Detailed Description

Deferred packet-forwarding system for the IPv4 router.

To forward each packet, the router must determine the MAC address for the next hop in the chain. If that information is not already present in the combined CIDR/ARP table, then the router must defer forwarding until the ARP query/response is completed.

The router2::DeferFwd class implements deferred forwarding, retaining packet pointers from the router's primary MultiBuffer. Most incoming packets trigger an ARP query; the packet can be forwarded after a matching ARP response. If there is no response, then the query is repeated with an increasing timeout. After several failed attempts, undeliverable packets trigger an ICMP error to the original sender.

Definition at line 55 of file router2_deferfwd.h.

#include <router2_deferfwd.h>

Inheritance diagram for satcat5::router2::DeferFwd:

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Collaboration diagram for satcat5::router2::DeferFwd:

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Public Member Functions
bool	accept (const satcat5::eth::PluginPacket &meta)
	Accept this packet into the queue?

virtual void	gateway_change (const satcat5::ip::Addr &dstaddr, const satcat5::ip::Addr &gateway)
	Callback for changes to gateway configuration. More...

void	timer_once (unsigned msec)
	Configure a one-time notification after X milliseconds.

void	timer_every (unsigned msec)
	Configure a repeating notification every X milliseconds.

void	timer_stop ()
	Stop all future notifications.

unsigned	timer_interval () const
	Accessor for recurring timer interval, if one is set.

unsigned	timer_remaining () const
	Accessor for time to next event, if one is set.

Static Public Member Functions
static unsigned	count_timer ()
	Count all objects of this type, including idle timers.

Protected Member Functions
	DeferFwd (satcat5::router2::Dispatch parent, satcat5::router2::DeferPkt buff, unsigned bcount)
	Constructor should only be accessed by children, and requires a backing array of empty DeferPkt objects.

void	arp_event (const satcat5::eth::MacAddr &mac, const satcat5::ip::Addr &ip) override
	Callback for any announced MAC/IP address pair. More...

void	timer_event () override
	Child class MUST override this method.

satcat5::router2::DeferPkt *	request_arp (satcat5::router2::DeferPkt *pkt)

satcat5::router2::DeferPkt *	request_fwd (satcat5::router2::DeferPkt *pkt, const satcat5::eth::MacAddr &dst)

Protected Attributes
satcat5::router2::Dispatch *const	m_parent

satcat5::eth::ProtoArp *	m_arp

satcat5::util::TimeVal	m_tref

satcat5::util::List< satcat5::router2::DeferPkt >	m_active

satcat5::util::List< satcat5::router2::DeferPkt >	m_empty

Private Member Functions
void	query (unsigned elapsed_msec)

Private Attributes
satcat5::eth::ArpListener *	m_next

unsigned	m_trem

unsigned	m_tnext

Member Function Documentation

◆ arp_event()

void DeferFwd::arp_event	(	const satcat5::eth::MacAddr &	mac,
		const satcat5::ip::Addr &	ip
	)

overrideprotectedvirtual

Callback for any announced MAC/IP address pair.

Child class MUST override this method.

Implements satcat5::eth::ArpListener.

Definition at line 84 of file router2_deferfwd.cc.

◆ gateway_change()

virtual void satcat5::eth::ArpListener::gateway_change	(	const satcat5::ip::Addr &	dstaddr,
		const satcat5::ip::Addr &	gateway
	)

inlinevirtualinherited

Callback for changes to gateway configuration.

Child class MAY override this method.

Reimplemented in satcat5::ip::Address, and satcat5::test::CountArpResponse.

Definition at line 56 of file eth_arp.h.

The documentation for this class was generated from the following files:

Detailed Description

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Member Function Documentation

◆ arp_event()

◆ gateway_change()