This is a test application that acts as a transport layer proxy. Note that is has only been tested with a TCP transport.

One simple way to test the application is to add a tap interface to vpp, start a python `SimpleHTTPServer `that listens for connections incoming on the tap interface and, finally, a client that connects via a second vpp interface to the proxied content. The second interface can be a dpdk interface or another tap interface. In the example below, we use a dpdk interface.

Start vpp with a dpdk interface and add a tap interface:

```
# set int ip address <dpdk-interface> 6.0.1.1/24
# set int state <dpdk-interface> up
# create tap host-ip4-addr 6.0.2.2/24
# set int ip addr tap0 6.0.2.1/24
# set int state tap0 up
```

Start the proxy app on the host:

```
# test proxy server server-uri tcp://0.0.0.0/80 client-uri tcp://6.0.2.2/80
```

From a different host with connectivity to the `dpdk-interface `:

[http://6.0.1.1/test-content](http://6.0.1.1/test-content)

```
$ wget
```

Note that this assumes that a file named "test-content" exists in the folder wherefrom the `SimpleHTTPServer `was started.

## Test the proxy with namespaces
In this example, we create two namespaces, one from the client and an other one for the server, both are connected through a VPP instance that will proxy a tcp connection.

Create the client namespace:

```
# ip netns add client
# ip link add vpp0 type veth peer name client
# ip link set dev client netns client
# ip netns exec client ip link set dev lo up
# ip netns exec client ip link set dev client up
# ip netns exec client ip addr add 10.0.0.1/24 dev client
# ip link set dev vpp0 up
```

Create the server namespace:

```
# ip netns add server
# ip link add vpp1 type veth peer name server
# ip link set dev server netns server
# ip netns exec server ip link set dev lo up
# ip netns exec server ip link set dev server up
# ip netns exec server ip addr add 10.0.1.1/24 dev server
# ip link set dev vpp1 up
```

Run and configure VPP:

```
# vpp unix { cli-listen /run/vpp/cli-vpp1.sock } api-segment { prefix vpp1 }
# vppctl -s /run/vpp/cli-vpp1.sock create host-interface name vpp0
# vppctl -s /run/vpp/cli-vpp1.sock set interface state host-vpp0 up
# vppctl -s /run/vpp/cli-vpp1.sock set interface ip address host-vpp0 10.0.0.2/24
# vppctl -s /run/vpp/cli-vpp1.sock create host-interface name vpp1
# vppctl -s /run/vpp/cli-vpp1.sock set interface state host-vpp1 up
# vppctl -s /run/vpp/cli-vpp1.sock set interface ip address host-vpp1 10.0.1.2/24
```

Run the proxy:

```
# vppctl -s /run/vpp/cli-vpp1.sock test proxy server server-uri tcp://10.0.0.2/555 client-uri tcp://10.0.1.1/666
```

And test it:

```
# ip netns exec server truncate -s 10M 10M
# ip netns exec server python -m SimpleHTTPServer 666 &
# ip netns exec client wget 10.0.0.2:555/10M -O rcv.img
```