%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2005-2016. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
%%
-module(httpd_cgi).
-export([parse_headers/1, handle_headers/1]).
-include_lib("inets/src/inets_app/inets_internal.hrl").
%%%=========================================================================
%%% Internal application API
%%%=========================================================================
%%--------------------------------------------------------------------------
%% parse_headers([Bin, Data, Header, Headers]) -> {RevHeaders, Body} |
%% {Module, Function, Args}
%% Bin = Data = binary()
%% Header = string() - Accumulator should be [] in first call
%% Headers = [Header] - Accumulator should be [] in first call
%% Body = string()
%% RevHeaders = string() - Note CGI-headers not HTTP-headers
%%
%% Description: Parses "<<Bin/binary, Data/binary>>" returned from the
%% CGI-script until it findes the end of the CGI-headers (at least one
%% CGI-HeaderField must be supplied) then it returns the CGI-headers
%% and maybe some body data. If {Module, Function, Args} is
%% returned it means that more data needs to be collected from the
%% cgi-script as the end of the headers was not yet found. When more
%% data has been collected call Module:Function([NewData | Args]).
%%
%% NOTE: The headers are backwards and should
%% be so, devide_and_reverse_headers will reverse them back after
%% taking advantage of the fact that they where backwards.
%%--------------------------------------------------------------------------
parse_headers([Data, Bin, Header, Headers]) ->
parse_headers(<<Bin/binary, Data/binary>>, Header, Headers).
%%--------------------------------------------------------------------------
%% handle_headers(CGIHeaders) -> {ok, HTTPHeaders, StatusCode} |
%% {proceed, AbsPath}
%% CGIHeaders = [string()]
%% HTTPHeaders = [{HeaderField, HeaderValue}]
%% HeaderField = string()
%% HeaderValue = string()
%% StatusCode = integer()
%%
%% Description: Interprets CGI headers and creates HTTP headers and a
%% appropriate HTTP status code. Note if a CGI location header is present
%% the return value will be {proceed, AbsPath}
%%--------------------------------------------------------------------------
handle_headers(CGIHeaders) ->
handle_headers(CGIHeaders, [], {200, "ok"}).
%%%========================================================================
%%% Internal functions
%%%========================================================================
parse_headers(<<>>, Header, Headers) ->
{?MODULE, parse_headers, [<<>>, Header, Headers]};
parse_headers(<<?CR,?LF>>, Header, Headers) ->
{?MODULE, parse_headers, [<<?CR,?LF>>, Header, Headers]};
parse_headers(<<?LF>>, Header, Headers) ->
{?MODULE, parse_headers, [<<?LF>>, Header, Headers]};
parse_headers(<<?CR, ?LF, ?CR, ?LF, Rest/binary>>, Header, Headers) ->
{ok, {[lists:reverse([?LF, ?CR | Header]) | Headers], Rest}};
parse_headers(<<?LF, ?LF, Rest/binary>>, Header, Headers) ->
{ok, {[lists:reverse([?LF | Header]) | Headers], Rest}};
parse_headers(<<?CR, ?LF, Rest/binary>>, Header, Headers) ->
parse_headers(Rest, [], [lists:reverse([?LF, ?CR | Header]) | Headers]);
parse_headers(<<?LF, Rest/binary>>, Header, Headers) ->
parse_headers(Rest, [], [lists:reverse([?LF | Header]) | Headers]);
parse_headers(<<Octet, Rest/binary>>, Header, Headers) ->
parse_headers(Rest, [Octet | Header], Headers).
handle_headers([], HTTPHeaders, Status) ->
{ok, HTTPHeaders, Status};
handle_headers([CGIHeader | CGIHeaders], HTTPHeaders, Status) ->
{FieldName, FieldValue} = httpd_response:split_header(CGIHeader, []),
case FieldName of
"content-type" ->
handle_headers(CGIHeaders,
[{FieldName, FieldValue} | HTTPHeaders],
Status);
"location" ->
case http_request:is_absolut_uri(FieldValue) of
true ->
handle_headers(CGIHeaders,
[{FieldName, FieldValue} |
HTTPHeaders], {302, "Redirect"});
false ->
{proceed, FieldValue}
end;
"status" ->
CodePhrase =
case httpd_util:split(FieldValue," ",2) of
{ok,[Code, Phrase]} ->
{list_to_integer(Code), Phrase};
_ ->
{200, "OK"}
end,
handle_headers(CGIHeaders, HTTPHeaders, CodePhrase);
_ -> %% Extension headers
handle_headers(CGIHeaders,
[{FieldName, FieldValue} | HTTPHeaders], Status)
end.
