(一百四十五)Android P wifi连接流程

1. Settings

WifiSettings

    @Override
    public void onSubmit(WifiDialog dialog) {
        if (mDialog != null) {
            submit(mDialog.getController());
        }
    }

    /* package */ void submit(WifiConfigController configController) {

        final WifiConfiguration config = configController.getConfig();

        if (config == null) {
            if (mSelectedAccessPoint != null
                    && mSelectedAccessPoint.isSaved()) {
                connect(mSelectedAccessPoint.getConfig(), true /* isSavedNetwork */);
            }
        } else if (configController.getMode() == WifiConfigUiBase.MODE_MODIFY) {
            mWifiManager.save(config, mSaveListener);
        } else {
            mWifiManager.save(config, mSaveListener);
            if (mSelectedAccessPoint != null) { // Not an "Add network"
                connect(config, false /* isSavedNetwork */);
            }
        }

        mWifiTracker.resumeScanning();
    }

    protected void connect(final WifiConfiguration config, boolean isSavedNetwork) {
        // Log subtype if configuration is a saved network.
        mMetricsFeatureProvider.action(getVisibilityLogger(), MetricsEvent.ACTION_WIFI_CONNECT,
                isSavedNetwork);
        mWifiManager.connect(config, mConnectListener);
        mClickedConnect = true;
    }

 

2. framework

WifiManager

    /**
     * Connect to a network with the given configuration. The network also
     * gets added to the list of configured networks for the foreground user.
     *
     * For a new network, this function is used instead of a
     * sequence of addNetwork(), enableNetwork(), and reconnect()
     *
     * @param config the set of variables that describe the configuration,
     *            contained in a {@link WifiConfiguration} object.
     * @param listener for callbacks on success or failure. Can be null.
     * @throws IllegalStateException if the WifiManager instance needs to be
     * initialized again
     *
     * @hide
     */
    @SystemApi
    public void connect(WifiConfiguration config, ActionListener listener) {
        if (config == null) throw new IllegalArgumentException("config cannot be null");
        // Use INVALID_NETWORK_ID for arg1 when passing a config object
        // arg1 is used to pass network id when the network already exists
        getChannel().sendMessage(CONNECT_NETWORK, WifiConfiguration.INVALID_NETWORK_ID,
                putListener(listener), config);
    }

WifiServiceImpl

                case WifiManager.CONNECT_NETWORK: {
                    if (checkChangePermissionAndReplyIfNotAuthorized(
                            msg, WifiManager.CONNECT_NETWORK_FAILED)) {
                        WifiConfiguration config = (WifiConfiguration) msg.obj;
                        int networkId = msg.arg1;
                        Slog.d(TAG, "CONNECT "
                                + " nid=" + Integer.toString(networkId)
                                + " config=" + config
                                + " uid=" + msg.sendingUid
                                + " name="
                                + mContext.getPackageManager().getNameForUid(msg.sendingUid));
                        if (config != null) {
                            /* Command is forwarded to state machine */
                            mWifiStateMachine.sendMessage(Message.obtain(msg));
                        } else if (config == null
                                && networkId != WifiConfiguration.INVALID_NETWORK_ID) {
                            mWifiStateMachine.sendMessage(Message.obtain(msg));
                        } else {
                            Slog.e(TAG, "ClientHandler.handleMessage ignoring invalid msg=" + msg);
                            replyFailed(msg, WifiManager.CONNECT_NETWORK_FAILED,
                                    WifiManager.INVALID_ARGS);
                        }
                    }
                    break;
                }

WifiStateMachine

  class ConnectModeState extends State {
...
                case WifiManager.CONNECT_NETWORK:
                    /**
                     * The connect message can contain a network id passed as arg1 on message or
                     * or a config passed as obj on message.
                     * For a new network, a config is passed to create and connect.
                     * For an existing network, a network id is passed
                     */
                    netId = message.arg1;
                    config = (WifiConfiguration) message.obj;
                    boolean hasCredentialChanged = false;
                    // New network addition.
                    if (config != null) {
                        result = mWifiConfigManager.addOrUpdateNetwork(config, message.sendingUid);
                        if (!result.isSuccess()) {
                            loge("CONNECT_NETWORK adding/updating config=" + config + " failed");
                            messageHandlingStatus = MESSAGE_HANDLING_STATUS_FAIL;
                            replyToMessage(message, WifiManager.CONNECT_NETWORK_FAILED,
                                    WifiManager.ERROR);
                            break;
                        }
                        netId = result.getNetworkId();
                        hasCredentialChanged = result.hasCredentialChanged();
                    }
                    if (!connectToUserSelectNetwork(
                            netId, message.sendingUid, hasCredentialChanged)) {
                        messageHandlingStatus = MESSAGE_HANDLING_STATUS_FAIL;
                        replyToMessage(message, WifiManager.CONNECT_NETWORK_FAILED,
                                WifiManager.NOT_AUTHORIZED);
                        break;
                    }
                    mWifiMetrics.logStaEvent(StaEvent.TYPE_CONNECT_NETWORK, config);
                    broadcastWifiCredentialChanged(WifiManager.WIFI_CREDENTIAL_SAVED, config);
                    replyToMessage(message, WifiManager.CONNECT_NETWORK_SUCCEEDED);
                    break;

这边发现在连接之前会更新一下WifiConfigManager里的config,看了下主要会把连接的uid的更新名字和时间更新到config里去。

    /**
     * Create a new internal WifiConfiguration object by copying over parameters from the provided
     * external configuration to a copy of the existing internal WifiConfiguration object.
     *
     * @param internalConfig WifiConfiguration object in our internal map.
     * @param externalConfig WifiConfiguration object provided from the external API.
     * @return Copy of existing WifiConfiguration object with parameters merged from the provided
     * configuration.
     */
    private WifiConfiguration updateExistingInternalWifiConfigurationFromExternal(
            WifiConfiguration internalConfig, WifiConfiguration externalConfig, int uid) {
        WifiConfiguration newInternalConfig = new WifiConfiguration(internalConfig);

        // Copy over all the public elements from the provided configuration.
        mergeWithInternalWifiConfiguration(newInternalConfig, externalConfig);

        // Add debug information for network update.
        newInternalConfig.lastUpdateUid = uid;
        newInternalConfig.lastUpdateName = mContext.getPackageManager().getNameForUid(uid);
        newInternalConfig.updateTime = createDebugTimeStampString(mClock.getWallClockMillis());

        return newInternalConfig;
    }

再回头看下连接流程

    /**
     * Initiates connection to a network specified by the user/app. This method checks if the
     * requesting app holds the NETWORK_SETTINGS permission.
     *
     * @param netId Id network to initiate connection.
     * @param uid UID of the app requesting the connection.
     * @param forceReconnect Whether to force a connection even if we're connected to the same
     *                       network currently.
     */
    private boolean connectToUserSelectNetwork(int netId, int uid, boolean forceReconnect) {
        logd("connectToUserSelectNetwork netId " + netId + ", uid " + uid
                + ", forceReconnect = " + forceReconnect);
        if (mWifiConfigManager.getConfiguredNetwork(netId) == null) {
            loge("connectToUserSelectNetwork Invalid network Id=" + netId);
            return false;
        }
        if (!mWifiConfigManager.enableNetwork(netId, true, uid)
                || !mWifiConfigManager.updateLastConnectUid(netId, uid)) {
            logi("connectToUserSelectNetwork Allowing uid " + uid
                    + " with insufficient permissions to connect=" + netId);
        } else if (mWifiPermissionsUtil.checkNetworkSettingsPermission(uid)) {
            // Note user connect choice here, so that it will be considered in the next network
            // selection.
            mWifiConnectivityManager.setUserConnectChoice(netId);
        }
        if (!forceReconnect && mWifiInfo.getNetworkId() == netId) {
            // We're already connected to the user specified network, don't trigger a
            // reconnection unless it was forced.
            logi("connectToUserSelectNetwork already connecting/connected=" + netId);
        } else {
            mWifiConnectivityManager.prepareForForcedConnection(netId);
            startConnectToNetwork(netId, uid, SUPPLICANT_BSSID_ANY);
        }
        return true;
    }

稍微看下setUserConnectChoice,大概意思是将该次连接的网络优先级提到最高,下次连接优先考虑。

WifiConnectivityManager
    /**
     * Handler when user specifies a particular network to connect to
     */
    public void setUserConnectChoice(int netId) {
        localLog("setUserConnectChoice: netId=" + netId);

        mNetworkSelector.setUserConnectChoice(netId);
    }
WifiNetworkSelector
    /**
     * This API is called when user explicitly selects a network. Currently, it is used in following
     * cases:
     * (1) User explicitly chooses to connect to a saved network.
     * (2) User saves a network after adding a new network.
     * (3) User saves a network after modifying a saved network.
     * Following actions will be triggered:
     * 1. If this network is disabled, we need re-enable it again.
     * 2. This network is favored over all the other networks visible in latest network
     *    selection procedure.
     *
     * @param netId  ID for the network chosen by the user
     * @return true -- There is change made to connection choice of any saved network.
     *         false -- There is no change made to connection choice of any saved network.
     */
    public boolean setUserConnectChoice(int netId) {
        localLog("userSelectNetwork: network ID=" + netId);
        WifiConfiguration selected = mWifiConfigManager.getConfiguredNetwork(netId);

        if (selected == null || selected.SSID == null) {
            localLog("userSelectNetwork: Invalid configuration with nid=" + netId);
            return false;
        }

        // Enable the network if it is disabled.
        if (!selected.getNetworkSelectionStatus().isNetworkEnabled()) {
            mWifiConfigManager.updateNetworkSelectionStatus(netId,
                    WifiConfiguration.NetworkSelectionStatus.NETWORK_SELECTION_ENABLE);
        }

        boolean change = false;
        String key = selected.configKey();
        // This is only used for setting the connect choice timestamp for debugging purposes.
        long currentTime = mClock.getWallClockMillis();
        List savedNetworks = mWifiConfigManager.getSavedNetworks();

        for (WifiConfiguration network : savedNetworks) {
            WifiConfiguration.NetworkSelectionStatus status = network.getNetworkSelectionStatus();
            if (network.networkId == selected.networkId) {
                if (status.getConnectChoice() != null) {
                    localLog("Remove user selection preference of " + status.getConnectChoice()
                            + " Set Time: " + status.getConnectChoiceTimestamp() + " from "
                            + network.SSID + " : " + network.networkId);
                    mWifiConfigManager.clearNetworkConnectChoice(network.networkId);
                    change = true;
                }
                continue;
            }

            if (status.getSeenInLastQualifiedNetworkSelection()
                    && (status.getConnectChoice() == null
                    || !status.getConnectChoice().equals(key))) {
                localLog("Add key: " + key + " Set Time: " + currentTime + " to "
                        + toNetworkString(network));
                mWifiConfigManager.setNetworkConnectChoice(network.networkId, key, currentTime);
                change = true;
            }
        }

        return change;
    }
WifiConfigManager
    /**
     * Set the {@link NetworkSelectionStatus#mConnectChoice} &
     * {@link NetworkSelectionStatus#mConnectChoiceTimestamp} for the provided network.
     *
     * This is invoked by Network Selector when the user overrides the currently connected network
     * choice.
     *
     * @param networkId              network ID corresponding to the network.
     * @param connectChoiceConfigKey ConfigKey corresponding to the network which was chosen over
     *                               this network.
     * @param timestamp              timestamp at which the choice was made.
     * @return true if the network was found, false otherwise.
     */
    public boolean setNetworkConnectChoice(
            int networkId, String connectChoiceConfigKey, long timestamp) {
        if (mVerboseLoggingEnabled) {
            Log.v(TAG, "Set network connect choice " + connectChoiceConfigKey + " for " + networkId);
        }
        WifiConfiguration config = getInternalConfiguredNetwork(networkId);
        if (config == null) {
            return false;
        }
        config.getNetworkSelectionStatus().setConnectChoice(connectChoiceConfigKey);
        config.getNetworkSelectionStatus().setConnectChoiceTimestamp(timestamp);
        saveToStore(false);
        return true;
    }
WifiConfiguration.java
        /**
         * set user preferred choice over this configuration
         * @param newConnectChoice, the configKey of user preferred choice over this configuration
         */
        public void setConnectChoice(String newConnectChoice) {
            mConnectChoice = newConnectChoice;
        }
这个choice会在如下类中起作用,具体逻辑待续
    /**
     * Overrides the {@code candidate} chosen by the {@link #mEvaluators} with the user chosen
     * {@link WifiConfiguration} if one exists.
     *
     * @return the user chosen {@link WifiConfiguration} if one exists, {@code candidate} otherwise
     */
    private WifiConfiguration overrideCandidateWithUserConnectChoice(
            @NonNull WifiConfiguration candidate) {
        WifiConfiguration tempConfig = candidate;
        WifiConfiguration originalCandidate = candidate;
        ScanResult scanResultCandidate = candidate.getNetworkSelectionStatus().getCandidate();

        while (tempConfig.getNetworkSelectionStatus().getConnectChoice() != null) {
            String key = tempConfig.getNetworkSelectionStatus().getConnectChoice();
            tempConfig = mWifiConfigManager.getConfiguredNetwork(key);

            if (tempConfig != null) {
                WifiConfiguration.NetworkSelectionStatus tempStatus =
                        tempConfig.getNetworkSelectionStatus();
                if (tempStatus.getCandidate() != null && tempStatus.isNetworkEnabled()) {
                    scanResultCandidate = tempStatus.getCandidate();
                    candidate = tempConfig;
                }
            } else {
                localLog("Connect choice: " + key + " has no corresponding saved config.");
                break;
            }
        }

        if (candidate != originalCandidate) {
            localLog("After user selection adjustment, the final candidate is:"
                    + WifiNetworkSelector.toNetworkString(candidate) + " : "
                    + scanResultCandidate.BSSID);
        }
        return candidate;
    }

继续梳理连接流程

    /**
     * Automatically connect to the network specified
     *
     * @param networkId ID of the network to connect to
     * @param uid UID of the app triggering the connection.
     * @param bssid BSSID of the network
     */
    public void startConnectToNetwork(int networkId, int uid, String bssid) {
        sendMessage(CMD_START_CONNECT, networkId, uid, bssid);
    }



    class ConnectModeState extends State {
...
                case CMD_START_CONNECT:
                    /* connect command coming from auto-join */
                    netId = message.arg1;
                    int uid = message.arg2;
                    bssid = (String) message.obj;

                    synchronized (mWifiReqCountLock) {
                        if (!hasConnectionRequests()) {
                            if (mNetworkAgent == null) {
                                loge("CMD_START_CONNECT but no requests and not connected,"
                                        + " bailing");
                                break;
                            } else if (!mWifiPermissionsUtil.checkNetworkSettingsPermission(uid)) {
                                loge("CMD_START_CONNECT but no requests and connected, but app "
                                        + "does not have sufficient permissions, bailing");
                                break;
                            }
                        }
                    }

                    config = mWifiConfigManager.getConfiguredNetworkWithoutMasking(netId);
                    logd("CMD_START_CONNECT sup state "
                            + mSupplicantStateTracker.getSupplicantStateName()
                            + " my state " + getCurrentState().getName()
                            + " nid=" + Integer.toString(netId)
                            + " roam=" + Boolean.toString(mIsAutoRoaming));
                    if (config == null) {
                        loge("CMD_START_CONNECT and no config, bail out...");
                        break;
                    }
                    mTargetNetworkId = netId;
                    setTargetBssid(config, bssid);

                    if (mEnableConnectedMacRandomization.get()) {
                        configureRandomizedMacAddress(config);
                    }

                    String currentMacAddress = mWifiNative.getMacAddress(mInterfaceName);
                    mWifiInfo.setMacAddress(currentMacAddress);
                    Log.i(TAG, "Connecting with " + currentMacAddress + " as the mac address");

                    reportConnectionAttemptStart(config, mTargetRoamBSSID,
                            WifiMetricsProto.ConnectionEvent.ROAM_UNRELATED);
                    if (mWifiNative.connectToNetwork(mInterfaceName, config)) {
                        mWifiMetrics.logStaEvent(StaEvent.TYPE_CMD_START_CONNECT, config);
                        lastConnectAttemptTimestamp = mClock.getWallClockMillis();
                        targetWificonfiguration = config;
                        mIsAutoRoaming = false;
                        if (getCurrentState() != mDisconnectedState) {
                            transitionTo(mDisconnectingState);
                        }
                    } else {
                        loge("CMD_START_CONNECT Failed to start connection to network " + config);
                        reportConnectionAttemptEnd(
                                WifiMetrics.ConnectionEvent.FAILURE_CONNECT_NETWORK_FAILED,
                                WifiMetricsProto.ConnectionEvent.HLF_NONE);
                        replyToMessage(message, WifiManager.CONNECT_NETWORK_FAILED,
                                WifiManager.ERROR);
                        break;
                    }
                    break;

1)校验下是否有连接请求

2)获取下密码未隐藏的config,只可以在WiFi 堆栈中调用,api中不要调用,与普通获取config的区别在于密码有没有被替换为*

    /**
     * Helper method to mask all passwords/keys from the provided WifiConfiguration object. This
     * is needed when the network configurations are being requested via the public WifiManager
     * API's.
     * This currently masks the following elements: psk, wepKeys & enterprise config password.
     */
    private void maskPasswordsInWifiConfiguration(WifiConfiguration configuration) {
        if (!TextUtils.isEmpty(configuration.preSharedKey)) {
            configuration.preSharedKey = PASSWORD_MASK;
        }
        if (configuration.wepKeys != null) {
            for (int i = 0; i < configuration.wepKeys.length; i++) {
                if (!TextUtils.isEmpty(configuration.wepKeys[i])) {
                    configuration.wepKeys[i] = PASSWORD_MASK;
                }
            }
        }
        if (!TextUtils.isEmpty(configuration.enterpriseConfig.getPassword())) {
            configuration.enterpriseConfig.setPassword(PASSWORD_MASK);
        }
    }

3)连接的时候有没有使用随机mac,以隐藏mac

                    if (mEnableConnectedMacRandomization.get()) {
                        configureRandomizedMacAddress(config);
                    }

     /**
     * Dynamically change the MAC address to use the locally randomized
     * MAC address generated for each network.
     * @param config WifiConfiguration with mRandomizedMacAddress to change into. If the address
     * is masked out or not set, it will generate a new random MAC address.
     */
    private void configureRandomizedMacAddress(WifiConfiguration config) {
        if (config == null) {
            Log.e(TAG, "No config to change MAC address to");
            return;
        }
        MacAddress currentMac = MacAddress.fromString(mWifiNative.getMacAddress(mInterfaceName));
        MacAddress newMac = config.getOrCreateRandomizedMacAddress();
        mWifiConfigManager.setNetworkRandomizedMacAddress(config.networkId, newMac);

        if (!WifiConfiguration.isValidMacAddressForRandomization(newMac)) {
            Log.wtf(TAG, "Config generated an invalid MAC address");
        } else if (currentMac.equals(newMac)) {
            Log.d(TAG, "No changes in MAC address");
        } else {
            mWifiMetrics.logStaEvent(StaEvent.TYPE_MAC_CHANGE, config);
            boolean setMacSuccess =
                    mWifiNative.setMacAddress(mInterfaceName, newMac);
            Log.d(TAG, "ConnectedMacRandomization SSID(" + config.getPrintableSsid()
                    + "). setMacAddress(" + newMac.toString() + ") from "
                    + currentMac.toString() + " = " + setMacSuccess);
        }
    }

 

WifiNative

    /**
     * Add the provided network configuration to wpa_supplicant and initiate connection to it.
     * This method does the following:
     * 1. Abort any ongoing scan to unblock the connection request.
     * 2. Remove any existing network in wpa_supplicant(This implicitly triggers disconnect).
     * 3. Add a new network to wpa_supplicant.
     * 4. Save the provided configuration to wpa_supplicant.
     * 5. Select the new network in wpa_supplicant.
     * 6. Triggers reconnect command to wpa_supplicant.
     *
     * @param ifaceName Name of the interface.
     * @param configuration WifiConfiguration parameters for the provided network.
     * @return {@code true} if it succeeds, {@code false} otherwise
     */
    public boolean connectToNetwork(@NonNull String ifaceName, WifiConfiguration configuration) {
        // Abort ongoing scan before connect() to unblock connection request.
        mWificondControl.abortScan(ifaceName);
        return mSupplicantStaIfaceHal.connectToNetwork(ifaceName, configuration);
    }

 

SupplicantStaIfaceHal

    /**
     * Add the provided network configuration to wpa_supplicant and initiate connection to it.
     * This method does the following:
     * 1. If |config| is different to the current supplicant network, removes all supplicant
     * networks and saves |config|.
     * 2. Select the new network in wpa_supplicant.
     *
     * @param ifaceName Name of the interface.
     * @param config WifiConfiguration parameters for the provided network.
     * @return {@code true} if it succeeds, {@code false} otherwise
     */
    public boolean connectToNetwork(@NonNull String ifaceName, @NonNull WifiConfiguration config) {
        synchronized (mLock) {
            logd("connectToNetwork " + config.configKey());
            WifiConfiguration currentConfig = getCurrentNetworkLocalConfig(ifaceName);
            if (WifiConfigurationUtil.isSameNetwork(config, currentConfig)) {
                String networkSelectionBSSID = config.getNetworkSelectionStatus()
                        .getNetworkSelectionBSSID();
                String networkSelectionBSSIDCurrent =
                        currentConfig.getNetworkSelectionStatus().getNetworkSelectionBSSID();
                if (Objects.equals(networkSelectionBSSID, networkSelectionBSSIDCurrent)) {
                    logd("Network is already saved, will not trigger remove and add operation.");
                } else {
                    logd("Network is already saved, but need to update BSSID.");
                    if (!setCurrentNetworkBssid(
                            ifaceName,
                            config.getNetworkSelectionStatus().getNetworkSelectionBSSID())) {
                        loge("Failed to set current network BSSID.");
                        return false;
                    }
                    mCurrentNetworkLocalConfigs.put(ifaceName, new WifiConfiguration(config));
                }
            } else {
                mCurrentNetworkRemoteHandles.remove(ifaceName);
                mCurrentNetworkLocalConfigs.remove(ifaceName);
                if (!removeAllNetworks(ifaceName)) {
                    loge("Failed to remove existing networks");
                    return false;
                }
                Pair pair =
                        addNetworkAndSaveConfig(ifaceName, config);
                if (pair == null) {
                    loge("Failed to add/save network configuration: " + config.configKey());
                    return false;
                }
                mCurrentNetworkRemoteHandles.put(ifaceName, pair.first);
                mCurrentNetworkLocalConfigs.put(ifaceName, pair.second);
            }
            SupplicantStaNetworkHal networkHandle =
                    checkSupplicantStaNetworkAndLogFailure(ifaceName, "connectToNetwork");
            if (networkHandle == null || !networkHandle.select()) {
                loge("Failed to select network configuration: " + config.configKey());
                return false;
            }
            return true;
        }
    }

SupplicantStaNetworkHal

    /**
     * Trigger a connection to this network.
     *
     * @return true if it succeeds, false otherwise.
     */
    public boolean select() {
        synchronized (mLock) {
            final String methodStr = "select";
            if (!checkISupplicantStaNetworkAndLogFailure(methodStr)) return false;
            try {
                SupplicantStatus status =  mISupplicantStaNetwork.select();
                return checkStatusAndLogFailure(status, methodStr);
            } catch (RemoteException e) {
                handleRemoteException(e, methodStr);
                return false;
            }
        }
    }

通过hidl调用到supplicant

sta_network

Return StaNetwork::select(select_cb _hidl_cb)
{
	return validateAndCall(
	    this, SupplicantStatusCode::FAILURE_NETWORK_INVALID,
	    &StaNetwork::selectInternal, _hidl_cb);
}

SupplicantStatus StaNetwork::selectInternal()
{
	struct wpa_ssid *wpa_ssid = retrieveNetworkPtr();
	if (wpa_ssid->disabled == 2) {
		return {SupplicantStatusCode::FAILURE_UNKNOWN, ""};
	}
	struct wpa_supplicant *wpa_s = retrieveIfacePtr();
	wpa_s->scan_min_time.sec = 0;
	wpa_s->scan_min_time.usec = 0;
	// Make sure that the supplicant is updated to the latest
	// MAC address, which might have changed due to MAC randomization.
	wpa_supplicant_update_mac_addr(wpa_s);
	wpa_supplicant_select_network(wpa_s, wpa_ssid);
	return {SupplicantStatusCode::SUCCESS, ""};
}

 

 

3.总结

Android P流程和Android O总体没变化,状态机那边主要是启动的时候根据模式抽出来了,连接流程还是在WifiStateMachine里。流程图就不重新画了,和Android O一模一样的。

(一百四十五)Android P wifi连接流程_第1张图片

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