We Keep Coding

epson ip printer insert cut-line after printing

I have below code to print a simple txt file on a epson ip ticket printer. How can I add a paper cut line / paper cut?
Socket clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
clientSocket.NoDelay = true;
IPAddress ip = IPAddress.Parse("000.000.000.000");
IPEndPoint ipep = new IPEndPoint(ip, 9100);
clientSocket.Connect(ipep);
byte[] fileBytes = File.ReadAllBytes("C:/xxx/xxx.txt");
clientSocket.Send(fileBytes);
clientSocket.Close();

UDP Multicast not receiving data

I'm trying to write a simple client to receive multicast data. I've tried many different iterations and none of them work. The environment that I am using is .netcore 2.2.2 and in a linux environment. I can see that the data is being sent to the proper interface via tcpdump but my client always gets stuck at the receive. I also have a program that was written in Java by a previous developer which properly receives data from interfaces below so I can confirm that the route does indeed work.
Attempt #1
mcastSocket = new Socket(AddressFamily.InterNetwork,
SocketType.Dgram,
ProtocolType.Udp);
IPAddress localIPAddr = IPAddress.Parse("10.51.254.2");
EndPoint localEP = (EndPoint)new IPEndPoint(localIPAddr, mcastPort);
mcastSocket.Bind(localEP);
mcastOption = new MulticastOption(mcastAddress, localIPAddr);
mcastSocket.SetSocketOption(SocketOptionLevel.IP,
SocketOptionName.AddMembership,
mcastOption);
EndPoint remoteEp = new IPEndPoint(mcastAddress, mcastPort);
// I have tried using (localIPAddr, mcastPort), (IPAddress.Any, 0),
// (localIPAddr, 0), (IPAddress.Any, mcastPort)
byte[] arr = new byte[4096];
Console.WriteLine("Socket setup");
var receivedBytes = mcastSocket.ReceiveFrom(arr, ref remoteEp );
Console.WriteLine("Got data");
Attempt#2
UdpClient client = new UdpClient();
client.ExclusiveAddressUse = false;
IPEndPoint localEp = new IPEndPoint(IPAddress.Parse("10.51.254.2"), 14382);
client.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
client.ExclusiveAddressUse = false;
client.Client.Bind(localEp);
client.JoinMulticastGroup(IPAddress.Parse("224.0.31.130"), IPAddress.Parse("10.51.254.2"));
Console.WriteLine("Listening this will never quit so you will need to ctrl-c it");
IPEndPoint remoteEp = new IPEndPoint(IPAddress.Parse("224.0.31.130"), 14382);
EndPoint remoteEndPoint = (EndPoint) new IPEndPoint(IPAddress.Any, 0);
while (true)
{
Byte[] data = client.Receive(ref remoteEndPoint);
Console.WriteLine("got data");
}
Any help would be greatly appreciated.
FIXED using the following code
try
{
mcastSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
IPAddress localIPAddr = IPAddress.Parse("10.51.254.2");
IPEndPoint localEP = new IPEndPoint(IPAddress.Any, mcastPort);
mcastSocket.Bind(localEP);
MulticastOption option = new MulticastOption(mcastAddress, localIPAddr);
mcastSocket.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.AddMembership, option);
EndPoint remoteEp = new IPEndPoint(localIPAddr, mcastPort);
byte[] arr = new byte[4096];
while (true)
{
var receivedBytes = mcastSocket.ReceiveFrom(arr, ref remoteEp);
Console.WriteLine($"Got data {receivedBytes}");
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}

How can I add SSL encryption to available TCP/IP socket

I am going to upgrade a system which used TCP connection without SSL. I want to add SSL encryption to the current connection without changing much in code. This is what there was previously in the code.
IPAddress ipAddress = IPAddress.Parse(IpAddress);
IPEndPoint remoteEP = new IPEndPoint(ipAddress, Port);
// Create a TCP/IP socket.
var client = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
client.BeginConnect(remoteEP,new AsyncCallback(ConnectCallback), client);
What I tried is this,
IPAddress ipAddress = IPAddress.Parse(IpAddress);
IPEndPoint remoteEP = new IPEndPoint(ipAddress, Port);
// Create a TCP/IP socket.
var client = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
client.BeginConnect(remoteEP, new AsyncCallback(ConnectCallback), client);
while (!client.Connected) { }
NetworkStream stream = new NetworkStream(client);
SslStream ssl = new SslStream(stream, false, ValidateServerCertificate);
But this is not doing what I need. At least ValidateServerCertificate delegate is not called.
What's wrong with my code?
IMPORTANT
I cannot remove this socket named client during the change because it will affect lot of other codes.

Sending and Receiving UDP packets

The following code sends a packet on port 15000:
int port = 15000;
UdpClient udp = new UdpClient();
//udp.EnableBroadcast = true; //This was suggested in a now deleted answer
IPEndPoint groupEP = new IPEndPoint(IPAddress.Broadcast, port);
string str4 = "I want to receive this!";
byte[] sendBytes4 = Encoding.ASCII.GetBytes(str4);
udp.Send(sendBytes4, sendBytes4.Length, groupEP);
udp.Close();
However, it's kind of useless if I can't then receive it on another computer. All I need is to send a command to another computer on the LAN, and for it to receive it and do something.
Without using a Pcap library, is there any way I can accomplish this? The computer my program is communicating with is Windows XP 32-bit, and the sending computer is Windows 7 64-bit, if it makes a difference. I've looked into various net send commands, but I can't figure them out.
I also have access to the computer (the XP one)'s local IP, by being able to physically type 'ipconfig' on it.
EDIT: Here's the Receive function I'm using, copied from somewhere:
public void ReceiveBroadcast(int port)
{
Debug.WriteLine("Trying to receive...");
UdpClient client = null;
try
{
client = new UdpClient(port);
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
IPEndPoint server = new IPEndPoint(IPAddress.Broadcast, port);
byte[] packet = client.Receive(ref server);
Debug.WriteLine(Encoding.ASCII.GetString(packet));
}
I'm calling ReceiveBroadcast(15000) but there's no output at all.

Here is the simple version of Server and Client to send/receive UDP packets
Server
IPEndPoint ServerEndPoint= new IPEndPoint(IPAddress.Any,9050);
Socket WinSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
WinSocket.Bind(ServerEndPoint);
Console.Write("Waiting for client");
IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0)
EndPoint Remote = (EndPoint)(sender);
int recv = WinSocket.ReceiveFrom(data, ref Remote);
Console.WriteLine("Message received from {0}:", Remote.ToString());
Console.WriteLine(Encoding.ASCII.GetString(data, 0, recv));
Client
IPEndPoint RemoteEndPoint= new IPEndPoint(
IPAddress.Parse("ServerHostName"), 9050);
Socket server = new Socket(AddressFamily.InterNetwork,
SocketType.Dgram, ProtocolType.Udp);
string welcome = "Hello, are you there?";
data = Encoding.ASCII.GetBytes(welcome);
server.SendTo(data, data.Length, SocketFlags.None, RemoteEndPoint);

Winforms C# app using sockets works under winXp, but throws error under Windows 7

Here's the properties and the method that connects.
protected Socket _socketConnection =
new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
private string _host = "";
private string _hostIpAddress = "";
private int _port = 0;
public void Connect()
{
// don't allow two connections
if (_socketConnection.Connected)
return;
// get the ip address from the hostname
IPHostEntry ipHostEntry = Dns.GetHostByName(_host);
_hostIpAddress = ipHostEntry.AddressList[0].ToString();
// create the socket endpoint
IPAddress ipAddress = IPAddress.Parse(_hostIpAddress);
IPEndPoint ipEndPoint = new IPEndPoint(ipAddress, _port);
// connect
try
{
_socketConnection.Connect(ipEndPoint);
if (OnConnect != null)
OnConnect();
}
catch
{
throw;
}
}
When I run the app under Windows 7 I get the following error:
An unknown, invalid, or unsupported option or level was specified in a getsockopt or setsockopt call.
I've seen messages that talk about setting a particular option on the socket, but this is an app that has been working for years and is only happening when this app is installed on Windows 7.
Is there a compatibility flag to tweak or something?
Thanks!

Perhaps on Win7 you get a IPv6 as the _hostIpAddress. Try using something like this when instantiating the socket:
if(Socket.OSSupportsIPv6 && _hostIpAddress.AddressFamily == AddressFamily.InterNetworkV6)
{
// newer OS
_socketConnection = new Socket(
AddressFamily.InterNetworkV6,
SocketType.Stream,
ProtocolType.Tcp);
_socketConnection.SetSocketOption(SocketOptionLevel.IPv6, SocketOptionName.IPv6Only, 0);
} else {
// older OS
_socketConnection = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
}