Comment 7 for bug 761955

Klaus Warnke (k-warnke) wrote :

Hello Didier,

I don't exactly understand what you mean, sorry.

Maybe the fix is wrong, because I don't understand the whole source
code. This is more a proposal, but it works for me (I can decompress
packets with 16bit IP-ID in extension 3 now). I looked around where
the IP-ID was handled in other cases (compressed) and copied...

To transmit the IP-ID in extension-3 uncompressed is wrong, even it is
possible, because the field is 16bit is size.

See RFC3095 page 85:
IP-ID: See the beginning of section 5.7.

And there: page 75.
IP-ID: A compressed IP-ID field

And finally 4.5.5. Offset IP-ID encoding.

Here the IP-ID is transmitted uncompressed:

/* always transmit IP-ID in Network Byte Order */
id = ipv4_get_id_nbo(ip, g_context->ip_flags.info.v4.nbo);

This is the place, where the extension-3 is handled, I hope.

Could you agree?

The fix should send/recv the IP-ID compressed instead.
The 16bit IP-ID field in extension-3 only (Part-6).

br, Klaus