12月30日网络编程

作业：

1、将广播发送和接收端实现一遍，完成一个发送端发送信息，对应多个接收端接收信息实验。

发送端：

#include <myhead.h>

#define IP "192.168.124.255"
#define PORT 6666
int main(int argc, const char *argv[])
{
    //1、创建套接字
    int oldfd = socket(AF_INET,SOCK_DGRAM,0);
    if(oldfd==-1)
    {
        perror("socket");
        return -1;
    }

    //2、设置允许广播
    int k = 999;
    if(setsockopt(oldfd,SOL_SOCKET,SO_BROADCAST,&k,sizeof(k))==-1)
    {
        perror("setsockopt");
        return -1;
    }
    printf("允许广播设置成功\n");
    
    struct sockaddr_in broadcast = {
        .sin_family = AF_INET,
        .sin_port = htons(PORT),//发送到该端口
        .sin_addr.s_addr = inet_addr(IP)
    };
        
    char buff[1024];
    while(1)
    {
        fgets(buff,sizeof(buff),stdin);
        sendto(oldfd,buff,sizeof(buff),0,(struct sockaddr *)&broadcast,sizeof(broadcast));
        if(strcmp(buff,"quit")==0)
        {
            printf("发送端退出\n");
            break;
        }
    }
    close(oldfd);
    return 0;
}

接收端

#include <myhead.h>

#define IP "192.168.124.255"
#define PORT 6666
int main(int argc, const char *argv[])
{
    //1、创建套接字
    int oldfd = socket(AF_INET,SOCK_DGRAM,0);
    if(oldfd==-1)
    {
        perror("socket");
        return -1;
    }
    //2、填充广播地址信息结构体
    struct sockaddr_in send = {
        .sin_family = AF_INET,
        .sin_port = htons(PORT),
        .sin_addr.s_addr = inet_addr(IP)
    };
    
    #if 1
    if(bind(oldfd,(struct sockaddr *)&send,sizeof(send))==-1)
    {
        perror("bind");
        return -1;
    }
    #endif
    //接收消息
    char buff[1024];
    while(1)
    {
        recvfrom(oldfd,buff,sizeof(buff),0,NULL,NULL);
        printf("%s",buff);
    }
    return 0;
}

2、使用多线程基于TCP协议的并发执行，一个服务器对应多个客户端实现通信实验。

//TCP多线程并发 服务器
#include <myhaed.h>

#define IP "192.168.124.40"
#define PORT 1234

void *fun(void *fd)  //子线程函数体
{
	int newfd=*(int *)fd;
	char buff[1024];
	while(1)
	{
		int res=recv(newfd,buff,sizeof(buff),0);
		if(res==0)
		{
			printf("客户端下线\n");
			break;
		}
		printf("%s\n",buff);
		strcat(buff,"今晚早睡");
		send(newfd,buff,sizeof(buff),0);
	}
	pthread_exit(NULL);//子线程退出
}

int main(int argc,const char *argv[])
{
	//1.创建套接字
	int oldfd=socket(AF_INET,SOCK_STREAM,0);
	if(oldfd==-1)
	{
		perror("socket");
		return -1;
	}

	//2.绑定(旧套接字绑定本机端口信息,为监听不同客户端连接做准备)
	struct sockaddr_in server={
		.sin_family=AF_INET,
		,sin_port=htons(PORT),
		.sin_addr.s_addr=inet_addr(IP)
	};
	if(bind(oldfd,(struct sockaddr *)&server,sizeof(server))=-1)
	{
		perror("bind");
		return -1;
	}

	//3.监听
	if(listen(oldfd,20)==-1)
	{
		perror("listen");
		return -1;
	}

	//4.发送消息
	struct sockaddr_in client;
	int client_len=sizeof(client);
	while(1)
	{
		//接收客户端请求,并生成新的套接字
		int newfd=accept(oldfd,(struct sockaddr *)&client,&client_len);
		if(newfd==-1)
		{
			perror("accept");
			return -1;
		}

		//创建子线程与客户端通话	
		pthread_t tid;
		if(pthread_create(&tid,NULL,fun,&newfd)==-1)
		{
			perror("pthread_create");
			return -1;
		}
	}

	pthread_join(tid,NULL);//回收子线程资源
	close(newfd);
	close(oldfd);
	return 0;
}

//TCP多线程并发 客户端
#include <myhead.h>

#define IP "192.168.124.40"
#define SERPORT PORT 1234

int main(int argc, const char *argv[])
{
    //1、创建套接字
    int oldfd = socket(AF_INET,SOCK_STREAM,0);
    if(oldfd==-1)
    {
        perror("socket");
        return -1;
    }
#if 0
    //2.绑定固定的IP和端口号
    struct sockaddr_in client = {
        .sin_family  =AF_INET,
        .sin_port = htons(6789),//自定义端口号
        .sin_addr.s_addr = inet_addr(IP)
    };
    if(bind(oldfd,(struct sockaddr *)&client,sizeof(client))==-1)
    {
        perror("bind");
        return -1;
    }
#endif
    //4.连接服务器
    struct sockaddr_in server = {
        .sin_family  =AF_INET,
        .sin_port = htons(SERPORT),//注意端口号需要服务器端口
        .sin_addr.s_addr = inet_addr(IP)
    };

    if(connect(oldfd,(struct sockaddr *)&server,sizeof(server))==-1)
    {
        perror("connect");
        return -1;
    }

    //5.收发消息
    char buff[1024];
    while(1)
    {
        fgets(buff,sizeof(buff),stdin);
        buff[strlen(buff)-1] = '\0';
        send(oldfd,buff,strlen(buff),0);
        if(strcmp(buff,"quit")==0)//退出客户端
        {
            break;
        }
        bzero(buff,sizeof(buff));
        recv(oldfd,buff,sizeof(buff),0);//阻塞接收服务器消息
        printf("服务器发来消息：%s\n",buff);
    }
    return 0;
}