1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/bpf.h> 3 4 #include "bpf_helpers.h" 5 6 struct { 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 static volatile int selector; 14 15 #define TAIL_FUNC(x) \ 16 SEC("classifier/" #x) \ 17 int bpf_func_##x(struct __sk_buff *skb) \ 18 { \ 19 return x; \ 20 } 21 TAIL_FUNC(0) 22 TAIL_FUNC(1) 23 TAIL_FUNC(2) 24 25 SEC("classifier") 26 int entry(struct __sk_buff *skb) 27 { 28 bpf_tail_call(skb, &jmp_table, selector); 29 return 3; 30 } 31 32 char __license[] SEC("license") = "GPL"; 33 int _version SEC("version") = 1; 34