4.13作业

 udpTFTP

#include <2503.h>

int do_downlond(int sfd, struct sockaddr_in seraddr)
{
	char buf[516]="";//数据包 
	int file_fd; //open 产生的  文件描述符
	char filename[128] = "";//文件名
	printf("输入文件名:\n");
	scanf("%s",filename);
	unsigned short num =1;
	unsigned short code_num;
	snprintf(buf,sizeof(buf),"%c%c%s%c%s%c",0,1,filename,0,"octet",0);

	//给服务器 发送一下 请求
	if(-1 == sendto(sfd,buf,sizeof(buf),0,(struct sockaddr *)&seraddr,sizeof(seraddr)))
	{
		perror("sendto error");
		return -1;
	}
	printf("%d%d%s%c%s%c",0,1,filename,0,"octet",0);
	printf("发送成功--------------\n");

	struct sockaddr_in ser_com={0};// 定义 接受 服务器 发来的ip port
	socklen_t ser_len = sizeof(ser_com);
	int ret;
	while(1)
	{
		memset(buf,0,sizeof(buf));//置空字符串
		//接受 服务器 发送的数据包
		if(0>=(ret = recvfrom(sfd,buf,sizeof(buf),0,(struct sockaddr*)&ser_com,&ser_len)))
		{
			perror("recvfrom error");
			return -1;
		}

		printf("%s\n",buf);
		unsigned short *p = (unsigned short*)buf;
		unsigned short code = *p;

		printf("%#x | %d\n",ntohs(code),buf[1]);

		code_num = ntohs(*((short*)(buf+2)));// 存储块 编号
		printf("%d\n",code_num);

		//通过接受的 数据包的 操作码 操作
		if(buf[1] == 3)
		{
			printf("进入接受\n");
			if(code_num == 1)
			{
				umask(0);
				file_fd = open(filename,O_WRONLY|O_CREAT|O_TRUNC,0664);
				printf("打开文件一次\n");
			}
			if(code_num == num)
			{
				//写入本地文件
				write(file_fd,buf+4,ret-4);

				//回复 服务器 前四个 字节
				buf[1] = 4;
				if(-1 == sendto(sfd,buf,4,0,(struct sockaddr*)&ser_com,sizeof(ser_com)))
				{
					perror("sendto error");
					return -1;
				}
				num++;
			}
			if(ret-4<512)
			{
				printf("文件下载结束...\n");
				break;
			}
		}else if(buf[1] == 5)
		{
			printf("[%d]:错误信息:%s",code_num,buf+4);
			break;
		}
	}
	return -1;
}

int do_uploading(int sfd, struct sockaddr_in seraddr)
{
	char buf[516]="";//数据包 
	int file_fd; //open 产生的  文件描述符
	char filename[128] = "";//文件名
	printf("输入文件名:\n");
	scanf("%s",filename);
	unsigned short num =0;
	unsigned short code_num;
	int ret;
	snprintf(buf,sizeof(buf),"%c%c%s%c%s%c",0,2,filename,0,"octet",0);

	//给服务器 发请求
	if(-1 == sendto(sfd,buf,sizeof(buf),0,(struct sockaddr*)&seraddr,sizeof(seraddr)))
	{
		perror("sendto error");
		return -1;
	}
	printf("上传请求发送成功......\n");

	struct sockaddr_in ser_com = {0};
	socklen_t ser_len = sizeof(ser_com);

	while(1)
	{
		memset(buf,0,sizeof(buf));
		if(0>(ret= recvfrom(sfd,buf,sizeof(buf),0,(struct sockaddr*)&ser_com,&ser_len)))
		{
			perror("recvfrom error");
			return -1;
		}

		unsigned short *p = (unsigned short*)buf;
		unsigned short code = *p;

		printf("%#x | %d\n",ntohs(code),buf[1]);
	

		code_num = ntohs(*((short*)(buf+2)));// 存储块 编号
		printf("编号 buf=[%d]\n",buf[3]);
		printf("code_num=%d\n",code_num);

		if(buf[1] == 4)
		{
			// 打开要上传的 文件
			if(code_num==0)
			{
				file_fd = open(filename,O_RDONLY);
			}
			memset(buf,0,sizeof(buf));
			ret = read(file_fd,buf+4,512);
			if(ret<0)
			{
				perror("ret error");
				return -1;
			}
			if(ret == 0)
			{
				printf("读取完毕..\n");
				break;
			}
			num++;
			buf[1]=3;
			printf("buf=[%d]\n",buf[3]);
			buf[3]++;
			if(-1 == sendto(sfd,buf,sizeof(buf),0,(struct sockaddr*)&ser_com,sizeof(ser_com)))
			{
				perror("sendto ssserrpr");
				return -1;
			}
			printf("发送成功\n");
			if(ret <512)
			{
				printf("上传完了\n");
				break;
			}
		}else if(buf[1] == 5)
		{
			printf("[%d]:错误信息:%s",code_num,buf+4);
			break;
		}
	}
	return -1;
}

int main(int argc, const char *argv[])
{
	//1.套接字 socket
	int sfd = socket(AF_INET,SOCK_DGRAM,0);
	if(-1 == sfd)
	{
		perror("socket error");
		return -1;
	}
	struct sockaddr_in seraddr;
	seraddr.sin_family = AF_INET;
	seraddr.sin_port = (htons(69));
	seraddr.sin_addr.s_addr = inet_addr("192.168.128.74");
	char choose;
	while(1)
	{
		printf("-------------------------------------------------\n");
		printf("-----------------1. 下载---------------------\n");
		printf("-----------------2. 上传---------------------\n");
		printf("-----------------3. 退出---------------------\n");
		printf("请输入您的选择:\n");
		scanf("%c",&choose);
		switch(choose)
		{
		case '1':
			do_downlond(sfd,seraddr);
			break;
		case '2':
			do_uploading(sfd,seraddr);
			break;
		case '3':
			printf("退出了\n");
			close(sfd);
			return -1;
		}
	}



	return 0;
}