Libmemif Examples

Example source code is located in …/vpp/extras/libmemif/examples/ directory. The compiled binaries are located in …/vpp/extras/libmemif/build/examples/.

ICMP Responder

Application Source Code: …/vpp/extras/libmemif/examples/icmp_responder

In this example, memif endpoint connects to an external application. The example application can resolve ARP and reply to ICMPv4 packets. The program will exit once the interface is disconnected Memif receive mode: interrupt.

VPP (memif master) <–> icmp_responder app (memif slave)

Start VPP and configure memif interface:

make run
DBGvpp# create interface memif id 0 master
DBGvpp# set int state memif0/0 up
DBGvpp# set int ip address memif0/0

Start icmp_responder example app:


Memif in slave mode will try to connect every 2 seconds. If connection establishment is successful, the memif connected message will show:

INFO: memif connected!

Note: Error messages like “unmatched interface id” are printed only in debug mode.

Verify that the memif is connected on VPP side:

DBGvpp# sh memif
interface memif0/0
remote-name "ICMP_Responder"
remote-interface "memif_connection"
id 0 mode ethernet file /run/vpp/memif.sock
flags admin-up connected
listener-fd 12 conn-fd 13
num-s2m-rings 1 num-m2s-rings 1 buffer-size 0
    master-to-slave ring 0:
    region 0 offset 32896 ring-size 1024 int-fd 16
    head 0 tail 0 flags 0x0000 interrupts 0
    master-to-slave ring 0:
    region 0 offset 0 ring-size 1024 int-fd 15
    head 0 tail 0 flags 0x0001 interrupts 0

Send ping from VPP to icmp_responder (Default IPv4:

DBGvpp# ping
64 bytes from icmp_seq=2 ttl=64 time=.1888 ms
64 bytes from icmp_seq=3 ttl=64 time=.1985 ms
64 bytes from icmp_seq=4 ttl=64 time=.1813 ms
64 bytes from icmp_seq=5 ttl=64 time=.1929 ms

Statistics: 5 sent, 4 received, 20% packet loss


Application Source Code: …/vpp/extras/libmemif/examples/loopback

In this example, two memif endpoints are connected to create a loopback. Once connected, a test packet is sent out the memif master interface to the memif slave interface, which replies with the same packet in a zero-copy way. In reverse mode, the packet is sent from the slave interface and is looped back by the master interface.

Running The Loopback Application

Start the loopback example:


You should see the Received correct data. message:

INFO: Received correct data.
INFO: Stopping the program