path: root/kernel/bpf/core.c
diff options
authorDaniel Borkmann <>2015-03-14 02:27:16 +0100
committerDavid S. Miller <>2015-03-15 21:57:25 -0400
commit03e69b508b6f7c51743055c9f61d1dfeadf4b635 (patch)
tree4c9199cde0fe876871e20352666d40721d4c1d5f /kernel/bpf/core.c
parent12028820423bd7705beb5e09889faab95c545ea1 (diff)
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 <> Signed-off-by: David S. Miller <>
Diffstat (limited to 'kernel/bpf/core.c')
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 50603aec766a..c1dbbb5d289b 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -661,6 +661,8 @@ const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
const struct bpf_func_proto bpf_map_update_elem_proto __weak;
const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
+const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
/* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
* skb_copy_bits(), so provide a weak definition of it for NET-less config.