18c2ecf20Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0
28c2ecf20Sopenharmony_ci#include <linux/bpf.h>
38c2ecf20Sopenharmony_ci#include <bpf/bpf_helpers.h>
48c2ecf20Sopenharmony_ci
58c2ecf20Sopenharmony_cistruct {
68c2ecf20Sopenharmony_ci	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
78c2ecf20Sopenharmony_ci	__uint(max_entries, 2);
88c2ecf20Sopenharmony_ci	__uint(key_size, sizeof(__u32));
98c2ecf20Sopenharmony_ci	__uint(value_size, sizeof(__u32));
108c2ecf20Sopenharmony_ci} jmp_table SEC(".maps");
118c2ecf20Sopenharmony_ci
128c2ecf20Sopenharmony_ci#define TAIL_FUNC(x) 				\
138c2ecf20Sopenharmony_ci	SEC("classifier/" #x)			\
148c2ecf20Sopenharmony_ci	int bpf_func_##x(struct __sk_buff *skb)	\
158c2ecf20Sopenharmony_ci	{					\
168c2ecf20Sopenharmony_ci		return x;			\
178c2ecf20Sopenharmony_ci	}
188c2ecf20Sopenharmony_ciTAIL_FUNC(0)
198c2ecf20Sopenharmony_ciTAIL_FUNC(1)
208c2ecf20Sopenharmony_ci
218c2ecf20Sopenharmony_cistatic __noinline
228c2ecf20Sopenharmony_ciint subprog_tail(struct __sk_buff *skb)
238c2ecf20Sopenharmony_ci{
248c2ecf20Sopenharmony_ci	bpf_tail_call_static(skb, &jmp_table, 0);
258c2ecf20Sopenharmony_ci
268c2ecf20Sopenharmony_ci	return skb->len * 2;
278c2ecf20Sopenharmony_ci}
288c2ecf20Sopenharmony_ci
298c2ecf20Sopenharmony_ciSEC("classifier")
308c2ecf20Sopenharmony_ciint entry(struct __sk_buff *skb)
318c2ecf20Sopenharmony_ci{
328c2ecf20Sopenharmony_ci	bpf_tail_call_static(skb, &jmp_table, 1);
338c2ecf20Sopenharmony_ci
348c2ecf20Sopenharmony_ci	return subprog_tail(skb);
358c2ecf20Sopenharmony_ci}
368c2ecf20Sopenharmony_ci
378c2ecf20Sopenharmony_cichar __license[] SEC("license") = "GPL";
388c2ecf20Sopenharmony_ciint _version SEC("version") = 1;
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