Re: [Bloat] high speed packet and protocol processing in userspace?

[Eric Dumazet <eric.dumazet@gmail.com>]

On Thu, 2017-03-16 at 11:52 -0400, Michael Richardson wrote:
> Dave Taht <dave.taht@gmail.com> wrote:
>     > Is it faster to execute 17 bpf vm instructions on (nearly) every
>     > packet, or to use all that old stuff?
> 
>     > bpf example for the babel protocol:
> 
> I have no data for you.  Andrew McGregor might know more?
> My understanding is that there is a JIT for ebpf.


ebpf is pretty fast.

> 
>     > B) Are there any means of easily abstracting deeper protocol processing
>     > into a higher level grammar, better than tcpdump? I found one tool,
>     > that I like conceptually - for deeply decoding a protocol -
> 
> tcpdump just exposes the libpcap compiler.  It has many annoying limitations.
> 
>     > I've googled, and thunk, and maybe I'm merely asking the wrong
>     > questions, and "the packet analysis tool to end all tools" already
>     > exists?
> 
> Yes, people have produced them, but they go nowhere because they are too
> specialized, or too general.  The question is: are you trying to build a tcp
> stack that punts packets at applications, or do "analysis" --- which I interpret
> to mean to collect statistics.

Note that you can use C to write your parser, then use LLVM to generate
native eBPF code.


> 
>     > C) Are vendors like mellonox or others doing network offloads parsing
>     > bpf or ebpf directly yet?
> 
> I don't know.

Netronome is (kind of)
drivers/net/ethernet/netronome/nfp