How to forward packets based on HTTP header content?

varange · 11-22-2006, 10:53 PM

I'm looking for a way to route http request packets that arrive at our gateway to different hosts based on the contents of the http header. For example, requests for www.onedomain.com should be routed to one host, while requests to www.anotherdomain.com are to be routed to a different host.

Someone suggested using Squid in a reverse kinda way, but that seems kludgy.

The "strings" extension to iptables is reported to be dodgy.

Another suggestion is Apache reverse proxy.

If you've done this before, or know how to do it, please respond.

immortaltechnique · 11-22-2006, 11:49 PM

hi have you thought of trying it using ipforwarding?
Am not quite sure why you specified HTTP alone but it should work.
The Linux kernel configuration parameter to activate this is named net.ipv4.ip_forward and can be found in the file /etc/sysctl.conf. Remove the "#" from the line related to packet forwarding.

PHP Code:


			
Before:

 

# Disables packet forwarding 

net.ipv4.ip_forward=0

 

After:

 

# Enables packet forwarding 

net.ipv4.ip_forward=

This enables packet forwarding only when you reboot at which time Linux will create a file in one of the subdirectories of the special RAM memory-based /proc filesystem. To activate the feature immediately you have to force Linux to read the /etc/sysctl.conf file with the sysctl command using the -p switch.

PHP Code:


			
[root@bigboy tmp] sysctl -p

sysctl -p

net.ipv4.ip_forward = 1

net.ipv4.conf.default.rp_filter = 1

kernel.sysrq = 0

kernel.core_uses_pid = 1

[root@bigboy tmp]#

All the best.

amitsharma_26 · 11-23-2006, 10:19 AM

acid_kewpie answered it at http://www.linuxquestions.org/questi...d.php?t=503451

chort · 11-23-2006, 08:54 PM

This is not, strictly speaking, routing since it's operating at the application layer rather than the network layer. It also does not require packet forwarding, again because it's not at the network layer. Finally, it's not really based on content, it's based on the protocol-specific resource that the external client is trying to reach.

Now that all the technical terms are sorted, yes Apache with mod_proxy is exactly what you want. If you are still stuck after reading the posts from acid_kewpie, head over to www.apache.org and go to the documentation section for the relevant version of Apache.

varange · 11-24-2006, 02:39 PM

Thanks for all the super help and info!