oracular (3) ares_dns_rr.3.gz

Provided by: libc-ares-dev_1.33.0-1_amd64 bug

NAME

       ares_dns_record_rr_add,           ares_dns_record_rr_cnt,          ares_dns_record_rr_del,
       ares_dns_record_rr_get,        ares_dns_record_rr_get_const,         ares_dns_rr_get_addr,
       ares_dns_rr_get_addr6,            ares_dns_rr_get_bin,           ares_dns_rr_get_abin_cnt,
       ares_dns_rr_get_abin,  ares_dns_rr_get_class,  ares_dns_rr_get_name,  ares_dns_rr_get_opt,
       ares_dns_rr_get_opt_byid,           ares_dns_rr_get_opt_cnt,          ares_dns_rr_get_str,
       ares_dns_rr_get_ttl,   ares_dns_rr_get_type,   ares_dns_rr_get_u16,   ares_dns_rr_get_u32,
       ares_dns_rr_get_u8,    ares_dns_rr_key_t,   ares_dns_rr_set_addr,   ares_dns_rr_set_addr6,
       ares_dns_rr_set_bin,  ares_dns_rr_add_abin,   ares_dns_rr_del_abin,   ares_dns_rr_set_opt,
       ares_dns_rr_set_str,    ares_dns_rr_set_u16,    ares_dns_rr_set_u32,   ares_dns_rr_set_u8,
       ares_dns_section_t,  ares_tlsa_match_t,  ares_tlsa_selector_t,  ares_tlsa_usage_t  -   DNS
       Resource Record creating, reading, and writing functions.

SYNOPSIS

       #include <ares.h>

       size_t ares_dns_record_rr_cnt(const ares_dns_record_t *dnsrec,
                                     ares_dns_section_t       sect);

       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);

       ares_dns_rr_t *ares_dns_record_rr_get(ares_dns_record_t *dnsrec,
                                             ares_dns_section_t sect,
                                             size_t             idx);

       const ares_dns_rr_t *ares_dns_record_rr_get_const(const ares_dns_record_t *dnsrec,
                                                         ares_dns_section_t sect,
                                                         size_t idx);

       ares_status_t ares_dns_record_rr_del(ares_dns_record_t *dnsrec,
                                            ares_dns_section_t sect,
                                            size_t             idx);

       const char *ares_dns_rr_get_name(const ares_dns_rr_t *rr);

       ares_dns_rec_type_t ares_dns_rr_get_type(const ares_dns_rr_t *rr);

       ares_dns_class_t ares_dns_rr_get_class(const ares_dns_rr_t *rr);

       unsigned int ares_dns_rr_get_ttl(const ares_dns_rr_t *rr);

       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);

       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);

       ares_status_t ares_dns_rr_set_str(ares_dns_rr_t    *dns_rr,
                                         ares_dns_rr_key_t key,
                                         const char       *val);

       ares_status_t ares_dns_rr_set_u8(ares_dns_rr_t    *dns_rr,
                                        ares_dns_rr_key_t key,
                                        unsigned char     val);

       ares_status_t ares_dns_rr_set_u16(ares_dns_rr_t    *dns_rr,
                                         ares_dns_rr_key_t key,
                                         unsigned short    val);

       ares_status_t ares_dns_rr_set_u32(ares_dns_rr_t    *dns_rr,
                                         ares_dns_rr_key_t key,
                                         unsigned int      val);

       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);

       ares_status_t ares_dns_rr_add_abin(ares_dns_rr_t *dns_rr,
                                          ares_dns_rr_key_t key,
                                          const unsigned char *val,
                                          size_t len);

       ares_status_t ares_dns_rr_del_abin(ares_dns_rr_t *dns_rr,
                                          ares_dns_rr_key_t key,
                                          size_t idx);

       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);

       ares_status_t ares_dns_rr_del_opt_byid(ares_dns_rr_t       *dns_rr,
                                              ares_dns_rr_key_t    key,
                                              unsigned short       opt);

       const struct in_addr *ares_dns_rr_get_addr(const ares_dns_rr_t *dns_rr,
                                                  ares_dns_rr_key_t key);

       const struct ares_in6_addr *ares_dns_rr_get_addr6(const ares_dns_rr_t *dns_rr,
                                                         ares_dns_rr_key_t key);

       const char *ares_dns_rr_get_str(const ares_dns_rr_t *dns_rr,
                                       ares_dns_rr_key_t    key);

       unsigned char ares_dns_rr_get_u8(const ares_dns_rr_t *dns_rr,
                                        ares_dns_rr_key_t    key);

       unsigned short ares_dns_rr_get_u16(const ares_dns_rr_t *dns_rr,
                                          ares_dns_rr_key_t    key);

       unsigned int ares_dns_rr_get_u32(const ares_dns_rr_t *dns_rr,
                                        ares_dns_rr_key_t    key);

       const unsigned char *ares_dns_rr_get_bin(const ares_dns_rr_t *dns_rr,
                                                ares_dns_rr_key_t key,
                                                size_t *len);

       size_t ares_dns_rr_get_abin_cnt(const ares_dns_rr_t *dns_rr,
                                       ares_dns_rr_key_t key);

       const unsigned char *ares_dns_rr_get_abin(const ares_dns_rr_t *dns_rr,
                                                 ares_dns_rr_key_t key, size_t idx,
                                                 size_t *len);

       size_t ares_dns_rr_get_opt_cnt(const ares_dns_rr_t *dns_rr,
                                      ares_dns_rr_key_t    key);

       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);

       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);

ENUMERATIONS

       ares_dns_section_t - DNS RR section types:
           ARES_SECTION_ANSWER - Answer section
           ARES_SECTION_AUTHORITY - Authority section
           ARES_SECTION_ADDITIONAL - Additional Information section

       ares_dns_rr_key_t - Keys used for handling RR record parameters:
           ARES_RR_A_ADDR - A Record. Address. Datatype: ARES_DATATYPE_INADDR
           ARES_RR_NS_NSDNAME - NS Record. Name. Datatype: ARES_DATATYPE_NAME
           ARES_RR_CNAME_CNAME - CNAME Record. CName. Datatype: ARES_DATATYPE_NAME
           ARES_RR_SOA_MNAME   -   SOA   Record.   MNAME,   Primary  Source  of  Data.  Datatype:
           ARES_DATATYPE_NAME
           ARES_RR_SOA_RNAME - SOA  Record.  RNAME,  Mailbox  of  person  responsible.  Datatype:
           ARES_DATATYPE_NAME
           ARES_RR_SOA_SERIAL - SOA Record. Serial, version. Datatype: ARES_DATATYPE_U32
           ARES_RR_SOA_REFRESH   -   SOA   Record.  Refresh,  zone  refersh  interval.  Datatype:
           ARES_DATATYPE_U32
           ARES_RR_SOA_RETRY - SOA  Record.  Retry,  failed  refresh  retry  interval.  Datatype:
           ARES_DATATYPE_U32
           ARES_RR_SOA_EXPIRE   -  SOA  Record.  Expire,  upper  limit  on  authority.  Datatype:
           ARES_DATATYPE_U32
           ARES_RR_SOA_MINIMUM - SOA Record. Minimum, RR TTL. Datatype: ARES_DATATYPE_U32
           ARES_RR_PTR_DNAME -  PTR Record. DNAME, pointer domain. Datatype: ARES_DATATYPE_NAME
           ARES_RR_HINFO_CPU - HINFO Record. CPU. Datatype: ARES_DATATYPE_STR
           ARES_RR_HINFO_OS - HINFO Record. OS. Datatype: ARES_DATATYPE_STR
           ARES_RR_MX_PREFERENCE - MX Record. Preference. Datatype: ARES_DATATYPE_U16
           ARES_RR_MX_EXCHANGE - MX Record. Exchange, domain. Datatype: ARES_DATATYPE_NAME
           ARES_RR_TXT_DATA - TXT Record. Data. Datatype: ARES_DATATYPE_ABINP
           ARES_RR_SIG_TYPE_COVERED - SIG Record. Type Covered. Datatype: ARES_DATATYPE_U16
           ARES_RR_SIG_ALGORITHM - SIG Record. Algorithm. Datatype: ARES_DATATYPE_U8
           ARES_RR_SIG_LABELS - SIG Record. Labels. Datatype: ARES_DATATYPE_U8
           ARES_RR_SIG_ORIGINAL_TTL - SIG Record. Original TTL. Datatype: ARES_DATATYPE_U32
           ARES_RR_SIG_EXPIRATION - SIG Record. Signature Expiration. Datatype: ARES_DATATYPE_U32
           ARES_RR_SIG_INCEPTION - SIG Record. Signature Inception. Datatype: ARES_DATATYPE_U32
           ARES_RR_SIG_KEY_TAG - SIG Record. Key Tag. Datatype: ARES_DATATYPE_U16
           ARES_RR_SIG_SIGNERS_NAME - SIG Record. Signer's Name. Datatype: ARES_DATATYPE_NAME
           ARES_RR_SIG_SIGNATURE - SIG Record. Signature. Datatype: ARES_DATATYPE_BIN
           ARES_RR_AAAA_ADDR - AAAA Record. Address. Datatype: ARES_DATATYPE_INADDR6
           ARES_RR_SRV_PRIORITY - SRV Record. Priority. Datatype: ARES_DATATYPE_U16
           ARES_RR_SRV_WEIGHT - SRV Record. Weight. Datatype: ARES_DATATYPE_U16
           ARES_RR_SRV_PORT - SRV Record. Port. Datatype: ARES_DATATYPE_U16
           ARES_RR_SRV_TARGET - SRV Record. Target domain. Datatype: ARES_DATATYPE_NAME
           ARES_RR_NAPTR_ORDER - NAPTR Record. Order. Datatype: ARES_DATATYPE_U16
           ARES_RR_NAPTR_PREFERENCE - NAPTR Record. Preference. Datatype: ARES_DATATYPE_U16
           ARES_RR_NAPTR_FLAGS - NAPTR Record. Flags. Datatype: ARES_DATATYPE_STR
           ARES_RR_NAPTR_SERVICES - NAPTR Record. Services. Datatype: ARES_DATATYPE_STR
           ARES_RR_NAPTR_REGEXP - NAPTR Record. Regexp. Datatype: ARES_DATATYPE_STR
           ARES_RR_NAPTR_REPLACEMENT - NAPTR Record. Replacement. Datatype: ARES_DATATYPE_NAME
           ARES_RR_OPT_UDP_SIZE - OPT Record. UDP Size. Datatype: ARES_DATATYPE_U16
           ARES_RR_OPT_VERSION - OPT Record. Version. Datatype: ARES_DATATYPE_U8
           ARES_RR_OPT_FLAGS - OPT Record. Flags. Datatype: ARES_DATATYPE_U16
           ARES_RR_OPT_OPTIONS  -  OPT   Record.   Options.   See   ares_opt_param_t.   Datatype:
           ARES_DATATYPE_OPT
           ARES_RR_TLSA_CERT_USAGE  -  TLSA  Record.  Certificate  Usage.  See ares_tlsa_usage_t.
           Datatype: ARES_DATATYPE_U8
           ARES_RR_TLSA_SELECTOR - TLSA Record.  Selector.  See  ares_tlsa_selector_t.  Datatype:
           ARES_DATATYPE_U8
           ARES_RR_TLSA_MATCH  -  TLSA  Record.  Matching  Type. See ares_tlsa_match_t. Datatype:
           ARES_DATATYPE_U8
           ARES_RR_TLSA_DATA   -   TLSA   Record.   Certificate   Association   Data.   Datatype:
           ARES_DATATYPE_BIN
           ARES_RR_SVCB_PRIORITY - SVCB Record. SvcPriority. Datatype: ARES_DATATYPE_U16
           ARES_RR_SVCB_TARGET - SVCB Record. TargetName. Datatype: ARES_DATATYPE_NAME
           ARES_RR_SVCB_PARAMS   -  SVCB  Record.  SvcParams.  See  ares_svcb_param_t.  Datatype:
           ARES_DATATYPE_OPT
           ARES_RR_HTTPS_PRIORITY - HTTPS Record. SvcPriority. Datatype: ARES_DATATYPE_U16
           ARES_RR_HTTPS_TARGET - HTTPS Record. TargetName. Datatype: ARES_DATATYPE_NAME
           ARES_RR_HTTPS_PARAMS -  HTTPS  Record.  SvcParams.  See  ares_svcb_param_t.  Datatype:
           ARES_DATATYPE_OPT
           ARES_RR_URI_PRIORITY - URI Record. Priority. Datatype: ARES_DATATYPE_U16
           ARES_RR_URI_WEIGHT - URI Record. Weight. Datatype: ARES_DATATYPE_U16
           ARES_RR_URI_TARGET - URI Record. Target domain. Datatype: ARES_DATATYPE_NAME
           ARES_RR_CAA_CRITICAL - CAA Record. Critical flag. Datatype: ARES_DATATYPE_U8
           ARES_RR_CAA_TAG - CAA Record. Tag/Property. Datatype: ARES_DATATYPE_STR
           ARES_RR_CAA_VALUE - CAA Record. Value. Datatype: ARES_DATATYPE_BINP
           ARES_RR_RAW_RR_TYPE - RAW Record. RR Type. Datatype: ARES_DATATYPE_U16
           ARES_RR_RAW_RR_DATA - RAW Record. RR Data. Datatype: ARES_DATATYPE_BIN

       ares_tlsa_usage_t - TLSA Record ARES_RR_TLSA_CERT_USAGE known values
           ARES_TLSA_USAGE_CA - Certificate Usage 0. CA Constraint
           ARES_TLSA_USAGE_SERVICE - Certificate Usage 1. Service Certificate Constraint
           ARES_TLSA_USAGE_TRUSTANCHOR - Certificate Usage 2. Trust Anchor Assertion
           ARES_TLSA_USAGE_DOMAIN - Certificate Usage 3. Domain-issued certificate

       ares_tlsa_selector_t - TLSA Record ARES_RR_TLSA_SELECTOR known values:
           ARES_TLSA_SELECTOR_FULL - Full Certificate
           ARES_TLSA_SELECTOR_SUBJPUBKEYINFO - DER-encoded SubjectPublicKeyInfo

       ares_tlsa_match_t - TLSA Record ARES_RR_TLSA_MATCH known values:
           ARES_TLSA_MATCH_EXACT - Exact match
           ARES_TLSA_MATCH_SHA256 - Sha256 match
           ARES_TLSA_MATCH_SHA512 - Sha512 match

DESCRIPTION

       The  ares_dns_record_rr_cnt(3)  function returns the number of resource records in the DNS
       record provided by the dnsrec parameter for the section provided in the sect parameter.

       The ares_dns_record_rr_add(3) function adds a new resource record entry the the DNS record
       provided  by  the  dnsrec  parameter.   The  resulting  resource record is stored into the
       variable pointed to by rr_out.   The  DNS  section  the  resource  record  belongs  to  is
       specified  by  the sect parameter.  The domain name associated with the resource record is
       specified by the name parameter, which can not be NULL but may be an empty string, or ".".
       The  resource  record  type  is specified in the type parameter, along with the DNS record
       class in the rclass parameter, and the Time To Live (TTL) in the ttl parameter.

       The ares_dns_record_rr_get(3) and ares_dns_record_rr_get_const(3) functions  are  used  to
       retrieve the resource record pointer from the DNS record provided in the dnsrec parameter,
       for the resource record section provided in the sect parameter, for the specified index in
       the  idx  parameter.   The  index must be less than ares_dns_record_rr_cnt(3).  The former
       returns a writable pointer to the resource record, while the latter  returns  a  read-only
       pointer to the resource record.

       The  ares_dns_record_rr_del(3)  is  used  to  delete a resource record from the DNS record
       specified in the dnsrec parameter.  Its primary  use  is  to  remove  a  ARES_REC_TYPE_OPT
       record  when  needing  to  retry  a  query  without  EDNS  support.  The DNS RR section is
       specified via the sect parameter, and  the  index  to  remove  is  specified  in  the  idx
       parameter.  The index must be less than ares_dns_record_rr_cnt(3).

       The  ares_dns_rr_get_name(3)  function is used to retrieve the resource record domain name
       from the Resource Record pointer provided in the rr parameter.

       The ares_dns_rr_get_type(3) function is used to retrieve the resource record type from the
       Resource Record pointer provided in the rr parameter.

       The  ares_dns_rr_get_class(3)  function is used to retrieve the resource record class from
       the Resource Record pointer provided in the rr parameter.

       The ares_dns_rr_get_ttl(3) function is used to retrieve the resource record class Time  to
       Live (TTL) from the Resource Record pointer provided in the rr parameter.

       The  ares_dns_rr_set_addr(3)  function  is  used to set an IPv4 address for the associated
       resource record key/parameter when the datatype  is  ARES_DATATYPE_INADDR.   The  resource
       record  to  be modified is provided in the dns_rr parameter, the key/parameter is provided
       in the key parameter, and the value is provided in the addr parameter.

       The ares_dns_rr_set_addr6(3) function is used to set an IPv6 address  for  the  associated
       resource  record  key/parameter  when the datatype is ARES_DATATYPE_INADDR6.  The resource
       record to be modified is provided in the dns_rr parameter, the key/parameter  is  provided
       in the key parameter, and the value is provided in the addr parameter.

       The  ares_dns_rr_set_str(3)  function  is used to set a string for the associated resource
       record key/parameter when the datatype is ARES_DATATYPE_STR or  ARES_DATATYPE_NAME.   Most
       strings  are  limited  to  255 bytes, however some records, such as a TXT record may allow
       longer as they are output as multiple strings. The  resource  record  to  be  modified  is
       provided  in the dns_rr parameter, the key/parameter is provided in the key parameter, and
       the value is provided in the val parameter.

       The ares_dns_rr_set_u8(3) function  is  used  to  set  an  8bit  unsigned  value  for  the
       associated  resource  record  key/parameter  when  the  datatype is ARES_DATATYPE_U8.  The
       resource record to be modified is provided in the dns_rr parameter, the  key/parameter  is
       provided in the key parameter, and the value is provided in the val parameter.

       The  ares_dns_rr_set_u16(3)  function  is  used  to  set  an  16bit unsigned value for the
       associated resource record key/parameter when  the  datatype  is  ARES_DATATYPE_U16.   The
       resource  record  to be modified is provided in the dns_rr parameter, the key/parameter is
       provided in the key parameter, and the value is provided in the val parameter.

       The ares_dns_rr_set_u32(3) function is used  to  set  an  32bit  unsigned  value  for  the
       associated  resource  record  key/parameter  when  the datatype is ARES_DATATYPE_U32.  The
       resource record to be modified is provided in the dns_rr parameter, the  key/parameter  is
       provided in the key parameter, and the value is provided in the val parameter.

       The  ares_dns_rr_set_bin(3)  function  is  used  to  set a binary value for the associated
       resource   record   key/parameter   when   the   datatype    is    ARES_DATATYPE_BIN    or
       ARES_DATATYPE_BINP.   The  resource  record  to  be  modified  is  provided  in the dns_rr
       parameter, the key/parameter is provided in the key parameter, and the value  is  provided
       in the val parameter. And the associated value length is provided in the len parameter.

       The ares_dns_rr_add_abin(3) function is used to append a binary value in the array for the
       associated resource record key/parameter when the datatype  is  ARES_DATATYPE_ABINP.   The
       resource  record  to be modified is provided in the dns_rr parameter, the key/parameter is
       provided in the key parameter, and the value is provided in the  val  parameter.  And  the
       associated value length is provided in the len parameter.

       The ares_dns_rr_del_abin(3) function is used to delete a binary value in the array for the
       associated resource record key/parameter when the datatype  is  ARES_DATATYPE_ABINP.   The
       resource  record  to be modified is provided in the dns_rr parameter, the key/parameter is
       provided in the key parameter, and the index to remove is provided in the idx parameter.

       The ares_dns_rr_set_opt(3) function is used to set option/parameter keys  and  values  for
       the  resource  record  when  the datatype is ARES_DATATYPE_OPT.  The resource record to be
       modified is provided in the dns_rr parameter.  They key/parameter is provided in  the  key
       parameter.   The option/parameter value specific to the resource record is provided in the
       opt parameter, and this is left to the user to determine the  appropriate  value  to  use.
       Some  known values may be provided by ares_svcb_param_t and ares_opt_param_t enumerations.
       The value for the option is always provided in binary form in val with length provided  in
       val_len.

       The  ares_dns_rr_del_opt_byid(3)  function  is  used  to  delete option/parameter keys and
       values for the resource record when  the  datatype  is  ARES_DATATYPE_OPT.   The  resource
       record to be modified is provided in the dns_rr parameter.  They key/parameter is provided
       in the key parameter.  The option/parameter value  specific  to  the  resource  record  is
       provided  in  the  opt  parameter.   This  function  returns ARES_SUCCESS if the record is
       successfully removed, or ARES_ENOTFOUND if the record could not be found.

       The ares_dns_rr_get_addr(3) function is  used  to  retrieve  the  IPv4  address  from  the
       resource  record  when  the  datatype  is  ARES_DATATYPE_INADDR.   The  resource record is
       provided in the dns_rr parameter and the key/parameter to retrieve is provided in the  key
       parameter.

       The  ares_dns_rr_get_addr6(3)  function  is  used  to  retrieve  the IPv6 address from the
       resource record when the  datatype  is  ARES_DATATYPE_INADDR6.   The  resource  record  is
       provided  in the dns_rr parameter and the key/parameter to retrieve is provided in the key
       parameter.

       The ares_dns_rr_get_str(3) function is used to retrieve a string from the resource  record
       when  the  datatype  is  ARES_DATATYPE_STR  or ARES_DATATYPE_NAME.  The resource record is
       provided in the dns_rr parameter and the key/parameter to retrieve is provided in the  key
       parameter.

       The  ares_dns_rr_get_u8(3)  function is used to retrieve an 8bit integer from the resource
       record when the datatype is ARES_DATATYPE_U8.  The resource  record  is  provided  in  the
       dns_rr parameter and the key/parameter to retrieve is provided in the key parameter.

       The  ares_dns_rr_get_u16(3) function is used to retrieve a 16bit integer from the resource
       record when the datatype is ARES_DATATYPE_U16.  The resource record  is  provided  in  the
       dns_rr parameter and the key/parameter to retrieve is provided in the key parameter.

       The  ares_dns_rr_get_u32(3) function is used to retrieve a 32bit integer from the resource
       record when the datatype is ARES_DATATYPE_U32.  The resource record  is  provided  in  the
       dns_rr parameter and the key/parameter to retrieve is provided in the key parameter.

       The  ares_dns_rr_get_bin(3)  function  is  used  to retrieve binary data from the resource
       record when the datatype is ARES_DATATYPE_BIN or ARES_DATATYPE_BINP.  The resource  record
       is  provided  in the dns_rr parameter and the key/parameter to retrieve is provided in the
       key parameter, and length is stored into the variable pointed to by len.

       The ares_dns_rr_get_abin_cnt(3) function is used to retrieve the count  of  the  array  of
       stored  binary  values  from the resource record when the datatype is ARES_DATATYPE_ABINP.
       The resource record is provided in the dns_rr parameter and the key/parameter to  retrieve
       is provided in the key parameter.

       The  ares_dns_rr_get_abin(3)  function  is  used to retrieve binary data from the resource
       record array when the datatype is ARES_DATATYPE_ABINP.  The resource record is provided in
       the  dns_rr  parameter and the key/parameter to retrieve is provided in the key parameter,
       and the index to retrieve from the array is provided by the idx parameter, and  length  is
       stored into the variable pointed to by len.

       The   ares_dns_rr_get_opt_cnt(3)   function   is   used   to   retrieve   the   count   of
       options/parameters  associated  with  the   resource   record   when   the   datatype   is
       ARES_DATATYPE_OPT.   The  resource  record  is  provided  in  the dns_rr parameter and the
       key/parameter to retrieve is provided in the key.

       The ares_dns_rr_get_opt(3) function is used  to  retrieve  binary  option  data  from  the
       resource  record  when  the  datatype  is  ARES_DATATYPE_OPT for the specified index.  The
       resource record is provided in the dns_rr parameter and the key/parameter to  retrieve  is
       provided  in  the key parameter, the index to retrieve the option data from is provided in
       the idx parameter.  The value is stored into the variable pointed to by val and length  is
       stored into the variable pointed to by val_len.

       The  ares_dns_rr_get_opt_byid(3)  function is used to retrieve binary option data from the
       resource  record  when  the  datatype  is  ARES_DATATYPE_OPT  for  the  specified   option
       identifier, if it exists.  The resource record is provided in the dns_rr parameter and the
       key/parameter to retrieve is provided in the key parameter, the identifier to retrieve the
       option  data from is provided in the opt parameter.  The value is stored into the variable
       pointed to by val and length is stored into the variable pointed to by val_len.

RETURN VALUES

       ares_dns_record_rr_cnt(3) and ares_dns_rr_get_opt_cnt(3) return the respective counts.

       ares_dns_record_rr_add(3),       ares_dns_record_rr_del(3),       ares_dns_rr_set_addr(3),
       ares_dns_rr_set_addr6(3),          ares_dns_rr_set_str(3),          ares_dns_rr_set_u8(3),
       ares_dns_rr_set_u16(3),          ares_dns_rr_set_u32(3),           ares_dns_rr_set_bin(3),
       ares_dns_rr_add_abin(3), ares_dns_rr_del_abin(3), and ares_dns_rr_set_opt(3) all return an
       ares_status_t error code.  ARES_SUCCESS is returned on success, ARES_ENOMEM is returned on
       out of memory, ARES_EFORMERR is returned on misuse.

       ares_dns_rr_get_name(3),         ares_dns_rr_get_type(3),        ares_dns_rr_get_class(3),
       ares_dns_rr_get_ttl(3),         ares_dns_rr_get_addr(3),         ares_dns_rr_get_addr6(3),
       ares_dns_rr_get_str(3),           ares_dns_rr_get_u8(3),           ares_dns_rr_get_u16(3),
       ares_dns_rr_get_u32(3),        ares_dns_rr_get_bin(3),        ares_dns_rr_get_abin_cnt(3),
       ares_dns_rr_get_abin(3),  ares_dns_rr_get_opt(3)  all  return  their  prescribed  datatype
       values and in general can't fail except for misuse cases, in which a 0 (or  NULL)  may  be
       returned, however 0 can also be a valid return value for most of these functions.

       ares_dns_record_rr_get(3)  and  ares_dns_record_rr_get_const(3)  will return the requested
       resource record pointer or NULL on failure (misuse).

       ares_dns_rr_get_opt_byid(3) will return ARES_TRUE  if  the  option  was  found,  otherwise
       ARES_FALSE if not found (or misuse).

AVAILABILITY

       These functions were first introduced in c-ares version 1.22.0.

SEE ALSO

       ares_dns_mapping(3), ares_dns_record(3), ares_free_string(3)

                                         12 November 2023                          ARES_DNS_RR(3)