I''m trying to configure a linux server that shapes both incoming and
outgoing traffic. The problem is that I get a kernel panic ("Unable to
handle kernel NULL pointer dereference at virtual address 0000003c...")
everytime I load the traffic shaping rules and then try to edit a file
with vim (!!??) via a remote connection using ssh.
I configured the server (RedHat 9) as follows:
1. Downloaded from www.kernel.org the 2.4.21 kernel sources and from
www.netfilter.org the iptables 1.2.8 sources
2. Patched both kernel and iptables sources with IMQ patches, build and
install both of them
3. Defined the following script:
#!/bin/sh
modprobe imq numdevs=1
tc qdisc add dev imq0 root handle 1: htb default 20 r2q 1
tc class add dev imq0 parent 1: classid 1:1 htb rate 256kbit ceil
256kbit
tc class add dev imq0 parent 1:1 classid 1:10 htb rate 25kbit ceil
256kbit
tc class add dev imq0 parent 1:1 classid 1:20 htb rate 231kbit ceil
256kbit
tc filter add dev imq0 protocol ip parent 1:0 prio 1 u32 match ip src
10.5.1.150 flowid 1:10
tc filter add dev imq0 protocol ip parent 1:0 prio 2 u32 match ip dst
10.5.1.150 flowid 1:10
iptables -t mangle -A POSTROUTING -o eth0 -j IMQ --todev 0
iptables -t mangle -A POSTROUTING -o eth1 -j IMQ --todev 0
iptables -t mangle -A PREROUTING -i eth0 -j IMQ --todev 0
ip link set imq0 up
4. The server''s eth0 ip address is 10.5.220.220/16; I logon on to it
(using ssh) from 10.5.1.150, then I try to edit (using vim) the script
described in 3) and I get the kernel panic.
Anybody know what could be the cause of this strange behaviour? Are the
rules defined above wrong?
Any hint/suggestion/etc will be welcome :)
Best wishes,
Toshiro.
--
Toshiro Viera <tviera@arnaldocastro.com.uy>
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Toshiro Viera wrote:> 4. The server''s eth0 ip address is 10.5.220.220/16; I logon on to it > (using ssh) from 10.5.1.150, then I try to edit (using vim) the script > described in 3) and I get the kernel panic. > > Anybody know what could be the cause of this strange behaviour? Are the > rules defined above wrong? > Any hint/suggestion/etc will be welcome :)I''m thinking one of two things, either a) when you''re ssh''ed in, and then open vim, it sends a certain (too much?) amount of traffic through whatever qdisc/class ssh goes through, and this is causing your kernel problem - try doing ls in a large directory, or cat''ting a largish text file. does the panic still occur ? b) you''ve got some bug in your kernel and/or vim, that''s only evident when you''ve loaded the imq modules - try running vim in the same circumstance with the imq module loaded, but no queues setup, then add one at a time. good luck. -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Damion de Soto - Software Engineer email: damion@snapgear.com SnapGear --- ph: +61 7 3435 2809 | Custom Embedded Solutions fax: +61 7 3891 3630 | and Security Appliances web: http://www.snapgear.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
El jue, 28-08-2003 a las 20:39, Damion de Soto escribió:> Toshiro Viera wrote: > > > 4. The server''s eth0 ip address is 10.5.220.220/16; I logon on to it > > (using ssh) from 10.5.1.150, then I try to edit (using vim) the script > > described in 3) and I get the kernel panic. > > > > Anybody know what could be the cause of this strange behaviour? Are the > > rules defined above wrong? > > Any hint/suggestion/etc will be welcome :) > > I''m thinking one of two things, either > a) when you''re ssh''ed in, and then open vim, it sends a certain (too much?) amount > of traffic through whatever qdisc/class ssh goes through, and this is causing your > kernel problem - try doing ls in a large directory, or cat''ting a largish text file. > does the panic still occur ? >Yes, it still happens. -- Toshiro Viera <tviera@arnaldocastro.com.uy> _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/