#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<unistd.h>
#include<sys/stat.h>
#include<sys/types.h>
#include<fcntl.h>
#include<pthread.h>
#include<sys/wait.h>
#include<signal.h>
#include<sys/socket.h>
#include<arpa/inet.h>
#include<netinet/in.h>
#include<time.h>
#define ERR_MSG(msg) do{\
fprintf(stderr, "line:%d ", __LINE__);\
perror(msg);\
}while(0)
#define SER_IP "192.168.116.201" //服务器ＩＰ:w
#define SER_PORT 69
int do_download(int cfd,struct sockaddr_in sin){
char filename[20] = "";
char buf[516] = {0};
printf("请输入要下载的文件名>>> ");
scanf("%s", filename);
while(getchar()!=10);
short* p1 = (short*)buf;
*p1 = htons(1);
char* p2 = buf+2;
strcpy(p2, filename);
char* p4 = p2+strlen(p2)+1;
strcpy(p4, "octet");
int size = 4+strlen(p2)+strlen(p4);
//发送下载请求
if(sendto(cfd, buf, sizeof(buf), 0, (struct sockaddr*)&sin, sizeof(sin)) < 0)
{
ERR_MSG("sendto");
return -1;
}
printf("发送成功\n");
socklen_t addrlen=sizeof(sin);
ssize_t res=0;
unsigned short num=1;
int fd=-1;
//int fd=open(filename,O_WRONLY|O_CREAT|O_TRUNC,0664);//打开对应文件
while(1){
bzero(buf,sizeof(buf));
res=recvfrom(cfd,buf,sizeof(buf),0,(struct sockaddr*)&sin,&addrlen);
if(res<0){
ERR_MSG("recvfrom");
return -1;
}
if(buf[1]==3){//数据包头
if(htons(num)==*(unsigned short*)(buf+2)){//数据包编号确认
num++;
if(fd==-1){
fd=open(filename,O_WRONLY|O_CREAT|O_TRUNC,0664);
}
printf("数据包编号正确\n");
int ssize=write(fd,buf+4,res-4);//将数据内容写入文件
buf[1]=4;
//*(unsigned short*)(buf+2)=htons(num);
int sres=sendto(cfd,buf,4,0,(struct sockaddr*)&sin,sizeof(sin));//发送应答包
if(res<516){//退出
printf("download success\n");
break;
}
}
}else if(buf[1]==5){
printf("收到错误包\n");
fprintf(stderr, "DOWNLOAD_ERROR:%d : %s\n", ntohs(*(short*)(buf+2)), buf+4);
break;
continue;
}
}
close(fd);//关闭文件
return 0;
}
int do_upload(int cfd, struct sockaddr_in sin)
{
//组包准备发送下载请求
char buf[516]="";
char name[20]="";
printf("请输入要上传的文件名>>> ");
scanf("%s",name);
while(getchar()!=10);
unsigned short *p1=(short*)buf; //操作码
*p1=htons(2);
char *p2=buf+2; //文件名
strcpy(p2,name);
char *p3=p2+strlen(p2); //第一个0
*p3=0;
char *p4=p3+1; //模式
strcpy(p4,"octet");
size_t size=2+strlen(p2)+1+strlen(p4)+1; //操作码+文件名+0+模式+0
//发送上传请求
if(sendto(cfd,buf,sizeof(buf),0,(struct sockaddr*)&sin,sizeof(sin)) < 0)
{
ERR_MSG("sendto");
return -1;
}
//创建下载文件并清空
socklen_t addrlen = sizeof(sin);
ssize_t res = 0;
unsigned short num = 0; //记录本地的块编号
int fd=open(name,O_RDONLY);
if(fd < 0)
{
fprintf(stderr,"未找到该文件\n");//原因可能是没有该文件
return -1;
}
//发送上传请求
while(1)
{
res=recvfrom(cfd,buf,sizeof(buf),0,(struct sockaddr*)&sin,&addrlen);
if(4==res){//接受应答包
if(buf[1]==4){
if(htons(num)==*(short*)(buf+2)){
num++;
printf("正确接受应答包%d %d\n",__LINE__,ntohs(*(short*)(buf+2)));
}
}else{
fprintf(stderr,"接受错误\n");
return -1;
}
}
else if(5 == buf[1]) //错误包
{
printf("错误: %d %s\n",ntohs(*(short*)(buf+2)),buf+4);
close(fd);
return -1;
}else if(res<0){
ERR_MSG("recvfrom");
return -1;
}
//发送数据
bzero(buf+4,512);
ssize_t size_r=read(fd,buf+4,512);
buf[1]=3;
//使用应答包的块编号
*(unsigned short*)(buf+2)=htons(num);
res = sendto(cfd,buf,size_r+4,0,(struct sockaddr*)&sin,addrlen);//发送数据包
if(res < 0)
{
ERR_MSG("sendto");
return -1;
}
if(size_r<512)break;//文件读取完毕
}
close(fd);
return 0;
}
int main(int argc, const char *argv[])
{
int cfd = socket(AF_INET, SOCK_DGRAM, 0);
if(cfd < 0)
{
ERR_MSG("socket");
return -1;
}
struct sockaddr_in sin;
sin.sin_family = AF_INET;
sin.sin_port = htons(SER_PORT);
sin.sin_addr.s_addr = inet_addr(SER_IP);
char c = 0;
while(1)
{
system("clear");
printf("---------------------------\n");
printf("----------1. 下载----------\n");
printf("----------2. 上传----------\n");
printf("----------3. 退出----------\n");
printf("---------------------------\n");
c = getchar();
while(getchar() != 10);
switch(c)
{
case '1':
do_download(cfd, sin);
break;
case '2':
do_upload(cfd,sin);
break;
case '3':
goto END;
break;
default:
printf("输入错误，请重新输入\n");
}
printf("输入任意字符清屏>>>");
while(getchar()!=10);
}
END:
close(cfd);
return 0;
}
效果图：
1下载
客户端
服务器端
下载5.png成果
2上传
客户端
服务器端
上传成功
