Handling combined header

src/mochiweb_headers.erl

@@ -6,7 +6,7 @@
 -module(mochiweb_headers).
 -author('bob@mochimedia.com').
 -export([empty/0, from_list/1, insert/3, enter/3, get_value/2, lookup/2]).
--export([delete_any/2, get_primary_value/2]).
+-export([delete_any/2, get_primary_value/2, get_combined_value/2]).
 -export([default/3, enter_from_list/2, default_from_list/2]).
 -export([to_list/1, make/1]).
 -export([from_binary/1]).
@@ -112,6 +112,34 @@ get_primary_value(K, T) ->
             lists:takewhile(fun (C) -> C =/= $; end, V)
     end.
 
+%% @spec get_combined_value(key(), headers()) -> string() | undefined
+%% @doc Return the value from the given header using a case insensitive search.
+%%      If the value of the header is a comma-separated list where holds values
+%%      are all identical, the identical value will be returned.
+%%      undefined will be returned for keys that are not present or the
+%%      values in the list are not the same.
+%%
+%%      NOTE: The process isn't designed for a general purpose. If you need
+%%            to access all values in the combined header, please refer to
+%%            '''tokenize_header_value/1'''.
+%%
+%%      Section 4.2 of the RFC 2616 (HTTP 1.1) describes multiple message-header
+%%      fields with the same field-name may be present in a message if and only
+%%      if the entire field-value for that header field is defined as a
+%%      comma-separated list [i.e., #(values)].
+get_combined_value(K, T) ->
+    case get_value(K, T) of
+        undefined ->
+            undefined;
+        V ->
+            case sets:to_list(sets:from_list(tokenize_header_value(V))) of
+                [Val] ->
+                    Val;
+                _ ->
+                    undefined
+            end
+    end.
+
 %% @spec lookup(key(), headers()) -> {value, {key(), string()}} | none
 %% @doc Return the case preserved key and value for the given header using
 %%      a case insensitive search. none will be returned for keys that are
@@ -164,6 +192,49 @@ delete_any(K, T) ->
 
 %% Internal API
 
+tokenize_header_value(undefined) ->
+    undefined;
+tokenize_header_value(V) ->
+    reversed_tokens(trim_and_reverse(V, false), [], []).
+
+trim_and_reverse([S | Rest], Reversed) when S=:=$ ; S=:=$\n; S=:=$\t ->
+    trim_and_reverse(Rest, Reversed);
+trim_and_reverse(V, false) ->
+    trim_and_reverse(lists:reverse(V), true);
+trim_and_reverse(V, true) ->
+    V.
+
+reversed_tokens([], [], Acc) ->
+    Acc;
+reversed_tokens([], Token, Acc) ->
+    [Token | Acc];
+reversed_tokens("\"" ++ Rest, [], Acc) ->
+    case extract_quoted_string(Rest, []) of
+        {String, NewRest} ->
+            reversed_tokens(NewRest, [], [String | Acc]);
+        undefined ->
+            undefined
+    end;
+reversed_tokens("\"" ++ _Rest, _Token, _Acc) ->
+    undefined;
+reversed_tokens([C | Rest], [], Acc) when C=:=$ ;C=:=$\n;C=:=$\t;C=:=$, ->
+    reversed_tokens(Rest, [], Acc);
+reversed_tokens([C | Rest], Token, Acc) when C=:=$ ;C=:=$\n;C=:=$\t;C=:=$, ->
+    reversed_tokens(Rest, [], [Token | Acc]);
+reversed_tokens([C | Rest], Token, Acc) ->
+    reversed_tokens(Rest, [C | Token], Acc);
+reversed_tokens(_, _, _) ->
+    undefeined.
+
+extract_quoted_string([], _Acc) ->
+    undefined;
+extract_quoted_string("\"\\" ++ Rest, Acc) ->
+    extract_quoted_string(Rest, "\"" ++ Acc);
+extract_quoted_string("\"" ++ Rest, Acc) ->
+    {Acc, Rest};
+extract_quoted_string([C | Rest], Acc) ->
+    extract_quoted_string(Rest, [C | Acc]).
+
 expand({array, L}) ->
     mochiweb_util:join(lists:reverse(L), ", ");
 expand(V) ->
@@ -237,6 +308,37 @@ get_primary_value_test() ->
        get_primary_value(<<"baz">>, H)),
     ok.
 
+get_combined_value_test() ->
+    H = make([{hdr, foo}, {baz, <<"wibble,taco">>}, {content_length, "123, 123"},
+              {test, " 123,  123,     123  , 123,123 "},
+              {test2, "456,  123,     123  , 123"},
+              {test3, "123"}, {test4, " 123, "}]),
+    ?assertEqual(
+       "foo",
+       get_combined_value(hdr, H)),
+    ?assertEqual(
+       undefined,
+       get_combined_value(bar, H)),
+    ?assertEqual(
+       undefined,
+       get_combined_value(<<"baz">>, H)),
+    ?assertEqual(
+       "123",
+       get_combined_value(<<"content_length">>, H)),
+    ?assertEqual(
+       "123",
+       get_combined_value(<<"test">>, H)),
+    ?assertEqual(
+       undefined,
+       get_combined_value(<<"test2">>, H)),
+    ?assertEqual(
+       "123",
+       get_combined_value(<<"test3">>, H)),
+    ?assertEqual(
+       "123",
+       get_combined_value(<<"test4">>, H)),
+    ok.
+
 set_cookie_test() ->
     H = make([{"set-cookie", foo}, {"set-cookie", bar}, {"set-cookie", baz}]),
     ?assertEqual(
@@ -296,4 +398,23 @@ headers_test() ->
     [] = ?MODULE:to_list(?MODULE:from_binary([<<"\r\n\r\n">>])),
     ok.
 
+tokenize_header_value_test() ->
+    ?assertEqual(["a quote in a \"quote\"."],
+                 tokenize_header_value("\"a quote in a \\\"quote\\\".\"")),
+    ?assertEqual(["abc"], tokenize_header_value("abc")),
+    ?assertEqual(["abc", "def"], tokenize_header_value("abc def")),
+    ?assertEqual(["abc", "def"], tokenize_header_value("abc , def")),
+    ?assertEqual(["abc", "def"], tokenize_header_value(",abc ,, def,,")),
+    ?assertEqual(["abc def"], tokenize_header_value("\"abc def\"      ")),
+    ?assertEqual(["abc, def"], tokenize_header_value("\"abc, def\"")),
+    ?assertEqual(["\\a\\$"], tokenize_header_value("\"\\a\\$\"")),
+    ?assertEqual(["abc def", "foo, bar", "12345", ""],
+                 tokenize_header_value("\"abc def\" \"foo, bar\" , 12345, \"\"")),
+    ?assertEqual(undefined,
+                 tokenize_header_value(undefined)),
+    ?assertEqual(undefined,
+                 tokenize_header_value("umatched quote\"")),
+    ?assertEqual(undefined,
+                 tokenize_header_value("\"unmatched quote")).
+
 -endif.

src/mochiweb_multipart.erl

@@ -128,7 +128,7 @@ default_file_handler_1(Filename, ContentType, Acc) ->
 
 parse_multipart_request(Req, Callback) ->
     %% TODO: Support chunked?
-    Length = list_to_integer(Req:get_header_value("content-length")),
+    Length = list_to_integer(Req:get_combined_header_value("content-length")),
     Boundary = iolist_to_binary(
                  get_boundary(Req:get_header_value("content-type"))),
     Prefix = <<"\r\n--", Boundary/binary>>,

src/mochiweb_request.erl

@@ -11,7 +11,7 @@
 
 -define(QUIP, "Any of you quaids got a smint?").
 
--export([get_header_value/1, get_primary_header_value/1, get/1, dump/0]).
+-export([get_header_value/1, get_primary_header_value/1, get_combined_header_value/1, get/1, dump/0]).
 -export([send/1, recv/1, recv/2, recv_body/0, recv_body/1, stream_body/3]).
 -export([start_response/1, start_response_length/1, start_raw_response/1]).
 -export([respond/1, ok/1]).
@@ -52,6 +52,9 @@ get_header_value(K) ->
 get_primary_header_value(K) ->
     mochiweb_headers:get_primary_value(K, Headers).
 
+get_combined_header_value(K) ->
+    mochiweb_headers:get_combined_value(K, Headers).
+
 %% @type field() = socket | scheme | method | raw_path | version | headers | peer | path | body_length | range
 
 %% @spec get(field()) -> term()
@@ -167,7 +170,7 @@ recv(Length, Timeout) ->
 body_length() ->
     case get_header_value("transfer-encoding") of
         undefined ->
-            case get_header_value("content-length") of
+            case get_combined_header_value("content-length") of
                 undefined ->
                     undefined;
                 Length ->
@@ -389,8 +392,8 @@ should_close() ->
                 andalso get_header_value("connection") =/= "Keep-Alive")
         %% unread data left on the socket, can't safely continue
         orelse (DidNotRecv
-                andalso get_header_value("content-length") =/= undefined
-                andalso list_to_integer(get_header_value("content-length")) > 0)
+                andalso get_combined_header_value("content-length") =/= undefined
+                andalso list_to_integer(get_combined_header_value("content-length")) > 0)
         orelse (DidNotRecv
                 andalso get_header_value("transfer-encoding") =:= "chunked").