Add MDNS e2e test

core/backends/lan/mdns_wrapper.cpp

@@ -98,12 +98,12 @@ static int query_callback(int sock, const struct sockaddr* from, size_t addrlen,
 
     switch (record_type) {
     case MDNS_RECORDTYPE_PTR: {
-        // We don't use mdns_record_parse_ptr() because we want to extract just the service name instead of the full "<service-name>.<_service-type>._tcp.local." string
-        mdns_string_pair_t serviceNamePos = mdns_get_next_substring(data, size, record_offset);
-        discoveredService->name = QString::fromLatin1((char *)data + serviceNamePos.offset, serviceNamePos.length);
-        //static char serviceNameBuffer[256];
-        //mdns_string_t serviceName = mdns_record_parse_ptr(data, size, record_offset, record_length, serviceNameBuffer, sizeof(serviceNameBuffer));
-        //discoveredService->name = QString::fromLatin1(serviceName.str, serviceName.length);
+        // We don't use mdns_record_parse_ptr() because we want to extract just the service name instead of the full "<instance-name>._<service-type>._tcp.local." string
+        mdns_string_pair_t instanceNamePos = mdns_get_next_substring(data, size, record_offset);
+        discoveredService->name = QString::fromLatin1((char *)data + instanceNamePos.offset, instanceNamePos.length);
+        //static char instanceNameBuffer[256];
+        //mdns_string_t instanceName = mdns_record_parse_ptr(data, size, record_offset, record_length, instanceNameBuffer, sizeof(instanceNameBuffer));
+        //discoveredService->name = QString::fromLatin1(instanceName.str, instanceName.length);
         if (discoveredService->address == QHostAddress::Null) {
             discoveredService->address = QHostAddress(from); // In case we don't receive a A record, use from as address
         }
@@ -309,11 +309,11 @@ static mdns_record_t createMdnsRecord(const Announcer::AnnouncedInfo &self,
     answer.rclass = 0;
     answer.ttl = 0;
     switch (record_type) {
-    case MDNS_RECORDTYPE_PTR: // maps "<_service-type>._tcp.local." to "<service-name>.<_service-type>._tcp.local."
+    case MDNS_RECORDTYPE_PTR: // maps "_<service-type>._tcp.local." to "<instance-name>._<service-type>._tcp.local."
         answer.name = createMdnsString(self.serviceType);
         answer.data.ptr.name = createMdnsString(self.serviceInstance);
         break;
-    case MDNS_RECORDTYPE_SRV: // maps "<service-name>.<_service-type>._tcp.local." to "<hostname>.local." and port
+    case MDNS_RECORDTYPE_SRV: // maps "<instance-name>._<service-type>._tcp.local." to "<hostname>.local." and port
         answer.name = createMdnsString(self.serviceInstance);
         answer.data.srv.name = createMdnsString(self.hostname);
         answer.data.srv.port = self.port;
@@ -544,14 +544,14 @@ int Announcer::listenForQueries()
     return numSockets;
 }
 
-Announcer::Announcer(const QString &serviceName, const QString &serviceType, uint16_t port)
+Announcer::Announcer(const QString &instanceName, const QString &serviceType, uint16_t port)
 {
     self.serviceType = serviceType.toLatin1();
     if (!self.serviceType.endsWith('.')) {
         // mdns.h needs all the qualified names to end with dot for some reason
         self.serviceType.append('.');
     }
-    self.serviceInstance = serviceName.toLatin1() + '.' + self.serviceType;
+    self.serviceInstance = instanceName.toLatin1() + '.' + self.serviceType;
     self.hostname = QHostInfo::localHostName().toLatin1() + ".local.";
     self.port = port;
     detectHostAddresses();

core/backends/lan/mdns_wrapper.h

@@ -13,30 +13,32 @@
 #include <QString>
 #include <QVector>
 
-/*
+#include "kdeconnectcore_export.h"
+
+/**
  * A Qt wrapper for the mdns.h header-only library
  * from https://github.com/mjansson/mdns
  */
 namespace MdnsWrapper
 {
 
-class Discoverer : public QObject
+class KDECONNECTCORE_EXPORT Discoverer : public QObject
 {
     Q_OBJECT
 
 public:
     struct MdnsService {
-        QString name;
+        QString name; // The instance-name part in "<instance-name>._<service-type>._tcp.local."
         uint16_t port;
-        QHostAddress address;
+        QHostAddress address; // An IPv4 address (IPv6 addresses are ignored)
         QMap<QString, QString> txtRecords;
     };
 
-    // serviceType must be of the form "_<name>._<tcp/udp>.local"
+    // serviceType must be of the form "_<service-type>._<tcp/udp>.local"
     void startDiscovering(const QString &serviceType);
     void stopDiscovering();
 
-    void sendQuery(const QString &serviceName);
+    void sendQuery(const QString &serviceType);
 
 Q_SIGNALS:
     void serviceFound(const MdnsWrapper::Discoverer::MdnsService &service);
@@ -48,14 +50,14 @@ private:
     QVector<QSocketNotifier *> responseSocketNotifiers;
 };
 
-class Announcer : public QObject
+class KDECONNECTCORE_EXPORT Announcer : public QObject
 {
     Q_OBJECT
 
 public:
     struct AnnouncedInfo {
-        QByteArray serviceType; // ie: "<_service-type>._tcp.local."
-        QByteArray serviceInstance; // ie: "<service-name>.<_service-type>._tcp.local."
+        QByteArray serviceType; // ie: "_<service-type>._tcp.local."
+        QByteArray serviceInstance; // ie: "<instance-name>._<service-type>._tcp.local."
         QByteArray hostname; // ie: "<hostname>.local."
         QVector<QHostAddress> addressesV4;
         QVector<QHostAddress> addressesV6;
@@ -63,8 +65,8 @@ public:
         QHash<QByteArray, QByteArray> txtRecords;
     };
 
-    // serviceType must be of the form "_<name>._<tcp/udp>.local"
-    Announcer(const QString &serviceName, const QString &serviceType, uint16_t port);
+    // serviceType must be of the form "_<service-type>._<tcp/udp>.local"
+    Announcer(const QString &instanceName, const QString &serviceType, uint16_t port);
 
     void putTxtRecord(const QString &key, const QString &value)
     {

core/backends/lan/mdnsdiscovery.cpp

@@ -23,7 +23,7 @@ MdnsDiscovery::MdnsDiscovery(LanLinkProvider *lanLinkProvider)
     mdnsAnnouncer.putTxtRecord(QStringLiteral("type"), config.deviceType().toString());
     mdnsAnnouncer.putTxtRecord(QStringLiteral("protocol"), QString::number(NetworkPacket::s_protocolVersion));
 
-    connect(&mdnsDiscoverer, &MdnsWrapper::Discoverer::serviceFound, [lanLinkProvider](const MdnsWrapper::Discoverer::MdnsService &service) {
+    connect(&mdnsDiscoverer, &MdnsWrapper::Discoverer::serviceFound, this, [lanLinkProvider](const MdnsWrapper::Discoverer::MdnsService &service) {
         if (KdeConnectConfig::instance().deviceId() == service.name) {
             qCDebug(KDECONNECT_CORE) << "Discovered myself, ignoring";
             return;

tests/CMakeLists.txt

@@ -12,3 +12,4 @@ set(kdeconnect_libraries
 
 ecm_add_test(pluginloadtest.cpp LINK_LIBRARIES ${kdeconnect_libraries})
 ecm_add_test(sendfiletest.cpp LINK_LIBRARIES ${kdeconnect_libraries})
+ecm_add_test(mdnstest.cpp LINK_LIBRARIES ${kdeconnect_libraries})

tests/mdnstest.cpp

@@ -0,0 +1,62 @@
+/**
+ * SPDX-FileCopyrightText: 2023 Albert Vaca Cintora <albertvaka@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
+ */
+
+#include <QCoreApplication>
+#include <QObject>
+#include <QSignalSpy>
+#include <QSocketNotifier>
+#include <QStandardPaths>
+#include <QTest>
+
+#include "core/backends/lan/mdns_wrapper.h"
+#include "kdeconnect-version.h"
+
+class TestMdns : public QObject
+{
+    Q_OBJECT
+public:
+    TestMdns()
+    {
+    }
+
+private Q_SLOTS:
+    void testAnounceAndDiscover()
+    {
+        QString instanceName = QStringLiteral("myinstance");
+        uint16_t instancePort = 1716;
+        QString serviceType = QStringLiteral("_test._udp.local");
+        QString txtKey = QStringLiteral("keyerino");
+        QString txtValue = QStringLiteral("valuerino");
+
+        MdnsWrapper::Announcer announcer(instanceName, serviceType, instancePort);
+        announcer.putTxtRecord(txtKey, txtValue);
+
+        MdnsWrapper::Discoverer discoverer;
+
+        QSignalSpy spy(&discoverer, &MdnsWrapper::Discoverer::serviceFound);
+
+        connect(&discoverer, &MdnsWrapper::Discoverer::serviceFound, this, [instanceName, instancePort, txtKey, txtValue](const MdnsWrapper::Discoverer::MdnsService &service) {
+            QCOMPARE(instanceName, service.name);
+            QCOMPARE(instancePort, service.port);
+            QVERIFY(service.txtRecords.size() == 1);
+            QVERIFY(service.txtRecords.contains(txtKey));
+            QCOMPARE(txtValue, service.txtRecords.value(txtKey));
+        });
+
+        announcer.startAnnouncing();
+        discoverer.startDiscovering(serviceType);
+
+        QVERIFY(spy.wait(2000));
+        QVERIFY(spy.count() > 0);
+
+        discoverer.stopDiscovering();
+        announcer.stopAnnouncing();
+    }
+};
+
+QTEST_MAIN(TestMdns);
+
+#include "mdnstest.moc"