[631] in linux-net channel archive
Bad c'sums and skput:over in 1.3.7
daemon@ATHENA.MIT.EDU (Paul Gortmaker)
Sat Jul 8 02:14:05 1995
From: Paul Gortmaker <gpg109@rsphy1.anu.edu.au>
To: iialan@www.linux.org.uk (Alan Cox)
Date: Fri, 7 Jul 1995 14:17:47 +1000 (EST)
Cc: linux-net@vger.rutgers.edu
Hi Alan,
With 1.3.7 on an ISA lance (79c960) it won't even get past launching
the net daemons without panicking. I tried three times and got
Kernel Panic skput:over: 001be180:60
Kernel Panic skput:over: 001be180:247
Kernel Panic skput:over: 001be180:92
Perhaps this is related to the "double lock on device queue" messages that
are generated under heavy traffic (even with 1.3.6).
On another box (ne2000) it boots okay, but there is a strange problem that
appears to be bogons. I have a hunch that it is sending out packets with
bad checksums as they seem to be silently ignored.
If I do a "strace -o outfile ping -c1 a_host" I see that it sends the
query packet to the nameserver via sendto(), and then select() eventually
times out and it goes onto the next nameserver in resolv.conf -- This
repeats for all nameservers and then of course it finally fails saying that
"a_host" is unknown (when it is a perfectly valid host).
But if I repeat the above with a different host (also perfectly valid
name) everything works fine.
The real trick is when the name in question has a certain number of
characters. Any names with either 2, 6, 10, 14, 18, ... n, (n+4)
characters will fail the lookup. For example, try this:
ne2k_box:~# ping -c1 a
ping: unknown host a
ne2k_box:~# ping -c1 ab
^C or wait 3 mins to timeout on all nameservers...
ne2k_box:~# ping -c1 abcab
ping: unknown host abcab
ne2k_box:~# ping -c1 abcabc
^C or wait 3 mins to timeout on all nameservers...
ne2k_box:~# ping -c1 abcabcabc
ping: unknown host abcabcabc
ne2k_box:~# ping -c1 abcabcabca
^C or wait 3 mins to timeout on all nameservers...
Oh, and another minor nit -- the prototype for eth_copy_and_sum() should
be stuck in some header file somewhere so gcc doesn't complain when
compiling the lance driver (and others that use it).
Regards,
Paul.
