[Vtun-Users] IPv4+TCP/UDP/ICMP header compressor

[Vladimir N. Oleynik]

Hi, all.

It my the new year holiday work with vtund 3.0.1 :)
IPv4+TCP/UDP/ICMP header compressor for a tun-device only IPv4 packets.
Typical size less is 20 bytes (-25 bytes for a TCP handshake/close).
It do not send any added traffic always.
It is not like VJ TCP header compression.
It have not state and full stable with loses packets.

Other changes:
- zlib_compressor removed (need flag bit for me), use lzo_compressor;
- check out size of lzo_compressor, if really size less, out
a packet with new bit flag (length|flags as COMPRESSED)
- if IP headers compressor called, lzo compressor run for a IP protocol
body only. The lzo compressor can not good compress header, but for
texts-like body the result is very good: size IPhc+LZO(body) less vs
size LZO(full_datagram).

See attach.
Warning: with crypto do not tested!


--w
Network administrator of Simbirsk Treasury dept. region.