utils.lua File Reference

Defines general utility functions. More...

Go to the source code of this file.

Functions
function	printf (str,...)
	Print a formatted string. More...
function	errorf (str,...)
	Print a formatted error string. More...
function	mapVarArg (f,...)
	TODO. More...
function	map (t, f)
	TODO. More...
function	tostringall (...)
	TODO. More...
function	tonumberall (...)
	TODO. More...
function	toCsv (...)
	TODO. More...
function	printCsv (...)
	TODO. More...
function	poissonDelay (average)
	Get the time to wait (in byte-times) for the next packet based on a poisson process. More...
function	rateToByteDelay (rate, size)
	TODO. More...
function	bswap16 (n)
	Byte swap for 16 bit integers. More...
function	checksum (data, len)
	Calculate a 16 bit checksum. More...
function	parseMacAddress (mac)
	Parse a string to a MAC address. More...
function	parseIPAddress (ip)
	Parse a string to an IP address. More...
function	parseIP4Address (ip)
	Parse a string to an IPv4 address. More...
function	parseIP6Address (ip)
	Parse a string to an IPv6 address. More...
function	getTimeMicros ()
	Retrieve the system time with microseconds accuracy. More...
function	dumpHex (data, bytes)
	Print a hex dump of cdata. More...
function	mergeTables (...)
	Merge tables. More...
function	range (max, start,...)
	Return all integerss in the range [start, max]. More...
function	incAndWrap (val, max)
	Increment a wrapping counter, i.e. More...

Detailed Description

Defines general utility functions.

Todo:

TODO docu

local unpackers ... crashes lua2dox parser

Definition in file utils.lua.

Function Documentation

function bswap16

(

n

)

Byte swap for 16 bit integers.

Parameters

n	16 bit integer

Returns

Byte swapped integer

function checksum	(	data	,
		len
	)

Calculate a 16 bit checksum.

Parameters

data	cdata to calculate the checksum for.
len	Number of bytes to calculate the checksum for.

Returns

16 bit integer

function dumpHex	(	data	,
		bytes
	)

Print a hex dump of cdata.

Parameters

data	The cdata to be dumped.
bytes	Number of bytes to dump.

function errorf	(	str	,
			...
	)

Print a formatted error string.

Todo:

docu

Parameters

str
args

Examples:

l2-poisson-load-latency.lua, l3-tcp-syn-flood.lua, and timestamps.lua.

function getTimeMicros

(

)

Retrieve the system time with microseconds accuracy.

Todo:

use some C function to get microseconds.

Returns

System time in hh:mm:ss.uuuuuu format.

function incAndWrap	(	val	,
		max
	)

Increment a wrapping counter, i.e.

(val + 1) % max This function is optimized to generate branchless code and faster than a naive modulo-based implementation.

Note

: all attempts to wrap this in a nice and simple class have failed (~30% performance impact).

Parameters

val	Current value (number)
max	Maximum allowed value of val (number)

Returns

Incremented and wrapped number

Examples:

l3-tcp-syn-flood.lua.

function map	(	t	,
		f
	)

TODO.

Todo:

docu

Parameters

t
f

Returns

function mapVarArg	(	f	,
			...
	)

TODO.

Todo:

docu

Parameters

f
args

Returns

function mergeTables

(

...

)

Merge tables.

Parameters

args	Arbitrary amount of tables to get merged.

function parseIP4Address

(

ip

)

Parse a string to an IPv4 address.

Parameters

ip	address in string format

Returns

address in uint32 format or nil if invalid address

function parseIP6Address

(

ip

)

Parse a string to an IPv6 address.

Parameters

ip	address in string format

Returns

address in ip6_address format or nil if invalid address

function parseIPAddress

(

ip

)

Parse a string to an IP address.

Returns

address ip address in ip4_address or ip6_address format or nil if invalid address

boolean true if IPv4 address, false otherwise

Examples:

l3-tcp-syn-flood.lua, and quality-of-service-test.lua.

function parseMacAddress

(

mac

)

Parse a string to a MAC address.

Parameters

mac	address in string format

Returns

address in mac_address format or nil if invalid address

function poissonDelay

(

average

)

Get the time to wait (in byte-times) for the next packet based on a poisson process.

Parameters

average

the average wait time between two packets

Returns

the number of byte-times to wait to achieve the given average wait-time

Examples:

l2-poisson-load-latency.lua.

function printCsv

(

...

)

TODO.

Todo:

docu

Parameters

args

Returns

function printf	(	str	,
			...
	)

Print a formatted string.

Todo:

docu

Parameters

str
args
return

Examples:

l3-tcp-syn-flood.lua, and quality-of-service-test.lua.

function range	(	max	,
		start	,
			...
	)

Return all integerss in the range [start, max].

Parameters

max	upper bound
start	lower bound, default = 1

function rateToByteDelay	(	rate	,
		size
	)

TODO.

Todo:

docu

Parameters

rate
size

Returns

function toCsv

(

...

)

TODO.

Todo:

docu

Parameters

args

Returns

function tonumberall

(

...

)

TODO.

Todo:

docu

Parameters

args

Returns

Examples:

l2-poisson-load-latency.lua.

function tostringall

(

...

)

TODO.

Todo:

docu

Parameters

args

Returns