Long-Obsolete DECnet Networking Code In The Linux Kernel Expected To Finally Be Removed

[cj.wijtmans]

Now all we need is a tinfoil hat against 5G that spreads COVID.

You say that but tcp/ip had major security issues in the same way NSA puts backdoors in its algorithms.

[Eumaios]

While I appreciate the history lessons, acknowledging their contribution is a different thing to keeping code to deal with it alive in a mainstream kernel where no devices alive use it. . . .

I believe CommunityMember was reminiscing, /not/ advocating retaining the code.

[oiaohm]

About time. TokenRing was removed 10 years ago. But there are still several other candidates that I think are obsolete such as AppleTalk, ArcNet, FDDI, HamRadio, HIPPI in addition to ATM, EISA and PCMCIA and probably quite a few more.

https://mijndingen.nl/baycom-modem-usb-kiss-interface/ Fun part is the HamRadio part of the Linux kernel is not dead. Yes hamradio operators are doing lots things to keep on using the baycom designed modems with radio. The TCM3105 at the core modem does still does very well in particular conditionsl. Yes the Z8530 based hardware there are still users of it. Both of these happen to at times out perform the modern solutions with different noise problems. Yes particularly noise problems adversely effect new hardware and the old primitive stuff does care about it.. Of course there are particular radio conditions that screw over the old hardware and the modern hardware does better. This has resulted in HamRadio operators being a bit if a pack rat with this stuff. Could be another 30 years before we can remove that hamradio stuff.

Appletalk is not quite yet. MacOS 11 Big Sur in 2020 was when Appletalk was correctly removed. Yes there are Printers made in 2019 that you need appletalk enabled by some machine on the network that they behave self correctly. Yes this is stupid that appletalk enabled over ethernet make everything happy not that you have to use appletalk to print or anything.

PCMCIA you can buy this in to USB. Yes this can get really stupid using a PCMCIA USB card in a PCMCIA to USB adaptor so having the worlds worse USB hub.

https://docs.kernel.org/networking/arcnet.html

Arcnet yes the docs is worth a read it absolutely for sure on the cutting block. The maintainer is sure its been patched and patched and patched and never tested so most likely is already dead. On the ATM mailing list next kernel release we should see a removal patch the drivers never got developed really to a functional state with ATM.

Rob72 Its not that simple to clean though the list as the Appletalk, PCMCIA and HamRadio stuff shows. You are right there are things in the Linux kernel like Arcnet and ATM that absolutely should go because there is no confirm that the drivers in fact work let alone do something useful.

[sinepgib]

I was going to muse about making a protocol bridge as a userspace service, which perhaps can still access networking devices at some lower level. But, then I'd be venturing well outside the realm of my expertise.

Worst case you can do kernel bypass with the likes of DPDK, but then you lose the regular uses of the card. A middle ground could be setting up an AF_XDP socket. If the headers match DECnet, send to your userspace service (the one that installed the BPF program), otherwise send it to the regular route. Because AF_XDP is (more or less) zero copy, there's virtually no overhead for either party.

[Eirikr1848]

Well hot dang, that's super interesting. 40+ years old!? Sheesh

[sinepgib]

Well hot dang, that's super interesting. 40+ years old!? Sheesh

TCP is 48 years old. 44 if we start counting from the time where IP and TCP were split.

[carewolf]

Thank you. I came here to mention AppleTalk specifially, but I think you have it covered. These things just don't need to be supported by a modern kernel. Although, it looks like ArcNet is probably still in use.

Considering AppleTalk is a misfeature and will break the network even when working right, it shouldn't be supported by any hardware or OS. I remember back in the day we had to form mobs with torches and pitchforks to hunt down mac users connected to the ethernet and force them to disconnect as Appletalk caused O(n²) network traffic with n being the number of Macs connected.