[apps/low-level-can-service.git] / CAN-binder / low-can-binding / low-can-binding.cpp

/*
 * Copyright (C) 2015, 2016 "IoT.bzh"
 * Author "Romain Forlot" <romain.forlot@iot.bzh>
 * Author "Loic Collignon" <loic.collignon@iot.bzh>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "low-can-binding.hpp"

#include <map>
#include <queue>
#include <mutex>
#include <vector>
#include <thread>
#include <time.h>
#include <linux/can.h>
#include <json-c/json.h>

#include "openxc.pb.h"
#include "configuration.hpp"
#include "can/can-bus.hpp"
#include "can/can-signals.hpp"
#include "can/can-message.hpp"
#include "utils/timer.hpp"
#include "utils/signals.hpp"
#include "diagnostic/diagnostic-message.hpp"
#include "utils/openxc-utils.hpp"

extern "C"
{
        #include <afb/afb-service-itf.h>
};

// Interface between the daemon and the binding
const struct afb_binding_interface *binder_interface;

void on_no_clients(std::string message)
{
        DiagnosticRequest* diag_req = configuration_t::instance().get_request_from_diagnostic_message(message);
        if(diag_req != nullptr)
        {
                active_diagnostic_request_t* adr = configuration_t::instance().get_diagnostic_manager().find_recurring_request(diag_req);
                if( adr != nullptr)
                        configuration_t::instance().get_diagnostic_manager().cleanup_request(adr, true);
        }
}

///******************************************************************************
///
///             Subscription and unsubscription
///
///*******************************************************************************/

static int make_subscription_unsubscription(struct afb_req request, const std::string& sig_name, std::map<std::string, struct afb_event>& s, bool subscribe)
{
        /* Make the subscription or unsubscription to the event */
        if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, s[sig_name])) < 0)
        {
                ERROR(binder_interface, "%s: Operation goes wrong for signal: %s", __FUNCTION__, sig_name.c_str());
                return 0;
        }
        return 1;
}

static int create_event_handle(const std::string& sig_name, std::map<std::string, struct afb_event>& s)
{
        s[sig_name] = afb_daemon_make_event(binder_interface->daemon, sig_name.c_str());
        if (!afb_event_is_valid(s[sig_name]))
        {
                ERROR(binder_interface, "%s: Can't create an event for %s, something goes wrong.", __FUNCTION__, sig_name.c_str());
                return 0;
        }
        return 1;
}

/// @brief Will determine if it is needed or not to create the event handle and checks it to be sure that
/// we got a valid afb_event to get subscribe or unsubscribe. Then launch the subscription or unsubscription
/// against the application framework using that event handle.
static int subscribe_unsubscribe_signal(struct afb_req request, bool subscribe, const std::string& sig)
{
        int ret;

        utils::signals_manager_t& sm = utils::signals_manager_t::instance();

        std::lock_guard<std::mutex> subscribed_signals_lock(sm.get_subscribed_signals_mutex());
        std::map<std::string, struct afb_event>& s = sm.get_subscribed_signals();
        if (s.find(sig) != s.end())
        {
                if (!afb_event_is_valid(s[sig]) && !subscribe)
                {
                        NOTICE(binder_interface, "%s: Event isn't valid, no need to unsubscribed.", __FUNCTION__);
                        ret = -1;
                }
                else
                {
                        // Event it isn't valid annymore, recreate it
                        ret = create_event_handle(sig, s);
                }
        }
        else
        {
                /* Event doesn't exist , so let's create it */
                struct afb_event empty_event = {nullptr, nullptr};
                s[sig] = empty_event;
                ret = create_event_handle(sig, s);
        }

        // Check whether or not the event handler has been correctly created and
        // make the subscription/unsubscription operation is so.
        if (ret <= 0)
                return ret;
        return make_subscription_unsubscription(request, sig, s, subscribe);
}

///
/// @brief subscribe to all signals in the vector signals
///
/// @param[in] afb_req request : contain original request use to subscribe or unsubscribe
/// @param[in] subscribe boolean value used to chose between a subscription operation or an unsubscription
/// @param[in] signals -  struct containing vectors with can_signal_t and diagnostic_messages to subscribe
///
/// @return Number of correctly subscribed signal
///
static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const struct utils::signals_found& signals)
{
        int ret,  rets = 0;

        //TODO: Implement way to dynamically call the right function no matter
        // how much signals types we have.
        configuration_t& conf = configuration_t::instance();

        for(const auto& sig : signals.diagnostic_messages)
        {
                DiagnosticRequest* diag_req = conf.get_request_from_diagnostic_message(sig->get_name());

                // If the requested diagnostic message isn't supported by the car then unsubcribe it
                // no matter what we want, worse case will be a fail unsubscription but at least we don't
                // poll a PID for nothing.
                if(sig->get_supported() && subscribe)
                {
                                float frequency = sig->get_frequency();
                                subscribe = conf.get_diagnostic_manager().add_recurring_request(
                                        diag_req, sig->get_name().c_str(), false, sig->get_decoder(), sig->get_callback(), (float)frequency);
                                        //TODO: Adding callback requesting ignition status:     diag_req, sig.c_str(), false, diagnostic_message_t::decode_obd2_response, diagnostic_message_t::check_ignition_status, frequency);
                }
                else
                {
                        conf.get_diagnostic_manager().cleanup_request(
                                conf.get_diagnostic_manager().find_recurring_request(diag_req), true);
                        WARNING(binder_interface, "%s: signal: %s isn't supported. Canceling operation.", __FUNCTION__, sig->get_name().c_str());
                        return -1;
                }

                ret = subscribe_unsubscribe_signal(request, subscribe, sig->get_name());
                if(ret <= 0)
                        return ret;
                rets++;
                DEBUG(binder_interface, "%s: Signal: %s subscribed", __FUNCTION__, sig->get_name().c_str());
        }

        for(const auto& sig: signals.can_signals)
        {
                ret = subscribe_unsubscribe_signal(request, subscribe, sig->get_name());
                if(ret <= 0)
                        return ret;
                rets++;
                DEBUG(binder_interface, "%s: signal: %s subscribed", __FUNCTION__, sig->get_name().c_str());
        }
        return rets;
}

static const std::vector<std::string> parse_signals_from_request(struct afb_req request, bool subscribe)
{
        int i, n;
        std::vector<std::string> ret;
        struct json_object *args, *a, *x;

        /* retrieve signals to subscribe */
        args = afb_req_json(request);
        if (args == NULL || !json_object_object_get_ex(args, "event", &a))
        {
                ret.push_back("*");
        }
        else if (json_object_get_type(a) != json_type_array)
        {
                ret.push_back(json_object_get_string(a));
        }
        else
        {
                n = json_object_array_length(a);
                for (i = 0 ; i < n ; i++)
                {
                        x = json_object_array_get_idx(a, i);
                        ret.push_back(json_object_get_string(x));
                }
        }

        return ret;
}

extern "C"
{
        static void subscribe(struct afb_req request)
        {
                std::vector<std::string> signals;
                struct utils::signals_found sf;
                int ok = 0, total = 0;

                signals = parse_signals_from_request(request, true);

                for(const auto& sig: signals)
                {
                        openxc_DynamicField search_key = build_DynamicField(sig);
                        sf = utils::signals_manager_t::instance().find_signals(search_key);
                        total = (int)sf.can_signals.size() + (int)sf.diagnostic_messages.size();

                        if (sf.can_signals.empty() && sf.diagnostic_messages.empty())
                                NOTICE(binder_interface, "%s: No signal(s) found for %s.", __FUNCTION__, sig.c_str());
                        else
                                ok = subscribe_unsubscribe_signals(request, subscribe, sf);
                }

                NOTICE(binder_interface, "%s: Subscribed/unsubscribe correctly to %d/%d signal(s).", __FUNCTION__, ok, total);
                if (ok)
                        afb_req_success(request, NULL, NULL);
                else
                        afb_req_fail(request, "error", NULL);
        }

        static void unsubscribe(struct afb_req request)
        {
                parse_signals_from_request(request, false);
        }

        static const struct afb_verb_desc_v1 verbs[]=
        {
                { .name= "subscribe",   .session= AFB_SESSION_NONE, .callback= subscribe,       .info= "subscribe to notification of CAN bus messages." },
                { .name= "unsubscribe", .session= AFB_SESSION_NONE, .callback= unsubscribe,     .info= "unsubscribe a previous subscription." }
        };

        static const struct afb_binding binding_desc {
                AFB_BINDING_VERSION_1,
                {
                        "Low level CAN bus service",
                        "low-can",
                        verbs
                }
        };

        const struct afb_binding *afbBindingV1Register (const struct afb_binding_interface *itf)
        {
                binder_interface = itf;

                return &binding_desc;
        }

        /// @brief Initialize the binding.
        ///
        /// @param[in] service Structure which represent the Application Framework Binder.
        ///
        /// @return Exit code, zero if success.
        int afbBindingV1ServiceInit(struct afb_service service)
        {
                can_bus_t& can_bus_manager = configuration_t::instance().get_can_bus_manager();

                /// Initialize CAN socket
                if(can_bus_manager.init_can_dev() == 0)
                {
                        can_bus_manager.start_threads();

                        /// Initialize Diagnostic manager that will handle obd2 requests.
                        /// We pass by default the first CAN bus device to its Initialization.
                        /// TODO: be able to choose the CAN bus device that will be use as Diagnostic bus.
                        if(configuration_t::instance().get_diagnostic_manager().initialize())
                                return 0;
                }

                ERROR(binder_interface, "%s: There was something wrong with CAN device Initialization. Check your config file maybe", __FUNCTION__);
                return 1;
        }
};