Wireshark · Wireshark-dev: Re: [Wireshark-dev] Roofnet Dissector

[Nicola Arnoldi <nicola.arnoldi@xxxxxxxxxxxx>]

Guys, you're great in showing such an interest in helping me with that
dissector.

For the capture, you'll need to wait until monday (I have those files in
my office).

Let me answer to your questions a little bit in detail.
---------------------------------
FIXED LENGTH HEADER

> - type (are there any fixed values?)

enum sr2packet_type { 
	SR2_PT_QUERY = 0x01,
	SR2_PT_REPLY = 0x02,
	SR2_PT_DATA  = 0x04,
	SR2_PT_GATEWAY = 0x08,
};

> - nlinks : this field is used to tell how many fields there will be in
> the variable length header. Right?

Yes of course. Actually, if nlinks=N the fields in the variable length
header are not N.
Look at the PDF I sent you. If multiple links are present in the current
route the 32 bit fields are N*5 + 1, as the end of the first hop is
exactly the first hop of the folloing hop.
Those are simply IPv4 addresses.

> - next : semantic ?

Next is a number indicating the number of hops traversed so far by the
packet.

> - flags : bit X means ... ?
enum sr2packet_flags {
	SR2_FLAG_ERROR = (1<<0),
	SR2_FLAG_UPDATE = (1<<1),
};


> - Query Dst : IPv4 ?

Yes, it's an IPv4 address.


Anyway, if you provide me with a working version of the dissector (and
explain me how to install and use it), I can easily adjust it as soon as
I will learn more on the packet structure.


Thanks everybody, you rock!

Nicola


On dom, 2006-12-10 at 05:39 +0100, Sebastien Tandel wrote:
> Hi,
> 
>    I've looked at the pdf you sent. May you define further the following
> fields :
> 

> 
> Is this header used for the purpose of an improved source routing?
> 
> Can you send me a sample capture file?
> 
> thanx,
> Sebastien Tandel
> 
> 
> Nicola Arnoldi wrote:
> > Here you will find informations for designing a dissector for the
> > Roofnet Layer 2.5 routing protocol for wireless mesh network of
> > http://pdos.csail.mit.edu/roofnet/.
> >
> > The Layer 2.5 works as follows.
> >
> > - Inside the MAC 802.11 frame a 1500 byte datagram is located.
> >
> > It consists of a 400 byte header and a 1100 byte data field. (see
> > attachment for a pictorial representation)
> >
> >
> > The 400-bytes header contains a lot of informations. Some of them are
> > fixed, such as the protocol version and other stuff (160 bytes).
> >
> > The variable-length part of the header contains routing information of a
> > multi-hop transmission. More specifically, those bytes contain the IP
> > addresses of the hops involved in the route of the current datagram.
> >
> > So, 1100+400 bytes form the payload of Layer 2 MAC protocol.
> >
> > In the data field a standard UDP or TCP datagrams may be carried.
> >
> > I hope everything is clear.
> >
> > If you need a sample capture just tell me.
> >
> > Regards
> >
> > Nicola Arnoldi
> >
> >
> > On ven, 2006-12-08 at 15:16 -0800, Stephen Fisher wrote: 
> >   
> >> On Thu, Dec 07, 2006 at 10:22:26AM +0100, Nicola Arnoldi wrote:
> >>
> >>     
> >>> If you're into wireless mesh networking stuff, you've probably heard 
> >>> about Roofnet, an MIT project with WMNs. Well, Roofnet introduces a 
> >>> 2.5 OSI Layer, with certain headers. Anyone designed a dissector for 
> >>> Roofnet or is anyone interested into it?
> >>>       
> >>> If so, please contact me, I will be happy to provide the packet 
> >>> structure...
> >>>       
> >> Feel free to send a link to the packet structure and a link to a sample 
> >> capture file to the list.  Someone may have time to work on a dissector 
> >> for it.  If you don't hear anything back, add it to the wish list (again 
> >> with the structure and a capture file) at 
> >> http://wiki.wireshark.org/WishList
> >>
> >>
> >> Steve
> >> _______________________________________________
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> >> Wireshark-dev@xxxxxxxxxxxxx
> >> http://www.wireshark.org/mailman/listinfo/wireshark-dev
> >>     
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>