1 #include <linux/bpf.h>
2 #include "bpf_helpers.h"
3 #include "bpf_util.h"
4 #include "bpf_endian.h"
5
6 int _version SEC("version") = 1;
7
8 #define bpf_printk(fmt, ...) \
9 ({ \
10 char ____fmt[] = fmt; \
11 bpf_trace_printk(____fmt, sizeof(____fmt), \
12 ##__VA_ARGS__); \
13 })
14
15 struct bpf_map_def SEC("maps") sock_map_rx = {
16 .type = BPF_MAP_TYPE_SOCKMAP,
17 .key_size = sizeof(int),
18 .value_size = sizeof(int),
19 .max_entries = 20,
20 };
21
22 struct bpf_map_def SEC("maps") sock_map_tx = {
23 .type = BPF_MAP_TYPE_SOCKMAP,
24 .key_size = sizeof(int),
25 .value_size = sizeof(int),
26 .max_entries = 20,
27 };
28
29 struct bpf_map_def SEC("maps") sock_map_msg = {
30 .type = BPF_MAP_TYPE_SOCKMAP,
31 .key_size = sizeof(int),
32 .value_size = sizeof(int),
33 .max_entries = 20,
34 };
35
36 struct bpf_map_def SEC("maps") sock_map_break = {
37 .type = BPF_MAP_TYPE_ARRAY,
38 .key_size = sizeof(int),
39 .value_size = sizeof(int),
40 .max_entries = 20,
41 };
42
43 SEC("sk_skb2")
bpf_prog2(struct __sk_buff * skb)44 int bpf_prog2(struct __sk_buff *skb)
45 {
46 void *data_end = (void *)(long) skb->data_end;
47 void *data = (void *)(long) skb->data;
48 __u32 lport = skb->local_port;
49 __u32 rport = skb->remote_port;
50 __u8 *d = data;
51 __u8 sk, map;
52
53 if (data + 8 > data_end)
54 return SK_DROP;
55
56 map = d[0];
57 sk = d[1];
58
59 d[0] = 0xd;
60 d[1] = 0xe;
61 d[2] = 0xa;
62 d[3] = 0xd;
63 d[4] = 0xb;
64 d[5] = 0xe;
65 d[6] = 0xe;
66 d[7] = 0xf;
67
68 if (!map)
69 return bpf_sk_redirect_map(skb, &sock_map_rx, sk, 0);
70 return bpf_sk_redirect_map(skb, &sock_map_tx, sk, 0);
71 }
72
73 char _license[] SEC("license") = "GPL";
74
