1 files changed, 316 insertions, 0 deletions

diff --git a/src/core/file_sys/ncch_container.cpp b/src/core/file_sys/ncch_container.cpp
new file mode 100644
index 000000000..59c72f3e9
--- /dev/null
+++ b/src/core/file_sys/ncch_container.cpp
@@ -0,0 +1,316 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <cinttypes>
+#include <cstring>
+#include <memory>
+#include "common/common_types.h"
+#include "common/logging/log.h"
+#include "core/core.h"
+#include "core/file_sys/ncch_container.h"
+#include "core/loader/loader.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// FileSys namespace
+
+namespace FileSys {
+
+static const int kMaxSections = 8;   ///< Maximum number of sections (files) in an ExeFs
+static const int kBlockSize = 0x200; ///< Size of ExeFS blocks (in bytes)
+
+/**
+ * Get the decompressed size of an LZSS compressed ExeFS file
+ * @param buffer Buffer of compressed file
+ * @param size Size of compressed buffer
+ * @return Size of decompressed buffer
+ */
+static u32 LZSS_GetDecompressedSize(const u8* buffer, u32 size) {
+    u32 offset_size = *(u32*)(buffer + size - 4);
+    return offset_size + size;
+}
+
+/**
+ * Decompress ExeFS file (compressed with LZSS)
+ * @param compressed Compressed buffer
+ * @param compressed_size Size of compressed buffer
+ * @param decompressed Decompressed buffer
+ * @param decompressed_size Size of decompressed buffer
+ * @return True on success, otherwise false
+ */
+static bool LZSS_Decompress(const u8* compressed, u32 compressed_size, u8* decompressed,
+                            u32 decompressed_size) {
+    const u8* footer = compressed + compressed_size - 8;
+    u32 buffer_top_and_bottom = *reinterpret_cast<const u32*>(footer);
+    u32 out = decompressed_size;
+    u32 index = compressed_size - ((buffer_top_and_bottom >> 24) & 0xFF);
+    u32 stop_index = compressed_size - (buffer_top_and_bottom & 0xFFFFFF);
+
+    memset(decompressed, 0, decompressed_size);
+    memcpy(decompressed, compressed, compressed_size);
+
+    while (index > stop_index) {
+        u8 control = compressed[--index];
+
+        for (unsigned i = 0; i < 8; i++) {
+            if (index <= stop_index)
+                break;
+            if (index <= 0)
+                break;
+            if (out <= 0)
+                break;
+
+            if (control & 0x80) {
+                // Check if compression is out of bounds
+                if (index < 2)
+                    return false;
+                index -= 2;
+
+                u32 segment_offset = compressed[index] | (compressed[index + 1] << 8);
+                u32 segment_size = ((segment_offset >> 12) & 15) + 3;
+                segment_offset &= 0x0FFF;
+                segment_offset += 2;
+
+                // Check if compression is out of bounds
+                if (out < segment_size)
+                    return false;
+
+                for (unsigned j = 0; j < segment_size; j++) {
+                    // Check if compression is out of bounds
+                    if (out + segment_offset >= decompressed_size)
+                        return false;
+
+                    u8 data = decompressed[out + segment_offset];
+                    decompressed[--out] = data;
+                }
+            } else {
+                // Check if compression is out of bounds
+                if (out < 1)
+                    return false;
+                decompressed[--out] = compressed[--index];
+            }
+            control <<= 1;
+        }
+    }
+    return true;
+}
+
+NCCHContainer::NCCHContainer(const std::string& filepath) : filepath(filepath) {
+    file = FileUtil::IOFile(filepath, "rb");
+}
+
+Loader::ResultStatus NCCHContainer::OpenFile(const std::string& filepath) {
+    this->filepath = filepath;
+    file = FileUtil::IOFile(filepath, "rb");
+
+    if (!file.IsOpen()) {
+        LOG_WARNING(Service_FS, "Failed to open %s", filepath.c_str());
+        return Loader::ResultStatus::Error;
+    }
+
+    LOG_DEBUG(Service_FS, "Opened %s", filepath.c_str());
+    return Loader::ResultStatus::Success;
+}
+
+Loader::ResultStatus NCCHContainer::Load() {
+    if (is_loaded)
+        return Loader::ResultStatus::Success;
+
+    // Reset read pointer in case this file has been read before.
+    file.Seek(0, SEEK_SET);
+
+    if (file.ReadBytes(&ncch_header, sizeof(NCCH_Header)) != sizeof(NCCH_Header))
+        return Loader::ResultStatus::Error;
+
+    // Skip NCSD header and load first NCCH (NCSD is just a container of NCCH files)...
+    if (Loader::MakeMagic('N', 'C', 'S', 'D') == ncch_header.magic) {
+        LOG_DEBUG(Service_FS, "Only loading the first (bootable) NCCH within the NCSD file!");
+        ncch_offset = 0x4000;
+        file.Seek(ncch_offset, SEEK_SET);
+        file.ReadBytes(&ncch_header, sizeof(NCCH_Header));
+    }
+
+    // Verify we are loading the correct file type...
+    if (Loader::MakeMagic('N', 'C', 'C', 'H') != ncch_header.magic)
+        return Loader::ResultStatus::ErrorInvalidFormat;
+
+    // System archives and DLC don't have an extended header but have RomFS
+    if (ncch_header.extended_header_size) {
+        if (file.ReadBytes(&exheader_header, sizeof(ExHeader_Header)) != sizeof(ExHeader_Header))
+            return Loader::ResultStatus::Error;
+
+        is_compressed = (exheader_header.codeset_info.flags.flag & 1) == 1;
+        u32 entry_point = exheader_header.codeset_info.text.address;
+        u32 code_size = exheader_header.codeset_info.text.code_size;
+        u32 stack_size = exheader_header.codeset_info.stack_size;
+        u32 bss_size = exheader_header.codeset_info.bss_size;
+        u32 core_version = exheader_header.arm11_system_local_caps.core_version;
+        u8 priority = exheader_header.arm11_system_local_caps.priority;
+        u8 resource_limit_category =
+            exheader_header.arm11_system_local_caps.resource_limit_category;
+
+        LOG_DEBUG(Service_FS, "Name:                        %s", exheader_header.codeset_info.name);
+        LOG_DEBUG(Service_FS, "Program ID:                  %016" PRIX64, ncch_header.program_id);
+        LOG_DEBUG(Service_FS, "Code compressed:             %s", is_compressed ? "yes" : "no");
+        LOG_DEBUG(Service_FS, "Entry point:                 0x%08X", entry_point);
+        LOG_DEBUG(Service_FS, "Code size:                   0x%08X", code_size);
+        LOG_DEBUG(Service_FS, "Stack size:                  0x%08X", stack_size);
+        LOG_DEBUG(Service_FS, "Bss size:                    0x%08X", bss_size);
+        LOG_DEBUG(Service_FS, "Core version:                %d", core_version);
+        LOG_DEBUG(Service_FS, "Thread priority:             0x%X", priority);
+        LOG_DEBUG(Service_FS, "Resource limit category:     %d", resource_limit_category);
+        LOG_DEBUG(Service_FS, "System Mode:                 %d",
+                  static_cast<int>(exheader_header.arm11_system_local_caps.system_mode));
+
+        if (exheader_header.system_info.jump_id != ncch_header.program_id) {
+            LOG_ERROR(Service_FS, "ExHeader Program ID mismatch: the ROM is probably encrypted.");
+            return Loader::ResultStatus::ErrorEncrypted;
+        }
+
+        has_exheader = true;
+    }
+
+    // DLC can have an ExeFS and a RomFS but no extended header
+    if (ncch_header.exefs_size) {
+        exefs_offset = ncch_header.exefs_offset * kBlockSize;
+        u32 exefs_size = ncch_header.exefs_size * kBlockSize;
+
+        LOG_DEBUG(Service_FS, "ExeFS offset:                0x%08X", exefs_offset);
+        LOG_DEBUG(Service_FS, "ExeFS size:                  0x%08X", exefs_size);
+
+        file.Seek(exefs_offset + ncch_offset, SEEK_SET);
+        if (file.ReadBytes(&exefs_header, sizeof(ExeFs_Header)) != sizeof(ExeFs_Header))
+            return Loader::ResultStatus::Error;
+
+        has_exefs = true;
+    }
+
+    if (ncch_header.romfs_offset != 0 && ncch_header.romfs_size != 0)
+        has_romfs = true;
+
+    is_loaded = true;
+    return Loader::ResultStatus::Success;
+}
+
+Loader::ResultStatus NCCHContainer::LoadSectionExeFS(const char* name, std::vector<u8>& buffer) {
+    if (!file.IsOpen())
+        return Loader::ResultStatus::Error;
+
+    Loader::ResultStatus result = Load();
+    if (result != Loader::ResultStatus::Success)
+        return result;
+
+    if (!has_exefs)
+        return Loader::ResultStatus::ErrorNotUsed;
+
+    LOG_DEBUG(Service_FS, "%d sections:", kMaxSections);
+    // Iterate through the ExeFs archive until we find a section with the specified name...
+    for (unsigned section_number = 0; section_number < kMaxSections; section_number++) {
+        const auto& section = exefs_header.section[section_number];
+
+        // Load the specified section...
+        if (strcmp(section.name, name) == 0) {
+            LOG_DEBUG(Service_FS, "%d - offset: 0x%08X, size: 0x%08X, name: %s", section_number,
+                      section.offset, section.size, section.name);
+
+            s64 section_offset =
+                (section.offset + exefs_offset + sizeof(ExeFs_Header) + ncch_offset);
+            file.Seek(section_offset, SEEK_SET);
+
+            if (strcmp(section.name, ".code") == 0 && is_compressed) {
+                // Section is compressed, read compressed .code section...
+                std::unique_ptr<u8[]> temp_buffer;
+                try {
+                    temp_buffer.reset(new u8[section.size]);
+                } catch (std::bad_alloc&) {
+                    return Loader::ResultStatus::ErrorMemoryAllocationFailed;
+                }
+
+                if (file.ReadBytes(&temp_buffer[0], section.size) != section.size)
+                    return Loader::ResultStatus::Error;
+
+                // Decompress .code section...
+                u32 decompressed_size = LZSS_GetDecompressedSize(&temp_buffer[0], section.size);
+                buffer.resize(decompressed_size);
+                if (!LZSS_Decompress(&temp_buffer[0], section.size, &buffer[0], decompressed_size))
+                    return Loader::ResultStatus::ErrorInvalidFormat;
+            } else {
+                // Section is uncompressed...
+                buffer.resize(section.size);
+                if (file.ReadBytes(&buffer[0], section.size) != section.size)
+                    return Loader::ResultStatus::Error;
+            }
+            return Loader::ResultStatus::Success;
+        }
+    }
+    return Loader::ResultStatus::ErrorNotUsed;
+}
+
+Loader::ResultStatus NCCHContainer::ReadRomFS(std::shared_ptr<FileUtil::IOFile>& romfs_file,
+                                              u64& offset, u64& size) {
+    if (!file.IsOpen())
+        return Loader::ResultStatus::Error;
+
+    Loader::ResultStatus result = Load();
+    if (result != Loader::ResultStatus::Success)
+        return result;
+
+    if (!has_romfs) {
+        LOG_DEBUG(Service_FS, "RomFS requested from NCCH which has no RomFS");
+        return Loader::ResultStatus::ErrorNotUsed;
+    }
+
+    u32 romfs_offset = ncch_offset + (ncch_header.romfs_offset * kBlockSize) + 0x1000;
+    u32 romfs_size = (ncch_header.romfs_size * kBlockSize) - 0x1000;
+
+    LOG_DEBUG(Service_FS, "RomFS offset:           0x%08X", romfs_offset);
+    LOG_DEBUG(Service_FS, "RomFS size:             0x%08X", romfs_size);
+
+    if (file.GetSize() < romfs_offset + romfs_size)
+        return Loader::ResultStatus::Error;
+
+    // We reopen the file, to allow its position to be independent from file's
+    romfs_file = std::make_shared<FileUtil::IOFile>(filepath, "rb");
+    if (!romfs_file->IsOpen())
+        return Loader::ResultStatus::Error;
+
+    offset = romfs_offset;
+    size = romfs_size;
+
+    return Loader::ResultStatus::Success;
+}
+
+Loader::ResultStatus NCCHContainer::ReadProgramId(u64_le& program_id) {
+    Loader::ResultStatus result = Load();
+    if (result != Loader::ResultStatus::Success)
+        return result;
+
+    program_id = ncch_header.program_id;
+    return Loader::ResultStatus::Success;
+}
+
+bool NCCHContainer::HasExeFS() {
+    Loader::ResultStatus result = Load();
+    if (result != Loader::ResultStatus::Success)
+        return false;
+
+    return has_exefs;
+}
+
+bool NCCHContainer::HasRomFS() {
+    Loader::ResultStatus result = Load();
+    if (result != Loader::ResultStatus::Success)
+        return false;
+
+    return has_romfs;
+}
+
+bool NCCHContainer::HasExHeader() {
+    Loader::ResultStatus result = Load();
+    if (result != Loader::ResultStatus::Success)
+        return false;
+
+    return has_exheader;
+}
+
+} // namespace FileSys