40 lines · c
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 13int selector = 0;14 15#define TAIL_FUNC(x) \16 SEC("tc") \17 int classifier_##x(struct __sk_buff *skb) \18 { \19 return x; \20 }21TAIL_FUNC(0)22TAIL_FUNC(1)23TAIL_FUNC(2)24 25SEC("tc")26int entry(struct __sk_buff *skb)27{28 int idx = 0;29 30 if (selector == 1234)31 idx = 1;32 else if (selector == 5678)33 idx = 2;34 35 bpf_tail_call(skb, &jmp_table, idx);36 return 3;37}38 39char __license[] SEC("license") = "GPL";40