Thread (53 messages) 53 messages, 14 authors, 2013-04-09

Re: [PATCH 2/6] xen-netfront: reduce gso_max_size to account for ethernet header

From: David Miller <davem@davemloft.net>
Date: 2013-03-25 16:18:12

From: Wei Liu <redacted>
Date: Mon, 25 Mar 2013 11:08:18 +0000
The maximum packet including ethernet header that can be handled by netfront /
netback wire format is 65535. Reduce gso_max_size accordingly.

Drop skb and print warning when skb->len > 65535. This can 1) save the effort
to send malformed packet to netback, 2) help spotting misconfiguration of
netfront in the future.

Signed-off-by: Wei Liu <redacted>
This is effectively the default already, you don't need to change this
value explicitly.

->gso_max_size is set by default to 65536 and then TCP performs this
calculation:

                xmit_size_goal = ((sk->sk_gso_max_size - 1) -                          
                                  inet_csk(sk)->icsk_af_ops->net_header_len -          
                                  inet_csk(sk)->icsk_ext_hdr_len -                     
                                  tp->tcp_header_len);                                 

thereby making it adhere to your limits just fine.
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help