Re: [mpls-linux-general] Problems with MPLS 128, kernel crash

[<pim...@in...>]

"James R. Leu" wrote:
> 
> *sigh*
> 
> I have seen this before.  I must be doing something wrong with the way I
> handle skbs.  I haven't been able to figure out what, but I must be doing
> something wrong.
Probably not saying something new but: 
sending packets slow: works
sending packets "fast" with debugging on: works
sending fast without debugging on a rate limited queue: *bang*	

My guess would be that something goes wrong when dropping packets.

Pim.
> 
> Jim
> 
> BTW ... impressive instructions :-)
> 
> On Tue, Apr 02, 2002 at 04:09:06PM +0200, pim...@in... wrote:
> > Hi James,
> >
> > I am able to crash the kernel (2.4.17+MPLS128+(ftos&dscp) patches from
> > iptables-1.2.6a) if debugging is off.
> >
> > Attached is the script that sets up the DS tree.
> >
> > cat /proc/net/mpls* (only relevant bits)
> > 0x00000003 0/0/0 2 SET_EXP(01) EXP2TC( EXP(0)->TC(ffff) EXP(1)->TC(00b8)
> > EXP(2)->TC(0028) EXP(3)->TC(0030) EXP(4)->TC(0048) EXP(5)->TC(0050)
> > EXP(6)->TC(0068) EXP(7)->TC(0070) ) PUSH(gen 21650) SET(eth2,10.0.4.1)
> > T21650/1        0x00000003
> >
> > traffic is mapped on T21650/1 via iptables (default gateway on table 2)
> >
> > ping -f 10.0.2.2
> > .... (couple packets are sent)
> > *crash*
> >
> > [console]
> > length:4
> > warning: kfree pased on skb still on list from 0xc01f9e18
> > kernel BUG: at skbuff.c:321
> > ...
> > kernel panic: Aiee killing the interrupt handler...
> >
> > I want to stress the fact that I am only able to reproduce it when
> > debugging is off.
> > Let me know if you need additional information/want me to test
> > something.
> >
> > Pim.
> >
> > --
> > Pim Van Heuven            Ghent University - IMEC
> > Department  of  Information  Technology   (INTEC)
> > Sint-Pietersnieuwstraat, 41 B-9000, Gent, Belgium
> > pim...@in...
> >         DiffServ/MPLS(RSVP-TE) for Linux:
> >         http://dsmpls.atlantis.rug.ac.be
> > #!/bin/bash
> > # This script will set-up an example DS tree
> >
> > IFACES="eth1 eth2 eth3"
> > TC=/usr/local/bin/tc
> >
> > if test $# -gt 0
> > then
> >   case $1 in
> >   s|-s)
> >       if test $# -gt 1
> >       then
> >               $TC -s qdisc ls dev $2
> >       else
> >               for i in $IFACES; do echo "***"$i"***"
> >               $TC -s qdisc ls dev eth2; done
> >       fi;;
> >   d|-d)
> >       if test $# -gt 1
> >       then
> >               $TC qdisc del root dev $2
> >               $TC filter del root dev $2
> >               $TC class del root dev $2
> >       else
> >               for i in $IFACES; do
> >               $TC qdisc del root dev $i
> >               $TC filter del root dev $i
> >               $TC class del root dev $i
> >               done
> >       fi;;
> >   h|-h|--help|-help)
> >         echo $0
> >       echo "     -s show statistics"
> >       echo "     -d delete filters and qdiscs"
> >       echo "     install qdiscs and filers"
> >   esac
> >   exit
> > else
> >
> > #iptables -A OUTPUT -t mangle -p rsvp -o eth0 -j DROP
> >
> > for i in $IFACES; do
> >
> >   echo Configuring interface $i
> >
> >   echo DSMARK on $i
> >   $TC qdisc add dev $i root handle 1:0 dsmark indices 64 default_index 0 #tcindex classid 2.2 #set_tc_index
> >
> >   echo Main Filter on $i
> >   $TC filter add dev $i parent 1:0 protocol mpls tcindex mask 0xfc shift 2
> >   echo prio
> >
> > ##### Set up of the proper qdisc on $i
> >
> > # First a DSMARK qdisc is introduced in order to retrieve TOS from IP header
> > #$TC qdisc add dev $i handle 1:0 root dsmark indices 64 #set_tc_index
> > $TC filter add dev $i parent 1:0 protocol mpls prio 1 tcindex mask 0xfc shift 2 pass_on
> >
> > # Second a CBQ qdisc is used in order to support EF, AF and BE classes
> > $TC qdisc add dev $i parent 1:0 handle 2:0 cbq bandwidth 100Mbit cell 8 avpkt 1000 mpu 64
> > $TC filter add dev $i parent 2:0 protocol mpls prio 1 tcindex mask 0xf0 shift 4 pass_on
> >
> > ## Definition of the CBQ leaf classes to support AF, EF and BE
> > echo AF1
> > ## AF Class 1 specific setup
> > $TC class add dev $i parent 2:0 classid 2:1 cbq bandwidth 100Mbit rate 15Mbit \
> >     avpkt 1000 prio 5 allot 1514 weight 1.5Mbit maxburst 21 defmap 0 borrow
> > $TC filter add dev $i parent 2:0 protocol mpls prio 1 handle 1 tcindex classid 2:1
> > $TC qdisc add dev $i parent 2:1 gred setup DPs 3 default 2 grio
> > # --- AF Class 1 DP 1---
> >    $TC filter add dev $i parent 1:0 protocol mpls prio 1 handle 0x0a tcindex classid 1:111
> >    $TC qdisc change dev $i parent 2:1 gred limit 600KB min 150KB max 450KB burst 200 \
> >        avpkt 1000 bandwidth 100Mbit DP 1 probability 0.02 prio 2
> > # --- AF Class 1 DP 2---
> >    $TC filter add dev $i parent 1:0 protocol mpls prio 1 handle 0x0c tcindex classid 1:112
> >    $TC qdisc change dev $i parent 2:1 gred limit 600KB min 150KB max 450KB burst 200 \
> >        avpkt 1000 bandwidth 100Mbit DP 2 probability 0.04 prio 3
> >
> > ## AF Class 2 specific setup
> > echo AF2
> > $TC class add dev $i parent 2:0 classid 2:2 cbq bandwidth 100Mbit rate 15Mbit \
> >     avpkt 1000 prio 4 allot 1514 weight 1.5Mbit maxburst 21 defmap 0 borrow
> > $TC filter add dev $i parent 2:0 protocol mpls prio 1 handle 2 tcindex classid 2:2
> > $TC qdisc add dev $i parent 2:2 gred setup DPs 3 default 2 grio
> > # --- AF Class 2 DP 1---
> >    $TC filter add dev $i parent 1:0 protocol mpls prio 1 handle 0x12 tcindex classid 1:121
> >    $TC qdisc change dev $i parent 2:2 gred limit 600KB min 150KB max 450KB burst 200 \
> >        avpkt 1000 bandwidth 100Mbit DP 1 probability 0.02 prio 2
> > # --- AF Class 2 DP 2---
> >   $TC filter add dev $i parent 1:0 protocol mpls prio 1 handle 0x14 tcindex classid 1:122
> >    $TC qdisc change dev $i parent 2:2 gred limit 600KB min 150KB max 450KB burst 200 \
> >        avpkt 1000 bandwidth 100Mbit DP 2 probability 0.04 prio 3
> >
> > ## AF Class 3 specific setup
> > echo AF3
> > $TC class add dev $i parent 2:0 classid 2:3 cbq bandwidth 100Mbit rate 15Mbit \
> >     avpkt 1000 prio 3 allot 1514 weight 1.5Mbit maxburst 21 defmap 0 borrow
> > $TC filter add dev $i parent 2:0 protocol mpls prio 1 handle 3 tcindex classid 2:3
> > $TC qdisc add dev $i parent 2:3 gred setup DPs 3 default 2 grio
> > # --- AF Class 3 DP 1---
> >    $TC filter add dev $i parent 1:0 protocol mpls prio 1 handle 0x1a tcindex classid 1:131
> >    $TC qdisc change dev $i parent 2:3 gred limit 600KB min 150KB max 450KB burst 200 \
> >        avpkt 1000 bandwidth 100Mbit DP 1 probability 0.02 prio 2
> > # --- AF Class 3 DP 2---
> >    $TC filter add dev $i parent 1:0 protocol mpls prio 1 handle 0x1c tcindex classid 1:132
> >    $TC qdisc change dev $i parent 2:3 gred limit 600KB min 150KB max 450KB burst 200 \
> >        avpkt 1000 bandwidth 100Mbit DP 2 probability 0.04 prio 3
> >
> > ## EF class specific setup
> > echo EF
> > $TC class add dev $i parent 2:0 classid 2:5 cbq bandwidth 100Mbit rate 10Mbit \
> >     avpkt 1000 prio 1 bounded allot 1514 weight 1Mbit maxburst 10 defmap 0
> > $TC qdisc add dev $i parent 2:5 pfifo limit 10
> > $TC filter add dev $i parent 1:0 protocol mpls prio 1 handle 0x2e tcindex classid 1:151
> > $TC filter add dev $i parent 2:0 protocol mpls prio 1 handle 5 tcindex classid 2:5
> >
> > ## BE class specific setup
> > echo BE
> > $TC class add dev $i parent 2:0 classid 2:6 cbq bandwidth 100Mbit rate 30Mbit \
> >     avpkt 1000 prio 7 allot 1514 weight 3Mbit maxburst 21 borrow
> > $TC qdisc add dev $i parent 2:6 red limit 600KB min 150KB max 450KB burst 200 \
> >     avpkt 1000 bandwidth 100Mbit probability 0.4
> > $TC filter add dev $i parent 1:0 protocol mpls prio 1 handle 0x0 tcindex classid 1:161
> > $TC filter add dev $i parent 2:0 protocol mpls prio 1 handle 6 tcindex classid 2:6
> >
> > ## OSPF - RSVP Pipe class specific setup
> > echo OSPF \& RSVP filter
> > $TC class add dev $i parent 2:0 classid 2:7 cbq bandwidth 100Mbit rate 1Mbit \
> >     avpkt 1000 prio 1 bounded allot 1514 weight 1Mbit maxburst 10 defmap 0
> > $TC qdisc add dev $i parent 2:5 pfifo limit 10
> > $TC filter add dev $i parent 1:0 protocol mpls prio 1 handle 0x30 tcindex classid 1:171
> > $TC filter add dev $i parent 2:0 protocol mpls prio 1 handle 7 tcindex classid 2:7
> >
> > done
> >
> > fi
> >
> >
> >
> >
> >
> 
> --
> James R. Leu

-- 
Pim Van Heuven            Ghent University - IMEC
Department  of  Information  Technology   (INTEC)
Sint-Pietersnieuwstraat, 41 B-9000, Gent, Belgium
pim...@in...
        DiffServ/MPLS(RSVP-TE) for Linux:
        http://dsmpls.atlantis.rug.ac.be