作业

1、将TCP的CS模型再敲一遍

tcpserver.c

#include <myhead.h>
#define SERPORT 1111
#define SERIP "192.168.58.128"
#define BACKLOG 40
int main(int argc, const char *argv[])
{
	int oldfd = socket(AF_INET,SOCK_STREAM,0);//1、产生一个原始套接字文件描述符
	if(oldfd==-1)
	{
		perror("socket");
		return -1;
	}
	printf("旧的套接字创建成功\n");
	//2、绑定主机的IP和端口号
	struct sockaddr_in  sin= {
		.sin_family = AF_INET, //使用IPv4通信协议族
		.sin_port = htons(SERPORT),  //设置端口号
		.sin_addr.s_addr = inet_addr(SERIP)     //设置IP地址为本机IP
	};//定义服务器地址结构体变量
	if(bind(oldfd,(struct sockaddr *)&sin,sizeof(sin))==-1)//2、绑定ip
	{
		perror("bind");
		return -1;
	}
	printf("绑定成功\n");
	if(listen(oldfd,BACKLOG)==-1)//3、监听客户端请求
	{
		perror("listen");
		return -1;
	}
	printf("监听成功\n");

	//使用新描述符通信
	char buff[1024] = "";
	int newfd;
	struct sockaddr_in  cin;//定义获取客户端信息的结构体
	socklen_t cinlen = sizeof(cin);//获取结构体大小
	newfd = accept(oldfd,(struct sockaddr *)&cin,&cinlen);//4、接收请求，创建新的描述符用于通信
	if(newfd==-1)
	{
		perror("accept");
		return -1;
	}
	printf("%s:%d客户端发来连接请求\n",inet_ntoa(cin.sin_addr),ntohs(cin.sin_port));
	while(1)//5、收发消息
	{


		//int len = read(newfd,buff,sizeof(buff));
		memset(buff,0,sizeof(buff));//清空缓冲区
		int len = recv(newfd,buff,sizeof(buff),0);

		printf("读取的信息：%s\n",buff);
		if(len==0)
		{
			printf("你客户跑了\n");
		}
		strcat(buff,"520");
		//write(newfd,buff,sizeof(buff));
		send(newfd,buff,sizeof(buff),0);
		memset(buff,0,sizeof(buff));//清空缓冲区

	}
	close(oldfd);
	close(newfd);
	return 0;
}

tcpclient.c

#include <myhead.h>

#define CLIPORT 1111
#define CLIIP "192.168.58.128"
int main(int argc, const char *argv[])
{
	int oldfd = socket(AF_INET,SOCK_STREAM,0);//1、创建原始套节字
	if(oldfd==-1)
	{
		perror("socket");
		return -1;
	}
	//2、bind可选


	//3、连接服务器
	struct sockaddr_in cin = {
		.sin_family = AF_INET,//IPV4通信
		.sin_port = htons(CLIPORT),//端口号转为网络字节序
		.sin_addr.s_addr = inet_addr(CLIIP)//IP地址转为网络字节序
	};

	if(connect(oldfd,(struct sockaddr *)&cin,sizeof(cin))==-1)
	{
		perror("connect");
		return -1;
	}
	printf("连接服务器成功\n");
	char buff[1024] = "";
	while(1)//4、收发消息
	{
		memset(buff,0,sizeof(buff));
		printf("客户端发信息：");
		fgets(buff,sizeof(buff),stdin);

		send(oldfd,buff,sizeof(buff),0);//阻塞发送

		recv(oldfd,buff,sizeof(buff),0);//阻塞接收
		printf("收到服务器的消息：%s\n",buff);
	}
	close(oldfd);
	return 0;
}

2、UDP服务器中，使用connect函数，实现唯一的客户端与服务器通话

udpserver.c

#include <myhead.h>
#define SERPORT 8888
#define SERIP "192.168.58.128"

int main(int argc, const char *argv[])
{
	//1、创建套接字
	int oldfd = socket(AF_INET,SOCK_DGRAM,0);//SOCK_DGRAM:UDP
	if(oldfd==-1)
	{
		perror("socket");
		return -1;
	}
	//2、绑定
	struct sockaddr_in sin = {
		.sin_family = AF_INET,
		.sin_port = htons(SERPORT),
		.sin_addr.s_addr = inet_addr(SERIP)
	};
	if(bind(oldfd,(struct sockaddr *)&sin,sizeof(sin))==-1)
	{
		perror("bind");
		return -1;
	}
	//3、收发消息
	struct sockaddr_in cin;
	socklen_t cinlen = sizeof(cin);

	connect(sockfd, (struct sockaddr*)&cin, sizeof(cin));
	char buff[100];
	while(1)
	{
		memset(buff,0,sizeof(buff));
		int len = recvfrom(oldfd,buff,sizeof(buff),0,(struct sockaddr *)&cin,&cinlen);//不用管谁发的
		if(len==0)
		{
			printf("客户端跑了\n");
			break;
		}
		printf("服务器接收的信息：%s\n",buff);
		//printf("服务器发消息：");
		//fgets(buff,sizeof(buff),stdin);
		//sendto(oldfd,buff,sizeof(buff),0,(struct sockaddr *)&cin,sizeof(cin));
		//printf("发送成功\n");
	}
	close(oldfd);
	return 0;
}

udpclient.c

#include <myhead.h>
#define CLIPORT 8888
#define CLIIP "192.168.58.128"
int main(int argc, const char *argv[])
{
	int oldfd = socket(AF_INET,SOCK_DGRAM,0);//1、创建套接字
	if(oldfd ==-1)
	{
		perror("socket");
		return -1;
	}

	struct sockaddr_in cin = {
		.sin_family = AF_INET,
		.sin_port = htons(CLIPORT),
		.sin_addr.s_addr = inet_addr(CLIIP)
	};

	char buff[1024]  ="";
	while(1)//2、收发信息
	{
		printf("客户端发消息：");
		fgets(buff,sizeof(buff),stdin);
		sendto(oldfd,buff,sizeof(buff),0,(struct sockaddr *)&cin,sizeof(cin));
		printf("发送成功\n");
	}
	close(oldfd);
	return 0;
}

知识梳理

TCP和UDP通信基础：

基于TCP通信的流程