ser.c

基于TCP的控制台下局域网ftp（C/S）,能够实现简单ftp命令。具有简单的客户端身份认证功能。内含简单的makefile文件

#include "server.h"

void cmd_put(int sock,char *fileName);
void cmd_help(int sock);
int usrcheck ( int usrchecksock);

int rval,i,j;
char client_cmd[10] , cmd_arg[20] ,usr_msg[50]; 

char currentDirPath[200];
char currentDirName[30];
struct usrcheck
  {
   	char usrname[20];
	char psword[10];
  };
struct usrcheck usr_psword_check[4]={{"root","123456"},{"linqiangyun","fengyun"},{"fanchao","123456"},{"redhat","123456"}};
													

char usr_msg_1[50]="please enter the username:";
char usr_msg_2[50]="please enter the password:";
char usr_msg_4[50]="welcome! have fun!";				

char help[300]="***Use <put> to upload a file to server\n***Use <help> to get help\n***Use <quit> to exit\n";

/***************help**************/
/*********************************/

void cmd_help(int sock)
{
	write(sock,help,sizeof help);
}




/*******读取数据实现发送端上传*******/
/************************************/

void cmd_put(int sock,char *fileName)
{ 
	int fd,numread;
	long fileSize;

	char filePath[200], buf[dataLen];
	strcpy(filePath,currentDirPath);
	strcat(filePath,"/");
	strcat(filePath,fileName);


	fd=open(filePath,O_RDWR|O_CREAT, S_IREAD|S_IWRITE);
	if(fd!=-1)
	{ 
		memset(buf,0,dataLen);
		read(sock,&fileSize,sizeof(long));

		while(fileSize>0)
		{
			numread=read(sock,buf,dataLen);
			write(fd,buf,numread);
			fileSize=fileSize-numread;
		}

		close(fd);
		printf("Transfer completed\n");
	}
	else
	{
		printf("open file >s failed\n",filePath);
	}

}

/****************用户验证*************/
/*************************************/
int usrcheck ( int usrchecksock)
{ 
	 printf("Waiting for user enter username and password!\n");
	 rval=0;
	 int i;
	 rval=write(usrchecksock,usr_msg_1,sizeof usr_msg_1);	
	 if ( rval<0 || rval==0)		
	 {
		perror("write\n");
		return 0;
	 }
		memset(usr_msg,0,sizeof usr_msg);
		rval=read(usrchecksock,usr_msg,sizeof usr_msg); 				
		if ( rval<0 || rval==0)
		{
		 perror("read\n");
		 return 0;
		}
	for ( i=0;i<4;i++)	
	{
	  if(strcmp(usr_msg,usr_psword_check[i].usrname)==0)
	  {
		rval=write(usrchecksock,usr_msg_2,sizeof usr_msg_2);
		if(rval<0||rval==0)
		 {	
		   perror("write\n");
		  return 0;
		 }	
		else break;
	  }	
	}  

	/*Usrname error*/
	if ( i==4)
	 {return 0;}

	  memset(usr_msg,0,sizeof usr_msg);
	  rval=read(usrchecksock,usr_msg,sizeof usr_msg);
	  if ( rval<0 || rval==0)
	  {
		perror("read passwd error\n");
		return 0;
	  }
	if ( strcmp(usr_msg,usr_psword_check[i].psword)==0)
	{
		printf("correct password!now waiting for commands!\n");
		rval=write(usrchecksock,usr_msg_4,sizeof usr_msg_4);
		if ( rval<0 || rval==0)
		{	
			perror("write\n");
			return 0;
		}
		else 
		 {
		   close(usrchecksock);
		   return 1;
		 }
	}
	else										
	return 0;
}