samples/bpf/sockex1_kern.c

   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
   8 struct {
   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
  15 SEC("socket1")
  16 int 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 }
  30 char _license[] SEC("license") = "GPL";