packet-socket
Node.js package implementing socket for receiving OSI layer 2 packets
API
Assume that packet-socket module is required in following examples.
var packet = require('packet-socket')
Opening socket
var socket = packet.openSocket({device: 'lo'})
openSocket call accepts options object as argument. Option device should contain interface name on which open raw packet socket.
Closing socket
socket.close()
Few words about address
Some functions require address as an argument. Formats accepted:
- String 'aa:bb:cc:11:22:33'
- Array [0xaa, 0xbb, 0xcc, 0x11, 0x22, 0x33]
- Buffer new Buffer([0xaa, 0xbb, 0xcc, 0x11, 0x22, 0x33])
Joining and leaving Multicast Membership
socket.joinMC(packet.PROMISCIOUS)
socket.joinMC(packet.ALL_MULTICAST)
socket.joinMC('11:00:de:ad:be:ef')
socket.leaveMC(packet.PROMISCIOUS)
socket.leaveMC(packet.ALL_MULTICAST)
socket.leaveMC('11:00:de:ad:be:ef')
joinMC or leaveMC method accepts as argument either multicast address or integer constant:
- PROMISCIOUS - sets interface to PROMISCIOUS mode, catching all packets
- ALL_MULTICAST - catch all multicast messages
Sending
packet.send(new Buffer('message to send'), '58:00:00:00:00:01', function(err, bytes) {
})
Callback function argument will provide information if send failed, then err will contain information, if it is null, then bytes will contain number of bytes transferred.
Events
Socket returned by openSocket can emit events:
- message - this event is emited when packet is received, it contain buffer with message received, source and destination addresses (in string format)
packet.on('message', function(message, source, destination) {
});
- error - this event is emited in case of any error, it contain error object
packet.on('error', function(error) {});
Packet socket root reqirement
Opening packet (man 7 packet) socket requires root permission or cap_net_raw capability
Testing
Module contains unit test, which can be invoked by command
npm test
This however requires build suite ready, with CppUTest libraries installed.