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621 lines
21 KiB
621 lines
21 KiB
.\" Copyright (C) 2023 The c-ares project and its contributors. |
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.\" SPDX-License-Identifier: MIT |
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.\" |
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.TH ARES_DNS_RR 3 "12 November 2023" |
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.SH NAME |
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DNS Resource record creating, reading, and writing functions. |
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.SH SYNOPSIS |
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.nf |
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#include <ares.h> |
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|
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size_t ares_dns_record_rr_cnt(const ares_dns_record_t *dnsrec, |
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ares_dns_section_t sect); |
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ares_status_t ares_dns_record_rr_add(ares_dns_rr_t **rr_out, |
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ares_dns_record_t *dnsrec, |
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ares_dns_section_t sect, |
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const char *name, |
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ares_dns_rec_type_t type, |
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ares_dns_class_t rclass, |
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unsigned int ttl); |
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ares_dns_rr_t *ares_dns_record_rr_get(ares_dns_record_t *dnsrec, |
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ares_dns_section_t sect, |
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size_t idx); |
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ares_status_t ares_dns_record_rr_del(ares_dns_record_t *dnsrec, |
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ares_dns_section_t sect, |
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size_t idx); |
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const char *ares_dns_rr_get_name(const ares_dns_rr_t *rr); |
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ares_dns_rec_type_t ares_dns_rr_get_type(const ares_dns_rr_t *rr); |
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ares_dns_class_t ares_dns_rr_get_class(const ares_dns_rr_t *rr); |
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unsigned int ares_dns_rr_get_ttl(const ares_dns_rr_t *rr); |
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ares_status_t ares_dns_rr_set_addr(ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key, |
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const struct in_addr *addr); |
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ares_status_t ares_dns_rr_set_addr6(ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key, |
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const struct ares_in6_addr *addr); |
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ares_status_t ares_dns_rr_set_str(ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key, |
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const char *val); |
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ares_status_t ares_dns_rr_set_u8(ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key, |
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unsigned char val); |
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ares_status_t ares_dns_rr_set_u16(ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key, |
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unsigned short val); |
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ares_status_t ares_dns_rr_set_u32(ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key, |
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unsigned int val); |
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ares_status_t ares_dns_rr_set_bin(ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key, |
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const unsigned char *val, |
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size_t len); |
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ares_status_t ares_dns_rr_set_opt(ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key, |
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unsigned short opt, |
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const unsigned char *val, |
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size_t val_len); |
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const struct in_addr *ares_dns_rr_get_addr(const ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key); |
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const struct ares_in6_addr *ares_dns_rr_get_addr6(const ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key); |
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const char *ares_dns_rr_get_str(const ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key); |
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unsigned char ares_dns_rr_get_u8(const ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key); |
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unsigned short ares_dns_rr_get_u16(const ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key); |
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unsigned int ares_dns_rr_get_u32(const ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key); |
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const unsigned char *ares_dns_rr_get_bin(const ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key, |
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size_t *len); |
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size_t ares_dns_rr_get_opt_cnt(const ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key); |
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unsigned short ares_dns_rr_get_opt(const ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key, |
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size_t idx, |
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const unsigned char **val, |
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size_t *val_len); |
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ares_bool_t ares_dns_rr_get_opt_byid(const ares_dns_rr_t *dns_rr, |
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ares_dns_rr_key_t key, |
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unsigned short opt, |
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const unsigned char **val, |
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size_t *val_len); |
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.fi |
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.SH ENUMERATIONS |
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|
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.B ares_dns_section_t - |
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DNS RR section types: |
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.RS 4 |
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.B ARES_SECTION_ANSWER |
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- Answer section |
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.br |
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.B ARES_SECTION_AUTHORITY |
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- Authority section |
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.br |
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.B ARES_SECTION_ADDITIONAL |
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- Additional Information section |
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.br |
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.RE |
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|
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.B ares_dns_rr_key_t - |
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Keys used for handling RR record parameters: |
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.RS 4 |
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.B ARES_RR_A_ADDR |
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- A Record. Address. Datatype: \fIARES_DATATYPE_INADDR\fP |
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.br |
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.B ARES_RR_NS_NSDNAME |
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- NS Record. Name. Datatype: \fIARES_DATATYPE_NAME\fP |
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.br |
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.B ARES_RR_CNAME_CNAME |
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- CNAME Record. CName. Datatype: \fIARES_DATATYPE_NAME\fP |
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.br |
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.B ARES_RR_SOA_MNAME |
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- SOA Record. MNAME, Primary Source of Data. Datatype: \fIARES_DATATYPE_NAME\fP |
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.br |
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.B ARES_RR_SOA_RNAME |
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- SOA Record. RNAME, Mailbox of person responsible. Datatype: \fIARES_DATATYPE_NAME\fP |
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.br |
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.B ARES_RR_SOA_SERIAL |
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- SOA Record. Serial, version. Datatype: \fIARES_DATATYPE_U32\fP |
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.br |
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.B ARES_RR_SOA_REFRESH |
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- SOA Record. Refresh, zone refersh interval. Datatype: \fIARES_DATATYPE_U32\fP |
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.br |
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.B ARES_RR_SOA_RETRY |
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- SOA Record. Retry, failed refresh retry interval. Datatype: \fIARES_DATATYPE_U32\fP |
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.br |
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.B ARES_RR_SOA_EXPIRE |
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- SOA Record. Expire, upper limit on authority. Datatype: \fIARES_DATATYPE_U32\fP |
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.br |
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.B ARES_RR_SOA_MINIMUM |
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- SOA Record. Minimum, RR TTL. Datatype: \fIARES_DATATYPE_U32\fP |
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.br |
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.B ARES_RR_PTR_DNAME |
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- PTR Record. DNAME, pointer domain. Datatype: \fIARES_DATATYPE_NAME\fP |
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.br |
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.B ARES_RR_HINFO_CPU |
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- HINFO Record. CPU. Datatype: \fIARES_DATATYPE_STR\fP |
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.br |
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.B ARES_RR_HINFO_OS |
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- HINFO Record. OS. Datatype: \fIARES_DATATYPE_STR\fP |
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.br |
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.B ARES_RR_MX_PREFERENCE |
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- MX Record. Preference. Datatype: \fIARES_DATATYPE_U16\fP |
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.br |
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.B ARES_RR_MX_EXCHANGE |
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- MX Record. Exchange, domain. Datatype: \fIARES_DATATYPE_NAME\fP |
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.br |
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.B ARES_RR_TXT_DATA |
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- TXT Record. Data. Datatype: \fIARES_DATATYPE_BINP\fP |
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.br |
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.B ARES_RR_AAAA_ADDR |
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- AAAA Record. Address. Datatype: \fIARES_DATATYPE_INADDR6\fP |
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.br |
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.B ARES_RR_SRV_PRIORITY |
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- SRV Record. Priority. Datatype: \fIARES_DATATYPE_U16\fP |
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.br |
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.B ARES_RR_SRV_WEIGHT |
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- SRV Record. Weight. Datatype: \fIARES_DATATYPE_U16\fP |
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.br |
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.B ARES_RR_SRV_PORT |
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- SRV Record. Port. Datatype: \fIARES_DATATYPE_U16\fP |
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.br |
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.B ARES_RR_SRV_TARGET |
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- SRV Record. Target domain. Datatype: \fIARES_DATATYPE_NAME\fP |
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.br |
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.B ARES_RR_NAPTR_ORDER |
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- NAPTR Record. Order. Datatype: \fIARES_DATATYPE_U16\fP |
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.br |
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.B ARES_RR_NAPTR_PREFERENCE |
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- NAPTR Record. Preference. Datatype: \fIARES_DATATYPE_U16\fp |
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.br |
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.B ARES_RR_NAPTR_FLAGS |
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- NAPTR Record. Flags. Datatype: \fIARES_DATATYPE_STR\fP |
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.br |
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.B ARES_RR_NAPTR_SERVICES |
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- NAPTR Record. Services. Datatype: \fIARES_DATATYPE_STR\fP |
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.br |
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.B ARES_RR_NAPTR_REGEXP |
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- NAPTR Record. Regexp. Datatype: \fIARES_DATATYPE_STR\fP |
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.br |
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.B ARES_RR_NAPTR_REPLACEMENT |
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- NAPTR Record. Replacement. Datatype: \fIARES_DATATYPE_NAME\fP |
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.br |
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.B ARES_RR_OPT_UDP_SIZE |
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- OPT Record. UDP Size. Datatype: \fIARES_DATATYPE_U16\fP |
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.br |
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.B ARES_RR_OPT_VERSION |
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- OPT Record. Version. Datatype: \fIARES_DATATYPE_U8\fP |
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.br |
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.B ARES_RR_OPT_FLAGS |
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- OPT Record. Flags. Datatype: \fIARES_DATATYPE_U16\fP |
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.br |
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.B ARES_RR_OPT_OPTIONS |
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- OPT Record. Options. See \fIares_opt_param_t\fP. Datatype: \fIARES_DATATYPE_OPT\fP |
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.br |
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.B ARES_RR_TLSA_CERT_USAGE |
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- TLSA Record. Certificate Usage. See \fIares_tlsa_usage_t\fP. Datatype: \fIARES_DATATYPE_U8\fP |
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.br |
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.B ARES_RR_TLSA_SELECTOR |
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- TLSA Record. Selector. See \fIares_tlsa_selector_t\fP. Datatype: \fIARES_DATATYPE_U8\fP |
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.br |
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.B ARES_RR_TLSA_MATCH |
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- TLSA Record. Matching Type. See \fIares_tlsa_match_t\fP. Datatype: \fIARES_DATATYPE_U8\fP |
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.br |
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.B ARES_RR_TLSA_DATA |
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- TLSA Record. Certificate Association Data. Datatype: \fIARES_DATATYPE_BIN\fP |
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.br |
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.B ARES_RR_SVCB_PRIORITY |
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- SVCB Record. SvcPriority. Datatype: \fIARES_DATATYPE_U16\fP |
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.br |
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.B ARES_RR_SVCB_TARGET |
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- SVCB Record. TargetName. Datatype: \fIARES_DATATYPE_NAME\fP |
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.br |
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.B ARES_RR_SVCB_PARAMS |
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- SVCB Record. SvcParams. See \fIares_svcb_param_t\fP. Datatype: \fIARES_DATATYPE_OPT\fP |
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.br |
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.B ARES_RR_HTTPS_PRIORITY |
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- HTTPS Record. SvcPriority. Datatype: \fIARES_DATATYPE_U16\fP |
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.br |
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.B ARES_RR_HTTPS_TARGET |
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- HTTPS Record. TargetName. Datatype: \fIARES_DATATYPE_NAME\fP |
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.br |
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.B ARES_RR_HTTPS_PARAMS |
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- HTTPS Record. SvcParams. See \fIares_svcb_param_t\fP. Datatype: \fIARES_DATATYPE_OPT\fP |
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.br |
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.B ARES_RR_URI_PRIORITY |
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- URI Record. Priority. Datatype: \fIARES_DATATYPE_U16\fP |
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.br |
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.B ARES_RR_URI_WEIGHT |
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- URI Record. Weight. Datatype: \fIARES_DATATYPE_U16\fP |
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.br |
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.B ARES_RR_URI_TARGET |
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- URI Record. Target domain. Datatype: \fIARES_DATATYPE_NAME\fP |
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.br |
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.B ARES_RR_CAA_CRITICAL |
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- CAA Record. Critical flag. Datatype: \fIARES_DATATYPE_U8\fP |
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.br |
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.B ARES_RR_CAA_TAG |
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- CAA Record. Tag/Property. Datatype: \fIARES_DATATYPE_STR\fP |
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.br |
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.B ARES_RR_CAA_VALUE |
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- CAA Record. Value. Datatype: \fIARES_DATATYPE_BINP\fP |
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.br |
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.B ARES_RR_RAW_RR_TYPE |
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- RAW Record. RR Type. Datatype: \fIARES_DATATYPE_U16\fP |
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.br |
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.B ARES_RR_RAW_RR_DATA |
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- RAW Record. RR Data. Datatype: \fIARES_DATATYPE_BIN\fP |
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.br |
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.RE |
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.B ares_tlsa_usage_t - |
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TLSA Record \fIARES_RR_TLSA_CERT_USAGE\fP known values |
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.RS 4 |
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.B ARES_TLSA_USAGE_CA |
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- Certificate Usage 0. CA Constraint |
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.br |
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.B ARES_TLSA_USAGE_SERVICE |
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- Certificate Usage 1. Service Certificate Constraint |
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.br |
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.B ARES_TLSA_USAGE_TRUSTANCHOR |
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- Certificate Usage 2. Trust Anchor Assertation |
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.br |
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.B ARES_TLSA_USAGE_DOMAIN |
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- Certificate Usage 3. Domain-issued certificate |
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.br |
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.RE |
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|
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.B ares_tlsa_selector_t - |
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TLSA Record \fIARES_RR_TLSA_SELECTOR\fP known values: |
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.RS 4 |
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.B ARES_TLSA_SELECTOR_FULL |
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- Full Certificate |
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.br |
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.B ARES_TLSA_SELECTOR_SUBJPUBKEYINFO |
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- DER-encoded SubjectPublicKeyInfo |
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.br |
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.RE |
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.B ares_tlsa_match_t - |
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TLSA Record \fIARES_RR_TLSA_MATCH\fP known values: |
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.RS 4 |
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.B ARES_TLSA_MATCH_EXACT |
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- Exact match |
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.br |
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.B ARES_TLSA_MATCH_SHA256 |
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- Sha256 match |
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.br |
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.B ARES_TLSA_MATCH_SHA512 |
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- Sha512 match |
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.br |
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.RE |
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.SH DESCRIPTION |
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The \fIares_dns_record_rr_cnt(3)\fP function returns the number of resource |
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records in the DNS record provided by the |
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.IR dnsrec |
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parameter for the section provided in the |
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.IR sect |
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parameter. |
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|
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The \fIares_dns_record_rr_add(3)\fP function adds a new resource record entry |
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the the DNS record provided by the |
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.IR dnsrec |
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parameter. The resulting resource record is stored into the variable pointed to by |
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.IR rr_out. |
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The DNS section the resource record belongs to is specified by the |
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.IR sect |
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parameter. The domain name associated with the resource record is specified by the |
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.IR name |
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parameter, which can not be NULL but may be an empty string, or ".". The resource |
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record type is specified in the |
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.IR type |
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parameter, along withe the DNS record class in the |
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.IR rclass |
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parameter, and the Time To Live (TTL) in the |
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.IR ttl |
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parameter. |
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The \fIares_dns_record_rr_get(3)\fP function is used to retrieve the resource |
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record pointer from the DNS record provided in the |
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.IR dnsrec |
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parameter, for the resource record section provided in the |
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.IR sect |
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parameter, for the specified index in the |
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.IR idx |
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parameter. The index must be less than \fIares_dns_record_rr_cnt(3)\fP. |
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The \fIares_dns_record_rr_del(3)\fP is used to delete a resource record from |
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the DNS record specified in the |
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.IR dnsrec |
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parameter. Its primary use is to remove a \fIARES_REC_TYPE_OPT\fP record when |
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needing to retry a query without EDNS support. The DNS RR section is specified |
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via the |
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.IR sect |
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parameter, and the index to remove is specified in the |
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.IR idx |
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parameter. The index must be less than \fIares_dns_record_rr_cnt(3)\fP. |
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|
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The \fIares_dns_rr_get_name(3)\fP function is used to retrieve the resource |
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record domain name from the Resource Record pointer provided in the |
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.IR rr |
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parameter. |
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|
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The \fIares_dns_rr_get_type(3)\fP function is used to retrieve the resource |
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record type from the Resource Record pointer provided in the |
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.IR rr |
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parameter. |
|
|
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The \fIares_dns_rr_get_class(3)\fP function is used to retrieve the resource |
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record class from the Resource Record pointer provided in the |
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.IR rr |
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parameter. |
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|
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The \fIares_dns_rr_get_ttl(3)\fP function is used to retrieve the resource |
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record class Time to Live (TTL) from the Resource Record pointer provided in the |
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.IR rr |
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parameter. |
|
|
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The \fIares_dns_rr_set_addr(3)\fP function is used to set an IPv4 address for the |
|
associated resource record key/parameter when the datatype is \fIARES_DATATYPE_INADDR\fP. |
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The resource record to be modified is provided in the |
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.IR dns_rr |
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parameter, the key/parameter is provided in the |
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.IR key |
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parameter, and the value is provided in the |
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.IR addr |
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parameter. |
|
|
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The \fIares_dns_rr_set_addr6(3)\fP function is used to set an IPv6 address for the |
|
associated resource record key/parameter when the datatype is \fIARES_DATATYPE_INADDR6\fP. |
|
The resource record to be modified is provided in the |
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.IR dns_rr |
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parameter, the key/parameter is provided in the |
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.IR key |
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parameter, and the value is provided in the |
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.IR addr |
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parameter. |
|
|
|
The \fIares_dns_rr_set_str(3)\fP function is used to set a string for the |
|
associated resource record key/parameter when the datatype is \fIARES_DATATYPE_STR\fP |
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or \fIARES_DATATYPE_NAME\fP. Most strings are limited to 255 bytes, |
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however some records, such as a TXT record may allow longer as they are output |
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as multiple strings. The resource record to be modified is |
|
provided in the |
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.IR dns_rr |
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parameter, the key/parameter is provided in the |
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.IR key |
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parameter, and the value is provided in the |
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.IR val |
|
parameter. |
|
|
|
The \fIares_dns_rr_set_u8(3)\fP function is used to set an 8bit unsigned value for the |
|
associated resource record key/parameter when the datatype is \fIARES_DATATYPE_U8\fP. |
|
The resource record to be modified is provided in the |
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.IR dns_rr |
|
parameter, the key/parameter is provided in the |
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.IR key |
|
parameter, and the value is provided in the |
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.IR val |
|
parameter. |
|
|
|
The \fIares_dns_rr_set_u16(3)\fP function is used to set an 16bit unsigned value for the |
|
associated resource record key/parameter when the datatype is \fIARES_DATATYPE_U16\fP. |
|
The resource record to be modified is provided in the |
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.IR dns_rr |
|
parameter, the key/parameter is provided in the |
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.IR key |
|
parameter, and the value is provided in the |
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.IR val |
|
parameter. |
|
|
|
The \fIares_dns_rr_set_u32(3)\fP function is used to set an 32bit unsigned value for the |
|
associated resource record key/parameter when the datatype is \fIARES_DATATYPE_U32\fP. |
|
The resource record to be modified is provided in the |
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.IR dns_rr |
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parameter, the key/parameter is provided in the |
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.IR key |
|
parameter, and the value is provided in the |
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.IR val |
|
parameter. |
|
|
|
The \fIares_dns_rr_set_bin(3)\fP function is used to set an binary value for the |
|
associated resource record key/parameter when the datatype is \fIARES_DATATYPE_BIN\fP |
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or \fIARES_DATATYPE_BINP\fP. |
|
The resource record to be modified is provided in the |
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.IR dns_rr |
|
parameter, the key/parameter is provided in the |
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.IR key |
|
parameter, and the value is provided in the |
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.IR val |
|
parameter. And the associated value length is provided in the |
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.IR len |
|
parameter. |
|
|
|
The \fIares_dns_rr_set_opt(3)\fP function is used to set option/parameter keys and |
|
values for the resource record when the datatype if \fIARES_DATATYPE_OPT\fP. The |
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resource record to be modified is provided in the |
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.IR dns_rr |
|
parameter. They key/parameter is provided in the |
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.IR key |
|
parameter. The option/parameter value specific to the resource record is provided |
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in the |
|
.IR opt |
|
parameter, and this is left to the user to determine the appropriate value to |
|
use. Some known values may be provided by \fIares_svcb_param_t\fP and \fIares_opt_param_t\fP |
|
enumerations. The value for the option is always provided in binary form in |
|
.IR val |
|
with length provided in |
|
.IR val_len. |
|
|
|
The \fIares_dns_rr_get_addr(3)\fP function is used to retrieve the IPv4 address |
|
from the resource record when the datatype is \fIARES_DATATYPE_INADDR\fP. The |
|
resource record is provided in the |
|
.IR dns_rr |
|
parameter and the key/parameter to retrieve is provided in the |
|
.IR key |
|
parameter. |
|
|
|
The \fIares_dns_rr_get_addr6(3)\fP function is used to retrieve the IPv6 address |
|
from the resource record when the datatype is \fIARES_DATATYPE_INADDR6\fP. The |
|
resource record is provided in the |
|
.IR dns_rr |
|
parameter and the key/parameter to retrieve is provided in the |
|
.IR key |
|
parameter. |
|
|
|
The \fIares_dns_rr_get_str(3)\fP function is used to retrieve a string |
|
from the resource record when the datatype is \fIARES_DATATYPE_STR\fP or |
|
\fIARES_DATATYPE_NAME\fP. The resource record is provided in the |
|
.IR dns_rr |
|
parameter and the key/parameter to retrieve is provided in the |
|
.IR key |
|
parameter. |
|
|
|
The \fIares_dns_rr_get_u8(3)\fP function is used to retrieve an 8bit integer |
|
from the resource record when the datatype is \fIARES_DATATYPE_U8\fP. |
|
The resource record is provided in the |
|
.IR dns_rr |
|
parameter and the key/parameter to retrieve is provided in the |
|
.IR key |
|
parameter. |
|
|
|
The \fIares_dns_rr_get_u16(3)\fP function is used to retrieve a 16bit integer |
|
from the resource record when the datatype is \fIARES_DATATYPE_U16\fP. |
|
The resource record is provided in the |
|
.IR dns_rr |
|
parameter and the key/parameter to retrieve is provided in the |
|
.IR key |
|
parameter. |
|
|
|
The \fIares_dns_rr_get_u32(3)\fP function is used to retrieve a 32bit integer |
|
from the resource record when the datatype is \fIARES_DATATYPE_U32\fP. |
|
The resource record is provided in the |
|
.IR dns_rr |
|
parameter and the key/parameter to retrieve is provided in the |
|
.IR key |
|
parameter. |
|
|
|
The \fIares_dns_rr_get_bin(3)\fP function is used to retrieve binary data |
|
from the resource record when the datatype is \fIARES_DATATYPE_BIN\fP or |
|
\fIARES_DATATYPE_BINP\fP. |
|
The resource record is provided in the |
|
.IR dns_rr |
|
parameter and the key/parameter to retrieve is provided in the |
|
.IR key |
|
parameter, and length is stored into the variable pointed to by |
|
.IR len. |
|
|
|
The \fIares_dns_rr_get_opt_cnt(3)\fP function is used to retrieve the count |
|
of options/parameters associated with the resource record when the datatype |
|
is \fIARES_DATATYPE_OPT\fP. |
|
The resource record is provided in the |
|
.IR dns_rr |
|
parameter and the key/parameter to retrieve is provided in the |
|
.IR key. |
|
|
|
The \fIares_dns_rr_get_opt(3)\fP function is used to retrieve binary option data |
|
from the resource record when the datatype is \fIARES_DATATYPE_OPT\fP for the |
|
specified index. |
|
The resource record is provided in the |
|
.IR dns_rr |
|
parameter and the key/parameter to retrieve is provided in the |
|
.IR key |
|
parameter, the index to retrieve the option data from is provided in the |
|
.IR idx |
|
parameter. The value is stored into the variable pointed to by |
|
.IR val |
|
and length is stored into the variable pointed to by |
|
.IR val_len. |
|
|
|
The \fIares_dns_rr_get_opt_byid(3)\fP function is used to retrieve binary option data |
|
from the resource record when the datatype is \fIARES_DATATYPE_OPT\fP for the |
|
specified option identifier, if it exists. |
|
The resource record is provided in the |
|
.IR dns_rr |
|
parameter and the key/parameter to retrieve is provided in the |
|
.IR key |
|
parameter, the identifier to retrieve the option data from is provided in the |
|
.IR opt |
|
parameter. The value is stored into the variable pointed to by |
|
.IR val |
|
and length is stored into the variable pointed to by |
|
.IR val_len. |
|
|
|
|
|
.SH RETURN VALUES |
|
|
|
\fIares_dns_record_rr_cnt(3)\fP and \fIares_dns_rr_get_opt_cnt(3)\fP return the |
|
respective counts. |
|
|
|
\fIares_dns_record_rr_add(3)\fP, \fIares_dns_record_rr_del(3)\fP, |
|
\fIares_dns_rr_set_addr(3)\fP, \fIares_dns_rr_set_addr6(3)\fP, |
|
\fIares_dns_rr_set_str(3)\fP, \fIares_dns_rr_set_u8(3)\fP, |
|
\fIares_dns_rr_set_u16(3)\fP, \fIares_dns_rr_set_u32(3)\fP, |
|
\fIares_dns_rr_set_bin(3)\fP, and \fIares_dns_rr_set_opt(3)\fP all |
|
return an \fIares_status_t\fP error code. |
|
.B ARES_SUCCESS |
|
is returned on success, |
|
.B ARES_ENOMEM |
|
is returned on out of memory, |
|
.B ARES_EFORMERR |
|
is returned on misuse. |
|
|
|
|
|
\fIares_dns_rr_get_name(3)\fP, \fIares_dns_rr_get_type(3)\fP, |
|
\fIares_dns_rr_get_class(3)\fP, \fIares_dns_rr_get_ttl(3)\fP, |
|
\fIares_dns_rr_get_addr(3)\fP, \fIares_dns_rr_get_addr6(3)\fP, |
|
\fIares_dns_rr_get_str(3)\fP, \fIares_dns_rr_get_u8(3)\fP, |
|
\fIares_dns_rr_get_u16(3)\fP, \fIares_dns_rr_get_u32(3)\fP, |
|
\fIares_dns_rr_get_bin(3)\fP, \fIares_dns_rr_get_opt(3)\fP 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. |
|
|
|
\fIares_dns_record_rr_get(3)\fP will return the requested resource record |
|
pointer or NULL on failure (misuse). |
|
|
|
\fIares_dns_rr_get_opt_by_id(3)\fP will return ARES_TRUE if the option was |
|
found, otherwise ARES_FALSE if not found (or misuse). |
|
|
|
.SH AVAILABILITY |
|
These functions were first introduced in c-ares version 1.22.0. |
|
.SH SEE ALSO |
|
.BR ares_dns_mapping (3), |
|
.BR ares_dns_record (3), |
|
.BR ares_free_string (3) |
|
.SH AUTHOR |
|
Copyright (C) 2023 The c-ares project and its members.
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