Re: nfnl_listen: recvmsg overrun: No buffer space available" in nfct_event_conntrack() call

[Pablo Neira Ayuso <pablo@netfilter.org>]

Pablo Neira Ayuso wrote:
> Павел Коколемин wrote:
>> When LAN users start network scanners (NetLook, for example),
>> sometimes I receive error in console:
>> "nfnl_listen: recvmsg overrun: No buffer space available"
>> generated in nfct_event_conntrack() (recvmsg() returns ENOBUFS error 
>> code).
>> This message generated in nfnl_listen().
> 
> Increase netlink buffer size via nfnl_rcvsiz() (libnfnetlink), the 
> default size is available in /proc/sys/net/core/rmem_max. BTW, this 
> message means that you have probably lost some log messages because the 
> rate was so high that the buffer could not back off.

Sorry, I didn't notice that there is no way to access nfnl_handle from 
libnetfilter_conntrack, instead use setsockopt(nfct_fd(h), SOL_SOCKET, 
SO_RCVBUFFORCE, &size, socklen) to set the buffer size. Anyway I'll cook 
a patch for this asap, this issue is important.

-- 
The dawn of the fourth age of Linux firewalling is coming; a time of 
great struggle and heroic deeds -- J.Kadlecsik got inspired by J.Morris