Back to the Future

After a week working on customer projects I got back at kernel hacking, initially going back in time some 20 years to work on merging an old LLC (802.2) series of patches I wrote in the 2.6.0-test1 days that were forward ported by Jochen Friedrich, that also fixed some bugs that were preventing him from using an HP printer that only talks LLC2 (connection oriented) over Token Ring, now his CUPS backend works just fine 8)

Then back to the future to implement DCCPv6, that was rather easy as most of the infrastructure was already in place for TCP, I just had to tweak the timewait and request sock hierarchies to work just like the inet_sock one, i.e. having a pointer to where in the per protocol slab objects the IPv6 specific bits are located, in fact I used an offset variable in struct inet_timewait_sock, not a pointer like struct inet_sock’s pinfo6, that probably I’ll convert to offsets too so as to save precious bytes in 64bit architectures.

Ah, the LLC2 tests were made using openssh patched to work with PF_LLC sockets, ‘ssh -5 00:04:76:3B:53:C1’ and look ma, no TCP/IP 8)

DCCPv6 was tested using a supercharged, get{name,addr}info enabled ttcp tool, another one that looks like an animal at Jurassic Park 8)

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  • Raman Muthukrishnan  On January 11, 2006 at 5:30 am

    Hi Arnold,

    I read the description above that you had use tests to verify the working of LLC-2. I built a small hardware logic with LLC-2 and did some basic testing with linux LLC-2. But I need to do more sophisticated testing. Will it be possible to get the test suite which you used?


  • admin  On January 15, 2006 at 8:19 am

    Raman, I tested this code using some applications such as openssh, vsftpd, ncftp all converted to use PF_LLC sockets, you can find the patches at my ftp area.

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