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Subject: Calculating a hash from a eBPF program?
From: Dan Siemon <dan@coverfire.com>
Date: Tue, 27 Jun 2017 16:45:45 -0400
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[This isn't strictly an XDP question, I'm using cls_bpf but I don't
know of a better place to ask]

Is there a way to calculate a hash of a struct or other data from
within an eBPF program? I need to build a classifier that can hash a
flow encapsulated in protocols like PPPoE or GTP-U. Basically like
cls_flow's use of jhash2 but at a different offset. I looked at the
helpers in bpf.h but don't see anything helpful there.

Thanks.