1#include <linux/bpf.h>
2#include "bpf_helpers.h"
3#include "bpf_util.h"
4#include "bpf_endian.h"
5
6int _version SEC("version") = 1;
7
8#define bpf_printk(fmt, ...)					\
9({								\
10	       char ____fmt[] = fmt;				\
11	       bpf_trace_printk(____fmt, sizeof(____fmt),	\
12				##__VA_ARGS__);			\
13})
14
15SEC("sk_skb1")
16int bpf_prog1(struct __sk_buff *skb)
17{
18	void *data_end = (void *)(long) skb->data_end;
19	void *data = (void *)(long) skb->data;
20	__u32 lport = skb->local_port;
21	__u32 rport = skb->remote_port;
22	__u8 *d = data;
23
24	if (data + 10 > data_end)
25		return skb->len;
26
27	/* This write/read is a bit pointless but tests the verifier and
28	 * strparser handler for read/write pkt data and access into sk
29	 * fields.
30	 */
31	d[7] = 1;
32	return skb->len;
33}
34
35char _license[] SEC("license") = "GPL";
36