162306a36Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0
262306a36Sopenharmony_ci#include <linux/bpf.h>
362306a36Sopenharmony_ci#include <bpf/bpf_helpers.h>
462306a36Sopenharmony_ci
562306a36Sopenharmony_cistruct {
662306a36Sopenharmony_ci	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
762306a36Sopenharmony_ci	__uint(max_entries, 2);
862306a36Sopenharmony_ci	__uint(key_size, sizeof(__u32));
962306a36Sopenharmony_ci	__uint(value_size, sizeof(__u32));
1062306a36Sopenharmony_ci} jmp_table SEC(".maps");
1162306a36Sopenharmony_ci
1262306a36Sopenharmony_ci#define TAIL_FUNC(x) 				\
1362306a36Sopenharmony_ci	SEC("tc")				\
1462306a36Sopenharmony_ci	int classifier_##x(struct __sk_buff *skb)	\
1562306a36Sopenharmony_ci	{					\
1662306a36Sopenharmony_ci		return x;			\
1762306a36Sopenharmony_ci	}
1862306a36Sopenharmony_ciTAIL_FUNC(0)
1962306a36Sopenharmony_ciTAIL_FUNC(1)
2062306a36Sopenharmony_ci
2162306a36Sopenharmony_cistatic __noinline
2262306a36Sopenharmony_ciint subprog_tail(struct __sk_buff *skb)
2362306a36Sopenharmony_ci{
2462306a36Sopenharmony_ci	bpf_tail_call_static(skb, &jmp_table, 0);
2562306a36Sopenharmony_ci
2662306a36Sopenharmony_ci	return skb->len * 2;
2762306a36Sopenharmony_ci}
2862306a36Sopenharmony_ci
2962306a36Sopenharmony_ciSEC("tc")
3062306a36Sopenharmony_ciint entry(struct __sk_buff *skb)
3162306a36Sopenharmony_ci{
3262306a36Sopenharmony_ci	bpf_tail_call_static(skb, &jmp_table, 1);
3362306a36Sopenharmony_ci
3462306a36Sopenharmony_ci	return subprog_tail(skb);
3562306a36Sopenharmony_ci}
3662306a36Sopenharmony_ci
3762306a36Sopenharmony_cichar __license[] SEC("license") = "GPL";
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