Example setup {#libmemif_example_setup_doc}

VPP-memif master icmp_responder slave

Libmemif example app(s) use memif default socket file: /run/vpp/memif.sock.

Run VPP and icmpr-epoll example (default example when running in container).

Other examples work similar to icmpr-epoll. Brief explanation can be found in @ref libmemif_examples_doc .

VPP-side config:

DBGvpp# create memif id 0 master
DBGvpp# set int state memif0/0 up
DBGvpp# set int ip address memif0/0 192.168.1.1/24

icmpr-epoll:

conn 0 0

Memif in slave mode will try to connect every 2 seconds. If connection establishment is successfull, a message will show.

INFO: memif connected!

Error messages like "unmatched interface id" are printed only in debug mode.

Check connected status. Use show command in icmpr-epoll:

show
MEMIF DETAILS
==============================
interface index: 0
	interface ip: 192.168.1.2
	interface name: memif_connection
	app name: ICMP_Responder
	remote interface name: memif0/0
	remote app name: VPP 17.10-rc0~132-g62f9cdd
	id: 0
	secret: 
	role: slave
	mode: ethernet
	socket filename: /run/vpp/memif.sock
	rx queues:
		queue id: 0
		ring size: 1024
		buffer size: 2048
	tx queues:
		queue id: 0
		ring size: 1024
		buffer size: 2048
	link: up
interface index: 1
	no connection

Use sh memif command in VPP:

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 icmpr-epoll:

DBGvpp# ping 192.168.1.2
64 bytes from 192.168.1.2: icmp_seq=2 ttl=64 time=.1888 ms
64 bytes from 192.168.1.2: icmp_seq=3 ttl=64 time=.1985 ms
64 bytes from 192.168.1.2: icmp_seq=4 ttl=64 time=.1813 ms
64 bytes from 192.168.1.2: icmp_seq=5 ttl=64 time=.1929 ms

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

multiple queues VPP-memif slave icmp_responder master

Run icmpr-epoll as in previous example setup. Run VPP with startup conf, enabling 2 worker threads. Example startup.conf:

unix {
  interactive
  nodaemon
  full-coredump
}

cpu {
  workers 2
}

VPP-side config:

DBGvpp# create memif id 0 slave rx-queues 2 tx-queues 2
DBGvpp# set int state memif0/0 up
DBGvpp# set int ip address memif0/0 192.168.1.1/24

icmpr-epoll:

conn 0 1

When connection is established a message will print:

INFO: memif connected!

Error messages like "unmatched interface id" are printed only in debug mode.

Check connected status. Use show command in icmpr-epoll:

show
MEMIF DETAILS
==============================
interface index: 0
	interface ip: 192.168.1.2
	interface name: memif_connection
	app name: ICMP_Responder
	remote interface name: memif0/0
	remote app name: VPP 17.10-rc0~132-g62f9cdd
	id: 0
	secret: 
	role: master
	mode: ethernet
	socket filename: /run/vpp/memif.sock
	rx queues:
		queue id: 0
		ring size: 1024
		buffer size: 2048
		queue id: 1
		ring size: 1024
		buffer size: 2048
	tx queues:
		queue id: 0
		ring size: 1024
		buffer size: 2048
		queue id: 1
		ring size: 1024
		buffer size: 2048
	link: up
interface index: 1
	no connection

Use sh memif command in VPP:

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 slave connected
  listener-fd -1 conn-fd 12
  num-s2m-rings 2 num-m2s-rings 2 buffer-size 2048
    slave-to-master ring 0:
      region 0 offset 0 ring-size 1024 int-fd 14
      head 0 tail 0 flags 0x0000 interrupts 0
    slave-to-master ring 1:
      region 0 offset 32896 ring-size 1024 int-fd 15
      head 0 tail 0 flags 0x0000 interrupts 0
    slave-to-master ring 0:
      region 0 offset 65792 ring-size 1024 int-fd 16
      head 0 tail 0 flags 0x0001 interrupts 0
    slave-to-master ring 1:
      region 0 offset 98688 ring-size 1024 int-fd 17
      head 0 tail 0 flags 0x0001 interrupts 0

Send ping from VPP to icmpr-epoll:

DBGvpp# ping 192.168.1.2
64 bytes from 192.168.1.2: icmp_seq=2 ttl=64 time=.1439 ms
64 bytes from 192.168.1.2: icmp_seq=3 ttl=64 time=.2184 ms
64 bytes from 192.168.1.2: icmp_seq=4 ttl=64 time=.1458 ms
64 bytes from 192.168.1.2: icmp_seq=5 ttl=64 time=.1687 ms

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

icmp_responder master icmp_responder slave

Example apps can only repond to ping. This setup creates connection between two applications using libmemif. Traffic functionality is the same as when connection to VPP. App can receive ARP/ICMP request and transmit response, but can not send ARP/ICMP request.

Run two instances of icmpr-epoll example.

If not running in container, make sure folder /run/vpp/ exists before creating memif master. Instance 1 will be in master mode, instance 2 in slave mode. instance 1:

conn 0 1

instance 2:

conn 0 0

In 2 seconds, both instances should print connected! message:

INFO: memif connected!

Check peer interface names using show command.