services/src/common_event_subscriber_manager.cpp

/*
 * Copyright (c) 2021-2022 Huawei Device Co., Ltd.
 * 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.
 */

#include <csignal>
#include <utility>
#include <vector>
#include <set>

#include "ability_manager_client.h"
#include "common_event_subscriber_manager.h"
#include "event_log_wrapper.h"
#include "event_report.h"
#include "hisysevent.h"
#include "hitrace_meter_adapter.h"
#include "subscriber_death_recipient.h"

namespace OHOS {
namespace EventFwk {
constexpr int32_t LENGTH = 80;
constexpr int32_t SIGNAL_KILL = 9;
static constexpr int32_t SUBSCRIBE_EVENT_MAX_NUM = 512;
static constexpr char CES_REGISTER_EXCEED_LIMIT[] = "Kill Reason: CES Register exceed limit";

CommonEventSubscriberManager::CommonEventSubscriberManager()
    : death_(sptr<IRemoteObject::DeathRecipient>(new (std::nothrow) SubscriberDeathRecipient()))
{
}

CommonEventSubscriberManager::~CommonEventSubscriberManager()
{
    EVENT_LOGI("~CommonEventSubscriberManager");
}

std::shared_ptr<EventSubscriberRecord> CommonEventSubscriberManager::InsertSubscriber(
    const SubscribeInfoPtr &eventSubscribeInfo, const sptr<IRemoteObject> &commonEventListener,
    const struct tm &recordTime, const EventRecordInfo &eventRecordInfo)
{
    HITRACE_METER_NAME(HITRACE_TAG_NOTIFICATION, __PRETTY_FUNCTION__);
    EVENT_LOGD("enter");

    if (eventSubscribeInfo == nullptr) {
        EVENT_LOGE("eventSubscribeInfo is null");
        return nullptr;
    }

    if (commonEventListener == nullptr) {
        EVENT_LOGE("commonEventListener is null");
        return nullptr;
    }

    std::vector<std::string> events = eventSubscribeInfo->GetMatchingSkills().GetEvents();
    if (events.size() == 0 || events.size() > SUBSCRIBE_EVENT_MAX_NUM) {
        EVENT_LOGE("subscribed events size is error");
        return nullptr;
    }

    auto record = std::make_shared<EventSubscriberRecord>();
    if (record == nullptr) {
        EVENT_LOGE("Failed to create EventSubscriberRecord");
        return nullptr;
    }

    record->eventSubscribeInfo = eventSubscribeInfo;
    record->commonEventListener = commonEventListener;
    record->recordTime = recordTime;
    record->eventRecordInfo = eventRecordInfo;

    if (death_ != nullptr) {
        commonEventListener->AddDeathRecipient(death_);
    }

    if (!InsertSubscriberRecordLocked(events, record)) {
        return nullptr;
    }

    return record;
}

int CommonEventSubscriberManager::RemoveSubscriber(const sptr<IRemoteObject> &commonEventListener)
{
    HITRACE_METER_NAME(HITRACE_TAG_NOTIFICATION, __PRETTY_FUNCTION__);
    EVENT_LOGD("enter");

    if (commonEventListener == nullptr) {
        EVENT_LOGE("commonEventListener is null");
        return ERR_INVALID_VALUE;
    }

    int res = RemoveSubscriberRecordLocked(commonEventListener);

    if (death_ != nullptr) {
        commonEventListener->RemoveDeathRecipient(death_);
    }
    return res;
}

std::vector<std::shared_ptr<EventSubscriberRecord>> CommonEventSubscriberManager::GetSubscriberRecords(
    const CommonEventRecord &eventRecord)
{
    EVENT_LOGD("enter");

    auto records = std::vector<SubscriberRecordPtr>();

    GetSubscriberRecordsByWantLocked(eventRecord, records);

    return records;
}

std::shared_ptr<EventSubscriberRecord> CommonEventSubscriberManager::GetSubscriberRecord(
    const sptr<IRemoteObject> &commonEventListener)
{
    std::lock_guard<std::mutex> lock(mutex_);

    for (auto it = subscribers_.begin(); it != subscribers_.end(); ++it) {
        if (commonEventListener == (*it)->commonEventListener) {
            return *it;
        }
    }

    return nullptr;
}

void CommonEventSubscriberManager::DumpDetailed(
    const std::string &title, const SubscriberRecordPtr &record, const std::string format, std::string &dumpInfo)
{
    if (record == nullptr || record->eventSubscribeInfo == nullptr) {
        EVENT_LOGE("record or eventSubscribeInfo is null");
        return;
    }
    char systime[LENGTH];
    strftime(systime, sizeof(char) * LENGTH, "%Y%m%d %I:%M %p", &record->recordTime);

    std::string recordTime = format + "Time: " + std::string(systime) + "\n";
    std::string pid = format + "PID: " + std::to_string(record->eventRecordInfo.pid) + "\n";
    std::string uid = format + "UID: " + std::to_string(record->eventRecordInfo.uid) + "\n";
    std::string bundleName = format + "BundleName: " + record->eventRecordInfo.bundleName + "\n";
    std::string priority = format + "Priority: " + std::to_string(record->eventSubscribeInfo->GetPriority()) + "\n";
    std::string userId;
    switch (record->eventSubscribeInfo->GetUserId()) {
        case UNDEFINED_USER:
            userId = "UNDEFINED_USER";
            break;
        case ALL_USER:
            userId = "ALL_USER";
            break;
        default:
            userId = std::to_string(record->eventSubscribeInfo->GetUserId());
            break;
    }
    userId = format + "USERID: " + userId + "\n";
    std::string permission = format + "Permission: " + record->eventSubscribeInfo->GetPermission() + "\n";
    std::string deviceId = format + "DevicedID: " + record->eventSubscribeInfo->GetDeviceId() + "\n";

    std::string events = format + "\tEvent: ";
    std::string separator;
    size_t countSize = record->eventSubscribeInfo->GetMatchingSkills().CountEvent();
    for (size_t eventNum = 0; eventNum < countSize; ++eventNum) {
        if (eventNum == 0) {
            separator = "";
        } else {
            separator = ", ";
        }
        events = events + separator + record->eventSubscribeInfo->GetMatchingSkills().GetEvent(eventNum);
    }
    events = events + "\n";

    std::string entities = format + "\tEntity: ";
    size_t entitySize = record->eventSubscribeInfo->GetMatchingSkills().CountEntities();
    for (size_t entityNum = 0; entityNum < entitySize; ++entityNum) {
        if (entityNum == 0) {
            separator = "";
        } else {
            separator = ", ";
        }
        entities = entities + separator + record->eventSubscribeInfo->GetMatchingSkills().GetEntity(entityNum);
    }
    entities = entities + "\n";

    std::string scheme = format + "\tScheme: ";
    size_t schemeSize = record->eventSubscribeInfo->GetMatchingSkills().CountSchemes();
    for (size_t schemeNum = 0; schemeNum < schemeSize; ++schemeNum) {
        if (schemeNum == 0) {
            separator = "";
        } else {
            separator = ", ";
        }
        scheme = scheme + separator + record->eventSubscribeInfo->GetMatchingSkills().GetScheme(schemeNum);
    }
    scheme = scheme + "\n";

    std::string matchingSkills = format + "MatchingSkills:\n" + events + entities + scheme;

    std::string isFreeze = record->isFreeze ? "true" : "false";
    isFreeze = format + "IsFreeze: " + isFreeze + "\n";

    std::string freezeTime;
    if (record->freezeTime == 0) {
        freezeTime = format + "FreezeTime:  -\n";
    } else {
        freezeTime = format + "FreezeTime: " + std::to_string(record->freezeTime) + "\n";
    }

    dumpInfo = title + recordTime + pid + uid + bundleName + priority + userId + permission + deviceId +
               matchingSkills + isFreeze + freezeTime;
}

void CommonEventSubscriberManager::DumpState(const std::string &event, const int32_t &userId,
    std::vector<std::string> &state)
{
    EVENT_LOGD("enter");

    std::vector<SubscriberRecordPtr> records;

    std::lock_guard<std::mutex> lock(mutex_);
    GetSubscriberRecordsByEvent(event, userId, records);

    if (records.size() == 0) {
        state.emplace_back("Subscribers:\tNo information");
        return;
    }

    size_t num = 0;
    for (auto record : records) {
        num++;
        std::string title = std::to_string(num);
        if (num == 1) {
            title = "Subscribers:\tTotal " + std::to_string(records.size()) + " subscribers\nNO " + title + "\n";
        } else {
            title = "NO " + title + "\n";
        }
        std::string dumpInfo;
        DumpDetailed(title, record, "\t", dumpInfo);
        state.emplace_back(dumpInfo);
    }
}

bool CommonEventSubscriberManager::InsertSubscriberRecordLocked(
    const std::vector<std::string> &events, const SubscriberRecordPtr &record)
{
    EVENT_LOGD("enter");

    if (events.size() == 0) {
        EVENT_LOGE("No subscribed events");
        return false;
    }

    if (record == nullptr) {
        EVENT_LOGE("record is null");
        return false;
    }

    std::lock_guard<std::mutex> lock(mutex_);

    pid_t pid = record->eventRecordInfo.pid;

    if (CheckSubscriberCountReachedMaxinum()) {
        std::vector<std::pair<pid_t, uint32_t>> vtSubscriberCounts = GetTopSubscriberCounts(1);
        pid_t killedPid = (*vtSubscriberCounts.begin()).first;
        if (pid == killedPid) {
            return false;
        }

        AAFwk::ExitReason reason = { AAFwk::REASON_RESOURCE_CONTROL, "Kill Reason: CES Register exceed limit"};
        AAFwk::AbilityManagerClient::GetInstance()->RecordProcessExitReason(killedPid, reason);

        if (kill(killedPid, SIGNAL_KILL) < 0) {
            EVENT_LOGE("kill pid=%{public}d which has the most subscribers failed", killedPid);
        } else {
            EVENT_LOGI("kill pid=%{public}d which has the most subscribers successfully", killedPid);
        }

        int result = HiSysEventWrite(HiviewDFX::HiSysEvent::Domain::FRAMEWORK, "PROCESS_KILL",
            HiviewDFX::HiSysEvent::EventType::FAULT, "PID", killedPid, "PROCESS_NAME",
            record->eventRecordInfo.bundleName, "MSG", CES_REGISTER_EXCEED_LIMIT);
        EVENT_LOGE("hisysevent write result=%{public}d, send event [FRAMEWORK,PROCESS_KILL], pid=%{public}d,"
            " bundleName=%{public}s, msg=%{public}s", result, killedPid, record->eventRecordInfo.bundleName.c_str(),
            CES_REGISTER_EXCEED_LIMIT);
    }

    for (auto event : events) {
        auto infoItem = eventSubscribers_.find(event);
        if (infoItem != eventSubscribers_.end()) {
            infoItem->second.insert(record);

            if (infoItem->second.size() > MAX_SUBSCRIBER_NUM_PER_EVENT && record->eventSubscribeInfo != nullptr) {
                SendSubscriberExceedMaximumHiSysEvent(record->eventSubscribeInfo->GetUserId(), event,
                    infoItem->second.size());
            }
        } else {
            std::multiset<SubscriberRecordPtr> EventSubscribersPtr;
            EventSubscribersPtr.insert(record);
            eventSubscribers_[event] = EventSubscribersPtr;
        }
    }

    subscribers_.emplace_back(record);
    subscriberCounts_[pid]++;

    return true;
}

int CommonEventSubscriberManager::RemoveSubscriberRecordLocked(const sptr<IRemoteObject> &commonEventListener)
{
    if (commonEventListener == nullptr) {
        EVENT_LOGE("commonEventListener is null");
        return ERR_INVALID_VALUE;
    }

    std::lock_guard<std::mutex> lock(mutex_);
    std::vector<std::string> events;

    for (auto it = subscribers_.begin(); it != subscribers_.end(); ++it) {
        if (commonEventListener == (*it)->commonEventListener) {
            RemoveFrozenEventsBySubscriber((*it));
            (*it)->commonEventListener = nullptr;
            events = (*it)->eventSubscribeInfo->GetMatchingSkills().GetEvents();
            EVENT_LOGI("Unsubscribe subscriberID: %{public}s", (*it)->eventRecordInfo.subId.c_str());
            subscribers_.erase(it);
            pid_t pid = (*it)->eventRecordInfo.pid;
            subscriberCounts_[pid] > 1 ? subscriberCounts_[pid]-- : subscriberCounts_.erase(pid);
            break;
        }
    }

    for (auto event : events) {
        for (auto it = eventSubscribers_[event].begin(); it != eventSubscribers_[event].end(); ++it) {
            if ((commonEventListener == (*it)->commonEventListener) || ((*it)->commonEventListener == nullptr)) {
                (*it)->commonEventListener = nullptr;
                eventSubscribers_[event].erase(it);
                break;
            }
        }
        if (eventSubscribers_[event].size() == 0) {
            eventSubscribers_.erase(event);
        }
    }

    return ERR_OK;
}

bool CommonEventSubscriberManager::CheckSubscriberByUserId(const int32_t &subscriberUserId, const bool &isSystemApp,
    const int32_t &userId)
{
    if (subscriberUserId == ALL_USER) {
        return true;
    }

    if (isSystemApp && (userId == UNDEFINED_USER || userId == ALL_USER)) {
        return true;
    }

    if (!isSystemApp && subscriberUserId == userId) {
        return true;
    }

    if (isSystemApp && (subscriberUserId == userId ||
        (subscriberUserId >= SUBSCRIBE_USER_SYSTEM_BEGIN && subscriberUserId <= SUBSCRIBE_USER_SYSTEM_END))) {
        return true;
    }

    return false;
}

void CommonEventSubscriberManager::GetSubscriberRecordsByWantLocked(const CommonEventRecord &eventRecord,
    std::vector<SubscriberRecordPtr> &records)
{
    std::lock_guard<std::mutex> lock(mutex_);

    if (eventSubscribers_.size() <= 0) {
        return;
    }

    auto recordsItem = eventSubscribers_.find(eventRecord.commonEventData->GetWant().GetAction());
    if (recordsItem == eventSubscribers_.end()) {
        return;
    }

    bool isSystemApp = (eventRecord.eventRecordInfo.isSystemApp || eventRecord.eventRecordInfo.isSubsystem) &&
        !eventRecord.eventRecordInfo.isProxy;

    auto bundleName = eventRecord.eventRecordInfo.bundleName;
    auto uid = eventRecord.eventRecordInfo.uid;

    for (auto it = (recordsItem->second).begin(); it != (recordsItem->second).end(); it++) {
        if ((*it)->eventSubscribeInfo == nullptr) {
            continue;
        }

        if (!(*it)->eventSubscribeInfo->GetMatchingSkills().Match(eventRecord.commonEventData->GetWant())) {
            continue;
        }

        if (!eventRecord.publishInfo->GetBundleName().empty() &&
            eventRecord.publishInfo->GetBundleName() != (*it)->eventRecordInfo.bundleName) {
            continue;
        }

        auto publisherBundleName = (*it)->eventSubscribeInfo->GetPublisherBundleName();
        if (!publisherBundleName.empty() && publisherBundleName != bundleName) {
            continue;
        }

        auto publisherUid = (*it)->eventSubscribeInfo->GetPublisherUid();
        if (publisherUid > 0 && uid > 0 && static_cast<uid_t>(publisherUid) != uid) {
            continue;
        }

        if (CheckSubscriberByUserId((*it)->eventSubscribeInfo->GetUserId(), isSystemApp, eventRecord.userId)) {
            records.emplace_back(*it);
        }
    }
}

void CommonEventSubscriberManager::GetSubscriberRecordsByEvent(
    const std::string &event, const int32_t &userId, std::vector<SubscriberRecordPtr> &records)
{
    if (event.empty() && userId == ALL_USER) {
        records = subscribers_;
    } else if (event.empty()) {
        for (auto recordPtr : subscribers_) {
            if (recordPtr->eventSubscribeInfo->GetUserId() == userId) {
                records.emplace_back(recordPtr);
            }
        }
    } else if (userId == ALL_USER) {
        auto infoItem = eventSubscribers_.find(event);
        if (infoItem != eventSubscribers_.end()) {
            for (auto recordPtr : infoItem->second) {
                records.emplace_back(recordPtr);
            }
        }
    } else {
        auto infoItem = eventSubscribers_.find(event);
        if (infoItem != eventSubscribers_.end()) {
            for (auto recordPtr : infoItem->second) {
                if (CheckSubscriberByUserId(recordPtr->eventSubscribeInfo->GetUserId(), true, userId)) {
                    records.emplace_back(recordPtr);
                }
            }
        }
    }
}

void CommonEventSubscriberManager::UpdateFreezeInfo(
    const uid_t &uid, const bool &freezeState, const int64_t &freezeTime)
{
    EVENT_LOGD("enter");

    std::lock_guard<std::mutex> lock(mutex_);
    for (auto recordPtr : subscribers_) {
        if (recordPtr->eventRecordInfo.uid == uid) {
            if (freezeState) {
                recordPtr->freezeTime = freezeTime;
            } else {
                recordPtr->freezeTime = 0;
            }
            recordPtr->isFreeze = freezeState;
            EVENT_LOGD("recordPtr->uid: %{public}d", recordPtr->eventRecordInfo.uid);
            EVENT_LOGD("recordPtr->isFreeze: %{public}d", recordPtr->isFreeze);
        }
    }
}

void CommonEventSubscriberManager::UpdateAllFreezeInfos(const bool &freezeState, const int64_t &freezeTime)
{
    EVENT_LOGD("enter");

    std::lock_guard<std::mutex> lock(mutex_);
    for (auto recordPtr : subscribers_) {
        if (freezeState) {
            recordPtr->freezeTime = freezeTime;
        } else {
            recordPtr->freezeTime = 0;
        }
        recordPtr->isFreeze = freezeState;
    }
    EVENT_LOGD("all subscribers update freeze state to %{public}d", freezeState);
}

void CommonEventSubscriberManager::InsertFrozenEvents(
    const SubscriberRecordPtr &subscriberRecord, const CommonEventRecord &eventRecord)
{
    EVENT_LOGD("enter");

    if (subscriberRecord == nullptr) {
        EVENT_LOGE("subscriberRecord is null");
        return;
    }

    auto record = std::make_shared<CommonEventRecord>(eventRecord);
    std::lock_guard<std::mutex> lock(mutex_);
    auto frozenRecordsItem = frozenEvents_.find(subscriberRecord->eventRecordInfo.uid);
    if (frozenRecordsItem != frozenEvents_.end()) {
        auto eventRecordsItem = frozenRecordsItem->second.find(*subscriberRecord);
        if (eventRecordsItem != frozenRecordsItem->second.end()) {
            eventRecordsItem->second.emplace_back(record);
            time_t backRecordTime = mktime(&eventRecordsItem->second.back()->recordTime);
            time_t frontRecordTime = mktime(&eventRecordsItem->second.front()->recordTime);
            time_t timeDiff = backRecordTime - frontRecordTime;
            if (timeDiff > FREEZE_EVENT_TIMEOUT) {
                eventRecordsItem->second.erase(eventRecordsItem->second.begin());
            }
        } else {
            std::vector<EventRecordPtr> EventRecords;
            EventRecords.emplace_back(record);
            frozenRecordsItem->second[*subscriberRecord] = EventRecords;
        }
    } else {
        std::map<EventSubscriberRecord, std::vector<EventRecordPtr>> frozenRecords;
        std::vector<EventRecordPtr> EventRecords;
        EventRecords.emplace_back(record);
        frozenRecords[*subscriberRecord] = EventRecords;
        frozenEvents_[subscriberRecord->eventRecordInfo.uid] = frozenRecords;
    }
}

std::map<EventSubscriberRecord, std::vector<EventRecordPtr>> CommonEventSubscriberManager::GetFrozenEvents(
    const uid_t &uid)
{
    EVENT_LOGD("enter");

    std::map<EventSubscriberRecord, std::vector<EventRecordPtr>> frozenEvents;
    std::lock_guard<std::mutex> lock(mutex_);
    auto infoItem = frozenEvents_.find(uid);
    if (infoItem != frozenEvents_.end()) {
        frozenEvents = infoItem->second;
    }

    RemoveFrozenEvents(uid);

    return frozenEvents;
}

std::map<uid_t, FrozenRecords> CommonEventSubscriberManager::GetAllFrozenEvents()
{
    EVENT_LOGD("enter");
    std::lock_guard<std::mutex> lock(mutex_);
    return std::move(frozenEvents_);
}

void CommonEventSubscriberManager::RemoveFrozenEvents(const uid_t &uid)
{
    EVENT_LOGD("enter");
    auto infoItem = frozenEvents_.find(uid);
    if (infoItem != frozenEvents_.end()) {
        frozenEvents_.erase(uid);
    }
}

void CommonEventSubscriberManager::RemoveFrozenEventsBySubscriber(const SubscriberRecordPtr &subscriberRecord)
{
    EVENT_LOGD("enter");

    auto frozenRecordsItem = frozenEvents_.find(subscriberRecord->eventRecordInfo.uid);
    if (frozenRecordsItem != frozenEvents_.end()) {
        auto eventRecordsItems = frozenRecordsItem->second.find(*subscriberRecord);
        if (eventRecordsItems != frozenRecordsItem->second.end()) {
            frozenRecordsItem->second.erase(*subscriberRecord);
        }
    }
}

void CommonEventSubscriberManager::SendSubscriberExceedMaximumHiSysEvent(int32_t userId, const std::string &eventName,
    uint32_t subscriberNum)
{
    EventInfo eventInfo;
    eventInfo.userId = userId;
    eventInfo.eventName = eventName;
    eventInfo.subscriberNum = subscriberNum;
    EventReport::SendHiSysEvent(SUBSCRIBER_EXCEED_MAXIMUM, eventInfo);
}

bool CommonEventSubscriberManager::CheckSubscriberCountReachedMaxinum()
{
    uint32_t subscriberCount = subscribers_.size();
    uint32_t maxSubscriberNum = GetUintParameter("hiviewdfx.ces.subscriber_limit",
        DEFAULT_MAX_SUBSCRIBER_NUM_ALL_APP);
    if (subscriberCount == (uint32_t)(maxSubscriberNum * WARNING_REPORT_PERCENTAGE)) {
        EVENT_LOGW("subscribers reaches the alarm threshold");
        PrintSubscriberCounts(GetTopSubscriberCounts());
        return false;
    }
    if (subscriberCount == maxSubscriberNum) {
        EVENT_LOGE("subscribers reaches the maxinum");
        PrintSubscriberCounts(GetTopSubscriberCounts());
        return true;
    }
    return false;
}

std::vector<std::pair<pid_t, uint32_t>> CommonEventSubscriberManager::GetTopSubscriberCounts(size_t topNum)
{
    topNum = subscriberCounts_.size() < topNum ? subscriberCounts_.size() : topNum;

    std::vector<std::pair<pid_t, uint32_t>> vtSubscriberCounts;
    std::set<pid_t> pidSet;
    for (size_t i = 0; i < topNum; i++) {
        std::pair<pid_t, uint32_t> curPair;
        for (auto it = subscriberCounts_.begin(); it != subscriberCounts_.end(); it++) {
            pid_t pid = it->first;
            uint32_t count = it->second;
            if (pidSet.find(pid) != pidSet.end()) {
                continue;
            }
            if (curPair.second < count) {
                curPair = std::make_pair(pid, count);
            }
        }
        pidSet.insert(curPair.first);
        vtSubscriberCounts.push_back(curPair);
    }

    return vtSubscriberCounts;
}

void CommonEventSubscriberManager::PrintSubscriberCounts(std::vector<std::pair<pid_t, uint32_t>> vtSubscriberCounts)
{
    EVENT_LOGI("Start to print top App by subscribers in descending order");
    int index = 1;
    for (auto vtIt = vtSubscriberCounts.begin(); vtIt != vtSubscriberCounts.end(); vtIt++) {
        EVENT_LOGI("top%{public}d pid=%{public}d subscribers=%{public}d", index, vtIt->first, vtIt->second);
        index++;
    }
}
}  // namespace EventFwk
}  // namespace OHOS