Monthly Archives: February 2011

Geo::IP support for IPv6 geolocation

We're currently looking into IPv6-enabling our services. One of the missing bits is being able to geolocate IPv6 client addresses. We're using the MaxMind GeoIP database. The main Perl library for this is Geo::IP.

The current version of Geo::IP out on CPAN, 1.38, does not support IPv6 lookups. I contacted the maintainer of Geo::IP asking for more information. In the meanwhile, I hacked together just enough of IPv6 support to be able to successfully geolocate a test address. Later on, I discovered that IPv6 is already available in the hopefully soon-to-be-released version of Geo::IP archived at Sourceforge.

Let's hope it lands on CPAN soon. In the meantime, if you really really want, you can try out my changes against CPAN v1.38. It was enough for me to start testing the integration with our other code and projects.

My Geo::IP with IPv6 support

Disable evil page back/forward keys on a Lenovo T500 Thinkpad

Currently I'm using a Lenovo Thinkpad T500. A fine machine. Apart from the awful keyboard layout. The ESC key is way too high, causing useless "F1" hits. But the stupidest thing on this layout is the placement of two evil evil keys that perform browser back and forward functions.

These keys are labeled with a page/document icon and arrows going left and right. I would really like to find whoeve r decided to place these keys there, and punish him with a couple of years of typing with his own keyboard layout :) It happened to me already a couple of times (even more, like right now for example) that I'm typing this long text in a browser text area, and then by accident I hit the evil "page back" key. Oops. F**k! And you just lost 10 minutes of editing because the browser is stupid and won't allow you to go back to your half-edited textarea. Isn't that great?. Fantastic, I'd say.

Today I had had enough of it. That's how you fix it:

Create a ~/.xmodmaprc file or similar, since the name doesn't matter, with the following content:

! Disable the idiot XF86Back and XF86Forward
! keys on the Lenovo T500 keyboard
! They mess up when editing textareas within
! the browser, causing so much waste of time and
! frustration.
! Cosimo, 23/Feb/2011

! XF86Back
keycode 166 = NoSymbol

! XF86Forward
keycode 167 = NoSymbol

And then run:

$ xmodmap ~/.xmodmaprc

VoilĂ , done. Thanks, xmodmap and thanks unnamed Lenovo keyboard engineer.

How to convert Opera contacts file to Mutt aliases format

Recently I've been looking more and more into mutt, the email client. I've been a very happy M2 (Opera built-in email client) user for almost 3 years now. But still I felt I was missing something if I didn't try out mutt. I've been a pine user as well, many many years ago :) So, decided to give it a go, I started about a month ago.

I struggled a bit while getting a reasonable .muttrc file together. Fortunately, there's plenty of examples out there. After getting a working config, the problem was to get back my contacts list.

Mutt has a simple address book integration (through abook) and stores the contacts into an alias file, typically ~/.mutt/aliases. Now, Opera can of course export all your mail contacts to an .adr file, a simple "addressbook" text file. Did that, and I needed to convert it to mutt's aliases format.

Ten minutes later, a Perl script to do just that was ready. Here it is:

#!/usr/bin/env perl
# Convert Opera contacts file (.adr) into
# mutt aliases file format.
# Usage:
#   perl < ~/.opera/contacts.adr >> ~/.mutt/aliases
# Cosimo, 31/Jan/2011

use strict;
use warnings;
use utf8;

sub harvest ($) {
    my ($contact_info) = @_;

    my ($id)    = $contact_info =~ m{^ s+ ID   = (.*) $}mx;
    my ($name)  = $contact_info =~ m{^ s+ NAME = (.*) $}mx;
    my ($email) = $contact_info =~ m{^ s+ MAIL = (.*) $}mx;

    return if ! $id and ! $email;

    return {
        ID    => $id,
        NAME  => $name,
        MAIL => $email,


my $adr_file_contents = q{};
$adr_file_contents .= $_ while <STDIN>;

my @contacts = split m{#CONTACT}, $adr_file_contents;

for (@contacts) {
    my $contact = harvest($_) or next;
    my ($first_word) = $contact->{MAIL} =~ m{ (S+) @ }x;
    printf "alias %s %s <%s>n",
        lc($first_word), $contact->{NAME}, $contact->{MAIL};

Download link:

Ubuntu 10.10, modperl and Apache segfaulting fixed

Last month, before moving to Melbourne, where I am now, to work in the Opera Australia office for a few months, I had to setup a laptop for all the development work I normally do. So I chose Ubuntu 10.10 amd64. I have to say I'm quite happy with it. Everything works out of the box for me, including a Quickcam 9000 USB camera I used to shoot this poor time-lapse video from my new office window. Woot!

Anyway, the development environment for one particular project consists of Apache and mod_perl. So I setup the usual list of dependencies, but when I tried to start Apache to run the test suite, it would always stop right away with a segmentation fault.

Didn't really dig into the problem. Just straced the apache process, and that's what I got:

[apache starts up, reads a bunch of Perl modules, and opens the access  
brk(0x7f342adbd000)                     = 0x7f342adbd000
brk(0x7f342adde000)                     = 0x7f342adde000
brk(0x7f342adff000)                     = 0x7f342adff000
brk(0x7f342ae20000)                     = 0x7f342ae20000
brk(0x7f342ae41000)                     = 0x7f342ae41000
stat("/usr/lib/perl5/auto/DBI/", 0x7f341e8459b0) = -1 ENOENT (No  
such file or directory)
stat("/home/cosimo/src/auth-svn/lib/auto/DBI/", 0x7fffc4e2d520)  
= -1 ENOENT (No such file or directory)
0x7fffc4e2d520) = -1 ENOENT (No such file or directory)
stat("/etc/perl/auto/DBI/", 0x7fffc4e2d520) = -1 ENOENT (No such  
file or directory)
stat("/usr/local/lib/perl/5.10.1/auto/DBI/", 0x7fffc4e2d520) =  
-1 ENOENT (No such file or directory)
stat("/usr/local/share/perl/5.10.1/auto/DBI/", 0x7fffc4e2d520) =  
-1 ENOENT (No such file or directory)
stat("/usr/lib/perl5/auto/DBI/", 0x7fffc4e2d520) = -1 ENOENT (No  
such file or directory)
stat("/usr/share/perl5/auto/DBI/", 0x7fffc4e2d520) = -1 ENOENT  
(No such file or directory)
stat("/usr/lib/perl/5.10/auto/DBI/", 0x7fffc4e2d520) = -1 ENOENT  
(No such file or directory)
stat("/usr/share/perl/5.10/auto/DBI/", 0x7fffc4e2d520) = -1  
ENOENT (No such file or directory)
stat("/usr/local/lib/site_perl/auto/DBI/", 0x7fffc4e2d520) = -1  
ENOENT (No such file or directory)
stat("./auto/DBI/", 0x7fffc4e2d520) = -1 ENOENT (No such file or  
stat("/var/tmp/test_cosimo_22931/auto/DBI/", 0x7fffc4e2d520) =  
-1 ENOENT (No such file or directory)
--- SIGSEGV (Segmentation fault) @ 0 (0) ---
+++ killed by SIGSEGV +++

I thought it would be wiser to ask for advice on the DBI and mod_perl mailing lists. Tim Bunce suggested to try and get a stack trace of Apache. Why didn't I think of that in the first place? A few days later, I got my stack trace:

# gdb -c ./core /usr/sbin/apache2 
Reading symbols from ... 
Core was generated by `/usr/sbin/apache2 -d /var/tmp/test_cosimo_9727 -k 
start -C User cosimo -C Group ...'. 

Program terminated with signal 11, Segmentation fault. 
#0 0x00007fdaedfed858 in XS_Class__XSAccessor_END () 
from /usr/lib/perl5/auto/Class/XSAccessor/ 
(gdb) backtrace 
#0 0x00007fdaedfed858 in XS_Class__XSAccessor_END () 
from /usr/lib/perl5/auto/Class/XSAccessor/ 
#1 0x00007fdaf83cf845 in Perl_pp_entersub () from /usr/lib/ 
#2 0x00007fdaf83752c6 in Perl_call_sv () from /usr/lib/ 
#3 0x00007fdaf86ad40b in modperl_perl_call_list () 
from /usr/lib/apache2/modules/ 
#4 0x00007fdaf86b5786 in modperl_perl_destruct () 
from /usr/lib/apache2/modules/ 
#5 0x00007fdaf86a6256 in modperl_interp_destroy () 
from /usr/lib/apache2/modules/ 
#6 0x00007fdaf86a6715 in modperl_tipool_destroy () 
from /usr/lib/apache2/modules/ 
#7 0x00007fdaf86a62b2 in modperl_interp_pool_destroy () 
from /usr/lib/apache2/modules/ 
#8 0x00007fdaf98fd4e3 in ?? () from /usr/lib/ 
#9 0x00007fdaf98fc3b1 in apr_pool_destroy () from /usr/lib/ 
#10 0x00007fdaf98fc27f in apr_pool_clear () from /usr/lib/ 
#11 0x00007fdafa1b960d in main (argc=11, argv=0x7fff93b50ef8) 
at /build/buildd/apache2-2.2.16/server/main.c:692

Even if you don't know anything about stack traces, this output gently points to Class::XSAccessor. Perrin Harkins on the mod_perl list suggested to update Class::XSAccessor to the latest CPAN version, since its changelog mentioned some segmentation faults fixed in 0.10.

And that did it. No more segfaults on Ubuntu 10.10. Solution: upgrade Class::XSAccessor to 0.10+. Thanks to Class::XSAccessor maintainer(s)!