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Diffstat (limited to 'apps/chttpd/src/chttpd_rewrite.erl')
| -rw-r--r-- | apps/chttpd/src/chttpd_rewrite.erl | 418 |
1 files changed, 0 insertions, 418 deletions
diff --git a/apps/chttpd/src/chttpd_rewrite.erl b/apps/chttpd/src/chttpd_rewrite.erl deleted file mode 100644 index fbf246ab..00000000 --- a/apps/chttpd/src/chttpd_rewrite.erl +++ /dev/null @@ -1,418 +0,0 @@ -% 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. -% -% bind_path is based on bind method from Webmachine - - -%% @doc Module for URL rewriting by pattern matching. - --module(chttpd_rewrite). --export([handle_rewrite_req/3]). --include_lib("couch/include/couch_db.hrl"). - --define(SEPARATOR, $\/). --define(MATCH_ALL, '*'). - - -%% doc The http rewrite handler. All rewriting is done from -%% /dbname/_design/ddocname/_rewrite by default. -%% -%% each rules should be in rewrites member of the design doc. -%% Ex of a complete rule : -%% -%% { -%% .... -%% "rewrites": [ -%% { -%% "from": "", -%% "to": "index.html", -%% "method": "GET", -%% "query": {} -%% } -%% ] -%% } -%% -%% from: is the path rule used to bind current uri to the rule. It -%% use pattern matching for that. -%% -%% to: rule to rewrite an url. It can contain variables depending on binding -%% variables discovered during pattern matching and query args (url args and from -%% the query member.) -%% -%% method: method to bind the request method to the rule. by default "*" -%% query: query args you want to define they can contain dynamic variable -%% by binding the key to the bindings -%% -%% -%% to and from are path with patterns. pattern can be string starting with ":" or -%% "*". ex: -%% /somepath/:var/* -%% -%% This path is converted in erlang list by splitting "/". Each var are -%% converted in atom. "*" is converted to '*' atom. The pattern matching is done -%% by splitting "/" in request url in a list of token. A string pattern will -%% match equal token. The star atom ('*' in single quotes) will match any number -%% of tokens, but may only be present as the last pathtern in a pathspec. If all -%% tokens are matched and all pathterms are used, then the pathspec matches. It works -%% like webmachine. Each identified token will be reused in to rule and in query -%% -%% The pattern matching is done by first matching the request method to a rule. by -%% default all methods match a rule. (method is equal to "*" by default). Then -%% It will try to match the path to one rule. If no rule match, then a 404 error -%% is displayed. -%% -%% Once a rule is found we rewrite the request url using the "to" and -%% "query" members. The identified token are matched to the rule and -%% will replace var. if '*' is found in the rule it will contain the remaining -%% part if it exists. -%% -%% Examples: -%% -%% Dispatch rule URL TO Tokens -%% -%% {"from": "/a/b", /a/b?k=v /some/b?k=v var =:= b -%% "to": "/some/"} k = v -%% -%% {"from": "/a/b", /a/b /some/b?var=b var =:= b -%% "to": "/some/:var"} -%% -%% {"from": "/a", /a /some -%% "to": "/some/*"} -%% -%% {"from": "/a/*", /a/b/c /some/b/c -%% "to": "/some/*"} -%% -%% {"from": "/a", /a /some -%% "to": "/some/*"} -%% -%% {"from": "/a/:foo/*", /a/b/c /some/b/c?foo=b foo =:= b -%% "to": "/some/:foo/*"} -%% -%% {"from": "/a/:foo", /a/b /some/?k=b&foo=b foo =:= b -%% "to": "/some", -%% "query": { -%% "k": ":foo" -%% }} -%% -%% {"from": "/a", /a?foo=b /some/b foo =:= b -%% "to": "/some/:foo", -%% }} - - - -handle_rewrite_req(#httpd{ - path_parts=[DbName, <<"_design">>, DesignName, _Rewrite|PathParts], - method=Method, - mochi_req=MochiReq}=Req, _Db, DDoc) -> - - % we are in a design handler - DesignId = <<"_design/", DesignName/binary>>, - Prefix = <<"/", DbName/binary, "/", DesignId/binary>>, - QueryList = couch_httpd:qs(Req), - QueryList1 = [{to_atom(K), V} || {K, V} <- QueryList], - - #doc{body={Props}} = DDoc, - - % get rules from ddoc - case couch_util:get_value(<<"rewrites">>, Props) of - undefined -> - couch_httpd:send_error(Req, 404, <<"rewrite_error">>, - <<"Invalid path.">>); - Rules -> - % create dispatch list from rules - DispatchList = [make_rule(Rule) || {Rule} <- Rules], - - %% get raw path by matching url to a rule. - RawPath = case try_bind_path(DispatchList, Method, PathParts, - QueryList1) of - no_dispatch_path -> - throw(not_found); - {NewPathParts, Bindings} -> - Parts = [mochiweb_util:quote_plus(X) || X <- NewPathParts], - - % build new path, reencode query args, eventually convert - % them to json - Path = lists:append( - string:join(Parts, [?SEPARATOR]), - case Bindings of - [] -> []; - _ -> [$?, encode_query(Bindings)] - end), - - % if path is relative detect it and rewrite path - case mochiweb_util:safe_relative_path(Path) of - undefined -> - ?b2l(Prefix) ++ "/" ++ Path; - P1 -> - ?b2l(Prefix) ++ "/" ++ P1 - end - - end, - - % normalize final path (fix levels "." and "..") - RawPath1 = ?b2l(iolist_to_binary(normalize_path(RawPath))), - - ?LOG_DEBUG("rewrite to ~p ~n", [RawPath1]), - - % build a new mochiweb request - MochiReq1 = mochiweb_request:new(MochiReq:get(socket), - MochiReq:get(method), - RawPath1, - MochiReq:get(version), - MochiReq:get(headers)), - - % cleanup, It force mochiweb to reparse raw uri. - MochiReq1:cleanup(), - - chttpd:handle_request(MochiReq1) - end. - - - -%% @doc Try to find a rule matching current url. If none is found -%% 404 error not_found is raised -try_bind_path([], _Method, _PathParts, _QueryList) -> - no_dispatch_path; -try_bind_path([Dispatch|Rest], Method, PathParts, QueryList) -> - [{PathParts1, Method1}, RedirectPath, QueryArgs] = Dispatch, - case bind_method(Method1, Method) of - true -> - case bind_path(PathParts1, PathParts, []) of - {ok, Remaining, Bindings} -> - Bindings1 = Bindings ++ QueryList, - - % we parse query args from the rule and fill - % it eventually with bindings vars - QueryArgs1 = make_query_list(QueryArgs, Bindings1, []), - - % remove params in QueryLists1 that are already in - % QueryArgs1 - Bindings2 = lists:foldl(fun({K, V}, Acc) -> - K1 = to_atom(K), - KV = case couch_util:get_value(K1, QueryArgs1) of - undefined -> [{K1, V}]; - _V1 -> [] - end, - Acc ++ KV - end, [], Bindings1), - - FinalBindings = Bindings2 ++ QueryArgs1, - NewPathParts = make_new_path(RedirectPath, FinalBindings, - Remaining, []), - {NewPathParts, FinalBindings}; - fail -> - try_bind_path(Rest, Method, PathParts, QueryList) - end; - false -> - try_bind_path(Rest, Method, PathParts, QueryList) - end. - -%% rewriting dynamically the quey list given as query member in -%% rewrites. Each value is replaced by one binding or an argument -%% passed in url. -make_query_list([], _Bindings, Acc) -> - Acc; -make_query_list([{Key, {Value}}|Rest], Bindings, Acc) -> - Value1 = to_json({Value}), - make_query_list(Rest, Bindings, [{to_atom(Key), Value1}|Acc]); -make_query_list([{Key, Value}|Rest], Bindings, Acc) when is_binary(Value) -> - Value1 = replace_var(Key, Value, Bindings), - make_query_list(Rest, Bindings, [{to_atom(Key), Value1}|Acc]); -make_query_list([{Key, Value}|Rest], Bindings, Acc) when is_list(Value) -> - Value1 = replace_var(Key, Value, Bindings), - make_query_list(Rest, Bindings, [{to_atom(Key), Value1}|Acc]); -make_query_list([{Key, Value}|Rest], Bindings, Acc) -> - make_query_list(Rest, Bindings, [{to_atom(Key), Value}|Acc]). - -replace_var(Key, Value, Bindings) -> - case Value of - <<":", Var/binary>> -> - get_var(Var, Bindings, Value); - _ when is_list(Value) -> - Value1 = lists:foldr(fun(V, Acc) -> - V1 = case V of - <<":", VName/binary>> -> - case get_var(VName, Bindings, V) of - V2 when is_list(V2) -> - iolist_to_binary(V2); - V2 -> V2 - end; - _ -> - - V - end, - [V1|Acc] - end, [], Value), - to_json(Value1); - _ when is_binary(Value) -> - Value; - _ -> - case Key of - <<"key">> -> to_json(Value); - <<"startkey">> -> to_json(Value); - <<"endkey">> -> to_json(Value); - _ -> - lists:flatten(?JSON_ENCODE(Value)) - end - end. - - -get_var(VarName, Props, Default) -> - VarName1 = list_to_atom(binary_to_list(VarName)), - couch_util:get_value(VarName1, Props, Default). - -%% doc: build new patch from bindings. bindings are query args -%% (+ dynamic query rewritten if needed) and bindings found in -%% bind_path step. -make_new_path([], _Bindings, _Remaining, Acc) -> - lists:reverse(Acc); -make_new_path([?MATCH_ALL], _Bindings, Remaining, Acc) -> - Acc1 = lists:reverse(Acc) ++ Remaining, - Acc1; -make_new_path([?MATCH_ALL|_Rest], _Bindings, Remaining, Acc) -> - Acc1 = lists:reverse(Acc) ++ Remaining, - Acc1; -make_new_path([P|Rest], Bindings, Remaining, Acc) when is_atom(P) -> - P2 = case couch_util:get_value(P, Bindings) of - undefined -> << "undefined">>; - P1 -> P1 - end, - make_new_path(Rest, Bindings, Remaining, [P2|Acc]); -make_new_path([P|Rest], Bindings, Remaining, Acc) -> - make_new_path(Rest, Bindings, Remaining, [P|Acc]). - - -%% @doc If method of the query fith the rule method. If the -%% method rule is '*', which is the default, all -%% request method will bind. It allows us to make rules -%% depending on HTTP method. -bind_method(?MATCH_ALL, _Method) -> - true; -bind_method(Method, Method) -> - true; -bind_method(_, _) -> - false. - - -%% @doc bind path. Using the rule from we try to bind variables given -%% to the current url by pattern matching -bind_path([], [], Bindings) -> - {ok, [], Bindings}; -bind_path([?MATCH_ALL], Rest, Bindings) when is_list(Rest) -> - {ok, Rest, Bindings}; -bind_path(_, [], _) -> - fail; -bind_path([Token|RestToken],[Match|RestMatch],Bindings) when is_atom(Token) -> - bind_path(RestToken, RestMatch, [{Token, Match}|Bindings]); -bind_path([Token|RestToken], [Token|RestMatch], Bindings) -> - bind_path(RestToken, RestMatch, Bindings); -bind_path(_, _, _) -> - fail. - - -%% normalize path. -normalize_path(Path) -> - "/" ++ string:join(normalize_path1(string:tokens(Path, - "/"), []), [?SEPARATOR]). - - -normalize_path1([], Acc) -> - lists:reverse(Acc); -normalize_path1([".."|Rest], Acc) -> - Acc1 = case Acc of - [] -> [".."|Acc]; - [T|_] when T =:= ".." -> [".."|Acc]; - [_|R] -> R - end, - normalize_path1(Rest, Acc1); -normalize_path1(["."|Rest], Acc) -> - normalize_path1(Rest, Acc); -normalize_path1([Path|Rest], Acc) -> - normalize_path1(Rest, [Path|Acc]). - - -%% @doc transform json rule in erlang for pattern matching -make_rule(Rule) -> - Method = case couch_util:get_value(<<"method">>, Rule) of - undefined -> '*'; - M -> list_to_atom(?b2l(M)) - end, - QueryArgs = case couch_util:get_value(<<"query">>, Rule) of - undefined -> []; - {Args} -> Args - end, - FromParts = case couch_util:get_value(<<"from">>, Rule) of - undefined -> ['*']; - From -> - parse_path(From) - end, - ToParts = case couch_util:get_value(<<"to">>, Rule) of - undefined -> - throw({error, invalid_rewrite_target}); - To -> - parse_path(To) - end, - [{FromParts, Method}, ToParts, QueryArgs]. - -parse_path(Path) -> - {ok, SlashRE} = re:compile(<<"\\/">>), - path_to_list(re:split(Path, SlashRE), [], 0). - -%% @doc convert a path rule (from or to) to an erlang list -%% * and path variable starting by ":" are converted -%% in erlang atom. -path_to_list([], Acc, _DotDotCount) -> - lists:reverse(Acc); -path_to_list([<<>>|R], Acc, DotDotCount) -> - path_to_list(R, Acc, DotDotCount); -path_to_list([<<"*">>|R], Acc, DotDotCount) -> - path_to_list(R, [?MATCH_ALL|Acc], DotDotCount); -path_to_list([<<"..">>|R], Acc, DotDotCount) when DotDotCount == 2 -> - case couch_config:get("httpd", "secure_rewrites", "true") of - "false" -> - path_to_list(R, [<<"..">>|Acc], DotDotCount+1); - _Else -> - ?LOG_INFO("insecure_rewrite_rule ~p blocked", [lists:reverse(Acc) ++ [<<"..">>] ++ R]), - throw({insecure_rewrite_rule, "too many ../.. segments"}) - end; -path_to_list([<<"..">>|R], Acc, DotDotCount) -> - path_to_list(R, [<<"..">>|Acc], DotDotCount+1); -path_to_list([P|R], Acc, DotDotCount) -> - P1 = case P of - <<":", Var/binary>> -> - list_to_atom(binary_to_list(Var)); - _ -> P - end, - path_to_list(R, [P1|Acc], DotDotCount). - -encode_query(Props) -> - Props1 = lists:foldl(fun ({K, V}, Acc) -> - V1 = case is_list(V) of - true -> V; - false when is_binary(V) -> - V; - false -> - mochiweb_util:quote_plus(V) - end, - [{K, V1} | Acc] - end, [], Props), - lists:flatten(mochiweb_util:urlencode(Props1)). - -to_atom(V) when is_atom(V) -> - V; -to_atom(V) when is_binary(V) -> - to_atom(?b2l(V)); -to_atom(V) -> - list_to_atom(V). - -to_json(V) -> - iolist_to_binary(?JSON_ENCODE(V)). |