Programming :: Receiving The Entire Message Using TCP Socket?
Apr 15, 2010
I am trying to create a socket server in user space and a client in kernel space and send big messages (a little over 64kbytes) between them.
I used an kernel socket programming examplefrom this link - url for the kernel client side.
When the client in kernel side sends out a 64k message, usually, the server side in the user space will get a big part of the message, but will stuck at waiting for the recv() to return to get the rest of it. So I am chopping the packets into small pieces, 1000 bytes each to send to the server. But only some times, the packets will all arrive at the server/receiver side, and the server and assemble the whole message. Many times, the server is stuck at waiting for the last a couple of byte from the sending side. From the sending side printk log, it has already sent every thing.
I am attaching some log here, and the code at the end. Can someone give me some idea on how to force the data to arrive at the receiver side? Maybe the kernel on the receiver side is holding part of the packet so
the receiver program in the user space is blocked at recv()? I tried adding TCP_NODELAY on sockets on both sender and receiver sides, both it did not help.
I got a connection from (10.16.216.217 , 1489)
- Server side stuck on recv()-
bytes_recieved 17384
bytes_recieved 32768, total received 50152, expected 65540
- Client side is already done -
code....
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May 19, 2010
I have a server which is used by number of client Apps. Now when a client initiates a sendto request to a server it has to respond(after recvfrom) by sending a message using sendto back to client and this should be done back and forth.
What I dont understand is, does the client have to open a new port to receive packets from client? If yes, then how will server know to what port of the client(assuming server ports are well-known to clients)?
I had given up on sending messages back and forth using UDP and switched to TCP. I could send a read and write message back and forth. But the trouble comes when I have more than one client wanting to talk to server using SOCK_STREAM. The first one gets through but the second client seems to get blocked forever(but I got no error upon socket creation or upon connect with the server on the same port as the previous client)..
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Jan 28, 2011
currently I've got a big problem on programming with sockets. I use the winsock2 API and want to receive data from a multicast adress running on a UNIX-PC. The connection works fine and I really receive data from this group, but as it seems not the right packages. The received data is saved in a char[]. E.g. at received_msg[12] is a float value. This one I would like to read out, convert and use it in later progress the next value is y at received_msg[16]. The same Code works on a Unix PC with unix sockets but converted to winsock I've got the described problem and I have to make this code work under windows.
Here a piece of the code (received_msg[12]='3f'):
Buffer is a struct containing the two float values x and y. If I convert the char as this under windows the value of x is a huge number. The correct value is around 192, so receveid_message[12] should be 1.92. Could it be that the Unix-PC is sending data in an other way than the winsock receive it?
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May 11, 2011
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....
Code:
/* tcpserver.c */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
[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..
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Mar 8, 2011
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..?
client.c
Serv_Addr.sin_family = AF_INET;
Serv_Addr.sin_addr.s_addr = inet_addr("127.0.0.1");
Serv_Addr.sin_port = htons(26553);
if( 0 > connect (Serv_Fds,&Serv_Addr,sizeof(Serv_Addr)) )
{
perror("connect");
return 0;
[Code]....
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Jul 6, 2010
i'm writing a simple program of client socket program. Here below is the code sample which i'm writing...
Code:
//tcp_client.c
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include<string.h>
#include<stdlib.h>
[Code].....
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.
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Mar 30, 2009
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....
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Feb 8, 2010
I am running Postfix 2.6.1 on Suse 11.2, and am receiving an error message on my windows machine saying "Recipient address rejected: Relay access denied." If I login to my email on the local machine or via squirrelmail I have no problem sending mail. The output of postconf -n is as follows:
server:~ # postconf -n
alias_maps = hash:/etc/aliases
biff = no
[code]....
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Mar 8, 2011
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.
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May 16, 2011
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.
#include<stdio.h>
#include<stdlib.h>
#include<sys/socket.h>
#include<sys/types.h>
#include<netdb.h>
#include<unistd.h>
#include<pthread.h>
#include<string.h>
[Code]....
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Aug 25, 2010
how to use socket programming in order to implement chatting feature
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Feb 19, 2011
I'm trying to send an image (which can vary in file size) from a python server to an android client . I'm not getting any errors and the file is being created client side however it always seems to fall short of the total file size. I have tried many different options in regards to input streams and buffer sizes but I have had no luck.
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Dec 5, 2010
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'
[Code]...
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Mar 28, 2011
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.
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Jul 23, 2011
My program is creating 4 threads per transaction. Threads doing nothing but simply sleeping.
Now, when transaction ends, I want to wake up all the threads from sleeping. For this I am using pthread_kill() to wake up the threads using signal SIGUSR2.
Problem raises when I put more transactions(eg. 100 trans). My process gets hangup.
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Apr 15, 2009
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.
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Jan 30, 2011
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:
Code:
struct sockaddr_in sock;
sock.sin_family=AF_INET;
[code]...
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Nov 11, 2010
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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:
Code:
ParsePrismHeader(unsigned char *packet,int len)
{
wlan_header *wlan;ieee_802_11_header *i802;u_int16_t eth_type;
unsigned char *mac;unsigned char *mac2;
wlan = (wlan_header *)packet;
i802 = (ieee_802_11_header *)(packet + wlan->msglen);
[Code]...
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Jul 23, 2010
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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.
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Mar 16, 2010
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:
Code:
#include<sys/types.h>
#include<stdio.h>
#include<stdlib.h>
#include<sys/socket.h>
#include<unistd.h>
#include<netinet/in.h>
#include<arpa/inet.h>
[Code]....
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Jul 21, 2010
Where is the perl module for programming with sockets?
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Jan 15, 2010
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.
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Jun 22, 2009
this is my client and server. I can receive text file. but I can't send other type of file like PDF,Docx,Odt
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Apr 26, 2011
I install and configure the vncserver following and reading 1000papers, but all of this present the same problem; when i try to connect to my vncserver,recive this mesage: unable connect to socket: No route to host (113) The OS version is Fedora Core 14 and tigervnc-server i try different solutions including:Allow TCP connection modifing files /etc/gdm/custom.conf and /usr/share/gdm/gdm.chemas Disable SELinux removing iptables Here follow the vncserver configuration:
[code].....
The ip address of the vncserver is correct because i can do ssh on it. Where or what can i do?
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Jan 11, 2010
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Sep 15, 2010
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Jan 24, 2011
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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.
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Oct 20, 2010
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Mar 26, 2010
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Jul 16, 2010
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.
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The function for openning the socket and perform a connection:
Code:
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