[please review] TSO mbuf chain length limiting patch

[Colin Percival]

On 06/03/12 15:56, Bjoern A. Zeeb wrote:
> On 3. Jun 2012, at 16:51 , Colin Percival wrote:
>> I've attached a new patch which:
>> 1. adds a IFCAP_TSO_MSS "capability" and a if_tx_tso_mss field to struct ifnet,
>> 2. sets these in netfront when the IFCAP_TSO4 flag is set,
>> 3. extends tcp_maxmtu to read this value,
>> 4. adds a tx_tso_mss field to struct tcpcb,
>> 5. makes tcp_mss_update set tx_tso_mss using tcp_maxmtu, and
>> 6. limits TSO lengths to tx_tso_mss in tcp_output.
> 
> general question - what happens in the IPv6 case?

It should work just fine; when I said "tcp_maxmtu" I really meant "tcp_maxmtu
and tcp_maxmtu6".

Of course, this all only affects TSO, and the netfront driver doesn't enable
TSO for IPv6 (yet), so in a sense the real answer is "nothing at all".  But
the infrastructure will be in place for when it's needed.

-- 
Colin Percival
Security Officer Emeritus, FreeBSD | The power to serve
Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid