1// SPDX-License-Identifier: GPL-2.0
 2
 3#include <linux/bpf.h>
 4#include <bpf/bpf_helpers.h>
 5
 6__noinline
 7long changes_pkt_data(struct __sk_buff *sk)
 8{
 9	return bpf_skb_pull_data(sk, 0);
10}
11
12__noinline __weak
13long does_not_change_pkt_data(struct __sk_buff *sk)
14{
15	return 0;
16}
17
18SEC("?tc")
19int main_with_subprogs(struct __sk_buff *sk)
20{
21	changes_pkt_data(sk);
22	does_not_change_pkt_data(sk);
23	return 0;
24}
25
26SEC("?tc")
27int main_changes(struct __sk_buff *sk)
28{
29	bpf_skb_pull_data(sk, 0);
30	return 0;
31}
32
33SEC("?tc")
34int main_does_not_change(struct __sk_buff *sk)
35{
36	return 0;
37}
38
39char _license[] SEC("license") = "GPL";