dbus: Rename old D-Bus API files to include "_old"

[hostap-gosc2009.git] / wpa_supplicant / dbus / dbus_new_helpers.c

/*
 * WPA Supplicant / dbus-based control interface
 * Copyright (c) 2006, Dan Williams <dcbw@redhat.com> and Red Hat, Inc.
 * Copyright (c) 2009, Witold Sowa <witold.sowa@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"

#include "common.h"
#include "eloop.h"
#include "dbus_common.h"
#include "dbus_common_i.h"
#include "dbus_new_helpers.h"

/**
 * struct wpa_dbus_method_desc - DBus method description
 */
struct wpa_dbus_method_desc {
        /* pointer to next description in list */
        struct wpa_dbus_method_desc *next;

        /* method interface */
        char *dbus_interface;
        /* method name */
        char *dbus_method;

        /* method handling function */
        WPADBusMethodHandler method_handler;
        /* handler function argument */
        void *handler_argument;
        /* function used to free handler argument */
        WPADBusArgumentFreeFunction argument_free_func;

        /* number of method arguments */
        int args_num;
        /* array of arguments */
        struct wpa_dbus_argument args[];
};


/**
 * struct wpa_dbus_signal_desc - DBus signal description
 */
struct wpa_dbus_signal_desc {
        /* pointer to next description in list */
        struct wpa_dbus_signal_desc *next;

        /* signal interface */
        char *dbus_interface;
        /* signal name */
        char *dbus_signal;

        /* number of signal arguments */
        int args_num;
        /* array of arguments */
        struct wpa_dbus_argument args[0];
};


/**
 * struct wpa_dbus_property_desc - DBus property description
 */
struct wpa_dbus_property_desc {
        /* pointer to next description in list */
        struct wpa_dbus_property_desc *next;

        /* property interface */
        char *dbus_interface;
        /* property name */
        char *dbus_property;
        /* property type signature in DBus type notation */
        char *type;

        /* property access permissions */
        enum dbus_prop_access access;

        /* property getter function */
        WPADBusPropertyAccessor getter;
        /* property setter function */
        WPADBusPropertyAccessor setter;
        /* argument for getter and setter functions */
        void *user_data;
        /* function used to free accessors argument */
        WPADBusArgumentFreeFunction user_data_free_func;
};


#ifdef CONFIG_CTRL_IFACE_DBUS_INTRO
#include <libxml/tree.h>

struct interfaces {
        struct interfaces *next;
        char *dbus_interface;
        xmlNodePtr interface_node;
};
#endif /* CONFIG_CTRL_IFACE_DBUS_INTRO */


#ifdef CONFIG_CTRL_IFACE_DBUS_INTRO

/**
 * extract_interfaces - Extract interfaces from methods, signals and props
 * @obj_dsc: Description of object from which interfaces will be extracted
 * @root_node: root node of XML introspection document
 * Returns: List of interfaces found in object description
 *
 * Iterates over all methods, signals and properties registered with
 * object and collects all declared DBus interfaces and create interface's
 * node in XML root node for each. Returned list elements contains interface
 * name and XML node of corresponding interface.
 */
static struct interfaces * extract_interfaces(
        struct wpa_dbus_object_desc *obj_dsc, xmlNodePtr root_node)
{
        struct wpa_dbus_method_desc *method_dsc = obj_dsc->methods;
        struct wpa_dbus_signal_desc *signal_dsc = obj_dsc->signals;
        struct wpa_dbus_property_desc *property_dsc = obj_dsc->properties;
        struct interfaces *head = NULL;
        struct interfaces *iface, *last;
        int len;

        /* extract interfaces from methods */
        while (method_dsc) {
                iface = head;
                last = NULL;

                /* go to next method if its interface is already extracted */
                while (iface) {
                        if (!os_strcmp(iface->dbus_interface,
                                       method_dsc->dbus_interface))
                                break;
                        last = iface;
                        iface = iface->next;
                }
                if (iface) {
                        method_dsc = method_dsc->next;
                        continue;
                }

                iface = os_zalloc(sizeof(struct interfaces));
                if (!iface) {
                        wpa_printf(MSG_ERROR, "Not enough memory to create "
                                "interface introspection data");
                        method_dsc = method_dsc->next;
                        continue;
                }

                if (last)
                        last->next = iface;
                else
                        head = iface;

                len = os_strlen(method_dsc->dbus_interface) + 1;
                iface->dbus_interface = os_malloc(len);
                if (!iface->dbus_interface) {
                        wpa_printf(MSG_ERROR, "Not enough memory to create "
                                   "interface introspection data (interface "
                                   "name)");
                        method_dsc = method_dsc->next;
                        continue;
                }
                os_strncpy(iface->dbus_interface, method_dsc->dbus_interface,
                           len);

                iface->interface_node = xmlNewChild(root_node, NULL,
                                                    BAD_CAST "interface",
                                                    NULL);
                xmlNewProp(iface->interface_node, BAD_CAST "name",
                           BAD_CAST method_dsc->dbus_interface);

                method_dsc = method_dsc->next;
        }

        /* extract interfaces from signals */
        while (signal_dsc) {
                iface = head;
                last = NULL;

                /* go to next signal if its interface is already extracted */
                while (iface) {
                        if (!os_strcmp(iface->dbus_interface,
                                       signal_dsc->dbus_interface))
                                break;
                        last = iface;
                        iface = iface->next;
                }
                if (iface) {
                        signal_dsc = signal_dsc->next;
                        continue;
                }

                iface = os_zalloc(sizeof(struct interfaces));
                if (!iface) {
                        wpa_printf(MSG_ERROR, "Not enough memory to create "
                                   "interface introspection data");
                        signal_dsc = signal_dsc->next;
                        continue;
                }

                if (last)
                        last->next = iface;
                else
                        head = iface;

                len = os_strlen(signal_dsc->dbus_interface) + 1;
                iface->dbus_interface = os_malloc(len);
                if (!iface->dbus_interface) {
                        wpa_printf(MSG_ERROR, "Not enough memory to create "
                                   "interface introspection data (interface "
                                   "name)");
                        signal_dsc = signal_dsc->next;
                        continue;
                }
                os_strncpy(iface->dbus_interface, signal_dsc->dbus_interface,
                           len);

                iface->interface_node = xmlNewChild(root_node, NULL,
                                                    BAD_CAST "interface",
                                                    NULL);
                xmlNewProp(iface->interface_node, BAD_CAST "name",
                           BAD_CAST signal_dsc->dbus_interface);

                signal_dsc = signal_dsc->next;
        }

        /* extract interfaces from properties */
        while (property_dsc) {
                iface = head;
                last = NULL;

                /* go to next property if its interface is already extracted */
                while (iface) {
                        if (!os_strcmp(iface->dbus_interface,
                                       property_dsc->dbus_interface))
                                break;
                        last = iface;
                        iface = iface->next;
                }
                if (iface) {
                        property_dsc = property_dsc->next;
                        continue;
                }

                iface = os_zalloc(sizeof(struct interfaces));
                if (!iface) {
                        wpa_printf(MSG_ERROR, "Not enough memory to create "
                                   "interface introspection data");
                        property_dsc = property_dsc->next;
                        continue;
                }

                if (last)
                        last->next = iface;
                else
                        head = iface;

                len = os_strlen(property_dsc->dbus_interface) + 1;
                iface->dbus_interface = os_malloc(len);
                if (!iface->dbus_interface) {
                        wpa_printf(MSG_ERROR, "Not enough memory to create "
                                   "interface introspection data (interface "
                                   "name)");
                        property_dsc = property_dsc->next;
                        continue;
                }
                os_strncpy(iface->dbus_interface, property_dsc->dbus_interface,
                           len);

                iface->interface_node = xmlNewChild(root_node, NULL,
                                                    BAD_CAST "interface",
                                                    NULL);
                xmlNewProp(iface->interface_node, BAD_CAST "name",
                           BAD_CAST property_dsc->dbus_interface);

                property_dsc = property_dsc->next;
        }

        return head;
}


/**
 * introspect - Responds for Introspect calls on object
 * @message: Message with Introspect call
 * @obj_dsc: Object description on which Introspect was called
 * Returns: Message with introspection result XML string as only argument
 *
 * Iterates over all methods, signals and properties registered with
 * object and generates introspection data for the object as XML string.
 */
static DBusMessage * introspect(DBusMessage *message,
                                struct wpa_dbus_object_desc *obj_dsc)
{

        DBusMessage *reply;
        struct interfaces *ifaces, *tmp;
        struct wpa_dbus_signal_desc *signal_dsc;
        struct wpa_dbus_method_desc *method_dsc;
        struct wpa_dbus_property_desc *property_dsc;
        xmlChar *intro_str;
        char **children;
        int i, s;

        xmlDocPtr doc = NULL;
        xmlNodePtr root_node = NULL, node = NULL, iface_node = NULL;
        xmlNodePtr method_node = NULL, signal_node = NULL;
        xmlNodePtr property_node = NULL, arg_node = NULL;

        /* root node and dtd */
        doc = xmlNewDoc(BAD_CAST "1.0");
        root_node = xmlNewNode(NULL, BAD_CAST "node");
        xmlDocSetRootElement(doc, root_node);
        xmlCreateIntSubset(doc, BAD_CAST "node",
                           BAD_CAST DBUS_INTROSPECT_1_0_XML_PUBLIC_IDENTIFIER,
                           BAD_CAST DBUS_INTROSPECT_1_0_XML_SYSTEM_IDENTIFIER);

        /* Add Introspectable interface */
        iface_node = xmlNewChild(root_node, NULL, BAD_CAST "interface", NULL);
        xmlNewProp(iface_node, BAD_CAST "name",
                   BAD_CAST WPA_DBUS_INTROSPECTION_INTERFACE);

        /* Add Introspect method */
        method_node = xmlNewChild(iface_node, NULL, BAD_CAST "method", NULL);
        xmlNewProp(method_node, BAD_CAST "name",
                   BAD_CAST WPA_DBUS_INTROSPECTION_METHOD);
        arg_node = xmlNewChild(method_node, NULL, BAD_CAST "arg", NULL);
        xmlNewProp(arg_node, BAD_CAST "name", BAD_CAST "data");
        xmlNewProp(arg_node, BAD_CAST "type", BAD_CAST "s");
        xmlNewProp(arg_node, BAD_CAST "direction", BAD_CAST "out");


        /* Add Properties interface */
        iface_node = xmlNewChild(root_node, NULL,
                                 BAD_CAST "interface", NULL);
        xmlNewProp(iface_node, BAD_CAST "name",
                   BAD_CAST WPA_DBUS_PROPERTIES_INTERFACE);

        /* Add Get method */
        method_node = xmlNewChild(iface_node, NULL, BAD_CAST "method", NULL);
        xmlNewProp(method_node, BAD_CAST "name",
                   BAD_CAST WPA_DBUS_PROPERTIES_GET);
        arg_node = xmlNewChild(method_node, NULL, BAD_CAST "arg", NULL);
        xmlNewProp(arg_node, BAD_CAST "name", BAD_CAST "interface");
        xmlNewProp(arg_node, BAD_CAST "type", BAD_CAST "s");
        xmlNewProp(arg_node, BAD_CAST "direction", BAD_CAST "in");
        arg_node = xmlNewChild(method_node, NULL, BAD_CAST "arg", NULL);
        xmlNewProp(arg_node, BAD_CAST "name", BAD_CAST "propname");
        xmlNewProp(arg_node, BAD_CAST "type", BAD_CAST "s");
        xmlNewProp(arg_node, BAD_CAST "direction", BAD_CAST "in");
        arg_node = xmlNewChild(method_node, NULL, BAD_CAST "arg", NULL);
        xmlNewProp(arg_node, BAD_CAST "name", BAD_CAST "value");
        xmlNewProp(arg_node, BAD_CAST "type", BAD_CAST "v");
        xmlNewProp(arg_node, BAD_CAST "direction", BAD_CAST "out");
        method_node = xmlNewChild(iface_node, NULL, BAD_CAST "method", NULL);

        /* Add GetAll method */
        xmlNewProp(method_node, BAD_CAST "name",
                   BAD_CAST WPA_DBUS_PROPERTIES_GETALL);
        arg_node = xmlNewChild(method_node, NULL, BAD_CAST "arg", NULL);
        xmlNewProp(arg_node, BAD_CAST "name", BAD_CAST "interface");
        xmlNewProp(arg_node, BAD_CAST "type", BAD_CAST "s");
        xmlNewProp(arg_node, BAD_CAST "direction", BAD_CAST "in");
        arg_node = xmlNewChild(method_node, NULL, BAD_CAST "arg", NULL);
        xmlNewProp(arg_node, BAD_CAST "name", BAD_CAST "props");
        xmlNewProp(arg_node, BAD_CAST "type", BAD_CAST "a{sv}");
        xmlNewProp(arg_node, BAD_CAST "direction", BAD_CAST "out");
        method_node = xmlNewChild(iface_node, NULL, BAD_CAST "method", NULL);

        /* Add Set method */
        xmlNewProp(method_node, BAD_CAST "name",
                   BAD_CAST WPA_DBUS_PROPERTIES_SET);
        arg_node = xmlNewChild(method_node, NULL, BAD_CAST "arg", NULL);
        xmlNewProp(arg_node, BAD_CAST "name", BAD_CAST "interface");
        xmlNewProp(arg_node, BAD_CAST "type", BAD_CAST "s");
        xmlNewProp(arg_node, BAD_CAST "direction", BAD_CAST "in");
        arg_node = xmlNewChild(method_node, NULL, BAD_CAST "arg", NULL);
        xmlNewProp(arg_node, BAD_CAST "name", BAD_CAST "propname");
        xmlNewProp(arg_node, BAD_CAST "type", BAD_CAST "s");
        xmlNewProp(arg_node, BAD_CAST "direction", BAD_CAST "in");
        arg_node = xmlNewChild(method_node, NULL, BAD_CAST "arg", NULL);
        xmlNewProp(arg_node, BAD_CAST "name", BAD_CAST "value");
        xmlNewProp(arg_node, BAD_CAST "type", BAD_CAST "v");
        xmlNewProp(arg_node, BAD_CAST "direction", BAD_CAST "in");

        /* get all interfaces registered with object */
        ifaces = extract_interfaces(obj_dsc, root_node);

        /* create methods' nodes */
        method_dsc = obj_dsc->methods;
        while (method_dsc) {

                struct interfaces *iface = ifaces;
                while (iface) {
                        if (!os_strcmp(iface->dbus_interface,
                                       method_dsc->dbus_interface))
                                break;
                        iface = iface->next;
                }
                if (!iface)
                        continue;

                iface_node = iface->interface_node;
                method_node = xmlNewChild(iface_node, NULL, BAD_CAST "method",
                                          NULL);
                xmlNewProp(method_node, BAD_CAST "name",
                           BAD_CAST method_dsc->dbus_method);

                /* create args' nodes */
                for (i = 0; i < method_dsc->args_num; i++) {
                        struct wpa_dbus_argument arg = method_dsc->args[i];
                        arg_node = xmlNewChild(method_node, NULL,
                                               BAD_CAST "arg", NULL);
                        if (arg.name && strlen(arg.name)) {
                                xmlNewProp(arg_node, BAD_CAST "name",
                                           BAD_CAST arg.name);
                        }
                        xmlNewProp(arg_node, BAD_CAST "type",
                                   BAD_CAST arg.type);
                        xmlNewProp(arg_node, BAD_CAST "direction",
                                   BAD_CAST (arg.dir == ARG_IN ?
                                             "in" : "out"));
                }
                method_dsc = method_dsc->next;
        }

        /* create signals' nodes */
        signal_dsc = obj_dsc->signals;
        while (signal_dsc) {

                struct interfaces *iface = ifaces;
                while (iface) {
                        if (!os_strcmp(iface->dbus_interface,
                                       signal_dsc->dbus_interface))
                                break;
                        iface = iface->next;
                }
                if (!iface)
                        continue;

                iface_node = iface->interface_node;
                signal_node = xmlNewChild(iface_node, NULL, BAD_CAST "signal",
                                          NULL);
                xmlNewProp(signal_node, BAD_CAST "name",
                           BAD_CAST signal_dsc->dbus_signal);

                /* create args' nodes */
                for (i = 0; i < signal_dsc->args_num; i++) {
                        struct wpa_dbus_argument arg = signal_dsc->args[i];
                        arg_node = xmlNewChild(signal_node, NULL,
                                               BAD_CAST "arg", NULL);
                        if (arg.name && strlen(arg.name)) {
                                xmlNewProp(arg_node, BAD_CAST "name",
                                           BAD_CAST arg.name);
                        }
                        xmlNewProp(arg_node, BAD_CAST "type",
                                   BAD_CAST arg.type);
                }
                signal_dsc = signal_dsc->next;
        }

        /* create properties' nodes */
        property_dsc = obj_dsc->properties;
        while (property_dsc) {

                struct interfaces *iface = ifaces;
                while (iface) {
                        if (!os_strcmp(iface->dbus_interface,
                                       property_dsc->dbus_interface))
                                break;
                        iface = iface->next;
                }
                if (!iface)
                        continue;

                iface_node = iface->interface_node;
                property_node = xmlNewChild(iface_node, NULL,
                                            BAD_CAST "property", NULL);
                xmlNewProp(property_node, BAD_CAST "name",
                           BAD_CAST property_dsc->dbus_property);
                xmlNewProp(property_node, BAD_CAST "type",
                           BAD_CAST property_dsc->type);
                xmlNewProp(property_node, BAD_CAST "access", BAD_CAST
                           (property_dsc->access == R ? "read" :
                            (property_dsc->access == W ?
                             "write" : "readwrite")));

                property_dsc = property_dsc->next;
        }

        /* add child nodes to introspection tree; */
        dbus_connection_list_registered(obj_dsc->connection,
                                        dbus_message_get_path(message),
                                        &children);
        for (i = 0; children[i]; i++) {
                node = xmlNewChild(root_node, NULL, BAD_CAST "node", NULL);
                xmlNewProp(node, BAD_CAST "name", BAD_CAST children[i]);
        }
        dbus_free_string_array(children);


        xmlDocDumpFormatMemory(doc, &intro_str, &s, 1);

        xmlFreeDoc(doc);

        while (ifaces) {
                tmp = ifaces;
                ifaces = ifaces->next;
                os_free(tmp->dbus_interface);
                os_free(tmp);
        }

        reply = dbus_message_new_method_return(message);
        if (reply == NULL) {
                xmlFree(intro_str);
                return NULL;
        }

        dbus_message_append_args(reply, DBUS_TYPE_STRING, &intro_str,
                                 DBUS_TYPE_INVALID);

        xmlFree(intro_str);

        return reply;
}

#else /* CONFIG_CTRL_IFACE_DBUS_INTRO */

/**
 * introspect - Responds for Introspect calls on object
 * @message: Message with Introspect call
 * @obj_dsc: Object description on which Introspect was called
 * Returns: Message with introspection result XML string as only argument
 *
 * Returns error informing that introspection support was not compiled.
 */
static DBusMessage * introspect(DBusMessage *message,
                                struct wpa_dbus_object_desc *obj_dsc)
{
        return dbus_message_new_error(message, DBUS_ERROR_UNKNOWN_METHOD,
                                      "wpa_supplicant was compiled without "
                                      "introspection support.");
}

#endif /* CONFIG_CTRL_IFACE_DBUS_INTRO */


/**
 * recursive_iter_copy - Reads arguments from one iterator and
 * writes to another recursively
 * @from: iterator to read from
 * @to: iterator to write to
 *
 * Copies one iterator's elements to another. If any element in
 * iterator is of container type, its content is copied recursively
 */
static void recursive_iter_copy(DBusMessageIter *from, DBusMessageIter *to)
{

        char *subtype = NULL;
        int type;

        /* iterate over iterator to copy */
        while ((type = dbus_message_iter_get_arg_type (from)) !=
               DBUS_TYPE_INVALID) {

                /* simply copy basic type entries */
                if (dbus_type_is_basic(type)) {
                        if (dbus_type_is_fixed(type)) {
                                /*
                                 * According to DBus documentation all
                                 * fixed-length types are guaranteed to fit
                                 * 8 bytes
                                 */
                                dbus_uint64_t v;
                                dbus_message_iter_get_basic (from, &v);
                                dbus_message_iter_append_basic (to, type, &v);
                        } else {
                                char *v;
                                dbus_message_iter_get_basic (from, &v);
                                dbus_message_iter_append_basic (to, type, &v);
                        }
                } else {
                        /* recursively copy container type entries */
                        DBusMessageIter write_subiter, read_subiter;

                        dbus_message_iter_recurse(from, &read_subiter);

                        if (type == DBUS_TYPE_VARIANT ||
                            type == DBUS_TYPE_ARRAY) {
                                subtype = dbus_message_iter_get_signature(
                                        &read_subiter);
                        }

                        dbus_message_iter_open_container(to, type, subtype,
                                                         &write_subiter);

                        recursive_iter_copy(&read_subiter, &write_subiter);

                        dbus_message_iter_close_container(to, &write_subiter);
                        if (subtype)
                                dbus_free(subtype);
                }

                dbus_message_iter_next(from);
        }
}


/**
 * get_all_properties - Responds for GetAll properties calls on object
 * @message: Message with GetAll call
 * @interface: interface name which properties will be returned
 * @property_dsc: list of object's properties
 * Returns: Message with dict of variants as argument with properties values
 *
 * Iterates over all properties registered with object and execute getters
 * of those, which are readable and which interface matches interface
 * specified as argument. Returned message contains one dict argument
 * with properties names as keys and theirs values as values.
 */
static DBusMessage * get_all_properties(
        DBusMessage *message, char *interface,
        struct wpa_dbus_property_desc *property_dsc)
{
        /* Create and initialize the return message */
        DBusMessage *reply = dbus_message_new_method_return(message);
        DBusMessage *getterReply = NULL;
        DBusMessageIter iter, dict_iter, entry_iter, ret_iter;
        int counter = 0;

        dbus_message_iter_init_append(reply, &iter);

        dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY,
                                         DBUS_DICT_ENTRY_BEGIN_CHAR_AS_STRING
                                         DBUS_TYPE_STRING_AS_STRING
                                         DBUS_TYPE_VARIANT_AS_STRING
                                         DBUS_DICT_ENTRY_END_CHAR_AS_STRING,
                                         &dict_iter);

        while (property_dsc) {
                if (!os_strncmp(property_dsc->dbus_interface, interface,
                                WPAS_DBUS_INTERFACE_MAX) &&
                    property_dsc->access != W && property_dsc->getter) {

                        getterReply = property_dsc->getter(
                                message, property_dsc->user_data);
                        dbus_message_iter_init(getterReply, &ret_iter);

                        dbus_message_iter_open_container(&dict_iter,
                                                         DBUS_TYPE_DICT_ENTRY,
                                                         NULL, &entry_iter);
                        dbus_message_iter_append_basic(
                                &entry_iter, DBUS_TYPE_STRING,
                                &(property_dsc->dbus_property));

                        recursive_iter_copy(&ret_iter, &entry_iter);

                        dbus_message_iter_close_container(&dict_iter,
                                                          &entry_iter);
                        dbus_message_unref(getterReply);
                        counter++;
                }
                property_dsc = property_dsc->next;
        }
        dbus_message_iter_close_container(&iter, &dict_iter);

        if (counter == 0) {
                dbus_message_unref(reply);
                reply = dbus_message_new_error(message,
                                               DBUS_ERROR_INVALID_ARGS,
                                               "No readable properties in "
                                               "this interface");
        }

        return reply;
}


static int is_signature_correct(DBusMessage *message,
                                struct wpa_dbus_method_desc *method_dsc)
{
        /* According to DBus documentation max length of signature is 255 */
#define MAX_SIG_LEN 256
        char registered_sig[MAX_SIG_LEN], *pos;
        const char *sig = dbus_message_get_signature(message);
        int i, ret;

        pos = registered_sig;
        *pos = '\0';

        for (i = 0; i < method_dsc->args_num; i++) {
                struct wpa_dbus_argument arg = method_dsc->args[i];
                if (arg.dir == ARG_IN) {
                        size_t blen = registered_sig + MAX_SIG_LEN - pos;
                        ret = os_snprintf(pos, blen, "%s", arg.type);
                        if (ret < 0 || (size_t) ret >= blen)
                                return 0;
                        pos += ret;
                }
        }

        return !os_strncmp(registered_sig, sig, MAX_SIG_LEN);
}


static DBusMessage * properties_get_all(DBusMessage *message, char *interface,
                                        struct wpa_dbus_object_desc *obj_dsc)
{
        if (os_strcmp(dbus_message_get_signature(message), "s") != 0)
                return dbus_message_new_error(message, DBUS_ERROR_INVALID_ARGS,
                                              NULL);

        return get_all_properties(message, interface,
                                  obj_dsc->properties);
}


static DBusMessage * properties_get(DBusMessage *message,
                                    struct wpa_dbus_property_desc *dsc)
{
        if (os_strcmp(dbus_message_get_signature(message), "ss"))
                return dbus_message_new_error(message, DBUS_ERROR_INVALID_ARGS,
                                              NULL);

        if (dsc->access != W && dsc->getter)
                return dsc->getter(message, dsc->user_data);

        return dbus_message_new_error(message, DBUS_ERROR_INVALID_ARGS,
                                      "Property is write-only");
}


static DBusMessage * properties_set(DBusMessage *message,
                                    struct wpa_dbus_property_desc *dsc)
{
        if (os_strcmp(dbus_message_get_signature(message), "ssv"))
                return dbus_message_new_error(message, DBUS_ERROR_INVALID_ARGS,
                                              NULL);

        if (dsc->access != R && dsc->setter)
                return dsc->setter(message, dsc->user_data);

        return dbus_message_new_error(message, DBUS_ERROR_INVALID_ARGS,
                                      "Property is read-only");
}


static DBusMessage *
properties_get_or_set(DBusMessage *message, DBusMessageIter *iter,
                      char *interface,
                      struct wpa_dbus_object_desc *obj_dsc)
{
        struct wpa_dbus_property_desc *property_dsc;
        char *property;
        const char *method;

        method = dbus_message_get_member(message);
        property_dsc = obj_dsc->properties;

        /* Second argument: property name (DBUS_TYPE_STRING) */
        if (!dbus_message_iter_next(iter) ||
            dbus_message_iter_get_arg_type(iter) != DBUS_TYPE_STRING) {
                return dbus_message_new_error(message, DBUS_ERROR_INVALID_ARGS,
                                              NULL);
        }
        dbus_message_iter_get_basic(iter, &property);

        while (property_dsc) {
                /* compare property names and
                 * interfaces */
                if (!os_strncmp(property_dsc->dbus_property, property,
                                WPAS_DBUS_METHOD_SIGNAL_PROP_MAX) &&
                    !os_strncmp(property_dsc->dbus_interface, interface,
                                WPAS_DBUS_INTERFACE_MAX))
                        break;

                property_dsc = property_dsc->next;
        }
        if (property_dsc == NULL) {
                wpa_printf(MSG_DEBUG, "no property handler for %s.%s on %s",
                           interface, property,
                           dbus_message_get_path(message));
                return dbus_message_new_error(message, DBUS_ERROR_INVALID_ARGS,
                                              "No such property");
        }

        if (os_strncmp(WPA_DBUS_PROPERTIES_GET, method,
                       WPAS_DBUS_METHOD_SIGNAL_PROP_MAX) == 0)
                return properties_get(message, property_dsc);

        return properties_set(message, property_dsc);
}


static DBusMessage * properties_handler(DBusMessage *message,
                                        struct wpa_dbus_object_desc *obj_dsc)
{
        DBusMessageIter iter;
        char *interface;
        const char *method;

        method = dbus_message_get_member(message);
        dbus_message_iter_init(message, &iter);

        if (!os_strncmp(WPA_DBUS_PROPERTIES_GET, method,
                        WPAS_DBUS_METHOD_SIGNAL_PROP_MAX) ||
            !os_strncmp(WPA_DBUS_PROPERTIES_SET, method,
                        WPAS_DBUS_METHOD_SIGNAL_PROP_MAX) ||
            !os_strncmp(WPA_DBUS_PROPERTIES_GETALL, method,
                        WPAS_DBUS_METHOD_SIGNAL_PROP_MAX)) {
                /* First argument: interface name (DBUS_TYPE_STRING) */
                if (dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_STRING)
                {
                        return dbus_message_new_error(message,
                                                      DBUS_ERROR_INVALID_ARGS,
                                                      NULL);
                }

                dbus_message_iter_get_basic(&iter, &interface);

                if (!os_strncmp(WPA_DBUS_PROPERTIES_GETALL, method,
                                WPAS_DBUS_METHOD_SIGNAL_PROP_MAX)) {
                        /* GetAll */
                        return properties_get_all(message, interface, obj_dsc);
                }
                /* Get or Set */
                return properties_get_or_set(message, &iter, interface,
                                             obj_dsc);
        }
        return dbus_message_new_error(message, DBUS_ERROR_UNKNOWN_METHOD,
                                      NULL);
}


static DBusMessage * msg_method_handler(DBusMessage *message,
                                        struct wpa_dbus_object_desc *obj_dsc)
{
        struct wpa_dbus_method_desc *method_dsc = obj_dsc->methods;
        const char *method;
        const char *msg_interface;

        method = dbus_message_get_member(message);
        msg_interface = dbus_message_get_interface(message);

        /* try match call to any registered method */
        while (method_dsc) {
                /* compare method names and interfaces */
                if (!os_strncmp(method_dsc->dbus_method, method,
                                WPAS_DBUS_METHOD_SIGNAL_PROP_MAX) &&
                    !os_strncmp(method_dsc->dbus_interface, msg_interface,
                                WPAS_DBUS_INTERFACE_MAX))
                        break;

                method_dsc = method_dsc->next;
        }
        if (method_dsc == NULL) {
                wpa_printf(MSG_DEBUG, "no method handler for %s.%s on %s",
                           msg_interface, method,
                           dbus_message_get_path(message));
                return dbus_message_new_error(message,
                                              DBUS_ERROR_UNKNOWN_METHOD, NULL);
        }

        if (!is_signature_correct(message, method_dsc)) {
                return dbus_message_new_error(message, DBUS_ERROR_INVALID_ARGS,
                                              NULL);
        }

        return method_dsc->method_handler(message,
                                          method_dsc->handler_argument);
}


/**
 * message_handler - Handles incoming DBus messages
 * @connection: DBus connection on which message was received
 * @message: Received message
 * @user_data: pointer to description of object to which message was sent
 * Returns: Returns information whether message was handled or not
 *
 * Reads message interface and method name, then checks if they matches one
 * of the special cases i.e. introspection call or properties get/getall/set
 * methods and handles it. Else it iterates over registered methods list
 * and tries to match method's name and interface to those read from message
 * If appropriate method was found its handler function is called and
 * response is sent. Otherwise, the DBUS_ERROR_UNKNOWN_METHOD error message
 * will be sent.
 */
static DBusHandlerResult message_handler(DBusConnection *connection,
                                         DBusMessage *message, void *user_data)
{
        struct wpa_dbus_object_desc *obj_dsc = user_data;
        const char *method;
        const char *path;
        const char *msg_interface;
        DBusMessage *reply;

        /* get method, interface and path the message is addressed to */
        method = dbus_message_get_member(message);
        path = dbus_message_get_path(message);
        msg_interface = dbus_message_get_interface(message);
        if (!method || !path || !msg_interface)
                return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;

        wpa_printf(MSG_MSGDUMP, "dbus: %s.%s (%s)",
                   msg_interface, method, path);

        /* if message is introspection method call */
        if (!os_strncmp(WPA_DBUS_INTROSPECTION_METHOD, method,
                        WPAS_DBUS_METHOD_SIGNAL_PROP_MAX) &&
            !os_strncmp(WPA_DBUS_INTROSPECTION_INTERFACE, msg_interface,
                        WPAS_DBUS_INTERFACE_MAX))
                reply = introspect(message, obj_dsc);
        else if (!os_strncmp(WPA_DBUS_PROPERTIES_INTERFACE, msg_interface,
                             WPAS_DBUS_INTERFACE_MAX)) {
                /* if message is properties method call */
                reply = properties_handler(message, obj_dsc);
        } else {
                reply = msg_method_handler(message, obj_dsc);
        }

        /* If handler succeed returning NULL, reply empty message */
        if (!reply)
                reply = dbus_message_new_method_return(message);
        if (reply) {
                if (!dbus_message_get_no_reply(message))
                        dbus_connection_send(connection, reply, NULL);
                dbus_message_unref(reply);
        }
        return DBUS_HANDLER_RESULT_HANDLED;
}


/**
 * free_dbus_object_desc - Frees object description data structure
 * @connection: DBus connection
 * @obj_dsc: Object description to free
 *
 * Frees each of properties, methods and signals description lists and
 * the object description structure itself.
 */
void free_dbus_object_desc(struct wpa_dbus_object_desc *obj_dsc)
{
        struct wpa_dbus_method_desc *method_dsc, *tmp_met_dsc;
        struct wpa_dbus_signal_desc *signal_dsc, *tmp_sig_dsc;
        struct wpa_dbus_property_desc *property_dsc, *tmp_prop_dsc;
        int i;

        if (!obj_dsc)
                return;

        /* free methods */
        method_dsc = obj_dsc->methods;

        while (method_dsc) {
                tmp_met_dsc = method_dsc;
                method_dsc = method_dsc->next;

                os_free(tmp_met_dsc->dbus_interface);
                os_free(tmp_met_dsc->dbus_method);

                for (i = 0; i < tmp_met_dsc->args_num; i++) {
                        os_free(tmp_met_dsc->args[i].name);
                        os_free(tmp_met_dsc->args[i].type);
                }

                if (tmp_met_dsc->argument_free_func)
                        tmp_met_dsc->argument_free_func(
                                tmp_met_dsc->handler_argument);

                os_free(tmp_met_dsc);
        }

        /* free signals */
        signal_dsc = obj_dsc->signals;

        while (signal_dsc) {
                tmp_sig_dsc = signal_dsc;
                signal_dsc = signal_dsc->next;

                os_free(tmp_sig_dsc->dbus_interface);
                os_free(tmp_sig_dsc->dbus_signal);

                for (i = 0; i < tmp_sig_dsc->args_num; i++) {
                        os_free(tmp_sig_dsc->args[i].name);
                        os_free(tmp_sig_dsc->args[i].type);
                }

                os_free(tmp_sig_dsc);
        }

        /* free properties */
        property_dsc = obj_dsc->properties;

        while (property_dsc) {
                tmp_prop_dsc = property_dsc;
                property_dsc = property_dsc->next;

                os_free(tmp_prop_dsc->dbus_interface);
                os_free(tmp_prop_dsc->dbus_property);
                os_free(tmp_prop_dsc->type);

                if (tmp_prop_dsc->user_data_free_func)
                        tmp_prop_dsc->user_data_free_func(
                                tmp_prop_dsc->user_data);

                os_free(tmp_prop_dsc);
        }

        os_free(obj_dsc);
}


static void free_dbus_object_desc_cb(DBusConnection *connection, void *obj_dsc)
{
        free_dbus_object_desc(obj_dsc);
}

/**
 * wpa_dbus_ctrl_iface_init - Initialize dbus control interface
 * @application_data: Pointer to application specific data structure
 * @dbus_path: DBus path to interface object
 * @dbus_service: DBus service name to register with
 * @messageHandler: a pointer to function which will handle dbus messages
 * coming on interface
 * Returns: 0 on success, -1 on failure
 *
 * Initialize the dbus control interface and start receiving commands from
 * external programs over the bus.
 */
int wpa_dbus_ctrl_iface_init(struct wpas_dbus_priv *iface,
                             char *dbus_path, char *dbus_service,
                             struct wpa_dbus_object_desc *obj_desc)
{
        DBusError error;
        int ret = -1;
        DBusObjectPathVTable wpa_vtable = {
                &free_dbus_object_desc_cb, &message_handler,
                NULL, NULL, NULL, NULL
        };

        obj_desc->connection = iface->con;

        /* Register the message handler for the global dbus interface */
        if (!dbus_connection_register_object_path(iface->con,
                                                  dbus_path, &wpa_vtable,
                                                  obj_desc)) {
                perror("dbus_connection_register_object_path[dbus]");
                wpa_printf(MSG_ERROR, "Could not set up DBus message "
                           "handler.");
                return -1;
        }

        /* Register our service with the message bus */
        dbus_error_init(&error);
        switch (dbus_bus_request_name(iface->con, dbus_service,
                                      0, &error)) {
        case DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER:
                ret = 0;
                break;
        case DBUS_REQUEST_NAME_REPLY_EXISTS:
        case DBUS_REQUEST_NAME_REPLY_IN_QUEUE:
        case DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER:
                perror("dbus_bus_request_name[dbus]");
                wpa_printf(MSG_ERROR, "Could not request DBus service name: "
                           "already registered.");
                break;
        default:
                perror("dbus_bus_request_name[dbus]");
                wpa_printf(MSG_ERROR, "Could not request DBus service name: "
                           "%s %s.", error.name, error.message);
                break;
        }
        dbus_error_free(&error);

        if (ret != 0)
                return -1;

        wpa_printf(MSG_DEBUG, "Providing DBus service '%s'.", dbus_service);

        return 0;
}


/**
 * wpa_dbus_register_object_per_iface - Register a new object with dbus
 * @ctrl_iface: pointer to dbus private data
 * @path: DBus path to object
 * @ifname: interface name
 * @obj_desc: description of object's methods, signals and properties
 * Returns: 0 on success, -1 on error
 *
 * Registers a new interface with dbus and assigns it a dbus object path.
 */
int wpa_dbus_register_object_per_iface(
        struct wpas_dbus_priv *ctrl_iface,
        const char *path, const char *ifname,
        struct wpa_dbus_object_desc *obj_desc)
{
        DBusConnection *con;

        DBusObjectPathVTable vtable = {
                &free_dbus_object_desc_cb, &message_handler,
                NULL, NULL, NULL, NULL
        };

        /* Do nothing if the control interface is not turned on */
        if (ctrl_iface == NULL)
                return 0;

        con = ctrl_iface->con;
        obj_desc->connection = con;

        /* Register the message handler for the interface functions */
        if (!dbus_connection_register_object_path(con, path, &vtable,
                                                  obj_desc)) {
                perror("wpa_dbus_register_iface [dbus]");
                wpa_printf(MSG_ERROR, "Could not set up DBus message "
                           "handler for interface %s\n"
                           "and object %s.", ifname, path);
                return -1;
        }

        return 0;
}


/**
 * wpa_dbus_unregister_object_per_iface - Unregisters DBus object
 * @ctrl_iface: Pointer to dbus private data
 * @path: DBus path to object which will be unregistered
 * Returns: Zero on success and -1 on failure
 *
 * Unregisters DBus object given by its path
 */
int wpa_dbus_unregister_object_per_iface(
        struct wpas_dbus_priv *ctrl_iface, const char *path)
{
        DBusConnection *con = ctrl_iface->con;
        if (!dbus_connection_unregister_object_path(con, path))
                return -1;

        return 0;
}


/**
 * wpa_dbus_method_register - Registers DBus method for given object
 * @obj_dsc: Object description for which a method will be registered
 * @dbus_interface: DBus interface under which method will be registered
 * @dbus_method: a name the method will be registered with
 * @method_handler: a function which will be called to handle this method call
 * @handler_argument: an additional argument passed to handler function
 * @argument_free_func: function used to free handler argument
 * @args: method arguments list
 * Returns: Zero on success and -1 on failure
 *
 * Registers DBus method under given name and interface for the object.
 * Method calls will be handled with given handling function and optional
 * argument passed to this function. Handler function is required to return
 * a DBusMessage pointer which will be response to method call. Any method
 * call before being handled must have registered appropriate handler by
 * using this function.
 */
int wpa_dbus_method_register(struct wpa_dbus_object_desc *obj_dsc,
                             const char *dbus_interface,
                             const char *dbus_method,
                             WPADBusMethodHandler method_handler,
                             void *handler_argument,
                             WPADBusArgumentFreeFunction argument_free_func,
                             const struct wpa_dbus_argument args[])
{
        struct wpa_dbus_method_desc *method_dsc = obj_dsc->methods;
        struct wpa_dbus_method_desc *prev_desc;
        int args_num = 0;
        int interface_len, method_len, i, len, error;

        prev_desc = NULL;
        while (method_dsc) {
                prev_desc = method_dsc;
                method_dsc = method_dsc->next;
        }

        /* count args */
        if (args) {
                while (args[args_num].name && args[args_num].type)
                        args_num++;
        }

        method_dsc = os_zalloc(sizeof(struct wpa_dbus_method_desc) +
                               args_num * sizeof(struct wpa_dbus_argument));
        if (!method_dsc)
                goto err;

        if (prev_desc == NULL)
                obj_dsc->methods = method_dsc;
        else
                prev_desc->next = method_dsc;

        /* copy interface name */
        interface_len = os_strlen(dbus_interface) + 1;
        method_dsc->dbus_interface = os_malloc(interface_len);
        if (!method_dsc->dbus_interface)
                goto err;
        os_strncpy(method_dsc->dbus_interface, dbus_interface, interface_len);

        /* copy method name */
        method_len = os_strlen(dbus_method) + 1;
        method_dsc->dbus_method = os_malloc(method_len);
        if (!method_dsc->dbus_method)
                goto err;
        os_strncpy(method_dsc->dbus_method, dbus_method, method_len);

        /* copy arguments */
        error = 0;
        method_dsc->args_num = args_num;
        for (i = 0; i < args_num; i++) {
                len = os_strlen(args[i].name) + 1;
                method_dsc->args[i].name = os_malloc(len);
                if (!method_dsc->args[i].name) {
                        error = 1;
                        continue;
                }
                os_strncpy(method_dsc->args[i].name, args[i].name, len);

                len = os_strlen(args[i].type) + 1;
                method_dsc->args[i].type = os_malloc(len);
                if (!method_dsc->args[i].type) {
                        error = 1;
                        continue;
                }
                os_strncpy(method_dsc->args[i].type, args[i].type, len);

                method_dsc->args[i].dir = args[i].dir;
        }
        if (error)
                goto err;

        method_dsc->method_handler = method_handler;
        method_dsc->handler_argument = handler_argument;
        method_dsc->argument_free_func = argument_free_func;
        method_dsc->next = NULL;

        return 0;

err:
        wpa_printf(MSG_WARNING, "Failed to register dbus method %s in "
                   "interface %s", dbus_method, dbus_interface);
        if (method_dsc) {
                os_free(method_dsc->dbus_interface);
                os_free(method_dsc->dbus_method);
                for (i = 0; i < method_dsc->args_num; i++) {
                        os_free(method_dsc->args[i].name);
                        os_free(method_dsc->args[i].type);
                }

                if (prev_desc == NULL)
                        obj_dsc->methods = NULL;
                else
                        prev_desc->next = NULL;

                os_free(method_dsc);
        }

        return -1;
}


/**
 * wpa_dbus_signal_register - Registers DBus signal for given object
 * @obj_dsc: Object description for which a signal will be registered
 * @dbus_interface: DBus interface under which signal will be registered
 * @dbus_signal: a name the signal will be registered with
 * @args: signal arguments list
 * Returns: Zero on success and -1 on failure
 *
 * Registers DBus signal under given name and interface for the object.
 * Signal registration is NOT required in order to send signals, but not
 * registered signals will not be respected in introspection data
 * therefore it is highly recommended to register every signal before
 * using it.
 */
int wpa_dbus_signal_register(struct wpa_dbus_object_desc *obj_dsc,
                             const char *dbus_interface,
                             const char *dbus_signal,
                             const struct wpa_dbus_argument args[])
{

        struct wpa_dbus_signal_desc *signal_dsc = obj_dsc->signals;
        struct wpa_dbus_signal_desc *prev_desc;
        int args_num = 0;
        int interface_len, signal_len, i, len, error = 0;

        prev_desc = NULL;
        while (signal_dsc) {
                prev_desc = signal_dsc;
                signal_dsc = signal_dsc->next;
        }

        /* count args */
        if (args) {
                while (args[args_num].name && args[args_num].type)
                        args_num++;
        }

        signal_dsc = os_zalloc(sizeof(struct wpa_dbus_signal_desc) +
                               args_num * sizeof(struct wpa_dbus_argument));
        if (!signal_dsc)
                goto err;

        if (prev_desc == NULL)
                obj_dsc->signals = signal_dsc;
        else
                prev_desc->next = signal_dsc;

        /* copy interface name */
        interface_len = strlen(dbus_interface) + 1;
        signal_dsc->dbus_interface = os_malloc(interface_len);
        if (!signal_dsc->dbus_interface)
                goto err;
        os_strncpy(signal_dsc->dbus_interface, dbus_interface, interface_len);

        /* copy signal name */
        signal_len = strlen(dbus_signal) + 1;
        signal_dsc->dbus_signal = os_malloc(signal_len);
        if (!signal_dsc->dbus_signal)
                goto err;
        os_strncpy(signal_dsc->dbus_signal, dbus_signal, signal_len);

        /* copy arguments */
        signal_dsc->args_num = args_num;
        for (i = 0; i < args_num; i++) {
                len = os_strlen(args[i].name) + 1;
                signal_dsc->args[i].name = os_malloc(len);
                if (!signal_dsc->args[i].name) {
                        error = 1;
                        continue;
                }
                os_strncpy(signal_dsc->args[i].name, args[i].name, len);

                len = strlen(args[i].type) + 1;
                signal_dsc->args[i].type = os_malloc(len);
                if (!signal_dsc->args[i].type) {
                        error = 1;
                        continue;
                }
                os_strncpy(signal_dsc->args[i].type, args[i].type, len);
        }
        if (error)
                goto err;

        signal_dsc->next = NULL;

        return 0;

err:
        wpa_printf(MSG_WARNING, "Failed to register dbus signal %s in "
                   "interface %s", dbus_signal, dbus_interface);
        if (signal_dsc) {
                os_free(signal_dsc->dbus_interface);
                os_free(signal_dsc->dbus_signal);
                for (i = 0; i < signal_dsc->args_num; i++) {
                        os_free(signal_dsc->args[i].name);
                        os_free(signal_dsc->args[i].type);
                }

                if (prev_desc == NULL)
                        obj_dsc->signals = NULL;
                else
                        prev_desc->next = NULL;

                os_free(signal_dsc);
        }

        return -1;
}


/**
 * wpa_dbus_property_register - Registers DBus property for given object
 * @obj_dsc: Object description for which a property will be registered
 * @dbus_interface: DBus interface under which method will be registered
 * @dbus_property: a name the property will be registered with
 * @type: a property type signature in form of DBus type description
 * @getter: a function called in order to get property value
 * @setter: a function called in order to set property value
 * @user_data: additional argument passed to setter or getter
 * @user_data_free_func: function used to free additional argument
 * @access: property access permissions specifier (R, W or RW)
 * Returns: Zero on success and -1 on failure
 *
 * Registers DBus property under given name and interface for the object.
 * Property are set with giver setter function and get with getter.
 * Additional argument is passed to getter or setter. Getter or setter
 * are required to return DBusMessage which is response to Set/Get method
 * calls. Every property must be registered by this function before being
 * used.
 */
int wpa_dbus_property_register(struct wpa_dbus_object_desc *obj_dsc,
                               const char *dbus_interface,
                               const char *dbus_property,
                               const char *type,
                               WPADBusPropertyAccessor getter,
                               WPADBusPropertyAccessor setter,
                               void *user_data,
                               WPADBusArgumentFreeFunction user_data_free_func,
                               enum dbus_prop_access _access)
{
        struct wpa_dbus_property_desc *property_dsc = obj_dsc->properties;
        struct wpa_dbus_property_desc *prev_desc;
        int interface_len, property_len, type_len;

        prev_desc = NULL;
        while (property_dsc) {
                prev_desc = property_dsc;
                property_dsc = property_dsc->next;
        }

        property_dsc = os_zalloc(sizeof(struct wpa_dbus_property_desc));
        if (!property_dsc)
                goto err;

        if (prev_desc == NULL)
                obj_dsc->properties = property_dsc;
        else
                prev_desc->next = property_dsc;

        /* copy interface name */
        interface_len = os_strlen(dbus_interface) + 1;
        property_dsc->dbus_interface = os_malloc(interface_len);
        if (!property_dsc->dbus_interface)
                goto err;
        os_strncpy(property_dsc->dbus_interface, dbus_interface,
                   interface_len);

        /* copy property name */
        property_len = os_strlen(dbus_property) + 1;
        property_dsc->dbus_property = os_malloc(property_len);
        if (!property_dsc->dbus_property)
                goto err;
        os_strncpy(property_dsc->dbus_property, dbus_property, property_len);

        /* copy property type */
        type_len = os_strlen(type) + 1;
        property_dsc->type = os_malloc(type_len);
        if (!property_dsc->type)
                goto err;
        os_strncpy(property_dsc->type, type, type_len);

        property_dsc->getter = getter;
        property_dsc->setter = setter;
        property_dsc->user_data = user_data;
        property_dsc->user_data_free_func = user_data_free_func;
        property_dsc->access = _access;
        property_dsc->next = NULL;

        return 0;

err:
        wpa_printf(MSG_WARNING, "Failed to register dbus property %s in "
                   "interface %s", dbus_property, dbus_interface);
        if (property_dsc) {
                os_free(property_dsc->dbus_interface);
                os_free(property_dsc->dbus_property);
                os_free(property_dsc->type);

                if (prev_desc == NULL)
                        obj_dsc->properties = NULL;
                else
                        prev_desc->next = NULL;

                os_free(property_dsc);
        }

        return -1;
}


/**
 * wpas_dbus_signal_network_added - Send a property changed signal
 * @iface: dbus priv struct
 * @property_getter: propperty getter used to fetch new property value
 * @getter_arg: argument passed to property getter
 * @path: path to object which property has changed
 * @interface_name: signal and property interface
 * @property_name: name of property which has changed
 *
 * Notify listeners about changing value of some property. Signal
 * contains property name and its value fetched using given property
 * getter.
 */
void wpa_dbus_signal_property_changed(struct wpas_dbus_priv *iface,
                                      WPADBusPropertyAccessor property_getter,
                                      void *getter_arg,
                                      const char *path,
                                      const char *interface_name,
                                      const char *property_name)
{

        DBusConnection *connection;
        DBusMessage *_signal, *getter_reply;
        DBusMessageIter prop_iter, signal_iter, dict_iter, entry_iter;

        if (!iface)
                return;
        connection = iface->con;

        if (!property_getter) {
                wpa_printf(MSG_ERROR, "wpa_dbus_signal_property_changed"
                           "[dbus]: property getter not specified");
                return;
        }

        if (!path || !interface_name || !property_name) {
                wpa_printf(MSG_ERROR, "wpa_dbus_signal_property_changed"
                           "[dbus]: path interface of property not specified");
                return;
        }

        getter_reply = property_getter(NULL, getter_arg);
        if (!getter_reply ||
            dbus_message_get_type(getter_reply) == DBUS_MESSAGE_TYPE_ERROR) {
                wpa_printf(MSG_ERROR, "wpa_dbus_signal_property_changed"
                           "[dbus]: cannot get new value of property %s",
                           property_name);
                return;
        }

        _signal = dbus_message_new_signal(path, interface_name,
                                          "PropertiesChanged");
        if (!_signal) {
                wpa_printf(MSG_ERROR, "wpa_dbus_signal_property_changed"
                           "[dbus]: cannot allocate signal");
                dbus_message_unref(getter_reply);
                return;
        }

        dbus_message_iter_init(getter_reply, &prop_iter);
        dbus_message_iter_init_append(_signal, &signal_iter);

        if (!dbus_message_iter_open_container(&signal_iter, DBUS_TYPE_ARRAY,
                                              "{sv}", &dict_iter)) {
                wpa_printf(MSG_ERROR, "wpa_dbus_signal_property_changed"
                           "[dbus]: out of memory. cannot open dictionary");
                goto err;
        }

        if (!dbus_message_iter_open_container(&dict_iter, DBUS_TYPE_DICT_ENTRY,
                                              NULL, &entry_iter)) {
                wpa_printf(MSG_ERROR, "iwpa_dbus_signal_property_changed"
                           "[dbus]: out of memory. cannot open dictionary "
                           "element");
                goto err;
        }

        if (!dbus_message_iter_append_basic(&entry_iter, DBUS_TYPE_STRING,
                                            &property_name)) {
                wpa_printf(MSG_ERROR, "wpa_dbus_signal_property_changed"
                           "[dbus]: out of memory. cannot open add property "
                           "name");
                goto err;
        }

        recursive_iter_copy(&prop_iter, &entry_iter);

        if (!dbus_message_iter_close_container(&dict_iter, &entry_iter)) {
                wpa_printf(MSG_ERROR, "wpa_dbus_signal_property_changed"
                           "[dbus]: out of memory. cannot close dictionary "
                           "element");
                goto err;
        }

        if (!dbus_message_iter_close_container(&signal_iter, &dict_iter)) {
                wpa_printf(MSG_ERROR, "wpa_dbus_signal_property_changed"
                           "[dbus]: out of memory. cannot close dictionary");
                goto err;
        }

        dbus_connection_send(connection, _signal, NULL);

err:
        dbus_message_unref(getter_reply);
        dbus_message_unref(_signal);

}