IPv6 nostalgia
2011/06/08
It is World IPv6 Day today and I’m getting nostalgic. This is how the 6BONE looked in its very last day:
My last 6BONE map
The code that was constructing this diagram was running from July 16, 1998 until June 10, 2006. I had just finished reading “Practical Reusable Unix Software” (which is now available for download) and was trying to do something cool using graphviz. Yep, almost the same time as the Internet Mapping Project began.
I believe the World IPv6 Day is as close a date as we can get to a new Internet Flag Day. This time the switch will not happen in a day but gradually and very (very) slowly. Hopefully in 30 years from today, no IPv4 islands will exist.
Μπακάρντι-γκρέιπφρουτ
2011/02/20
Αν θυμάμαι καλά ήταν 1997 και έβρεχε. Με τον Ντίνο είχαμε φύγει από το Εργαστήριο και λέγαμε να πάμε καμιά βόλτα:
- Ρε συ μου έχουν πει για ένα μπαρ που το έχει ένας παππούς και παίζει Τζαζ.
- Ξέρεις που είναι;
- Κάπου στο Κολωνάκι
- ΟΚ, θα πάρουμε τους δρόμους με τη σειρά και θα το βρούμε.
Μπήκαμε μέσα, κάτσαμε δεξιά στη γωνία της μπάρας και μετά από λίγο ήρθε ο παππούς για να πάρει παραγγελία:
- Μάγκες, άμα ξαναμπείτε μέσα και δε χαιρετήσετε, δε θα σας σερβίρω.
Σιγά-σιγά φτάσαμε να κλείνουμε το μαγαζί με τον παππού να μας κερνάει τσίπουρα.
HOUMF! Con version 0.0 (mind recompilation)
2011/01/06
mind recompilation by skotos
Αντιγράφω από το Internet Archive:
Το HOUMF! Con version 0.0 διεξήχθη το Σάββατο 6 Ιανουαρίου 2001 στο Αμφιθέατρο Πληροφορικής στην Πολυτεχνειούπολη Ζωγράφου (Εθνικό Μετσόβειο Πολυτεχνείο). Υπολογίζεται ότι περίπου 150 άτομα συγκεντρώθηκαν εκεί και εξέφρασαν τη βούλησή τους να δοθεί συνέχεια…
Το HOUMF! Con version 0.0 εστίασε την προσοχή του στη συνάθροιση ανθρώπων με κάτι-παραπάνω-από-απλές γνώσεις πληροφορικής και με ενδιαφέροντα στους τομείς ασφάλειας δικτύων/ υπολογιστών και προχωρημένων τεχνικών προγραμματισμού. Βασικός σκοπός ήταν να γνωριστούμε μεταξύ μας καλύτερα και να θέσουμε τις βάσεις για περαιτέρω συνεννόηση και συνεργασία.
Η συνάθροιση αυτή ήταν κρίσιμης σημασίας, καθώς θα έθετε τις βάσεις για τη διοργάνωση ενός πλήρους Con. Τόσο το μικρό χρονικό διάστημα για τη διοργάνωση όσο και η δύσκολα προβλέψιμη ανταπόκριση που θα είχε, κατέστησε το version 0.0 κάτι σαν demo version, ενδεικτικό για τις μελλοντικές προοπτικές.
Η διοργάνωση του version 0.0 ήταν ιδιαίτερα επίπονη, αλλά και διδακτική, καθώς αποτελεί χρήσιμη εμπειρία και παρακαταθήκη για τη διοργάνωση ενός πλήρους HOUMF! Con.
Οι διοργανωτές (aka HOUMFers – houmfers@houmf.org) ήταν (με αλφαβητική σειρά): Budha, databus, DiJ, N3tKick3r, night, Prowler, w0lverine. Τη διοργάνωση υποστήριξαν το HACK.gr και το #/dev/urandom.
It was fun after all…
Ticket to the Con
TCPMUX – a mostly overlooked TCP service
2010/12/20
TCPMUX is described in RFC-1078 (written some 20 years ago). A reference implementation by Network Wizards can be found at ftp://ftp.nw.com/nw/software/tcpmux.c . It is also implemented in DragonFlyBSD’s inetd, NetBSD’s inetd and FreeBSD’s inetd. OpenBSD does not support for it.
The Protocol
A TCP client connects to a foreign host on TCP port 1. It sends the service name followed by a carriage-return line-feed . The service name is never case sensitive. The server replies with a single character indicating positive (“+”) or negative (“-”) acknowledgment, immediately followed by an optional message of explanation, terminated with a . If the reply was positive, the selected protocol begins; otherwise the connection is closed.
The 15+ years I have been a sysadmin I have never seen anyone making a use of it, which is a pity: Most of the time I see fellow sysadmins who want to write a custom daemon, either write it as a standalone server (usually starting with passivesock.c or passiveTCP.c from Comer’s Internetworking with TCP/IP vol.3), or writing is as a simple stdin/stdout application that is started via inetd. The most trivial problem is sometimes more than trivial:
- What port will this application run on?
It seems that 65535 ports is a lot of freedom to choose from and most people want to use “interesting” port numbers (for any definition of interesting). Add firewall policies and router access lists in the picture, you can have a non-technical deadlock in no time!
TCPMUX might be a choice to help simplify / avoid such situations. Any service that supports TCPMUX listens on port 1/tcp and can be forked by inetd(8) (either internally or externally with the help of a tiny server). After all, it can be considered as an “inetd inside inetd” (the classic inetd responding to requests on a port, TCPMUX responding to requests based on the name of the service) and even if you do not want to use TCPMUX, a similar (homegrown) solution might be the answer to keeping your packet filters lean and less complex. It does not have to be less complex than it has to be though. The Wikipedia article on tcpmux clearly identifies risks that come with deploying it. Personally, I view tcpmux as an old and simple TCP RPC mechanism.
Appendix: tcpmux.c
Since the Network Wizards site seems to be down / taken over by some other entity, here is the original tcpmux daemon code:
On the prehistory of Greek CERT(s)
2010/10/20
Lately I find myself attending meetings where the need for a single coordinating body over the various efforts of computer / network / cyber security is stressed. Roll back 15 years:
Once upon a time (circa 1996) the GRNET-CERT was formed. It was nothing official, just three guys (me, Georgios Koutepas and Costas Troulos) and a mail alias. Since we had no funding and the legal landscape was non-existent our main focus was on trying to stop whatever incidents occurred. It seemed to work pretty well at the time. We even managed to find some funding and some of us attened FIRST‘s 1998 and 1999 meetings. With the emergence of the GRNET2 project GRNET-CERT was handed over to another institute for operations. Our interests had already shifted from (pure) incident response and we never really followed-up the national progress on that front.
In the meantime the Greek state responded to the void that was forming regarding the legal side of matters. And it did so in the wisest of ways that we are used to being treated to. It formed a multitude of authorities to cover the area, sometimes conflicting one another. Nature abhors vacuum, but as Rob Pike said “sometimes when you fill the vacuum, it still sucks”. There can appear types of incidents that might require reporting to three (or even four) different authorities with no clear roadmap on what one is expected to do if one receives conflicting guidance on subjects that at times require rapid response.
It is a saddening thought to see that the manpower and the resources exist (something that was not that obvious back in 1996), that people with skill, knowledge and willingness to work exist, yet the overall progress is kind of minimal.
30 χρόνια επιτυχίες
2010/09/12
Kat was a Greek computer that dual-booted MS-DOS and Apple II
Ψάχνοντας για την ιστορία της Gigatronics και του Kat, έπεσα πάνω σε αυτό το PDF. Χρήσιμο ανάγνωσμα για όσους ενδιαφέρονται για την ανάπτυξη της Πληροφορικής στην Ελλάδα, τότε που ήμασταν παιδιά.
C interpreters
2010/09/03
I spotted today on Hacker News an article about PicoC, a small C interpreter. This triggered my memory in a journey back in 1994 when I had asked over at comp.compilers whether any C interpreter existed. It was then that I learned about ICI, a cool C-like scripting language that deserves more attention, the Quincy C interpreter which evolved to an IDE, and Smac, the C-like
interpreter that comes embedded with the XCoral editor.
Then there are also CINT which is part of an even more interesting project, and of course Ch.
But the coolest interpreter that I’ve seen, is written by Diomidis Spinellis:
#include "/dev/tty"
It changed the rules for the IOCCC.
WorldWideWeb – Executive Summary
2010/08/06
In August 6, 1991 Tim Berners-Lee posted his “WorldWideWeb – Executive Summary” on the USENET.
“In the old days” when security information was scarce and many of us began shaping our security mentality (be it white, gray or black) by reading “Improving the Security of Your Site by Breaking Into it” and the Computer Security FAQ and running tools like iss and Crack. I think it was there that I first read about Arto Karila’s PhD thesis. Even though it is an OSI based document, it helped understand basic concepts. However there were two problems with the document:
- It was hard to find, and
- It was in a weird PostScript format that even modern versions of ghostscript refuse to display.
With the help of a friend I managed to transform it to PDF and upload it to Scribd: Open Systems Security – an Architectural Framework
Of historical value mostly.
