Segfault in examples/dns on a malformed DNS packet

[pictyeye]

The attached packet (found using AFL) triggers a segmentation fault in act_domain (dns.c): segfaulter.txt (NB: I had to base64 encode the packet to submit the issue on GH)

To reproduce the bug, you must first run the dns server using

scons examples
build/opt/examples/dns

Then, you can trigger the segfault using

openssl enc -d -base64 < segfaulter.txt | nc localhost 53