/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef _BPF_NETWORKSTATS_H
#define _BPF_NETWORKSTATS_H

#include <bpf/BpfMap.h>
#include "netd.h"

namespace android {
namespace bpf {

// TODO: set this to a proper value based on the map size;
constexpr int TAG_STATS_MAP_SOFT_LIMIT = 3;
constexpr int UID_ALL = -1;
//constexpr int TAG_ALL = -1;
constexpr int TAG_NONE = 0;
constexpr int SET_ALL = -1;
constexpr int SET_DEFAULT = 0;
constexpr int SET_FOREGROUND = 1;

// The limit for stats received by a unknown interface;
constexpr const int64_t MAX_UNKNOWN_IFACE_BYTES = 100 * 1000;

// This is used by
// frameworks/base/core/jni/com_android_internal_net_NetworkStatsFactory.cpp
// make sure it is consistent with the JNI code before changing this.
struct stats_line {
    char iface[32];
    uint32_t uid;
    uint32_t set;
    uint32_t tag;
    int64_t rxBytes;
    int64_t rxPackets;
    int64_t txBytes;
    int64_t txPackets;

    stats_line& operator=(const stats_line& rhs);
    stats_line& operator+=(const stats_line& rhs);
};

bool operator==(const stats_line& lhs, const stats_line& rhs);
bool operator<(const stats_line& lhs, const stats_line& rhs);

// This mirrors BpfMap.h's:
//   Result<Value> readValue(const Key key) const
// for a BpfMap<uint32_t, IfaceValue>
using IfIndexToNameFunc = std::function<Result<IfaceValue>(const uint32_t)>;

// For test only
int bpfGetUidStatsInternal(uid_t uid, StatsValue* stats,
                           const BpfMapRO<uint32_t, StatsValue>& appUidStatsMap);
// For test only
int bpfGetIfaceStatsInternal(const char* iface, StatsValue* stats,
                             const BpfMapRO<uint32_t, StatsValue>& ifaceStatsMap,
                             const IfIndexToNameFunc ifindex2name);
// For test only
int bpfGetIfIndexStatsInternal(uint32_t ifindex, StatsValue* stats,
                               const BpfMapRO<uint32_t, StatsValue>& ifaceStatsMap);
// For test only
int parseBpfNetworkStatsDetailInternal(std::vector<stats_line>& lines,
                                       const BpfMapRO<StatsKey, StatsValue>& statsMap,
                                       const IfIndexToNameFunc ifindex2name);
// For test only
int cleanStatsMapInternal(const base::unique_fd& cookieTagMap, const base::unique_fd& tagStatsMap);

template <class Key>
void maybeLogUnknownIface(int ifaceIndex, const BpfMapRO<Key, StatsValue>& statsMap,
                          const Key& curKey, int64_t* unknownIfaceBytesTotal) {
    // Have we already logged an error?
    if (*unknownIfaceBytesTotal == -1) {
        return;
    }

    // Are we undercounting enough data to be worth logging?
    auto statsEntry = statsMap.readValue(curKey);
    if (!statsEntry.ok()) {
        // No data is being undercounted.
        return;
    }

    *unknownIfaceBytesTotal += (statsEntry.value().rxBytes + statsEntry.value().txBytes);
    if (*unknownIfaceBytesTotal >= MAX_UNKNOWN_IFACE_BYTES) {
        ALOGE("Unknown name for ifindex %d with more than %" PRId64 " bytes of traffic", ifaceIndex,
              *unknownIfaceBytesTotal);
        *unknownIfaceBytesTotal = -1;
    }
}

// For test only
int parseBpfNetworkStatsDevInternal(std::vector<stats_line>& lines,
                                    const BpfMapRO<uint32_t, StatsValue>& statsMap,
                                    const IfIndexToNameFunc ifindex2name);

void bpfRegisterIface(const char* iface);
int bpfGetUidStats(uid_t uid, StatsValue* stats);
int bpfGetIfaceStats(const char* iface, StatsValue* stats);
int bpfGetIfIndexStats(int ifindex, StatsValue* stats);
int parseBpfNetworkStatsDetail(std::vector<stats_line>* lines);

int parseBpfNetworkStatsDev(std::vector<stats_line>* lines);
void groupNetworkStats(std::vector<stats_line>& lines);
int cleanStatsMap();
}  // namespace bpf
}  // namespace android

#endif  // _BPF_NETWORKSTATS_H