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

1 files changed, 303 insertions, 0 deletions

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