  */
 350
 351 /**
 352  * Needed for making an "unconst" list "const"
 353  */
 354 _PUBLIC_ const char **const_str_list(char **list);
 355
 356 /**
 357  * str_list_make, v3 version. The v4 version does not
 358  * look at quoted strings with embedded blanks, so
 359  * do NOT merge this function please!
 360  */
 361 char **str_list_make_v3(TALLOC_CTX *mem_ctx, const char *string,
 362         const char *sep);
 363
 364
 365 const char **str_list_make_v3_const(TALLOC_CTX *mem_ctx,
 366                                     const char *string,
 367                                     const char *sep);
 368
 369 /* The following definitions come from lib/util/util.c  */
 370
 371
 372 /**
 373  Find a suitable temporary directory. The result should be copied immediately
 374  as it may be overwritten by a subsequent call.
 375 **/
 376 _PUBLIC_ const char *tmpdir(void);
 377
 378 /**
 379  * Creates and immediately unlinks a file. Returns open file descriptor.
 380  **/
 381 _PUBLIC_ int create_unlink_tmp(const char *dir);
 382
 383 /**
 384  Check if a file exists - call vfs_file_exist for samba files.
 385 **/
 386 _PUBLIC_ bool file_exist(const char *fname);
 387
 388 /**
 389  * @brief Return a files modification time.
 390  *
 391  * @param fname  The name of the file.
 392  *
 393  * @param mt     A pointer to store the modification time.
 394  *
 395  * @return 0 on success, errno otherwise.
 396  */
 397 _PUBLIC_ int file_modtime(const char *fname, struct timespec *mt);
 398
 399 /**
 400  Check if a directory exists.
 401 **/
 402 _PUBLIC_ bool directory_exist(const char *dname);
 403
 404 /**
 405  Check file permissions.
 406 **/
 407 _PUBLIC_ bool file_check_permissions(const char *fname,
 408                                      uid_t uid,
 409                                      mode_t file_perms,
 410                                      struct stat *pst);
 411
 412 /**
 413  * Try to create the specified directory if it didn't exist.
 414  *
 415  * @retval true if the directory already existed and has the right permissions
 416  * or was successfully created.
 417  */
 418 _PUBLIC_ bool directory_create_or_exist(const char *dname, mode_t dir_perms);
 419
 420 /**
 421  * @brief Try to create a specified directory and the parent directory if they
 422  *        don't exist.
 423  *
 424  * @param[in]  dname     The directory path to create.
 425  *
 426  * @param[in]  dir_perms The permission of the directories.
 427  *
 428  * @return true on success, false otherwise.
 429  */
 430 _PUBLIC_ bool directory_create_or_exists_recursive(
 431                 const char *dname,
 432                 mode_t dir_perms);
 433
 434 _PUBLIC_ bool directory_create_or_exist_strict(const char *dname,
 435                                                uid_t uid,
 436                                                mode_t dir_perms);
 437
 438 #include "blocking.h"
 439
 440 /**
 441  Sleep for a specified number of milliseconds.
 442 **/
 443 _PUBLIC_ void smb_msleep(unsigned int t);
 444
 445 /**
 446  Get my own name, return in talloc'ed storage.
 447 **/
 448 _PUBLIC_ char* get_myname(TALLOC_CTX *mem_ctx);
 449
 450 /**
 451  Check if a process exists. Does this work on all unixes?
 452 **/
 453 _PUBLIC_ bool process_exists_by_pid(pid_t pid);
 454
 455 /**
 456  Simple routine to do POSIX file locking. Cruft in NFS and 64->32 bit mapping
 457  is dealt with in posix.c
 458 **/
 459 _PUBLIC_ bool fcntl_lock(int fd, int op, off_t offset, off_t count, int type);
 460
 461 /**
 462  * Write dump of binary data to the log file.
 463  *
 464  * The data is only written if the log level is at least level.
 465  * 16 zero bytes in a row are omitted
 466  */
 467 _PUBLIC_ void dump_data_skip_zeros(int level, const uint8_t *buf, int len);
 468
 469 /**
 470  malloc that aborts with smb_panic on fail or zero size.
 471 **/
 472 _PUBLIC_ void *smb_xmalloc(size_t size);
 473
 474 /**
 475  Memdup with smb_panic on fail.
 476 **/
 477 _PUBLIC_ void *smb_xmemdup(const void *p, size_t size);
 478
 479 /**
 480  strdup that aborts on malloc fail.
 481 **/
 482 _PUBLIC_ char *smb_xstrdup(const char *s);
 483
 484 char *smb_xstrndup(const char *s, size_t n);
 485
 486 /**
 487  Like strdup but for memory.
 488 **/
 489 _PUBLIC_ void *smb_memdup(const void *p, size_t size);
 490
 491 /**
 492  * see if a range of memory is all zero. A NULL pointer is considered
 493  * to be all zero
 494  */
 495 _PUBLIC_ bool all_zero(const uint8_t *ptr, size_t size);
 496
 497 /**
 498   realloc an array, checking for integer overflow in the array size
 499 */
 500 _PUBLIC_ void *realloc_array(void *ptr, size_t el_size, unsigned count, bool free_on_fail);
 501
 502 void *malloc_array(size_t el_size, unsigned int count);
 503
 504 void *memalign_array(size_t el_size, size_t align, unsigned int count);
 505
 506 void *calloc_array(size_t size, size_t nmemb);
 507
 508 /* The following definitions come from lib/util/fsusage.c  */
 509
 510
 511 /**
 512  * Retrieve amount of free disk space.
 513  * this does all of the system specific guff to get the free disk space.
 514  * It is derived from code in the GNU fileutils package, but has been
 515  * considerably mangled for use here
 516  *
 517  * results are returned in *dfree and *dsize, in 512 byte units
 518 */
 519 _PUBLIC_ int sys_fsusage(const char *path, uint64_t *dfree, uint64_t *dsize);
 520
 521 /* The following definitions come from lib/util/ms_fnmatch.c  */
 522
 523
 524 /**
 525  * @file
 526  * @brief MS-style Filename matching
 527  */
 528
 529 int ms_fnmatch_protocol(const char *pattern, const char *string, int protocol,
 530                         bool is_case_sensitive);
 531
 532 /** a generic fnmatch function - uses for non-CIFS pattern matching */
 533 int gen_fnmatch(const char *pattern, const char *string);
 534
 535 #include "become_daemon.h"
 536
 537 /**
 538  * @brief Get a password from the console.
 539  *
 540  * You should make sure that the buffer is an empty string!
 541  *
 542  * You can also use this function to ask for a username. Then you can fill the
 543  * buffer with the username and it is shows to the users. If the users just
 544  * presses enter the buffer will be untouched.
 545  *
 546  * @code
 547  *   char username[128];
 548  *
 549  *   snprintf(username, sizeof(username), "john");
 550  *
 551  *   smb_getpass("Username:", username, sizeof(username), 1, 0);
 552  * @endcode
 553  *
 554  * The prompt will look like this:
 555  *
 556  *   Username: [john]
 557  *
 558  * If you press enter then john is used as the username, or you can type it in
 559  * to change it.
 560  *
 561  * @param[in]  prompt   The prompt to show to ask for the password.
 562  *
 563  * @param[out] buf    The buffer the password should be stored. It NEEDS to be
 564  *                    empty or filled out.
 565  *
 566  * @param[in]  len      The length of the buffer.
 567  *
 568  * @param[in]  echo     Should we echo what you type.
 569  *
 570  * @param[in]  verify   Should we ask for the password twice.
 571  *
 572  * @return              0 on success, -1 on error.
 573  */
 574 _PUBLIC_ int samba_getpass(const char *prompt, char *buf, size_t len,
 575                            bool echo, bool verify);
 576
 577 /**
 578  * Load a ini-style file.
 579  */
 580 bool pm_process( const char *fileName,
 581                  bool (*sfunc)(const char *, void *),
 582                  bool (*pfunc)(const char *, const char *, void *),
 583                                  void *userdata);
 584 bool pm_process_with_flags(const char *filename,
 585                            bool allow_empty_values,
 586                            bool (*sfunc)(const char *section, void *private_data),
 587                            bool (*pfunc)(const char *name, const char *value,
 588                                          void *private_data),
 589                            void *private_data);
 590
 591 void print_asc(int level, const uint8_t *buf,int len);
 592 void print_asc_cb(const uint8_t *buf, int len,
 593                   void (*cb)(const char *buf, void *private_data),
 594                   void *private_data);
 595
 596 /**
 597  * Add an id to an array of ids.
 598  *
 599  * num should be a pointer to an integer that holds the current
 600  * number of elements in ids. It will be updated by this function.
 601  */
 602
 603 bool add_uid_to_array_unique(TALLOC_CTX *mem_ctx, uid_t uid,
 604                              uid_t **uids, uint32_t *num_uids);
 605 bool add_gid_to_array_unique(TALLOC_CTX *mem_ctx, gid_t gid,
 606                              gid_t **gids, uint32_t *num_gids);
 607
 608 /**
 609  * Allocate anonymous shared memory of the given size
 610  */
 611 void *anonymous_shared_allocate(size_t bufsz);
 612 void *anonymous_shared_resize(void *ptr, size_t new_size, bool maymove);
 613 void anonymous_shared_free(void *ptr);
 614
 615 /*
 616   run a command as a child process, with a timeout.
 617
 618   any stdout/stderr from the child will appear in the Samba logs with
 619   the specified log levels
 620
 621   If callback is set then the callback is called on completion
 622   with the return code from the command
 623  */
 624 struct tevent_context;
 625 struct tevent_req;
 626 struct tevent_req *samba_runcmd_send(TALLOC_CTX *mem_ctx,
 627                                      struct tevent_context *ev,
 628                                      struct timeval endtime,
 629                                      int stdout_log_level,
 630                                      int stderr_log_level,
 631                                      const char * const *argv0, ...);
 632 int samba_runcmd_recv(struct tevent_req *req, int *perrno);
 633 int samba_runcmd_export_stdin(struct tevent_req *req);
 634
 635 #ifdef DEVELOPER
 636 void samba_start_debugger(void);
 637 #endif
 638
 639 /*
 640  * Samba code should use samba_tevent_context_init() instead of
 641  * tevent_context_init() in order to get the debug output.
 642  */
 643 struct tevent_context *samba_tevent_context_init(TALLOC_CTX *mem_ctx);
 644
 645 /*
 646  * if same samba code needs to use a specific tevent backend
 647  * it can use something like this:
 648  *
 649  * samba_tevent_set_debug(ev, "pysmb_tevent");
 650  */
 651 void samba_tevent_set_debug(struct tevent_context *ev, const char *name);
 652
 653 static inline char nybble_to_hex_lower(uint8_t val)
 654 {
 655         return hexchars_lower[val & 0xf];
 656 }
 657
 658 static inline char nybble_to_hex_upper(uint8_t val)
 659 {
 660         return hexchars_upper[val & 0xf];
 661 }
 662
 663 #endif /* _SAMBA_UTIL_H_ */