tools/testing/selftests/bpf/progs/sockmap_parse_prog.c

   1 #include <linux/bpf.h>
   2 #include <bpf/bpf_helpers.h>
   3 #include <bpf/bpf_endian.h>
   4
   5 int _version SEC("version") = 1;
   6
   7 SEC("sk_skb1")
   8 int 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
  37 char _license[] SEC("license") = "GPL";