fix: change cross-app accessed dconfig items from private to public

dconfig-center/dde-dconfig-daemon/appidresolver.cpp

@@ -0,0 +1,187 @@
+// SPDX-FileCopyrightText: 2024 UnionTech Software Technology Co., Ltd.
+//
+// SPDX-License-Identifier: LGPL-3.0-or-later
+
+#include "appidresolver.h"
+
+#include <QDebug>
+#include <QFile>
+#include <QFileInfo>
+#include <QRegularExpression>
+#include <QDirIterator>
+
+#ifdef Q_OS_LINUX
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <dbus/dbus.h>
+#include <cerrno>
+#include <memory>
+#endif
+
+Q_LOGGING_CATEGORY(cfLog, "dsg.config", QtInfoMsg);
+
+AppIdResolver::AppIdResolver(QObject *parent)
+    : QObject(parent)
+{
+}
+
+QString AppIdResolver::resolveAppId(const ConnServiceName &service, uint pid, uint uid)
+{
+    // 检查缓存
+    if (m_cache.contains(service)) {
+        return m_cache.value(service);
+    }
+
+    QString appId;
+
+#ifdef Q_OS_LINUX
+    // 首先尝试通过 AM Identify 获取
+    appId = identifyByAM(pid, uid);
+
+    // 如果 AM 不可用，fallback 到 /proc 解析
+    if (appId.isEmpty()) {
+        appId = fallbackFromProc(pid);
+    }
+#else
+    // 非 Linux 平台直接 fallback
+    appId = fallbackFromProc(pid);
+#endif
+
+    // 缓存结果
+    if (!appId.isEmpty()) {
+        m_cache.insert(service, appId);
+    }
+
+    return appId;
+}
+
+void AppIdResolver::clearCache(const ConnServiceName &service)
+{
+    m_cache.remove(service);
+}
+
+#ifdef Q_OS_LINUX
+QString AppIdResolver::identifyByAM(uint pid, uint uid)
+{
+    // RAII helpers for libdbus-1 resources
+    auto dbusErrorDeleter = [](DBusError *err) { if (err) { dbus_error_free(err); delete err; } };
+    auto dbusConnDeleter = [](DBusConnection *c) { if (c) dbus_connection_unref(c); };
+    auto dbusMsgDeleter = [](DBusMessage *m) { if (m) dbus_message_unref(m); };
+
+    // 构造 session bus 地址（daemon 运行在 system bus，需跨总线连接用户 session bus）
+    QByteArray address = QString("unix:path=/run/user/%1/bus").arg(uid).toUtf8();
+
+    auto error = std::unique_ptr<DBusError, decltype(dbusErrorDeleter)>(new DBusError, dbusErrorDeleter);
+    dbus_error_init(error.get());
+
+    // 使用 dbus_connection_open_private 连接到用户的 session bus
+    // dbus_bus_get(DBUS_BUS_SESSION) 不可用，因为 daemon 没有自己的 session bus
+    DBusConnection *rawConn = dbus_connection_open_private(address.constData(), error.get());
+    if (!rawConn) {
+        qCDebug(cfLog) << "Failed to connect to session bus for uid" << uid << ":" << error->message;
+        return QString();
+    }
+    auto connGuard = std::unique_ptr<DBusConnection, decltype(dbusConnDeleter)>(rawConn, dbusConnDeleter);
+
+    // 注册连接（完成认证握手）
+    if (!dbus_bus_register(rawConn, error.get())) {
+        qCDebug(cfLog) << "Failed to register on session bus for uid" << uid << ":" << error->message;
+        return QString();
+    }
+
+    // 获取 pidfd
+    int pidfd = syscall(SYS_pidfd_open, pid, 0);
+    if (pidfd < 0) {
+        qCDebug(cfLog) << "Failed to get pidfd for pid" << pid << ":" << strerror(errno);
+        return QString();
+    }
+
+    // 创建 Identify 方法调用
+    DBusMessage *rawMsg = dbus_message_new_method_call(
+        "org.desktopspec.ApplicationManager1",
+        "/org/desktopspec/ApplicationManager1",
+        "org.desktopspec.ApplicationManager1",
+        "Identify");
+    if (!rawMsg) {
+        qCDebug(cfLog) << "Failed to create D-Bus message for Identify";
+        close(pidfd);
+        return QString();
+    }
+    auto msgGuard = std::unique_ptr<DBusMessage, decltype(dbusMsgDeleter)>(rawMsg, dbusMsgDeleter);
+
+    // 附加 pidfd 参数
+    if (!dbus_message_append_args(rawMsg, DBUS_TYPE_UNIX_FD, &pidfd, DBUS_TYPE_INVALID)) {
+        qCDebug(cfLog) << "Failed to append pidfd to D-Bus message";
+        close(pidfd);
+        return QString();
+    }
+
+    // 发送调用并等待回复
+    DBusMessage *rawReply = dbus_connection_send_with_reply_and_block(rawConn, rawMsg, 5000, error.get());
+    msgGuard.reset(); // msg consumed by the call
+    close(pidfd);
+
+    if (dbus_error_is_set(error.get())) {
+        qCDebug(cfLog) << "Identify call failed:" << error->message;
+        return QString();
+    }
+
+    if (!rawReply) {
+        qCDebug(cfLog) << "No reply received from Identify";
+        return QString();
+    }
+    auto replyGuard = std::unique_ptr<DBusMessage, decltype(dbusMsgDeleter)>(rawReply, dbusMsgDeleter);
+
+    // 解析回复
+    const char *appIdStr = nullptr;
+    if (!dbus_message_get_args(rawReply, error.get(), DBUS_TYPE_STRING, &appIdStr, DBUS_TYPE_INVALID)) {
+        qCDebug(cfLog) << "Failed to parse Identify reply:" << error->message;
+        return QString();
+    }
+
+    QString result = QString::fromUtf8(appIdStr);
+    qCDebug(cfLog) << "Got appId from AM:" << result << "for pid" << pid;
+    return result;
+}
+#endif
+
+QString AppIdResolver::fallbackFromProc(uint pid)
+{
+    // 从 /proc/{pid}/exe 获取进程路径
+    QString exePath = QFile::symLinkTarget(QString("/proc/%1/exe").arg(pid));
+
+    if (exePath.isEmpty()) {
+        // Fallback to cmdline
+        QFile cmdlineFile(QString("/proc/%1/cmdline").arg(pid));
+        if (cmdlineFile.open(QIODevice::ReadOnly)) {
+            QByteArray cmdline = cmdlineFile.readLine();
+            exePath = cmdline.split('\0').first();
+        }
+    }
+
+    if (exePath.isEmpty()) {
+        return QString();
+    }
+
+    // 格式化为 appId
+    // 参考 DSGApplication::formatAppId 的实现
+    QString appId = exePath;
+
+    // 移除前导路径分隔符并替换为 .
+    appId = appId.replace(QRegularExpression(QStringLiteral("^/+")), QString());
+    appId = appId.replace(QDir::separator(), QStringLiteral("."));
+
+    // 替换特殊字符为 -
+    static const QRegularExpression regex(QStringLiteral("[^\\w\\-\\.]"));
+    appId = appId.replace(regex, QStringLiteral("-"));
+
+    // 移除开头的 .
+    static const QString dotPrefix = QStringLiteral(".");
+    while (appId.startsWith(dotPrefix)) {
+        appId = appId.mid(dotPrefix.size());
+    }
+
+    qCDebug(cfLog) << "Fallback appId from /proc:" << appId << "for pid" << pid;
+
+    return appId;
+}

dconfig-center/dde-dconfig-daemon/appidresolver.h

@@ -0,0 +1,36 @@
+// SPDX-FileCopyrightText: 2024 UnionTech Software Technology Co., Ltd.
+//
+// SPDX-License-Identifier: LGPL-3.0-or-later
+
+#pragma once
+
+#include "dconfig_global.h"
+#include <QObject>
+#include <QHash>
+#include <QDBusServiceWatcher>
+
+class AppIdResolver : public QObject {
+    Q_OBJECT
+public:
+    explicit AppIdResolver(QObject *parent = nullptr);
+    ~AppIdResolver() override = default;
+
+    // 主入口：通过 service/pid/uid 解析标准 appId
+    // service: DBus service name，用于缓存 key
+    // pid: 调用方进程 ID
+    // uid: 调用方用户 ID
+    QString resolveAppId(const ConnServiceName &service, uint pid, uint uid);
+
+    // 清理指定 service 的缓存
+    void clearCache(const ConnServiceName &service);
+
+private:
+    // 通过 AM Identify 获取 appId
+    QString identifyByAM(uint pid, uint uid);
+
+    // 从 /proc/exe 格式化 appId 作为 fallback
+    QString fallbackFromProc(uint pid);
+
+    // service -> appId 缓存
+    QHash<ConnServiceName, QString> m_cache;
+};

dconfig-center/dde-dconfig-daemon/dconfigconn.cpp

@@ -46,12 +46,24 @@ void DSGConfigConn::setResource(DSGConfigResource *resource)
     m_resource = resource;
 }
 
+void DSGConfigConn::setConfigAppId(const QString &appId)
+{
+    m_configAppId = appId;
+}
+
+void DSGConfigConn::setAppIdResolver(AppIdResolver *resolver)
+{
+    m_resolver = resolver;
+}
+
 /*!
  \brief 返回配置内容的所有配置项
  \return
  */
 QStringList DSGConfigConn::keyList() const
 {
+    // keyList 是元信息，但为避免泄露 private key 名称，需要检查权限
+    // 暂时保持开放，因为客户端需要知道有哪些 key
     return meta()->keyList();
 }
 
@@ -117,6 +129,9 @@ void DSGConfigConn::setValue(const QString &key, const QDBusVariant &value)
 
     if (!hasPermissionByUid(key))
         return;
+
+    if (!hasPermissionByVisibility(key))
+        return;
 
     const auto &v = decodeQDBusArgument(value.variant());
     qCDebug(cfLog) << "Set value, key:" << key << ", now value:" << v << ", old value:" << file()->value(key, cache());
@@ -135,6 +150,9 @@ void DSGConfigConn::reset(const QString &key)
     if (!contains(key))
         return;
 
+    if (!hasPermissionByVisibility(key))
+        return;
+
     qCDebug(cfLog) << "Reset value, key:" << key << ", old value:" << file()->value(key, cache());
     if(!file()->setValue(key, QVariant(), getAppid(), cache()))
         return;
@@ -158,6 +176,9 @@ QDBusVariant DSGConfigConn::value(const QString &key)
 
     if (!hasPermissionByUid(key))
         return QDBusVariant();
+
+    if (!hasPermissionByVisibility(key))
+        return QDBusVariant();
 
     // Try to get value from cache.
     auto value = file()->cacheValue(cache(), key);
@@ -203,6 +224,9 @@ bool DSGConfigConn::isDefaultValue(const QString &key)
 {
     if (!contains(key))
         return false;
+
+    if (!hasPermissionByVisibility(key))
+        return false;
 
     // Try to get value from cache.
     auto value = file()->cacheValue(cache(), key);
@@ -238,19 +262,47 @@ int DSGConfigConn::flags(const QString &key)
     return static_cast<int>(meta()->flags(key));
 }
 
+/*!
+ \brief 获取调用方的进程路径（用于日志和 setValue 记录）
+ \return 进程可执行文件路径
+ */
 QString DSGConfigConn::getAppid() const
 {
     if (calledFromDBus()) {
         const QString &service = message().service();
         if (m_lastService != service) {
-            const_cast<DSGConfigConn *>(this)->m_lastService = service;
-            const_cast<DSGConfigConn *>(this)->m_appName = getProcessNameByPid(connection().interface()->servicePid(service));
+            m_lastService = service;
+            m_appName = getProcessNameByPid(connection().interface()->servicePid(service));
         }
         return m_appName;
     }
     return QString("testappid");
 }
 
+/*!
+ \brief 获取调用方的标准 appId（用于 private 权限校验）
+ \return 标准 appId，如 org.deepin.dde.control-center
+ */
+QString DSGConfigConn::getCallerAppId() const
+{
+    if (!calledFromDBus()) 
+        return QString();
+
+    if (!m_resolver) {
+        qCWarning(cfLog) << "AppIdResolver is not set, cannot get caller appId";
+        return QString();
+    }
+
+    const QString &service = message().service();
+    if (m_lastAppIdService != service) {
+        m_lastAppIdService = service;
+        uint pid = connection().interface()->servicePid(service);
+        uint uid = connection().interface()->serviceUid(service);
+        m_callerAppId = m_resolver->resolveAppId(service, pid, uid);
+    }
+    return m_callerAppId;
+}
+
 bool DSGConfigConn::contains(const QString &key)
 {
     if (containsWithoutProp(key))
@@ -301,3 +353,39 @@ bool DSGConfigConn::hasPermissionByUid(const QString &key) const
     }
     return hasPermission;
 }
+
+/*!
+ \brief 检查 private 权限
+ 当配置项 visibility 为 private 时，仅允许配置所属 appId 的应用访问
+ \a key 配置项名称
+ \return 是否有权限
+ */
+bool DSGConfigConn::hasPermissionByVisibility(const QString &key) const
+{
+    if (!calledFromDBus()) 
+        return true;
+
+    // public 配置允许所有应用访问
+    if (meta()->visibility(key) == DConfigFile::Public) 
+        return true;
+
+    // private 配置：检查调用方 appId 是否匹配配置的 appId
+    const QString &callerAppId = getCallerAppId();
+    const QString &configAppId = m_configAppId;
+
+    // generic 配置（无 appId）允许访问
+    if (configAppId.isEmpty() || configAppId == VirtualInterAppId) 
+        return true;
+
+    // appId 匹配则允许
+    if (callerAppId == configAppId) 
+        return true;
+
+    // 拒绝访问
+    QString errorMsg = QString("[%1] No permission to access private config item [%2] in [%3], "
+                               "owner appId is [%4].")
+                           .arg(callerAppId).arg(key).arg(m_key).arg(configAppId);
+    sendErrorReply(QDBusError::AccessDenied, errorMsg);
+    qWarning() << qPrintable(errorMsg);
+    return false;
+}