There are two programs that I made that didn't work. There are the server and the client. The server accepts many client by giving a user an ID (starting from 0). The server sends out the command to the specific client based up the server's id. (Example: 200 client are connected to 1 server. The server's selected id is '5', so the server will send the command to all of the client, and the client will ask the server what ID he wants to execute his command on, and if it's '5', that client will execute and send data to the server). The client has many commands, but to create the smallest code with the same error, I only use 1 command (dir). Basically, the server sends the command to the client and if it matches with the client current id and the server current id, it will process the command. By default, the server's current ID is 10. Here are the list of the commands to help the people who wants to answer:
Server Command:
list (Shows all of the users ID connected and the server's current ID) --> Happens on server
dir (request the client to send its dir listing) --> Sent by the client, read by the Server
set (set the server's current id to any number) (example: 'set 4')
Client:
using System;
using System.Speech.Synthesis;
using System.Windows.Forms;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Net.Sockets;
using System.Net;
namespace clientControl
{
class Program
{
public static string directory = #"C:\";
public static int id = -10;
public static Socket sck = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
static void Main(string[] args)
{
Connect();
getSession();
ReadResponse(sck);
}
static byte[] readResponseFunc()
{
long fileSize = 0;
string fileSizeInString = null;
byte[] fileSizeInByteArray = new byte[1024];
int fileSizeLength = sck.Receive(fileSizeInByteArray);
for (int i = 0; i < fileSizeLength; i++)
{
fileSizeInString = fileSizeInString + (char)fileSizeInByteArray[i];
}
try
{
fileSize = Convert.ToInt64(fileSizeInString);
}
catch { Console.WriteLine(fileSizeInString); }
sck.Send(Encoding.ASCII.GetBytes("a"));
byte[] responseUnknown = new byte[1];
sck.Receive(responseUnknown);
if (Encoding.ASCII.GetString(responseUnknown) == "b")
{
byte[] dataInByteArray = new byte[fileSize];
int dataLength = sck.Receive(dataInByteArray);
return dataInByteArray;
}
return Encoding.ASCII.GetBytes("ERROR RESPONSE FUNC");
}
static void getSession()
{
byte[] message_1 = Encoding.ASCII.GetBytes("make_id");
sck.Send(Encoding.ASCII.GetBytes(message_1.Length.ToString()));
byte[] responseUnknown = new byte[1];
if (Encoding.ASCII.GetString(responseUnknown) == "a")
{
sck.Send(Encoding.ASCII.GetBytes("b"));
sck.Send(message_1);
}
byte[] receivedID = readResponseFunc();
id = Convert.ToInt32(Encoding.ASCII.GetString(receivedID));
}
static bool SocketConnected(Socket s)
{
bool part1 = s.Poll(1000, SelectMode.SelectRead);
bool part2 = (s.Available == 0);
if (part1 && part2)
return false;
else
return true;
}
static void ReadResponse(Socket sck)
{
while (true)
{
if (SocketConnected(sck) == true)
{
try
{
string response = Encoding.ASCII.GetString(readResponseFunc());
byte[] message_1 = Encoding.ASCII.GetBytes("get_id");
sck.Send(Encoding.ASCII.GetBytes(message_1.Length.ToString()));
byte[] responseUnknown = new byte[1];
if (Encoding.ASCII.GetString(responseUnknown) == "a")
{
sck.Send(Encoding.ASCII.GetBytes("b"));
sck.Send(message_1);
}
byte[] response_2InByteArray = readResponseFunc();
string response_2 = Encoding.ASCII.GetString(response_2InByteArray);
if (Convert.ToInt32(response_2) == id)
{
if (response == "dir")
{
string resultOfDirring = "Current Directory: " + directory + "\n\n";
string[] folderListingArray = Directory.GetDirectories(directory);
foreach (string dir in folderListingArray)
{
string formed = "DIRECTORY: " + Path.GetFileName(dir);
resultOfDirring = resultOfDirring + formed + Environment.NewLine;
}
string[] fileListingArray = Directory.GetFiles(directory);
foreach (var file in fileListingArray)
{
FileInfo fileInfo = new FileInfo(file);
string formed = "FILE: " + Path.GetFileName(file) + " - FILE SIZE: " + fileInfo.Length + " BYTES";
resultOfDirring = resultOfDirring + formed + Environment.NewLine;
}
byte[] message_11 = Encoding.ASCII.GetBytes(resultOfDirring);
sck.Send(Encoding.ASCII.GetBytes(message_11.Length.ToString()));
byte[] responseUnknown_11 = new byte[1];
if (Encoding.ASCII.GetString(responseUnknown_11) == "a")
{
sck.Send(Encoding.ASCII.GetBytes("b"));
sck.Send(message_11);
}
}
}
else { }
}
catch { if (SocketConnected(sck) == false) { Console.WriteLine("Client Disconnected: " + sck.RemoteEndPoint); break; }; }
}
else if (SocketConnected(sck) == false) { Console.WriteLine("Client Disconnected: " + sck.RemoteEndPoint); break; }
}
}
static void Connect()
{
while (true)
{
try
{
sck.Connect(IPAddress.Parse("127.0.0.1"), 80);
break;
}
catch { }
}
}
}
}
Server:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.IO;
using System.Text;
using System.Threading;
namespace serverControl
{
class Program
{
public static int ftpNum = 1;
public static List<int> listOfClient = new List<int>();
public static TcpListener server = new TcpListener(IPAddress.Parse("127.0.0.1"), 80);
public static string message = null;
public static int id = 0;
public static int selected_id = 10;
static void Main(string[] args)
{
server.Start();
Thread startHandlingClientThread = new Thread(startHandlingClient);
startHandlingClientThread.Start();
while (true)
{
Console.Write(":> ");
string rawmessage = Console.ReadLine();
if (rawmessage == "list")
{
Console.WriteLine("SELECTED ID: " + selected_id);
Console.WriteLine("List of Clients ID:");
for (int i = 0; i < listOfClient.Count; i++)
{
Console.WriteLine(listOfClient[i]);
}
message = rawmessage+"PREVENT_REPETITION_IN_COMMAND";
}
else if (rawmessage.Contains("set ")) { int wantedChangeId = Convert.ToInt32(rawmessage.Replace("set ", "")); selected_id = wantedChangeId; message = rawmessage+ "PREVENT_REPETITION_IN_COMMAND"; }
else
{
message = rawmessage;
}
}
}
static byte[] readResponseFunc(Socket sck)
{
long fileSize = 0;
string fileSizeInString = null;
byte[] fileSizeInByteArray = new byte[1024];
int fileSizeLength = sck.Receive(fileSizeInByteArray);
for (int i = 0; i < fileSizeLength; i++)
{
fileSizeInString = fileSizeInString + (char)fileSizeInByteArray[i];
}
fileSize = Convert.ToInt64(fileSizeInString);
sck.Send(Encoding.ASCII.GetBytes("a"));
byte[] responseUnknown = new byte[1];
sck.Receive(responseUnknown);
if (Encoding.ASCII.GetString(responseUnknown) == "b")
{
byte[] dataInByteArray = new byte[fileSize];
int dataLength = sck.Receive(dataInByteArray);
return dataInByteArray;
}
return Encoding.ASCII.GetBytes("ERROR RESPONSE FUNC");
}
static void startHandlingClient()
{
while (true)
{
handleClient(server);
}
}
static void handleClient(TcpListener clientToAccept)
{
Socket sck = clientToAccept.AcceptSocket();
Thread myNewThread = new Thread(() => ReadResponse(sck));
myNewThread.Start();
}
static bool SocketConnected(Socket s)
{
bool part1 = s.Poll(1000, SelectMode.SelectRead);
bool part2 = (s.Available == 0);
if (part1 && part2)
return false;
else
return true;
}
static void ReadResponse(Socket sck)
{
Thread myNewThread = new Thread(() => SendtoClient(sck));
myNewThread.Start();
Thread.Sleep(2000);
while (true)
{
if (SocketConnected(sck) == true)
{
try
{
byte[] dataInByteArray = readResponseFunc(sck);
string response = Encoding.ASCII.GetString(dataInByteArray);
Console.WriteLine("res: " + response);
if (response != "make_id" && response != "get_id") { Console.WriteLine(response); }
if (response == "make_id")
{
Console.WriteLine("Someone wants an ID");
byte[] message_1 = Encoding.ASCII.GetBytes(id.ToString());
listOfClient.Add(id);
// START
sck.Send(Encoding.ASCII.GetBytes(message_1.Length.ToString()));
byte[] responseUnknown = new byte[1];
if (Encoding.ASCII.GetString(responseUnknown) == "a")
{
sck.Send(Encoding.ASCII.GetBytes("b"));
sck.Send(message_1);
}
id++;
}
if (response == "get_id")
{
byte[] message_1 = Encoding.ASCII.GetBytes(selected_id.ToString());
sck.Send(Encoding.ASCII.GetBytes(message_1.Length.ToString()));
byte[] responseUnknown = new byte[1];
if (Encoding.ASCII.GetString(responseUnknown) == "a")
{
sck.Send(Encoding.ASCII.GetBytes("b"));
sck.Send(message_1);
}
}
}
catch { if (SocketConnected(sck) == false) { Console.WriteLine("Client Disconnected: " + sck.RemoteEndPoint); break; }; }
}
else if (SocketConnected(sck) == false) { Console.WriteLine("Client Disconnected: " + sck.RemoteEndPoint); break; }
}
}
static void SendtoClient(Socket sck)
{
string tempmessage = null;
while (true)
{
if (SocketConnected(sck) == true)
{
if (tempmessage != message)
{
if (!message.Contains("PREVENT_REPETITION_IN_COMMAND"))
{
byte[] message_1 = Encoding.ASCII.GetBytes(message);
sck.Send(Encoding.ASCII.GetBytes(message_1.Length.ToString()));
byte[] responseUnknown = new byte[1];
if (Encoding.ASCII.GetString(responseUnknown) == "a")
{
sck.Send(Encoding.ASCII.GetBytes("b"));
sck.Send(message_1);
}
}
tempmessage = message;
}
}
else if (SocketConnected(sck) == false)
{ Console.WriteLine("Client Disconnected: " + sck.RemoteEndPoint); break; }
}
}
}
}
Problem:
The problem is within the GetSession or the ReadResponseFunc function. The client thinks that his ID received by the server is 'a' (it's suppose to be an integer). I don't want a solution that suggest me to use other libs or
the TcpClient class
Bounty:
I'll put up a bounty with no expiry time to those who solve the problem.
The logic in your code is very confusing. My question to you: Why are you sending 'a' and 'b' back and forth between the server and client? Is it some sort of confirmation that the message has been received?
Anyways, throughout the quick tests I've done just now, it seems that the problem is Line 59 of your server:
sck.Send(Encoding.ASCII.GetBytes("a"));
Here's what I figured out during testing:
Server executes.
Client executes.
Client sends server the length of "make_id" (Line 51 of client)
Client waits for a response to return.
Server reads the value and sends back 'a' (Line 59 of server)
You may want to spend some time to straighten out your protocol so it's less confusing and more organized. That would help people like me and you spot bugs much more easily.
The user 'Bobby' has already found your problem. Credits go to him.
I further suggest that you use less threads, as thread synchronisation needs some effort when doing it right: all data that is accessed from different threads must be secured by locks, so that no outdated values remain in the CPU caches. Use .net Monitor from the "threading synchronisation primitives" for that job.
About the threads themselves:
You should have only one thread in the server. This thread takes all clients from a list (secured by Monitor), in which they were added when connection attempts were received. On each client it checks for incoming messages, evaluates them and replies with own messages if needed.
The client also has just one thread, that will loop (dont forget a sleep in the loop or you will have 100% usage of the used CPU core), send messages when desired and wait for replies when messages were sent.
About the messages:
I already gave some proposals in a comment to Bobby's answer. I suggest you create a CMessage class that has a Serialize() and Deserialze() to create a byte array to send from the CMessage members (serializing the content) or vice versa filling the members from the received bytes. You then may use this class in both programs and you'll have common solution.
Related
Here is how my Client connects to the server:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using System.Net.Sockets;
using System.IO;
using System;
using System.Text.RegularExpressions;
using UnityEngine.SceneManagement;
using Newtonsoft.Json;
using System.Linq;
public class ClientWorldServer : MonoBehaviour {
public bool socketReady;
public static TcpClient socket;
public static NetworkStream stream;
public static StreamWriter writer;
public static StreamReader reader;
public void ConnectToWorldServer()
{
if (socketReady)
{
return;
}
//Default host and port values;
string host = "127.0.0.1";
int port = 8080;
try
{
socket = new TcpClient(host, port);
stream = socket.GetStream();
writer = new StreamWriter(stream);
reader = new StreamReader(stream);
socketReady = true;
}
catch (Exception e)
{
Debug.Log("Socket error : " + e.Message);
}
}
}
Here is how i send data to the server using my Send function:
public void Send(string header, Dictionary<string, string> data)
{
if (stream.CanRead)
{
socketReady = true;
}
if (!socketReady)
{
return;
}
JsonData SendData = new JsonData();
SendData.header = "1x" + header;
foreach (var item in data)
{
SendData.data.Add(item.Key.ToString(), item.Value.ToString());
}
SendData.connectionId = connectionId;
string json = JsonConvert.SerializeObject(SendData);
var howManyBytes = json.Length * sizeof(Char);
writer.WriteLine(json);
writer.Flush();
Debug.Log("Client World:" + json);
}
As you can see i'm sending the data to the Stream like a string not like a byte array. As far as i know i should send the data as byte array prepending the size of the message and following the message. On the server side i have no clue how i can read that data.
Here is how i read it now(it works for now, but it will not work if i try to send more messages at once):
class WorldServer
{
public List<ServerClient> clients = new List<ServerClient>();
public List<ServerClient> disconnectList;
public List<CharactersOnline> charactersOnline = new List<CharactersOnline>();
public int port = 8080;
private TcpListener server;
private bool serverStarted;
private int connectionIncrementor;
private string mysqlConnectionString = #"server=xxx;userid=xxx;password=xxx;database=xx";
private MySqlConnection mysqlConn = null;
private MySqlDataReader mysqlReader;
static void Main(string[] args)
{
WorldServer serverInstance = new WorldServer();
Console.WriteLine("Starting World Server...");
try
{
serverInstance.mysqlConn = new MySqlConnection(serverInstance.mysqlConnectionString);
serverInstance.mysqlConn.Open();
Console.WriteLine("Connected to MySQL version: " + serverInstance.mysqlConn.ServerVersion + "\n");
}
catch (Exception e)
{
Console.WriteLine("MySQL Error: " + e.ToString());
}
finally
{
if (serverInstance.mysqlConn != null)
{
serverInstance.mysqlConn.Close();
}
}
serverInstance.clients = new List<ServerClient>();
serverInstance.disconnectList = new List<ServerClient>();
try
{
serverInstance.server = new TcpListener(IPAddress.Any, serverInstance.port);
serverInstance.server.Start();
serverInstance.StartListening();
serverInstance.serverStarted = true;
Console.WriteLine("Server has been started on port: " + serverInstance.port);
}
catch (Exception e)
{
Console.WriteLine("Socket error: " + e.Message);
}
new Thread(() =>
{
Thread.CurrentThread.IsBackground = true;
/* run your code here */
while (true)
{
string input = Console.ReadLine();
string[] commands = input.Split(':');
if (commands[0] == "show online players")
{
Console.WriteLine("Showing connections\n");
foreach (CharactersOnline c in serverInstance.charactersOnline)
{
Console.WriteLine("Character name: " + c.characterName + "Character ID: " + c.characterId + "Connection id: " + c.connectionId + "\n");
}
}
continue;
}
}).Start();
while (true)
{
serverInstance.Update();
}
}
private void Update()
{
//Console.WriteLine("Call");
if (!serverStarted)
{
return;
}
foreach (ServerClient c in clients.ToList())
{
// Is the client still connected?
if (!IsConnected(c.tcp))
{
c.tcp.Close();
disconnectList.Add(c);
Console.WriteLine(c.connectionId + " has disconnected.");
CharacterLogout(c.connectionId);
continue;
//Console.WriteLine("Check for connection?\n");
}
else
{
// Check for message from Client.
NetworkStream s = c.tcp.GetStream();
if (s.DataAvailable)
{
StreamReader reader = new StreamReader(s, true);
string data = reader.ReadLine();
if (data != null)
{
OnIncomingData(c, data);
}
}
//continue;
}
}
for (int i = 0; i < disconnectList.Count - 1; i++)
{
clients.Remove(disconnectList[i]);
disconnectList.RemoveAt(i);
}
}
private void OnIncomingData(ServerClient c, string data)
{
Console.WriteLine(data);
dynamic json = JsonConvert.DeserializeObject(data);
string header = json.header;
//Console.WriteLine("Conn ID:" + json.connectionId);
string connId = json.connectionId;
int.TryParse(connId, out int connectionId);
string prefix = header.Substring(0, 2);
if (prefix != "1x")
{
Console.WriteLine("Unknown packet: " + data + "\n");
}
else
{
string HeaderPacket = header.Substring(2);
switch (HeaderPacket)
{
default:
Console.WriteLine("Unknown packet: " + data + "\n");
break;
case "004":
int accountId = json.data["accountId"];
SelectAccountCharacters(accountId, connectionId);
break;
case "005":
int characterId = json.data["characterId"];
getCharacterDetails(characterId, connectionId);
break;
case "006":
int charId = json.data["characterId"];
SendDataForSpawningOnlinePlayers(charId, connectionId);
break;
case "008":
Dictionary<string, string> dictObj = json.data.ToObject<Dictionary<string, string>>();
UpdateCharacterPosition(dictObj, connectionId);
break;
}
}
private bool IsConnected(TcpClient c)
{
try
{
if (c != null && c.Client != null && c.Client.Connected)
{
if (c.Client.Poll(0, SelectMode.SelectRead))
{
return !(c.Client.Receive(new byte[1], SocketFlags.Peek) == 0);
}
return true;
}
else
{
return false;
}
}
catch
{
return false;
}
}
private void StartListening()
{
server.BeginAcceptTcpClient(OnConnection, server);
}
private void OnConnection(IAsyncResult ar)
{
connectionIncrementor++;
TcpListener listener = (TcpListener)ar.AsyncState;
clients.Add(new ServerClient(listener.EndAcceptTcpClient(ar)));
clients[clients.Count - 1].connectionId = connectionIncrementor;
StartListening();
//Send a message to everyone, say someone has connected!
Dictionary<string, string> SendDataBroadcast = new Dictionary<string, string>();
SendDataBroadcast.Add("connectionId", clients[clients.Count - 1].connectionId.ToString());
Broadcast("001", SendDataBroadcast, clients, clients[clients.Count - 1].connectionId);
Console.WriteLine(clients[clients.Count - 1].connectionId + " has connected.");
}
And this is how the server send back data to the client:
private void Send(string header, Dictionary<string, string> data, int cnnId)
{
foreach (ServerClient c in clients.ToList())
{
if (c.connectionId == cnnId)
{
try
{
//Console.WriteLine("Sending...");
StreamWriter writer = new StreamWriter(c.tcp.GetStream());
if (header == null)
{
header = "000";
}
JsonData SendData = new JsonData();
SendData.header = "0x" + header;
foreach (var item in data)
{
SendData.data.Add(item.Key.ToString(), item.Value.ToString());
}
SendData.connectionId = cnnId;
string JSonData = JsonConvert.SerializeObject(SendData);
writer.WriteLine(JSonData);
writer.Flush();
//Console.WriteLine("Trying to send data to connection id: " + cnnId + " data:" + sendData);
}
catch (Exception e)
{
Console.WriteLine("Write error : " + e.Message + " to client " + c.connectionId);
}
}
}
}
Here is my ServerClient class:
public class ServerClient
{
public TcpClient tcp;
public int accountId;
public int connectionId;
public ServerClient(TcpClient clientSocket)
{
tcp = clientSocket;
}
}
Can you please show me how i should modify my Send function on the client to send the data as byte array so i can create "TCP Message Framing" and how should i change my the following part on the server:
foreach (ServerClient c in clients.ToList())
{
// Is the client still connected?
if (!IsConnected(c.tcp))
{
c.tcp.Close();
disconnectList.Add(c);
Console.WriteLine(c.connectionId + " has disconnected.");
CharacterLogout(c.connectionId);
continue;
//Console.WriteLine("Check for connection?\n");
}
else
{
// Check for message from Client.
NetworkStream s = c.tcp.GetStream();
if (s.DataAvailable)
{
StreamReader reader = new StreamReader(s, true);
string data = reader.ReadLine();
if (data != null)
{
OnIncomingData(c, data);
}
}
//continue;
}
}
which is responsible for receving data on the server ?
Is it possible to change only these parts from the Client and on the Server and make it continue to work but this time properly with TCP Message Framing ?
Of course the listener on the client and the Send function of the server i'll remake once i understand how this framing should look like.
Your frames are already defined by cr/lf - so that much already exists; what you need to do is to keep a back buffer per stream - something like a MemoryStream might be sufficient, depending on how big you need to scale; then essentially what you're looking to do is something like:
while (s.DataAvailable)
{
// try to read a chunk of data from the inbound stream
int bytesRead = s.Read(someBuffer, 0, someBuffer.Length);
if(bytesRead > 0) {
// append to our per-socket back-buffer
perSocketStream.Position = perSocketStream.Length;
perSocketStream.Write(someBuffer, 0, bytesRead);
int frameSize; // detect any complete frame(s)
while((frameSize = DetectFirstCRLF(perSocketStream)) >= 0) {
// decode it as text
var backBuffer = perSocketStream.GetBuffer();
string message = encoding.GetString(
backBuffer, 0, frameSize);
// remove the frame from the start by copying down and resizing
Buffer.BlockCopy(backBuffer, frameSize, backBuffer, 0,
(int)(backBuffer.Length - frameSize));
perSocketStream.SetLength(backBuffer.Length - frameSize);
// process it
ProcessMessage(message);
}
}
}
I'm sorry if I'm asking something asked before.
I'm developing a program that reads data received via TCP and using a StreamReader, and I just can't find how to make sure that any data won't be missed. Is there any way to create a middle buffer to read from there or something like that?
Here are the methods I've created for receiving data and write it to a text box:
public static void Connect(string IP, string port)
{
try
{
client = new TcpClient();
IPEndPoint IP_End = new IPEndPoint(IPAddress.Parse(IP), int.Parse(port));
client.Connect(IP_End);
if (client.Connected)
{
connected = "Connected to Exemys!" + "\r\n";
STR = new StreamReader(client.GetStream());
bgWorker = true;
}
}
catch (Exception x)
{
MessageBox.Show(x.Message.ToString());
}
}
-
public static void MessageReceiving(TextBox textBox)
{
try
{
string values =Conection.STR.ReadLine();
textBox.Invoke(new MethodInvoker(delegate () { textBox.AppendText("Exemys : " + values.Substring(2) + Environment.NewLine); }));
try
{
string messagetype = values.Substring(5, 1);
string ID = values.Substring(3, 2);
string checksum = values.Substring(values.Length - 2, 2);
if (checksum == CalcularChecksum(values.Substring(3, values.Length - 5)))
{
if (messagetype == "N")
{
if (ID == "01")
{
ID1 = values.Substring(3, 2);
messagetype1 = values.Substring(5, 1);
capacity1 = values.Substring(6, 1);
pressure1 = values.Split(',')[1];
sequencetime1 = values.Split(',')[2];
runstatus1 = values.Split(',')[3];
mode1 = values.Split(',')[4].Substring(0, 1);
checksum1 = CalcularChecksum(values.Substring(3, values.Length - 5));
}
if (ID == "02")
{
ID2 = values.Substring(3, 2);
messagetype2 = values.Substring(5, 1);
capacity2 = values.Substring(6, 1);
pressure2 = values.Split(',')[1];
sequencetime2 = values.Split(',')[2];
runstatus2 = values.Split(',')[3];
mode2 = values.Split(',')[4].Substring(0, 1);
checksum2 = CalcularChecksum(values.Substring(3, values.Length - 5));
}
}
}
}
catch(Exception x)
{
MessageBox.Show(x.Message.ToString());
}
}
catch (Exception)
{
MessageBox.Show("Client disconnected.");
}
}
Edit: what I'm trying to ask is how to always process the entire data before continue receiving? That would be the question.
A TCP stream is a stream of bytes that ends when the socket is closed by you or the remote peer or breaks because of network issues. In order to get everything from the stream you need to call the StreamReader.ReadLine method inside a loop into a buffer until some stop condition applies.
...
try
{
while(true)
{
...
input = STR.ReadLine();
if (input == <some stop condition>)
break;
...
}
}
...
That's a highly simplified example. TCP reading with partial buffer handling can be a complex beast so I recommend to use a library or framework if you're doing more than some hobby project.
Thanks for the response, but after searching, I've found what I was looking for. I wanted to store those messages (data) that were entering to make sure that I won't lose them (for any reason, more precisely that the receiving process would be faster than the message processing operation), so I used Queue to achieve this.
public static void RecepcionMensajes(TextBox textBox)
{
if (client.Connected == true)
{
try
{
string fifo = Conexion.STR.ReadLine();
Queue mensajes = new Queue();
//Aquí se ponen en cola los mensajes que van llegando, utilizando el sistema FIFO.
mensajes.Enqueue(fifo);
string values = mensajes.Dequeue().ToString();
textBox.Invoke(new MethodInvoker(delegate () { textBox.AppendText("Exemys : " + values.Substring(2) + Environment.NewLine); }));
I want to creating circle buffer in c#.
i have Arduino board that sending a lot of data
when discard buffer in serial port command some of data will be lost.
at this situation I need circle buffer for my data to ricived them .
InputData = ComPort.ReadByte();
object firstByte = InputData;
if (ComPort.IsOpen==true)
{
s = Convert.ToString(Convert.ToChar(firstByte));
temp1 += s;
lock (firstByte) {
if (Convert.ToInt32( firstByte)== 13)
{
temp = temp1;
temp1 = "";
LstGetInfo.BeginInvoke(new Action(()=>
{
if (temp !=null)
{
LstGetInfo.Items.Add(temp);
if (LstGetInfo.Items.Count >= 100)
{
LstGetInfo.Items.Clear();
// ComPort.DiscardInBuffer();
//ComPort.DiscardOutBuffer();
}
FileStream fs = new FileStream(filename, FileMode.Append);
var data = System.Text.Encoding.UTF8.GetBytes(String.Format("{0} {1}", temp, DateTime.Now.ToString("hh mm ss")) +"\r\n");
fs.Write(data, 0, data.Length);
fs.Close();
}
}));
LstGetInfo.BeginInvoke(new Action(() =>
{
LstGetInfo.TopIndex = LstGetInfo.Items.Count - 1;
}));
}
}
any solution for this problem ?
Try following :
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace ConsoleApplication72
{
class Program
{
static string buffer = "";
static void Main(string[] args)
{
}
static void AddToBuffer(byte[] rxData)
{
buffer += Encoding.UTF8.GetString(rxData);
}
static string ReadLine()
{
int returnIndex = buffer.IndexOf("\n");
if (returnIndex >= 0)
{
string line = buffer.Substring(0, returnIndex);
buffer = buffer.Remove(0, returnIndex + 1);
return line;
}
else
{
return "";
}
}
}
}
My code has shown below:
i already setup winpcap too. There arent any problem with programs which used by pcapdotnet
i think problem should be in layers but i dont know very well.
Console.Write("\r IP:Port = ");
string[] answer = Console.ReadLine().Split(':');
//answer[0] = ip , answer[1] = port
Console.WriteLine(answer[0] + "-"+answer[1]);
Attack_Void(answer[0], Convert.ToInt32(answer[1]));
Console.ReadKey();
}
private static void Attack_Void (string ip,int port)
{
try
{
IList<LivePacketDevice> allDevices = LivePacketDevice.AllLocalMachine;
PacketDevice selectedDevice = allDevices[0];
Console.WriteLine(selectedDevice.Description);
PacketCommunicator communicator = selectedDevice.Open(100, PacketDeviceOpenAttributes.Promiscuous, 1000);
while (true)
{
Thread tret = new Thread(() => Attack_Thread(communicator, ip, port));
tret.Start();
tret.Join();
tret.Abort();
}
} catch(Exception ex)
{
Console.WriteLine(ex.ToString());
}
}
private static void Attack_Thread(PacketCommunicator comm,string ip,int port)
{
string rnd_ip = random_ip();
comm.SendPacket(UdpPacket(rnd_ip,ip,port,false,100));
//comm.SendPacket(Udp_Pack_2());
PacketCounter++;
Console.WriteLine("Veriler {0} ip adresine, {1} ip adresinden gönderildi. NO: {2} ",ip,rnd_ip,Convert.ToString(PacketCounter));
}
private static string random_ip()
{
string srcip = rnd.Next(0, 255) + "." + rnd.Next(0, 255) + "." + rnd.Next(0, 255) + "." + rnd.Next(0, 255);
return srcip;
}
private static Packet UdpPacket(string src_ip, string rem_ip, int rem_port, bool default_port, int src_port)
{
int port;
if (default_port == true)
{
port = src_port;
} else { port = rnd.Next(0, 65535); }
EthernetLayer ethernetLayer = new EthernetLayer {
Source = new MacAddress("48:E2:44:5E:A8:07"),
Destination = new MacAddress("48:E2:44:5E:A8:07") };
IpV4Layer ipv4Layer = new IpV4Layer
{
// Source = new IpV4Address(src_ip),
Source = new IpV4Address("127.0.0.1"),
CurrentDestination = new IpV4Address(rem_ip),
Fragmentation = IpV4Fragmentation.None,
HeaderChecksum = null, // Will be filled automatically.
Identification = 123,
Options = IpV4Options.None,
Protocol = null,
Ttl = 100,
TypeOfService = 0,
};
UdpLayer udpLayer =
new UdpLayer
{
SourcePort = (ushort)port,
DestinationPort = (ushort)rem_port, //port
Checksum = null,
CalculateChecksumValue = true,
};
PayloadLayer payloadLayer =
new PayloadLayer
{
Data = new Datagram(new byte[] { 0x28 }),
};
PacketBuilder builder = new PacketBuilder(ethernetLayer, ipv4Layer, udpLayer, payloadLayer);
return builder.Build(DateTime.Now);
}
These are my code i actually made a udp server to take packet from this program but i cant send packet.
Also it doesnt give any errors.
And i dont know if my network modem enabled spoofing
Try this but remember it works only with IPv4.
using PcapDotNet.Core;
using PcapDotNet.Core.Extensions;
using PcapDotNet.Packets;
using PcapDotNet.Packets.Ethernet;
using PcapDotNet.Packets.IpV4;
using PcapDotNet.Packets.Transport;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Net;
using System.Net.NetworkInformation;
using System.Net.Sockets;
namespace UDP
{
public static class NetworkDevice
{
private static string GetLocalMachineIpAddress()
{
if (!NetworkInterface.GetIsNetworkAvailable())
{
throw new Exception("Network is not available. Please check connection to the internet.");
}
using (Socket socket = new Socket(System.Net.Sockets.AddressFamily.InterNetwork, SocketType.Dgram, 0))
{
socket.Connect("8.8.8.8", 65530);
IPEndPoint endPoint = socket.LocalEndPoint as IPEndPoint;
return endPoint.Address.ToString();
}
}
public static PacketDevice GetIpv4PacketDevice()
{
string localMachineIpAddress = GetLocalMachineIpAddress();
IEnumerable<LivePacketDevice> ipV4adapters = LivePacketDevice.AllLocalMachine.Where(w =>
(w.Addresses.Select(s => s.Address.Family))
.Contains(SocketAddressFamily.Internet));
foreach (var adapter in ipV4adapters)
{
var adapterAddresses = adapter.Addresses
.Where(w => w.Address.Family == SocketAddressFamily.Internet)
.Select(s => ((IpV4SocketAddress)s.Address).Address.ToString());
if (adapterAddresses.Contains(localMachineIpAddress))
return adapter;
}
throw new ArgumentException("System didn't find any adapter.");
}
}
public static class DefaultGateway
{
private static IPAddress GetDefaultGateway()
{
return NetworkInterface
.GetAllNetworkInterfaces()
.Where(n => n.OperationalStatus == OperationalStatus.Up)
.SelectMany(n => n.GetIPProperties()?.GatewayAddresses)
.Select(g => g?.Address)
.FirstOrDefault(a => a != null);
}
private static string GetMacAddressFromResultOfARPcommand(string[] commandResult, string separator)
{
string macAddress = commandResult[3].Substring(Math.Max(0, commandResult[3].Length - 2))
+ separator + commandResult[4] + separator + commandResult[5] + separator + commandResult[6]
+ separator + commandResult[7] + separator
+ commandResult[8].Substring(0, 2);
return macAddress;
}
public static string GetMacAddress(char separator = ':')
{
IPAddress defaultGateway = GetDefaultGateway();
if (defaultGateway == null)
{
throw new Exception("System didn't find the default gateway.");
}
string defaultGatewayIpAddress = defaultGateway.ToString();
return GetMacAddress(defaultGatewayIpAddress, separator);
}
public static string GetMacAddress(string ipAddress, char separator)
{
Process process = new Process();
process.StartInfo.FileName = "arp";
process.StartInfo.Arguments = "-a " + ipAddress;
process.StartInfo.UseShellExecute = false;
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.CreateNoWindow = true;
process.Start();
string strOutput = process.StandardOutput.ReadToEnd();
string[] substrings = strOutput.Split('-');
if (substrings.Length <= 8)
{
throw new Exception("System didn't find the default gateway mac address.");
}
return GetMacAddressFromResultOfARPcommand(substrings, separator.ToString());
}
}
public class UdpProcessor
{
private string _destinationMacAddress;
private string _destinationIPAddress;
private ushort _destinationPort;
private string _sourceMacAddress;
private string _sourceIPAddress;
private ushort _sourcePort;
private static LivePacketDevice _device = null;
public UdpProcessor(string destinationIp)
{
_sourcePort = 55555;
_destinationPort = 44444;
_device = NetworkDevice.GetIpv4PacketDevice() as LivePacketDevice;
_destinationIPAddress = destinationIp;
_sourceIPAddress = _device.Addresses[1].Address.ToString().Split(' ')[1]; //todo
_sourceMacAddress = (_device as LivePacketDevice).GetMacAddress().ToString();
_destinationMacAddress = DefaultGateway.GetMacAddress();
}
private EthernetLayer CreateEthernetLayer()
{
return new EthernetLayer
{
Source = new MacAddress(_sourceMacAddress),
Destination = new MacAddress(_destinationMacAddress),
EtherType = EthernetType.None,
};
}
private IpV4Layer CreateIpV4Layer()
{
return new IpV4Layer
{
Source = new IpV4Address(_sourceIPAddress),
CurrentDestination = new IpV4Address(_destinationIPAddress),
Fragmentation = IpV4Fragmentation.None,
HeaderChecksum = null,
Identification = 123,
Options = IpV4Options.None,
Protocol = null,
Ttl = 100,
TypeOfService = 0,
};
}
private UdpLayer CreateUdpLayer()
{
return new UdpLayer
{
SourcePort = _sourcePort,
DestinationPort = _destinationPort,
Checksum = null,
CalculateChecksumValue = true,
};
}
public void SendUDP()
{
EthernetLayer ethernetLayer = CreateEthernetLayer();
IpV4Layer ipV4Layer = CreateIpV4Layer();
UdpLayer udpLayer = CreateUdpLayer();
PacketBuilder builder = new PacketBuilder(ethernetLayer, ipV4Layer, udpLayer);
using (PacketCommunicator communicator = _device.Open(100, PacketDeviceOpenAttributes.Promiscuous, 1000))
{
communicator.SendPacket(builder.Build(DateTime.Now));
}
}
}
class Program
{
static void Main(string[] args)
{
Console.Write("\r IP:Port = ");
string ipAddress = Console.ReadLine();
new UdpProcessor(ipAddress).SendUDP();
Console.ReadKey();
}
}
}
Result in wireshark:
first question here!
I have written and borrowed code to form a IP Address and MAC address finder console application. It send Asynchrous Ping request, and for every IP Address it finds it does and ARP request to find the MAC address.
How can I configure this to work with a different submask than /24 (255.255.255.0) to find IP Address's?
This is NOT for a botnet. It is for my friend who is a network technician.
using System;
using System.Diagnostics;
using System.Net;
using System.Net.NetworkInformation;
using System.Net.Sockets;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading;
namespace FindIpAndMacPro
{
internal class Program
{
private static CountdownEvent _countdown;
private static int _upCount;
private static readonly object LockObj = new object();
private static void Main()
{
_countdown = new CountdownEvent(1);
var sw = new Stopwatch();
sw.Start();
Console.Write("Skriv in IP-Adress");
string ipBase = Console.ReadLine();
for (int i = 0; i < 255; i++)
{
string ip = ipBase + "." + i;
//Console.WriteLine(ip);
var p = new Ping();
p.PingCompleted += PPingCompleted;
_countdown.AddCount();
p.SendAsync(ip, 100, ip);
}
_countdown.Signal();
_countdown.Wait();
sw.Stop();
new TimeSpan(sw.ElapsedTicks);
Console.WriteLine("Took {0} milliseconds. {1} hosts active.", sw.ElapsedMilliseconds, _upCount);
Console.WriteLine("External IP (whatismyip.com): {0}", GetExternalIp());
Console.ReadLine();
}
private static void PPingCompleted (object sender, PingCompletedEventArgs e)
{
var ip = (string) e.UserState;
if (e.Reply != null && e.Reply.Status == IPStatus.Success)
{
{
string name;
string macAddress = "";
try
{
IPHostEntry hostEntry = Dns.GetHostEntry(ip);
name = hostEntry.HostName;
macAddress = GetMac(ip);
}
catch (SocketException)
{
name = "?";
}
Console.WriteLine("{0} | {1} ({2}) is up: ({3} ms)", ip, macAddress, name, e.Reply.RoundtripTime);
}
lock (LockObj)
{
_upCount++;
}
}
else if (e.Reply == null)
{
Console.WriteLine("Pinging {0} failed. (Null Reply object?)", ip);
}
_countdown.Signal();
}
[DllImport ("iphlpapi.dll")]
public static extern int SendARP (int destIp, int srcIp, [Out] byte[] pMacAddr, ref int phyAddrLen);
private static string GetMac (String ip)
{
IPAddress addr = IPAddress.Parse(ip);
var mac = new byte[6];
int len = mac.Length;
SendARP(ConvertIpToInt32(addr), 0, mac, ref len);
return BitConverter.ToString(mac, 0, len);
}
private static Int32 ConvertIpToInt32 (IPAddress apAddress)
{
byte[] bytes = apAddress.GetAddressBytes();
return BitConverter.ToInt32(bytes, 0);
}
private static string GetExternalIp()
{
const string whatIsMyIp = "http://automation.whatismyip.com/n09230945.asp";
var wc = new WebClient();
var utf8 = new UTF8Encoding();
string requestHtml = "";
try
{
requestHtml = utf8.GetString(wc.DownloadData(whatIsMyIp));
}
catch (WebException we)
{
Console.WriteLine(we.ToString());
}
return requestHtml;
}
}
}
first of all you had to calculate the network from subnetmask.if your subnetmask is 255.255.248.0 then you can easly calculate by subtracting the subnetmask from 255. example: 192.168.32.0/21 (255.255.248.0)
255.255.255.255
-255.255.248.0
---------------
0 . 0 . 7 . 255
the network range is from 192.168.32.0 to 192.168.39.255 (32 + 7)
every 0 is your ipBase here 192.168. the rest is done with for loops. so for all possible networks you need up to 4 for loops. one for every octet of an ip address.
maybe you can use an existing class for calculating subnets but i don't know such a class