xref: /openbmc/linux/samples/bpf/sockex1_kern.c (revision a8085782)
1 #include <uapi/linux/bpf.h>
2 #include <uapi/linux/if_ether.h>
3 #include <uapi/linux/ip.h>
4 #include "bpf_helpers.h"
5 
6 struct bpf_map_def SEC("maps") my_map = {
7 	.type = BPF_MAP_TYPE_ARRAY,
8 	.key_size = sizeof(u32),
9 	.value_size = sizeof(long),
10 	.max_entries = 256,
11 };
12 
13 SEC("socket1")
14 int bpf_prog1(struct sk_buff *skb)
15 {
16 	int index = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
17 	long *value;
18 
19 	value = bpf_map_lookup_elem(&my_map, &index);
20 	if (value)
21 		__sync_fetch_and_add(value, 1);
22 
23 	return 0;
24 }
25 char _license[] SEC("license") = "GPL";
26