upnptasksearch.cpp

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// Program Name: upnptasksearch.cpp
// Created     : Oct. 24, 2005
//
// Purpose     : UPnp Task to handle Discovery Responses
//                                                                            
// Copyright (c) 2005 David Blain <dblain@mythtv.org>
//                                          
// Licensed under the GPL v2 or later, see LICENSE for details
//
 
#include <chrono> // for milliseconds
#include <cstdlib>
#include <thread> // for sleep_for
 
#include <QDateTime>
#include <QFile>
#include <QStringList>
#include <QNetworkInterface>
#include <utility>
 
#include "libmythbase/compat.h"
#include "libmythbase/configuration.h"
#include "libmythbase/mythdate.h"
#include "libmythbase/mythlogging.h"
#include "libmythbase/mythrandom.h"
#include "libmythbase/mythversion.h"
 
#include "upnp.h"
#include "upnptasksearch.h"
 
static QPair<QHostAddress, int> kLinkLocal6 =
                            QHostAddress::parseSubnet("fe80::/10");
 
//
// UPnpSearchTask Implementation
//
 
//
 
UPnpSearchTask::UPnpSearchTask( int          nServicePort, 
                                const QHostAddress& peerAddress,
                                int          nPeerPort,  
                                QString      sST, 
                                QString      sUDN ) :
    Task("UPnpSearchTask"),
    m_nServicePort(nServicePort),
    m_peerAddress(peerAddress),
    m_nPeerPort(nPeerPort),
    m_sST(std::move(sST)),
    m_sUDN(std::move(sUDN))
{
    m_nMaxAge     = XmlConfiguration().GetDuration<std::chrono::seconds>("UPnP/SSDP/MaxAge" , 1h);
} 
 
//
 
void UPnpSearchTask::SendMsg( MSocketDevice  *pSocket,
                              const QString&  sST,
                              const QString&  sUDN )
{
    QString sUSN;
 
    if (( sUDN.length() > 0) && ( sUDN != sST ))
        sUSN = sUDN + "::" + sST;
    else
        sUSN = sST;
 
    QString sDate = MythDate::current().toString( "d MMM yyyy hh:mm:ss" );
 
    QString sData = QString ( "CACHE-CONTROL: max-age=%1\r\n"
                              "DATE: %2\r\n"
                              "EXT:\r\n"
                              "Server: %3\r\n"
                              "ST: %4\r\n"
                              "USN: %5\r\n"
                              "Content-Length: 0\r\n\r\n" )
                              .arg( m_nMaxAge.count()    )
                              .arg( sDate,
                                    HttpServer::GetServerVersion(),
                                    sST,
                                    sUSN );
 
#if 0
    LOG(VB_UPNP, LOG_DEBUG, QString("UPnpSearchTask::SendMsg : %1 : %2 ")
                        .arg(sST) .arg(sUSN));
 
    LOG(VB_UPNP, LOG_DEBUG,
        QString("UPnpSearchTask::SendMsg    m_peerAddress = %1 Port=%2")
                        .arg(m_peerAddress.toString()) .arg(m_nPeerPort));
#endif
 
    // TODO: When we add dynamic handling of interfaces the information
    // for each address on the system should be available from the
    // "central" location on request.
    //
    // loop through all available interfaces
    QList<QNetworkInterface> IFs = QNetworkInterface::allInterfaces();
    for (const auto & qni : std::as_const(IFs))
    {
        QList<QNetworkAddressEntry> netAddressList = qni.addressEntries();
        for (const auto & netAddr : std::as_const(netAddressList))
        {
            QString ip_subnet = QString("%1/%2").arg(netAddr.ip().toString()).arg(netAddr.prefixLength());
            QPair<QHostAddress, int> subnet = QHostAddress::parseSubnet(ip_subnet);
            if (m_peerAddress.isInSubnet(subnet)) {
                LOG(VB_UPNP, LOG_DEBUG, QString("UPnpSearchTask::SendMsg : IP: [%1], Found network [%2], relevant to peer [%3]")
                    .arg(netAddr.ip().toString(), subnet.first.toString(), m_peerAddress.toString()));
 
                QString ipaddress;
                QHostAddress ip = netAddr.ip();
                // Descope the Link Local address. The scope is only valid
                // on the server sending the announcement, not the clients
                // that receive it
                ip.setScopeId(QString());
 
                // If this looks like an IPv6 address, then enclose it in []'s
                if (ip.protocol() == QAbstractSocket::IPv6Protocol)
                    ipaddress = "[" + ip.toString() + "]";
                else
                    ipaddress = ip.toString();
 
                QString sHeader = QString ( "HTTP/1.1 200 OK\r\n"
                                            "LOCATION: http://%1:%2/getDeviceDesc\r\n" )
                                    .arg( ipaddress )
                                    .arg( m_nServicePort);
 
 
                QString  sPacket  = sHeader + sData;
                QByteArray scPacket = sPacket.toUtf8();
 
                // ------------------------------------------------------------------
                // Send Packet to UDP Socket (Send same packet twice)
                // ------------------------------------------------------------------
 
                pSocket->writeBlock( scPacket, scPacket.length(), m_peerAddress,
                                    m_nPeerPort );
 
                std::this_thread::sleep_for(std::chrono::milliseconds(MythRandom(0, 250)));
 
                pSocket->writeBlock( scPacket, scPacket.length(), m_peerAddress,
                                    m_nPeerPort );
            }
        }
    }
}
 
//
 
void UPnpSearchTask::Execute( TaskQueue * /*pQueue*/ )
{
    auto *pSocket = new MSocketDevice( MSocketDevice::Datagram );
 
    // ----------------------------------------------------------------------
    // Refresh IP Address List in case of changes
    // ----------------------------------------------------------------------
 
    m_addressList = UPnp::g_IPAddrList;
 
    // ----------------------------------------------------------------------
    // Check to see if this is a rootdevice or all request.
    // ----------------------------------------------------------------------
 
    UPnpDevice &device = UPnp::g_UPnpDeviceDesc.m_rootDevice;
 
    if ((m_sST == "upnp:rootdevice") || (m_sST == "ssdp:all" ))
    {
        SendMsg( pSocket, "upnp:rootdevice", device.GetUDN() );
 
        if (m_sST == "ssdp:all")
            ProcessDevice( pSocket, &device );
    }
    else
    {
        // ------------------------------------------------------------------
        // Send Device/Service specific response.
        // ------------------------------------------------------------------
 
        SendMsg( pSocket, m_sST, m_sUDN );
    }
 
    delete pSocket;
    pSocket = nullptr;
}
 
//
 
void UPnpSearchTask::ProcessDevice(
    MSocketDevice *pSocket, UPnpDevice *pDevice)
{
    // ----------------------------------------------------------------------
    // Loop for each device and send the 2 required messages
    //
    // -=>TODO: We need to add support to only notify 
    //          Version 1 of a service.
    // ----------------------------------------------------------------------
 
    SendMsg( pSocket, pDevice->GetUDN(), "" );
    SendMsg( pSocket, pDevice->m_sDeviceType, pDevice->GetUDN() );
        
    // ------------------------------------------------------------------
    // Loop for each service in this device and send the 1 required message
    // ------------------------------------------------------------------
 
    for (auto sit = pDevice->m_listServices.cbegin();
         sit != pDevice->m_listServices.cend(); ++sit)
        SendMsg(pSocket, (*sit)->m_sServiceType, pDevice->GetUDN());
 
    // ----------------------------------------------------------------------
    // Process any Embedded Devices
    // ----------------------------------------------------------------------
 
    for (auto *device : std::as_const(pDevice->m_listDevices))
        ProcessDevice( pSocket, device);
}