Send and Capture icmp packets with type&code using hping

Here TCL script files are run at terminals of different hosts setup in a mininet environment. The code at one host generates packets of different ICMP types and codes (Please refer to different types and codes associated with ICMP packets at https://www.iana.org/assignments/icmp-parameters/icmp-parameters.xhtml). The code run at the second host captures these packets and extract the type and code fields. Here hping3, TCL and mininet are installed on Ubuntu system for the experiment.

I)   SCRIPTS

Script for creating mininet hosts

~~~~~~~~~~~~~~~~~~~~

Save the following in net.py

from mininet.topo import Topo

class MyTopo( Topo ):

    def __init__( self ):

        Topo.__init__( self )

        # Add hosts and switches
        left_host = self.addHost( 'h0' )
        right_host = self.addHost( 'h1' )
        centre_switch = self.addSwitch( 's0' )

        # Add links
        self.addLink( left_host, centre_switch )
        self.addLink( right_host, centre_switch )
        self.addLink( centre_switch, left_host )
        self.addLink( centre_switch, right_host )

topos = { 'mytopo': ( lambda: MyTopo() ) }

Script for capturing ICMP packets

~~~~~~~~~~~~~~~~~~~~~

Save the following in receive_ICMP.htcl

while 1 {
        set p [lindex [hping recv h2-eth0] 0]
        puts "type is [hping getfield icmp type $p] and code is [hping getfield icmp code $p]"
    }

Script for sending ICMP packets

~~~~~~~~~~~~~~~~~~~~

The script iterates over different types and codes of ICMP and creates the packets. Save the following in send_ICMP.htcl

 foreach i {5 8 9 10 11 12 13 14 15 16 17 18} {
    if {$i==5} {
        foreach j {0 1 2 3} {
            hping send "ip(daddr=10.0.0.2)+icmp(type=$i,code=$j)"
        }
    } elseif {$i==8 || $i == 9 || $i == 10 || $i == 13 || $i == 14 || $i ==  15 || $i == 16 || $i == 17 || $i == 18} {
        foreach j {0} {
            hping send "ip(daddr=10.0.0.2)+icmp(type=$i,code=$j)"
        }
    } elseif {$i == 11 || $i == 12} {
        foreach j {0 1} {
            hping send "ip(daddr=10.0.0.2)+icmp(type=$i,code=$j)"
        }
    }
}

 

II)   EXECUTION STEPS

1) Create two hosts (h0 and h1) in mininet by running

sudo mn --custom net.py --topo mytopo

 
2) Listen for packets and print icmp types and codes using tcl script 'receive_ICMP.htcl' from h1 host

hping3 exec receive_ICMPv1.htcl

 
3) Send icmp packets of different types and codes using tcl script 'send_ICMP.htcl' from h0 host

hping3 exec send_ICMPv1.htcl

Type and code fields of ICMP packets are captured and printed at h1 host