[project @ 2005-04-03 10:56:49 by bursa]

Talloc memory allocation functions from Samba.

svn path=/import/netsurf/; revision=1591

2 files changed, 1198 insertions, 0 deletions

diff --git a/utils/talloc.c b/utils/talloc.c
new file mode 100644
index 000000000..661282a87
--- /dev/null
+++ b/utils/talloc.c
@@ -0,0 +1,1067 @@
+/* 
+   Samba Unix SMB/CIFS implementation.
+
+   Samba trivial allocation library - new interface
+
+   NOTE: Please read talloc_guide.txt for full documentation
+
+   Copyright (C) Andrew Tridgell 2004
+   
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+/*
+  inspired by http://swapped.cc/halloc/
+*/
+
+
+#ifdef _SAMBA_BUILD_
+#include "includes.h"
+#else
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include "talloc.h"
+/* assume a modern system */
+#define HAVE_VA_COPY
+#endif
+
+/* use this to force every realloc to change the pointer, to stress test
+   code that might not cope */
+#define ALWAYS_REALLOC 0
+
+
+#define MAX_TALLOC_SIZE 0x10000000
+#define TALLOC_MAGIC 0xe814ec4f
+#define TALLOC_MAGIC_FREE 0x7faebef3
+#define TALLOC_MAGIC_REFERENCE ((const char *)1)
+
+/* by default we abort when given a bad pointer (such as when talloc_free() is called 
+   on a pointer that came from malloc() */
+#ifndef TALLOC_ABORT
+#define TALLOC_ABORT(reason) abort()
+#endif
+
+#ifndef discard_const_p
+#if defined(__intptr_t_defined) || defined(HAVE_INTPTR_T)
+# define discard_const_p(type, ptr) ((type *)((intptr_t)(ptr)))
+#else
+# define discard_const_p(type, ptr) ((type *)(ptr))
+#endif
+#endif
+
+/* this null_context is only used if talloc_enable_leak_report() or
+   talloc_enable_leak_report_full() is called, otherwise it remains
+   NULL
+*/
+static const void *null_context;
+static void *cleanup_context;
+
+
+struct talloc_reference_handle {
+	struct talloc_reference_handle *next, *prev;
+	void *ptr;
+};
+
+typedef int (*talloc_destructor_t)(void *);
+
+struct talloc_chunk {
+	struct talloc_chunk *next, *prev;
+	struct talloc_chunk *parent, *child;
+	struct talloc_reference_handle *refs;
+	size_t size;
+	unsigned magic;
+	talloc_destructor_t destructor;
+	const char *name;
+};
+
+/* panic if we get a bad magic value */
+static struct talloc_chunk *talloc_chunk_from_ptr(const void *ptr)
+{
+	struct talloc_chunk *tc = discard_const_p(struct talloc_chunk, ptr)-1;
+	if (tc->magic != TALLOC_MAGIC) { 
+		if (tc->magic == TALLOC_MAGIC_FREE) {
+			TALLOC_ABORT("Bad talloc magic value - double free"); 
+		} else {
+			TALLOC_ABORT("Bad talloc magic value - unknown value"); 
+		}
+	}
+
+	return tc;
+}
+
+/* hook into the front of the list */
+#define _TLIST_ADD(list, p) \
+do { \
+        if (!(list)) { \
+		(list) = (p); \
+		(p)->next = (p)->prev = NULL; \
+	} else { \
+		(list)->prev = (p); \
+		(p)->next = (list); \
+		(p)->prev = NULL; \
+		(list) = (p); \
+	}\
+} while (0)
+
+/* remove an element from a list - element doesn't have to be in list. */
+#define _TLIST_REMOVE(list, p) \
+do { \
+	if ((p) == (list)) { \
+		(list) = (p)->next; \
+		if (list) (list)->prev = NULL; \
+	} else { \
+		if ((p)->prev) (p)->prev->next = (p)->next; \
+		if ((p)->next) (p)->next->prev = (p)->prev; \
+	} \
+	if ((p) && ((p) != (list))) (p)->next = (p)->prev = NULL; \
+} while (0)
+
+
+/*
+  return the parent chunk of a pointer
+*/
+static struct talloc_chunk *talloc_parent_chunk(const void *ptr)
+{
+	struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr);
+	while (tc->prev) tc=tc->prev;
+	return tc->parent;
+}
+
+void *talloc_parent(const void *ptr)
+{
+	struct talloc_chunk *tc = talloc_parent_chunk(ptr);
+	return (void *)(tc+1);
+}
+
+/* 
+   Allocate a bit of memory as a child of an existing pointer
+*/
+void *_talloc(const void *context, size_t size)
+{
+	struct talloc_chunk *tc;
+
+	if (context == NULL) {
+		context = null_context;
+	}
+
+	if (size >= MAX_TALLOC_SIZE) {
+		return NULL;
+	}
+
+	tc = malloc(sizeof(*tc)+size);
+	if (tc == NULL) return NULL;
+
+	tc->size = size;
+	tc->magic = TALLOC_MAGIC;
+	tc->destructor = NULL;
+	tc->child = NULL;
+	tc->name = NULL;
+	tc->refs = NULL;
+
+	if (context) {
+		struct talloc_chunk *parent = talloc_chunk_from_ptr(context);
+
+		tc->parent = parent;
+
+		if (parent->child) {
+			parent->child->parent = NULL;
+		}
+
+		_TLIST_ADD(parent->child, tc);
+	} else {
+		tc->next = tc->prev = tc->parent = NULL;
+	}
+
+	return (void *)(tc+1);
+}
+
+
+/*
+  setup a destructor to be called on free of a pointer
+  the destructor should return 0 on success, or -1 on failure.
+  if the destructor fails then the free is failed, and the memory can
+  be continued to be used
+*/
+void talloc_set_destructor(const void *ptr, int (*destructor)(void *))
+{
+	struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr);
+	tc->destructor = destructor;
+}
+
+/*
+  increase the reference count on a piece of memory. 
+*/
+void talloc_increase_ref_count(const void *ptr)
+{
+	talloc_reference(null_context, ptr);
+}
+
+/*
+  helper for talloc_reference()
+*/
+static int talloc_reference_destructor(void *ptr)
+{
+	struct talloc_reference_handle *handle = ptr;
+	struct talloc_chunk *tc1 = talloc_chunk_from_ptr(ptr);
+	struct talloc_chunk *tc2 = talloc_chunk_from_ptr(handle->ptr);
+	if (tc1->destructor != (talloc_destructor_t)-1) {
+		tc1->destructor = NULL;
+	}
+	_TLIST_REMOVE(tc2->refs, handle);
+	talloc_free(handle);
+	return 0;
+}
+
+/*
+  make a secondary reference to a pointer, hanging off the given context.
+  the pointer remains valid until both the original caller and this given
+  context are freed.
+  
+  the major use for this is when two different structures need to reference the 
+  same underlying data, and you want to be able to free the two instances separately,
+  and in either order
+*/
+void *talloc_reference(const void *context, const void *ptr)
+{
+	struct talloc_chunk *tc;
+	struct talloc_reference_handle *handle;
+	if (ptr == NULL) return NULL;
+
+	tc = talloc_chunk_from_ptr(ptr);
+	handle = talloc_named_const(context, sizeof(*handle), TALLOC_MAGIC_REFERENCE);
+
+	if (handle == NULL) return NULL;
+
+	/* note that we hang the destructor off the handle, not the
+	   main context as that allows the caller to still setup their
+	   own destructor on the context if they want to */
+	talloc_set_destructor(handle, talloc_reference_destructor);
+	handle->ptr = discard_const_p(void, ptr);
+	_TLIST_ADD(tc->refs, handle);
+	return handle->ptr;
+}
+
+/*
+  remove a secondary reference to a pointer. This undo's what
+  talloc_reference() has done. The context and pointer arguments
+  must match those given to a talloc_reference()
+*/
+static int talloc_unreference(const void *context, const void *ptr)
+{
+	struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr);
+	struct talloc_reference_handle *h;
+
+	if (context == NULL) {
+		context = null_context;
+	}
+
+	for (h=tc->refs;h;h=h->next) {
+		struct talloc_chunk *p = talloc_parent_chunk(h);
+		if ((p==NULL && context==NULL) || p+1 == context) break;
+	}
+	if (h == NULL) {
+		return -1;
+	}
+
+	talloc_set_destructor(h, NULL);
+	_TLIST_REMOVE(tc->refs, h);
+	talloc_free(h);
+	return 0;
+}
+
+/*
+  remove a specific parent context from a pointer. This is a more
+  controlled varient of talloc_free()
+*/
+int talloc_unlink(const void *context, void *ptr)
+{
+	struct talloc_chunk *tc_p, *new_p;
+	void *new_parent;
+
+	if (ptr == NULL) {
+		return -1;
+	}
+
+	if (context == NULL) {
+		context = null_context;
+	}
+
+	if (talloc_unreference(context, ptr) == 0) {
+		return 0;
+	}
+
+	if (context == NULL) {
+		if (talloc_parent_chunk(ptr) != NULL) {
+			return -1;
+		}
+	} else {
+		if (talloc_chunk_from_ptr(context) != talloc_parent_chunk(ptr)) {
+			return -1;
+		}
+	}
+	
+	tc_p = talloc_chunk_from_ptr(ptr);
+
+	if (tc_p->refs == NULL) {
+		return talloc_free(ptr);
+	}
+
+	new_p = talloc_parent_chunk(tc_p->refs);
+	if (new_p) {
+		new_parent = new_p+1;
+	} else {
+		new_parent = NULL;
+	}
+
+	if (talloc_unreference(new_parent, ptr) != 0) {
+		return -1;
+	}
+
+	talloc_steal(new_parent, ptr);
+
+	return 0;
+}
+
+/*
+  add a name to an existing pointer - va_list version
+*/
+static void talloc_set_name_v(const void *ptr, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
+
+static void talloc_set_name_v(const void *ptr, const char *fmt, va_list ap)
+{
+	struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr);
+	tc->name = talloc_vasprintf(ptr, fmt, ap);
+	if (tc->name) {
+		talloc_set_name_const(tc->name, ".name");
+	}
+}
+
+/*
+  add a name to an existing pointer
+*/
+void talloc_set_name(const void *ptr, const char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	talloc_set_name_v(ptr, fmt, ap);
+	va_end(ap);
+}
+
+/*
+   more efficient way to add a name to a pointer - the name must point to a 
+   true string constant
+*/
+void talloc_set_name_const(const void *ptr, const char *name)
+{
+	struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr);
+	tc->name = name;
+}
+
+/*
+  create a named talloc pointer. Any talloc pointer can be named, and
+  talloc_named() operates just like talloc() except that it allows you
+  to name the pointer.
+*/
+void *talloc_named(const void *context, size_t size, const char *fmt, ...)
+{
+	va_list ap;
+	void *ptr;
+
+	ptr = _talloc(context, size);
+	if (ptr == NULL) return NULL;
+
+	va_start(ap, fmt);
+	talloc_set_name_v(ptr, fmt, ap);
+	va_end(ap);
+
+	return ptr;
+}
+
+/*
+  create a named talloc pointer. Any talloc pointer can be named, and
+  talloc_named() operates just like talloc() except that it allows you
+  to name the pointer.
+*/
+void *talloc_named_const(const void *context, size_t size, const char *name)
+{
+	void *ptr;
+
+	ptr = _talloc(context, size);
+	if (ptr == NULL) {
+		return NULL;
+	}
+
+	talloc_set_name_const(ptr, name);
+
+	return ptr;
+}
+
+/*
+  return the name of a talloc ptr, or "UNNAMED"
+*/
+const char *talloc_get_name(const void *ptr)
+{
+	struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr);
+	if (tc->name == TALLOC_MAGIC_REFERENCE) {
+		return ".reference";
+	}
+	if (tc->name) {
+		return tc->name;
+	}
+	return "UNNAMED";
+}
+
+
+/*
+  check if a pointer has the given name. If it does, return the pointer,
+  otherwise return NULL
+*/
+void *talloc_check_name(const void *ptr, const char *name)
+{
+	const char *pname;
+	if (ptr == NULL) return NULL;
+	pname = talloc_get_name(ptr);
+	if (pname == name || strcmp(pname, name) == 0) {
+		return discard_const_p(void, ptr);
+	}
+	return NULL;
+}
+
+
+/*
+  this is for compatibility with older versions of talloc
+*/
+void *talloc_init(const char *fmt, ...)
+{
+	va_list ap;
+	void *ptr;
+
+	ptr = _talloc(NULL, 0);
+	if (ptr == NULL) return NULL;
+
+	va_start(ap, fmt);
+	talloc_set_name_v(ptr, fmt, ap);
+	va_end(ap);
+
+	return ptr;
+}
+
+
+/* 
+   free a talloc pointer. This also frees all child pointers of this 
+   pointer recursively
+
+   return 0 if the memory is actually freed, otherwise -1. The memory
+   will not be freed if the ref_count is > 1 or the destructor (if
+   any) returns non-zero
+*/
+int talloc_free(void *ptr)
+{
+	struct talloc_chunk *tc;
+
+	if (ptr == NULL) {
+		return -1;
+	}
+
+	tc = talloc_chunk_from_ptr(ptr);
+
+	if (tc->refs) {
+		talloc_reference_destructor(tc->refs);
+		return -1;
+	}
+
+	if (tc->destructor) {
+		talloc_destructor_t d = tc->destructor;
+		if (d == (talloc_destructor_t)-1) {
+			return -1;
+		}
+		tc->destructor = (talloc_destructor_t)-1;
+		if (d(ptr) == -1) {
+			tc->destructor = d;
+			return -1;
+		}
+		tc->destructor = NULL;
+	}
+
+	while (tc->child) {
+		/* we need to work out who will own an abandoned child
+		   if it cannot be freed. In priority order, the first
+		   choice is owner of any remaining reference to this
+		   pointer, the second choice is our parent, and the
+		   final choice is the null context. */
+		void *child = tc->child+1;
+		const void *new_parent = null_context;
+		if (tc->child->refs) {
+			struct talloc_chunk *p = talloc_parent_chunk(tc->child->refs);
+			if (p) new_parent = p+1;
+		}
+		if (talloc_free(child) == -1) {
+			if (new_parent == null_context) {
+				struct talloc_chunk *p = talloc_parent_chunk(ptr);
+				if (p) new_parent = p+1;
+			}
+			talloc_steal(new_parent, child);
+		}
+	}
+
+	if (tc->parent) {
+		_TLIST_REMOVE(tc->parent->child, tc);
+		if (tc->parent->child) {
+			tc->parent->child->parent = tc->parent;
+		}
+	} else {
+		if (tc->prev) tc->prev->next = tc->next;
+		if (tc->next) tc->next->prev = tc->prev;
+	}
+
+	tc->magic = TALLOC_MAGIC_FREE;
+
+	free(tc);
+	return 0;
+}
+
+
+
+/*
+  A talloc version of realloc. The context argument is only used if
+  ptr is NULL
+*/
+void *_talloc_realloc(const void *context, void *ptr, size_t size, const char *name)
+{
+	struct talloc_chunk *tc;
+	void *new_ptr;
+
+	/* size zero is equivalent to free() */
+	if (size == 0) {
+		talloc_free(ptr);
+		return NULL;
+	}
+
+	if (size >= MAX_TALLOC_SIZE) {
+		return NULL;
+	}
+
+	/* realloc(NULL) is equavalent to malloc() */
+	if (ptr == NULL) {
+		return talloc_named_const(context, size, name);
+	}
+
+	tc = talloc_chunk_from_ptr(ptr);
+
+	/* don't allow realloc on referenced pointers */
+	if (tc->refs) {
+		return NULL;
+	}
+
+	/* by resetting magic we catch users of the old memory */
+	tc->magic = TALLOC_MAGIC_FREE;
+
+#if ALWAYS_REALLOC
+	new_ptr = malloc(size + sizeof(*tc));
+	if (new_ptr) {
+		memcpy(new_ptr, tc, tc->size + sizeof(*tc));
+		free(tc);
+	}
+#else
+	new_ptr = realloc(tc, size + sizeof(*tc));
+#endif
+	if (!new_ptr) {	
+		tc->magic = TALLOC_MAGIC; 
+		return NULL; 
+	}
+
+	tc = new_ptr;
+	tc->magic = TALLOC_MAGIC;
+	if (tc->parent) {
+		tc->parent->child = new_ptr;
+	}
+	if (tc->child) {
+		tc->child->parent = new_ptr;
+	}
+
+	if (tc->prev) {
+		tc->prev->next = tc;
+	}
+	if (tc->next) {
+		tc->next->prev = tc;
+	}
+
+	tc->size = size;
+	talloc_set_name_const(tc+1, name);
+
+	return (void *)(tc+1);
+}
+
+/* 
+   move a lump of memory from one talloc context to another return the
+   ptr on success, or NULL if it could not be transferred.
+   passing NULL as ptr will always return NULL with no side effects.
+*/
+void *talloc_steal(const void *new_ctx, const void *ptr)
+{
+	struct talloc_chunk *tc, *new_tc;
+
+	if (!ptr) {
+		return NULL;
+	}
+
+	if (new_ctx == NULL) {
+		new_ctx = null_context;
+	}
+
+	tc = talloc_chunk_from_ptr(ptr);
+
+	if (new_ctx == NULL) {
+		if (tc->parent) {
+			_TLIST_REMOVE(tc->parent->child, tc);
+			if (tc->parent->child) {
+				tc->parent->child->parent = tc->parent;
+			}
+		} else {
+			if (tc->prev) tc->prev->next = tc->next;
+			if (tc->next) tc->next->prev = tc->prev;
+		}
+		
+		tc->parent = tc->next = tc->prev = NULL;
+		return discard_const_p(void, ptr);
+	}
+
+	new_tc = talloc_chunk_from_ptr(new_ctx);
+
+	if (tc == new_tc) {
+		return discard_const_p(void, ptr);
+	}
+
+	if (tc->parent) {
+		_TLIST_REMOVE(tc->parent->child, tc);
+		if (tc->parent->child) {
+			tc->parent->child->parent = tc->parent;
+		}
+	} else {
+		if (tc->prev) tc->prev->next = tc->next;
+		if (tc->next) tc->next->prev = tc->prev;
+	}
+
+	tc->parent = new_tc;
+	if (new_tc->child) new_tc->child->parent = NULL;
+	_TLIST_ADD(new_tc->child, tc);
+
+	return discard_const_p(void, ptr);
+}
+
+/*
+  return the total size of a talloc pool (subtree)
+*/
+off_t talloc_total_size(const void *ptr)
+{
+	off_t total = 0;
+	struct talloc_chunk *c, *tc;
+	
+	if (ptr == NULL) {
+		ptr = null_context;
+	}
+	if (ptr == NULL) {
+		return 0;
+	}
+
+	tc = talloc_chunk_from_ptr(ptr);
+
+	total = tc->size;
+	for (c=tc->child;c;c=c->next) {
+		total += talloc_total_size(c+1);
+	}
+	return total;
+}
+
+/*
+  return the total number of blocks in a talloc pool (subtree)
+*/
+off_t talloc_total_blocks(const void *ptr)
+{
+	off_t total = 0;
+	struct talloc_chunk *c, *tc = talloc_chunk_from_ptr(ptr);
+
+	total++;
+	for (c=tc->child;c;c=c->next) {
+		total += talloc_total_blocks(c+1);
+	}
+	return total;
+}
+
+/*
+  return the number of external references to a pointer
+*/
+static int talloc_reference_count(const void *ptr)
+{
+	struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr);
+	struct talloc_reference_handle *h;
+	int ret = 0;
+
+	for (h=tc->refs;h;h=h->next) {
+		ret++;
+	}
+	return ret;
+}
+
+/*
+  report on memory usage by all children of a pointer, giving a full tree view
+*/
+void talloc_report_depth(const void *ptr, FILE *f, int depth)
+{
+	struct talloc_chunk *c, *tc = talloc_chunk_from_ptr(ptr);
+
+	for (c=tc->child;c;c=c->next) {
+		if (c->name == TALLOC_MAGIC_REFERENCE) {
+			struct talloc_reference_handle *handle = (void *)(c+1);
+			const char *name2 = talloc_get_name(handle->ptr);
+			fprintf(f, "%*sreference to: %s\n", depth*4, "", name2);
+		} else {
+			const char *name = talloc_get_name(c+1);
+			fprintf(f, "%*s%-30s contains %6lu bytes in %3lu blocks (ref %d)\n", 
+				depth*4, "",
+				name,
+				(unsigned long)talloc_total_size(c+1),
+				(unsigned long)talloc_total_blocks(c+1),
+				talloc_reference_count(c+1));
+			talloc_report_depth(c+1, f, depth+1);
+		}
+	}
+
+}
+
+/*
+  report on memory usage by all children of a pointer, giving a full tree view
+*/
+void talloc_report_full(const void *ptr, FILE *f)
+{
+	if (ptr == NULL) {
+		ptr = null_context;
+	}
+	if (ptr == NULL) return;
+
+	fprintf(f,"full talloc report on '%s' (total %lu bytes in %lu blocks)\n", 
+		talloc_get_name(ptr), 
+		(unsigned long)talloc_total_size(ptr),
+		(unsigned long)talloc_total_blocks(ptr));
+
+	talloc_report_depth(ptr, f, 1);
+	fflush(f);
+}
+
+/*
+  report on memory usage by all children of a pointer
+*/
+void talloc_report(const void *ptr, FILE *f)
+{
+	struct talloc_chunk *c, *tc;
+
+	if (ptr == NULL) {
+		ptr = null_context;
+	}
+	if (ptr == NULL) return;
+       
+	fprintf(f,"talloc report on '%s' (total %lu bytes in %lu blocks)\n", 
+		talloc_get_name(ptr), 
+		(unsigned long)talloc_total_size(ptr),
+		(unsigned long)talloc_total_blocks(ptr));
+
+	tc = talloc_chunk_from_ptr(ptr);
+
+	for (c=tc->child;c;c=c->next) {
+		fprintf(f, "\t%-30s contains %6lu bytes in %3lu blocks\n", 
+			talloc_get_name(c+1),
+			(unsigned long)talloc_total_size(c+1),
+			(unsigned long)talloc_total_blocks(c+1));
+	}
+	fflush(f);
+}
+
+/*
+  report on any memory hanging off the null context
+*/
+static void talloc_report_null(void)
+{
+	if (talloc_total_size(null_context) != 0) {
+		talloc_report(null_context, stderr);
+	}
+}
+
+/*
+  report on any memory hanging off the null context
+*/
+static void talloc_report_null_full(void)
+{
+	if (talloc_total_size(null_context) != 0) {
+		talloc_report_full(null_context, stderr);
+	}
+}
+
+/*
+  enable tracking of the NULL context
+*/
+void talloc_enable_null_tracking(void)
+{
+	if (null_context == NULL) {
+		null_context = talloc_named_const(NULL, 0, "null_context");
+	}
+}
+
+/*
+  enable leak reporting on exit
+*/
+void talloc_enable_leak_report(void)
+{
+	talloc_enable_null_tracking();
+	atexit(talloc_report_null);
+}
+
+/*
+  enable full leak reporting on exit
+*/
+void talloc_enable_leak_report_full(void)
+{
+	talloc_enable_null_tracking();
+	atexit(talloc_report_null_full);
+}
+
+/* 
+   talloc and zero memory. 
+*/
+void *_talloc_zero(const void *ctx, size_t size, const char *name)
+{
+	void *p = talloc_named_const(ctx, size, name);
+
+	if (p) {
+		memset(p, '\0', size);
+	}
+
+	return p;
+}
+
+
+/*
+  memdup with a talloc. 
+*/
+void *_talloc_memdup(const void *t, const void *p, size_t size, const char *name)
+{
+	void *newp = talloc_named_const(t, size, name);
+
+	if (newp) {
+		memcpy(newp, p, size);
+	}
+
+	return newp;
+}
+
+/*
+  strdup with a talloc 
+*/
+char *talloc_strdup(const void *t, const char *p)
+{
+	char *ret;
+	if (!p) {
+		return NULL;
+	}
+	ret = talloc_memdup(t, p, strlen(p) + 1);
+	if (ret) {
+		talloc_set_name_const(ret, ret);
+	}
+	return ret;
+}
+
+/*
+  strndup with a talloc 
+*/
+char *talloc_strndup(const void *t, const char *p, size_t n)
+{
+	size_t len;
+	char *ret;
+
+	for (len=0; p[len] && len<n; len++) ;
+
+	ret = _talloc(t, len + 1);
+	if (!ret) { return NULL; }
+	memcpy(ret, p, len);
+	ret[len] = 0;
+	talloc_set_name_const(ret, ret);
+	return ret;
+}
+
+#ifndef VA_COPY
+#ifdef HAVE_VA_COPY
+#define VA_COPY(dest, src) va_copy(dest, src)
+#elif defined(HAVE___VA_COPY)
+#define VA_COPY(dest, src) __va_copy(dest, src)
+#else
+#define VA_COPY(dest, src) (dest) = (src)
+#endif
+#endif
+
+char *talloc_vasprintf(const void *t, const char *fmt, va_list ap)
+{	
+	int len;
+	char *ret;
+	va_list ap2;
+	
+	VA_COPY(ap2, ap);
+
+	len = vsnprintf(NULL, 0, fmt, ap2);
+
+	ret = _talloc(t, len+1);
+	if (ret) {
+		VA_COPY(ap2, ap);
+		vsnprintf(ret, len+1, fmt, ap2);
+		talloc_set_name_const(ret, ret);
+	}
+
+	return ret;
+}
+
+
+/*
+  Perform string formatting, and return a pointer to newly allocated
+  memory holding the result, inside a memory pool.
+ */
+char *talloc_asprintf(const void *t, const char *fmt, ...)
+{
+	va_list ap;
+	char *ret;
+
+	va_start(ap, fmt);
+	ret = talloc_vasprintf(t, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+
+
+/**
+ * Realloc @p s to append the formatted result of @p fmt and @p ap,
+ * and return @p s, which may have moved.  Good for gradually
+ * accumulating output into a string buffer.
+ **/
+
+static char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
+
+static char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap)
+{	
+	struct talloc_chunk *tc;
+	int len, s_len;
+	va_list ap2;
+
+	if (s == NULL) {
+		return talloc_vasprintf(NULL, fmt, ap);
+	}
+
+	tc = talloc_chunk_from_ptr(s);
+
+	VA_COPY(ap2, ap);
+
+	s_len = tc->size - 1;
+	len = vsnprintf(NULL, 0, fmt, ap2);
+
+	s = talloc_realloc(NULL, s, char, s_len + len+1);
+	if (!s) return NULL;
+
+	VA_COPY(ap2, ap);
+
+	vsnprintf(s+s_len, len+1, fmt, ap2);
+	talloc_set_name_const(s, s);
+
+	return s;
+}
+
+/*
+  Realloc @p s to append the formatted result of @p fmt and return @p
+  s, which may have moved.  Good for gradually accumulating output
+  into a string buffer.
+ */
+char *talloc_asprintf_append(char *s, const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	s = talloc_vasprintf_append(s, fmt, ap);
+	va_end(ap);
+	return s;
+}
+
+/*
+  alloc an array, checking for integer overflow in the array size
+*/
+void *_talloc_array(const void *ctx, size_t el_size, unsigned count, const char *name)
+{
+	if (count >= MAX_TALLOC_SIZE/el_size) {
+		return NULL;
+	}
+	return talloc_named_const(ctx, el_size * count, name);
+}
+
+/*
+  alloc an zero array, checking for integer overflow in the array size
+*/
+void *_talloc_zero_array(const void *ctx, size_t el_size, unsigned count, const char *name)
+{
+	if (count >= MAX_TALLOC_SIZE/el_size) {
+		return NULL;
+	}
+	return _talloc_zero(ctx, el_size * count, name);
+}
+
+
+/*
+  realloc an array, checking for integer overflow in the array size
+*/
+void *_talloc_realloc_array(const void *ctx, void *ptr, size_t el_size, unsigned count, const char *name)
+{
+	if (count >= MAX_TALLOC_SIZE/el_size) {
+		return NULL;
+	}
+	return _talloc_realloc(ctx, ptr, el_size * count, name);
+}
+
+/*
+  a function version of talloc_realloc(), so it can be passed as a function pointer
+  to libraries that want a realloc function (a realloc function encapsulates
+  all the basic capabilities of an allocation library, which is why this is useful)
+*/
+void *talloc_realloc_fn(const void *context, void *ptr, size_t size)
+{
+	return _talloc_realloc(context, ptr, size, NULL);
+}
+
+
+static void talloc_autofree(void)
+{
+	talloc_free(cleanup_context);
+	cleanup_context = NULL;
+}
+
+/*
+  return a context which will be auto-freed on exit
+  this is useful for reducing the noise in leak reports
+*/
+void *talloc_autofree_context(void)
+{
+	if (cleanup_context == NULL) {
+		cleanup_context = talloc_named_const(NULL, 0, "autofree_context");
+		atexit(talloc_autofree);
+	}
+	return cleanup_context;
+}
+
+
diff --git a/utils/talloc.h b/utils/talloc.h
new file mode 100644
index 000000000..8b448f63c
--- /dev/null
+++ b/utils/talloc.h
@@ -0,0 +1,131 @@
+#ifndef _TALLOC_H_
+#define _TALLOC_H_
+/* 
+   Unix SMB/CIFS implementation.
+   Samba temporary memory allocation functions
+
+   Copyright (C) Andrew Tridgell 2004-2005
+   
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+/* this is only needed for compatibility with the old talloc */
+typedef void TALLOC_CTX;
+
+/*
+  this uses a little trick to allow __LINE__ to be stringified
+*/
+#define _STRING_LINE_(s)    #s
+#define _STRING_LINE2_(s)   _STRING_LINE_(s)
+#define __LINESTR__       _STRING_LINE2_(__LINE__)
+#define __location__ __FILE__ ":" __LINESTR__
+
+#ifndef TALLOC_DEPRECATED
+#define TALLOC_DEPRECATED 0
+#endif
+
+/* useful macros for creating type checked pointers */
+#define talloc(ctx, type) (type *)talloc_named_const(ctx, sizeof(type), #type)
+#define talloc_size(ctx, size) talloc_named_const(ctx, size, __location__)
+
+#define talloc_new(ctx) talloc_named_const(ctx, 0, "talloc_new: " __location__)
+
+#define talloc_zero(ctx, type) (type *)_talloc_zero(ctx, sizeof(type), #type)
+#define talloc_zero_size(ctx, size) _talloc_zero(ctx, size, __location__)
+
+#define talloc_zero_array(ctx, type, count) (type *)_talloc_zero_array(ctx, sizeof(type), count, #type)
+#define talloc_array(ctx, type, count) (type *)_talloc_array(ctx, sizeof(type), count, #type)
+#define talloc_array_size(ctx, size, count) _talloc_array(ctx, size, count, __location__)
+
+#define talloc_realloc(ctx, p, type, count) (type *)_talloc_realloc_array(ctx, p, sizeof(type), count, #type)
+#define talloc_realloc_size(ctx, ptr, size) _talloc_realloc(ctx, ptr, size, __location__)
+
+#define talloc_memdup(t, p, size) _talloc_memdup(t, p, size, __location__)
+
+#define malloc_p(type) (type *)malloc(sizeof(type))
+#define malloc_array_p(type, count) (type *)realloc_array(NULL, sizeof(type), count)
+#define realloc_p(p, type, count) (type *)realloc_array(p, sizeof(type), count)
+
+#define data_blob(ptr, size) data_blob_named(ptr, size, "DATA_BLOB: "__location__)
+#define data_blob_talloc(ctx, ptr, size) data_blob_talloc_named(ctx, ptr, size, "DATA_BLOB: "__location__)
+#define data_blob_dup_talloc(ctx, blob) data_blob_talloc_named(ctx, (blob)->data, (blob)->length, "DATA_BLOB: "__location__)
+
+#define talloc_set_type(ptr, type) talloc_set_name_const(ptr, #type)
+#define talloc_get_type(ptr, type) (type *)talloc_check_name(ptr, #type)
+
+
+#if TALLOC_DEPRECATED
+#define talloc_zero_p(ctx, type) talloc_zero(ctx, type)
+#define talloc_p(ctx, type) talloc(ctx, type)
+#define talloc_array_p(ctx, type, count) talloc_array(ctx, type, count)
+#define talloc_realloc_p(ctx, p, type, count) talloc_realloc(ctx, p, type, count)
+#define talloc_destroy(ctx) talloc_free(ctx)
+#endif
+
+#ifndef PRINTF_ATTRIBUTE
+#if (__GNUC__ >= 3)
+/** Use gcc attribute to check printf fns.  a1 is the 1-based index of
+ * the parameter containing the format, and a2 the index of the first
+ * argument. Note that some gcc 2.x versions don't handle this
+ * properly **/
+#define PRINTF_ATTRIBUTE(a1, a2) __attribute__ ((format (__printf__, a1, a2)))
+#else
+#define PRINTF_ATTRIBUTE(a1, a2)
+#endif
+#endif
+
+
+/* The following definitions come from talloc.c  */
+void *_talloc(const void *context, size_t size);
+void talloc_set_destructor(const void *ptr, int (*destructor)(void *));
+void talloc_increase_ref_count(const void *ptr);
+void *talloc_reference(const void *context, const void *ptr);
+int talloc_unlink(const void *context, void *ptr);
+void talloc_set_name(const void *ptr, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
+void talloc_set_name_const(const void *ptr, const char *name);
+void *talloc_named(const void *context, size_t size, 
+		   const char *fmt, ...) PRINTF_ATTRIBUTE(3,4);
+void *talloc_named_const(const void *context, size_t size, const char *name);
+const char *talloc_get_name(const void *ptr);
+void *talloc_check_name(const void *ptr, const char *name);
+void talloc_report_depth(const void *ptr, FILE *f, int depth);
+void *talloc_parent(const void *ptr);
+void *talloc_init(const char *fmt, ...) PRINTF_ATTRIBUTE(1,2);
+int talloc_free(void *ptr);
+void *_talloc_realloc(const void *context, void *ptr, size_t size, const char *name);
+void *talloc_steal(const void *new_ctx, const void *ptr);
+off_t talloc_total_size(const void *ptr);
+off_t talloc_total_blocks(const void *ptr);
+void talloc_report_full(const void *ptr, FILE *f);
+void talloc_report(const void *ptr, FILE *f);
+void talloc_enable_null_tracking(void);
+void talloc_enable_leak_report(void);
+void talloc_enable_leak_report_full(void);
+void *_talloc_zero(const void *ctx, size_t size, const char *name);
+void *_talloc_memdup(const void *t, const void *p, size_t size, const char *name);
+char *talloc_strdup(const void *t, const char *p);
+char *talloc_strndup(const void *t, const char *p, size_t n);
+char *talloc_vasprintf(const void *t, const char *fmt, va_list ap) PRINTF_ATTRIBUTE(2,0);
+char *talloc_asprintf(const void *t, const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
+char *talloc_asprintf_append(char *s,
+			     const char *fmt, ...) PRINTF_ATTRIBUTE(2,3);
+void *_talloc_array(const void *ctx, size_t el_size, unsigned count, const char *name);
+void *_talloc_zero_array(const void *ctx, size_t el_size, unsigned count, const char *name);
+void *_talloc_realloc_array(const void *ctx, void *ptr, size_t el_size, unsigned count, const char *name);
+void *talloc_realloc_fn(const void *context, void *ptr, size_t size);
+void *talloc_autofree_context(void);
+
+#endif
+