Implement pairing via GUI

app/backend/computermanager.cpp

@@ -4,6 +4,7 @@
 #include <QThread>
 #include <QUdpSocket>
 #include <QHostInfo>
+#include <QThreadPool>
 
 #define SER_HOSTS "hosts"
 #define SER_NAME "hostname"
@@ -331,27 +332,54 @@ QVector<NvComputer*> ComputerManager::getComputers()
     return QVector<NvComputer*>::fromList(m_KnownHosts.values());
 }
 
-void ComputerManager::deleteHost(NvComputer* computer)
+class DeferredHostDeletionTask : public QRunnable
 {
-    QWriteLocker lock(&m_Lock);
+public:
+    DeferredHostDeletionTask(ComputerManager* cm, NvComputer* computer)
+        : m_Computer(computer),
+          m_ComputerManager(cm) {}
 
-    QThread* pollingThread = m_PollThreads[computer->uuid];
-    if (pollingThread != nullptr) {
-        pollingThread->requestInterruption();
+    void run()
+    {
+        QWriteLocker lock(&m_ComputerManager->m_Lock);
 
-        // We must wait here because we're going to delete computer
-        // and we can't do that out from underneath the poller.
-        pollingThread->wait();
+        QThread* pollingThread = m_ComputerManager->m_PollThreads[m_Computer->uuid];
+        if (pollingThread != nullptr) {
+            pollingThread->requestInterruption();
 
-        // The thread is safe to delete now
-        Q_ASSERT(pollingThread->isFinished());
-        delete pollingThread;
+            // We must wait here because we're going to delete computer
+            // and we can't do that out from underneath the poller.
+            pollingThread->wait();
+
+            // The thread is safe to delete now
+            Q_ASSERT(pollingThread->isFinished());
+            delete pollingThread;
+        }
+
+        m_ComputerManager->m_PollThreads.remove(m_Computer->uuid);
+        m_ComputerManager->m_KnownHosts.remove(m_Computer->uuid);
+
+        delete m_Computer;
     }
 
-    m_PollThreads.remove(computer->uuid);
-    m_KnownHosts.remove(computer->uuid);
+private:
+    NvComputer* m_Computer;
+    ComputerManager* m_ComputerManager;
+};
 
-    delete computer;
+void ComputerManager::deleteHost(NvComputer* computer)
+{
+    // Punt to a worker thread to avoid stalling the
+    // UI while waiting for the polling thread to die
+    QThreadPool::globalInstance()->start(new DeferredHostDeletionTask(this, computer));
+}
+
+void ComputerManager::pairHost(NvComputer* computer, QString pin)
+{
+    // Punt to a worker thread to avoid stalling the
+    // UI while waiting for pairing to complete
+    PendingPairingTask* pairing = new PendingPairingTask(this, computer, pin);
+    QThreadPool::globalInstance()->start(pairing);
 }
 
 void ComputerManager::stopPollingAsync()

app/backend/computermanager.h

@@ -1,5 +1,6 @@
 #pragma once
 #include "nvhttp.h"
+#include "nvpairingmanager.h"
 
 #include <qmdnsengine/server.h>
 #include <qmdnsengine/cache.h>
@@ -10,6 +11,7 @@
 #include <QThread>
 #include <QReadWriteLock>
 #include <QSettings>
+#include <QRunnable>
 
 class NvComputer
 {
@@ -239,6 +241,8 @@ class ComputerManager : public QObject
 {
     Q_OBJECT
 
+    friend class DeferredHostDeletionTask;
+
 public:
     explicit ComputerManager(QObject *parent = nullptr);
 
@@ -248,6 +252,8 @@ public:
 
     Q_INVOKABLE bool addNewHost(QString address, bool mdns);
 
+    void pairHost(NvComputer* computer, QString pin);
+
     QVector<NvComputer*> getComputers();
 
     // computer is deleted inside this call
@@ -256,6 +262,8 @@ public:
 signals:
     void computerStateChanged(NvComputer* computer);
 
+    void pairingCompleted(NvComputer* computer, QString error);
+
 private slots:
     void handleComputerStateChanged(NvComputer* computer);
 
@@ -275,3 +283,54 @@ private:
     QMdnsEngine::Cache m_MdnsCache;
     QVector<MdnsPendingComputer*> m_PendingResolution;
 };
+
+class PendingPairingTask : public QObject, public QRunnable
+{
+    Q_OBJECT
+
+public:
+    PendingPairingTask(ComputerManager* computerManager, NvComputer* computer, QString pin)
+        : m_ComputerManager(computerManager),
+          m_Computer(computer),
+          m_Pin(pin)
+    {
+        connect(this, &PendingPairingTask::pairingCompleted,
+                computerManager, &ComputerManager::pairingCompleted);
+    }
+
+signals:
+    void pairingCompleted(NvComputer* computer, QString error);
+
+private:
+    void run()
+    {
+        NvPairingManager pairingManager(m_Computer->activeAddress);
+
+        try {
+           NvPairingManager::PairState result = pairingManager.pair(m_Computer->appVersion, m_Pin);
+           switch (result)
+           {
+           case NvPairingManager::PairState::PIN_WRONG:
+               emit pairingCompleted(m_Computer, "The PIN from the PC didn't match. Please try again.");
+               break;
+           case NvPairingManager::PairState::FAILED:
+               emit pairingCompleted(m_Computer, "Pairing failed. Please try again.");
+               break;
+           case NvPairingManager::PairState::ALREADY_IN_PROGRESS:
+               emit pairingCompleted(m_Computer, "Another pairing attempt is already in progress.");
+               break;
+           case NvPairingManager::PairState::PAIRED:
+               emit pairingCompleted(m_Computer, nullptr);
+               break;
+           }
+        } catch (const GfeHttpResponseException& e) {
+            emit pairingCompleted(m_Computer,
+                                  QString::fromLocal8Bit(e.getStatusMessage()) +
+                                  " (Error " + QString::number(e.getStatusCode()));
+        }
+    }
+
+    ComputerManager* m_ComputerManager;
+    NvComputer* m_Computer;
+    QString m_Pin;
+};

app/backend/nvhttp.cpp

@@ -25,9 +25,8 @@ NvHTTP::NvHTTP(QString address) :
 }
 
 QVector<int>
-NvHTTP::getServerVersionQuad(QString serverInfo)
+NvHTTP::parseQuad(QString quad)
 {
-    QString quad = getXmlString(serverInfo, "appversion");
     QStringList parts = quad.split(".");
     QVector<int> ret;
 

app/backend/nvhttp.h

@@ -91,7 +91,7 @@ public:
 
     static
     QVector<int>
-    getServerVersionQuad(QString serverInfo);
+    parseQuad(QString quad);
 
     void
     quitApp();

app/backend/nvpairingmanager.cpp

@@ -42,12 +42,6 @@ NvPairingManager::~NvPairingManager()
     EVP_PKEY_free(m_PrivateKey);
 }
 
-QString
-NvPairingManager::generatePinString()
-{
-    return QString::asprintf("%04d", QRandomGenerator::global()->bounded(10000));
-}
-
 QByteArray
 NvPairingManager::generateRandomBytes(int length)
 {
@@ -167,9 +161,9 @@ NvPairingManager::saltPin(QByteArray salt, QString pin)
 }
 
 NvPairingManager::PairState
-NvPairingManager::pair(QString serverInfo, QString pin)
+NvPairingManager::pair(QString appVersion, QString pin)
 {
-    int serverMajorVersion = NvHTTP::getServerVersionQuad(serverInfo).at(0);
+    int serverMajorVersion = NvHTTP::parseQuad(appVersion).at(0);
     qDebug() << "Pairing with server generation: " << serverMajorVersion;
 
     QCryptographicHash::Algorithm hashAlgo;

app/backend/nvpairingmanager.h

@@ -23,11 +23,8 @@ public:
 
     ~NvPairingManager();
 
-    QString
-    generatePinString();
-
     PairState
-    pair(QString serverInfo, QString pin);
+    pair(QString appVersion, QString pin);
 
 private:
     QByteArray