[Olsr-dev] mDns plugin improvement

[Henning Rogge]

I don't think this TTL 255 thing is really useful. Especially with
IPv4, where it can wreck havoc when you have a multicast capable
interface. Better just set it to TTL 1 as normal and forget about this
dubious "security extension".

Henning

On Wed, May 30, 2012 at 7:36 PM, Ferry Huberts <(spam-protected)> wrote:
>
>
> On 30-05-12 19:25, Teco Boot wrote:
>>
>> mDNS packets SHOULD have TTL 255.
>>
>>> 11.  Source Address Check
>>>
>>>    All Multicast DNS responses (including responses sent via unicast)
>>>    SHOULD be sent with IP TTL set to 255. This is recommended to provide
>>>    backwards-compatibility with older Multicast DNS Queriers
>>>    (implementing draft-cheshire-dnsext-multicastdns-04.txt, published
>>>    February 2004) that check the IP TTL on reception to determine
>>>    whether the packet originated on the local link. These older Queriers
>>>    discard all packets with TTLs other than 255.
>>>
>>
>
> so that would be a NAK then I guess
>
>
>> Why not the more standard method using a hash table, like bmf? Costs more
>> CPU / memory, but it is much safer. p2pd has / had this. We didn't push
>> this version I think, because there was an issue with latest
>> modifications.
>> nyway, we should get rid of 2 out of 3 plugins.
>>
>> If you want to keep it this way, you could make a config parameter, and
>> make this behavior non-default. Or better: use the hashing code out of
>> bmf.
>>
>> Teco
>>
>> Op 30 mei 2012, om 18:56 heeft Alessandro Gnagni het volgende geschreven:
>>
>>>
>>> https://github.com/zioproto/olsrd-gsoc2012/commit/5e26a83646023c4fd4b09bb05e81a35ee8d60311
>>>
>>> i modified the mDns plugin to avoid packet loop, anyone can give me some
>>> feedback? Thx
>>>
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>>
>>
>>
>
> --
> Ferry Huberts
>
>
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