LXR linux/samples/bpf/sockex1

   1#include <uapi/linux/bpf.h>
   2#include <uapi/linux/if_ether.h>
   3#include <uapi/linux/if_packet.h>
   4#include <uapi/linux/ip.h>
   5#include <bpf/bpf_helpers.h>
   6#include "bpf_legacy.h"
   7
   8struct {
   9        __uint(type, BPF_MAP_TYPE_ARRAY);
  10        __type(key, u32);
  11        __type(value, long);
  12        __uint(max_entries, 256);
  13} my_map SEC(".maps");
  14
  15SEC("socket1")
  16int bpf_prog1(struct __sk_buff *skb)
  17{
  18        int index = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
  19        long *value;
  20
  21        if (skb->pkt_type != PACKET_OUTGOING)
  22                return 0;
  23
  24        value = bpf_map_lookup_elem(&my_map, &index);
  25        if (value)
  26                __sync_fetch_and_add(value, skb->len);
  27
  28        return 0;
  29}
  30char _license[] SEC("license") = "GPL";
  31