On 3/15/24 11:30 AM, Stanislav Fomichev wrote:
On 03/15, Alexandre Cassen wrote:
On 15/03/2024 18:31, Stanislav Fomichev wrote:
On 03/14, Alexandre Cassen wrote:
Hello,
While implementing a large scale L2 processing soft, there is a need for
high perf ingress handling.
In short: using BPF socket_filter prog with a hash func over ethernet
address to distribute load across multiple PF_PACKET sockets: mainly
filtering out non related hkey packets. It simplify userland app by using
multiple PF_PACKET sockets in dedicated pthread.
Longer discussion + quick source code illustration here:
https://github.com/acassen/bpf-pfpacket-rps
My question would be related to sockmap. I tried to figure out how to
perform the same policing design using sockmap. And cant find my way around
it :/ If bpf verdict prog can get socket fd from __sk_buff then it could
drives the same hash/policing decision.
Is it possible to get socket fd from __sk_buff from sockmap verdict prog ?
Don't have an answer about sockmap, but I'd suggest you look at AF_XDP
if you want the best perf out there with raw frames.
IIRC, it just recently got a mode where you can redirect into multiple
sockets (== consumer threads):
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=2863d665ea41
thanks for replying, __sk_buff bpf mirror doesnt export struct sock as
present into kernel skbuff, so no options but extending.
AF_XDP is an option. Will extend test code with it later on.
We do export bpf_sock in __sk_buff:
__bpf_md_ptr(struct bpf_sock *, sk);
But it has a very minimal set of 'struct sock' fields exported.
You could use bpf_core_cast() in bpf_core_read.h to cast 'struct bpf_sock' to kernel 'struct sock'.
