>
> This is expected.
> An incoming packet is masked with 0x1FE0 at offset 20 and the
> value is compared to 6880. If they match, success.
> So between 1-10000, you essentially have some starting at 6880.
> And then at a large number prolly around port 15000, you have
> a few more. and the pattern repeats etc.
>
> cheers,
> jamal
>
> On Wed, 2010-02-24 at 14:52 -0800, Andrew Morton wrote:
>> (switched to email. Please respond via emailed reply-to-all, not via the
>> bugzilla web interface).
>>
>> On Tue, 23 Feb 2010 20:56:09 GMT
bugzilla-daemon@bugzilla.kernel.org wrote:
>>
>> >
http://bugzilla.kernel.org/show_bug.cgi?id=15379
>> >
>> > Summary: u32 classifier port range calculation error
>> > Product: Networking
>> > Version: 2.5
>> > Kernel Version: All (2.6.32 tested)
>> > Platform: All
>> > OS/Version: Linux
>> > Tree: Mainline
>> > Status: NEW
>> > Severity: normal
>> > Priority: P1
>> > Component: Other
>> > AssignedTo:
acme@ghostprotocols.net
>> > ReportedBy:
reinaldoc@gmail.com
>> > Regression: No
>> >
>> >
>> > U32 classifier have a problem on mask calculation of IP port range value.
>> >
>> > To reproduce the problem:
>> >
>> > ##### MASK CALCULATION FOR PORT RANGE 6880->6911
>> >
>> > echo "obase=16;(2^13)-32" | bc
>> > 1FE0
>> >
>> > Example:
>> >
>> > ###### TC SAMPLE RULES
>> > tc qdisc del dev eth0 root >/dev/null 2>&1
>> >
>> > tc qdisc add dev eth0 root handle 1: htb default 1100
>> > tc class add dev eth0 root classid 1:1000 htb rate 1000Mbit ceil 1000Mbit
>> > tc class add dev eth0 classid 1:1100 parent 1:1000 htb prio 0 rate 999Mbit
>> > ceil 999Mbit
>> > tc class add dev eth0 classid 1:1200 parent 1:1000 htb prio 0 rate 1Mbit
>> > ceil 1Mbit
>> >
>> > tc filter add dev eth0 protocol ip prio 1 parent 1: u32 flowid 1:1200 match ip
>> > dport 6880 0x1FE0
>> >
>> > ###### STATS CLEAN ** success 0
>> > tc -s filter show dev eth0
>> > filter parent 1: protocol ip pref 1 u32
>> > filter parent 1: protocol ip pref 1 u32 fh 800: ht divisor 1
>> > filter parent 1: protocol ip pref 1 u32 fh 800::800 order 2048 key ht 800 bkt 0
>> > flowid 1:1200 (rule hit 116 success 0)
>> > match 00001ae0/00001fe0 at 20 (success 0 )
>> >
>> > ###### SENDING PACKETS I
>> > # nmap example.ufpa.br -p 1-10000
>> >
>> > ###### STATS I ** success 32 (OK)
>> > # tc -s filter show dev eth0
>> > filter parent 1: protocol ip pref 1 u32
>> > filter parent 1: protocol ip pref 1 u32 fh 800: ht divisor 1
>> > filter parent 1: protocol ip pref 1 u32 fh 800::800 order 2048 key ht 800 bkt 0
>> > flowid 1:1200 (rule hit 12676 success 32)
>> > match 00001ae0/00001fe0 at 20 (success 32 )
>> >
>> > ###### SENDING PACKETS II
>> > # nmap example.ufpa.br -p 10000-20000
>> >
>> > ###### STATS II ** success 64 (ERROR) - should not match
>> >
>> > # tc -s filter show dev eth0
>> > filter parent 1: protocol ip pref 1 u32
>> > filter parent 1: protocol ip pref 1 u32 fh 800: ht divisor 1
>> > filter parent 1: protocol ip pref 1 u32 fh 800::800 order 2048 key ht 800 bkt 0
>> > flowid 1:1200 (rule hit 25172 success 64)
>> > match 00001ae0/00001fe0 at 20 (success 64 )
>> >
>> > ###### SENDING PACKETS III
>> > # nmap example.ufpa.br -p 20000-30000
>> >
>> > ###### STATS III ** success 96 (ERROR) - should not match
>> >
>> > # tc -s filter show dev eth0
>> > filter parent 1: protocol ip pref 1 u32
>> > filter parent 1: protocol ip pref 1 u32 fh 800: ht divisor 1
>> > filter parent 1: protocol ip pref 1 u32 fh 800::800 order 2048 key ht 800 bkt 0
>> > flowid 1:1200 (rule hit 43131 success 96)
>> > match 00001ae0/00001fe0 at 20 (success 96 )
>> >
>> > ### End
>>
>> --
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>
