3.18 Bug with traffic control filters

3.18 Bug with traffic control filters

[Klaus Kinski]

Hello all,
I recently discovered a long standing problem in 3.18 regarding tc u32 filters:

===========================

#!/bin/bash
INTERFACE=lan1
ADM_TOS=0x10
STR_TOS=0x04
DFL_TOS=0x00

tc qdisc del dev ${INTERFACE} root
tc qdisc add dev ${INTERFACE} root handle 1: prio bands 4 priomap 2 3 3 3 2 3 1 1 2 2 2 2 2 2 2 2
for band in $(seq 1 4); do
tc qdisc add dev ${INTERFACE} parent 1:$band handle $(expr $band + 20) pfifo
done

tc filter add dev ${INTERFACE} parent 1: protocol ip prio 2 u32 match ip tos ${ADM_TOS} 0x1E flowid 1:2
tc filter add dev ${INTERFACE} parent 1: protocol ip prio 3 u32 match ip tos ${STR_TOS} 0x1E flowid 1:3
tc filter add dev ${INTERFACE} parent 1: protocol ip prio 4 u32 match ip tos ${DFL_TOS} 0x1E flowid 1:4

uname -a >> test.log
tc filter show dev ${INTERFACE} >> test.log
===========================

I get the following log:
===========================
Linux himonn-0-011 3.18.76 #1 SMP Wed Oct 18 17:43:37 CEST 2017 i686 i686 i686 GNU/Linux
filter parent 1: protocol ip pref 2 u32
filter parent 1: protocol ip pref 2 u32 fh 800: ht divisor 1
===========================

The expected output (4.0.9 is fine) is:
===========================
Linux himonn-0-011 4.0.9 #1 SMP Wed Oct 18 17:10:02 CEST 2017 i686 i686 i686 GNU/Linux
filter parent 1: protocol ip pref 2 u32
filter parent 1: protocol ip pref 2 u32 fh 800: ht divisor 1
filter parent 1: protocol ip pref 2 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:2
match 00100000/001e0000 at 0
filter parent 1: protocol ip pref 3 u32
filter parent 1: protocol ip pref 3 u32 fh 801: ht divisor 1
filter parent 1: protocol ip pref 3 u32 fh 801::800 order 2048 key ht 801 bkt 0 flowid 1:3
match 00040000/001e0000 at 0
filter parent 1: protocol ip pref 4 u32
filter parent 1: protocol ip pref 4 u32 fh 802: ht divisor 1
filter parent 1: protocol ip pref 4 u32 fh 802::800 order 2048 key ht 802 bkt 0 flowid 1:4
match 00000000/001e0000 at 0
===========================

The problem was obviously fixed in later releases, but I'm currently stuck at 3.18. Can anybody point me to the patch that fixed this problem (or alternatively that caused the breakage)? It's broken in 3.14, 3,15, 3.16 and 3.18 (didn't check 3.17) but it was fine in 3.13:
===========================
Linux himonn-0-011 3.13.11-ckt39 #2 SMP Wed Oct 18 14:42:49 CEST 2017 i686 i686 i686 GNU/Linux
filter parent 1: protocol ip pref 2 u32
filter parent 1: protocol ip pref 2 u32 fh 800: ht divisor 1
filter parent 1: protocol ip pref 2 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:2
match 00100000/001e0000 at 0
filter parent 1: protocol ip pref 3 u32
filter parent 1: protocol ip pref 3 u32 fh 801: ht divisor 1
filter parent 1: protocol ip pref 3 u32 fh 801::800 order 2048 key ht 801 bkt 0 flowid 1:3
match 00040000/001e0000 at 0
filter parent 1: protocol ip pref 4 u32
filter parent 1: protocol ip pref 4 u32 fh 802: ht divisor 1
filter parent 1: protocol ip pref 4 u32 fh 802::800 order 2048 key ht 802 bkt 0 flowid 1:4
match 00000000/001e0000 at 0
===========================

Thanks in advance
  Joerg

Re: 3.18 Bug with traffic control filters

[Greg KH]

On Wed, Oct 18, 2017 at 04:30:39PM +0000, Klaus Kinski wrote:
> Hello all,
> I recently discovered a long standing problem in 3.18 regarding tc u32 filters:
> 
> ===========================

<snip>

This means nothing to us, sorry.

Do you have a problem in 4.14-rc5?  If not, can you run 'git bisect' to
find the patch that fixes the issue?

If it is an issue in Linus's tree, then please bring this up on the
netdev mailing list.

thanks,

greg k-h

AW: 3.18 Bug with traffic control filters

[J Pommnitz]

Greg,

just wanted to let you know, that a git bisect identified the following fix:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b057df24a7536cce6c372efe9d0e3d1558afedf4

The patch applies to 3.18 and fixes the problem.

Regards
  Joerg

P.S.: Sorry if you get this twice. The first attempt was rejected by vger for violating the HTML ban.

Von: Greg KH <gregkh@linuxfoundation.org>
Gesendet: Mittwoch, 18. Oktober 2017 18:45
An: Klaus Kinski
Cc: stable@vger.kernel.org
Betreff: Re: 3.18 Bug with traffic control filters
�   
On Wed, Oct 18, 2017 at 04:30:39PM +0000, Klaus Kinski wrote:
> Hello all,
> I recently discovered a long standing problem in 3.18 regarding tc u32 filters:
> 
> ===========================

<snip>

This means nothing to us, sorry.

Do you have a problem in 4.14-rc5?� If not, can you run 'git bisect' to
find the patch that fixes the issue?

If it is an issue in Linus's tree, then please bring this up on the
netdev mailing list.

thanks,

greg k-h
    

Re: 3.18 Bug with traffic control filters

[Greg KH]

On Tue, Oct 24, 2017 at 09:47:03AM +0000, J Pommnitz wrote:
> Greg,
> 
> just wanted to let you know, that a git bisect identified the following fix:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b057df24a7536cce6c372efe9d0e3d1558afedf4
> 
> 
> The patch applies to 3.18 and fixes the problem.

Ah, very nice, thanks, I'll go queue that up.

greg k-h