ams_mitm: implement layeredfs

Makefile

@@ -16,7 +16,7 @@ include $(DEVKITPRO)/libnx/switch_rules
 # INCLUDES is a list of directories containing header files
 #---------------------------------------------------------------------------------
 TARGET		:=	$(notdir $(CURDIR))
-SOURCES		:=	source source/ams source/hos source/result source/os source/os/impl source/dd source/sf source/sf/cmif source/sf/hipc source/dmnt source/spl source/spl/smc source/updater source/patcher source/map source/rnd source/util source/sm source/cfg source/pm source/hid source/ldr source/kvdb source/settings source/boot2
+SOURCES		:=	source source/ams source/hos source/result source/os source/os/impl source/dd source/fs source/sf source/sf/cmif source/sf/hipc source/dmnt source/spl source/spl/smc source/updater source/patcher source/map source/rnd source/util source/sm source/cfg source/pm source/hid source/ldr source/kvdb source/settings source/boot2
 DATA		:=	data
 INCLUDES	:=  include
 

include/stratosphere/fs.hpp

@@ -22,4 +22,5 @@
 #include "fs/fs_remote_filesystem.hpp"
 #include "fs/fs_istorage.hpp"
 #include "fs/fs_remote_storage.hpp"
+#include "fs/fs_file_storage.hpp"
 #include "fs/fs_query_range.hpp"

include/stratosphere/fs/fs_file_storage.hpp

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2018-2019 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#include "fs_common.hpp"
+#include "fs_istorage.hpp"
+#include "fsa/fs_ifile.hpp"
+
+namespace ams::fs {
+
+    class FileStorage : public IStorage {
+        private:
+            static constexpr s64 InvalidSize = -1;
+        private:
+            std::unique_ptr<fsa::IFile> unique_file;
+            std::shared_ptr<fsa::IFile> shared_file;
+            fsa::IFile *base_file;
+            s64 size;
+        public:
+            FileStorage(fsa::IFile *f) : unique_file(f), size(InvalidSize) {
+                this->base_file = this->unique_file.get();
+            }
+
+            FileStorage(std::unique_ptr<fsa::IFile> f) : unique_file(std::move(f)), size(InvalidSize) {
+                this->base_file = this->unique_file.get();
+            }
+
+            FileStorage(std::shared_ptr<fsa::IFile> f) : shared_file(f), size(InvalidSize) {
+                this->base_file = this->shared_file.get();
+            }
+
+            virtual ~FileStorage() { /* ... */ }
+        protected:
+            Result UpdateSize();
+        public:
+            virtual Result Read(s64 offset, void *buffer, size_t size) override;
+            virtual Result Write(s64 offset, const void *buffer, size_t size) override;
+            virtual Result Flush() override;
+            virtual Result GetSize(s64 *out_size) override;
+            virtual Result SetSize(s64 size) override;
+            virtual Result OperateRange(void *dst, size_t dst_size, OperationId op_id, s64 offset, s64 size, const void *src, size_t src_size) override;
+    };
+
+}

source/fs/fs_file_storage.cpp

@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2018-2019 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stratosphere.hpp>
+
+namespace ams::fs {
+
+    Result FileStorage::UpdateSize() {
+        R_UNLESS(this->size == InvalidSize, ResultSuccess());
+        return this->base_file->GetSize(&this->size);
+    }
+
+    Result FileStorage::Read(s64 offset, void *buffer, size_t size) {
+        /* Immediately succeed if there's nothing to read. */
+        R_UNLESS(size > 0, ResultSuccess());
+
+        /* Validate buffer. */
+        R_UNLESS(buffer != nullptr, fs::ResultNullptrArgument());
+
+        /* Ensure our size is valid. */
+        R_TRY(this->UpdateSize());
+
+        /* Ensure our access is valid. */
+        R_UNLESS(IStorage::IsRangeValid(offset, size, this->size), fs::ResultOutOfRange());
+
+        size_t read_size;
+        return this->base_file->Read(&read_size, offset, buffer, size);
+    }
+
+    Result FileStorage::Write(s64 offset, const void *buffer, size_t size) {
+        /* Immediately succeed if there's nothing to write. */
+        R_UNLESS(size > 0, ResultSuccess());
+
+        /* Validate buffer. */
+        R_UNLESS(buffer != nullptr, fs::ResultNullptrArgument());
+
+        /* Ensure our size is valid. */
+        R_TRY(this->UpdateSize());
+
+        /* Ensure our access is valid. */
+        R_UNLESS(IStorage::IsRangeValid(offset, size, this->size), fs::ResultOutOfRange());
+
+        return this->base_file->Write(offset, buffer, size, fs::WriteOption());
+    }
+
+    Result FileStorage::Flush() {
+        return this->base_file->Flush();
+    }
+
+    Result FileStorage::GetSize(s64 *out_size) {
+        R_TRY(this->UpdateSize());
+        *out_size = this->size;
+        return ResultSuccess();
+    }
+
+    Result FileStorage::SetSize(s64 size) {
+        this->size = InvalidSize;
+        return this->base_file->SetSize(size);
+    }
+
+    Result FileStorage::OperateRange(void *dst, size_t dst_size, OperationId op_id, s64 offset, s64 size, const void *src, size_t src_size) {
+        switch (op_id) {
+            case OperationId::InvalidateCache:
+            case OperationId::QueryRange:
+                if (size == 0) {
+                    if (op_id == OperationId::QueryRange) {
+                        R_UNLESS(dst != nullptr,                     fs::ResultNullptrArgument());
+                        R_UNLESS(dst_size == sizeof(QueryRangeInfo), fs::ResultInvalidSize());
+                        reinterpret_cast<QueryRangeInfo *>(dst)->Clear();
+                    }
+                    return ResultSuccess();
+                }
+                R_TRY(this->UpdateSize());
+                R_UNLESS(IStorage::IsOffsetAndSizeValid(offset, size), fs::ResultOutOfRange());
+                return this->base_file->OperateRange(dst, dst_size, op_id, offset, size, src, src_size);
+            default:
+                return fs::ResultUnsupportedOperation();
+        }
+    }
+
+}