gopacket

Documentation

Overview

gopacket is a simple example showing how to answer APR and ICMP echo requests through a memif interface. This example is mostly identical to icmp-responder example, but it is using MemifPacketHandle API to read and write packets using gopacket API.

The appropriate VPP configuration for the opposite memif is:

vpp$ create memif socket id 1 filename /tmp/gopacket-example
vpp$ create interface memif id 1 socket-id 1 slave secret secret no-zero-copy
vpp$ set int state memif1/1 up
vpp$ set int ip address memif1/1 192.168.1.2/24

To start the example, simply type:

root$ ./gopacket

gopacket needs to be run as root so that it can access the socket created by VPP.

Normally, the memif interface is in the master mode. Pass CLI flag "--slave" to create memif in the slave mode:

root$ ./gopacket --slave

Don't forget to put the opposite memif into the master mode in that case.

To verify the connection, run:

vpp$ ping 192.168.1.1
64 bytes from 192.168.1.1: icmp_seq=2 ttl=255 time=.6974 ms
64 bytes from 192.168.1.1: icmp_seq=3 ttl=255 time=.6310 ms
64 bytes from 192.168.1.1: icmp_seq=4 ttl=255 time=1.0350 ms
64 bytes from 192.168.1.1: icmp_seq=5 ttl=255 time=.5359 ms

Statistics: 5 sent, 4 received, 20% packet loss
vpp$ sh ip arp
Time           IP4       Flags      Ethernet              Interface
68.5648   192.168.1.1     D    aa:aa:aa:aa:aa:aa memif0/1

Note: it is expected that the first ping is shown as lost. It was actually converted to an ARP request. This is a VPP feature common to all interface types.

Stop the example with an interrupt signal.