%% Copyright (c) 2017-2022 Guilherme Andrade
%%
%% 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 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.
%%
%% locus is an independent project and has not been authorized, sponsored,
%% or otherwise approved by MaxMind.
%% @reference <a target="_parent" href="https://maxmind.github.io/MaxMind-DB/">
%% MaxMind DB File Format Specification</a>
%% @doc API for working with MMDB - metadata
-module(locus_mmdb_metadata).
%% ------------------------------------------------------------------
%% API Function Exports
%% ------------------------------------------------------------------
-export([parse_and_validate/1]).
%% ------------------------------------------------------------------
%% Macro Definitions
%% ------------------------------------------------------------------
-define(METADATA_MARKER, "\xab\xcd\xefMaxMind.com").
%% ------------------------------------------------------------------
%% Type Definitions
%% ------------------------------------------------------------------
-type t()
:: #{ binary_format_version := binary_format_version(),
node_count := locus_mmdb_data:uint32(),
record_size := locus_mmdb_data:uint16(),
ip_version := 4 | 6,
database_type := locus_mmdb_data:utf8_string(),
languages => [locus_mmdb_data:utf8_string()],
build_epoch := locus_mmdb_data:uint64(), % UNIX timestamp
description => #{locus_mmdb_data:utf8_string() => locus_mmdb_data:utf8_string()},
{'$_unrecognized_properties'} => #{locus_mmdb_data:utf8_string()
:= locus_mmdb_data_raw:value()}
}.
-export_type([t/0]).
-type binary_format_version() :: {2, locus_mmdb_data:uint16()}. % {Major, Minor}
-export_type([binary_format_version/0]).
-type parse_or_validation_error()
:: {marker_not_found, bitstring()}
| {atom(), term(), list()} % Stacktrace
| {not_a_map, term()}
| {incompatible_binary_format_version, {locus_mmdb_data_raw:uint16(),
locus_mmdb_data_raw:uint16()}}
| {invalid_binary_format_minor_version, term()}
| {invalid_binary_format_major_version, term()}
| {missing_metadata_keys, [unicode:unicode_binary(), ...]}
| {invalid_node_count, locus_mmdb_data_raw:value()}
| {missing_node_count, locus_mmdb_data_raw:map_()}
| {invalid_record_size, locus_mmdb_data_raw:value()}
| {missing_record_size, locus_mmdb_data_raw:map_()}
| {invalid_ip_version, locus_mmdb_data_raw:value()}
| {missing_ip_version, locus_mmdb_data_raw:map_()}
| {invalid_database_type, locus_mmdb_data_raw:value()}
| {missing_database_type, locus_mmdb_data_raw:map_()}
| {languages_not_an_array, locus_mmdb_data_raw:value()}
| {bad_languages, {language_number, pos_integer(), not_an_utf8_string,
locus_mmdb_data_raw:value()}}
| {description_not_a_map, locus_mmdb_data_raw:value()}
| {bad_description, {for_language_code, unicode:unicode_binary(),
{not_an_utf8_string, locus_mmdb_data_raw:value()}}}.
-export_type([parse_or_validation_error/0]).
%% ------------------------------------------------------------------
%% API Function Definitions
%% ------------------------------------------------------------------
%% @doc Parses and validates `Metadata' out of `EncodedDatabase'
%%
%% To proceed further with `TreeAndDataSection',
%% see {@link locus_mmdb:unpack_tree_data_and_data_section/2}.
%%
-spec parse_and_validate(EncodedDatabase) -> {ok, Metadata, TreeAndDataSection}
| {error, Reason}
when EncodedDatabase :: binary(),
Metadata :: t(),
TreeAndDataSection :: binary(),
Reason :: parse_or_validation_error().
parse_and_validate(EncodedDatabase) ->
case binary:matches(EncodedDatabase, <<?METADATA_MARKER>>) of
[_|_] = PossibleMetadataMarkers ->
{MetadataStart, _} = lists:last(PossibleMetadataMarkers),
<<TreeAndDataSection:MetadataStart/bytes,
?METADATA_MARKER,
EncodedMetadata/bytes>> = EncodedDatabase,
parse_and_validate(EncodedMetadata, TreeAndDataSection);
[] ->
{error, {marker_not_found, <<?METADATA_MARKER>>}}
end.
%% ------------------------------------------------------------------
%% Internal Function Definitions
%% ------------------------------------------------------------------
parse_and_validate(EncodedMetadata, TreeAndDataSection) ->
try locus_mmdb_data_codec:parse_on_index(0, EncodedMetadata, _Raw = true) of
{RawMetadata, _RemainingData} ->
validate(RawMetadata, TreeAndDataSection)
catch
Class:Reason:Stacktrace ->
{error, {Class, Reason, Stacktrace}}
end.
validate({map, MetadataMap}, TreeAndDataSection) ->
case validate_version(MetadataMap) of
{ok, Metadata} ->
{ok, Metadata, TreeAndDataSection};
{error, _} = Error ->
Error
end;
validate(NotAMap, _OtherSections) ->
{error, {not_a_map, NotAMap}}.
validate_version(#{<<"binary_format_major_version">> := MajorVersion,
<<"binary_format_minor_version">> := MinorVersion
} = MetadataMap)
->
case {MajorVersion, MinorVersion} of
{{uint16, 2}, {uint16, MinorVersionValue}} when MinorVersionValue >= 0 ->
RequiredKeys = [node_count, record_size, ip_version,
database_type, languages, build_epoch, description],
Acc0 = [{binary_format_version, {2, MinorVersionValue}}],
RemainingMetadataMap = maps:without([<<"binary_format_major_version">>,
<<"binary_format_minor_version">>],
MetadataMap),
validate_recur(RequiredKeys, RemainingMetadataMap, Acc0);
{{uint16, MajorVersionValue}, {uint16, MinorVersionValue}} ->
{error, {incompatible_binary_format_version, {MajorVersionValue, MinorVersionValue}}};
{{uint16, _}, _} ->
{error, {invalid_binary_format_minor_version, MinorVersion}};
{_, _} ->
{error, {invalid_binary_format_major_version, MajorVersion}}
end;
validate_version(MetadataMap) ->
RequiredKeys = [<<"binary_format_major_version">>, <<"binary_format_minor_version">>],
MissingKeys = RequiredKeys -- maps:keys(MetadataMap),
{error, {missing_metadata_keys, MissingKeys}}.
validate_recur([node_count | Next], MetadataMap, Acc) ->
case maps:take(<<"node_count">>, MetadataMap) of
{{uint32, NodeCountValue}, RemainingMetadataMap} ->
UpdatedAcc = [{node_count, NodeCountValue} | Acc],
validate_recur(Next, RemainingMetadataMap, UpdatedAcc);
{InvalidNodeCount, _} ->
{error, {invalid_node_count, InvalidNodeCount}};
error ->
{error, {missing_node_count, MetadataMap}}
end;
validate_recur([record_size | Next], MetadataMap, Acc) ->
case maps:take(<<"record_size">>, MetadataMap) of
{{uint16, RecordSizeValue}, RemainingMetadataMap} ->
UpdatedAcc = [{record_size, RecordSizeValue} | Acc],
validate_recur(Next, RemainingMetadataMap, UpdatedAcc);
{InvalidRecordSize, _} ->
{error, {invalid_record_size, InvalidRecordSize}};
error ->
{error, {missing_record_size, MetadataMap}}
end;
validate_recur([ip_version | Next], MetadataMap, Acc) ->
case maps:take(<<"ip_version">>, MetadataMap) of
{{uint16, IpVersionValue}, RemainingMetadataMap}
when IpVersionValue =:= 6; IpVersionValue =:= 4 ->
UpdatedAcc = [{ip_version, IpVersionValue} | Acc],
validate_recur(Next, RemainingMetadataMap, UpdatedAcc);
{InvalidIpVersion, _} ->
{error, {invalid_ip_version, InvalidIpVersion}};
error ->
{error, {missing_ip_version, MetadataMap}}
end;
validate_recur([database_type | Next], MetadataMap, Acc) ->
case maps:take(<<"database_type">>, MetadataMap) of
{{utf8_string, DatabaseTypeValue}, RemainingMetadataMap} ->
UpdatedAcc = [{database_type, DatabaseTypeValue} | Acc],
validate_recur(Next, RemainingMetadataMap, UpdatedAcc);
{InvalidDatabaseType, _} ->
{error, {invalid_database_type, InvalidDatabaseType}};
error ->
{error, {missing_database_type, MetadataMap}}
end;
validate_recur([languages | Next], MetadataMap, Acc) ->
case validate_languages(MetadataMap) of
{ok, LanguageValues, RemainingMetadataMap} ->
UpdatedAcc = [{languages, LanguageValues} | Acc],
validate_recur(Next, RemainingMetadataMap, UpdatedAcc);
{error, _} = Error ->
Error;
skip ->
validate_recur(Next, MetadataMap, Acc)
end;
validate_recur([build_epoch | Next], MetadataMap, Acc) ->
case maps:take(<<"build_epoch">>, MetadataMap) of
{{uint64, BuildEpochValue}, RemainingMetadataMap} ->
UpdatedAcc = [{build_epoch, BuildEpochValue} | Acc],
validate_recur(Next, RemainingMetadataMap, UpdatedAcc);
{InvalidBuildEpoch, _} ->
{error, {invalid_build_epoch, InvalidBuildEpoch}};
error ->
{error, {missing_build_epoch, MetadataMap}}
end;
validate_recur([description | Next], MetadataMap, Acc) ->
case validate_description(MetadataMap) of
{ok, DescriptionValue, RemainingMetadataMap} ->
UpdatedAcc = [{description, DescriptionValue} | Acc],
validate_recur(Next, RemainingMetadataMap, UpdatedAcc);
{error, _} = Error ->
Error;
skip ->
validate_recur(Next, MetadataMap, Acc)
end;
validate_recur([], MetadataMap, Acc) ->
case map_size(MetadataMap) =:= 0 of
true ->
Metadata = maps:from_list(Acc),
{ok, Metadata};
false ->
UpdatedAcc = [{{'$_unrecognized_properties'}, MetadataMap}],
Metadata = maps:from_list(UpdatedAcc),
{ok, Metadata}
end.
validate_languages(MetadataMap) ->
case maps:take(<<"languages">>, MetadataMap) of
{{array, Elements}, RemainingMetadataMap} ->
validate_languages_recur(Elements, RemainingMetadataMap, _Acc0 = []);
{NotAnArray, _} ->
{error, {languages_not_an_array, NotAnArray}};
error ->
% `languages' is optional
skip
end.
validate_languages_recur([{utf8_string, LanguageValue} | Next],
RemainingMetadataMap, Acc) ->
UpdatedAcc = [LanguageValue | Acc],
validate_languages_recur(Next, RemainingMetadataMap, UpdatedAcc);
validate_languages_recur([BadLanguage | _Next],
_RemainingMetadataMap, Acc) ->
Position = length(Acc) + 1,
{error, {bad_languages, {language_number, Position, not_an_utf8_string, BadLanguage}}};
validate_languages_recur([], RemainingMetadataMap, Acc) ->
LanguageValues = lists:reverse(Acc),
{ok, LanguageValues, RemainingMetadataMap}.
validate_description(MetadataMap) ->
case maps:take(<<"description">>, MetadataMap) of
{{map, Map}, RemainingMetadataMap} ->
KvList = maps:to_list(Map),
validate_description_recur(KvList, RemainingMetadataMap, _Acc0 = []);
{NotAMap, _} ->
{error, {description_not_a_map, NotAMap}};
error ->
% `description' is optional
skip
end.
validate_description_recur([{<<LanguageCode/bytes>>, {utf8_string, LocalizedDescription}}
| Next],
RemainingMetadataMap, Acc) ->
UpdatedAcc = [{LanguageCode, LocalizedDescription} | Acc],
validate_description_recur(Next, RemainingMetadataMap, UpdatedAcc);
validate_description_recur([{<<LanguageCode/bytes>>, BadLocalizedDescription}
| _Next],
_RemainingMetadataMap, _Acc) ->
{error, {bad_description, {for_language_code, LanguageCode,
{not_an_utf8_string, BadLocalizedDescription}}}};
validate_description_recur([], RemainingMetadataMap, Acc) ->
Description = maps:from_list(Acc),
{ok, Description, RemainingMetadataMap}.
