tcp.lua File Reference

Transmission control protocol (TCP) utility. More...

Go to the source code of this file.

Functions
function tcpHeader	setSrcPort (int)
	Set the source port. More...
function tcpHeader	getSrcPort ()
	Retrieve the source port. More...
function tcpHeader	getSrcPortString ()
	Retrieve the source port. More...
function tcpHeader	setDstPort (int)
	Set the destination port. More...
function tcpHeader	getDstPort ()
	Retrieve the destination port. More...
function tcpHeader	getDstPortString ()
	Retrieve the destination port. More...
function tcpHeader	setSeqNumber (int)
	Set the sequence number. More...
function tcpHeader	getSeqNumber ()
	Retrieve the sequence number. More...
function tcpHeader	getSeqNumberString ()
	Retrieve the sequence number. More...
function tcpHeader	setAckNumber (int)
	Set the acknowledgement number. More...
function tcpHeader	getAckNumber ()
	Retrieve the acknowledgement number. More...
function tcpHeader	getAckNumberString ()
	Retrieve the acknowledgement number. More...
function tcpHeader	setDataOffset (int)
	Set the data offset. More...
function tcpHeader	getDataOffset ()
	Retrieve the data offset. More...
function tcpHeader	getDataOffsetString ()
	Retrieve the data offset. More...
function tcpHeader	setReserved (int)
	Set the reserved field. More...
function tcpHeader	getReserved ()
	Retrieve the reserved field. More...
function tcpHeader	getReservedString ()
	Retrieve the reserved field. More...
function tcpHeader	setFlags (int)
	Set the flags. More...
function tcpHeader	getFlags ()
	Retrieve the flags. More...
function tcpHeader	getFlagsString ()
	Retrieve the flags. More...
function tcpHeader	setUrg ()
	Set the Urg flag.
function tcpHeader	unsetUrg ()
	Unset the Urg flag.
function tcpHeader	getUrg ()
	Retrieve the Urg flag. More...
function tcpHeader	getUrgString ()
	Retrieve the Urg flag. More...
function tcpHeader	setAck ()
	Set the Ack flag.
function tcpHeader	unsetAck ()
	Unset the Ack flag.
function tcpHeader	getAck ()
	Retrieve the Ack flag. More...
function tcpHeader	getAckString ()
	Retrieve the Ack flag. More...
function tcpHeader	setPsh ()
	Set the Psh flag.
function tcpHeader	unsetPsh ()
	Unset the Psh flag.
function tcpHeader	getPsh ()
	Retrieve the Psh flag. More...
function tcpHeader	getPshString ()
	Retrieve the Psh flag. More...
function tcpHeader	setRst ()
	Set the Rst flag.
function tcpHeader	unsetRst ()
	Unset the Rst flag.
function tcpHeader	getRst ()
	Retrieve the Rst flag. More...
function tcpHeader	getRstString ()
	Retrieve the Rst flag. More...
function tcpHeader	setSyn ()
	Set the Syn flag.
function tcpHeader	unsetSyn ()
	Unset the Syn flag.
function tcpHeader	getSyn ()
	Retrieve the Syn flag. More...
function tcpHeader	getSynString ()
	Retrieve the Syn flag. More...
function tcpHeader	setFin ()
	Set the Fin flag.
function tcpHeader	unsetFin ()
	Unset the Fin flag.
function tcpHeader	getFin ()
	Retrieve the Fin flag. More...
function tcpHeader	getFinString ()
	Retrieve the Fin flag. More...
function tcpHeader	setWindow (int)
	Set the window field. More...
function tcpHeader	getWindow ()
	Retrieve the window field. More...
function tcpHeader	getWindowString ()
	Retrieve the window field. More...
function tcpHeader	setChecksum (int)
	Set the checksum. More...
function tcpHeader	calculateChecksum (len)
	Calculate the checksum. More...
function tcpHeader	getChecksum ()
	Retrieve the checksum. More...
function tcpHeader	getChecksumString ()
	Retrieve the checksum. More...
function tcpHeader	setUrgentPointer (int)
	Set the urgent pointer. More...
function tcpHeader	getUrgentPointer ()
	Retrieve the urgent pointer. More...
function tcpHeader	getUrgentPointerString ()
	Retrieve the urgent pointer. More...
function tcpHeader	fill (args, pre)
	Set all members of the ip header. More...
function tcpHeader	get (pre)
	Retrieve the values of all members. More...
function tcpHeader	getString ()
	Retrieve the values of all members. More...
function tcpHeader	resolveNextHeader ()
	Resolve which header comes after this one (in a packet). More...
function tcpHeader	setDefaultNamedArgs (pre, namedArgs, nextHeader, accumulatedLength)
	Change the default values for namedArguments (for fill/get). More...

Variables
local	tcpHeader = {}
	Module for tcp_header struct (see headers.lua).
pkt	getTcp4Packet = packetCreate("eth", "ip4", "tcp")
	Cast the packet to a Tcp (IP4) packet.
pkt	getTcp6Packet = packetCreate("eth", "ip6", "tcp")
	Cast the packet to a Tcp (IP6) packet.
pkt	getTcpPacket = function(self, ip4)
	Cast the packet to a Tcp packet, either using IP4 (nil/true) or IP6 (false), depending on the passed boolean.

Detailed Description

Transmission control protocol (TCP) utility.

Utility functions for the tcp_header struct defined in headers.lua .
Includes:

• TCP constants
• TCP header utility
• Definition of TCP packets

Definition in file tcp.lua.

Function Documentation

function tcpHeader calculateChecksum

(

len

)

Calculate the checksum.

Parameters

len	Number of bytes to calculate the checksum over.

Todo:

FIXME NYI

function tcpHeader fill	(	args	,
		pre
	)

Set all members of the ip 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: Src, Dst, SeqNumber, AckNumber, DataOffset, Reserved, Flags, Urg, Ack, Psh, Rst, Syn, Fin, Window, Checksum, UrgentPointer
pre	prefix for namedArgs. Default 'tcp'. fill() --- only default values fill{ tcpSrc=1234, ipTTL=100 } --- all members are set to default values with the exception of tcpSrc

function tcpHeader get

(

pre

)

Retrieve the values of all members.

Returns

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

See Also

tcpHeader:fill

function tcpHeader getAck

(

)

Retrieve the Ack flag.

Returns

Flag as 1 bit integer.

function tcpHeader getAckNumber

(

)

Retrieve the acknowledgement number.

Returns

Seq number as 8 bit integer.

function tcpHeader getAckNumberString

(

)

Retrieve the acknowledgement number.

Returns

Ack number in string format.

function tcpHeader getAckString

(

)

Retrieve the Ack flag.

Returns

Flag in string format.

function tcpHeader getChecksum

(

)

Retrieve the checksum.

Returns

Checksum as 16 bit integer.

function tcpHeader getChecksumString

(

)

Retrieve the checksum.

Returns

Checksum in string format.

function tcpHeader getDataOffset

(

)

Retrieve the data offset.

Returns

Offset as 4 bit integer.

function tcpHeader getDataOffsetString

(

)

Retrieve the data offset.

Returns

Offset in string format.

function tcpHeader getDstPort

(

)

Retrieve the destination port.

Returns

Port as 16 bit integer.

Examples:

quality-of-service-test.lua.

function tcpHeader getDstPortString

(

)

Retrieve the destination port.

Returns

Port in string format.

function tcpHeader getFin

(

)

Retrieve the Fin flag.

Returns

Flag as 1 bit integer.

function tcpHeader getFinString

(

)

Retrieve the Fin flag.

Returns

Flag in string format.

function tcpHeader getFlags

(

)

Retrieve the flags.

Returns

Flags as 6 bit integer.

function tcpHeader getFlagsString

(

)

Retrieve the flags.

Returns

Flags in string format.

function tcpHeader getPsh

(

)

Retrieve the Psh flag.

Returns

Flag as 1 bit integer.

function tcpHeader getPshString

(

)

Retrieve the Psh flag.

Returns

Flag in string format.

function tcpHeader getReserved

(

)

Retrieve the reserved field.

Returns

Reserved field as 6 bit integer.

function tcpHeader getReservedString

(

)

Retrieve the reserved field.

Returns

Reserved field in string format.

function tcpHeader getRst

(

)

Retrieve the Rst flag.

Returns

Flag as 1 bit integer.

function tcpHeader getRstString

(

)

Retrieve the Rst flag.

Returns

Flag in string format.

function tcpHeader getSeqNumber

(

)

Retrieve the sequence number.

Returns

Seq number as 8 bit integer.

function tcpHeader getSeqNumberString

(

)

Retrieve the sequence number.

Returns

Sequence number in string format.

function tcpHeader getSrcPort

(

)

Retrieve the source port.

Returns

Port as 16 bit integer.

function tcpHeader getSrcPortString

(

)

Retrieve the source port.

Returns

Port in string format.

function tcpHeader getString

(

)

Retrieve the values of all members.

Returns

Values in string format.

function tcpHeader getSyn

(

)

Retrieve the Syn flag.

Returns

Flag as 1 bit integer.

function tcpHeader getSynString

(

)

Retrieve the Syn flag.

Returns

Flag in string format.

function tcpHeader getUrg

(

)

Retrieve the Urg flag.

Returns

Flag as 1 bit integer.

function tcpHeader getUrgentPointer

(

)

Retrieve the urgent pointer.

Returns

Urgent pointer as 16 bit integer.

function tcpHeader getUrgentPointerString

(

)

Retrieve the urgent pointer.

Returns

Urgent pointer in string format.

function tcpHeader getUrgString

(

)

Retrieve the Urg flag.

Returns

Flag in string format.

function tcpHeader getWindow

(

)

Retrieve the window field.

Returns

Window as 16 bit integer.

function tcpHeader getWindowString

(

)

Retrieve the window field.

Returns

Window in string format.

function tcpHeader 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 tcpHeader setAckNumber

(

int

)

Set the acknowledgement number.

Parameters

int	Ack number as 8 bit integer.

function tcpHeader setChecksum

(

int

)

Set the checksum.

Parameters

int	Checksum as 16 bit integer.

function tcpHeader setDataOffset

(

int

)

Set the data offset.

Parameters

int	Offset as 4 bit integer. Header size is counted in 32 bit words (min. 5 (no options), max. 15)

function tcpHeader 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. 'tcp'
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

tcpHeader:fill

function tcpHeader setDstPort

(

int

)

Set the destination port.

Parameters

int	Port as 16 bit integer.

function tcpHeader setFlags

(

int

)

Set the flags.

Parameters

int	Flags as 6 bit integer.

Todo:

TODO RFC 3168 specifies new CWR and ECE flags (reserved reduced to 4 bit)

function tcpHeader setReserved

(

int

)

Set the reserved field.

Parameters

int	Reserved field as 6 bit integer.

function tcpHeader setSeqNumber

(

int

)

Set the sequence number.

Parameters

int	Sequence number as 8 bit integer.

function tcpHeader setSrcPort

(

int

)

Set the source port.

Parameters

int	Port as 16 bit integer.

function tcpHeader setUrgentPointer

(

int

)

Set the urgent pointer.

Parameters

int	Urgent pointer as 16 bit integer.

function tcpHeader setWindow

(

int

)

Set the window field.

Parameters

int	Window as 16 bit integer.