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33b57e0cc7
Current max cgroup storage value size is 4k (PAGE_SIZE). The other local storages accept up to 64k (BPF_LOCAL_STORAGE_MAX_VALUE_SIZE). Let's align max cgroup value size with the other storages. For percpu, the max is 32k (PCPU_MIN_UNIT_SIZE) because percpu allocator is not happy about larger values. netcnt test is extended to exercise those maximum values (non-percpu max size is close to, but not real max). v4: * remove inner union (Andrii Nakryiko) * keep net_cnt on the stack (Andrii Nakryiko) v3: * refine SIZEOF_BPF_LOCAL_STORAGE_ELEM comment (Yonghong Song) * anonymous struct in percpu_net_cnt & net_cnt (Yonghong Song) * reorder free (Yonghong Song) v2: * cap max_value_size instead of BUILD_BUG_ON (Martin KaFai Lau) Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20210727222335.4029096-1-sdf@google.com
71 lines
1.5 KiB
C
71 lines
1.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/bpf.h>
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#include <linux/version.h>
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#include <bpf/bpf_helpers.h>
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#include "netcnt_common.h"
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#define MAX_BPS (3 * 1024 * 1024)
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#define REFRESH_TIME_NS 100000000
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#define NS_PER_SEC 1000000000
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struct {
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__uint(type, BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE);
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__type(key, struct bpf_cgroup_storage_key);
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__type(value, union percpu_net_cnt);
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} percpu_netcnt SEC(".maps");
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struct {
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__uint(type, BPF_MAP_TYPE_CGROUP_STORAGE);
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__type(key, struct bpf_cgroup_storage_key);
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__type(value, union net_cnt);
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} netcnt SEC(".maps");
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SEC("cgroup/skb")
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int bpf_nextcnt(struct __sk_buff *skb)
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{
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union percpu_net_cnt *percpu_cnt;
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char fmt[] = "%d %llu %llu\n";
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union net_cnt *cnt;
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__u64 ts, dt;
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int ret;
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cnt = bpf_get_local_storage(&netcnt, 0);
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percpu_cnt = bpf_get_local_storage(&percpu_netcnt, 0);
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percpu_cnt->packets++;
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percpu_cnt->bytes += skb->len;
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if (percpu_cnt->packets > MAX_PERCPU_PACKETS) {
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__sync_fetch_and_add(&cnt->packets,
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percpu_cnt->packets);
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percpu_cnt->packets = 0;
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__sync_fetch_and_add(&cnt->bytes,
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percpu_cnt->bytes);
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percpu_cnt->bytes = 0;
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}
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ts = bpf_ktime_get_ns();
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dt = ts - percpu_cnt->prev_ts;
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dt *= MAX_BPS;
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dt /= NS_PER_SEC;
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if (cnt->bytes + percpu_cnt->bytes - percpu_cnt->prev_bytes < dt)
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ret = 1;
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else
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ret = 0;
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if (dt > REFRESH_TIME_NS) {
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percpu_cnt->prev_ts = ts;
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percpu_cnt->prev_packets = cnt->packets;
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percpu_cnt->prev_bytes = cnt->bytes;
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}
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return !!ret;
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}
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char _license[] SEC("license") = "GPL";
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__u32 _version SEC("version") = LINUX_VERSION_CODE;
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