fs.mitm: experimental support for save redirection to sd.

common/defaults/system_settings.ini

@@ -15,4 +15,10 @@ dmnt_cheats_enabled_by_default = u8!0x1
 ; Controls whether dmnt should always save cheat toggle state
 ; for restoration on new game launch. 1 = always save toggles,
 ; 0 = only save toggles if toggle file exists.
-dmnt_always_save_cheat_toggles = u8!0x0
+dmnt_always_save_cheat_toggles = u8!0x0
+; Controls whether fs.mitm should redirect save files
+; to directories on the sd card.
+; 0 = Do not redirect, 1 = Redirect.
+; NOTE: EXPERIMENTAL
+; If you do not know what you are doing, do not touch this yet.
+fsmitm_redirect_saves_to_sd = u8!0x0

stratosphere/ams_mitm/source/fs_mitm/fs_dir_utils.cpp

@@ -60,20 +60,20 @@ Result FsDirUtils::CopyFile(IFileSystem *dst_fs, IFileSystem *src_fs, const FsPa
 
         offset += read_size;
     }
-    
+
     return ResultSuccess;
 }
 
 Result FsDirUtils::CopyDirectoryRecursively(IFileSystem *dst_fs, IFileSystem *src_fs, const FsPath &dst_path, const FsPath &src_path, void *work_buf, size_t work_buf_size) {
     FsPath work_path = dst_path;
 
-    return IterateDirectoryRecursively(src_fs, src_path, 
+    return IterateDirectoryRecursively(src_fs, src_path,
         [&](const FsPath &path, const FsDirectoryEntry *dir_ent) -> Result { /* On Enter Directory */
             /* Update path, create new dir. */
             strncat(work_path.str, dir_ent->name, sizeof(work_path) - strnlen(work_path.str, sizeof(work_path) - 1) - 1);
             strncat(work_path.str, "/", sizeof(work_path) - strnlen(work_path.str, sizeof(work_path) - 1) - 1);
             return dst_fs->CreateDirectory(work_path);
-        }, 
+        },
         [&](const FsPath &path, const FsDirectoryEntry *dir_ent) -> Result { /* On Exit Directory */
             /* Check we have a parent directory. */
             const size_t work_path_len = strnlen(work_path.str, sizeof(work_path));
@@ -89,9 +89,45 @@ Result FsDirUtils::CopyDirectoryRecursively(IFileSystem *dst_fs, IFileSystem *sr
             p[1] = 0;
 
             return ResultSuccess;
-        }, 
+        },
         [&](const FsPath &path, const FsDirectoryEntry *dir_ent) -> Result { /* On File */
             /* Just copy the file to the new fs. */
             return CopyFile(dst_fs, src_fs, work_path, path, dir_ent, work_buf, work_buf_size);
         });
-}
+}
+
+Result FsDirUtils::EnsureDirectoryExists(IFileSystem *fs, const FsPath &path) {
+    FsPath normal_path;
+    size_t normal_path_len;
+    Result rc;
+
+    /* Normalize the path. */
+    if (R_FAILED((rc = FsPathUtils::Normalize(normal_path.str, sizeof(normal_path.str) - 1, path.str, &normal_path_len)))) {
+        return rc;
+    }
+
+    /* Repeatedly call CreateDirectory on each directory leading to the target. */
+    for (size_t i = 1; i < normal_path_len; i++) {
+        /* If we detect a separator, we're done. */
+        if (normal_path.str[i] == '/') {
+            normal_path.str[i] = 0;
+            {
+                rc = fs->CreateDirectory(normal_path);
+                if (rc == ResultFsPathAlreadyExists) {
+                    rc = ResultSuccess;
+                }
+                if (R_FAILED(rc)) {
+                    return rc;
+                }
+            }
+            normal_path.str[i] = '/';
+        }
+    }
+
+    /* Call CreateDirectory on the final path. */
+    rc = fs->CreateDirectory(normal_path);
+    if (rc == ResultFsPathAlreadyExists) {
+        rc = ResultSuccess;
+    }
+    return rc;
+}

stratosphere/ams_mitm/source/fs_mitm/fs_dir_utils.hpp

@@ -132,6 +132,9 @@ class FsDirUtils {
         static Result CopyDirectoryRecursively(IFileSystem *fs, const FsPath &dst_path, const FsPath &src_path, void *work_buf, size_t work_buf_size) {
             return CopyDirectoryRecursively(fs, fs, dst_path, src_path, work_buf, work_buf_size);
         }
+        
+        /* Ensure directory existence. */
+        static Result EnsureDirectoryExists(IFileSystem *fs, const FsPath &path);
 
         /* Other Utility. */
         template<typename F>

stratosphere/ams_mitm/source/fs_mitm/fs_directory_savedata_filesystem.cpp

@@ -166,6 +166,27 @@ void DirectorySaveDataFileSystem::OnWritableFileClose() {
     /* TODO: Abort if < 0? N does not. */
 }
 
+Result DirectorySaveDataFileSystem::CopySaveFromProxy() {
+    if (this->proxy_save_fs != nullptr) {
+        Result rc;
+
+        /* Get a buffer to work with. */
+        void *work_buf = nullptr;
+        size_t work_buf_size = 0;
+        if (R_FAILED((rc = this->AllocateWorkBuffer(&work_buf, &work_buf_size, IdealWorkBuffersize)))) {
+            return rc;
+        }
+        ON_SCOPE_EXIT { free(work_buf); };
+
+        rc = FsDirUtils::CopyDirectoryRecursively(this, this->proxy_save_fs.get(), FsPathUtils::RootPath, FsPathUtils::RootPath, work_buf, work_buf_size);
+        if (R_FAILED(rc)) {
+            return rc;
+        }
+        return this->Commit();
+    }
+    return ResultSuccess;
+}
+
 /* ================================================================================================ */
 
 Result DirectorySaveDataFileSystem::CreateFileImpl(const FsPath &path, uint64_t size, int flags) {

stratosphere/ams_mitm/source/fs_mitm/fs_directory_savedata_filesystem.hpp

@@ -35,12 +35,13 @@ class DirectorySaveDataFileSystem : public IFileSystem {
     private:
         std::shared_ptr<IFileSystem> shared_fs;
         std::unique_ptr<IFileSystem> unique_fs;
+        std::unique_ptr<IFileSystem> proxy_save_fs;
         IFileSystem *fs;
         HosMutex lock;
         size_t open_writable_files = 0;
 
     public:
-        DirectorySaveDataFileSystem(IFileSystem *fs) : unique_fs(fs) {
+        DirectorySaveDataFileSystem(IFileSystem *fs, std::unique_ptr<IFileSystem> pfs) : unique_fs(fs), proxy_save_fs(std::move(pfs)) {
             this->fs = this->unique_fs.get();
             Result rc = this->Initialize();
             if (R_FAILED(rc)) {
@@ -48,7 +49,7 @@ class DirectorySaveDataFileSystem : public IFileSystem {
             }
         }
 
-        DirectorySaveDataFileSystem(std::unique_ptr<IFileSystem> fs) : unique_fs(std::move(fs)) {
+        DirectorySaveDataFileSystem(std::unique_ptr<IFileSystem> fs, std::unique_ptr<IFileSystem> pfs) : unique_fs(std::move(fs)), proxy_save_fs(std::move(pfs)) {
             this->fs = this->unique_fs.get();
             Result rc = this->Initialize();
             if (R_FAILED(rc)) {
@@ -56,7 +57,7 @@ class DirectorySaveDataFileSystem : public IFileSystem {
             }
         }
 
-        DirectorySaveDataFileSystem(std::shared_ptr<IFileSystem> fs) : shared_fs(fs) {
+        DirectorySaveDataFileSystem(std::shared_ptr<IFileSystem> fs, std::unique_ptr<IFileSystem> pfs) : shared_fs(fs), proxy_save_fs(std::move(pfs)) {
             this->fs = this->shared_fs.get();
             Result rc = this->Initialize();
             if (R_FAILED(rc)) {
@@ -64,7 +65,6 @@ class DirectorySaveDataFileSystem : public IFileSystem {
             }
         }
 
-
         virtual ~DirectorySaveDataFileSystem() { }
 
     private:
@@ -79,6 +79,7 @@ class DirectorySaveDataFileSystem : public IFileSystem {
         }
     public:
         void OnWritableFileClose();
+        Result CopySaveFromProxy();
     public:
         virtual Result CreateFileImpl(const FsPath &path, uint64_t size, int flags) override;
         virtual Result DeleteFileImpl(const FsPath &path) override;

stratosphere/ams_mitm/source/fs_mitm/fs_ifilesystem.hpp

@@ -198,13 +198,18 @@ class IFileSystem {
 
 class IFileSystemInterface : public IServiceObject {
     private:
-        std::unique_ptr<IFileSystem> base_fs;
+        std::unique_ptr<IFileSystem> unique_fs;
+        std::shared_ptr<IFileSystem> shared_fs;
+        IFileSystem *base_fs;
     public:
-        IFileSystemInterface(IFileSystem *fs) : base_fs(fs) {
+        IFileSystemInterface(IFileSystem *fs) : unique_fs(fs) {
-            /* ... */
+            this->base_fs = this->unique_fs.get();
         };
-        IFileSystemInterface(std::unique_ptr<IFileSystem> fs) : base_fs(std::move(fs)) {
+        IFileSystemInterface(std::unique_ptr<IFileSystem> fs) : unique_fs(std::move(fs)) {
-            /* ... */
+            this->base_fs = this->unique_fs.get();
+        };
+        IFileSystemInterface(std::shared_ptr<IFileSystem> fs) : shared_fs(fs) {
+            this->base_fs = this->shared_fs.get();
         };
 
     private:

stratosphere/ams_mitm/source/fs_mitm/fs_save_utils.cpp

@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2018 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 <cstring>
+#include <cstdlib>
+#include <switch.h>
+
+#include "fs_save_utils.hpp"
+
+Result FsSaveUtils::GetSaveDataSpaceIdString(const char **out_str, u8 space_id) {
+    const char *str = nullptr;
+
+    switch (space_id) {
+        case FsSaveDataSpaceId_NandSystem:
+        case 100: /* ProperSystem */
+        case 101: /* SafeMode */
+            str = "sys";
+            break;
+        case FsSaveDataSpaceId_NandUser:
+            str = "user";
+            break;
+        case FsSaveDataSpaceId_SdCard:
+            str = "sd_sys";
+            break;
+        case FsSaveDataSpaceId_TemporaryStorage:
+            str = "temp";
+            break;
+        case 4: /* SdUser */
+            str = "sd_user";
+            break;
+        default: /* Unexpected */
+            str = nullptr;
+            break;
+    }
+
+    if (str == nullptr) {
+        return ResultFsInvalidSaveDataSpaceId;
+    }
+
+    if (out_str) {
+        *out_str = str;
+    }
+
+    return ResultSuccess;
+}
+
+Result FsSaveUtils::GetSaveDataTypeString(const char **out_str, u8 save_data_type) {
+    const char *str = nullptr;
+
+    switch (save_data_type) {
+        case FsSaveDataType_SystemSaveData:
+            str = "system";
+            break;
+        case FsSaveDataType_SaveData:
+            str = "account";
+            break;
+        case FsSaveDataType_BcatDeliveryCacheStorage:
+            str = "bcat";
+            break;
+        case FsSaveDataType_DeviceSaveData:
+            str = "device";
+            break;
+        case FsSaveDataType_TemporaryStorage:
+            str = "temp";
+            break;
+        case FsSaveDataType_CacheStorage:
+            str = "cache";
+            break;
+        case 6: /* System Bcat Save */
+            str = "bcat_sys";
+            break;
+        default: /* Unexpected */
+            str = nullptr;
+            break;
+    }
+
+    if (str == nullptr) {
+        /* TODO: Better result? */
+        return ResultFsInvalidArgument;
+    }
+
+    if (out_str) {
+        *out_str = str;
+    }
+
+    return ResultSuccess;
+}
+
+Result FsSaveUtils::GetSaveDataDirectoryPath(FsPath &out_path, u8 space_id, u8 save_data_type, u64 title_id, u128 user_id, u64 save_id) {
+    const char *space_id_str, *save_type_str;
+    Result rc;
+
+    /* Get space_id, save_data_type strings. */
+    if (R_FAILED((rc = GetSaveDataSpaceIdString(&space_id_str, space_id))) || R_FAILED((rc = GetSaveDataTypeString(&save_type_str, save_data_type)))) {
+        return rc;
+    }
+
+    /* Clear and initialize the path. */
+    std::memset(&out_path, 0, sizeof(out_path));
+    const bool is_system = (save_id != 0 && user_id == 0);
+    size_t out_path_len;
+    if (is_system) {
+        out_path_len = static_cast<size_t>(snprintf(out_path.str, sizeof(out_path.str), "/atmosphere/saves/sysnand/%s/%s/%016lx",
+                                                    space_id_str, save_type_str, save_id));
+    } else {
+        out_path_len = static_cast<size_t>(snprintf(out_path.str, sizeof(out_path.str), "/atmosphere/saves/sysnand/%s/%s/%016lx/%016lx%016lx",
+                                                    space_id_str, save_type_str, title_id, static_cast<u64>(user_id >> 64ul), static_cast<u64>(user_id)));
+    }
+    if (out_path_len >= sizeof(out_path)) {
+        /* TODO: Should we abort here? */
+        return ResultFsTooLongPath;
+    }
+
+    return ResultSuccess;
+}

stratosphere/ams_mitm/source/fs_mitm/fs_save_utils.hpp

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2018 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 <switch.h>
+
+#include "fs_path_utils.hpp"
+#include "fs_ifilesystem.hpp"
+
+class FsSaveUtils {
+    private:
+        static Result GetSaveDataSpaceIdString(const char **out_str, u8 space_id);
+        static Result GetSaveDataTypeString(const char **out_str, u8 save_data_type);
+    public:
+        static Result GetSaveDataDirectoryPath(FsPath &out_path, u8 space_id, u8 save_data_type, u64 title_id, u128 user_id, u64 save_id);
+};

stratosphere/ams_mitm/source/fs_mitm/fs_shim.c

@@ -225,6 +225,46 @@ Result fsOpenFileSystemWithIdFwd(Service* s, FsFileSystem* out, u64 titleId, FsF
     return rc;
 }
 
+Result fsOpenSaveDataFileSystemFwd(Service *s, FsFileSystem* out, u8 inval, FsSave *save) {
+    IpcCommand c;
+    ipcInitialize(&c);
+
+    struct {
+        u64 magic;
+        u64 cmd_id;
+        u64 inval;//Actually u8.
+        FsSave save;
+    } PACKED *raw;
+
+    raw = serviceIpcPrepareHeader(s, &c, sizeof(*raw));
+
+    raw->magic = SFCI_MAGIC;
+    raw->cmd_id = 51;
+    raw->inval = (u64)inval;
+    memcpy(&raw->save, save, sizeof(FsSave));
+
+    Result rc = serviceIpcDispatch(s);
+
+    if (R_SUCCEEDED(rc)) {
+        IpcParsedCommand r;
+        struct {
+            u64 magic;
+            u64 result;
+        } *resp;
+
+        serviceIpcParse(s, &r, sizeof(*resp));
+        resp = r.Raw;
+
+        rc = resp->result;
+
+        if (R_SUCCEEDED(rc)) {
+            serviceCreateSubservice(&out->s, s, &r, 0);
+        }
+    }
+
+    return rc;
+}
+
 /* Missing FS File commands. */
 Result fsFileOperateRange(FsFile* f, u32 op_id, u64 off, u64 len, FsRangeInfo *out) {
     IpcCommand c;

stratosphere/ams_mitm/source/fs_mitm/fs_shim.h

@@ -22,6 +22,7 @@ Result fsOpenDataStorageByCurrentProcessFwd(Service* s, FsStorage* out);
 Result fsOpenDataStorageByDataIdFwd(Service* s, FsStorageId storage_id, u64 data_id, FsStorage* out);
 Result fsOpenFileSystemWithPatchFwd(Service* s, FsFileSystem* out, u64 titleId, FsFileSystemType fsType);
 Result fsOpenFileSystemWithIdFwd(Service* s, FsFileSystem* out, u64 titleId, FsFileSystemType fsType, const char* contentPath);
+Result fsOpenSaveDataFileSystemFwd(Service* s, FsFileSystem* out, u8 inval, FsSave *save);
 
 /* Missing FS File commands. */
 Result fsFileOperateRange(FsFile* f, u32 op_id, u64 off, u64 len, FsRangeInfo *out);

stratosphere/ams_mitm/source/fs_mitm/fsmitm_service.cpp

@@ -13,7 +13,7 @@
  * 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 <map>
 #include <memory>
 #include <mutex>
@@ -28,6 +28,8 @@
 #include "fsmitm_romstorage.hpp"
 #include "fsmitm_layeredrom.hpp"
 
+#include "fs_dir_utils.hpp"
+#include "fs_save_utils.hpp"
 #include "fs_subdirectory_filesystem.hpp"
 #include "fs_directory_savedata_filesystem.hpp"
 
@@ -41,7 +43,7 @@ static bool StorageCacheGetEntry(u64 title_id, std::shared_ptr<IStorageInterface
     if (g_StorageCache.find(title_id) == g_StorageCache.end()) {
         return false;
     }
-    
+
     auto intf = g_StorageCache[title_id].lock();
     if (intf != nullptr) {
         *out = intf;
@@ -52,7 +54,7 @@ static bool StorageCacheGetEntry(u64 title_id, std::shared_ptr<IStorageInterface
 
 static void StorageCacheSetEntry(u64 title_id, std::shared_ptr<IStorageInterface> *ptr) {
     std::scoped_lock<HosMutex> lock(g_StorageCacheLock);
-    
+
     /* Ensure we always use the cached copy if present. */
     if (g_StorageCache.find(title_id) != g_StorageCache.end()) {
         auto intf = g_StorageCache[title_id].lock();
@@ -60,7 +62,7 @@ static void StorageCacheSetEntry(u64 title_id, std::shared_ptr<IStorageInterface
             *ptr = intf;
         }
     }
-    
+
     g_StorageCache[title_id] = *ptr;
 }
 
@@ -87,7 +89,7 @@ Result FsMitmService::OpenHblWebContentFileSystem(Out<std::shared_ptr<IFileSyste
     std::shared_ptr<IFileSystemInterface> fs = nullptr;
     u32 out_domain_id = 0;
     Result rc = ResultSuccess;
-    
+
     ON_SCOPE_EXIT {
         if (R_SUCCEEDED(rc)) {
             out_fs.SetValue(std::move(fs));
@@ -96,12 +98,13 @@ Result FsMitmService::OpenHblWebContentFileSystem(Out<std::shared_ptr<IFileSyste
             }
         }
     };
-    
+
     /* Mount the SD card using fs.mitm's session. */
     FsFileSystem sd_fs;
     rc = fsMountSdcard(&sd_fs);
     if (R_SUCCEEDED(rc)) {
-        fs = std::make_shared<IFileSystemInterface>(std::make_unique<SubDirectoryFileSystem>(std::make_shared<ProxyFileSystem>(sd_fs), AtmosphereHblWebContentDir));
+        std::unique_ptr<IFileSystem> web_ifs = std::make_unique<SubDirectoryFileSystem>(std::make_shared<ProxyFileSystem>(sd_fs), AtmosphereHblWebContentDir);
+        fs = std::make_shared<IFileSystemInterface>(std::move(web_ifs));
         if (out_fs.IsDomain()) {
             out_domain_id = sd_fs.s.object_id;
         }
@@ -130,7 +133,7 @@ Result FsMitmService::OpenFileSystemWithPatch(Out<std::shared_ptr<IFileSystemInt
             return ResultAtmosphereMitmShouldForwardToSession;
         }
     }
-    
+
     return this->OpenHblWebContentFileSystem(out_fs);
 }
 
@@ -138,7 +141,7 @@ Result FsMitmService::OpenFileSystemWithId(Out<std::shared_ptr<IFileSystemInterf
     /* Check for eligibility. */
     {
         FsDir d;
-        if (!Utils::IsWebAppletTid(this->title_id) || filesystem_type != FsFileSystemType_ContentManual || !Utils::IsHblTid(title_id) || 
+        if (!Utils::IsWebAppletTid(this->title_id) || filesystem_type != FsFileSystemType_ContentManual || !Utils::IsHblTid(title_id) ||
             R_FAILED(Utils::OpenSdDir(AtmosphereHblWebContentDir, &d))) {
             return ResultAtmosphereMitmShouldForwardToSession;
         }
@@ -158,12 +161,90 @@ Result FsMitmService::OpenFileSystemWithId(Out<std::shared_ptr<IFileSystemInterf
     return this->OpenHblWebContentFileSystem(out_fs);
 }
 
+Result FsMitmService::OpenSaveDataFileSystem(Out<std::shared_ptr<IFileSystemInterface>> out_fs, u8 space_id, FsSave save_struct) {
+    bool should_redirect_saves = false;
+    if (R_FAILED(Utils::GetSettingsItemBooleanValue("atmosphere", "fsmitm_redirect_saves_to_sd", &should_redirect_saves))) {
+        return ResultAtmosphereMitmShouldForwardToSession;
+    }
+
+    /* For now, until we're sure this is robust, only intercept normal savedata. */
+    if (!should_redirect_saves || save_struct.SaveDataType != FsSaveDataType_SaveData) {
+        return ResultAtmosphereMitmShouldForwardToSession;
+    }
+
+    /* Verify we can open the save. */
+    FsFileSystem save_fs;
+    if (R_FAILED(fsOpenSaveDataFileSystemFwd(this->forward_service.get(), &save_fs, space_id, &save_struct))) {
+        return ResultAtmosphereMitmShouldForwardToSession;
+    }
+    std::unique_ptr<IFileSystem> save_ifs = std::make_unique<ProxyFileSystem>(save_fs);
+
+    {
+        std::shared_ptr<IFileSystemInterface> fs = nullptr;
+        u32 out_domain_id = 0;
+        Result rc = ResultSuccess;
+
+        ON_SCOPE_EXIT {
+            if (R_SUCCEEDED(rc)) {
+                out_fs.SetValue(std::move(fs));
+                if (out_fs.IsDomain()) {
+                    out_fs.ChangeObjectId(out_domain_id);
+                }
+            }
+        };
+
+        /* Mount the SD card using fs.mitm's session. */
+        FsFileSystem sd_fs;
+        if (R_FAILED((rc = fsMountSdcard(&sd_fs)))) {
+            return rc;
+        }
+        std::shared_ptr<IFileSystem> sd_ifs = std::make_shared<ProxyFileSystem>(sd_fs);
+
+
+        /* Verify that we can open the save directory, and that it exists. */
+        const u64 target_tid = save_struct.titleID == 0 ? this->title_id : save_struct.titleID;
+        FsPath save_dir_path;
+        if (R_FAILED((rc = FsSaveUtils::GetSaveDataDirectoryPath(save_dir_path, space_id, save_struct.SaveDataType, target_tid, save_struct.userID, save_struct.saveID)))) {
+            return rc;
+        }
+
+        /* Check if this is the first time we're making the save. */
+        bool is_new_save = false;
+        {
+            DirectoryEntryType ent;
+            if (sd_ifs->GetEntryType(&ent, save_dir_path) == ResultFsPathNotFound) {
+                is_new_save = true;
+            }
+        }
+
+        /* Ensure the directory exists. */
+        if (R_FAILED((rc = FsDirUtils::EnsureDirectoryExists(sd_ifs.get(), save_dir_path)))) {
+            return rc;
+        }
+
+        std::shared_ptr<DirectorySaveDataFileSystem> dirsave_ifs = std::make_shared<DirectorySaveDataFileSystem>(new SubDirectoryFileSystem(sd_ifs, save_dir_path.str), std::move(save_ifs));
+
+        /* If it's the first time we're making the save, copy existing savedata over. */
+        if (is_new_save) {
+            /* TODO: Check error? */
+            dirsave_ifs->CopySaveFromProxy();
+        }
+
+        fs = std::make_shared<IFileSystemInterface>(static_cast<std::shared_ptr<IFileSystem>>(dirsave_ifs));
+        if (out_fs.IsDomain()) {
+            out_domain_id = sd_fs.s.object_id;
+        }
+
+        return rc;
+    }
+}
+
 /* Gate access to the BIS partitions. */
 Result FsMitmService::OpenBisStorage(Out<std::shared_ptr<IStorageInterface>> out_storage, u32 bis_partition_id) {
     std::shared_ptr<IStorageInterface> storage = nullptr;
     u32 out_domain_id = 0;
     Result rc = ResultSuccess;
-    
+
     ON_SCOPE_EXIT {
         if (R_SUCCEEDED(rc)) {
             out_storage.SetValue(std::move(storage));
@@ -172,7 +253,7 @@ Result FsMitmService::OpenBisStorage(Out<std::shared_ptr<IStorageInterface>> out
             }
         }
     };
-    
+
     {
         FsStorage bis_storage;
         rc = fsOpenBisStorageFwd(this->forward_service.get(), &bis_storage, bis_partition_id);
@@ -195,7 +276,7 @@ Result FsMitmService::OpenBisStorage(Out<std::shared_ptr<IStorageInterface>> out
                 if (is_sysmodule || has_bis_write_flag) {
                     /* Sysmodules should still be allowed to read and write. */
                     storage = std::make_shared<IStorageInterface>(new ProxyStorage(bis_storage));
-                } else if (Utils::IsHblTid(this->title_id) && 
+                } else if (Utils::IsHblTid(this->title_id) &&
                     ((BisStorageId_BcPkg2_1 <= bis_partition_id && bis_partition_id <= BisStorageId_BcPkg2_6) || bis_partition_id == BisStorageId_Boot1)) {
                     /* Allow HBL to write to boot1 (safe firm) + package2. */
                     /* This is needed to not break compatibility with ChoiDujourNX, which does not check for write access before beginning an update. */
@@ -211,7 +292,7 @@ Result FsMitmService::OpenBisStorage(Out<std::shared_ptr<IStorageInterface>> out
             }
         }
     }
-    
+
     return rc;
 }
 
@@ -220,27 +301,27 @@ Result FsMitmService::OpenDataStorageByCurrentProcess(Out<std::shared_ptr<IStora
     std::shared_ptr<IStorageInterface> storage = nullptr;
     u32 out_domain_id = 0;
     Result rc = ResultSuccess;
-    
+
     if (!this->should_override_contents) {
         return ResultAtmosphereMitmShouldForwardToSession;
     }
-    
+
     bool has_cache = StorageCacheGetEntry(this->title_id, &storage);
-    
+
     ON_SCOPE_EXIT {
         if (R_SUCCEEDED(rc)) {
             if (!has_cache) {
                 StorageCacheSetEntry(this->title_id, &storage);
             }
-            
+
             out_storage.SetValue(std::move(storage));
             if (out_storage.IsDomain()) {
                 out_storage.ChangeObjectId(out_domain_id);
             }
         }
     };
-    
+
-    
+
     if (has_cache) {
         if (out_storage.IsDomain()) {
             FsStorage s = {0};
@@ -257,7 +338,7 @@ Result FsMitmService::OpenDataStorageByCurrentProcess(Out<std::shared_ptr<IStora
     } else {
         FsStorage data_storage;
         FsFile data_file;
-        
+
         rc = fsOpenDataStorageByCurrentProcessFwd(this->forward_service.get(), &data_storage);
 
         Log(armGetTls(), 0x100);
@@ -279,7 +360,7 @@ Result FsMitmService::OpenDataStorageByCurrentProcess(Out<std::shared_ptr<IStora
             }
         }
     }
-    
+
     return rc;
 }
 
@@ -288,30 +369,30 @@ Result FsMitmService::OpenDataStorageByDataId(Out<std::shared_ptr<IStorageInterf
     FsStorageId storage_id = (FsStorageId)sid;
     FsStorage data_storage;
     FsFile data_file;
-    
+
     if (!this->should_override_contents) {
         return ResultAtmosphereMitmShouldForwardToSession;
     }
-        
+
     std::shared_ptr<IStorageInterface> storage = nullptr;
     u32 out_domain_id = 0;
     Result rc = ResultSuccess;
-    
+
     bool has_cache = StorageCacheGetEntry(data_id, &storage);
-    
+
     ON_SCOPE_EXIT {
         if (R_SUCCEEDED(rc)) {
             if (!has_cache) {
                 StorageCacheSetEntry(data_id, &storage);
             }
-            
+
             out_storage.SetValue(std::move(storage));
             if (out_storage.IsDomain()) {
                 out_storage.ChangeObjectId(out_domain_id);
             }
         }
     };
-    
+
     if (has_cache) {
         if (out_storage.IsDomain()) {
             FsStorage s = {0};
@@ -346,6 +427,6 @@ Result FsMitmService::OpenDataStorageByDataId(Out<std::shared_ptr<IStorageInterf
             }
         }
     }
-    
+
     return rc;
 }

stratosphere/ams_mitm/source/fs_mitm/fsmitm_service.hpp

@@ -13,7 +13,7 @@
  * 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 <switch.h>
 #include <stratosphere.hpp>
@@ -23,12 +23,14 @@
 
 enum FspSrvCmd : u32 {
     FspSrvCmd_OpenFileSystemDeprecated = 0,
-    
+
     FspSrvCmd_SetCurrentProcess = 1,
-    
+
     FspSrvCmd_OpenFileSystemWithPatch = 7,
     FspSrvCmd_OpenFileSystemWithId = 8,
-    
+
+    FspSrvCmd_OpenSaveDataFileSystem = 51,
+
     FspSrvCmd_OpenBisStorage = 12,
     FspSrvCmd_OpenDataStorageByCurrentProcess = 200,
     FspSrvCmd_OpenDataStorageByDataId = 202,
@@ -48,13 +50,13 @@ class FsMitmService : public IMitmServiceObject {
                 this->should_override_contents = (this->title_id >= TitleId_ApplicationStart || Utils::HasSdMitMFlag(this->title_id)) && Utils::HasOverrideButton(this->title_id);
             }
         }
-        
+
         static bool ShouldMitm(u64 pid, u64 tid) {
             /* Don't Mitm KIPs */
             if (pid < 0x50) {
                 return false;
             }
-            
+
             static std::atomic_bool has_launched_qlaunch = false;
 
             /* TODO: intercepting everything seems to cause issues with sleep mode, for some reason. */
@@ -62,10 +64,10 @@ class FsMitmService : public IMitmServiceObject {
             if (tid == TitleId_AppletQlaunch) {
                 has_launched_qlaunch = true;
             }
-            
+
             return has_launched_qlaunch || tid == TitleId_Ns || tid >= TitleId_ApplicationStart || Utils::HasSdMitMFlag(tid);
         }
-        
+
         static void PostProcess(IMitmServiceObject *obj, IpcResponseContext *ctx);
     private:
         Result OpenHblWebContentFileSystem(Out<std::shared_ptr<IFileSystemInterface>> &out);
@@ -73,6 +75,7 @@ class FsMitmService : public IMitmServiceObject {
         /* Overridden commands. */
         Result OpenFileSystemWithPatch(Out<std::shared_ptr<IFileSystemInterface>> out, u64 title_id, u32 filesystem_type);
         Result OpenFileSystemWithId(Out<std::shared_ptr<IFileSystemInterface>> out, InPointer<char> path, u64 title_id, u32 filesystem_type);
+        Result OpenSaveDataFileSystem(Out<std::shared_ptr<IFileSystemInterface>> out, u8 space_id, FsSave save_struct);
         Result OpenBisStorage(Out<std::shared_ptr<IStorageInterface>> out, u32 bis_partition_id);
         Result OpenDataStorageByCurrentProcess(Out<std::shared_ptr<IStorageInterface>> out);
         Result OpenDataStorageByDataId(Out<std::shared_ptr<IStorageInterface>> out, u64 data_id, u8 storage_id);
@@ -81,6 +84,7 @@ class FsMitmService : public IMitmServiceObject {
             /* TODO MakeServiceCommandMeta<FspSrvCmd_OpenFileSystemDeprecated, &FsMitmService::OpenFileSystemDeprecated>(), */
             MakeServiceCommandMeta<FspSrvCmd_OpenFileSystemWithPatch, &FsMitmService::OpenFileSystemWithPatch, FirmwareVersion_200>(),
             MakeServiceCommandMeta<FspSrvCmd_OpenFileSystemWithId, &FsMitmService::OpenFileSystemWithId, FirmwareVersion_200>(),
+            MakeServiceCommandMeta<FspSrvCmd_OpenSaveDataFileSystem, &FsMitmService::OpenSaveDataFileSystem>(),
             MakeServiceCommandMeta<FspSrvCmd_OpenBisStorage, &FsMitmService::OpenBisStorage>(),
             MakeServiceCommandMeta<FspSrvCmd_OpenDataStorageByCurrentProcess, &FsMitmService::OpenDataStorageByCurrentProcess>(),
             MakeServiceCommandMeta<FspSrvCmd_OpenDataStorageByDataId, &FsMitmService::OpenDataStorageByDataId>(),

stratosphere/ams_mitm/source/utils.cpp

@@ -640,3 +640,15 @@ Result Utils::GetSettingsItemValueSize(const char *name, const char *key, u64 *o
 Result Utils::GetSettingsItemValue(const char *name, const char *key, void *out, size_t max_size, u64 *out_size) {
     return SettingsItemManager::GetValue(name, key, out, max_size, out_size);
 }
+
+Result Utils::GetSettingsItemBooleanValue(const char *name, const char *key, bool *out) {
+    u8 val = 0;
+    u64 out_size;
+    Result rc = Utils::GetSettingsItemValue(name, key, &val, sizeof(val), &out_size);
+    if (R_SUCCEEDED(rc)) {
+        if (out) {
+            *out = val != 0;
+        }
+    }
+    return rc;
+}

stratosphere/ams_mitm/source/utils.hpp

@@ -13,7 +13,7 @@
  * 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 <switch.h>
 #include <stratosphere.hpp>
@@ -46,45 +46,47 @@ class Utils {
     public:
         static bool IsSdInitialized();
         static void WaitSdInitialized();
-        
+
         static Result OpenSdFile(const char *fn, int flags, FsFile *out);
         static Result OpenSdFileForAtmosphere(u64 title_id, const char *fn, int flags, FsFile *out);
         static Result OpenRomFSSdFile(u64 title_id, const char *fn, int flags, FsFile *out);
         static Result OpenSdDir(const char *path, FsDir *out);
         static Result OpenSdDirForAtmosphere(u64 title_id, const char *path, FsDir *out);
-        static Result OpenRomFSSdDir(u64 title_id, const char *path, FsDir *out);        
+        static Result OpenRomFSSdDir(u64 title_id, const char *path, FsDir *out);
-        
+
         static Result OpenRomFSFile(FsFileSystem *fs, u64 title_id, const char *fn, int flags, FsFile *out);
         static Result OpenRomFSDir(FsFileSystem *fs, u64 title_id, const char *path, FsDir *out);
-        
+
         static Result SaveSdFileForAtmosphere(u64 title_id, const char *fn, void *data, size_t size);
-        
+
         static bool HasSdRomfsContent(u64 title_id);
-        
+
         /* Delayed Initialization + MitM detection. */
         static void InitializeThreadFunc(void *args);
-        
+
         static bool IsHblTid(u64 tid);
         static bool IsWebAppletTid(u64 tid);
-        
+
         static bool HasTitleFlag(u64 tid, const char *flag);
         static bool HasHblFlag(const char *flag);
         static bool HasGlobalFlag(const char *flag);
         static bool HasFlag(u64 tid, const char *flag);
-        
+
         static bool HasSdMitMFlag(u64 tid);
         static bool HasSdDisableMitMFlag(u64 tid);
-        
+
-        
+
         static bool IsHidAvailable();
         static Result GetKeysHeld(u64 *keys);
-        
+
         static OverrideKey GetTitleOverrideKey(u64 tid);
         static bool HasOverrideButton(u64 tid);
-        
+
         /* Settings! */
         static Result GetSettingsItemValueSize(const char *name, const char *key, u64 *out_size);
         static Result GetSettingsItemValue(const char *name, const char *key, void *out, size_t max_size, u64 *out_size);
+
+        static Result GetSettingsItemBooleanValue(const char *name, const char *key, bool *out);
     private:
         static void RefreshConfiguration();
 };

stratosphere/libstratosphere

@@ -1 +1 @@
-Subproject commit b6ca2d89ae5106ea21454f332f07076159ad2e92
+Subproject commit 8021b07eb82b9941c1820b211bbe6d898589e59b