text: #include <uapi/linux/bpf.h>
  #include "bpf_helpers.h"
  
  SEC("sk_skb/simple-eq-linux")
  int prog_simple_eq_linux(struct __sk_buff *skb)
  {
  	char *data = (char *)(long)skb->data;
  	char *data_end = (char *)(long)skb->data_end;
  	if (data == data_end) return 1;
  	data[0] = (char)0xF;
  	return 0;
  }
  
  char _license[] SEC("license") = "GPL";
  u32 _version SEC("version") = 0x041800;
  