tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 __u32 len = (__u32) data_end - (__u32) data;
24 int err;
25
26 if (data + 10 > data_end) {
27 err = bpf_skb_pull_data(skb, 10);
28 if (err)
29 return SK_DROP;
30
31 data_end = (void *)(long)skb->data_end;
32 data = (void *)(long)skb->data;
33 if (data + 10 > data_end)
34 return SK_DROP;
35 }
36
37 /* This write/read is a bit pointless but tests the verifier and
38 * strparser handler for read/write pkt data and access into sk
39 * fields.
40 */
41 d = data;
42 d[7] = 1;
43 return skb->len;
44}
45
46char _license[] SEC("license") = "GPL";