/*
* Copyright (C) 2007 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.
*/
package com.android.server;
import android.net.LocalSocket;
import android.net.LocalSocketAddress;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.Message;
import android.os.SystemClock;
import android.util.Slog;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
/**
* Generic connector class for interfacing with a native
* daemon which uses the libsysutils FrameworkListener
* protocol.
*/
final class NativeDaemonConnector implements Runnable, Handler.Callback, Watchdog.Monitor {
private static final boolean LOCAL_LOGD = false;
private BlockingQueue<String> mResponseQueue;
private OutputStream mOutputStream;
private String TAG = "NativeDaemonConnector";
private String mSocket;
private INativeDaemonConnectorCallbacks mCallbacks;
private Handler mCallbackHandler;
/** Lock held whenever communicating with native daemon. */
private Object mDaemonLock = new Object();
private final int BUFFER_SIZE = 4096;
class ResponseCode {
public static final int ActionInitiated = 100;
public static final int CommandOkay = 200;
// The range of 400 -> 599 is reserved for cmd failures
public static final int OperationFailed = 400;
public static final int CommandSyntaxError = 500;
public static final int CommandParameterError = 501;
public static final int UnsolicitedInformational = 600;
//
public static final int FailedRangeStart = 400;
public static final int FailedRangeEnd = 599;
}
NativeDaemonConnector(INativeDaemonConnectorCallbacks callbacks,
String socket, int responseQueueSize, String logTag) {
mCallbacks = callbacks;
if (logTag != null)
TAG = logTag;
mSocket = socket;
mResponseQueue = new LinkedBlockingQueue<String>(responseQueueSize);
}
@Override
public void run() {
HandlerThread thread = new HandlerThread(TAG + ".CallbackHandler");
thread.start();
mCallbackHandler = new Handler(thread.getLooper(), this);
while (true) {
try {
listenToSocket();
} catch (Exception e) {
Slog.e(TAG, "Error in NativeDaemonConnector", e);
SystemClock.sleep(5000);
}
}
}
@Override
public boolean handleMessage(Message msg) {
String event = (String) msg.obj;
try {
if (!mCallbacks.onEvent(msg.what, event, event.split(" "))) {
Slog.w(TAG, String.format(
"Unhandled event '%s'", event));
}
} catch (Exception e) {
Slog.e(TAG, String.format(
"Error handling '%s'", event), e);
}
return true;
}
private void listenToSocket() throws IOException {
LocalSocket socket = null;
try {
socket = new LocalSocket();
LocalSocketAddress address = new LocalSocketAddress(mSocket,
LocalSocketAddress.Namespace.RESERVED);
socket.connect(address);
InputStream inputStream = socket.getInputStream();
mOutputStream = socket.getOutputStream();
mCallbacks.onDaemonConnected();
byte[] buffer = new byte[BUFFER_SIZE];
int start = 0;
while (true) {
int count = inputStream.read(buffer, start, BUFFER_SIZE - start);
if (count < 0) break;
// Add our starting point to the count and reset the start.
count += start;
start = 0;
for (int i = 0; i < count; i++) {
if (buffer[i] == 0) {
String event = new String(buffer, start, i - start);
if (LOCAL_LOGD) Slog.d(TAG, String.format("RCV <- {%s}", event));
String[] tokens = event.split(" ", 2);
try {
int code = Integer.parseInt(tokens[0]);
if (code >= ResponseCode.UnsolicitedInformational) {
mCallbackHandler.sendMessage(
mCallbackHandler.obtainMessage(code, event));
} else {
try {
mResponseQueue.put(event);
} catch (InterruptedException ex) {
Slog.e(TAG, "Failed to put response onto queue", ex);
}
}
} catch (NumberFormatException nfe) {
Slog.w(TAG, String.format("Bad msg (%s)", event));
}
start = i + 1;
}
}
// We should end at the amount we read. If not, compact then
// buffer and read again.
if (start != count) {
final int remaining = BUFFER_SIZE - start;
System.arraycopy(buffer, start, buffer, 0, remaining);
start = remaining;
} else {
start = 0;
}
}
} catch (IOException ex) {
Slog.e(TAG, "Communications error", ex);
throw ex;
} finally {
synchronized (mDaemonLock) {
if (mOutputStream != null) {
try {
mOutputStream.close();
} catch (IOException e) {
Slog.w(TAG, "Failed closing output stream", e);
}
mOutputStream = null;
}
}
try {
if (socket != null) {
socket.close();
}
} catch (IOException ex) {
Slog.w(TAG, "Failed closing socket", ex);
}
}
}
private void sendCommandLocked(String command) throws NativeDaemonConnectorException {
sendCommandLocked(command, null);
}
/**
* Sends a command to the daemon with a single argument
*
* @param command The command to send to the daemon
* @param argument The argument to send with the command (or null)
*/
private void sendCommandLocked(String command, String argument)
throws NativeDaemonConnectorException {
if (command != null && command.indexOf('\0') >= 0) {
throw new IllegalArgumentException("unexpected command: " + command);
}
if (argument != null && argument.indexOf('\0') >= 0) {
throw new IllegalArgumentException("unexpected argument: " + argument);
}
if (LOCAL_LOGD) Slog.d(TAG, String.format("SND -> {%s} {%s}", command, argument));
if (mOutputStream == null) {
Slog.e(TAG, "No connection to daemon", new IllegalStateException());
throw new NativeDaemonConnectorException("No output stream!");
} else {
StringBuilder builder = new StringBuilder(command);
if (argument != null) {
builder.append(argument);
}
builder.append('\0');
try {
mOutputStream.write(builder.toString().getBytes());
} catch (IOException ex) {
Slog.e(TAG, "IOException in sendCommand", ex);
}
}
}
/**
* Issue a command to the native daemon and return the responses
*/
public ArrayList<String> doCommand(String cmd) throws NativeDaemonConnectorException {
synchronized (mDaemonLock) {
return doCommandLocked(cmd);
}
}
private ArrayList<String> doCommandLocked(String cmd) throws NativeDaemonConnectorException {
mResponseQueue.clear();
sendCommandLocked(cmd);
ArrayList<String> response = new ArrayList<String>();
boolean complete = false;
int code = -1;
while (!complete) {
try {
// TODO - this should not block forever
String line = mResponseQueue.take();
if (LOCAL_LOGD) Slog.d(TAG, String.format("RSP <- {%s}", line));
String[] tokens = line.split(" ");
try {
code = Integer.parseInt(tokens[0]);
} catch (NumberFormatException nfe) {
throw new NativeDaemonConnectorException(
String.format("Invalid response from daemon (%s)", line));
}
if ((code >= 200) && (code < 600)) {
complete = true;
}
response.add(line);
} catch (InterruptedException ex) {
Slog.e(TAG, "Failed to process response", ex);
}
}
if (code >= ResponseCode.FailedRangeStart &&
code <= ResponseCode.FailedRangeEnd) {
/*
* Note: The format of the last response in this case is
* "NNN <errmsg>"
*/
throw new NativeDaemonConnectorException(
code, cmd, response.get(response.size()-1).substring(4));
}
return response;
}
/**
* Issues a list command and returns the cooked list
*/
public String[] doListCommand(String cmd, int expectedResponseCode)
throws NativeDaemonConnectorException {
ArrayList<String> rsp = doCommand(cmd);
String[] rdata = new String[rsp.size()-1];
int idx = 0;
for (int i = 0; i < rsp.size(); i++) {
String line = rsp.get(i);
try {
String[] tok = line.split(" ");
int code = Integer.parseInt(tok[0]);
if (code == expectedResponseCode) {
rdata[idx++] = line.substring(tok[0].length() + 1);
} else if (code == NativeDaemonConnector.ResponseCode.CommandOkay) {
if (LOCAL_LOGD) Slog.d(TAG, String.format("List terminated with {%s}", line));
int last = rsp.size() -1;
if (i != last) {
Slog.w(TAG, String.format("Recv'd %d lines after end of list {%s}", (last-i), cmd));
for (int j = i; j <= last ; j++) {
Slog.w(TAG, String.format("ExtraData <%s>", rsp.get(i)));
}
}
return rdata;
} else {
throw new NativeDaemonConnectorException(
String.format("Expected list response %d, but got %d",
expectedResponseCode, code));
}
} catch (NumberFormatException nfe) {
throw new NativeDaemonConnectorException(
String.format("Error reading code '%s'", line));
}
}
throw new NativeDaemonConnectorException("Got an empty response");
}
/** {@inheritDoc} */
public void monitor() {
synchronized (mDaemonLock) { }
}
}