Upgrading gcc to upgrade clamav to 0.92

I have problem upgrading my clamav 0.91.2 to 0.92 due to bug in gcc 4.0.1 on my Mandriva 2006. So I upgraded my gcc to 4.1.2. I chose to compile from source. It is advisable to refer to successful builds pertaining to the version of gcc to get a clue whether it will successfully build on your target system. I didn't choose later version because I couldn't find any successful build for my system. So I played safe. :P

Download: GNU gcc 4.1.2 (China Mirror)

You have to download at least gcc-core-4.1.2.tar.bz2 and gcc-4.1.2.tar.bz2. I also downloaded gcc-g++-4.1.2.tar.bz2, and gcc-objc-4.1.2.tar.bz2. I didn't download the others because I didn't need them. You may want to download them depends on your requirement.

Untar the tarballs
tar xjvf gcc-core-4.1.2.tar.bz2
tar xjvf gcc-4.1.2.tar.bz2
tar xjvf gcc-g++-4.1.2.tar.bz2
tar xjvf gcc-objc-4.1.2.tar.bz2

The above commands will untar the tarballs into a dir that is gcc-4.1.2. Then, as usual, run ./configure, make and make install. Before you run ./configure, please run ./configure --help to view what parameters needed. Some of the options are autodetected and included by configure itself (ie c/c++ libraries,headers ,etc).

configure
./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var

then you can run make and make install to install it to your system. clamav 0.92 will be successfully compiled with this version of gcc.

UPDATE: Reported that gcc < 4.0 can compile clamav 0.92 successfully. So you don't need to upgrade if you use that version of gcc. Also reported that using the 'buggy' gcc, one can use -O0 as optimization flag to avoid the bug.

upgrading clamav from source
Please read my article here. The steps are still the same.

Good luck!

Upgrading to latest clamav for impatient sysadmin :)

I've just upgraded clamav to the latest (at the time of writing is version 0.91.1) for my firewall (Mandrake 10.1). For impatient sysadmin like me, waiting for official packages to release might take longer than u might expect. So the best way to upgrade is by compiling from source. This was how I did it.

Stopping the service
It's advisable to stop clamav service before installing the new one.

service clamd stop

Downloading the package
wget http://freshmeat.net/redir/clamav/29355/url_tgz/clamav-0.91.1.tar.gz

Extracting the package
tar xzvf clamav-0.91.1.tar.gz

Configure...
cd clamav-0.91.1
./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var --enable-id-check --enable-dns-fix --enable-bigstack

Note: this configure arguments matching with the previous installation by rpm except for --enable-big-stack and --enable-dns-fix (I think).

Compile and install
make
make install (as root)

Restart the service
service clamd start

Updating the virus database definition
freshclam

Checking clamav version
clamav-config --version

Dansguardian - web content filtering for all

What is dansguardian?

(Excerpt from dansguardian's website)

DansGuardian is an award winning Open Source web content filter which currently runs on Linux, FreeBSD, OpenBSD, NetBSD, Mac OS X, HP-UX, and Solaris. It filters the actual content of pages based on many methods including phrase matching, PICS filtering and URL filtering. It does not purely filter based on a banned list of sites like lesser totally commercial filters.

DansGuardian is designed to be completely flexible and allows you to tailor the filtering to your exact needs. It can be as draconian or as unobstructive as you want. The default settings are geared towards what a primary school might want but DansGuardian puts you in control of what you want to block.

DansGuardian is a true web content filter.

Where to download?

The latest beta when this article is published is 2.9.8.5. Download it here. Beta doesn't mean it is unstable. From my experience, it is a very reliable piece of software. Downloading source code and compile it yourself is the best way to take full advantage of its (latest) capabilities and speed.

My setup

I have more than 200 clients in my network. To provide a fast and reliable internet connection, I have to use a proxy server and dansguardian is used for filtering unwanted websites and scanning for viruses of downloaded files and websites.

Startup script
Startup script can be taken from [source dir]/data/scripts/systemv-init. Copy it to init.d:

~#cp systemv-init /etc/init.d/dansguardian

Run chkconfig to make it start across booting properly:

~#chkconfig --add dansguardian
~#chkconfig --level 35 dansguardian on

Note: For Fedora users, you may need to use /sbin/chkconfig instead of chkconfig.

How to upgrade?

If you have installed dansguardian via package manager, it is easy to upgrade it with package manager too. So you don't need to mess up with compilation and dependencies. It will take care of them for you. I like to download source code because I can download the latest and to take the advantage of its speed. You can not always get the latest packages with package manager and the package may not optimized for your machine. YMMV.

Steps:
1. Download the latest source code.
2. Extract it: tar xzvf dansguardian-2.9.8.5.tar.gz
3. cd into the source dir.
4. configure : ./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var --enable-clamd=yes
5. Run make : make
6. Install : make install

If you have previous version of dansguardian, please backup directory /etc/dansguardian/lists because installing the new one will overwrite all the files in it. You don't want to refill all the sites you have entered in all files in there for banned sites , exception site (unfiltered sites) etc2.

Configuration
The main configuration file for dansguardian is /etc/dansguardian/dansguardian.conf. It is heavily documented. Tkae your time to read the comments in there before modifying. Below is the most important directives to be modified (example):

filter_ip = 192.168.5.2
filter_port = 3128
proxy_ip = 127.0.0.1

Note: 192.168.5.2 is the IP which dansguardian will listen on. If left empty, it will listen on all IPs. For increase security, please state IP(s) that it needs to listen on. filter_port is the port it will bind to. proxy _ip is the ip where the proxy server (daemon, e.g squid) listens on. Note that you must run proxy server before running dansguardian or it will fail to start.

Integration with antivirus

Dansguardian can use antivirus for content scanning of viruses. I use clamav for this. You need to uncomment the directive contentscanner and modify file /etc/dansguardian/contentscanners/clamdscan.conf.

contentscanner = '/etc/dansguardian/contentscanners/clamdscan.conf'

In this file, change clamdudsfile like this :

clamdudsfile = '/tmp/clamd'

/tmp/clamd is the socket file for my clamav daemon (clamd). Change it accordingly.

Setting up virus scanner for mail server

This task is quite simple and the tools are readily available on the internet. In the spirit of Open Source, may of the tools are made free and come with source code. Binary version for may distros are available too. It's only a matter of choice and how we're going to set things up.

Antivirus
Clam antivirus is one of the best antiviri around. So far she can detect almost 97% of Windows viri and worms. Those viri are always reached our computers over network and internet. The main medium is email. I personally got in average 5 to 10 emails containing virus. That's why, antivirus is really important these days.

Trashscan
This is a script invoked by procmail to scan and send a notice to the sender if the mail contains virus. trasscan comes with clamav package.

Setting up procmailrc for scanning

#
# procmail configuration for TrashScan:
# ZapCoded by Trashware; 13.10.2002
#

# [ ... ]

# ----------------------------------------------------------------------------- #
# Virus scan section ... #
# ----------------------------------------------------------------------------- #

# 1. Run TrashScan
:0
* multipart
* !^X-Virus-Scan:
| /usr/local/sbin/trashscan


# 2. Filter tagged virus mails
:0:
* ^X-Virus-Scan: Suspicious
/dev/null

The last line will delete the mail containing virus.