TCP并发服务器设计

TCP并发服务器是通过创建子进程来处理不同客户端的请求实现的

server.c

/*
**   TCP并发服务器
*/

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

#define portnumber 3333

int main( int argc, char *argv[] )
{
	int sockfd, temp_fd;
	struct sockaddr_in server_addr;
	struct sockaddr_in client_addr;
	int sin_size;
	int nbytes;
	char buffer[1024];
	int n_fork;

	/* （1）分配空间和初始化  */
	/* 服务器端开始建立sockfd描述符 */
	if( ( sockfd = socket(AF_INET, SOCK_STREAM, 0) ) == -1 )
	{                  // AF_INET:IPV4;SOCK_STREAM:TCP
		perror("call to socket");
		exit(1);
	}
	/* 服务器端填充 sockaddr结构 */
	bzero( &server_addr, sizeof(struct sockaddr_in) );		//server_addr初始化置0
	server_addr.sin_family = AF_INET;						//internet
	server_addr.sin_addr.s_addr = htonl(INADDR_ANY);        //INADDR_ANY 表示主机可以是任意IP地址，即服务器程序可以绑定到所有的IP上
	//server_addr.sin_addr.s_addr=inet_addr("192.168.1.1"); //用于绑定到一个固定IP,inet_addr用于把数字加格式的ip转化为整形ip
	server_addr.sin_port = htons(portnumber);				// (将本机器上的short数据转化为网络上的short数据)端口号
	
	/*捆绑sockfd描述符到IP地址**/
	if( bind( sockfd, (struct sockaddr *)(&server_addr), sizeof(server_addr) ) == -1 )
	{
		perror("call to bind");
		exit(1);
	}

	/* 设置允许连接的最大客户端数 */
	if( listen( sockfd, 5 ) == -1 )
	{
		perror("call to listen");
		exit(1);
	}
	printf("Accepting connections ...\n");

	while(1)
	{
		/* 服务器阻塞,直到客户程序建立连接 */ 
		sin_size = sizeof( struct sockaddr_in );
		temp_fd = accept( sockfd, (struct sockaddr *)( &client_addr ), &sin_size );
		if( temp_fd == -1 )
		{
			perror("call to accept");
			exit(1);
		}
		/**创建子进程在处理器客户端的请求*/
		if( ( n_fork = fork() ) == 0)
		{
			fprintf(stderr,"Server get connection from %s\n",inet_ntoa(client_addr.sin_addr));
			if( ( nbytes = read( temp_fd, buffer, 1024 ) ) == -1 )
			{
				perror("call to read");
				exit(1);
			}
			buffer[nbytes] = '\0';
			printf( "Server received %s\n", buffer );		
			
		}
		/**本次通信结束**/
		else
			close(temp_fd);

		/*下次循环*/
	}
	
	/**结束通信**/
	close(sockfd);
	exit(0);

}

 

client.c

/*
**TCP客户端通信服务程序
**执行时，需要写入server的ip 
** 如： ./client  115.158.92.170
*/

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

#define portnumber 3333

int main( int argc, char *argv[] )
{
	int sockfd;
	char buffer[1024];
	struct sockaddr_in server_addr;
	struct hostent *host;

	if( argc != 2 )
	{	
		fprintf(stderr,"Usage:%s hostname \a\n",argv[0]); 
		exit(1); 	
	}

	/*使用hostname查询host名字*/
	if( ( host = gethostbyname( argv[1] ) ) == NULL )
	{
		perror("Error resolving local host\n");
		exit(1);
	}

	/* 客户程序开始建立 sockfd描述符 */ 
	if( ( sockfd = socket( AF_INET, SOCK_STREAM, 0 ) ) == -1 )
	{
		perror("Error opening socket");
		exit(1);
	}

	/* 客户端程序填充服务端的资料 */ 
	bzero(&server_addr,sizeof(server_addr));				 // 初始化,置0
	server_addr.sin_family=AF_INET;							 // IPV4
	server_addr.sin_port=htons(portnumber);					 // (将本机器上的short数据转化为网络上的short数据)端口号
	server_addr.sin_addr=*((struct in_addr *)host->h_addr);  // IP地址

	/* 客户端程序发起连接请求 */ 
	if( connect( sockfd, (struct sockaddr *)(&server_addr), sizeof(struct sockaddr) ) == -1)
	{
		perror("Error connecting to socket\n");
		exit(1);
	}

	/* 连接成功了 */ 
	printf("Please input char:\n");

	/* 发送数据 */
	fgets(buffer,1024,stdin); 
	write(sockfd,buffer,strlen(buffer)); 

	/* 结束通讯 */ 
	close(sockfd); 
	exit(0); 

}