xref: /openbmc/linux/samples/bpf/sockex1_kern.c (revision 0da85d1e)
1 #include <uapi/linux/bpf.h>
2 #include <uapi/linux/if_ether.h>
3 #include <uapi/linux/if_packet.h>
4 #include <uapi/linux/ip.h>
5 #include "bpf_helpers.h"
6 
7 struct bpf_map_def SEC("maps") my_map = {
8 	.type = BPF_MAP_TYPE_ARRAY,
9 	.key_size = sizeof(u32),
10 	.value_size = sizeof(long),
11 	.max_entries = 256,
12 };
13 
14 SEC("socket1")
15 int bpf_prog1(struct __sk_buff *skb)
16 {
17 	int index = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
18 	long *value;
19 
20 	if (skb->pkt_type != PACKET_OUTGOING)
21 		return 0;
22 
23 	value = bpf_map_lookup_elem(&my_map, &index);
24 	if (value)
25 		__sync_fetch_and_add(value, skb->len);
26 
27 	return 0;
28 }
29 char _license[] SEC("license") = "GPL";
30