Configure DHCP server on device before handshake

Change the procedure for a newly detected device: First configure the
network and then do the handshake for the device information.

The configuring the network part is new and incorporates a new service
NetworkConfigurationService. On the device it relies on a script
b2qt-gadget-network.sh (or as specified in a command line parameter)
which does the actual configuring of the USB network interface.

The network configuration to apply is selected from a list of hardcoded
candidates from the private use IPv4 ranges available. They are checked
against the existing networks on the host and an unused one is picked.

On the device the USB interface is configured to use this network and to
act as a DHCP server for it. Host will then pick up an IP from this DHCP
server automatically. Previous configuration of the host network is thus
not necessary and is removed.

Task-number: QTBUG-58614
Change-Id: I6a4ed34ef7d5cba9e55e6fa4f07725bb3c00d795
Reviewed-by: Samuli Piippo <samuli.piippo@qt.io>

3 files changed, 121 insertions, 0 deletions

diff --git a/tests/tests.pro b/tests/tests.pro
index cbd10df..7de79f3 100644
--- a/tests/tests.pro
+++ b/tests/tests.pro
@@ -4,6 +4,7 @@ CONFIG += ordered
 SUBDIRS = \
     tst_qdbmessage.pro \
     tst_stream.pro \
+    tst_subnet.pro \
 
 config_libusb10 {
     SUBDIRS += \
diff --git a/tests/tst_subnet.cpp b/tests/tst_subnet.cpp
new file mode 100644
index 0000000..5aa36cf
--- /dev/null
+++ b/tests/tst_subnet.cpp
@@ -0,0 +1,100 @@
+/******************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Debug Bridge.
+**
+** $QT_BEGIN_LICENSE:COMM$
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** $QT_END_LICENSE$
+**
+******************************************************************************/
+#include "../qdb/server/subnet.h"
+
+#include <QtCore/qstring.h>
+#include <QtTest>
+
+using Subnets = std::vector<Subnet>;
+
+bool operator==(const Subnet &lhs, const Subnet &rhs)
+{
+    return lhs.address == rhs.address
+            && lhs.prefixLength == rhs.prefixLength;
+}
+
+class tst_Subnet : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void freeSubnets();
+    void freeSubnets_data();
+    void usedSubnets();
+    void usedSubnets_data();
+};
+
+void tst_Subnet::freeSubnets()
+{
+    QFETCH(Subnets, candidates);
+    QFETCH(Subnets, useds);
+
+    const std::pair<Subnet, bool> result = findUnusedSubnet(candidates, useds);
+    QCOMPARE(result.second, true);
+    QCOMPARE(result.first, candidates[0]);
+}
+
+void tst_Subnet::freeSubnets_data()
+{
+    QTest::addColumn<Subnets>("candidates");
+    QTest::addColumn<Subnets>("useds");
+
+    Subnets candidates = {{QHostAddress{"172.31.0.1"}, 30}};
+    Subnets subnets = {{QHostAddress{"10.9.7.70"}, 22}};
+    QTest::newRow("1") << candidates << subnets;
+    subnets = {{QHostAddress{"10.9.7.70"}, 22},
+               {QHostAddress{"10.30.7.0"}, 22}};
+    QTest::newRow("2") << candidates << subnets;
+    candidates = {{QHostAddress{"10.9.7.254"}, 22}};
+    subnets = {{QHostAddress{"10.9.8.1"}, 22}};
+    QTest::newRow("3") << candidates << subnets;
+}
+
+void tst_Subnet::usedSubnets()
+{
+    QFETCH(Subnets, candidates);
+    QFETCH(Subnets, useds);
+
+    const std::pair<Subnet, bool> result = findUnusedSubnet(candidates, useds);
+    QCOMPARE(result.second, false);
+}
+
+void tst_Subnet::usedSubnets_data()
+{
+    QTest::addColumn<Subnets>("candidates");
+    QTest::addColumn<Subnets>("useds");
+
+    Subnets candidates = {{QHostAddress{"10.9.7.0"}, 30}};
+    Subnets subnets = {{QHostAddress{"10.9.4.70"}, 22}};
+    QTest::newRow("1") << candidates << subnets;
+    candidates = {{QHostAddress{"10.0.0.0"}, 8}};
+    subnets = {{QHostAddress{"10.200.100.1"}, 24}};
+    QTest::newRow("2") << candidates << subnets;
+    candidates = {{QHostAddress{"10.9.4.70"}, 22}};
+    subnets = {{QHostAddress{"192.168.12.1"}, 24},
+               {QHostAddress{"172.16.45.1"}, 24},
+               {QHostAddress{"10.9.0.1"}, 16}};
+    QTest::newRow("3") << candidates << subnets;
+}
+
+QTEST_APPLESS_MAIN(tst_Subnet)
+
+#include "tst_subnet.moc"
diff --git a/tests/tst_subnet.pro b/tests/tst_subnet.pro
new file mode 100644
index 0000000..9a5a1bc
--- /dev/null
+++ b/tests/tst_subnet.pro
@@ -0,0 +1,20 @@
+QT -= gui
+QT += network testlib
+
+CONFIG += c++11
+CONFIG += testcase
+
+TARGET = tst_subnet
+CONFIG += console
+CONFIG -= app_bundle
+
+TEMPLATE = app
+
+INCLUDEPATH += $$PWD/../
+
+HEADERS += \
+    ../qdb/server/subnet.h \
+
+SOURCES += \
+    ../qdb/server/subnet.cpp \
+    tst_subnet.cpp \