isolationRunner/DBusConnection.cpp

#include "DBusConnection.h"
#include "IsolationManager.h"

#include <QDBusConnection>
#include <QDBusError>
#include <QSettings>
#include <QDebug>
#include <qdbusargument.h>
#include <QXmlStreamWriter>
#include <QBuffer>
#include <cstdlib>

constexpr const char *SERVICE_NAME = "org.tom.IsolationRunner";

DBusConnection::DBusConnection(IsolationManager *parent)
  : QDBusAbstractAdaptor(parent),
  m_parent(parent)
{
    /*
     * Registering ourself like this means that all public slots will become
     * remote-callable.
     */
    if (!QDBusConnection::sessionBus().isConnected())
        throw std::runtime_error("Failed to find the DBUS session");
    QDBusConnection::sessionBus().registerObject("/apps", parent);
    if (!QDBusConnection::sessionBus().registerService(SERVICE_NAME))
        throw std::runtime_error("Registration with DBus failed, am I already running?");
}

void DBusConnection::run(const QString &fullPath, const QStringList &arguments, const QDBusMessage &message)
{
    run2(message);
}

void DBusConnection::run2(const QDBusMessage &message)
{
    /*
     * The complex run option. With more features.
     * 0: app-name
     * 1: app-arguments
     * 2: executable-path (if different from 0)
     * 3: bool: lockdown (minimum rights)
     * 4: bool: autodelete
     * 5: string: jailId
     */
    const auto args = message.arguments();
    if (args.size() < 2) {
        QDBusConnection::sessionBus().send(message.createErrorReply(QDBusError::InvalidArgs, "Need more args"));
        return;
    }
    QString profileName = args.at(0).toString();
    if (!args.at(1).canConvert(QMetaType::QStringList)) {
        QDBusConnection::sessionBus().send(message.createErrorReply(QDBusError::InvalidArgs, "invalid args"));
        return;
    }
    QStringList arguments = args.at(1).toStringList();

    bool lockdown = false;
    bool autoDelete = false;
    QString jailId; // to run a specific executable in an existing jailId, this is the 'id'
    QString vpnConf, vpnAc;
    if (args.size() >= 4)
        lockdown = args.at(3).toBool();
    if (args.size() >= 5)
        autoDelete = args.at(4).toBool(); // auto-delete is not allowed for existing profiles
    if (args.size() >= 6)
        jailId = args.at(5).toString();
    if (args.size() >= 8) {
        vpnAc = args.at(6).toString();
        vpnConf = args.at(7).toString();
    }

    // jailId means that the profile we run in is defined by the ID,
    // instead of the executable.
    if (!jailId.isEmpty()) {
        if (autoDelete)
            return fail(message, "not valid combination of options");
        profileName = jailId;
    }
    else if (autoDelete) // avoid app namespace collisions.
        profileName += QString("_tmp-%1").arg(std::rand());

    auto existingAppData = m_parent->lookupApp(profileName, IsolationManager::OnlyExisting);
    if (!jailId.isEmpty()) {
        int jail = existingAppData.appId;

        // is jailId an int based ID?
        bool isNumberId = false;
        if (existingAppData.appId == -1) {
            jail = jailId.toInt(&isNumberId);
            if (!isNumberId)
                return fail(message, "jail not found");
        }
        for (const auto &profile : m_parent->listProfiles()) {
            if (profile.jailId == jail) {
                if (!profile.active)
                    return fail(message, "jail not running");
                if (isNumberId)
                    existingAppData = m_parent->lookupApp(profile.name, IsolationManager::OnlyExisting);
                break;
            }
        }

        assert(jail > 1);
        assert(existingAppData.appId > 0);
    }
    if (existingAppData.appId == -1) {
        if (!jailId.isEmpty())
            return fail(message, "jail not found");
        QString exe;
        if (args.size() >= 3)
            exe = args.at(2).toString();
        if (exe.isEmpty())
            exe = args.at(0).toString();

        if (!exe.startsWith("/"))
            return fail(message, "Invalid path, not absolute");

        QFileInfo info(exe);
        if (!info.exists())
            return fail(message, "File not found");
        else if (!info.isExecutable())
            return fail(message, "Path doesn't point to an executable");

        // create new entry
        auto entry = m_parent->startEditApp(profileName, IsolationManager::MaybeCreate);
        entry->setValue("path-to-exe", exe);
        if (lockdown)
            entry->setValue("denied", "homedir dbus git ssh media dbus-system audio");
        if (!vpnAc.isEmpty())
            entry->setValue("vpnAc", vpnAc);
        if (!vpnConf.isEmpty())
            entry->setValue("vpnConf", vpnConf);
    }
    else if (!jailId.isEmpty()) {
        auto appData = existingAppData;
        // no init script should be run
        appData.initScript.clear();
        if (args.size() >= 3)
            appData.pathToExe = args.at(2).toString();
        if (appData.pathToExe.isEmpty())
            appData.pathToExe = args.at(0).toString();
        if (!appData.pathToExe.startsWith('/'))
            appData.pathToExe = "/usr/bin/" + appData.pathToExe;

        QFileInfo exe(appData.pathToExe);
        if (!exe.isExecutable())
            return fail(message, "Path doesn't point to an executable");

        auto answer = m_parent->startApplicationRequest(appData, arguments);
        if (answer == "ok")
            QDBusConnection::sessionBus().send(message.createReply(answer));
        else
            fail(message, answer);
       return;
    } else {
        QString exe;
        if (args.size() >= 3)
            exe = args.at(2).toString();
        if (!exe.isEmpty() && existingAppData.pathToExe != exe) // reject.
            return fail(message, "Exe path not accepted (try without)");
    }

    auto appData = m_parent->lookupApp(profileName, IsolationManager::OnlyExisting);
    assert(appData.appId != -1);
    appData.autoDelete = autoDelete;

    auto answer = m_parent->startApplicationRequest(appData, arguments);
    if (answer == "ok")
        QDBusConnection::sessionBus().send(message.createReply(answer));
    else
        fail(message, answer);
}

QDBusVariant DBusConnection::listProfiles(bool verbose) const
{
    auto profileInfos = m_parent->listProfiles();
    std::sort(profileInfos.begin(), profileInfos.end(),
            [](const IsolationManager::ProfileInfo &a,
            const IsolationManager::ProfileInfo &b) {
        return a.lastRun > b.lastRun;
    });

    QStringList answer;
    for (const auto &profileInfo : profileInfos) {
        QString profile = profileInfo.active ? "*" : " ";
        if (verbose)
            profile = profile % " " % QString::number(profileInfo.jailId);
        profile = profile % " " % profileInfo.name;
        answer.append(profile);
        if (verbose && !profileInfo.exe.startsWith("/usr/bin/")
                && !profileInfo.exe.startsWith("/bin/")) {
            // if the exe isn't in /usr/bin or /bin, show it in verbose mode
            answer << QString("    -> ") % profileInfo.exe;
        }
    }
    return QDBusVariant(answer);
}

void DBusConnection::details(const QString &profile, const QDBusMessage &message) const
{
    if (profile.isEmpty())
        QDBusConnection::sessionBus().send(message.createErrorReply(QDBusError::InvalidArgs, "Missing arg"));
    QString path(profile);
    if (!profile.startsWith("/"))
        path = "/bin/" + profile;

    auto appData = m_parent->lookupApp(path, IsolationManager::OnlyExisting);
    if (appData.appId == -1) {
        bool isNum;
        const int profileId = profile.toLongLong(&isNum);
        if (isNum) {
            // the user-entered number may be a appId
            for (const auto &profile : m_parent->listProfiles()) {
                if (profileId == profile.jailId) {
                    appData = m_parent->lookupApp(profile.name, IsolationManager::OnlyExisting);
                    assert(appData.appId == profile.jailId);
                    break;
                }
            }
        }
    }

    if (appData.appId == -1) {
        QDBusConnection::sessionBus().send(message.createErrorReply(QDBusError::InvalidArgs, "unknown profile"));
        return;
    }

    QBuffer data;
    data.open(QIODevice::WriteOnly);
    QXmlStreamWriter writer(&data);
    writer.setAutoFormatting(true);
    writer.writeStartDocument();
    writer.writeStartElement("app");
    writer.writeAttribute("name", appData.profileName);
    writer.writeAttribute("id", QString::number(appData.appId));
    writer.writeAttribute("exe", appData.pathToExe);
    for (const auto &denied : std::as_const(appData.denied)) {
        writer.writeStartElement("denied");
        writer.writeCharacters(denied);
        writer.writeEndElement();
    }
    for (const auto &allowed : std::as_const(appData.allowed)) {
        writer.writeStartElement("allowed");
        writer.writeCharacters(allowed);
        writer.writeEndElement();
    }

    QString appStateFile = m_parent->stateFile(appData.appId);
    if (QFile::exists(appStateFile)) {
        QSettings appState(appStateFile, QSettings::IniFormat);
        writer.writeStartElement("lastRun");
        writer.writeAttribute("start", appState.value("start").toDateTime().toString(Qt::ISODate));
        int pid = appState.value("pid").toInt();
        if (pid && QFile::exists(QString("/proc/%1").arg(pid) )) {
            writer.writeAttribute("pid", QString::number(pid));
        }
        writer.writeEndElement();
    }
    writer.writeEndElement();
    QDBusConnection::sessionBus().send(message.createReply(QString::fromLatin1(data.buffer())));
}

void DBusConnection::setRights(const QString &profile, const QStringList &denied, const QStringList &allowed)
{
    // this method is allowed to create the app if it does not exist.
    QString path(profile);
    if (!profile.startsWith("/"))
        path = "/bin/" + profile;
    auto appData = m_parent->lookupApp(path, IsolationManager::MaybeCreate);
    appData.setAllowed(allowed);
    appData.setDenied(denied);

    QSettings entry(m_parent->dbDir().absoluteFilePath(appData.profileName + ".info"), QSettings::IniFormat);
    entry.setValue("denied", appData.denied.join(' '));
    entry.setValue("allowed", appData.allowed.join(' '));
}

void DBusConnection::fail(const QDBusMessage &message, const QString &errorMessage) const
{
    QDBusConnection::sessionBus().send(message.createErrorReply(QDBusError::InvalidArgs, errorMessage));
}