ebpf: add prandom helper for packet sampling
This work is similar to commit 4cd3675ebf74 ("filter: added BPF
random opcode") and adds a possibility for packet sampling in eBPF.
Currently, this is only possible in classic BPF and useful to
combine sampling with f.e. packet sockets, possible also with tc.
Example function proto-type looks like:
u32 (*prandom_u32)(void) = (void *)BPF_FUNC_get_prandom_u32;
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 80f2e0f..50bf95e 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -154,4 +154,6 @@
extern const struct bpf_func_proto bpf_map_update_elem_proto;
extern const struct bpf_func_proto bpf_map_delete_elem_proto;
+extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
+
#endif /* _LINUX_BPF_H */