| 1 | #include <linux/bpf.h> |
|---|---|
| 2 | #include <bpf/bpf_helpers.h> |
| 3 | #include <bpf/bpf_endian.h> |
| 4 | |
| 5 | SEC("sk_skb1") |
| 6 | int 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 | |
| 33 | char _license[] SEC("license") = "GPL"; |
| 34 |