sockets

How to correctly relay TCP traffic between sockets?

I'm trying to write some Python code that will establish an invisible relay between two TCP sockets. My current technique is to set up two threads, each one reading and subsequently writing 1kb of data at a time in a particular direction (i.e. 1 thread for A to B, 1 thread for B to A). This works for some applications and protocols, but...

When binding a client TCP socket to a specific local port with Winsock, SO_REUSEADDR does not have any effect

I'm binding a client TCP socket to a specific local port. To handle the situation where the socket remains in TIME_WAIT state for some time, I use setsockopt() with SO_REUSEADDR on a socket. It works on Linux, but does not work on Windows, I get WSAEADDRINUSE on connect() call when the previous connection is still in TIME_WAIT. MSDN is...

How do I check if output stream of a socket is closed?

I have this code: public void post(String message) { output.close(); final String mess = message; (new Thread() { public void run() { while (true) { try { output.println(mess); System.out.println("The following message was successfully sent:"); ...

C question on casting

Can anybody explain me this statement! pin.sin_addr.s_addr = ((struct in_addr *)(hp->h_addr))->s_addr; ...

Is it possible to send datagrams over TCP?

In theory nothing prevents using TCP socket with SOCK_DGRAM. What you'll get is reliable datagram transport. Is this possible using Berkeley sockets? ...

Flex: client / server messaging question (RPC or socket ?)

hi, I'm building a Flex application, which is going to perform many server requests (let's say, that almost all interactions require an update from server). At the moment I'm using remote procedure calls for it. But I was wondering if using a socket would be better. In other terms, is maybe better to keep the connection alive rather t...

Raw Sockets on Android

I want to create an application that runs on Android and uses Raw Sockets. I see there isn't any raw socket support in the java.net.* or the android.net.* libraries. Are raw sockets possible on Android? ...

How to recover gracefully from a C# udp socket exception

Context: I'm porting a linux perl app to C#, the server listens on a udp port and maintains multiple concurrent dialogs with remote clients via a single udp socket. During testing, I send out high volumes of packets to the udp server, randomly restarting the clients to observe the server registering the new connections. The problem is th...

Reason for not properly closed socket?

Here is what I am trying to do: The server sends message to connected clients when new messages are available. The client, on the other hand, when connected, tries to send a message to the server using send() and then receive message using recv(), right after that, the client calls close() to close the connection. Sometimes, after the c...

parallel-python error: RuntimeError("Socket connection is broken")

I am using a simple program to send a function: import pp nodes=('mosura02','mosura03','mosura04','mosura05','mosura06', 'mosura09','mosura10','mosura11','mosura12') nodes=('miner:60001',) def pptester(): js=pp.Server(ppservers=nodes) js.set_ncpus(0) tmp=[] for i in range(200): tmp.append(js.submit(ppworktest,(...

Can I force Apache 2.2 connection close from inside a C module?

Hello, We'd like to have a more fine-grained control on the connections we serve in a C++ Apache 2.2 module (on CentOS 5). One of the connections needs to stay alive for a few multiple requests, so we set "KeepAlive" to "On" and set a short keep-alive period. But for every such connection we have a few more connections from the browse...

Java: Sockets or RMI?

Hi, I need to separate our application into a light-weight gui application and a business logic application. This won't be a client/server setup as such, as the 'server' component will only have one client. The other limitation in the application is that it has only one entry/exit point. Therefore if we were to use RMI, it would only e...

Receiving broadcast packets using packet socket

Hello I try to send DHCP RENEW packets to the network and receive the responses. I broadcast the packet and I can see that it's successfully sent using Wireshark. But I have difficulties receiving the responses.I use packet sockets to catch the packets. I can see that there are responses to my RENEW packet using Wireshark, but my functi...

C# Proxy using Sockets, how should I do this?

I'm writing a proxy using .NET and C#. I haven't done much Socket programming, and I am not sure the best way to go about it. What would be the best way to implement this? Should I use Synchronous Sockets, Asynchronous sockets? Please help! It must... Accept Connections from the client on two different ports, and be able t...

Marshal.PtrToStructure (and back again) and generic solution for endianness swapping

I have a system where a remote agent sends serialized structures (from an embedded C system) for me to read and store via IP/UDP. In some cases I need to send back the same structure types. I thought I had a nice setup using Marshal.PtrToStructure (receive) and Marshal.StructureToPtr (send). However, a small gotcha is that the network bi...

Sockets and COBOL

I have received a job at a hospital which still uses COBOL for all organizational work, the whole (now 20 Terabyte) database (Which was a homebrew in, guess what, COBOL) is filled with the data of every patient since the last 45 (or so) years. So that was my story. Now to my question: Currently, all sockets were (from what I've seen) i...

FTP monitoring and downloading of new files

Hi Guys, I have an FTP monitoring/downloading application using C# sockets. I got this error message: 421 Disconnecting you since you were inactive for 300 seconds. Can someone have an explanation for this? I did a search on this one but still I can't seem to find a good explanation. Thanks. ...

Need Descriptive architecture to develop file server in dot net.

Hello All, I have to develop a file server service that transfer file form a specified location to its client.Client when starts, requests file to server for current date. Server transfer those file to client. Now constrains are as 1.Application run in intranet. 2.Need to transfer multiple file at a single transaction. 3.File size may ...

How to to icmps and traceroutes in Java

For some reason i cannot even phantom, Java does not have primitives for ICMPs and traceroute. Any idea how to overcome this? Basically im building code that should run in *nix and windows, and need a piece of code that will run in both platforms.. Thanks! ...

How can I send the output of external programs to a Perl socket?

I have just started to learn socket programming using Perl. Is there a method to send the output (STDOUT) data/images from already running scripts/tools using Perl socket programming? ...