Detailed Description

Protocol handler for the Internet Control Message Protocol (ICMP).

ICMP provides various auxiliary services to support IPv4 networks, ranging from "ping" (ICMP Echo/Reply) to error reporting (e.g., "Destination host unreachable").

Definition at line 79 of file ip_icmp.h.

#include <ip_icmp.h>

Inheritance diagram for satcat5::ip::ProtoIcmp:

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Collaboration diagram for satcat5::ip::ProtoIcmp:

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Public Member Functions
	ProtoIcmp (satcat5::ip::Dispatch *iface)
	Link this handler to an IPv4 network interface.

bool	send_error (u16 type, satcat5::io::Readable *src, uint32_t arg=0)
	Send a specific error message. More...

bool	send_ping (satcat5::ip::Address &dst)
	Initiate a ping (Echo request = Type 8.0). More...

bool	send_timereq (satcat5::ip::Address &dst)
	Initiate a timestamp request. More...

void	set_log_cooldown (unsigned wait_msec)
	Adjust the rate-limit for ICMP error logging. More...


void	add (satcat5::ip::PingListener *cb)
	Add/remove callback handlers for Ping responses.

void	remove (satcat5::ip::PingListener *cb)
	Add/remove callback handlers for Ping responses.

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

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

bool	write_icmp (satcat5::io::Writeable wr, unsigned wcount, u16 data)

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

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

satcat5::util::List< satcat5::ip::PingListener >	m_listeners

unsigned	m_wait_msec

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

Private Member Functions
void	query (unsigned elapsed_msec)

Private Attributes
satcat5::net::Protocol *	m_next
	Linked list of Protocols.

unsigned	m_trem

unsigned	m_tnext

Member Function Documentation

◆ frame_rcvd()

void ProtoIcmp::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 191 of file ip_icmp.cc.

◆ send_error()

bool ProtoIcmp::send_error	(	u16	type,
		satcat5::io::Readable *	src,
		uint32_t	arg = `0`
	)

Send a specific error message.

This method is used to send various error-messages, such as "Destination unreachable" (Type 3.x, arg = unused) or "Redirect" (Type 5.x, arg = new address). Note: Readable "src" should contain the first 8 bytes after the IP header of the frame that triggered this error. Returns true if frame sent successfully, false otherwise.

Definition at line 120 of file ip_icmp.cc.

◆ send_ping()

bool ProtoIcmp::send_ping ( satcat5::ip::Address & dst )

Initiate a ping (Echo request = Type 8.0).

Returns true if frame sent successfully, false otherwise.

Definition at line 151 of file ip_icmp.cc.

◆ send_timereq()

bool ProtoIcmp::send_timereq ( satcat5::ip::Address & dst )

Initiate a timestamp request.

Returns true if frame sent successfully, false otherwise.

Definition at line 168 of file ip_icmp.cc.

◆ set_log_cooldown()

void satcat5::ip::ProtoIcmp::set_log_cooldown ( unsigned wait_msec )

inline

Adjust the rate-limit for ICMP error logging.

Incoming ICMP errors (e.g., "Destination Unreachable...") are written to the SatCat5 log. If log message forwarding fails with another ICMP error, this can produce an infinite loop. Prevent this with a rate limit (SATCAT5_ICMP_LOG_COOLDOWN) or override at runtime. A value of zero disables this rate-limit.

Definition at line 111 of file ip_icmp.h.

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

Detailed Description

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes