Add support for decrypted NCA files (#567)

* Start to add NCA support in loader

* More nca stuff

* More changes to nca.cpp

* Now identifies decrypted NCA cont.

* Game list fixes and more structs and stuff

* More updates to Nca class

* Now reads ExeFs (i think)

* ACTUALLY LOADS EXEFS!

* RomFS loads and games execute

* Cleanup and Finalize

* plumbing, cleanup and testing

* fix some things that i didnt think of before

* Preliminary Review Changes

* Review changes for bunnei and subv

6 files changed, 434 insertions, 11 deletions

diff --git a/src/core/loader/loader.cpp b/src/core/loader/loader.cpp
index 6a4fd38cb..20cc0bac0 100644
--- a/src/core/loader/loader.cpp
+++ b/src/core/loader/loader.cpp
@@ -9,6 +9,7 @@
 #include "core/hle/kernel/process.h"
 #include "core/loader/deconstructed_rom_directory.h"
 #include "core/loader/elf.h"
+#include "core/loader/nca.h"
 #include "core/loader/nro.h"
 #include "core/loader/nso.h"
 
@@ -32,6 +33,7 @@ FileType IdentifyFile(FileUtil::IOFile& file, const std::string& filepath) {
     CHECK_TYPE(ELF)
     CHECK_TYPE(NSO)
     CHECK_TYPE(NRO)
+    CHECK_TYPE(NCA)
 
 #undef CHECK_TYPE
 
@@ -57,6 +59,8 @@ FileType GuessFromExtension(const std::string& extension_) {
         return FileType::NRO;
     else if (extension == ".nso")
         return FileType::NSO;
+    else if (extension == ".nca")
+        return FileType::NCA;
 
     return FileType::Unknown;
 }
@@ -69,6 +73,8 @@ const char* GetFileTypeString(FileType type) {
         return "NRO";
     case FileType::NSO:
         return "NSO";
+    case FileType::NCA:
+        return "NCA";
     case FileType::DeconstructedRomDirectory:
         return "Directory";
     case FileType::Error:
@@ -104,6 +110,10 @@ static std::unique_ptr<AppLoader> GetFileLoader(FileUtil::IOFile&& file, FileTyp
     case FileType::NRO:
         return std::make_unique<AppLoader_NRO>(std::move(file), filepath);
 
+    // NX NCA file format.
+    case FileType::NCA:
+        return std::make_unique<AppLoader_NCA>(std::move(file), filepath);
+
     // NX deconstructed ROM directory.
     case FileType::DeconstructedRomDirectory:
         return std::make_unique<AppLoader_DeconstructedRomDirectory>(std::move(file), filepath);
diff --git a/src/core/loader/loader.h b/src/core/loader/loader.h
index b1aabb1cb..b76f7b13d 100644
--- a/src/core/loader/loader.h
+++ b/src/core/loader/loader.h
@@ -29,6 +29,7 @@ enum class FileType {
     ELF,
     NSO,
     NRO,
+    NCA,
     DeconstructedRomDirectory,
 };
 
diff --git a/src/core/loader/nca.cpp b/src/core/loader/nca.cpp
new file mode 100644
index 000000000..067945d46
--- /dev/null
+++ b/src/core/loader/nca.cpp
@@ -0,0 +1,303 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <vector>
+
+#include "common/common_funcs.h"
+#include "common/file_util.h"
+#include "common/logging/log.h"
+#include "common/swap.h"
+#include "core/core.h"
+#include "core/file_sys/program_metadata.h"
+#include "core/file_sys/romfs_factory.h"
+#include "core/hle/kernel/process.h"
+#include "core/hle/kernel/resource_limit.h"
+#include "core/hle/service/filesystem/filesystem.h"
+#include "core/loader/nca.h"
+#include "core/loader/nso.h"
+#include "core/memory.h"
+
+namespace Loader {
+
+// Media offsets in headers are stored divided by 512. Mult. by this to get real offset.
+constexpr u64 MEDIA_OFFSET_MULTIPLIER = 0x200;
+
+constexpr u64 SECTION_HEADER_SIZE = 0x200;
+constexpr u64 SECTION_HEADER_OFFSET = 0x400;
+
+enum class NcaContentType : u8 { Program = 0, Meta = 1, Control = 2, Manual = 3, Data = 4 };
+
+enum class NcaSectionFilesystemType : u8 { PFS0 = 0x2, ROMFS = 0x3 };
+
+struct NcaSectionTableEntry {
+    u32_le media_offset;
+    u32_le media_end_offset;
+    INSERT_PADDING_BYTES(0x8);
+};
+static_assert(sizeof(NcaSectionTableEntry) == 0x10, "NcaSectionTableEntry has incorrect size.");
+
+struct NcaHeader {
+    std::array<u8, 0x100> rsa_signature_1;
+    std::array<u8, 0x100> rsa_signature_2;
+    u32_le magic;
+    u8 is_system;
+    NcaContentType content_type;
+    u8 crypto_type;
+    u8 key_index;
+    u64_le size;
+    u64_le title_id;
+    INSERT_PADDING_BYTES(0x4);
+    u32_le sdk_version;
+    u8 crypto_type_2;
+    INSERT_PADDING_BYTES(15);
+    std::array<u8, 0x10> rights_id;
+    std::array<NcaSectionTableEntry, 0x4> section_tables;
+    std::array<std::array<u8, 0x20>, 0x4> hash_tables;
+    std::array<std::array<u8, 0x10>, 0x4> key_area;
+    INSERT_PADDING_BYTES(0xC0);
+};
+static_assert(sizeof(NcaHeader) == 0x400, "NcaHeader has incorrect size.");
+
+struct NcaSectionHeaderBlock {
+    INSERT_PADDING_BYTES(3);
+    NcaSectionFilesystemType filesystem_type;
+    u8 crypto_type;
+    INSERT_PADDING_BYTES(3);
+};
+static_assert(sizeof(NcaSectionHeaderBlock) == 0x8, "NcaSectionHeaderBlock has incorrect size.");
+
+struct Pfs0Superblock {
+    NcaSectionHeaderBlock header_block;
+    std::array<u8, 0x20> hash;
+    u32_le size;
+    INSERT_PADDING_BYTES(4);
+    u64_le hash_table_offset;
+    u64_le hash_table_size;
+    u64_le pfs0_header_offset;
+    u64_le pfs0_size;
+    INSERT_PADDING_BYTES(432);
+};
+static_assert(sizeof(Pfs0Superblock) == 0x200, "Pfs0Superblock has incorrect size.");
+
+static bool IsValidNca(const NcaHeader& header) {
+    return header.magic == Common::MakeMagic('N', 'C', 'A', '2') ||
+           header.magic == Common::MakeMagic('N', 'C', 'A', '3');
+}
+
+// TODO(DarkLordZach): Add support for encrypted.
+class Nca final {
+    std::vector<FileSys::PartitionFilesystem> pfs;
+    std::vector<u64> pfs_offset;
+
+    u64 romfs_offset = 0;
+    u64 romfs_size = 0;
+
+    boost::optional<u8> exefs_id = boost::none;
+
+    FileUtil::IOFile file;
+    std::string path;
+
+    u64 GetExeFsFileOffset(const std::string& file_name) const;
+    u64 GetExeFsFileSize(const std::string& file_name) const;
+
+public:
+    ResultStatus Load(FileUtil::IOFile&& file, std::string path);
+
+    FileSys::PartitionFilesystem GetPfs(u8 id) const;
+
+    u64 GetRomFsOffset() const;
+    u64 GetRomFsSize() const;
+
+    std::vector<u8> GetExeFsFile(const std::string& file_name);
+};
+
+static bool IsPfsExeFs(const FileSys::PartitionFilesystem& pfs) {
+    // According to switchbrew, an exefs must only contain these two files:
+    return pfs.GetFileSize("main") > 0 && pfs.GetFileSize("main.npdm") > 0;
+}
+
+ResultStatus Nca::Load(FileUtil::IOFile&& in_file, std::string in_path) {
+    file = std::move(in_file);
+    path = in_path;
+    file.Seek(0, SEEK_SET);
+    std::array<u8, sizeof(NcaHeader)> header_array{};
+    if (sizeof(NcaHeader) != file.ReadBytes(header_array.data(), sizeof(NcaHeader)))
+        NGLOG_CRITICAL(Loader, "File reader errored out during header read.");
+
+    NcaHeader header{};
+    std::memcpy(&header, header_array.data(), sizeof(NcaHeader));
+    if (!IsValidNca(header))
+        return ResultStatus::ErrorInvalidFormat;
+
+    int number_sections =
+        std::count_if(std::begin(header.section_tables), std::end(header.section_tables),
+                      [](NcaSectionTableEntry entry) { return entry.media_offset > 0; });
+
+    for (int i = 0; i < number_sections; ++i) {
+        // Seek to beginning of this section.
+        file.Seek(SECTION_HEADER_OFFSET + i * SECTION_HEADER_SIZE, SEEK_SET);
+        std::array<u8, sizeof(NcaSectionHeaderBlock)> array{};
+        if (sizeof(NcaSectionHeaderBlock) !=
+            file.ReadBytes(array.data(), sizeof(NcaSectionHeaderBlock)))
+            NGLOG_CRITICAL(Loader, "File reader errored out during header read.");
+
+        NcaSectionHeaderBlock block{};
+        std::memcpy(&block, array.data(), sizeof(NcaSectionHeaderBlock));
+
+        if (block.filesystem_type == NcaSectionFilesystemType::ROMFS) {
+            romfs_offset = header.section_tables[i].media_offset * MEDIA_OFFSET_MULTIPLIER;
+            romfs_size =
+                header.section_tables[i].media_end_offset * MEDIA_OFFSET_MULTIPLIER - romfs_offset;
+        } else if (block.filesystem_type == NcaSectionFilesystemType::PFS0) {
+            Pfs0Superblock sb{};
+            // Seek back to beginning of this section.
+            file.Seek(SECTION_HEADER_OFFSET + i * SECTION_HEADER_SIZE, SEEK_SET);
+            if (sizeof(Pfs0Superblock) != file.ReadBytes(&sb, sizeof(Pfs0Superblock)))
+                NGLOG_CRITICAL(Loader, "File reader errored out during header read.");
+
+            u64 offset = (static_cast<u64>(header.section_tables[i].media_offset) *
+                          MEDIA_OFFSET_MULTIPLIER) +
+                         sb.pfs0_header_offset;
+            FileSys::PartitionFilesystem npfs{};
+            ResultStatus status = npfs.Load(path, offset);
+
+            if (status == ResultStatus::Success) {
+                pfs.emplace_back(std::move(npfs));
+                pfs_offset.emplace_back(offset);
+            }
+        }
+    }
+
+    for (size_t i = 0; i < pfs.size(); ++i) {
+        if (IsPfsExeFs(pfs[i]))
+            exefs_id = i;
+    }
+
+    return ResultStatus::Success;
+}
+
+FileSys::PartitionFilesystem Nca::GetPfs(u8 id) const {
+    return pfs[id];
+}
+
+u64 Nca::GetExeFsFileOffset(const std::string& file_name) const {
+    if (exefs_id == boost::none)
+        return 0;
+    return pfs[*exefs_id].GetFileOffset(file_name) + pfs_offset[*exefs_id];
+}
+
+u64 Nca::GetExeFsFileSize(const std::string& file_name) const {
+    if (exefs_id == boost::none)
+        return 0;
+    return pfs[*exefs_id].GetFileSize(file_name);
+}
+
+u64 Nca::GetRomFsOffset() const {
+    return romfs_offset;
+}
+
+u64 Nca::GetRomFsSize() const {
+    return romfs_size;
+}
+
+std::vector<u8> Nca::GetExeFsFile(const std::string& file_name) {
+    std::vector<u8> out(GetExeFsFileSize(file_name));
+    file.Seek(GetExeFsFileOffset(file_name), SEEK_SET);
+    file.ReadBytes(out.data(), GetExeFsFileSize(file_name));
+    return out;
+}
+
+AppLoader_NCA::AppLoader_NCA(FileUtil::IOFile&& file, std::string filepath)
+    : AppLoader(std::move(file)), filepath(std::move(filepath)) {}
+
+FileType AppLoader_NCA::IdentifyType(FileUtil::IOFile& file, const std::string&) {
+    file.Seek(0, SEEK_SET);
+    std::array<u8, 0x400> header_enc_array{};
+    if (0x400 != file.ReadBytes(header_enc_array.data(), 0x400))
+        return FileType::Error;
+
+    // TODO(DarkLordZach): Assuming everything is decrypted. Add crypto support.
+    NcaHeader header{};
+    std::memcpy(&header, header_enc_array.data(), sizeof(NcaHeader));
+
+    if (IsValidNca(header) && header.content_type == NcaContentType::Program)
+        return FileType::NCA;
+
+    return FileType::Error;
+}
+
+ResultStatus AppLoader_NCA::Load(Kernel::SharedPtr<Kernel::Process>& process) {
+    if (is_loaded) {
+        return ResultStatus::ErrorAlreadyLoaded;
+    }
+    if (!file.IsOpen()) {
+        return ResultStatus::Error;
+    }
+
+    nca = std::make_unique<Nca>();
+    ResultStatus result = nca->Load(std::move(file), filepath);
+    if (result != ResultStatus::Success) {
+        return result;
+    }
+
+    result = metadata.Load(nca->GetExeFsFile("main.npdm"));
+    if (result != ResultStatus::Success) {
+        return result;
+    }
+    metadata.Print();
+
+    const FileSys::ProgramAddressSpaceType arch_bits{metadata.GetAddressSpaceType()};
+    if (arch_bits == FileSys::ProgramAddressSpaceType::Is32Bit) {
+        return ResultStatus::ErrorUnsupportedArch;
+    }
+
+    VAddr next_load_addr{Memory::PROCESS_IMAGE_VADDR};
+    for (const auto& module : {"rtld", "main", "subsdk0", "subsdk1", "subsdk2", "subsdk3",
+                               "subsdk4", "subsdk5", "subsdk6", "subsdk7", "sdk"}) {
+        const VAddr load_addr = next_load_addr;
+        next_load_addr = AppLoader_NSO::LoadModule(module, nca->GetExeFsFile(module), load_addr);
+        if (next_load_addr) {
+            NGLOG_DEBUG(Loader, "loaded module {} @ 0x{:X}", module, load_addr);
+        } else {
+            next_load_addr = load_addr;
+        }
+    }
+
+    process->program_id = metadata.GetTitleID();
+    process->svc_access_mask.set();
+    process->address_mappings = default_address_mappings;
+    process->resource_limit =
+        Kernel::ResourceLimit::GetForCategory(Kernel::ResourceLimitCategory::APPLICATION);
+    process->Run(Memory::PROCESS_IMAGE_VADDR, metadata.GetMainThreadPriority(),
+                 metadata.GetMainThreadStackSize());
+
+    if (nca->GetRomFsSize() > 0)
+        Service::FileSystem::RegisterFileSystem(std::make_unique<FileSys::RomFS_Factory>(*this),
+                                                Service::FileSystem::Type::RomFS);
+
+    is_loaded = true;
+    return ResultStatus::Success;
+}
+
+ResultStatus AppLoader_NCA::ReadRomFS(std::shared_ptr<FileUtil::IOFile>& romfs_file, u64& offset,
+                                      u64& size) {
+    if (nca->GetRomFsSize() == 0) {
+        NGLOG_DEBUG(Loader, "No RomFS available");
+        return ResultStatus::ErrorNotUsed;
+    }
+
+    romfs_file = std::make_shared<FileUtil::IOFile>(filepath, "rb");
+
+    offset = nca->GetRomFsOffset();
+    size = nca->GetRomFsSize();
+
+    NGLOG_DEBUG(Loader, "RomFS offset:           0x{:016X}", offset);
+    NGLOG_DEBUG(Loader, "RomFS size:             0x{:016X}", size);
+
+    return ResultStatus::Success;
+}
+
+AppLoader_NCA::~AppLoader_NCA() = default;
+
+} // namespace Loader
diff --git a/src/core/loader/nca.h b/src/core/loader/nca.h
new file mode 100644
index 000000000..3b6c451d0
--- /dev/null
+++ b/src/core/loader/nca.h
@@ -0,0 +1,49 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <string>
+#include "common/common_types.h"
+#include "core/file_sys/partition_filesystem.h"
+#include "core/file_sys/program_metadata.h"
+#include "core/hle/kernel/kernel.h"
+#include "core/loader/loader.h"
+
+namespace Loader {
+
+class Nca;
+
+/// Loads an NCA file
+class AppLoader_NCA final : public AppLoader {
+public:
+    AppLoader_NCA(FileUtil::IOFile&& file, std::string filepath);
+
+    /**
+     * Returns the type of the file
+     * @param file FileUtil::IOFile open file
+     * @param filepath Path of the file that we are opening.
+     * @return FileType found, or FileType::Error if this loader doesn't know it
+     */
+    static FileType IdentifyType(FileUtil::IOFile& file, const std::string& filepath);
+
+    FileType GetFileType() override {
+        return IdentifyType(file, filepath);
+    }
+
+    ResultStatus Load(Kernel::SharedPtr<Kernel::Process>& process) override;
+
+    ResultStatus ReadRomFS(std::shared_ptr<FileUtil::IOFile>& romfs_file, u64& offset,
+                           u64& size) override;
+
+    ~AppLoader_NCA();
+
+private:
+    std::string filepath;
+    FileSys::ProgramMetadata metadata;
+
+    std::unique_ptr<Nca> nca;
+};
+
+} // namespace Loader
diff --git a/src/core/loader/nso.cpp b/src/core/loader/nso.cpp
index 01be9e217..845ed7e90 100644
--- a/src/core/loader/nso.cpp
+++ b/src/core/loader/nso.cpp
@@ -66,8 +66,22 @@ FileType AppLoader_NSO::IdentifyType(FileUtil::IOFile& file, const std::string&)
     return FileType::Error;
 }
 
+static std::vector<u8> DecompressSegment(const std::vector<u8>& compressed_data,
+                                         const NsoSegmentHeader& header) {
+    std::vector<u8> uncompressed_data;
+    uncompressed_data.resize(header.size);
+    const int bytes_uncompressed = LZ4_decompress_safe(
+        reinterpret_cast<const char*>(compressed_data.data()),
+        reinterpret_cast<char*>(uncompressed_data.data()), compressed_data.size(), header.size);
+
+    ASSERT_MSG(bytes_uncompressed == header.size && bytes_uncompressed == uncompressed_data.size(),
+               "{} != {} != {}", bytes_uncompressed, header.size, uncompressed_data.size());
+
+    return uncompressed_data;
+}
+
 static std::vector<u8> ReadSegment(FileUtil::IOFile& file, const NsoSegmentHeader& header,
-                                   int compressed_size) {
+                                   size_t compressed_size) {
     std::vector<u8> compressed_data;
     compressed_data.resize(compressed_size);
 
@@ -77,22 +91,65 @@ static std::vector<u8> ReadSegment(FileUtil::IOFile& file, const NsoSegmentHeade
         return {};
     }
 
-    std::vector<u8> uncompressed_data;
-    uncompressed_data.resize(header.size);
-    const int bytes_uncompressed = LZ4_decompress_safe(
-        reinterpret_cast<const char*>(compressed_data.data()),
-        reinterpret_cast<char*>(uncompressed_data.data()), compressed_size, header.size);
-
-    ASSERT_MSG(bytes_uncompressed == header.size && bytes_uncompressed == uncompressed_data.size(),
-               "{} != {} != {}", bytes_uncompressed, header.size, uncompressed_data.size());
-
-    return uncompressed_data;
+    return DecompressSegment(compressed_data, header);
 }
 
 static constexpr u32 PageAlignSize(u32 size) {
     return (size + Memory::PAGE_MASK) & ~Memory::PAGE_MASK;
 }
 
+VAddr AppLoader_NSO::LoadModule(const std::string& name, const std::vector<u8>& file_data,
+                                VAddr load_base) {
+    if (file_data.size() < sizeof(NsoHeader))
+        return {};
+
+    NsoHeader nso_header;
+    std::memcpy(&nso_header, file_data.data(), sizeof(NsoHeader));
+
+    if (nso_header.magic != Common::MakeMagic('N', 'S', 'O', '0'))
+        return {};
+
+    // Build program image
+    Kernel::SharedPtr<Kernel::CodeSet> codeset = Kernel::CodeSet::Create("");
+    std::vector<u8> program_image;
+    for (int i = 0; i < nso_header.segments.size(); ++i) {
+        std::vector<u8> compressed_data(nso_header.segments_compressed_size[i]);
+        for (int j = 0; j < nso_header.segments_compressed_size[i]; ++j)
+            compressed_data[j] = file_data[nso_header.segments[i].offset + j];
+        std::vector<u8> data = DecompressSegment(compressed_data, nso_header.segments[i]);
+        program_image.resize(nso_header.segments[i].location);
+        program_image.insert(program_image.end(), data.begin(), data.end());
+        codeset->segments[i].addr = nso_header.segments[i].location;
+        codeset->segments[i].offset = nso_header.segments[i].location;
+        codeset->segments[i].size = PageAlignSize(static_cast<u32>(data.size()));
+    }
+
+    // MOD header pointer is at .text offset + 4
+    u32 module_offset;
+    std::memcpy(&module_offset, program_image.data() + 4, sizeof(u32));
+
+    // Read MOD header
+    ModHeader mod_header{};
+    // Default .bss to size in segment header if MOD0 section doesn't exist
+    u32 bss_size{PageAlignSize(nso_header.segments[2].bss_size)};
+    std::memcpy(&mod_header, program_image.data() + module_offset, sizeof(ModHeader));
+    const bool has_mod_header{mod_header.magic == Common::MakeMagic('M', 'O', 'D', '0')};
+    if (has_mod_header) {
+        // Resize program image to include .bss section and page align each section
+        bss_size = PageAlignSize(mod_header.bss_end_offset - mod_header.bss_start_offset);
+    }
+    codeset->data.size += bss_size;
+    const u32 image_size{PageAlignSize(static_cast<u32>(program_image.size()) + bss_size)};
+    program_image.resize(image_size);
+
+    // Load codeset for current process
+    codeset->name = name;
+    codeset->memory = std::make_shared<std::vector<u8>>(std::move(program_image));
+    Core::CurrentProcess()->LoadModule(codeset, load_base);
+
+    return load_base + image_size;
+}
+
 VAddr AppLoader_NSO::LoadModule(const std::string& path, VAddr load_base) {
     FileUtil::IOFile file(path, "rb");
     if (!file.IsOpen()) {
diff --git a/src/core/loader/nso.h b/src/core/loader/nso.h
index 1ae30a824..386f4d39a 100644
--- a/src/core/loader/nso.h
+++ b/src/core/loader/nso.h
@@ -29,6 +29,9 @@ public:
         return IdentifyType(file, filepath);
     }
 
+    static VAddr LoadModule(const std::string& name, const std::vector<u8>& file_data,
+                            VAddr load_base);
+
     static VAddr LoadModule(const std::string& path, VAddr load_base);
 
     ResultStatus Load(Kernel::SharedPtr<Kernel::Process>& process) override;