How to create Dict of {String, Variant} for D-Bus method?

Question

I'm trying to call D-Bus method, but don't understand how to add needed args.

• Method name: CreateSession (String destination, Dict of {String, Variant} args) ↦ (Object Path session)
• Bus Name: org.bluez.obex
• Object Path: /org/bluez/obex
• Interface: org.bluez.obex.Client1

I successfully can call this method in D-Feet app with this arguments:

"D0:9C:7A:A1:A4:63",{'Target':GLib.Variant('s','OPP')}

But how make the same using only dbus.h?

Here's my code:

// Do before compile sudo apt-get install -y libdbus-1-dev
// gcc -o test -Wall test.c `pkg-config --cflags dbus-1` `pkg-config --libs dbus-1`
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dbus/dbus.h>
 
int main() {
    DBusConnection *sesBusCon;
    DBusError error;
    DBusMessage *call;
    DBusMessage *reply;

    dbus_error_init(&error);
    if (dbus_error_is_set(&error)) {
        fprintf(stderr, "%s", error.message);
        return 1;
    }
    
    sesBusCon = dbus_bus_get(DBUS_BUS_SESSION, &error);
    if (dbus_error_is_set(&error)) {
        fprintf(stderr, "%s", error.message);
        return 1;
    }
    
    call = dbus_message_new_method_call("org.bluez.obex", "/org/bluez/obex", "org.bluez.obex.Client1", "CreateSession");     
    
    reply = dbus_connection_send_with_reply_and_block (sesBusCon, call, 100000, &error);
    if (dbus_error_is_set(&error)) {
        fprintf(stderr, "%s", error.message);
        return 1;
    }
    
    return 0;
}

Answer 1

Maybe it helps someone:

// Do before compile sudo apt-get install -y libdbus-1-dev
// gcc -o test -Wall test.c `pkg-config --cflags dbus-1` `pkg-config --libs dbus-1`
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dbus/dbus.h>
 
int main() {
    DBusConnection *sesBusCon;
    DBusError error;
    DBusMessage *call;
    DBusMessage *reply;
    DBusMessageIter iterInit, iterDict, iterEntry, iterValue;

    dbus_error_init(&error);
    if (dbus_error_is_set(&error)) {
        fprintf(stderr, "%s", error.message);
        return 1;
    }
    
    sesBusCon = dbus_bus_get(DBUS_BUS_SESSION, &error);
    if (dbus_error_is_set(&error)) {
        fprintf(stderr, "%s", error.message);
        return 1;
    }
    
    call = dbus_message_new_method_call("org.bluez.obex", "/org/bluez/obex", "org.bluez.obex.Client1", "CreateSession");

    char *destination = "D0:9C:7A:A1:A4:63";
    dbus_message_append_args(call, DBUS_TYPE_STRING, &destination, DBUS_TYPE_INVALID);
    
    dbus_message_iter_init_append(call, &iterInit);
    dbus_message_iter_open_container(&iterInit, 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, &iterDict);
    
        dbus_message_iter_open_container(&iterDict, DBUS_TYPE_DICT_ENTRY, NULL, &iterEntry);
        char *key = "Target";
        dbus_message_iter_append_basic(&iterEntry, DBUS_TYPE_STRING, &key);
        dbus_message_iter_open_container(&iterEntry, DBUS_TYPE_VARIANT, DBUS_TYPE_STRING_AS_STRING, &iterValue);
        void *val = "OPP";
        dbus_message_iter_append_basic(&iterValue, DBUS_TYPE_STRING, &val);
        dbus_message_iter_close_container(&iterEntry, &iterValue);
        dbus_message_iter_close_container(&iterDict, &iterEntry);
    
    dbus_message_iter_close_container(&iterInit, &iterDict);
    
    DBusPendingCall* replyPending;
    DBusMessage* replyMessage;
    DBusMessageIter replyIter;
    
    dbus_connection_send_with_reply(sesBusCon, call, &replyPending, -1);
    dbus_pending_call_block(replyPending);
    
    if (dbus_pending_call_get_completed (replyPending))
    {
        replyMessage = dbus_pending_call_steal_reply(replyPending);
        dbus_message_iter_init(replyMessage, &replyIter);
        char *objectPath;
        dbus_message_iter_get_basic(&replyIter, &objectPath);
        printf("object path %s \n",objectPath);
    }
    
    
    return 0;
}