Re: Wireless Interface APIs needed

[Vasudeo Bidve <vkbidve gmail com>]

On Fri, Nov 28, 2014 at 5:35 PM, Lubomir Rintel <lrintel redhat com> wrote:
> On Fri, 2014-11-28 at 16:33 +0530, Vasudeo Bidve wrote:
> > Hi,
> >
> > I am working on a networking project where only Wi-Fi interfaces are
> > used on all hosts for communication. It has to be a private network,
> > operating on IPv6 without using DHCP(v6). So obviously, the trick is
> > to assign Link-Local IPv6 addresses to all hosts using their
> > respective MAC ids and proceed.
> >
> > I did a proof-of-concept of such networking using Ethernet and PCs
> > with ubuntu (14.04 LTS). But this is not working with wireless
> > interfaces.
> >
> > I tried to do this with command line utilities like 'iw' and
> > 'iwconfig' on my PCs, but as soon as I plug in the USB-wifi adapter,
> > the network-manager in ubuntu sets it in 'managed' mode, which I don't
> > want. Further, if I try to assign another mode, I get an error message
> > as 'device is busy'.
>
> That's possible because AP scan is running.

So is it possible to interrupt/stop it, so that I can add/delete wireless modes?

> > Then by taking the link down, it doesn't add any
> > modes. Using the network setting panel in ubuntu, I can configure it
> > in 'ad-hoc' mode, but I want to do it programmatically (through a C
> > code, shell script, anything) without using that network-manager
> > utility finally in my project.
>
> Wrong list, possibly? :) Any particular reason you won't use
> NetworkManager?

In my final project, the network formation and operational algorithms
will be non-standard (proprietory) ones. So NetworkManager might not
fit to the purpose.

> See "unmanaged-devices" in NetworkManager.conf(5) manual.
>
> > In my project, finally all PCs will be replaced by embedded linux
> > SBCs. USB wi-fi adapters will possibly be replaced by wi-fi modules.
> > But programmatically, they should be able to communicate with each
> > other at Link-Local IPv6 addresses in Ad-Hoc mode.
> >
> > At this moment, what I need is a set of wireless interface APIs, (of
> > course with some helpful documentation) to configure the wifi
> > interface in Ad-Hoc mode (possibly in AP/Station mode as and when
> > needed), get a Link-Local IPv6 address assigned to itself and start
> > networking. Any URL to such information will also do.
> >
> > If there is any step-by-step guide (or example codes) then it will be
> > even more helpful.
> >
> > I am hopeful from this group because the network-manager internally
> > *USES* these APIs and you people must be knowing what I need.
>
> We use the same nl80211 API as "iw" does. We also talk to wpa_supplicant
> via DBus.

Can you please point me to the specific URL? I tried to look on web,
but didn't find it? Also some step-by-step guide (or any example code)
will be useful.

> Lubo