/* MIT License * * Copyright (c) 2023 Brad House * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. * * SPDX-License-Identifier: MIT */ #ifndef __ARES_DNS_RECORD_H #define __ARES_DNS_RECORD_H /* Include ares.h, not this file directly */ #ifdef __cplusplus extern "C" { #endif /*! \addtogroup ares_dns_record DNS Record Handling * * This is a set of functions to create and manipulate DNS records. * * @{ */ /*! DNS Record types handled by c-ares. Some record types may only be valid * on requests (e.g. ARES_REC_TYPE_ANY), and some may only be valid on * responses */ typedef enum { ARES_REC_TYPE_A = 1, /*!< Host address. */ ARES_REC_TYPE_NS = 2, /*!< Authoritative server. */ ARES_REC_TYPE_CNAME = 5, /*!< Canonical name. */ ARES_REC_TYPE_SOA = 6, /*!< Start of authority zone. */ ARES_REC_TYPE_PTR = 12, /*!< Domain name pointer. */ ARES_REC_TYPE_HINFO = 13, /*!< Host information. */ ARES_REC_TYPE_MX = 15, /*!< Mail routing information. */ ARES_REC_TYPE_TXT = 16, /*!< Text strings. */ ARES_REC_TYPE_AAAA = 28, /*!< RFC 3596. Ip6 Address. */ ARES_REC_TYPE_SRV = 33, /*!< RFC 2782. Server Selection. */ ARES_REC_TYPE_NAPTR = 35, /*!< RFC 3403. Naming Authority Pointer */ ARES_REC_TYPE_OPT = 41, /*!< RFC 6891. EDNS0 option (meta-RR) */ ARES_REC_TYPE_TLSA = 52, /*!< RFC 6698. DNS-Based Authentication of Named * Entities (DANE) Transport Layer Security * (TLS) Protocol: TLSA */ ARES_REC_TYPE_SVCB = 64, /*!< RFC 9460. General Purpose Service Binding */ ARES_REC_TYPE_HTTPS = 65, /*!< RFC 9460. Service Binding type for use with * HTTPS */ ARES_REC_TYPE_ANY = 255, /*!< Wildcard match. Not response RR. */ ARES_REC_TYPE_URI = 256, /*!< RFC 7553. Uniform Resource Identifier */ ARES_REC_TYPE_CAA = 257, /*!< RFC 6844. Certification Authority * Authorization. */ ARES_REC_TYPE_RAW_RR = 65536 /*!< Used as an indicator that the RR record * is not parsed, but provided in wire * format */ } ares_dns_rec_type_t; /*! DNS Classes for requests and responses. */ typedef enum { ARES_CLASS_IN = 1, /*!< Internet */ ARES_CLASS_CHAOS = 3, /*!< CHAOS */ ARES_CLASS_HESOID = 4, /*!< Hesoid [Dyer 87] */ ARES_CLASS_NONE = 254, /*!< RFC 2136 */ ARES_CLASS_ANY = 255 /*!< Any class (requests only) */ } ares_dns_class_t; /*! DNS RR Section type */ typedef enum { ARES_SECTION_ANSWER = 1, /*!< Answer section */ ARES_SECTION_AUTHORITY = 2, /*!< Authority section */ ARES_SECTION_ADDITIONAL = 3 /*!< Additional information section */ } ares_dns_section_t; /*! DNS Header opcodes */ typedef enum { ARES_OPCODE_QUERY = 0, /*!< Standard query */ ARES_OPCODE_IQUERY = 1, /*!< Inverse query. Obsolete. */ ARES_OPCODE_STATUS = 2, /*!< Name server status query */ ARES_OPCODE_NOTIFY = 4, /*!< Zone change notification (RFC 1996) */ ARES_OPCODE_UPDATE = 5, /*!< Zone update message (RFC2136) */ } ares_dns_opcode_t; /*! DNS Header flags */ typedef enum { ARES_FLAG_QR = 1 << 0, /*!< QR. If set, is a response */ ARES_FLAG_AA = 1 << 1, /*!< Authoritative Answer. If set, is authoritative */ ARES_FLAG_TC = 1 << 2, /*!< Truncation. If set, is truncated response */ ARES_FLAG_RD = 1 << 3, /*!< Recursion Desired. If set, recursion is desired */ ARES_FLAG_RA = 1 << 4, /*!< Recursion Available. If set, server supports * recursion */ ARES_FLAG_AD = 1 << 5, /*!< RFC 2065. Authentic Data bit indicates in a * response that the data included has been verified by * the server providing it */ ARES_FLAG_CD = 1 << 6, /*!< RFC 2065. Checking Disabled bit indicates in a * query that non-verified data is acceptable to the * resolver sending the query. */ } ares_dns_flags_t; /*! DNS Response Codes from server */ typedef enum { ARES_RCODE_NOERROR = 0, /*!< Success */ ARES_RCODE_FORMERR = 1, /*!< Format error. The name server was unable * to interpret the query. */ ARES_RCODE_SERVFAIL = 2, /*!< Server Failure. The name server was * unable to process this query due to a * problem with the nameserver */ ARES_RCODE_NXDOMAIN = 3, /*!< Name Error. Meaningful only for * responses from an authoritative name * server, this code signifies that the * domain name referenced in the query does * not exist. */ ARES_RCODE_NOTIMP = 4, /*!< Not implemented. The name server does * not support the requested kind of * query */ ARES_RCODE_REFUSED = 5, /*!< Refused. The name server refuses to * perform the specified operation for * policy reasons. */ ARES_RCODE_YXDOMAIN = 6, /*!< RFC 2136. Some name that ought not to * exist, does exist. */ ARES_RCODE_YXRRSET = 7, /*!< RFC 2136. Some RRset that ought to not * exist, does exist. */ ARES_RCODE_NXRRSET = 8, /*!< RFC 2136. Some RRset that ought to exist, * does not exist. */ ARES_RCODE_NOTAUTH = 9, /*!< RFC 2136. The server is not authoritative * for the zone named in the Zone section. */ ARES_RCODE_NOTZONE = 10, /*!< RFC 2136. A name used in the Prerequisite * or Update Section is not within the zone * denoted by the Zone Section. */ ARES_RCODE_DSOTYPEI = 11, /*!< RFC 8409. DSO-TYPE Not implemented */ ARES_RCODE_BADSIG = 16, /*!< RFC 8945. TSIG Signature Failure */ ARES_RCODE_BADKEY = 17, /*!< RFC 8945. Key not recognized. */ ARES_RCODE_BADTIME = 18, /*!< RFC 8945. Signature out of time window. */ ARES_RCODE_BADMODE = 19, /*!< RFC 2930. Bad TKEY Mode */ ARES_RCODE_BADNAME = 20, /*!< RFC 2930. Duplicate Key Name */ ARES_RCODE_BADALG = 21, /*!< RFC 2930. Algorithm not supported */ ARES_RCODE_BADTRUNC = 22, /*!< RFC 8945. Bad Truncation */ ARES_RCODE_BADCOOKIE = 23, /*!< RVC 7973. Bad/missing Server Cookie */ } ares_dns_rcode_t; /*! Data types used */ typedef enum { ARES_DATATYPE_INADDR = 1, /*!< struct in_addr * type */ ARES_DATATYPE_INADDR6 = 2, /*!< struct ares_in6_addr * type */ ARES_DATATYPE_U8 = 3, /*!< 8bit unsigned integer */ ARES_DATATYPE_U16 = 4, /*!< 16bit unsigned integer */ ARES_DATATYPE_U32 = 5, /*!< 32bit unsigned integer */ ARES_DATATYPE_NAME = 6, /*!< Null-terminated string of a domain name */ ARES_DATATYPE_STR = 7, /*!< Null-terminated string */ ARES_DATATYPE_BIN = 8, /*!< Binary data */ ARES_DATATYPE_BINP = 9, /*!< Officially defined as binary data, but likely * printable. Guaranteed to have a NULL * terminator for convenience (not included in * length) */ ARES_DATATYPE_OPT = 10, /*!< Array of options. 16bit identifier, BIN * data. */ } ares_dns_datatype_t; /*! Keys used for all RR Types. We take the record type and multiply by 100 * to ensure we have a proper offset between keys so we can keep these sorted */ typedef enum { /*! A Record. Address. Datatype: INADDR */ ARES_RR_A_ADDR = (ARES_REC_TYPE_A * 100) + 1, /*! NS Record. Name. Datatype: NAME */ ARES_RR_NS_NSDNAME = (ARES_REC_TYPE_NS * 100) + 1, /*! CNAME Record. CName. Datatype: NAME */ ARES_RR_CNAME_CNAME = (ARES_REC_TYPE_CNAME * 100) + 1, /*! SOA Record. MNAME, Primary Source of Data. Datatype: NAME */ ARES_RR_SOA_MNAME = (ARES_REC_TYPE_SOA * 100) + 1, /*! SOA Record. RNAME, Mailbox of person responsible. Datatype: NAME */ ARES_RR_SOA_RNAME = (ARES_REC_TYPE_SOA * 100) + 2, /*! SOA Record. Serial, version. Datatype: U32 */ ARES_RR_SOA_SERIAL = (ARES_REC_TYPE_SOA * 100) + 3, /*! SOA Record. Refresh, zone refersh interval. Datatype: U32 */ ARES_RR_SOA_REFRESH = (ARES_REC_TYPE_SOA * 100) + 4, /*! SOA Record. Retry, failed refresh retry interval. Datatype: U32 */ ARES_RR_SOA_RETRY = (ARES_REC_TYPE_SOA * 100) + 5, /*! SOA Record. Expire, upper limit on authority. Datatype: U32 */ ARES_RR_SOA_EXPIRE = (ARES_REC_TYPE_SOA * 100) + 6, /*! SOA Record. Minimum, RR TTL. Datatype: U32 */ ARES_RR_SOA_MINIMUM = (ARES_REC_TYPE_SOA * 100) + 7, /*! PTR Record. DNAME, pointer domain. Datatype: NAME */ ARES_RR_PTR_DNAME = (ARES_REC_TYPE_PTR * 100) + 1, /*! HINFO Record. CPU. Datatype: STR */ ARES_RR_HINFO_CPU = (ARES_REC_TYPE_HINFO * 100) + 1, /*! HINFO Record. OS. Datatype: STR */ ARES_RR_HINFO_OS = (ARES_REC_TYPE_HINFO * 100) + 2, /*! MX Record. Preference. Datatype: U16 */ ARES_RR_MX_PREFERENCE = (ARES_REC_TYPE_MX * 100) + 1, /*! MX Record. Exchange, domain. Datatype: NAME */ ARES_RR_MX_EXCHANGE = (ARES_REC_TYPE_MX * 100) + 2, /*! TXT Record. Data. Datatype: BINP */ ARES_RR_TXT_DATA = (ARES_REC_TYPE_TXT * 100) + 1, /*! AAAA Record. Address. Datatype: INADDR6 */ ARES_RR_AAAA_ADDR = (ARES_REC_TYPE_AAAA * 100) + 1, /*! SRV Record. Priority. Datatype: U16 */ ARES_RR_SRV_PRIORITY = (ARES_REC_TYPE_SRV * 100) + 2, /*! SRV Record. Weight. Datatype: U16 */ ARES_RR_SRV_WEIGHT = (ARES_REC_TYPE_SRV * 100) + 3, /*! SRV Record. Port. Datatype: U16 */ ARES_RR_SRV_PORT = (ARES_REC_TYPE_SRV * 100) + 4, /*! SRV Record. Target domain. Datatype: NAME */ ARES_RR_SRV_TARGET = (ARES_REC_TYPE_SRV * 100) + 5, /*! NAPTR Record. Order. Datatype: U16 */ ARES_RR_NAPTR_ORDER = (ARES_REC_TYPE_NAPTR * 100) + 1, /*! NAPTR Record. Preference. Datatype: U16 */ ARES_RR_NAPTR_PREFERENCE = (ARES_REC_TYPE_NAPTR * 100) + 2, /*! NAPTR Record. Flags. Datatype: STR */ ARES_RR_NAPTR_FLAGS = (ARES_REC_TYPE_NAPTR * 100) + 3, /*! NAPTR Record. Services. Datatype: STR */ ARES_RR_NAPTR_SERVICES = (ARES_REC_TYPE_NAPTR * 100) + 4, /*! NAPTR Record. Regexp. Datatype: STR */ ARES_RR_NAPTR_REGEXP = (ARES_REC_TYPE_NAPTR * 100) + 5, /*! NAPTR Record. Replacement. Datatype: NAME */ ARES_RR_NAPTR_REPLACEMENT = (ARES_REC_TYPE_NAPTR * 100) + 6, /*! OPT Record. UDP Size. Datatype: U16 */ ARES_RR_OPT_UDP_SIZE = (ARES_REC_TYPE_OPT * 100) + 1, /*! OPT Record. Version. Datatype: U8 */ ARES_RR_OPT_VERSION = (ARES_REC_TYPE_OPT * 100) + 3, /*! OPT Record. Flags. Datatype: U16 */ ARES_RR_OPT_FLAGS = (ARES_REC_TYPE_OPT * 100) + 4, /*! OPT Record. Options. Datatype: OPT */ ARES_RR_OPT_OPTIONS = (ARES_REC_TYPE_OPT * 100) + 5, /*! TLSA Record. Certificate Usage. Datatype: U8 */ ARES_RR_TLSA_CERT_USAGE = (ARES_REC_TYPE_TLSA * 100) + 1, /*! TLSA Record. Selector. Datatype: U8 */ ARES_RR_TLSA_SELECTOR = (ARES_REC_TYPE_TLSA * 100) + 2, /*! TLSA Record. Matching Type. Datatype: U8 */ ARES_RR_TLSA_MATCH = (ARES_REC_TYPE_TLSA * 100) + 3, /*! TLSA Record. Certificate Association Data. Datatype: BIN */ ARES_RR_TLSA_DATA = (ARES_REC_TYPE_TLSA * 100) + 4, /*! SVCB Record. SvcPriority. Datatype: U16 */ ARES_RR_SVCB_PRIORITY = (ARES_REC_TYPE_SVCB * 100) + 1, /*! SVCB Record. TargetName. Datatype: NAME */ ARES_RR_SVCB_TARGET = (ARES_REC_TYPE_SVCB * 100) + 2, /*! SVCB Record. SvcParams. Datatype: OPT */ ARES_RR_SVCB_PARAMS = (ARES_REC_TYPE_SVCB * 100) + 3, /*! HTTPS Record. SvcPriority. Datatype: U16 */ ARES_RR_HTTPS_PRIORITY = (ARES_REC_TYPE_HTTPS * 100) + 1, /*! HTTPS Record. TargetName. Datatype: NAME */ ARES_RR_HTTPS_TARGET = (ARES_REC_TYPE_HTTPS * 100) + 2, /*! HTTPS Record. SvcParams. Datatype: OPT */ ARES_RR_HTTPS_PARAMS = (ARES_REC_TYPE_HTTPS * 100) + 3, /*! URI Record. Priority. Datatype: U16 */ ARES_RR_URI_PRIORITY = (ARES_REC_TYPE_URI * 100) + 1, /*! URI Record. Weight. Datatype: U16 */ ARES_RR_URI_WEIGHT = (ARES_REC_TYPE_URI * 100) + 2, /*! URI Record. Target domain. Datatype: NAME */ ARES_RR_URI_TARGET = (ARES_REC_TYPE_URI * 100) + 3, /*! CAA Record. Critical flag. Datatype: U8 */ ARES_RR_CAA_CRITICAL = (ARES_REC_TYPE_CAA * 100) + 1, /*! CAA Record. Tag/Property. Datatype: STR */ ARES_RR_CAA_TAG = (ARES_REC_TYPE_CAA * 100) + 2, /*! CAA Record. Value. Datatype: BINP */ ARES_RR_CAA_VALUE = (ARES_REC_TYPE_CAA * 100) + 3, /*! RAW Record. RR Type. Datatype: U16 */ ARES_RR_RAW_RR_TYPE = (ARES_REC_TYPE_RAW_RR * 100) + 1, /*! RAW Record. RR Data. Datatype: BIN */ ARES_RR_RAW_RR_DATA = (ARES_REC_TYPE_RAW_RR * 100) + 2, } ares_dns_rr_key_t; /*! TLSA Record ARES_RR_TLSA_CERT_USAGE known values */ typedef enum { /*! Certificate Usage 0. CA Constraint. */ ARES_TLSA_USAGE_CA = 0, /*! Certificate Usage 1. Service Certificate Constraint. */ ARES_TLSA_USAGE_SERVICE = 1, /*! Certificate Usage 2. Trust Anchor Assertion. */ ARES_TLSA_USAGE_TRUSTANCHOR = 2, /*! Certificate Usage 3. Domain-issued certificate. */ ARES_TLSA_USAGE_DOMAIN = 3 } ares_tlsa_usage_t; /*! TLSA Record ARES_RR_TLSA_SELECTOR known values */ typedef enum { /*! Full Certificate */ ARES_TLSA_SELECTOR_FULL = 0, /*! DER-encoded SubjectPublicKeyInfo */ ARES_TLSA_SELECTOR_SUBJPUBKEYINFO = 1 } ares_tlsa_selector_t; /*! TLSA Record ARES_RR_TLSA_MATCH known values */ typedef enum { /*! Exact match */ ARES_TLSA_MATCH_EXACT = 0, /*! Sha256 match */ ARES_TLSA_MATCH_SHA256 = 1, /*! Sha512 match */ ARES_TLSA_MATCH_SHA512 = 2 } ares_tlsa_match_t; /*! SVCB (and HTTPS) RR known parameters */ typedef enum { /*! Mandatory keys in this RR (RFC 9460 Section 8) */ ARES_SVCB_PARAM_MANDATORY = 0, /*! Additional supported protocols (RFC 9460 Section 7.1) */ ARES_SVCB_PARAM_ALPN = 1, /*! No support for default protocol (RFC 9460 Section 7.1) */ ARES_SVCB_PARAM_NO_DEFAULT_ALPN = 2, /*! Port for alternative endpoint (RFC 9460 Section 7.2) */ ARES_SVCB_PARAM_PORT = 3, /*! IPv4 address hints (RFC 9460 Section 7.3) */ ARES_SVCB_PARAM_IPV4HINT = 4, /*! RESERVED (held for Encrypted ClientHello) */ ARES_SVCB_PARAM_ECH = 5, /*! IPv6 address hints (RFC 9460 Section 7.3) */ ARES_SVCB_PARAM_IPV6HINT = 6 } ares_svcb_param_t; /*! OPT RR known parameters */ typedef enum { /*! RFC 8764. Apple's DNS Long-Lived Queries Protocol */ ARES_OPT_PARAM_LLQ = 1, /*! http://files.dns-sd.org/draft-sekar-dns-ul.txt: Update Lease */ ARES_OPT_PARAM_UL = 2, /*! RFC 5001. Name Server Identification */ ARES_OPT_PARAM_NSID = 3, /*! RFC 6975. DNSSEC Algorithm Understood */ ARES_OPT_PARAM_DAU = 5, /*! RFC 6975. DS Hash Understood */ ARES_OPT_PARAM_DHU = 6, /*! RFC 6975. NSEC3 Hash Understood */ ARES_OPT_PARAM_N3U = 7, /*! RFC 7871. Client Subnet */ ARES_OPT_PARAM_EDNS_CLIENT_SUBNET = 8, /*! RFC 7314. Expire Timer */ ARES_OPT_PARAM_EDNS_EXPIRE = 9, /*! RFC 7873. Client and Server Cookies */ ARES_OPT_PARAM_COOKIE = 10, /*! RFC 7828. TCP Keepalive timeout */ ARES_OPT_PARAM_EDNS_TCP_KEEPALIVE = 11, /*! RFC 7830. Padding */ ARES_OPT_PARAM_PADDING = 12, /*! RFC 7901. Chain query requests */ ARES_OPT_PARAM_CHAIN = 13, /*! RFC 8145. Signaling Trust Anchor Knowledge in DNSSEC */ ARES_OPT_PARAM_EDNS_KEY_TAG = 14, /*! RFC 8914. Extended ERROR code and message */ ARES_OPT_PARAM_EXTENDED_DNS_ERROR = 15, } ares_opt_param_t; /*! Data type for option records for keys like ARES_RR_OPT_OPTIONS and * ARES_RR_HTTPS_PARAMS returned by ares_dns_opt_get_datatype() */ typedef enum { /*! No value allowed for this option */ ARES_OPT_DATATYPE_NONE = 1, /*! List of strings, each prefixed with a single octet representing the length */ ARES_OPT_DATATYPE_STR_LIST = 2, /*! List of 8bit integers, concatenated */ ARES_OPT_DATATYPE_U8_LIST = 3, /*! 16bit integer in network byte order */ ARES_OPT_DATATYPE_U16 = 4, /*! list of 16bit integer in network byte order, concatenated. */ ARES_OPT_DATATYPE_U16_LIST = 5, /*! 32bit integer in network byte order */ ARES_OPT_DATATYPE_U32 = 6, /*! list 32bit integer in network byte order, concatenated */ ARES_OPT_DATATYPE_U32_LIST = 7, /*! List of ipv4 addresses in network byte order, concatenated */ ARES_OPT_DATATYPE_INADDR4_LIST = 8, /*! List of ipv6 addresses in network byte order, concatenated */ ARES_OPT_DATATYPE_INADDR6_LIST = 9, /*! Binary Data */ ARES_OPT_DATATYPE_BIN = 10, /*! DNS Domain Name Format */ ARES_OPT_DATATYPE_NAME = 11 } ares_dns_opt_datatype_t; /*! Data type for flags to ares_dns_parse() */ typedef enum { ARES_DNS_PARSE_AN_BASE_RAW = 1 << 0, /*!< Parse Answers from RFC 1035 that allow name compression as RAW */ ARES_DNS_PARSE_NS_BASE_RAW = 1 << 1, /*!< Parse Authority from RFC 1035 that allow name compression as RAW */ ARES_DNS_PARSE_AR_BASE_RAW = 1 << 2, /*!< Parse Additional from RFC 1035 that allow name compression as RAW */ ARES_DNS_PARSE_AN_EXT_RAW = 1 << 3, /*!< Parse Answers from later RFCs (no name compression) RAW */ ARES_DNS_PARSE_NS_EXT_RAW = 1 << 4, /*!< Parse Authority from later RFCs (no name compression) as RAW */ ARES_DNS_PARSE_AR_EXT_RAW = 1 << 5, /*!< Parse Additional from later RFCs (no name compression) as RAW */ } ares_dns_parse_flags_t; /*! String representation of DNS Record Type * * \param[in] type DNS Record Type * \return string */ CARES_EXTERN const char *ares_dns_rec_type_tostr(ares_dns_rec_type_t type); /*! String representation of DNS Class * * \param[in] qclass DNS Class * \return string */ CARES_EXTERN const char *ares_dns_class_tostr(ares_dns_class_t qclass); /*! String representation of DNS OpCode * * \param[in] opcode DNS OpCode * \return string */ CARES_EXTERN const char *ares_dns_opcode_tostr(ares_dns_opcode_t opcode); /*! String representation of DNS Resource Record Parameter * * \param[in] key DNS Resource Record parameter * \return string */ CARES_EXTERN const char *ares_dns_rr_key_tostr(ares_dns_rr_key_t key); /*! String representation of DNS Resource Record section * * \param[in] section Section * \return string */ CARES_EXTERN const char *ares_dns_section_tostr(ares_dns_section_t section); /*! Convert DNS class name as string to ares_dns_class_t * * \param[out] qclass Pointer passed by reference to write class * \param[in] str String to convert * \return ARES_TRUE on success */ CARES_EXTERN ares_bool_t ares_dns_class_fromstr(ares_dns_class_t *qclass, const char *str); /*! Convert DNS record type as string to ares_dns_rec_type_t * * \param[out] qtype Pointer passed by reference to write record type * \param[in] str String to convert * \return ARES_TRUE on success */ CARES_EXTERN ares_bool_t ares_dns_rec_type_fromstr(ares_dns_rec_type_t *qtype, const char *str); /*! Convert DNS response code as string to from ares_dns_rcode_t * * \param[in] rcode Response code to convert * \return ARES_TRUE on success */ CARES_EXTERN const char *ares_dns_rcode_tostr(ares_dns_rcode_t rcode); /*! Convert any valid ip address (ipv4 or ipv6) into struct ares_addr and * return the starting pointer of the network byte order address and the * length of the address (4 or 16). * * \param[in] ipaddr ASCII string form of the ip address * \param[in,out] addr Must set "family" member to one of AF_UNSPEC, * AF_INET, AF_INET6 on input. * \param[out] ptr_len Length of binary form address * \return Pointer to start of binary address or NULL on error. */ CARES_EXTERN const void *ares_dns_pton(const char *ipaddr, struct ares_addr *addr, size_t *out_len); /*! Convert an ip address into the PTR format for in-addr.arpa or in6.arpa * * \param[in] addr properly filled address structure * \return String representing PTR, use ares_free_string() to free */ CARES_EXTERN char *ares_dns_addr_to_ptr(const struct ares_addr *addr); /*! The options/parameters extensions to some RRs can be somewhat opaque, this * is a helper to return the best match for a datatype for interpreting the * option record. * * \param[in] key Key associated with options/parameters * \param[in] opt Option Key/Parameter * \return Datatype */ CARES_EXTERN ares_dns_opt_datatype_t ares_dns_opt_get_datatype(ares_dns_rr_key_t key, unsigned short opt); /*! The options/parameters extensions to some RRs can be somewhat opaque, this * is a helper to return the name if the option is known. * * \param[in] key Key associated with options/parameters * \param[in] opt Option Key/Parameter * \return name, or NULL if not known. */ CARES_EXTERN const char *ares_dns_opt_get_name(ares_dns_rr_key_t key, unsigned short opt); /*! Retrieve a list of Resource Record keys that can be set or retrieved for * the Resource record type. * * \param[in] type Record Type * \param[out] cnt Number of keys returned * \return array of keys associated with Resource Record */ CARES_EXTERN const ares_dns_rr_key_t * ares_dns_rr_get_keys(ares_dns_rec_type_t type, size_t *cnt); /*! Retrieve the datatype associated with a Resource Record key. * * \param[in] key Resource Record Key * \return datatype */ CARES_EXTERN ares_dns_datatype_t ares_dns_rr_key_datatype(ares_dns_rr_key_t key); /*! Retrieve the DNS Resource Record type associated with a Resource Record key. * * \param[in] key Resource Record Key * \return DNS Resource Record Type */ CARES_EXTERN ares_dns_rec_type_t ares_dns_rr_key_to_rec_type(ares_dns_rr_key_t key); /*! Opaque data type representing a DNS RR (Resource Record) */ struct ares_dns_rr; /*! Typedef for opaque data type representing a DNS RR (Resource Record) */ typedef struct ares_dns_rr ares_dns_rr_t; /*! Opaque data type representing a DNS Query Data QD Packet */ struct ares_dns_qd; /*! Typedef for opaque data type representing a DNS Query Data QD Packet */ typedef struct ares_dns_qd ares_dns_qd_t; /*! Opaque data type representing a DNS Packet */ struct ares_dns_record; /*! Typedef for opaque data type representing a DNS Packet */ typedef struct ares_dns_record ares_dns_record_t; /*! Create a new DNS record object * * \param[out] dnsrec Pointer passed by reference for a newly allocated * record object. Must be ares_dns_record_destroy()'d by * caller. * \param[in] id DNS Query ID. If structuring a new query to be sent * with ares_send(), this value should be zero. * \param[in] flags DNS Flags from \ares_dns_flags_t * \param[in] opcode DNS OpCode (typically ARES_OPCODE_QUERY) * \param[in] rcode DNS RCode * \return ARES_SUCCESS on success */ CARES_EXTERN ares_status_t ares_dns_record_create(ares_dns_record_t **dnsrec, unsigned short id, unsigned short flags, ares_dns_opcode_t opcode, ares_dns_rcode_t rcode); /*! Destroy a DNS record object * * \param[in] dnsrec Initialized record object */ CARES_EXTERN void ares_dns_record_destroy(ares_dns_record_t *dnsrec); /*! Get the DNS Query ID * * \param[in] dnsrec Initialized record object * \return DNS query id */ CARES_EXTERN unsigned short ares_dns_record_get_id(const ares_dns_record_t *dnsrec); /*! Get the DNS Record Flags * * \param[in] dnsrec Initialized record object * \return One or more \ares_dns_flags_t */ CARES_EXTERN unsigned short ares_dns_record_get_flags(const ares_dns_record_t *dnsrec); /*! Get the DNS Record OpCode * * \param[in] dnsrec Initialized record object * \return opcode */ CARES_EXTERN ares_dns_opcode_t ares_dns_record_get_opcode(const ares_dns_record_t *dnsrec); /*! Get the DNS Record RCode * * \param[in] dnsrec Initialized record object * \return rcode */ CARES_EXTERN ares_dns_rcode_t ares_dns_record_get_rcode(const ares_dns_record_t *dnsrec); /*! Add a query to the DNS Record. Typically a record will have only 1 * query. Most DNS servers will reject queries with more than 1 question. * * \param[in] dnsrec Initialized record object * \param[in] name Name/Hostname of request * \param[in] qtype Type of query * \param[in] qclass Class of query (typically ARES_CLASS_IN) * \return ARES_SUCCESS on success */ CARES_EXTERN ares_status_t ares_dns_record_query_add(ares_dns_record_t *dnsrec, const char *name, ares_dns_rec_type_t qtype, ares_dns_class_t qclass); /*! Get the count of queries in the DNS Record * * \param[in] dnsrec Initialized record object * \return count of queries */ CARES_EXTERN size_t ares_dns_record_query_cnt(const ares_dns_record_t *dnsrec); /*! Get the data about the query at the provided index. * * \param[in] dnsrec Initialized record object * \param[in] idx Index of query * \param[out] name Optional. Returns name, may pass NULL if not desired. * \param[out] qtype Optional. Returns record type, may pass NULL. * \param[out] qclass Optional. Returns class, may pass NULL. * \return ARES_SUCCESS on success */ CARES_EXTERN ares_status_t ares_dns_record_query_get( const ares_dns_record_t *dnsrec, size_t idx, const char **name, ares_dns_rec_type_t *qtype, ares_dns_class_t *qclass); /*! Get the count of Resource Records in the provided section * * \param[in] dnsrec Initialized record object * \param[in] sect Section. ARES_SECTION_ANSWER is most used. * \return count of resource records. */ CARES_EXTERN size_t ares_dns_record_rr_cnt(const ares_dns_record_t *dnsrec, ares_dns_section_t sect); /*! Add a Resource Record to the DNS Record. * * \param[out] rr_out Pointer to created resource record. This pointer * is owned by the DNS record itself, this is just made * available to facilitate adding RR-specific fields. * \param[in] dnsrec Initialized record object * \param[in] sect Section to add resource record to * \param[in] name Resource Record name/hostname * \param[in] type Record Type * \param[in] rclass Class * \param[in] ttl TTL * \return ARES_SUCCESS on success */ CARES_EXTERN ares_status_t ares_dns_record_rr_add( ares_dns_rr_t **rr_out, ares_dns_record_t *dnsrec, ares_dns_section_t sect, const char *name, ares_dns_rec_type_t type, ares_dns_class_t rclass, unsigned int ttl); /*! Fetch a resource record based on the section and index. * * \param[in] dnsrec Initialized record object * \param[in] sect Section for resource record * \param[in] idx Index of resource record in section * \return NULL on misuse, otherwise a pointer to the resource record */ CARES_EXTERN ares_dns_rr_t *ares_dns_record_rr_get(ares_dns_record_t *dnsrec, ares_dns_section_t sect, size_t idx); /*! Remove the resource record based on the section and index * * \param[in] dnsrec Initialized record object * \param[in] sect Section for resource record * \param[in] idx Index of resource record in section * \return ARES_SUCCESS on success, otherwise an error code. */ CARES_EXTERN ares_status_t ares_dns_record_rr_del(ares_dns_record_t *dnsrec, ares_dns_section_t sect, size_t idx); /*! Retrieve the resource record Name/Hostname * * \param[in] rr Pointer to resource record * \return Name */ CARES_EXTERN const char *ares_dns_rr_get_name(const ares_dns_rr_t *rr); /*! Retrieve the resource record type * * \param[in] rr Pointer to resource record * \return type */ CARES_EXTERN ares_dns_rec_type_t ares_dns_rr_get_type(const ares_dns_rr_t *rr); /*! Retrieve the resource record class * * \param[in] rr Pointer to resource record * \return class */ CARES_EXTERN ares_dns_class_t ares_dns_rr_get_class(const ares_dns_rr_t *rr); /*! Retrieve the resource record TTL * * \param[in] rr Pointer to resource record * \return TTL */ CARES_EXTERN unsigned int ares_dns_rr_get_ttl(const ares_dns_rr_t *rr); /*! Set ipv4 address data type for specified resource record and key. Can * only be used on keys with datatype ARES_DATATYPE_INADDR * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \param[in] addr Pointer to ipv4 address to use. * \return ARES_SUCCESS on success */ CARES_EXTERN ares_status_t ares_dns_rr_set_addr(ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key, const struct in_addr *addr); /*! Set ipv6 address data type for specified resource record and key. Can * only be used on keys with datatype ARES_DATATYPE_INADDR6 * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \param[in] addr Pointer to ipv6 address to use. * \return ARES_SUCCESS on success */ CARES_EXTERN ares_status_t ares_dns_rr_set_addr6(ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key, const struct ares_in6_addr *addr); /*! Set string data for specified resource record and key. Can * only be used on keys with datatype ARES_DATATYPE_STR or ARES_DATATYPE_NAME. * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \param[in] val Pointer to string to set. * \return ARES_SUCCESS on success */ CARES_EXTERN ares_status_t ares_dns_rr_set_str(ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key, const char *val); /*! Set 8bit unsigned integer for specified resource record and key. Can * only be used on keys with datatype ARES_DATATYPE_U8 * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \param[in] val 8bit unsigned integer * \return ARES_SUCCESS on success */ CARES_EXTERN ares_status_t ares_dns_rr_set_u8(ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key, unsigned char val); /*! Set 16bit unsigned integer for specified resource record and key. Can * only be used on keys with datatype ARES_DATATYPE_U16 * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \param[in] val 16bit unsigned integer * \return ARES_SUCCESS on success */ CARES_EXTERN ares_status_t ares_dns_rr_set_u16(ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key, unsigned short val); /*! Set 32bit unsigned integer for specified resource record and key. Can * only be used on keys with datatype ARES_DATATYPE_U32 * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \param[in] val 32bit unsigned integer * \return ARES_SUCCESS on success */ CARES_EXTERN ares_status_t ares_dns_rr_set_u32(ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key, unsigned int val); /*! Set binary (BIN or BINP) data for specified resource record and key. Can * only be used on keys with datatype ARES_DATATYPE_BIN or ARES_DATATYPE_BINP. * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \param[in] val Pointer to binary data. * \param[in] len Length of binary data * \return ARES_SUCCESS on success */ CARES_EXTERN ares_status_t ares_dns_rr_set_bin(ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key, const unsigned char *val, size_t len); /*! Set the option for the RR * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \param[in] opt Option record key id. * \param[out] val Optional. Value to associate with option. * \param[out] val_len Length of value passed. * \return ARES_SUCCESS on success */ CARES_EXTERN ares_status_t ares_dns_rr_set_opt(ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key, unsigned short opt, const unsigned char *val, size_t val_len); /*! Retrieve a pointer to the ipv4 address. Can only be used on keys with * datatype ARES_DATATYPE_INADDR. * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \return pointer to ipv4 address or NULL on error */ CARES_EXTERN const struct in_addr * ares_dns_rr_get_addr(const ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key); /*! Retrieve a pointer to the ipv6 address. Can only be used on keys with * datatype ARES_DATATYPE_INADDR6. * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \return pointer to ipv6 address or NULL on error */ CARES_EXTERN const struct ares_in6_addr * ares_dns_rr_get_addr6(const ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key); /*! Retrieve a pointer to the string. Can only be used on keys with * datatype ARES_DATATYPE_STR and ARES_DATATYPE_NAME. * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \return pointer string or NULL on error */ CARES_EXTERN const char *ares_dns_rr_get_str(const ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key); /*! Retrieve an 8bit unsigned integer. Can only be used on keys with * datatype ARES_DATATYPE_U8. * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \return 8bit unsigned integer */ CARES_EXTERN unsigned char ares_dns_rr_get_u8(const ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key); /*! Retrieve an 16bit unsigned integer. Can only be used on keys with * datatype ARES_DATATYPE_U16. * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \return 16bit unsigned integer */ CARES_EXTERN unsigned short ares_dns_rr_get_u16(const ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key); /*! Retrieve an 32bit unsigned integer. Can only be used on keys with * datatype ARES_DATATYPE_U32. * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \return 32bit unsigned integer */ CARES_EXTERN unsigned int ares_dns_rr_get_u32(const ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key); /*! Retrieve a pointer to the binary data. Can only be used on keys with * datatype ARES_DATATYPE_BIN or ARES_DATATYPE_BINP. If BINP, the data is * guaranteed to have a NULL terminator which is NOT included in the length. * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \param[out] len Length of binary data returned * \return pointer binary data or NULL on error */ CARES_EXTERN const unsigned char * ares_dns_rr_get_bin(const ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key, size_t *len); /*! Retrieve the number of options stored for the RR. * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \return count, or 0 if none. */ CARES_EXTERN size_t ares_dns_rr_get_opt_cnt(const ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key); /*! Retrieve the option for the RR by index. * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \param[in] idx Index of option record * \param[out] val Optional. Pointer passed by reference to hold value. * Options may not have values. Value if returned is * guaranteed to be NULL terminated, however in most * cases it is not printable. * \param[out] val_len Optional. Pointer passed by reference to hold value * length. * \return option key/id on success, 65535 on misuse. */ CARES_EXTERN unsigned short ares_dns_rr_get_opt(const ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key, size_t idx, const unsigned char **val, size_t *val_len); /*! Retrieve the option for the RR by the option key/id. * * \param[in] dns_rr Pointer to resource record * \param[in] key DNS Resource Record Key * \param[in] opt Option record key id (this is not the index). * \param[out] val Optional. Pointer passed by reference to hold value. * Options may not have values. Value if returned is * guaranteed to be NULL terminated, however in most cases * it is not printable. * \param[out] val_len Optional. Pointer passed by reference to hold value * length. * \return ARES_TRUE on success, ARES_FALSE on misuse. */ CARES_EXTERN ares_bool_t ares_dns_rr_get_opt_byid(const ares_dns_rr_t *dns_rr, ares_dns_rr_key_t key, unsigned short opt, const unsigned char **val, size_t *val_len); /*! Parse a complete DNS message. * * \param[in] buf pointer to bytes to be parsed * \param[in] buf_len Length of buf provided * \param[in] flags Flags dictating how the message should be parsed. * \param[out] dnsrec Pointer passed by reference for a new DNS record object * that must be ares_dns_record_destroy()'d by caller. * \return ARES_SUCCESS on success */ CARES_EXTERN ares_status_t ares_dns_parse(const unsigned char *buf, size_t buf_len, unsigned int flags, ares_dns_record_t **dnsrec); /*! Write a complete DNS message * * \param[in] dnsrec Pointer to initialized and filled DNS record object. * \param[out] buf Pointer passed by reference to be filled in with with * DNS message. Must be ares_free()'d by caller. * \param[out] buf_len Length of returned buffer containing DNS message. * \return ARES_SUCCESS on success */ CARES_EXTERN ares_status_t ares_dns_write(ares_dns_record_t *dnsrec, unsigned char **buf, size_t *buf_len); /*! @} */ #ifdef __cplusplus } #endif #endif /* __ARES_DNS_RECORD_H */