Re: How to classify a port range?

[Yassen Damyanov <yd@itlabs.bg>]

On 11/25/2016 1:29 AM, Andy Furniss wrote:
> I've never used ematch so don't know if this is correct or not, but -
>
> http://serverfault.com/questions/231880/how-to-match-port-range-using-u32-filter

Thanks much, Andy. Would be great if this solves the problem, but it 
doesn't seem to work, unfortunately:

# tc qdisc add dev $DEV root handle 1:0 htb
# tc class add dev $DEV parent 1:0 classid 1:1 htb rate 2mbit
# tc filter add dev $DEV parent 1:0 protocol ip prio 1 basic match 
"cmp(u16 at 0 layer transport gt 4000) and cmp(u16 at 0 layer transport 
lt 6000)" flowid 1:1

After running an iperf client against another machine in the local net, 
there's no shaping happening, and the 1:1 class is not visited:

class htb 1:1 root prio 0 quantum 25000 rate 2000Kbit ceil 2000Kbit 
linklayer ethernet burst 1600b/1 mpu 0b overhead 0b cburst 1600b/1 mpu 
0b overhead 0b level 0
  Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
  rate 0bit 0pps backlog 0b 0p requeues 0
  lended: 0 borrowed: 0 giants: 0
  tokens: 100000 ctokens: 100000

If I use a single port match:
# tc qdisc add dev $DEV root handle 1:0 htb
# tc class add dev $DEV parent 1:0 classid 1:1 htb rate 2mbit
# tc filter add dev $DEV parent 1:0 protocol ip prio 1 u32 match ip 
dport 5001 0xffff flowid 1:1

then the traffic is indeed limited to 1.9 Mbits/sec and the class stats 
look different:

class htb 1:1 root prio 0 quantum 25000 rate 2000Kbit ceil 2000Kbit 
linklayer ethernet burst 1600b/1 mpu 0b overhead 0b cburst 1600b/1 mpu 
0b overhead 0b level 0
  Sent 1507824 bytes 1000 pkt (dropped 0, overlimits 0 requeues 0)
  rate 0bit 0pps backlog 0b 0p requeues 0
  lended: 484 borrowed: 0 giants: 0
  tokens: -3139 ctokens: -3139

Does anyone know what might be wrong with that ematch use?

-Y.


On 11/25/2016 1:29 AM, Andy Furniss wrote:
> Yassen Damyanov wrote:
>> Hello LARTC guys,
>>
>> I am working on an OSS Python wrapper library intended to help with
>> expressing a traffic control structure as a tree of Python objects. This
>> structure should later be able to represent itself as a series of tc
>> commands. (Your suggestions for getting this thing useful would be
>> invaluable.)
>>
>> I have questions, inevitably. Currently heaviest part seems to be the
>> issue of classifying a set of tcp or udp ports to get shaped under a
>> common rate limit. (I need to later simulate packet loss for flows on
>> these ports, but first things first.)
>>
>> Can you help me get on the right direction here? Using u32 seems
>> daunting for this particular case. Is there another way to do the match?
>>
>> I've read the relevant parts of the LARTC HowTo and couple more
>> documents but still cannot get it right.
>>
>> Any help would be much appreciated!
>> Thanks in advance,
>> Yassen D.
>>
>
> I've never used ematch so don't know if this is correct or not, but -
>
> http://serverfault.com/questions/231880/how-to-match-port-range-using-u32-filter


-- 

Yassen Damyanov
M: +359-888-665-235
E: <yd@itlabs.bg>