datasocket.cpp

在Linux下使用GCC编制的FTP服务器

#include <strings.h>
#include "Tools.h"
#include "CtrlSocket.h"
#include "DataSocket.h"

//用于数据传输的子线程入口点函数
void *CDataSocket::Dispatch(void *pvParam)
{
	CDataSocket *pThis=(CDataSocket *)pvParam;
	int iRet=-10;
	if(pThis->m_nRunType==LIST)
		iRet=pThis->List();
	else if(pThis->m_nRunType==RETR)
		iRet=pThis->Retr();
	else if(pThis->m_nRunType==STOR)
		iRet=pThis->Stor();
	pThis->Close();
	return (void *)iRet;
}

CDataSocket::CDataSocket()
{
	Close();
	m_dwThreadId=0;//现在还不能肯定新线程ID是否不为0!!!!
	m_bAllowRun=false;
}

CDataSocket::~CDataSocket()
{

}

//开始运行工作线程
int CDataSocket::Run(CDataSocket::RUN_TYPE nRunType)
{
	Stop();	
	m_bAllowRun=true;//置允许子线程运行标志
	m_nRunType=nRunType;
	pthread_create(
		&m_dwThreadId,
		NULL,
		Dispatch,
		this);
	return 0;
}

//停止工作线程
int CDataSocket::Stop()
{
	if(m_dwThreadId != 0){
		m_bAllowRun=false;
		pthread_join(m_dwThreadId,NULL);
		m_dwThreadId=0;
	}
	return 0;
}

int CDataSocket::PreparePasv()
{
	sockaddr_in addrIp,addrPort={0};
	size_t nSize=sizeof(sockaddr_in);
	unsigned int nSvrIp,nSvrPort;
	//
	getsockname(*(m_pSockCtrl),(sockaddr *)&addrIp,&nSize);
	nSvrIp=ntohl(addrIp.sin_addr.s_addr);
	m_sockListen.Create();
	if(m_sockListen.Bind(0)!=0){
		m_pSockCtrl->Response("450 Internal error.");
		return -1;
	}
	getsockname(m_sockListen,(sockaddr *)&addrPort,&nSize);
	nSvrPort=ntohs(addrPort.sin_port);
	listen(m_sockListen,1);
	m_nConnType=PASV;
	m_pSockCtrl->Response(
		"227 Entering Passive Mode (%d,%d,%d,%d,%d,%d).",
		nSvrIp>>24 & 0xff,
		nSvrIp>>16 & 0xff,
		nSvrIp>>8 & 0xff,
		nSvrIp & 0xff,
		nSvrPort>>8 & 0xff,
		nSvrPort>>0 & 0xff);
	return 0;
}

int CDataSocket::PreparePort(const char *pszAddr)
{
	unsigned int nAddr[6];
	int iRet=sscanf(
		pszAddr,
		"%u,%u,%u,%u,%u,%u",
		nAddr+0,
		nAddr+1,
		nAddr+2,
		nAddr+3,
		nAddr+4,
		nAddr+5);
	if(iRet!=6){
		m_pSockCtrl->Response("501 Invalid parameter.");
		return -1;
	}
	m_nClientIp=nAddr[0]<<24 |
	 			nAddr[1]<<16 |
				nAddr[2]<<8	 |
				nAddr[3];
	m_nClientPort=nAddr[4]<<8 | nAddr[5];	
	m_nConnType=PORT;
	m_pSockCtrl->Response("200 Port command successful.");
	return 0;
}

int CDataSocket::List()
{
	int iRet,iSent=0;
	//
	if(Connect()!=0)
		return -1;
	while(m_bAllowRun && iSent<(int)m_sList.length()){
		iRet=Send(m_sList.c_str()+iSent,m_sList.length()-iSent);
		if(iRet<1 && errno!=EWOULDBLOCK){
			break;
		}
		iSent+=iRet;
	}
	m_pSockCtrl->Response("260 Transfer complete.");
	return iSent;
}

int CDataSocket::Retr()
{
	int iRet;
	FILE *pStream=NULL;
	char chBuf[512],*pchHead,*pchTail;//尾指针指向第1个无效字节
	bool bReadFileContinue=true;
	//
	if(Connect()!=0)
		return -1;
	pStream=fopen(m_sFile.c_str(),"rb");
	if(pStream==NULL){
		m_pSockCtrl->Response("550 open file failed.");
		return -2;
	}
	pchHead=pchTail=chBuf;
	while(m_bAllowRun){
		if(bReadFileContinue && pchHead>=pchTail){
			iRet=fread(chBuf,1,sizeof(chBuf),pStream);
			if(iRet>0){
				pchHead=chBuf;
				pchTail=pchHead+iRet;
			}
			bReadFileContinue=(iRet>0);		
		}
		if(pchHead>=pchTail)
			break;
		iRet=Send(pchHead,pchTail-pchHead);
		if(iRet<1 && errno!=EWOULDBLOCK){
			break;
		}
		pchHead+=iRet;
	}
	fclose(pStream);
	m_pSockCtrl->Response("260 Transfer complete.");
	return 0;
}

int CDataSocket::Stor()
{
	int iRet,iAllTime;
	FILE *pStream=NULL;
	char chBuf[512];//尾指针指向第1个无效字节
	//
	if(Connect()!=0)
		return -1;
	pStream=fopen(m_sFile.c_str(),"wb");
	if(pStream==NULL){
		m_pSockCtrl->Response("550 open file failed.");
		return -2;
	}
	while(m_bAllowRun){
		iRet=Recv(chBuf,sizeof(chBuf));
		if(iRet==0){
			break;//对方断开连接
		}
		if(iRet>0){
			if(iRet!=(int)fwrite(chBuf,1,iRet,pStream)){
				break;
			}
			iAllTime=0;
		}else if(errno!=EWOULDBLOCK){
			break;
		}
		if(++iAllTime>(m_iTimeout/TIME_SLICE))
			break;
	}
	fclose(pStream);
	m_pSockCtrl->Response("260 Transfer complete.");
	return 0;
}

int CDataSocket::Connect()
{
	int iRet=-1;
	if(m_nConnType==PORT){
		Create();
		iRet=CMySocket::Connect(m_nClientIp,m_nClientPort);
	}else if(m_nConnType==PASV){
		//accept不能设置超时，通过采用非阻塞模式和select来
		//检查客户端的连接超时
		m_sockListen.SetBlockMode(false);
		fd_set setRead;
		int iAllTime=0;
		timeval timeout;
		timeout.tv_sec=TIME_SLICE/1000;	//1秒
		timeout.tv_usec=0;
		FD_ZERO(&setRead);	
		//
		while(m_bAllowRun){//每1000毫秒循环一次
			FD_SET(m_sockListen,&setRead);//捕捉接收连接事件
			if(select(m_sockListen+1,&setRead,NULL,NULL,&timeout)<0)
				break;
			if(FD_ISSET(m_sockListen,&setRead)){//来了连接请求
				Detach();
				m_sockListen.Accept(this);
				m_sockListen.Close();
				iRet=0;
				break;
			}
			if(++iAllTime>(m_iTimeout/TIME_SLICE))
				break;
		}
	}
	if(iRet==0){
		SetTimeout(TIME_SLICE);
		m_pSockCtrl->Response("150 Connect succeed.");
	}else{
		m_pSockCtrl->Response("425 Can't open data connection.");
	}
	return iRet;
}