| // Copyright 2023 The ChromiumOS Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef DNS_PROXY_DNS_UTIL_H_ |
| #define DNS_PROXY_DNS_UTIL_H_ |
| |
| #include <string> |
| |
| #include <base/strings/string_piece.h> |
| |
| namespace dns_proxy { |
| // TODO(crbug.com/751899): The DNS name validation code is adapted from |
| // dns_util* in Chrome: |
| // |
| // https://chromium.googlesource.com/chromium/src/+/3674d6f0ac52b4c7e3c21aa76f1cf842692ec692/net/dns/dns_util.h |
| // |
| // It would be better to include it in libchrome so that the code is |
| // maintained in one place. |
| |
| // DNSDomainFromDot - convert a domain string to DNS format. From DJB's |
| // public domain DNS library. |
| // |
| // dotted: a string in dotted form: "www.google.com" |
| // out: a result in DNS form: "\x03www\x06google\x03com\x00" |
| bool DNSDomainFromDot(std::string_view dotted, std::string* out); |
| |
| // Checks that a hostname is valid. Simple wrapper around DNSDomainFromDot. |
| bool IsValidDNSDomain(std::string_view dotted); |
| |
| // 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; https://tools.ietf.org/html/rfc7719#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. |
| bool IsValidHostLabelCharacter(char c, bool is_first_char); |
| |
| } // namespace dns_proxy |
| |
| #endif // DNS_PROXY_DNS_UTIL_H_ |
