This source file includes following definitions.
- SEC
1
2
3 #include <stddef.h>
4 #include <string.h>
5 #include <linux/bpf.h>
6 #include <linux/if_ether.h>
7 #include <linux/ip.h>
8 #include <linux/pkt_cls.h>
9 #include "bpf_helpers.h"
10
11 int _version SEC("version") = 1;
12
13 struct {
14 __uint(type, MAP_TYPE);
15 __uint(max_entries, 32);
16 __uint(map_flags, 0);
17 __uint(key_size, 0);
18 __uint(value_size, sizeof(__u32));
19 } map_in SEC(".maps");
20
21 struct {
22 __uint(type, MAP_TYPE);
23 __uint(max_entries, 32);
24 __uint(map_flags, 0);
25 __uint(key_size, 0);
26 __uint(value_size, sizeof(__u32));
27 } map_out SEC(".maps");
28
29 SEC("test")
30 int _test(struct __sk_buff *skb)
31 {
32 void *data_end = (void *)(long)skb->data_end;
33 void *data = (void *)(long)skb->data;
34 struct ethhdr *eth = (struct ethhdr *)(data);
35 __u32 value;
36 int err;
37
38 if (eth + 1 > data_end)
39 return TC_ACT_SHOT;
40
41 struct iphdr *iph = (struct iphdr *)(eth + 1);
42
43 if (iph + 1 > data_end)
44 return TC_ACT_SHOT;
45
46 err = bpf_map_pop_elem(&map_in, &value);
47 if (err)
48 return TC_ACT_SHOT;
49
50 iph->daddr = value;
51
52 err = bpf_map_push_elem(&map_out, &iph->saddr, 0);
53 if (err)
54 return TC_ACT_SHOT;
55
56 return TC_ACT_OK;
57 }
58
59 char _license[] SEC("license") = "GPL";