Re: nl80211 scanning from userspace

[Johannes Berg <johannes@sipsolutions.net>]

On Mon, 2010-08-16 at 17:22 -0400, Christopher Piggott wrote:
> It's hard to figure out what's going on sometimes.  I set up an error handler:
> 
> static int error_handler(struct sockaddr_nl *nla, struct nlmsgerr
> *err, void *arg) {
>     printf("ERROR %s (%d)\n", strerror(err->error), err->error);
>     return NL_SKIP;
> }
> 
> which also returns -95 (operation not supported) just as you said.
> So, I'll have to figure out what you mean by "dumping."
> 
> I did find this:
> 
>         mcid = nl_get_multicast_id(state->nl_sock, "nl80211", "scan");
> 
> in iw:event.c and traced it to some code in iw:genl.c, a file that
> starts out by commenting "This ought to be provided by libnl".  That
> situation doesn't seem to have changed.
> 
> Is this the area of the code you mean when you say "dump" ?  That I
> need to register myself to receive the scan results?

No, you need to use NLM_F_DUMP etc. Really, check wpa_supplicant :)

johannes