Reworked subscription to integrate filtering.

- Creation of an object which old the subscription context
(filter, signal) : low_can_subscription_t
- Move socket from can_signal_t to this new object.
- Adding a member to can_message_t to transport subscription_id to be able to
retrieve it with all the context through running.

Change-Id: I87be8cd6c3c93a81040357920d8c081a316800c3
Signed-off-by: Romain Forlot <romain.forlot@iot.bzh>

4 files changed, 346 insertions, 74 deletions

diff --git a/CAN-binder/low-can-binding/binding/low-can-cb.cpp b/CAN-binder/low-can-binding/binding/low-can-cb.cpp
index 8141c3d3..e34ceaa3 100644
--- a/CAN-binder/low-can-binding/binding/low-can-cb.cpp
+++ b/CAN-binder/low-can-binding/binding/low-can-cb.cpp
@@ -35,20 +35,214 @@
 #include "../utils/signals.hpp"
 #include "../diagnostic/diagnostic-message.hpp"
 #include "../utils/openxc-utils.hpp"
+#include "canutil/write.h"
 
 extern "C"
 {
 	#include <afb/afb-service-itf.h>
 };
 
-void on_no_clients(std::string message)
+///******************************************************************************
+///
+///	low_can_subscription_t object
+///
+///*******************************************************************************/
+
+low_can_subscription_t::low_can_subscription_t()
+	: index_{-1},
+	sig_name_{},
+	bus_name_{""},
+	can_id_{0},
+	bit_position_{0},
+	bit_size_{0},
+	factor_{-1.0},
+	offset_{-1},
+	socket_{}
+{}
+
+low_can_subscription_t::low_can_subscription_t(struct event_filter_t event_filter)
+	: event_filter_{event_filter}
+{}
+
+low_can_subscription_t::low_can_subscription_t( low_can_subscription_t&& s)
+	: index_{s.index_},
+	sig_name_{s.sig_name_},
+	bus_name_{s.bus_name_},
+	can_id_{s.can_id_},
+	bit_position_{s.bit_position_},
+	bit_size_{s.bit_size_},
+	factor_{s.factor_},
+	offset_{s.offset_},
+	event_filter_{s.event_filter_},
+	socket_{std::move(s.socket_)}
+{}
+
+	low_can_subscription_t& low_can_subscription_t::operator=(const low_can_subscription_t& s)
+{
+	socket_ = std::move(s.socket_);
+	return *this;
+}
+
+low_can_subscription_t::operator bool() const
+{
+	return socket_.socket() != INVALID_SOCKET;
+}
+
+int low_can_subscription_t::get_index() const
+{
+	return index_;
+}
+
+const std::string low_can_subscription_t::get_sig_name() const
+{
+	return sig_name_;
+}
+
+float low_can_subscription_t::get_frequency() const
+{
+	return event_filter_.frequency;
+}
+
+float low_can_subscription_t::get_min() const
+{
+	return event_filter_.min;
+}
+
+float low_can_subscription_t::get_max() const
+{
+	return event_filter_.max;
+}
+
+utils::socketcan_bcm_t& low_can_subscription_t::get_socket()
+{
+	return socket_;
+}
+
+void low_can_subscription_t::set_frequency(float freq)
 {
-	DiagnosticRequest* diag_req = configuration_t::instance().get_request_from_diagnostic_message(message);
+	event_filter_.frequency = freq;
+}
+
+void low_can_subscription_t::set_min(float min)
+{
+	event_filter_.min = min;
+}
+
+void low_can_subscription_t::set_max(float max)
+{
+	event_filter_.max = max;
+}
+
+/// @brief Create a RX_SETUP receive job used by the BCM socket.
+///
+/// @return 0 if ok else -1
+int low_can_subscription_t::create_rx_filter(const std::string& bus_name, const std::string& sig_name, uint32_t can_id, uint8_t bit_position, uint8_t bit_size, float factor, float offset)
+{
+	// Make sure that socket has been opened.
+	if(! socket_)
+	{
+		socket_.open(bus_name);
+		index_ = (int)socket_.socket();
+	}
+
+	sig_name_ = sig_name;
+	bus_name_ = bus_name;
+	can_id_ = can_id;
+	bit_position_ = bit_position;
+	bit_size_ = bit_size;
+	factor_ = factor;
+	offset_ = offset;
+
+	struct utils::simple_bcm_msg bcm_msg;
+	struct can_frame cfd;
+
+	memset(&cfd, 0, sizeof(cfd));
+	memset(&bcm_msg.msg_head, 0, sizeof(bcm_msg.msg_head));
+	float val = (float)(1 << bit_size_) - 1;
+
+	struct timeval freq;
+	frequency_clock_t f(event_filter_.frequency);
+	freq = f.get_timeval_from_period();
+
+	bcm_msg.msg_head.opcode  = RX_SETUP;
+	bcm_msg.msg_head.can_id  = can_id_;
+	bcm_msg.msg_head.flags = SETTIMER|RX_NO_AUTOTIMER;
+	bcm_msg.msg_head.ival2.tv_sec = freq.tv_sec ;
+	bcm_msg.msg_head.ival2.tv_usec = freq.tv_usec;
+	bcm_msg.msg_head.nframes = 1;
+	bitfield_encode_float(val,
+										bit_position_,
+										bit_size_,
+										factor_,
+										offset_,
+										cfd.data,
+										CAN_MAX_DLEN);
+
+	bcm_msg.frames = cfd;
+
+	if(socket_ << bcm_msg)
+		return 0;
+	return -1;
+}
+
+/// @brief Create a RX_SETUP receive job used by the BCM socket.
+///
+/// @return 0 if ok else -1
+int low_can_subscription_t::create_rx_filter()
+{
+	// Make sure that socket has been opened.
+	if(! socket_)
+	{
+		socket_.open(bus_name_);
+		index_ = (int)socket_.socket();
+	}
+
+	struct utils::simple_bcm_msg bcm_msg;
+	struct can_frame cfd;
+
+	memset(&cfd, 0, sizeof(cfd));
+	memset(&bcm_msg.msg_head, 0, sizeof(bcm_msg.msg_head));
+	float val = (float)(1 << bit_size_) - 1;
+
+	struct timeval freq;
+	frequency_clock_t f(event_filter_.frequency);
+	freq = f.get_timeval_from_period();
+
+	bcm_msg.msg_head.opcode  = RX_SETUP;
+	bcm_msg.msg_head.can_id  = can_id_;
+	bcm_msg.msg_head.flags = SETTIMER|RX_NO_AUTOTIMER;
+	bcm_msg.msg_head.ival2.tv_sec = freq.tv_sec ;
+	bcm_msg.msg_head.ival2.tv_usec = freq.tv_usec;
+	bcm_msg.msg_head.nframes = 1;
+	bitfield_encode_float(val,
+										bit_position_,
+										bit_size_,
+										factor_,
+										offset_,
+										cfd.data,
+										CAN_MAX_DLEN);
+
+	bcm_msg.frames = cfd;
+
+	if(socket_ << bcm_msg)
+		return 0;
+	return -1;
+}
+
+///******************************************************************************
+///
+///		SystemD event loop Callbacks
+///
+///*******************************************************************************/
+
+void on_no_clients(const std::string& message)
+{
+	DiagnosticRequest* diag_req = application_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);
+		active_diagnostic_request_t* adr = application_t::instance().get_diagnostic_manager().find_recurring_request(diag_req);
 		if( adr != nullptr)
-			configuration_t::instance().get_diagnostic_manager().cleanup_request(adr, true);
+			application_t::instance().get_diagnostic_manager().cleanup_request(adr, true);
 	}
 	delete diag_req;
 	diag_req = nullptr;
@@ -56,7 +250,7 @@ void on_no_clients(std::string message)
 
 static void push_n_notify(const can_message_t& cm)
 {
-	can_bus_t& cbm = configuration_t::instance().get_can_bus_manager();
+	can_bus_t& cbm = application_t::instance().get_can_bus_manager();
 	std::lock_guard<std::mutex> can_message_lock(cbm.get_can_message_mutex());
 	{ cbm.push_new_can_message(cm); }
 	cbm.get_new_can_message_cv().notify_one();
@@ -65,18 +259,18 @@ static void push_n_notify(const can_message_t& cm)
 int read_message(sd_event_source *s, int fd, uint32_t revents, void *userdata)
 {
 	can_message_t cm;
-	can_signal_t* sig;
-	diagnostic_manager_t& diag_m = configuration_t::instance().get_diagnostic_manager();
+	low_can_subscription_t* can_subscription;
+	diagnostic_manager_t& diag_m = application_t::instance().get_diagnostic_manager();
 
 	if(userdata != nullptr)
 	{
-		sig = (can_signal_t*)userdata;
-		utils::socketcan_bcm_t s = sig->get_socket();
+		can_subscription = (low_can_subscription_t*)userdata;
+		utils::socketcan_bcm_t& s = can_subscription->get_socket();
 		s >> cm;
 	}
 	else
 	{
-		utils::socketcan_bcm_t s = diag_m.get_socket();
+		utils::socketcan_bcm_t& s = diag_m.get_socket();
 		s >> cm;
 	}
 
@@ -88,9 +282,9 @@ int read_message(sd_event_source *s, int fd, uint32_t revents, void *userdata)
 		sd_event_source_unref(s);
 		if(userdata != nullptr)
 		{
-			sig->get_socket().close();
-			sig->create_rx_filter();
-			NOTICE(binder_interface, "%s: Recreated RX_SETUP BCM job for signal: %s", __FUNCTION__, sig->get_name().c_str());
+			can_subscription->get_socket().close();
+			can_subscription->create_rx_filter();
+			NOTICE(binder_interface, "%s: Recreated RX_SETUP BCM job for can_subscription: %s", __FUNCTION__, can_subscription->get_sig_name().c_str());
 		}
 		else
 		{
@@ -104,72 +298,73 @@ int read_message(sd_event_source *s, int fd, uint32_t revents, void *userdata)
 	return 0;
 }
 
-
 ///******************************************************************************
 ///
 ///		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)
+static int make_subscription_unsubscription(struct afb_req request, std::shared_ptr<low_can_subscription_t>& can_subscription, std::map<int, std::pair<std::shared_ptr<low_can_subscription_t>, 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)
+	if (((subscribe ? afb_req_subscribe : afb_req_unsubscribe)(request, s[can_subscription->get_index()].second)) < 0)
 	{
-		ERROR(binder_interface, "%s: Operation goes wrong for signal: %s", __FUNCTION__, sig_name.c_str());
-		return 0;
+		ERROR(binder_interface, "%s: Operation goes wrong for signal: %s", __FUNCTION__, can_subscription->get_sig_name().c_str());
+		return -1;
 	}
-	return 1;
+	return 0;
 }
 
-static int create_event_handle(const std::string& sig_name, std::map<std::string, struct afb_event>& s)
+static int create_event_handle(std::shared_ptr<low_can_subscription_t>& can_subscription, std::map<int, std::pair<std::shared_ptr<low_can_subscription_t>, 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]))
+	int sub_index = can_subscription->get_index();
+	struct afb_event event = afb_daemon_make_event(binder_interface->daemon, can_subscription->get_sig_name().c_str());
+	s[sub_index] = std::make_pair(can_subscription, event);
+	if (!afb_event_is_valid(s[sub_index].second))
 	{
-		ERROR(binder_interface, "%s: Can't create an event for %s, something goes wrong.", __FUNCTION__, sig_name.c_str());
-		return 0;
+		ERROR(binder_interface, "%s: Can't create an event for %s, something goes wrong.", __FUNCTION__, can_subscription->get_sig_name().c_str());
+		return -1;
 	}
-	return 1;
+	return 0;
 }
 
 /// @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)
+static int subscribe_unsubscribe_signal(struct afb_req request, bool subscribe, std::shared_ptr<low_can_subscription_t>& can_subscription)
 {
 	int ret;
-
+	int sub_index = can_subscription->get_index();
 	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())
+	std::map<int, std::pair<std::shared_ptr<low_can_subscription_t>, struct afb_event> >& s = sm.get_subscribed_signals();
+	if (can_subscription && s.find(sub_index) != s.end())
 	{
-		if (!afb_event_is_valid(s[sig]) && !subscribe)
+		if (!afb_event_is_valid(s[sub_index].second) && !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);
+			// Event it isn't valid anymore, recreate it
+			ret = create_event_handle(can_subscription, 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);
+		s[sub_index] = std::make_pair(can_subscription, empty_event);
+		ret = create_event_handle(can_subscription, s);
 	}
 
 	// Check whether or not the event handler has been correctly created and
 	// make the subscription/unsubscription operation is so.
-	if (ret <= 0)
+	if (ret < 0)
 		return ret;
-	return make_subscription_unsubscription(request, sig, s, subscribe);
+	return make_subscription_unsubscription(request, can_subscription, s, subscribe);
 }
 
 ///
@@ -181,7 +376,7 @@ static int subscribe_unsubscribe_signal(struct afb_req request, bool subscribe,
 ///
 /// @return Number of correctly subscribed signal
 ///
-static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const struct utils::signals_found& signals)
+static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe, const struct utils::signals_found& signals, struct event_filter_t& event_filter)
 {
 	int rets = 0;
 
@@ -200,9 +395,15 @@ static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe,
 		// poll a PID for nothing.
 		if(sig->get_supported() && subscribe)
 		{
-			float frequency = sig->get_frequency();
-			diag_m.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);
+			float frequency;
+
+			if(event_filter.frequency >= 0)
+				{ frequency = event_filter.frequency; }
+			else
+				{ frequency = sig->get_frequency(); }
+
+			diag_m.add_recurring_request(diag_req, sig->get_name().c_str(), false, sig->get_decoder(), sig->get_callback(), 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
 		{
@@ -214,8 +415,9 @@ static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe,
 			return -1;
 		}
 
-		ret = subscribe_unsubscribe_signal(request, subscribe, sig->get_name());
-		if(ret <= 0)
+		std::shared_ptr<low_can_subscription_t> can_subscription(new low_can_subscription_t(event_filter));
+		ret = subscribe_unsubscribe_signal(request, subscribe, can_subscription);
+		if(ret < 0)
 			return ret;
 		rets++;
 		DEBUG(binder_interface, "%s: Signal: %s subscribed", __FUNCTION__, sig->get_name().c_str());
@@ -223,25 +425,32 @@ static int subscribe_unsubscribe_signals(struct afb_req request, bool subscribe,
 
 	for(const auto& sig: signals.can_signals)
 	{
-		if(sig->create_rx_filter() <= 0 && 
-			subscribe_unsubscribe_signal(request, subscribe, sig->get_name()) <=0)
-		{
-			return -1;
-		}
+		std::shared_ptr<low_can_subscription_t> can_subscription(new low_can_subscription_t(event_filter));
+		if(can_subscription->create_rx_filter(sig->get_message()->get_bus_device_name(),
+		sig->get_name(),
+		sig->get_message()->get_id(),
+		sig->get_bit_position(),
+		sig->get_bit_size(),
+		sig->get_factor(),
+		sig->get_offset()) < 0)
+			{return -1;}
+		else if(subscribe_unsubscribe_signal(request, subscribe, can_subscription) < 0)
+			{return -1;}
+
 		struct sd_event_source* e_source;
-		sd_event_add_io(afb_daemon_get_event_loop(binder_interface->daemon), &e_source, sig->get_socket().socket(), EPOLLIN, read_message, sig.get());
+		sd_event_add_io(afb_daemon_get_event_loop(binder_interface->daemon), &e_source, can_subscription->get_socket().socket(), EPOLLIN, read_message, sig.get());
 		rets++;
 		DEBUG(binder_interface, "%s: signal: %s subscribed", __FUNCTION__, sig->get_name().c_str());
 	}
 	return rets;
 }
 
-static int process_args(struct afb_req request, const std::map<std::string, struct event_filter_t>& args, bool subscribe)
+static int process_args(struct afb_req request, std::map<std::string, struct event_filter_t>& args, bool subscribe)
 {
 	struct utils::signals_found sf;
 	int ok = 0, total = 0;
 
-	for(const auto& sig: args)
+	for(auto& sig: args)
 	{
 		openxc_DynamicField search_key = build_DynamicField(sig.first);
 		sf = utils::signals_manager_t::instance().find_signals(search_key);
@@ -250,38 +459,35 @@ static int process_args(struct afb_req request, const std::map<std::string, stru
 		if (sf.can_signals.empty() && sf.diagnostic_messages.empty())
 			NOTICE(binder_interface, "%s: No signal(s) found for %s.", __FUNCTION__, sig.first.c_str());
 		else
-			ok = subscribe_unsubscribe_signals(request, subscribe, sf);
+			ok = subscribe_unsubscribe_signals(request, subscribe, sf, sig.second);
 	}
 	NOTICE(binder_interface, "%s: Subscribed/unsubscribe correctly to %d/%d signal(s).", __FUNCTION__, ok, total);
 	return ok;
 }
 
-static int parse_filter(json_object* event, struct event_filter_t* event_filter)
+static int parse_filter(json_object* event,  struct event_filter_t& event_filter)
 {
 	struct json_object  *filter, *obj;
 	int ret = 0;
 
 	if (json_object_object_get_ex(event, "filter", &filter))
 	{
-		event_filter->frequency = -1.0;
-		event_filter->min = -1.0;
-		event_filter->max = -1.0;
 		if (json_object_object_get_ex(filter, "frequency", &obj)
 		&& json_object_get_type(obj) == json_type_double)
 		{
-			event_filter->frequency = json_object_get_double(obj);
+			event_filter.frequency = (float)json_object_get_double(obj);
 			ret += 1;
 		}
 		if (json_object_object_get_ex(filter, "min", &obj)
 		&& json_object_get_type(obj) == json_type_double)
 		{
-			event_filter->min = json_object_get_double(obj);
+			event_filter.min = (float)json_object_get_double(obj);
 			ret += 2;
 		}
 		if (json_object_object_get_ex(filter, "max", &obj)
 		&& json_object_get_type(obj) == json_type_double)
 		{
-			event_filter->max = json_object_get_double(obj);
+			event_filter.max = (float)json_object_get_double(obj);
 			ret += 4;
 		}
 	}
@@ -292,22 +498,21 @@ static int parse_filter(json_object* event, struct event_filter_t* event_filter)
 static const std::map<std::string, struct event_filter_t> parse_args_from_request(struct afb_req request)
 {
 	int i, n;
- 	std::map<std::string, struct event_filter_t> ret;
+ 	std::map<std::string,  struct event_filter_t > ret;
 	struct json_object *args, *event, *x;
 	struct event_filter_t event_filter;
-	
+
 	/* retrieve signals to subscribe */
 	args = afb_req_json(request);
 	if (args == NULL || !json_object_object_get_ex(args, "event", &event))
 	{
-		event = json_object_new_string("*");
-		parse_filter(event, &event_filter);
+		parse_filter(json_object_new_string("*"), event_filter);
 		ret["*"] = event_filter;
 	}
 	else if (json_object_get_type(event) != json_type_array)
 	{
 		const std::string event_pattern = std::string(json_object_get_string(event));
-		parse_filter(event, &event_filter);
+		parse_filter(event, event_filter);
 		ret[event_pattern] = event_filter;
 	}
 	else
@@ -317,7 +522,7 @@ static const std::map<std::string, struct event_filter_t> parse_args_from_reques
 		{
 			x = json_object_array_get_idx(event, i);
 			const std::string event_pattern = std::string(json_object_get_string(x));
-			parse_filter(x, &event_filter);
+			parse_filter(x, event_filter);
 			ret[event_pattern] = event_filter;
 		}
 	}
@@ -329,7 +534,7 @@ void subscribe(struct afb_req request)
 {
 	bool subscribe = true;
 
-	const std::map<std::string, struct event_filter_t> args = parse_args_from_request(request);
+	 std::map<std::string, struct event_filter_t> args = parse_args_from_request(request);
 
 	if (process_args(request, args, subscribe) > 0)
 		afb_req_success(request, NULL, NULL);
@@ -340,8 +545,8 @@ void subscribe(struct afb_req request)
 void unsubscribe(struct afb_req request)
 {
 	bool subscribe = false;
-	
-	const std::map<std::string, struct event_filter_t> args = parse_args_from_request(request);
+
+	std::map<std::string, struct event_filter_t>  args = parse_args_from_request(request);
 
 	if (process_args(request, args, subscribe) > 0)
 		afb_req_success(request, NULL, NULL);
diff --git a/CAN-binder/low-can-binding/binding/low-can-cb.hpp b/CAN-binder/low-can-binding/binding/low-can-cb.hpp
new file mode 100644
index 00000000..1608db7d
--- /dev/null
+++ b/CAN-binder/low-can-binding/binding/low-can-cb.hpp
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2015, 2016 "IoT.bzh"
+ * Author "Romain Forlot" <romain.forlot@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 <string>
+#include "../utils/socketcan-bcm.hpp"
+
+struct event_filter_t
+{
+	float frequency;
+	float min;
+	float max;
+};
+
+class low_can_subscription_t
+{
+private:
+	int index_;
+
+	/// Signal part
+	std::string sig_name_;
+	std::string bus_name_;
+	uint32_t can_id_;
+	uint8_t bit_position_; /*!< bitPosition_ - The starting bit of the signal in its CAN message (assuming
+									*	non-inverted bit numbering, i.e. the most significant bit of
+									*	each byte is 0) */
+	uint8_t bit_size_; /*!< bit_size_ - The width of the bit field in the CAN message. */
+	float factor_; /*!< factor_ - The final value will be multiplied by this factor. Use 1 if you
+							*	don't need a factor. */
+	float offset_; /*!< offset_ - The final value will be added to this offset. Use 0 if you
+							*	don't need an offset. */
+
+	/// Filtering part
+	struct event_filter_t event_filter_ = {-1.0, -1.0, -1.0};
+
+	utils::socketcan_bcm_t socket_;
+public:
+	low_can_subscription_t();
+	low_can_subscription_t(struct event_filter_t event_filter);
+	low_can_subscription_t(const low_can_subscription_t& s) = delete;
+	low_can_subscription_t(low_can_subscription_t&& s);
+
+	low_can_subscription_t& operator=(const low_can_subscription_t& s);
+	explicit operator bool() const;
+
+	int get_index() const;
+	const std::string get_sig_name() const;
+	float get_frequency() const;
+	float get_min() const;
+	float get_max() const;
+	utils::socketcan_bcm_t& get_socket();
+
+	void set_frequency(float freq);
+	void set_min(float min);
+	void set_max(float max);
+
+	int create_rx_filter();
+	int create_rx_filter(const std::string& bus_name, const std::string& sig_name, uint32_t can_id, uint8_t bit_position, uint8_t bit_size, float factor, float offset);
+};
diff --git a/CAN-binder/low-can-binding/binding/low-can-hat.cpp b/CAN-binder/low-can-binding/binding/low-can-hat.cpp
index 5cefc817..8713a2c8 100644
--- a/CAN-binder/low-can-binding/binding/low-can-hat.cpp
+++ b/CAN-binder/low-can-binding/binding/low-can-hat.cpp
@@ -17,6 +17,7 @@
  */
 
 #include "low-can-hat.hpp"
+#include "low-can-cb.hpp"
 
 #include <map>
 #include <queue>
diff --git a/CAN-binder/low-can-binding/binding/low-can-hat.hpp b/CAN-binder/low-can-binding/binding/low-can-hat.hpp
index c0756f81..a1c8dad1 100644
--- a/CAN-binder/low-can-binding/binding/low-can-hat.hpp
+++ b/CAN-binder/low-can-binding/binding/low-can-hat.hpp
@@ -31,13 +31,7 @@ extern "C" struct afb_binding_interface;
 
 extern const struct afb_binding_interface *binder_interface;
 
-struct event_filter_t {
-	double frequency;
-	double min;
-	double max;
-};
-
-void on_no_clients(std::string message);
+void on_no_clients(const std::string& message);
 int read_message(sd_event_source *s, int fd, uint32_t revents, void *userdata);
 
 void subscribe(struct afb_req request);