Not supported.

Not supported.

Not supported.

Not supported.

Not supported.

This event is generated whenever the IF_OPER_UP LINK flag gets set, and received by if_8023. It will automatically call the dispatch_link_up() callback from main with the appropriate attributes.

This event is generated when the IF_OPER_UP LINK flag is unset. The dispatch_link_down() calback from main is called automatically.

For each configred periodic report there's a timer that triggers a message of this type at the specified interval.

For configured thresholds, a threshold check is performed periodically, according to the default_th_period launching parameter. A Link_Parameters_Report message is sent everytime one of these checks detects a crossing of the subscribed nature.

Statistical counts for packets and bytes are obtained via the RTNL_GET_LINK Netlink command.

Currently, not all parameters types are supported. Only the following:

This command is immediatly responded with the list of supported Events and Commands. This list of supported Events and Commands is statically configured in the code, inside functions set_supported_event_list and set_supported_command_list of main.

The event subcription is set based on the supported Events and Commands list. The resulting list is always considered at the event dispatch callbacks, such that only subscribed events are transmitted. All supported events are always successfully subscribed, even ones already subscribed.

The event unsubcription is set based on the subscribed Events and Commands list. All supported events are always successfully unsubscribed, even ones already unsubscribed.

The support parameters for this command include only some statistical counts, obtained via the RTNL_GET_LINK Netlink command.

Currently, not all parameters types are supported. Only the following:

New thresholds are added to one of two lists:

If the request is used to remove thresholds, the indicated ones are removed from the respective lists.

This command is translated to kernel invocations, via the if_8023 module.

Only the following LINK_AC_TYPE actions are supported:

No LINK_AC_ATTR is supported.

Events from the kernel are received via Netlink sockets. Depending on the desired events, it migh be necessary to subscribe to the according multicast groups. The if_80211 module automatically subscribes to the RTMGRP_LINK multicast group:

if_8023::if_8023(boost::asio::io_service &ios, mih::mac_addr mac) : _ctx(ios)
{
	// ...
	_socket.join_multicast_group(RTMGRP_LINK);
	// ...
}

The handle_nl_event() method from the if_8023 component is the handler for events received from the subcribed Netlink multicast groups. In order to generate events from this handler, the if_8023 module accepts callback registrations that are to be invoked after specific events occur. For example, a link_up_handler callback is defined as follows:

typedef boost::function<void(mih::link_tuple_id &tuple_id,
                             boost::optional<mih::link_addr> &old_router,
                             boost::optional<mih::link_addr> &new_router,
                             boost::optional<bool> &ip_renew,
                             boost::optional<mih::ip_mob_mgmt> &mobility_management)> link_up_handler;

// new callback
typedef boost::function<void(mih::link_tuple_id &tuple_id)> new_event_handler;

Once registered in the if_8023 object, the callback may then used in this manner:

int handle_nl_event(nl_msg *msg, void *arg)
{
	nlwrap::nl_msg m(msg);

	// ...
	if (link_is_up) {
		// parse message attributes into...
		mih::link_tuple_id lid;
		boost::optional<mih::link_addr> old_router;
		boost::optional<mih::link_addr> new_router;
		boost::optional<bool> ip_renew;
		boost::optional<mih::ip_mob_mgmt> mobility_management;

		// dispatch callback
		ios.dispatch(boost::bind(_link_up_handler, lid, old_router, new_router, ip_renew, mobility_management));
	}

	// new event
	else if (new_event_occurred) {
		// parse message attributes into...
		mih::link_tuple_id lid;

		// dispatch callback
		ios.dispatch(boost::bind(_new_event_handler, lid));
	}
}

An event received at the callback must then be delivered to the MIHF, similarly to command responses (although the TID is not set as in that case).

void dispatch_new_event(mih::link_tuple_id &lid)
{
	if (!subscribed_event_list.get(mih::evt_new_event)) {
		return;
	}

	mih::message m;
	m << mih::indication(mih::indication::new_event);

	ls->async_send(m);
}

The Link_Parameters_Report event is an example of a "manually" triggered event. These type of events are dispatched in the same way of regular events:

void dispatch_new_event(mih::link_tuple_id &lid)
{
	if (!subscribed_event_list.get(mih::evt_new_event)) {
		return;
	}

	mih::message m;
	m << mih::indication(mih::indication::new_event);

	ls->async_send(m);
}

They can be generated in any way the programmer desires. The implementation of the Link_Parameters_Report is done via independent threads which poll for information at regular intervals and, if the conditions designate the generation of an event, the dispath_event() method is called with the appropriate parameters.

The periodic execution of the thread should be handled with the boost::io_service mechanisms, in order to prevent concurrent operation with other Link SAP services. the timer_task class assists in the creation of periodic code snippets, and is used for the management of configured thresholds and consequent generation of Link_Parameters_Report events.