Description

This test is intended to test fragmentation offload on virtual machine

How to test

boot a virtual machine
log into this virtual machine, and disable gso function of nic, only enable tso. if you check the function of gso, just disable tso and enable gso
ethtool -K eth0 gso off

ethtool -K etho tso on
check if success to setup tso/gso on guest
```
ethtool -k eth0
```

listen tcp packets on host

nc -l 5334 |tee /tmp/frag_offload.dd >/dev/null

use dd to create a 10M file on guest

dd if=/dev/urandom of=/tmp/frag_offload.dd bs=10M count=1

use tcpdump capture the packets on data link layer on guest

tcpdump -e port 5334 1 >/tmp/frag_offload.tcpdump 2>/dev/null

sent the 10M file to host

cat /tmp/frag_offlaod.dd |nc $hostIP 5334

check if there exists some packet larger than MTU
compute md5sum of /tmp/frag_offload.dd on host and the virtual machine, and check if they are same
```
md5sum /tmp/frag_offload.dd
```