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authorMagnus Klaar <[email protected]>2012-04-14 00:54:20 +0200
committerLoïc Hoguin <[email protected]>2012-12-01 14:11:21 +0100
commit3e0e50731156647574e08e277cb39fe2fd63a86d (patch)
treebfd0eb6099013185aa7eb9676a60a69985243eae /src/cowboy_multipart.erl
parent72b26c6d0c55a4fe33807451c6c7d78c99e4f426 (diff)
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Return full packet as multipart body if possible
Diffstat (limited to 'src/cowboy_multipart.erl')
-rw-r--r--src/cowboy_multipart.erl92
1 files changed, 75 insertions, 17 deletions
diff --git a/src/cowboy_multipart.erl b/src/cowboy_multipart.erl
index fc889ef..a9c378e 100644
--- a/src/cowboy_multipart.erl
+++ b/src/cowboy_multipart.erl
@@ -74,17 +74,51 @@ parse(Bin, Boundary) ->
more(Bin, fun (NewBin) -> parse(NewBin, Boundary) end).
-type pattern() :: {binary:cp(), non_neg_integer()}.
+-type patterns() :: {pattern(), pattern()}.
-%% @doc Return a compiled binary pattern with its size in bytes.
-%% The pattern is the boundary prepended with "\r\n--".
--spec pattern(binary()) -> pattern().
+%% @doc Return two compiled binary patterns with their sizes in bytes.
+%% The boundary pattern is the boundary prepended with "\r\n--".
+%% The boundary suffix pattern matches all prefixes of the boundary.
+-spec pattern(binary()) -> patterns().
pattern(Boundary) ->
MatchPattern = <<"\r\n--", Boundary/binary>>,
- {binary:compile_pattern(MatchPattern), byte_size(MatchPattern)}.
+ MatchPrefixes = prefixes(MatchPattern),
+ {{binary:compile_pattern(MatchPattern), byte_size(MatchPattern)},
+ {binary:compile_pattern(MatchPrefixes), byte_size(MatchPattern)}}.
+
+%% @doc Return all prefixes of a binary string.
+%% The list of prefixes includes the full string.
+-spec prefixes(binary()) -> [binary()].
+prefixes(<<C, Rest/binary>>) ->
+ prefixes(Rest, <<C>>).
+
+-spec prefixes(binary(), binary()) -> [binary()].
+prefixes(<<C, Rest/binary>>, Acc) ->
+ [Acc|prefixes(Rest, <<Acc/binary, C>>)];
+prefixes(<<>>, Acc) ->
+ [Acc].
+
+%% @doc Test if a boundary is a possble suffix.
+%% The patterns are expected to have been returned from `pattern/1`.
+-spec suffix_match(binary(), patterns()) -> nomatch | {integer(), integer()}.
+suffix_match(Bin, {_Boundary, {Pat, Len}}) ->
+ Size = byte_size(Bin),
+ suffix_match(Bin, Pat, Size, max(-Size, -Len)).
+
+-spec suffix_match(binary(), tuple(), non_neg_integer(), 0|neg_integer()) ->
+ nomatch | {integer(), integer()}.
+suffix_match(_Bin, _Pat, _Size, _Match=0) ->
+ nomatch;
+suffix_match(Bin, Pat, Size, Match) when Match < 0 ->
+ case binary:match(Bin, Pat, [{scope, {Size, Match}}]) of
+ {Pos, Len}=Part when Pos + Len =:= Size -> Part;
+ {_, Len} -> suffix_match(Bin, Pat, Size, Match + Len);
+ nomatch -> nomatch
+ end.
%% @doc Parse remaining characters of a line beginning with the boundary.
%% If followed by "--", <em>eof</em> is returned and parsing is finished.
--spec parse_boundary_tail(binary(), pattern()) -> more(part_result()).
+-spec parse_boundary_tail(binary(), patterns()) -> more(part_result()).
parse_boundary_tail(Bin, Pattern) when byte_size(Bin) >= 2 ->
case Bin of
<<"--", _Rest/binary>> ->
@@ -100,7 +134,7 @@ parse_boundary_tail(Bin, Pattern) ->
more(Bin, fun (NewBin) -> parse_boundary_tail(NewBin, Pattern) end).
%% @doc Skip whitespace and unknown chars until CRLF.
--spec parse_boundary_eol(binary(), pattern()) -> more(part_result()).
+-spec parse_boundary_eol(binary(), patterns()) -> more(part_result()).
parse_boundary_eol(Bin, Pattern) ->
case binary:match(Bin, <<"\r\n">>) of
{CrlfStart, _Length} ->
@@ -115,7 +149,7 @@ parse_boundary_eol(Bin, Pattern) ->
more(Rest, fun (NewBin) -> parse_boundary_eol(NewBin, Pattern) end)
end.
--spec parse_boundary_crlf(binary(), pattern()) -> more(part_result()).
+-spec parse_boundary_crlf(binary(), patterns()) -> more(part_result()).
parse_boundary_crlf(<<"\r\n", Rest/binary>>, Pattern) ->
% The binary is at least 2 bytes long as this function is only called by
% parse_boundary_eol/3 when CRLF has been found so a more tuple will never
@@ -127,11 +161,11 @@ parse_boundary_crlf(Bin, Pattern) ->
% considered part of the boundary so EOL needs to be searched again.
parse_boundary_eol(Bin, Pattern).
--spec parse_headers(binary(), pattern()) -> more(part_result()).
+-spec parse_headers(binary(), patterns()) -> more(part_result()).
parse_headers(Bin, Pattern) ->
parse_headers(Bin, Pattern, []).
--spec parse_headers(binary(), pattern(), http_headers()) -> more(part_result()).
+-spec parse_headers(binary(), patterns(), http_headers()) -> more(part_result()).
parse_headers(Bin, Pattern, Acc) ->
case erlang:decode_packet(httph_bin, Bin, []) of
{ok, {http_header, _, Name, _, Value}, Rest} ->
@@ -150,8 +184,8 @@ parse_headers(Bin, Pattern, Acc) ->
more(Bin, fun (NewBin) -> parse_headers(NewBin, Pattern, Acc) end)
end.
--spec parse_body(binary(), pattern()) -> more(body_result()).
-parse_body(Bin, Pattern = {P, PSize}) when byte_size(Bin) >= PSize ->
+-spec parse_body(binary(), patterns()) -> more(body_result()).
+parse_body(Bin, Pattern = {{P, PSize}, _}) when byte_size(Bin) >= PSize ->
case binary:match(Bin, P) of
{0, _Length} ->
<<_:PSize/binary, Rest/binary>> = Bin,
@@ -163,19 +197,27 @@ parse_body(Bin, Pattern = {P, PSize}) when byte_size(Bin) >= PSize ->
FResult = end_of_part(Rest, Pattern),
{body, PBody, fun () -> FResult end};
nomatch ->
- PartialLength = byte_size(Bin) - PSize + 1,
- <<PBody:PartialLength/binary, Rest/binary>> = Bin,
- {body, PBody, fun () -> parse_body(Rest, Pattern) end}
+ case suffix_match(Bin, Pattern) of
+ nomatch ->
+ %% Prefix of boundary not found at end of input. it's
+ %% safe to return the whole binary. Saves copying of
+ %% next input onto tail of current input binary.
+ {body, Bin, fun () -> parse_body(<<>>, Pattern) end};
+ {BoundaryStart, Len} ->
+ PBody = binary:part(Bin, BoundaryStart, Len),
+ Rest = binary:part(Bin, 0, BoundaryStart),
+ {body, PBody, fun () -> parse_body(Rest, Pattern) end}
+ end
end;
parse_body(Bin, Pattern) ->
more(Bin, fun (NewBin) -> parse_body(NewBin, Pattern) end).
--spec end_of_part(binary(), pattern()) -> end_of_part().
+-spec end_of_part(binary(), patterns()) -> end_of_part().
end_of_part(Bin, Pattern) ->
{end_of_part, fun () -> parse_boundary_tail(Bin, Pattern) end}.
--spec skip(binary(), pattern()) -> more(part_result()).
-skip(Bin, Pattern = {P, PSize}) ->
+-spec skip(binary(), patterns()) -> more(part_result()).
+skip(Bin, Pattern = {{P, PSize}, _}) ->
case binary:match(Bin, P) of
{BoundaryStart, _Length} ->
% Boundary found, proceed with parsing of the next part.
@@ -255,4 +297,20 @@ title(Bin) ->
),
iolist_to_binary(Title).
+suffix_test_() ->
+ [?_assertEqual(Part, suffix_match(Packet, pattern(Boundary))) ||
+ {Part, Packet, Boundary} <- [
+ {nomatch, <<>>, <<"ABC">>},
+ {{0, 1}, <<"\r">>, <<"ABC">>},
+ {{0, 2}, <<"\r\n">>, <<"ABC">>},
+ {{0, 4}, <<"\r\n--">>, <<"ABC">>},
+ {{0, 5}, <<"\r\n--A">>, <<"ABC">>},
+ {{0, 6}, <<"\r\n--AB">>, <<"ABC">>},
+ {{0, 7}, <<"\r\n--ABC">>, <<"ABC">>},
+ {nomatch, <<"\r\n--AB1">>, <<"ABC">>},
+ {{1, 1}, <<"1\r">>, <<"ABC">>},
+ {{2, 2}, <<"12\r\n">>, <<"ABC">>},
+ {{3, 4}, <<"123\r\n--">>, <<"ABC">>}
+ ]].
+
-endif.