信息安全实践第四次作业远程控制系统

1、四 川 大 学 计 算 机 学 院、软 件 学 院实 验 报 告 学号： 姓名：专业： 班级： 第 3 周 课程名称 信息安全产品开发实践  实验课时4实验项目远程控制系统实验时间2013.9.27实验目的 利用流套接字实现一个简单的远程控制系统  实验环境 虚拟机 Ubuntu-VMware Workstation  实验内容（算法、程序、步骤和方法） 服务器服务器代码中有两个死循环，外部是为了重复连接客户端（即使对方断了此次连接仍然能继续等待并连接下一客户端），要注意每连接一次客户端套接字都会不同，而且除了连接客户端的套接字以外还有监听套接字。#include

2、<stdlib.h>#include<stdio.h>#include<sys/socket.h>#include<netdb.h>#include<string.h>#include<unistd.h>#include<netinet/in.h>#include<arpa/inet.h>#define PORT 8900#defineSIZE 2048/* 2K BUFFER */void exec (char* command,char* result)FILE * in;int len;cha

3、r c;len=0;bzero(result,sizeof(result);in=popen(command,"r");if (NULL=in)fprintf(stderr,"error in create a pipen");/return -1;while(c=fgetc(in)!=EOF)&&(len<SIZE)resultlen=c;len+;resultlen='0'pclose(in);if (0=len)sprintf(result,"%s cannot executen",comm

4、and);int main(int argc,char* argv)struct sockaddr_in server;struct sockaddr_in client;int len;int port;int listend;int connectd;int sendnum;int opt;int recvnum;char send_buf2048;char recv_buf2048;int rvalue;char cmd10; /* these two var used to deal with cd command */char path2048;port= PORT;memset(s

5、end_buf,0,2048);memset(recv_buf,0,2048);opt = SO_REUSEADDR;if (-1=(listend=socket(AF_INET,SOCK_STREAM,0)/使用TCP创建监听用的套接字perror("create listen socket errorn");exit(1);setsockopt(listend,SOL_SOCKET,SO_REUSEADDR,&opt,sizeof(opt);#ifdef DEBUGprintf("the listen id is %dn",listend);

6、#endifmemset(&server,0,sizeof(struct sockaddr_in);server.sin_family = AF_INET;/IPv4协议server.sin_addr.s_addr = htonl(INADDR_ANY);/接收任意地址server.sin_port = htons(port);/设置端口号if (-1=bind(listend,(struct sockaddr *)&server,sizeof(struct sockaddr)/绑定perror("bind errorn");exit(1); if (-1=

7、listen(listend,5) perror("listen errorn");exit(1); while(1)/外部死循环，用来重复连接客户端if (-1=(connectd=accept(listend,(struct sockaddr*)&client,&len)/创建新的套接字连接客户端perror("create connect socket errorn");continue;while (1)memset(recv_buf,0,2048);#ifdef DEBUGprintf("the connect id

8、is %d",connect);printf("the client ip addr is %s",inet_ntoa(client.sin_addr);#endif#ifdef DEBUGprintf("the send num is %d",sendnum);printf("the client ip addr is %s",inet_ntoa(client.sin_addr);#endifif (0>(recvnum = recv(connectd,recv_buf,sizeof(recv_buf),0)perr

9、or("recv errorn");close(connectd);continue;recv_bufrecvnum-1='0'/这里要注意-1，不然会保留换行符if (0=strcmp(recv_buf,"quit")|(0=strcmp(recv_buf,"QUIT")/结束对话，跳出内部循环，继续外部循环printf("overn");break;sscanf(recv_buf,"%s %s",cmd,path);if (0=strcmp("cd",cm

10、d) |(0=strcmp("CD",cmd)chdir(path);continue;exec(recv_buf,send_buf);rvalue=-1;rvalue=send(connectd,send_buf,sizeof(send_buf),0); close(listend); return 0;  （接上）实验内容（算法、程序、步骤和方法）客户端客户端代码中只有一个死循环，和上次实验差别不大。#include<stdlib.h>#include<stdio.h>#include<sys/socket.h>#inclu

11、de<netdb.h>#include<string.h>#include<unistd.h>#include<netinet/in.h>#include<arpa/inet.h>#define SIZE 2048void print_usage (char* cmd )fprintf(stderr,"Usage:%s ip addressn",cmd);int main(int argc,char* argv)struct sockaddr_in server;int ret;int len;int port;i

12、nt sockfd;int sendnum;int recvnum;char send_buf2048;char recv_buf2048;int rvalue;char bufferSIZE;char cmd10; if (2>argc)| (argc >3)print_usage(argv0);exit(1);if (3=argc) /这里的端口号从主函数参数获取port = atoi(argv2);if (-1=(sockfd=socket(AF_INET,SOCK_STREAM,0)perror("can not create socketn");exi

13、t(1);memset(&server,0,sizeof(struct sockaddr_in);server.sin_family = AF_INET;server.sin_addr.s_addr = inet_addr(argv1);server.sin_port = htons(port);if (0>(ret=connect(sockfd,(struct sockaddr*)&server,sizeof(struct sockaddr)perror("connect error");close(sockfd);exit(1);while(1)/

14、这边只需一个死循环memset(buffer,0,2048);fprintf(stderr,"TCP>");fgets(buffer,SIZE,stdin);rvalue=send(sockfd,buffer,strlen(buffer),0);if (0=strcmp(buffer,"quitn")|(0=strcmp(buffer,"QUITn")/结束对话close(sockfd);break;if (0>rvalue)fprintf(stderr,"error in receiving datan");continue;sscanf(buffer,"%s",cmd);if (0=strcmp("cd",cmd)|(0=strcmp("CD",cmd)continue;/如果是cd命令则没有返回内容直接重新开始循环len=sizeof(struct sockaddr);if (0>(len=recv(sockfd,buffer,2048,0)perror("recv data errorn");close(sockfd);exit(1);bufferlen='0'printf(&