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Tangentially: I am interested in sponsoring an open source (Apache License) implementation of BPF bytecode in DynASM (or LuaJIT). The use case is to execute packet filters compiled by libpcap. Ideally we'd win shootouts (like http://carnivore.it/2011/12/28/bpf_performance).

Get in touch if you are the person to do this :-) luke@snabb.co

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Hi Luke, Take a look at bpfjit in NetBSD. It uses bsd licensed sljit library to generate code for multiple platforms. The library has some slight overhead over hand-written assembly but it gives you a single codebase for all platforms. At the very least, you can borrow some optimisations from my code. http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/net/bpfjit.c?onl... PS I can't work on sponsored projects. Alex

Thanks for the pointer!

Do you also know a lightweight way to compile pcap-filters into BPF code?

Not sure there is. There seems to be a lot of optimisation done, and there only seem to be a couple of heavyweight implementations.

From my humble experience, even the simplest implementations of BPF runtime are fast enough. Maybe just jitted interpreter in LUA would do for most use cases.

BPF is generally pretty fast.

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