[PATCH 3/4] [gprs] Fix hardcoded IP addresses in GPRS UDP communication

[Harald Welte]

Hi Sylvain,

On Fri, Nov 20, 2009 at 03:11:33PM +0100, Sylvain Munaut wrote:
 
> >> +		/* FIXME: Just take the first ip.access bts we find */
> >> +	llist_for_each_entry(bts, &e1h->gsmnet->bts_list, list) {
> >> +		if (!is_ipaccess_bts(bts))
> >> +			continue;
> >> +		break;
> >
> > msg->trx will be set, so you can simply dereference msg->trx->bts to get to the
> > bts to which this should be sent.
> 
> That was my first thought. But it's not set (or at least not always),
> leading to a seg fault when I tried that. For examples packets send
> with gprs_ns_tx_simple don't have it set. And I didn't see any clean way
> to get it from where those were generated.

ok, we need to fix those. I understand that the NS layer does not know yet
which BTS has sent it.  That's what the ns_link structure was intended for.

However, what makes probably even more sense is to identify the BTS based on
its source IP address in the input/ipaccess.c code.  So for every packet we
receive, we iterate over all BTS's and compare the source IP address.  If we
have a match, we assign msg->trx = bts->c0 and all higher layers have that
knowledge and can use it.

Regards,
-- 
- Harald Welte <laforge at gnumonks.org>           http://laforge.gnumonks.org/
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