1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/bpf.h>
 3#include <bpf/bpf_helpers.h>
 4#include "xdpsock.h"
 5
 6/* This XDP program is only needed for the XDP_SHARED_UMEM mode.
 7 * If you do not use this mode, libbpf can supply an XDP program for you.
 8 */
 9
10struct {
11	__uint(type, BPF_MAP_TYPE_XSKMAP);
12	__uint(max_entries, MAX_SOCKS);
13	__uint(key_size, sizeof(int));
14	__uint(value_size, sizeof(int));
15} xsks_map SEC(".maps");
16
17static unsigned int rr;
18
19SEC("xdp_sock") int xdp_sock_prog(struct xdp_md *ctx)
20{
21	rr = (rr + 1) & (MAX_SOCKS - 1);
22
23	return bpf_redirect_map(&xsks_map, rr, XDP_DROP);
24}