On 25 August 2015 at 11:33, Thomas Graf <tgraf@xxxxxxx> wrote: > On 08/24/15 at 05:32pm, Joe Stringer wrote: >> Add support for using conntrack helpers to assist protocol detection. >> The new OVS_CT_ATTR_HELPER attribute of the CT action specifies a helper >> to be used for this connection. If no helper is specified, then helpers >> will be automatically applied as per the sysctl configuration of >> net.netfilter.nf_conntrack_helper. >> >> The helper may be specified as part of the conntrack action, eg: >> ct(helper=ftp). Initial packets for related connections should be >> committed to allow later packets for the flow to be considered >> established. >> >> Example ovs-ofctl flows allowing FTP connections from ports 1->2: >> in_port=1,tcp,action=ct(helper=ftp,commit),2 >> in_port=2,tcp,ct_state=-trk,action=ct(recirc) >> in_port=2,tcp,ct_state=+trk-new+est,action=1 >> in_port=2,tcp,ct_state=+trk+rel,action=1 > > Not subject to this patch but we may want to revisit the syntax of the > state flags. It's neatly compressed like this but ct_state=untracked > ct_state=related might be more readable. The +trk should be implicit > for anything !untracked Fair criticism. My thoughts were that this was a reasonable middleground between representing masked flags like "ct_state=0xc2/0xc3" vs. having overly verbose state descriptions like the corresponding "ct_state=tracked,!new,established,reply_direction". Either way, we need to represent the three possible states for each flag: set and we care about the value, unset and we care about the value, or we don't care about the value. Arguably the example above is a bit imprecise, because the +trk flows intersect. Omitting the "+trk" would make all of the return flows intersect. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
