bpf: add bpf_set_hash helper for tc progs
Allow for tc BPF programs to set a skb->hash, apart from clearing
and triggering a recalc that we have right now. It allows for BPF
to implement a custom hashing routine for skb_get_hash().
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 9b2c10b..f94b48b 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -513,6 +513,11 @@ union bpf_attr {
* Get the owner uid of the socket stored inside sk_buff.
* @skb: pointer to skb
* Return: uid of the socket owner on success or overflowuid if failed.
+ *
+ * u32 bpf_set_hash(skb, hash)
+ * Set full skb->hash.
+ * @skb: pointer to skb
+ * @hash: hash to set
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -562,7 +567,8 @@ union bpf_attr {
FN(xdp_adjust_head), \
FN(probe_read_str), \
FN(get_socket_cookie), \
- FN(get_socket_uid),
+ FN(get_socket_uid), \
+ FN(set_hash),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call