iam just trying to connect to server which accepts one client and server will read(blocking operation) infinitely, but After closing the client socket the server "read operation" is returning zero and "errno variable(in errno.h)" value is also zero. how can i detect whether a client socket is closed/active..?
I have been developing some code which I have been testing an another i386 system. However I have been getting some weird data received on a socket I am communicating with some 3rd party hardware, I have opened a socket to read data on the hardware's telnet port. The data being read is as expected and my code appears to function correctly.
However I have now began testing the code on a target platform, this platform is of a better spec than my development system. When I read data from the socket using recv(), all the expected data has not been read.A chunk of data from the beginning is missing and a portion of data that would be at the end is now at the beginning of the buffer. I'll try and illustrate this below.
I am making a library, but I am facing a strange problem while sending data over network using ethernet.
I am sending 39 bytes of the data from one server to slave application but some time slave receives 39 bytes and some time it receives 29 bytes. And when ever slave receives 29 bytes all the memories to which my pointers are pointing get changed. This problem is only when I am sending data from the server to slave, while sending data from slave to server I am facing no such issue.
the above code works fine.if we copmile and run ./a.exe 192.xx.xx.xxx 1111 and press enter it works fine..everytime it asks "Please enter the message: " and if give that will be displayed in server. but my problem is i dont want to print everytime "Please enter the message: " i just want to feed some words one by one to the socket.
im getting that error in my code for some reason. I compiled my code, and when i try to run this server it throws me an error on my call to setsocketopt(). The only way it can reach that part of my loop is if it succeeds when it calls sock() so I dont understand why the error says its an operation on a non-socket. Im just trying to set up a server to pass messages from a client to it a viceversa. Here is the code:
Code: int main() { int socket_fd, new_socket_fd, k; struct addrinfo hints, *server_info, *p; struct sockaddr_storage peer_address; code....
I have a device that is working on modbus protocol andI have written a small program(with block TCP read method ) to read its registers via modbus protocol.my program is working very well but except those times that I unplug the Ethernet cable or turning off the modbus gateway during programs work.at this time my program stops on recv system call (if it reach this system call exacly when I unplug Ethernet cable or turning off the modbus gateway during programs work).I changed my source to work in nonblock TCP method, at this time with the same situation my program does not stop/block on recv system call but after pluging back the Ethernet cable or resuming the connectivity situation back it reads data incorrectly .this is my code:Quote:
I have a server listening on incoming client connections. Once the client establishes SSL connection with the server, the server waits on read() from the client. Only Client can disconnect the connection. I want to have a timer in the server program to wait for x secs after read() and then disconnect the Client connection.
i have a server program which accept multiple client connection and am using polling. like every 2 secs it will look to client whether any data is received after it binded. i have used setitimer but there is runtime error i got.. the server accept all client connection but doesn't execute any msg which client sent.
i have problem in socket programming, while displaying received message in file,i got a problem... i cant able to write it in the file.... this is the code....
now my problem is run time error i can able to create file but i cant able to write file....log.txt contain nothing.... as here i have give sample code... dont say not initialising function and all.... i have initialised , please only see func1() - my problem is only not able to write msg which i got received from the client..
When sending data over the socket, the sending socket includes 0x00 after each sent byte. I wonder how this can be avoided -- I just want to transfer the data in the tx_buffer as it is.
# ./serv & [1] 6895 # ./EUG 127.0.0.1 EUG: Data to be transmitted: 0x35 0x32 0x30 0xff 0x03 0x31 EUG: Data - #Bytes transmitted: 6 ./serv: Here is the message: '5'
Is it possible to swap a client ip and port ? This is what I am trying to do. Let say you have Comp1 and Comp2 And you have Server between them. My goal is to get Comp1 and Comp2 know each others IP So Comp1 connects to server And server stores comp1's IP In a text file or other place And Comp2 connect to server And server also stores his info And then both comp1 and comp2 dowload the tex file And use the info on it.
How can we build a packet using C?we have a structure called sockaddr_in which is use to for IPv4,so that we can define address,port and etc in this way:
This is my main question:Quote: In raw socket sniffing: how do I copy data from a structure into a char[] or pointer? My problem: I started doing some raw socket programming in OpenWRT (I'm a newbie) for research. It's been a long time since the last time I programmed in C, so here's my newbie question/problem.
I'm receiving packets and using an .h file with the structures to get the information of each 802.11 packet in monitor mode (attached to this post).My (simple) goal is to get the Tx MAC Address. No luck. This is my "read the prism header" function:
I am currently doing a research on video transmission over wireless LAN. I tend to transmit my offline file (xx.svc) from server to client.It may sound stupid (since I have a very little knowledge about c programming and raw socket), but my biggest challenges is that when I want to write the file to the buffer, how actually to define/include the file at the programming coding? where I need to locate the file? Is it at the same folder with my c programming, or somewhere in the linuxinclude folder?
Can anyone just give a simple example on how to include a file and write it into a buffer before send it through raw socket.
I am looking to be able to connect to an IRC server in a C program. I have followed some instructions from an old book I have however it doesn't seem to be working. I've tried connecting to localhost on my ssh port and it still doesn't want to work. This is what I have so far as a piece of skeleton test code:
I have currently had the need to go back to basic socket programming, and implemented a simple udp packet sender. But I realized I needed to be able to select which network interface to send the packets from.
The reason is so that one of the interfaces has vlan tagging, and I need my UDP packets to be accordingly vlan tagged. For example, one of the interfaces is eth1.200.
Has anyone had an issue with gdb not being able to send a UDP msg across a socket?
I have ComponentA sending a msg to ComponentB utilizing gdb. ComponentB gets the msg. ComponentB sends a msg to ComponentC. ComponentC does stuff to the msg and sends a msg back to ComponentB using gdb. ComponentB never seems to receive the 2nd message.
If I don't use gdb the messages Tx and Rx without an issue.
I'm flying blind without gdb to figure out a different bug.
How does bind system call names a socket.Code:bind(server_sockfd, (struct sockaddr *)&server_address, server_len);I see use of bind in majority of programms as above.But any of the arguments is not the name of socket.
(Let me first of all state that I am a newbie to any form of programming.) I have been trying to create an IP header + TCP header and send this to another machine on my network.using C)I used the normal stuff: two structures for the headers, a sockaddr_in structure, call to function socket with SOCK_RAW, setsockopt with HDRINCL and call to sendto.All functions seem to return fine (values other then -1) the function that I have used to calculate the checksum for the IPheader matches the value that I manually calculated. I just don?t see the anything coming out of the interface on whireshark.I assumed that it had something do with my piece of code so I used two examples (including mixter void ru rawip html A brief programming tutorial in C for raw sockets[/url]). They show exactly the same thing functions return fine but no packets being send.I use Ubuntu 9.04 2.6.28-14-genericThe machine has two interfaces one with an ip address the other interface is in promiscuous mode. (both interfaces connected to a switch with port mirroring) I can see all normal traffic in/out.
I am programming an application with an ARM device with an embedded version of Linux. My application talks to a java application via socket. If there is any connection problems, it attempts the connection again. My problem is that after exactly 146 times, there is a Segmentation Fault. Apparently this happens in opening the socket, which is not successful after this amount of attempts.
Following, some code that I'm using:
The function for openning the socket and perform a connection:
I need to read data from a socket but it should be always listening because data arrives continuously .. I thought something like this would do it but it doesn't work .... I already set the socket options before
I don't have the IP address & Port of the server but I know the hostname (URL) to establish a connection.How can I use it to get connected to the particular host?
Been trying all sorts of different things to implement a non-blocking send on a TCP server socket.As I kill the client, the server keeps blocking on the send no matter what. Am I missing something? Any other way to do that without involving any additional thread?
I want to configure socket timer to release socket(port) once the connection is terminated. Do we have something in Linux OS to configure this delay to release socket?.
Any command, link or man-page anything will be helpful.