On Fri, Apr 24, 2015 at 8:51 AM, Jiri Pirko <j...@resnulli.us> wrote: > Per Davem's request, I prepared this patchset which introduces programmable > flow dissector. For current users of flow_keys, there is a wrapper > skb_flow_dissect_flow_keys which maintains the previous behaviour. > For purposes of cls_flower, couple of new dissection keys were introduced. > > Note that this dissector can be also eventually used by openvswitch code. > > Also, I plan to get rid of *skb_flow_get_ports(export) and *__skb_get_poff as > their functionality can be now implemented by skb_flow_dissect as well. > > Ideas, comments? > HI Jiri,
Looking a little more closely at your patches I'm not convinced this complexity is justified; it seems like this is moving flow_dissector to be more of a general packet parser rather than adhering to its original prinicples which was to extract just enough information from packet to create a good hash for the packet's flow. For improving packet hashing, I would rather judiciously extend the flow_keys structure to include full IPv6 address, add a *few* other fields such as VLAN and flow label, and then hash over the the whole structure especially eliminating use of xor which doesn't do squat in making a DOS resilient hash. We are potentially calling flow_dissector on every RX packets, and many TX packets via skb_hash-- this needs to be simple and efficient. Also, making something like IP address and ports optional to return doesn't seem like a lot of value to me-- why not just always return it to the caller in flow_keys and they can ignore any fields they want-- adding conditionals for IP address and ports inclusion will only slow down the common critical path use case. I imagine programmatic packet parser might have some interesting use cases, but maybe this should be spun off as a separate function. If we did that then the output wouldn't need to be limited to just the restricted flow identification fields, but could include whatever else in a packet might be interesting-- TOS, TTL, TCP flags, both inner and outer addresses, etc. btw, can you please split the cosmetic changes and material changes into two patch sets, this will make reviewing them a lot easier! Thanks, Tom > Jiri Pirko (15): > net: change name of flow_dissector header to match the .c file name > flow_dissector: remove unused function flow_get_hlen declaration > net: move *skb_get_poff declarations into correct header > flow_dissector: fix doc for __skb_get_hash and remove couple of empty > lines > net: move __skb_get_hash function declaration to flow_dissector.h > net: move __skb_tx_hash to skbuff.c > net: move netdev_pick_tx and dependencies to net/core/dev.c > flow_dissector: fix doc for skb_get_poff > flow_dissector: introduce programable flow_dissector > flow_dissect: use programable dissector in skb_flow_dissect and > friends > flow_dissector: add missing header includes > flow_dissector: introduce support for ipv6 addressses > flow_dissector: introduce support for Ethernet addresses > flow_dissector: change port array into src,dst tuple > tc: introduce Flower classifier > > drivers/net/bonding/bond_main.c | 20 +- > drivers/net/ethernet/cisco/enic/enic_clsf.c | 29 +- > drivers/net/ethernet/cisco/enic/enic_ethtool.c | 10 +- > drivers/net/hyperv/netvsc_drv.c | 8 +- > include/linux/skbuff.h | 11 +- > include/net/flow_dissector.h | 152 ++++++ > include/net/flow_keys.h | 45 -- > include/net/ip.h | 10 +- > include/net/ipv6.h | 10 +- > include/uapi/linux/pkt_cls.h | 31 ++ > net/core/dev.c | 78 +++ > net/core/filter.c | 1 + > net/core/flow_dissector.c | 376 ++++++++------ > net/core/skbuff.c | 28 + > net/ethernet/eth.c | 7 +- > net/sched/Kconfig | 10 + > net/sched/Makefile | 1 + > net/sched/cls_flow.c | 22 +- > net/sched/cls_flower.c | 688 > +++++++++++++++++++++++++ > net/sched/sch_choke.c | 6 +- > net/sched/sch_fq_codel.c | 10 +- > net/sched/sch_hhf.c | 10 +- > net/sched/sch_sfb.c | 22 +- > net/sched/sch_sfq.c | 10 +- > 24 files changed, 1292 insertions(+), 303 deletions(-) > create mode 100644 include/net/flow_dissector.h > delete mode 100644 include/net/flow_keys.h > create mode 100644 net/sched/cls_flower.c > > -- > 1.9.3 > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
