networkstuff.h

In this article, I will explain how to create UDP packets and then send them to a remote server thro

//copyright emmanuel herrera 2008

#ifndef _NETWORKSTUFF_H
#define _NETWORKSTUFF_H

#include "Includes.h"

struct  DeviceInfo
{
	bool Exists;
	UINT IP; //In case IP spoofing is not supported, use real IP
	UINT DefaultGateway;   // Where the packet is first sent
	unsigned char GatewayPhysicalAddress[6]; //MAC of destination (gateway)
	unsigned char PhysicalAddress[6]; //Source MAC in case MAC spoofing is not supported
};

// there is a better way to do this, but i forgot how  and this is how the RFC spec says to do it. 

unsigned short BytesTo16(unsigned char X,unsigned char Y)
{
         unsigned short Tmp = X;
         Tmp = Tmp << 8;
         Tmp = Tmp | Y; 
         return Tmp;
}
unsigned int BytesTo32(unsigned char W,unsigned char X,unsigned char Y,unsigned char Z)
{
         unsigned int Tmp = W;
         Tmp = Tmp << 8;
         Tmp = Tmp | X;
         Tmp = Tmp << 8;
         Tmp = Tmp | Y;
         Tmp = Tmp << 8;
         Tmp = Tmp | Z;
         return Tmp;
}

void ShowDeviceList(void)
{
	char Error[PCAP_ERRBUF_SIZE];
	pcap_if_t* Devices;pcap_findalldevs_ex(PCAP_SRC_IF_STRING,NULL,&Devices,Error);
	int i = 1;
	for(pcap_if_t* CurrentDevice = Devices;CurrentDevice != NULL;CurrentDevice = CurrentDevice->next)
	{
		cout<<i << ". "<<  CurrentDevice->description << endl;
		i++;
	}
}

unsigned char* MACStringToBytes(LPSTR String)
{
	char* Tmp = new char[strlen(String)];
	memcpy((void*)Tmp,(void*)String,strlen(String));
	unsigned char* Returned = new unsigned char[6];
	for(int i = 0;i<6;i++)
	{
		sscanf(Tmp,"%2X",&Returned[i]);
		memmove((void*)(Tmp),(void*)(Tmp+3),19-i*3);
	}
	return Returned;
}
		
DeviceInfo GetAdapterInfo(pcap_if_t* Device)
{
	DeviceInfo DevInfo;
	ZeroMemory(&DevInfo,sizeof(DevInfo));

	IP_ADAPTER_INFO* AdapterInfo = new IP_ADAPTER_INFO [48];
	ULONG AIS = sizeof(IP_ADAPTER_INFO) * 48;

	GetAdaptersInfo(AdapterInfo,&AIS);
	
	for(IP_ADAPTER_INFO* Current = AdapterInfo;Current != NULL;Current = Current->Next)
	{
		if(strstr(Device->name,Current->AdapterName)!=0)
		
		{	
			DevInfo.IP = BytesTo32(Device->addresses->addr->sa_data[2],Device->addresses->addr->sa_data[3],
			Device->addresses->addr->sa_data[4],Device->addresses->addr->sa_data[5]);

			DevInfo.DefaultGateway = inet_addr(Current->GatewayList.IpAddress.String);	// DevInfo.DefaultGateway
			DevInfo.IP = inet_addr(Current->IpAddressList.IpAddress.String); //DevInfo.IP
			memcpy((void*)DevInfo.PhysicalAddress,(void*)(Current->Address),6); //DevInfo.PhysicalAddress
			ULONG MACSize = 6;
			if(SendARP(DevInfo.DefaultGateway,NULL,(void*)DevInfo.GatewayPhysicalAddress,&MACSize)!=NO_ERROR){cout << "SendARP Failed. No default gateway\n"; }
			DevInfo.Exists = true;
			return DevInfo;
		}
	}
	DevInfo.Exists = false;
	return DevInfo;
}
#endif