LCX端口转发源码分析

      lcx.exe算是端口转发工具中普及率特别高的吧。当然，最近也出了好些Web端口转发工具，这个待后续再分析一下。我从网上下载了一个lcx的源码片段，结合源码谈谈自己的认识。

      lcx工作原理是使不同端口之间形成一个回路，这样就可以进行端口转发。常用于外网连接内网3389端口。具体使用方法网上一堆。

      这个程序主要采用Socket来实现，有几个比较重要的函数：bind2bind、bind2conn、conn2conn及transmitdata。transmitdata函数是核心，这个函数作用是使得不同端口之间的数据形成一个回路。

      注意源代码中的setsocket函数，其中设置了SO_REUSEADDR。设置SO_REUSEADDR之后，可以应用的一种场景就是同一个端口可以绑定多个socket。查看相关资料可以得知，其实设置SO_REUSEADDR之后，还有其他几种应用场景。我试了一下，你把setsocket函数注释掉，在运行这个端口转发程序时，本地listen的时候设置的两个端口不一样程序还是可以正常运行的。启用setsocket函数之后，本地listen的时候，可以设置两个端口为同一个值，但是这样设置的时候，我在虚拟机中无法远程连接，一直就是尝试连接也不报错。原因不因，未深入分析。

      网上很多的源码其实是有问题的，下面我分享一个稍作修改的源代码，能够在windows xp +vc6.0下编译通过，理论上是可以在windows系列所有32位版本下运行的。对于64位系统，我也修改了一个版本，在windows 7 x64+vs2013编译通过，主要用于64位windows下运行。可执行文件我就不放出来了，自己编译运行差不多就OK了。

      Windows XP +VC6.0下编译通过的源码：

/*

************************************************************************************

* 

* HTran.cpp - HUC Packet Transmit Tool.

*

* Copyright (C) 2000-2004 HUC All Rights Reserved.

*

* Author : lion

* : lion#cnhonker.net

* : <a href="http://www.cnhonker.com" target="_blank">http://www.cnhonker.com</a>

* :

* Notice : Thx to bkbll (bkbll#cnhonker.net)

* :

* Date : 2003-10-20

* :

* Complie : cl HTran.cpp

* :

* Usage : E:\>HTran

* : ======================== HUC Packet Transmit Tool V1.00 =======================

* : =========== Code by lion & bkbll, Welcome to <a href="http://www.cnhonker.com" target="_blank">http://www.cnhonker.com</a> ==========

* :

* : [Usage of Packet Transmit:]

* : HTran - [-log logfile]

* :

* : [option:]

* : -listen 

* : -tran 

* : -slave 

*

************************************************************************************

*/

#include <stdio.h>

#include <stdlib.h>

#include <winsock2.h>

#include <signal.h>

#include <errno.h>

#include <io.h> 

#pragma comment(lib, "ws2_32.lib")

 

#define VERSION "1.00"

#define TIMEOUT 300

#define MAXSIZE 20480

#define HOSTLEN 40

#define CONNECTNUM 5

 

// define 2 socket struct

struct transocket 

{

	SOCKET fd1;

	SOCKET fd2;

};

 

// define function 

void ver();

void usage(char *prog);

void transmitdata(LPVOID data);

void getctrlc(int j);

void closeallfd();

void makelog(char *buffer, int length);

void proxy(int port);

void bind2bind(int port1, int port2);

void bind2conn(int port1, char *host, int port2);

void conn2conn(char *host1, int port1, char *host2, int port2);

int testifisvalue(char *str);

int create_socket();

int create_server(int sockfd, int port);

int client_connect(int sockfd, char* server, int port);

 

// define GLOBAL variable here

extern int errno;

FILE *fp;

int method=0;

//int connectnum=0;

 

//************************************************************************************

// 

// function main 主要是处理用户参数输入的问题

//

//************************************************************************************

VOID main(int argc, char* argv[])

{

	char **p;

	char sConnectHost[HOSTLEN], sTransmitHost[HOSTLEN];

	int iConnectPort=0, iTransmitPort=0;

	char *logfile=NULL;

	 

	ver();

	memset(sConnectHost, 0, HOSTLEN);

	memset(sTransmitHost, 0, HOSTLEN);

	 

	p=argv;

	while(*p)

	{

		if(stricmp(*p, "-log") == 0)

		{

			if(testifisvalue(*(p+1)))

			{

				logfile = *(++p);

			} 

			else

			{

				printf("[-] ERROR: Must supply logfile name.\r\n");

				return;

			}

			p++;

			continue;

		}

		p++;

	}

	 

	if(logfile !=NULL)

	{

		fp=fopen(logfile,"a");

		if(fp == NULL ) 

		{

			printf("[-] ERROR: open logfile");

			return;

		}

	 

		makelog("====== Start ======\r\n", 22);

	}

	 

	 

	// Win Start Winsock.

	WSADATA wsadata;

	WSAStartup(MAKEWORD(2, 2), &wsadata);

	 

	signal(SIGINT, &getctrlc);

	 

	if(argc > 2)

	{

		if(stricmp(argv[1], "-listen") == 0 && argc >= 4)

		{

			iConnectPort = atoi(argv[2]);

			iTransmitPort = atoi(argv[3]);

			method = 1;

		}

		else

		if(stricmp(argv[1], "-tran") == 0 && argc >= 5)

		{

			iConnectPort = atoi(argv[2]);

			strncpy(sTransmitHost, argv[3], HOSTLEN);

			iTransmitPort = atoi(argv[4]);

			method = 2;

		}

		else

		if(stricmp(argv[1], "-slave") == 0 && argc >= 6)

		{

			strncpy(sConnectHost, argv[2], HOSTLEN);

			iConnectPort = atoi(argv[3]);

			strncpy(sTransmitHost, argv[4], HOSTLEN);

			iTransmitPort = atoi(argv[5]);

			method = 3;

		}

	}

	 

	switch(method)

	{

		case 1:

		bind2bind(iConnectPort, iTransmitPort);

		break;

		case 2:

		bind2conn(iConnectPort, sTransmitHost, iTransmitPort);

		break;

		case 3:

		conn2conn(sConnectHost, iConnectPort, sTransmitHost, iTransmitPort);

		break;

		default:

		usage(argv[0]);

		break;

	}

	 

	if(method)

	{

		closeallfd();

	}

	 

	WSACleanup();

	 

	return;

}

 

 

//************************************************************************************

// 

// print version message

//

//************************************************************************************

VOID ver() 

{ 

	printf("======================== HUC Packet Transmit Tool V%s =======================\r\n", VERSION);

	printf("=========== Code by lion & bkbll, Welcome to http://www.cnhonker.com==========\r\n\n");

}

 

//************************************************************************************

// 

// print usage message

//

//************************************************************************************

VOID usage(char* prog) 

{ 

	printf("[Usage of Packet Transmit:]\r\n");

	printf(" %s - [-log logfile]\n\n", prog);

	printf("[option:]\n");

	printf(" -listen \n");

	printf(" -tran \n");

	printf(" -slave \n\n");

	return;

}

 

//************************************************************************************

// 

// test if is value 

//

//************************************************************************************

int testifisvalue(char *str)

{

	if(str == NULL ) return(0);

	if(str[0]=='-') return(0);

	return(1);

}

 

//************************************************************************************

// 

// LocalHost:ConnectPort transmit to LocalHost:TransmitPort

//

//************************************************************************************

void bind2bind(int port1, int port2)

{

	SOCKET fd1,fd2, sockfd1, sockfd2;

	struct sockaddr_in client1,client2;

	int size1,size2;

	 

	HANDLE hThread=NULL;

	transocket sock;

	DWORD dwThreadID;

	 

	if((fd1=create_socket())==0) return;

	if((fd2=create_socket())==0) return;

	 

	printf("[+] Listening port %d ......\r\n",port1);

	fflush(stdout);

	 

	if(create_server(fd1, port1)==0)

	{

		closesocket(fd1);

		return;

	}

	 

	printf("[+] Listen OK!\r\n");

	printf("[+] Listening port %d ......\r\n",port2);

	fflush(stdout);

	if(create_server(fd2, port2)==0)

	{

		closesocket(fd2);

		return;

	}

	 

	printf("[+] Listen OK!\r\n");

	size1=size2=sizeof(struct sockaddr);

	while(1)

	{

		printf("[+] Waiting for Client on port:%d ......\r\n",port1);

		if((sockfd1 = accept(fd1,(struct sockaddr *)&client1,&size1))<0)

		{

			printf("[-] Accept1 error.\r\n");

			continue;

		}

	 

	printf("[+] Accept a Client on port %d from %s ......\r\n", port1, inet_ntoa(client1.sin_addr));

	printf("[+] Waiting another Client on port:%d....\r\n", port2);

	if((sockfd2 = accept(fd2, (struct sockaddr *)&client2, &size2))<0)

	{

		printf("[-] Accept2 error.\r\n");

		closesocket(sockfd1);

		continue;

	}

	 

	printf("[+] Accept a Client on port %d from %s\r\n",port2, inet_ntoa(client2.sin_addr));

	printf("[+] Accept Connect OK!\r\n");

	 

	sock.fd1 = sockfd1;

	sock.fd2 = sockfd2;

	 

	hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)transmitdata, (LPVOID)&sock, 0, &dwThreadID); 

	if(hThread == NULL) 

	{

		TerminateThread(hThread, 0);

		return;

	}

	 

	Sleep(1000);

	printf("[+] CreateThread OK!\r\n\n");

	}

}

 

//************************************************************************************

// 

// LocalHost:ConnectPort transmit to TransmitHost:TransmitPort

//

//************************************************************************************

void bind2conn(int port1, char *host, int port2)

{

	SOCKET sockfd,sockfd1,sockfd2;

	struct sockaddr_in remote;

	int size;

	char buffer[1024];

	 

	HANDLE hThread=NULL;

	transocket sock;

	DWORD dwThreadID;

	 

	if (port1 > 65535 || port1 < 1)

	{

		printf("[-] ConnectPort invalid.\r\n");

		return;

	}

	 

	if (port2 > 65535 || port2 < 1)

	{

		printf("[-] TransmitPort invalid.\r\n");

		return;

	}

	 

	memset(buffer,0,1024);

	if((sockfd=create_socket()) == INVALID_SOCKET) return;

	 

	if(create_server(sockfd, port1) == 0) 

	{

		closesocket(sockfd);

		return;

	}

	 

	size=sizeof(struct sockaddr);

	while(1)

	{

		printf("[+] Waiting for Client ......\r\n"); 

		if((sockfd1=accept(sockfd,(struct sockaddr *)&remote,&size))<0)

		{

		printf("[-] Accept error.\r\n");

		continue;

	}

	 

	printf("[+] Accept a Client from %s:%d ......\r\n",

	inet_ntoa(remote.sin_addr), ntohs(remote.sin_port));

	if((sockfd2=create_socket())==0) 

	{

		closesocket(sockfd1);

		continue; 

	}

	printf("[+] Make a Connection to %s:%d ......\r\n",host,port2);

	fflush(stdout);

	 

	if(client_connect(sockfd2,host,port2)==0)

	{

		closesocket(sockfd2);

		sprintf(buffer,"[SERVER]connection to %s:%d error\r\n", host, port2);

		send(sockfd1,buffer,strlen(buffer),0);

		memset(buffer, 0, 1024);

		closesocket(sockfd1);

		continue;

	}

	 

	printf("[+] Connect OK!\r\n");

	 

	sock.fd1 = sockfd1;

	sock.fd2 = sockfd2;

	 

	hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)transmitdata, (LPVOID)&sock, 0, &dwThreadID); 

	if(hThread == NULL) 

	{

		TerminateThread(hThread, 0);

		return;

	}

	 

	Sleep(1000);

	printf("[+] CreateThread OK!\r\n\n");

	}

}

 

//************************************************************************************

// 

// ConnectHost:ConnectPort transmit to TransmitHost:TransmitPort

//

//************************************************************************************

void conn2conn(char *host1,int port1,char *host2,int port2)

{

	SOCKET sockfd1,sockfd2;

	 

	HANDLE hThread=NULL;

	transocket sock;

	DWORD dwThreadID;

	fd_set fds;

	int l;

	char buffer[MAXSIZE];

	 

	while(1)

	{

	 

		if((sockfd1=create_socket())==0) return;

		if((sockfd2=create_socket())==0) return;

		 

		printf("[+] Make a Connection to %s:%d....\r\n",host1,port1);

		fflush(stdout);

		if(client_connect(sockfd1,host1,port1)==0) 

		{

			closesocket(sockfd1);

			closesocket(sockfd2);

			continue;

		}

		 

		// fix by bkbll 

		// if host1:port1 recved data, than connect to host2,port2

		l=0;

		memset(buffer,0,MAXSIZE);

		while(1)

		{

			FD_ZERO(&fds);

			FD_SET(sockfd1, &fds);

			if (select(sockfd1+1, &fds, NULL, NULL, NULL) == SOCKET_ERROR) 

			{

				if (errno == WSAEINTR) continue;

				break;

			}

			if (FD_ISSET(sockfd1, &fds)) 

			{

				l=recv(sockfd1, buffer, MAXSIZE, 0);

				break;

			}

			Sleep(5);

		}

		 

		if(l<=0) 

		{ 

			printf("[-] There is a error...Create a new connection.\r\n");

			continue;

		}

		while(1)

		{

			printf("[+] Connect OK!\r\n");

			printf("[+] Make a Connection to %s:%d....\r\n", host2,port2);

			fflush(stdout);

			if(client_connect(sockfd2,host2,port2)==0) 

			{

				closesocket(sockfd1);

				closesocket(sockfd2);

				continue;

			}

			 

			if(send(sockfd2,buffer,l,0)==SOCKET_ERROR)

			{ 

				printf("[-] Send failed.\r\n");

				continue;

			}

			 

			l=0;

			memset(buffer,0,MAXSIZE);

			break;

		}

		 

		printf("[+] All Connect OK!\r\n");

		 

		sock.fd1 = sockfd1;

		sock.fd2 = sockfd2;

			 

		hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)transmitdata, (LPVOID)&sock, 0, &dwThreadID); 

		if(hThread == NULL) 

		{

			TerminateThread(hThread, 0);

			return;

		}

		 

		// connectnum++;

		 

		Sleep(1000);

		printf("[+] CreateThread OK!\r\n\n");

	}

}

 

//************************************************************************************

// 

// Socket Transmit to Socket

//

//************************************************************************************

void transmitdata(LPVOID data)

{

SOCKET fd1, fd2;

transocket *sock;

struct timeval timeset;

fd_set readfd,writefd;

int result,i=0;

char read_in1[MAXSIZE],send_out1[MAXSIZE];

char read_in2[MAXSIZE],send_out2[MAXSIZE];

int read1=0,totalread1=0,send1=0;

int read2=0,totalread2=0,send2=0;

int sendcount1,sendcount2;

int maxfd;

struct sockaddr_in client1,client2;

int structsize1,structsize2;

char host1[20],host2[20];

int port1=0,port2=0;

char tmpbuf[100];

 

sock = (transocket *)data;

fd1 = sock->fd1;

fd2 = sock->fd2;

 

memset(host1,0,20);

memset(host2,0,20);

memset(tmpbuf,0,100);

 

structsize1=sizeof(struct sockaddr);

structsize2=sizeof(struct sockaddr);

 

if(getpeername(fd1,(struct sockaddr *)&client1,&structsize1)<0)

{

strcpy(host1, "fd1");

}

else

{ 

// printf("[+]got, ip:%s, port:%d\r\n",inet_ntoa(client1.sin_addr),ntohs(client1.sin_port));

strcpy(host1, inet_ntoa(client1.sin_addr));

port1=ntohs(client1.sin_port);

}

 

if(getpeername(fd2,(struct sockaddr *)&client2,&structsize2)<0)

{

strcpy(host2,"fd2");

}

else

{ 

// printf("[+]got, ip:%s, port:%d\r\n",inet_ntoa(client2.sin_addr),ntohs(client2.sin_port));

strcpy(host2, inet_ntoa(client2.sin_addr));

port2=ntohs(client2.sin_port);

}

 

printf("[+] Start Transmit (%s:%d <-> %s:%d) ......\r\n\n", host1, port1, host2, port2);

 

maxfd=max(fd1,fd2)+1;

memset(read_in1,0,MAXSIZE);

memset(read_in2,0,MAXSIZE);

memset(send_out1,0,MAXSIZE);

memset(send_out2,0,MAXSIZE);

 

timeset.tv_sec=TIMEOUT;

timeset.tv_usec=0;

 

while(1)

{

FD_ZERO(&readfd);

FD_ZERO(&writefd);

 

FD_SET((UINT)fd1, &readfd);

FD_SET((UINT)fd1, &writefd);

FD_SET((UINT)fd2, &writefd);

FD_SET((UINT)fd2, &readfd);

 

result=select(maxfd,&readfd,&writefd,NULL,&timeset);

if((result<0) && (errno!=EINTR))

{

printf("[-] Select error.\r\n");

break;

}

else if(result==0)

{

printf("[-] Socket time out.\r\n");

break;

}

 

if(FD_ISSET(fd1, &readfd))

{

/* must < MAXSIZE-totalread1, otherwise send_out1 will flow */

if(totalread1 < MAXSIZE) {

read1=recv(fd1, read_in1, MAXSIZE-totalread1, 0); 

if((read1==SOCKET_ERROR) || (read1==0))

{

printf("[-] Read fd1 data error,maybe close?\r\n");

break;

}

 

memcpy(send_out1+totalread1,read_in1,read1);

sprintf(tmpbuf,"\r\nRecv %5d bytes from %s:%d\r\n", read1, host1, port1);

printf(" Recv %5d bytes %16s:%d\r\n", read1, host1, port1);

makelog(tmpbuf,strlen(tmpbuf));

makelog(read_in1,read1);

totalread1+=read1;

memset(read_in1,0,MAXSIZE);

}

}

 

if(FD_ISSET(fd2, &writefd))

{

int err=0;

sendcount1=0;

while(totalread1>0)

{

send1=send(fd2, send_out1+sendcount1, totalread1, 0);

if(send1==0)break;

if((send1<0) && (errno!=EINTR))

{

printf("[-] Send to fd2 unknow error.\r\n");

err=1;

break;

}

 

if((send1<0) && (errno==ENOSPC)) break;

sendcount1+=send1;

totalread1-=send1;

 

printf(" Send %5d bytes %16s:%d\r\n", send1, host2, port2);

}

 

if(err==1) break;

if((totalread1>0) && (sendcount1>0))

{

/* move not sended data to start addr */

memcpy(send_out1,send_out1+sendcount1,totalread1);

memset(send_out1+totalread1,0,MAXSIZE-totalread1);

}

else

memset(send_out1,0,MAXSIZE);

}

 

if(FD_ISSET(fd2, &readfd))

{

if(totalread2 < MAXSIZE) {

read2=recv(fd2,read_in2,MAXSIZE-totalread2, 0); 

if(read2==0)break;

if((read2<0) && (errno!=EINTR))

{

printf("[-] Read fd2 data error,maybe close?\r\n\r\n");

break;

}

 

memcpy(send_out2+totalread2,read_in2,read2);

sprintf(tmpbuf, "\r\nRecv %5d bytes from %s:%d\r\n", read2, host2, port2);

printf(" Recv %5d bytes %16s:%d\r\n", read2, host2, port2);

makelog(tmpbuf,strlen(tmpbuf));

makelog(read_in2,read2);

totalread2+=read2;

memset(read_in2,0,MAXSIZE);

}

}

 

if(FD_ISSET(fd1, &writefd))

{

int err2=0;

sendcount2=0;

while(totalread2>0)

{

send2=send(fd1, send_out2+sendcount2, totalread2, 0);

if(send2==0)break;

if((send2<0) && (errno!=EINTR))

{

printf("[-] Send to fd1 unknow error.\r\n");

err2=1;

break;

}

if((send2<0) && (errno==ENOSPC)) break;

sendcount2+=send2;

totalread2-=send2;

 

printf(" Send %5d bytes %16s:%d\r\n", send2, host1, port1);

}

if(err2==1) break;

if((totalread2>0) && (sendcount2 > 0))

{

/* move not sended data to start addr */

memcpy(send_out2, send_out2+sendcount2, totalread2);

memset(send_out2+totalread2, 0, MAXSIZE-totalread2);

}

else

memset(send_out2,0,MAXSIZE);

}

 

Sleep(5);

}

 

closesocket(fd1);

closesocket(fd2);

// if(method == 3)

// connectnum --;

 

printf("\r\n[+] OK! I Closed The Two Socket.\r\n"); 

}

 

void getctrlc(int j)

{

	printf("\r\n[-] Received Ctrl+C\r\n");

	closeallfd();

	exit(0);

}

 

void closeallfd()

{

	int i;

	 

	printf("[+] Let me exit ......\r\n");

	fflush(stdout);

	 

	for(i=3; i<256; i++)

	{

		closesocket(i); 

	}

	 

	if(fp != NULL) 

	{

		fprintf(fp,"\r\n====== Exit ======\r\n");

		fclose(fp);

	}

	 

	printf("[+] All Right!\r\n");

}

 

int create_socket()

{ 

	int sockfd;

 

	sockfd=socket(AF_INET,SOCK_STREAM,0);

	if(sockfd<0)

	{

		printf("[-] Create socket error.\r\n");

		return(0);

	}

 

	return(sockfd); 

}

 

int create_server(int sockfd,int port)

{

	struct sockaddr_in srvaddr;

	int on=1;

 

	memset(&srvaddr, 0, sizeof(struct sockaddr));

 

	srvaddr.sin_port=htons(port);

	srvaddr.sin_family=AF_INET;

	srvaddr.sin_addr.s_addr=htonl(INADDR_ANY);

 

	setsockopt(sockfd,SOL_SOCKET,SO_REUSEADDR, (char*)&on,sizeof(on)); //so I can rebind the port

 

	if(bind(sockfd,(struct sockaddr *)&srvaddr,sizeof(struct sockaddr))<0)

	{

		printf("[-] Socket bind error.\r\n");

		return(0);

	}

 

	if(listen(sockfd,CONNECTNUM)<0)

	{

		printf("[-] Socket Listen error.\r\n");

		return(0);

	}

 

	return(1);

}

 

int client_connect(int sockfd,char* server,int port)

{

	struct sockaddr_in cliaddr;

	struct hostent *host;

 

	if(!(host=gethostbyname(server)))

	{

		printf("[-] Gethostbyname(%s) error:%s\n",server,strerror(errno));

		return(0);

	}

 

	memset(&cliaddr, 0, sizeof(struct sockaddr));

	cliaddr.sin_family=AF_INET;

	cliaddr.sin_port=htons(port);

	cliaddr.sin_addr=*((struct in_addr *)host->h_addr);

 

	if(connect(sockfd,(struct sockaddr *)&cliaddr,sizeof(struct sockaddr))<0)

	{

		printf("[-] Connect error.\r\n");

		return(0);

	}

	return(1);

}

 

void makelog(char *buffer,int length)

{

	if(fp !=NULL)

	{

		// fprintf(fp, "%s", buffer);

		// printf("%s",buffer);

		write(fileno(fp),buffer,length);

		// fflush(fp);

	}

}

      附上效果图一张：

 33

     Windows7 64+VS2013编译通过的源码：

/*

************************************************************************************

*

* PortTrans.cpp - Port Forwarding.

*

* Copyright (C) 2015 HUC All Rights Reserved.

*

* Author : pandas

* : 

* :

* Date : 2015-4-9

* :

* Complie : cl PortTrans.cpp

* :

* Usage : D:\>PortTrans

* : ======================== Port Forwarding Tool V1.00 =======================

* :	========================== Improved by pandas ===========================

* :

* : [Usage of Port Forwarding:]

* : PortTrans - [-log logfile]

* :

* : [option:]

* : -listen

* : -tran

* : -slave

*

************************************************************************************

*/

#define _WINSOCK_DEPRECATED_NO_WARNINGS

#define  _CRT_SECURE_NO_WARNINGS

#include <stdio.h>

#include <stdlib.h>

#include <winsock2.h>

#include <signal.h>

#include <errno.h>

#include <io.h> 

#pragma comment(lib, "ws2_32.lib")

#define VERSION "1.00"

#define TIMEOUT 300

#define MAXSIZE 20480

#define HOSTLEN 40

#define CONNECTNUM 5

// define 2 socket struct

struct transocket

{

	SOCKET fd1;

	SOCKET fd2;

};

// define function 

void ver();

void usage(char *prog);

void transmitdata(LPVOID data);

void getctrlc(int j);

void closeallfd();

void makelog(char *buffer, int length);

void proxy(int port);

void bind2bind(int port1, int port2);

void bind2conn(int port1, char *host, int port2);

void conn2conn(char *host1, int port1, char *host2, int port2);

int testifisvalue(char *str);

int create_socket();

int create_server(int sockfd, int port);

int client_connect(int sockfd, char* server, int port);

// define GLOBAL variable here

//int error;

FILE *fp;

int method = 0;

//int connectnum=0;

//************************************************************************************

// 

// function main 主要是处理用户参数输入的问题

//

//************************************************************************************

VOID main(int argc, char* argv[])

{

	char **p;

	char sConnectHost[HOSTLEN], sTransmitHost[HOSTLEN];

	int iConnectPort = 0, iTransmitPort = 0;

	char *logfile = NULL;

	errno_t err;

	ver();

	memset(sConnectHost, 0, HOSTLEN);

	memset(sTransmitHost, 0, HOSTLEN);

	p = argv;

	while (*p)

	{

		if (_stricmp(*p, "-log") == 0)

		{

			if (testifisvalue(*(p + 1)))

			{

				logfile = *(++p);

			}

			else

			{

				printf("[-] ERROR: Must supply logfile name.\r\n");

				return;

			}

			//p++;

			continue;

		}

		p++;

	}

	if (logfile != NULL)

	{

		//fp = fopen(logfile, "a");

		err = fopen_s(&fp, logfile, "a");

		if (fp == NULL)

		{

			printf("[-] ERROR: open logfile");

			return;

		}

		makelog("====== Start ======\r\n", 22);

	}

	// Win Start Winsock.

	WSADATA wsadata;

	WSAStartup(MAKEWORD(2, 2), &wsadata);

	signal(SIGINT, &getctrlc);

	if (argc > 2)

	{

		if (_stricmp(argv[1], "-listen") == 0 && argc >= 4)

		{

			iConnectPort = atoi(argv[2]);

			iTransmitPort = atoi(argv[3]);

			method = 1;

		}

		else

			if (_stricmp(argv[1], "-tran") == 0 && argc >= 5)

			{

				iConnectPort = atoi(argv[2]);

				strncpy_s(sTransmitHost, argv[3], HOSTLEN);

				iTransmitPort = atoi(argv[4]);

				method = 2;

			}

			else

				if (_stricmp(argv[1], "-slave") == 0 && argc >= 6)

				{

					strncpy_s(sConnectHost, argv[2], HOSTLEN);

					iConnectPort = atoi(argv[3]);

					strncpy_s(sTransmitHost, argv[4], HOSTLEN);

					iTransmitPort = atoi(argv[5]);

					method = 3;

				}

	}

	switch (method)

	{

	case 1:

		bind2bind(iConnectPort, iTransmitPort);

		break;

	case 2:

		bind2conn(iConnectPort, sTransmitHost, iTransmitPort);

		break;

	case 3:

		conn2conn(sConnectHost, iConnectPort, sTransmitHost, iTransmitPort);

		break;

	default:

		usage(argv[0]);

		break;

	}

	if (method)

	{

		closeallfd();

	}

	WSACleanup();

	return;

}

//************************************************************************************

// 

// print version message

//

//************************************************************************************

VOID ver()

{

	printf("======================== Port Forwarding Tool V%s =======================\r\n", VERSION);

	printf("========================== Improved by pandas ===========================\r\n\n");

}

//************************************************************************************

// 

// print usage message

//

//************************************************************************************

VOID usage(char* prog)

{

	printf("[Usage of Packet Transmit:]\r\n");

	printf(" %s - [-log logfile]\n\n", prog);

	printf("[option:]\n");

	printf(" -listen \n");

	printf(" -tran \n");

	printf(" -slave \n\n");

	return;

}

//************************************************************************************

// 

// test if is value 

//

//************************************************************************************

int testifisvalue(char *str)

{

	if (str == NULL) return(0);

	if (str[0] == '-') return(0);

	return(1);

}

//************************************************************************************

// 

// LocalHost:ConnectPort transmit to LocalHost:TransmitPort

//

//************************************************************************************

void bind2bind(int port1, int port2)

{

	SOCKET fd1, fd2, sockfd1, sockfd2;

	struct sockaddr_in client1, client2;

	int size1, size2;

	HANDLE hThread = NULL;

	transocket sock;

	DWORD dwThreadID;

	if ((fd1 = create_socket()) == 0) return;

	if ((fd2 = create_socket()) == 0) return;

	printf("[+] Listening port %d ......\r\n", port1);

	fflush(stdout);

	if (create_server(fd1, port1) == 0)

	{

		closesocket(fd1);

		return;

	}

	printf("[+] Listen OK!\r\n");

	printf("[+] Listening port %d ......\r\n", port2);

	fflush(stdout);

	if (create_server(fd2, port2) == 0)

	{

		closesocket(fd2);

		return;

	}

	printf("[+] Listen OK!\r\n");

	size1 = size2 = sizeof(struct sockaddr);

	while (1)

	{

		printf("[+] Waiting for Client on port:%d ......\r\n", port1);

		if ((sockfd1 = accept(fd1, (struct sockaddr *)&client1, &size1))<0)

		{

			printf("[-] Accept1 error.\r\n");

			continue;

		}

		printf("[+] Accept a Client on port %d from %s ......\r\n", port1, inet_ntoa(client1.sin_addr));

		printf("[+] Waiting another Client on port:%d....\r\n", port2);

		if ((sockfd2 = accept(fd2, (struct sockaddr *)&client2, &size2))<0)

		{

			printf("[-] Accept2 error.\r\n");

			closesocket(sockfd1);

			continue;

		}

		printf("[+] Accept a Client on port %d from %s\r\n", port2, inet_ntoa(client2.sin_addr));

		printf("[+] Accept Connect OK!\r\n");

		sock.fd1 = sockfd1;

		sock.fd2 = sockfd2;

		hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)transmitdata, (LPVOID)&sock, 0, &dwThreadID);

		if (hThread == NULL)

		{

			TerminateThread(hThread, 0);

			return;

		}

		Sleep(1000);

		printf("[+] CreateThread OK!\r\n\n");

	}

}

//************************************************************************************

// 

// LocalHost:ConnectPort transmit to TransmitHost:TransmitPort

//

//************************************************************************************

void bind2conn(int port1, char *host, int port2)

{

	SOCKET sockfd, sockfd1, sockfd2;

	struct sockaddr_in remote;

	int size;

	char buffer[1024];

	HANDLE hThread = NULL;

	transocket sock;

	DWORD dwThreadID;

	if (port1 > 65535 || port1 < 1)

	{

		printf("[-] ConnectPort invalid.\r\n");

		return;

	}

	if (port2 > 65535 || port2 < 1)

	{

		printf("[-] TransmitPort invalid.\r\n");

		return;

	}

	memset(buffer, 0, 1024);

	if ((sockfd = create_socket()) == INVALID_SOCKET) return;

	if (create_server(sockfd, port1) == 0)

	{

		closesocket(sockfd);

		return;

	}

	size = sizeof(struct sockaddr);

	while (1)

	{

		printf("[+] Waiting for Client ......\r\n");

		if ((sockfd1 = accept(sockfd, (struct sockaddr *)&remote, &size))<0)

		{

			printf("[-] Accept error.\r\n");

			continue;

		}

		printf("[+] Accept a Client from %s:%d ......\r\n",

			inet_ntoa(remote.sin_addr), ntohs(remote.sin_port));

		if ((sockfd2 = create_socket()) == 0)

		{

			closesocket(sockfd1);

			continue;

		}

		printf("[+] Make a Connection to %s:%d ......\r\n", host, port2);

		fflush(stdout);

		if (client_connect(sockfd2, host, port2) == 0)

		{

			closesocket(sockfd2);

			sprintf_s(buffer, "[SERVER]connection to %s:%d error\r\n", host, port2);

			send(sockfd1, buffer, strlen(buffer), 0);

			memset(buffer, 0, 1024);

			closesocket(sockfd1);

			continue;

		}

		printf("[+] Connect OK!\r\n");

		sock.fd1 = sockfd1;

		sock.fd2 = sockfd2;

		hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)transmitdata, (LPVOID)&sock, 0, &dwThreadID);

		if (hThread == NULL)

		{

			TerminateThread(hThread, 0);

			return;

		}

		Sleep(1000);

		printf("[+] CreateThread OK!\r\n\n");

	}

}

//************************************************************************************

// 

// ConnectHost:ConnectPort transmit to TransmitHost:TransmitPort

//

//************************************************************************************

void conn2conn(char *host1, int port1, char *host2, int port2)

{

	SOCKET sockfd1, sockfd2;

	HANDLE hThread = NULL;

	transocket sock;

	DWORD dwThreadID;

	fd_set fds;

	int l;

	char buffer[MAXSIZE];

	while (1)

	{

		/*

		while(connectnum)

		{

		if(connectnum < CONNECTNUM)

		{

		Sleep(10000);

		break;

		}

		else

		{

		Sleep(TIMEOUT*1000);

		continue;

		}

		}

		*/

		if ((sockfd1 = create_socket()) == 0) return;

		if ((sockfd2 = create_socket()) == 0) return;

		printf("[+] Make a Connection to %s:%d....\r\n", host1, port1);

		fflush(stdout);

		if (client_connect(sockfd1, host1, port1) == 0)

		{

			closesocket(sockfd1);

			closesocket(sockfd2);

			continue;

		}

		// fix by bkbll 

		// if host1:port1 recved data, than connect to host2,port2

		l = 0;

		memset(buffer, 0, MAXSIZE);

		while (1)

		{

			FD_ZERO(&fds);

			FD_SET(sockfd1, &fds);

			if (select(sockfd1 + 1, &fds, NULL, NULL, NULL) == SOCKET_ERROR)

			{

				if (errno== WSAEINTR) continue;

				break;

			}

			if (FD_ISSET(sockfd1, &fds))

			{

				l = recv(sockfd1, buffer, MAXSIZE, 0);

				break;

			}

			Sleep(5);

		}

		if (l <= 0)

		{

			printf("[-] There is a error...Create a new connection.\r\n");

			continue;

		}

		while (1)

		{

			printf("[+] Connect OK!\r\n");

			printf("[+] Make a Connection to %s:%d....\r\n", host2, port2);

			fflush(stdout);

			if (client_connect(sockfd2, host2, port2) == 0)

			{

				closesocket(sockfd1);

				closesocket(sockfd2);

				continue;

			}

			if (send(sockfd2, buffer, l, 0) == SOCKET_ERROR)

			{

				printf("[-] Send failed.\r\n");

				continue;

			}

			l = 0;

			memset(buffer, 0, MAXSIZE);

			break;

		}

		printf("[+] All Connect OK!\r\n");

		sock.fd1 = sockfd1;

		sock.fd2 = sockfd2;

		hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)transmitdata, (LPVOID)&sock, 0, &dwThreadID);

		if (hThread == NULL)

		{

			TerminateThread(hThread, 0);

			return;

		}

		// connectnum++;

		Sleep(1000);

		printf("[+] CreateThread OK!\r\n\n");

	}

}

//************************************************************************************

// 

// Socket Transmit to Socket

//

//************************************************************************************

void transmitdata(LPVOID data)

{

	SOCKET fd1, fd2;

	transocket *sock;

	struct timeval timeset;

	fd_set readfd, writefd;

	int result, i = 0;

	char read_in1[MAXSIZE], send_out1[MAXSIZE];

	char read_in2[MAXSIZE], send_out2[MAXSIZE];

	int read1 = 0, totalread1 = 0, send1 = 0;

	int read2 = 0, totalread2 = 0, send2 = 0;

	int sendcount1, sendcount2;

	int maxfd;

	struct sockaddr_in client1, client2;

	int structsize1, structsize2;

	char host1[20], host2[20];

	int port1 = 0, port2 = 0;

	char tmpbuf[100];

	sock = (transocket *)data;

	fd1 = sock->fd1;

	fd2 = sock->fd2;

	memset(host1, 0, 20);

	memset(host2, 0, 20);

	memset(tmpbuf, 0, 100);

	structsize1 = sizeof(struct sockaddr);

	structsize2 = sizeof(struct sockaddr);

	if (getpeername(fd1, (struct sockaddr *)&client1, &structsize1)<0)

	{

		strcpy_s(host1, "fd1");

	}

	else

	{

		// printf("[+]got, ip:%s, port:%d\r\n",inet_ntoa(client1.sin_addr),ntohs(client1.sin_port));

		strcpy_s(host1, inet_ntoa(client1.sin_addr));

		port1 = ntohs(client1.sin_port);

	}

	if (getpeername(fd2, (struct sockaddr *)&client2, &structsize2)<0)

	{

		strcpy_s(host2, "fd2");

	}

	else

	{

		// printf("[+]got, ip:%s, port:%d\r\n",inet_ntoa(client2.sin_addr),ntohs(client2.sin_port));

		strcpy_s(host2, inet_ntoa(client2.sin_addr));

		port2 = ntohs(client2.sin_port);

	}

	printf("[+] Start Transmit (%s:%d <-> %s:%d) ......\r\n\n", host1, port1, host2, port2);

	maxfd = max(fd1, fd2) + 1;

	memset(read_in1, 0, MAXSIZE);

	memset(read_in2, 0, MAXSIZE);

	memset(send_out1, 0, MAXSIZE);

	memset(send_out2, 0, MAXSIZE);

	timeset.tv_sec = TIMEOUT;

	timeset.tv_usec = 0;

	while (1)

	{

		FD_ZERO(&readfd);

		FD_ZERO(&writefd);

		FD_SET((UINT)fd1, &readfd);

		FD_SET((UINT)fd1, &writefd);

		FD_SET((UINT)fd2, &writefd);

		FD_SET((UINT)fd2, &readfd);

		result = select(maxfd, &readfd, &writefd, NULL, &timeset);

		if ((result<0) && (errno!= EINTR))

		{

			printf("[-] Select error.\r\n");

			break;

		}

		else if (result == 0)

		{

			printf("[-] Socket time out.\r\n");

			break;

		}

		if (FD_ISSET(fd1, &readfd))

		{

			/* must < MAXSIZE-totalread1, otherwise send_out1 will flow */

			if (totalread1 < MAXSIZE) {

				read1 = recv(fd1, read_in1, MAXSIZE - totalread1, 0);

				if ((read1 == SOCKET_ERROR) || (read1 == 0))

				{

					printf("[-] Read fd1 data error,maybe close?\r\n");

					break;

				}

				memcpy(send_out1 + totalread1, read_in1, read1);

				sprintf_s(tmpbuf, "\r\nRecv %5d bytes from %s:%d\r\n", read1, host1, port1);

				printf(" Recv %5d bytes %16s:%d\r\n", read1, host1, port1);

				makelog(tmpbuf, strlen(tmpbuf));

				makelog(read_in1, read1);

				totalread1 += read1;

				memset(read_in1, 0, MAXSIZE);

			}

		}

		if (FD_ISSET(fd2, &writefd))

		{

			int err = 0;

			sendcount1 = 0;

			while (totalread1>0)

			{

				send1 = send(fd2, send_out1 + sendcount1, totalread1, 0);

				if (send1 == 0)break;

				if ((send1<0) && (errno != EINTR))

				{

					printf("[-] Send to fd2 unknow error.\r\n");

					err = 1;

					break;

				}

				if ((send1<0) && (errno == ENOSPC)) break;

				sendcount1 += send1;

				totalread1 -= send1;

				printf(" Send %5d bytes %16s:%d\r\n", send1, host2, port2);

			}

			if (err == 1) break;

			if ((totalread1>0) && (sendcount1>0))

			{

				/* move not sended data to start addr */

				memcpy(send_out1, send_out1 + sendcount1, totalread1);

				memset(send_out1 + totalread1, 0, MAXSIZE - totalread1);

			}

			else

				memset(send_out1, 0, MAXSIZE);

		}

		if (FD_ISSET(fd2, &readfd))

		{

			if (totalread2 < MAXSIZE) {

				read2 = recv(fd2, read_in2, MAXSIZE - totalread2, 0);

				if (read2 == 0)break;

				if ((read2<0) && (errno != EINTR))

				{

					printf("[-] Read fd2 data error,maybe close?\r\n\r\n");

					break;

				}

				memcpy(send_out2 + totalread2, read_in2, read2);

				sprintf_s(tmpbuf, "\r\nRecv %5d bytes from %s:%d\r\n", read2, host2, port2);

				printf(" Recv %5d bytes %16s:%d\r\n", read2, host2, port2);

				makelog(tmpbuf, strlen(tmpbuf));

				makelog(read_in2, read2);

				totalread2 += read2;

				memset(read_in2, 0, MAXSIZE);

			}

		}

		if (FD_ISSET(fd1, &writefd))

		{

			int err2 = 0;

			sendcount2 = 0;

			while (totalread2>0)

			{

				send2 = send(fd1, send_out2 + sendcount2, totalread2, 0);

				if (send2 == 0)break;

				if ((send2<0) && (errno != EINTR))

				{

					printf("[-] Send to fd1 unknow error.\r\n");

					err2 = 1;

					break;

				}

				if ((send2<0) && (errno == ENOSPC)) break;

				sendcount2 += send2;

				totalread2 -= send2;

				printf(" Send %5d bytes %16s:%d\r\n", send2, host1, port1);

			}

			if (err2 == 1) break;

			if ((totalread2>0) && (sendcount2 > 0))

			{

				/* move not sended data to start addr */

				memcpy(send_out2, send_out2 + sendcount2, totalread2);

				memset(send_out2 + totalread2, 0, MAXSIZE - totalread2);

			}

			else

				memset(send_out2, 0, MAXSIZE);

		}

		Sleep(5);

	}

	closesocket(fd1);

	closesocket(fd2);

	// if(method == 3)

	// connectnum --;

	printf("\r\n[+] OK! I Closed The Two Socket.\r\n");

}

void getctrlc(int j)

{

	printf("\r\n[-] Received Ctrl+C\r\n");

	closeallfd();

	exit(0);

}

void closeallfd()

{

	int i;

	printf("[+] Let me exit ......\r\n");

	fflush(stdout);

	for (i = 3; i<256; i++)

	{

		closesocket(i);

	}

	if (fp != NULL)

	{

		fprintf(fp, "\r\n====== Exit ======\r\n");

		fclose(fp);

	}

	printf("[+] All Right!\r\n");

}

int create_socket()

{

	int sockfd;

	sockfd = socket(AF_INET, SOCK_STREAM, 0);

	if (sockfd<0)

	{

		printf("[-] Create socket error.\r\n");

		return(0);

	}

	return(sockfd);

}

int create_server(int sockfd, int port)

{

	struct sockaddr_in srvaddr;

	int on = 1;

	memset(&srvaddr, 0, sizeof(struct sockaddr));

	srvaddr.sin_port = htons(port);

	srvaddr.sin_family = AF_INET;

	srvaddr.sin_addr.s_addr = htonl(INADDR_ANY);

	setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, (char*)&on, sizeof(on)); //so I can rebind the port

	if (bind(sockfd, (struct sockaddr *)&srvaddr, sizeof(struct sockaddr))<0)

	{

		printf("[-] Socket bind error.\r\n");

		return(0);

	}

	if (listen(sockfd, CONNECTNUM)<0)

	{

		printf("[-] Socket Listen error.\r\n");

		return(0);

	}

	return(1);

}

int client_connect(int sockfd, char* server, int port)

{

	struct sockaddr_in cliaddr;

	struct hostent *host;

	if (!(host = gethostbyname(server)))

	{

		printf("[-] Gethostbyname(%s) error:%s\n", server, strerror(errno));

		return(0);

	}

	memset(&cliaddr, 0, sizeof(struct sockaddr));

	cliaddr.sin_family = AF_INET;

	cliaddr.sin_port = htons(port);

	cliaddr.sin_addr = *((struct in_addr *)host->h_addr);

	if (connect(sockfd, (struct sockaddr *)&cliaddr, sizeof(struct sockaddr))<0)

	{

		printf("[-] Connect error.\r\n");

		return(0);

	}

	return(1);

}

void makelog(char *buffer, int length)

{

	if (fp != NULL)

	{

		_write(_fileno(fp), buffer, length);

	}

}


      注意，VS2013编译出来的程序在其他计算机上运行时，可能出现如下问题：


 30



      这是由于需要MSVCR120.dll这个动态链接库来支持C函数库和C++的STL标准库。对于这个问题的解决方法是：可以把C/C++运行时库MSVCR120编译到你的exe里，这样你的程序复制到任意windows上就能直接运行了。项目 - 属性 - 配置属性 - C/C++ - 代码生成 - 运行库 - 多线程(/MT)。这样生成的EXE会增大一些，取决于你用到了多少库函数。具体设置如下图所示：


 31



      最后，附上效果图一张：


 32



      采用这种方式进行端口转发，其实速度有些慢，有时候会比较卡。对于Web端口转发工具及HTTP版本的LCX，后续我再分析一下。



      以上源码仅供学习之用，请不要用于非法途径。




 
   






            

            
posted @ 
2015-04-13 00:31 
ShadonSniper 
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