1 #ifndef _TALLOC_H_
2 #define _TALLOC_H_
3 /*
4    Unix SMB/CIFS implementation.
5    Samba temporary memory allocation functions
6 
7    Copyright (C) Andrew Tridgell 2004-2005
8    Copyright (C) Stefan Metzmacher 2006
9 
10      ** NOTE! The following LGPL license applies to the talloc
11      ** library. This does NOT imply that all of Samba is released
12      ** under the LGPL
13 
14    This library is free software; you can redistribute it and/or
15    modify it under the terms of the GNU Lesser General Public
16    License as published by the Free Software Foundation; either
17    version 3 of the License, or (at your option) any later version.
18 
19    This library is distributed in the hope that it will be useful,
20    but WITHOUT ANY WARRANTY; without even the implied warranty of
21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
22    Lesser General Public License for more details.
23 
24    You should have received a copy of the GNU Lesser General Public
25    License along with this library; if not, see <http://www.gnu.org/licenses/>.
26 */
27 
28 #include <stdlib.h>
29 #include <stdio.h>
30 #include <stdarg.h>
31 
32 #ifdef __cplusplus
33 extern "C" {
34 #endif
35 
36 /**
37  * @defgroup talloc The talloc API
38  *
39  * talloc is a hierarchical, reference counted memory pool system with
40  * destructors. It is the core memory allocator used in Samba.
41  *
42  * @{
43  */
44 
45 #define TALLOC_VERSION_MAJOR 2
46 #define TALLOC_VERSION_MINOR 3
47 
48 int talloc_version_major(void);
49 int talloc_version_minor(void);
50 /* This is mostly useful only for testing */
51 int talloc_test_get_magic(void);
52 
53 /**
54  * @brief Define a talloc parent type
55  *
56  * As talloc is a hierarchial memory allocator, every talloc chunk is a
57  * potential parent to other talloc chunks. So defining a separate type for a
58  * talloc chunk is not strictly necessary. TALLOC_CTX is defined nevertheless,
59  * as it provides an indicator for function arguments. You will frequently
60  * write code like
61  *
62  * @code
63  *      struct foo *foo_create(TALLOC_CTX *mem_ctx)
64  *      {
65  *              struct foo *result;
66  *              result = talloc(mem_ctx, struct foo);
67  *              if (result == NULL) return NULL;
68  *                      ... initialize foo ...
69  *              return result;
70  *      }
71  * @endcode
72  *
73  * In this type of allocating functions it is handy to have a general
74  * TALLOC_CTX type to indicate which parent to put allocated structures on.
75  */
76 typedef void TALLOC_CTX;
77 
78 /*
79   this uses a little trick to allow __LINE__ to be stringified
80 */
81 #ifndef __location__
82 #define __TALLOC_STRING_LINE1__(s)    #s
83 #define __TALLOC_STRING_LINE2__(s)   __TALLOC_STRING_LINE1__(s)
84 #define __TALLOC_STRING_LINE3__  __TALLOC_STRING_LINE2__(__LINE__)
85 #define __location__ __FILE__ ":" __TALLOC_STRING_LINE3__
86 #endif
87 
88 #ifndef TALLOC_DEPRECATED
89 #define TALLOC_DEPRECATED 0
90 #endif
91 
92 #ifndef PRINTF_ATTRIBUTE
93 #if (__GNUC__ >= 3)
94 /** Use gcc attribute to check printf fns.  a1 is the 1-based index of
95  * the parameter containing the format, and a2 the index of the first
96  * argument. Note that some gcc 2.x versions don't handle this
97  * properly **/
98 #define PRINTF_ATTRIBUTE(a1, a2) __attribute__ ((format (__printf__, a1, a2)))
99 #else
100 #define PRINTF_ATTRIBUTE(a1, a2)
101 #endif
102 #endif
103 
104 #ifndef _DEPRECATED_
105 #ifdef HAVE___ATTRIBUTE__
106 #define _DEPRECATED_ __attribute__ ((deprecated))
107 #else
108 #define _DEPRECATED_
109 #endif
110 #endif
111 #ifdef DOXYGEN
112 
113 /**
114  * @brief Create a new talloc context.
115  *
116  * The talloc() macro is the core of the talloc library. It takes a memory
117  * context and a type, and returns a pointer to a new area of memory of the
118  * given type.
119  *
120  * The returned pointer is itself a talloc context, so you can use it as the
121  * context argument to more calls to talloc if you wish.
122  *
123  * The returned pointer is a "child" of the supplied context. This means that if
124  * you talloc_free() the context then the new child disappears as well.
125  * Alternatively you can free just the child.
126  *
127  * @param[in]  ctx      A talloc context to create a new reference on or NULL to
128  *                      create a new top level context.
129  *
130  * @param[in]  type     The type of memory to allocate.
131  *
132  * @return              A type casted talloc context or NULL on error.
133  *
134  * @code
135  *      unsigned int *a, *b;
136  *
137  *      a = talloc(NULL, unsigned int);
138  *      b = talloc(a, unsigned int);
139  * @endcode
140  *
141  * @see talloc_zero
142  * @see talloc_array
143  * @see talloc_steal
144  * @see talloc_free
145  */
146 void *talloc(const void *ctx, #type);
147 #else
148 #define talloc(ctx, type) (type *)talloc_named_const(ctx, sizeof(type), #type)
149 void *_talloc(const void *context, size_t size);
150 #endif
151 
152 /**
153  * @brief Create a new top level talloc context.
154  *
155  * This function creates a zero length named talloc context as a top level
156  * context. It is equivalent to:
157  *
158  * @code
159  *      talloc_named(NULL, 0, fmt, ...);
160  * @endcode
161  * @param[in]  fmt      Format string for the name.
162  *
163  * @param[in]  ...      Additional printf-style arguments.
164  *
165  * @return              The allocated memory chunk, NULL on error.
166  *
167  * @see talloc_named()
168  */
169 void *talloc_init(const char *fmt, ...) PRINTF_ATTRIBUTE(1,2);
170 
171 #ifdef DOXYGEN
172 /**
173  * @brief Free a chunk of talloc memory.
174  *
175  * The talloc_free() function frees a piece of talloc memory, and all its
176  * children. You can call talloc_free() on any pointer returned by
177  * talloc().
178  *
179  * The return value of talloc_free() indicates success or failure, with 0
180  * returned for success and -1 for failure. A possible failure condition
181  * is if the pointer had a destructor attached to it and the destructor
182  * returned -1. See talloc_set_destructor() for details on
183  * destructors. Likewise, if "ptr" is NULL, then the function will make
184  * no modifications and return -1.
185  *
186  * From version 2.0 and onwards, as a special case, talloc_free() is
187  * refused on pointers that have more than one parent associated, as talloc
188  * would have no way of knowing which parent should be removed. This is
189  * different from older versions in the sense that always the reference to
190  * the most recently established parent has been destroyed. Hence to free a
191  * pointer that has more than one parent please use talloc_unlink().
192  *
193  * To help you find problems in your code caused by this behaviour, if
194  * you do try and free a pointer with more than one parent then the
195  * talloc logging function will be called to give output like this:
196  *
197  * @code
198  *   ERROR: talloc_free with references at some_dir/source/foo.c:123
199  *     reference at some_dir/source/other.c:325
200  *     reference at some_dir/source/third.c:121
201  * @endcode
202  *
203  * Please see the documentation for talloc_set_log_fn() and
204  * talloc_set_log_stderr() for more information on talloc logging
205  * functions.
206  *
207  * If <code>TALLOC_FREE_FILL</code> environment variable is set,
208  * the memory occupied by the context is filled with the value of this variable.
209  * The value should be a numeric representation of the character you want to
210  * use.
211  *
212  * talloc_free() operates recursively on its children.
213  *
214  * @param[in]  ptr      The chunk to be freed.
215  *
216  * @return              Returns 0 on success and -1 on error. A possible
217  *                      failure condition is if the pointer had a destructor
218  *                      attached to it and the destructor returned -1. Likewise,
219  *                      if "ptr" is NULL, then the function will make no
220  *                      modifications and returns -1.
221  *
222  * Example:
223  * @code
224  *      unsigned int *a, *b;
225  *      a = talloc(NULL, unsigned int);
226  *      b = talloc(a, unsigned int);
227  *
228  *      talloc_free(a); // Frees a and b
229  * @endcode
230  *
231  * @see talloc_set_destructor()
232  * @see talloc_unlink()
233  */
234 int talloc_free(void *ptr);
235 #else
236 #define talloc_free(ctx) _talloc_free(ctx, __location__)
237 int _talloc_free(void *ptr, const char *location);
238 #endif
239 
240 /**
241  * @brief Free a talloc chunk's children.
242  *
243  * The function walks along the list of all children of a talloc context and
244  * talloc_free()s only the children, not the context itself.
245  *
246  * A NULL argument is handled as no-op.
247  *
248  * @param[in]  ptr      The chunk that you want to free the children of
249  *                      (NULL is allowed too)
250  */
251 void talloc_free_children(void *ptr);
252 
253 #ifdef DOXYGEN
254 /**
255  * @brief Assign a destructor function to be called when a chunk is freed.
256  *
257  * The function talloc_set_destructor() sets the "destructor" for the pointer
258  * "ptr". A destructor is a function that is called when the memory used by a
259  * pointer is about to be released. The destructor receives the pointer as an
260  * argument, and should return 0 for success and -1 for failure.
261  *
262  * The destructor can do anything it wants to, including freeing other pieces
263  * of memory. A common use for destructors is to clean up operating system
264  * resources (such as open file descriptors) contained in the structure the
265  * destructor is placed on.
266  *
267  * You can only place one destructor on a pointer. If you need more than one
268  * destructor then you can create a zero-length child of the pointer and place
269  * an additional destructor on that.
270  *
271  * To remove a destructor call talloc_set_destructor() with NULL for the
272  * destructor.
273  *
274  * If your destructor attempts to talloc_free() the pointer that it is the
275  * destructor for then talloc_free() will return -1 and the free will be
276  * ignored. This would be a pointless operation anyway, as the destructor is
277  * only called when the memory is just about to go away.
278  *
279  * @param[in]  ptr      The talloc chunk to add a destructor to.
280  *
281  * @param[in]  destructor  The destructor function to be called. NULL to remove
282  *                         it.
283  *
284  * Example:
285  * @code
286  *      static int destroy_fd(int *fd) {
287  *              close(*fd);
288  *              return 0;
289  *      }
290  *
291  *      int *open_file(const char *filename) {
292  *              int *fd = talloc(NULL, int);
293  *              *fd = open(filename, O_RDONLY);
294  *              if (*fd < 0) {
295  *                      talloc_free(fd);
296  *                      return NULL;
297  *              }
298  *              // Whenever they free this, we close the file.
299  *              talloc_set_destructor(fd, destroy_fd);
300  *              return fd;
301  *      }
302  * @endcode
303  *
304  * @see talloc()
305  * @see talloc_free()
306  */
307 void talloc_set_destructor(const void *ptr, int (*destructor)(void *));
308 
309 /**
310  * @brief Change a talloc chunk's parent.
311  *
312  * The talloc_steal() function changes the parent context of a talloc
313  * pointer. It is typically used when the context that the pointer is
314  * currently a child of is going to be freed and you wish to keep the
315  * memory for a longer time.
316  *
317  * To make the changed hierarchy less error-prone, you might consider to use
318  * talloc_move().
319  *
320  * If you try and call talloc_steal() on a pointer that has more than one
321  * parent then the result is ambiguous. Talloc will choose to remove the
322  * parent that is currently indicated by talloc_parent() and replace it with
323  * the chosen parent. You will also get a message like this via the talloc
324  * logging functions:
325  *
326  * @code
327  *   WARNING: talloc_steal with references at some_dir/source/foo.c:123
328  *     reference at some_dir/source/other.c:325
329  *     reference at some_dir/source/third.c:121
330  * @endcode
331  *
332  * To unambiguously change the parent of a pointer please see the function
333  * talloc_reparent(). See the talloc_set_log_fn() documentation for more
334  * information on talloc logging.
335  *
336  * @param[in]  new_ctx  The new parent context.
337  *
338  * @param[in]  ptr      The talloc chunk to move.
339  *
340  * @return              Returns the pointer that you pass it. It does not have
341  *                      any failure modes.
342  *
343  * @note It is possible to produce loops in the parent/child relationship
344  * if you are not careful with talloc_steal(). No guarantees are provided
345  * as to your sanity or the safety of your data if you do this.
346  */
347 void *talloc_steal(const void *new_ctx, const void *ptr);
348 #else /* DOXYGEN */
349 /* try to make talloc_set_destructor() and talloc_steal() type safe,
350    if we have a recent gcc */
351 #if (__GNUC__ >= 3)
352 #define _TALLOC_TYPEOF(ptr) __typeof__(ptr)
353 #define talloc_set_destructor(ptr, function)				      \
354 	do {								      \
355 		int (*_talloc_destructor_fn)(_TALLOC_TYPEOF(ptr)) = (function);	      \
356 		_talloc_set_destructor((ptr), (int (*)(void *))_talloc_destructor_fn); \
357 	} while(0)
358 /* this extremely strange macro is to avoid some braindamaged warning
359    stupidity in gcc 4.1.x */
360 #define talloc_steal(ctx, ptr) ({ _TALLOC_TYPEOF(ptr) __talloc_steal_ret = (_TALLOC_TYPEOF(ptr))_talloc_steal_loc((ctx),(ptr), __location__); __talloc_steal_ret; })
361 #else /* __GNUC__ >= 3 */
362 #define talloc_set_destructor(ptr, function) \
363 	_talloc_set_destructor((ptr), (int (*)(void *))(function))
364 #define _TALLOC_TYPEOF(ptr) void *
365 #define talloc_steal(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_steal_loc((ctx),(ptr), __location__)
366 #endif /* __GNUC__ >= 3 */
367 void _talloc_set_destructor(const void *ptr, int (*_destructor)(void *));
368 void *_talloc_steal_loc(const void *new_ctx, const void *ptr, const char *location);
369 #endif /* DOXYGEN */
370 
371 /**
372  * @brief Assign a name to a talloc chunk.
373  *
374  * Each talloc pointer has a "name". The name is used principally for
375  * debugging purposes, although it is also possible to set and get the name on
376  * a pointer in as a way of "marking" pointers in your code.
377  *
378  * The main use for names on pointer is for "talloc reports". See
379  * talloc_report() and talloc_report_full() for details. Also see
380  * talloc_enable_leak_report() and talloc_enable_leak_report_full().
381  *
382  * The talloc_set_name() function allocates memory as a child of the
383  * pointer. It is logically equivalent to:
384  *
385  * @code
386  *      talloc_set_name_const(ptr, talloc_asprintf(ptr, fmt, ...));
387  * @endcode
388  *
389  * @param[in]  ptr      The talloc chunk to assign a name to.
390  *
391  * @param[in]  fmt      Format string for the name.
392  *
393  * @param[in]  ...      Add printf-style additional arguments.
394  *
395  * @return              The assigned name, NULL on error.
396  *
397  * @note Multiple calls to talloc_set_name() will allocate more memory without
398  * releasing the name. All of the memory is released when the ptr is freed
399  * using talloc_free().
400  */
401 const char *talloc_set_name(const void *ptr, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
402 
403 #ifdef DOXYGEN
404 /**
405  * @brief Change a talloc chunk's parent.
406  *
407  * This function has the same effect as talloc_steal(), and additionally sets
408  * the source pointer to NULL. You would use it like this:
409  *
410  * @code
411  *      struct foo *X = talloc(tmp_ctx, struct foo);
412  *      struct foo *Y;
413  *      Y = talloc_move(new_ctx, &X);
414  * @endcode
415  *
416  * @param[in]  new_ctx  The new parent context.
417  *
418  * @param[in]  pptr     Pointer to a pointer to the talloc chunk to move.
419  *
420  * @return              The pointer to the talloc chunk that moved.
421  *                      It does not have any failure modes.
422  *
423  */
424 void *talloc_move(const void *new_ctx, void **pptr);
425 #else
426 #define talloc_move(ctx, pptr) (_TALLOC_TYPEOF(*(pptr)))_talloc_move((ctx),(void *)(pptr))
427 void *_talloc_move(const void *new_ctx, const void *pptr);
428 #endif
429 
430 /**
431  * @brief Assign a name to a talloc chunk.
432  *
433  * The function is just like talloc_set_name(), but it takes a string constant,
434  * and is much faster. It is extensively used by the "auto naming" macros, such
435  * as talloc_p().
436  *
437  * This function does not allocate any memory. It just copies the supplied
438  * pointer into the internal representation of the talloc ptr. This means you
439  * must not pass a name pointer to memory that will disappear before the ptr
440  * is freed with talloc_free().
441  *
442  * @param[in]  ptr      The talloc chunk to assign a name to.
443  *
444  * @param[in]  name     Format string for the name.
445  */
446 void talloc_set_name_const(const void *ptr, const char *name);
447 
448 /**
449  * @brief Create a named talloc chunk.
450  *
451  * The talloc_named() function creates a named talloc pointer. It is
452  * equivalent to:
453  *
454  * @code
455  *      ptr = talloc_size(context, size);
456  *      talloc_set_name(ptr, fmt, ....);
457  * @endcode
458  *
459  * @param[in]  context  The talloc context to hang the result off.
460  *
461  * @param[in]  size     Number of char's that you want to allocate.
462  *
463  * @param[in]  fmt      Format string for the name.
464  *
465  * @param[in]  ...      Additional printf-style arguments.
466  *
467  * @return              The allocated memory chunk, NULL on error.
468  *
469  * @see talloc_set_name()
470  */
471 void *talloc_named(const void *context, size_t size,
472 		   const char *fmt, ...) PRINTF_ATTRIBUTE(3,4);
473 
474 /**
475  * @brief Basic routine to allocate a chunk of memory.
476  *
477  * This is equivalent to:
478  *
479  * @code
480  *      ptr = talloc_size(context, size);
481  *      talloc_set_name_const(ptr, name);
482  * @endcode
483  *
484  * @param[in]  context  The parent context.
485  *
486  * @param[in]  size     The number of char's that we want to allocate.
487  *
488  * @param[in]  name     The name the talloc block has.
489  *
490  * @return             The allocated memory chunk, NULL on error.
491  */
492 void *talloc_named_const(const void *context, size_t size, const char *name);
493 
494 #ifdef DOXYGEN
495 /**
496  * @brief Untyped allocation.
497  *
498  * The function should be used when you don't have a convenient type to pass to
499  * talloc(). Unlike talloc(), it is not type safe (as it returns a void *), so
500  * you are on your own for type checking.
501  *
502  * Best to use talloc() or talloc_array() instead.
503  *
504  * @param[in]  ctx     The talloc context to hang the result off.
505  *
506  * @param[in]  size    Number of char's that you want to allocate.
507  *
508  * @return             The allocated memory chunk, NULL on error.
509  *
510  * Example:
511  * @code
512  *      void *mem = talloc_size(NULL, 100);
513  * @endcode
514  */
515 void *talloc_size(const void *ctx, size_t size);
516 #else
517 #define talloc_size(ctx, size) talloc_named_const(ctx, size, __location__)
518 #endif
519 
520 #ifdef DOXYGEN
521 /**
522  * @brief Allocate into a typed pointer.
523  *
524  * The talloc_ptrtype() macro should be used when you have a pointer and want
525  * to allocate memory to point at with this pointer. When compiling with
526  * gcc >= 3 it is typesafe. Note this is a wrapper of talloc_size() and
527  * talloc_get_name() will return the current location in the source file and
528  * not the type.
529  *
530  * @param[in]  ctx      The talloc context to hang the result off.
531  *
532  * @param[in]  type     The pointer you want to assign the result to.
533  *
534  * @return              The properly casted allocated memory chunk, NULL on
535  *                      error.
536  *
537  * Example:
538  * @code
539  *       unsigned int *a = talloc_ptrtype(NULL, a);
540  * @endcode
541  */
542 void *talloc_ptrtype(const void *ctx, #type);
543 #else
544 #define talloc_ptrtype(ctx, ptr) (_TALLOC_TYPEOF(ptr))talloc_size(ctx, sizeof(*(ptr)))
545 #endif
546 
547 #ifdef DOXYGEN
548 /**
549  * @brief Allocate a new 0-sized talloc chunk.
550  *
551  * This is a utility macro that creates a new memory context hanging off an
552  * existing context, automatically naming it "talloc_new: __location__" where
553  * __location__ is the source line it is called from. It is particularly
554  * useful for creating a new temporary working context.
555  *
556  * @param[in]  ctx      The talloc parent context.
557  *
558  * @return              A new talloc chunk, NULL on error.
559  */
560 void *talloc_new(const void *ctx);
561 #else
562 #define talloc_new(ctx) talloc_named_const(ctx, 0, "talloc_new: " __location__)
563 #endif
564 
565 #ifdef DOXYGEN
566 /**
567  * @brief Allocate a 0-initizialized structure.
568  *
569  * The macro is equivalent to:
570  *
571  * @code
572  *      ptr = talloc(ctx, type);
573  *      if (ptr) memset(ptr, 0, sizeof(type));
574  * @endcode
575  *
576  * @param[in]  ctx      The talloc context to hang the result off.
577  *
578  * @param[in]  type     The type that we want to allocate.
579  *
580  * @return              Pointer to a piece of memory, properly cast to 'type *',
581  *                      NULL on error.
582  *
583  * Example:
584  * @code
585  *      unsigned int *a, *b;
586  *      a = talloc_zero(NULL, unsigned int);
587  *      b = talloc_zero(a, unsigned int);
588  * @endcode
589  *
590  * @see talloc()
591  * @see talloc_zero_size()
592  * @see talloc_zero_array()
593  */
594 void *talloc_zero(const void *ctx, #type);
595 
596 /**
597  * @brief Allocate untyped, 0-initialized memory.
598  *
599  * @param[in]  ctx      The talloc context to hang the result off.
600  *
601  * @param[in]  size     Number of char's that you want to allocate.
602  *
603  * @return              The allocated memory chunk.
604  */
605 void *talloc_zero_size(const void *ctx, size_t size);
606 #else
607 #define talloc_zero(ctx, type) (type *)_talloc_zero(ctx, sizeof(type), #type)
608 #define talloc_zero_size(ctx, size) _talloc_zero(ctx, size, __location__)
609 void *_talloc_zero(const void *ctx, size_t size, const char *name);
610 #endif
611 
612 /**
613  * @brief Return the name of a talloc chunk.
614  *
615  * @param[in]  ptr      The talloc chunk.
616  *
617  * @return              The current name for the given talloc pointer.
618  *
619  * @see talloc_set_name()
620  */
621 const char *talloc_get_name(const void *ptr);
622 
623 /**
624  * @brief Verify that a talloc chunk carries a specified name.
625  *
626  * This function checks if a pointer has the specified name. If it does
627  * then the pointer is returned.
628  *
629  * @param[in]  ptr       The talloc chunk to check.
630  *
631  * @param[in]  name      The name to check against.
632  *
633  * @return               The pointer if the name matches, NULL if it doesn't.
634  */
635 void *talloc_check_name(const void *ptr, const char *name);
636 
637 /**
638  * @brief Get the parent chunk of a pointer.
639  *
640  * @param[in]  ptr      The talloc pointer to inspect.
641  *
642  * @return              The talloc parent of ptr, NULL on error.
643  */
644 void *talloc_parent(const void *ptr);
645 
646 /**
647  * @brief Get a talloc chunk's parent name.
648  *
649  * @param[in]  ptr      The talloc pointer to inspect.
650  *
651  * @return              The name of ptr's parent chunk.
652  */
653 const char *talloc_parent_name(const void *ptr);
654 
655 /**
656  * @brief Get the total size of a talloc chunk including its children.
657  *
658  * The function returns the total size in bytes used by this pointer and all
659  * child pointers. Mostly useful for debugging.
660  *
661  * Passing NULL is allowed, but it will only give a meaningful result if
662  * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
663  * been called.
664  *
665  * @param[in]  ptr      The talloc chunk.
666  *
667  * @return              The total size.
668  */
669 size_t talloc_total_size(const void *ptr);
670 
671 /**
672  * @brief Get the number of talloc chunks hanging off a chunk.
673  *
674  * The talloc_total_blocks() function returns the total memory block
675  * count used by this pointer and all child pointers. Mostly useful for
676  * debugging.
677  *
678  * Passing NULL is allowed, but it will only give a meaningful result if
679  * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
680  * been called.
681  *
682  * @param[in]  ptr      The talloc chunk.
683  *
684  * @return              The total size.
685  */
686 size_t talloc_total_blocks(const void *ptr);
687 
688 #ifdef DOXYGEN
689 /**
690  * @brief Duplicate a memory area into a talloc chunk.
691  *
692  * The function is equivalent to:
693  *
694  * @code
695  *      ptr = talloc_size(ctx, size);
696  *      if (ptr) memcpy(ptr, p, size);
697  * @endcode
698  *
699  * @param[in]  t        The talloc context to hang the result off.
700  *
701  * @param[in]  p        The memory chunk you want to duplicate.
702  *
703  * @param[in]  size     Number of char's that you want copy.
704  *
705  * @return              The allocated memory chunk.
706  *
707  * @see talloc_size()
708  */
709 void *talloc_memdup(const void *t, const void *p, size_t size);
710 #else
711 #define talloc_memdup(t, p, size) _talloc_memdup(t, p, size, __location__)
712 void *_talloc_memdup(const void *t, const void *p, size_t size, const char *name);
713 #endif
714 
715 #ifdef DOXYGEN
716 /**
717  * @brief Assign a type to a talloc chunk.
718  *
719  * This macro allows you to force the name of a pointer to be of a particular
720  * type. This can be used in conjunction with talloc_get_type() to do type
721  * checking on void* pointers.
722  *
723  * It is equivalent to this:
724  *
725  * @code
726  *      talloc_set_name_const(ptr, #type)
727  * @endcode
728  *
729  * @param[in]  ptr      The talloc chunk to assign the type to.
730  *
731  * @param[in]  type     The type to assign.
732  */
733 void talloc_set_type(const char *ptr, #type);
734 
735 /**
736  * @brief Get a typed pointer out of a talloc pointer.
737  *
738  * This macro allows you to do type checking on talloc pointers. It is
739  * particularly useful for void* private pointers. It is equivalent to
740  * this:
741  *
742  * @code
743  *      (type *)talloc_check_name(ptr, #type)
744  * @endcode
745  *
746  * @param[in]  ptr      The talloc pointer to check.
747  *
748  * @param[in]  type     The type to check against.
749  *
750  * @return              The properly casted pointer given by ptr, NULL on error.
751  */
752 type *talloc_get_type(const void *ptr, #type);
753 #else
754 #define talloc_set_type(ptr, type) talloc_set_name_const(ptr, #type)
755 #define talloc_get_type(ptr, type) (type *)talloc_check_name(ptr, #type)
756 #endif
757 
758 #ifdef DOXYGEN
759 /**
760  * @brief Safely turn a void pointer into a typed pointer.
761  *
762  * This macro is used together with talloc(mem_ctx, struct foo). If you had to
763  * assign the talloc chunk pointer to some void pointer variable,
764  * talloc_get_type_abort() is the recommended way to get the convert the void
765  * pointer back to a typed pointer.
766  *
767  * @param[in]  ptr      The void pointer to convert.
768  *
769  * @param[in]  type     The type that this chunk contains
770  *
771  * @return              The same value as ptr, type-checked and properly cast.
772  */
773 void *talloc_get_type_abort(const void *ptr, #type);
774 #else
775 #ifdef TALLOC_GET_TYPE_ABORT_NOOP
776 #define talloc_get_type_abort(ptr, type) (type *)(ptr)
777 #else
778 #define talloc_get_type_abort(ptr, type) (type *)_talloc_get_type_abort(ptr, #type, __location__)
779 #endif
780 void *_talloc_get_type_abort(const void *ptr, const char *name, const char *location);
781 #endif
782 
783 /**
784  * @brief Find a parent context by name.
785  *
786  * Find a parent memory context of the current context that has the given
787  * name. This can be very useful in complex programs where it may be
788  * difficult to pass all information down to the level you need, but you
789  * know the structure you want is a parent of another context.
790  *
791  * @param[in]  ctx      The talloc chunk to start from.
792  *
793  * @param[in]  name     The name of the parent we look for.
794  *
795  * @return              The memory context we are looking for, NULL if not
796  *                      found.
797  */
798 void *talloc_find_parent_byname(const void *ctx, const char *name);
799 
800 #ifdef DOXYGEN
801 /**
802  * @brief Find a parent context by type.
803  *
804  * Find a parent memory context of the current context that has the given
805  * name. This can be very useful in complex programs where it may be
806  * difficult to pass all information down to the level you need, but you
807  * know the structure you want is a parent of another context.
808  *
809  * Like talloc_find_parent_byname() but takes a type, making it typesafe.
810  *
811  * @param[in]  ptr      The talloc chunk to start from.
812  *
813  * @param[in]  type     The type of the parent to look for.
814  *
815  * @return              The memory context we are looking for, NULL if not
816  *                      found.
817  */
818 void *talloc_find_parent_bytype(const void *ptr, #type);
819 #else
820 #define talloc_find_parent_bytype(ptr, type) (type *)talloc_find_parent_byname(ptr, #type)
821 #endif
822 
823 /**
824  * @brief Allocate a talloc pool.
825  *
826  * A talloc pool is a pure optimization for specific situations. In the
827  * release process for Samba 3.2 we found out that we had become considerably
828  * slower than Samba 3.0 was. Profiling showed that malloc(3) was a large CPU
829  * consumer in benchmarks. For Samba 3.2 we have internally converted many
830  * static buffers to dynamically allocated ones, so malloc(3) being beaten
831  * more was no surprise. But it made us slower.
832  *
833  * talloc_pool() is an optimization to call malloc(3) a lot less for the use
834  * pattern Samba has: The SMB protocol is mainly a request/response protocol
835  * where we have to allocate a certain amount of memory per request and free
836  * that after the SMB reply is sent to the client.
837  *
838  * talloc_pool() creates a talloc chunk that you can use as a talloc parent
839  * exactly as you would use any other ::TALLOC_CTX. The difference is that
840  * when you talloc a child of this pool, no malloc(3) is done. Instead, talloc
841  * just increments a pointer inside the talloc_pool. This also works
842  * recursively. If you use the child of the talloc pool as a parent for
843  * grand-children, their memory is also taken from the talloc pool.
844  *
845  * If there is not enough memory in the pool to allocate the new child,
846  * it will create a new talloc chunk as if the parent was a normal talloc
847  * context.
848  *
849  * If you talloc_free() children of a talloc pool, the memory is not given
850  * back to the system. Instead, free(3) is only called if the talloc_pool()
851  * itself is released with talloc_free().
852  *
853  * The downside of a talloc pool is that if you talloc_move() a child of a
854  * talloc pool to a talloc parent outside the pool, the whole pool memory is
855  * not free(3)'ed until that moved chunk is also talloc_free()ed.
856  *
857  * @param[in]  context  The talloc context to hang the result off.
858  *
859  * @param[in]  size     Size of the talloc pool.
860  *
861  * @return              The allocated talloc pool, NULL on error.
862  */
863 void *talloc_pool(const void *context, size_t size);
864 
865 #ifdef DOXYGEN
866 /**
867  * @brief Allocate a talloc object as/with an additional pool.
868  *
869  * This is like talloc_pool(), but's it's more flexible
870  * and allows an object to be a pool for its children.
871  *
872  * @param[in] ctx                   The talloc context to hang the result off.
873  *
874  * @param[in] type                  The type that we want to allocate.
875  *
876  * @param[in] num_subobjects        The expected number of subobjects, which will
877  *                                  be allocated within the pool. This allocates
878  *                                  space for talloc_chunk headers.
879  *
880  * @param[in] total_subobjects_size The size that all subobjects can use in total.
881  *
882  *
883  * @return              The allocated talloc object, NULL on error.
884  */
885 void *talloc_pooled_object(const void *ctx, #type,
886 			   unsigned num_subobjects,
887 			   size_t total_subobjects_size);
888 #else
889 #define talloc_pooled_object(_ctx, _type, \
890 			     _num_subobjects, \
891 			     _total_subobjects_size) \
892 	(_type *)_talloc_pooled_object((_ctx), sizeof(_type), #_type, \
893 					(_num_subobjects), \
894 					(_total_subobjects_size))
895 void *_talloc_pooled_object(const void *ctx,
896 			    size_t type_size,
897 			    const char *type_name,
898 			    unsigned num_subobjects,
899 			    size_t total_subobjects_size);
900 #endif
901 
902 /**
903  * @brief Free a talloc chunk and NULL out the pointer.
904  *
905  * TALLOC_FREE() frees a pointer and sets it to NULL. Use this if you want
906  * immediate feedback (i.e. crash) if you use a pointer after having free'ed
907  * it.
908  *
909  * @param[in]  ctx      The chunk to be freed.
910  */
911 #define TALLOC_FREE(ctx) do { if (ctx != NULL) { talloc_free(ctx); ctx=NULL; } } while(0)
912 
913 /* @} ******************************************************************/
914 
915 /**
916  * \defgroup talloc_ref The talloc reference function.
917  * @ingroup talloc
918  *
919  * This module contains the definitions around talloc references
920  *
921  * @{
922  */
923 
924 /**
925  * @brief Increase the reference count of a talloc chunk.
926  *
927  * The talloc_increase_ref_count(ptr) function is exactly equivalent to:
928  *
929  * @code
930  *      talloc_reference(NULL, ptr);
931  * @endcode
932  *
933  * You can use either syntax, depending on which you think is clearer in
934  * your code.
935  *
936  * @param[in]  ptr      The pointer to increase the reference count.
937  *
938  * @return              0 on success, -1 on error.
939  */
940 int talloc_increase_ref_count(const void *ptr);
941 
942 /**
943  * @brief Get the number of references to a talloc chunk.
944  *
945  * @param[in]  ptr      The pointer to retrieve the reference count from.
946  *
947  * @return              The number of references.
948  */
949 size_t talloc_reference_count(const void *ptr);
950 
951 #ifdef DOXYGEN
952 /**
953  * @brief Create an additional talloc parent to a pointer.
954  *
955  * The talloc_reference() function makes "context" an additional parent of
956  * ptr. Each additional reference consumes around 48 bytes of memory on intel
957  * x86 platforms.
958  *
959  * If ptr is NULL, then the function is a no-op, and simply returns NULL.
960  *
961  * After creating a reference you can free it in one of the following ways:
962  *
963  * - you can talloc_free() any parent of the original pointer. That
964  *   will reduce the number of parents of this pointer by 1, and will
965  *   cause this pointer to be freed if it runs out of parents.
966  *
967  * - you can talloc_free() the pointer itself if it has at maximum one
968  *   parent. This behaviour has been changed since the release of version
969  *   2.0. Further information in the description of "talloc_free".
970  *
971  * For more control on which parent to remove, see talloc_unlink()
972  * @param[in]  ctx      The additional parent.
973  *
974  * @param[in]  ptr      The pointer you want to create an additional parent for.
975  *
976  * @return              The original pointer 'ptr', NULL if talloc ran out of
977  *                      memory in creating the reference.
978  *
979  * @warning You should try to avoid using this interface. It turns a beautiful
980  *          talloc-tree into a graph. It is often really hard to debug if you
981  *          screw something up by accident.
982  *
983  * Example:
984  * @code
985  *      unsigned int *a, *b, *c;
986  *      a = talloc(NULL, unsigned int);
987  *      b = talloc(NULL, unsigned int);
988  *      c = talloc(a, unsigned int);
989  *      // b also serves as a parent of c.
990  *      talloc_reference(b, c);
991  * @endcode
992  *
993  * @see talloc_unlink()
994  */
995 void *talloc_reference(const void *ctx, const void *ptr);
996 #else
997 #define talloc_reference(ctx, ptr) (_TALLOC_TYPEOF(ptr))_talloc_reference_loc((ctx),(ptr), __location__)
998 void *_talloc_reference_loc(const void *context, const void *ptr, const char *location);
999 #endif
1000 
1001 /**
1002  * @brief Remove a specific parent from a talloc chunk.
1003  *
1004  * The function removes a specific parent from ptr. The context passed must
1005  * either be a context used in talloc_reference() with this pointer, or must be
1006  * a direct parent of ptr.
1007  *
1008  * You can just use talloc_free() instead of talloc_unlink() if there
1009  * is at maximum one parent. This behaviour has been changed since the
1010  * release of version 2.0. Further information in the description of
1011  * "talloc_free".
1012  *
1013  * @param[in]  context  The talloc parent to remove.
1014  *
1015  * @param[in]  ptr      The talloc ptr you want to remove the parent from.
1016  *
1017  * @return              0 on success, -1 on error.
1018  *
1019  * @note If the parent has already been removed using talloc_free() then
1020  * this function will fail and will return -1.  Likewise, if ptr is NULL,
1021  * then the function will make no modifications and return -1.
1022  *
1023  * @warning You should try to avoid using this interface. It turns a beautiful
1024  *          talloc-tree into a graph. It is often really hard to debug if you
1025  *          screw something up by accident.
1026  *
1027  * Example:
1028  * @code
1029  *      unsigned int *a, *b, *c;
1030  *      a = talloc(NULL, unsigned int);
1031  *      b = talloc(NULL, unsigned int);
1032  *      c = talloc(a, unsigned int);
1033  *      // b also serves as a parent of c.
1034  *      talloc_reference(b, c);
1035  *      talloc_unlink(b, c);
1036  * @endcode
1037  */
1038 int talloc_unlink(const void *context, void *ptr);
1039 
1040 /**
1041  * @brief Provide a talloc context that is freed at program exit.
1042  *
1043  * This is a handy utility function that returns a talloc context
1044  * which will be automatically freed on program exit. This can be used
1045  * to reduce the noise in memory leak reports.
1046  *
1047  * Never use this in code that might be used in objects loaded with
1048  * dlopen and unloaded with dlclose. talloc_autofree_context()
1049  * internally uses atexit(3). Some platforms like modern Linux handles
1050  * this fine, but for example FreeBSD does not deal well with dlopen()
1051  * and atexit() used simultaneously: dlclose() does not clean up the
1052  * list of atexit-handlers, so when the program exits the code that
1053  * was registered from within talloc_autofree_context() is gone, the
1054  * program crashes at exit.
1055  *
1056  * @return              A talloc context, NULL on error.
1057  */
1058 void *talloc_autofree_context(void) _DEPRECATED_;
1059 
1060 /**
1061  * @brief Get the size of a talloc chunk.
1062  *
1063  * This function lets you know the amount of memory allocated so far by
1064  * this context. It does NOT account for subcontext memory.
1065  * This can be used to calculate the size of an array.
1066  *
1067  * @param[in]  ctx      The talloc chunk.
1068  *
1069  * @return              The size of the talloc chunk.
1070  */
1071 size_t talloc_get_size(const void *ctx);
1072 
1073 /**
1074  * @brief Show the parentage of a context.
1075  *
1076  * @param[in]  context            The talloc context to look at.
1077  *
1078  * @param[in]  file               The output to use, a file, stdout or stderr.
1079  */
1080 void talloc_show_parents(const void *context, FILE *file);
1081 
1082 /**
1083  * @brief Check if a context is parent of a talloc chunk.
1084  *
1085  * This checks if context is referenced in the talloc hierarchy above ptr.
1086  *
1087  * @param[in]  context  The assumed talloc context.
1088  *
1089  * @param[in]  ptr      The talloc chunk to check.
1090  *
1091  * @return              Return 1 if this is the case, 0 if not.
1092  */
1093 int talloc_is_parent(const void *context, const void *ptr);
1094 
1095 /**
1096  * @brief Change the parent context of a talloc pointer.
1097  *
1098  * The function changes the parent context of a talloc pointer. It is typically
1099  * used when the context that the pointer is currently a child of is going to be
1100  * freed and you wish to keep the memory for a longer time.
1101  *
1102  * The difference between talloc_reparent() and talloc_steal() is that
1103  * talloc_reparent() can specify which parent you wish to change. This is
1104  * useful when a pointer has multiple parents via references.
1105  *
1106  * @param[in]  old_parent
1107  * @param[in]  new_parent
1108  * @param[in]  ptr
1109  *
1110  * @return              Return the pointer you passed. It does not have any
1111  *                      failure modes.
1112  */
1113 void *talloc_reparent(const void *old_parent, const void *new_parent, const void *ptr);
1114 
1115 /* @} ******************************************************************/
1116 
1117 /**
1118  * @defgroup talloc_array The talloc array functions
1119  * @ingroup talloc
1120  *
1121  * Talloc contains some handy helpers for handling Arrays conveniently
1122  *
1123  * @{
1124  */
1125 
1126 #ifdef DOXYGEN
1127 /**
1128  * @brief Allocate an array.
1129  *
1130  * The macro is equivalent to:
1131  *
1132  * @code
1133  *      (type *)talloc_size(ctx, sizeof(type) * count);
1134  * @endcode
1135  *
1136  * except that it provides integer overflow protection for the multiply,
1137  * returning NULL if the multiply overflows.
1138  *
1139  * @param[in]  ctx      The talloc context to hang the result off.
1140  *
1141  * @param[in]  type     The type that we want to allocate.
1142  *
1143  * @param[in]  count    The number of 'type' elements you want to allocate.
1144  *
1145  * @return              The allocated result, properly cast to 'type *', NULL on
1146  *                      error.
1147  *
1148  * Example:
1149  * @code
1150  *      unsigned int *a, *b;
1151  *      a = talloc_zero(NULL, unsigned int);
1152  *      b = talloc_array(a, unsigned int, 100);
1153  * @endcode
1154  *
1155  * @see talloc()
1156  * @see talloc_zero_array()
1157  */
1158 void *talloc_array(const void *ctx, #type, unsigned count);
1159 #else
1160 #define talloc_array(ctx, type, count) (type *)_talloc_array(ctx, sizeof(type), count, #type)
1161 void *_talloc_array(const void *ctx, size_t el_size, unsigned count, const char *name);
1162 #endif
1163 
1164 #ifdef DOXYGEN
1165 /**
1166  * @brief Allocate an array.
1167  *
1168  * @param[in]  ctx      The talloc context to hang the result off.
1169  *
1170  * @param[in]  size     The size of an array element.
1171  *
1172  * @param[in]  count    The number of elements you want to allocate.
1173  *
1174  * @return              The allocated result, NULL on error.
1175  */
1176 void *talloc_array_size(const void *ctx, size_t size, unsigned count);
1177 #else
1178 #define talloc_array_size(ctx, size, count) _talloc_array(ctx, size, count, __location__)
1179 #endif
1180 
1181 #ifdef DOXYGEN
1182 /**
1183  * @brief Allocate an array into a typed pointer.
1184  *
1185  * The macro should be used when you have a pointer to an array and want to
1186  * allocate memory of an array to point at with this pointer. When compiling
1187  * with gcc >= 3 it is typesafe. Note this is a wrapper of talloc_array_size()
1188  * and talloc_get_name() will return the current location in the source file
1189  * and not the type.
1190  *
1191  * @param[in]  ctx      The talloc context to hang the result off.
1192  *
1193  * @param[in]  ptr      The pointer you want to assign the result to.
1194  *
1195  * @param[in]  count    The number of elements you want to allocate.
1196  *
1197  * @return              The allocated memory chunk, properly casted. NULL on
1198  *                      error.
1199  */
1200 void *talloc_array_ptrtype(const void *ctx, const void *ptr, unsigned count);
1201 #else
1202 #define talloc_array_ptrtype(ctx, ptr, count) (_TALLOC_TYPEOF(ptr))talloc_array_size(ctx, sizeof(*(ptr)), count)
1203 #endif
1204 
1205 #ifdef DOXYGEN
1206 /**
1207  * @brief Get the number of elements in a talloc'ed array.
1208  *
1209  * A talloc chunk carries its own size, so for talloc'ed arrays it is not
1210  * necessary to store the number of elements explicitly.
1211  *
1212  * @param[in]  ctx      The allocated array.
1213  *
1214  * @return              The number of elements in ctx.
1215  */
1216 size_t talloc_array_length(const void *ctx);
1217 #else
1218 #define talloc_array_length(ctx) (talloc_get_size(ctx)/sizeof(*ctx))
1219 #endif
1220 
1221 #ifdef DOXYGEN
1222 /**
1223  * @brief Allocate a zero-initialized array
1224  *
1225  * @param[in]  ctx      The talloc context to hang the result off.
1226  *
1227  * @param[in]  type     The type that we want to allocate.
1228  *
1229  * @param[in]  count    The number of "type" elements you want to allocate.
1230  *
1231  * @return              The allocated result casted to "type *", NULL on error.
1232  *
1233  * The talloc_zero_array() macro is equivalent to:
1234  *
1235  * @code
1236  *     ptr = talloc_array(ctx, type, count);
1237  *     if (ptr) memset(ptr, 0, sizeof(type) * count);
1238  * @endcode
1239  */
1240 void *talloc_zero_array(const void *ctx, #type, unsigned count);
1241 #else
1242 #define talloc_zero_array(ctx, type, count) (type *)_talloc_zero_array(ctx, sizeof(type), count, #type)
1243 void *_talloc_zero_array(const void *ctx,
1244 			 size_t el_size,
1245 			 unsigned count,
1246 			 const char *name);
1247 #endif
1248 
1249 #ifdef DOXYGEN
1250 /**
1251  * @brief Change the size of a talloc array.
1252  *
1253  * The macro changes the size of a talloc pointer. The 'count' argument is the
1254  * number of elements of type 'type' that you want the resulting pointer to
1255  * hold.
1256  *
1257  * talloc_realloc() has the following equivalences:
1258  *
1259  * @code
1260  *      talloc_realloc(ctx, NULL, type, 1) ==> talloc(ctx, type);
1261  *      talloc_realloc(ctx, NULL, type, N) ==> talloc_array(ctx, type, N);
1262  *      talloc_realloc(ctx, ptr, type, 0)  ==> talloc_free(ptr);
1263  * @endcode
1264  *
1265  * The "context" argument is only used if "ptr" is NULL, otherwise it is
1266  * ignored.
1267  *
1268  * @param[in]  ctx      The parent context used if ptr is NULL.
1269  *
1270  * @param[in]  ptr      The chunk to be resized.
1271  *
1272  * @param[in]  type     The type of the array element inside ptr.
1273  *
1274  * @param[in]  count    The intended number of array elements.
1275  *
1276  * @return              The new array, NULL on error. The call will fail either
1277  *                      due to a lack of memory, or because the pointer has more
1278  *                      than one parent (see talloc_reference()).
1279  */
1280 void *talloc_realloc(const void *ctx, void *ptr, #type, size_t count);
1281 #else
1282 #define talloc_realloc(ctx, p, type, count) (type *)_talloc_realloc_array(ctx, p, sizeof(type), count, #type)
1283 void *_talloc_realloc_array(const void *ctx, void *ptr, size_t el_size, unsigned count, const char *name);
1284 #endif
1285 
1286 #ifdef DOXYGEN
1287 /**
1288  * @brief Untyped realloc to change the size of a talloc array.
1289  *
1290  * The macro is useful when the type is not known so the typesafe
1291  * talloc_realloc() cannot be used.
1292  *
1293  * @param[in]  ctx      The parent context used if 'ptr' is NULL.
1294  *
1295  * @param[in]  ptr      The chunk to be resized.
1296  *
1297  * @param[in]  size     The new chunk size.
1298  *
1299  * @return              The new array, NULL on error.
1300  */
1301 void *talloc_realloc_size(const void *ctx, void *ptr, size_t size);
1302 #else
1303 #define talloc_realloc_size(ctx, ptr, size) _talloc_realloc(ctx, ptr, size, __location__)
1304 void *_talloc_realloc(const void *context, void *ptr, size_t size, const char *name);
1305 #endif
1306 
1307 /**
1308  * @brief Provide a function version of talloc_realloc_size.
1309  *
1310  * This is a non-macro version of talloc_realloc(), which is useful as
1311  * libraries sometimes want a ralloc function pointer. A realloc()
1312  * implementation encapsulates the functionality of malloc(), free() and
1313  * realloc() in one call, which is why it is useful to be able to pass around
1314  * a single function pointer.
1315  *
1316  * @param[in]  context  The parent context used if ptr is NULL.
1317  *
1318  * @param[in]  ptr      The chunk to be resized.
1319  *
1320  * @param[in]  size     The new chunk size.
1321  *
1322  * @return              The new chunk, NULL on error.
1323  */
1324 void *talloc_realloc_fn(const void *context, void *ptr, size_t size);
1325 
1326 /* @} ******************************************************************/
1327 
1328 /**
1329  * @defgroup talloc_string The talloc string functions.
1330  * @ingroup talloc
1331  *
1332  * talloc string allocation and manipulation functions.
1333  * @{
1334  */
1335 
1336 /**
1337  * @brief Duplicate a string into a talloc chunk.
1338  *
1339  * This function is equivalent to:
1340  *
1341  * @code
1342  *      ptr = talloc_size(ctx, strlen(p)+1);
1343  *      if (ptr) memcpy(ptr, p, strlen(p)+1);
1344  * @endcode
1345  *
1346  * This functions sets the name of the new pointer to the passed
1347  * string. This is equivalent to:
1348  *
1349  * @code
1350  *      talloc_set_name_const(ptr, ptr)
1351  * @endcode
1352  *
1353  * @param[in]  t        The talloc context to hang the result off.
1354  *
1355  * @param[in]  p        The string you want to duplicate.
1356  *
1357  * @return              The duplicated string, NULL on error.
1358  */
1359 char *talloc_strdup(const void *t, const char *p);
1360 
1361 /**
1362  * @brief Append a string to given string.
1363  *
1364  * The destination string is reallocated to take
1365  * <code>strlen(s) + strlen(a) + 1</code> characters.
1366  *
1367  * This functions sets the name of the new pointer to the new
1368  * string. This is equivalent to:
1369  *
1370  * @code
1371  *      talloc_set_name_const(ptr, ptr)
1372  * @endcode
1373  *
1374  * If <code>s == NULL</code> then new context is created.
1375  *
1376  * @param[in]  s        The destination to append to.
1377  *
1378  * @param[in]  a        The string you want to append.
1379  *
1380  * @return              The concatenated strings, NULL on error.
1381  *
1382  * @see talloc_strdup()
1383  * @see talloc_strdup_append_buffer()
1384  */
1385 char *talloc_strdup_append(char *s, const char *a);
1386 
1387 /**
1388  * @brief Append a string to a given buffer.
1389  *
1390  * This is a more efficient version of talloc_strdup_append(). It determines the
1391  * length of the destination string by the size of the talloc context.
1392  *
1393  * Use this very carefully as it produces a different result than
1394  * talloc_strdup_append() when a zero character is in the middle of the
1395  * destination string.
1396  *
1397  * @code
1398  *      char *str_a = talloc_strdup(NULL, "hello world");
1399  *      char *str_b = talloc_strdup(NULL, "hello world");
1400  *      str_a[5] = str_b[5] = '\0'
1401  *
1402  *      char *app = talloc_strdup_append(str_a, ", hello");
1403  *      char *buf = talloc_strdup_append_buffer(str_b, ", hello");
1404  *
1405  *      printf("%s\n", app); // hello, hello (app = "hello, hello")
1406  *      printf("%s\n", buf); // hello (buf = "hello\0world, hello")
1407  * @endcode
1408  *
1409  * If <code>s == NULL</code> then new context is created.
1410  *
1411  * @param[in]  s        The destination buffer to append to.
1412  *
1413  * @param[in]  a        The string you want to append.
1414  *
1415  * @return              The concatenated strings, NULL on error.
1416  *
1417  * @see talloc_strdup()
1418  * @see talloc_strdup_append()
1419  * @see talloc_array_length()
1420  */
1421 char *talloc_strdup_append_buffer(char *s, const char *a);
1422 
1423 /**
1424  * @brief Duplicate a length-limited string into a talloc chunk.
1425  *
1426  * This function is the talloc equivalent of the C library function strndup(3).
1427  *
1428  * This functions sets the name of the new pointer to the passed string. This is
1429  * equivalent to:
1430  *
1431  * @code
1432  *      talloc_set_name_const(ptr, ptr)
1433  * @endcode
1434  *
1435  * @param[in]  t        The talloc context to hang the result off.
1436  *
1437  * @param[in]  p        The string you want to duplicate.
1438  *
1439  * @param[in]  n        The maximum string length to duplicate.
1440  *
1441  * @return              The duplicated string, NULL on error.
1442  */
1443 char *talloc_strndup(const void *t, const char *p, size_t n);
1444 
1445 /**
1446  * @brief Append at most n characters of a string to given string.
1447  *
1448  * The destination string is reallocated to take
1449  * <code>strlen(s) + strnlen(a, n) + 1</code> characters.
1450  *
1451  * This functions sets the name of the new pointer to the new
1452  * string. This is equivalent to:
1453  *
1454  * @code
1455  *      talloc_set_name_const(ptr, ptr)
1456  * @endcode
1457  *
1458  * If <code>s == NULL</code> then new context is created.
1459  *
1460  * @param[in]  s        The destination string to append to.
1461  *
1462  * @param[in]  a        The source string you want to append.
1463  *
1464  * @param[in]  n        The number of characters you want to append from the
1465  *                      string.
1466  *
1467  * @return              The concatenated strings, NULL on error.
1468  *
1469  * @see talloc_strndup()
1470  * @see talloc_strndup_append_buffer()
1471  */
1472 char *talloc_strndup_append(char *s, const char *a, size_t n);
1473 
1474 /**
1475  * @brief Append at most n characters of a string to given buffer
1476  *
1477  * This is a more efficient version of talloc_strndup_append(). It determines
1478  * the length of the destination string by the size of the talloc context.
1479  *
1480  * Use this very carefully as it produces a different result than
1481  * talloc_strndup_append() when a zero character is in the middle of the
1482  * destination string.
1483  *
1484  * @code
1485  *      char *str_a = talloc_strdup(NULL, "hello world");
1486  *      char *str_b = talloc_strdup(NULL, "hello world");
1487  *      str_a[5] = str_b[5] = '\0'
1488  *
1489  *      char *app = talloc_strndup_append(str_a, ", hello", 7);
1490  *      char *buf = talloc_strndup_append_buffer(str_b, ", hello", 7);
1491  *
1492  *      printf("%s\n", app); // hello, hello (app = "hello, hello")
1493  *      printf("%s\n", buf); // hello (buf = "hello\0world, hello")
1494  * @endcode
1495  *
1496  * If <code>s == NULL</code> then new context is created.
1497  *
1498  * @param[in]  s        The destination buffer to append to.
1499  *
1500  * @param[in]  a        The source string you want to append.
1501  *
1502  * @param[in]  n        The number of characters you want to append from the
1503  *                      string.
1504  *
1505  * @return              The concatenated strings, NULL on error.
1506  *
1507  * @see talloc_strndup()
1508  * @see talloc_strndup_append()
1509  * @see talloc_array_length()
1510  */
1511 char *talloc_strndup_append_buffer(char *s, const char *a, size_t n);
1512 
1513 /**
1514  * @brief Format a string given a va_list.
1515  *
1516  * This function is the talloc equivalent of the C library function
1517  * vasprintf(3).
1518  *
1519  * This functions sets the name of the new pointer to the new string. This is
1520  * equivalent to:
1521  *
1522  * @code
1523  *      talloc_set_name_const(ptr, ptr)
1524  * @endcode
1525  *
1526  * @param[in]  t        The talloc context to hang the result off.
1527  *
1528  * @param[in]  fmt      The format string.
1529  *
1530  * @param[in]  ap       The parameters used to fill fmt.
1531  *
1532  * @return              The formatted string, NULL on error.
1533  */
1534 char *talloc_vasprintf(const void *t, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
1535 
1536 /**
1537  * @brief Format a string given a va_list and append it to the given destination
1538  *        string.
1539  *
1540  * @param[in]  s        The destination string to append to.
1541  *
1542  * @param[in]  fmt      The format string.
1543  *
1544  * @param[in]  ap       The parameters used to fill fmt.
1545  *
1546  * @return              The formatted string, NULL on error.
1547  *
1548  * @see talloc_vasprintf()
1549  */
1550 char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
1551 
1552 /**
1553  * @brief Format a string given a va_list and append it to the given destination
1554  *        buffer.
1555  *
1556  * @param[in]  s        The destination buffer to append to.
1557  *
1558  * @param[in]  fmt      The format string.
1559  *
1560  * @param[in]  ap       The parameters used to fill fmt.
1561  *
1562  * @return              The formatted string, NULL on error.
1563  *
1564  * @see talloc_vasprintf()
1565  */
1566 char *talloc_vasprintf_append_buffer(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
1567 
1568 /**
1569  * @brief Format a string.
1570  *
1571  * This function is the talloc equivalent of the C library function asprintf(3).
1572  *
1573  * This functions sets the name of the new pointer to the new string. This is
1574  * equivalent to:
1575  *
1576  * @code
1577  *      talloc_set_name_const(ptr, ptr)
1578  * @endcode
1579  *
1580  * @param[in]  t        The talloc context to hang the result off.
1581  *
1582  * @param[in]  fmt      The format string.
1583  *
1584  * @param[in]  ...      The parameters used to fill fmt.
1585  *
1586  * @return              The formatted string, NULL on error.
1587  */
1588 char *talloc_asprintf(const void *t, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
1589 
1590 /**
1591  * @brief Append a formatted string to another string.
1592  *
1593  * This function appends the given formatted string to the given string. Use
1594  * this variant when the string in the current talloc buffer may have been
1595  * truncated in length.
1596  *
1597  * This functions sets the name of the new pointer to the new
1598  * string. This is equivalent to:
1599  *
1600  * @code
1601  *      talloc_set_name_const(ptr, ptr)
1602  * @endcode
1603  *
1604  * If <code>s == NULL</code> then new context is created.
1605  *
1606  * @param[in]  s        The string to append to.
1607  *
1608  * @param[in]  fmt      The format string.
1609  *
1610  * @param[in]  ...      The parameters used to fill fmt.
1611  *
1612  * @return              The formatted string, NULL on error.
1613  */
1614 char *talloc_asprintf_append(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
1615 
1616 /**
1617  * @brief Append a formatted string to another string.
1618  *
1619  * This is a more efficient version of talloc_asprintf_append(). It determines
1620  * the length of the destination string by the size of the talloc context.
1621  *
1622  * Use this very carefully as it produces a different result than
1623  * talloc_asprintf_append() when a zero character is in the middle of the
1624  * destination string.
1625  *
1626  * @code
1627  *      char *str_a = talloc_strdup(NULL, "hello world");
1628  *      char *str_b = talloc_strdup(NULL, "hello world");
1629  *      str_a[5] = str_b[5] = '\0'
1630  *
1631  *      char *app = talloc_asprintf_append(str_a, "%s", ", hello");
1632  *      char *buf = talloc_strdup_append_buffer(str_b, "%s", ", hello");
1633  *
1634  *      printf("%s\n", app); // hello, hello (app = "hello, hello")
1635  *      printf("%s\n", buf); // hello (buf = "hello\0world, hello")
1636  * @endcode
1637  *
1638  * If <code>s == NULL</code> then new context is created.
1639  *
1640  * @param[in]  s        The string to append to
1641  *
1642  * @param[in]  fmt      The format string.
1643  *
1644  * @param[in]  ...      The parameters used to fill fmt.
1645  *
1646  * @return              The formatted string, NULL on error.
1647  *
1648  * @see talloc_asprintf()
1649  * @see talloc_asprintf_append()
1650  */
1651 char *talloc_asprintf_append_buffer(char *s, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
1652 
1653 /* @} ******************************************************************/
1654 
1655 /**
1656  * @defgroup talloc_debug The talloc debugging support functions
1657  * @ingroup talloc
1658  *
1659  * To aid memory debugging, talloc contains routines to inspect the currently
1660  * allocated memory hierarchy.
1661  *
1662  * @{
1663  */
1664 
1665 /**
1666  * @brief Walk a complete talloc hierarchy.
1667  *
1668  * This provides a more flexible reports than talloc_report(). It
1669  * will recursively call the callback for the entire tree of memory
1670  * referenced by the pointer. References in the tree are passed with
1671  * is_ref = 1 and the pointer that is referenced.
1672  *
1673  * You can pass NULL for the pointer, in which case a report is
1674  * printed for the top level memory context, but only if
1675  * talloc_enable_leak_report() or talloc_enable_leak_report_full()
1676  * has been called.
1677  *
1678  * The recursion is stopped when depth >= max_depth.
1679  * max_depth = -1 means only stop at leaf nodes.
1680  *
1681  * @param[in]  ptr      The talloc chunk.
1682  *
1683  * @param[in]  depth    Internal parameter to control recursion. Call with 0.
1684  *
1685  * @param[in]  max_depth  Maximum recursion level.
1686  *
1687  * @param[in]  callback  Function to be called on every chunk.
1688  *
1689  * @param[in]  private_data  Private pointer passed to callback.
1690  */
1691 void talloc_report_depth_cb(const void *ptr, int depth, int max_depth,
1692 			    void (*callback)(const void *ptr,
1693 					     int depth, int max_depth,
1694 					     int is_ref,
1695 					     void *private_data),
1696 			    void *private_data);
1697 
1698 /**
1699  * @brief Print a talloc hierarchy.
1700  *
1701  * This provides a more flexible reports than talloc_report(). It
1702  * will let you specify the depth and max_depth.
1703  *
1704  * @param[in]  ptr      The talloc chunk.
1705  *
1706  * @param[in]  depth    Internal parameter to control recursion. Call with 0.
1707  *
1708  * @param[in]  max_depth  Maximum recursion level.
1709  *
1710  * @param[in]  f        The file handle to print to.
1711  */
1712 void talloc_report_depth_file(const void *ptr, int depth, int max_depth, FILE *f);
1713 
1714 /**
1715  * @brief Print a summary report of all memory used by ptr.
1716  *
1717  * This provides a more detailed report than talloc_report(). It will
1718  * recursively print the entire tree of memory referenced by the
1719  * pointer. References in the tree are shown by giving the name of the
1720  * pointer that is referenced.
1721  *
1722  * You can pass NULL for the pointer, in which case a report is printed
1723  * for the top level memory context, but only if
1724  * talloc_enable_leak_report() or talloc_enable_leak_report_full() has
1725  * been called.
1726  *
1727  * @param[in]  ptr      The talloc chunk.
1728  *
1729  * @param[in]  f        The file handle to print to.
1730  *
1731  * Example:
1732  * @code
1733  *      unsigned int *a, *b;
1734  *      a = talloc(NULL, unsigned int);
1735  *      b = talloc(a, unsigned int);
1736  *      fprintf(stderr, "Dumping memory tree for a:\n");
1737  *      talloc_report_full(a, stderr);
1738  * @endcode
1739  *
1740  * @see talloc_report()
1741  */
1742 void talloc_report_full(const void *ptr, FILE *f);
1743 
1744 /**
1745  * @brief Print a summary report of all memory used by ptr.
1746  *
1747  * This function prints a summary report of all memory used by ptr. One line of
1748  * report is printed for each immediate child of ptr, showing the total memory
1749  * and number of blocks used by that child.
1750  *
1751  * You can pass NULL for the pointer, in which case a report is printed
1752  * for the top level memory context, but only if talloc_enable_leak_report()
1753  * or talloc_enable_leak_report_full() has been called.
1754  *
1755  * @param[in]  ptr      The talloc chunk.
1756  *
1757  * @param[in]  f        The file handle to print to.
1758  *
1759  * Example:
1760  * @code
1761  *      unsigned int *a, *b;
1762  *      a = talloc(NULL, unsigned int);
1763  *      b = talloc(a, unsigned int);
1764  *      fprintf(stderr, "Summary of memory tree for a:\n");
1765  *      talloc_report(a, stderr);
1766  * @endcode
1767  *
1768  * @see talloc_report_full()
1769  */
1770 void talloc_report(const void *ptr, FILE *f);
1771 
1772 /**
1773  * @brief Enable tracking the use of NULL memory contexts.
1774  *
1775  * This enables tracking of the NULL memory context without enabling leak
1776  * reporting on exit. Useful for when you want to do your own leak
1777  * reporting call via talloc_report_null_full();
1778  */
1779 void talloc_enable_null_tracking(void);
1780 
1781 /**
1782  * @brief Enable tracking the use of NULL memory contexts.
1783  *
1784  * This enables tracking of the NULL memory context without enabling leak
1785  * reporting on exit. Useful for when you want to do your own leak
1786  * reporting call via talloc_report_null_full();
1787  */
1788 void talloc_enable_null_tracking_no_autofree(void);
1789 
1790 /**
1791  * @brief Disable tracking of the NULL memory context.
1792  *
1793  * This disables tracking of the NULL memory context.
1794  */
1795 void talloc_disable_null_tracking(void);
1796 
1797 /**
1798  * @brief Enable leak report when a program exits.
1799  *
1800  * This enables calling of talloc_report(NULL, stderr) when the program
1801  * exits. In Samba4 this is enabled by using the --leak-report command
1802  * line option.
1803  *
1804  * For it to be useful, this function must be called before any other
1805  * talloc function as it establishes a "null context" that acts as the
1806  * top of the tree. If you don't call this function first then passing
1807  * NULL to talloc_report() or talloc_report_full() won't give you the
1808  * full tree printout.
1809  *
1810  * Here is a typical talloc report:
1811  *
1812  * @code
1813  * talloc report on 'null_context' (total 267 bytes in 15 blocks)
1814  *      libcli/auth/spnego_parse.c:55  contains     31 bytes in   2 blocks
1815  *      libcli/auth/spnego_parse.c:55  contains     31 bytes in   2 blocks
1816  *      iconv(UTF8,CP850)              contains     42 bytes in   2 blocks
1817  *      libcli/auth/spnego_parse.c:55  contains     31 bytes in   2 blocks
1818  *      iconv(CP850,UTF8)              contains     42 bytes in   2 blocks
1819  *      iconv(UTF8,UTF-16LE)           contains     45 bytes in   2 blocks
1820  *      iconv(UTF-16LE,UTF8)           contains     45 bytes in   2 blocks
1821  * @endcode
1822  */
1823 void talloc_enable_leak_report(void);
1824 
1825 /**
1826  * @brief Enable full leak report when a program exits.
1827  *
1828  * This enables calling of talloc_report_full(NULL, stderr) when the
1829  * program exits. In Samba4 this is enabled by using the
1830  * --leak-report-full command line option.
1831  *
1832  * For it to be useful, this function must be called before any other
1833  * talloc function as it establishes a "null context" that acts as the
1834  * top of the tree. If you don't call this function first then passing
1835  * NULL to talloc_report() or talloc_report_full() won't give you the
1836  * full tree printout.
1837  *
1838  * Here is a typical full report:
1839  *
1840  * @code
1841  * full talloc report on 'root' (total 18 bytes in 8 blocks)
1842  *      p1                             contains     18 bytes in   7 blocks (ref 0)
1843  *      r1                             contains     13 bytes in   2 blocks (ref 0)
1844  *      reference to: p2
1845  *      p2                             contains      1 bytes in   1 blocks (ref 1)
1846  *      x3                             contains      1 bytes in   1 blocks (ref 0)
1847  *      x2                             contains      1 bytes in   1 blocks (ref 0)
1848  *      x1                             contains      1 bytes in   1 blocks (ref 0)
1849  * @endcode
1850  */
1851 void talloc_enable_leak_report_full(void);
1852 
1853 /**
1854  * @brief Set a custom "abort" function that is called on serious error.
1855  *
1856  * The default "abort" function is <code>abort()</code>.
1857  *
1858  * The "abort" function is called when:
1859  *
1860  * <ul>
1861  *  <li>talloc_get_type_abort() fails</li>
1862  *  <li>the provided pointer is not a valid talloc context</li>
1863  *  <li>when the context meta data are invalid</li>
1864  *  <li>when access after free is detected</li>
1865  * </ul>
1866  *
1867  * Example:
1868  *
1869  * @code
1870  * void my_abort(const char *reason)
1871  * {
1872  *      fprintf(stderr, "talloc abort: %s\n", reason);
1873  *      abort();
1874  * }
1875  *
1876  *      talloc_set_abort_fn(my_abort);
1877  * @endcode
1878  *
1879  * @param[in]  abort_fn      The new "abort" function.
1880  *
1881  * @see talloc_set_log_fn()
1882  * @see talloc_get_type()
1883  */
1884 void talloc_set_abort_fn(void (*abort_fn)(const char *reason));
1885 
1886 /**
1887  * @brief Set a logging function.
1888  *
1889  * @param[in]  log_fn      The logging function.
1890  *
1891  * @see talloc_set_log_stderr()
1892  * @see talloc_set_abort_fn()
1893  */
1894 void talloc_set_log_fn(void (*log_fn)(const char *message));
1895 
1896 /**
1897  * @brief Set stderr as the output for logs.
1898  *
1899  * @see talloc_set_log_fn()
1900  * @see talloc_set_abort_fn()
1901  */
1902 void talloc_set_log_stderr(void);
1903 
1904 /**
1905  * @brief Set a max memory limit for the current context hierarchy
1906  *	  This affects all children of this context and constrain any
1907  *	  allocation in the hierarchy to never exceed the limit set.
1908  *	  The limit can be removed by setting 0 (unlimited) as the
1909  *	  max_size by calling the function again on the same context.
1910  *	  Memory limits can also be nested, meaning a child can have
1911  *	  a stricter memory limit than a parent.
1912  *	  Memory limits are enforced only at memory allocation time.
1913  *	  Stealing a context into a 'limited' hierarchy properly
1914  *	  updates memory usage but does *not* cause failure if the
1915  *	  move causes the new parent to exceed its limits. However
1916  *	  any further allocation on that hierarchy will then fail.
1917  *
1918  * @warning talloc memlimit functionality is deprecated. Please
1919  *	    consider using cgroup memory limits instead.
1920  *
1921  * @param[in]	ctx		The talloc context to set the limit on
1922  * @param[in]	max_size	The (new) max_size
1923  */
1924 int talloc_set_memlimit(const void *ctx, size_t max_size) _DEPRECATED_;
1925 
1926 /* @} ******************************************************************/
1927 
1928 #if TALLOC_DEPRECATED
1929 #define talloc_zero_p(ctx, type) talloc_zero(ctx, type)
1930 #define talloc_p(ctx, type) talloc(ctx, type)
1931 #define talloc_array_p(ctx, type, count) talloc_array(ctx, type, count)
1932 #define talloc_realloc_p(ctx, p, type, count) talloc_realloc(ctx, p, type, count)
1933 #define talloc_destroy(ctx) talloc_free(ctx)
1934 #define talloc_append_string(c, s, a) (s?talloc_strdup_append(s,a):talloc_strdup(c, a))
1935 #endif
1936 
1937 #ifndef TALLOC_MAX_DEPTH
1938 #define TALLOC_MAX_DEPTH 10000
1939 #endif
1940 
1941 #ifdef __cplusplus
1942 } /* end of extern "C" */
1943 #endif
1944 
1945 #endif
1946