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diff --git a/extras/libmemif/README.md b/extras/libmemif/README.md index 3b692b1..854aa96 100644 --- a/extras/libmemif/README.md +++ b/extras/libmemif/README.md @@ -103,6 +103,14 @@ Do not touch memif after it was closed, let garbage collector to remove the `Memif` instance. In the end, `Cleanup()` will also ensure that all active memif interfaces are closed before the cleanup finalizes. +To use libmemif with `google/gopacket`, simply call `Memif.NewPacketHandle()` +to create `google/gopacket/PacketDataSource` from memif queue. After this you +can use gopacket API to read from `MemifPacketHandle` as normal. You can pass +optional `rxCount` when creating the packet handle and then when reading data, +handle will try to read more packets at once and cache them for next iteration. +Handle also includes convenience method `MemifPacketHandle.WritePacketData()` +that is simply calling 1 `Memif.TxBurst()` for provided data. + ### Examples **Go-libmemif** ships with two simple examples demonstrating the usage @@ -185,4 +193,55 @@ vpp$ sh ip arp It was actually converted to an ARP request. This is a VPP specific feature common to all interface types. -Stop the example with an interrupt signal (^C).
\ No newline at end of file +Stop the example with an interrupt signal (^C). + +#### GoPacket ICMP Responder + +*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 + specific feature common to all interface types. + +Stop the example with an interrupt signal (^C). |