Dear all,
it is pretty quite on this list. I'm not sure whether this is a good
sign or not.
I unfortunately had to cancel the retreat in November due to lack of
signups (3 people managed to sign up within the deadline) :/ While late
signups are possible, it is always a burden.
But I have some exciting MirageOS related news that I find worth
sharing, and hope to engage discussions by doing so. Maybe it is also
worth to restart weekly / biweekly MirageOS meetings (as in the old
days) -- what do you think?
Some repositories in the mirage organization are suffering from bitrot,
and/or lack of cleanups or reviews (such as the ocaml-solo5 PR waiting
since a long time for proper reviews that would enable to use OCaml 5)
-- my personal experience with OCaml 5 from a resource perspective is
not very good, that's why I don't really care about that too much (and
am happy that 4.14 is under long-term support).
## MirageVPN / OpenVPN
We at robur managed to receive EU (NGI Assure) funding to work on
MirageVPN (an OpenVPN implementation), which we started back in 2019 -
to add more mdoern crypto and more recent features (tls-crypt, ..), a
server implementation, a QubesOS client unikernel, ... --
https://nlnet.nl/project/MirageVPN/ \o/
The source is developed at https://github.com/robur-coop/miragevpn (also
see our blog entries at https://blog.robur.coop)
In case you are using OpenVPN and are looking for a replacement, please
have a try (and/or open issues if you're stuck / missing features).
## DNSvizor / DNSmasq
We at robur also managed to receive EU (NGI0 Entrust) funding to work on
DNSvizor (a DNS resolver and DHCP server - basically a DNSmasq
replacement) https://nlnet.nl/project/DNSvizor/ (earlier funding for
this project didn't pan out due to how to direct the money --
https://nlnet.nl/project/Robur/) -- but we already have a basic
repository up and running https://github.com/robur-coop/dnsvizor
At the earlier retreats previous versions of such a unikernel were
actively being used - and we also discovered some issues that were then
fixed on site. But now, finally putting several months of effort into it
(in 2024) will hopefully result in a useful unikernel.
Again, if you wish for some features, or have a DNSmasq in production
that you're keen on having replaced, don't hesitate to open an issue
(and provide us with your configuration).
## uTCP
Since August I've motivated myself to work a bit more on uTCP, a TCP/IP
stack that originated from Netsem, a formal model in HOL4.
Apart from minor bugfixes to get it compiling again, I pushed it into
production (first for retreat.mirage.io, then once the resource leakage
was sorted, also on a.ns.robur.coop, and now finally as tls reverse
proxy on *.robur.coop).
Some highlights from the last months:
making it usable:
- properly set initial window
- segment reassembly
performance:
- improve performance of checksum computation by a factor of 5
- avoid lots of allocations (improved performance by factor of 3)
correctness
- drop connection in LAST ACK if FIN was received
- fix exceptions (Cstruct.shift exceeding send queue, Cstruct.shiftv
with negative amount)
- no longer being stuck in various states (CLOSE WAIT, FIN WAIT 2)
[which turned out to be an issue in the model]
- avoid usage of multiple maps
convenience:
- add metrics and monitoring
- since mirage 4.4.1, using uTCP is possible without too much headache
(still some, see
https://github.com/mirage/retreat.mirage.io/blob/748f29e20499a8b508b11a302e8890202202e854/config.ml#L36-L69
for an example)
It is now in a nice shape - while working on it, I also discovered that
mirage-tcpip has some issues (apart from resource leaks, it also doesn't
validate any checksum). There are still some open issues to work on
before releasing an initial version (such as path MTU discovery,
selective acknowledgement, congestion control, increase initial window
size, accurate byte counting). But the upside is that even the reverse
TLS tunnel that carries quite some load doesn't seem to leak memory anymore.
repository: https://github.com/robur-coop/utcp
blog article:https://hannes.robur.coop/Posts/TCP-ns
network semantics: https://www.cl.cam.ac.uk/~pes20/Netsem/
JACM journal paper (2019): http://www.cl.cam.ac.uk/~pes20/Netsem/paper3.pdf
## NetHSM
The first (to my knowledge) commercial product using MirageOS (and Muen)
is now for sale; it is a "Hardware Security Module", so something you
can store your private keys which hopefully never get extracted. With
the robur team (namely Steffi and Martin) I was involved in the early
days (doing system design and implementation) [though I've not followed
changes in later years]. See their announcement at
https://www.nitrokey.com/news/2023/after-8-years-development-nethsm-10-available-first-open-source-hardware-security-module
NB: I don't agree with everything they say. I'm especially sad how they
did a code dump on GitHub instead of preserving the commit history.
Best,
Hannes
