Re: [PATCH bpf-next] bpf: add bpf_ct_lookup_{tcp,udp}() helpers
From: Daniel Borkmann <daniel@iogearbox.net>
Date: 2020-01-20 21:11:55
Also in:
bpf, linux-kselftest, lkml
On 1/20/20 9:10 PM, Matt Cover wrote:
On Mon, Jan 20, 2020 at 11:11 AM Matt Cover [off-list ref] wrote:quoted
On Sat, Jan 18, 2020 at 8:05 PM John Fastabend [off-list ref] wrote:quoted
Matthew Cover wrote:quoted
Allow looking up an nf_conn. This allows eBPF programs to leverage nf_conntrack state for similar purposes to socket state use cases, as provided by the socket lookup helpers. This is particularly useful when nf_conntrack state is locally available, but socket state is not. Signed-off-by: Matthew Cover <redacted> ---Couple coding comments below. Also looks like a couple build errors so fix those up. I'm still thinking over this though.Thank you for taking the time to look this over. I will be looking into the build issues.Looks like I missed static inline on a couple functions when nf_conntrack isn't builtin. I'll include the fix in v2.
One of the big issues I'd see with this integration is that literally no-one will be able to use it unless they manually recompile their distro kernel with ct as builtin instead of module .. Have you considered writing a tcp/udp ct in plain bpf? Perhaps would make sense to have some sort of tools/lib/bpf/util/ with bpf prog library code that can be included.