Search Results: "steve"

27 September 2022

Steve McIntyre: Firmware again - updates, how I'm voting and why!

Updates Back in April I wrote about issues with how we handle firmware in Debian, and I also spoke about it at DebConf in July. Since then, we've started the General Resolution process - this led to a lot of discussion on the the debian-vote mailing list and we're now into the second week of the voting phase. The discussion has caught the interest of a few news sites along the way: My vote I've also had several people ask me how I'm voting myself, as I started this GR in the first place. I'm happy to oblige! Here's my vote, sorted into preference order:
  [1] Choice 5: Change SC for non-free firmware in installer, one installer
  [2] Choice 1: Only one installer, including non-free firmware
  [3] Choice 6: Change SC for non-free firmware in installer, keep both installers
  [4] Choice 2: Recommend installer containing non-free firmware
  [5] Choice 3: Allow presenting non-free installers alongside the free one
  [6] Choice 7: None Of The Above
  [7] Choice 4: Installer with non-free software is not part of Debian
Why have I voted this way? Fundamentally, my motivation for starting this vote was to ask the project for clear positive direction on a sensible way forward with non-free firmware support. Thus, I've voted all of the options that do that above NOTA. On those terms, I don't like Choice 4 here - IMHO it leaves us in the same unclear situation as before. I'd be happy for us to update the Social Contract for clarity, and I know some people would be much more comfortable if we do that explicitly here. Choice 1 was my initial personal preference as we started the GR, but since then I've been convinced that also updating the SC would be a good idea, hence Choice 5. I'd also rather have a single image / set of images produced, for the two reasons I've outlined before. It's less work for our images team to build and test all the options. But, much more importantly: I believe it's less likely to confuse new users. I appreciate that not everybody agrees with me here, and this is part of the reason why we're voting! Other Debian people have also blogged about their voting choices (Gunnar Wolf and Ian Jackson so far), and I thank them for sharing their reasoning too. For the avoidance of doubt: my goal for this vote was simply to get a clear direction on how to proceed here. Although I proposed Choice 1 (Only one installer, including non-free firmware), I also seconded several of the other ballot options. Of course I will accept the will of the project when the result is announced - I'm not going to do anything silly like throw a tantrum or quit the project over this! Finally If you're a DD and you haven't voted already, please do so - this is an important choice for the Debian project.

23 September 2022

Gunnar Wolf: 6237415

Years ago, it was customary that some of us stated publicly the way we think in time of Debian General Resolutions (GRs). And even if we didn t, vote lists were open (except when voting for people, i.e. when electing a DPL), so if interested we could understand what our different peers thought. This is the first vote, though, where a Debian vote is protected under voting secrecy. I think it is sad we chose that path, as I liken a GR vote more with a voting process within a general assembly of a cooperative than with a countrywide voting one; I feel that understanding who is behind each posture helps us better understand the project as a whole. But anyway, I m digressing Even though I remained quiet during much of the discussion period (I was preparing and attending a conference), I am very much interested in this vote I am the maintainer for the Raspberry Pi firmware, and am a seconder for two of them. Many people know me for being quite inflexible in my interpretation of what should be considered Free Software, and I m proud of it. But still, I believer it to be fundamental for Debian to be able to run on the hardware most users have. So My vote was as follows:
[6] Choice 1: Only one installer, including non-free firmware
[2] Choice 2: Recommend installer containing non-free firmware
[3] Choice 3: Allow presenting non-free installers alongside the free one
[7] Choice 4: Installer with non-free software is not part of Debian
[4] Choice 5: Change SC for non-free firmware in installer, one installer
[1] Choice 6: Change SC for non-free firmware in installer, keep both installers
[5] Choice 7: None Of The Above
For people reading this not into Debian s voting processes: Debian uses the cloneproof Schwatz sequential dropping Condorcet method, which means we don t only choose our favorite option (which could lead to suboptimal strategic voting outcomes), but we rank all the options according to our preferences. To read this vote, we should first locate position of None of the above , which for my ballot is #5. Let me reorder the ballot according to my preferences:
[1] Choice 6: Change SC for non-free firmware in installer, keep both installers
[2] Choice 2: Recommend installer containing non-free firmware
[3] Choice 3: Allow presenting non-free installers alongside the free one
[4] Choice 5: Change SC for non-free firmware in installer, one installer
[5] Choice 7: None Of The Above
[6] Choice 1: Only one installer, including non-free firmware
[7] Choice 4: Installer with non-free software is not part of Debian
This is, I don t agree either with Steve McIntyre s original proposal, Choice 1 (even though I seconded it, this means, I think it s very important to have this vote, and as a first proposal, it s better than the status quo maybe it s contradictory that I prefer it to the status quo, but ranked it below NotA. Well, more on that when I present Choice 5). My least favorite option is Choice 4, presented by Simon Josefsson, which represents the status quo: I don t want Debian not to have at all an installer that cannot be run on most modern hardware with reasonably good user experience (i.e. network support or the ability to boot at all!) Slightly above my acceptability threshold, I ranked Choice 5, presented by Russ Allbery. Debian s voting and its constitution rub each other in interesting ways, so the Project Secretary has to run the votes as they are presented but he has interpreted Choice 1 to be incompatible with the Social Contract (as there would no longer be a DFSG-free installer available), and if it wins, it could lead him to having to declare the vote invalid. I don t want that to happen, and that s why I ranked Choice 1 below None of the above.
[update/note] Several people have asked me to back that the Secretary said so. I can refer to four mails: 2022.08.29, 2022.08.30, 2022.09.02, 2022.09.04.
Other than that, Choice 6 (proposed by Holger Levsen), Choice 2 (proposed by me) and Choice 3 (proposed by Bart Martens) are very much similar; the main difference is that Choice 6 includes a modification to the Social Contract expressing that:
The Debian official media may include firmware that is otherwise not
part of the Debian system to enable use of Debian with hardware that
requires such firmware.
I believe choices 2 and 3 to be mostly the same, being Choice 2 more verbose in explaining the reasoning than Choice 3. Oh! And there are always some more bits to the discussion For example, given they hold modifications to the Social Contract, both Choice 5 and Choice 6 need a 3:1 supermajority to be valid. So, lets wait until the beginning of October to get the results, and to implement the changes they will (or not?) allow. If you are a Debian Project Member, please vote!

Steve Kemp: Lisp macros are magical

In my previous post I introduced yet another Lisp interpreter. When it was posted there was no support for macros. Since I've recently returned from a visit to the UK, and caught COVID-19 while I was there, I figured I'd see if my brain was fried by adding macro support. I know lisp macros are awesome, it's one of those things that everybody is told. Repeatedly. I've used macros in my emacs programming off and on for a good few years, but despite that I'd not really given them too much thought. If you know anything about lisp you know that it's all about the lists, the parenthesis, and the macros. Here's a simple macro I wrote:
 (define if2 (macro (pred one two)
     (if ~pred (begin ~one ~two))))
The standard lisp if function allows you to write:
 (if (= 1 a) (print "a == 1") (print "a != 1"))
There are three arguments supplied to the if form: My if2 macro instead has three arguments: This means I can write:
 (if2 blah
    (one..)
    (two..))
Rather than:
 (if blah
    (begin
       (one..)
       (two..)))
It is simple, clear, and easy to understand and a good building-block for writing a while function:
 (define while-fun (lambda (predicate body)
    (if2 (predicate)
       (body)
       (while-fun predicate body))))
There you see that if the condition is true then we call the supplied body, and then recurse. Doing two actions as a result of the single if test is a neat shortcut. Of course we need to wrap that up in a macro, for neatness:
(define while (macro (expression body)
                 (list 'while-fun
                       (list 'lambda '() expression)
                       (list 'lambda '() body))))
Now we're done, and we can run a loop five times like so:
(let ((a 5))
  (while (> a 0)
     (begin
        (print "(while) loop - iteration %s" a)
        (set! a (- a 1) true))))
Output:
(while) loop - iteration 5
(while) loop - iteration 4
(while) loop - iteration 3
(while) loop - iteration 2
(while) loop - iteration 1
We've gone from using lists to having a while-loop, with a couple of simple macros and one neat recursive function. There are a lot of cute things you can do with macros, and now I'm starting to appreciate them a little more. Of course it's not quite as magical as FORTH, but damn close!

11 September 2022

Andrew Cater: 202209110020 - Debian release day(s) - Cambridge - post 4

RattusRattus, Isy, smcv have all just left after a very long day. Steve is finishing up the final stages. The mayhem has quietened, the network cables are coiled, pretty much everything is tidied away. A new experience for two of us - I just hope it hasn't put them off too much.The IRC channels are quiet and we can put this one to bed after a good day's work well done.

1 September 2022

Shirish Agarwal: Culture, Books, Friends

Culture Just before I start, I would like to point out that this post may or would probably be NSFW. Again, what is SFW (Safe at Work) and NSFW that so much depends on culture and perception of culture from wherever we are or wherever we take birth? But still, to be on the safe side I have put it as NSFW. Now there have been a few statements and ideas that gave me a pause. This will be a sort of chaotic blog post as I am in such a phase today. For e.g. while I do not know which culture or which country this comes from, somebody shared that in some cultures one can talk/comment May your poop be easy and with a straight face. I dunno which culture is this but if somebody asked me that I would just die from laughing or maybe poop there itself. While I can understand if it is a constipated person, but a whole culture? Until and unless their DNA is really screwed, I don t think so but then what do I know? I do know that we shit when we have extreme reactions of either joy or fear. And IIRC, this comes from mammal response when they were in dangerous situations and we got the same as humans evolved. I would really be interested to know which culture is that. I did come to know that the Japanese do wish that you may not experience hard work or something to that effect while ironically they themselves are becoming extinct due to hard work and not enough relaxation, toxic workplace is common in Japan according to social scientists and population experts. Another term that I couldn t figure out is The Florida Man Strikes again and this term is usually used when somebody does something stupid or something weird. While it is exclusively used in the American context, I am curious to know how that came about. Why does Florida have such people or is it an exaggeration? I have heard the term e.g. What happens in Vegas, stays in Vegas . Think it is also called Sin city although why just Vegas is beyond me?

Omicron-8712 Blood pressure machine I felt so stupid. I found another site or e-commerce site called Wellness Forever. They had the blood pressure machine I wanted, an Omron-8172. I bought it online and they delivered the same within half an hour. Amazon took six days and in the end, didn t deliver it at all. I tried taking measurements from it yesterday. I have yet to figure out what it all means but I did get measurements of 109 SYS, 88 DIA and Pulse is 72. As far as the pulse is concerned, guess that is normal, the others just don t know. If only I had known this couple of months ago. I was able to register the product as well as download and use the Omron Connect app. For roughly INR 2.5k you have a sort of health monitoring system. It isn t Star Trek Tricorder in any shape or form but it will have to do while the tricorder gets invented. And while we are on the subject let s not forget Elizabeth Holmes and the scam called Theranos. It really is something to see How Elizabeth Holmes modeled so much of herself on Steve Jobs mimicking how he left college/education halfway. A part of me is sad that Theranos is not real. Joe Scott just a few days ago shared some perspectives on the same just a few days ago. The idea in itself is pretty seductive, to say the least, and that is the reason the scam went on for more than a decade and perhaps would have been longer if some people hadn t gotten the truth out. I do see potentially, something like that coming on as A.I. takes a bigger role in automating testing. Half a decade to a decade from now, who knows if there is an algorithm that is able to do what is needed? If such a product were to come to the marketplace at a decent price, it would revolutionize medicine, especially in countries like India, South Africa, and all sorts of remote places. Especially, with all sorts of off-grid technologies coming and maturing in the marketplace. Before I forget, there is a game called Cell on Android that tells or shares about the evolution of life on earth. It also shares credence to the idea that life has come 6 times on Earth and has been destroyed multiple times by asteroids. It is in the idle sort of game format, so you can see the humble beginnings from the primordial soup to various kinds of cells and bacteria to finally a mammal. This is where I am and a long way to go.

Indian Bureaucracy One of the few things that Britishers gave to India, is the bureaucracy and the bureaucracy tests us in myriad ways. It would be full 2 months on 5th September and I haven t yet got a death certificate. And I need that for a sundry number of things. The same goes for a disability certificate. What is and was interesting is my trip to the local big hospital called Sassoon Hospital. My mum had shared incidents that occurred in the 1950s when she and the family had come to Pune. According to her, when she was alive, while Sassoon was the place to be, it was big and chaotic and you never knew where you are going. That was in 1950, I had the same experience in 2022. The term/adage the more things change, the more they remain the same seems to be held true for Sassoon Hospital. Btw, those of you who think the Devil exists, he is totally a fallacy. There is a popular myth that the devil comes to deal that he/she/they come to deal with you when somebody close to you passes, I was waiting desperately for him when mum passed. Any deal that he/she/they would have offered me I would have gladly taken, but all my wait was all for nothing. While I believe evil exists, that is manifested by humans and nobody else. The whole idea and story of the devil is just to control young children and nothing beyond that

Debconf 2023, friends, JPEGOptim, and EV s Quite a number of friends had gone to Albania this year as India won the right to host Debconf for the year 2023. While I did lurk on the Debconf orga IRC channel, I m not sure how helpful I would be currently. One news that warmed my heart is some people would be coming to India to check the site way before and make sure things go smoothly. Nothing like having more eyes (in this case bodies) to throw at a problem and hopefully it will be sorted. While I have not been working for the last couple of years, one of the things that I had to do and have been doing is moving a lot of stuff online. This is in part due to the Government s own intention of having everything on the cloud. One of the things I probably may have shared it more than enough times is that the storage most of these sites give is like the 1990s. I tried jpegoptim and while it works, it degrades the quality of the image quite a bit. The whole thing seems backward, especially as newer and newer smartphones are capturing more data per picture (megapixel resolution), case in point Samsung Galaxy A04 that is being introduced. But this is not only about newer phones, even my earlier phone, Samsung J-5/500 which I bought in 2016 took images at 5 MB. So it is not a new issue but a continuous issue. And almost all Govt. sites have the upper band fixed at 1 MB. But this is not limited to Govt. sites alone, most sites in India are somewhat frozen in the 1990s. And it isn t as if resources for designing web pages using HTML5, CSS3, Javascript, Python, or Java aren t available. If worse comes to worst, one can even use amp to make his, her or their point. But this is if they want to do stuff. I would be sharing a few photos with commentary, there are still places where I can put photos apart from social media

Friends Last week, Saturday suddenly all the friends decided to show up. I have no clue one way or the other why but am glad they showed up.
Mahendra, Akshat, Shirish and Sagar Sukhose (Mangesh's friend). Mahendra, Akshat, Shirish and Sagar Sukhose (Mangesh s friend) at Bal Gandharva..
Electric scooter as shared by Akshat seen in Albania Electric scooter as shared by Akshat seen in Albania
Somebody making a  real-life replica of Wall Street on F.C. Road (Commercial, all glass)Somebody making a real-life replica of Wall Street on F.C. Road (Commercial, all glass)
Ganesh Idol near my houseGanesh Idol near my house
Wearing new clothesWearing new clothes
I will have to be a bit rapid about what I am sharing above so here goes nothing

1. The first picture shows Mahendra, Akshat, me, and Sagar Sukhose (Mangesh s friend). The picture was taken by Mangesh Diwate. We talked quite a bit of various things that could be done in Debian. A few of the things that I shared were (bringing more stuff from BSD to Debian, I am sure there s still quite a lot of security software that could be advantageous to have in Debian.) The best person to talk to or guide about this would undoubtedly be Paul Wise or as he is affectionally called Pabs. He is one of the shy ones and yet knows so much about how things work. The one and only time I met him is 2016. The other thing that we talked about is porting Debian to one of the phones. This has been done in the past and done by a Puneitie some 4-5 years back. While I don t recollect the gentleman s name, I remember that the porting was done on a Motorola phone as that was the easiest to do. He had tried some other mobile but that didn t work. Making Debian available on phone is hard work. Just to have an idea, I went to the xda developers forum and found out that while M51 has been added, my specific phone model is not there. A Samsung Galaxy M52G Android (samsung; SM-M526B; lahaina; arm64-v8a) v12 . You look at the chat and you understand how difficult the process might be. One of the other ideas that Akshat pitched was Debian Astro, this is something that is close to the heart of many, including me. I also proposed to have some kind of web app or something where we can find and share about the various astronomy and related projects done by various agencies. While there is a NASA app, nothing comes close to JSR and that site just shares stuff, no speculation. There are so many projects taken or being done by the EU, JAXA, ISRO, and even middle-east countries are trying but other than people who are following some of the developments, we hear almost nothing. Even the Chinese have made some long strides but most people know nothing about the same. And it s sad to know that those developments are not being known, shared, or even speculated about as much as say NASA or SpaceX is. How do we go about it and how do we get people to contribute or ask questions around it would be interesting. 2. The second picture was something that was shared by Akshat. Akshat was sharing how in Albania people are moving on these electric scooters . I dunno if that is the right word for it or what. I had heard from a couple of friends who had gone to Vietnam a few years ago how most people in Vietnam had modified their scooters and they were snaking lines of electric wires charging scooters. I have no clue whether they were closer to Vespa or something like above. In India, the Govt. is in partnership with the oil, gas, and coal mafia just as it was in Australia (the new Govt. in Australia is making changes) the same thing is here. With the humongous profits that the oil sector provides the petro states and others, Corruption is bound to happen. We talk and that s the extent of things. 3. The third picture is from a nearby area called F.C. Road or Fergusson College Road. The area has come up quite sharply (commercially) in the last few years. Apparently, Mr. Kushal is making a real-life replica of Wall Street which would be given to commercial tenants. Right now the real estate market is tight in India, we will know how things pan out in the next few years. 4. Number four is an image of a Ganesh idol near my house. There is a 10-day festival of the elephant god that people used to celebrate every year. For the last couple of years because of the pandemic, people were unable to celebrate the festival as it is meant to celebrate. This time some people are going overboard while others are cautious and rightfully so. 5. Last and not least, one of the things that people do at this celebration is to have new clothes, so I shared a photo of a gentleman who had bought and was wearing new clothes. While most countries around the world are similar, Latin America is very similar to India in many ways, perhaps Gunnar can share. especially about religious activities. The elephant god is known for his penchant for sweets and that can be seen from his rounded stomach, that is also how he is celebrated. He is known to make problems disappear or that is supposed to be his thing. We do have something like 4 billion gods, so each one has to be given some work or quality to justify the same

28 August 2022

Andrew Cater: Debian Barbeque, Cambridge 2022

And here we are: second day of the barbeque in Cambridge. Lots of food - as always - some alcohol, some soft drinks, coffee.Lots of good friends, and banter and good natured argument. For a couple of folk, it's their first time here - but most people have known each other for years. Lots of reminiscing, some crochet from two of us. Multiple technical discussions weaving and overlapping
Not just meat and vegetarian options for food: a fresh loaf, gingerbread of various sorts, fresh Belgian-style waffles.I''m in the front room: four of us silently on laptops, one on a phone. Sounds of a loud game of Mao from the garden - all very normal for this time of year.Thanks to Jo and Steve, to all the cooks and folk sorting things out. One more night and I'll have done my first full BBQ here. Diet and slimming - what diet?

22 August 2022

Jonathan Wiltshire: Team Roles and Tuckman s Model, for Debian teams

When I first moved from being a technical consultant to a manager of other consultants, I took a 5-day course Managing Technical Teams a bootstrap for managing people within organisations, but with a particular focus on technical people. We do have some particular quirks, after all Two elements of that course keep coming to mind when doing Debian work, and they both relate to how teams fit together and get stuff done. Tuckman s four stages model In the mid-1960s Bruce W. Tuckman developed a four-stage descriptive model of the stages a project team goes through in its lifetime. They are:
Resolved disagreements and personality clashes result in greater intimacy, and a spirit of co-operation emerges.
Teams need to understand these stages because a team can regress to earlier stages when its composition or goals change. A new member, the departure of an existing member, changes in supervisor or leadership style can all lead a team to regress to the storming stage and fail to perform for a time. When you see a team member say this, as I observed in an IRC channel recently, you know the team is performing:
nice teamwork these busy days Seen on IRC in the channel of a performing team
Tuckman s model describes a team s performance overall, but how can team members establish what they can contribute and how can they go doing so confidently and effectively? Belbin s Team Roles
The types of behaviour in which people engage are infinite. But the range of useful behaviours, which make an effective contribution to team performance, is finite. These behaviours are grouped into a set number of related clusters, to which the term Team Role is applied. Belbin, R M. Team Roles at Work. Oxford: Butterworth-Heinemann, 2010
Dr Meredith Belbin s thesis, based on nearly ten years research during the 1970s and 1980s, is that each team has a number of roles which need to be filled at various times, but they re not innate characteristics of the people filling them. People may have attributes which make them more or less suited to each role, and they can consciously take up a role if they recognise its need in the team at a particular time. Belbin s nine team roles are: (adapted from https://www.belbin.com/media/3471/belbin-team-role-descriptions-2022.pdf) A well-balanced team, Belbin asserts, isn t comprised of multiples of nine individuals who fit into one of these roles permanently. Rather, it has a number of people who are comfortable to wear some of these hats as the need arises. It s even useful to use the team roles as language: for example, someone playing a shaper might say the way we ve always done this is holding us back , to which a co-ordinator s could respond Steve, Joanna put on your Plant hats and find some new ideas. Talk to Susan and see if she knows someone who s tackled this before. Present the options to Nigel and he ll help evaluate which ones might work for us. Teams in Debian There are all sort of teams in Debian those which are formally brought into operation by the DPL or the constitution; package maintenance teams; public relations teams; non-technical content teams; special interest teams; and a whole heap of others. Teams can be formal and informal, fleeting or long-lived, two people working together or dozens. But they all have in common the Tuckman stages of their development and the Belbin team roles they need to fill to flourish. At some stage in their existence, they will all experience new or departing team members and a period of re-forming, norming and storming perhaps fleetingly, perhaps not. And at some stage they will all need someone to step into a team role, play the part and get the team one step further towards their goals. Footnote Belbin Associates, the company Meredith Belbin established to promote and continue his work, offers a personalised report with guidance about which roles team members show the strongest preferences for, and how to make best use of them in various settings. They re quick to complete and can also take into account observers , i.e. how others see a team member. All my technical staff go through this process blind shortly after they start, so as not to bias their input, and then we discuss the roles and their report in detail as a one-to-one. There are some teams in Debian for which this process and discussion as a group activity could be invaluable. I have no particular affiliation with Belbin Associates other than having used the reports and the language of team roles for a number of years. If there s sufficient interest for a BoF session at the next DebConf, I could probably be persuaded to lead it.
Photo by Josh Calabrese on Unsplash

15 July 2022

Steve Kemp: So we come to Lisp

Recently I've been working with simple/trivial scripting languages, and I guess I finally reached a point where I thought "Lisp? Why not". One of the reasons for recent experimentation was thinking about the kind of minimalism that makes implementing a language less work - being able to actually use the language to write itself. FORTH is my recurring example, because implementing it mostly means writing a virtual machine which consists of memory ("cells") along with a pair of stacks, and some primitives for operating upon them. Once you have that groundwork in place you can layer the higher-level constructs (such as "for", "if", etc). Lisp allows a similar approach, albeit with slightly fewer low-level details required, and far less tortuous thinking. Lisp always feels higher-level to me anyway, given the explicit data-types ("list", "string", "number", etc). Here's something that works in my toy lisp:
;; Define a function,  fact , to calculate factorials (recursively).
(define fact (lambda (n)
  (if (<= n 1)
    1
      (* n (fact (- n 1))))))
;; Invoke the factorial function, using apply
(apply (list 1 2 3 4 5 6 7 8 9 10)
  (lambda (x)
    (print "%s! => %s" x (fact x))))
The core language doesn't have helpful functions to filter lists, or build up lists by applying a specified function to each member of a list, but adding them is trivial using the standard car, cdr, and simple recursion. That means you end up writing lots of small functions like this:
(define zero? (lambda (n) (if (= n 0) #t #f)))
(define even? (lambda (n) (if (zero? (% n 2)) #t #f)))
(define odd?  (lambda (n) (! (even? n))))
(define sq    (lambda (x) (* x x)))
Once you have them you can use them in a way that feels simple and natural:
(print "Even numbers from 0-10: %s"
  (filter (nat 11) (lambda (x) (even? x))))
(print "Squared numbers from 0-10: %s"
  (map (nat 11) (lambda (x) (sq x))))
This all feels very sexy and simple, because the implementations of map, apply, filter are all written using the lisp - and they're easy to write. Lisp takes things further than some other "basic" languages because of the (infamous) support for Macros. But even without them writing new useful functions is pretty simple. Where things struggle? I guess I don't actually have a history of using lisp to actually solve problems - although it's great for configuring my editor.. Anyway I guess the journey continues. Having looked at the obvious "minimal core" languages I need to go further afield: I'll make an attempt to look at some of the esoteric programming languages, and see if any of those are fun to experiment with.

9 July 2022

Andrew Cater: Testing 11.4 Debian media images - almost finished - 20220709 1933 UTC

We're flagging a bit now, I think but close to the end. The standard Debian images caused no problems: Sledge and I are just finishing up the last few live images to test now.Thanks, as ever, to the crew: RattusRattus and Isy, Sledge struggling through feeling awful. No debian-edu testing today, unfortunately, but that almost never breaks anyway.Everyone's getting geared up for Kosovo - you'll see the other three there with any luck - and you'd catch all of us at the BBQ in Cambridge. It's going to be a hugely busy month and a bit for Steve and the others. :)

1 July 2022

Steve Kemp: An update on my simple golang TCL interpreter

So my previous post introduced a trivial interpreter for a TCL-like language. In the past week or two I've cleaned it up, fixed a bunch of bugs, and added 100% test-coverage. I'm actually pretty happy with it now. One of the reasons for starting this toy project was to experiment with how easy it is to extend the language using itself Some things are simple, for example replacing this:
puts "3 x 4 = [expr 3 * 4]"
With this:
puts "3 x 4 = [* 3 4]"
Just means defining a function (proc) named *. Which we can do like so:
proc *  a b   
    expr $a * $b
 
(Of course we don't have lists, or variadic arguments, so this is still a bit of a toy example.) Doing more than that is hard though without support for more primitives written in the parent language than I've implemented. The obvious thing I'm missing is a native implementation of upvalue, which is TCL primitive allowing you to affect/update variables in higher-scopes. Without that you can't write things as nicely as you would like, and have to fall back to horrid hacks or be unable to do things.
# define a procedure to run a body N times
proc repeat  n body   
    set res ""
    while  > $n 0   
        decr n
        set res [$body]
     
    $res
 
# test it out
set foo 12
repeat 5   incr foo  
#  foo is now 17 (i.e. 12 + 5)
A similar story implementing the loop word, which should allow you to set the contents of a variable and run a body a number of times:
proc loop  var min max bdy   
    // result
    set res ""
    // set the variable.  Horrid.
    // We miss upvalue here.
    eval "set $var [set min]"
    // Run the test
    while  <= [set "$$var"] $max    
        set res [$bdy]
        // This is a bit horrid
        // We miss upvalue here, and not for the first time.
        eval  incr "$var" 
     
    // return the last result
    $res
 
loop cur 0 10   puts "current iteration $cur ($min->$max)"  
# output is:
# => current iteration 0 (0-10)
# => current iteration 1 (0-10)
# ...
That said I did have fun writing some simple test-cases, and implementing assert, assert_equal, etc. In conclusion I think the number of required primitives needed to implement your own control-flow, and run-time behaviour, is a bit higher than I'd like. Writing switch, repeat, while, and similar primitives inside TCL is harder than creating those same things in FORTH, for example.

29 June 2022

Tim Retout: Git internals and SHA-1

LWN reminds us that Git still uses SHA-1 by default. Commit or tag signing is not a mitigation, and to understand why you need to know a little about Git s internal structure. Git internally looks rather like a content-addressable filesystem, with four object types: tags, commits, trees and blobs. Content-addressable means changing the content of an object changes the way you address or reference it, and this is achieved using a cryptographic hash function. Here is an illustration of the internal structure of an example repository I created, containing two files (./foo.txt and ./bar/bar.txt) committed separately, and then tagged: Graphic showing an example Git internal structure featuring tags, commits, trees and blobs, and how these relate to each other. You can see how trees represent directories, blobs represent files, and so on. Git can avoid internal duplication of files or directories which remain identical. The hash function allows very efficient lookup of each object within git s on-disk storage. Tag and commit signatures do not directly sign the files in the repository; that is, the input to the signature function is the content of the tag/commit object, rather than the files themselves. This is analogous to the way that GPG signatures actually sign a cryptographic hash of your email, and there was a time when this too defaulted to SHA-1. An attacker who can break that hash function can bypass the guarantees of the signature function. A motivated attacker might be able to replace a blob, commit or tree in a git repository using a SHA-1 collision. Replacing a blob seems easier to me than a commit or tree, because there is no requirement that the content of the files must conform to any particular format. There is one key technical mitigation to this in Git, which is the SHA-1DC algorithm; this aims to detect and prevent known collision attacks. However, I will have to leave the cryptanalysis of this to the cryptographers! So, is this in your threat model? Do we need to lobby GitHub for SHA-256 support? Either way, I look forward to the future operational challenge of migrating the entire world s git repositories across to SHA-256.

21 June 2022

Steve Kemp: Writing a simple TCL interpreter in golang

Recently I was reading Antirez's piece TCL the Misunderstood again, which is a nice defense of the utility and value of the TCL language. TCL is one of those scripting languages which used to be used a hell of a lot in the past, for scripting routers, creating GUIs, and more. These days it quietly lives on, but doesn't get much love. That said it's a remarkably simple language to learn, and experiment with. Using TCL always reminds me of FORTH, in the sense that the syntax consists of "words" with "arguments", and everything is a string (well, not really, but almost. Some things are lists too of course). A simple overview of TCL would probably begin by saying that everything is a command, and that the syntax is very free. There are just a couple of clever rules which are applied consistently to give you a remarkably flexible environment. To get started we'll set a string value to a variable:
  set name "Steve Kemp"
  => "Steve Kemp"
Now you can output that variable:
  puts "Hello, my name is $name"
  => "Hello, my name is Steve Kemp"
OK, it looks a little verbose due to the use of set, and puts is less pleasant than print or echo, but it works. It is readable. Next up? Interpolation. We saw how $name expanded to "Steve Kemp" within the string. That's true more generally, so we can do this:
 set print pu
 set me    ts
 $print$me "Hello, World"
 => "Hello, World"
There "$print" and "$me" expanded to "pu" and "ts" respectively. Resulting in:
 puts "Hello, World"
That expansion happened before the input was executed, and works as you'd expect. There's another form of expansion too, which involves the [ and ] characters. Anything within the square-brackets is replaced with the contents of evaluating that body. So we can do this:
 puts "1 + 1 = [expr 1 + 1]"
 => "1 + 1 = 2"
Perhaps enough detail there, except to say that we can use and to enclose things that are NOT expanded, or executed, at parse time. This facility lets us evaluate those blocks later, so you can write a while-loop like so:
 set cur 1
 set max 10
 while   expr $cur <= $max    
       puts "Loop $cur of $max"
       incr cur
  
Anyway that's enough detail. Much like writing a FORTH interpreter the key to implementing something like this is to provide the bare minimum of primitives, then write the rest of the language in itself. You can get a usable scripting language with only a small number of the primitives, and then evolve the rest yourself. Antirez also did this, he put together a small TCL interpreter in C named picol: Other people have done similar things, recently I saw this writeup which follows the same approach: So of course I had to do the same thing, in golang: My code runs the original code from Antirez with only minor changes, and was a fair bit of fun to put together. Because the syntax is so fluid there's no complicated parsing involved, and the core interpreter was written in only a few hours then improved step by step. Of course to make a language more useful you need I/O, beyond just writing to the console - and being able to run the list-operations would make it much more useful to TCL users, but that said I had fun writing it, it seems to work, and once again I added fuzz-testers to the lexer and parser to satisfy myself it was at least somewhat robust. Feedback welcome, but even in quiet isolation it's fun to look back at these "legacy" languages and recognize their simplicity lead to a lot of flexibility.

3 May 2022

Steve Kemp: A plea for books ..

Recently I've been getting much more interested in the "retro" computers of my youth, partly because I've been writing crazy code in Z80 assembly-language, and partly because I've been preparing to introduce our child to his first computer: I've got a few books, books I've hoarded for 30+ years, but I'd love to collect some more. So here's my request: I'd be happy to pay 5-10 each for any book I don't yet own, and I'd also be more than happy to cover the cost of postage to Finland. I'd be particularly pleased to see anything from Melbourne House, and while low-level is best, the coding-books from Usbourne (The Mystery Of Silver Mountain, etc, etc) wouldn't go amiss either. I suspect most people who have collected and kept these wouldn't want to part with them, but just in case ..

26 April 2022

Steve Kemp: Porting a game from CP/M to the ZX Spectrum 48k

Back in April 2021 I introduced a simple text-based adventure game, The Lighthouse of Doom, which I'd written in Z80 assembly language for CP/M systems. As it was recently the 40th Anniversary of the ZX Spectrum 48k, the first computer I had, and the reason I got into programming in the first place, it crossed my mind that it might be possible to port my game from CP/M to the ZX Spectrum. To recap my game is a simple text-based adventure game, which you can complete in fifteen minutes, or less, with a bunch of Paw Patrol easter-eggs. My code is largely table-based, having structures that cover objects, locations, and similar state-things. Most of the code involves working with those objects, with only a few small platform-specific routines being necessary: My feeling was that I could replace the use of those CP/M functions with something custom, and I'd have done the 99% of the work. Of course the devil is always in the details. Let's start. To begin with I'm lucky in that I'm using the pasmo assembler which is capable of outputting .TAP files, which can be loaded into ZX Spectrum emulators. I'm not going to walk through all the code here, because that is available within the project repository, but here's a very brief getting-started guide which demonstrates writing some code on a Linux host, and generating a TAP file which can be loaded into your favourite emulator. As I needed similar routines I started working out how to read keyboard input, clear the screen, and output messages which is what the following sample will demonstrate.. First of all you'll need to install the dependencies, specifically the assembler and an emulator to run the thing:
# apt install pasmo spectemu-x11
Now we'll create a simple assembly-language file, to test things out - save the following as hello.z80:
    ; Code starts here
    org 32768
    ; clear the screen
    call cls
    ; output some text
    ld   de, instructions                  ; DE points to the text string
    ld   bc, instructions_end-instructions ; BC contains the length
    call 8252
    ; wait for a key
    ld hl,0x5c08        ; LASTK
    ld a,255
    ld (hl),a
wkey:
    cp (hl)             ; wait for the value to change
    jr z, wkey
    ; get the key and save it
    ld a,(HL)
    push af
    ; clear the screen
    call cls
    ; show a second message
    ld de, you_pressed
    ld bc, you_pressed_end-you_pressed
    call 8252
    ;; Output the ASCII character in A
    ld a,2
    call 0x1601
    pop af
    call 0x0010
    ; loop forever.  simple demo is simple
endless:
    jr endless
cls:
    ld a,2
    call 0x1601  ; ROM_OPEN_CHANNEL
    call 0x0DAF  ; ROM_CLS
    ret
instructions:
    defb 'Please press a key to continue!'
instructions_end:
you_pressed:
    defb 'You pressed:'
you_pressed_end:
end 32768
Now you can assemble that into a TAP file like so:
$ pasmo --tapbas hello.z80 hello.tap
The final step is to load it in the emulator:
$ xspect -quick-load -load-immed -tap hello.tap
The reason I specifically chose that emulator was because it allows easily loading of a TAP file, without waiting for the tape to play, and without the use of any menus. (If you can tell me how to make FUSE auto-start like that, I'd love to hear!) I wrote a small number of "CP/M emulation functions" allowing me to clear the screen, pause, prompt for input, and output text, which will work via the primitives available within the standard ZX Spectrum ROM. Then I reworked the game a little to cope with the different screen resolution (though only minimally, some of the text still breaks lines in unfortunate spots): The end result is reasonably playable, even if it isn't quite as nice as the CP/M version (largely because of the unfortunate word-wrapping, and smaller console-area). So now my repository contains a .TAP file which can be loaded into your emulator of choice, available from the releases list. Here's a brief teaser of what you can expect:
Outstanding bugs? Well the line-input is a bit horrid, and unfortunately this was written for CP/M accessed over a terminal - so I'd assumed a "standard" 80x25 resolution, which means that line/word-wrapping is broken in places. That said it didn't take me too long to make the port, and it was kinda fun.

21 April 2022

Andy Simpkins: Firmware and Debian

There has been a flurry of activity on the Debian mailing lists ever since Steve McIntyre raised the issue of including non-free firmware as part of official Debian installation images. Firstly I should point out that I am in complete agreement with Steve s proposal to include non-free firmware as part of an installation image. Likewise I think that we should have a separate archive section for firmware. Because without doing so it will soon become almost impossible to install onto any new hardware. However, as always the issue is more nuanced than a first glance would suggest. Lets start by defining what is firmware? Firmware is any software that runs outside the orchestration of the operating system. Typically firmware will be executed on a processor(s) separate from the processor(s) running the OS, but this does not need to be the case. As Debian we are content that our systems can operate using fully free and open source software and firmware. We can install our OS without needing any non-free firmware. This is an illusion! Each and every PC platform contains non-free firmware It may be possible to run free firmware on some Graphics controllers, Wi-Fi chip-sets, or Ethernet cards and we can (and perhaps should) choose to spend our money on systems where this is the case. When installing a new system we might still be forced to hold our nose and install with non-free firmware on the peripheral before we are able to upgrade it to FLOSS firmware later if this is exists or is even possible to do so. However after the installation we are running a full FLOSS system in terms of software and firmware. We all (almost without exception) are running propitiatory firmware whether we like it or not. Even after carefully selecting graphics and network hardware with FLOSS firmware options we still haven t escaped from non-free-firmware. Other peripherals contain firmware too each keyboard, disk (SSDs and Spinning rust). Even your USB memory stick that you use to contain the Debian installation image contains a microcontroller and hence also contains firmware that runs on it.
  1. Much of this firmware can not even be updated.
  2. Some can be updated, but is stored in FLASH ROM and the hardware vendor has defeated all programming methods (possibly circumnavigated with a hardware mod).
  3. Some of it can be updated but requires external device programmers (and often the programming connections are a series of test points dotted around the board and not on a header in order to make programming as difficult as possible).
  4. Sometimes the firmware can be updated from within the host operating system (i.e. Debian)
  5. Sometimes, as Steve pointed out in his post, the hardware vendor has enough firmware on a peripheral to perform basic functions perhaps enough to install the OS, but requires additional firmware to enable specific feature (i.e. higher screen resolutions, hardware accelerated functions etc.)
  6. Finally some vendors don t even bother with any non-volatile storage beyond a basic boot loader and firmware must be loaded before the device can be used in any mode.
What about the motherboard? If we are lucky we might be able to run a FLOSS implementation of the UEFI subsystem (edk2/tianocore for example), indeed the non AMD64/i386 platforms based around ARM, MIPS architectures are often the most free when it comes to firmware. What about the microcode on the processor? Personally I wasn t aware that that this was updatable firmware until the Spectre and Meltdown classes of vulnerabilities arose a few years back. So back to Debian images including non-free firmware. This is specifically to address the last two use cases mentioned above, i.e. where firmware needs to be loaded to achieve a minimum functioning of a device. Although it could also include motherboard support, and microcode as well. As far as I can tell the proposal exists for several reasons: #1 Because some freely distributable firmware is required for more and more devices, in order to install Debian, or because whilst Debian can be installed a desktop environment can not be started or fully function #2 Because frankly it is less work to produce, test and maintain fewer installation images As someone who performs tests on our images, this clearly gets my vote :-) and perhaps most important of all.. #3 Because our least experienced users, and new users will download an official image and give up if things don t just work TM Steve s proposal option 5 would address theses issues and I fully support it. I would love to see separate repositories for firmware and firmware-none free. Additionally to accompany firmware non-free I would like to have information on what the firmware actually does. Can I run my hardware without it, what function(s) are limited without the firmware, better yet is there a FLOSS equivalent that I can load instead? Is this something that we can present in Debian installer? I would love not to require non-free firmware, but if I can t, I would love if DI would enable a user to make an informed choice as to what, if any, firmware is installed. Should we be requesting (requiring?) this information for any non-free firmware image that we carry in the archive? Finally lets consider firmware in the wider general case, not just the case where we need to load firmware from within Debian each and every boot. Personally I am annoyed whenever a hardware manufacturer has gone out of their way to prevent firmware updates. Lets face it software contains bugs, and we can assume that the software making up a firmware image will as well. Critical (security) vulnerabilities found in firmware, especially if this runs on the same processor(s) as the OS can impact on the wider system, not just the device itself. This will mean that, without updatable firmware, the hardware itself should be withdrawn from use whilst it would otherwise still function. By preventing firmware updates vendors are forcing early obsolescence in the hardware they sell, perhaps good for their bottom line, but certainly no good for users or the environment. Here I can practice what I preach. As an Electronic Engineer / Systems architect I have been beating the drum for In System Updatable firmware for ALL programmable devices in a system, be it a simple peripheral or a deeply embedded system. I can honestly say that over the last 20 years (yes I have been banging this particular drum for that long) I have had 100% success in arguing this case commercially. Having device programmers in R&D departments is one thing, but that is additional cost for production, and field service. Needing custom programming headers or even a bed of nails fixture to connect your target device to a programmer is more trouble than it is worth. Finally, the ability to update firmware in the field means that you can launch your product on schedule, make a sale and ship to a customer even if the first thing that you need to do is download an update. Offering that to any project manager will make you very popular indeed. So what if this firmware is non-free? As long as the firmware resides in non-volatile media without needing the OS to interact with it, we as a project don t need to carry it in our archives. And we as principled individuals can vote with our feet and wallets by choosing to purchase devices that have free firmware. But where that isn t an option, I ll take updatable but non-free firmware over non-free firmware that can not be updated any day of the week. Sure, the manufacture can choose to no longer support the firmware, and it is shocking how soon this happens often in the consumer market, the manufacture has withdrawn support for a product before it even reaches the end user (In which case we should boycott that manufacture in future until they either change their ways of go bust). But again if firmware can be updated in system that would at least allow the possibility of open firmware to arise. Indeed the only commercial case I have seen to argue against updatable firmware has been either for DRM, in which case good lets get rid of both, or for RF licence compliance, and even then it is tenuous because in this case the manufacture wants ISP for its own use right up until a device is shipped out the door, typically achived by blowing one time programmable fuse links .

19 April 2022

Steve McIntyre: Firmware - what are we going to do about it?

TL;DR: firmware support in Debian sucks, and we need to change this. See the "My preference, and rationale" Section below. In my opinion, the way we deal with (non-free) firmware in Debian is a mess, and this is hurting many of our users daily. For a long time we've been pretending that supporting and including (non-free) firmware on Debian systems is not necessary. We don't want to have to provide (non-free) firmware to our users, and in an ideal world we wouldn't need to. However, it's very clearly no longer a sensible path when trying to support lots of common current hardware. Background - why has (non-free) firmware become an issue? Firmware is the low-level software that's designed to make hardware devices work. Firmware is tightly coupled to the hardware, exposing its features, providing higher-level functionality and interfaces for other software to use. For a variety of reasons, it's typically not Free Software. For Debian's purposes, we typically separate firmware from software by considering where the code executes (does it run on a separate processor? Is it visible to the host OS?) but it can be difficult to define a single reliable dividing line here. Consider the Intel/AMD CPU microcode packages, or the U-Boot firmware packages as examples. In times past, all necessary firmware would normally be included directly in devices / expansion cards by their vendors. Over time, however, it has become more and more attractive (and therefore more common) for device manufacturers to not include complete firmware on all devices. Instead, some devices just embed a very simple set of firmware that allows for upload of a more complete firmware "blob" into memory. Device drivers are then expected to provide that blob during device initialisation. There are a couple of key drivers for this change: Due to these reasons, more and more devices in a typical computer now need firmware to be uploaded at runtime for them to function correctly. This has grown: At the beginning of this timeline, a typical Debian user would be able to use almost all of their computer's hardware without needing any firmware blobs. It might have been inconvenient to not be able to use the WiFi, but most laptops had wired ethernet anyway. The WiFi could always be enabled and configured after installation. Today, a user with a new laptop from most vendors will struggle to use it at all with our firmware-free Debian installation media. Modern laptops normally don't come with wired ethernet now. There won't be any usable graphics on the laptop's screen. A visually-impaired user won't get any audio prompts. These experiences are not acceptable, by any measure. There are new computers still available for purchase today which don't need firmware to be uploaded, but they are growing less and less common. Current state of firmware in Debian For clarity: obviously not all devices need extra firmware uploading like this. There are many devices that depend on firmware for operation, but we never have to think about them in normal circumstances. The code is not likely to be Free Software, but it's not something that we in Debian must spend our time on as we're not distributing that code ourselves. Our problems come when our user needs extra firmware to make their computer work, and they need/expect us to provide it. We have a small set of Free firmware binaries included in Debian main, and these are included on our installation and live media. This is great - we all love Free Software and this works. However, there are many more firmware binaries that are not Free. If we are legally able to redistribute those binaries, we package them up and include them in the non-free section of the archive. As Free Software developers, we don't like providing or supporting non-free software for our users, but we acknowledge that it's sometimes a necessary thing for them. This tension is acknowledged in the Debian Free Software Guidelines. This tension extends to our installation and live media. As non-free is officially not considered part of Debian, our official media cannot include anything from non-free. This has been a deliberate policy for many years. Instead, we have for some time been building a limited parallel set of "unofficial non-free" images which include non-free firmware. These non-free images are produced by the same software that we use for the official images, and by the same team. There are a number of issues here that make developers and users unhappy:
  1. Building, testing and publishing two sets of images takes more effort.
  2. We don't really want to be providing non-free images at all, from a philosophy point of view. So we mainly promote and advertise the preferred official free images. That can be a cause of confusion for users. We do link to the non-free images in various places, but they're not so easy to find.
  3. Using non-free installation media will cause more installations to use non-free software by default. That's not a great story for us, and we may end up with more of our users using non-free software and believing that it's all part of Debian.
  4. A number of users and developers complain that we're wasting their time by publishing official images that are just not useful for a lot (a majority?) of users.
We should do better than this. Options The status quo is a mess, and I believe we can and should do things differently. I see several possible options that the images team can choose from here. However, several of these options could undermine the principles of Debian. We don't want to make fundamental changes like that without the clear backing of the wider project. That's why I'm writing this...
  1. Keep the existing setup. It's horrible, but maybe it's the best we can do? (I hope not!)
  2. We could just stop providing the non-free unofficial images altogether. That's not really a promising route to follow - we'd be making it even harder for users to install our software. While ideologically pure, it's not going to advance the cause of Free Software.
  3. We could stop pretending that the non-free images are unofficial, and maybe move them alongside the normal free images so they're published together. This would make them easier to find for people that need them, but is likely to cause users to question why we still make any images without firmware if they're otherwise identical.
  4. The images team technically could simply include non-free into the official images, and add firmware packages to the input lists for those images. However, that would still leave us with problem 3 from above (non-free generally enabled on most installations).
  5. We could split out the non-free firmware packages into a new non-free-firmware component in the archive, and allow a specific exception only to allow inclusion of those packages on our official media. We would then generate only one set of official media, including those non-free firmware packages. (We've already seen various suggestions in recent years to split up the non-free component of the archive like this, for example into non-free-firmware, non-free-doc, non-free-drivers, etc. Disagreement (bike-shedding?) about the split caused us to not make any progress on this. I believe this project should be picked up and completed. We don't have to make a perfect solution here immediately, just something that works well enough for our needs today. We can always tweak and improve the setup incrementally if that's needed.)
These are the most likely possible options, in my opinion. If you have a better suggestion, please let us know! I'd like to take this set of options to a GR, and do it soon. I want to get a clear decision from the wider Debian project as to how to organise firmware and installation images. If we do end up changing how we do things, I want a clear mandate from the project to do that. My preference, and rationale Mainly, I want to see how the project as a whole feels here - this is a big issue that we're overdue solving. What would I choose to do? My personal preference would be to go with option 5: split the non-free firmware into a special new component and include that on official media. Does that make me a sellout? I don't think so. I've been passionately supporting and developing Free Software for more than half my life. My philosophy here has not changed. However, this is a complex and nuanced situation. I firmly believe that sharing software freedom with our users comes with a responsibility to also make our software useful. If users can't easily install and use Debian, that helps nobody. By splitting things out here, we would enable users to install and use Debian on their hardware, without promoting/pushing higher-level non-free software in general. I think that's a reasonable compromise. This is simply a change to recognise that hardware requirements have moved on over the years. Further work If we do go with the changes in option 5, there are other things we could do here for better control of and information about non-free firmware:
  1. Along with adding non-free firmware onto media, when the installer (or live image) runs, we should make it clear exactly which firmware packages have been used/installed to support detected hardware. We could link to docs about each, and maybe also to projects working on Free re-implementations.
  2. Add an option at boot to explicitly disable the use of the non-free firmware packages, so that users can choose to avoid them.
Acknowledgements Thanks to people who reviewed earlier versions of this document and/or made suggestions for improvement, in particular:

26 March 2022

Andrew Cater: Part way through testing Debian media images 20220326 1555UTC - Found a new useful utility

For various obscure reasons, I have a mirror of Debian in one room and the main laptop and so on I use in another. The mirror is connected to a fast Internet line - and has a 1Gb Ethernet cable into the back directly from the router, the laptop and everything else - not so much, everything is wired, but depends on a WiFi link across the property. One end is fast - one end runs like a snail.Steve suggested I use a different tool to make images directly on the mirror machine - jigit. Slightly less polished than jigdo but - if you're on the same machine - blazingly fast. I just used it to make the Blu-Ray sized .iso and was very pleasantly surprised. jigit-mkimage -j [jigdo file] -t [template file] -m Debian=[path to mirror of Debian] -o [output filename]
Another nice surprise for me - I have a horrible old Lenovo Ideapad. It's one of the Bay Trail Intel machines with a 32 bit UEFI and a 64 bit processor. I rescued it from the junk heap. Reinstalling it with an image today fixed an issue I had with slow boot and has turned it into an adequate machine for web browsing.All in all, I've done relatively few tests so far - but it's been a good day, as ever.More later.


2 March 2022

Antoine Beaupr : procmail considered harmful

TL;DR: procmail is a security liability and has been abandoned upstream for the last two decades. If you are still using it, you should probably drop everything and at least remove its SUID flag. There are plenty of alternatives to chose from, and conversion is a one-time, acceptable trade-off.

Procmail is unmaintained procmail is unmaintained. The "Final release", according to Wikipedia, dates back to September 10, 2001 (3.22). That release was shipped in Debian since then, all the way back from Debian 3.0 "woody", twenty years ago. Debian also ships 25 uploads on top of this, with 3.22-21 shipping the "3.23pre" release that has been rumored since at least the November 2001, according to debian/changelog at least:
procmail (3.22-1) unstable; urgency=low
  * New upstream release, which uses the  standard' format for Maildir
    filenames and retries on name collision. It also contains some
    bug fixes from the 3.23pre snapshot dated 2001-09-13.
  * Removed  sendmail' from the Recommends field, since we already
    have  exim' (the default Debian MTA) and  mail-transport-agent'.
  * Removed suidmanager support. Conflicts: suidmanager (<< 0.50).
  * Added support for DEB_BUILD_OPTIONS in the source package.
  * README.Maildir: Do not use locking on the example recipe,
    since it's wrong to do so in this case.
 -- Santiago Vila <sanvila@debian.org>  Wed, 21 Nov 2001 09:40:20 +0100
All Debian suites from buster onwards ship the 3.22-26 release, although the maintainer just pushed a 3.22-27 release to fix a seven year old null pointer dereference, after this article was drafted. Procmail is also shipped in all major distributions: Fedora and its derivatives, Debian derivatives, Gentoo, Arch, FreeBSD, OpenBSD. We all seem to be ignoring this problem. The upstream website (http://procmail.org/) has been down since about 2015, according to Debian bug #805864, with no change since. In effect, every distribution is currently maintaining its fork of this dead program. Note that, after filing a bug to keep Debian from shipping procmail in a stable release again, I was told that the Debian maintainer is apparently in contact with the upstream. And, surprise! they still plan to release that fabled 3.23 release, which has been now in "pre-release" for all those twenty years. In fact, it turns out that 3.23 is considered released already, and that the procmail author actually pushed a 3.24 release, codenamed "Two decades of fixes". That amounts to 25 commits since 3.23pre some of which address serious security issues, but none of which address fundamental issues with the code base.

Procmail is insecure By default, procmail is installed SUID root:mail in Debian. There's no debconf or pre-seed setting that can change this. There has been two bug reports against the Debian to make this configurable (298058, 264011), but both were closed to say that, basically, you should use dpkg-statoverride to change the permissions on the binary. So if anything, you should immediately run this command on any host that you have procmail installed on:
dpkg-statoverride --update --add root root 0755 /usr/bin/procmail
Note that this might break email delivery. It might also not work at all, thanks to usrmerge. Not sure. Yes, everything is on fire. This is fine. In my opinion, even assuming we keep procmail in Debian, that default should be reversed. It should be up to people installing procmail to assign it those dangerous permissions, after careful consideration of the risk involved. The last maintainer of procmail explicitly advised us (in that null pointer dereference bug) and other projects (e.g. OpenBSD, in [2]) to stop shipping it, back in 2014. Quote:
Executive summary: delete the procmail port; the code is not safe and should not be used as a basis for any further work.
I just read some of the code again this morning, after the original author claimed that procmail was active again. It's still littered with bizarre macros like:
#define bit_set(name,which,value) \
  (value?(name[bit_index(which)] =bit_mask(which)):\
  (name[bit_index(which)]&=~bit_mask(which)))
... from regexp.c, line 66 (yes, that's a custom regex engine). Or this one:
#define jj  (aleps.au.sopc)
It uses insecure functions like strcpy extensively. malloc() is thrown around gotos like it's 1984 all over again. (To be fair, it has been feeling like 1984 a lot lately, but that's another matter entirely.) That null pointer deref bug? It's fixed upstream now, in this commit merged a few hours ago, which I presume might be in response to my request to remove procmail from Debian. So while that's nice, this is the just tip of the iceberg. I speculate that one could easily find an exploitable crash in procmail if only by running it through a fuzzer. But I don't need to speculate: procmail had, for years, serious security issues that could possibly lead to root privilege escalation, remotely exploitable if procmail is (as it's designed to do) exposed to the network. Maybe I'm overreacting. Maybe the procmail author will go through the code base and do a proper rewrite. But I don't think that's what is in the cards right now. What I expect will happen next is that people will start fuzzing procmail, throw an uncountable number of bug reports at it which will get fixed in a trickle while never fixing the underlying, serious design flaws behind procmail.

Procmail has better alternatives The reason this is so frustrating is that there are plenty of modern alternatives to procmail which do not suffer from those problems. Alternatives to procmail(1) itself are typically part of mail servers. For example, Dovecot has its own LDA which implements the standard Sieve language (RFC 5228). (Interestingly, Sieve was published as RFC 3028 in 2001, before procmail was formally abandoned.) Courier also has "maildrop" which has its own filtering mechanism, and there is fdm (2007) which is a fetchmail and procmail replacement. Update: there's also mailprocessing, which is not an LDA, but processing an existing folder. It was, however, specifically designed to replace complex Procmail rules. But procmail, of course, doesn't just ship procmail; that would just be too easy. It ships mailstat(1) which we could probably ignore because it only parses procmail log files. But more importantly, it also ships:
  • lockfile(1) - conditional semaphore-file creator
  • formail(1) - mail (re)formatter
lockfile(1) already has a somewhat acceptable replacement in the form of flock(1), part of util-linux (which is Essential, so installed on any normal Debian system). It might not be a direct drop-in replacement, but it should be close enough. formail(1) is similar: the courier maildrop package ships reformail(1) which is, presumably, a rewrite of formail. It's unclear if it's a drop-in replacement, but it should probably possible to port uses of formail to it easily.
Update: the maildrop package ships a SUID root binary (two, even). So if you want only reformail(1), you might want to disable that with:
dpkg-statoverride --update --add root root 0755 /usr/bin/lockmail.maildrop 
dpkg-statoverride --update --add root root 0755 /usr/bin/maildrop
It would be perhaps better to have reformail(1) as a separate package, see bug 1006903 for that discussion.
The real challenge is, of course, migrating those old .procmailrc recipes to Sieve (basically). I added a few examples in the appendix below. You might notice the Sieve examples are easier to read, which is a nice added bonus.

Conclusion There is really, absolutely, no reason to keep procmail in Debian, nor should it be used anywhere at this point. It's a great part of our computing history. May it be kept forever in our museums and historical archives, but not in Debian, and certainly not in actual release. It's just a bomb waiting to go off. It is irresponsible for distributions to keep shipping obsolete and insecure software like this for unsuspecting users. Note that I am grateful to the author, I really am: I used procmail for decades and it served me well. But now, it's time to move, not bring it back from the dead.

Appendix

Previous work It's really weird to have to write this blog post. Back in 2016, I rebuilt my mail setup at home and, to my horror, discovered that procmail had been abandoned for 15 years at that point, thanks to that LWN article from 2010. I would have thought that I was the only weirdo still running procmail after all those years and felt kind of embarrassed to only "now" switch to the more modern (and, honestly, awesome) Sieve language. But no. Since then, Debian shipped three major releases (stretch, buster, and bullseye), all with the same vulnerable procmail release. Then, in early 2022, I found that, at work, we actually had procmail installed everywhere, possibly because userdir-ldap was using it for lockfile until 2019. I sent a patch to fix that and scrambled to remove get rid of procmail everywhere. That took about a day. But many other sites are now in that situation, possibly not imagining they have this glaring security hole in their infrastructure.

Procmail to Sieve recipes I'll collect a few Sieve equivalents to procmail recipes here. If you have any additions, do contact me. All Sieve examples below assume you drop the file in ~/.dovecot.sieve.

deliver mail to "plus" extension folder Say you want to deliver user+foo@example.com to the folder foo. You might write something like this in procmail:
MAILDIR=$HOME/Maildir/
DEFAULT=$MAILDIR
LOGFILE=$HOME/.procmail.log
VERBOSE=off
EXTENSION=$1            # Need to rename it - ?? does not like $1 nor 1
:0
* EXTENSION ?? [a-zA-Z0-9]+
        .$EXTENSION/
That, in sieve language, would be:
require ["variables", "envelope", "fileinto", "subaddress"];
########################################################################
# wildcard +extension
# https://doc.dovecot.org/configuration_manual/sieve/examples/#plus-addressed-mail-filtering
if envelope :matches :detail "to" "*"  
  # Save name in $ name  in all lowercase
  set :lower "name" "$ 1 ";
  fileinto "$ name ";
  stop;
 

Subject into folder This would file all mails with a Subject: line having FreshPorts in it into the freshports folder, and mails from alternc.org mailing lists into the alternc folder:
:0
## mailing list freshports
* ^Subject.*FreshPorts.*
.freshports/
:0
## mailing list alternc
* ^List-Post.*mailto:.*@alternc.org.*
.alternc/
Equivalent Sieve:
if header :contains "subject" "FreshPorts"  
    fileinto "freshports";
  elsif header :contains "List-Id" "alternc.org"  
    fileinto "alternc";
 

Mail sent to root to a reports folder This double rule:
:0
* ^Subject: Cron
* ^From: .*root@
.rapports/
Would look something like this in Sieve:
if header :comparator "i;octet" :contains "Subject" "Cron"  
  if header :regex :comparator "i;octet"  "From" ".*root@"  
        fileinto "rapports";
   
 
Note that this is what the automated converted does (below). It's not very readable, but it works.

Bulk email I didn't have an equivalent of this in procmail, but that's something I did in Sieve:
if header :contains "Precedence" "bulk"  
    fileinto "bulk";
 

Any mailing list This is another rule I didn't have in procmail but I found handy and easy to do in Sieve:
if exists "List-Id"  
    fileinto "lists";
 

This or that I wouldn't remember how to do this in procmail either, but that's an easy one in Sieve:
if anyof (header :contains "from" "example.com",
           header :contains ["to", "cc"] "anarcat@example.com")  
    fileinto "example";
 
You can even pile up a bunch of options together to have one big rule with multiple patterns:
if anyof (exists "X-Cron-Env",
          header :contains ["subject"] ["security run output",
                                        "monthly run output",
                                        "daily run output",
                                        "weekly run output",
                                        "Debian Package Updates",
                                        "Debian package update",
                                        "daily mail stats",
                                        "Anacron job",
                                        "nagios",
                                        "changes report",
                                        "run output",
                                        "[Systraq]",
                                        "Undelivered mail",
                                        "Postfix SMTP server: errors from",
                                        "backupninja",
                                        "DenyHosts report",
                                        "Debian security status",
                                        "apt-listchanges"
                                        ],
           header :contains "Auto-Submitted" "auto-generated",
           envelope :contains "from" ["nagios@",
                                      "logcheck@",
                                      "root@"])
     
    fileinto "rapports";
 

Automated script There is a procmail2sieve.pl script floating around, and mentioned in the dovecot documentation. It didn't work very well for me: I could use it for small things, but I mostly wrote the sieve file from scratch.

Progressive migration Enrico Zini has progressively migrated his procmail setup to Sieve using a clever way: he hooked procmail inside sieve so that he could deliver to the Dovecot LDA and progressively migrate rules one by one, without having a "flag day". See this explanatory blog post for the details, which also shows how to configure Dovecot as an LMTP server with Postfix.

Other examples The Dovecot sieve examples are numerous and also quite useful. At the time of writing, they include virus scanning and spam filtering, vacation auto-replies, includes, archival, and flags.

Harmful considered harmful I am aware that the "considered harmful" title has a long and controversial history, being considered harmful in itself (by some people who are obviously not afraid of contradictions). I have nevertheless deliberately chosen that title, partly to make sure this article gets maximum visibility, but more specifically because I do not have doubts at this moment that procmail is, clearly, a bad idea at this moment in history.

Developing story I must also add that, incredibly, this story has changed while writing it. This article is derived from this bug I filed in Debian to, quite frankly, kick procmail out of Debian. But filing the bug had the interesting effect of pushing the upstream into action: as mentioned above, they have apparently made a new release and merged a bunch of patches in a new git repository. This doesn't change much of the above, at this moment. If anything significant comes out of this effort, I will try to update this article to reflect the situation. I am actually happy to retract the claims in this article if it turns out that procmail is a stellar example of defensive programming and survives fuzzing attacks. But at this moment, I'm pretty confident that will not happen, at least not in scope of the next Debian release cycle.

5 February 2022

Steve Kemp: Removing my last server?

In the past I used to run a number of virtual machines, or dedicated hosts. Currently I'm cut things down to only a single machine which I'm planning to remove. Email Email used to be hosted via dovecot, and then read with mutt-ng on the host itself. Later I moved to reading mail with my own console-based email client. Eventually I succumbed, and now I pay for Google's Workspace product. Git Repositories I used to use gitbucket for hosting a bunch of (mostly private) git repositories. A bad shutdown/reboot of my host trashed the internal database so that was broken. I replaced the use of gitbucket, which was very pretty, with gitolite to perform access-control, and avoid the need of a binary database. I merged a bunch of repositories, removed the secret things from there where possible, and finally threw them on a second github account. GPG-encryption added where appropriate. Static Hosts Static websites I used to host upon my own machine are now hosted via netlify. There aren't many of them, and they are rarely updated, I guess I care less. Dynamic Hosts That leaves only dynamic hosts. I used to have a couple of these, most notably the debian-administration.org, but that was archived and the final commercial thing I did was retired in January. I now have only one dynamic site up and running, https://api.steve.fi/, this provides two dynamic endpoints: Both of these are used by my tram-display device. Running these two services locally, in Docker, would probably be fine. However there is a third "secret" API - blog-comment submission. When a comment is received upon this blog it is written to a local filesystem, and an email is sent to me. The next time my blog is built rsync is used to get the remote-comments and add them to the blog. (Spam deleted first, of course). Locally the comments are added into the git-repository this blog is built from - and the remote files deleted now and again. Maybe I should just switch from writing the blog-comment to disk, and include all the meta-data in the email? I don't wanna go connecting to Gmail via IMAP, but I could probably copy and paste from the email to my local blog-repository. I can stop hosting the tram-APIs publicly, but the blog comment part is harder. I guess I just need to receive incoming FORM-submission, and send an email. Or maybe I drop blog-comments and sidestep the problem entirely? After all I wrote five posts in the whole of last year ..

22 January 2022

Steve Kemp: Visiting the UK was difficult, but worth it

So in my previous post I mentioned that we were going to spend the Christmas period in the UK, which we did. We spent a couple of days there, meeting my parents, and family. We also persuaded my sister to drive us to Scarborough so that we could hang out on the beach for an afternoon. Finland has lots of lakes, but it doesn't have proper waves. So it was surprisingly good just to wade in the sea and see waves! Unfortunately our child was a wee bit too scared to ride on a donkey! Unfortunately upon our return to Finland we all tested positive for COVID-19, me first, then the child, and about three days later my wife. We had negative tests in advance of our flights home, so we figure that either the tests were broken, or we were infected in the airplane/airport. Thankfully things weren't too bad, we stayed indoors for the appropriate length of time, and a combination of a couple of neighbours and online shopping meant we didn't run out of food. Since I've been back home I've been automating AWS activities with aws-utils, and updating my simple host-automation system, marionette. Marionette is something that was inspired by puppet, the configuration management utility, but it runs upon localhost only. Despite the small number of integrated primitives it actually works surprisingly well, and although I don't expect it will ever become popular it was an interesting research project. The aws-utilities? They were specifically put together because I've worked in a few places where infrastructure is setup with terraform, or cloudformation, but there are always the odd thing that is configured manually. Typically we'll have an openvpn gateway which uses a manually maintained IP allow-list, or some admin-server which has a security-group maintained somewhat manually. Having the ability to update a bunch of rules with your external IP, as a single command, across a number of AWS accounts/roles, and a number of security-groups is an enormous time-saver when your home IP changes. I'd quite like to add more things to that collection, but there's no particular rush.

Next.