enable the opnsense test ruleset and try to download the eicar virus:

http://www.eicar.org/download/eicar.com.txt

it should block (over http)

closes https://github.com/opnsense/core/issues/884

Only one function left.  :)

BTW: 5000 commits on master branch, yay, party!

Needs a bit of observation, but as far as I can see the only difference
is that is_numeric() will also take int values and return true for them,
ctype_digit() will only return true for string values that have digits.

Taken from: http://www.iana.org/assignments/icmp-parameters/icmp-parameters.xhtml