tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2#include <linux/bpf.h>
3#include <linux/version.h>
4
5#include "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
13struct bpf_map_def SEC("maps") percpu_netcnt = {
14 .type = BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE,
15 .key_size = sizeof(struct bpf_cgroup_storage_key),
16 .value_size = sizeof(struct percpu_net_cnt),
17};
18
19BPF_ANNOTATE_KV_PAIR(percpu_netcnt, struct bpf_cgroup_storage_key,
20 struct percpu_net_cnt);
21
22struct bpf_map_def SEC("maps") netcnt = {
23 .type = BPF_MAP_TYPE_CGROUP_STORAGE,
24 .key_size = sizeof(struct bpf_cgroup_storage_key),
25 .value_size = sizeof(struct net_cnt),
26};
27
28BPF_ANNOTATE_KV_PAIR(netcnt, struct bpf_cgroup_storage_key,
29 struct net_cnt);
30
31SEC("cgroup/skb")
32int bpf_nextcnt(struct __sk_buff *skb)
33{
34 struct percpu_net_cnt *percpu_cnt;
35 char fmt[] = "%d %llu %llu\n";
36 struct net_cnt *cnt;
37 __u64 ts, dt;
38 int ret;
39
40 cnt = bpf_get_local_storage(&netcnt, 0);
41 percpu_cnt = bpf_get_local_storage(&percpu_netcnt, 0);
42
43 percpu_cnt->packets++;
44 percpu_cnt->bytes += skb->len;
45
46 if (percpu_cnt->packets > MAX_PERCPU_PACKETS) {
47 __sync_fetch_and_add(&cnt->packets,
48 percpu_cnt->packets);
49 percpu_cnt->packets = 0;
50
51 __sync_fetch_and_add(&cnt->bytes,
52 percpu_cnt->bytes);
53 percpu_cnt->bytes = 0;
54 }
55
56 ts = bpf_ktime_get_ns();
57 dt = ts - percpu_cnt->prev_ts;
58
59 dt *= MAX_BPS;
60 dt /= NS_PER_SEC;
61
62 if (cnt->bytes + percpu_cnt->bytes - percpu_cnt->prev_bytes < dt)
63 ret = 1;
64 else
65 ret = 0;
66
67 if (dt > REFRESH_TIME_NS) {
68 percpu_cnt->prev_ts = ts;
69 percpu_cnt->prev_packets = cnt->packets;
70 percpu_cnt->prev_bytes = cnt->bytes;
71 }
72
73 return !!ret;
74}
75
76char _license[] SEC("license") = "GPL";
77__u32 _version SEC("version") = LINUX_VERSION_CODE;