xref: /linux/tools/testing/selftests/bpf/progs/netcnt_prog.c (revision 1ac731c529cd4d6adbce134754b51ff7d822b145)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/bpf.h>
3 #include <linux/version.h>
4 
5 #include <bpf/bpf_helpers.h>
6 #include "netcnt_common.h"
7 
8 #define MAX_BPS	(3 * 1024 * 1024)
9 
10 #define REFRESH_TIME_NS	100000000
11 #define NS_PER_SEC	1000000000
12 
13 struct {
14 	__uint(type, BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE);
15 	__type(key, struct bpf_cgroup_storage_key);
16 	__type(value, union percpu_net_cnt);
17 } percpu_netcnt SEC(".maps");
18 
19 struct {
20 	__uint(type, BPF_MAP_TYPE_CGROUP_STORAGE);
21 	__type(key, struct bpf_cgroup_storage_key);
22 	__type(value, union net_cnt);
23 } netcnt SEC(".maps");
24 
25 SEC("cgroup/skb")
bpf_nextcnt(struct __sk_buff * skb)26 int bpf_nextcnt(struct __sk_buff *skb)
27 {
28 	union percpu_net_cnt *percpu_cnt;
29 	union net_cnt *cnt;
30 	__u64 ts, dt;
31 	int ret;
32 
33 	cnt = bpf_get_local_storage(&netcnt, 0);
34 	percpu_cnt = bpf_get_local_storage(&percpu_netcnt, 0);
35 
36 	percpu_cnt->packets++;
37 	percpu_cnt->bytes += skb->len;
38 
39 	if (percpu_cnt->packets > MAX_PERCPU_PACKETS) {
40 		__sync_fetch_and_add(&cnt->packets,
41 				     percpu_cnt->packets);
42 		percpu_cnt->packets = 0;
43 
44 		__sync_fetch_and_add(&cnt->bytes,
45 				     percpu_cnt->bytes);
46 		percpu_cnt->bytes = 0;
47 	}
48 
49 	ts = bpf_ktime_get_ns();
50 	dt = ts - percpu_cnt->prev_ts;
51 
52 	dt *= MAX_BPS;
53 	dt /= NS_PER_SEC;
54 
55 	if (cnt->bytes + percpu_cnt->bytes - percpu_cnt->prev_bytes < dt)
56 		ret = 1;
57 	else
58 		ret = 0;
59 
60 	if (dt > REFRESH_TIME_NS) {
61 		percpu_cnt->prev_ts = ts;
62 		percpu_cnt->prev_packets = cnt->packets;
63 		percpu_cnt->prev_bytes = cnt->bytes;
64 	}
65 
66 	return !!ret;
67 }
68 
69 char _license[] SEC("license") = "GPL";
70