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") 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