Re: Broken ARP (was Re: ARP responses broken!)

From: Sampsa Ranta (sampsa@netsonic.fi)
Date: Wed Apr 18 2001 - 17:21:29 EST


On Wed, 18 Apr 2001, Julian Anastasov wrote:

>
> Hello,
>
> Sampsa Ranta wrote:
>
> > The code I used to do the trick at my network was as simple as this,
> > in function arp_rcv, the problem is ip_dev_find that does know if there
> > are other devices with same IP address.
>
> I don't think this is your problem. You patch is not correct.
> In fact, you implement the same function as in "hidden" but you are
> missing some things. Please, read the "hidden" flag description in
> the kernel docs. You must solve the case where your ARP probes are sent
> always through one device due to your routing (this is out traffic,
> yes?). These probes soon or later will cause you problems because
> they change the entry in the remote hosts' ARP tables. You so carefully
> tried to advertise the address on specific interface and now the other
> hosts again talk to one card only.
>
> who-has 194.29.192.1 tell 194.29.192.38
>
> and your are dead :)
>
> So, please try "hidden" before going into more problems with
> these patches (I see two in this thread, and I saw so many before).

Are you referring to the arp_solicit()?

       if (skb && inet_addr_type(skb->nh.iph->saddr) == RTN_LOCAL)
                saddr = skb->nh.iph->saddr;
       else
                saddr = inet_select_addr(dev, target, RT_SCOPE_LINK);

Why is this hidden flag removed in 2.4 series with replacing no
functionality that would help to solve the problems?

 - Sampsa Ranta
   sampsa@netsonic.fi

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Mon Apr 23 2001 - 21:00:29 EST