[Click] Problems Modifying Data Poritons of Packets

[Beyers Cronje]

Beta,

I've never looked at RatedSource so I cant answer the internals of
this element, but the Bad IP Version error seems to indicate you are
setting the packet data incorrectly. Have a look at FastTCPFlows
element on how to create a TCP packet in your code.

Beyers

On 8/11/05, betamaz <betamaz at gmail.com> wrote:
> Hi,
> 
> I worte a new element called RatedPacketGenerator which is based on
> RatedSource. My element basically changes the data portion of a packet based
> on a specific set of rules.
> I have a bunch of question. First, in RatedSource the only place the data
> portion is set is in RatedSource::setup_packet(). Also, I noticed that when
> the size of data meets minimum requirement then the element does not use
> pull. So, my only option was to change the data in RatedSource::run_task()
> which is a BIG!!!! waste, since run_task is called way more than the number
> of packets created. Is there any way to imporve this??
> 
> Second, when I do change the data portion, I do not see the packet changing
> (when looking at the output of Print) of my configuration:
> 
> RatedPacketGenerator(LIMIT 1000, STOP true)
> // -> Queue(200)
> -> Strip(14)
> -> Align(4, 0) // in case we're not on x86
> // -> CheckIPHeader(BADSRC 18.26.4.255 <http://18.26.4.255>
> 2.255.255.255<http://2.255.255.255>
> 1.255.255.255 <http://1.255.255.255>)
> -> Print(PACKET, NBYTES 88, TIMESTAMP true)
> -> Counter
> -> Discard;
> 
> 
> Finally, setting the data portion of the packet in the .cc file (of both
> RatedSource.cc and RatedPacketGenerator.cc) rather than in the configuration
> gives me the following error (after setup_packet finishes):
> [conf]%click packetgen.click
> IP header check failed: bad IP version
> 
> Which is why is commented out CheckIPHeader from the configuration. I cant
> figure out why its fine when the data is set in the configuration:
> 
> RatedSource(DATA \<00 00 c0 ae 67 ef 00 00 00 00 00 00 08 00
> 45 00 00 28 00 00 00 00 40 11 77 c3 01 00 00 01
> 02 00 00 02 13 69 13 69 00 14 d6 41 55 44 50 20
> 70 61 63 6b 65 74 21 0a>, LIMIT 50, STOP true)
> // -> Queue(200)
> -> Strip(14)
> -> Align(4, 0) // in case we're not on x86
> -> CheckIPHeader(BADSRC 18.26.4.255 <http://18.26.4.255>
> 2.255.255.255<http://2.255.255.255>
> 1.255.255.255 <http://1.255.255.255>)
> -> Print(PACKET, NBYTES 88, TIMESTAMP true)
> -> Counter
> -> Discard;
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