| // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef NET_DNS_DNS_UTIL_H_ |
| #define NET_DNS_DNS_UTIL_H_ |
| |
| #include <string> |
| #include <vector> |
| |
| #include "base/strings/string_piece.h" |
| #include "base/strings/string_util.h" |
| #include "base/time/time.h" |
| #include "net/base/address_family.h" |
| #include "net/base/ip_endpoint.h" |
| #include "net/base/net_export.h" |
| #include "net/base/network_change_notifier.h" |
| #include "net/dns/public/dns_over_https_server_config.h" |
| #include "net/dns/public/dns_query_type.h" |
| #include "net/dns/public/secure_dns_mode.h" |
| #include "third_party/abseil-cpp/absl/types/optional.h" |
| |
| namespace base { |
| class BigEndianReader; |
| } // namespace base |
| |
| namespace net { |
| |
| // 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: "www.google.com" |
| // out: a result in DNS form: "\x03www\x06google\x03com\x00" |
| NET_EXPORT bool DNSDomainFromDot(const base::StringPiece& dotted, |
| std::string* out); |
| |
| // DNSDomainFromUnrestrictedDot - convert a domain string to DNS format. Adapted |
| // from DJB's public domain DNS library. No validation of the characters in |
| // `dotted` is performed. |
| // |
| // dotted: a string in dotted form: "Foo Printer._tcp.local" |
| // out: a result in DNS form: "\x0bFoo Printer\x04_tcp\x05local\x00" |
| NET_EXPORT bool DNSDomainFromUnrestrictedDot(const base::StringPiece& dotted, |
| std::string* out); |
| |
| // Checks that a hostname is valid. Simple wrapper around DNSDomainFromDot. |
| NET_EXPORT_PRIVATE bool IsValidDNSDomain(const base::StringPiece& dotted); |
| |
| // Checks that a hostname is valid. Simple wrapper around |
| // DNSDomainFromUnrestrictedDot. |
| NET_EXPORT_PRIVATE bool IsValidUnrestrictedDNSDomain( |
| const base::StringPiece& 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. |
| // |
| // TODO(crbug.com/1065133): In the future, when we can remove support for |
| // invalid names, this can be a private implementation detail of |
| // `DNSDomainFromDot`, and need not be NET_EXPORT_PRIVATE. |
| NET_EXPORT_PRIVATE bool IsValidHostLabelCharacter(char c, bool is_first_char); |
| |
| // Converts a domain in DNS format to a dotted string. Excludes the dot at the |
| // end. Returns nullopt on malformed input. |
| // |
| // If `require_complete` is true, input will be considered malformed if it does |
| // not contain a terminating zero-length label. If false, assumes the standard |
| // terminating zero-length label at the end if not included in the input. |
| // |
| // DNS name compression (see RFC 1035, section 4.1.4) is disallowed and |
| // considered malformed. To handle a potentially compressed name, in a |
| // DnsResponse object, use DnsRecordParser::ReadName(). |
| NET_EXPORT absl::optional<std::string> DnsDomainToString( |
| base::StringPiece dns_name, |
| bool require_complete = false); |
| NET_EXPORT absl::optional<std::string> DnsDomainToString( |
| base::BigEndianReader& reader, |
| bool require_complete = false); |
| |
| // Return the expanded template when no variables have corresponding values. |
| NET_EXPORT_PRIVATE std::string GetURLFromTemplateWithoutParameters( |
| const std::string& server_template); |
| |
| NET_EXPORT_PRIVATE |
| base::TimeDelta GetTimeDeltaForConnectionTypeFromFieldTrialOrDefault( |
| const char* field_trial_name, |
| base::TimeDelta default_delta, |
| NetworkChangeNotifier::ConnectionType connection_type); |
| |
| // Creates a 2-byte string that represents the name pointer defined in Section |
| // 4.1.1 of RFC 1035 for the given offset. The first two bits in the first byte |
| // of the name pointer are ones, and the rest 14 bits are given to `offset`, |
| // which specifies an offset from the start of the message for the pointed name. |
| // Note that `offset` must be less than 2^14 - 1 by definition. |
| NET_EXPORT std::string CreateNamePointer(uint16_t offset); |
| |
| // Convert a DnsQueryType enum to the wire format integer representation. |
| NET_EXPORT_PRIVATE uint16_t DnsQueryTypeToQtype(DnsQueryType dns_query_type); |
| |
| NET_EXPORT DnsQueryType |
| AddressFamilyToDnsQueryType(AddressFamily address_family); |
| |
| // Uses the hardcoded upgrade mapping to discover DoH service(s) associated with |
| // a DoT hostname. Providers with a disabled `base::Feature` are not eligible |
| // for upgrade. |
| NET_EXPORT_PRIVATE std::vector<DnsOverHttpsServerConfig> |
| GetDohUpgradeServersFromDotHostname(const std::string& dot_server); |
| |
| // Uses the hardcoded upgrade mapping to discover DoH service(s) associated with |
| // a list of insecure DNS servers. Server ordering is preserved across the |
| // mapping. Providers with a disabled `base::Feature` are not eligible for |
| // upgrade. |
| NET_EXPORT_PRIVATE std::vector<DnsOverHttpsServerConfig> |
| GetDohUpgradeServersFromNameservers(const std::vector<IPEndPoint>& dns_servers); |
| |
| // Returns the provider id to use in UMA histogram names. If there is no |
| // provider id that matches `doh_server`, returns "Other". |
| NET_EXPORT_PRIVATE std::string GetDohProviderIdForHistogramFromServerConfig( |
| const DnsOverHttpsServerConfig& doh_server); |
| |
| // Returns the provider id to use in UMA histogram names. If there is no |
| // provider id that matches `nameserver`, returns "Other". |
| NET_EXPORT_PRIVATE std::string GetDohProviderIdForHistogramFromNameserver( |
| const IPEndPoint& nameserver); |
| |
| NET_EXPORT_PRIVATE std::string SecureDnsModeToString( |
| const SecureDnsMode secure_dns_mode); |
| |
| // std::map-compliant Compare for two dotted-format domain names. Returns true |
| // iff `lhs` is before `rhs` in strict weak ordering. |
| class NET_EXPORT_PRIVATE DomainNameComparator { |
| public: |
| bool operator()(base::StringPiece lhs, base::StringPiece rhs) const { |
| return base::CompareCaseInsensitiveASCII(lhs, rhs) < 0; |
| } |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_DNS_DNS_UTIL_H_ |