Re: Wireless Interface APIs needed

[Lubomir Rintel <lrintel redhat com>]

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.

> 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?

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.

Lubo