hasna dahnini wrote:
I want to know how I can get the signal from the USB port and analyse it
on Ethereal ?
What do you mean by "get the signal from the USB port"?
If you mean that you want to use Ethereal as a USB analyzer rather than
as an analyzer for networks such as Ethernet, Token Ring, PPP, 802.11,
FDDI, etc., capturing raw USB traffic (e.g. between a keyboard, mouse,
camera, etc. and a host), the answer is "you can't". The mechanism
Ethereal uses to capture packets is the libpcap/WinPcap library, which,
at least at present, doesn't support capturing on raw USB because
nobody's contribute to the libpcap developers any code to do so.
Libpcap/WinPcap depend on mechanisms provided by the core operating
system on top of which it runs; perhaps none of those operating systems
provide a mechanism for capturing raw USB traffic, in which case it'd be
impossible to contribute code for libpcap to do so - you'd first have to
develop code for the OS in question to do so, and then make
libpcap/WinPcap use that code.
If you mean that, as per Laurent Rabret's mail, you want to capture
regular network traffic on a modem of some sort (802.11, ADSL, etc.)
that connects to the host on a USB port, then you might be able to
capture that traffic, but
1) it won't look like raw USB traffic, it'll probably look like 802.11
or Ethernet traffic if it's a USB 802.11 interface, or PPP traffic if
it's an ADSL modem, or something such as that;
2) whether you'll be able to capture on it depends on whether the
driver for the USB device supports that.
For ADSL modems, the traffic will *probably* look like PPP traffic, at
least as presented to the part of the OS's networking stack that would
connect to the packet capture mechanism (although I can't guarantee
that). Whether you could capture on that would depend on whether the
capture mechanism supports capturing on PPP interfaces; on most UN*Xes
it will probably do so, and on Windows you will, as per Laurent Rabret's
mail, need WinPcap 3.1 beta 4, at least on Windows NT 4.0/2000/XP/Server
2003 (Windows 95/98/Me, if they support ADSL modems, might not require
that).
For 802.11 interfaces, it will probably work as well as it does with
other 802.11 interfaces; unfortunately, on Windows, that all too often
means "not very well". See
http://www.ethereal.com/faq#q5.41
and
http://www.ethereal.com/faq#q5.42
for the full sad story of 802.11 capture with WinPcap applications
(WinDump, Analyzer, Ethereal, etc.) on 802.11 interfaces on Windows. It
might work better on Linux or various BSDs if they have drivers for the
interface.