LXR linux/tools/testing/selftests/bpf/progs/sockmap_parse

   1#include <linux/bpf.h>
   2#include <bpf/bpf_helpers.h>
   3#include <bpf/bpf_endian.h>
   4
   5int _version SEC("version") = 1;
   6
   7SEC("sk_skb1")
   8int bpf_prog1(struct __sk_buff *skb)
   9{
  10        void *data_end = (void *)(long) skb->data_end;
  11        void *data = (void *)(long) skb->data;
  12        __u32 lport = skb->local_port;
  13        __u32 rport = skb->remote_port;
  14        __u8 *d = data;
  15        int err;
  16
  17        if (data + 10 > data_end) {
  18                err = bpf_skb_pull_data(skb, 10);
  19                if (err)
  20                        return SK_DROP;
  21
  22                data_end = (void *)(long)skb->data_end;
  23                data = (void *)(long)skb->data;
  24                if (data + 10 > data_end)
  25                        return SK_DROP;
  26        }
  27
  28        /* This write/read is a bit pointless but tests the verifier and
  29         * strparser handler for read/write pkt data and access into sk
  30         * fields.
  31         */
  32        d = data;
  33        d[7] = 1;
  34        return skb->len;
  35}
  36
  37char _license[] SEC("license") = "GPL";
  38