Atmosphere/libraries/libstratosphere/source/fs/fsa/fs_mount_utils.cpp

173 lines
6.5 KiB
C++

/*
* Copyright (c) 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 "fs_filesystem_accessor.hpp"
#include "fs_mount_utils.hpp"
#include "fs_user_mount_table.hpp"
namespace ams::fs::impl {
namespace {
const char *FindMountNameDriveSeparator(const char *path) {
for (const char *cur = path; cur < path + MountNameLengthMax + 1 && *cur != StringTraits::NullTerminator; ++cur) {
if (*cur == StringTraits::DriveSeparator) {
return cur;
}
}
return nullptr;
}
constexpr bool IsHostRootPath(const char *path) {
#if defined(ATMOSPHERE_OS_HORIZON) || defined(ATMOSPHERE_OS_WINDOWS)
return fs::IsWindowsDrive(path) || fs::IsUncPath(path);
#elif defined(ATMOSPHERE_OS_LINUX) || defined(ATMOSPHERE_OS_MACOS)
return fs::IsPathAbsolute(path);
#else
#error "Unknown OS for host path identification"
#endif
}
Result GetMountNameAndSubPath(MountName *out_mount_name, const char **out_sub_path, const char *path) {
/* Handle the Host-path case. */
if (IsHostRootPath(path)) {
std::strncpy(out_mount_name->str, HostRootFileSystemMountName, MountNameLengthMax);
out_mount_name->str[MountNameLengthMax] = '\x00';
*out_sub_path = path;
R_SUCCEED();
}
/* Locate the drive separator. */
const char *drive_separator = FindMountNameDriveSeparator(path);
R_UNLESS(drive_separator != nullptr, fs::ResultInvalidMountName());
/* Ensure the mount name isn't too long. */
const size_t len = drive_separator - path;
R_UNLESS(0 < len, fs::ResultInvalidMountName());
R_UNLESS(len <= MountNameLengthMax, fs::ResultInvalidMountName());
/* Ensure the result sub-path is valid. */
const char *sub_path = drive_separator + 1;
const auto starts_with_dir = (sub_path[0] == StringTraits::DirectorySeparator) || (sub_path[0] == StringTraits::AlternateDirectorySeparator);
R_UNLESS(starts_with_dir, fs::ResultInvalidPathFormat());
/* Set output. */
std::memcpy(out_mount_name->str, path, len);
out_mount_name->str[len] = StringTraits::NullTerminator;
*out_sub_path = sub_path;
R_SUCCEED();
}
}
bool IsValidMountName(const char *name) {
if (name[0] == StringTraits::NullTerminator) {
return false;
}
if ((('a' <= name[0] && name[0] <= 'z') || ('A' <= name[0] && name[0] <= 'Z')) && name[1] == StringTraits::NullTerminator) {
return false;
}
size_t len = 0;
for (const char *cur = name; *cur != StringTraits::NullTerminator; ++cur) {
if (*cur == StringTraits::DriveSeparator || *cur == StringTraits::DirectorySeparator) {
return false;
}
if ((++len) > MountNameLengthMax) {
return false;
}
}
return util::VerifyUtf8String(name, len);
}
bool IsReservedMountName(const char *name) {
return name[0] == ReservedMountNamePrefixCharacter;
}
Result CheckMountName(const char *name) {
R_TRY(CheckMountNameAllowingReserved(name));
R_UNLESS(!impl::IsReservedMountName(name), fs::ResultInvalidMountName());
R_SUCCEED();
}
Result CheckMountNameAllowingReserved(const char *name) {
R_UNLESS(name != nullptr, fs::ResultInvalidMountName());
R_UNLESS(impl::IsValidMountName(name), fs::ResultInvalidMountName());
R_SUCCEED();
}
Result FindFileSystem(FileSystemAccessor **out_accessor, const char **out_sub_path, const char *path) {
R_UNLESS(out_accessor != nullptr, fs::ResultUnexpectedInFindFileSystemA());
R_UNLESS(out_sub_path != nullptr, fs::ResultUnexpectedInFindFileSystemA());
R_UNLESS(path != nullptr, fs::ResultNullptrArgument());
R_UNLESS(strncmp(path, HostRootFileSystemMountName, util::Strnlen(HostRootFileSystemMountName, sizeof(MountName))) != 0, fs::ResultNotMounted());
MountName mount_name;
R_TRY(GetMountNameAndSubPath(std::addressof(mount_name), out_sub_path, path));
R_RETURN(impl::Find(out_accessor, mount_name.str));
}
Result Unmount(const char *name) {
impl::FileSystemAccessor *accessor;
R_TRY(impl::Find(std::addressof(accessor), name));
if (accessor->IsFileDataCacheAttachable()) {
/* TODO: Data cache purge */
}
impl::Unregister(name);
R_SUCCEED();
}
}
namespace ams::fs {
Result ConvertToFsCommonPath(char *dst, size_t dst_size, const char *src) {
/* Ensure neither argument is nullptr. */
AMS_FS_R_UNLESS(dst != nullptr, fs::ResultNullptrArgument());
AMS_FS_R_UNLESS(src != nullptr, fs::ResultNullptrArgument());
/* Get the mount name and sub path for the path. */
MountName mount_name;
const char *sub_path;
AMS_FS_R_TRY(impl::GetMountNameAndSubPath(std::addressof(mount_name), std::addressof(sub_path), src));
impl::FileSystemAccessor *accessor;
AMS_FS_R_TRY(impl::Find(std::addressof(accessor), mount_name.str));
AMS_FS_R_TRY(accessor->GetCommonMountName(dst, dst_size));
const auto mount_name_len = util::Strnlen(dst, dst_size);
const auto common_path_len = util::SNPrintf(dst + mount_name_len, dst_size - mount_name_len, "%s", sub_path);
AMS_FS_R_UNLESS(static_cast<size_t>(common_path_len) < dst_size - mount_name_len, fs::ResultTooLongPath());
R_SUCCEED();
}
void Unmount(const char *mount_name) {
AMS_FS_R_ABORT_UNLESS(AMS_FS_IMPL_ACCESS_LOG_UNMOUNT(impl::Unmount(mount_name), mount_name, AMS_FS_IMPL_ACCESS_LOG_FORMAT_MOUNT, mount_name));
}
}