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1// SPDX-License-Identifier: GPL-2.02#include <linux/bpf.h>3 4#include <bpf/bpf_helpers.h>5 6struct {7 __uint(type, BPF_MAP_TYPE_PROG_ARRAY);8 __uint(max_entries, 3);9 __uint(key_size, sizeof(__u32));10 __uint(value_size, sizeof(__u32));11} jmp_table SEC(".maps");12 13#define TAIL_FUNC(x) \14 SEC("tc") \15 int classifier_##x(struct __sk_buff *skb) \16 { \17 return x; \18 }19TAIL_FUNC(0)20TAIL_FUNC(1)21TAIL_FUNC(2)22 23SEC("tc")24int entry(struct __sk_buff *skb)25{26 /* Multiple locations to make sure we patch27 * all of them.28 */29 bpf_tail_call_static(skb, &jmp_table, 0);30 bpf_tail_call_static(skb, &jmp_table, 0);31 bpf_tail_call_static(skb, &jmp_table, 0);32 bpf_tail_call_static(skb, &jmp_table, 0);33 34 bpf_tail_call_static(skb, &jmp_table, 1);35 bpf_tail_call_static(skb, &jmp_table, 1);36 bpf_tail_call_static(skb, &jmp_table, 1);37 bpf_tail_call_static(skb, &jmp_table, 1);38 39 bpf_tail_call_static(skb, &jmp_table, 2);40 bpf_tail_call_static(skb, &jmp_table, 2);41 bpf_tail_call_static(skb, &jmp_table, 2);42 bpf_tail_call_static(skb, &jmp_table, 2);43 44 return 3;45}46 47char __license[] SEC("license") = "GPL";48