/
record.ex
67 lines (54 loc) · 1.85 KB
/
record.ex
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defmodule DNS.Record do
@moduledoc """
Struct definition for serializing and parsing DNS records.
"""
record = Record.extract(:dns_rec, from_lib: "kernel/src/inet_dns.hrl")
keys = :lists.map(&elem(&1, 0), record)
vals = :lists.map(&{&1, [], nil}, keys)
pairs = :lists.zip(keys, vals)
defstruct record
@type t :: %__MODULE__{}
@doc """
Converts a `DNS.Record` struct to a `:dns_rec` record.
"""
def to_record(struct) do
header = DNS.Header.to_record(struct.header)
queries = Enum.map(struct.qdlist, &DNS.Query.to_record/1)
answers = Enum.map(struct.anlist, &DNS.Resource.to_record/1)
additional = Enum.map(struct.arlist, &DNS.Resource.to_record/1)
_to_record(%{struct | header: header, qdlist: queries, anlist: answers, arlist: additional})
end
defp _to_record(%DNS.Record{unquote_splicing(pairs)}) do
{:dns_rec, unquote_splicing(vals)}
end
@doc """
Converts a `:dns_rec` record into a `DNS.Record`.
"""
def from_record(dns_rec)
def from_record({:dns_rec, unquote_splicing(vals)}) do
struct = %DNS.Record{unquote_splicing(pairs)}
header = DNS.Header.from_record(struct.header)
queries = Enum.map(struct.qdlist, &DNS.Query.from_record(&1))
answers =
Enum.map(struct.anlist, &DNS.Resource.from_record(&1))
|> Enum.reject(&is_nil/1)
additional =
Enum.map(struct.arlist, &DNS.Resource.from_record(&1))
|> Enum.reject(&is_nil/1)
%{struct | header: header, qdlist: queries, anlist: answers, arlist: additional}
end
@doc """
Decodes a binary record into a `DNS.Record` struct.
"""
@spec decode(binary) :: DNS.Record.t()
def decode(data) do
{:ok, record} = :inet_dns.decode(data)
from_record(record)
end
@doc """
Serializes a `DNS.Record` into its binary representation.
"""
def encode(struct) do
:inet_dns.encode(to_record(struct))
end
end