前往小程序,Get更优阅读体验!
立即前往
首页
学习
活动
专区
工具
TVP
发布
社区首页 >专栏 >Android9.0Wifi热点开启流程梳理

Android9.0Wifi热点开启流程梳理

作者头像
用户7557625
发布2020-07-15 11:14:45
发布2020-07-15 11:14:45
4.4K0
举报
文章被收录于专栏:程序猿的那点事

Android9.0中对热点做了较大改动,将热点很大程度从Wifi中剥离出来了。 下面我们看一下热点是怎么开启的。

首先是在WifiTetherSettings中,调用startTether()函数,可以看到startTether函数中主要是调用了WifiTetherSwitchBarController.java中的startTether()函数。 源码路径: http://androidxref.com/9.0.0_r3/xref/packages/apps/Settings/src/com/android/settings/wifi/tether/WifiTetherSettings.java#174

代码语言:javascript
复制
    private void startTether() {
          mRestartWifiApAfterConfigChange = false;
          mSwitchBarController.startTether();
    }

然后我们看WifiTetherSwitchBarController里的startTether函数,WifiTetherSwitchBarController是用来控制开关栏切换的,可以看到他调用了ConnectivityManager的startTethering函数。 源码路径: http://androidxref.com/9.0.0_r3/xref/packages/apps/Settings/src/com/android/settings/wifi/tether/WifiTetherSwitchBarController.java#107

代码语言:javascript
复制
    void startTether() {
        mSwitchBar.setEnabled(false);
        mConnectivityManager.startTethering(TETHERING_WIFI, true /* showProvisioningUi */,
                mOnStartTetheringCallback, new Handler(Looper.getMainLooper()));
    }

然后在这里调用了ConnectivityService的startTethering函数。 源码路径: http://androidxref.com/9.0.0_r3/xref/frameworks/base/core/java/android/net/ConnectivityManager.java#2261

代码语言:javascript
复制
    public void startTethering(int type, boolean showProvisioningUi,
            final OnStartTetheringCallback callback, Handler handler) {
        try {
            String pkgName = mContext.getOpPackageName();
            Log.i(TAG, "startTethering caller:" + pkgName);
            mService.startTethering(type, wrappedCallback, showProvisioningUi, pkgName);
        } catch (RemoteException e) {
            Log.e(TAG, "Exception trying to start tethering.", e);
            wrappedCallback.send(TETHER_ERROR_SERVICE_UNAVAIL, null);
        }
    }

在ConnectivityService中,会跳到Tethering.java的startTethering函数。 源码路径: http://androidxref.com/9.0.0_r3/xref/frameworks/base/services/core/java/com/android/server/ConnectivityService.java#3232

代码语言:javascript
复制
    public void startTethering(int type, ResultReceiver receiver, boolean showProvisioningUi,
            String callerPkg) {
        ConnectivityManager.enforceTetherChangePermission(mContext, callerPkg);
        if (!isTetheringSupported()) {
            receiver.send(ConnectivityManager.TETHER_ERROR_UNSUPPORTED, null);
            return;
        }
        mTethering.startTethering(type, receiver, showProvisioningUi);
    }

在Tethering.java中,函数的调用顺序如下:startTethering—>enableTetheringInternal—>setWifiTethering。在setWifiTethering中,调用了WifiManager的startSoftAp函数。 源码路径: http://androidxref.com/9.0.0_r3/xref/frameworks/base/services/core/java/com/android/server/connectivity/Tethering.java#368

代码语言:javascript
复制
368    public void startTethering(int type, ResultReceiver receiver, boolean showProvisioningUi) {
        if (!isTetherProvisioningRequired()) {
            enableTetheringInternal(type, true, receiver);
            return;
        }

        if (showProvisioningUi) {
            runUiTetherProvisioningAndEnable(type, receiver);
        } else {
            runSilentTetherProvisioningAndEnable(type, receiver);
        }
    }
代码语言:javascript
复制
    private void enableTetheringInternal(int type, boolean enable, ResultReceiver receiver) {
        boolean isProvisioningRequired = enable && isTetherProvisioningRequired();
        int result;
        switch (type) {
            case TETHERING_WIFI:
                result = setWifiTethering(enable);
                if (isProvisioningRequired && result == TETHER_ERROR_NO_ERROR) {
                    scheduleProvisioningRechecks(type);
                }
                sendTetherResult(receiver, result);
                break;
代码语言:javascript
复制
    private int setWifiTethering(final boolean enable) {
        int rval = TETHER_ERROR_MASTER_ERROR;
        final long ident = Binder.clearCallingIdentity();
        try {
            synchronized (mPublicSync) {
                mWifiTetherRequested = enable;
                final WifiManager mgr = getWifiManager();
                if ((enable && mgr.startSoftAp(null /* use existing wifi config */)) ||
                    (!enable && mgr.stopSoftAp())) {
                    rval = TETHER_ERROR_NO_ERROR;
                }
            }
        } finally {
            Binder.restoreCallingIdentity(ident);
        }
        return rval;
    }

在这里调用了WifiServiceImpl.java的startSoftAp函数。 源码路径: http://androidxref.com/9.0.0_r3/xref/frameworks/base/wifi/java/android/net/wifi/WifiManager.java#1909

代码语言:javascript
复制
    public boolean startSoftAp(@Nullable WifiConfiguration wifiConfig) {
        try {
            return mService.startSoftAp(wifiConfig);
        } catch (RemoteException e) {
            throw e.rethrowFromSystemServer();
        }
    }

在这里调用了startSoftApInternal函数,然后向WifiController的状态机发送了CMD_SET_AP消息。 源码路径: http://androidxref.com/9.0.0_r3/xref/frameworks/opt/net/wifi/service/java/com/android/server/wifi/WifiServiceImpl.java#1004

代码语言:javascript
复制
    public boolean startSoftAp(WifiConfiguration wifiConfig) {
        // NETWORK_STACK is a signature only permission.
        enforceNetworkStackPermission();

        mLog.info("startSoftAp uid=%").c(Binder.getCallingUid()).flush();

        synchronized (mLocalOnlyHotspotRequests) {
            // If a tethering request comes in while we have LOHS running (or requested), call stop
            // for softap mode and restart softap with the tethering config.
            if (!mLocalOnlyHotspotRequests.isEmpty()) {
                stopSoftApInternal();
            }
            return startSoftApInternal(wifiConfig, WifiManager.IFACE_IP_MODE_TETHERED);
        }
    }
代码语言:javascript
复制
    private boolean startSoftApInternal(WifiConfiguration wifiConfig, int mode) {
        mLog.trace("startSoftApInternal uid=% mode=%")
                .c(Binder.getCallingUid()).c(mode).flush();

        // null wifiConfig is a meaningful input for CMD_SET_AP
        if (wifiConfig == null || WifiApConfigStore.validateApWifiConfiguration(wifiConfig)) {
            SoftApModeConfiguration softApConfig = new SoftApModeConfiguration(mode, wifiConfig);
            mWifiController.sendMessage(CMD_SET_AP, 1, 0, softApConfig);
            return true;
        }
        Slog.e(TAG, "Invalid WifiConfiguration");
        return false;
    }

在这里,处理结果是调用WifiStateMachinePrime的enterSoftAPMode方法。 源码路径: http://androidxref.com/9.0.0_r3/xref/frameworks/opt/net/wifi/service/java/com/android/server/wifi/WifiController.java#593

代码语言:javascript
复制
    class DefaultState extends State {
                case CMD_SET_AP:
                    // note: CMD_SET_AP is handled/dropped in ECM mode - will not start here

                    // first make sure we aren't in airplane mode
                    if (mSettingsStore.isAirplaneModeOn()) {
                        log("drop softap requests when in airplane mode");
                        break;
                    }
                    if (msg.arg1 == 1) {
                        SoftApModeConfiguration config = (SoftApModeConfiguration) msg.obj;
                       mWifiStateMachinePrime.enterSoftAPMode((SoftApModeConfiguration) msg.obj);
                    } else {
                        mWifiStateMachinePrime.stopSoftAPMode();
                    }
                    break;

在WifiStateMachinePrime中,创建了SoftApManager对象,并且调用了start方法。 源码路径: http://androidxref.com/9.0.0_r3/xref/frameworks/opt/net/wifi/service/java/com/android/server/wifi/WifiStateMachinePrime.java#549

代码语言:javascript
复制
    public void enterSoftAPMode(@NonNull SoftApModeConfiguration wifiConfig) {
        mHandler.post(() -> {
            startSoftAp(wifiConfig);
        });
    }
代码语言:javascript
复制
    private void startSoftAp(SoftApModeConfiguration softapConfig) {
        Log.d(TAG, "Starting SoftApModeManager");

        WifiConfiguration config = softapConfig.getWifiConfiguration();
        if (config != null && config.SSID != null) {
            Log.d(TAG, "Passing config to SoftApManager! " + config);
        } else {
            config = null;
        }

        SoftApCallbackImpl callback = new SoftApCallbackImpl();
        ActiveModeManager manager = mWifiInjector.makeSoftApManager(callback, softapConfig);
        callback.setActiveModeManager(manager);
        manager.start();
        mActiveModeManagers.add(manager);
        updateBatteryStatsWifiState(true);
    }

在这里,StateMachine发送了消息CMD_START,然后由IdleState 处理,这里主要的处理结果就是调用startSoftAp方法。在startSoftAp里,调用了WifiNative.java的startSoftAp方法。 源码路径: http://androidxref.com/9.0.0_r3/xref/frameworks/opt/net/wifi/service/java/com/android/server/wifi/SoftApManager.java#142

代码语言:javascript
复制
    public void start() {
        mStateMachine.sendMessage(SoftApStateMachine.CMD_START, mApConfig);
    }
代码语言:javascript
复制
        private class IdleState extends State {
            public boolean processMessage(Message message) {
                switch (message.what) {
                    case CMD_START:
                        mApInterfaceName = mWifiNative.setupInterfaceForSoftApMode(
                                mWifiNativeInterfaceCallback);
                        if (TextUtils.isEmpty(mApInterfaceName)) {
                            Log.e(TAG, "setup failure when creating ap interface.");
                            updateApState(WifiManager.WIFI_AP_STATE_FAILED,
                                    WifiManager.WIFI_AP_STATE_DISABLED,
                                    WifiManager.SAP_START_FAILURE_GENERAL);
                            mWifiMetrics.incrementSoftApStartResult(
                                    false, WifiManager.SAP_START_FAILURE_GENERAL);
                            break;
                        }
                        updateApState(WifiManager.WIFI_AP_STATE_ENABLING,
                                WifiManager.WIFI_AP_STATE_DISABLED, 0);
                        int result = startSoftAp((WifiConfiguration) message.obj);
                        if (result != SUCCESS) {
                            int failureReason = WifiManager.SAP_START_FAILURE_GENERAL;
                            if (result == ERROR_NO_CHANNEL) {
                                failureReason = WifiManager.SAP_START_FAILURE_NO_CHANNEL;
                            }
                            updateApState(WifiManager.WIFI_AP_STATE_FAILED,
                                          WifiManager.WIFI_AP_STATE_ENABLING,
                                          failureReason);
                            stopSoftAp();
                            mWifiMetrics.incrementSoftApStartResult(false, failureReason);
                            break;
                        }
                        transitionTo(mStartedState);
                        break;
代码语言:javascript
复制
    private int startSoftAp(WifiConfiguration config) {
        if (config == null || config.SSID == null) {
            Log.e(TAG, "Unable to start soft AP without valid configuration");
            return ERROR_GENERIC;
        }

        // Make a copy of configuration for updating AP band and channel.
        WifiConfiguration localConfig = new WifiConfiguration(config);

        int result = ApConfigUtil.updateApChannelConfig(
                mWifiNative, mCountryCode,
                mWifiApConfigStore.getAllowed2GChannel(), localConfig);

        if (result != SUCCESS) {
            Log.e(TAG, "Failed to update AP band and channel");
            return result;
        }

        // Setup country code if it is provided.
        if (mCountryCode != null) {
            // Country code is mandatory for 5GHz band, return an error if failed to set
            // country code when AP is configured for 5GHz band.
            if (!mWifiNative.setCountryCodeHal(
                    mApInterfaceName, mCountryCode.toUpperCase(Locale.ROOT))
                    && config.apBand == WifiConfiguration.AP_BAND_5GHZ) {
                Log.e(TAG, "Failed to set country code, required for setting up "
                        + "soft ap in 5GHz");
                return ERROR_GENERIC;
            }
        }
        if (localConfig.hiddenSSID) {
            Log.d(TAG, "SoftAP is a hidden network");
        }
        if (!mWifiNative.startSoftAp(mApInterfaceName, localConfig, mSoftApListener)) {
            Log.e(TAG, "Soft AP start failed");
            return ERROR_GENERIC;
        }
        Log.d(TAG, "Soft AP is started");

        return SUCCESS;
    }

在这里,主要是调用WificondControl.java的startHostapd方法。 源码路径: http://androidxref.com/9.0.0_r3/xref/frameworks/opt/net/wifi/service/java/com/android/server/wifi/WifiNative.java#1250

代码语言:javascript
复制
    public boolean startSoftAp(
            @NonNull String ifaceName, WifiConfiguration config, SoftApListener listener) {
        if (!mWificondControl.startHostapd(ifaceName, listener)) {
            Log.e(TAG, "Failed to start hostapd");
            mWifiMetrics.incrementNumSetupSoftApInterfaceFailureDueToHostapd();
            return false;
        }
        if (!waitForHostapdConnection()) {
            Log.e(TAG, "Failed to establish connection to hostapd");
            mWifiMetrics.incrementNumSetupSoftApInterfaceFailureDueToHostapd();
            return false;
        }
        if (!mHostapdHal.registerDeathHandler(new HostapdDeathHandlerInternal())) {
            Log.e(TAG, "Failed to register hostapd death handler");
            mWifiMetrics.incrementNumSetupSoftApInterfaceFailureDueToHostapd();
            return false;
        }
        if (!mHostapdHal.addAccessPoint(ifaceName, config)) {
            Log.e(TAG, "Failed to add acccess point");
            mWifiMetrics.incrementNumSetupSoftApInterfaceFailureDueToHostapd();
            return false;
        }
        return true;
    }

在这里可以看到创建了IApInterface 对象,然后调用了他的startHostapd方法。而IApInterface 是由ap_interface_impl.cpp实现的。 源码路径: http://androidxref.com/9.0.0_r3/xref/frameworks/opt/net/wifi/service/java/com/android/server/wifi/WificondControl.java#787

代码语言:javascript
复制
    public boolean startHostapd(@NonNull String ifaceName,
                               SoftApListener listener) {
        IApInterface iface = getApInterface(ifaceName);
        if (iface == null) {
            Log.e(TAG, "No valid ap interface handler");
            return false;
        }
        try {
            IApInterfaceEventCallback  callback = new ApInterfaceEventCallback(listener);
            mApInterfaceListeners.put(ifaceName, callback);
            boolean success = iface.startHostapd(callback);
            if (!success) {
                Log.e(TAG, "Failed to start hostapd.");
                return false;
            }
        } catch (RemoteException e) {
            Log.e(TAG, "Exception in starting soft AP: " + e);
            return false;
        }
        return true;
    }

在这里又调用了hostapd_manager的StartHostapd函数。 源码路径: http://androidxref.com/9.0.0_r3/xref/system/connectivity/wificond/ap_interface_impl.cpp#86

代码语言:javascript
复制
bool ApInterfaceImpl::StartHostapd() {
  return hostapd_manager_->StartHostapd();
}

然后在hostapd_manager.cpp里调用了StartHostapd方法。 源码路径: http://androidxref.com/9.0.0_r3/xref/frameworks/opt/net/wifi/libwifi_system/hostapd_manager.cpp#26

代码语言:javascript
复制
bool HostapdManager::StartHostapd() {
  if (property_set("ctl.start", kHostapdServiceName) != 0) {
    LOG(ERROR) << "Failed to start SoftAP";
    return false;
      LOG(DEBUG) << "SoftAP started successfully";
  return true;
}

再往后就是底层C的代码了,不是特别看得懂。然后返回success的话,热点就成功打开了,状态也变为started。

本文参与 腾讯云自媒体同步曝光计划,分享自作者个人站点/博客。
原始发表:2019/06/29 ,如有侵权请联系 cloudcommunity@tencent.com 删除

本文分享自 作者个人站点/博客 前往查看

如有侵权,请联系 cloudcommunity@tencent.com 删除。

本文参与 腾讯云自媒体同步曝光计划  ,欢迎热爱写作的你一起参与!

评论
登录后参与评论
0 条评论
热度
最新
推荐阅读
领券
问题归档专栏文章快讯文章归档关键词归档开发者手册归档开发者手册 Section 归档