From 17fc204122adc609900250bcd61ed751348cb41e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20St=C3=BCrz?= <simon.stuerz@nymea.io>
Date: Tue, 3 May 2022 14:30:01 +0200
Subject: [PATCH] Fix discovery behaviour if the resouce is not available

---
 .../network/networkdevicediscoveryimpl.cpp    | 28 +++++++++++++++----
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/libnymea-core/hardware/network/networkdevicediscoveryimpl.cpp b/libnymea-core/hardware/network/networkdevicediscoveryimpl.cpp
index fafbcc60..5a7299dc 100644
--- a/libnymea-core/hardware/network/networkdevicediscoveryimpl.cpp
+++ b/libnymea-core/hardware/network/networkdevicediscoveryimpl.cpp
@@ -84,8 +84,11 @@ NetworkDeviceDiscoveryImpl::NetworkDeviceDiscoveryImpl(QObject *parent) :
     m_cacheSettings = new QSettings(NymeaSettings::cachePath() + "/network-device-discovery.cache", QSettings::IniFormat);
     loadNetworkDeviceCache();
 
-    // Start the monitor timer in any case, we do also the cache cleanup there...
-    m_monitorTimer->start();
+    // Start the timer only if the resource is available
+    if (available()) {
+        // Start the monitor timer in any case, we do also the cache cleanup there...
+        m_monitorTimer->start();
+    }
 }
 
 NetworkDeviceDiscoveryImpl::~NetworkDeviceDiscoveryImpl()
@@ -100,9 +103,17 @@ NetworkDeviceDiscoveryReply *NetworkDeviceDiscoveryImpl::discover()
         return m_currentReply;
     }
 
-    qCInfo(dcNetworkDeviceDiscovery()) << "Starting network device discovery ...";
     m_currentReply = new NetworkDeviceDiscoveryReplyImpl(this);
+
+    if (!available()) {
+        qCWarning(dcNetworkDeviceDiscovery()) << "The network discovery is not available. Please make sure the binary has the required capability (CAP_NET_RAW) or start the application as root.";
+        // Finish the discovery in the next event loop so anny connections after the creation will work as expected
+        QTimer::singleShot(0, this, &NetworkDeviceDiscoveryImpl::finishDiscovery);
+        return m_currentReply;
+    }
+
     connect(m_currentReply, &NetworkDeviceDiscoveryReplyImpl::networkDeviceInfoAdded, this, &NetworkDeviceDiscoveryImpl::updateCache);
+    qCInfo(dcNetworkDeviceDiscovery()) << "Starting network device discovery ...";
 
     if (m_ping->available())
         pingAllNetworkDevices();
@@ -136,15 +147,16 @@ bool NetworkDeviceDiscoveryImpl::running() const
 NetworkDeviceMonitor *NetworkDeviceDiscoveryImpl::registerMonitor(const MacAddress &macAddress)
 {
     qCInfo(dcNetworkDeviceDiscovery()) << "Register new network device monitor for" << macAddress;
-    // Make sure we creare only one monitor per mac
+    // Make sure we create only one monitor per MAC
     if (m_monitors.contains(macAddress))
         return m_monitors.value(macAddress);
 
     if (macAddress.isNull()) {
-        qCWarning(dcNetworkDeviceDiscovery()) << "Could not register monitor for invalid" << macAddress.toString();
+        qCWarning(dcNetworkDeviceDiscovery()) << "Could not register monitor for invalid" << macAddress;
         return nullptr;
     }
 
+
     // Fill in cached information
     NetworkDeviceInfo info;
     if (m_networkInfoCache.contains(macAddress)) {
@@ -155,9 +167,13 @@ NetworkDeviceMonitor *NetworkDeviceDiscoveryImpl::registerMonitor(const MacAddre
 
     NetworkDeviceMonitorImpl *monitor = new NetworkDeviceMonitorImpl(macAddress, this);
     monitor->setNetworkDeviceInfo(info);
-
     m_monitors.insert(macAddress, monitor);
 
+    if (!available()) {
+        qCWarning(dcNetworkDeviceDiscovery()) << "Registered monitor but the hardware resource is not available. The monitor will not work as expected" << monitor;
+        return monitor;
+    }
+
     // Restart the monitor timer since we evaluate this one now
     m_monitorTimer->start();