Detailed Description

Protocol handler and dispatch unit for Internet Protocol v4 (IPv4).

This class implements the "net::Dispatch" API for IPv4 frames.

The IP dispatch subsystem must be attached to an Ethernet interface, accepting all incoming traffic with EtherType 0x0800 (IPv4). Incoming packets are checked for validity and then sorted by IP protocol number (i.e., ICMP, UDP, TCP, etc.).

The system includes static routing tables for next-hop routing, inheriting all functionality from the ip::Table class.

For an all-in-one container with ip::Dispatch and other components required for UDP communications, use ip::Stack.

Definition at line 39 of file ip_dispatch.h.

#include <ip_dispatch.h>

Inheritance diagram for satcat5::ip::Dispatch:

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Collaboration diagram for satcat5::ip::Dispatch:

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Public Member Functions
	Dispatch (const satcat5::ip::Addr &addr, satcat5::eth::Dispatch iface, satcat5::ip::Table route)
	Link this object to an Ethernet interface. More...

satcat5::io::Writeable *	open_reply (const satcat5::net::Type &type, unsigned len) override
	Get Writeable object for reply to the last received datagram.

satcat5::io::Writeable *	open_write (const satcat5::eth::MacAddr &mac, const satcat5::eth::VlanTag &vtag, const satcat5::ip::Addr &ip, u8 protocol, unsigned len)
	Get Writeable object for sending to a specific IP/MAC address.

void	set_addr (const satcat5::ip::Addr &addr)
	Set the local IP-address.

satcat5::ip::Header	next_header (u8 protocol, const satcat5::ip::Addr &dst, unsigned inner_bytes, u8 ttl=SATCAT5_IP_TTL)
	Create a basic IPv4 header with the specified information. More...

satcat5::eth::ProtoArp *	arp ()

satcat5::ip::ProtoIcmp *	icmp ()

satcat5::igmp::Client *	igmp ()

satcat5::eth::Dispatch *	iface () const

satcat5::ip::Addr	ipaddr () const

satcat5::eth::MacAddr	macaddr () const

satcat5::eth::VlanTag	reply_vtag () const

satcat5::eth::MacAddr	reply_mac () const

bool	reply_is_multicast () const

satcat5::ip::Addr	reply_ip () const

const satcat5::ip::Header &	reply_hdr () const

void	set_ipaddr (const satcat5::ip::Addr &addr)

void	set_macaddr (const satcat5::eth::MacAddr &macaddr)

satcat5::ip::Table *	table ()

void	set_ident (u16 ident)
	For testing purposes only, reset the "ident" field. More...

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

void	add (satcat5::net::Protocol *proto)
	Register a Protocol object.

void	remove (satcat5::net::Protocol *proto)
	Unregister a Protocol object.

bool	bound (const satcat5::net::Type &type) const
	Check if a given net::Type has a matching Protocol.


void	route_clear (bool lockdown=true)
	Routing table shortcuts. More...

bool	route_cache (const satcat5::ip::Addr &gateway, const satcat5::eth::MacAddr &dstmac)
	Routing table shortcuts. More...

bool	route_default (const satcat5::ip::Addr &gateway, const satcat5::eth::MacAddr &dstmac=satcat5::eth::MACADDR_NONE)
	Routing table shortcuts. More...

bool	route_local (const satcat5::ip::Subnet &subnet)
	Routing table shortcuts. More...

bool	route_simple (const satcat5::ip::Addr &gateway, const satcat5::ip::Mask &subnet=satcat5::ip::MASK_24)
	Routing table shortcuts. More...

bool	route_static (const satcat5::ip::Subnet &subnet, const satcat5::ip::Addr &gateway, const satcat5::eth::MacAddr &dstmac=satcat5::eth::MACADDR_NONE)
	Routing table shortcuts. More...

bool	route_remove (const satcat5::ip::Subnet &subnet)
	Routing table shortcuts. More...

bool	route_remove (const satcat5::ip::Addr &addr)
	Routing table shortcuts. More...

satcat5::ip::Route	route_lookup (const satcat5::ip::Addr &dstaddr) const
	Routing table shortcuts. More...

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

void	frame_rcvd (satcat5::io::LimitedRead &src) override
	Dispatch calls frame_rcvd(...) for each incoming frame with with a matching net::Type value. More...

bool	deliver (const satcat5::net::Type &type, satcat5::io::Readable *src, unsigned len)
	Deliver current message by calling Protocol::frame_rcvd(...). More...

Protected Attributes
satcat5::eth::Dispatch *const	m_iface

satcat5::ip::Table *const	m_route

satcat5::ip::Addr	m_addr

satcat5::eth::ProtoArp	m_arp

satcat5::ip::ProtoIcmp	m_icmp

satcat5::igmp::Client	m_igmp

satcat5::ip::Addr	m_reply_dst

satcat5::ip::Addr	m_reply_src

satcat5::ip::Header	m_reply_hdr

u16	m_ident

satcat5::net::Type	m_filter
	Incoming packet filter.

satcat5::util::List< satcat5::net::Protocol >	m_list
	Linked list of Protocol objects.

Private Attributes
satcat5::eth::ArpListener *	m_next

Constructor & Destructor Documentation

◆ Dispatch()

Dispatch::Dispatch	(	const satcat5::ip::Addr &	addr,
		satcat5::eth::Dispatch *	iface,
		satcat5::ip::Table *	route
	)

Link this object to an Ethernet interface.

Constructor requires the local address (may be ADDR_NONE), an Ethernet interface, and a time reference. The address may be changed later if desired.

Definition at line 21 of file ip_dispatch.cc.

Member Function Documentation

◆ arp_event()

void Dispatch::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 101 of file ip_dispatch.cc.

◆ deliver()

bool Dispatch::deliver	(	const satcat5::net::Type &	type,
		satcat5::io::Readable *	src,
		unsigned	len
	)

protectedinherited

Deliver current message by calling Protocol::frame_rcvd(...).

Note: Caller is responsible for read_finalize(), if required.

Returns: True if a matching Protocol is found.

Definition at line 25 of file net_dispatch.cc.

◆ frame_rcvd()

void Dispatch::frame_rcvd ( satcat5::io::LimitedRead & src )

overrideprotectedvirtual

Dispatch calls frame_rcvd(...) for each incoming frame with with a matching net::Type value.

The child class SHOULD read the frame contents from the provided "src" object, which is only valid until the function returns.

To send a reply:

Call m_iface->open_reply() to obtain a Writable object. (This also writes out any applicable frame headers.)
Write frame contents, then call write_finalize().

The child class MUST override this method.

Implements satcat5::net::Protocol.

Definition at line 106 of file ip_dispatch.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.

◆ next_header()

Header Dispatch::next_header	(	u8	protocol,
		const satcat5::ip::Addr &	dst,
		unsigned	inner_bytes,
		u8	ttl = `SATCAT5_IP_TTL`
	)

Create a basic IPv4 header with the specified information.

protocol Packet type (ICMP/UDP/etc)
dst Destination IP address
inner_bytes Length of contained packet
ttl Time-to-live (optional)

Definition at line 79 of file ip_dispatch.cc.

◆ route_cache()

bool satcat5::ip::Dispatch::route_cache	(	const satcat5::ip::Addr &	gateway,
		const satcat5::eth::MacAddr &	dstmac
	)

inline

Routing table shortcuts.

See also: ip_table.h

Definition at line 85 of file ip_dispatch.h.

◆ route_clear()

void satcat5::ip::Dispatch::route_clear ( bool lockdown = true )

inline

Routing table shortcuts.

See also: ip_table.h

Definition at line 83 of file ip_dispatch.h.

◆ route_default()

bool satcat5::ip::Dispatch::route_default	(	const satcat5::ip::Addr &	gateway,
		const satcat5::eth::MacAddr &	dstmac = `satcat5::eth::MACADDR_NONE`
	)

inline

Routing table shortcuts.

See also: ip_table.h

Definition at line 89 of file ip_dispatch.h.

◆ route_local()

bool satcat5::ip::Dispatch::route_local ( const satcat5::ip::Subnet & subnet )

inline

Routing table shortcuts.

See also: ip_table.h

Definition at line 93 of file ip_dispatch.h.

◆ route_lookup()

satcat5::ip::Route satcat5::ip::Dispatch::route_lookup ( const satcat5::ip::Addr & dstaddr ) const

inline

Routing table shortcuts.

See also: ip_table.h

Definition at line 108 of file ip_dispatch.h.

◆ route_remove() [1/2]

bool satcat5::ip::Dispatch::route_remove ( const satcat5::ip::Addr & addr )

inline

Routing table shortcuts.

See also: ip_table.h

Definition at line 106 of file ip_dispatch.h.

◆ route_remove() [2/2]

bool satcat5::ip::Dispatch::route_remove ( const satcat5::ip::Subnet & subnet )

inline

Routing table shortcuts.

See also: ip_table.h

Definition at line 104 of file ip_dispatch.h.

◆ route_simple()

bool satcat5::ip::Dispatch::route_simple	(	const satcat5::ip::Addr &	gateway,
		const satcat5::ip::Mask &	subnet = `satcat5::ip::MASK_24`
	)

inline

Routing table shortcuts.

See also: ip_table.h

Definition at line 95 of file ip_dispatch.h.

◆ route_static()

bool satcat5::ip::Dispatch::route_static	(	const satcat5::ip::Subnet &	subnet,
		const satcat5::ip::Addr &	gateway,
		const satcat5::eth::MacAddr &	dstmac = `satcat5::eth::MACADDR_NONE`
	)

inline

Routing table shortcuts.

See also: ip_table.h

Definition at line 99 of file ip_dispatch.h.

◆ set_ident()

void satcat5::ip::Dispatch::set_ident ( u16 ident )

inline

For testing purposes only, reset the "ident" field.

(This is unsafe, but simplifies certain unit tests.)

Definition at line 145 of file ip_dispatch.h.

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

Detailed Description

Public Member Functions

Protected Member Functions

Protected Attributes

Private Attributes

Constructor & Destructor Documentation

◆ Dispatch()

Member Function Documentation

◆ arp_event()

◆ deliver()

◆ frame_rcvd()

◆ gateway_change()

◆ next_header()

◆ route_cache()

◆ route_clear()

◆ route_default()

◆ route_local()

◆ route_lookup()

◆ route_remove() [1/2]

◆ route_remove() [2/2]

◆ route_simple()

◆ route_static()

◆ set_ident()