I need to create a C/C++ program in Linux that succeeds in detecting how many tcp-sockets and what tcp-sockets are created by the other processes in the system in a particular time interval (e.g., the interval time this application is running in). Then, I'd need to get some information like local/remote port number and local/remote ip address of each of these sockets.
View 8 RepliesI 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:
Code:
try:
socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
socket.connect( (self.host, self.port) )
connected = True
except:
connected = False
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?
I am trying to make a file proxy server...that is any request of file a client makes goes to the proxy server...it checks it in cache if not there then asks main server for the file. to act as a server for client and as client for server...how to do it in a single program. I tried with 2sockets with different ports one for client-proxy server and one for proxyserver-main server.But it does not workAm i doing something wrong or is there any other method
View 2 Replies View RelatedI am trying to write a chat program with sockets as part of my project. I made a socket server, using fork ,I tried to connect it with different clients.Each client will send messages to others through server.So server has a shared memory storing every clients username and client id. But the problem facing is first client is able to sent messages to every other client formed after that.But second client onwards it is not able to sent message to previously connected ones. Server is not able to write on those client id's.
View 4 Replies View RelatedIs there any way to implement a simple ping script in C (unix)? I'm programming simple OpenWRT scripts.
I have found some examples of ping in C:
[URL]
However, nothing happens, nothing is sent.
When I look at the code, in the portion where the socket is created, I can see that the socket is not binding to any interface:
Code:
if ((sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)) == -1)
{
perror("socket");
exit(EXIT_FAILURE);
}
setsockopt(sockfd, IPPROTO_IP, IP_HDRINCL, &optval, sizeof(int));
Instead, it uses "setsockopt" to set some options.
My guess is that it is trying to send packets over the eth0 interface instead over the wl0 (wireless) interface (which is the one I want to use to send pings).
Now, my question is: Is there any other way to send pings in C by binding to an interface?
I am struggling a little on how to best approach this problem. I have wrote a server program that runs via xinetd, that obviously spits out data at the client end. Fairly straightforward stuff?There is a point in my server code where I need to display an image/gui i.e something that runs on X11 that prompts a user to perform a task on the display connected at the the server side.So far I have written a test program that displays some text at the client end and then launches the browser at the server end. I have also set the following export. Code: export DISPLAY=:0 and then goes on to launch my web browser. Works great when ran locally on the server and when I remotely telnet in to the server and run the code.
However when I try to run the same piece of code as a xinetd service the export seems to have zero affect and the client terminal window displays errors associated with there not being a X11 server running.The code launches fine when I create a socket to serverip:6556 it just the ability to display gui programs to another display that does not seem to be working.
Can someone help me with this problem,trying to send a packet,using tcp/ip,the packet should look like this:
Code:
field 1: SOCKS protocol version, 1 byte (0x05 for this version)
field 2: status, 1 byte:
0x00 = request granted
0x01 = general failure
0x02 = connection not allowed by ruleset
0x03 = network unreachable
0x04 = host unreachable
0x05 = connection refused by destination host
0x06 = TTL expired
0x07 = command not supported / protocol error
0x08 = address type not supported
field 3: reserved, must be 0x00
field 4: address type, 1 byte:
0x01 = IPv4 address
0x03 = Domain name
0x04 = IPv6 address
field 5: destination address of
4 bytes for IPv4 address
1 byte of name length followed by the name for Domain name
16 bytes for IPv6 address
field 6: network byte order port number, 2 bytes
and this is my code:
Code:
int domainLen = strlen(domain);
char reply[domainLen + 7];
reply[0] = 5; // version
reply[1] = 0; // succed
reply[2] = 0; // reserved
reply[3] = 3; // its a domain
reply[4] = domainLen;; // lenght of domain
for(int j = 0; j < domainLen; ++j)
{
reply[j + 5] = domain[j];
}
reply[5 + domainLen] = 80; // port
reply[20] = '�';
Send(reply, sizeof(reply));
domain is "www.google.com". Am I doing it right ? I dont know much about bits.
I am doing a project where 2 clients connect to server and communicate (chat) and transfer data one after other using sockets. I have working code for this in C language. Now our main aim is to create a communication link where two clients transfer multiple streams data parallely. To be more precise i want to transfer images files and audio files parallel at same time, so is it possible to send data parallel using one socket connection?
View 3 Replies View RelatedI have a problem creating my second socket in client file. the program was running well but when I try to add another socket to connect to the same server, I got a problem connecting to the first socket! it doesn't make sense. the original code was:
sockfd[i] = socket(AF_INET, SOCK_STREAM, 0);
if(sockfd[i] < 0) error("(MAIN) - Error openning socket 1");
port_num[i] = portno;
bzero((char*) &serv_addr[i], sizeof(serv_addr[i]));
[Code].....
I am using the API libpcap in order to filter the traffic of the port 53 from my PC ro other PCs, in other words the DNS traffic.I want to get more information about the DNS traffic that is being sent to the DNS server, in other words the queries. So far I have no idea how to read the information data or payload of the UDP package in order to read the content of the traffic for example if there is any PTR, A, MX, etc Resource Record.According to the RFC 1053 there is a header that is possible to use in order to easily get this info.
View 5 Replies View RelatedNextPendingConnection () returns a new socket with respect to a new client. This new QSocket is passed to the connect () function which connects it to a SLOT 'xyz' with SIGNAL 'readyRead()'. Now in the SLOT 'xyz' how I am supposed to automate the monitoring of ALL connected sockets to see whether some data is available on them? One pathetic way would be to run all the sockets through a for loop and check each one of them for the data. Secondly, I read up on QSocketNotifier() here: [URL]. But I am not sure if that is the correct thing.
View 3 Replies View RelatedI 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.
char info [256];
bzero(info, 256);
//memset(&info,0,sizeof(info));
read(socket, info, 255);
write(socket, HTTP, 255);
FILE *fl= fopen(info,"rb");
fseek(fl, 0, SEEK_END);
long len = ftell(fl);
printf("largo: %ld", len);
unsigned char *ret = (char*) malloc(len);
fseek(fl, 0, SEEK_SET);
fread(ret, 1, len, fl);
However, it's supposed to be shown in Mozilla Firefox (as the client). But it is not doing it, so.. It's just not getting the complete file.
I have a problem passing a file descriptor from one process to another.
I have two processes A and B. Both are running in different network and
filesystem namespaces, so it is impossible to use unix domain sockets or
net sockets to pass a file descriptor from process A to process B.
The usage of STREAMS is also impossible, as you can see in
fixunix.com/unix/84093-streams-pipes-ioctl-i_sendfd.html
[quotation begin]
Linux doesn't have STREAMS, which are the System V way
of doing this task. ...
[quotation end]
Are there additional possibilities for file descriptor passing like
using named pipes or something like that or does anybody know
a good workaround for this problem ?
I have written a server application which has select for both incoming new client connection requests and incoming data from client. I am able to process incoming connection requests and client data.
For example, server has 8 clients connected to it. If client 3 disconnects from server, how will server come to know this client has disconnected and to close its client socket fd gracefully? Does server's select get data on that client socket fd as 'close' data or any error code in recv() function that notifies server to close this client socket fd? Also if client disconnects abruptly without sending close request to server, how should server handle this? Does server get "EPIPE" error?
Hi, is it possible to send a request to a http server without using sockets?
View 7 Replies View RelatedIam using socket programming in one of my problem. The scenario is like this.
=>one module is working as a socket server(process p1) is able to handle client sockets on that port.
=>one module is working as socket client (process p2) is connected to server socket and Tx/Rx data on this socket. This module has some more threads, based on received data from server socket it will connect to http on other thread and get information...
=>one more module is working as socket client (process p3) is also connected to server socket and doing some other transactions.
Here my problem is when in presence of p2, p3 http connection taking more time than the expected. If we wont start p3(means only one server-client socket) then http connection is fast enough.
constructing a protocol where in it involves sending and receiving different files, so sending data over consists of file name, size of the file and content of the file, so while receiving can i use functions like strchr() to differentiate these fields for sockets? so to allocate memory for file to save i need to have its size.
View 3 Replies View RelatedI'm trying to add local sockets in my multi-threaded application in order to exchange data between threads. The only problem I got is that most of the information available on the net is related to internet oriented socket programming whileI want to perform local connections. got a thread that does the sniffing via libpcap. And I would like that thread to send each captured packet to a second thread that will analyse the packetof the thread implementations is written in separate .h file.Or maybe there is a more effective method of exchanging data between threads
View 14 Replies View RelatedI am working on a script and I want it to detect if CTRL+C is pressed at any time during the script and have it not Break the script and display a message stating to use CTRL+Z instead. How can I do that?
View 9 Replies View RelatedMy C++ program must be able to detect EVERY Wireless Network Interfaces under Linux operating system and display the interface names on the screen.How can my application achieve this?Is there any sample codes?Is there any third party libraries can do this?Notes: The detected wireless network interfaces should also include the virtual interfaces, like the one created by Aircrack-NG's Airmon-NG script.
View 1 Replies View RelatedI am attempting to write a server application in C on a linux machine which listens for TCP connections and transfers data. I am trying to detecton the server side when the connection is broken. The closest thing that I got to work was looking at the return value from sending data. For example the server�s job is to mainly read data from the socket but to test if the connection is still up the server sends data periodically back to the client. I look at the return value from send() to determine if the connection is broken e.g.
Code:int ret = send(session->clientSocket, &data[sentCnt], count - sentCnt, MSG_NOSIGNAL)I found that this does not immediately return an error when the connection is broken. The reason for this is because even though the connection is broken send() is still successful because it is able to put it on the network buffer. To fix the issue I did the following things;
Code:
//set send timeout
struct timeval timeout;
[code]...
I have question about the UNIX sockets. my goal is to connect multiple sockets from a single client to a single server and keep them open...I'm not sure if that is possible to create or not. Do you have any suggestion or an example of code?
View 1 Replies View RelatedI write the network driver. Transmission of packets in user space I do through netlink socket`s. In user space there is a handling of packets and their transmission on other device (however, it isn't important).
Problem in that any time, packets through the driver in system, and is reverse, are transferred normally. But then there comes the moment when the kernel crash. If to look in syslog it seems to me that comes deadlock. Also I think that it is related with netlink socket`s.
I can't find the information on that anywhere how correctly to use netlink socket`s in kernel space. Can at you will any a reason into the account of synchronization of sockets and the driver in kernel space?
I can give the driver code if it is necessary.
We have a system where users can upload files, and then various things happen depending on what kind file it is. The check uses the file command.But for Office 2007 files, the file command says it is a ZIP file.
These files are in fact ZIP files, I can unzip them, and then I get a lot of small weird files. We don't need to do anything about these files, but it's a problem when the system handles them as ZIP files.So I need some way of detecting these files, and not by file extension (.docx) since it is often incorrect. Many of the users are Macintosh users and they don't always use a file extension at all.
I will have to code this. However I am lacking of time since I have too much to do. make a short code bash/dash to prompt the country with Zenity, then, get the PLS or m3u url and prompt with another zenity which radio to play. http://www.listenlive.eu/index.html
My code to get url's radio country.htm is:
Code:
Using C++, I want to process sub-folders on my home folder sequentially each with a special naming format and containing some binary files in it:
Code:
1/
2/
3/
4/
5/
6/
...
Give above folders, I will process files in 1/ at first, 2/ at second, 3/ at third, and so on.
For some n/ folder, if I realize that n/ actually does not exist in local file system, I do not want to wait for it. Hence I will keep processing (n+1)/ folder, and so on.
However, when processing some (n+m)/ folder, previously not processed n/ folder may have been created on local file system. In this case, I do not want to miss processing it, but somehow detect its creation and process it. After processing n/ folder, I want to continue from (n+m+1)/.
Ok so Basically i have 2 questions
1. i know how to create a file with c++ using but is there a way to save it to a specific location on your computer with windows and linux
Code:
2. i need to know how to run/execute/open a file in a c++ program im using and its not working
Code:
im trying to build a simple program for my C programming class, this is the source code
#include <stdio.h>
int main()
{
int length, width, length, height, area, perimeter;
perimeter = width + length + height;
area = width * length + heigth;
[Code]...
i dont see any error (you might)but every time i run it it runs but after it asks me to input for the width i do it but it doesn't take me to the length, it just stays blank until i input another value in the same place for the width, it asks me for 4 inputs in total i don;t know why, and after i run it different times it gives me different values for the perimeter and are. how can I fix this?
What's the total no. that the OS can create? Does this differ from 32-bit?
View 1 Replies View RelatedI found some interesting behavior when discussing the pow function from Math.h with someone. I am well aware of the need to compile with the -lm flag, but to my surprise this actually isn't necessary if the arguments to the pow function are literals. For example, this program compiles in gcc without using -lm:
Code:
#include <stdio.h>
#include <math.h>
int main()
[code]....
If I try to change the call to any of these:
Code:
double bCubed = pow(2.0, e);
Code:
double bCubed = pow(b, 3.0);
Code:
double bCubed = pow(b, e);
Then the -lm option is required or else it can't compile. So does anyone know why it's necessary to use -lm when the argument(s) is/are variable(s) but it works fine if both arguments are literal values? As a side note, any of the above compile with g++ however. Also, if it helps, this is the version of gcc I'm using:
gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-44)
This doesn't happen on my Mac however that is running: i686-apple-darwin9-gcc-4.0.1 (GCC) 4.0.1 (Apple Inc. build 5484)