Atmosphere/libraries/libstratosphere/source/fs/fs_path_utils.cpp
2020-12-06 19:56:45 -08:00

131 lines
5.3 KiB
C++

/*
* Copyright (c) 2018-2020 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>
namespace ams::fs {
namespace {
class PathVerifier {
private:
u32 invalid_chars[6];
u32 separators[2];
public:
PathVerifier() {
/* Convert all invalid characters. */
u32 *dst_invalid = this->invalid_chars;
for (const char *cur = ":*?<>|"; *cur != '\x00'; ++cur) {
AMS_ASSERT(dst_invalid < std::end(this->invalid_chars));
const auto result = util::ConvertCharacterUtf8ToUtf32(dst_invalid, cur);
AMS_ASSERT(result == util::CharacterEncodingResult_Success);
++dst_invalid;
}
AMS_ASSERT(dst_invalid == std::end(this->invalid_chars));
/* Convert all separators. */
u32 *dst_sep = this->separators;
for (const char *cur = "/\\"; *cur != '\x00'; ++cur) {
AMS_ASSERT(dst_sep < std::end(this->separators));
const auto result = util::ConvertCharacterUtf8ToUtf32(dst_sep, cur);
AMS_ASSERT(result == util::CharacterEncodingResult_Success);
++dst_sep;
}
AMS_ASSERT(dst_sep == std::end(this->separators));
}
Result Verify(const char *path, int max_path_len, int max_name_len) const {
AMS_ASSERT(path != nullptr);
auto cur = path;
auto name_len = 0;
for (auto path_len = 0; path_len <= max_path_len && name_len <= max_name_len; ++path_len) {
/* We're done, if the path is terminated. */
R_SUCCEED_IF(*cur == '\x00');
/* Get the current utf-8 character. */
util::CharacterEncodingResult result;
char char_buf[4] = {};
result = util::PickOutCharacterFromUtf8String(char_buf, std::addressof(cur));
R_UNLESS(result == util::CharacterEncodingResult_Success, fs::ResultInvalidCharacter());
/* Convert the current utf-8 character to utf-32. */
u32 path_char = 0;
result = util::ConvertCharacterUtf8ToUtf32(std::addressof(path_char), char_buf);
R_UNLESS(result == util::CharacterEncodingResult_Success, fs::ResultInvalidCharacter());
/* Check if the character is invalid. */
for (const auto invalid : this->invalid_chars) {
R_UNLESS(path_char != invalid, fs::ResultInvalidCharacter());
}
/* Increment name length. */
++name_len;
/* Check for separator. */
for (const auto sep : this->separators) {
if (path_char == sep) {
name_len = 0;
break;
}
}
}
/* The path was too long. */
return fs::ResultTooLongPath();
}
};
PathVerifier g_path_verifier;
}
Result VerifyPath(const char *path, int max_path_len, int max_name_len) {
return g_path_verifier.Verify(path, max_path_len, max_name_len);
}
bool IsSubPath(const char *lhs, const char *rhs) {
AMS_ASSERT(lhs != nullptr);
AMS_ASSERT(rhs != nullptr);
/* Special case certain paths. */
if (IsUnc(lhs) && !IsUnc(rhs)) {
return false;
}
if (!IsUnc(lhs) && IsUnc(rhs)) {
return false;
}
if (PathNormalizer::IsSeparator(lhs[0]) && PathNormalizer::IsNullTerminator(lhs[1]) && PathNormalizer::IsSeparator(rhs[0]) && !PathNormalizer::IsNullTerminator(rhs[1])) {
return true;
}
if (PathNormalizer::IsSeparator(rhs[0]) && PathNormalizer::IsNullTerminator(rhs[1]) && PathNormalizer::IsSeparator(lhs[0]) && !PathNormalizer::IsNullTerminator(lhs[1])) {
return true;
}
/* Check subpath. */
for (size_t i = 0; /* No terminating condition */; i++) {
if (PathNormalizer::IsNullTerminator(lhs[i])) {
return PathNormalizer::IsSeparator(rhs[i]);
} else if (PathNormalizer::IsNullTerminator(rhs[i])) {
return PathNormalizer::IsSeparator(lhs[i]);
} else if (lhs[i] != rhs[i]) {
return false;
}
}
}
}