RPC Ubus Session ID

When calling a ubus function via the package uhttpd-mod-ubus I will always get a result 2 / invalid argument.

The problem is that the rpc call will unconditionally sent the ubus session ID to verify the authorization. Looking at ubus -v monitor I get:

-> c15a547b #751d66fa         invoke: {"objid":-1920601747,"method":"access","data":{"ubus_rpc_session":"xxxx","object":"avarangedcd","function":"test"},"user":"root","group":"root"

My function is :

        ubus.add("avarangedcd", {
            "test": {"method": self.callback_test, "signature": {} }
        })

And my remote call conatains of:

URL: /ubus
POST DATA: {'jsonrpc': '2.0', 'id': 1, 'method': 'call', 'params': ['xxxx', 'avarangedcd', 'test', {}]}
RESPONSE: 200 {'jsonrpc': '2.0', 'id': 1, 'result': [2]}

As a workaround I change my function to:

            ubus.add("avarangedcd", {
                "test": {"method": self.callback_test, "signature": {"ubus_rpc_session": ubus.BLOBMSG
_TYPE_STRING}}
            })

The correct solution would be here to make an exception for ubus_rpc_session: https://gitlab.nic.cz/turris/python-ubus/-/blob/master/ubus_python.c#L789

E.g. something like this:

    blob_for_each_attr(cur, args, idx) {
		const char *name = blobmsg_name(cur);
		int type = blobmsg_type(cur);
		int pol_idx;

		// Skip comparision if RPC session ID is given
                if (!strcmp("ubus_rpc_session", name)) {
                    continue;
                }

		// Iterate through policies
		for (pol_idx = 0; pol_idx < n_policies; pol_idx++) {
                        // Skip ubus_rpc_session

			if (!strcmp(name, policies[pol_idx].name)) {
				passed_count += 1;
				int pol_type = policies[pol_idx].type;
				if (pol_type != BLOBMSG_TYPE_UNSPEC && pol_type != type) {
					return false;
				}
				break;
			}
		}

``