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| author | Jakub Kicinski <kuba@kernel.org> | 2024-07-05 17:45:49 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-07-05 17:45:50 -0700 |
| commit | 73d4d645a668e5fca71aa6717b24acfb12ef8ef6 (patch) | |
| tree | aa262e31790be385daa6e5845f0e60c1e4fb0d16 /net/openvswitch/datapath.h | |
| parent | 064fbc4e9b5a6dbda7fe7b67dc7e9e95d31f8d75 (diff) | |
| parent | 30d772a03582bd10447af1bcdd1c731c89b54174 (diff) | |
Merge branch 'net-openvswitch-add-sample-multicasting'
Adrian Moreno says:
====================
net: openvswitch: Add sample multicasting.
** Background **
Currently, OVS supports several packet sampling mechanisms (sFlow,
per-bridge IPFIX, per-flow IPFIX). These end up being translated into a
userspace action that needs to be handled by ovs-vswitchd's handler
threads only to be forwarded to some third party application that
will somehow process the sample and provide observability on the
datapath.
A particularly interesting use-case is controller-driven
per-flow IPFIX sampling where the OpenFlow controller can add metadata
to samples (via two 32bit integers) and this metadata is then available
to the sample-collecting system for correlation.
** Problem **
The fact that sampled traffic share netlink sockets and handler thread
time with upcalls, apart from being a performance bottleneck in the
sample extraction itself, can severely compromise the datapath,
yielding this solution unfit for highly loaded production systems.
Users are left with little options other than guessing what sampling
rate will be OK for their traffic pattern and system load and dealing
with the lost accuracy.
Looking at available infrastructure, an obvious candidated would be
to use psample. However, it's current state does not help with the
use-case at stake because sampled packets do not contain user-defined
metadata.
** Proposal **
This series is an attempt to fix this situation by extending the
existing psample infrastructure to carry a variable length
user-defined cookie.
The main existing user of psample is tc's act_sample. It is also
extended to forward the action's cookie to psample.
Finally, a new OVS action (OVS_SAMPLE_ATTR_PSAMPLE) is created.
It accepts a group and an optional cookie and uses psample to
multicast the packet and the metadata.
====================
Link: https://patch.msgid.link/20240704085710.353845-1-amorenoz@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/openvswitch/datapath.h')
| -rw-r--r-- | net/openvswitch/datapath.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/openvswitch/datapath.h b/net/openvswitch/datapath.h index 0cd29971a907..9ca6231ea647 100644 --- a/net/openvswitch/datapath.h +++ b/net/openvswitch/datapath.h @@ -115,12 +115,15 @@ struct datapath { * fragmented. * @acts_origlen: The netlink size of the flow actions applied to this skb. * @cutlen: The number of bytes from the packet end to be removed. + * @probability: The sampling probability that was applied to this skb; 0 means + * no sampling has occurred; U32_MAX means 100% probability. */ struct ovs_skb_cb { struct vport *input_vport; u16 mru; u16 acts_origlen; u32 cutlen; + u32 probability; }; #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb) |