【Day4】网络编程

1.思维导图：

2.广播
接收方：

#include 
#include 
#include 
#include 
#include 
#include 

#define ERR_MSG(msg) do{\
	fprintf(stderr,"line:%d: %s %s \n",__LINE__,__FILE__,__func__);\
	perror(msg);\
}while(0);

#define IP "192.168.2.255"//广播地址
#define PORT 6666//1024~49151，网络字节序

int main(int argc, const char *argv[])
{
	//创建报式套接字
	int sfd = socket(AF_INET,SOCK_DGRAM,0);
	if(sfd < 0){
		ERR_MSG("socket");
		return -1;
	}
	int broad = 1;
	//设置允许广播
	setsockopt(sfd,SOL_SOCKET,SO_BROADCAST,&broad,sizeof(broad));

	//绑定发送方自身的地址信息结构体----》非必须绑定
	//若不绑定操作系统会自动给发送方绑定一个IP和端口

	//填充服务器的地址信息结构体，给sendto函数使用
	//真实的地址信息结构体根据地址族指定AF_INET:man 7 IP
	struct sockaddr_in sin;
	sin.sin_family = AF_INET;//必须填AF_INET;
	sin.sin_port = htons(PORT);//1024~49151，网络字节序
	sin.sin_addr.s_addr = inet_addr(IP);//ifconfig出来的本机ip
	
	char buf[128] = "";
	while(1){
		
		//发送数据
		printf("发送端发出消息：");
		scanf(" %s",buf);
		if(sendto(sfd,buf,sizeof(buf),0,(struct sockaddr*)&sin,sizeof(sin))<0){
			ERR_MSG("sendto");
			return -1;
		}
		
		printf("send success__%d__\n",__LINE__);

			
	}
	//关闭套接字
	close(sfd);
	return 0;
}

发送方：

#include 
#include 
#include 
#include 
#include 
#include 
#define ERR_MSG(msg) do{\
	fprintf(stderr,"line:%d: %s %s \n",__LINE__,__FILE__,__func__);\
	perror(msg);\
}while(0);

#define IP "192.168.2.255"//ifconfig出来的本机IP
#define PORT 6666//1024~49151，网络字节序

int main(int argc, const char *argv[])
{
	//创建报式套接字
	int sfd = socket(AF_INET,SOCK_DGRAM,0);
	if(sfd < 0){
		ERR_MSG("socket");
		return -1;
	}

	//填充接收方的地址信息结构体
	//真实的地址信息结构体根据地址族指定AF_INET:man 7 IP
	struct sockaddr_in sin;
	sin.sin_family = AF_INET;//必须填AF_INET;
	sin.sin_port = htons(PORT);//1024~49151，网络字节序
	sin.sin_addr.s_addr = inet_addr(IP);//广播IP
	//绑定地址信息结构体
	if(bind(sfd,(struct sockaddr*)&sin,sizeof(sin))<0){
		ERR_MSG("bind");
		return -1;
	}
	printf("bind success__%d__\n",__LINE__);
	
	char buf[128] = "";
	struct sockaddr_in cin;
	socklen_t addrlen = sizeof(cin);
	while(1){
		bzero(buf,sizeof(buf));	
		//接收
		if(recvfrom(sfd,buf,sizeof(buf),0,(struct sockaddr*)&cin,&addrlen)<0){
			ERR_MSG("recvfrom");
			return -1;
		}
		printf("[%s:%d] : %s\n",inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),buf);
		
		
	}
	//关闭套接字
	close(sfd);
	return 0;
}

3.组播
发送方：

#include 
#include 
#include 
#include 
#include 
#include 
#define ERR_MSG(msg) do{\
	fprintf(stderr,"line:%d: %s %s \n",__LINE__,__FILE__,__func__);\
	perror(msg);\
}while(0);

#define IP "224.1.2.3"//组播IP 224.0.0.0～239.255.255.255或0.0.0.0
#define PORT 6666//1024~49151，网络字节序

int main(int argc, const char *argv[])
{
	//创建报式套接字
	int sfd = socket(AF_INET,SOCK_DGRAM,0);
	if(sfd < 0){
		ERR_MSG("socket");
		return -1;
	}

	//绑定客户端自身的地址信息结构体----》非必须绑定
	//若不绑定操作系统会自动给客户端绑定一个IP和端口

	//填充服务器的地址信息结构体，给sendto函数使用
	//真实的地址信息结构体根据地址族指定AF_INET:man 7 IP
	struct sockaddr_in sin;
	sin.sin_family = AF_INET;//必须填AF_INET;
	sin.sin_port = htons(PORT);//1024~49151，网络字节序
	sin.sin_addr.s_addr = inet_addr(IP);//组播ip
	
	char buf[128] = "";
	struct sockaddr_in rcvaddr;
	socklen_t addrlen = sizeof(rcvaddr);
	while(1){
		
		//发送数据
		printf("发送方发出消息：");
		scanf(" %s",buf);
		if(sendto(sfd,buf,sizeof(buf),0,(struct sockaddr*)&sin,sizeof(sin))<0){
			ERR_MSG("sendto");
			return -1;
		}
		
		printf("send success__%d__\n",__LINE__);
		
	}
	//关闭套接字
	close(sfd);
	return 0;
}

接收方：

#include 
#include 
#include 
#include 
#include 
#include 

#define ERR_MSG(msg) do{\
    fprintf(stderr, "line:%d: %s %s\n", __LINE__, __FILE__, __func__);\
    perror(msg);\
}while(0)                                                                                 

#define GRP_IP  "224.1.2.3"     //组播IP 224.0.0.0-239.255.255.255
#define LOL_IP  "192.168.2.155" //ifconfig, 本机IP

#define PORT 6666           //1024~49151，网络字节序

int main(int argc, const char *argv[])
{
    //创建报式套接字
    int sfd = socket(AF_INET, SOCK_DGRAM, 0);
    if(sfd < 0)
    {
        ERR_MSG("socket");
        return -1;
    }
    printf("create socket success sfd=%d __%d__\n", sfd, __LINE__);

    //加入多播组
    struct ip_mreqn mq;
    mq.imr_multiaddr.s_addr = inet_addr(GRP_IP);    //组播IP的网络字节序
    mq.imr_address.s_addr   = inet_addr(LOL_IP);    //ifconfig出来的本机IP
    mq.imr_ifindex          = 2;                    //网络设备索引号

    if(setsockopt(sfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mq, sizeof(mq)) < 0)
    {
        ERR_MSG("setsockopt");
        return -1;
    }
    printf("加入多播组 %s 成功 __%d__\n", GRP_IP, __LINE__);


    //填充接收方的地址信息结构体，
    //真实的地址信息结构体根据地址族指定AF_INET:man 7 IP
    struct sockaddr_in sin;
    sin.sin_family      = AF_INET;
    sin.sin_port        = htons(PORT);
    sin.sin_addr.s_addr = inet_addr(GRP_IP);    //组播IP 224.0.0.0-239.255.255.255

    //绑定地址信息结构体
    if(bind(sfd, (struct sockaddr*)&sin, sizeof(sin)) < 0)
    {
        ERR_MSG("bind");
        return -1;
    }
    printf("bind success __%d__\n", __LINE__);

    char buf[128] = "";
    struct sockaddr_in cin;         //存储数据包是从哪里来的
    socklen_t addrlen = sizeof(cin);
    while(1)
    {
        bzero(buf, sizeof(buf));
        //接收数据
        if(recvfrom(sfd, buf, sizeof(buf), 0, (struct sockaddr*)&cin, &addrlen) < 0)
        {
            ERR_MSG("recvfrom");
            return -1;
        }
        printf("[%s:%d] : %s\n", inet_ntoa(cin.sin_addr), ntohs(cin.sin_port), buf);
    }


    //关闭套接字
    close(sfd);
    return 0;
}

4.多进程并发服务器

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#define ERR_MSG(msg) do{\
	fprintf(stderr, "line:%d: %s %s\n", __LINE__, __FILE__, __func__);\
	perror(msg);\
}while(0)

int del_cli_msg(int newfd, struct sockaddr_in cin);
#define IP "192.168.2.155"  //ifconfig出来的本机IP
#define PORT 6666           //1024~49151，网络字节序
void handler(int sig)
{
    while(waitpid(-1, NULL, WNOHANG) > 0);
}
int main(int argc, const char *argv[])
{
	//捕获17) SIGCHLD信号
    if(signal(SIGCHLD, handler) ==SIG_ERR)
    {
        ERR_MSG("signal");
        return -1;
    }

	//创建套接字
	int sfd = socket(AF_INET,SOCK_STREAM,0);
	if(sfd<0){
		ERR_MSG("socket");
		return -1;
	}
	printf("socket success __%d__",__LINE__);
	int reuse = 1;
	if(setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse)) < 0)
	{
		ERR_MSG("setsockopt");
		return -1;
	}
	printf("允许端口快速重用成功 __%d__\n", __LINE__);
	//填充地址结构体
	struct sockaddr_in sin;
	sin.sin_family = AF_INET;
	sin.sin_port = htons(PORT);
	sin.sin_addr.s_addr = inet_addr(IP);
	socklen_t addrlen = sizeof(sin);
	//绑定
	if(bind(sfd,(struct sockaddr*)&sin,addrlen)<0){
		ERR_MSG("bind");
		return -1;
	}
	printf("bind success __%d__\n", __LINE__);
	if(listen(sfd,128)<0){
		ERR_MSG("listen");
		return -1;
	}
	printf("listen success __%d__\n", __LINE__);
	struct sockaddr_in cin;
	socklen_t cadddrlen = sizeof(cin);
	int pid = -1;
	int newfd = -1;
	while(1){
		newfd = accept(sfd,(struct sockaddr *)&cin,&cadddrlen);
		if(newfd<0){
			ERR_MSG("accept");
			return -1;
		}
		if((pid=fork())==0){
			close(sfd);
			del_cli_msg(newfd,cin);
			exit(0);
		}else if(pid>0){
			close(newfd);
		}else{
			ERR_MSG("fork");
			return -1;
		}
	}
	return 0;
}
int del_cli_msg(int newfd, struct sockaddr_in cin){
	char buf[128] = "";		
	ssize_t res = 0;

	bzero(buf,sizeof(buf));
	while(1){
		
		//接收
		res = recv(newfd,buf,sizeof(buf),0);
		if(res<0){
			ERR_MSG("recv");
		}else if(res==0){
			 printf("[%s:%d] 客户端下线 newfd=%d __%d__\n",\
                    inet_ntoa(cin.sin_addr),ntohs(cin.sin_port), newfd, __LINE__);
            break;
		}
		printf("[%s:%d] newfd=%d :%s __%d__\n",inet_ntoa(cin.sin_addr),ntohs(cin.sin_port), newfd, buf, __LINE__);
		//发送
 		strcat(buf, "*_*");
        if(send(newfd, buf, sizeof(buf), 0) < 0)
        {
            ERR_MSG("send");
            return -1;
        }
        printf("send success __%d__\n", __LINE__);
	}
	close(newfd);
	return 0;
}

5.多线程并发服务器

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#define ERR_MSG(msg) do{\
	fprintf(stderr, "line:%d: %s %s\n", __LINE__, __FILE__, __func__);\
	perror(msg);\
}while(0)
struct climsg
{
    int newfd;
    struct sockaddr_in cin;
};
void* del_cli_msg(void *arg);
#define IP "192.168.2.155"  //ifconfig出来的本机IP
#define PORT 6666           //1024~49151，网络字节序
int main(int argc, const char *argv[])
{

	//创建套接字
	int sfd = socket(AF_INET,SOCK_STREAM,0);
	if(sfd<0){
		ERR_MSG("socket");
		return -1;
	}
	printf("socket success __%d__",__LINE__);
	int reuse = 1;
	if(setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse)) < 0)
	{
		ERR_MSG("setsockopt");
		return -1;
	}
	printf("允许端口快速重用成功 __%d__\n", __LINE__);
	//填充地址结构体
	struct sockaddr_in sin;
	sin.sin_family = AF_INET;
	sin.sin_port = htons(PORT);
	sin.sin_addr.s_addr = inet_addr(IP);
	socklen_t addrlen = sizeof(sin);
	//绑定
	if(bind(sfd,(struct sockaddr*)&sin,addrlen)<0){
		ERR_MSG("bind");
		return -1;
	}
	printf("bind success __%d__\n", __LINE__);
	if(listen(sfd,128)<0){
		ERR_MSG("listen");
		return -1;
	}
	printf("listen success __%d__\n", __LINE__);
	struct sockaddr_in cin;
	socklen_t cadddrlen = sizeof(cin);
	pthread_t tid = -1;
	int newfd = -1;
	struct climsg info;
	while(1){
		newfd = accept(sfd,(struct sockaddr *)&cin,&cadddrlen);
		if(newfd<0){
			ERR_MSG("accept");
			return -1;
		}
		info.newfd = newfd;
		info.cin = cin;
		if(pthread_create(&tid,NULL,del_cli_msg,&info)!=0){
			ERR_MSG("pthread_create");
			return -1;
		}
		pthread_detach(tid);
	}
	close(sfd);
	return 0;
}
void* del_cli_msg(void * arg){
	char buf[128] = "";		
	ssize_t res = 0;
	int newfd = ((struct climsg *)arg)->newfd;
	struct sockaddr_in cin = ((struct climsg *)arg)->cin;
	bzero(buf,sizeof(buf));
	while(1){

		//接收
		res = recv(newfd,buf,sizeof(buf),0);
		if(res<0){
			ERR_MSG("recv");
		}else if(res==0){
			 printf("[%s:%d] 客户端下线 newfd=%d __%d__\n",\
                    inet_ntoa(cin.sin_addr),ntohs(cin.sin_port), newfd, __LINE__);
            break;
		}
		printf("[%s:%d] newfd=%d :%s __%d__\n",inet_ntoa(cin.sin_addr),ntohs(cin.sin_port), newfd, buf, __LINE__);
		//发送
 		strcat(buf, "*_*");
        if(send(newfd, buf, sizeof(buf), 0) < 0)
        {
            ERR_MSG("send");
        }
        printf("send success __%d__\n", __LINE__);
	}
	close(newfd);
}

作业：tftp上传

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#define ERR_MSG(msg) do{\
	fprintf(stderr,"line:%d: %s %s \n",__LINE__,__FILE__,__func__);\
	perror(msg);\
}while(0);

#define IP "192.168.2.30"//ifconfig出来的本机IP
#define PORT 69//1024~49151，网络字节序

int main(int argc, const char *argv[])
{
	//创建报式套接字
	int sfd = socket(AF_INET,SOCK_DGRAM,0);
	if(sfd < 0){
		ERR_MSG("socket");
		return -1;
	}
	printf("socket success__%d__\n",__LINE__);
	//填充服务器地址信息结构体
	struct sockaddr_in sin;
	sin.sin_family = AF_INET;
	sin.sin_port = htons(PORT);
	sin.sin_addr.s_addr = inet_addr(IP);

	char buf[516] = "";
	int len = sprintf(buf,"%c%c%s%c%s%c",0,2,"1.png",0,"octet",0);
	//向服务器发送请求
	if(sendto(sfd,buf,len,0,(struct sockaddr*)&sin,sizeof(sin))<0){
		ERR_MSG("sendto");
		return -1;
	}
	printf("sendto success__%d__\n",__LINE__);
	struct sockaddr_in rcvaddr;
	socklen_t addrlen = sizeof(rcvaddr);
	short *block ;
	short *op;
	//接收ack包得到临时端口
	if(recvfrom(sfd,buf,4,0,(struct sockaddr*)&rcvaddr,&addrlen)<0){
		ERR_MSG("recvfrom");
		return -1;
	}else {
		op = (short*)buf;//记录ACK包中的操作码
		block = (short*)(buf+2);//记录ACK中的块编号
	}
	//只读模式打开文件
	int fd = open("./1.png",O_RDONLY);
	if(fd<0){
		ERR_MSG("open");
		return -1;
	}
	printf("open success__%d__\n",__LINE__);
	ssize_t datalen = 0;
	short lastbock;
	short blk = 0;
	while(1){
		//组数据包
		sprintf(buf,"%c%c",0,3);
		*block = htons(++blk);
		lastbock = *block;
		datalen = read(fd,buf+4,512);
		if(datalen<0){
			ERR_MSG("read");
			return -1;
		}
		printf("read success__%d_read:%ld_\n",__LINE__,datalen);
		while(1){
		//发数据包
		if(sendto(sfd,buf,datalen+4,0,(struct sockaddr*)&rcvaddr,sizeof(rcvaddr))<0){
			ERR_MSG("sendto");
			return -1;
		}
		printf("sendto success__%d__\n",__LINE__);
		//阻塞方式接收ACK包
		if(recvfrom(sfd,buf,4,0,(struct sockaddr*)&rcvaddr,&addrlen)>0){	
			if(*op==htons(4)||*block!=lastbock){
				//发送完最后一个数据包并接到ACK包结束
				if(datalen<512){
					printf("上传完毕\n");
					return 0;
				}
				break;
			}		
		}
	}
	}
	return 0;
}

输出：