（TCP IP网络编程）实验一 流式套接字编程

一．实验目的

1）熟悉Linux环境下流式套接字编程的基本模型、函数使用细节等，掌握Linux环境下流式套接字编程的具体过程。
2）熟悉Windows环境下流式套接字编程的基本模型、函数使用细节等，掌握Windows环境下流式套接字编程的具体过程。

二．实验内容

（1） 使用流式套接字实现一个Linux环境下的迭代回声服务器端(及客户端)；
（2） 使用流式套接字实现一个Windows环境下的迭代回声服务器端(及客户端)。
（3）使服务器端和客户端各传递1次字符串。考虑到使用TCP协议，所以传递字符串前先以4字节整数型方式传递字符串长度。连接时服务器端和客户端数据传输格式如下。

另外，不限制字符串传输顺序及种类，但须进行3次数据交换。
（4）创建收发文件的服务器端/客户端，实现顺序如下。
 客户端接受用户输入的传输文件名。
 客户端请求服务器端传输该文件名所指文件。
 如果指定文件存在，服务器端就将其发送给客户端；反之，则断开连接。

三．实验过程

（1）Linux实现

Server.c：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>

void error_handling(char *message);

int main(int argc, char *argv[])
{
	int serv_sock;
	int clnt_sock;
	int str_len, i;

	struct sockaddr_in serv_addr;
	struct sockaddr_in clnt_addr;
	socklen_t clnt_addr_size;

	char message[]="Hello World!";
	
	if(argc!=2){
		printf("Usage : %s <port>\n", argv[0]);
		exit(1);
	}
	
	serv_sock=socket(PF_INET, SOCK_STREAM, 0);
	if(serv_sock == -1)
		error_handling("socket() error");
	
	memset(&serv_addr, 0, sizeof(serv_addr));
	serv_addr.sin_family=AF_INET;
	serv_addr.sin_addr.s_addr=htonl(INADDR_ANY);
	serv_addr.sin_port=htons(atoi(argv[1]));
	
	if(bind(serv_sock, (struct sockaddr*) &serv_addr, sizeof(serv_addr))==-1 )
		error_handling("bind() error"); 
	
	if(listen(serv_sock, 5)==-1)
		error_handling("listen() error");
	
	clnt_addr_size=sizeof(clnt_addr);  

	for(i=0; i<5; i++)
	{
		clnt_sock=accept(serv_sock, (struct sockaddr*)&clnt_addr, &clnt_addr_size);
		if(clnt_sock==-1)
			error_handling("accept() error");
		else
			printf("Connected client %d \n", i+1);
	
		write(clnt_sock, message, sizeof(message));

		close(clnt_sock);
	}	
	close(serv_sock);
	return 0;
}

void error_handling(char *message)
{
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

Client.c:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>

void error_handling(char *message);

int main(int argc, char* argv[])
{
	int sock;
	struct sockaddr_in serv_addr;
	char message[30];
	int str_len;
	
	if(argc!=3){
		printf("Usage : %s <IP> <port>\n", argv[0]);
		exit(1);
	}
	
	sock=socket(PF_INET, SOCK_STREAM, 0);
	if(sock == -1)
		error_handling("socket() error");
	
	memset(&serv_addr, 0, sizeof(serv_addr));
	serv_addr.sin_family=AF_INET;
	serv_addr.sin_addr.s_addr=inet_addr(argv[1]);
	serv_addr.sin_port=htons(atoi(argv[2]));
		
	if(connect(sock, (struct sockaddr*)&serv_addr, sizeof(serv_addr))==-1) 
		error_handling("connect() error!");
	
	str_len=read(sock, message, sizeof(message)-1);
	if(str_len==-1)
		error_handling("read() error!");
	
	printf("Message from server: %s \n", message);  
	close(sock);
	return 0;
}

void error_handling(char *message)
{
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

结果：

（2）Windows实现：

Server_win.c:
#include <stdio.h>
#include <stdlib.h>
#include <winsock2.h>
void ErrorHandling(char* message);

int main(int argc, char* argv[])
{
	WSADATA	wsaData;
	SOCKET hServSock, hClntSock;
	SOCKADDR_IN servAddr, clntAddr;
	int strLen, i;

	int szClntAddr;
	char message[] = "Hello World!";

	if (argc != 2)
	{
		printf("Usage : %s <port>\n", argv[0]);
		exit(1);
	}

	if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
		ErrorHandling("WSAStartup() error!");

	hServSock = socket(PF_INET, SOCK_STREAM, 0);
	if (hServSock == INVALID_SOCKET)
		ErrorHandling("socket() error");

	memset(&servAddr, 0, sizeof(servAddr));
	servAddr.sin_family = AF_INET;
	servAddr.sin_addr.s_addr = htonl(INADDR_ANY);
	servAddr.sin_port = htons(atoi(argv[1]));

	if (bind(hServSock, (SOCKADDR*)&servAddr, sizeof(servAddr)) == SOCKET_ERROR)
		ErrorHandling("bind() error");

	if (listen(hServSock, 5) == SOCKET_ERROR)
		ErrorHandling("listen() error");

	szClntAddr = sizeof(clntAddr);
	for (i = 0; i < 5; i++)
	{
		hClntSock = accept(hServSock, (SOCKADDR*)&clntAddr, &szClntAddr);
		if (hClntSock == -1)
			ErrorHandling("accept() error");
		else
			printf("Connected client %d \n", i + 1);

		send(hClntSock, message, sizeof(message), 0);
		closesocket(hClntSock);
	}

	closesocket(hServSock);
	WSACleanup();
	return 0;
}

void ErrorHandling(char* message)
{
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

Client_win.c:
#include <stdio.h>
#include <stdlib.h>
#include <winsock2.h>
void ErrorHandling(char* message);

int main(int argc, char* argv[])
{
	WSADATA wsaData;
	SOCKET hSocket;
	SOCKADDR_IN servAddr;

	char message[30];
	int strLen;

	if (argc != 3)
	{
		printf("Usage : %s <IP> <port>\n", argv[0]);
		exit(1);
	}

	if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
		ErrorHandling("WSAStartup() error!");

	hSocket = socket(PF_INET, SOCK_STREAM, 0);
	if (hSocket == INVALID_SOCKET)
		ErrorHandling("socket() error");

	memset(&servAddr, 0, sizeof(servAddr));
	servAddr.sin_family = AF_INET;
	servAddr.sin_addr.s_addr = inet_addr(argv[1]);
	servAddr.sin_port = htons(atoi(argv[2]));

	if (connect(hSocket, (SOCKADDR*)&servAddr, sizeof(servAddr)) == SOCKET_ERROR)
		ErrorHandling("connect() error!");

	strLen = recv(hSocket, message, sizeof(message) - 1, 0);
	if (strLen == -1)
		ErrorHandling("read() error!");
	printf("Message from server: %s \n", message);

	closesocket(hSocket);
	WSACleanup();
	return 0;
}

void ErrorHandling(char* message)
{
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

结果：

（3）Linux实现

Server.c:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>

void error_handling(char *message);

int main(int argc, char *argv[])
{
	int serv_sock;
	int clnt_sock;
	int str_len, i;

	struct sockaddr_in serv_addr;
	struct sockaddr_in clnt_addr;
	socklen_t clnt_addr_size;

	char msg1[]="Hello client!";
	char msg2[]="I'm server.";
	char msg3[]="Nice to meet you.";
	char* str_arr[]={msg1, msg2, msg3};
	char read_buf[100];
	
	if(argc!=2){
		printf("Usage : %s <port>\n", argv[0]);
		exit(1);
	}
	
	serv_sock=socket(PF_INET, SOCK_STREAM, 0);
	if(serv_sock == -1)
		error_handling("socket() error");
	
	memset(&serv_addr, 0, sizeof(serv_addr));
	serv_addr.sin_family=AF_INET;
	serv_addr.sin_addr.s_addr=htonl(INADDR_ANY);
	serv_addr.sin_port=htons(atoi(argv[1]));
	
	if(bind(serv_sock, (struct sockaddr*)&serv_addr, sizeof(serv_addr))==-1)
		error_handling("bind() error"); 
	
	if(listen(serv_sock, 5)==-1)
		error_handling("listen() error");
	
	clnt_addr_size=sizeof(clnt_addr);  
	clnt_sock=accept(serv_sock, (struct sockaddr*)&clnt_addr,&clnt_addr_size);
	if(clnt_sock==-1)
		error_handling("accept() error");  
	
	for(i=0; i<3; i++)
	{
		str_len=strlen(str_arr[i])+1;
		write(clnt_sock, (char*)(&str_len), 4);
		write(clnt_sock, str_arr[i], str_len);
		
		read(clnt_sock, (char*)(&str_len), 4);
		read(clnt_sock, read_buf, str_len);
		puts(read_buf);
	}
	
	close(clnt_sock);
	close(serv_sock);
	return 0;
}

void error_handling(char *message)
{
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

Client.c:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>

void error_handling(char *message);

int main(int argc, char* argv[])
{
	int sock;
	struct sockaddr_in serv_addr;

	char msg1[]="Hello server!";
	char msg2[]="I'm client.";
	char msg3[]="Nice to meet you too!";
	char* str_arr[]={msg1, msg2, msg3};
	char read_buf[100];

	int str_len, i;
	
	if(argc!=3){
		printf("Usage : %s <IP> <port>\n", argv[0]);
		exit(1);
	}
	
	sock=socket(PF_INET, SOCK_STREAM, 0);
	if(sock == -1)
		error_handling("socket() error");
	
	memset(&serv_addr, 0, sizeof(serv_addr));
	serv_addr.sin_family=AF_INET;
	serv_addr.sin_addr.s_addr=inet_addr(argv[1]);
	serv_addr.sin_port=htons(atoi(argv[2]));
	
	if(connect(sock, (struct sockaddr*)&serv_addr, sizeof(serv_addr))==-1) 
		error_handling("connect() error!");

	for(i=0; i<3; i++)
	{
		read(sock, (char*)(&str_len), 4);
		read(sock, read_buf, str_len);
		puts(read_buf);

		str_len=strlen(str_arr[i])+1;
		write(sock, (char*)(&str_len), 4);
		write(sock, str_arr[i], str_len);
	}
	close(sock);
	return 0;
}

void error_handling(char *message)
{
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

结果：

（3）Windows实现

Server_win.c:
#include <stdio.h>
#include <stdlib.h>
#include <winsock2.h>
void ErrorHandling(char* message);

int main(int argc, char* argv[])
{
	WSADATA	wsaData;
	SOCKET hServSock, hClntSock;		
	SOCKADDR_IN servAddr, clntAddr;		

	int szClntAddr;

	char msg1[]="Hello client!";
	char msg2[]="I'm server.";
	char msg3[]="Nice to meet you.";
	char* str_arr[]={msg1, msg2, msg3};
	char read_buf[100];

	int str_len, i;

	if(argc!=2) 
	{
		printf("Usage : %s <port>\n", argv[0]);
		exit(1);
	}
  
	if(WSAStartup(MAKEWORD(2, 2), &wsaData)!=0)
		ErrorHandling("WSAStartup() error!"); 
	
	hServSock=socket(PF_INET, SOCK_STREAM, 0);
	if(hServSock==INVALID_SOCKET)
		ErrorHandling("socket() error");
  
	memset(&servAddr, 0, sizeof(servAddr));
	servAddr.sin_family=AF_INET;
	servAddr.sin_addr.s_addr=htonl(INADDR_ANY);
	servAddr.sin_port=htons(atoi(argv[1]));
	
	if(bind(hServSock, (SOCKADDR*) &servAddr, sizeof(servAddr))==SOCKET_ERROR)
		ErrorHandling("bind() error");  
	
	if(listen(hServSock, 5)==SOCKET_ERROR)
		ErrorHandling("listen() error");

	szClntAddr=sizeof(clntAddr);    	
	hClntSock=accept(hServSock, (SOCKADDR*)&clntAddr,&szClntAddr);
	if(hClntSock==INVALID_SOCKET)
		ErrorHandling("accept() error");  
	
	for(i=0; i<3; i++)
	{
		str_len=strlen(str_arr[i])+1;
		send(hClntSock, (char*)(&str_len), 4,0);
		send(hClntSock, str_arr[i], str_len,0);
		
		recv(hClntSock, (char*)(&str_len), 4,0);
		recv(hClntSock, read_buf, str_len,0);
		puts(read_buf);
	}
	closesocket(hClntSock);
	closesocket(hServSock);
	WSACleanup();
	return 0;
}

void ErrorHandling(char* message)
{
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

Client_win.c:
#include <stdio.h>
#include <stdlib.h>
#include <winsock2.h>
void ErrorHandling(char* message);

int main(int argc, char* argv[])
{
	WSADATA wsaData;
	SOCKET hSocket;
	SOCKADDR_IN servAddr;

	char msg1[]="Hello server!";
	char msg2[]="I'm client.";
	char msg3[]="Nice to meet you too!";
	char* str_arr[]={msg1, msg2, msg3};
	char read_buf[100];

	int str_len, i;

	if(argc!=3)
	{
		printf("Usage : %s <IP> <port>\n", argv[0]);
		exit(1);
	}

	if(WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
		ErrorHandling("WSAStartup() error!");  
	
	hSocket=socket(PF_INET, SOCK_STREAM, 0);
	if(hSocket==INVALID_SOCKET)
		ErrorHandling("socket() error");
	
	memset(&servAddr, 0, sizeof(servAddr));
	servAddr.sin_family=AF_INET;
	servAddr.sin_addr.s_addr=inet_addr(argv[1]);
	servAddr.sin_port=htons(atoi(argv[2]));
	
	if(connect(hSocket, (SOCKADDR*)&servAddr, sizeof(servAddr))==SOCKET_ERROR)
		ErrorHandling("connect() error!");
 
	for(i=0; i<3; i++)
	{
		recv(hSocket, (char*)(&str_len), 4,0);
		recv(hSocket, read_buf, str_len,0);
		puts(read_buf);

		str_len=strlen(str_arr[i])+1;
		send(hSocket, (char*)(&str_len), 4,0);
		send(hSocket, str_arr[i], str_len,0);
	}

	closesocket(hSocket);
	WSACleanup();
	return 0;
}

void ErrorHandling(char* message)
{
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

结果：

（4）Linux实现

Server.c:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>

#define BUF_SIZE 30
void error_handling(char *message);

int main(int argc, char *argv[])
{
	int serv_sd, clnt_sd;
	FILE * fp;
	char buf[BUF_SIZE];
	char file_name[BUF_SIZE];
	int read_cnt;
	
	struct sockaddr_in serv_adr, clnt_adr;
	socklen_t clnt_adr_sz;
	
	if(argc!=2) {
		printf("Usage: %s <port>\n", argv[0]);
		exit(1);
	}
	
	serv_sd=socket(PF_INET, SOCK_STREAM, 0);   
	
	memset(&serv_adr, 0, sizeof(serv_adr));
	serv_adr.sin_family=AF_INET;
	serv_adr.sin_addr.s_addr=htonl(INADDR_ANY);
	serv_adr.sin_port=htons(atoi(argv[1]));
	
	bind(serv_sd, (struct sockaddr*)&serv_adr, sizeof(serv_adr));
	listen(serv_sd, 5);
	
	clnt_adr_sz=sizeof(clnt_adr);    
	clnt_sd=accept(serv_sd, (struct sockaddr*)&clnt_adr, &clnt_adr_sz);
	
	read(clnt_sd, file_name, BUF_SIZE);
	fp=fopen(file_name, "rb");
	if(fp!=NULL)
	{
		while(1)
		{
			read_cnt=fread((void*)buf, 1, BUF_SIZE, fp);
			if(read_cnt<BUF_SIZE)
			{
				write(clnt_sd, buf, read_cnt);
				break;
			}
			write(clnt_sd, buf, BUF_SIZE);
		}
	}
	
	fclose(fp);
	close(clnt_sd); close(serv_sd);
	return 0;
}

void error_handling(char *message)
{
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

Client.c:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>

#define BUF_SIZE 30
void error_handling(char *message);

int main(int argc, char *argv[])
{
	int sd;
	FILE *fp;
	
	char buf[BUF_SIZE];
	char file_name[BUF_SIZE];
	int read_cnt;
	struct sockaddr_in serv_adr;
	if(argc!=3) {
		printf("Usage: %s <IP> <port>\n", argv[0]);
		exit(1);
	}
	
	printf("Input file name: ");
	scanf("%s", file_name);
	fp=fopen(file_name, "wb");

	sd=socket(PF_INET, SOCK_STREAM, 0);   
	memset(&serv_adr, 0, sizeof(serv_adr));
	serv_adr.sin_family=AF_INET;
	serv_adr.sin_addr.s_addr=inet_addr(argv[1]);
	serv_adr.sin_port=htons(atoi(argv[2]));

	connect(sd, (struct sockaddr*)&serv_adr, sizeof(serv_adr));
	write(sd, file_name, strlen(file_name)+1);	

	while((read_cnt=read(sd, buf, BUF_SIZE))!=0)
		fwrite((void*)buf, 1, read_cnt, fp);
			
        printf("发送成功！\n");


	fclose(fp);
	close(sd);
	return 0;
}

void error_handling(char *message)
{
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

结果：

（4）Windows实现

Server.c:

#include <stdio.h>
#include <stdlib.h>
#include <winsock2.h>
#define BUF_SIZE 30
void ErrorHandling(char* message);

int main(int argc, char* argv[])
{
	WSADATA	wsaData;
	SOCKET hServSock, hClntSock;
	SOCKADDR_IN servAddr, clntAddr;

	FILE* fp;
	char buf[BUF_SIZE];
	char file_name[BUF_SIZE];
	int read_cnt;

	int szClntAddr;

	if (argc != 2)
	{
		printf("Usage : %s <port>\n", argv[0]);
		exit(1);
	}

	if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
		ErrorHandling("WSAStartup() error!");

	hServSock = socket(PF_INET, SOCK_STREAM, 0);
	if (hServSock == INVALID_SOCKET)
		ErrorHandling("socket() error");

	memset(&servAddr, 0, sizeof(servAddr));
	servAddr.sin_family = AF_INET;
	servAddr.sin_addr.s_addr = htonl(INADDR_ANY);
	servAddr.sin_port = htons(atoi(argv[1]));

	bind(hServSock, (SOCKADDR*)&servAddr, sizeof(servAddr));
	listen(hServSock, 5);

	szClntAddr = sizeof(clntAddr);
	hClntSock = accept(hServSock, (SOCKADDR*)&clntAddr, &szClntAddr);
	if (hClntSock == INVALID_SOCKET)
		ErrorHandling("accept() error");

	recv(hClntSock, file_name, BUF_SIZE, 0);
	fp = fopen(file_name, "rb");
	if (fp != NULL)
	{
		while (1)
		{
			read_cnt = fread((void*)buf, 1, BUF_SIZE, fp);
			if (read_cnt < BUF_SIZE)
			{
				send(hClntSock, buf, read_cnt, 0);
				break;
			}
			send(hClntSock, buf, BUF_SIZE, 0);
		}
	}

	fclose(fp);
	closesocket(hClntSock); closesocket(hServSock);
	return 0;

}

void ErrorHandling(char* message)
{
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

Client.c:
#include <stdio.h>
#include <stdlib.h>
#include <winsock2.h>
#define BUF_SIZE 30
void ErrorHandling(char* message);

int main(int argc, char* argv[])
{
	WSADATA wsaData;
	SOCKET hSocket;
	SOCKADDR_IN servAddr;
	FILE* fp;

	char buf[BUF_SIZE];
	char file_name[BUF_SIZE];
	int read_cnt;

	int strLen;

	if (argc != 3)
	{
		printf("Usage : %s <IP> <port>\n", argv[0]);
		exit(1);
	}

	printf("Input file name: ");
	scanf("%s", file_name);
	fp = fopen(file_name, "wb");

	if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
		ErrorHandling("WSAStartup() error!");

	hSocket = socket(PF_INET, SOCK_STREAM, 0);
	if (hSocket == INVALID_SOCKET)
		ErrorHandling("socket() error");

	memset(&servAddr, 0, sizeof(servAddr));
	servAddr.sin_family = AF_INET;
	servAddr.sin_addr.s_addr = inet_addr(argv[1]);
	servAddr.sin_port = htons(atoi(argv[2]));

	connect(hSocket, (SOCKADDR*)&servAddr, sizeof(servAddr));

	send(hSocket, file_name, strlen(file_name) + 1,0);


	while ((read_cnt = recv(hSocket, buf, BUF_SIZE,0)) != 0)
		fwrite((void*)buf, 1, read_cnt, fp);

	printf("发送成功！");

	fclose(fp);
	closesocket(hSocket);
	WSACleanup();
	return 0;

}

void ErrorHandling(char* message)
{
	fputs(message, stderr);
	fputc('\n', stderr);
	exit(1);
}

结果：