bpf: add get_netns_cookie helper to cgroup_skb programs

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@gmail.com>
Link: https://lore.kernel.org/r/20250225125031.258740-1-mahe.tardy@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/net/core/filter.c b/net/core/filter.c
index 2ec162dd83c463640dcf3c151327206f519b217a..827108c6dad9f4c07d1e411920b86e4fdbbd5c10 100644 (file)
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -8075,6 +8075,8 @@ sk_filter_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
                return &bpf_skb_load_bytes_relative_proto;
        case BPF_FUNC_get_socket_cookie:
                return &bpf_get_socket_cookie_proto;
+       case BPF_FUNC_get_netns_cookie:
+               return &bpf_get_netns_cookie_proto;
        case BPF_FUNC_get_socket_uid:
                return &bpf_get_socket_uid_proto;
        case BPF_FUNC_perf_event_output: