// SPDX-License-Identifier: GPL-2.0
#include <linux/bpf.h>

#include <bpf/bpf_helpers.h>

struct {
        __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
        __uint(max_entries, 3);
        __uint(key_size, sizeof(__u32));
        __uint(value_size, sizeof(__u32));
} jmp_table SEC(".maps");

#define TAIL_FUNC(x)                            \
        SEC("tc")                               \
        int classifier_##x(struct __sk_buff *skb)       \
        {                                       \
                return x;                       \
        }
TAIL_FUNC(0)
TAIL_FUNC(1)
TAIL_FUNC(2)

SEC("tc")
int entry(struct __sk_buff *skb)
{
        /* Multiple locations to make sure we patch
         * all of them.
         */
        bpf_tail_call_static(skb, &jmp_table, 0);
        bpf_tail_call_static(skb, &jmp_table, 0);
        bpf_tail_call_static(skb, &jmp_table, 0);
        bpf_tail_call_static(skb, &jmp_table, 0);

        bpf_tail_call_static(skb, &jmp_table, 1);
        bpf_tail_call_static(skb, &jmp_table, 1);
        bpf_tail_call_static(skb, &jmp_table, 1);
        bpf_tail_call_static(skb, &jmp_table, 1);

        bpf_tail_call_static(skb, &jmp_table, 2);
        bpf_tail_call_static(skb, &jmp_table, 2);
        bpf_tail_call_static(skb, &jmp_table, 2);
        bpf_tail_call_static(skb, &jmp_table, 2);

        return 3;
}

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