reading streams and nested structures

[Dan Feerst]

I'm writing a program to read sections of the boot sector of a hard drive.
I'm fairly new to a few elements in this program so I have no doubt I did something dumb.

I have a structure that breaks the mbr apart, and one that breaks each partition apart. I am able to read from the mbr, but it appearently is hanging when I try to read from a partition. It compiles, but if you look at the function getPartition, the cout statement which prints "test2" doesn't print after the stream.read function. What am I doing wrong here?

#include <iostream>
#include <fstream>
using namespace std;
typedef unsigned int uint;
typedef unsigned char uchar;

struct partition_t{
	uchar status;
	uchar firstHead;
	uchar firstSector;
	uchar firstCylinder;
	uchar partitionType;
	uchar lastHead;
	uchar lastSector;
	uchar lastCylinder;
	uchar firstSectorLBA[4];
	uchar numberOfSectors[4];
	};

struct mbr_t{
	bool fileAccess; 
	partition_t partition1;
    partition_t partition2;
    partition_t partition3;
    partition_t partition4;
    bool partition1Valid;
	uchar bootSignature[2];  
	bool bootSignatureValid;
	}mbr;

partition_t getPartition( ifstream &stream, uint partNum ){
	partition_t output;
	uint baseOffset;
	switch( partNum ){
	    case 1:
		    baseOffset = 446;
		    break;
	    case 2:
		    baseOffset = 462;
		    break;
		case 3:
		    baseOffset = 478;
		    break;
		case 4:
		    baseOffset = 494;
		    break;       
	}
	if(stream.seekg( baseOffset ).good()){
	    /* Yes, I know, I'm being lazy with the error handling. I'll fix it later */
	    cout <<baseOffset<<endl;
	        cout <<"test"<<endl;
	    stream.read( reinterpret_cast<char*>( output.status ) ,1 );
	    	
	    stream.seekg( baseOffset + 1 );
	    cout <<"test2"<<endl;
	    stream.read( reinterpret_cast<char*>( output.firstHead ) ,1 );
	    /*add the rest of the partition stuff here*/
    }
return output;
}		
void printPartition( partition_t p ){
	
	cout << "Status: " << std::hex << (uint)p.status <<endl;
	cout << "Status: " << std::hex << (uint)p.firstHead <<endl;
}

mbr_t getBootSignature( istream &stream ){
	mbr_t output;
	if(stream.seekg( 510 ).good()){
		if(!stream.read( reinterpret_cast<char*>( output.bootSignature ), 2 ).fail()){
		    if( (mbr.bootSignature[0] != 0x55) || (mbr.bootSignature[1] != 0xaa) )
		        output.bootSignatureValid = false; 
	    }
	    else 
	        output.bootSignatureValid = false;
	}
	else 
	    output.bootSignatureValid = false;
	return output;
}

void printBootSignature(mbr_t MBR){
	cout << std::hex << (uint)MBR.bootSignature[0] << (uint)MBR.bootSignature[1] <<endl;
	}

int main(int argc, char** argv){  
    ifstream datafile ( argv[1] , ios::binary);
    mbr_t mbr;
    if(datafile.good()){
        cout << "Reading Data...\n";
        mbr = getBootSignature( datafile );
        printBootSignature(mbr);
        mbr.partition1 = getPartition( datafile, 1 );
        printPartition( mbr.partition1 );
        cout <<"test again"<<endl;
    }
    else mbr.fileAccess = false;
    return 0;
}