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
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