udp.lua File Reference

User datagram protocol (UDP) utility. More...

Go to the source code of this file.

Functions
function udpHeader	setSrcPort (int)
	Set the source port. More...
function udpHeader	getSrcPort ()
	Retrieve the UDP source port. More...
function udpHeader	getSrcPortString ()
	Retrieve the UDP source port. More...
function udpHeader	setDstPort (int)
	Set the destination port. More...
function udpHeader	getDstPort ()
	Retrieve the UDP destination port. More...
function udpHeader	getDstPortString ()
	Retrieve the UDP destination port. More...
function udpHeader	setLength (int)
	Set the length. More...
function udpHeader	getLength ()
	Retrieve the length. More...
function udpHeader	getLengthString ()
	Retrieve the length. More...
function udpHeader	setChecksum (int)
	Set the checksum. More...
function udpHeader	calculateChecksum (len)
	Calculate the checksum. More...
function udpHeader	getChecksum ()
	Retrieve the checksum. More...
function udpHeader	getChecksumString ()
	Retrieve the checksum. More...
function udpHeader	fill (args, pre)
	Set all members of the udp header. More...
function udpHeader	get (pre)
	Retrieve the values of all members. More...
function udpHeader	getString ()
	Retrieve the values of all members. More...
function udpHeader	resolveNextHeader ()
	Resolve which header comes after this one (in a packet). More...
function udpHeader	setDefaultNamedArgs (pre, namedArgs, nextHeader, accumulatedLength)
	Change the default values for namedArguments (for fill/get). More...

Variables
local	udp = {}
	Udp protocol constants.
udp	PORT_PTP_EVENTS = 319
	Well known port for Ptp event message.
udp	PORT_PTP_GENERAL_MESSAGES = 320
	Well known port for Ptp general message.
local	udpHeader = {}
	Module for udp_header struct (see headers.lua).
pkt	getUdp4Packet = packetCreate("eth", "ip4", "udp")
	Cast the packet to an Udp (IP4) packet.
pkt	getUdp6Packet = packetCreate("eth", "ip6", "udp")
	Cast the packet to an Udp (IP6) packet.
pkt	getUdpPacket = function(self, ip4)
	Cast the packet to an Udp packet, either using IP4 (nil/true) or IP6 (false), depending on the passed boolean.

Detailed Description

User datagram protocol (UDP) utility.

Utility functions for udp_header struct defined in headers.lua .
Includes:

• Udp constants
• Udp header utility
• Definition of Udp packets

Definition in file udp.lua.

Function Documentation

function udpHeader calculateChecksum

(

len

)

Calculate the checksum.

Todo:

FIXME NYI

function udpHeader fill	(	args	,
		pre
	)

Set all members of the udp header.

Per default, all members are set to default values specified in the respective set function. Optional named arguments can be used to set a member to a user-provided value.

Parameters

args	Table of named arguments. Available arguments: udpSrc, udpDst, udpLength, udpChecksum
pre	prefix for namedArgs. Default 'udp'. fill() --- only default values fill{ udpSrc=44566, ip6Length=101 } --- all members are set to default values with the exception of udpSrc

function udpHeader get

(

pre

)

Retrieve the values of all members.

Parameters

pre	prefix for namedArgs. Default 'udp'.

Returns

Table of named arguments. For a list of arguments see "See also".

See Also

udpHeader:fill

function udpHeader getChecksum

(

)

Retrieve the checksum.

Returns

Checksum as 16 bit integer.

function udpHeader getChecksumString

(

)

Retrieve the checksum.

Returns

Checksum as string.

function udpHeader getDstPort

(

)

Retrieve the UDP destination port.

Returns

Port as 16 bit integer.

function udpHeader getDstPortString

(

)

Retrieve the UDP destination port.

Returns

Port as string.

function udpHeader getLength

(

)

Retrieve the length.

Returns

Length as 16 bit integer.

function udpHeader getLengthString

(

)

Retrieve the length.

Returns

Length as string.

function udpHeader getSrcPort

(

)

Retrieve the UDP source port.

Returns

Port as 16 bit integer.

function udpHeader getSrcPortString

(

)

Retrieve the UDP source port.

Returns

Port as string.

function udpHeader getString

(

)

Retrieve the values of all members.

Returns

Values in string format.

function udpHeader resolveNextHeader

(

)

Resolve which header comes after this one (in a packet).

For instance: in tcp/udp based on the ports. This function must exist and is only used when get/dump is executed on an unknown (mbuf not yet casted to e.g. tcpv6 packet) packet (mbuf)

Returns

String next header (e.g. 'udp', 'icmp', nil)

function udpHeader setChecksum

(

int

)

Set the checksum.

Parameters

int	Checksum of the udp header as 16 bit integer.

function udpHeader setDefaultNamedArgs	(	pre	,
		namedArgs	,
		nextHeader	,
		accumulatedLength
	)

Change the default values for namedArguments (for fill/get).

This can be used to for instance calculate a length value based on the total packet length. See proto/ip4.setDefaultNamedArgs as an example. This function must exist and is only used by packet.fill.

Parameters

pre	The prefix used for the namedArgs, e.g. 'udp'
namedArgs	Table of named arguments (see See Also)
nextHeader	The header following after this header in a packet
accumulatedLength	The so far accumulated length for previous headers in a packet

Returns

Table of namedArgs

See Also

ip4Header:fill

function udpHeader setDstPort

(

int

)

Set the destination port.

Parameters

int	Destination port of the udp header as 16 bit integer.

function udpHeader setLength

(

int

)

Set the length.

Parameters

int	Length of the udp header plus payload (excluding l2 and l3). 16 bit integer.

function udpHeader setSrcPort

(

int

)

Set the source port.

Parameters

int	Source port of the udp header as 16 bit integer.