Re: [B.A.T.M.A.N.] [PATCH v5 3/4] batman-adv: B.A.T.M.A.N. V - implement GW selection logic

[Antonio Quartulli <a@unstable.cc>]

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On Mon, Jun 13, 2016 at 01:26:31PM +0200, Sven Eckelmann wrote:
> On Sunday 12 June 2016 12:14:25 Antonio Quartulli wrote:
> > +       if (orig_throughput < (gw_throughput + threshold))
> > +               goto out;
> 
> Possible overflow problem in batadv_v_gw_is_eligible. We don't
> know what the user will add here and what the gw_throughput is.
> 
> We already had a similar problem in the BATMAN_IV gw selection
> code which resulted in weird gw selections. See f63c54bba31d
> ("batman-adv: Avoid u32 overflow during gateway select").

Sven, correct me if I am wrong, but in f63c54bba31d we are changing the type of
the variables aimed to contain the value computed by the "overflowing"
operation, while in this case we have everything in a if condition: should the
temporary result be implicitly casted to a larger variable as required ?

I may be wrong - but I wanted to ask you to be sure.

Cheers,


-- 
Antonio Quartulli

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