hello....i am trying to establish a communication between server and client and later to do some communication between them, so first i am trying to establish communication and i see that server gives "segmentation fault" as the output. I am placing the code below, check it out and let me know where the errors are.

Server Program :

#include <stdio.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <arpa/inet.h>
#include <unistd.h>

#define MYPORT 51005
#define BACKLOG 10
#define MAXDATASIZE 1000


int main(int argc, char* argv[])
{
	int sockfd, numbytes, abcd;
	struct sockaddr_in my_addr;
	struct sockaddr_in their_addr;
	char buf[MAXDATASIZE];
	char *string;
	int sin_size;

	if((sockfd=socket(AF_INET,SOCK_STREAM,0))==-1)
	{
		perror("socket");
		exit(EXIT_FAILURE);
	}

//	Loading all the address values of the socket into the structure
	
	my_addr.sin_family = AF_INET;
	my_addr.sin_port = htons(MYPORT);
	my_addr.sin_addr.s_addr = INADDR_ANY; /* auto-fill with my IP */
	bzero(&(my_addr.sin_zero), 8);		  
	

	if(bind(sockfd,(struct sockaddr *)&my_addr,sizeof(struct sockaddr))==-1)
	{
		perror("bind");
		exit(EXIT_FAILURE);
	}
	

	if(listen(sockfd,BACKLOG)==-1)
	{
		perror("listen");
		exit(EXIT_FAILURE);
	}
	
	sin_size = sizeof(struct sockaddr_in);


	if(accept(sockfd,(struct sockaddr *)&their_addr,(socklen_t*)&sin_size)==-1)
	{
		perror ("accept");
		exit(EXIT_FAILURE);
	}
	else
	printf("\n connection established with the client %s",their_addr);
	
	
	
	close(sockfd);
	return 0;
}

Client Program :

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <unistd.h>
#include <sys/time.h>

//#define PORT 51005
#define MAXDATASIZE 1000


int main()
{
	int sockfd, numbytes, PORT;
	char buf[MAXDATASIZE];
	struct hostent *he;
	struct sockaddr_in their_addr;
	
//	As all processes are in the same system connection is made to localhost

	if ((he=gethostbyname("localhost")) == NULL)
	{
		herror("gethostbyname");
		exit(EXIT_FAILURE);
	}

//	A connection is being established for the process to the socket

	if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
	{
		perror("socket");
		exit(EXIT_FAILURE);
	}

//	Loading all the address values of the socket into the structure

	printf("Enter the port number : ");
	scanf("%d", &PORT);

	their_addr.sin_family = AF_INET;
	their_addr.sin_port = htons(PORT);
	their_addr.sin_addr = *((struct in_addr *)he->h_addr);
	bzero(&(their_addr.sin_zero), 8);
	
//	Connection is established between the processes using sockets using connect()

	if (connect(sockfd,(struct sockaddr *)&their_addr, sizeof(struct sockaddr)) ==-1)
	{
		perror("connect");
		exit(EXIT_FAILURE);
	}
	else printf("\n connection established");
	
	/*while(1)
	{
	if((numbytes=recv(sockfd, buf, MAXDATASIZE, 0)) == -1)
	{
			perror("recv");
			exit(EXIT_FAILURE);
	}
	buf[numbytes] = '\0';
	printf("\n %s", buf);
	}*/
	
	close(sockfd);
	return 0;
}

Line 62 in your server program...

printf("\n connection established with the client %s",their_addr);

their_addr is not a c-string.

Line 56

if(accept(sockfd,(struct sockaddr *)&their_addr,(socklen_t*)&sin_size)==-1)

the accept function returns a socket descriptor which should be saved and used as a client.

Edited 5 Years Ago by gerard4143: n/a

so what modification has to be made to the line 56, as the socket descriptor is being saved into sockfd rite??

so what modification has to be made to line 56?? as the socket descriptor is already being saved into sockfd rite??

Line 62 in your server program...

printf("\n connection established with the client %s",their_addr);

their_addr is not a c-string.

Line 56

if(accept(sockfd,(struct sockaddr *)&their_addr,(socklen_t*)&sin_size)==-1)

the accept function returns a socket descriptor which should be saved and used as a client.

Try something like

int clientfd;
    if(clientfd = accept(sockfd,(struct sockaddr *)&their_addr,(socklen_t*)&sin_size)==-1)

thnx it worked

Try something like

int clientfd;
    if(clientfd = accept(sockfd,(struct sockaddr *)&their_addr,(socklen_t*)&sin_size)==-1)
This article has been dead for over six months. Start a new discussion instead.