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 13 struct { 14 __u32 type; 15 struct bpf_cgroup_storage_key *key; 16 struct percpu_net_cnt *value; 17 } percpu_netcnt SEC(".maps") = { 18 .type = BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE, 19 }; 20 21 struct { 22 __u32 type; 23 struct bpf_cgroup_storage_key *key; 24 struct net_cnt *value; 25 } netcnt SEC(".maps") = { 26 .type = BPF_MAP_TYPE_CGROUP_STORAGE, 27 }; 28 29 SEC("cgroup/skb") 30 int bpf_nextcnt(struct __sk_buff *skb) 31 { 32 struct percpu_net_cnt *percpu_cnt; 33 char fmt[] = "%d %llu %llu\n"; 34 struct net_cnt *cnt; 35 __u64 ts, dt; 36 int ret; 37 38 cnt = bpf_get_local_storage(&netcnt, 0); 39 percpu_cnt = bpf_get_local_storage(&percpu_netcnt, 0); 40 41 percpu_cnt->packets++; 42 percpu_cnt->bytes += skb->len; 43 44 if (percpu_cnt->packets > MAX_PERCPU_PACKETS) { 45 __sync_fetch_and_add(&cnt->packets, 46 percpu_cnt->packets); 47 percpu_cnt->packets = 0; 48 49 __sync_fetch_and_add(&cnt->bytes, 50 percpu_cnt->bytes); 51 percpu_cnt->bytes = 0; 52 } 53 54 ts = bpf_ktime_get_ns(); 55 dt = ts - percpu_cnt->prev_ts; 56 57 dt *= MAX_BPS; 58 dt /= NS_PER_SEC; 59 60 if (cnt->bytes + percpu_cnt->bytes - percpu_cnt->prev_bytes < dt) 61 ret = 1; 62 else 63 ret = 0; 64 65 if (dt > REFRESH_TIME_NS) { 66 percpu_cnt->prev_ts = ts; 67 percpu_cnt->prev_packets = cnt->packets; 68 percpu_cnt->prev_bytes = cnt->bytes; 69 } 70 71 return !!ret; 72 } 73 74 char _license[] SEC("license") = "GPL"; 75 __u32 _version SEC("version") = LINUX_VERSION_CODE; 76