arp.lua File Reference

Address resolution protocol (ARP) utility. More...

Go to the source code of this file.

Functions
function arpHeader	setHardwareAddressType (int)
	Set the hardware address type. More...
function arpHeader	getHardwareAddressType ()
	Retrieve the hardware address type. More...
function arpHeader	getHardwareAddressTypeString ()
	Retrieve the hardware address type. More...
function arpHeader	setProtoAddressType (int)
	Set the protocol address type. More...
function arpHeader	getProtoAddressType ()
	Retrieve the protocol address type. More...
function arpHeader	getProtoAddressTypeString ()
	Retrieve the protocol address type. More...
function arpHeader	setHardwareAddressLength (int)
	Set the hardware address length. More...
function arpHeader	getHardwareAddressLength ()
	Retrieve the hardware address length. More...
function arpHeader	getHardwareAddressLengthString ()
	Retrieve the hardware address length. More...
function arpHeader	setProtoAddressLength (int)
	Set the protocol address length. More...
function arpHeader	getProtoAddressLength ()
	Retrieve the protocol address length. More...
function arpHeader	getProtoAddressLengthString ()
	Retrieve the protocol address length. More...
function arpHeader	setOperation (int)
	Set the operation. More...
function arpHeader	getOperation ()
	Retrieve the operation. More...
function arpHeader	getOperationString ()
	Retrieve the operation. More...
function arpHeader	setHardwareSrc (addr)
	Set the hardware source address. More...
function arpHeader	getHardwareSrc ()
	Retrieve the hardware source address. More...
function arpHeader	setHardwareSrcString (addr)
	Set the hardware source address. More...
function arpHeader	getHardwareSrcString ()
	Retrieve the hardware source address. More...
function arpHeader	setHardwareDst (addr)
	Set the hardware destination address. More...
function arpHeader	getHardwareDst ()
	Retrieve the hardware destination address. More...
function arpHeader	setHardwareDstString (addr)
	Set the hardware destination address. More...
function arpHeader	getHardwareDstString ()
	Retrieve the hardware destination address. More...
function arpHeader	setProtoSrc (addr)
	Set the protocol source address. More...
function arpHeader	getProtoSrc ()
	Retrieve the protocol source address. More...
function arpHeader	setProtoSrcString (addr)
	Set the protocol source address. More...
function arpHeader	getProtoSrcString ()
	Retrieve the protocol source address. More...
function arpHeader	setProtoDst (addr)
	Set the protocol destination address. More...
function arpHeader	getProtoDst ()
	Retrieve the protocol destination address. More...
function arpHeader	setProtoDstString (addr)
	Set the protocol destination address. More...
function arpHeader	getProtoDstString ()
	Retrieve the protocol destination address. More...
function arpHeader	fill (args, pre)
	Set all members of the ip header. More...
function arpHeader	get (pre)
	Retrieve the values of all members. More...
function arpHeader	getString ()
	Retrieve the values of all members. More...
function arpHeader	resolveNextHeader ()
	Resolve which header comes after this one (in a packet). More...
function arpHeader	setDefaultNamedArgs (pre, namedArgs, nextHeader, accumulatedLength)
	Change the default values for namedArguments (for fill/get). More...
local function	arpTask (qs)
	Arp handler task. More...
function arp	lookup (ip)
	Perform a lookup in the ARP table. More...
function arp	blockingLookup (ip, timeout)
	Perform a non-blocking lookup in the ARP table. More...

Variables
local	arp = {}
	Arp protocol constants.
arp	HARDWARE_ADDRESS_TYPE_ETHERNET = 1
	Hardware address type for ethernet.
arp	PROTO_ADDRESS_TYPE_IP = 0x0800
	Proto address type for IP (for ethernet based protocols uses etherType numbers ethernet.lua)
arp	OP_REQUEST = 1
	Operation: request.
arp	OP_REPLY = 2
	Operation: reply.
local	arpHeader = {}
	Module for arp_header struct (see headers.lua).
pkt	getArpPacket = packetCreate("eth", "arp")
	Cast the packet to an Arp packet.
arp	arpTask = "__MG_ARP_TASK"
	Arp handler task, responds to ARP queries for given IPs and performs arp lookups. More...
local	arpTable = ns:get()
	Arp table TODO docu.

Detailed Description

Address resolution protocol (ARP) utility.

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

• Arp constants
• Arp address utility
• Arp header utility
• Definition of Arp packets
• Arp handler task

Definition in file arp.lua.

Function Documentation

local function arpTask

(

qs

)

Arp handler task.

Parameters

qs

TODO

Todo:

TODO docu

function arp blockingLookup	(	ip	,
		timeout
	)

Perform a non-blocking lookup in the ARP table.

Parameters

ip	The ip address in string or cdata format to look up.
timeout	TODO

Todo:

FIXME: this only sends a single request

function arpHeader 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: HardwareAddressType, ProtoAddressType, HardwareAddressLength, ProtoAddressLength, Operation, HardwareSrc, HardwareDst, ProtoSrc, ProtoDst
pre	prefix for namedArgs. Default 'arp'. fill() --- only default values fill{ arpOperation=2, ipTTL=100 } --- all members are set to default values with the exception of arpOperation

function arpHeader get

(

pre

)

Retrieve the values of all members.

Parameters

pre	prefix for namedArgs. Default 'arp'.

Returns

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

See Also

arpHeader:fill

function arpHeader getHardwareAddressLength

(

)

Retrieve the hardware address length.

Returns

Length as 8 bit integer.

function arpHeader getHardwareAddressLengthString

(

)

Retrieve the hardware address length.

Returns

Length in string format.

function arpHeader getHardwareAddressType

(

)

Retrieve the hardware address type.

Returns

Type as 16 bit integer.

function arpHeader getHardwareAddressTypeString

(

)

Retrieve the hardware address type.

Returns

Type in string format.

function arpHeader getHardwareDst

(

)

Retrieve the hardware destination address.

Returns

Address in 'struct mac_address' format.

function arpHeader getHardwareDstString

(

)

Retrieve the hardware destination address.

Returns

Address in string format.

function arpHeader getHardwareSrc

(

)

Retrieve the hardware source address.

Returns

Address in 'struct mac_address' format.

function arpHeader getHardwareSrcString

(

)

Retrieve the hardware source address.

Returns

Address in string format.

function arpHeader getOperation

(

)

Retrieve the operation.

Returns

Operation as 16 bit integer.

function arpHeader getOperationString

(

)

Retrieve the operation.

Returns

Operation in string format.

function arpHeader getProtoAddressLength

(

)

Retrieve the protocol address length.

Returns

Length as 8 bit integer.

function arpHeader getProtoAddressLengthString

(

)

Retrieve the protocol address length.

Returns

Length in string format.

function arpHeader getProtoAddressType

(

)

Retrieve the protocol address type.

Returns

Type as 16 bit integer.

function arpHeader getProtoAddressTypeString

(

)

Retrieve the protocol address type.

Returns

Type in string format.

function arpHeader getProtoDst

(

)

Retrieve the protocol destination address.

Returns

Address in 'struct ip4_address' format.

function arpHeader getProtoDstString

(

)

Retrieve the protocol destination address.

Returns

Address in string format.

function arpHeader getProtoSrc

(

)

Retrieve the protocol source address.

Returns

Address in 'struct ip4_address' format.

function arpHeader getProtoSrcString

(

)

Retrieve the protocol source address.

Returns

Address in string format.

function arpHeader getString

(

)

Retrieve the values of all members.

Returns

Values in string format.

function arp lookup

(

ip

)

Perform a lookup in the ARP table.

Lookup the MAC address for a given IP. Blocks for up to 1 second if the arp task is not yet running Caution: this function uses locks and namespaces, must not be used in the fast path

Parameters

ip	The ip address in string or cdata format to look up.

function arpHeader 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 arpHeader 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. 'arp'
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

arpHeader:fill

function arpHeader setHardwareAddressLength

(

int

)

Set the hardware address length.

Parameters

int	Length as 8 bit integer.

function arpHeader setHardwareAddressType

(

int

)

Set the hardware address type.

Parameters

int	Type as 16 bit integer.

function arpHeader setHardwareDst

(

addr

)

Set the hardware destination address.

Parameters

addr	Address in 'struct mac_address' format.

function arpHeader setHardwareDstString

(

addr

)

Set the hardware destination address.

Parameters

addr	Address in string format.

function arpHeader setHardwareSrc

(

addr

)

Set the hardware source address.

Parameters

addr	Address in 'struct mac_address' format.

function arpHeader setHardwareSrcString

(

addr

)

Set the hardware source address.

Parameters

addr	Address in string format.

function arpHeader setOperation

(

int

)

Set the operation.

Parameters

int	Operation as 16 bit integer.

function arpHeader setProtoAddressLength

(

int

)

Set the protocol address length.

Parameters

int	Length as 8 bit integer.

function arpHeader setProtoAddressType

(

int

)

Set the protocol address type.

Parameters

int	Type as 16 bit integer.

function arpHeader setProtoDst

(

addr

)

Set the protocol destination address.

Parameters

addr	Address in 'struct ip4_address' format.

function arpHeader setProtoDstString

(

addr

)

Set the protocol destination address.

Parameters

addr	Address in string format.

function arpHeader setProtoSrc

(

addr

)

Set the protocol source address.

Parameters

addr	Address in 'struct ip4_address' format.

function arpHeader setProtoSrcString

(

addr

)

Set the protocol source address.

Parameters

addr	Address in source format.

Variable Documentation

arp arpTask = "__MG_ARP_TASK"

Arp handler task, responds to ARP queries for given IPs and performs arp lookups.

Todo:

TODO implement garbage collection/refreshing entries
the current implementation does not handle large tables efficiently

TODO multi-NIC support

Definition at line 233 of file arp.lua.