Qt UI: Runner: Use specialised QProcess subclass

This allows us to set the uid/gid in the executor process so that APK
inherits full root, which prevents a weird error that causes APK Tools
to write out all files as owned by the live user's GID when run under
live media.

4 files changed, 48 insertions, 1 deletions

diff --git a/ui/qt5/CMakeLists.txt b/ui/qt5/CMakeLists.txt
index 086abc7..74b9c68 100644
--- a/ui/qt5/CMakeLists.txt
+++ b/ui/qt5/CMakeLists.txt
@@ -44,6 +44,7 @@ set(RUN_QT_SOURCES
     horizonwizardpage.cc
     stepprogresswidget.cc
     runner/main.cc
+    runner/executorprocess.cc
     runner/executorwizard.cc
     runner/executepage.cc
     runner/errorpage.cc
diff --git a/ui/qt5/runner/executepage.cc b/ui/qt5/runner/executepage.cc
index 0d0980a..ce69c5e 100644
--- a/ui/qt5/runner/executepage.cc
+++ b/ui/qt5/runner/executepage.cc
@@ -13,6 +13,7 @@
 #include "executepage.hh"
 
 #include "executorwizard.hh"
+#include "executorprocess.hh"
 
 #include <QAbstractButton>
 #include <QGridLayout>
@@ -53,7 +54,7 @@ ExecutePage::ExecutePage(QWidget *parent) : HorizonWizardPage(parent) {
     this->current = Prepare;
     markRunning(this->current);
 
-    executor = new QProcess(this);
+    executor = new ExecutorProcess(this);
     executor->setProgram("hscript-executor");
     connect(executor, &QProcess::readyReadStandardError,
             this, &ExecutePage::executorReady);
diff --git a/ui/qt5/runner/executorprocess.cc b/ui/qt5/runner/executorprocess.cc
new file mode 100644
index 0000000..1712fd9
--- /dev/null
+++ b/ui/qt5/runner/executorprocess.cc
@@ -0,0 +1,20 @@
+/*
+ * executorprocess.cc - Implementation of the QProcess class for the executor
+ * horizon-run-qt5, the Qt 5 executor user interface for
+ * Project Horizon
+ *
+ * Copyright (c) 2023 Adélie Linux and contributors.  All rights reserved.
+ * This code is licensed under the AGPL 3.0 license, as noted in the
+ * LICENSE-code file in the root directory of this repository.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+#include "executorprocess.hh"
+
+#include <unistd.h>
+
+void ExecutorProcess::setupChildProcess() {
+    ::setuid(::geteuid());
+    ::setgid(::getegid());
+}
diff --git a/ui/qt5/runner/executorprocess.hh b/ui/qt5/runner/executorprocess.hh
new file mode 100644
index 0000000..bec1d18
--- /dev/null
+++ b/ui/qt5/runner/executorprocess.hh
@@ -0,0 +1,25 @@
+/*
+ * executorprocess.hh - Definition of the QProcess class for the executor
+ * horizon-run-qt5, the Qt 5 executor user interface for
+ * Project Horizon
+ *
+ * Copyright (c) 2023 Adélie Linux and contributors.  All rights reserved.
+ * This code is licensed under the AGPL 3.0 license, as noted in the
+ * LICENSE-code file in the root directory of this repository.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+#ifndef EXECUTORPROCESS_HH
+#define EXECUTORPROCESS_HH
+
+#include <QProcess>
+
+class ExecutorProcess : public QProcess {
+public:
+    ExecutorProcess(QObject *parent = nullptr) : QProcess(parent) {};
+protected:
+    void setupChildProcess() override;
+};
+
+#endif  /* !ERRORPAGE_HH */