1 #include <linux/bpf.h>
2 
3 #include <bpf/bpf_helpers.h>
4 #include <bpf/bpf_endian.h>
5 
6 int _version SEC("version") = 1;
7 
8 SEC("sk_msg1")
9 int bpf_prog1(struct sk_msg_md *msg)
10 {
11 	void *data_end = (void *)(long) msg->data_end;
12 	void *data = (void *)(long) msg->data;
13 
14 	char *d;
15 
16 	if (data + 8 > data_end)
17 		return SK_DROP;
18 
19 	bpf_printk("data length %i\n", (__u64)msg->data_end - (__u64)msg->data);
20 	d = (char *)data;
21 	bpf_printk("hello sendmsg hook %i %i\n", d[0], d[1]);
22 
23 	return SK_PASS;
24 }
25 
26 char _license[] SEC("license") = "GPL";
27