On 2/27/25 10:28 AM, Mahe Tardy wrote:
This is needed in the context of Cilium and Tetragon to retrieve netns cookie from hostns when traffic leaves Pod, so that we can correlate skb->sk's netns cookie. Signed-off-by: Mahe Tardy <mahe.tardy@xxxxxxxxx> --- This is a follow-up of c221d3744ad3 ("bpf: add get_netns_cookie helper to cgroup_skb programs") and eb62f49de7ec ("bpf: add get_netns_cookie helper to tc programs"), adding this helper respectively to cgroup_skb and tcx programs. I looked up a patch doing a similar thing c5dbb89fc2ac ("bpf: Expose bpf_get_socket_cookie to tracing programs") and there was an item about "sleepable context". It seems it indeed concerns tracing and LSM progs from reading 1e6c62a88215 ("bpf: Introduce sleepable BPF programs"). Is this needed here?
Regarding sleepable, I think the bpf_get_netns_cookie_sock is only reading, should be fine.
The immediate question is whether sock_net(sk) must be non-NULL for tracing.