From 8e50d6002bd12dde7e4ba4fd3da1b53864c4058c Mon Sep 17 00:00:00 2001
From: bunnei <bunneidev@gmail.com>
Date: Sat, 20 Jan 2018 21:32:36 -0500
Subject: fsp_srv: Various improvements to IStorage:Read implementation.

---
 src/core/hle/service/filesystem/fsp_srv.cpp | 92 +++++++++++++++--------------
 1 file changed, 49 insertions(+), 43 deletions(-)

(limited to 'src/core/hle/service/filesystem/fsp_srv.cpp')

diff --git a/src/core/hle/service/filesystem/fsp_srv.cpp b/src/core/hle/service/filesystem/fsp_srv.cpp
index 47a97f0fd..ef1915e5a 100644
--- a/src/core/hle/service/filesystem/fsp_srv.cpp
+++ b/src/core/hle/service/filesystem/fsp_srv.cpp
@@ -20,9 +20,8 @@ public:
     IStorage(std::unique_ptr<FileSys::StorageBackend>&& backend)
         : ServiceFramework("IStorage"), backend(std::move(backend)) {
         static const FunctionInfo functions[] = {
-            {0, &IStorage::Read, "Read"},       {1, &IStorage::Write, "Write"},
-            {2, &IStorage::Flush, "Flush"},     {3, &IStorage::SetSize, "SetSize"},
-            {4, &IStorage::GetSize, "GetSize"},
+            {0, &IStorage::Read, "Read"}, {1, nullptr, "Write"},   {2, nullptr, "Flush"},
+            {3, nullptr, "SetSize"},      {4, nullptr, "GetSize"},
         };
         RegisterHandlers(functions);
     }
@@ -32,49 +31,40 @@ private:
 
     void Read(Kernel::HLERequestContext& ctx) {
         IPC::RequestParser rp{ctx};
-        u64 offset = rp.Pop<u64>();
-        u64 length = rp.Pop<u64>();
+        const s64 offset = rp.Pop<s64>();
+        const s64 length = rp.Pop<s64>();
+        const auto& descriptor = ctx.BufferDescriptorB()[0];
 
-        LOG_DEBUG(Service, "called, offset=0x%llx, length=0x%llx", offset, length);
+        LOG_DEBUG(Service_FS, "called, offset=0x%llx, length=0x%llx", offset, length);
 
-        auto descriptor = ctx.BufferDescriptorB()[0];
-        std::vector<u8> output(length);
+        // Error checking
+        ASSERT_MSG(length == descriptor.Size(), "unexpected size difference");
+        if (length < 0) {
+            IPC::RequestBuilder rb{ctx, 2};
+            rb.Push(ResultCode(ErrorModule::FS, ErrorDescription::InvalidLength));
+            return;
+        }
+        if (offset < 0) {
+            IPC::RequestBuilder rb{ctx, 2};
+            rb.Push(ResultCode(ErrorModule::FS, ErrorDescription::InvalidOffset));
+            return;
+        }
 
+        // Read the data from the Storage backend
+        std::vector<u8> output(length);
         ResultVal<size_t> res = backend->Read(offset, length, output.data());
         if (res.Failed()) {
             IPC::RequestBuilder rb{ctx, 2};
             rb.Push(res.Code());
+            return;
         }
 
+        // Write the data to memory
         Memory::WriteBlock(descriptor.Address(), output.data(), descriptor.Size());
 
         IPC::RequestBuilder rb{ctx, 2};
         rb.Push(RESULT_SUCCESS);
     }
-
-    void Write(Kernel::HLERequestContext& ctx) {
-        IPC::RequestBuilder rb{ctx, 2};
-        rb.Push(RESULT_SUCCESS);
-        LOG_WARNING(Service, "(STUBBED) called");
-    }
-
-    void Flush(Kernel::HLERequestContext& ctx) {
-        IPC::RequestBuilder rb{ctx, 2};
-        rb.Push(RESULT_SUCCESS);
-        LOG_WARNING(Service, "(STUBBED) called");
-    }
-
-    void SetSize(Kernel::HLERequestContext& ctx) {
-        IPC::RequestBuilder rb{ctx, 2};
-        rb.Push(RESULT_SUCCESS);
-        LOG_WARNING(Service, "(STUBBED) called");
-    }
-
-    void GetSize(Kernel::HLERequestContext& ctx) {
-        IPC::RequestBuilder rb{ctx, 2};
-        rb.Push(RESULT_SUCCESS);
-        LOG_WARNING(Service, "(STUBBED) called");
-    }
 };
 
 FSP_SRV::FSP_SRV() : ServiceFramework("fsp-srv") {
@@ -87,46 +77,62 @@ FSP_SRV::FSP_SRV() : ServiceFramework("fsp-srv") {
     RegisterHandlers(functions);
 }
 
+void FSP_SRV::TryLoadRomFS() {
+    if (romfs) {
+        return;
+    }
+    FileSys::Path unused;
+    auto res = OpenFileSystem(Type::RomFS, unused);
+    if (res.Succeeded()) {
+        romfs = std::move(res.Unwrap());
+    }
+}
+
 void FSP_SRV::Initalize(Kernel::HLERequestContext& ctx) {
+    LOG_WARNING(Service_FS, "(STUBBED) called");
+
     IPC::RequestBuilder rb{ctx, 2};
     rb.Push(RESULT_SUCCESS);
-    LOG_WARNING(Service, "(STUBBED) called");
 }
 
 void FSP_SRV::GetGlobalAccessLogMode(Kernel::HLERequestContext& ctx) {
+    LOG_WARNING(Service_FS, "(STUBBED) called");
+
     IPC::RequestBuilder rb{ctx, 4};
     rb.Push(RESULT_SUCCESS);
     rb.Push<u32>(5);
-    LOG_WARNING(Service, "(STUBBED) called");
 }
 
 void FSP_SRV::OpenDataStorageByCurrentProcess(Kernel::HLERequestContext& ctx) {
-    FileSys::Path path;
-    auto filesystem = OpenFileSystem(Type::RomFS, path);
-    if (filesystem.Failed()) {
+    LOG_DEBUG(Service_FS, "called");
+
+    TryLoadRomFS();
+    if (!romfs) {
+        // TODO (bunnei): Find the right error code to use here
+        LOG_CRITICAL(Service_FS, "no file system interface available!");
         IPC::RequestBuilder rb{ctx, 2};
-        rb.Push(filesystem.Code());
+        rb.Push(ResultCode(-1));
         return;
     }
 
-    auto storage = filesystem.Unwrap()->OpenFile({}, {});
+    // Attempt to open a StorageBackend interface to the RomFS
+    auto storage = romfs->OpenFile({}, {});
     if (storage.Failed()) {
+        LOG_CRITICAL(Service_FS, "no storage interface available!");
         IPC::RequestBuilder rb{ctx, 2};
         rb.Push(storage.Code());
         return;
     }
 
-    // TODO: What if already opened?
-
     IPC::RequestBuilder rb{ctx, 2, 0, 0, 1};
     rb.Push(RESULT_SUCCESS);
     rb.PushIpcInterface<IStorage>(std::move(storage.Unwrap()));
-    LOG_WARNING(Service, "(STUBBED) called");
 }
 
 void FSP_SRV::OpenRomStorage(Kernel::HLERequestContext& ctx) {
+    LOG_WARNING(Service_FS, "(STUBBED) called, using OpenDataStorageByCurrentProcess");
     OpenDataStorageByCurrentProcess(ctx);
 }
 
-} // namespace Filesystem
+} // namespace FileSystem
 } // namespace Service
-- 
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