1#include <linux/bpf.h>
2#include <bpf/bpf_helpers.h>
3#include <bpf/bpf_endian.h>
4
5SEC("sk_skb1")
6int bpf_prog1(struct __sk_buff *skb)
7{
8	void *data_end = (void *)(long) skb->data_end;
9	void *data = (void *)(long) skb->data;
10	__u8 *d = data;
11	int err;
12
13	if (data + 10 > data_end) {
14		err = bpf_skb_pull_data(skb, 10);
15		if (err)
16			return SK_DROP;
17
18		data_end = (void *)(long)skb->data_end;
19		data = (void *)(long)skb->data;
20		if (data + 10 > data_end)
21			return SK_DROP;
22	}
23
24	/* This write/read is a bit pointless but tests the verifier and
25	 * strparser handler for read/write pkt data and access into sk
26	 * fields.
27	 */
28	d = data;
29	d[7] = 1;
30	return skb->len;
31}
32
33char _license[] SEC("license") = "GPL";
34