Even though I ve dealt with IPv6 for almost a decade, have delivered presentations, and given multi-day courses on IPv6 security aspects, I ve never actually added IPv6 to my own server/home network infrastructure because it seemed that Linux and/or Debian just weren t ready for it. This seems to have changed (although there are still a number of problems) and in less than a day, I put a few of my machines online. In the following, I d like to share with you how I did it.

Kernel versions and stateful connection tracking Unfortunately, I have to start off with some bad news: even though Debian etch, our current stable release, which uses a Linux kernel version 2.6.18, speaks IPv6, I cannot recommend it for deployment, as the 2.6.18 kernel does not support proper stateful connection tracking for IPv6, and thus makes it impossible to firewall hosts in a sensible manner (I always add local packet filters to all my hosts, and if only to guard against the situation when a user installs a malicious programme to listen on a high port). Of course, it is possible to configure a packet filter statelessly in an acceptable manner once you know the use case, so do with this information what you wish; I prefer to stay general for now. For me, a remedy is almost around the corner: the 2.6.24 kernel seems to support stateful connection tracking for IPv6, and it s even available for etch as it will be included in the upcoming etch-and-a-half release. I simply ended up using the kernel packages pre-release, and so far have not had a problem with it. To do so, add the following line to your /etc/apt/sources.list, making sure to use a close archive mirror:

deb http://ftp.xx.debian.org/debian etch-proposed-updates main

I then just upgraded the system and pulled in all proposed updates. As that may have let in software that won t be part of etch-and-a-half, or even lenny, you may want to pin the archive and only upgrade the kernel packages, by adding to /etc/apt/preferences (replacing amd64 with your architecture):

Package: *
Pin: release a=proposed-updates
Pin-Priority: -1
Package: linux-image-2.6.24-etchnhalf.1-amd64
Pin: release a=proposed-updates
Pin-Priority: 600

Alternatively, you could use the 2.6.24 linux kernel packages on backports.org.

Xen and IPv6 One drawback of switching to 2.6.24 is that you cannot run a dom0 on that machine any longer, so by practical extension, you cannot connect it to the IPv6 network with a packet filter in place. Supposedly, running 2.6.24 instances on a 2.6.18 dom0 is reported to work, however.

Configuring the packet filter The first thing I did was to configure the packet filter on each host appropriately. Unfortunately, this is harder than it should be, because to quote one of the netfilter developers when ip6tables was conceived, someone had a big bad brainfart : rather than adding IPv6 rules to your existing iptables ruleset, you have to create a new ruleset, duplicate all chains, networks, hosts, and individual rules, and maintain the two in parallel. Even though there are efforts of unification on the way, I speculate it ll take another couple of years until PF_INET6 will be fused into PF_INET and one will be able to do sensible cross-address-family packet filtering with Linux. Since I ve recently started to look (again) at pyroman, maybe the most logical way forward would be to extend it to write both, IPv4 and IPv6 rulesets from its knowledge about the hosts and networks you configured. Anyway, we want to get stuff working now! Thus, let s configure ourselves a packet filter. (Almost) all IPv6-related filtering must be configured via ip6tables (read on further down about IPv6 in IPv4 tunneling, the reason I said almost ). The following is a simple default ruleset to start with, which I put into /etc/network/ip6tables to load with ip6tables-restore:

*filter
:INPUT REJECT [0:0]
:FORWARD REJECT [0:0]
:OUTPUT ACCEPT [0:0]
:in-new - [0:0]
### INPUT chain
# allow all loopback traffic
-A INPUT -i lo -j ACCEPT
# RT0 processing is disabled since 2.6.20.9
#-A INPUT -m rt --rt-type 0 -j REJECT
# allow all ICMP traffic
-A INPUT -p icmpv6 -j ACCEPT
# packets belonging to an establish connection or related to one can pass
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
# packets that are out-of-sequence are silently dropped
-A INPUT -m state --state INVALID -j DROP
# new connections unknown to the kernel are handled in a separate chain
-A INPUT -m state --state NEW -j in-new
# pass SYN packets for SSH
-A in-new -p tcp -m tcp --dport 22 --syn -j ACCEPT
# log everything else
-A INPUT -m limit --limit 3/min --limit-burst 10 -j LOG --log-prefix "[INPUT6]: "
### OUTPUT chain
# RT0 processing is disabled since 2.6.20.9
#-A OUTPUT -m rt --rt-type 0 -j REJECT
# allow outgoing traffic, explicitly (despite chain policy)
-A OUTPUT -j ACCEPT
### FORWARD chain
# RT0 processing is disabled since 2.6.20.9
#-A FORWARD -m rt --rt-type 0 -j REJECT
# disallow forwarded traffic, explicitly (despite chain policy)
-A FORWARD -j REJECT
COMMIT

Note that this recipe is pretty much unusable on pre-2.6.20 kernels due to their broken implementation of stateful connection tracking. The ruleset should be fairly obvious, but you might wonder about my use of REJECT and allowing all ICMP after all, you ve heard for the past 30 years that ICMP is a bad hacker protocol , and Internet security is no domain for being nice to people, so to prevent any information disclosure, you should DROP connections, not let people know that they re simply not allowed. Well, to hell with all that! I don t see a single reason or attack vector that is foiled by DROP or disallowing ICMP. In fact, it s just security by obscurity, and might inconvenient at the same time. ICMP is also much more important with IPv6 than with IPv4 (it replaces ARP, for instance), and it s actually useful to be able to ping hosts, or get back informational messages on why something failed. Finally, rejecting traffic rather than dropping it doesn t suggest to a hacker that something s hidden here. Then there is RFC 4890, which almost made me puke. This document is part of the reason why I say: let s fix problems in the kernel, rather than shielding them with unreadable and unmanageable rulesets!

Getting connected If you already have an IPv6 address, you re basically ready to go, but may want to read further down on how to connect your local network to the IPv6 Internet as well. If you are searching for a provider, have a look at the list of providers with native IPv6 connectivity over at sixxs.net. If you are reading up to here, I assume you are connected to the Net with IPv4. There are two ways for you to move towards IPv6: 6to4 or by way of a tunnel provider. A Kiwi website explains how to setting up 6to4 connectivity, and thus I will concentrate only on the tunnel approach. Even though everyone can set up 6to4 in a breeze without any accounts or waiting, there are a number of security considerations, it s pretty ugly to debug (due in part to asymmetric routing), and makes your life unnecessarily difficult when all you have is a dynamic IP that changes from time to time. If you are stuck behind a NAT gateway, you cannot use 6to4 either. Thus, I prefer the tunnel approach. With the tunnel approach, IPv6 packets are wrapped up in IPv4 packets on your host, and sent to the IPv4 address of your tunnel provider, who has native IPv6 connectivity. The tunnel provider unwraps your packet and shoves the contained IPv6 packet onto the backbone. The IPv6 address you used as source address is routed to the tunnel provider, so any replies arrive at their machines, where they re again wrapped into IPv4 packets and sent to your (publicly-accessible) IPv4 address. Those IPv4 packets specify payload type 41 ( ipv6 ), which is why we need those -p ipv6 -j ACCEPT rules in the iptables ruleset. There are a few tunnel providers out there. I chose SixXS and have not regretted my choice. I shall thus assume that you do the same: sign up for an account right now, so that you have it by the time you finished reading this document! SixXS works on a credit system: tunnels and subnets cost credits, which you can accumulate by maintaining your tunnels properly. This ensures that everyone can play around, but to do more advanced stuff, you need to first display competence with the basic concepts. Your first step with SixXS will be to request a tunnel. SixXS offers three types of tunnels:

• static tunnels, for those with static IPs,
• heartbeat tunnels, for those with dynamic IPs, and
• AYIYA tunnels, for those behind NAT gateways.

Each of these tunnels have advantages and disadvantages, as everything does: the first two types of tunnels use IP protocol 41 packets to encapsulate the IPv6 packets. As such, there are security considerations involving the impersonation by spoofing, and all upstream firewalls must let protocol 41 pass. AYIYA addresses these problems by using signed packets, but that solution comes with extra computation overhead and smaller MTUs. I suggest to use the first type of tunnel that fits your situation. Debian s aiccu package can take care of heartbeat and AYIYA tunnels for you, and it can even set up static ones. During registration, you will also need to choose a PoP , which stands for Point of Presence . If your country only has a single PoP, that s the one you will end up using (unless you have a good reason for another one), but if there are more options, I strongly suggest that you go through the list of PoPs and select the one with the best roundtrip time and lowest latency from your location! Note that you must answer ping requests (ICMP echo-request) from the PoP you chose, or else the tunnel will not be created. Once your tunnel request gets approved, you ll get a /64 prefix, in which you only use two addresses: the PoP will configure the :1 address and you need to configure your host to use the :2 address on the tunnel interface. You ll also be told the IPv4 address of your PoP endpoint . Joey Hess taught me that aiccu can set up the interface for you, using the data it queries from the SixXS registration (TIC) server. I tried it, and it works. However, I prefer the pure ifupdown approach, as it makes things explicit and allows me to use the hooks for stuff like loading the packet filter. So in my /etc/network/interfaces, you can find:

auto sixxs
iface sixxs inet6 v4tunnel
  endpoint 194.1.163.40
  address 2001:41e0:ff00:3b::2
  netmask 64
  gateway 2001:41e0:ff00:3b::1
  ttl 64
  pre-up ip6tables-restore < /etc/network/ip6tables
  up ip link set mtu 1480 dev $IFACE
  up invoke-rc.d aiccu start
  down invoke-rc.d aiccu stop

Make sure to read about MTU values of the tunnel and adjust the 1480 value in the above to your tunnel settings and ISP connectivity. Also set ipv6_interface sixxs in /etc/aiccu.conf, if you are using aiccu, or else aiccu will bring up a duplicate/additional interface. If you tell it to use the same interface, it will actually execute all the same commands (which will fail), but won t report any errors. A future version will have a switch to prevent it from configuring the interface. Unfortunately, this will probably not work. The reason is that your regular IP packet filter (iptables, without the 6) doesn t let those encapsulating IPv4 packets pass, unless we tell it to; we probably want to do this early on in the chain, and also limit it to our tunnel peer, so:

iptables -I INPUT -p ipv6 -s 194.1.163.40/32 -j ACCEPT

For AYIYA, you need to open port 5072, either for UDP, TCP, or SCTP, depending on how you configured it. Also have a look at this FAQ entry on what a firewall needs to pass. If it still doesn t work, you have an upstream packet filter that needs some of those holes poked. Good luck. In most situations, the FORWARD chain does not get such a rule, since the tunnel terminates at the gateway, which routes to a native IPv6 network, or another tunnel. Allowing tunnels through a gateway is almost always a bad thing, as it would allow undetected and untraceable traffic from compromised boxes in the local network. The OUTPUT chain also does not need such a rule, if you have configured stateful filtering properly. Now bring up the interface and verify the connection:

# ifup sixxs
# ping6 -nc1 2001:41e0:ff00:3b::1
PING 2001:41e0:ff00:3b::1(2001:41e0:ff00:3b::1) 56 data bytes
64 bytes from 2001:41e0:ff00:3b::1: icmp_seq=1 ttl=64 time=74.0 ms
[...]
# ping6 -nc1 ipv6.aerasec.de
PING ipv6.aerasec.de(2001:a60:9002:1::184:1) 56 data bytes
64 bytes from 2001:a60:9002:1::184:1: icmp_seq=1 ttl=55 time=91.5 ms
[...]

Welcome to the Internet of the future!

Setting up an IPv6-capable gateway Your IPv6 connection works, but it s limited to a single address, and you do not get to specify the reverse DNS PTR record for it. Since the concept of NAT is mostly absent from IPv6 (thanks! thanks! thanks!), you will not be able to connect any other hosts to the IPv6 network. If your local network has a few hosts behind a gateway, you will need to request a subnet from SixXS and configure your gateway (which has the tunnel connection) appropriately. Don t worry, this is not really very difficult. First, request a subnet for your tunnel from your PoP via your SixXS homepage. Once approved, you will get a /48 prefix for your own use: 2^80 1.2 heptillion addresses which are yours to assign to every dust particle in your office or home, if you so desire. The way I set it up is to add the first of these addresses to your internal interface on the gateway, by adding the following two lines to the interface s stanza in /etc/network/interfaces; you will need the iproute package installed (which you should be using for everything network-related anyway):

up ip -6 addr add 2001:41e0:ff12::1/64 dev $IFACE
down ip -6 addr del 2001:41e0:ff12::1/64 dev $IFACE

Instead of bringing the interface down and up, just run ip -6 addr add 2001:41e0:ff12::1/64 dev eth0. Note the use of the /64 prefix instead of the /48 that got assigned, leaving only 20 pentillion addresses. Oh no! The reason for this is buried in the specs: basically, /48 is a site prefix, but individual networks should not be larger than /64, which is the prefix length of links in the IPv6 domain. Now is also a good time to enable IPv6 forwarding, e.g. like so:

# echo net.ipv6.conf.all.forwarding = 1 >> /etc/sysctl.conf
# sysctl -p /etc/sysctl.conf

Obviously, you will also need to change the policy on the ip6tables FORWARD chain. For now, let s just set it to accept. You should later create a proper ruleset, though!

# ip6tables -I FORWARD -j ACCEPT

Bringing IPv6 to your local network The final step is to spread the love to your local network. Refrain from selecting addresses from your subnet and assigning them to the local hosts, or wondering how to configure the DHCP server, because IPv6 does it differently: your gateway will advertise its routes (which includes a default route) to your network, and each host will pick an address based on its MAC address (unless it already has an EUI-64 address assigned. This all happens automagically, at least with current Debian and Windows machines. On the gateway, you need to install radvd and simply tell it which prefix to use on which interface. My /etc/radvd looks like this, and I won t explain it:

interface eth0
 
  AdvSendAdvert on;
  prefix 2001:41e0:ff12::/64
   
   ;
 ;

Note again how we advertise a /64 network rather than the /48 we own . You cannot advertise smaller networks if you want automatic configuration to work, and you should not use networks larger than /64 in any case. If 2^64 addresses are not enough for you, I trust you ll be able to figure out how to advertise another of your 65536 /64 prefixes in the /48 subnet to appropriate hosts. Restart radvd and run over to another host to witness how it automagically gets connected to the IPv6 network by scanning /var/log/kern.log and watching the output of ip -6 addr and ip -6 route. Try ping6ing from there! Find the dancing turtle! It should all work. If you don t like the automagic aspect of this, look into stateful configuration, using DHCPv6, as provided by dibbler-server and ?wide-dhcpv6-server.

Resolving names Take note of the IPv6 address of each host. There s a way to determine it given the host s MAC address, but this is easier (ipv6calc is also useful). You might want to let your local DNS server know by adding AAAA records in parallel to the existing A records, and possibly even adding PTR entries. If you re serious about IPv6, you can tell SixXS to delegate reverse lookups for the IPv6 addresses to your DNS servers, but you ought to refrain from polluting the DNS namespace. Note that bind9-host provides an improved host tool, which fetches all kinds of information about names, not just the one single information configured as default:

% host pulse.madduck.net
pulse.madduck.net has address 130.60.75.74
pulse.madduck.net has IPv6 address 2001:41e0:ff1a::1
pulse.madduck.net mail is handled by 99 b.mx.madduck.net.
pulse.madduck.net mail is handled by 10 a.mx.madduck.net.
% host 2001:41e0:ff1a::1
1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.a.1.f.f.0.e.1.4.1.0.0.2.ip6.arpa
domain name pointer pulse.madduck.net.

Oh, and if you re really that curious about how IPv6 addresses are computed from MAC addresses, read RFC 2464. Basically, given a prefix 2001:41e0:ff1a:: and a MAC address aa:bb:cc:dd:ee:ff, the resulting IPv6 address is obtained by:

1. inserting ff:fe into the middle of the MAC address to yield aa:bb:cc:ff:fe:dd:ee:ff;
2. flipping the second lowest bit of the first octet to yield a8:bb:cc:ff:fe:dd:ee:ff;
3. removing the odd colons to yield a8bb:ccff:fedd:eeff, the EUI-64;
4. concatenating the prefix and this result to get 2001:41e0:ff1a::a8bb:ccff:fedd:eeff.

If you find your (Windows) IPv6 addresses changing all the time, you might be faced by privacy features .

Remaining issues Even though my IPv6 connectivity works, I have two remaining issues.

Sending larger amounts of data to the network I am experiencing a curious issue where outgoing ssh IPv6 connections time out and outgoing data transfers hiccup. I have yet to find out what s going on.

Mapping names to laptops Laptops generally have two interfaces, one with a cable, and the other wireless. Both of these interfaces will have separate MAC addresses, and by extension, the laptop will have different IPv6 addresses depending on how it is connected to the local network. I want to be able to connect to laptops without knowing the medium they use to connect to the network. Unfortunately, there seems to be no feasible way. The solutions I see are:

• override the MAC address of one interface with that of the other, which is going to cause bgi problems in the case when the laptop (accidentally) gets connected to the same network twice;
• add both IPv6 addresses as AAAA records to the laptop s DNS name, which will cause random delays when connecting as the resolver may return the currently inactive address first;
• set up mobile IPv6, e.g. by following this Mobile IPv6 how-to, which would allow accessing the laptop uniformly, no matter where in the world it is. Unfortunately, Debian s support for Mobile IPv6 is severly lacking at time of writing. Also, Yves-Alexis Perez notes that this how-to is horribly outdated and promised to tend to it Real Soon Now .

The second solution works for me for now, but I am interested in the third. In response to this document, Andreas Henriksson has suggested the replace the stateless configuration (radvd) with stateful configuration, using DHCPv6. I have yet to investigate this option. Jeroen Massar suggests to unite cable and wireless into a bridged interface, which seems like a very good idea.

Credits Thanks to Bernhard Schmidt, William Boughton, and Jeroen Massar, and everyone on #ipv6/irc.freenode.org for their help over the past few weeks, and all those who fed back comments in response to this document!

This past week has been a really good ride on the medical front. As of yesterday, I've dropped the 1g of Tylenol I was taking first thing in the morning. Pills-wise, that leaves me with one Ultrum (Tramadol) at night before bed. Sleeping on my surgery site without pills still causes me to wake up in the middle of the night. Next week's goal is to drop the prescription drugs completely, except for an occasional one on the weekend when I'm doing a lot with Leif. As far as I know, it's okay to take Tylenol and have an occasional glass of wine - I'm going to check with the pharmacist - but there's a winery tour that I'm signed up for late next week...

I'm also back to Physical Therapy and have appointments booked for twice a week over the next few months. My PT doesn't seem to think that I'll need to stay that long, which would be awesome, but my hopes aren't high on that. We keep discovering new things like "Hey, if you had triceps, you could do this exercise that I want you to. But you don't, so do tricep pull downs for now." From not doing a whole lot, I find I have to ask other people to do things like open jars, or open heavy doors still. We'll see how it goes. My lifting/bending/twisting restrictions won't be lifted until August and then the use-more-than-4kg-weights exercises can finally start.

I'm biking around the campus at work a lot now. I'm getting braver with going out on the streets, and think that I'll probably be ready to try taking my road bike for a trip between home and work early next week. I'd originally hoped for this week, but I'm just not there yet.

In other news, I'm hoping that someone can point me to a freer replacement for this: I've wanted Angie to see the movie Wargames for a bit, so I plugged the Windows laptop into the TV and the stereo, rented it off of iTunes, made it full screen and we enjoyed the movie. I'm quite fussy about DRM when it comes to music or movies that I've purchased, but I'm less fussy where I've contracted to watch something for a day. Netflix has an on-demand movie service like iTunes as well, but neither of them seem to run under Linux or Wine. I suspect I'll need to find the person who was hacking wine to work with iTunes and see if (s)he likes occasional shipments of beer. =)

So I've been inexcusably tardy in announcing this, but Obey Arthur Liu is working on aptitude for Google's Summer of Code program. His goal is to write a third interface to the program, using GTK+ to produce the UI; as the abstract for his project states:

I will create a GTK+ GUI for Aptitude that will work alongside improved current ncurses and command-line interfaces. This will offer an alternative to Synaptic with an interface design geared toward usability and advanced functionality.

I'm looking forward to seeing what he comes up with! I think there are a lot of interesting possibilities in the design space of GUI package managers; hopefully he'll have time to explore at least a few of them. At the moment he's focusing on figuring out the care and feeding of the apt library backend and learning some of the quirks you have to deal with when writing a frontend against it. Arthur's blog can be found at http://www.milliways.fr and on Planet Debian. The Mercurial repository for his work can currently be found at http://dev.graffit.net/aptitude/hg/.

I maintain a bunch of SSL certificates, mostly signed by my own site authority. Too many not to automate, but not enough to warrant heavy machinery. Here's how I do it. The configuration files Each certificate needs a config to describe what's in it. I create each of these and name it with a .cnf suffix. Here's an example:

[ req ]
prompt                  = no
distinguished_name      = server_distinguished_name
[ server_distinguished_name ]
commonName              = server.usefulinc.com
stateOrProvinceName     = England
countryName             = GB
emailAddress            = edd@usefulinc.com
organizationName        = Useful Information Company
organizationalUnitName  = Hosting
[ req_extensions ]
subjectAltName=edd@usefulinc.com
issuerAltName=issuer:copy
nsCertType            = server
[ x509_extensions ]
subjectAltName=edd@usefulinc.com
issuerAltName=issuer:copy
nsCertType            = server

Let's say this config is server.cnf. I then just type make server.pem to generate the corresponding certificate and key, signed by my local certificate authority. As I don't want to attend the startup of every service, I ensure the key is password-less. The Makefile rules Here are the makefile steps I use to generate and sign keys.

.SUFFIXES: .pem .cnf
.cnf.pem:
        OPENSSL_CONF=$< openssl req -newkey rsa:1024 -keyout tempkey.pem -keyform PEM -out tempreq.pem -outform PEM
        openssl rsa <tempkey.pem >  basename $< .cnf _key.pem
        chmod 400  basename $< .cnf _key.pem
        OPENSSL_CONF=./usefulCA/openssl.cnf openssl ca -in tempreq.pem -out  basename $< .cnf _crt.pem
        rm -f tempkey.pem tempreq.pem
        cat  basename $< .cnf _key.pem  basename $< .cnf _crt.pem > $@
        chmod 400 $@
        ln -sf $@  openssl x509 -noout -hash < $@ .0

The resultant files are:

• server.pem — contains both certificate and key in one file
  
• server_crt.pem — certificate file
  
• server_key.pem — key file
  

Some notes on these steps: my site-local certificate authority is in the directory usefulCA, along with an OpenSSL config which describes my preferences. This config was created by copying and making appropriate adjustments to the default /etc/ssl/openssl.cnf which ships with Debian. For generating certificate signing requests to ship to a commercial certificate authority, it's a bit simpler. I save the config files with a .reqcnf suffix instead, and use this rule:

.SUFFIXES: .pem .cnf .reqcnf .csr
.reqcnf.csr:
        OPENSSL_CONF=$< openssl req -newkey rsa:1024 -keyout  basename $< .reqcnf .key -keyform PEM -out  basename $< .reqcnf .csr -outform PEM

And finally, a rule I use to sign incoming certificate requests from other systems:

.csr.pem:
        OPENSSL_CONF=./usefulCA/openssl.cnf openssl ca -in $< -out  basename $< .csr _crt.pem

I offer these without warranty in the hope they might be useful to somebody. They're not much more than a transcription of a how-to into a makefile, but it's just enough technology to ensure creating certificates isn't a big nuisance. Further reading

• A more complete guide to setting up a site-local certificate authority
  

Notes Why do I bother with a site-local CA, rather than just self-sign? It lets me bypass the annoyance of SSL warnings on clients once I've installed my own CA certificate, and gives me a coarse grained level of access control: for instance, only clients with certificates signed by my CA are allowed to access the site's LDAP server. My personal next step with this is to integrate the certificate production process with my emerging Puppet recipes for managing local infrastructure.Join the conversation about this post

If you re trying to blow up an airplane, and you re hip and plan to use liquids to take down the silver bird, the following tips may be useful to you:

• Should your liquid containers not all fit into the one-litre resealable bag, just use two. Leave one of them in your bag and put the other into the plastic box through the x-ray machine. It seems like security checkers don t notice or care.
• Alternatively, if you need a few more millilitres of liquid or gel, put it in a tube or bottle and write on it Novartis, Roche, Bayer, or any other known manufacturer of pharmaceuticals; make up fancy names or use existing ones. Be creative, although you don t have to. Even though the EU regulations dictate that only prescription medicine is exempt from the volume restrictions, noone has yet confiscated my tube of Voltaren, nor questioned it, and I ve had it with me on every trip for three years, at least. If desiging your own tube is too much, empty out an existing tube and refill it. Baby food containers work too, but then you ought to bring a baby along for credibility.
• If your detonation strategy involves more than one litre of liquid, don t give up. Writing 100ml on a 200 millilitre container should fool most of the security checkers. I ve tried it, taking the label off a 75ml deodorant spraycan and putting it on a 150ml shaving cream can, and at least in D sseldorf, they seemed pleased.
• If your explosive substance s amount is indicated in weight rather than volume (like yoghurt), be prepared to lie. Should the substance put 150g on the scale, make the label read 100g; the concept of density is beyond the brain capacity of your average checker, and I found it pointless to explain to them that one gramme is very rarely the same amount as one millilitre.
• Consider flying out of a non-German airport, where they won t let you take just a deodorant spray can and nothing else without a bag; you ll also have to buy a bag for one Euro in these places, while at Zurich or Dublin airports, you get those bags for free at least. (Remind me why we pay extraordinary amounts of airport taxes again?)

Of course, if you re serious about blowing up an aircraft, you re probably not going to need any of the above, as you ll already have a more convenient way to get your substances on the plane. At the checkpoint, you ll behave like the perfect citizen abiding by all rules; you wouldn t want to arouse suspicion, now would you? PS: this post purposely avoids the use of the word terrorist . PPS: of all the great experiences in airports this week, I especially loved how passengers, who checked in at the counters (and had to present their passports there), were again checked after border control in D sseldorf, while passengers like myself, who used the quick check-in terminals, were just waved through. NP: Disturbed: The Sickness

I have been trying to find a good way to explain the fact that the fundamental group of the group of rotations in dimension 3 is isomorphic to the multiplicative group +1,-1 . The first step is to identify the group of rotations with the configurations of a person standing vertically on the surface of the earth. In other words, each configuration is a point on a sphere and a direction (along the sphere) at that point. The above statement above can then be translated as follows. Consider all trajectories which start and end with me standing in Ecuador (on the equator) facing north. One such trajectory has me turning clockwise on my heels, while another has me turning anti-clockwise instead. Then the above statement says that there is a "continous deformation" of the first trajectory into the second! One problem is that explaining the term "continous deformation" is not easy! However, the following proof explains what one has in mind. Consider all circular tracks that have me travelling towards my right while facing a point (exactly) north of Ecuador. When this point becomes the north pole, I am travelling towards my right on the equator facing north. Similarly, consider all circular tracks that have me travelling towards my right while facing away from a point that is exactly south of Ecuador. When this point becomes the south pole, I am again travelling towards my right on the equator facing north. On the other hard, consider what happens as the centre of the circular track comes close to Ecuador and ends up somewhere near my shoes. In the first case, I am turning anti-clockwise on my heels, while in the second, I am turning clockwise on my heels! I am sure that there much better and more striking ways of explaining this to a lay audience, but I'm still looking for them ... Perhaps, I need to travel to Ecuador to get a better idea. To do that and come back to India, I need to find a hospital that will give me a Yellow Fever vaccination. Anyone knows one?

!?!?!?!?!? Why does it even ask me? Updated: because I had set signed.applets.codebase_principal_support in about:config to true to be able to pay my taxes online. I have set it back to false, and now the box doesn’t appear anymore.

In evaporation, the more energetic (i.e. warmer) a water molecule on the surface of an object is, the higher its chance of it turning to vapour. The higher the wind speed across this surface, the faster these warm molecules will be blown away. This is the concept of evaporative cooling. The same applies when a company starts to fail, though there is an additional feedback cycle which compounds the problem. First, the most energetic molecules staff depart. These are the ones who can see a future for themselves outside of their current employment — and there is a high correlation between these people and those who are most valuable for an organisation. So the company becomes slightly worse due to the better people leaving. But it’s an exponential effect: it will rapidly get worse unless steps are taken to improve things. Eventually, the company stagnates as all of the interesting and innovative people have found alternative employment and only the boring ones are left. So, the moral of the story: the more a company blows, the faster its employees leave.

Please help set a world record of most downloads in 24 hours by downloading a copy of Firefox 3.0 in the next 24 hours starting at 18:00 GMT today. Download yourself and get all your friends to do so as well. Only one download per computer is counted towards the record. More info on the record attempt. Firefox 3.0 Download record countdown timers. P.S. The SpreadFirefox web page is down at the moment. Overloaded less than 2 hours before the go time.

The overall situation (admittedly a bit of a stretch):

(The soil depends on the chicken to keep it fertilized. Work with me here.) There are an infinitude of cycles that could be extracted from this, but we're only interested in the set of shortest-length cycles. Exhibit A:
Exhibit B:
And the classic philosophical gem, Exhibit C:
Is the problem solved, then? Not quite. The current DebGraph cycle detection operator works well for dependencies, but we also want to discover cycles of conflicting packages. Furthermore, one of our documented use cases involves finding nodes that depend on and conflict with one another.

Launchpad, please stop mailing me mine own comments on bugs. I know what I said. kthxbye

Ten years ago, most of us wouldn't have dreamt we'd be managing terabits of storage, tens of megabits of bandwidth, arrays of network-distributed services. The height of a programmer's worry would likely be choice of UI toolkit or finding the right way to indent code, and the height of consumer concern deciding which room to put the new computer in. Now the problems associated with managing large networks are becoming real for everyone, right down to the consumer level. Stupendously large amounts of computing resource are available at an instant. Your household probably has more than a terabyte of storage already. Issues such as single sign-on are going to hit home over the next year, as networked computing and entertainment devices profilerate. Features such as Apple's Time Machine will be increasingly vital — software that makes traditionally gnarly sysadmin tasks consumer-friendly. The rebranding of .Mac into "Mobile Me" is also a step in this direction. The impact on developers As software developers, we also have to cope with the effects of this resource-richness. For small sums of money we can get access to large computing clusters, geographically redundant hosting services. Our programs have left the desktop and found their new home on the web. System administration issues loom large upon us, security concerns lurk auspiciously in the corners of our minds. Although the cost of infrastructure has dropped radically, other costs remain high and are going to stay that way. System administrators are not only grumpy, they demand high wages. Commercial software license fees spiral out of control: traditional per-CPU licensing models make little sense when you can quickly bring up tens of machines. The cost in power is already troubling large companies, and there's no reason to suspect the problems won't ripple down. Help is at hand from a variety of technologies. If they don't yet make massive resource management trivial, they at least make it possible. Some of these also inhabit the weird territory of being both the source of a problem and a solution at the same time: virtualization, for example. Distributed revision control systems Distributed revision control is a technology whose time has finally come in popular circles, thanks in part to Linus Torvald's Git system. DRCS has several important impacts on today's developer:

• Branching and, importantly, merging become much cheaper, allowing agile and flexible iterations of development.
• Loosely connected and geographically diverse development becomes much easier. Even within a single organization it is not uncommon to find teams spanning countries, time zones. Complex multi-site VPN setups aren't necessary when a few SSH keys can do the job.
• Revision control becomes packaging on the cheap. Like it or not, the mere tagging of a source tree has now become a valid option for releasing software.

All these trends lower the barrier to entry, increase collaboration and agility of development. You can the value of this as more software tools become free. Selling such tools is rapidly becoming a thing of the past, the advantages of sharing enable the developers at the sharp end to get their jobs done quicker. However, such increased agility and, well, messiness leave other problems to solve, which the next two technologies address. Virtualization Hardware-as-a-service, infrastructure-as-a-service, call it what you will. The ability to create what we used to call entire machines, pick them up and move them around the network is revolutionary, and it's something that will have a real impact on regular developers. The benefits are at several levels.

• Agile infrastructure — a ready supply of new machines makes it a lot easier and cheaper to test different scenarios, architectures, and to separate concerns. If things go wrong, throw away the image and start over. It's all about cutting the administration load.
• A packaging solution — the new macroeconomics of software distribution mean that distributing entire machine images which communicate exclusively via the network is now a feasible way to distribute your software. We must adjust to the notion of distributing appliances, not code. We may mourn the lost crafts of creating RPMs or installers, but let's face it, it's now a waste of time.
• New business models — your application can now be delivered as a black-box appliance, circumventing compatibility issues, or as a service, with virtualization part of the solution to scaling.

Configuration management Computing is a zero-sum game, and despite our increased ability to create and distribute software, problems still exist. We just pushed them to the next level. In good part, this next level is the problem of configuration management. We now have networks and clusters of (virtual) machines, software so agile we need six decimal places to describe its revision levels, and network and authentication paths that are starting to tangle. How do we manage that? One thing developers crave is repeatability. That's why we love our makefiles, autoconf, Ant, rake and so on. It's the one time even the most imperative-minded programmer writes declarative code. We like to say "let the world be like this." Our new sprawling world lacks this feature, and the best of our old toolkits — .debs, RPMs — address things only at the level of packages in a single environment. So developers must look to the world of operations, a territory we probably thought we needn't enter. In this world the new "make" is called Puppet. You write recipes to describe how things ought to be, and Puppet will make it so. I've been spending some time digging into Puppet, and feel excited by the confidence it's giving me. Now my applications exceed single source trees, and single machines, it gives me the means to tie the whole together. This article was going to be solely about Puppet, but that will have to wait now for another time. It's likely you'll have played with virtual machines and distributed revision control, but have you tried Puppet yet? Give it a spin, and let your mind wander over the benefits for your organization and development approaches. Conclusions
For developers and users alike, our world is changing. Hardware, connectivity and increasingly software is becoming cheap or free. The solidity of the old things we put value on — real things you can touch like disks — is eroding. What really matters is our data, our creations, and their communication. If they don't quite yet exist in a universal "cloud" yet, they're certainly getting frisky. As vendors provide solutions for consumers to manage their new domestic infrastructure, developers must look to network-aware toolkits and operations techniques to manage and get the best from their emergent infrastructures. Also on this topic:

• In search of agile infrastructure for web applications (June 2006)
  

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Even though the Debian installer can set up encrypted partitions, it is optimised for systems with a single data partition, unless you want to enter multiple passphrases when the system boots. The installer configures a LUKS volume using cryptsetup, but it provides no mechanism for the use of key files, only interactive passphrases. I like partitioning my disks and use different filesystems for /tmp, /home, /var, and /usr/local for a number of reasons. I don t like entering more passphrases than necessary. If you can identify with that, the following is for you.

Installing the system The first step to setting up an encrypted Debian system is to perform a normal Debian system installation. When you are asked to partition your harddrive and create filesystems, set up all partitions as encrypted volumes (I suggest to go with the installer defaults and use dm-crypt and AES with the default settings, simply because I have no reason to doubt the installer dveeloper team s choices). Make sure to erase the disks in the process the installer has an option for that. Set up the swap partition as an encrypted volume too, but don t worry too much about the settings at this point; we will recreate the swap partition later. Unless you want to boot off an external medium, such as a USB stick, you will need to create an unencrypted partition for /boot. I will return to this topic, which has security implications, further down. The installer will ask you for passphrases for each of the volumes you create. I suggest you pick a secure passphrase for the root volume (/), but simple passphrases for all the other ones (such as a ), since we will reconfigure them to use key files instead.

Using key files A key file is like a passphrase stored in a file on disk; as opposed to what you know , it s a what you have security asset. Thus, you need to store the file somewhere. When I boot up my system, I unlock the root partition with a passphrase entered interactively, which makes the root filesystem available. I store key files for all other volumes in /etc/keys. Obviously, I need to tell cryptsetup to use those. The first step is to create a key file for each partition and to add it as a decryption key to the LUKS volume. You can do all of the following without unmounting the filesystems. See the following example for hda6, which will prompt for the simple passphrase we entered above to unlock the key ring when adding the key file:

umask 077
mkdir /etc/keys
dd if=/dev/urandom of=/etc/keys/hda6.luks bs=4k count=1
cryptsetup luksAddKey /dev/hda6 /etc/keys/hda6.luks
cryptsetup luksKillSlot /dev/hda6 0 --key-file /etc/keys/hda6.luks

The last command wipes the simple passphrase from the key ring and thus makes it unusable. Now we need to tell cryptsetup to use the key file by editing /etc/crypttab and ensuring a line such as the following exists:

hda6_crypt /dev/hda6 /etc/keys/hda6.luks luks

This tells cryptsetup to create the cryptographic volume hda6_crypt from the base device /dev/hda6, using the key file we created above, and letting it know that it s dealing with a LUKS volume. Repeat this for every partition except your root and swap partitions.

Encrypting the swap partition If you are using an encrypted Debian system, you likely have some security requirements to meet. If that s the case, you must also use an encrypted swap partition. The swap partition can be encrypted in two ways:

• it can be recreated on every boot, using a random passphrase, or
• it can be created like the other encrypted volumes with a persistent passphrase

If you want to use suspend-to-disk, you cannot use the first approach as it would overwrite your memory footprint stored in the swap partition. Furthermore, you cannot use a key file like the other partitions, since the root filesystem is not (and must not) be mounted by the time the resume process starts and needs to read the decrypted swap partition. The way I solved this is by telling cryptsetup to compute the passphrase of the swap partition from the decryption key of the volume holding the root filesystem; the cryptsetup package implements this with /lib/cryptsetup/scripts/decrypt_derived. Thus, to set up the swap partition, I do the following, assuming hda2 is the partition holding the encrypted swap and the root filesystem is in hda5_crypt:

swapoff /dev/mapper/hda2_crypt
cryptsetup luksClose hda2_crypt
dd if=/dev/urandom of=/dev/hda2
/lib/cryptsetup/scripts/decrypt_derived hda5_crypt \
    cryptsetup luksFormat /dev/hda2 --key-file -
/lib/cryptsetup/scripts/decrypt_derived hda5_crypt \
    cryptsetup luksOpen /dev/hda2 hda2_crypt --key-file -
mkswap /dev/mapper/hda2_crypt

To tell the system about this swap partition, we need to add it to /etc/crypttab and /etc/fstab; make sure, those files contain lines like the following:

/etc/crypttab:
  hda2_crypt /dev/hda2 hda5_crypt luks,keyscript=/lib/cryptsetup/scripts/decrypt_derived
/etc/fstab:
  /dev/mapper/hda2_crypt swap swap sw 0 0

With this in place, as soon as you configure the system for suspend-to-disk, the swap partition will be automatically set up alongside the root filesystem very early during the boot sequence. To figure out which swap partition to make available at that point, cryptsetup checks the following:

• a line like RESUME=/dev/mapper/hda2_crypt in /etc/initramfs-tools/conf.d/resume
• a resume device setting in /etc/uswsusp.conf (see uswsusp.conf(5))
• an entry in /etc/suspend.conf
• a resume=/dev/mapper/hda2_crypt in the kernel command line

You can inspect /usr/share/initramfs-tools/hooks/cryptroot if you want to know more about this.

Using UUIDs Even though the above is all you have to do, you might want to consider replacing the device paths in /etc/crypttab with persistent ones. One motivation might be the ability to boot off your drive via a USB adapter, which might cause it to appear as /dev/sda instead of /dev/hda. udev is installed by default on Debian systems and it makes persistent links to partitions available under /dev/disk/by-uuid, using the UUID of the content structure (e.g. the LUKS header). It uses /lib/udev/vol_id to determine those link names. If you replace the entries in /etc/crypttab, make sure to update the initramfs (update-initramfs -u -k all) and consider to use the same approach for the /boot filesystem in /etc/fstab; you ll note that all other filesystems use persistent device paths thanks to the dm-crypt layer. If you ever end up booting off the disk through a USB adapter, you might face the problem where the usb_storage subsystem takes too long to activate, so that the cryptsetup script does not find the devices in time. You can either solve this by adding the rootdelay=x parameter or break=mount to the kernel command line. The first will cause the scripts to wait x seconds before trying to configure and mount the root filesystem; the second would give you a shell that you can exit as soon as the kernel spouted its device initialisation messages at you. If you got this far, you might even want to take it further and replace hda5_crypt with cr_root or the like to abstract those silly partition numbers away even further. This is easier than it sounds, but does require several steps. Do not do this if you re not comfortable reviving your system in case it fails to come back up!

1. replace the old names with the new names in /etc/crypttab for all volumes except the root volume. If you are using a derived passphrase for the swap partition, make sure to put the new name for the root volume into the third column of the swap partition s configuration line.
2. modify /etc/fstab accordingly, leave the root filesystem s device path alone.
3. call update-initramfs -u
4. modify your bootloader to ask the kernel to boot off the new root volume.
5. replace the root volume s old name with the new one in /etc/fstab.
6. reboot, and add break=mount to the kernel command line.
7. at the busybox prompt, edit (vi) /conf/conf.d/cryptroot and change the first field of the root volume s line to the new name.
8. exit the shell and watch the boot process complete.
9. finally, replace the root volume s old name with the new one in /etc/crypttab.

If the system fails to boot up again, you can use the backup initial ramdisk, which update-initramfs left in /boot.

Security implications Apart from the usual security implications related to cryptosystems, passphrases, mathematics, user stupidity, and so on, the approach I outlined will leave you with a pretty well-secured system. Obviously, you should make sure to lock your screen whenever you leave the system unattended or the entire encryption is basically useless. There are two attack vectors on your system, both involving physical access to the machine:

• theft of the machine or its RAM chip, freezing the latter, and scanning the working memory for the passphrase
• manipulation of the kernel or initramfs stored on the (unencrypted) /boot filesystem, in such a way as to obtain the passphrase. To do this, you would have to have access to my machine and return it to me without me noticing; once I restart and enter the passphrase, you d have to steal it again

Other than that, you should be careful when travelling to totalitarian countries, like the Excited States of America, China, and probably the UK. First off, encryption arouses suspicion, and second, border agents might ask you to decrypt the partitions for them to copy or scan, and refusal to do so might get your turned away at the border. When travelling to those countries, make sure to hide your data properly.

Speed implications Obviously, having your entire system encrypted (including swap) will slow it down. I don t have any quantitative information on that, but after several years of using full-disk encryption on my laptop (an X40, which isn t very powerful), I can say that it remains usable, if you don t rely on disk-intensive operations, such as compiling kernels and the like.

Alternative approaches Several alternative approaches exist, all involving an additional device:

• if you don t like to type in the passphrase for the root filesystem, you could store it on a USB key (or the like); cryptsetup provides /lib/cryptsetup/scripts/passdev, which can be used to deal with such a situation. You can find more information in cryptsetup s README.Debian file.
• if you don t like the unencrypted /boot partition, you could boot the system off a USB key, which you can keep separate from the system except for when booting and upgrading the kernel. All you need to do for that is install the bootloader and kernel onto the device and configure it to use the proper encryption volume on the harddisk as root filesystem.
• cryptsetup also comes with support for PKCS#15 smartcards (opensc and openct).

I have chosen neither of these approaches, because the extra security does not make up for the inconvenience, and the danger of an unbootable system in case of loss of forgetting of the additional device.

There has been a lot of talk recently about the cost of petrol, Colin Charles is one of the few people to consider the issue of wages in this discussion [1]. Unfortunately almost no-one seems to consider the overall cost of running a vehicle. While I can’t get the figures for Malaysia (I expect Colin will do that) I can get them for Australia. First I chose a car that’s cheap to buy, reasonably fuel efficient (small) and common (cheap parts from the wreckers) - the Toyota Corolla seemed like a good option.

A search on www.drive.com.au shows adverts for Corollas made in 1990 and 1991 for prices ranging from $3000 to $5000. Assuming some optimism on behalf of the advertisers I could probably buy one for about $2500. The current term deposit rate from the major Australian banks is just over 8%, so spending $2500 on a car (instead of having the money in a term deposit) means a loss of $200 per annum interest, if instead the car was purchased with a bank loan the rate would be significantly higher (car loans have quite high interest rates). Of course the real cost is whenever you sell a car and buy a newer one that costs more - but this is harder to estimate. The next issue is insurance, for a 1990 Corolla of the smallest engine size (as a rule of thumb the smaller the engine the smaller the insurance bill) comprehensive insurance (sans optional extras such as windscreen protection) would cost me $489 per annum, and third-party fire and theft would cost me $398. Of course those rates are for someone who is more than 25 years old and has a good driving record. The majority of people who “flip burgers” appear to be younger than 25 and would therefore pay more. Car registration starts at about $550 per annum (varies by state). Car service would cost at least $200 a year (for scheduled services). So it seems that the cost of a cheap car is around $1,350 per annum before you even drive it! Now with a car that’s 18 years old you have to expect that some parts are wearing out, including parts that make it unroadworthy and must be replaced. Assuming that $300 per annum is spent on parts and labor to repair parts that wear out seems quite conservative (especially if driving a car that costs less than $3,000 - one of the cheaper cars in that age range). That brings the total cost per year to $1,650 if you are lucky (if unlucky then expensive parts could wear out at financially inconvenient times). The amount of driving that I do is around 5,000 to 7,000km per annum (according to the ABS the average passenger vehicle was driven 14,100Km in 2005 [2]). Assuming 7.5L/100Km (one of the results that has been quoted for fuel efficiency of a car of that age) and 7,000Km of driving that would be 525L of petrol per year, at $1.70 that is $892. So at current fuel prices when driving a small car for minimal distances (either for environmental or financial reasons) the cost of petrol may be about 35% of the vehicle operating cost. If driven for the average distance the fuel cost will be about 52% of the total vehicle operating cost (which is about $3,400) - which seems like a reasonable incentive to save fuel. If someone wants to advocate measures to make cars more affordable for poor people then the first thing to consider would be a reduction in the vehicle registration fees (which are a significant part of the vehicle operating costs). Another would be government incentives for car sharing schemes (see my previous post on car sharing for details on what is on offer in Melbourne at the moment [5]), $3,400 would give 340 hours (or more with the weekend deals) of driving a shared car (including fuel) at current prices. A shared car would not be suitable for driving to work but would be good for most other car use. Also it should be noted that share cars are new and have all the latest safety features - I really wouldn’t want to be involved in a crash while driving a 20yo car. Unlike the costs of registration etc for owning a car, all the costs of a shared car will be reduced if you use it less. The tax rate for someone earning $28,579.20 is $2,850 plus 30c for each $1 over $25,000 [3], which is $3,923.76, which leaves a total after tax income of $24,655.44. Someone working 40 hours a week on the minimum income who drives an average distance will spend about 14% of their after-tax income on their car if they have a small old car and were able to buy it without borrowing money. According to the ABS the median income is actually slightly lower than full-time work at the minimum wage [4]. So it seems that there are many people who are working part-time and earning less money than they would if they worked full-time at the minimum wage. So the question for Colin is, how does this compare to Malaysia? Is someone on a minimal income in Malaysia going to spend ~7% of their after-tax income on paying insurance, tax, and basic maintenance on a car without the additional expense of driving it? How does the cost of the basic car ownership compare to the cost of fuel in Malaysia?

• [1] http://www.bytebot.net/blog/archives/2008/06/15/on-fuel-subsidies-and-earningspending-power


• [2] http://www.abs.gov.au/AUSSTATS/abs%40.nsf/mediareleasesbyReleaseDate/66E24E957EB09229CA2571E10077D71D?OpenDocument


• [3] http://www.ato.gov.au/individuals/content.asp?doc=/content/12333.htm&mnu=5053&mfp=001


• [4] http://www.abs.gov.au/AUSSTATS/abs%40.nsf/7d12b0f6763c78caca257061001cc588/96e08af8f4178a45ca257306000d4fd4!OpenDocument


• [5] http://etbe.coker.com.au/2008/04/13/car-sharing-in-melbourne/

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For those who care you can find NVIDIA 173.14.05 debs here I have a problem with X crashing at startup with a secondary non-nvidia card on my i386 box at work so I'm still trying to figure out that issue but for single card systems they should work fine.

update: It looks like 179.14.09 might fix my issue so hopefully I will make an upload soon. - sigh. no it didn't. I'll upload 173.14.09 this week though.

http://www.emdebian.org/buildd/

The scripts are in emdebian-tools 1.1.6 and with a few more fixes and tweaks, that will be the main body of v1.2.0 for Debian unstable.

A few issues with ssh and sudo passphrase caching vs running buildd scripts as root - I'll need to improve the documentation of the process before any other buildds can be set up. The need to have emdebian-tools and subversion installed inside the buildd chroot does make things a little more complicated than a standard wanna-build implementation - as does the need to download, build, install and clean-up cross dependencies.

This autobuilder is the Emdebian target package buildd - Hector Oron has another to build the cross-building toolchains. The toolchain autobuilder has fewer packages but each package is larger and is built for more architectures. Adding more architectures to the target autobuilder is quite difficult - packages that use cache files will need new cache files with different values for certain cache values. See the wiki for info on how to fix cache files. Each solves a different problem within the overall design of any buildd. In each case, instead of listening to email from incoming.debian.org, each buildd picks up the incoming data from the apt cache - a useful little time delay that gives me time to head-off certain problematic updates.

The target package autobuilder runs incrementally - a package is repeatedly rebuilt until it works and is then left alone until the next Debian release. There's lots of work available on the frontend if anyone fancies helping with the PHP. (See Emdebian SVN).

The advantage now is that as more packages fix their cross building bugs, more packages will autobuild without intervention which frees up more of my time to fix the more complicated problems. Equally, I can refer to the buildd logs in bug reports, helping everyone see what is going on.

Users of Debian derivatives sometimes report bugs that are not reported in the
Debian BTS, but that also affect Debian. It already happened a few times that
looking at the Ubuntu bugs for my packages allowed me to fix an unreported bug
in my Debian packages. But it’s difficult to keep track of the status of our packages in Ubuntu, since
Launchpad doesn’t provide a per-Debian-maintainer summary <insert here a rant
about closed-source software and how it restricts users>. Since it’s always fun to abuse proprietary software, I fetched all the bug data from Launchpad and inserted it in an SQLite DB (takes about 30 mins at 1200 HTTP requests/minute — it would be so much easier if the Launchpad devs added a text export of all bugs). The result is that there’s now an “Ubuntu” box on the Packages Tracking System, giving the current version in Ubuntu, a link to the Ubuntu patch (if any), and the number of open bugs. An Ubuntu column has also been added to the Debian Developer Packages Overview by Christoph Berg, with the current version in Ubuntu and the number of open bugs. It’s hidden by default: click on Display Configuration to enable it (then it’s stored in a cookie). I hope that this will help Debian maintainers to track what has been reported/fixed in Ubuntu. Also, if other Debian derivatives want to export the same kind of information, don’t hesitate to contact us. See for example:

• dpkg page on the PTS
• The Debian QA packages on DDPO

PS: the data might be slightly outdated, as it is processed on merkel.d.o, which was offline until recently. Expect it to be up-to-date in the next 24 hours.

Another point release of Postr which should fix Flickr authentication for good this time. Also the file size limit has been increased to 20Mb to match the new Flickr limits. The tarball is here, and packages for Debian are being worked on next.