1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/bpf.h> 3 4 #include <bpf/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 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 39 char __license[] SEC("license") = "GPL"; 40 int _version SEC("version") = 1; 41