Asterisk data retrieval API.

This module implements an abstraction for retrieving and exporting
asterisk data.
Developed by:
	Brett Bryant <brettbryant@gmail.com>
	Eliel C. Sardanons (LU1ALY) <eliels@gmail.com>
For the Google Summer of code 2009 Project.
Documentation can be found in doxygen format and inside the
header include/asterisk/data.h

Review: https://reviewboard.asterisk.org/r/275/



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@258517 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 2879 insertions, 0 deletions

diff --git a/main/data.c b/main/data.c
new file mode 100644
index 000000000..1b12d451f
--- /dev/null
+++ b/main/data.c
@@ -0,0 +1,2879 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2009, Eliel C. Sardanons (LU1ALY) <eliels@gmail.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*! \file
+ *
+ * \brief Data retrieval API.
+ *
+ * \author Brett Bryant <brettbryant@gmail.com>
+ * \author Eliel C. Sardanons (LU1ALY) <eliels@gmail.com>
+ */
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include "asterisk/_private.h"
+
+#include <regex.h>
+
+#include "asterisk/module.h"
+#include "asterisk/utils.h"
+#include "asterisk/lock.h"
+#include "asterisk/data.h"
+#include "asterisk/astobj2.h"
+#include "asterisk/xml.h"
+#include "asterisk/cli.h"
+#include "asterisk/term.h"
+#include "asterisk/manager.h"
+#include "asterisk/test.h"
+
+/*** DOCUMENTATION
+	<manager name="DataGet" language="en_US">
+		<synopsis>
+			Retrieve the data api tree.
+		</synopsis>
+		<syntax>
+			<xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
+			<parameter name="Path" required="true" />
+			<parameter name="Search" />
+			<parameter name="Filter" />
+		</syntax>
+		<description>
+			<para>Retrieve the data api tree.</para>
+		</description>
+	</manager>
+ ***/
+
+#define NUM_DATA_NODE_BUCKETS	59
+#define NUM_DATA_RESULT_BUCKETS 59
+#define NUM_DATA_SEARCH_BUCKETS 59
+#define NUM_DATA_FILTER_BUCKETS 59
+
+/*! \brief The last compatible version. */
+static const uint32_t latest_handler_compatible_version = 0;
+
+/*! \brief The last compatible version. */
+static const uint32_t latest_query_compatible_version = 0;
+
+/*! \brief Current handler structure version. */
+static const uint32_t current_handler_version = AST_DATA_HANDLER_VERSION;
+
+/*! \brief Current query structure version. */
+static const uint32_t current_query_version = AST_DATA_QUERY_VERSION;
+
+/*! \brief The data tree to be returned by the callbacks and
+	   managed by functions local to this file. */
+struct ast_data {
+	enum ast_data_type type;
+
+	/*! \brief The node content. */
+	union {
+		int32_t sint;
+		uint32_t uint;
+		double dbl;
+		unsigned int boolean:1;
+		char *str;
+		struct in_addr ipaddr;
+		void *ptr;
+	} payload;
+
+	/*! \brief The filter node that depends on the current node,
+	 * this is used only when creating the result tree. */
+	const struct data_filter *filter;
+
+	/*! \brief The list of nodes inside this node. */
+	struct ao2_container *children;
+	/*! \brief The name of the node. */
+	char name[0];
+};
+
+/*! \brief Type of comparisons allow in the search string. */
+enum data_search_comparison {
+	DATA_CMP_UNKNOWN,
+	DATA_CMP_EQ,	/* =  */
+	DATA_CMP_NEQ,	/* != */
+	DATA_CMP_GT,	/* >  */
+	DATA_CMP_GE,	/* >= */
+	DATA_CMP_LT,	/* <  */
+	DATA_CMP_LE	/* <= */
+};
+
+/*! \brief The list of nodes with their search requirement. */
+struct ast_data_search {
+	/*! \brief The value of the comparison. */
+	char *value;
+	/*! \brief The type of comparison. */
+	enum data_search_comparison cmp_type;
+	/*! \brief reference another node. */
+	struct ao2_container *children;
+	/*! \brief The name of the node we are trying to compare. */
+	char name[0];
+};
+
+struct data_filter;
+
+/*! \brief The filter node. */
+struct data_filter {
+	/*! \brief node childrens. */
+	struct ao2_container *children;
+	/*! \brief glob list */
+	AST_LIST_HEAD_NOLOCK(glob_list_t, data_filter) glob_list;
+	/*! \brief glob list entry */
+	AST_LIST_ENTRY(data_filter) list;
+	/*! \brief node name. */
+	char name[0];
+};
+
+/*! \brief A data container node pointing to the registered handler. */
+struct data_provider {
+	/*! \brief node content handler. */
+	const struct ast_data_handler *handler;
+	/*! \brief Module providing this handler. */
+	struct ast_module *module;
+	/*! \brief children nodes. */
+	struct ao2_container *children;
+	/*! \brief Who registered this node. */
+	const char *registrar;
+	/*! \brief Node name. */
+	char name[0];
+};
+
+/*! \brief This structure is used by the iterator. */
+struct ast_data_iterator {
+	/*! \brief The internal iterator. */
+	struct ao2_iterator internal_iterator;
+	/*! \brief The last returned node. */
+	struct ast_data *last;
+	/*! \brief The iterator pattern. */
+	const char *pattern;
+	/*! \brief The compiled patter. */
+	regex_t regex_pattern;
+	/*! \brief is a regular expression. */
+	unsigned int is_pattern:1;
+};
+
+struct {
+	/*! \brief The asterisk data main content structure. */
+	struct ao2_container *container;
+	/*! \brief asterisk data locking mechanism. */
+	ast_rwlock_t lock;
+} root_data;
+
+static void __data_result_print_cli(int fd, const struct ast_data *root, uint32_t depth);
+
+/*!
+ * \internal
+ * \brief Common string hash function.
+ * \see ast_data_init
+ */
+static int data_provider_hash(const void *obj, const int flags)
+{
+	const struct data_provider *node = obj;
+	return ast_str_case_hash(node->name);
+}
+
+/*!
+ * \internal
+ * \brief Compare two data_provider's.
+ * \see ast_data_init
+ */
+static int data_provider_cmp(void *obj1, void *obj2, int flags)
+{
+	struct data_provider *node1 = obj1, *node2 = obj2;
+	return strcasecmp(node1->name, node2->name) ? 0 : CMP_MATCH;
+}
+
+/*!
+ * \internal
+ * \brief Common string hash function for data nodes
+ */
+static int data_result_hash(const void *obj, const int flags)
+{
+	const struct ast_data *node = obj;
+	return ast_str_hash(node->name);
+}
+
+/*!
+ * \internal
+ * \brief Common string comparison function
+ */
+static int data_result_cmp(void *obj, void *arg, int flags)
+{
+	struct ast_data *node1 = obj, *node2 = arg;
+	return strcasecmp(node1->name, node2->name) ? 0 : CMP_MATCH;
+}
+
+/*!
+ * \internal
+ * \brief Lock the data registered handlers structure for writing.
+ * \see data_unlock
+ */
+#define data_write_lock() ast_rwlock_wrlock(&root_data.lock)
+
+/*!
+ * \internal
+ * \brief Lock the data registered handlers structure for reading.
+ * \see data_unlock
+ */
+#define data_read_lock() ast_rwlock_rdlock(&root_data.lock)
+
+/*!
+ * \internal
+ * \brief Unlock the data registered handlers structure.
+ */
+#define data_unlock() ast_rwlock_unlock(&root_data.lock)
+
+/*!
+ * \internal
+ * \brief Check if a version is compatible with the current core.
+ * \param[in] structure_version The current structure version.
+ * \param[in] latest_compatible The latest compatible version.
+ * \param[in] current The current Data API version.
+ * \retval 1 If the module is compatible.
+ * \retval 0 If the module is NOT compatible.
+ */
+static int data_structure_compatible(int structure_version, uint32_t latest_compatible,
+	uint32_t current)
+{
+	if (structure_version >= latest_compatible && structure_version <= current) {
+		return 1;
+	}
+
+	ast_log(LOG_ERROR, "A module is not compatible with the"
+		"current data api version\n");
+
+	return 0;
+}
+
+/*!
+ * \internal
+ * \brief Get the next node name in a path (/node1/node2)
+ *        Avoid null nodes like //node1//node2/node3.
+ * \param[in] path The path where we are going to search for the next node name.
+ * \retval The next node name we found inside the given path.
+ * \retval NULL if there are no more node names.
+ */
+static char *next_node_name(char **path)
+{
+	char *res;
+
+	do {
+		res = strsep(path, "/");
+	} while (res && ast_strlen_zero(res));
+
+	return res;
+}
+
+/*!
+ * \internal
+ * \brief Release the memory allocated by a call to ao2_alloc.
+ */
+static void data_provider_destructor(void *obj)
+{
+	struct data_provider *provider = obj;
+
+	ao2_ref(provider->children, -1);
+}
+
+/*!
+ * \internal
+ * \brief Create a new data node.
+ * \param[in] name The name of the node we are going to create.
+ * \param[in] handler The handler registered for this node.
+ * \param[in] registrar The name of the registrar.
+ * \retval NULL on error.
+ * \retval The allocated data node structure.
+ */
+static struct data_provider *data_provider_new(const char *name,
+	const struct ast_data_handler *handler, const char *registrar)
+{
+	struct data_provider *node;
+	size_t namelen;
+
+	namelen = strlen(name) + 1;
+
+	node = ao2_alloc(sizeof(*node) + namelen, data_provider_destructor);
+	if (!node) {
+		return NULL;
+	}
+
+	node->handler = handler;
+	node->registrar = registrar;
+	strcpy(node->name, name);
+
+	/* initialize the childrens container. */
+	if (!(node->children = ao2_container_alloc(NUM_DATA_NODE_BUCKETS,
+			data_provider_hash, data_provider_cmp))) {
+		ao2_ref(node, -1);
+		return NULL;
+	}
+
+	return node;
+}
+
+/*!
+ * \internal
+ * \brief Add a child node named 'name' to the 'parent' node.
+ * \param[in] parent Where to add the child node.
+ * \param[in] name The name of the child node.
+ * \param[in] handler The handler structure.
+ * \param[in] registrar Who registered this node.
+ * \retval NULL on error.
+ * \retval A newly allocated child in parent.
+ */
+static struct data_provider *data_provider_add_child(struct ao2_container *parent,
+	const char *name, const struct ast_data_handler *handler, const char *registrar)
+{
+	struct data_provider *child;
+
+	child = data_provider_new(name, handler, registrar);
+	if (!child) {
+		return NULL;
+	}
+
+	ao2_link(parent, child);
+
+	return child;
+}
+
+/*!
+ * \internal
+ * \brief Find a child node, based on his name.
+ * \param[in] parent Where to find the node.
+ * \param[in] name The node name to find.
+ * \param[in] registrar Also check if the node was being used by this registrar.
+ * \retval NULL if a node wasn't found.
+ * \retval The node found.
+ * \note Remember to decrement the ref count of the returned node after using it.
+ */
+static struct data_provider *data_provider_find(struct ao2_container *parent,
+	const char *name, const char *registrar)
+{
+	struct data_provider *find_node, *found;
+
+	/* XXX avoid allocating a new data node for searching... */
+	find_node = data_provider_new(name, NULL, NULL);
+	if (!find_node) {
+		return NULL;
+	}
+
+	found = ao2_find(parent, find_node, OBJ_POINTER);
+
+	/* free the created node used for searching. */
+	ao2_ref(find_node, -1);
+
+	if (found && found->registrar && registrar) {
+		if (strcmp(found->registrar, registrar)) {
+			/* if the name doesn't match, do not return this node. */
+			ast_debug(1, "Registrar doesn't match, node was registered"
+				" by '%s' and we are searching for '%s'\n",
+				found->registrar, registrar);
+			ao2_ref(found, -1);
+			return NULL;
+		}
+	}
+
+	return found;
+}
+
+/*!
+ * \internal
+ * \brief Release a group of nodes.
+ * \param[in] parent The parent node.
+ * \param[in] path The path of nodes to release.
+ * \param[in] registrar Who registered this node.
+ * \retval <0 on error.
+ * \retval 0 on success.
+ * \see data_provider_create
+ */
+static int data_provider_release(struct ao2_container *parent, const char *path,
+	const char *registrar)
+{
+	char *node_name, *rpath;
+	struct data_provider *child;
+	int ret = 0;
+
+	rpath = ast_strdupa(path);
+
+	node_name = next_node_name(&rpath);
+	if (!node_name) {
+		return -1;
+	}
+
+	child = data_provider_find(parent, node_name, registrar);
+	if (!child) {
+		return -1;
+	}
+
+	/* if this is not a terminal node. */
+	if (!child->handler && rpath) {
+		ret = data_provider_release(child->children, rpath, registrar);
+	}
+
+	/* if this node is empty, unlink it. */
+	if (!ret && !ao2_container_count(child->children)) {
+		ao2_unlink(parent, child);
+	}
+
+	ao2_ref(child, -1);
+
+	return ret;
+}
+
+/*!
+ * \internal
+ * \brief Release every node registered by 'registrar'.
+ * \param[in] parent The parent node.
+ * \param[in] registrar
+ * \see __ast_data_unregister
+ */
+static void data_provider_release_all(struct ao2_container *parent,
+	const char *registrar)
+{
+	struct ao2_iterator i;
+	struct data_provider *node;
+
+	i = ao2_iterator_init(parent, 0);
+	while ((node = ao2_iterator_next(&i))) {
+		if (!node->handler) {
+			/* this is a non-terminal node, go inside it. */
+			data_provider_release_all(node->children, registrar);
+			if (!ao2_container_count(node->children)) {
+				/* if this node was left empty, unlink it. */
+				ao2_unlink(parent, node);
+			}
+		} else {
+			if (!strcmp(node->registrar, registrar)) {
+				/* if the registrars match, release it! */
+				ao2_unlink(parent, node);
+			}
+		}
+		ao2_ref(node, -1);
+	}
+	ao2_iterator_destroy(&i);
+
+}
+
+/*!
+ * \internal
+ * \brief Create the middle nodes for the specified path (asterisk/testnode1/childnode)
+ * \param[in] parent Where to add the middle nodes structure.
+ * \param[in] path The path of nodes to add.
+ * \param[in] registrar Who is trying to create this node provider.
+ * \retval NULL on error.
+ * \retval The created node.
+ * \see data_provider_release
+ */
+static struct data_provider *data_provider_create(struct ao2_container *parent,
+	const char *path, const char *registrar)
+{
+	char *rpath, *node_name;
+	struct data_provider *child, *ret = NULL;
+
+	rpath = ast_strdupa(path);
+
+	node_name = next_node_name(&rpath);
+	if (!node_name) {
+		/* no more nodes to create. */
+		return NULL;
+	}
+
+	child = data_provider_find(parent, node_name, NULL);
+
+	if (!child) {
+		/* nodes without handler are non-terminal nodes. */
+		child = data_provider_add_child(parent, node_name, NULL, registrar);
+	}
+
+	if (rpath) {
+		ret = data_provider_create(child->children, rpath, registrar);
+		if (ret) {
+			ao2_ref(child, -1);
+		}
+	}
+
+	return ret ? ret : child;
+}
+
+int __ast_data_register(const char *path, const struct ast_data_handler *handler,
+	const char *registrar, struct ast_module *mod)
+{
+	struct data_provider *node;
+
+	if (!path) {
+		return -1;
+	}
+
+	/* check if the handler structure is compatible. */
+	if (!data_structure_compatible(handler->version,
+		latest_handler_compatible_version,
+		current_handler_version)) {
+		return -1;
+	}
+
+	/* create the node structure for the registered handler. */
+	data_write_lock();
+
+	node = data_provider_create(root_data.container, path, registrar);
+	if (!node) {
+		ast_log(LOG_ERROR, "Unable to create the specified path (%s) "
+			"for '%s'.\n", path, registrar);
+		data_unlock();
+		return -1;
+	}
+
+	if (ao2_container_count(node->children) || node->handler) {
+		ast_log(LOG_ERROR, "The node '%s' was already registered. "
+			"We were unable to register '%s' for registrar '%s'.\n",
+			node->name, path, registrar);
+		ao2_ref(node, -1);
+		data_unlock();
+		return -1;
+	}
+
+	/* add handler to that node. */
+	node->handler = handler;
+	node->module = mod;
+
+	ao2_ref(node, -1);
+
+	data_unlock();
+
+	return 0;
+}
+
+int __ast_data_register_multiple(const struct ast_data_entry *data_entries,
+	size_t entries, const char *registrar, struct ast_module *mod)
+{
+	int i, res;
+
+	for (i = 0; i < entries; i++) {
+		res = __ast_data_register(data_entries[i].path, data_entries[i].handler,
+				registrar, mod);
+		if (res) {
+			/* unregister all the already registered nodes, and make
+			 * this an atomic action. */
+			while ((--i) >= 0) {
+				__ast_data_unregister(data_entries[i].path, registrar);
+			}
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+int __ast_data_unregister(const char *path, const char *registrar)
+{
+	int ret = 0;
+
+	data_write_lock();
+	if (path) {
+		ret = data_provider_release(root_data.container, path, registrar);
+	} else {
+		data_provider_release_all(root_data.container, registrar);
+	}
+	data_unlock();
+
+	if (path && ret) {
+		ast_log(LOG_ERROR, "Unable to unregister '%s' for '%s'\n",
+			path, registrar);
+	}
+
+	return ret;
+}
+
+/*!
+ * \internal
+ * \brief Is a char used to specify a comparison?
+ * \param[in] a Character to evaluate.
+ * \retval 1 It is a char used to specify a comparison.
+ * \retval 0 It is NOT a char used to specify a comparison.
+ */
+static int data_search_comparison_char(char a)
+{
+	switch (a) {
+	case '!':
+	case '=':
+	case '<':
+	case '>':
+		return 1;
+	}
+
+	return 0;
+}
+
+/*!
+ * \internal
+ * \brief Get the type of comparison.
+ */
+static enum data_search_comparison data_search_comparison_type(const char *comparison)
+{
+	if (!strcmp(comparison, "=")) {
+		return DATA_CMP_EQ;
+	} else if (!strcmp(comparison, "!=")) {
+		return DATA_CMP_NEQ;
+	} else if (!strcmp(comparison, "<")) {
+		return DATA_CMP_LT;
+	} else if (!strcmp(comparison, ">")) {
+		return DATA_CMP_GT;
+	} else if (!strcmp(comparison, "<=")) {
+		return DATA_CMP_LE;
+	} else if (!strcmp(comparison, ">=")) {
+		return DATA_CMP_GE;
+	}
+
+	return DATA_CMP_UNKNOWN;
+}
+
+/*!
+ * \internal
+ * \brief Common string hash function for data nodes
+ */
+static int data_search_hash(const void *obj, const int flags)
+{
+	const struct ast_data_search *node = obj;
+	return ast_str_hash(node->name);
+}
+
+/*!
+ * \internal
+ * \brief Common string comparison function
+ */
+static int data_search_cmp(void *obj, void *arg, int flags)
+{
+	struct ast_data_search *node1 = obj, *node2 = arg;
+	return strcasecmp(node1->name, node2->name) ? 0 : CMP_MATCH;
+}
+
+/*!
+ * \internal
+ * \brief Destroy the ao2 search node.
+ */
+static void data_search_destructor(void *obj)
+{
+	struct ast_data_search *node = obj;
+
+	if (node->value) {
+		ast_free(node->value);
+	}
+
+	ao2_ref(node->children, -1);
+}
+
+/*!
+ * \internal
+ * \brief Allocate a search node.
+ * \retval NULL on error.
+ * \retval non-NULL The allocated search node structure.
+ */
+static struct ast_data_search *data_search_alloc(const char *name)
+{
+	struct ast_data_search *res;
+	size_t name_len = strlen(name) + 1;
+
+	res = ao2_alloc(sizeof(*res) + name_len, data_search_destructor);
+	if (!res) {
+		return NULL;
+	}
+
+	res->children = ao2_container_alloc(NUM_DATA_SEARCH_BUCKETS, data_search_hash,
+		data_search_cmp);
+
+	if (!res) {
+		ao2_ref(res, -1);
+		return NULL;
+	}
+
+	strcpy(res->name, name);
+
+	return res;
+}
+
+/*!
+ * \internal
+ * \brief Find a child node, based on his name.
+ * \param[in] parent Where to find the node.
+ * \param[in] name The node name to find.
+ * \retval NULL if a node wasn't found.
+ * \retval The node found.
+ * \note Remember to decrement the ref count of the returned node after using it.
+ */
+static struct ast_data_search *data_search_find(struct ao2_container *parent,
+	const char *name)
+{
+	struct ast_data_search *find_node, *found;
+
+	find_node = data_search_alloc(name);
+	if (!find_node) {
+		return NULL;
+	}
+
+	found = ao2_find(parent, find_node, OBJ_POINTER);
+
+	/* free the created node used for searching. */
+	ao2_ref(find_node, -1);
+
+	return found;
+}
+
+/*!
+ * \internal
+ * \brief Add a child node named 'name' to the 'parent' node.
+ * \param[in] parent Where to add the child node.
+ * \param[in] name The name of the child node.
+ * \retval NULL on error.
+ * \retval A newly allocated child in parent.
+ */
+static struct ast_data_search *data_search_add_child(struct ao2_container *parent,
+	const char *name)
+{
+	struct ast_data_search *child;
+
+	child = data_search_alloc(name);
+	if (!child) {
+		return NULL;
+	}
+
+	ao2_link(parent, child);
+
+	return child;
+}
+
+/*!
+ * \internal
+ * \brief Create the middle nodes for the specified path (asterisk/testnode1/childnode)
+ * \param[in] parent Where to add the middle nodes structure.
+ * \param[in] path The path of nodes to add.
+ * \retval NULL on error.
+ * \retval The created node.
+ */
+static struct ast_data_search *data_search_create(struct ao2_container *parent,
+	const char *path)
+{
+	char *rpath, *node_name;
+	struct ast_data_search *child = NULL;
+	struct ao2_container *current = parent;
+
+	rpath = ast_strdupa(path);
+
+	node_name = next_node_name(&rpath);
+	while (node_name) {
+		child = data_search_find(current, node_name);
+		if (!child) {
+			child = data_search_add_child(current, node_name);
+		}
+		ao2_ref(child, -1);
+		current = child->children;
+		node_name = next_node_name(&rpath);
+	}
+
+	return child;
+}
+
+/*!
+ * \internal
+ * \brief Allocate a tree with the search string parsed.
+ * \param[in] search_string The search string.
+ * \retval NULL on error.
+ * \retval non-NULL A dynamically allocated search tree.
+ */
+static struct ast_data_search *data_search_generate(const char *search_string)
+{
+	struct ast_str *name, *value, *comparison;
+	char *elements, *search_string_dup, *saveptr;
+	int i;
+	struct ast_data_search *root, *child;
+	enum data_search_comparison cmp_type;
+	size_t search_string_len;
+
+	if (!search_string) {
+		ast_log(LOG_ERROR, "You must pass a valid search string.\n");
+		return NULL;
+	}
+
+	search_string_len = strlen(search_string);
+
+	name = ast_str_create(search_string_len);
+	if (!name) {
+		return NULL;
+	}
+	value = ast_str_create(search_string_len);
+	if (!value) {
+		ast_free(name);
+		return NULL;
+	}
+	comparison = ast_str_create(search_string_len);
+	if (!comparison) {
+		ast_free(name);
+		ast_free(value);
+		return NULL;
+	}
+
+	search_string_dup = ast_strdupa(search_string);
+
+	/* Create the root node (just used as a container) */
+	root = data_search_alloc("/");
+	if (!root) {
+		ast_free(name);
+		ast_free(value);
+		ast_free(comparison);
+		return NULL;
+	}
+
+	for (elements = strtok_r(search_string_dup, ",", &saveptr); elements;
+		elements = strtok_r(NULL, ",", &saveptr)) {
+		/* Parse the name */
+		ast_str_reset(name);
+		for (i = 0; !data_search_comparison_char(elements[i]) &&
+			elements[i]; i++) {
+			ast_str_append(&name, 0, "%c", elements[i]);
+		}
+
+		/* check if the syntax is ok. */
+		if (!data_search_comparison_char(elements[i])) {
+			/* if this is the end of the string, then this is
+			 * an error! */
+			ast_log(LOG_ERROR, "Invalid search string!\n");
+			continue;
+		}
+
+		/* parse the comparison string. */
+		ast_str_reset(comparison);
+		for (; data_search_comparison_char(elements[i]) && elements[i]; i++) {
+			ast_str_append(&comparison, 0, "%c", elements[i]);
+		}
+
+		/* parse the value string. */
+		ast_str_reset(value);
+		for (; elements[i]; i++) {
+			ast_str_append(&value, 0, "%c", elements[i]);
+		}
+
+		cmp_type = data_search_comparison_type(ast_str_buffer(comparison));
+		if (cmp_type == DATA_CMP_UNKNOWN) {
+			ast_log(LOG_ERROR, "Invalid comparison '%s'\n",
+				ast_str_buffer(comparison));
+			continue;
+		}
+
+		/* add this node to the tree. */
+		child = data_search_create(root->children, ast_str_buffer(name));
+		if (child) {
+			child->cmp_type = cmp_type;
+			child->value = ast_strdup(ast_str_buffer(value));
+		}
+	}
+
+	ast_free(name);
+	ast_free(value);
+	ast_free(comparison);
+
+	return root;
+}
+
+/*!
+ * \internal
+ * \brief Release the allocated memory for the search tree.
+ * \param[in] search The search tree root node.
+ */
+static void data_search_release(struct ast_data_search *search)
+{
+	ao2_ref(search, -1);
+}
+
+/*!
+ * \internal
+ * \brief Based on the kind of comparison and the result in cmpval, return
+ *        if it matches.
+ * \param[in] cmpval A result returned by a strcmp() for example.
+ * \param[in] comparison_type The kind of comparison (<,>,=,!=,...)
+ * \retval 1 If the comparison doesn't match.
+ * \retval 0 If the comparison matches.
+ */
+static inline int data_search_comparison_result(int cmpval,
+	enum data_search_comparison comparison_type)
+{
+	switch (comparison_type) {
+	case DATA_CMP_GE:
+		if (cmpval >= 0) {
+			return 0;
+		}
+		break;
+	case DATA_CMP_LE:
+		if (cmpval <= 0) {
+			return 0;
+		}
+		break;
+	case DATA_CMP_EQ:
+		if (cmpval == 0) {
+			return 0;
+		}
+		break;
+	case DATA_CMP_NEQ:
+		if (cmpval != 0) {
+			return 0;
+		}
+		break;
+	case DATA_CMP_LT:
+		if (cmpval < 0) {
+			return 0;
+		}
+		break;
+	case DATA_CMP_GT:
+		if (cmpval > 0) {
+			return 0;
+		}
+		break;
+	case DATA_CMP_UNKNOWN:
+		break;
+	}
+	return 1;
+}
+
+/*!
+ * \internal
+ * \brief Get an internal node, from the search tree.
+ * \param[in] node A node container.
+ * \param[in] path The path to the needed internal node.
+ * \retval NULL if the internal node is not found.
+ * \retval non-NULL the internal node with path 'path'.
+ */
+static struct ast_data_search *data_search_get_node(const struct ast_data_search *node,
+	const char *path)
+{
+	char *savepath, *node_name;
+	struct ast_data_search *child, *current = (struct ast_data_search *) node;
+
+	if (!node) {
+		return NULL;
+	}
+
+	savepath = ast_strdupa(path);
+	node_name = next_node_name(&savepath);
+
+	while (node_name) {
+		child = data_search_find(current->children, node_name);
+		if (current != node) {
+			ao2_ref(current, -1);
+		}
+		if (!child) {
+			return NULL;
+		};
+		current = child;
+		node_name = next_node_name(&savepath);
+	}
+
+	return current;
+}
+
+int ast_data_search_cmp_string(const struct ast_data_search *root, const char *name,
+	char *value)
+{
+	struct ast_data_search *child;
+	enum data_search_comparison cmp_type;
+	int ret;
+
+	child = data_search_get_node(root, name);
+	if (!child) {
+		return 0;
+	}
+
+	ret = strcmp(value, child->value);
+	cmp_type = child->cmp_type;
+
+	ao2_ref(child, -1);
+
+	return data_search_comparison_result(ret, cmp_type);
+}
+
+int ast_data_search_cmp_ptr(const struct ast_data_search *root, const char *name,
+	void *ptr)
+{
+	struct ast_data_search *child;
+	enum data_search_comparison cmp_type;
+	void *node_ptr;
+
+	child = data_search_get_node(root, name);
+	if (!child) {
+		return 0;
+	}
+
+	cmp_type = child->cmp_type;
+
+	if (sscanf(child->value, "%p", &node_ptr) <= 0) {
+		return 1;
+	}
+
+	ao2_ref(child, -1);
+
+	return data_search_comparison_result((node_ptr - ptr), cmp_type);
+}
+
+int ast_data_search_cmp_ipaddr(const struct ast_data_search *root, const char *name,
+	struct in_addr addr)
+{
+	struct ast_data_search *child;
+	enum data_search_comparison cmp_type;
+	struct in_addr node_addr;
+
+	child = data_search_get_node(root, name);
+	if (!child) {
+		return 0;
+	}
+	cmp_type = child->cmp_type;
+
+	inet_aton(child->value, &node_addr);
+
+	ao2_ref(child, -1);
+
+	return data_search_comparison_result((node_addr.s_addr - addr.s_addr), cmp_type);
+}
+
+int ast_data_search_cmp_bool(const struct ast_data_search *root, const char *name,
+	unsigned int value)
+{
+	struct ast_data_search *child;
+	unsigned int node_value;
+	enum data_search_comparison cmp_type;
+
+	child = data_search_get_node(root, name);
+	if (!child) {
+		return 0;
+	}
+
+	node_value = abs(ast_true(child->value));
+	cmp_type = child->cmp_type;
+
+	ao2_ref(child, -1);
+
+	return data_search_comparison_result(value - node_value, cmp_type);
+}
+
+int ast_data_search_cmp_dbl(const struct ast_data_search *root, const char *name,
+	double value)
+{
+	struct ast_data_search *child;
+	double node_value;
+	enum data_search_comparison cmp_type;
+
+	child = data_search_get_node(root, name);
+	if (!child) {
+		return 0;
+	}
+
+	node_value = strtod(child->value, NULL);
+	cmp_type = child->cmp_type;
+
+	ao2_ref(child, -1);
+
+	return data_search_comparison_result(value - node_value, cmp_type);
+}
+
+int ast_data_search_cmp_uint(const struct ast_data_search *root, const char *name,
+	unsigned int value)
+{
+	struct ast_data_search *child;
+	unsigned int node_value;
+	enum data_search_comparison cmp_type;
+
+	child = data_search_get_node(root, name);
+	if (!child) {
+		return 0;
+	}
+
+	node_value = atoi(child->value);
+	cmp_type = child->cmp_type;
+
+	ao2_ref(child, -1);
+
+	return data_search_comparison_result(value - node_value, cmp_type);
+}
+
+int ast_data_search_cmp_int(const struct ast_data_search *root, const char *name,
+	int value)
+{
+	struct ast_data_search *child;
+	int node_value;
+	enum data_search_comparison cmp_type;
+
+	child = data_search_get_node(root, name);
+	if (!child) {
+		return 0;
+	}
+
+	node_value = atoi(child->value);
+	cmp_type = child->cmp_type;
+
+	ao2_ref(child, -1);
+
+	return data_search_comparison_result(value - node_value, cmp_type);
+}
+
+/*!
+ * \internal
+ * \brief Get the member pointer, from a mapping structure, based on its name.
+ * \XXX We will need to improve performance here!!.
+ * \retval <0 if the member was not found.
+ * \retval >=0 The member position in the mapping structure.
+ */
+static inline int data_search_mapping_find(const struct ast_data_mapping_structure *map,
+	size_t mapping_len,
+	const char *member_name)
+{
+	int i;
+
+	for (i = 0; i < mapping_len; i++) {
+		if (!strcmp(map[i].name, member_name)) {
+			return i;
+		}
+	}
+
+	return -1;
+}
+
+int ast_data_search_has_condition(const struct ast_data_search *search,
+	const char *compare_condition)
+{
+	struct ast_data_search *child;
+
+	child = data_search_get_node(search, compare_condition);
+	if (!child) {
+		return 0;
+	}
+
+	ao2_ref(child, -1);
+
+	return 1;
+}
+
+int __ast_data_search_cmp_structure(const struct ast_data_search *search,
+	const struct ast_data_mapping_structure *mapping, size_t mapping_len,
+	void *structure, const char *structure_name)
+{
+	struct ao2_iterator i;
+	struct ast_data_search *node, *struct_children;
+	int member, notmatch = 0;
+
+	if (!search) {
+		return 0;
+	}
+
+	struct_children = data_search_get_node(search, structure_name);
+	if (!struct_children) {
+		return 0;
+	}
+
+	i = ao2_iterator_init(struct_children->children, 0);
+	while ((node = ao2_iterator_next(&i))) {
+		member = data_search_mapping_find(mapping, mapping_len, node->name);
+		if (member < 0) {
+			/* the structure member name doesn't match! */
+			ao2_ref(node, -1);
+			ao2_ref(struct_children, -1);
+			ao2_iterator_destroy(&i);
+			return 0;
+		}
+
+		notmatch = 0;
+		switch (mapping[member].type) {
+		case AST_DATA_STRING:
+			notmatch = ast_data_search_cmp_string(struct_children,
+				node->name,
+				mapping[member].get.AST_DATA_STRING(structure));
+			break;
+		case AST_DATA_INTEGER:
+			notmatch = ast_data_search_cmp_int(struct_children,
+				node->name,
+				mapping[member].get.AST_DATA_INTEGER(structure));
+			break;
+		case AST_DATA_BOOLEAN:
+			notmatch = ast_data_search_cmp_bool(struct_children,
+				node->name,
+				mapping[member].get.AST_DATA_BOOLEAN(structure));
+			break;
+		case AST_DATA_UNSIGNED_INTEGER:
+			notmatch = ast_data_search_cmp_uint(struct_children,
+				node->name,
+				mapping[member].get.AST_DATA_UNSIGNED_INTEGER(structure));
+			break;
+		case AST_DATA_DOUBLE:
+			notmatch = ast_data_search_cmp_dbl(struct_children,
+				node->name,
+				mapping[member].get.AST_DATA_DOUBLE(structure));
+			break;
+		case AST_DATA_IPADDR:
+			notmatch = ast_data_search_cmp_ipaddr(struct_children,
+				node->name,
+				mapping[member].get.AST_DATA_IPADDR(structure));
+			break;
+		case AST_DATA_POINTER:
+			notmatch = ast_data_search_cmp_ptr(struct_children,
+				node->name,
+				mapping[member].get.AST_DATA_POINTER(structure));
+			break;
+		case AST_DATA_CONTAINER:
+			break;
+		}
+
+		ao2_ref(node, -1);
+	}
+	ao2_iterator_destroy(&i);
+
+	ao2_ref(struct_children, -1);
+
+	return notmatch;
+}
+
+/*!
+ * \internal
+ * \brief Release the memory allocated by a call to ao2_alloc.
+ */
+static void data_result_destructor(void *obj)
+{
+	struct ast_data *root = obj;
+
+	switch (root->type) {
+	case AST_DATA_POINTER:
+	case AST_DATA_STRING:
+		ast_free(root->payload.ptr);
+	case AST_DATA_CONTAINER:
+	case AST_DATA_INTEGER:
+	case AST_DATA_UNSIGNED_INTEGER:
+	case AST_DATA_DOUBLE:
+	case AST_DATA_BOOLEAN:
+	case AST_DATA_IPADDR:
+		ao2_ref(root->children, -1);
+		break;
+	}
+}
+
+static struct ast_data *data_result_create(const char *name)
+{
+	struct ast_data *res;
+	size_t namelen;
+
+	namelen = ast_strlen_zero(name) ? 1 : strlen(name) + 1;
+
+	res = ao2_alloc(sizeof(*res) + namelen, data_result_destructor);
+	if (!res) {
+		return NULL;
+	}
+
+	strcpy(res->name, namelen ? name : "");
+
+	/* initialize the children container */
+	res->children = ao2_container_alloc(NUM_DATA_RESULT_BUCKETS, data_result_hash,
+		data_result_cmp);
+	if (!res->children) {
+		ao2_ref(res, -1);
+		return NULL;
+	}
+
+	/* set this node as a container. */
+	res->type = AST_DATA_CONTAINER;
+
+	return res;
+}
+
+/*!
+ * \internal
+ * \brief Find a child node, based on its name.
+ * \param[in] root The starting point.
+ * \param[in] name The child name.
+ * \retval NULL if the node wasn't found.
+ * \retval non-NULL the node we were looking for.
+ */
+static struct ast_data *data_result_find_child(struct ast_data *root, const char *name)
+{
+	struct ast_data *found, *find_node;
+
+	find_node = data_result_create(name);
+	if (!find_node) {
+		return NULL;
+	}
+
+	found = ao2_find(root->children, find_node, OBJ_POINTER);
+
+	/* release the temporary created node used for searching. */
+	ao2_ref(find_node, -1);
+
+	return found;
+}
+
+/*!
+ * \internal
+ * \brief Get an internal node, from the result set.
+ * \param[in] node A node container.
+ * \param[in] path The path to the needed internal node.
+ * \retval NULL if the internal node is not found.
+ * \retval non-NULL the internal node with path 'path'.
+ */
+static struct ast_data *data_result_get_node(struct ast_data *node,
+	const char *path)
+{
+	char *savepath, *node_name;
+	struct ast_data *child, *current = node;
+
+	savepath = ast_strdupa(path);
+	node_name = next_node_name(&savepath);
+
+	while (node_name) {
+		child = data_result_find_child(current, node_name);
+		if (current != node) {
+			ao2_ref(current, -1);
+		}
+		if (!child) {
+			return NULL;
+		}
+		current = child;
+		node_name = next_node_name(&savepath);
+	}
+
+	/* do not increment the refcount of the returned object. */
+	if (current != node) {
+		ao2_ref(current, -1);
+	}
+
+	return current;
+}
+
+/*!
+ * \internal
+ * \brief Add a child to the specified root node.
+ * \param[in] root The root node pointer.
+ * \param[in] child The child to add to the root node.
+ */
+static void data_result_add_child(struct ast_data *root, struct ast_data *child)
+{
+	ao2_link(root->children, child);
+}
+
+/*!
+ * \internal
+ * \brief Common string hash function for data nodes
+ */
+static int data_filter_hash(const void *obj, const int flags)
+{
+	const struct data_filter *node = obj;
+	return ast_str_hash(node->name);
+}
+
+/*!
+ * \internal
+ * \brief Common string comparison function
+ */
+static int data_filter_cmp(void *obj, void *arg, int flags)
+{
+	struct data_filter *node1 = obj, *node2 = arg;
+	return strcasecmp(node1->name, node2->name) ? 0 : CMP_MATCH;
+}
+
+/*!
+ * \internal
+ * \brief Destroy a data filter tree.
+ * \param[in] obj Data filter list to be destroyed.
+ */
+static void data_filter_destructor(void *obj)
+{
+	struct data_filter *filter = obj, *globres;
+
+	AST_LIST_TRAVERSE(&(filter->glob_list), globres, list) {
+		ao2_ref(globres, -1);
+	}
+
+	ao2_ref(filter->children, -1);
+}
+
+/*!
+ * \internal
+ * \brief Allocate a filter node.
+ * \retval NULL on error.
+ * \retval non-NULL The allocated search node structure.
+ */
+static struct data_filter *data_filter_alloc(const char *name)
+{
+	char *globname, *token;
+	struct data_filter *res, *globfilter;
+	size_t name_len = strlen(name) + 1;
+
+	res = ao2_alloc(sizeof(*res) + name_len, data_filter_destructor);
+	if (!res) {
+		return NULL;
+	}
+
+	res->children = ao2_container_alloc(NUM_DATA_FILTER_BUCKETS, data_filter_hash,
+		data_filter_cmp);
+
+	if (!res) {
+		ao2_ref(res, -1);
+		return NULL;
+	}
+
+	strcpy(res->name, name);
+
+	if (strchr(res->name, '*')) {
+		globname = ast_strdupa(res->name);
+
+		while ((token = strsep(&globname, "*"))) {
+			globfilter = data_filter_alloc(token);
+			AST_LIST_INSERT_TAIL(&(res->glob_list), globfilter, list);
+		}
+	}
+
+	return res;
+}
+
+/*!
+ * \internal
+ * \brief Release a filter tree.
+ * \param[in] filter The filter tree root node.
+ */
+static void data_filter_release(struct data_filter *filter)
+{
+	ao2_ref(filter, -1);
+}
+
+/*!
+ * \internal
+ * \brief Find a child node, based on his name.
+ * \param[in] parent Where to find the node.
+ * \param[in] name The node name to find.
+ * \retval NULL if a node wasn't found.
+ * \retval The node found.
+ * \note Remember to decrement the ref count of the returned node after using it.
+ */
+static struct data_filter *data_filter_find(struct ao2_container *parent,
+	const char *name)
+{
+	int i, olend, orend, globfound;
+	size_t name_len = strlen(name), glob_len;
+	struct ao2_iterator iter;
+	struct data_filter *find_node, *found, *globres;
+
+	find_node = data_filter_alloc(name);
+	if (!find_node) {
+		return NULL;
+	}
+
+	found = ao2_find(parent, find_node, OBJ_POINTER);
+
+	/* free the created node used for searching. */
+	ao2_ref(find_node, -1);
+
+	if (found) {
+		return found;
+	}
+
+	iter = ao2_iterator_init(parent, 0);
+	while ((found = ao2_iterator_next(&iter))) {
+		if (!AST_LIST_EMPTY(&(found->glob_list))) {
+			i = 0;
+			globfound = 1;
+
+			olend = ast_strlen_zero(AST_LIST_FIRST(&(found->glob_list))->name);
+			orend = ast_strlen_zero(AST_LIST_LAST(&(found->glob_list))->name);
+
+			AST_LIST_TRAVERSE(&(found->glob_list), globres, list) {
+				if (!*globres->name) {
+					continue;
+				}
+
+				glob_len = strlen(globres->name);
+
+				if (!i && !olend) {
+					if (strncasecmp(name, globres->name, glob_len)) {
+						globfound = 0;
+						break;
+					}
+
+					i += glob_len;
+					continue;
+				}
+
+				for (globfound = 0; name_len - i >= glob_len; ++i) {
+					if (!strncasecmp(name + i, globres->name, glob_len)) {
+						globfound = 1;
+						i += glob_len;
+						break;
+					}
+				}
+
+				if (!globfound) {
+					break;
+				}
+			}
+
+			if (globfound && (i == name_len || orend)) {
+				ao2_iterator_destroy(&iter);
+				return found;
+			}
+		}
+
+		ao2_ref(found, -1);
+	}
+	ao2_iterator_destroy(&iter);
+
+	return NULL;
+}
+
+/*!
+ * \internal
+ * \brief Add a child to the specified node.
+ * \param[in] root The root node where to add the child.
+ * \param[in] name The name of the node to add.
+ * \note Remember to decrement the ref count after using the returned node.
+ */
+static struct data_filter *data_filter_add_child(struct ao2_container *root,
+	char *name)
+{
+	struct data_filter *node;
+
+	node = data_filter_find(root, name);
+	if (node) {
+		return node;
+	}
+
+	node = data_filter_alloc(name);
+	if (!node) {
+		return NULL;
+	}
+
+	ao2_link(root, node);
+
+	return node;
+}
+
+/*!
+ * \internal
+ * \brief Add a node to a filter list from a path
+ * \param[in] Filter list to add the path onto.
+ * \param[in] The path to add into the filter list.
+ * \retval NULL on error.
+ * \retval non-NULL A tree with the wanted nodes.
+ */
+static int data_filter_add_nodes(struct ao2_container *root, char *path)
+{
+	struct data_filter *node;
+	char *savepath, *saveptr, *token, *node_name;
+	int ret = 0;
+
+	if (!path) {
+		return 0;
+	}
+
+	savepath = ast_strdupa(path);
+
+	node_name = next_node_name(&savepath);
+
+	if (!node_name) {
+		return 0;
+	}
+
+	for (token = strtok_r(node_name, "|", &saveptr);
+			token; token = strtok_r(NULL, "|", &saveptr)) {
+		node = data_filter_add_child(root, token);
+		if (!node) {
+			continue;
+		}
+		data_filter_add_nodes(node->children, savepath);
+		ret = 1;
+		ao2_ref(node, -1);
+	}
+
+	return ret;
+}
+
+/*!
+ * \internal
+ * \brief Generate a filter list based on a filter string provided by the API user.
+ * \param[in] A filter string to create a filter from.
+ */
+static struct data_filter *data_filter_generate(const char *constfilter)
+{
+	struct data_filter *filter = NULL;
+	char *strfilter, *token, *saveptr;
+	int node_added = 0;
+
+	if (!constfilter) {
+		return NULL;
+	}
+
+	strfilter = ast_strdupa(constfilter);
+
+	filter = data_filter_alloc("/");
+	if (!filter) {
+		return NULL;
+	}
+
+	for (token = strtok_r(strfilter, ",", &saveptr); token;
+			token = strtok_r(NULL, ",", &saveptr)) {
+		node_added = data_filter_add_nodes(filter->children, token);
+	}
+
+	if (!node_added) {
+		ao2_ref(filter, -1);
+		return NULL;
+	}
+
+	return filter;
+}
+
+/*!
+ * \internal
+ * \brief Generate all the tree from a specified provider.
+ * \param[in] query The query executed.
+ * \param[in] root_provider The provider specified in the path of the query.
+ * \param[in] parent_node_name The root node name.
+ * \retval NULL on error.
+ * \retval non-NULL The generated result tree.
+ */
+static struct ast_data *data_result_generate_node(const struct ast_data_query *query,
+	const struct data_provider *root_provider,
+	const char *parent_node_name,
+	const struct ast_data_search *search,
+	const struct data_filter *filter)
+{
+	struct ast_data *generated, *node;
+	struct ao2_iterator i;
+	struct data_provider *provider;
+	struct ast_data_search *search_child = NULL;
+	struct data_filter *filter_child;
+
+	node = data_result_create(parent_node_name);
+	if (!node) {
+		ast_log(LOG_ERROR, "Unable to allocate '%s' node\n", parent_node_name);
+		return NULL;
+	}
+
+	if (root_provider->module) {
+		ast_module_ref(root_provider->module);
+	}
+
+	/* if this is a terminal node, just run the callback function. */
+	if (root_provider->handler && root_provider->handler->get) {
+		node->filter = filter;
+		root_provider->handler->get(search, node);
+		if (root_provider->module) {
+			ast_module_unref(root_provider->module);
+		}
+		return node;
+	}
+
+	if (root_provider->module) {
+		ast_module_unref(root_provider->module);
+	}
+
+	/* if this is not a terminal node, generate every child node. */
+	i = ao2_iterator_init(root_provider->children, 0);
+	while ((provider = ao2_iterator_next(&i))) {
+		filter_child = NULL;
+		generated = NULL;
+
+		/* get the internal search node. */
+		if (search) {
+			search_child = data_search_find(search->children, provider->name);
+		}
+		/* get the internal filter node. */
+		if (filter) {
+			filter_child = data_filter_find(filter->children, provider->name);
+		}
+
+		if (!filter || filter_child) {
+			/* only generate the internal node, if we have something to
+			 * generate based on the filtering string. */
+			generated = data_result_generate_node(query, provider,
+				provider->name,
+				search_child, filter_child);
+		}
+
+		/* decrement the refcount of the internal search node. */
+		if (search_child) {
+			ao2_ref(search_child, -1);
+		}
+
+		/* decrement the refcount of the internal filter node. */
+		if (filter_child) {
+			ao2_ref(filter_child, -1);
+		}
+
+		if (generated) {
+			data_result_add_child(node, generated);
+			ao2_ref(generated, -1);
+		}
+
+		ao2_ref(provider, -1);
+	}
+	ao2_iterator_destroy(&i);
+
+	return node;
+}
+
+/*!
+ * \internal
+ * \brief Generate a result tree based on a query.
+ * \param[in] query The complete query structure.
+ * \param[in] search_path The path to retrieve.
+ * \retval NULL on error.
+ * \retval non-NULL The generated data result.
+ */
+static struct ast_data *data_result_generate(const struct ast_data_query *query,
+	const char *search_path)
+{
+	char *node_name, *tmp_path;
+	struct data_provider *provider_child, *tmp_provider_child;
+	struct ast_data *result, *result_filtered;
+	struct ast_data_search *search = NULL, *search_child = NULL;
+	struct data_filter *filter = NULL, *filter_child = NULL;
+
+	if (!search_path) {
+		/* generate all the trees?. */
+		return NULL;
+	}
+
+	tmp_path = ast_strdupa(search_path);
+
+	/* start searching the root node name */
+	node_name = next_node_name(&tmp_path);
+	if (!node_name) {
+		return NULL;
+	}
+	provider_child = data_provider_find(root_data.container, node_name, NULL);
+
+	/* continue with the rest of the path. */
+	while (provider_child) {
+		node_name = next_node_name(&tmp_path);
+		if (!node_name) {
+			break;
+		}
+
+		tmp_provider_child = data_provider_find(provider_child->children,
+				node_name, NULL);
+
+		/* release the reference from this child */
+		ao2_ref(provider_child, -1);
+
+		provider_child = tmp_provider_child;
+	}
+
+	if (!provider_child) {
+		ast_log(LOG_ERROR, "Invalid path '%s', '%s' not found.\n",
+				tmp_path, node_name);
+		return NULL;
+	}
+
+	/* generate the search tree. */
+	if (query->search) {
+		search = data_search_generate(query->search);
+		if (search) {
+			search_child = data_search_find(search->children,
+				provider_child->name);
+		}
+	}
+
+	/* generate the filter tree. */
+	if (query->filter) {
+		filter = data_filter_generate(query->filter);
+		if (filter) {
+			filter_child = data_filter_find(filter->children,
+				provider_child->name);
+		}
+	}
+
+	result = data_result_generate_node(query, provider_child, provider_child->name,
+			search_child, filter_child);
+
+	/* release the requested provider. */
+	ao2_ref(provider_child, -1);
+
+	/* release the generated search tree. */
+	if (search_child) {
+		ao2_ref(search_child, -1);
+	}
+
+	if (filter_child) {
+		ao2_ref(filter_child, -1);
+	}
+
+	if (search) {
+		data_search_release(search);
+	}
+
+	result_filtered = result;
+
+	/* release the generated filter tree. */
+	if (filter) {
+		data_filter_release(filter);
+	}
+
+	return result_filtered;
+}
+
+struct ast_data *ast_data_get(const struct ast_data_query *query)
+{
+	struct ast_data *res;
+
+	/* check compatibility */
+	if (!data_structure_compatible(query->version, latest_query_compatible_version,
+		current_query_version)) {
+		return NULL;
+	}
+
+	data_read_lock();
+	res = data_result_generate(query, query->path);
+	data_unlock();
+
+	if (!res) {
+		ast_log(LOG_ERROR, "Unable to get data from %s\n", query->path);
+		return NULL;
+	}
+
+	return res;
+}
+
+/*!
+ * \internal
+ * \brief Helper function to move an ast_data tree to xml.
+ * \param[in] parent_data The initial ast_data node to be passed to xml.
+ * \param[out] parent_xml The root node to insert the xml.
+ */
+static void data_get_xml_add_child(struct ast_data *parent_data,
+	struct ast_xml_node *parent_xml)
+{
+	struct ao2_iterator i;
+	struct ast_data *node;
+	struct ast_xml_node *child_xml;
+	char node_content[256];
+
+	i = ao2_iterator_init(parent_data->children, 0);
+	while ((node = ao2_iterator_next(&i))) {
+		child_xml = ast_xml_new_node(node->name);
+		if (!child_xml) {
+			ao2_ref(node, -1);
+			continue;
+		}
+
+		switch (node->type) {
+		case AST_DATA_CONTAINER:
+			data_get_xml_add_child(node, child_xml);
+			break;
+		case AST_DATA_STRING:
+			ast_xml_set_text(child_xml, node->payload.str);
+			break;
+		case AST_DATA_INTEGER:
+			snprintf(node_content, sizeof(node_content), "%d",
+				node->payload.sint);
+			ast_xml_set_text(child_xml, node_content);
+			break;
+		case AST_DATA_UNSIGNED_INTEGER:
+			snprintf(node_content, sizeof(node_content), "%u",
+				node->payload.uint);
+			ast_xml_set_text(child_xml, node_content);
+			break;
+		case AST_DATA_DOUBLE:
+			snprintf(node_content, sizeof(node_content), "%f",
+				node->payload.dbl);
+			ast_xml_set_text(child_xml, node_content);
+			break;
+		case AST_DATA_BOOLEAN:
+			if (node->payload.boolean) {
+				ast_xml_set_text(child_xml, "true");
+			} else {
+				ast_xml_set_text(child_xml, "false");
+			}
+			break;
+		case AST_DATA_POINTER:
+			snprintf(node_content, sizeof(node_content), "%p",
+				node->payload.ptr);
+			ast_xml_set_text(child_xml, node_content);
+			break;
+		case AST_DATA_IPADDR:
+			snprintf(node_content, sizeof(node_content), "%s",
+				ast_inet_ntoa(node->payload.ipaddr));
+			ast_xml_set_text(child_xml, node_content);
+			break;
+		}
+		ast_xml_add_child(parent_xml, child_xml);
+
+		ao2_ref(node, -1);
+	}
+	ao2_iterator_destroy(&i);
+
+}
+
+struct ast_xml_doc *ast_data_get_xml(const struct ast_data_query *query)
+{
+	struct ast_xml_doc *doc;
+	struct ast_xml_node *root;
+	struct ast_data *res;
+
+	res = ast_data_get(query);
+	if (!res) {
+		return NULL;
+	}
+
+	doc = ast_xml_new();
+	if (!doc) {
+		return NULL;
+	}
+
+	root = ast_xml_new_node(res->name);
+	if (!root) {
+		ast_xml_close(doc);
+	}
+
+	ast_xml_set_root(doc, root);
+
+	data_get_xml_add_child(res, root);
+
+	ast_data_free(res);
+
+	return doc;
+}
+
+enum ast_data_type ast_data_retrieve_type(struct ast_data *node, const char *path)
+{
+	struct ast_data *internal;
+
+	internal = data_result_get_node(node, path);
+	if (!internal) {
+		return -1;
+	}
+
+	return internal->type;
+}
+
+char *ast_data_retrieve_name(struct ast_data *node)
+{
+	return node->name;
+}
+
+/*!
+ * \internal
+ * \brief Insert a child node inside a passed parent node.
+ * \param root Where we are going to insert the child node.
+ * \param name The name of the child node to add.
+ * \param type The type of content inside the child node.
+ * \param ptr The actual content of the child node.
+ * \retval NULL on error.
+ * \retval non-NULL The added child node pointer.
+ */
+static struct ast_data *__ast_data_add(struct ast_data *root, const char *name,
+	enum ast_data_type type, void *ptr)
+{
+	struct ast_data *node;
+	struct data_filter *filter, *filter_child = NULL;
+
+	if (!root || !root->children) {
+		/* invalid data result node. */
+		return NULL;
+	}
+
+	/* check if we need to add this node, based on the filter. */
+	if (root->filter) {
+		filter = data_filter_find(root->filter->children, name);
+		if (!filter) {
+			return NULL;
+		}
+		ao2_ref(filter, -1);
+	}
+
+	node = data_result_create(name);
+	if (!node) {
+		return NULL;
+	}
+
+	node->type = type;
+
+	switch (type) {
+	case AST_DATA_BOOLEAN:
+		node->payload.boolean = *(unsigned int *) ptr;
+		break;
+	case AST_DATA_INTEGER:
+		node->payload.sint = *(unsigned int *) ptr;
+		break;
+	case AST_DATA_UNSIGNED_INTEGER:
+		node->payload.sint = *(unsigned int *) ptr;
+		break;
+	case AST_DATA_DOUBLE:
+		node->payload.dbl = *(double *) ptr;
+		break;
+	case AST_DATA_STRING:
+	case AST_DATA_POINTER:
+		node->payload.ptr = ptr;
+		break;
+	case AST_DATA_IPADDR:
+		node->payload.ipaddr = *(struct in_addr *) ptr;
+		break;
+	case AST_DATA_CONTAINER:
+		if (root->filter) {
+			filter_child = data_filter_find(root->filter->children, name);
+			if (filter_child) {
+				/* do not increment the refcount because it is not neccesary. */
+				ao2_ref(filter_child, -1);
+			}
+		}
+		node->filter = filter_child;
+		break;
+	default:
+		break;
+	}
+
+	data_result_add_child(root, node);
+
+	ao2_ref(node, -1);
+
+	return node;
+}
+
+struct ast_data *ast_data_add_node(struct ast_data *root, const char *name)
+{
+	return __ast_data_add(root, name, AST_DATA_CONTAINER, NULL);
+}
+
+struct ast_data *ast_data_add_int(struct ast_data *root, const char *name, int value)
+{
+	return __ast_data_add(root, name, AST_DATA_INTEGER, &value);
+}
+
+struct ast_data *ast_data_add_uint(struct ast_data *root, const char *name,
+	unsigned int value)
+{
+	return __ast_data_add(root, name, AST_DATA_UNSIGNED_INTEGER, &value);
+}
+
+struct ast_data *ast_data_add_dbl(struct ast_data *root, const char *childname,
+	double dbl)
+{
+	return __ast_data_add(root, childname, AST_DATA_DOUBLE, &dbl);
+}
+
+struct ast_data *ast_data_add_bool(struct ast_data *root, const char *childname,
+	unsigned int boolean)
+{
+	return __ast_data_add(root, childname, AST_DATA_BOOLEAN, &boolean);
+}
+
+struct ast_data *ast_data_add_ipaddr(struct ast_data *root, const char *childname,
+	struct in_addr addr)
+{
+	return __ast_data_add(root, childname, AST_DATA_IPADDR, &addr);
+}
+
+struct ast_data *ast_data_add_ptr(struct ast_data *root, const char *childname,
+	void *ptr)
+{
+	return __ast_data_add(root, childname, AST_DATA_POINTER, ptr);
+}
+
+struct ast_data *ast_data_add_str(struct ast_data *root, const char *childname,
+	const char *value)
+{
+	char *name;
+	size_t namelen = 1 + (ast_strlen_zero(value) ? 0 : strlen(value));
+	struct ast_data *res;
+
+	if (!(name = ast_malloc(namelen))) {
+		return NULL;
+	}
+
+	strcpy(name, (ast_strlen_zero(value) ? "" : value));
+
+	res = __ast_data_add(root, childname, AST_DATA_STRING, name);
+	if (!res) {
+		ast_free(name);
+	}
+
+	return res;
+}
+
+int __ast_data_add_structure(struct ast_data *root,
+	const struct ast_data_mapping_structure *mapping, size_t mapping_len,
+	void *structure)
+{
+	int i;
+
+	for (i = 0; i < mapping_len; i++) {
+		switch (mapping[i].type) {
+		case AST_DATA_INTEGER:
+			ast_data_add_int(root, mapping[i].name,
+				mapping[i].get.AST_DATA_INTEGER(structure));
+			break;
+		case AST_DATA_UNSIGNED_INTEGER:
+			ast_data_add_uint(root, mapping[i].name,
+				mapping[i].get.AST_DATA_UNSIGNED_INTEGER(structure));
+			break;
+		case AST_DATA_DOUBLE:
+			ast_data_add_dbl(root, mapping[i].name,
+				mapping[i].get.AST_DATA_DOUBLE(structure));
+			break;
+		case AST_DATA_BOOLEAN:
+			ast_data_add_bool(root, mapping[i].name,
+				mapping[i].get.AST_DATA_BOOLEAN(structure));
+			break;
+		case AST_DATA_STRING:
+			ast_data_add_str(root, mapping[i].name,
+				mapping[i].get.AST_DATA_STRING(structure));
+			break;
+		case AST_DATA_CONTAINER:
+			break;
+		case AST_DATA_IPADDR:
+			ast_data_add_ipaddr(root, mapping[i].name,
+				mapping[i].get.AST_DATA_IPADDR(structure));
+			break;
+		case AST_DATA_POINTER:
+			ast_data_add_ptr(root, mapping[i].name,
+				mapping[i].get.AST_DATA_POINTER(structure));
+			break;
+		}
+	}
+
+	return 0;
+}
+
+void ast_data_remove_node(struct ast_data *root, struct ast_data *child)
+{
+	ao2_unlink(root->children, child);
+}
+
+void ast_data_free(struct ast_data *root)
+{
+	/* destroy it, this will destroy all the internal nodes. */
+	ao2_ref(root, -1);
+}
+
+struct ast_data_iterator *ast_data_iterator_init(struct ast_data *tree,
+	const char *elements)
+{
+	struct ast_data_iterator *iterator;
+	struct ao2_iterator i;
+	struct ast_data *internal = tree;
+	char *path, *ptr = NULL;
+
+	/* tree is the node we want to use to iterate? or we are going
+	 * to iterate thow an internal node? */
+	if (elements) {
+		path = ast_strdupa(elements);
+
+		ptr = strrchr(path, '/');
+		if (ptr) {
+			*ptr = '\0';
+			internal = data_result_get_node(tree, path);
+			if (!internal) {
+				return NULL;
+			}
+		}
+	}
+
+	iterator = ast_calloc(1, sizeof(*iterator));
+	if (!iterator) {
+		return NULL;
+	}
+
+	i = ao2_iterator_init(internal->children, 0);
+
+	iterator->pattern = (ptr ? strrchr(elements, '/') + 1 : elements);
+
+	/* is the last node a regular expression?, compile it! */
+	if (!regcomp(&(iterator->regex_pattern), iterator->pattern,
+			REG_EXTENDED | REG_NOSUB | REG_ICASE)) {
+		iterator->is_pattern = 1;
+	}
+
+	iterator->internal_iterator = i;
+
+	return iterator;
+}
+
+void ast_data_iterator_end(struct ast_data_iterator *iterator)
+{
+	/* decrement the reference counter. */
+	if (iterator->last) {
+		ao2_ref(iterator->last, -1);
+	}
+
+	/* release the generated pattern. */
+	if (iterator->is_pattern) {
+		regfree(&(iterator->regex_pattern));
+	}
+
+	ao2_iterator_destroy(&(iterator->internal_iterator));
+
+	ast_free(iterator);
+	iterator = NULL;
+}
+
+struct ast_data *ast_data_iterator_next(struct ast_data_iterator *iterator)
+{
+	struct ast_data *res;
+
+	if (iterator->last) {
+		/* release the last retrieved node reference. */
+		ao2_ref(iterator->last, -1);
+	}
+
+	while ((res = ao2_iterator_next(&iterator->internal_iterator))) {
+		/* if there is no node name pattern specified, return
+		 * the next node. */
+		if (!iterator->pattern) {
+			break;
+		}
+
+		/* if the pattern is a regular expression, check if this node
+		 * matches. */
+		if (iterator->is_pattern && !regexec(&(iterator->regex_pattern),
+			res->name, 0, NULL, 0)) {
+			break;
+		}
+
+		/* if there is a pattern specified, check if this node matches
+		 * the wanted node names. */
+		if (!iterator->is_pattern && (iterator->pattern &&
+				!strcasecmp(res->name, iterator->pattern))) {
+			break;
+		}
+
+		ao2_ref(res, -1);
+	}
+
+	iterator->last = res;
+
+	return res;
+}
+
+int ast_data_retrieve(struct ast_data *tree, const char *path,
+	struct ast_data_retrieve *content)
+{
+	struct ast_data *node;
+
+	if (!content) {
+		return -1;
+	}
+
+	node = data_result_get_node(tree, path);
+	if (!node) {
+		ast_log(LOG_ERROR, "Invalid internal node %s\n", path);
+		return -1;
+	}
+
+	content->type = node->type;
+	switch (node->type) {
+	case AST_DATA_STRING:
+		content->value.AST_DATA_STRING = node->payload.str;
+		break;
+	case AST_DATA_INTEGER:
+		content->value.AST_DATA_INTEGER = node->payload.sint;
+		break;
+	case AST_DATA_UNSIGNED_INTEGER:
+		content->value.AST_DATA_UNSIGNED_INTEGER = node->payload.uint;
+		break;
+	case AST_DATA_BOOLEAN:
+		content->value.AST_DATA_BOOLEAN = node->payload.boolean;
+		break;
+	case AST_DATA_IPADDR:
+		content->value.AST_DATA_IPADDR = node->payload.ipaddr;
+		break;
+	case AST_DATA_DOUBLE:
+		content->value.AST_DATA_DOUBLE = node->payload.dbl;
+		break;
+	case AST_DATA_CONTAINER:
+		break;
+	case AST_DATA_POINTER:
+		content->value.AST_DATA_POINTER = node->payload.ptr;
+		break;
+	}
+
+	return 0;
+}
+
+/*!
+ * \internal
+ * \brief One color for each node type.
+ */
+static const struct {
+	enum ast_data_type type;
+	int color;
+} data_result_color[] = {
+	{ AST_DATA_STRING, COLOR_CYAN },
+	{ AST_DATA_INTEGER, COLOR_RED },
+	{ AST_DATA_UNSIGNED_INTEGER, COLOR_RED },
+	{ AST_DATA_DOUBLE, COLOR_RED },
+	{ AST_DATA_BOOLEAN, COLOR_BRRED },
+	{ AST_DATA_CONTAINER, COLOR_GREEN },
+	{ AST_DATA_IPADDR, COLOR_BROWN },
+	{ AST_DATA_POINTER, COLOR_YELLOW },
+};
+
+/*!
+ * \internal
+ * \brief Get the color configured for a specific node type.
+ * \param[in] type The node type.
+ * \returns The color specified for the passed type.
+ */
+static int data_result_get_color(enum ast_data_type type)
+{
+	int i;
+	for (i = 0; i < ARRAY_LEN(data_result_color); i++) {
+		if (data_result_color[i].type == type) {
+			return data_result_color[i].color;
+		}
+	}
+
+	return COLOR_BLUE;
+}
+
+/*!
+ * \internal
+ * \brief Print a node to the CLI.
+ * \param[in] fd The CLI file descriptor.
+ * \param[in] node The node to print.
+ * \param[in] depth The actual node depth in the tree.
+ */
+static void data_result_print_cli_node(int fd, const struct ast_data *node, uint32_t depth)
+{
+	int i;
+	struct ast_str *tabs, *output;
+
+	tabs = ast_str_create(depth * 10 + 1);
+	if (!tabs) {
+		return;
+	}
+	ast_str_reset(tabs);
+	for (i = 0; i < depth; i++) {
+		ast_str_append(&tabs, 0, "  ");
+	}
+
+	output = ast_str_create(20);
+	if (!output) {
+		ast_free(tabs);
+		return;
+	}
+
+	ast_str_reset(output);
+	ast_term_color_code(&output, data_result_get_color(node->type), 0);
+
+	switch (node->type) {
+	case AST_DATA_POINTER:
+		ast_str_append(&output, 0, "%s%s: %p\n", ast_str_buffer(tabs),
+				node->name, node->payload.ptr);
+		break;
+	case AST_DATA_STRING:
+		ast_str_append(&output, 0, "%s%s: \"%s\"\n",
+				ast_str_buffer(tabs),
+				node->name,
+				node->payload.str);
+		break;
+	case AST_DATA_CONTAINER:
+		ast_str_append(&output, 0, "%s%s\n", ast_str_buffer(tabs),
+				node->name);
+		break;
+	case AST_DATA_INTEGER:
+		ast_str_append(&output, 0, "%s%s: %d\n", ast_str_buffer(tabs),
+				node->name,
+				node->payload.sint);
+		break;
+	case AST_DATA_UNSIGNED_INTEGER:
+		ast_str_append(&output, 0, "%s%s: %u\n", ast_str_buffer(tabs),
+				node->name,
+				node->payload.uint);
+		break;
+	case AST_DATA_DOUBLE:
+		ast_str_append(&output, 0, "%s%s: %lf\n", ast_str_buffer(tabs),
+				node->name,
+				node->payload.dbl);
+		break;
+	case AST_DATA_BOOLEAN:
+		ast_str_append(&output, 0, "%s%s: %s\n", ast_str_buffer(tabs),
+				node->name,
+				((node->payload.boolean) ? "True" : "False"));
+		break;
+	case AST_DATA_IPADDR:
+		ast_str_append(&output, 0, "%s%s: %s\n", ast_str_buffer(tabs),
+				node->name,
+				ast_inet_ntoa(node->payload.ipaddr));
+		break;
+	}
+
+	ast_free(tabs);
+
+	ast_term_color_code(&output, COLOR_WHITE, 0);
+
+	ast_cli(fd, "%s", ast_str_buffer(output));
+
+	ast_free(output);
+
+	if (node->type == AST_DATA_CONTAINER) {
+		__data_result_print_cli(fd, node, depth + 1);
+	}
+}
+
+/*!
+ * \internal
+ * \brief Print out an ast_data tree to the CLI.
+ * \param[in] fd The CLI file descriptor.
+ * \param[in] root The root node of the tree.
+ * \param[in] depth Actual depth.
+ */
+static void __data_result_print_cli(int fd, const struct ast_data *root, uint32_t depth)
+{
+	struct ao2_iterator iter;
+	struct ast_data *node;
+
+	if (root->type == AST_DATA_CONTAINER) {
+		iter = ao2_iterator_init(root->children, 0);
+		while ((node = ao2_iterator_next(&iter))) {
+			data_result_print_cli_node(fd, node, depth + 1);
+			ao2_ref(node, -1);
+		}
+		ao2_iterator_destroy(&iter);
+	} else {
+		data_result_print_cli_node(fd, root, depth);
+	}
+}
+
+/*!
+ * \internal
+ * \brief
+ * \param[in] fd The CLI file descriptor.
+ * \param[in] root The root node of the tree.
+ */
+static void data_result_print_cli(int fd, const struct ast_data *root)
+{
+	struct ast_str *output;
+
+	/* print the initial node. */
+	output = ast_str_create(30);
+	if (!output) {
+		return;
+	}
+
+	ast_term_color_code(&output, data_result_get_color(root->type), 0);
+	ast_str_append(&output, 0, "%s\n", root->name);
+	ast_term_color_code(&output, COLOR_WHITE, 0);
+	ast_cli(fd, "%s", ast_str_buffer(output));
+	ast_free(output);
+
+	__data_result_print_cli(fd, root, 0);
+}
+
+/*!
+ * \internal
+ * \brief Handle the CLI command "data get".
+ */
+static char *handle_cli_data_get(struct ast_cli_entry *e, int cmd,
+		struct ast_cli_args *a)
+{
+	struct ast_data_query query = {
+		.version = AST_DATA_QUERY_VERSION
+	};
+	struct ast_data *tree;
+
+	switch (cmd) {
+	case CLI_INIT:
+		e->command = "data get";
+		e->usage = ""
+			"Usage: data get <path> [<search> [<filter>]]\n"
+			"       Get the tree based on a path.\n";
+		return NULL;
+	case CLI_GENERATE:
+		return NULL;
+	}
+
+	if (a->argc < e->args + 1) {
+		return CLI_SHOWUSAGE;
+	}
+
+	query.path = (char *) a->argv[e->args];
+
+	if (a->argc > e->args + 1) {
+		query.search = (char *) a->argv[e->args + 1];
+	}
+
+	if (a->argc > e->args + 2) {
+		query.filter = (char *) a->argv[e->args + 2];
+	}
+
+	tree = ast_data_get(&query);
+	if (!tree) {
+		return CLI_FAILURE;
+	}
+
+	data_result_print_cli(a->fd, tree);
+
+	ast_data_free(tree);
+
+	return CLI_SUCCESS;
+}
+
+/*!
+ * \internal
+ * \brief Print the list of data providers.
+ * \param[in] fd The CLI file descriptor.
+ * \param[in] name The last node visited name.
+ * \param[in] container The childrens of the last node.
+ * \param[in] path The path to the current node.
+ */
+static void data_provider_print_cli(int fd, const char *name,
+	struct ao2_container *container, struct ast_str *path)
+{
+	struct ao2_iterator i;
+	struct ast_str *current_path;
+	struct data_provider *provider;
+
+	current_path = ast_str_create(60);
+	if (!current_path) {
+		return;
+	}
+
+	ast_str_reset(current_path);
+	if (path) {
+		ast_str_set(&current_path, 0, "%s/%s", ast_str_buffer(path), name);
+	} else {
+		ast_str_set(&current_path, 0, "%s", name);
+	}
+
+	i = ao2_iterator_init(container, 0);
+	while ((provider = ao2_iterator_next(&i))) {
+		if (provider->handler) {
+			/* terminal node, print it. */
+			ast_cli(fd, "%s/%s (", ast_str_buffer(current_path),
+				provider->name);
+			if (provider->handler->get) {
+				ast_cli(fd, "get");
+			}
+			ast_cli(fd, ") [%s]\n", provider->registrar);
+		}
+		data_provider_print_cli(fd, provider->name, provider->children,
+			current_path);
+		ao2_ref(provider, -1);
+	}
+	ao2_iterator_destroy(&i);
+
+	ast_free(current_path);
+}
+
+/*!
+ * \internal
+ * \brief Handle CLI command "data show providers"
+ */
+static char *handle_cli_data_show_providers(struct ast_cli_entry *e, int cmd,
+		struct ast_cli_args *a)
+{
+	switch (cmd) {
+	case CLI_INIT:
+		e->command = "data show providers";
+		e->usage = ""
+			"Usage: data show providers\n"
+			"       Show the list of registered providers\n";
+		return NULL;
+	case CLI_GENERATE:
+		return NULL;
+	}
+
+	data_read_lock();
+	data_provider_print_cli(a->fd, "", root_data.container, NULL);
+	data_unlock();
+
+	return CLI_SUCCESS;
+}
+
+/*!
+ * \internal
+ * \brief Data API CLI commands.
+ */
+static struct ast_cli_entry cli_data[] = {
+	AST_CLI_DEFINE(handle_cli_data_get, "Data API get"),
+	AST_CLI_DEFINE(handle_cli_data_show_providers, "Show data providers")
+};
+
+/*!
+ * \internal
+ * \brief Output a tree to the AMI.
+ * \param[in] s AMI session.
+ * \param[in] name The root node name.
+ * \param[in] container The root container.
+ * \param[in] path The current path.
+ */
+static void data_result_manager_output(struct mansession *s, const char *name,
+	struct ao2_container *container, struct ast_str *path, int id)
+{
+	struct ao2_iterator i;
+	struct ast_str *current_path;
+	struct ast_data *node;
+	int current_id = id;
+
+	current_path = ast_str_create(60);
+	if (!current_path) {
+		return;
+	}
+
+	ast_str_reset(current_path);
+	if (path) {
+		ast_str_set(&current_path, 0, "%s.%s", ast_str_buffer(path), name);
+	} else {
+		ast_str_set(&current_path, 0, "%s", name);
+	}
+
+	i = ao2_iterator_init(container, 0);
+	while ((node = ao2_iterator_next(&i))) {
+		/* terminal node, print it. */
+		if (node->type != AST_DATA_CONTAINER) {
+			astman_append(s, "%d-%s.%s", id, ast_str_buffer(current_path),
+					node->name);
+		}
+		switch (node->type) {
+		case AST_DATA_CONTAINER:
+			data_result_manager_output(s, node->name, node->children, current_path, ++current_id);
+			break;
+		case AST_DATA_INTEGER:
+			astman_append(s, ": %d\r\n", node->payload.sint);
+			break;
+		case AST_DATA_UNSIGNED_INTEGER:
+			astman_append(s, ": %u\r\n", node->payload.uint);
+			break;
+		case AST_DATA_STRING:
+			astman_append(s, ": %s\r\n", node->payload.str);
+			break;
+		case AST_DATA_IPADDR:
+			astman_append(s, ": %s\r\n", ast_inet_ntoa(node->payload.ipaddr));
+			break;
+		case AST_DATA_POINTER:
+			break;
+		case AST_DATA_DOUBLE:
+			astman_append(s, ": %f\r\n", node->payload.dbl);
+			break;
+		case AST_DATA_BOOLEAN:
+			astman_append(s, ": %s\r\n",
+				(node->payload.boolean ? "True" : "False"));
+			break;
+		}
+
+		ao2_ref(node, -1);
+	}
+	ao2_iterator_destroy(&i);
+
+	ast_free(current_path);
+}
+
+/*!
+ * \internal
+ * \brief Implements the manager action: "DataGet".
+ */
+static int manager_data_get(struct mansession *s, const struct message *m)
+{
+	const char *path = astman_get_header(m, "Path");
+	const char *search = astman_get_header(m, "Search");
+	const char *filter = astman_get_header(m, "Filter");
+	const char *id = astman_get_header(m, "ActionID");
+	struct ast_data *res;
+	struct ast_data_query query = {
+		.version = AST_DATA_QUERY_VERSION,
+		.path = (char *) path,
+		.search = (char *) search,
+		.filter = (char *) filter,
+	};
+
+	if (ast_strlen_zero(path)) {
+		astman_send_error(s, m, "'Path' parameter not specified");
+		return 0;
+	}
+
+	res = ast_data_get(&query);
+	if (!res) {
+		astman_send_error(s, m, "No data returned");
+		return 0;
+	}
+
+	astman_append(s, "Event: DataGet Tree\r\n");
+	if (!ast_strlen_zero(id)) {
+		astman_append(s, "ActionID: %s\r\n", id);
+	}
+	data_result_manager_output(s, res->name, res->children, NULL, 0);
+	astman_append(s, "\r\n");
+
+	ast_data_free(res);
+
+	return RESULT_SUCCESS;
+}
+
+#ifdef TEST_FRAMEWORK
+
+/*!
+ * \internal
+ * \brief Structure used to test how to add a complete structure,
+ *        and how to compare it.
+ */
+struct test_structure {
+	int a_int;
+	unsigned int b_bool:1;
+	char *c_str;
+	unsigned int a_uint;
+};
+
+/*!
+ * \internal
+ * \brief test_structure mapping.
+ */
+#define DATA_EXPORT_TEST_STRUCTURE(MEMBER)                              \
+	MEMBER(test_structure, a_int, AST_DATA_INTEGER)                 \
+	MEMBER(test_structure, b_bool, AST_DATA_BOOLEAN)                \
+	MEMBER(test_structure, c_str, AST_DATA_STRING)                  \
+	MEMBER(test_structure, a_uint, AST_DATA_UNSIGNED_INTEGER)
+
+AST_DATA_STRUCTURE(test_structure, DATA_EXPORT_TEST_STRUCTURE);
+
+/*!
+ * \internal
+ * \brief Callback implementation.
+ */
+static int test_data_full_provider(const struct ast_data_search *search,
+		struct ast_data *root)
+{
+	struct ast_data *test_structure;
+	struct test_structure local_test_structure = {
+		.a_int = 10,
+		.b_bool = 1,
+		.c_str = "test string",
+		.a_uint = 20
+	};
+
+	if (ast_data_search_cmp_structure(search, test_structure, &local_test_structure, "test_structure")) {
+		return 0;
+	}
+
+	test_structure = ast_data_add_node(root, "test_structure");
+	if (!test_structure) {
+		ast_debug(1, "Internal data api error\n");
+		return 0;
+	}
+
+	/* add the complete structure. */
+	ast_data_add_structure(test_structure, test_structure, &local_test_structure);
+
+	return 0;
+}
+
+/*!
+ * \internal
+ * \brief Handler definition for the full provider.
+ */
+static const struct ast_data_handler full_provider = {
+	.version = AST_DATA_HANDLER_VERSION,
+	.get = test_data_full_provider
+};
+
+/*!
+ * \internal
+ * \brief Structure used to define multiple providers at once.
+ */
+static const struct ast_data_entry test_providers[] = {
+	AST_DATA_ENTRY("test/node1/node11/node111", &full_provider)
+};
+
+AST_TEST_DEFINE(test_data_get)
+{
+	struct ast_data *res, *node;
+	struct ast_data_iterator *i;
+	struct ast_data_query query = {
+		.version = AST_DATA_QUERY_VERSION,
+		.path = "test/node1/node11/node111",
+		.search = "node111/test_structure/a_int=10",
+		.filter = "node111/test_structure/a*int"
+	};
+
+	switch (cmd) {
+	case TEST_INIT:
+		info->name = "data_test";
+		info->category = "main/data/";
+		info->summary = "Data API unit test";
+		info->description =
+			"Tests whether data API get implementation works as expected.";
+		return AST_TEST_NOT_RUN;
+	case TEST_EXECUTE:
+		break;
+	}
+
+	ast_data_register_multiple_core(test_providers, ARRAY_LEN(test_providers));
+
+	res = ast_data_get(&query);
+	if (!res) {
+		ast_test_status_update(test, "Unable to get tree.");
+		ast_data_unregister("test/node1/node11/node111");
+		return AST_TEST_FAIL;
+	}
+
+	/* initiate the iterator and check for errors. */
+	i = ast_data_iterator_init(res, "test_structure/");
+	if (!i) {
+		ast_test_status_update(test, "Unable to initiate the iterator.");
+		ast_data_free(res);
+		ast_data_unregister("test/node1/node11/node111");
+		return AST_TEST_FAIL;
+	}
+
+	/* walk the returned nodes. */
+	while ((node = ast_data_iterator_next(i))) {
+		if (!strcmp(ast_data_retrieve_name(node), "a_int")) {
+			if (ast_data_retrieve_int(node, "/") != 10) {
+				ast_data_iterator_end(i);
+				ast_data_free(res);
+				ast_data_unregister("test/node1/node11/node111");
+				return AST_TEST_FAIL;
+			}
+		} else if (!strcmp(ast_data_retrieve_name(node), "a_uint")) {
+			if (ast_data_retrieve_uint(node, "/") != 20) {
+				ast_data_iterator_end(i);
+				ast_data_free(res);
+				ast_data_unregister("test/node1/node11/node111");
+				return AST_TEST_FAIL;
+			}
+		}
+	}
+
+	/* finish the iterator. */
+	ast_data_iterator_end(i);
+
+	ast_data_free(res);
+
+	ast_data_unregister("test/node1/node11/node111");
+
+	return AST_TEST_PASS;
+}
+
+#endif
+
+int ast_data_init(void)
+{
+	int res = 0;
+
+	ast_rwlock_init(&root_data.lock);
+
+	if (!(root_data.container = ao2_container_alloc(NUM_DATA_NODE_BUCKETS,
+		data_provider_hash, data_provider_cmp))) {
+		return -1;
+	}
+
+	res |= ast_cli_register_multiple(cli_data, ARRAY_LEN(cli_data));
+
+	res |= ast_manager_register_xml("DataGet", 0, manager_data_get);
+
+#ifdef TEST_FRAMEWORK
+	AST_TEST_REGISTER(test_data_get);
+#endif
+
+	return res;
+}