Re: Mark traffic on one machine, match on another machine?

[Jack Bates <uo4zau@nottheoilrig.com>]

Thanks for this help, I think the marks are getting saved/restored 
successfully, and I can successfully classify request traffic from the 
proxy server based on the mark (statistics on the eth0.2 classes are 
incrementing) but response traffic from the origin server isn't getting 
classified yet (statistics on the ifb0 classes remain zero).

Here is my complete work in progress script. How can I investigate why 
response traffic isn't getting classified? Are there any more details 
that would help explain why not?

How can I classify traffic based on the restored mark? or is there 
another way to classify response traffic from the origin server based on 
the TOS/DSCP field of the request?

    1: # Save/restore connection mark based on TOS field
    2: iptables -A PREROUTING -t mangle -j CONNMARK --restore-mark
    3: iptables -A PREROUTING -t mangle -m tos --tos 12 -j MARK --set-mark 1
    4: iptables -A PREROUTING -t mangle -m tos --tos 28 -j MARK --set-mark 2
    5: iptables -A PREROUTING -t mangle -j CONNMARK --save-mark
    6:
    7: ifconfig ifb0 up
    8:
    9: insmod sch_ingress
   10: tc qdisc add dev eth0.2 ingress
   11:
   12: # Classify response traffic from origin server based on restored mark
   13: insmod cls_fw
   14: insmod act_mirred
   15: tc filter add dev eth0.2 parent ffff: protocol ip pref 1 handle 1 
fw flowid 2:1 action mirred egress redirect dev ifb0
   16: tc filter add dev eth0.2 parent ffff: protocol ip pref 1 handle 2 
fw flowid 2:3 action mirred egress redirect dev ifb0
   17:
   18: # Send unmarked traffic to class 2:2
   19: insmod cls_u32
   20: tc filter add dev eth0.2 parent ffff: protocol ip pref 1 u32 
match u32 0 0 flowid 2:2 action mirred egress redirect dev ifb0
   21:
   22: # Limit up and downstream to 1mbit, to "own" the queue
   23: insmod sch_tbf
   24: tc qdisc add dev eth0.2 root handle 1 tbf rate 1mbit burst 5k 
latency 70ms
   25: tc qdisc add dev ifb0 root handle 1 tbf rate 1mbit burst 5k 
latency 70ms
   26:
   27: # High, low, and "other" priority
   28: insmod sch_prio
   29: tc qdisc add dev eth0.2 parent 1: handle 2 prio
   30: tc qdisc add dev ifb0 parent 1: handle 2 prio
   31:
   32: # Classify request traffic from proxy server based on mark
   33: tc filter add dev eth0.2 parent 2: protocol ip pref 1 handle 1 fw 
flowid :1
   34: tc filter add dev eth0.2 parent 2: protocol ip pref 1 handle 2 fw 
flowid :3

On 05/12/12 01:12 AM, Eliezer Croitoru wrote:
> Thanks Anatoly,
>
> My idea was that based on a mark he will jump the packets to another
> table which HE will mark TOS/DSCP.
>
> Eliezer
>
> On 12/5/2012 4:39 AM, Anatoly Muliarski wrote:
>> Hi Jack,
>>
>> --restore-mark should be used for existing connections and to mark new
>> ones you may use something like that:
>>
>> iptables -t mangle -A PREROUTING -i eth0.2 -m tos --tos 1 -m conntrack
>> --cstate NEW,RELATED -j MARK --set-mark 1
>>
>> The main idea consists in marking packets on the physical input
>> interface and shaping them on ifb0( where they arrive already marked
>> ).
>> iptables' packet marks exist only in memory of one computer, TOS/DSCP
>> may be used for transmitting a map of them to another one.
>> BTW, use --restore-mark on the output interface of your shaper too.
>>
>> 2012/12/3, Jack Bates <uo4zau@nottheoilrig.com>:
>>> Thanks a lot for your help, how can I evaluate --restore-mark before I
>>> classify and shape response traffic from the origin server?
>>>
>>> I think you mean something like:
>>>
>>>     # Copy ctmart to nfmark (e.g. 1, 2)
>>>     iptables -A PREROUTING -t mangle -i eth0.2 -j CONNMARK
>>> --restore-mark
>>>
>>>     # Classify by nfmark (e.g. 1, 2), send unmarked traffic to class 2:2
>>>     tc filter add dev eth0.2 parent ffff: protocol ip handle 1 fw flowid
>>> 2:1 action mirred egress redirect dev ifb0
>>>     tc filter add dev eth0.2 parent ffff: protocol ip handle 2 fw flowid
>>> 2:3 action mirred egress redirect dev ifb0
>>>     tc filter add dev eth0.2 parent ffff: protocol ip u32 match u32 0 0
>>> flowid 2:2 action mirred egress redirect dev ifb0
>>>
>>> Just how can I get --restore-mark to evaluate before tc filter?
>>>
>>> Another way I can imagine is with the CLASSIFY target:
>>>
>>>     # Send unmarked traffic to class 2:2
>>>     iptables -A PREROUTING -t mangle -i eth0.2 -m connmark --mark 1 -j
>>> CLASSIFY 2:1
>>>     iptables -A PREROUTING -t mangle -i eth0.2 -m connmark --mark 2 -j
>>> CLASSIFY 2:3
>>>     iptables -A PREROUTING -t mangle -i eth0.2 -j CLASSIFY 2:2
>>>
>>> But I have the same challenge, how can I evaluate the CLASSIFY target
>>> before I shape traffic?
>>>
>>> Or is there another way to classify and shape response traffic from the
>>> origin server based on the TOS/DSCP field of the request?
>>>
>>> On 03/12/12 03:52 AM, Eliezer Croitoru wrote:
>>>> You use iptables mark + restore mark based on connection tracking.
>>>> you can mark the TOS on the outgoing postrouting table.
>>>> you can take a look at the iptabes man pages:
>>>> http://ipset.netfilter.org/iptables.man.html
>>>> which has --restore-mark  exaple.
>>>>
>>>> Eliezer
>>>>
>>>> On 12/3/2012 10:43 AM, Jack Bates wrote:
>>>>> I can imagine a couple ways of classifying traffic from our proxy
>>>>> server
>>>>> based on the TOS/DSCP field, and also how to set the connection mark
>>>>> based on this field. But how do I classify and shape response traffic
>>>>> from the origin server based on the connection mark?
>>> --
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>>
>>
>