Re: [Bugme-new] [Bug 8914] New: filter attached to prio qdisc breaks priomap handling of packets it does _not_ match
From: Andrew Morton <akpm@linux-foundation.org>
Date: 2007-08-21 18:30:04
On Tue, 21 Aug 2007 05:32:57 -0700 (PDT) bugme-daemon@bugzilla.kernel.org wrote:
http://bugzilla.kernel.org/show_bug.cgi?id=8914 Summary: filter attached to prio qdisc breaks priomap handling of packets it does _not_ match Product: Networking Version: 2.5 KernelVersion: 2.6.22.4 Platform: All OS/Version: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: IPV4 AssignedTo: shemminger@osdl.org ReportedBy: lionel@mamane.lu Most recent kernel where this bug did not occur: none known to me Distribution: Debian (sid / unstable / distro development bleeding edge) Hardware Environment: reproduced on i386 and x64-64 machines Software Environment: Debian, iproute 20070313-1 Problem Description: When I attach a filter to a prio qdisc, the packets that it does _not_ match are not correctly handled (enqueued) according to the priomap anymore, that is the same way than when there is no filter attached to the qdisc. They seem to always fall in the map for best effort traffic. Problem first noticed on Debian precompiled kernels (2.6.18-4-amd64, based on 2.6.18.7 and 2.6.22-1-686, based on 2.6.22.1), reproduced with self-compiled (with .config copied from Debian precompiled one) straight-from-kernel.org 2.6.22.4 . Steps to reproduce: Run attached script (as root), trying to ensure no other traffic happens over the interface: it installs qdiscs on interface ${TIF} (defaults to eth0), pings host ${PHOST} (defaults to master.debian.org - numerical IP hardcoded) with various IP TOS bits set, installs a filter that matches TCP (_not_ ICMP) and does the pings again. You have to ensure that pings to ${PHOST} leaver over ${TIF}. You may have to "modprobe em_cmp" before running the script. Notice how the first pings (before filters get installed) get in the right queue according to their TOS bits, but after the filter gets installed, they all end up in the "best effort" queue. The output I get (non-relevant bits snipped out) is: Running test on interface eth0 by pinging host 70.103.162.29 Pinging with normal service 1 times Pinging with minimise delay 2 times Pinging with minimise cost 4 times qdisc pfifo 22: parent 20:2 limit 1000p Sent 196 bytes 2 pkt (dropped 0, overlimits 0 requeues 0) qdisc pfifo 23: parent 20:3 limit 1000p Sent 98 bytes 1 pkt (dropped 0, overlimits 0 requeues 0) qdisc pfifo 24: parent 20:4 limit 1000p Sent 392 bytes 4 pkt (dropped 0, overlimits 0 requeues 0) Adding a filter that does _not_ match ICMP Pinging with normal service 8 times qdisc pfifo 22: parent 20:2 limit 1000p Sent 196 bytes 2 pkt (dropped 0, overlimits 0 requeues 0) qdisc pfifo 23: parent 20:3 limit 1000p Sent 924 bytes 10 pkt (dropped 0, overlimits 0 requeues 0) qdisc pfifo 24: parent 20:4 limit 1000p Sent 392 bytes 4 pkt (dropped 0, overlimits 0 requeues 0) Pinging with minimise delay 16 times qdisc pfifo 22: parent 20:2 limit 1000p Sent 196 bytes 2 pkt (dropped 0, overlimits 0 requeues 0) qdisc pfifo 23: parent 20:3 limit 1000p Sent 2492 bytes 26 pkt (dropped 0, overlimits 0 requeues 0) qdisc pfifo 24: parent 20:4 limit 1000p Sent 392 bytes 4 pkt (dropped 0, overlimits 0 requeues 0) Pinging with minimise cost 32 times qdisc pfifo 22: parent 20:2 limit 1000p Sent 196 bytes 2 pkt (dropped 0, overlimits 0 requeues 0) qdisc pfifo 23: parent 20:3 limit 1000p Sent 5628 bytes 58 pkt (dropped 0, overlimits 0 requeues 0) qdisc pfifo 24: parent 20:4 limit 1000p Sent 392 bytes 4 pkt (dropped 0, overlimits 0 requeues 0) The output I would expect is: (... snip ...) Adding a filter that does _not_ match ICMP Pinging with normal service 8 times qdisc pfifo 22: parent 20:2 limit 1000p Sent XXX bytes 2 pkt (dropped 0, overlimits 0 requeues 0) qdisc pfifo 23: parent 20:3 limit 1000p Sent XXX bytes 10 pkt (dropped 0, overlimits 0 requeues 0) qdisc pfifo 24: parent 20:4 limit 1000p Sent XXX bytes 4 pkt (dropped 0, overlimits 0 requeues 0) Pinging with minimise delay 16 times qdisc pfifo 22: parent 20:2 limit 1000p Sent XXX bytes 18 pkt (dropped 0, overlimits 0 requeues 0) qdisc pfifo 23: parent 20:3 limit 1000p Sent XXX bytes 10 pkt (dropped 0, overlimits 0 requeues 0) qdisc pfifo 24: parent 20:4 limit 1000p Sent XXX bytes 4 pkt (dropped 0, overlimits 0 requeues 0) Pinging with minimise cost 32 times qdisc pfifo 22: parent 20:2 limit 1000p Sent XXX bytes 18 pkt (dropped 0, overlimits 0 requeues 0) qdisc pfifo 23: parent 20:3 limit 1000p Sent XXX bytes 10 pkt (dropped 0, overlimits 0 requeues 0) qdisc pfifo 24: parent 20:4 limit 1000p Sent XXX bytes 36 pkt (dropped 0, overlimits 0 requeues 0)