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[sandbox] Do not use QFileEngine
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QFileEngine and related APIs are made private in Qt5. After this commit,
mapping file paths into sandbox is explicit -- code must be written to
support it.
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@martyone
martyone committed May 24, 2013
1 parent f0b9b4a commit 1831e39
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Showing 2 changed files with 39 additions and 94 deletions.
124 changes: 35 additions & 89 deletions libssu/sandbox.cpp
View file
Expand Up @@ -9,38 +9,28 @@

#include <stdlib.h>

#include <QtCore/QAbstractFileEngineHandler>
#include <QtCore/QDir>
#include <QtCore/QFSFileEngine>
#include <QtCore/QFileInfo>
#include <QtCore/QProcessEnvironment>
#include <QtCore/QSet>

#include "libssu/ssucoreconfig.h"
#include "constants.h"

class Sandbox::FileEngineHandler : public QAbstractFileEngineHandler {
public:
FileEngineHandler(const QString &sandboxPath, const QSet<QString> &overlayEnabledDirectories);

bool isDirectoryOverlayEnabled(const QString &path) const;

public:
// QAbstractFileEngineHandler
QAbstractFileEngine *create(const QString &fileName) const;

private:
const QString m_sandboxPath;
QSet<QString> m_overlayEnabledDirectories;
};

/**
* @class Sandbox
* @brief Simple sandboxing with Qt file system abstraction.
* @brief Helps to redirect file operations into sandbox directory
*
* The term <em>world files</em> is used to reffer files outside sandbox.
*
* Redirects all file operations on selected files to files under sandbox
* directory. The term <em>world files</em> is used to reffer files outside
* sandbox.
* To write a sandbox aware code, simply use the map() function to process paths
* before accessing them.
*
* @code
* QFile data(Sandbox::map("/usr/share/my_app/data"));
* data.open();
* ...
* @endcode
*
* Its effect is controlled by activate() and deactivate() calls. Only one
* Sandbox instance can be active at any time. Active sandbox is automatically
Expand All @@ -60,27 +50,22 @@ class Sandbox::FileEngineHandler : public QAbstractFileEngineHandler {
* The argument @scopes allows to control if the sandbox will be used by this
* process, its children processes (@c SSU_TESTS_SANDBOX environment variable
* will be exported), or both.
*
* Internally it is based on QAbstractFileEngineHandler.
*
* @attention QDir lists entries presented in the world directory. The behavior
* changed with Qt 4.8.0 (Qt commit b9b55234a777c3b206332bafbe227e1355ca9186)
*/

Sandbox *Sandbox::s_activeInstance = 0;

Sandbox::Sandbox()
: m_defaultConstructed(true), m_usage(UseDirectly), m_scopes(ThisProcess),
m_sandboxPath(QProcessEnvironment::systemEnvironment().value("SSU_TESTS_SANDBOX")),
m_prepared(false), m_handler(0){
m_prepared(false){
if (!activate()){
qFatal("%s: Failed to activate", Q_FUNC_INFO);
}
}

Sandbox::Sandbox(const QString &sandboxPath, Usage usage, Scopes scopes)
: m_defaultConstructed(false), m_usage(usage), m_scopes(scopes),
m_sandboxPath(sandboxPath), m_prepared(false), m_handler(0){
m_sandboxPath(sandboxPath), m_prepared(false){
Q_ASSERT(!sandboxPath.isEmpty());
}

Expand All @@ -107,12 +92,8 @@ bool Sandbox::activate(){
return false;
}

if (m_scopes & ThisProcess){
m_handler = new FileEngineHandler(m_workingSandboxPath, m_overlayEnabledDirectories);
}

if (m_scopes & ChildProcesses){
setenv("SSU_TESTS_SANDBOX", qPrintable(m_workingSandboxPath), 1);
setenv("SSU_TESTS_SANDBOX", qPrintable(m_workingSandboxDir.path()), 1);
}

s_activeInstance = this;
Expand All @@ -122,17 +103,27 @@ bool Sandbox::activate(){
void Sandbox::deactivate(){
Q_ASSERT(isActive());

if (m_scopes & ThisProcess){
delete m_handler;
}

if (m_scopes & ChildProcesses){
unsetenv("SSU_TESTS_SANDBOX");
}

s_activeInstance = 0;
}

QDir Sandbox::effectiveRootDir()
{
return s_activeInstance != 0 && s_activeInstance->m_scopes & ThisProcess
? s_activeInstance->m_workingSandboxDir
: QDir::root();
}

QString Sandbox::map(const QString &fileName)
{
return effectiveRootDir().filePath(
QDir::root().relativeFilePath(
QFileInfo(fileName).absoluteFilePath()));
}

/**
* Copies selected files into sandbox. Existing files in sandbox are not overwriten.
*
Expand All @@ -142,17 +133,14 @@ bool Sandbox::addWorldFiles(const QString &directory, QDir::Filters filters,
const QStringList &filterNames){
Q_ASSERT(!isActive());
Q_ASSERT(!directory.isEmpty());
Q_ASSERT(directory.startsWith('/'));
Q_ASSERT(!directory.contains(':')); // separator in environment variable
Q_ASSERT(!directory.contains("/./") && !directory.endsWith("/.")
&& !directory.contains("/../") && !directory.endsWith("/..")
&& !directory.contains("//"));

if (!prepare()){
return false;
}

const QString sandboxedDirectory = m_workingSandboxPath + directory;
const QString sandboxedDirectory = m_workingSandboxDir.filePath(
QDir::root().relativeFilePath(
QFileInfo(directory).absoluteFilePath()));

if (!QFileInfo(directory).exists()){
qWarning("%s: Directory does not exist: '%s'", Q_FUNC_INFO, qPrintable(directory));
Expand Down Expand Up @@ -184,7 +172,7 @@ bool Sandbox::addWorldFiles(const QString &directory, QDir::Filters filters,

foreach (const QFileInfo &worldEntryInfo, QDir(directory).entryInfoList(filterNames, filters)){

const QFileInfo sandboxEntryInfo(sandboxedDirectory + '/' + worldEntryInfo.fileName());
const QFileInfo sandboxEntryInfo(QDir(sandboxedDirectory).filePath(worldEntryInfo.fileName()));

if (worldEntryInfo.isDir()){
if (!sandboxEntryInfo.exists()){
Expand Down Expand Up @@ -213,8 +201,6 @@ bool Sandbox::addWorldFiles(const QString &directory, QDir::Filters filters,
}
}

m_overlayEnabledDirectories.insert(directory);

return true;
}

Expand Down Expand Up @@ -258,58 +244,18 @@ bool Sandbox::prepare(){
return false;
}

const QString sandboxCopyPath = QString("%1/configroot").arg(m_tempDir);
const QString sandboxCopyPath = QDir(m_tempDir).filePath("configroot");

if (QProcess::execute("cp", QStringList() << "-r" << m_sandboxPath << sandboxCopyPath) != 0){
qWarning("%s: Failed to copy sandbox directory", Q_FUNC_INFO);
return false;
}

m_workingSandboxPath = sandboxCopyPath;
m_workingSandboxDir = QDir(sandboxCopyPath);
} else{
m_workingSandboxPath = m_sandboxPath;
m_workingSandboxDir = QDir(m_sandboxPath);
}

m_prepared = true;
return true;
}

/*
* @class Sandbox::FileEngineHandler
*/

Sandbox::FileEngineHandler::FileEngineHandler(const QString &sandboxPath,
const QSet<QString> &overlayEnabledDirectories):
m_sandboxPath(sandboxPath), m_overlayEnabledDirectories(overlayEnabledDirectories){
Q_ASSERT(!sandboxPath.isEmpty());
}

bool Sandbox::FileEngineHandler::isDirectoryOverlayEnabled(const QString &path) const{
return m_overlayEnabledDirectories.contains(path);
}

QAbstractFileEngine *Sandbox::FileEngineHandler::create(const QString &fileName) const{
Q_ASSERT(!m_sandboxPath.isEmpty());

if (!fileName.startsWith('/')){
return 0;
}

const QString sandboxedFileName = m_sandboxPath + fileName;
QScopedPointer<QFSFileEngine> sandboxedFileEngine(new QFSFileEngine(sandboxedFileName));

const QAbstractFileEngine::FileFlags flags = sandboxedFileEngine->fileFlags(
QAbstractFileEngine::ExistsFlag | QAbstractFileEngine::DirectoryType);

if (!(flags & QAbstractFileEngine::ExistsFlag)){
return 0;
}

if (flags & QAbstractFileEngine::DirectoryType){
if (!isDirectoryOverlayEnabled(fileName)){
return 0;
}
}

return sandboxedFileEngine.take();
}
9 changes: 4 additions & 5 deletions libssu/sandbox_p.h
View file
Expand Up @@ -13,8 +13,6 @@
#include <QtCore/QString>

class Sandbox {
class FileEngineHandler;

public:
enum Usage {
UseDirectly,
Expand All @@ -36,6 +34,9 @@ class Sandbox {
void deactivate();
bool isActive() const;

static QDir effectiveRootDir();
static QString map(const QString &fileName);

bool addWorldFiles(const QString &directory, QDir::Filters filters = QDir::NoFilter,
const QStringList &filterNames = QStringList());
bool addWorldFile(const QString &file);
Expand All @@ -51,9 +52,7 @@ class Sandbox {
const QString m_sandboxPath;
bool m_prepared;
QString m_tempDir;
QString m_workingSandboxPath;
QSet<QString> m_overlayEnabledDirectories;
FileEngineHandler *m_handler;
QDir m_workingSandboxDir;
};

Q_DECLARE_OPERATORS_FOR_FLAGS(Sandbox::Scopes)
Expand Down

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