datagram | Easy data | Natural Language Processing library

I have four modules. The client is sending messages and the server is receiving messages. Once the server receives the message, it tries to send the message to the MPSC channel. I put the receiver in the other .rs file where I intend to receive the message.

I am not getting any message on the receiver side.

Maybe an infinite loop on the server side creates a problem, but is there a way to make this channel communication working?

client.rs

I am creating simple client server communication with unix datagram socket in Rust. I am receiving message to server from client with bytes length but not able to converting back to the original string I sent from client. I have tried https://doc.rust-lang.org/std/str/fn.from_utf8.html and from_utf8_lossy but had no success. Here is the code.

How to get original string on the server?

I'm currently trying to scan over all available channels while in monitor mode to find IP traffic on open networks around me. I noticed that IP in sniffed_packet was never true, and after some debugging, found that frames aren't being parsed properly.

I'm sniffing using this:

My DLL gets injected into a program and then hooks to connect, send, recv and closesocket functions using Detours. The point is to stop the program from connecting to some server and instead communicate with my DLL directly.

My recv function uses an infinite loop, just waiting for any data to send to the program. When closesocket is called that loop is broken and everything works fine.

But there's one program written in C# that just hangs when I close it. Its error log says:

SocketException: A request to send or receive data was disallowed because the socket is not connected and (when sending on a datagram socket using a sendto call) no address was supplied.

at System.Net.Sockets.Socket.Disconnect (Boolean reuseSocket) [0x00000] in :0

The exception is expected since the socket never connects to anything. But is there any workaround for this? What does System.Net.Sockets.Socket.Disconnect call under the hood? What other function do I need to hook to detect that?

I've tried hooking to shutdown, setsockopt, WSACancelBlockingCall, WSACleanup, WSASend, WSASendDisconnect, WSASendMsg, WSASendTo, WSARecv, WSARecvDisconnect and WSARecvFrom. None of them get called.

I'm trying to make a console chat app in python using socket library.

Whenever I send a message to the server, the server code crashes with the following message:

OSError: [WinError 10057] A request to send or receive data was disallowed because the socket is not connected and (when sending on a datagram socket using a sendto call) no address was supplied

Server code

I have the following data from a datagram message received by UDP socket:

I had a problem with UDP Datagrams in that I could not receive UDP packets from a server but I could send them. I looked through many examples but could not figure out what was wrong with my code. I finally found hints to what was going wrong from different sites.

I have thus updated the question here in case it might help someone in the future. The code below is working over a WiFi network on a LG phone and was built on Android Studio 4.2 (29/4/2021); SDK Platform 30; Kotlin 1.5.0

At the end of the code section below I have written some comments as to what was causing my code not to work.

This is my MainActivity code

I'm new to c++ and need help. I use an UDP server to receive structure however i have problem to read it , the client send a structure I call : ChannAccessReq so the structure is send and the server receive it with RECVFROM and I use a general structure by reading the header (H1) of the struct only and then i do a read when a condition is fullfill with a more precise structure (temp2) for the buffer. However the client need to send the message twice , the first time it goes until recvfrom and the second it reach read() (i think) I tried all the day and wonder if its the size of the buffer ?

I think the most sensitive part is in the server with the recvfrom() who have a struct different from the read() just after..

I hope it's clear!

here is the server :

I would like experts' advice on the usage of the socket option IP_MULTICAST_IF ("set multicast interface") combined with static multicast routes.

On a LAN, a multicast IP datagram is commonly sent in a multicast Ethernet frame (IP/MAC multicast destination address mapping). On a multi-homed Linux system (kernel 5.11), I have noticed that the socket option IP_MULTICAST_IF modifies the behavior as follow:

• Without static route, the multicast IP datagram is always sent in a multicast Ethernet frame, with or without IP_MULTICAST_IF.
• With a static route, without IP_MULTICAST_IF, the multicast IP datagram is sent in a multicast Ethernet frame.
• With a static route, with IP_MULTICAST_IF, the multicast IP datagram is sent in a unicast Ethernet frame to the gateway.

First question: With a static route for the multicast packet, should the multicast IP datagram be sent in a multicast Ethernet frame or in a unicast Ethernet frame to the gateway?

Second question: Whatever is the answer to the first question, why does the socket option IP_MULTICAST_IF switch from multicast to unicast MAC addressing?

The Linux man page ("man 7 ip") is not very explicit: