Develop Reference

Bluetooth connection problems

I have a client on a PC and a server on a tablet. I know the MAC addresses for both which means I do not do discoveries.
1. On the client if I use
connectString = "btspp://" + MACaddress + ":4;authenticate=false;encrypt=false;master=false";
It connects fine.
If I change the CN number (4) to anything else, it does not work. How is this number determined?
2. Everything works fine if the tablet is a Samsung with Android 5.0.2 When I use a Qunyico tablet with Android 10, it does not work. I get an error: Failed to connect; [10051] A socket operation was attempted to an unreachable network. What is the problem?
Client on PC – code taken from “Bluetooth-java-client-master”
public class IrcBluetoothClient {
private static void openConnection(String MACaddress) throws IOException {
// Tries to open the connection.
String connectString = "btspp://" + MACaddress + ":4;authenticate=false;encrypt=false;master=false";
StreamConnection connection = (StreamConnection) Connector.open(connectString);
if (connection == null) {
System.err.println("Could not open connection to address: " + MACaddress);
System.exit(1);
}
// Initializes the streams.
OutputStream output = connection.openOutputStream();
InputStreamReader isr = new InputStreamReader(System.in);
BufferedReader reader = new BufferedReader(isr);
// Starts the listening service for incoming messages.
ExecutorService service = Executors.newSingleThreadExecutor();
service.submit(new IncomingMessagesLoggingRunnable(connection));
// Main loop of the program which is not complete yet
LocalDevice localDevice = LocalDevice.getLocalDevice();
while (true) {
String toSend = reader.readLine();
byte[] toSendBytes = toSend.getBytes(StandardCharsets.US_ASCII);
output.write(toSendBytes);
System.out.println("[" + localDevice.getFriendlyName() + " - " +
localDevice.getBluetoothAddress() + "]: " + toSend);
System.exit(1);
}
Server on tablet – code taken from https://developer.android.com/guide/topics/connectivity/bluetooth
private static final UUID A_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
public BTacceptConnections( BluetoothAdapter mBluetoothAdapter) {
// Use a temporary object that is later assigned to mmServerSocket
// because mmServerSocket is final.
BluetoothServerSocket tmp = null;
try {
// A_UUID is the app's UUID string, also used by the client code.
tmp = mBluetoothAdapter.listenUsingRfcommWithServiceRecord(NAME, A_UUID);
} catch (IOException e) {
Log.e(TAG, "Socket's listen() method failed", e);
}
mmServerSocket = tmp;
// Closes the connect socket and causes the thread to finish.
public void cancel(){
try {
mmServerSocket.close();
}catch (IOException e){
}
runFlag = 1;
}
//***********************************************************************************************
//
// This thread runs all the time listening for incoming connections.
//
public void run() {
BluetoothSocket socket = null;
// Keep listening until exception occurs or a socket is returned.
while (runFlag == 0) {
try {
socket = mmServerSocket.accept();
} catch (IOException e) {
Log.e(TAG, "Socket's accept() method failed", e);
break;
}
if (socket != null) { // If a connection was accepted
// A connection was accepted. Perform work associated with
// the connection in a separate thread.
// manageMyConnectedSocket(socket);
}else{
try {
mmServerSocket.close();
} catch (IOException e) {
e.printStackTrace();
}
break;
}
}

I know the MAC addresses for both which means I do not do discoveries.
Official Linux Bluetooth protocol stack BlueZ uses D-BUS API to establish bluetooth communication. If you check adapter-api, scanning will create device objects that you need to establish a communication which means discovering is not only done to retrieve MAC addresses only.
Your case might be the same, I would suggest doing discovery first.

Android with AMQP

Im trying use use an AMQP message queue in one of my Android applications. I tested the code first in a java application and have no issues but when I put the same code into an Android app no error is thrown but the AMQP channel closes unexpectedly after the first message is received. I tried adding a shutdown listener to the channel but it didnt return anything. Can someone help me figure out why the Rabbitmq channel is closing?
// ------------------------------------------------------------------------
// Function to make AMQP connection and subscribe
// ------------------------------------------------------------------------
int connAmqp()
{
factory = new ConnectionFactory();
factory.setHost(PI_AMQP_BROKER_URL);
factory.setUsername(AMQP_BROKER_USERNAME);
factory.setPassword(AMQP_BROKER_PASSWORD);
factory.setPort(AMQP_BROKER_PORT);
connection=null;
connectionStatus = AMQP_CONNECTING;
try {
connection = factory.newConnection();
Log.i("log_amqp_conn","Successfully connected to AMQP broker");
connectionStatus = AMQP_CONNECTED;
channel = connection.createChannel();
channel.addShutdownListener(new ShutdownListener() {
#Override
public void shutdownCompleted(ShutdownSignalException cause) {
Log.w("log_amqp_shutdown",cause.getCause().toString());
}
});
channel.exchangeDeclare(AMQP_EXCHANGE_NAME, "topic");
Log.i("log_amqp_conn","Successfully connected to Exchange: " + AMQP_EXCHANGE_NAME);
channel.queueDeclare(RX_QUEUE_NAME, false, false, false, null);
String queueBind = RX_BINDING;
Log.i("log_amqp_conn","Successfully declared queue: " + RX_QUEUE_NAME);
channel.queueBind(RX_QUEUE_NAME, AMQP_EXCHANGE_NAME, queueBind);
Log.i("log_amqp_conn","Successfully binding to: " + queueBind);
} catch (TimeoutException e) {
Log.i("log_amqp_conn","Connection timeount - Failed to connect to AMQP broker");
Log.i("log_amqp_conn",e.toString());
connectionStatus = AMQP_NOTCONNECTED_TIMEOUT;
} catch (IOException e) {
Log.i("log_amqp_conn","Failed to connect to AMQP broker");
Log.i("log_amqp_conn",e.toString());
connectionStatus = AMQP_NOTCONNECTED_UNKNOWNREASON;
}catch (Exception e) {
Log.i("log_amqp_conn","Failed to connect to AMQP broker");
Log.i("log_amqp_conn",e.toString());
connectionStatus = AMQP_NOTCONNECTED_UNKNOWNREASON;
}
Log.i("log_amqp_conn"," [*] Waiting for messages.");
consumer = new DefaultConsumer(channel) {
#Override
public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body)
throws IOException {
Log.i("log_amqp_conn", "handleDelivery() called");
String message = new String(body, "UTF-8");
Log.i("log_amqp_conn"," [Rx] Received: " + message);
//DO SOME WORK HERE
}
};
try {
Log.i("log_amqp_conn", "basicConsume() called");
channel.basicConsume(RX_QUEUE_NAME, true, consumer);
} catch (IOException e) {
Log.e("log_amqp_consume",e.toString());
}
return 0;
}

After spending much time looking in the wrong places I found that the channel was closing due to an unhandled exception in the handleDelivery() function in the "//DO SOME WORK HERE" code. Turns out that if this method errors out that the AMQP channel will close. Thanks.

Android - checking if data connection is actually working

I am currently having a one special use case that I am quite confused how to solve.
We have been checking for internet connection with ConnectivityService that has those ConnectivityType.Wifi / ConnectivityType.Mobile with a property if it is connected / connecting. That is all good until you run into following case:
You have data enabled on your phone.
Data connection is connected.
However you don't pay for your data bill so you can't make any data transfers.
(make sure your wifi is turned off while trying this)
I thought that I would simply check as following:
private static bool CanReachServer()
{
var uri = new Uri(Platform.ApiServerUrl); // replace with https://www.google.com if you like
try
{
using (HttpClient httpClient = new HttpClient())
{
httpClient.Timeout = TimeSpan.FromMilliseconds(5000);
HttpRequestMessage httpRequestMessage = new HttpRequestMessage(HttpMethod.Get, uri);
var task = httpClient.SendAsync(httpRequestMessage);
task.Wait();
if (task.Result.IsSuccessStatusCode)
return true;
else
return false;
}
}
catch (Exception ex)
{
Util.Log(string.Format("{0} - {1}", ex.Message, ex.StackTrace));
return false;
}
}
But this comes with a result of a successful status 200 - which makes me really confused as I clearly can't access anything data oriented on my phone.

I suggest you to check connection by attempting to open a socket to a known host - if the connection is successful - you can be sure that you have network access, else you can check the Exception and handle it to show error connection.
public bool ActiveInternetConnectivity() {
try {
// connect to google on port 80, the HTTP port
var socket = new Java.Net.Socket("www.google.com", 80);
// the above would have thrown exception if failed, so we are good
socket.Close();
return true;
} catch (Exception ex) {
// check logcat to see why it failed, you could then catch and handle each exception independently ( time out, host unknown, end of stream, etc.. )
System.Diagnostics.Debug.WriteLine(ex);
// the connection has failed, return false
return false;
}
It's just an idea, codes are not fully tested.

Ended up implementing following solution that seem to be working quite reliably. You can also enforce reachability on the method.
public static NetworkState GetNetworkState(this Context context, bool testReachability = false)
{
var result = NetworkState.NoNetwork;
var connMgr = (ConnectivityManager)context.GetSystemService(Context.ConnectivityService);
var activeNetwork = connMgr.ActiveNetworkInfo;
if (activeNetwork == null || !activeNetwork.IsConnectedOrConnecting)
{
connMgr.Dispose();
return NetworkState.NoNetwork;
}
if (activeNetwork.Type == ConnectivityType.Wifi && activeNetwork.IsConnected)
{
if (testReachability)
{
if (CanReachServer())
result = NetworkState.WiFi;
}
else
{
result = NetworkState.WiFi;
}
}
else if (activeNetwork.Type == ConnectivityType.Mobile && activeNetwork.IsConnected)
{
if (testReachability)
{
if (CanReachServer())
result = NetworkState.Mobile;
}
else
{
result = NetworkState.Mobile;
}
}
activeNetwork.Dispose();
connMgr.Dispose();
return result;
}
private static bool CanReachServer()
{
var uri = new Uri(Platform.ApiServerUrl).GetLeftPart(UriPartial.Authority);
var task = Task.Factory.StartNew(() =>
{
try
{
using (URL url = new URL(uri))
{
using (HttpURLConnection urlc = (HttpURLConnection)url.OpenConnection())
{
urlc.SetRequestProperty("User-Agent", "Android Application");
urlc.SetRequestProperty("Connection", "close");
urlc.ConnectTimeout = 6000;
urlc.ReadTimeout = 10000;
urlc.Connect();
bool result = urlc.ResponseCode == HttpStatus.Ok;
urlc.Disconnect();
return result;
}
}
}
catch (Exception ex)
{
Util.Log(string.Format("{0} - {1}", ex.Message, ex.StackTrace));
return false;
}
});
task.Wait();
return task.Result;
}
}

Android VpnService to capture packets won't capture packets

I been searching for my answer for a couple of hours now and I can't figure it out. Please help.
What I want to do is to use the VpnService in Android to grab network packets like the application tPacketCapture
I started by using the ToyVpn sample code from google and modifying it so I don't send the data to a server. However, I'm not sure if this is correct.
My configure method uses the wlan ip address for binder.addAddress() before calling establish(). I am using a nexus 7 and I used "adb shell netcfg | grep wlan0" to get the address:
wlan0 UP 192.168.0.6/24 0x00001043 10:bf:48:bf:5f:9d
And add it in my method:
private void configure() throws Exception {
// If the old interface has exactly the same parameters, use it!
if (mInterface != null) {
Log.i(TAG, "Using the previous interface");
return;
}
// Configure a builder while parsing the parameters.
Builder builder = new Builder();
builder.setMtu(1500);
builder.addAddress("192.168.0.6", 24);
try {
mInterface.close();
} catch (Exception e) {
// ignore
}
mInterface = builder.establish();
}
After calling this, I call the run method which I modified to pass a String instead of a InetSocketAddress and this is not important because I am not using it anywhere:
private void run(String run) throws Exception {
configure();
FileInputStream in = new FileInputStream(mInterface.getFileDescriptor());
// Allocate the buffer for a single packet.
ByteBuffer packet = ByteBuffer.allocate(32767);
// We use a timer to determine the status of the tunnel. It
// works on both sides. A positive value means sending, and
// any other means receiving. We start with receiving.
int timer = 0;
// We keep forwarding packets till something goes wrong.
while (true) {
// Assume that we did not make any progress in this iteration.
boolean idle = true;
// Read the outgoing packet from the input stream.
int length = in.read(packet.array());
if (length > 0) {
Log.i(TAG,"************new packet");
while (packet.hasRemaining()) {
Log.i(TAG,""+packet.get());
//System.out.print((char) packet.get());
}
// Write the outgoing packet to the tunnel.
packet.limit(length);
// tunnel.write(packet);
packet.clear();
// There might be more outgoing packets.
idle = false;
// If we were receiving, switch to sending.
if (timer < 1) {
timer = 1;
}
}
}
}
When I do adb logcat, nothing is happening. Am I going about this correctly? I feel like I am missing something.
Thank you!
EDIT:
From the logs I see the following lines:
I/ActivityManager( 460): START u0 {act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=com.example.android.toyvpn/.ToyVpnClient} from pid 10247
I/ActivityManager( 460): Start proc com.example.android.toyvpn for activity com.example.android.toyvpn/.ToyVpnClient: pid=10287 uid=10122 gids={50122, 3003, 1028}
I/ActivityManager( 460): Displayed com.example.android.toyvpn/.ToyVpnClient: +1s144ms
I/Vpn ( 460): Switched from [Legacy VPN] to com.example.android.toyvpn
D/Vpn ( 460): setting state=IDLE, reason=prepare
I/ToyVpnService(10287): running vpnService
D/Vpn ( 460): setting state=CONNECTING, reason=establish
D/VpnJni ( 460): Address added on tun0: 192.168.0.6/24
I/Vpn ( 460): Established by com.example.android.toyvpn.ToyVpnService on tun0
W/ContextImpl( 460): Calling a method in the system process without a qualified user: android.app.ContextImpl.bindService:1406 com.android.server.connectivity.Vpn.establish:289 com.android.server.ConnectivityService.establishVpn:3263 android.net.IConnectivityManager$Stub.onTransact:504 android.os.Binder.execTransact:351
D/Vpn ( 460): setting state=AUTHENTICATING, reason=establish
So it seems to be connecting.
Full source:
public class ToyVpnService extends VpnService implements Handler.Callback, Runnable {
private static final String TAG = "ToyVpnService";
private Handler mHandler;
private Thread mThread;
private ParcelFileDescriptor mInterface;
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
// The handler is only used to show messages.
if (mHandler == null) {
mHandler = new Handler(this);
}
// Stop the previous session by interrupting the thread.
if (mThread != null) {
mThread.interrupt();
}
// Start a new session by creating a new thread.
mThread = new Thread(this, "ToyVpnThread");
mThread.start();
return START_STICKY;
}
#Override
public void onDestroy() {
if (mThread != null) {
mThread.interrupt();
}
}
#Override
public boolean handleMessage(Message message) {
if (message != null) {
Toast.makeText(this, message.what, Toast.LENGTH_SHORT).show();
}
return true;
}
#Override
public synchronized void run() {
Log.i(TAG,"running vpnService");
try {
runVpnConnection();
} catch (Exception e) {
e.printStackTrace();
//Log.e(TAG, "Got " + e.toString());
} finally {
try {
mInterface.close();
} catch (Exception e) {
// ignore
}
mInterface = null;
mHandler.sendEmptyMessage(R.string.disconnected);
Log.i(TAG, "Exiting");
}
}
private boolean runVpnConnection() throws Exception {
configure();
FileInputStream in = new FileInputStream(mInterface.getFileDescriptor());
// Allocate the buffer for a single packet.
ByteBuffer packet = ByteBuffer.allocate(32767);
// We keep forwarding packets till something goes wrong.
while (true) {
// Assume that we did not make any progress in this iteration.
boolean idle = true;
// Read the outgoing packet from the input stream.
int length = in.read(packet.array());
if (length > 0) {
Log.i(TAG,"************new packet");
System.exit(-1);
while (packet.hasRemaining()) {
Log.i(TAG,""+packet.get());
//System.out.print((char) packet.get());
}
packet.limit(length);
// tunnel.write(packet);
packet.clear();
// There might be more outgoing packets.
idle = false;
}
Thread.sleep(50);
}
}
public String getLocalIpAddress()
{
try {
for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();) {
NetworkInterface intf = en.nextElement();
for (Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements();) {
InetAddress inetAddress = enumIpAddr.nextElement();
Log.i(TAG,"****** INET ADDRESS ******");
Log.i(TAG,"address: "+inetAddress.getHostAddress());
Log.i(TAG,"hostname: "+inetAddress.getHostName());
Log.i(TAG,"address.toString(): "+inetAddress.getHostAddress().toString());
if (!inetAddress.isLoopbackAddress()) {
//IPAddresses.setText(inetAddress.getHostAddress().toString());
Log.i(TAG,"IS NOT LOOPBACK ADDRESS: "+inetAddress.getHostAddress().toString());
return inetAddress.getHostAddress().toString();
} else{
Log.i(TAG,"It is a loopback address");
}
}
}
} catch (SocketException ex) {
String LOG_TAG = null;
Log.e(LOG_TAG, ex.toString());
}
return null;
}
private void configure() throws Exception {
// If the old interface has exactly the same parameters, use it!
if (mInterface != null) {
Log.i(TAG, "Using the previous interface");
return;
}
// Configure a builder while parsing the parameters.
Builder builder = new Builder();
builder.setMtu(1500);
builder.addAddress("192.168.0.6", 24);
try {
mInterface.close();
} catch (Exception e) {
// ignore
}
mInterface = builder.establish();
}
}

Ok, it was not easy at all but I figured out how to capture packets. Since I am not extremely familiar with networking (but this new job is requesting that I am) I had difficulty with setting everything correctly. Basically after setting the right route in the VpnService.builder I got to receiving packets correctly.
So:
builder.addAddress("192.168.0.6", 24); // was wrong, you need to put an internal IP (10.0.2.0 for example)
and
builder.addRoute("0.0.0.0", 0); // needs to be this.
you don't need to set up a DnsServer through builder.addDnsServer() to make it work. Hope this helps anyone!

My configure method uses the wlan ip address for binder.addAddress() before >calling establish(). I am using a nexus 7 and I used "adb shell netcfg | grep >wlan0" to get the address:
wlan0 UP 192.168.0.6/24 0x00001043 10:bf:48:bf:5f:9d
I have wrote a simple script in python to show you netcfg graphically from adb.
It is updating every second.
https://github.com/ilanben/graphical_netcfg
Enjoy :)

commumicating between windows app and android app

I'm sorry if this is a very general question but I don't know where to start so I'm looking for ideas.
I have a windows app (music score editing) and I'm currently porting it to Andriod which is coming along well.
I would like to add the feature than documents created in the windows app can be sent to the users android tablet. I was wondering, how would I write some kind of listener on Android that the windows side could open a socket or something to and send data across to it, assuming both are on the same local network.
thanks

I think sending files directly over a local network isn't the best approach. You are prone to many user complaints that the sharing isn't working.. and this will mostly be due to their own network configuration issues.
Why not use a service like DropBox to implement file sharing?
Services like DropBox offer simple API that can be used in apps in order to save files into a remote folder, and read files from a remote folder.
This way, users will not have to be in the same network at all.. and most of the heavy-lifting of implementing file sharing will be done by a service that is focused around that.
Addition:
If you don't want to require an account for a separate service like DropBox, consider this approach: Implement a very simple DropBox-like service on your own web server. Make a simple script that will allow users to upload a file to your server anonymously via HTTP. After upload, they will receive a 5 digit id for this file, or some other link they could share. When using this id or link from the 2nd app, the file could be downloaded (again via HTTP). If you delete files automatically from the server after a few hours, you will not run out of space.
You can implement such a service with about 20 lines of PHP code. And the required apps code is extremely simple (since it only relies on HTTP). If you're worried about the costs of a web server, you can get one from about $5/month or even use a free service like Google App Engine (free if your bandwidth+space requirements are low).
Code example for the file upload. Downloading should be simple enough to do alone. Regarding the periodical file delete - the obvious approach is cron but I think it's easy to manage without it. Whenever you accept a new upload (in the PHP script), go over all the downloads and delete old ones.

i wrote a small thing so my windows app can find an instance of my android app running on the local network, here it is. this is the android code first
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Arrays;
import android.os.AsyncTask;
import android.util.Log;
public class TabSyncServer extends AsyncTask<Void, Void, Void> {
ServerSocket mServerSocket = null;
Socket mSocket = null;
DataInputStream mDataInputStream = null;
DataOutputStream mDataOutputStream = null;
#Override
protected void onPreExecute() {
try {
mServerSocket = new ServerSocket(2112);
//System.out.println("Listening :2112");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
protected Void doInBackground(Void... args) {
byte[] bytebuf = new byte[1024];
while (true) {
try {
mSocket = mServerSocket.accept();
mDataInputStream = new DataInputStream(mSocket.getInputStream());
mDataOutputStream = new DataOutputStream(mSocket.getOutputStream());
Log.d("TabSyncServer", "ip: " + mSocket.getInetAddress());
mDataInputStream.read(bytebuf);
String str = new String(bytebuf, "UTF8");
Log.d("TabSyncServer", "message: " + str);
if(str.contains("Hello Android")) {
Log.d("TabSyncServer", "sending reply");
mDataOutputStream.writeBytes("Hello Windows");
}
//
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
if (mSocket != null) {
try {
mSocket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (mDataInputStream != null) {
try {
mDataInputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (mDataOutputStream != null) {
try {
mDataOutputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
}
}
and the windows MFC code
void CMainFrame::OnBrowseMobile() {
CMobileSync* con = new CMobileSync();
CString ipaddr_base;
int my_last_digit;
if(!con->getMyIP(ipaddr_base, my_last_digit)) {
setMobilePath("Can't find local network");
return;
}
for(int i=1 ; i<98 ; i++) {
if(i==my_last_digit)
continue; // don;t check self
CString ipaddr; ipaddr.Format("%s.%d", ipaddr_base, i);
bool res = con->ConnectToHost(ipaddr);
if(res) {
res = con->SendMsg ("Hello Android");
if(res) {
TRACE1("send ok %s\n",ipaddr.GetBuffer());
#define RD_BUF_LEN 80
char buffer[RD_BUF_LEN];
if(con->ListenOnPortBlocking(buffer, RD_BUF_LEN)) {
if(strncmp(buffer, "Hello Windows", 12)==0) {
TRACE1("reply ok %s", buffer);
setMobilePath(ipaddr);
con->CloseConnection ();
return;
}
}
} else {
TRACE("send FAILED\n");
}
}
con->CloseConnection ();
}
setMobilePath("No TabTrax on local network");
}
#include "stdafx.h"
#include <winsock.h>
#include "MobileSync.h"
#define TTPORT 2112
bool CMobileSync::getMyIP(CString& ipaddr_front, int& ipaddr_lastdigit)
{
char szBuffer[1024];
#ifdef WIN32
WSADATA wsaData;
WORD wVersionRequested = MAKEWORD(2, 0);
if(::WSAStartup(wVersionRequested, &wsaData) != 0)
return false;
#endif
if(gethostname(szBuffer, sizeof(szBuffer)) == SOCKET_ERROR)
{
#ifdef WIN32
WSACleanup();
#endif
return false;
}
struct hostent *host = gethostbyname(szBuffer);
if(host == NULL)
{
#ifdef WIN32
WSACleanup();
#endif
return false;
}
//Obtain the computer's IP
unsigned char b1, b2, b3, b4;
b1 = ((struct in_addr *)(host->h_addr))->S_un.S_un_b.s_b1;
b2 = ((struct in_addr *)(host->h_addr))->S_un.S_un_b.s_b2;
b3 = ((struct in_addr *)(host->h_addr))->S_un.S_un_b.s_b3;
b4 = ((struct in_addr *)(host->h_addr))->S_un.S_un_b.s_b4;
ipaddr_front.Format("%d.%d.%d", b1, b2, b3);
ipaddr_lastdigit = b4;
#ifdef WIN32
WSACleanup();
#endif
return true;
}
//CONNECTTOHOST – Connects to a remote host
bool CMobileSync::ConnectToHost(const char* IPAddress)
{
//Start up Winsock…
WSADATA wsadata;
int error = WSAStartup(0x0202, &wsadata);
//Did something happen?
if (error)
return false;
//Did we get the right Winsock version?
if (wsadata.wVersion != 0x0202)
{
WSACleanup(); //Clean up Winsock
return false;
}
//Fill out the information needed to initialize a socket…
SOCKADDR_IN target; //Socket address information
target.sin_family = AF_INET; // address family Internet
target.sin_port = htons (TTPORT); //Port to connect on
target.sin_addr.s_addr = inet_addr (IPAddress); //Target IP
mSocket = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP); //Create socket
if (mSocket == INVALID_SOCKET)
{
return false; //Couldn't create the socket
}
//Try connecting...
if (connect(mSocket, (SOCKADDR *)&target, sizeof(target)) == SOCKET_ERROR)
{
return false; //Couldn't connect
}
return true; //Success
}
//CLOSECONNECTION – shuts down the socket and closes any connection on it
void CMobileSync::CloseConnection ()
{
//Close the socket if it exists
if (mSocket)
closesocket(mSocket);
mSocket=0;
WSACleanup(); //Clean up Winsock
}
int CMobileSync::SendMsg (char* szpText, int buflen)
{
if(buflen==0)
buflen = strlen(szpText);
int ret = send(mSocket, szpText, buflen, 0);
TRACE1("CMobileSync::SendMsg sent %d bytes\n", ret);
return ret;
}
WSADATA w;
//LISTENONPORT – Listens on a specified port for incoming connections
//or data
bool CMobileSync::ListenOnPortBlocking(char* buffer, int buflen)
{
//Now we can start listening (allowing as many connections as possible to
//be made at the same time using SOMAXCONN). You could specify any
//integer value equal to or lesser than SOMAXCONN instead for custom
//purposes). The function will not //return until a connection request is
//made
// listen(s, SOMAXCONN);
memset(buffer, 0, sizeof(buffer)); //Clear the buffer
int iTimeout = 1600;
setsockopt( mSocket, SOL_SOCKET, SO_RCVTIMEO, (const char *)&iTimeout, sizeof(iTimeout));
//Put the incoming text into our buffer
int ret = recv (mSocket, buffer, buflen-1, 0);
//Don't forget to clean up with CloseConnection()!
if(ret != SOCKET_ERROR)
return true;
int err = WSAGetLastError();
return false;
}
its not tested extensively but it is running
this maybe useful to someone