Opinions on Proxy Servers I'm writing

[Mike Tom Frantzen <frantzen () expert cc purdue edu>]

Hello World,

I've been writing a group of proxy servers recently in an attempt to avoid
studying for finals :-)

The proxies use Darren Reed's IPF/IPFilter to transparently redirect a
connection to the proxy running on localhost.  I've gotten them working on
OpenBSD 2.4, Sparc Solaris 2.7/5.7/7, and NetBSD 1.3.something.

What I have working:
        . A drop-in proxy that does no analysis (useful for full packet/header
                reassmbly)  Similar to the 'plug' in Ranum's FWTK.
        . An SMTP proxy.  I still need to fix up the line analysis portion.
                Still have to implement anti-spam relaying, and restrict
                commands (expn etc).... and more.
        . The groundwork of a Telnet proxy, just found out about 
                /usr/include/arpa/telnet.h, life is easier now!
        . Max connections allowed from a host (prevent resource attacks)

I have most of the skeleton stuff done for new proxies.


Planned:        - Ftp Proxy
                        . Dynamically open port for data connection.
                - Finger Proxy
                - Imap or Pop Proxy
                - Pattern matching/rewriting inside a packet.
                - Hooks for IPFWADM, IPCHAINS, and IPFW.
                        ( no it doesn't work in linux yet )
                - Some Authentication method ?


Any suggestions || comments || something you think would be cool to implement?
And yes I know about FWTK.  This will be done under the BSD license.

Keep in mind this is all subject to how much free time I have over the
summer and between classes/projects.


thanks,
.mike