exiled mind

Here's a quick and nasty hack/script to detect IPs in STDIN and find their reverse DNS. Complete with echo off.

Win.

#!/usr/bin/perl -w
#Code by Rhett Kipps - www.kipps.com.au
use strict;

my $stty_orig = `stty -g`;
`stty -echo`;
my $hostname;
while (<STDIN>) {
  if (/([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3})/) {
    $hostname = `host $1`;
    $hostname =~ s/.+?domain name pointer //;
    print $hostname;
  }
}

`stty $stty_orig`;

Situation

I live at a college at University of Queensland, where we have pretty restrictive internet access. Data can be unrestricted, charged at 15c/MB (AUD), or through a HTTP Proxy at a much cheaper rate.

In order to get around this, I put my traffic through a HTTP proxy through a VPN to a remote host.

There are a few things you should be aware of before you do this:

• You'll need software to tunnel the VPN through the proxy.
• The VPN software must run at Layer 4, using a TCP connection. As such, PPTP is unsuitable, as is IPSec.
• You'll need to fiddle with the static routes on your computer to ensure DNS/Proxy goes through your normal default route, while all other traffic goes through the VPN.
• Set up NAT on the remote host so you can access remote sites through it.

The Solution - Selection of Tools

In order to tunnel the VPN, I used HTTP Tunnel. This software has both a Windows and Unix client/server, and will allow you to tunnel arbitrary connections though a HTTP proxy, with support for proxy HTTP authentication.

Hardware:

• Celeron 1.5GHz
• 512MB DDR RAM
• 40GB HDD
• 14.1" XGA LCD (max res 1024x768)
• 16MB GeForce2Go Video Card
• Intel 82801CA/CAM AC'97 Audio (i810_audio module)
• Actiontec 56k Internal V.92 Modem (software-based)
• Onboard Ethernet (optional)

Software:

I am currently running Fedora Core 4 on my Inspiron 2650, with:

• a Vanilla 2.6.14.4 kernel
• Nvidia 1.0-7174 drivers

I've yet to get any form of suspend working and experience a white screen after exitting X (for shutdown, etc). This appears to be a Nvidia driver issue with the 2650's GeForce2Go.

Operating System Installation

To install Redhat on the Inspiron 2650, follow the graphical installer.  When asked to configure X, chose to use the vesa driver, as the default NVidia drivers do not work with the Geforce2Go.  You may save yourself some hassle if you set Redhat to use a text login, rather than a graphical login.

Hints

• From my experience, you are probably best off delaying the X configuration, and performing this manually, after installing NVidia's drivers.
• Some 2650 laptops may have different LCDs that are capable of higher resolutions (as optional upgrades).  In particular, mine supports 1024x768.  Your screen may use different Horizontal/Vertical refresh rates to what I have in my XF86Config file.
• Fedora Core 2 and other 2.6 based kernels appear to shut down the 2650's network interface when the laptop lid is shut. This appears to be related to http://www.ussg.iu.edu/hypermail/linux/kernel/0405.1/1285.html, where the laptop seems to hit 100% cpu usage when the lid is shut.
  Alexey Spirindov made me aware of the workaround for this issue, which involves applying the appropriate patch from acpi.sf.net and passing "acpi_osi=" as a kernel boot option.

  This solved the issue with kacpid hitting 100% cpu usage with the lid shut for 2.6.8.1 for me.

Configuring X Windows

In order to get 3D acceleration, you should download the latest NVidia drivers from www.nvidia.com, and make the necessary changes to your XF86Config file.

After a fair bit of playing around, I was able to successfully get X running at 1024x768.  You may notice the system console becomes flickery after X starts.  I fixed this by setting the LCD/CRT option in BIOS to LCD. Use my config file to find the proper freshrates.

NVidia and Lockups??

Where to start? Practically every NVidia release has issues. I'm trying version 1.0-7676 at the moment. It hard locks up the computer if you change between X and console. Originally, this was fixed by adding:
options nvidia NVreg_SoftEDIDs=0 NVreg_Mobile=2
to /etc/modprobe.conf. Now, it no longer works.

Someone suggested making sure intel_agp is not compiled into the kernel or a module. It may cause hard system lock ups. (I had this problem while switching back to console after X had started, or shutting down). It didn't work for me.

NVidia support under Linux with laptops seems to be very poor. The drivers aren't getting better. There are issues with nearly every release. Be prepared to try to find which patch to apply to the most recent version just to get 2.6 kernels to work with it =(

Download my XF86Config file

Download my X.org config

Audio

Running the 'sndconfig' tool (or the redhat-config-soundcard tool) in Redhat 8.0 found my sound card and configured sound correctly.  I am using the i810-audio module.

Network Card

Network support for the inbuilt network card uses the 3x95x module.  I found this card very well supported under Linux.

ACPI Power Management

• Battery Meter

  I finally managed to get the battery meter going, by getting the kernel source code to 2.4.20, and patching it with the ACPI patch available from acpi.sf.net. I then compiled all ACPI support options into the kernel.  I am using the Battery Charge Monitor (2.0.1) applet in Gnome.

  Recent 2.6 kernels include ACPI support by default. Finally things start getting easier!

  There used to be an ACPI polling issue such that the laptop would lock after being polled for ACPI battery status for a while. This issue has since been fixed.

• Suspend to RAM (s2r)

  I have managed to recover successfully from S2, if hotplug/network/X is not in use/running.

• Suspend to Disk (Hibernate)

  I have yet to get s2d working.

Contact Me

If you have any questions, comments, or suggestions, please email me (My first name at this domain).

Last modified: Thursday, 12 January 2006.

I have been unsuccessful at getting the NetJet-S to work under 2.6 kernels. I'm not sure if a separate voice patch needs to be applied, or if the 2.6 series has applied the voice patch, and it's another problem. I'm not sure if it's possible to get this working under 2.6 anymore.

Why?

Using the NetJet-S on an ISDN line means caller-ID information is sent before the phone starts ringing, allowing Asterisk to automatically answer the call depending upon caller-id. (A normal PSTN line only receives caller-id information between the 2nd-3rd ring?).

Asterisk can be configured to handle calls differently dependent upon the caller-id. In order to eliminate private calls, you'll need a device supported by Asterisk, such as the NetJet-S.

Requirements

There are a few steps in order to get everything working:

• You'll need to have kernel support for the NetJet-S using the hisax module.
• Patch the kernel with the 2.2.x/2.4.x voice patch available from the Traverse website.
• Configure Asterisk to use the isdn4linux hisax device.
• Create a rule to answer private calls.

Extracting/Patching the Kernel

Download the most recent 2.4.x kernel from ftp.kernel.org, and extract somewhere (probably /usr/src/linux).

After downloading the voice patch from the Traverse website, apply it to the kernel source.

Configuring the Kernel

Configure your kernel as described by Traverse in their instructions.

It is important you use a kernel version <= 2.4.x, as I am unaware of a voice patch available for the 2.6 branch.

Install Asterisk

Download and install Asterisk.

Configure Asterisk

Configuring Asterisk to use the isdn4linux device, by setting up /etc/asterisk/modem.conf to point to the device, similar to /dev/ttyI1. Also assign the MSN to be the phone number of the line you wish to answer the calls on.

Edit /etc/asterisk/extensions.conf to tell Asterisk to answer all calls with a caller-id of 0 (appears to be private on Telstra, may be "" on other carriers).

The "reject-call" file is a GSM sound file (Google for how to convert a .wav to .gsm), placed in /var/lib/asterisk/sounds.

exten => s/0,1,Answer                     ; Answer the line
exten => s/0,2,PlayBack(reject-call)  ; Play rejected message
exten => s/0,3,Hangup

Where reject-call.gsm is placed in astvarlibdir/sounds.

Conclusion

Hopefully I haven't missed too much, I set this up months ago, but it seems to work very well. If you have any problems, try checking /var/log/messages and /var/log/asterisk/*.

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