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, 5); 9 __uint(key_size, sizeof(__u32)); 10 __uint(value_size, sizeof(__u32)); 11 } jmp_table SEC(".maps"); 12 13 SEC("classifier/0") 14 int bpf_func_0(struct __sk_buff *skb) 15 { 16 bpf_tail_call(skb, &jmp_table, 1); 17 return 0; 18 } 19 20 SEC("classifier/1") 21 int bpf_func_1(struct __sk_buff *skb) 22 { 23 bpf_tail_call(skb, &jmp_table, 2); 24 return 1; 25 } 26 27 SEC("classifier/2") 28 int bpf_func_2(struct __sk_buff *skb) 29 { 30 return 2; 31 } 32 33 SEC("classifier/3") 34 int bpf_func_3(struct __sk_buff *skb) 35 { 36 bpf_tail_call(skb, &jmp_table, 4); 37 return 3; 38 } 39 40 SEC("classifier/4") 41 int bpf_func_4(struct __sk_buff *skb) 42 { 43 bpf_tail_call(skb, &jmp_table, 3); 44 return 4; 45 } 46 47 SEC("classifier") 48 int entry(struct __sk_buff *skb) 49 { 50 bpf_tail_call(skb, &jmp_table, 0); 51 /* Check multi-prog update. */ 52 bpf_tail_call(skb, &jmp_table, 2); 53 /* Check tail call limit. */ 54 bpf_tail_call(skb, &jmp_table, 3); 55 return 3; 56 } 57 58 char __license[] SEC("license") = "GPL"; 59 int _version SEC("version") = 1; 60