server.c

最传统得加密解密方法des,此源代码需在嵌入式linux下编译运行

//----------POWERED BY BOBO---------
//----------引入库函数------------------
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include "des.h"
//--------------------------------------
#define WAITBUF 10		//定义监听队列

void process_cli(int connectfd,struct sockaddr_in client);
main(int argc, char *argv[])
{
    int listenfd, connectfd;		//定义SOCKET参量
    struct sockaddr_in server;	//定义服务器端SOCKADDR结构
    struct sockaddr_in client;	//定义客户端SOCKADDR结构
    unsigned int sin_size, portnumber;//定义结构参数和端口变量

    if(argc != 2)			//判断输入参数是否正确
    {
        fprintf(stderr, "Usage:%s portnumber\a\n", argv[0]);
        exit(1);
    }

    if((portnumber = atoi(argv[1])) < 0)
    {
        fprintf(stderr, "Usage: %s portnumber error\a\n", argv[0]);
    }

    if((listenfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)	//建立SOCKET并判断是否成功
    {
        fprintf(stderr, "Socket error:%s\n\a", strerror(errno));
        exit(1);
    }
    //int opt;
    //setsockopt(listenfd,SOL_SOCKET,SO_REUSERADDR,&opt,sizeof(opt));
    bzero(&server, sizeof(struct sockaddr_in));		//重置
    server.sin_family = AF_INET;			//设置SOCKET DOMAIN
    server.sin_addr.s_addr = htonl(INADDR_ANY);		//设置IP地址
    server.sin_port = portnumber;			//设置端口号

    if(bind(listenfd,(struct sockaddr *)(&server), sizeof(struct sockaddr)) == -1)	//绑定SOCKET
    {
        fprintf(stderr, "Bind error:%s\n\a", strerror(errno));
        exit(1);
    }

    if(listen(listenfd, WAITBUF) == -1)			//设置监听
    {
        fprintf(stderr, "Listen error:%s\n\a", strerror(errno));
        exit(1);
    }
    sin_size = sizeof(struct sockaddr_in);
    while(1)						//此处循环等待客户端接入
    {
    
        if((connectfd = accept(listenfd, (struct sockaddr *)(&client), &sin_size)) == -1)
        {
            fprintf( stderr, "Accept error:%s\n\a", strerror(errno));
            exit(1);
        }//接收客户端信息将其存入客户端结构体
	process_cli(connectfd,client);
        //exit(1);
    }
    close(listenfd);
    //exit(0);
} 
void process_cli(int connectfd,struct sockaddr_in client)
{
	int num;			//定义接收数据长度
	char recvbuf[1024],sendbuf[1024];	//定义接收发送缓冲区
	char Key[8]="12345678";
	fprintf(stderr, "From %s:", inet_ntoa(client.sin_addr));
	while(num = recv(connectfd,recvbuf,1024,0))	//接收数据
	{
		recvbuf[num]='\0';
		printf("%s\n",recvbuf);
		des_go(sendbuf,recvbuf,strlen(recvbuf),Key,0);
		send(connectfd,sendbuf,strlen(sendbuf),0);	//发送数据
		//continue;
	}
	close(connectfd);
}