#MPTCP features that will be present in the future #Linux v6.12: 🐧

• Fallback to TCP in case of MPTCP blackhole 🕳: if a firewall explicitly blocks MPTCP
• This info is also cached: to directly fallback to TCP for 1h+, check the new blackhole_timeout sysctl
• New MIB counters for sent MP_JOIN to help in case of configuration issues 🔄
• CI: Code coverage – Coveralls 📈

(As always: these features have been added to Linus tree, hopefully they will still be there when this version will be released!)

If nothing changes, #MPTCP will be natively supported in the future #Apache HTTPD v2.5 🎉🌐

Thanks to Anthony for this work!

https://svn.apache.org/viewvc?view=revision&revision=1920586

For other apps with native MPTCP support: https://mptcp.dev/apps.html

A new macOS page 🌐 is available on our website for 🍏 iOS and OSX developers who are interested to enable #MPTCP in their apps:

https://www.mptcp.dev/macOS.html

If nothing changes, #MPTCP will be natively supported in the future #HAProxy v3.1.0 🎉🔀

Thanks to Anthony, Dorian, Willy and Matthieu for their work!

https://github.com/haproxy/haproxy/commit/20efb856e

MPTCP is (finally) going to be enabled in Azure Linux 3.0 🎉

https://github.com/microsoft/azurelinux/pull/10014

If you are using this distribution, you will soon be able to use MPTCP!

#cURL 8.9.0 now natively supports #MPTCP on Linux 🌐

curl --mptcp https://example.com

https://curl.se/docs/manpage.html#--mptcp

Thanks Dorian and the cURL maintainers for their help!

Can maintainers easily ignore old bugs they discover when working on new features? 🙈
Delaying these features now, or having to deal with bugs later, possibly when it is really not a good time for that? 🐛

I wrote a bit about this topic in my last blog post 📰 ⤵️

https://blog.mptcp.dev/2024/07/21/maintainers-responsibilities.html

I don't know if I did the good choice at the end, but don't hesitate to share your opinions! 😉

mptcp.dev website 🌐 has been updated last month. This new website was really needed to help supporting new users who are interested by #MPTCP. I wrote a blog post about that 📰:

https://blog.mptcp.dev/2024/05/03/supporting-new-users.html

This has been made possible thanks to @NGIZero support, making this MPTCP project more community oriented, and that's great 🎉

How we use GitHub Actions 🤖 with #KVM support and tools like virtme-ng, packaged in a Docker, to validate our #Linux kernel tests linked to #MPTCP: I recently wrote a blog post about that ⤵️

https://blog.mptcp.dev/2024/04/08/CI-new-feat.html

Our new 🆕 website is now online 👇

➡️ https://www.mptcp.dev 🌐

It is now for a wider audience:

• It now explains what is MPTCP and some concepts.
• Users will find how to configure the kernel, how to check it is working, how to force apps to use MPTCP, etc.
• Application developers will find how to add MPTCP native support, how to retrieve info from an app, etc.
• A list of frequently asked questions.
• A list of apps supporting MPTCP natively.

Feel free to have a look, and suggest modifications!

Thanks to everybody who was involved in this upgrade!

To celebrate that, we have a new logo! 🥳

Good news 🎉 From today, it is now possible to natively compress data used in #MPTCP connections with the #xz algorithm! It reduces data being exchanged, and connections are faster! 📈

To be able to achieve that, you need xz-utils >=5.6.0 🐟. Strangely, people have reported it doesn't accelerate #SSH connections! 📉🤔
Any DB specialists out there to help us investigating this with #perf?


(PS: we are sorry for what has happened to Lasse! Take care!)

Backporting bug 🐛 fixes to stable Linux kernel versions: I recently published a new blog post showing what kernel maintainers usually have to do:

https://blog.mptcp.dev/2024/03/04/backports.html

And some news about #MPTCP in the #Linux kernel as usual! 📰

Recently, I stopped my work at #Tessares and started a new challenge: Improving #MPTCP deployability, sponsored by @NGIZero (many thanks for letting me doing that!).

https://nlnet.nl/project/MPTCP-deployability/

My new blog is there if you want more details about this "Angel Project" and what I did so far: https://blog.mptcp.dev/2024/01/01/Angel-Project.html

My recent work for the #MPTCP upstream project was focused on the #CI migration to GitHub Actions 🤖, fixing issues with the new Netdev CI (finally 🎉) validating the selftests, fixing issues with external tools (QEmu, #ss from IPRoute2) 🐛, and more. I'm still proud to be sponsored by @NGIZero 😊

Find out more on this new blog post: https://blog.mptcp.dev/2024/02/02/CI-CI-CI.html

A part of #MPTCP kernel team is now at #KernelRecipes in Paris 🇫🇷. (Not to present but to learn from others!)

Talk to you there if you are around! 😉

#MPTCP in the future #Linux v6.5 version should have more exposed info:

• LSM/SELinux: correctly inherit labels on MPTCP subflows
• New ADD_ADDR (+ echo) transmission MIB counters
• New aggregated data counters exposed via Netlink and getsockopt(MPTCP_INFO)
• New getsockopt(MPTCP_FULL_INFO) aggregating MPTCP and subflows info (with ID)
• Some clean-up and small improvements (MPTCP and selftests + support of old kernels)

(These modifications are in Linus’ tree, hopefully everything will still be there when v6.5 will be released!)

#MPTCP in #Linux v6.4 got some improvements around the reception of connection requests:

• Some refactoring around the reception of MPCapable/MPJoin connection requests
• MPTCP_INFO and Netlink (ss -M) no longer fill info not used by the PM in used
• First subflow allocation is moved at MPCapable access time

Many fixes have also been done and backported to stable versions. There was even a special mention in v6.3-rc7 announcement 😄

Nothing particular stands out in the rc this week, unless you count the mptcp selftest changes that are about making the tests work on stable kernels too. That accounts for almost a quarter of the patch…

#GO: #MPTCP support in the core net package has been merged today. It will be available in the future Go 1.21.

An example on how to use it is visible here.

But more to come, e.g. the ability to check if a connection has fallen back to TCP (#59166)

The video recording of this presentation (#MPTCP in the Upstream #Linux kernel, #FOSDEM) is now available online!

https://fosdem.org/2023/schedule/event/mptcp_upstream/

PS: yes, we cannot hear them but a few people laughed, there were no long and embarrassing silences after the jokes 😛

If you are at #FOSDEM2023 (or you have an Internet access), come and join us in ~30 minutes for a short presentation about the long process to get #MPTCP in the upstream kernel!
Kernel devroom.
https://fosdem.org/2023/schedule/event/mptcp_upstream/