ref: 3a5ddf0610add4ea0663c4bf2d7f569ac723ad81
dir: /doc/api/libstd/dns.txt/
{
title: DNS
description: libstd: DNS
}
Networking
----------
pkg std =
type rectype = union
`DnsA /* host address */
`DnsNS /* authoritative name server */
`DnsCNAME /* canonical name for an alias */
`DnsSOA /* marks the start of a zone of authority */
`DnsWKS /* well known service description */
`DnsPTR /* domain name pointer */
`DnsHINFO /* host information */
`DnsMINFO /* mailbox or mail list information */
`DnsMX /* mail exchange */
`DnsTXT /* text strings */
`DnsAAAA /* ipv6 host address */
;;
type resolveerr = union
`Badhost
`Badsrv
`Badquery
`Badresp
;;
type hostinfo = struct
fam : sys.sockfam
stype : sys.socktype
ttl : uint32
addr : netaddr
;;
const resolve : (host : byte[:] -> result(hostinfo[:], resolveerr))
const resolvemx : (host : byte[:] -> result(hostinfo[:], resolveerr))
const resolverec : (host : byte[:], t : rectype -> result(hostinfo[:], resolveerr))
;;
Data Types
----------
type rectype = union
`DnsA /* host address */
`DnsNS /* authoritative name server */
`DnsCNAME /* canonical name for an alias */
`DnsSOA /* marks the start of a zone of authority */
`DnsWKS /* well known service description */
`DnsPTR /* domain name pointer */
`DnsHINFO /* host information */
`DnsMINFO /* mailbox or mail list information */
`DnsMX /* mail exchange */
`DnsTXT /* text strings */
`DnsAAAA /* ipv6 host address */
;;
This union contains all of the record types that we claim to know how to
resolve. At the moment, few of them have been tested sufficiently (only A
records can reasonably be said to be exercised).
type resolveerr = union
`Badhost
`Badsrv
`Badquery
`Badresp
;;
This union contains the errors that we can encounter when trying to resolve a
host.
type hostinfo = struct
fam : sys.sockfam
stype : sys.socktype
ttl : uint32
addr : netaddr
;;
DNS Resolution
--------------
const resolve : (host : byte[:] -> result(hostinfo[:], resolveerr))
Resolves the A or AAAA record for the host `host` using DNS. This function
does caching, expiring based on the TTL. Returns all of the host info entries sent
back by DNS or found in the cache on success, or a resolve error on failure.
const resolvemx : (host : byte[:] -> result(hostinfo[:], resolveerr))
Resolves the MX record for the host `host` using DNS. This function does
caching, expiring based on the TTL. Returns all of the host info entries sent
back by DNS or found in the cache on success, or a resolve error on failure.
const resolverec : (host : byte[:], t : rectype -> result(hostinfo[:], resolveerr))
Resolves a record from DNS. This function's interface is slightly broken, as
it will never work for TXT or CNAME records.