// SPDX-License-Identifier: GPL-2.0
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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struct {
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__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
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__uint(max_entries, 2);
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__uint(key_size, sizeof(__u32));
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__uint(value_size, sizeof(__u32));
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} jmp_table SEC(".maps");
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#define TAIL_FUNC(x) \
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SEC("classifier/" #x) \
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int bpf_func_##x(struct __sk_buff *skb) \
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{ \
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return x; \
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}
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TAIL_FUNC(0)
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TAIL_FUNC(1)
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static __noinline
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int subprog_tail(struct __sk_buff *skb)
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{
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bpf_tail_call_static(skb, &jmp_table, 0);
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return skb->len * 2;
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}
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SEC("classifier")
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int entry(struct __sk_buff *skb)
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{
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bpf_tail_call_static(skb, &jmp_table, 1);
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return subprog_tail(skb);
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}
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char __license[] SEC("license") = "GPL";
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int _version SEC("version") = 1;
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