blob: 7b53aec27e8f9dc70e7cb00bbb9cad8740b9dd5c [file] [log] [blame]
// Copyright 2020 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <string>
#include "base/optional.h"
#include "base/strings/string_piece.h"
#include "brillo/brillo_export.h"
namespace patchpanel {
// DNSDomainFromDot - convert a domain string to DNS format. From DJB's
// public domain DNS library. |dotted| may include only characters a-z, A-Z,
// 0-9, -, and _.
// dotted: a string in dotted form: ""
// out: a result in DNS form: "\x03www\x06google\x03com\x00"
BRILLO_EXPORT bool DNSDomainFromDot(const base::StringPiece& dotted,
std::string* out);
// Returns true if the character is valid in a DNS hostname label, whether in
// the first position or later in the label.
// This function asserts a looser form of the restrictions in RFC 7719 (section
// 2; hostnames can include
// characters a-z, A-Z, 0-9, -, and _, and any of those characters (except -)
// are legal in the first position. The looser rules are necessary to support
// service records (initial _), and non-compliant but attested hostnames that
// include _. These looser rules also allow Punycode and hence IDN.
// TODO(palmer): In the future, when we can remove support for invalid names,
// this can be a private implementation detail of |DNSDomainFromDot|, and need
// not be BRILLO_EXPORT.
BRILLO_EXPORT bool IsValidHostLabelCharacter(char c, bool is_first_char);
// Converts a domain in DNS format to a dotted string. Excludes the dot at the
// end. Assumes the standard terminating zero-length label at the end if not
// included in the input. Returns nullopt on malformed input.
BRILLO_EXPORT base::Optional<std::string> DnsDomainToString(
base::StringPiece dns_name);
} // namespace patchpanel