31 lines · 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 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