#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
#include "bpf_misc.h"

struct {
        __uint(type, BPF_MAP_TYPE_SOCKMAP);
        __uint(max_entries, 20);
        __type(key, int);
        __type(value, int);
} sock_map_rx SEC(".maps");

struct {
        __uint(type, BPF_MAP_TYPE_SOCKMAP);
        __uint(max_entries, 20);
        __type(key, int);
        __type(value, int);
} sock_map_tx SEC(".maps");

struct {
        __uint(type, BPF_MAP_TYPE_SOCKMAP);
        __uint(max_entries, 20);
        __type(key, int);
        __type(value, int);
} sock_map_msg SEC(".maps");

struct {
        __uint(type, BPF_MAP_TYPE_ARRAY);
        __uint(max_entries, 20);
        __type(key, int);
        __type(value, int);
} sock_map_break SEC(".maps");

SEC("sk_skb2")
int bpf_prog2(struct __sk_buff *skb)
{
        void *data_end = (void *)(long) skb->data_end;
        void *data = (void *)(long) skb->data;
        __u32 lport = skb->local_port;
        __u32 rport = skb->remote_port;
        __u8 *d = data;
        __u8 sk, map;

        __sink(lport);
        __sink(rport);

        if (data + 8 > data_end)
                return SK_DROP;

        map = d[0];
        sk = d[1];

        d[0] = 0xd;
        d[1] = 0xe;
        d[2] = 0xa;
        d[3] = 0xd;
        d[4] = 0xb;
        d[5] = 0xe;
        d[6] = 0xe;
        d[7] = 0xf;

        if (!map)
                return bpf_sk_redirect_map(skb, &sock_map_rx, sk, 0);
        return bpf_sk_redirect_map(skb, &sock_map_tx, sk, 0);
}

char _license[] SEC("license") = "GPL";