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_helpers.h"
   6
   7 struct bpf_map_def SEC("maps") my_map = {
   8         .type = BPF_MAP_TYPE_ARRAY,
   9         .key_size = sizeof(u32),
  10         .value_size = sizeof(long),
  11         .max_entries = 256,
  12 };
  13
  14 SEC("socket1")
  15 int bpf_prog1(struct __sk_buff *skb)
  16 {
  17         int index = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
  18         long *value;
  19
  20         if (skb->pkt_type != PACKET_OUTGOING)
  21                 return 0;
  22
  23         value = bpf_map_lookup_elem(&my_map, &index);
  24         if (value)
  25                 __sync_fetch_and_add(value, skb->len);
  26
  27         return 0;
  28 }
  29 char _license[] SEC("license") = "GPL";