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%% Copyright (c) 2015 Peter Morgan <peter.james.morgan@gmail.com> |
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%% |
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%% Licensed under the Apache License, Version 2.0 (the "License"); |
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%% you may not use this file except in compliance with the License. |
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%% You may obtain a copy of the License at |
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%% |
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%% http://www.apache.org/licenses/LICENSE-2.0 |
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%% |
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%% Unless required by applicable law or agreed to in writing, software |
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%% distributed under the License is distributed on an "AS IS" BASIS, |
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%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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%% See the License for the specific language governing permissions and |
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%% limitations under the License. |
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-module(pcapng_options). |
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-export([parse/2]). |
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-export([parse/3]). |
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-export([null_terminated/1]). |
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-spec parse(binary(), fun((binary()) -> integer())) -> map(). |
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parse(<<>>, _) -> |
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1526 |
#{}; |
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parse(Packet, I) -> |
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parse(Packet, I, #{}). |
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-spec parse(binary(), fun((binary()) -> integer()), map()) -> map(). |
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parse(<<>>, _, _) -> |
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#{}; |
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parse(Packet, I, Mapping) -> |
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options(Packet, I, maps:merge(Mapping, mapping()), #{}). |
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options(<<0:16, 0:16>>, _, _, Options) -> |
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Options; |
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options(<<Code:16/bits, Length:16/bits, Remainder/binary >>, I, Mapping, |
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Options) -> |
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#{body := Value, |
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remainder := OtherOptions} = pcapng:variable_length(Remainder, I(Length)), |
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case maps:get(I(Code), Mapping, I(Code)) of |
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{Name, #{module := Module, function := Function}} -> |
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options(OtherOptions, I, Mapping, |
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Options#{Name => Module:Function(Value)}); |
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{Name, Transform} when is_function(Transform) -> |
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options(OtherOptions, I, Mapping, |
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Options#{Name => Transform(Value)}); |
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Name -> |
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options(OtherOptions, I, Mapping, maps:put(Name, Value, Options)) |
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end. |
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mapping() -> |
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#{1 => {opt_comment, fun null_terminated/1}}. |
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-spec null_terminated(binary()) -> binary(). |
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null_terminated(Comment) -> |
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ZeroTerminated = byte_size(Comment) - 1, |
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case binary:match(Comment, <<0>>) of |
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{ZeroTerminated, 1} -> |
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binary:part(Comment, 0, ZeroTerminated); |
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nomatch -> |
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Comment |
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end. |