[Click] Strange buffer_length() value for packets of more than 1500 bytes

[Roman Chertov]

Click-1.7 is pretty old.  You need to try this with the current click 
source for people on the list to give you help.

Roman

On 12/16/2010 10:39 AM, Manel.Bourguiba at lip6.fr wrote:
> Hi all,
>
> I am using linuxmodule click-1.7 over linux-2.6.24.7 (but this is also
> the case with linux-2.6.18.2)
> If I send packets of 1480 bytes and with the default mtu of 1500, the
> the buffer size allocated at the receiver is of 1664,
> (p->buffer_length()= 1664 ) which is fine.
> However, when I send large packets of more than 1500 bytes, and set
> the mtu to a value>  1500,  the buffer allocated at the reception is
> always of 256 ((p->buffer_length()= 256)) whatever the packet size is.
> So, if I want to access to the data stored beyond the 256 bytes in
> that packet, the data I get is erroneous.
> So i am wondering if there is a limitation on the maximum buffers
> size? where this limitation is hard-coded? and why does it change with
> the mtu?
>
> Thanks for helping
>
>
> Ps: Click scripts are roughly :
>
> Sender :
> RatedSource ->UDPIPEncap ->  EtherEncap ->  ToDevice(eth0)
> Receiver:
> FromDevice(eth0) ->  Myelement ->  Discard
>
> In Myelement, I only get p->buffer_length() and p->  data() and p->end_data()
>
>
> Manel BOURGUIBA
> PhD Candidate
> PHARE - LIP6 - UPMC - Sorbonne Universités
> BC169 - Office 25/26-319
> 4 place Jussieu
> 75252 PARIS cedex 05
> +33 1 44 27 61 88
>
>
>
> _______________________________________________
> click mailing list
> click at amsterdam.lcs.mit.edu
> https://amsterdam.lcs.mit.edu/mailman/listinfo/click
>