Utility functions for packets (rte_mbuf). More...

Functions
function pkt	getTimestamp ()
	Retrieve the time stamp information. More...

function pkt	hasTimestamp ()
	Check if the PKT_RX_IEEE1588_TMST flag is set. More...

function pkt	setVlan (vlan, pcp, cfi)
	Offload VLAN tagging to the NIC for this packet.

function pkt	getVlan ()
	Get the VLAN associated with a received packet.

function pkt	setDelay (delay)
	Set the time to wait before the packet is sent for software rate-controlled send methods.

function pkt	setRate (rate)

function pkt	setSize (size)

function pkt	get ()
	Returns the packet data cast to the best fitting packet struct. More...

function pkt	dump (bytes)
	Dumps the packet data cast to the best fitting packet struct. More...

function pkt	offloadIPSec (idx, sec_type, esp_mode)
	Use IPsec offloading. More...

function pkt	setESPTrailerLength (len)
	Set the ESP trailer length. More...

function pkt	offloadIPChecksum (ipv4, l2_len, l3_len)
	Instruct the NIC to calculate the IP checksum for this packet. More...

function pkt	offloadUdpChecksum (ipv4, l2_len, l3_len)
	Instruct the NIC to calculate the IP and UDP checksum for this packet. More...

function pkt	offloadTcpChecksum (ipv4, l2_len, l3_len)
	Instruct the NIC to calculate the IP and TCP checksum for this packet. More...

function pkt	enableTimestamps ()

function	packetCreate (...)
	Create struct and functions for a new packet. More...

function	getHeaderMember (v)
	Get the name of the header and the name of the respective member of a packet. More...

function	packetGetHeaders (self)
	Get all headers of a packet as list. More...

function	packetGetHeader (self, h)
	Get the specified header of a packet (e.g. More...

function	packetDump (self, bytes)
	Print a hex dump of a packet. More...

function	packetFill (self, namedArgs)
	Set all members of all headers. More...

function	packetGet (self)
	Retrieve the values of all members as list of named arguments. More...

function	packetResolveLastHeader (self)
	Try to find out what the next header in the payload of this packet is. More...

function	packetSetLength (args)
	Set length for all headers. More...

function	packetCalculateChecksums (args)
	Calculate all checksums manually (not offloading them). More...

function	packetMakeStruct (...)
	Creates a packet struct (cdata) consisting of different headers. More...

Variables
local	pkt = {}
	Module for packets (rte_mbuf)

pkt	packetStructs = {}
	Table that contains the names and args of all created packet structs.

Detailed Description

Utility functions for packets (rte_mbuf).

Includes:

General functions (timestamping, rate control, ...)
Offloading
Create packet types

Definition in file packet.lua.

Function Documentation

function pkt dump ( bytes )

Dumps the packet data cast to the best fitting packet struct.

Parameters

bytes number of bytes to dump, optional

Examples:: l3-tcp-syn-flood.lua.

function pkt enableTimestamps ( )

Todo:: TODO docu

function pkt get ( )

Returns the packet data cast to the best fitting packet struct.

Starting with ethernet header.

Returns: packet data as cdata of best fitting packet

function getHeaderMember ( v )

Get the name of the header and the name of the respective member of a packet.

Parameters

v	Either the name of the header (then the member has the same name), or a table { header, member }

Returns: Name of the header; Name of the member

function pkt getTimestamp ( )

Retrieve the time stamp information.

Returns: The timestamp or nil if the packet was not time stamped.

function pkt hasTimestamp ( )

Check if the PKT_RX_IEEE1588_TMST flag is set.

Turns out that this flag is pretty pointless, it does not indicate if the packet was actually timestamped, just that it came from a queue/filter with timestamping enabled. You probably want to use device:hasTimestamp() and check the sequence number.

function pkt offloadIPChecksum	(	ipv4	,
		l2_len	,
		l3_len
	)

Instruct the NIC to calculate the IP checksum for this packet.

Parameters

ipv4	Boolean to decide whether the packet uses IPv4 (set to nil/true) or IPv6 (set to anything else). In case it is an IPv6 packet, do nothing (the header has no checksum).
l2_len	Length of the layer 2 header in bytes (default 14 bytes for ethernet).
l3_len	Length of the layer 3 header in bytes (default 20 bytes for IPv4).

function pkt offloadIPSec	(	idx	,
		sec_type	,
		esp_mode
	)

Use IPsec offloading.

Parameters

idx	SA_IDX to use
sec_type	IPSec type to use ("esp"/"ah")
esp_mode	ESP mode to use encrypt(1) or authenticate(0)

function pkt offloadTcpChecksum	(	ipv4	,
		l2_len	,
		l3_len
	)

Instruct the NIC to calculate the IP and TCP checksum for this packet.

Parameters

ipv4	Boolean to decide whether the packet uses IPv4 (set to nil/true) or IPv6 (set to anything else).
l2_len	Length of the layer 2 header in bytes (default 14 bytes for ethernet).
l3_len	Length of the layer 3 header in bytes (default 20 bytes for IPv4, 40 bytes for IPv6).

function pkt offloadUdpChecksum	(	ipv4	,
		l2_len	,
		l3_len
	)

Instruct the NIC to calculate the IP and UDP checksum for this packet.

Parameters

ipv4	Boolean to decide whether the packet uses IPv4 (set to nil/true) or IPv6 (set to anything else).
l2_len	Length of the layer 2 header in bytes (default 14 bytes for ethernet).
l3_len	Length of the layer 3 header in bytes (default 20 bytes for IPv4, 40 bytes for IPv6).

function packetCalculateChecksums ( args )

Calculate all checksums manually (not offloading them).

There also exist functions to calculate the checksum of only one header. Naming convention: pkt:calculate<member>Checksum() (for all existing packets member = {Ip, Tcp, Udp, Icmp})

Note: Calculating checksums manually is extremely slow compared to offloading this task to the NIC (~65% performance loss at the moment)

Todo:: Manual calculation of udp and tcp checksums NYI

function packetCreate ( ... )

Create struct and functions for a new packet.

For implemented headers (see proto/) these packets are defined in the section 'Packet struct' of each protocol file

Parameters

args	list of keywords (see makeStruct)

Returns: returns the constructor/cast function for this packet

See Also: packetMakeStruct

function packetDump	(	self	,
		bytes
	)

Print a hex dump of a packet.

Parameters

self	the packet
bytes	Number of bytes to dump. If no size is specified the payload is truncated.

function packetFill	(	self	,
		namedArgs
	)

Set all members of all headers.

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. The argument 'pktLength' can be used to automatically calculate and set the length member of headers (e.g. ip header).

fill() --- only default values
fill{ ethSrc="12:23:34:45:56:67", ipTTL=100 } --- all members are set to default values with the exception of ethSrc and ipTTL
fill{ pktLength=64 } --- only default values, length members of the headers are adjusted

Parameters

self	The packet
args	Table of named arguments. For a list of available arguments see "See also"

Note: This function is slow. If you want to modify members of a header during a time critical section of your script use the respective setters.

function packetGet ( self )

Retrieve the values of all members as list of named arguments.

Parameters

self	The packet

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

See Also: packetFill

function packetGetHeader	(	self	,
		h
	)

Get the specified header of a packet (e.g.

self.eth).

Parameters

self	the packet (cdata)
h	header to be returned

Returns: The member of the packet

function packetGetHeaders ( self )

Get all headers of a packet as list.

Parameters

self	The packet

Returns: Table of members of the packet

function packetMakeStruct ( ... )

Creates a packet struct (cdata) consisting of different headers.

Simply list the headers in the order you want them to be in a packet. If you want the member to be named differently, use the following syntax: normal: <header> ; different membername: { <header>, <member> }. Supported keywords: eth, arp, ptp, ip, ip6, udp, tcp, icmp

makeStruct('eth', { 'ip4', 'ip' }, 'udp') --- creates an UDP packet struct

--- the ip4 member of the packet is named 'ip'

The name of the created (internal) struct looks as follows: struct HEADER1_MEMBER1__HEADER2_MEMBER2 ... Only the "</strong>" (double underscore) has the special meaning of "a new header starts with name everything until "_" (single underscore)>, followed by the member name <everything after "_" until next header starts (indicated by next __)>"

Parameters

args list of keywords/tables of keyword-member pairs

Returns
name name of the struct

ctype ctype of the struct

function packetResolveLastHeader ( self )

Try to find out what the next header in the payload of this packet is.

This function is only used for buf:get/buf:dump

Parameters

self	The packet

function packetSetLength ( args )

Set length for all headers.

Necessary when sending variable sized packets.

Parameters

self	The packet
length	Length of the packet. Value for respective length member of headers get calculated using this value.

function pkt setESPTrailerLength ( len )

Set the ESP trailer length.

Parameters

len	ESP Trailer length in bytes

function pkt setRate ( rate )

Todo:: TODO docu

function pkt setSize ( size )

Todo:: TODO does

Functions

Variables

Detailed Description

Function Documentation