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| /* SPDX-License-Identifier: GPL-2.0 */
| // Copyright (c) 2018 Politecnico di Torino
| #include <stddef.h>
| #include <string.h>
| #include <linux/bpf.h>
| #include <linux/if_ether.h>
| #include <linux/ip.h>
| #include <linux/pkt_cls.h>
| #include <bpf/bpf_helpers.h>
|
| int _version SEC("version") = 1;
|
| struct {
| __uint(type, MAP_TYPE);
| __uint(max_entries, 32);
| __uint(map_flags, 0);
| __uint(key_size, 0);
| __uint(value_size, sizeof(__u32));
| } map_in SEC(".maps");
|
| struct {
| __uint(type, MAP_TYPE);
| __uint(max_entries, 32);
| __uint(map_flags, 0);
| __uint(key_size, 0);
| __uint(value_size, sizeof(__u32));
| } map_out SEC(".maps");
|
| SEC("test")
| int _test(struct __sk_buff *skb)
| {
| void *data_end = (void *)(long)skb->data_end;
| void *data = (void *)(long)skb->data;
| struct ethhdr *eth = (struct ethhdr *)(data);
| __u32 value;
| int err;
|
| if (eth + 1 > data_end)
| return TC_ACT_SHOT;
|
| struct iphdr *iph = (struct iphdr *)(eth + 1);
|
| if (iph + 1 > data_end)
| return TC_ACT_SHOT;
|
| err = bpf_map_pop_elem(&map_in, &value);
| if (err)
| return TC_ACT_SHOT;
|
| iph->daddr = value;
|
| err = bpf_map_push_elem(&map_out, &iph->saddr, 0);
| if (err)
| return TC_ACT_SHOT;
|
| return TC_ACT_OK;
| }
|
| char _license[] SEC("license") = "GPL";
|
|
