Linux Socket Program(TCP client & server)

client.c

/*
 * =====================================================================================
 *
 *       Filename:  client.c
 *
 *    Description:  
 *
 *        Version:  1.0
 *        Created:  2013年08月19日 17时19分33秒
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  YOUR NAME (), 
 *   Organization:  
 *
 * =====================================================================================
 */

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

#define SEVPORT 3333
#define MAXDATASIZE  (1024*5)

#define TIME_DIFF(t1,t2) (((t1).tv_sec-(t2).tv_sec)*1000+((t1).tv_usec-(t2).tv_usec)/1000)

main(int argc, char *argv[])
{
	int sockfd,sendbytes,recvbytes;
	char buf[MAXDATASIZE];
	struct hostent *host;
	struct sockaddr_in serv_addr;
	struct timeval timestamp;
	struct timeval timestamp_end;
	if(argc < 2){
		fprintf(stderr,"Please enter the server's hostname!\n");
		exit(1);
	}

	if((host=gethostbyname(argv[1])) == NULL){
		perror("gethostbyname:");
		exit(1);
	}
#ifdef CLIENT_DEBUG
	printf("hostent h_name: %s , h_aliases: %s,\
			h_addrtype: %d, h_length: %d, h_addr_list: %s\n",\
			host->h_name,*(host->h_aliases),host->h_addrtype,host->h_length,*(host->h_addr_list));
#endif

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

	serv_addr.sin_family = AF_INET;
	serv_addr.sin_port = htons(SEVPORT);
	serv_addr.sin_addr = *((struct in_addr *)host->h_addr);
	bzero(&(serv_addr.sin_zero),8);

	if(connect(sockfd,(struct sockaddr *)&serv_addr, \
					sizeof(struct sockaddr)) == -1){
		perror("connect:");
		exit(1);
	}
	memset(buf,0x15, sizeof(buf));
	gettimeofday(&timestamp,NULL);
		
	if((sendbytes = send(sockfd,buf,sizeof(buf),0)) == -1){
		perror("send:");
		exit(1);
	}

	gettimeofday(&timestamp_end, NULL);
	printf("sendbytes: %d,time_stamp: %ld ms\n",sendbytes,TIME_DIFF(timestamp_end,timestamp));

	if((recvbytes = recv(sockfd, buf,MAXDATASIZE,0)) == -1)
	{
		perror("recv");
		close(sockfd);
		exit(1);
	}
	printf("Client receive bytes: %d\n",recvbytes);
	close(sockfd);
}

server.c

/*
 * =====================================================================================
 *
 *       Filename:  server.c
 *
 *    Description:  
 *
 *        Version:  1.0
 *        Created:  2013年08月19日 16时26分25秒
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  YOUR NAME (), 
 *   Organization:  
 *
 * =====================================================================================
 */

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

#define SERVPORT 3333
#define BACKLOG 10
#define MAX_CONNECTED_NO 10
#define MAXDATASIZE (5*1024)

int main()
{
	struct sockaddr_in server_sockaddr,client_sockaddr;
	int sin_size,recvbytes,sendbytes;
	int sockfd,client_fd;
	char buf[MAXDATASIZE];

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

	int on;
	on = 1;
	setsockopt(sockfd,SOL_SOCKET,SO_REUSEADDR,&on,sizeof(on));

	server_sockaddr.sin_family=AF_INET;
	server_sockaddr.sin_port = htons(SERVPORT);
	server_sockaddr.sin_addr.s_addr=INADDR_ANY;
	memset(&(server_sockaddr.sin_zero),0,8);

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

	if(listen(sockfd,BACKLOG) == -1)
	{
		perror("listen:");
		exit(1);
	}
	printf("Start listen.....\n");

	sin_size = sizeof(struct sockaddr);
	if((client_fd = accept(sockfd,(struct sockaddr *)&client_sockaddr,&sin_size)) == -1)
	{
		perror("accept:");
		exit(1);
	}

	struct sockaddr_in peeraddr;
	int len = sizeof(peeraddr);
	char server_ip[20];
	printf("accept socket..... Client address: %s Port: %d\n",\
			inet_ntoa(client_sockaddr.sin_addr),ntohs(client_sockaddr.sin_port));	
	getsockname(client_fd,(struct sockaddr *)&peeraddr,&len);
	inet_ntop(AF_INET, &peeraddr.sin_addr,server_ip,sizeof(server_ip));
	printf("accept socket..... Server address: %s\n",server_ip);	

	if((recvbytes=recv(client_fd,buf,MAXDATASIZE,0)) == -1)
	{
		perror("recv:");	
		exit(1);
	}
	printf("Recv bytes: %d, buf: 0x%x\n",recvbytes, buf[2]);

	if((sendbytes = send(client_fd,buf,sizeof(buf),0)) == -1)
	{
		perror("send:");
		exit(1);
	}
	printf("Send butes: %d \n",sendbytes);
	close(sockfd);
}