Android(安卓)Softap启动分析

http://blog.csdn.net/airk000/article/details/9273599

设置中开关：

packages/apps/Settings/src/com/android/settings/TetherSettings.java

|----private void startTethering()

| |----mWifiApEnabler.setSoftapEnabled(true);

packages/apps/Settings/src/com/android/settings/wifi/WifiApEnabler.java

|----public void setSoftapEnabled(boolean enable)

| |----mWifiManager.setWifiApEnabled(null, enable)

框架：

frameworks/base/wifi/java/android/net/wifi/WifiManager.java

|----public boolean setWifiApEnabled(WifiConfiguration wifiConfig, boolean enabled)

| |----mService.setWifiApEnabled(wifiConfig, enabled);

IWifiManager.aidl

|----void setWifiApEnabled(in WifiConfiguration wifiConfig, boolean enable);

frameworks/base/services/java/com/android/server/WifiService.java

|----public void setWifiApEnabled(WifiConfiguration wifiConfig, boolean enabled)

| |----mWifiStateMachine.setWifiApEnabled(wifiConfig, enabled);

frameworks/base/wifi/java/android/net/wifi/WifiStateMachine.java

|----public void setWifiApEnabled(WifiConfiguration wifiConfig, boolean enable)

| |----sendMessage(obtainMessage(CMD_LOAD_DRIVER, WIFI_AP_STATE_ENABLING, 0));

| |----sendMessage(obtainMessage(CMD_START_AP, wifiConfig));

1.JAVA API部分

frameworks/base/wifi/java/android/net/wifi/WifiManager.java

[java] view plain copy

public boolean setWifiApEnabled(WifiConfiguration wifiConfig, boolean enabled) {
mService.setWifiApEnabled(wifiConfig, enabled);
}

2.服务器端进程

frameworks/base/services/java/com/android/server/WifiService.java

[java] view plain copy

public void setWifiApEnabled(WifiConfiguration wifiConfig, boolean enabled) {
mWifiStateMachine.setWifiApEnabled(wifiConfig, enabled);
}

消息循环，状态机

frameworks/base/wifi/java/android/net/wifi/WifiStateMachine.java

public void setWifiApEnabled(WifiConfiguration wifiConfig, boolean enable) {
if (enable) {
sendMessage(obtainMessage(CMD_LOAD_DRIVER, WIFI_AP_STATE_ENABLING, 0));
sendMessage(obtainMessage(CMD_START_AP, wifiConfig));
} else {
sendMessage(CMD_STOP_AP);
sendMessage(obtainMessage(CMD_UNLOAD_DRIVER, WIFI_AP_STATE_DISABLED, 0));
}
}

public WifiStateMachine(Context context, String wlanInterface) {

mWifiConfigStore = new WifiConfigStore(context, mWifiNative);

WifiApConfigStore wifiApConfigStore = WifiApConfigStore.makeWifiApConfigStore(

context, getHandler());
wifiApConfigStore.loadApConfiguration(); // private static final String AP_CONFIG_FILE = Environment.getDataDirectory() + "/misc/wifi/softap.conf";
mWifiApConfigChannel.connectSync(mContext, getHandler(), wifiApConfigStore.getMessenger());

}

class Initial State extends State {

if(mWifiNative.isDriverLoaded()){

transitionTo(mDriverLoadedState);

}

else{ //因为最开始驱动都是没有加载的，所以进入transitionTo(mDriverUnloadedState);

transitionTo(mDriverUnloadedState);

}

WifiStateMachine进入DriverUnloadedState

classDriverUnloadedState extends State {

publicboolean processMessage(Message message) {

switch(message.what) {

case CMD_LOAD_DRIVER:

transitionTo(mDriverLoadingState);

这里会处理刚才的CMD_LOAD_DRIVER这个消息，继续切换到mDriverLoadingState

classDriverLoadingState extends State {

publicvoid enter() {

newThread(new Runnable() {

publicvoid run() {

mWakeLock.acquire();

//enablingstate

switch(message.arg1){

case WIFI_AP_STATE_ENABLING:
mWifiMode = 1;
setWifiApState(WIFI_AP_STATE_ENABLING);

｝

if(mWifiNative.loadDriver()){ ---------------------------------------------------------->

sendMessage(CMD_LOAD_DRIVER_SUCCESS);

}

publicboolean processMessage(Message message) {

switch(message.what) {

caseCMD_LOAD_DRIVER_SUCCESS:

transitionTo(mDriverLoadedState);

}

这里会调用WifiNative.loadDriver()加载驱动，成功后发送消息CMD_LOAD_DRIVER_SUCCESS，然后进入mDriverLoadedState。否则发送CMD_LOAD_DRIVER_FAILURE，进入mDriverFailedState

来看另一个消息sendMessage（CMD_START_AP）

case CMD_START_AP:
transitionTo(mSoftApStartingState);

class SoftApStartingState extends State {
public void enter() {

final Message message = getCurrentMessage();
if (message.what == CMD_START_AP) {
final WifiConfiguration config = (WifiConfiguration) message.obj;

if (config == null) {
mWifiApConfigChannel.sendMessage(CMD_REQUEST_AP_CONFIG);
} else {
mWifiApConfigChannel.sendMessage(CMD_SET_AP_CONFIG, config);
startSoftApWithConfig(config);
}

frameworks/base/wifi/java/android/net/wifi/WifiApConfigStore.java

class WifiApConfigStore extends StateMachine {

class DefaultState extends State {

case WifiStateMachine.CMD_REQUEST_AP_CONFIG:
mReplyChannel.replyToMessage(message,
WifiStateMachine.CMD_RESPONSE_AP_CONFIG, mWifiApConfig);
break;

当前WIFI状态机状态为SoftApStartingState，所以回复消息在这里处理：

class SoftApStartingState{

case WifiStateMachine.CMD_RESPONSE_AP_CONFIG:
WifiConfiguration config = (WifiConfiguration) message.obj;
if (config != null) {
startSoftApWithConfig(config);
} else {
loge("Softap config is null!");
sendMessage(CMD_START_AP_FAILURE);
}
break;
case CMD_START_AP_SUCCESS:
setWifiApState(WIFI_AP_STATE_ENABLED);
transitionTo(mSoftApStartedState);
break;

private void startSoftApWithConfig(final WifiConfiguration config) {
// start hostapd on a seperate thread
new Thread(new Runnable() {
public void run() {
try {
mNwService.startAccessPoint(config, mInterfaceName);
} catch (Exception e) {
loge("Exception in softap start " + e);
try {
mNwService.stopAccessPoint(mInterfaceName);
mNwService.startAccessPoint(config, mInterfaceName);
} catch (Exception e1) {
loge("Exception in softap re-start " + e1);
sendMessage(CMD_START_AP_FAILURE);
return;
}
}
if (DBG) log("Soft AP start successful");
sendMessage(CMD_START_AP_SUCCESS);
}
}).start();
}

IBinder b = ServiceManager.getService(Context.NETWORKMANAGEMENT_SERVICE);
mNwService = INetworkManagementService.Stub.asInterface(b);

frameworks/base/services/java/com/android/server/NetworkManagementService.java

public void startAccessPoint(
WifiConfiguration wifiConfig, String wlanIface) {
mContext.enforceCallingOrSelfPermission(CONNECTIVITY_INTERNAL, TAG);
try {
wifiFirmwareReload(wlanIface, "AP"); //mConnector.execute("softap", "fwreload", wlanIface, mode); wlanIface就是prop指定的wifi.interface，默认为wlan0，mode为"AP"，共计四个参数
if (wifiConfig == null) {
mConnector.execute("softap", "set", wlanIface);
} else {
mConnector.execute("softap", "set", wlanIface, wifiConfig.SSID, //mConnector = new NativeDaemonConnector( new NetdCallbackReceiver(), "netd", 10, NETD_TAG, 160);
getSecurityType(wifiConfig), wifiConfig.preSharedKey);
}
mConnector.execute("softap", "startap");
} catch (NativeDaemonConnectorException e) {
throw e.rethrowAsParcelableException();
}
}

class InactiveState

case WifiStateMachine.CMD_SET_AP_CONFIG:
mWifiApConfig = (WifiConfiguration) message.obj;
transitionTo(mActiveState);
break;

class ActiveState extends State {
public void enter() {
new Thread(new Runnable() {
public void run() {
writeApConfiguration(mWifiApConfig);
sendMessage(WifiStateMachine.CMD_SET_AP_CONFIG_COMPLETED);
}
}).start();
}
public boolean processMessage(Message message) {
switch (message.what) {
//TODO: have feedback to the user when we do this
//to indicate the write is currently in progress
case WifiStateMachine.CMD_SET_AP_CONFIG:
deferMessage(message);
break;
case WifiStateMachine.CMD_SET_AP_CONFIG_COMPLETED:
transitionTo(mInactiveState);
break;
default:
return NOT_HANDLED;
}
return HANDLED;
}
}

这里的配置文件是通过WifiManager的setWifiApConfiguration接口生成的：

public boolean setWifiApConfiguration(WifiConfiguration wifiConfig) {
try {
mService.setWifiApConfiguration(wifiConfig);
return true;

public void setWifiApConfiguration(WifiConfiguration wifiConfig) {
enforceChangePermission();
if (wifiConfig == null)
return;
mWifiStateMachine.setWifiApConfiguration(wifiConfig);

真是的实现有抛给了WifiStateMachine：

public void setWifiApConfiguration(WifiConfiguration config) {
mWifiApConfigChannel.sendMessage(CMD_SET_AP_CONFIG, config);
}

class InactiveState extends State {
   public boolean processMessage(Message message) {
   switch (message.what) {
   case WifiStateMachine.CMD_SET_AP_CONFIG:
mWifiApConfig = (WifiConfiguration) message.obj;
transitionTo(mActiveState);     //触发ActiveState.enter()
   break ;

class ActiveState extends State {
   public void enter() {
   new Thread( new Runnable() {
   public void run() {
writeApConfiguration(mWifiApConfig);
sendMessage(WifiStateMachine.CMD_SET_AP_CONFIG_COMPLETED);
}
}).start();
    }

mConnector.execute("softap", "fwreload", wlanIface, mode);
mConnector.execute("softap", "set", wlanIface, softapIface, wifiConfig.SSID,
getSecurityType(wifiConfig), wifiConfig.preSharedKey);
mConnector.execute("softap", "startap");

固件重载

wlanIface就是prop指定的wifi.interface，默认为wlan0，mode为"AP"，共计四个参数。这两条命令都会最终执行到这里：

public NativeDaemonEvent[] execute(int timeout, String cmd, Object... args)
throws NativeDaemonConnectorException {
final ArrayList events = Lists.newArrayList();

final int sequenceNumber = mSequenceNumber.incrementAndGet();
final StringBuilder cmdBuilder =
new StringBuilder(Integer.toString(sequenceNumber)).append(' ');
final long startTime = SystemClock.elapsedRealtime();

makeCommand(cmdBuilder, cmd, args);

final String logCmd = cmdBuilder.toString(); /* includes cmdNum, cmd, args */
log("SND -> {" + logCmd + "}");

cmdBuilder.append('\0');
final String sentCmd = cmdBuilder.toString(); /* logCmd + \0 */

synchronized (mDaemonLock) {
if (mOutputStream == null) {
throw new NativeDaemonConnectorException("missing output stream");
} else {
try {
mOutputStream.write(sentCmd.getBytes(Charsets.UTF_8));
} catch (IOException e) {
throw new NativeDaemonConnectorException("problem sending command", e);
}
}
}

NativeDaemonEvent event = null;
do {
event = mResponseQueue.remove(sequenceNumber, timeout, sentCmd);
if (event == null) {
loge("timed-out waiting for response to " + logCmd);
throw new NativeDaemonFailureException(logCmd, event);
}
log("RMV <- {" + event + "}");
events.add(event);
} while (event.isClassContinue());

final long endTime = SystemClock.elapsedRealtime();
if (endTime - startTime > WARN_EXECUTE_DELAY_MS) {
loge("NDC Command {" + logCmd + "} took too long (" + (endTime - startTime) + "ms)");
}

if (event.isClassClientError()) {
throw new NativeDaemonArgumentException(logCmd, event);
}
if (event.isClassServerError()) {
throw new NativeDaemonFailureException(logCmd, event);
}

return events.toArray(new NativeDaemonEvent[events.size()]);
}

system/netd/CommandListener.cpp

int CommandListener::SoftapCmd::runCommand(SocketClient *cli,
int argc, char **argv) {
if (!strcmp(argv[1], "startap")) {
rc = sSoftapCtrl->startSoftap();
} else if (!strcmp(argv[1], "stopap")) {
rc = sSoftapCtrl->stopSoftap();
} else if (!strcmp(argv[1], "fwreload")) {
rc = sSoftapCtrl->fwReloadSoftap(argc, argv);
} else if (!strcmp(argv[1], "clients")) {
rc = sSoftapCtrl->clientsSoftap(&retbuf);
if (!rc) {
cli->sendMsg(ResponseCode::CommandOkay, retbuf, false);
free(retbuf);
return 0;
}
} else if (!strcmp(argv[1], "status")) {
asprintf(&retbuf, "Softap service %s", (sSoftapCtrl->isSoftapStarted() ? "started" : "stopped"));
cli->sendMsg(ResponseCode::SoftapStatusResult, retbuf, false);
free(retbuf);
return 0;
} else if (!strcmp(argv[1], "set")) {
rc = sSoftapCtrl->setSoftap(argc, argv);
} else {
cli->sendMsg(ResponseCode::CommandSyntaxError, "Softap Unknown cmd", false);
return 0;
}
}

system/netd/SoftapController.cpp

int SoftapController::setSoftap(int argc, char *argv[]) {
if (argc > 3) {
ssid = argv[3];
} else {
ssid = (char *)"AndroidAP";
}
asprintf(&wbuf, "interface=%s\ndriver=nl80211\nctrl_interface="
"/data/misc/wifi/hostapd\nssid=%s\nchannel=6\nieee80211n=1\n",
iface, ssid);
if (argc > 4) {
if (!strcmp(argv[4], "wpa-psk")) {
generatePsk(ssid, argv[5], psk_str);
asprintf(&fbuf, "%swpa=1\nwpa_pairwise=TKIP CCMP\nwpa_psk=%s\n", wbuf, psk_str);
} else if (!strcmp(argv[4], "wpa2-psk")) {
generatePsk(ssid, argv[5], psk_str);
asprintf(&fbuf, "%swpa=2\nrsn_pairwise=CCMP\nwpa_psk=%s\n", wbuf, psk_str);
} else if (!strcmp(argv[4], "open")) {
asprintf(&fbuf, "%s", wbuf);
}
} else {
asprintf(&fbuf, "%s", wbuf);
}
//static const char HOSTAPD_CONF_FILE[] = "/data/misc/wifi/hostapd.conf";
//配置文件/data/misc/wifi/hostapd.conf
fd = open(HOSTAPD_CONF_FILE, O_CREAT | O_TRUNC | O_WRONLY | O_NOFOLLOW, 0660);
if (write(fd, fbuf, strlen(fbuf)) < 0) {
ALOGE("Cannot write to \"%s\": %s", HOSTAPD_CONF_FILE, strerror(errno));
ret = -1;
}
}
int SoftapController::startSoftap() {
if ((pid = fork()) < 0) {
ALOGE("fork failed (%s)", strerror(errno));
return -1;
}
if (!pid) {
ensure_entropy_file_exists();
if (execl("/system/bin/hostapd", "/system/bin/hostapd",
"-e", WIFI_ENTROPY_FILE,
HOSTAPD_CONF_FILE, (char *) NULL)) {
ALOGE("execl failed (%s)", strerror(errno));
}
ALOGE("Should never get here!");
return -1;
} else {
mPid = pid;
ALOGD("Softap startap - Ok");
usleep(AP_BSS_START_DELAY);
}
}

固件重载

更多相关文章

随机推荐