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Date: Tue, 29 Dec 2015 16:26:10 -0600
Message-ID: <CAAN2wCD6Bdzzy=sHSww5QLR94bi52R=cDvq-sk+mo3sViFGjUQ@mail.gmail.com>
Subject: BPF Berkeley Packet Filter
From: Juan Herrera <mybsdmailing@gmail.com>
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Hello,

I have a question regarding Berkeley Packet filter, which is Can I read an
incoming packet length with BPF, I am working on a project that requires to
filter the receiving packets in the kernel before they get to userspace,
but I need to be able to read the packet length when applying BPF because I
(previously) encapsulated the packet with my own metadata before sending it
to the machine with BPF so I want to read packet length to decapsulate as I
know the value for the metadata at the end of the packet?


Thank you in advance!