WbemServices.cpp

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/* 
 * Confdump-Agent - Dump static and runtime system configuration
 * Copyright (C) 2009-2012  Straton IT, SAS
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3 as
 * published by the Free Software Foundation.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <comdef.h>
#include <wbemidl.h>

#include "QStringList"

#include "Confdump/System/Wmi/WbemServices.hpp"
#include "Confdump/System/Wmi/errors.hpp"
#include "Confdump/System/Wmi/NoSuchNamespace.hpp"
#include "Confdump/System/Wmi/NoSuchClass.hpp"

using boost::shared_ptr;


namespace Confdump
{
namespace System
{
namespace Wmi
{

WbemQueryIterator::WbemQueryIterator()
{
}

WbemQueryIterator::WbemQueryIterator( boost::shared_ptr<IEnumWbemClassObject> enumerator )
 : enumerator_( enumerator )
{
    increment(); // get the first element
}

WbemQueryIterator::~WbemQueryIterator()
{
}

bool WbemQueryIterator::equal(const WbemQueryIterator &other) const
{
    return element_ == other.element_;
}

void WbemQueryIterator::increment()
{
    IWbemClassObject *object = 0;
    ULONG count = 0;
    HRESULT hr = enumerator_->Next( WBEM_INFINITE, 1, &object, &count );
    throwOnWmiError( hr, "access the next WMI object" );
        
        if ( count )
        {
                element_ = guardComObject( object );
        }
        else // we're one-past-the-end
        {
                element_.reset();
                enumerator_.reset();
    }
}





WbemServices::WbemServices( ComContext::Guard guard )
 : comGuard_( guard ), wmiNamespace_( "root\\cimv2" )
{
    assert( guard );
}

WbemServices::~WbemServices()
{
}

namespace
{

shared_ptr<IWbemLocator> createLocator()
{
    IWbemLocator *locator = 0;
    HRESULT hr = CoCreateInstance(
        CLSID_WbemLocator,
        0,
        CLSCTX_INPROC_SERVER,
        IID_IWbemLocator,
        reinterpret_cast<void**>( &locator ) );
    throwOnComError( hr, "obtain the Wbem locator" );
    return guardComObject( locator );
}

shared_ptr<IWbemServices> servicesFromLocator( shared_ptr<IWbemLocator> locator, QString wmiNamespace )
{
    IWbemServices *services = 0;
    HRESULT hr = locator->ConnectServer(
        _bstr_t( wmiNamespace.toStdWString().c_str() ),
        0,                            /* User name */
        0,                            /* User password */
        0,                            /* Locale */
        0,                            /* Security flags */
        _bstr_t( L"" ),               /* Authority */
        0,                            /* Context object */
        &services );                  /* IWbemServices proxy */

    try {
                throwOnWmiError( hr, "connect to namespace "+wmiNamespace+" on the local computer" );
        }
        catch ( Win32Error &e )
        {
                if ( e.hresult() == NoSuchNamespace::hresult() )
                        throw NoSuchNamespace( wmiNamespace );
                else
                        throw;
        }

    return guardComObject( services );
}

}

void WbemServices::connect()
{
    shared_ptr<IWbemLocator> locator = createLocator();
    services_ = servicesFromLocator( locator, wmiNamespace_ );
}

void WbemServices::setWmiNamespace( QString ns )
{
    if ( wmiLists_.isNamespaceAllowed( ns ) )
        wmiNamespace_ = ns;
    else
        throw NoSuchThing( "Confdump will not query this namespace: " + ns );
}

boost::iterator_range<WbemQueryIterator> WbemServices::execQuery( const Query &query )
{
        assert( services_ );

        QString className = QString::fromLocal8Bit( query.getClass().c_str() );
        if ( !wmiLists_.isTableAllowed( wmiNamespace_, className ) )
                throw NoSuchThing( QString( "Confdump will not query this table: %1.%2" )
                        .arg( wmiNamespace_ ).arg( className ) );

        _bstr_t language( "WQL" );
    _bstr_t query_string( query.getQuery().c_str() );
    IEnumWbemClassObject *rawEnumerator = 0;

    HRESULT hr = services_->ExecQuery( language, query_string, 
        WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY,
        0, &rawEnumerator );
        throwOnWmiError( hr, QString::fromStdString( "run the WMI query " + query.getQuery() ) );

    shared_ptr<IEnumWbemClassObject> enumerator = guardComObject( rawEnumerator );

    try {
                return boost::iterator_range<WbemQueryIterator>( WbemQueryIterator( enumerator ), WbemQueryIterator() );
        }
        catch ( WmiError &e )
        {
                if ( e.hresult() == NoSuchClass::hresult() )
                        throw NoSuchClass( QString::fromStdString( query.getClass() ) );
                else
                        throw;
        }
}

boost::iterator_range<WbemQueryIterator> WbemServices::listAllClasses()
{
        assert( services_ );

    IEnumWbemClassObject *rawEnumerator = 0;

    HRESULT hr = services_->CreateClassEnum( 0,
        WBEM_FLAG_FORWARD_ONLY | WBEM_FLAG_RETURN_IMMEDIATELY | WBEM_FLAG_DEEP,
        0, &rawEnumerator );
    throwOnWmiError( hr, QString::fromStdString( "enumerate the WMI classes" ) );
    shared_ptr<IEnumWbemClassObject> enumerator = guardComObject( rawEnumerator );

    return boost::iterator_range<WbemQueryIterator>( WbemQueryIterator( enumerator ), WbemQueryIterator() );
}

}
}
}