1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2022 Intel */
3 
4 #include <linux/bpf.h>
5 #include <bpf/bpf_helpers.h>
6 
7 struct {
8 	__uint(type, BPF_MAP_TYPE_XSKMAP);
9 	__uint(max_entries, 1);
10 	__uint(key_size, sizeof(int));
11 	__uint(value_size, sizeof(int));
12 } xsk SEC(".maps");
13 
14 static unsigned int idx;
15 
16 SEC("xdp") int xsk_def_prog(struct xdp_md *xdp)
17 {
18 	return bpf_redirect_map(&xsk, 0, XDP_DROP);
19 }
20 
21 SEC("xdp") int xsk_xdp_drop(struct xdp_md *xdp)
22 {
23 	/* Drop every other packet */
24 	if (idx++ % 2)
25 		return XDP_DROP;
26 
27 	return bpf_redirect_map(&xsk, 0, XDP_DROP);
28 }
29 
30 char _license[] SEC("license") = "GPL";
31