[FS] Implement OpenDirectory

include/fs/archive_base.hpp

@@ -2,6 +2,7 @@
 #include <cassert>
 #include <cstdio>
 #include <cstring>
+#include <filesystem>
 #include <optional>
 #include <string>
 #include <type_traits>
@@ -111,6 +112,17 @@ struct ArchiveSession {
     ArchiveSession(ArchiveBase* archive, const FSPath& filePath, bool isOpen = true) : archive(archive), path(filePath), isOpen(isOpen) {}
 };
 
+struct DirectorySession {
+    ArchiveBase* archive = nullptr;
+    // For directories which are mirrored to a specific path on the disk, this contains that path
+    // Otherwise this is a nullopt
+    std::optional<std::filesystem::path> pathOnDisk;
+    bool isOpen;
+
+    DirectorySession(ArchiveBase* archive, std::filesystem::path path, bool isOpen = true) : archive(archive), pathOnDisk(path),
+        isOpen(isOpen) {}
+};
+
 // Represents a file descriptor obtained from OpenFile. If the optional is nullopt, opening the file failed.
 // Otherwise the fd of the opened file is returned (or nullptr if the opened file doesn't require one)
 using FileDescriptor = std::optional<FILE*>;
@@ -201,6 +213,10 @@ public:
     virtual FileDescriptor openFile(const FSPath& path, const FilePerms& perms) = 0;
 
     virtual ArchiveBase* openArchive(const FSPath& path) = 0;
+    virtual std::optional<DirectorySession> openDirectory(const FSPath& path) {
+        Helpers::panic("Unimplemented OpenDirectory for %s archive", name().c_str());
+        return std::nullopt;
+    }
 
     // Read size bytes from a file starting at offset "offset" into a certain buffer in memory
     // Returns the number of bytes read, or nullopt if the read failed

include/fs/archive_save_data.hpp

@@ -13,6 +13,7 @@ public:
 	FormatInfo getFormatInfo(const FSPath& path) override;
 
 	ArchiveBase* openArchive(const FSPath& path) override;
+	std::optional<DirectorySession> openDirectory(const FSPath& path) override;
 	FileDescriptor openFile(const FSPath& path, const FilePerms& perms) override;
 	std::optional<u32> readFile(FileSession* file, u64 offset, u32 size, u32 dataPointer) override;
 

include/kernel/kernel_types.hpp

@@ -27,7 +27,7 @@ namespace SVCResult {
 }
 
 enum class KernelObjectType : u8 {
-    AddressArbiter, Archive, File, MemoryBlock, Process, ResourceLimit, Session, Dummy,
+    AddressArbiter, Archive, Directory, File, MemoryBlock, Process, ResourceLimit, Session, Dummy,
     // Bundle waitable objects together in the enum to let the compiler optimize certain checks better
     Event, Mutex, Port, Semaphore, Timer, Thread
 };
@@ -144,6 +144,7 @@ static const char* kernelObjectTypeToString(KernelObjectType t) {
     switch (t) {
         case KernelObjectType::AddressArbiter: return "address arbiter";
         case KernelObjectType::Archive: return "archive";
+        case KernelObjectType::Directory: return "directory";
         case KernelObjectType::Event: return "event";
         case KernelObjectType::File: return "file";
         case KernelObjectType::MemoryBlock: return "memory block";

include/services/fs.hpp

@@ -29,6 +29,7 @@ class FSService {
 
 	ArchiveBase* getArchiveFromID(u32 id);
 	std::optional<Handle> openArchiveHandle(u32 archiveID, const FSPath& path);
+	std::optional<Handle> openDirectoryHandle(ArchiveBase* archive, const FSPath& path);
 	std::optional<Handle> openFileHandle(ArchiveBase* archive, const FSPath& path, const FSPath& archivePath, const FilePerms& perms);
 	FSPath readPath(u32 type, u32 pointer, u32 size);
 
@@ -42,6 +43,7 @@ class FSService {
 	void initializeWithSdkVersion(u32 messagePointer);
 	void isSdmcDetected(u32 messagePointer);
 	void openArchive(u32 messagePointer);
+	void openDirectory(u32 messagePointer);
 	void openFile(u32 messagePointer);
 	void openFileDirectly(u32 messagePointer);
 	void setPriority(u32 messagePointer);

src/core/fs/archive_save_data.cpp

@@ -53,6 +53,29 @@ FileDescriptor SaveDataArchive::openFile(const FSPath& path, const FilePerms& pe
 	return FileError;
 }
 
+std::optional<DirectorySession> SaveDataArchive::openDirectory(const FSPath& path) {
+	if (!cartHasSaveData()) {
+		printf("Tried to open SaveData directory without save data\n");
+		return std::nullopt;
+	}
+
+	if (path.type == PathType::UTF16) {
+		if (!isPathSafe<PathType::UTF16>(path))
+			Helpers::panic("Unsafe path in SaveData::OpenDirectory");
+
+		fs::path p = IOFile::getAppData() / "SaveData";
+		p += fs::path(path.utf16_string).make_preferred();
+
+		if (fs::is_directory(p)) {
+			return DirectorySession(this, p);
+		} else {
+			Helpers::panic("Directory not found in SaveData::OpenDirectory");
+		}
+	}
+
+	Helpers::panic("SaveDataArchive::OpenDirectory: Unimplemented path type");
+	return std::nullopt;
+}
 
 ArchiveBase::FormatInfo SaveDataArchive::getFormatInfo(const FSPath& path) {
 	Helpers::panic("Unimplemented SaveData::GetFormatInfo");

src/core/services/fs.cpp

@@ -14,6 +14,7 @@ namespace FSCommands {
 		OpenFileDirectly = 0x08030204,
 		DeleteFile = 0x08040142,
 		CreateFile = 0x08080202,
+		OpenDirectory = 0x080B0102,
 		OpenArchive = 0x080C00C2,
 		CloseArchive = 0x080E0080,
 		IsSdmcDetected = 0x08170000,
@@ -66,7 +67,7 @@ ArchiveBase* FSService::getArchiveFromID(u32 id) {
 	}
 }
 
-std::optional<Handle> FSService::openFileHandle(ArchiveBase* archive, const FSPath& path, const FSPath& archivePath,const FilePerms& perms) {
+std::optional<Handle> FSService::openFileHandle(ArchiveBase* archive, const FSPath& path, const FSPath& archivePath, const FilePerms& perms) {
 	FileDescriptor opened = archive->openFile(path, perms);
 	if (opened.has_value()) { // If opened doesn't have a value, we failed to open the file
 		auto handle = kernel.makeObject(KernelObjectType::File);
@@ -80,6 +81,19 @@ std::optional<Handle> FSService::openFileHandle(ArchiveBase* archive, const FSPa
 	}
 }
 
+std::optional<Handle> FSService::openDirectoryHandle(ArchiveBase* archive, const FSPath& path) {
+	std::optional<DirectorySession> opened = archive->openDirectory(path);
+	if (opened.has_value()) { // If opened doesn't have a value, we failed to open the directory
+		auto handle = kernel.makeObject(KernelObjectType::Directory);
+		auto& object = kernel.getObjects()[handle];
+		object.data = new DirectorySession(opened.value());
+
+		return handle;
+	} else {
+		return std::nullopt;
+	}
+}
+
 std::optional<Handle> FSService::openArchiveHandle(u32 archiveID, const FSPath& path) {
 	ArchiveBase* archive = getArchiveFromID(archiveID);
 
@@ -123,8 +137,9 @@ void FSService::handleSyncRequest(u32 messagePointer) {
 		case FSCommands::InitializeWithSdkVersion: initializeWithSdkVersion(messagePointer); break;
 		case FSCommands::IsSdmcDetected: isSdmcDetected(messagePointer); break;
 		case FSCommands::OpenArchive: openArchive(messagePointer); break;
-		case FSCommands::OpenFile: openFile(messagePointer); break;
+		case FSCommands::OpenDirectory: openDirectory(messagePointer); break;
-		case FSCommands::OpenFileDirectly: openFileDirectly(messagePointer); break;
+		case FSCommands::OpenFile: [[likely]] openFile(messagePointer); break;
+		case FSCommands::OpenFileDirectly: [[likely]] openFileDirectly(messagePointer); break;
 		case FSCommands::SetPriority: setPriority(messagePointer); break;
 		default: Helpers::panic("FS service requested. Command: %08X\n", command);
 	}
@@ -210,6 +225,32 @@ void FSService::openFile(u32 messagePointer) {
 	}
 }
 
+void FSService::openDirectory(u32 messagePointer) {
+	log("FS::OpenDirectory\n");
+	const Handle archiveHandle = (Handle)mem.read64(messagePointer + 4);
+	const u32 pathType = mem.read32(messagePointer + 12);
+	const u32 pathSize = mem.read32(messagePointer + 16);
+	const u32 pathPointer = mem.read32(messagePointer + 24);
+
+	KernelObject* archiveObject = kernel.getObject(archiveHandle, KernelObjectType::Archive);
+	if (archiveObject == nullptr) [[unlikely]] {
+		log("FS::OpenDirectory: Invalid archive handle %d\n", archiveHandle);
+		mem.write32(messagePointer + 4, Result::Failure);
+		return;
+	}
+
+	ArchiveBase* archive = archiveObject->getData<ArchiveSession>()->archive;
+	const auto dirPath = readPath(pathType, pathPointer, pathSize);
+	std::optional<Handle> dir = openDirectoryHandle(archive, dirPath);
+
+	if (dir.has_value()) {
+		mem.write32(messagePointer + 4, Result::Success);
+		mem.write32(messagePointer + 12, dir.value());
+	} else {
+		Helpers::panic("FS::OpenDirectory failed");
+	}
+}
+
 void FSService::openFileDirectly(u32 messagePointer) {
 	const u32 archiveID = mem.read32(messagePointer + 8);
 	const u32 archivePathType = mem.read32(messagePointer + 12);
@@ -247,7 +288,7 @@ void FSService::openFileDirectly(u32 messagePointer) {
 }
 
 void FSService::createFile(u32 messagePointer) {
-	const u32 archiveHandle = mem.read64(messagePointer + 8);
+	const Handle archiveHandle = mem.read64(messagePointer + 8);
 	const u32 filePathType = mem.read32(messagePointer + 16);
 	const u32 filePathSize = mem.read32(messagePointer + 20);
 	const u32 attributes = mem.read32(messagePointer + 24);