Atmosphere/libraries/libstratosphere/source/ncm/ncm_content_meta_utils.cpp
2021-07-08 02:37:26 -07:00

186 lines
7.7 KiB
C++

/*
* Copyright (c) 2019-2020 Adubbz, 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 <stratosphere.hpp>
#include "ncm_fs_utils.hpp"
namespace ams::ncm {
namespace {
using FilePathString = kvdb::BoundedString<64>;
bool IsContentMetaFileName(const char *name) {
return impl::PathView(name).HasSuffix(".cnmt");
}
Result MountContentMetaByRemoteFileSystemProxy(const char *mount_name, const char *path) {
return fs::MountContent(mount_name, path, fs::ContentType_Meta);
}
constinit MountContentMetaFunction g_mount_content_meta_func = MountContentMetaByRemoteFileSystemProxy;
}
Result ReadContentMetaPath(AutoBuffer *out, const char *path) {
/* Mount the content. */
auto mount_name = impl::CreateUniqueMountName();
R_TRY(g_mount_content_meta_func(mount_name.str, path));
ON_SCOPE_EXIT { fs::Unmount(mount_name.str); };
/* Open the root directory. */
auto root_path = impl::GetRootDirectoryPath(mount_name);
fs::DirectoryHandle dir;
R_TRY(fs::OpenDirectory(std::addressof(dir), root_path.str, fs::OpenDirectoryMode_File));
ON_SCOPE_EXIT { fs::CloseDirectory(dir); };
/* Loop directory reading until we find the entry we're looking for. */
while (true) {
/* Read one entry, and finish when we fail to read. */
fs::DirectoryEntry entry;
s64 num_read;
R_TRY(fs::ReadDirectory(std::addressof(num_read), std::addressof(entry), dir, 1));
if (num_read == 0) {
break;
}
/* If this is the content meta file, parse it. */
if (IsContentMetaFileName(entry.name)) {
/* Create the file path. */
FilePathString file_path(root_path.str);
file_path.Append(entry.name);
/* Open the content meta file. */
fs::FileHandle file;
R_TRY(fs::OpenFile(std::addressof(file), file_path, fs::OpenMode_Read));
ON_SCOPE_EXIT { fs::CloseFile(file); };
/* Get the meta size. */
s64 file_size;
R_TRY(fs::GetFileSize(std::addressof(file_size), file));
const size_t meta_size = static_cast<size_t>(file_size);
/* Create a buffer for the meta. */
R_TRY(out->Initialize(meta_size));
/* Read the meta into the buffer. */
return fs::ReadFile(file, 0, out->Get(), meta_size);
}
}
return ncm::ResultContentMetaNotFound();
}
Result ReadVariationContentMetaInfoList(s32 *out_count, std::unique_ptr<ContentMetaInfo[]> *out_meta_infos, const Path &path, FirmwareVariationId firmware_variation_id) {
AutoBuffer meta;
{
fs::ScopedAutoAbortDisabler aad;
R_TRY(ReadContentMetaPath(std::addressof(meta), path.str));
}
/* Create a reader for the content meta. */
PackagedContentMetaReader reader(meta.Get(), meta.GetSize());
/* Define a helper to output the base meta infos. */
const auto ReadMetaInfoListFromBase = [&] ALWAYS_INLINE_LAMBDA () -> Result {
/* Output the base content meta info count. */
*out_count = reader.GetContentMetaCount();
/* Create a buffer to hold the infos. NOTE: N does not check for nullptr before accessing. */
std::unique_ptr<ContentMetaInfo[]> buffer(new (std::nothrow) ContentMetaInfo[reader.GetContentMetaCount()]);
AMS_ABORT_UNLESS(buffer != nullptr);
/* Copy all base meta infos to output */
for (size_t i = 0; i < reader.GetContentMetaCount(); i++) {
buffer[i] = *reader.GetContentMetaInfo(i);
}
/* Write out the buffer we've populated. */
*out_meta_infos = std::move(buffer);
return ResultSuccess();
};
/* If there are no firmware variations to list, read meta infos from base. */
R_UNLESS(reader.GetExtendedDataSize() != 0, ReadMetaInfoListFromBase());
SystemUpdateMetaExtendedDataReader extended_data_reader(reader.GetExtendedData(), reader.GetExtendedDataSize());
util::optional<s32> firmware_variation_index = util::nullopt;
/* NOTE: Atmosphere extension to support downgrading. */
/* If all firmware variations refer to base, don't require the current variation be present. */
bool force_refer_to_base = true;
/* Find the input firmware variation id. */
for (size_t i = 0; i < extended_data_reader.GetFirmwareVariationCount(); i++) {
if (*extended_data_reader.GetFirmwareVariationId(i) == firmware_variation_id) {
firmware_variation_index = i;
break;
} else {
/* Check if the current variation refers to base. */
const FirmwareVariationInfo *cur_variation_info = extended_data_reader.GetFirmwareVariationInfo(i);
const bool cur_refers_to_base = extended_data_reader.GetHeader()->version == 1 || cur_variation_info->refer_to_base;
/* We force referral to base on unsupported variation only if all supported variations refer to base. */
force_refer_to_base &= cur_refers_to_base;
}
}
/* We couldn't find the input firmware variation id. */
if (!firmware_variation_index) {
/* Unless we can force a referral to base, the firmware isn't supported. */
R_UNLESS(force_refer_to_base, ncm::ResultInvalidFirmwareVariation());
/* Force a referral to base. */
return ReadMetaInfoListFromBase();
}
/* Obtain the variation info. */
const FirmwareVariationInfo *variation_info = extended_data_reader.GetFirmwareVariationInfo(*firmware_variation_index);
/* Refer to base if variation info says we should, or if version is 1. */
const bool refer_to_base = extended_data_reader.GetHeader()->version == 1 || variation_info->refer_to_base;
R_UNLESS(!refer_to_base, ReadMetaInfoListFromBase());
/* Output the content meta count. */
const u32 content_meta_count = variation_info->content_meta_count;
*out_count = content_meta_count;
/* We're done if there are no content metas to list. */
R_SUCCEED_IF(content_meta_count == 0);
/* Allocate a buffer for the content meta infos. */
std::unique_ptr<ContentMetaInfo[]> buffer(new (std::nothrow) ContentMetaInfo[content_meta_count]);
AMS_ABORT_UNLESS(buffer != nullptr);
/* Get the content meta infos. */
Span<const ContentMetaInfo> meta_infos;
extended_data_reader.GetContentMetaInfoList(std::addressof(meta_infos), content_meta_count);
/* Copy the meta infos to the buffer. */
for (size_t i = 0; i < content_meta_count; i++) {
buffer[i] = meta_infos[i];
}
/* Output the content meta info buffer. */
*out_meta_infos = std::move(buffer);
return ResultSuccess();
}
void SetMountContentMetaFunction(MountContentMetaFunction func) {
g_mount_content_meta_func = func;
}
}