Why?

While learning more about clojure, I wanted to do some network sniffing. Following a guide to raw traffic in clojure I needed to install jpcap in order to use libpcap from java.

Jpcap doesn’t provide a 64-bit version so I had to compile my own. Here’s the documentation of how I did it. A patch is provided at the end of the post.

Compiling jpcap 0.7 on 64-bit Ubuntu 10.10

1. First install sun java on ubuntu 10.10

2. Download jpcap or use the following command:

   wget http://netresearch.ics.uci.edu/kfujii/Jpcap/jpcap-0.7.tar.gz
   

3. Untar jpcap

   tar -xvf jpcap-0.7.tar.gz
   

4. Move into src directory

   cd jpcap-0.7/src/c/
   

5. Open up Makefile in your favorite editor (mine’s emacs)

   emacs Makefile
   

6. Change this line:

   JAVA_DIR = $(JAVA_HOME)
   

To This:

JAVA_DIR = /usr/lib/jvm/java-6-sun/

1. Change the compile options from this:

   COMPILE_OPTION = -shared -L.
   

To this:

COMPILE_OPTION = -shared -L. -fPIC

1. Save your file and close your editor.

2. Run make:

   make
   

3. Follow the jpcap installation instructions

Patch for more advanced users

Patch to do this automatically

How to patch

Let me know if you have any problems!

I found some information about how to do this on the web, but everything I saw talked about using an .htaccess file. I didn’t want to use an .htaccess file.

Here’s what I had to do in Ubuntu (this was on an old 8.10 server).

1. Enabled mod_rewrite:

     sudo a2enmod rewrite
     

2. Add the following in the VirtualHost section of my regular http setup to my config at /etc/apache2/sites-enabled/ :

     RewriteEngine On
     RewriteCond %{SERVER_PORT} 80
     RewriteCond %{REQUEST_URI} ^/foldername/.*
     RewriteRule ^(.*)$ https://host.name.com$1 [R,L]
     

3. Restart Apache:

     sudo service apache2 restart
     

Make sure if you use this to change foldername to the name of the folder where you want to enforce HTTPS and host.name.com to the name of your host.

So after struggling for a while with this, the answer is surprisingly simple.

For a bridge that you've created with brctl, you can use this simple command:

brctl setageing <bridgename> 0


This command tells Linux to forget every MAC address that it sees on
the bridge, making it act as a hub.

Here's the source.