Wireshark · Wireshark-dev: Re: [Wireshark-dev] Rev 38350 Capture Options Changes - Named Pipe?

[Joerg Mayer <jmayer@xxxxxxxxx>]

On Thu, Aug 11, 2011 at 07:41:25PM -0700, Guy Harris wrote:
> On Aug 11, 2011, at 6:00 AM, Joerg Mayer wrote:
> 
> > While everyone seems to be adding their wishes, now that someone is actually
> > is working on that code: Would it make sense to add a button (or whatever)
> > to scan for newly created/activated interfaces? When I'm running Wireshark
> > and add a new interface (I'm on Linux and run e.g. "iw dev wlan0 interface add
> > mon0 type monitor" + "ifconfig mon0 up"
> 
> Actually, in that case, if Wireshark is using libpcap 1.1.0 or later, selecting wlan0 and checking the monitor mode checkbox should cause Wireshark to tell libpcap to do all that for you (by telling it to capture in monitor mode).

I'm running libpcap version 1.3.0-PRE-GIT_2011_07_06 (including the remote pcap
patch).

> > or just up an interface that was down,
> > I need to restart Wireshark for the new interface to be detected.
> 
> That sounds like a bug - it shouldn't be caching the interface list in Wireshark forever; at least if you open a new "Capture Options" dialog, it should re-run dumpcap to get the interface list again.
> 
> It won't update the interface list on the welcome page...

It doesn't work for me on neither welcome page nor capture options page - it does
work on the interface list page - so it looks like a wireshark buglet.

> > Checking
> > for new interfaces at runtime
> 
> ...but I'll see whether adding an API to libpcap to provide a way to be notified when new interfaces appear is possible.  (It's going to be platform-dependent - there's probably something in Linux to do it, maybe netlink, it'd probably be done in Mac OS X with the System Configuration framework, etc..)
> 
> > or be shown also interfaces that are admin down would be a nice to have :-)
> 
> If it's not showing them to you, it's probably not possible to capture on them; what happens if you try to run tcpdump or dumpcap on them?  On OS X Snow Leopard, at least:
[...]
> BPF won't let you bind to a device that's not up; I'd have to look at other BPF implementations to see if they impose similar restrictions.  I also tried it on my Ubuntu 9.10 virtual machine, and, after configuring an interface down, I got the same error (ENETDOWN in both cases).

OK, that was easy to misunderstand:
If I'm on wlan0 I normally have my eth0 admin down. In order to capture on eth0
I need to ifconfig eth0 up first. I'd like to see the Interface listed and then
have libpcap do the ifconifg <int> up for me.

 Thanks!
     Joerg
-- 
Joerg Mayer                                           <jmayer@xxxxxxxxx>
We are stuck with technology when what we really want is just stuff that
works. Some say that should read Microsoft instead of technology.