wslc: prevent session name squatting for default WSLc sessions

localization/strings/en-US/Resources.resw

@@ -1935,6 +1935,15 @@ Usage:
     <value>Session termination failed: '{}'</value>
     <comment>{FixedPlaceholder="{}"}Command line arguments, file names and string inserts should not be translated</comment>
   </data>
+  <data name="MessageWslcDefaultSessionNotFound" xml:space="preserve">
+    <value>Default session not found</value>
+  </data>
+  <data name="MessageWslcOpenDefaultSessionFailed" xml:space="preserve">
+    <value>Failed to open default session</value>
+  </data>
+  <data name="MessageWslcTerminateDefaultSessionFailed" xml:space="preserve">
+    <value>Default session termination failed</value>
+  </data>
   <data name="MessageWslcShellExited" xml:space="preserve">
     <value>{} exited with: {}</value>
     <comment>{FixedPlaceholder="{}"}{FixedPlaceholder="{}"}Command line arguments, file names and string inserts should not be translated</comment>

src/windows/common/CMakeLists.txt

@@ -49,6 +49,7 @@ set(SOURCES
     WslTelemetry.cpp
     wslutil.cpp
     install.cpp
+    WSLCUserSettings.cpp
     )
 
 set(HEADERS
@@ -130,11 +131,19 @@ set(HEADERS
     WslSecurity.h
     WslTelemetry.h
     wslutil.h
+    EnumVariantMap.h
+    WSLCUserSettings.h
+    WSLCSessionDefaults.h
     )
 
 add_library(common STATIC ${SOURCES} ${HEADERS})
-add_dependencies(common wslserviceidl localization wslservicemc wslinstalleridl)
+add_dependencies(common wslserviceidl localization wslservicemc wslinstalleridl yaml-cpp)
 
 target_precompile_headers(common PRIVATE precomp.h)
 set_target_properties(common PROPERTIES FOLDER windows)
 target_include_directories(common PUBLIC ${CMAKE_CURRENT_BINARY_DIR}/../service/mc/${TARGET_PLATFORM}/${CMAKE_BUILD_TYPE})
+
+# WSLCUserSettings.cpp uses yaml-cpp headers.
+set_source_files_properties(WSLCUserSettings.cpp PROPERTIES
+    INCLUDE_DIRECTORIES "${yaml-cpp_SOURCE_DIR}/include"
+    COMPILE_DEFINITIONS "YAML_CPP_STATIC_DEFINE")

src/windows/common/WSLCSessionDefaults.h

@@ -0,0 +1,25 @@
+/*++
+
+Copyright (c) Microsoft. All rights reserved.
+
+Module Name:
+
+    WSLCSessionDefaults.h
+
+Abstract:
+
+    Shared constants for WSLc session naming and storage.
+
+--*/
+#pragma once
+
+#include <cstdint>
+
+namespace wsl::windows::wslc {
+
+inline constexpr const wchar_t DefaultSessionName[] = L"wslc-cli";
+inline constexpr const wchar_t DefaultAdminSessionName[] = L"wslc-cli-admin";
+inline constexpr const wchar_t DefaultStorageSubPath[] = L"wslc\\sessions";
+inline constexpr uint32_t DefaultBootTimeoutMs = 30000;
+
+} // namespace wsl::windows::wslc

src/windows/wslc/settings/UserSettings.cpp → src/windows/common/WSLCUserSettings.cpp

@@ -4,18 +4,23 @@ Copyright (c) Microsoft. All rights reserved.
 
 Module Name:
 
-    UserSettings.cpp
+    WSLCUserSettings.cpp
 
 Abstract:
 
     Implementation of UserSettings — YAML loading and validation.
 
 --*/
-#include "UserSettings.h"
+#include "precomp.h"
+#include "WSLCUserSettings.h"
 #include "filesystem.hpp"
 #include "string.hpp"
 #include "wslutil.h"
+
+#pragma warning(push)
+#pragma warning(disable : 4251 4275)
 #include <yaml-cpp/yaml.h>
+#pragma warning(pop)
 #include <algorithm>
 #include <format>
 #include <fstream>
@@ -25,7 +30,6 @@ using namespace wsl::windows::common::string;
 
 namespace wsl::windows::wslc::settings {
 
-// Default settings file template — written on first run.
 // All entries are commented out; the values shown are the built-in defaults.
 // TODO: localization for comments needed?
 static constexpr std::string_view s_DefaultSettingsTemplate =

src/windows/wslc/settings/UserSettings.h → src/windows/common/WSLCUserSettings.h

@@ -4,7 +4,7 @@ Copyright (c) Microsoft. All rights reserved.
 
 Module Name:
 
-    UserSettings.h
+    WSLCUserSettings.h
 
 Abstract:
 
@@ -156,9 +156,7 @@ class UserSettings
     // Overwrites the settings file with the commented-out defaults template.
     void Reset() const;
 
-protected:
-    // Loads settings from an explicit directory. Used by the singleton (via
-    // the private zero-arg constructor) and by test subclasses.
+    // Loads settings from an explicit directory.
     explicit UserSettings(const std::filesystem::path& settingsDir);
     ~UserSettings() = default;
 

src/windows/common/wslutil.cpp

@@ -153,6 +153,8 @@ static const std::map<HRESULT, LPCWSTR> g_commonErrors{
     X(WSLC_E_VOLUME_NOT_FOUND),
     X(WSLC_E_CONTAINER_NOT_RUNNING),
     X(WSLC_E_CONTAINER_IS_RUNNING),
+    X(WSLC_E_SESSION_RESERVED),
+    X(WSLC_E_INVALID_SESSION_NAME),
     X_WIN32(RPC_S_SERVER_UNAVAILABLE),
     X_WIN32(ERROR_ELEVATION_REQUIRED)};
 

src/windows/service/exe/CMakeLists.txt

@@ -71,7 +71,8 @@ target_link_libraries(wslservice
                       legacy_stdio_definitions
                       VirtDisk.lib
                       Winhttp.lib
-                      Synchronization.lib)
+                      Synchronization.lib
+                      yaml-cpp)
 
 target_precompile_headers(wslservice REUSE_FROM common)
 set_target_properties(wslservice PROPERTIES FOLDER windows)