Hello netfilter group, Currently, I know that IPTABLES, listens to see where a packet is going to and/or which port it's attempting to connect, as well as NAT capabilities.
However, is there a way to look at the content of the packet, that hasn't been encrypted, read to see if there is mail header information, or a virus, and block the transmission? The Scenario for such a question: I have about 500 Publicly accessible PCs, some behind an IPTABLES NAT for testing purposes. I have prevented web based SSL communications, to block on line bank statement, credit card purchases, and other SSL based transaction. I was getting to many complaints from user's requesting that we remove their personal information from the PCs, and I was getting tired of having to explain to them what a public terminal is. I began to block certain email sites as well, for example, hotmail, yahoo, excite, and others to name a few. I was asked that we prevent users from considering these machines as their personal workstations. However, the email sites have become vast, and blocking everyone of them is damn near impossible. I was hoping with IPTABLES, I can or could read the packet, check the contents, and intelligently deny or accept the packet based on the content. Please let me know if this is something that is doable, or will I have to write code that works with IPTABLES for such a task? Thanks, Tanniel Simonian Programmer/Analyst III UC Riverside Libraries
