Networking :: Socat - Sending Binary Data From Client To Server
Apr 15, 2010
I am trying to redirect connection to port 8980 to execute a telnet command to a local machine
by issuing the following command :
In Server 1 :
socat TCP-LISTEN:8980,fork EXEC:/myscript,reuseaddr
My script contains
#!/bin/bash
telnet 192.168.20.12 //local Server 2
I am sending Binary data from the client to Server 2 via Server 1. So it happens that I have some characters in Hex translated to special characters in ASCII like open brackets or Commas etc.. and that closed the socket between the two machines.
shed some light on what I am doing. I am wondering if I just havehings back to front.Server (MESH):Fedora 13Firewall ports open tcp 22(ssh), tcp 873(rsync)sshd service started
I am coding a http server which has to send the file(s) such as images, .avi files, .mpeg, that the client is going to request. I have been trying of sending files through sockets.
I am using centos 5, want to send a sets of binary data to other bluetooth device I know how to sent a file but dont know how to sent raw data. My case is like this I have a bluetooth device I need to send data to then after it process I need to get it back, I plan to do this all using terminal is that possible?
we have a minor issue with time synchronization in proprietary equipment.the client needs to synchronize time with server, but not using NTP.it is not very important so doesn't need to be done often.the problem is that it won't synchronize. I can see the server is sending tcp packet with date&time, but the client ignores it.I suspect the problem is in format (manual specifies there are two possible options like MM: DD: YYYY and so on, but server seems to use some other)Is there an easy way to run some program in Linux Debian, to send that simple packet with correct date?
i have problem in sending emails using outlook on my client machines i.e XP i am getting the error Relay access denied. i am using fedora 9 as our server. with dovecot and postfix and fetchmail.it was working fine previously .
Since today morning we are getting this error, could not track down the cause
We are running : Postfix Amavist and Clam
70A6C45A1CE: to=<actualemailid@yahoo.com>, relay=none, delay=0, status=deferred (delivery temporarily suspended: lost connection with 127.0.0.1[127.0.0.1] while sending end of data -- message may be sent more than once).
I would like to send a data using one thread and receive a data using other thread by using a same socket connection using USD sockets. The calls i am using for sending and receiving are send(), recv(). let me know is it possible to send and receive the data parallel (Full duplex communication)?
I want to send raw data to a usart port of my board connected to linux box. i know the command
echo "abcxyz" > /dev/<usb_dev_file_name>
would write the raw bits for characters abcxyz to the usb device but the problem is how do i know which device file to write to?there are so many in my /dev.
I'm working on testing some software, and I have a question. We have several files of binary data that we need to push through our application to test. It communicates via simple TCP sockets. Is there a way I can send this data to the socket from the command line? I tried doing something like this, but telnet never picked up the data.
I am writing a code in Python where a socket client changes data with the server. That works nice if the connection is up. However it is also supposed to work offline. So I need to be able to detect if the connection is up before sending data, but I was not able to do so. A summary of the code is like that:
if connected: data = "some data byte" try: socket.send(data) except: connected=False socket.close()
If I unplug the cable after the connection is ready then the socket sends data and does not detect the connection failure. What is amazing is that the client detects the connection failure just after the cable has been plugged again. Of course there is a loop in the code above and always that connected==False a new connection is made. How could the program detect the connection failure before sending data and then lead the code to an exception?
Here is my problems :I have two networks :1. LAN (10.1.x.x subnet 255.255.0.0), and2. my internet public (IP 202.xx.xxx.xxxx subnet 255.255.255.240)I have an application in my LAN PC (10.1.2.240) which broadcast udp packet to its client. The client in my LAN can receive the udp packet, no problem.My question is how netcat/socat can RELAY the udp broadcast packet to one of my IP public address so the message can be received by other client from internet ?
trying to create something that will periodically send messages to a serial device using socat, take the response from the device and format it, then take the formated data and send it out UDP to a specific IP/Port.I tried to do something along the lines ofsocat <readline> <serial device> | parse script/program | socat -u <readline> <UDP:IP:Port> but didn't have any success.socat READLINE,history=$HOME/.cmd_history /dev/ttyS1,raw,echo=0,crnl | format.sh | socat -u READLINE,history=$HOME/.cmd_history UDP:IP:Port
i have installed nfs server on my redhat machine.when i want to mount shared data from client(suse)machine the following error occur. "mount.nfs: mount to NFS server '10.3.31.146:/home/usbtest' failed: System Error: No route to host" both machines ping each other successfully.
i have server and client, my client is sending data of 100 bytes at a time but server side i am receiving 50 bytes once and in next iteration i am calling recv function for receiving remaining 50 bytes but the receive is blocked it doesn't reading any data? Does any body have a idea let me know
I am writing a TCP server in C, and the server listens to incoming client connections and accepts them. It then creates a thread to handle the client. The clients are expected to only receive data from my server and not send any data. So if I use a select() call with a recv(), I believe that the recv() will just block forever since there will not be any data coming from the client. If I use a non-blocking recv(), then this will just return a 0 which tells me nothing because the client is not expected to send any data. I am not sure if I have misunderstood some socket concepts, but I need a solution to detect when the client has disconnected so that I can close the socket and stop sending data to the client. As I understand it, simple ACKs etc are not captured by the recv(), and only data sent by the client will cause recv() to return a non-zero value, so I am not sure how to know when the client has disconnected.
I manually rotated my catalina.out file, and now the file jumps to 30+Mb and when I try to view it, less tells me it might be a binary file. It sure appears to have binary data in it, about 30meg of it.
I did the rotate via a copy: copy catalina.out to another file cat /dev/null > catalina.out
I have tried using echo: echo "" > catalina.out ...also with the same result.
This application isn't something I can just bounce when necessary. It kind of appears that the original file is still there - sort of. But is it not readable text anymore.
SunOS 5.10 tomcat 5.5.26 (version required by app vendor)
I have created a file using open() and written data to it. Data appears as normal characters in the file. How to save these characters in a binary format in that file using C language? Here I mean that the characters should be actually stored as 0 and 1. Do I have to convert the whole data using some function or there is some standard way to do it in Linux?
Can I make my messages directly appear at client from server? Normally we type tailf /var/log/messages to see messages sent by other machine. So can I send my messages directly at command prompt?
In order to debug a problem, I want to list down as many as possible reasons of a server (SOAP server running on Fedora 10) sneding RST in middle of packet transfer. Please note that in my case, SYN and ACK of initial handshake went through. Server received request from client and started data transfer but then suddenly, server sent RST in between data transfer.
I am seeing log messages that I don't understand. If I run tail -f /var/log/messages, some times I will see this this sort of repeating pattern. I don't know if I have cut at the start of the sequence or not. Incidentally, this is a normaly well-behaved client/host.
[Code].....
Why is the client repeatedly sending the (1/4) message and then timing out?
I need to know how to configure automate sending sms if server reboot and shutdown? Now i just set sms notification once my server it's UP by create scripts in /etc/rc.d/rc.local while booting then from server sending sms notification. SMS - using gnokii attached mobibe phone. Server - Fedora 10
I have a question regarding Bluetooth with Bluedevil. Finally I got a connection working in one direction: sending files from my mobile (Google Nexus One with Android 2.3.3) to the computer. But I can not send files from my computer to the phone. I also tried to send files from my desktop to my Laptop and it fails. I also tried it the other way around: from Laptop to Desktop... fail.
What is it? Is it still a bug in Bluedevil and all I can do is wait? Or is there some package missing? The following packages (regarding bluetooth) are installed:
I have a desklet that, occasionally after toying with network stuff, will tell me that large amounts of data are being sent/received. What's a good way to determine what processes are occupying these resources?!
