1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/bpf.h> 3 #include <bpf/bpf_helpers.h> 4 #include "bpf_legacy.h" 5 6 struct { 7 __uint(type, BPF_MAP_TYPE_PROG_ARRAY); 8 __uint(max_entries, 1); 9 __uint(key_size, sizeof(__u32)); 10 __uint(value_size, sizeof(__u32)); 11 } jmp_table SEC(".maps"); 12 13 int count = 0; 14 15 static __noinline 16 int subprog_tail(struct __sk_buff *skb) 17 { 18 bpf_tail_call_static(skb, &jmp_table, 0); 19 return 0; 20 } 21 22 SEC("tc") 23 int entry(struct __sk_buff *skb) 24 { 25 int ret = 1; 26 27 count++; 28 subprog_tail(skb); 29 subprog_tail(skb); 30 31 return ret; 32 } 33 34 char __license[] SEC("license") = "GPL"; 35