[HECnet] Announcing new release of Linux DECnet

Sometime around mid-2022 the Linux kernel developers decided to remove the DECnet code from the Linux kernel. Kernel 6.0.x was the last release which included source code for a DECnet implementation. More recently, there has been some discussion around removing the code from the Long Term Support kernels. These changes mean that the repository I have been maintaining at <https://github.com/JohnForecast/RaspbianDECnet> can no longer be installed on recent releases. Over the past year or so, I have been working on a replacement for this repository with the following characteristics: - Designed to be built as an external kernel module This simplifies and speeds up the installation since we no longer need to rebuild the entire kernel. - Can only be built as an ethernet endnode Again this substantially simplifies the kernel code. The routing code was alway marked as “experimental” and I never tried to get it running. If you need a DECnet router, pyDECnet or Route20 are much better solutions. - Minimize the use of Linux kernel frameworks Many of the problems with keeping RaspbianDECnet running between Linux versions were changes to the kernel framework APIs. By limiting the use of these APIs I am hoping that the kernel module will need fewer changes to keep up with kernel changes. So far, I have had to make one additional conditional code change at kernel 6.5 and that was in the socket layer so all networking code would need to be changed. In addition to a new kernel module there have been a number of changes to the userland code: - What used to be “fal2” is now the default file access listener. The old “fal” is still available in the “fal-old” directory - What used to be “nml2” is now the default and only network management listener. - There is now a subset implementation of “ncp” which is sufficient to support all of the requests available from the Linux network management listener. It does implement a “tell” prefix so all of these commands may be issued to remote systems. In addition, it implements “ncp copy known nodes from <node name/address>” to update the local node name database. - The new kernel module now supports node counters as defined in the Network Management Specification and the ncp/nml combination are able to display and zero them. - The installation procedure is no longer targeted solely at Raspberry Pi releases. The current procedure supports installation on systems derived from Debian or Fedora although only a limited number of distributions have been tested (see README.DECnet). This new release is available at: <https://github.com/JohnForecast/LinuxDECnet> and should be considered to be in Beta test at this time. See README.DECnet in the top level directory for more information and installation instructions.