path: root/src/widget.cpp

// Copyright 2013, University of Freiburg,
// Author: Manuel Schneider <ms1144>

#include <stdio.h>
#include <sys/types.h>
#include <ifaddrs.h>
#include <netinet/in.h>
#include <string.h>
#include <arpa/inet.h>

#include <iostream>
#include <algorithm>

#include <QString>
#include <QDebug>
#include <QSet>

#include "widget.h"
#include "ui_widget.h"
#include "timeoutdialog.h"

#define INTERFACE "eth0"
#define GROUP_SPECIFIC "SpecificSettings"
#define OPENSLXCONFIG "/opt/openslx/config"
#define OPENSLXCONFIG_IPKEY "SLX_PXE_CLIENT_IP"

//#define DEBUG


//_____________________________________________________________________________
Widget::Widget(QWidget *parent) :
    QWidget(parent),
    _ui(new Ui::Widget)
{
  _ui->setupUi(this);


  // Get initial data (to be freed)
  _display = XOpenDisplay(NULL);
  _screenResources = XRRGetScreenResourcesCurrent(_display,
                                                  DefaultRootWindow(_display));

  // Get the information about the X elements
  updateScreenResources();

  switch ( _connectedOutputList.size() ){
    /*************************************************************************/
    case 1:// In case of one connected output - xrandr --auto
      qDebug() << "Normal output";
      exit(0);
      break;
    /*************************************************************************/
    case 2: // In case of two connected outputs

      // Check if one of the connected outputs is a beamer. This program only
      // adresses cases in which eiter of the outouts is a beamer. Meaning
      // either output one has dimension zero or output tow has no dimension.
      // The case of two beamers is not covered.
#ifdef DEBUG
      if ( true ) {
#else
      if ( ((_outputMap[_connectedOutputList[0]]->mm_width == 0
           && _outputMap[_connectedOutputList[0]]->mm_height == 0 )
          && ! (_outputMap[_connectedOutputList[1]]->mm_width == 0
           && _outputMap[_connectedOutputList[1]]->mm_height == 0 ))
          || ( ! (_outputMap[_connectedOutputList[0]]->mm_width == 0
           && _outputMap[_connectedOutputList[0]]->mm_height == 0 )
          && (_outputMap[_connectedOutputList[1]]->mm_width == 0
           && _outputMap[_connectedOutputList[1]]->mm_height == 0 )) ) {
#endif

        qDebug() << "BEAMER CONNECTED!";

        // Get a human readable reference
        if (_outputMap[_connectedOutputList[0]]->mm_width == 0
             && _outputMap[_connectedOutputList[0]]->mm_height == 0 ) {
          _beamer = _connectedOutputList[0];
          _monitor = _connectedOutputList[1];
        } else {
          _beamer = _connectedOutputList[1];
          _monitor = _connectedOutputList[0];

        }

        // Try to get the ip of the machine
        QSettings SLXsettings(OPENSLXCONFIG, QSettings::NativeFormat);
        QString IP;
        if ( SLXsettings.contains(OPENSLXCONFIG_IPKEY) ) {
          IP = SLXsettings.value(OPENSLXCONFIG_IPKEY).toString();
          qDebug() << "IP is" << IP;
        } else
          qDebug() << "No IP found!";

        // remove the ' around the ip
        IP.remove('\'');

        // Try to get beamer config related to the ip of the machine
        QSettings settings(QCoreApplication::arguments()[1], QSettings::NativeFormat);

        // Find any information saved about this ip. This config is assumed
        // to be tested on this system and will be applied immediately.
        settings.beginGroup(GROUP_SPECIFIC);
        if ( settings.contains(IP) ) {
          // First get a useful representation
          unsigned int width, height;
          QStringList modeAsStrings =
              settings.value(IP)
              .toString().split("x", QString::SkipEmptyParts);
          qDebug() << "Found Ip setting" << modeAsStrings;
          width = modeAsStrings.at(0).toInt();
          height = modeAsStrings.at(1).toInt();

          // Find a mode that matches the string
          // No sanity check here as the modes have to exist and be tested
          RRMode m1,m2;
          for (int i = 0; i < _outputMap[_monitor]->nmode; ++i){
            if ( width == _modeMap[_outputMap[_monitor]->modes[i]]->width
                 && height == _modeMap[_outputMap[_monitor]->modes[i]]->height )
              m1 = _modeMap[_outputMap[_monitor]->modes[i]]->id;
          }
          for (int i = 0; i < _outputMap[_beamer]->nmode; ++i){
            if ( width == _modeMap[_outputMap[_beamer]->modes[i]]->width
                 && height == _modeMap[_outputMap[_beamer]->modes[i]]->height )
              m2 = _modeMap[_outputMap[_beamer]->modes[i]]->id;
          }

          qDebug() << "Found modes are" << m1 << m2;
          qDebug() << "Witdth" << width ;
          qDebug() << "Height" << height ;

  // Apply the mode via xrandr
  QProcess p;
  QStringList arguments;
  arguments << "--output" << _outputMap[_monitor]->name
            << "--mode" << settings.value(IP).toString()
            << "--output" << _outputMap[_beamer]->name
            << "--mode" << settings.value(IP).toString()
            << "--same-as" <<_outputMap[_monitor]->name;
  qDebug() << arguments ;

  p.start("xrandr", arguments);
  p.waitForFinished();

  qDebug() << p.readAllStandardOutput();
  qDebug() << p.readAllStandardError();


//
//          // Set screensize
//          XRRSetScreenSize(_display, DefaultRootWindow(_display),
//                           width,
//                           height,
//                           25.4 * width / 96, // standard dpi that X uses
//                           25.4 * height / 96); // standard dpi that X uses
//
//          // Apply the modes
//          qDebug() << "Apply mode m1 " << m1;
//          qDebug() << XRRSetCrtcConfig(_display,
//                                       _screenResources,
//                                       _outputMap[_monitor]->crtc,
//                                       CurrentTime,
//                                       0, 0,
//                                       m1,
//                                       RR_Rotate_0,
//                                       &_monitor, 1);
//
//          qDebug() << "Apply mode m2 " << m2;
//          qDebug() << XRRSetCrtcConfig(_display,
//                                       _screenResources,
//                                       _outputMap[_beamer]->crtc,
//                                       CurrentTime,
//                                       0, 0,
//                                       m2,
//                                       RR_Rotate_0,
//                                       &_beamer, 1);
        }
        settings.endGroup();

        // Check if the beamer transmitted reliable data.
        bool gotEDID = false;
        int nprop;
        Atom *props = XRRListOutputProperties(_display, _beamer, &nprop);
        for (int i = 0; i < nprop; ++i) {
          char *atom_name = XGetAtomName (_display, props[i]);
          if ( strcmp (atom_name, "EDID") == 0) {
            gotEDID = true;
            XFree (atom_name);
            break;
          }
          XFree (atom_name);
        }
        free(props);

        // Intersect them by the resolution sorted, dont care about O(n³)
        QList<QPair<XRRModeInfo*, XRRModeInfo*> > commonModes;

        // Iterate over the modes the monitor supports
        for (int i = 0; i < _outputMap[_monitor]->nmode; ++i) {

          XRRModeInfo* monitorMode = _modeMap[_outputMap[_monitor]->modes[i]];

          // Skip interlaces modes
          if ( monitorMode->modeFlags & RR_Interlace )
            continue;

          // Iterate over the modes the beamer supports
          for (int j = 0; j < _outputMap[_beamer]->nmode; ++j) {

            XRRModeInfo* beamerMode = _modeMap[_outputMap[_beamer]->modes[j]];

            // Skip interlaces modes
            if ( beamerMode->modeFlags & RR_Interlace )
              continue;

            // Only if the modes have the same size, list them in common modes
            if ( monitorMode->height == beamerMode->height
                 && monitorMode->width == beamerMode->width ) {

//              qDebug() << "Potential common mode"
//                       << monitorMode->width
//                       << monitorMode->height ;

              // Build a sorted list of common modes in descending order
              QList<QPair<XRRModeInfo*, XRRModeInfo*> >::iterator k = commonModes.begin();
              for (;;++k) {

                // If at the end, the mode to insert is the smallest, insert.
                // This has to be first to avoid segfaults
                if (k == commonModes.end()) {

                  commonModes.insert(k, qMakePair (monitorMode, beamerMode));
//                  qDebug() << "Smallest"
//                           << monitorMode->width
//                           << monitorMode->height ;
                  break;
                }

                // If the mode to insert is larger than k, insert.
                if ( monitorMode->width > k->first->width) {
                  commonModes.insert(k, qMakePair (monitorMode, beamerMode));
//                  qDebug() << "Insert"
//                           << monitorMode->width
//                           << monitorMode->height ;
                  break;
                }

                // If the width is the same ...
                if ( monitorMode->width == k->first->width ) {

                  // ... and the height is the same, the mode already exists
                  if ( monitorMode->height == k->first->height ) {
//                    qDebug() << "Already exists"
//                             << monitorMode->width
//                             << monitorMode->height ;
                    break;
                  }

                  // ... and the height is larger, insert.
                  if ( monitorMode->height > k->first->height ) {
                    commonModes.insert(k, qMakePair (monitorMode, beamerMode));
//                    qDebug() << "Insert"
//                             << monitorMode->width
//                             << monitorMode->height ;
                    break;
                  }
                }
              }
            }
          }
        }

        // If the beamer transmits no reliable EDID data add modes
#ifdef DEBUG
        gotEDID = false;
#endif
        if (gotEDID) {

          qDebug() << "GOT EDID!";

          // Extract the preferred mode of the beamer
          RRMode preferredBeamerModeId;
          for (int i = 0; i < _outputMap[_beamer]->nmode; ++i) {
            if (i < _outputMap[_beamer]->npreferred) {
              preferredBeamerModeId = _outputMap[_beamer]->modes[i];
              break;
            }
          }

          // Compute the aspect ratio of the beamer
          float aspectRatio = (float)_modeMap[preferredBeamerModeId]->width
                     / _modeMap[preferredBeamerModeId]->height;          

          // Fill widget with data
          for (  QList<QPair<XRRModeInfo*, XRRModeInfo*> >::iterator i = commonModes.begin();
                i != commonModes.end(); ++i ) {
            float modeAspectRatio = ((float)i->first->width / i->first->height);
            if ( modeAspectRatio == aspectRatio ) // TODO APPROX
              _ui->comboBox->addItem(i->first->name,
                                     QList<QVariant>()
                                     << QVariant((qulonglong)i->first->id)
                                     << QVariant((qulonglong)i->second->id));
          }
        } else {

          qDebug() << "NO EDID!";

          // Fill widget with data without AR match
          // Fill widget with data
          for ( QList<QPair<XRRModeInfo*, XRRModeInfo*> >::iterator i = commonModes.begin();
                i != commonModes.end(); ++i ) {
            qDebug() << "Insert into QComboBox"
                     << i->first->width << "x" << i->first->height
                     << "\t\tBEAMER:" << QVariant((qulonglong)i->first->id).toULongLong()
                     << " \tMONITOR:" << QVariant((qulonglong)i->second->id).toULongLong();
            _ui->comboBox->addItem(i->first->name,
                                   QList<QVariant>()
                                   << QVariant((qulonglong)i->first->id)
                                   << QVariant((qulonglong)i->second->id));
          }
        }

        // Remove borders and stuff
        setWindowFlags(windowFlags() | Qt::FramelessWindowHint);
       // setStyleSheet("background:transparent;");
       // setAttribute(Qt::WA_TranslucentBackground);

        // Resize widget to its content
        resize(sizeHint());

        // Center dialog on screenbottom
        const QRect desktopRect = QApplication::desktop()->screenGeometry();
        this->move( desktopRect.width()/2-this->width()/2,
                    desktopRect.height()-this->height());

        // Connect button signal to appropriate slot
        connect(_ui->pushButton, SIGNAL(clicked()), this, SLOT(handleButton()));


      } // End of the beamer section
      /*********************************************************************/
      // If NEITHER of the outputs is a beamer (likely dualscreen setup)
      else {
        // TODO(manuel): Furture feature. Setup dualscreen
        qDebug() << "Dual output";
        exit(0);
      }
      break;
    /*************************************************************************/
    default:
      // If there are more than 3 outputs
      // its up to the user. Quit.
      qDebug() << ">2 outputs. Quit.";
      exit(0);
      break;
    }
    /*************************************************************************/
}

//___________________________________________________________________________
void Widget::updateScreenResources()
{
  // Clear the modemap (nothing to be freed, stored in screenResources)
  _modeMap.clear();

  // Create the modemap
  qDebug() << "_MODES_";
  for (int i = 0; i < _screenResources->nmode; ++i) {
    _modeMap.insert(
          _screenResources->modes[i].id,
          &_screenResources->modes[i]);
    qDebug() << _screenResources->modes[i].id << "\t"
             << _screenResources->modes[i].width << "x" << _screenResources->modes[i].height;
  }

  // Clear the crtmap
  for (CrtcMap::iterator it = _crtcMap.begin();
       it != _crtcMap.end();) {
    XRRFreeCrtcInfo(*it);
    it = _crtcMap.erase(it);
  }

  // Create crtcMap
  for (int i = 0; i < _screenResources->ncrtc; ++i) {
    XRRCrtcInfo * info = XRRGetCrtcInfo(
                           _display,
                           _screenResources,
                           _screenResources->crtcs[i]);
    _crtcMap.insert(
          _screenResources->crtcs[i],
          info);
  }

  // Clear the outputmap
  for (OutputMap::iterator it = _outputMap.begin();
       it != _outputMap.end();) {
    XRRFreeOutputInfo(*it);
    it = _outputMap.erase(it);
  }

  // Create outputmap and connectedOutputMap
  for (int i = 0; i < _screenResources->noutput; ++i) {
    XRROutputInfo* info = XRRGetOutputInfo(
                           _display,
                           _screenResources,
                           _screenResources->outputs[i]);
    _outputMap.insert(
          _screenResources->outputs[i],
          info);

    // Store the connected ones separate
    if ( info->connection == RR_Connected )
      _connectedOutputList.push_back(_screenResources->outputs[i]);
  }
}

//___________________________________________________________________________
Widget::~Widget()
{
  delete _ui;
  XCloseDisplay(_display);
  XRRFreeScreenResources(_screenResources);
}

//___________________________________________________________________________
void Widget::handleButton()
{
  // Backup the crtcinfos
  qDebug() <<  "Backup the crtc infos";
  CrtcMap backup;
  for ( CrtcMap::iterator it = _crtcMap.begin();
        it != _crtcMap.end(); ++it ) {

    qDebug() <<  "  Key is " << it.key();
    backup[it.key()] = new XRRCrtcInfo;
    backup[it.key()]->x = it.value()->x;
    backup[it.key()]->y = it.value()->y;
    backup[it.key()]->mode = it.value()->mode;
    qDebug() <<  "  Moed is " << backup[it.key()]->mode;
    backup[it.key()]->rotation = it.value()->rotation;
    backup[it.key()]->noutput = it.value()->noutput;
    backup[it.key()]->outputs = new RROutput[it.value()->noutput];
    for (int i = 0; i < it.value()->noutput; ++i) {
      backup[it.key()]->outputs[i] = it.value()->outputs[i];
    }
  }

  // Get the modes from QComboBox
  QList<QVariant> modes = _ui->comboBox->itemData( _ui->comboBox->currentIndex()).toList();
  XRRModeInfo* monitorMode = _modeMap[modes[0].toULongLong()];
  XRRModeInfo* beamerMode = _modeMap[modes[1].toULongLong()];

  // Set screensize
  uint width = monitorMode->width;
  uint height = monitorMode->height;

  qDebug() <<  " Set screensize to" << width << height;
  XRRSetScreenSize(_display, DefaultRootWindow(_display),
                   width,
                   height,
                   25.4 * width / 96,  // standard dpi that X uses
                   25.4 * height / 96); // standard dpi that X uses

  // Apply the modes
  qDebug() <<  "Apply the modes" << monitorMode->id << beamerMode->id;
  XRRSetCrtcConfig(_display,
                   _screenResources,
                   _outputMap[_monitor]->crtc,
                   CurrentTime,
                   0, 0, monitorMode->id,
                   RR_Rotate_0,
                   &_monitor, 1);
  XRRSetCrtcConfig(_display,
                   _screenResources,
                   _outputMap[_beamer]->crtc,
                   CurrentTime,
                   0, 0, beamerMode->id,
                   RR_Rotate_0,
                   &_beamer, 1);

  // Center widget on screenbottom
  qDebug() <<  "Center widget on screenbottom";
  this->move( width/2  - this->width()/2, height - this->height());

  // Show a dialog asking if the res should be kept
  qDebug() <<  "Show a dialog asking if the res should be kept";
  TimeOutDialog *keepDialog = new TimeOutDialog(15, this);
  keepDialog->setWindowTitle(" ");
  keepDialog->setLabelText("Do you want to keep this resolution?");
  keepDialog->setCancelButtonText("Keep");
  keepDialog->move( width/2  - this->width()/2, height/2 - this->height());
  keepDialog->exec();

  // If the dialog was not canceled revert the resolution
  qDebug() <<  "// If the dialog was not canceled revert the resolution";
  if ( ! keepDialog->wasCanceled()) {

    // First disconnect all crts to avoid conflicts
    qDebug() <<  "disconnect all crts to avoid conflicts";
    for ( CrtcMap::iterator it = _crtcMap.begin();
          it != _crtcMap.end(); ++it ) {
      XRRSetCrtcConfig(_display,
                       _screenResources,
                       it.key(),
                       CurrentTime,
                       0, 0,
                       None,
                       RR_Rotate_0,
                       NULL, 0);
    }

    // Then calc backed up screensize
    qDebug() <<  "Then calc backed up screensize...";
    QSize ScreenSize(0,0);
    for ( CrtcMap::iterator it = backup.begin();
          it != backup.end(); ++it ) {
      // Dangerzone. Only access existing modes!
      if ( it.value()->mode != None ) {
        ScreenSize.setWidth(
              std::max((uint)ScreenSize.width(),
                       it.value()->x+_modeMap[it.value()->mode]->width));
        ScreenSize.setHeight(
              std::max((uint)ScreenSize.height(),
                       it.value()->y+_modeMap[it.value()->mode]->height));
      }    
    }
    qDebug() <<  "screensize is" << ScreenSize;

    // Set screensize
    qDebug() <<  "Apply screensize";
    XRRSetScreenSize(_display, DefaultRootWindow(_display),
                     ScreenSize.width(),
                     ScreenSize.height(),
                     25.4 * ScreenSize.width() / 96,  // standard dpi that X uses
                     25.4 * ScreenSize.height() / 96); // standard dpi that X uses

    // Then apply the backup
    qDebug() <<  "Then apply the backup";
    for ( CrtcMap::iterator it = backup.begin();
          it != backup.end(); ++it ) {

      qDebug() <<  "CRTC" << it.key() << "MODE" << it.value()->mode;
      XRRSetCrtcConfig(_display,
                       _screenResources,
                       it.key(),
                       CurrentTime,
                       it.value()->x,
                       it.value()->y,
                       it.value()->mode,
                       it.value()->rotation,
                       it.value()->outputs,
                       it.value()->noutput);
    }

    // Again center dialog on screenbottom
    qDebug() <<  "Again center dialog on screenbottom";
    this->move( ScreenSize.width()/2  - this->width()/2,
                ScreenSize.height() - this->height());

  } // End of Revert section

  // Delete the backup
  qDebug() <<  "Delete the backup";
  for ( CrtcMap::iterator it = backup.begin();
        it != backup.end(); ++it ) {
    delete[] it.value()->outputs;
    delete it.value();
  }

  // Intenal settings changed. Update!
  updateScreenResources();
}



///////////////////////////  CODE PAPIERKORB  /////////////////////////////////


//  // Apply the mode via xrandr
//  QProcess p;
//  QStringList arguments;
//  arguments << "--output" << _outputMap[_monitor]->name
//            << "--mode" << _ui->comboBox->currentText()
//            << "--output" << _outputMap[_beamer]->name
//            << "--mode" << _ui->comboBox->currentText()
//            << "--same-as" <<_outputMap[_monitor]->name;
//  p.start("xrandr", arguments);
//  p.waitForFinished();

//          // TO BE DONE VIA BASH
//        // Iterate over the modes in the config file
//        for (QList<QString>::const_iterator it =
//             Config::inst()->getModeLines().begin();
//             it != Config::inst()->getModeLines().end(); ++it) {
//          // Add mode to xrandr
//          QProcess p;
//          QStringList arguments;
//          arguments << "--current" << "--newmode"
//                    << it->split(" ", QString::SkipEmptyParts);
//          p.start("xrandr", arguments);
//          p.waitForFinished();
//        }

//          // TO BE DONE VIA BASH
//          // Iterate over all modes and add them to the outputs,
//          // if the AR matches.
//          for(ModeMap::iterator it = _modeMap.begin();
//              it != _modeMap.end(); ++it) {
//            float MODEAR = ((float)(*it)->width / (*it)->height);
//            if ( MODEAR == AR ) {
//              XRRAddOutputMode(_display, _beamer, (*it)->id);
//              XRRAddOutputMode(_display, _monitor, (*it)->id);
//            }
//          }

// TO BE DONE VIA BASH
//          // Iterate over all modes and add them to the outputs
//          for(ModeMap::iterator it = _modeMap.begin();
//              it != _modeMap.end(); ++it) {
//            XRRAddOutputMode(_display, _beamer, (*it)->id);
//            XRRAddOutputMode(_display, _monitor, (*it)->id);

//        // Get the names of the modes and intersect
//        QSet<XRRModeInfo*> beamerModes, monitorModes;
//        for (int i = 0; i < _outputMap[_beamer]->nmode; ++i)
//          beamerModes.insert(_modeMap[_outputMap[_beamer]->modes[i]]);
//        for (int i = 0; i < _outputMap[_monitor]->nmode; ++i)
//          monitorModes.insert(_modeMap[_outputMap[_monitor]->modes[i]]);

//        // Intersect them by the resolution sorted
//        // dont care about O(n³)
//        QList<XRRModeInfo*> commonModes;
//        for (QSet<XRRModeInfo*>::iterator i = beamerModes.begin();
//             i != beamerModes.end(); ++i) {
//          if ((*i)->modeFlags & RR_Interlace) continue;
//          for (QSet<XRRModeInfo*>::iterator j = monitorModes.begin();
//               j != monitorModes.end(); ++j) {
//            if ((*j)->modeFlags & RR_Interlace) continue;
//            QList<XRRModeInfo*>::iterator k = commonModes.begin();
//            for (;;) {
//              if (k == commonModes.end()){
//                commonModes.insert(k, *i);
//                break;
//              }
//              if ( (*i)->width == (*k)->width ) {
//                if ( (*i)->height == (*k)->height )
//                  break;
//                if ( (*i)->height > (*k)->height ) {
//                  commonModes.insert(k, *i);
//                  break;
//                }
//              }
//              if ( (*i)->width > (*k)->width ) {
//                commonModes.insert(k, *i);
//                break;
//              }
//              ++k;
//            }
//          }
//        }//          }

//  // First get a useful representation
//  qDebug() <<  "// First get a useful representation";
//  unsigned int width, height;
//  QStringList modeAsStrings =
//      _ui->comboBox->currentText().split("x", QString::SkipEmptyParts);
//  width = modeAsStrings.at(0).toInt();
//  height = modeAsStrings.at(1).toInt();
//  // Find a mode that matches the string
//  RRMode m1,m2;
//  qDebug() <<  "// Find a mode that matches the string";
//  for (int i = 0; i < _outputMap[_monitor]->nmode; ++i){
//    if ( width == _modeMap[_outputMap[_monitor]->modes[i]]->width
//         && height == _modeMap[_outputMap[_monitor]->modes[i]]->height
//         && !(_modeMap[_outputMap[_monitor]->modes[i]]->modeFlags & RR_Interlace) ) // skip interlaced modes
//      m1 = _modeMap[_outputMap[_monitor]->modes[i]]->id;
//  }
//  qDebug() <<  "// Find a mode that matches the string";
//  for (int i = 0; i < _outputMap[_beamer]->nmode; ++i){
//    if ( width == _modeMap[_outputMap[_beamer]->modes[i]]->width
//         && height == _modeMap[_outputMap[_beamer]->modes[i]]->height
//         && !(_modeMap[_outputMap[_beamer]->modes[i]]->modeFlags & RR_Interlace) ) // skip interlaced modes
//      m2 = _modeMap[_outputMap[_beamer]->modes[i]]->id;
//  }






//        struct ifaddrs * ifAddrStruct=NULL;
//        struct ifaddrs * ifa=NULL;
//        void * tmpAddrPtr=NULL;
//        QString ipV4;
//        qDebug() << "Ip is" << ipV4;
//        getifaddrs(&ifAddrStruct);
//        // Iterate through the adresses.
//        for (ifa = ifAddrStruct; ifa != NULL; ifa = ifa->ifa_next) {
//            // If the address is IP V4 and the interface is _if
//            if (ifa ->ifa_addr->sa_family==AF_INET
//                && ( strcmp(ifa->ifa_name, INTERFACE) == 0) ) {
//                // Get the IP
//                tmpAddrPtr=&((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
//                // convert to readable form
//                char addressBuffer[INET_ADDRSTRLEN];
//                inet_ntop(AF_INET, tmpAddrPtr, addressBuffer, INET_ADDRSTRLEN);
//                ipV4 = addressBuffer;
//            }
//        }
//        // clean up
//        if (ifAddrStruct!=NULL)
//            freeifaddrs(ifAddrStruct);