gecko-dev/dom/filesystem/FileSystemUtils.cpp

88 lines
2.3 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/dom/FileSystemUtils.h"
namespace mozilla {
namespace dom {
namespace {
bool
TokenizerIgnoreNothing(char16_t /* aChar */)
{
return false;
}
} // anonymous namespace
/* static */ bool
FileSystemUtils::IsDescendantPath(nsIFile* aFile,
nsIFile* aDescendantFile)
{
nsAutoString path;
nsresult rv = aFile->GetPath(path);
if (NS_WARN_IF(NS_FAILED(rv))) {
return false;
}
nsAutoString descendantPath;
rv = aDescendantFile->GetPath(descendantPath);
if (NS_WARN_IF(NS_FAILED(rv))) {
return false;
}
// Check the sub-directory path to see if it has the parent path as prefix.
if (descendantPath.Length() <= path.Length() ||
!StringBeginsWith(descendantPath, path)) {
return false;
}
return true;
}
/* static */ bool
FileSystemUtils::IsValidRelativeDOMPath(const nsAString& aPath,
nsTArray<nsString>& aParts)
{
// We don't allow empty relative path to access the root.
if (aPath.IsEmpty()) {
return false;
}
// Leading and trailing "/" are not allowed.
if (aPath.First() == FILESYSTEM_DOM_PATH_SEPARATOR_CHAR ||
aPath.Last() == FILESYSTEM_DOM_PATH_SEPARATOR_CHAR) {
return false;
}
NS_NAMED_LITERAL_STRING(kCurrentDir, ".");
NS_NAMED_LITERAL_STRING(kParentDir, "..");
// Split path and check each path component.
nsCharSeparatedTokenizerTemplate<TokenizerIgnoreNothing>
tokenizer(aPath, FILESYSTEM_DOM_PATH_SEPARATOR_CHAR);
while (tokenizer.hasMoreTokens()) {
nsDependentSubstring pathComponent = tokenizer.nextToken();
// The path containing empty components, such as "foo//bar", is invalid.
// We don't allow paths, such as "../foo", "foo/./bar" and "foo/../bar",
// to walk up the directory.
if (pathComponent.IsEmpty() ||
pathComponent.Equals(kCurrentDir) ||
pathComponent.Equals(kParentDir)) {
return false;
}
aParts.AppendElement(pathComponent);
}
return true;
}
} // namespace dom
} // namespace mozilla