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Diffstat (limited to 'apps/couch/src/couch_httpd_vhost.erl')
| -rw-r--r-- | apps/couch/src/couch_httpd_vhost.erl | 407 |
1 files changed, 407 insertions, 0 deletions
diff --git a/apps/couch/src/couch_httpd_vhost.erl b/apps/couch/src/couch_httpd_vhost.erl new file mode 100644 index 00000000..03dd02ae --- /dev/null +++ b/apps/couch/src/couch_httpd_vhost.erl @@ -0,0 +1,407 @@ +% 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. + + + +-module(couch_httpd_vhost). +-behaviour(gen_server). + +-export([start_link/0, init/1, handle_call/3, handle_info/2, handle_cast/2]). +-export([code_change/3, terminate/2]). +-export([match_vhost/1, urlsplit_netloc/2]). +-export([redirect_to_vhost/2]). + +-include("couch_db.hrl"). + +-define(SEPARATOR, $\/). +-define(MATCH_ALL, {bind, '*'}). + +-record(vhosts, { + vhost_globals, + vhosts = [], + vhost_fun +}). + + +%% doc the vhost manager. +%% This gen_server keep state of vhosts added to the ini and try to +%% match the Host header (or forwarded) against rules built against +%% vhost list. +%% +%% Declaration of vhosts take place in the configuration file : +%% +%% [vhosts] +%% example.com = /example +%% *.example.com = /example +%% +%% The first line will rewrite the rquest to display the content of the +%% example database. This rule works only if the Host header is +%% 'example.com' and won't work for CNAMEs. Second rule on the other hand +%% match all CNAMES to example db. So www.example.com or db.example.com +%% will work. +%% +%% The wildcard ('*') should always be the last in the cnames: +%% +%% "*.db.example.com = /" will match all cname on top of db +%% examples to the root of the machine. +%% +%% +%% Rewriting Hosts to path +%% ----------------------- +%% +%% Like in the _rewrite handler you could match some variable and use +%them to create the target path. Some examples: +%% +%% [vhosts] +%% *.example.com = /* +%% :dbname.example.com = /:dbname +%% :ddocname.:dbname.example.com = /:dbname/_design/:ddocname/_rewrite +%% +%% First rule pass wildcard as dbname, second do the same but use a +%% variable name and the third one allows you to use any app with +%% @ddocname in any db with @dbname . +%% +%% You could also change the default function to handle request by +%% changing the setting `redirect_vhost_handler` in `httpd` section of +%% the Ini: +%% +%% [httpd] +%% redirect_vhost_handler = {Module, Fun} +%% +%% The function take 2 args : the mochiweb request object and the target +%%% path. + +start_link() -> + gen_server:start_link({local, ?MODULE}, ?MODULE, [], []). + +%% @doc Try to find a rule matching current Host heade. some rule is +%% found it rewrite the Mochiweb Request else it return current Request. +match_vhost(MochiReq) -> + {ok, MochiReq1} = gen_server:call(couch_httpd_vhost, {match_vhost, + MochiReq}), + + MochiReq1. + + +%% -------------------- +%% gen_server functions +%% -------------------- + +init(_) -> + process_flag(trap_exit, true), + + % init state + VHosts = make_vhosts(), + VHostGlobals = re:split( + couch_config:get("httpd", "vhost_global_handlers", ""), + ", ?", + [{return, list}] + ), + + % Set vhost fun + DefaultVHostFun = "{couch_httpd_vhost, redirect_to_vhost}", + VHostFun = couch_httpd:make_arity_2_fun( + couch_config:get("httpd", "redirect_vhost_handler", DefaultVHostFun) + ), + + + Self = self(), + % register for changes in vhosts section + ok = couch_config:register( + fun("vhosts") -> + ok = gen_server:call(Self, vhosts_changed, infinity) + end + ), + + % register for changes in vhost_global_handlers key + ok = couch_config:register( + fun("httpd", "vhost_global_handlers") -> + ok = gen_server:call(Self, vhosts_global_changed, infinity) + end + ), + + ok = couch_config:register( + fun("httpd", "redirect_vhost_handler") -> + ok = gen_server:call(Self, fun_changed, infinity) + end + ), + + {ok, #vhosts{ + vhost_globals = VHostGlobals, + vhosts = VHosts, + vhost_fun = VHostFun} + }. + + +handle_call({match_vhost, MochiReq}, _From, State) -> + #vhosts{ + vhost_globals = VHostGlobals, + vhosts = VHosts, + vhost_fun = Fun + } = State, + + {"/" ++ VPath, Query, Fragment} = mochiweb_util:urlsplit_path(MochiReq:get(raw_path)), + VPathParts = string:tokens(VPath, "/"), + + XHost = couch_config:get("httpd", "x_forwarded_host", "X-Forwarded-Host"), + VHost = case MochiReq:get_header_value(XHost) of + undefined -> + case MochiReq:get_header_value("Host") of + undefined -> []; + Value1 -> Value1 + end; + Value -> Value + end, + {VHostParts, VhostPort} = split_host_port(VHost), + FinalMochiReq = case try_bind_vhost(VHosts, lists:reverse(VHostParts), + VhostPort, VPathParts) of + no_vhost_matched -> MochiReq; + {VhostTarget, NewPath} -> + case vhost_global(VHostGlobals, MochiReq) of + true -> + MochiReq; + _Else -> + NewPath1 = mochiweb_util:urlunsplit_path({NewPath, Query, + Fragment}), + MochiReq1 = mochiweb_request:new(MochiReq:get(socket), + MochiReq:get(method), + NewPath1, + MochiReq:get(version), + MochiReq:get(headers)), + Fun(MochiReq1, VhostTarget) + end + end, + {reply, {ok, FinalMochiReq}, State}; + +% update vhosts +handle_call(vhosts_changed, _From, State) -> + {reply, ok, State#vhosts{vhosts= make_vhosts()}}; + + +% update vhosts_globals +handle_call(vhosts_global_changed, _From, State) -> + VHostGlobals = re:split( + couch_config:get("httpd", "vhost_global_handlers", ""), + ", ?", + [{return, list}] + ), + {reply, ok, State#vhosts{vhost_globals=VHostGlobals}}; +% change fun +handle_call(fun_changed, _From, State) -> + DefaultVHostFun = "{couch_httpd_vhosts, redirect_to_vhost}", + VHostFun = couch_httpd:make_arity_2_fun( + couch_config:get("httpd", "redirect_vhost_handler", DefaultVHostFun) + ), + {reply, ok, State#vhosts{vhost_fun=VHostFun}}. + +handle_cast(_Msg, State) -> + {noreply, State}. + +handle_info(_Msg, State) -> + {noreply, State}. + +terminate(_Reason, _State) -> + ok. + +code_change(_OldVsn, State, _Extra) -> + {ok, State}. + + +append_path("/"=_Target, "/"=_Path) -> + "/"; +append_path(Target, Path) -> + Target ++ Path. + +% default redirect vhost handler + +redirect_to_vhost(MochiReq, VhostTarget) -> + Path = MochiReq:get(raw_path), + Target = append_path(VhostTarget, Path), + + ?LOG_DEBUG("Vhost Target: '~p'~n", [Target]), + + Headers = mochiweb_headers:enter("x-couchdb-vhost-path", Path, + MochiReq:get(headers)), + + % build a new mochiweb request + MochiReq1 = mochiweb_request:new(MochiReq:get(socket), + MochiReq:get(method), + Target, + MochiReq:get(version), + Headers), + % cleanup, It force mochiweb to reparse raw uri. + MochiReq1:cleanup(), + + MochiReq1. + +%% if so, then it will not be rewritten, but will run as a normal couchdb request. +%* normally you'd use this for _uuids _utils and a few of the others you want to +%% keep available on vhosts. You can also use it to make databases 'global'. +vhost_global( VhostGlobals, MochiReq) -> + RawUri = MochiReq:get(raw_path), + {"/" ++ Path, _, _} = mochiweb_util:urlsplit_path(RawUri), + + Front = case couch_httpd:partition(Path) of + {"", "", ""} -> + "/"; % Special case the root url handler + {FirstPart, _, _} -> + FirstPart + end, + [true] == [true||V <- VhostGlobals, V == Front]. + +%% bind host +%% first it try to bind the port then the hostname. +try_bind_vhost([], _HostParts, _Port, _PathParts) -> + no_vhost_matched; +try_bind_vhost([VhostSpec|Rest], HostParts, Port, PathParts) -> + {{VHostParts, VPort, VPath}, Path} = VhostSpec, + case bind_port(VPort, Port) of + ok -> + case bind_vhost(lists:reverse(VHostParts), HostParts, []) of + {ok, Bindings, Remainings} -> + case bind_path(VPath, PathParts) of + {ok, PathParts1} -> + Path1 = make_target(Path, Bindings, Remainings, []), + {make_path(Path1), make_path(PathParts1)}; + fail -> + try_bind_vhost(Rest, HostParts, Port, + PathParts) + end; + fail -> try_bind_vhost(Rest, HostParts, Port, PathParts) + end; + fail -> try_bind_vhost(Rest, HostParts, Port, PathParts) + end. + +%% doc: build new patch from bindings. bindings are query args +%% (+ dynamic query rewritten if needed) and bindings found in +%% bind_path step. +%% TODO: merge code wit rewrite. But we need to make sure we are +%% in string here. +make_target([], _Bindings, _Remaining, Acc) -> + lists:reverse(Acc); +make_target([?MATCH_ALL], _Bindings, Remaining, Acc) -> + Acc1 = lists:reverse(Acc) ++ Remaining, + Acc1; +make_target([?MATCH_ALL|_Rest], _Bindings, Remaining, Acc) -> + Acc1 = lists:reverse(Acc) ++ Remaining, + Acc1; +make_target([{bind, P}|Rest], Bindings, Remaining, Acc) -> + P2 = case couch_util:get_value({bind, P}, Bindings) of + undefined -> "undefined"; + P1 -> P1 + end, + make_target(Rest, Bindings, Remaining, [P2|Acc]); +make_target([P|Rest], Bindings, Remaining, Acc) -> + make_target(Rest, Bindings, Remaining, [P|Acc]). + +%% bind port +bind_port(Port, Port) -> ok; +bind_port('*', _) -> ok; +bind_port(_,_) -> fail. + +%% bind bhost +bind_vhost([],[], Bindings) -> {ok, Bindings, []}; +bind_vhost([?MATCH_ALL], [], _Bindings) -> fail; +bind_vhost([?MATCH_ALL], Rest, Bindings) -> {ok, Bindings, Rest}; +bind_vhost([], _HostParts, _Bindings) -> fail; +bind_vhost([{bind, Token}|Rest], [Match|RestHost], Bindings) -> + bind_vhost(Rest, RestHost, [{{bind, Token}, Match}|Bindings]); +bind_vhost([Cname|Rest], [Cname|RestHost], Bindings) -> + bind_vhost(Rest, RestHost, Bindings); +bind_vhost(_, _, _) -> fail. + +%% bind path +bind_path([], PathParts) -> + {ok, PathParts}; +bind_path(_VPathParts, []) -> + fail; +bind_path([Path|VRest],[Path|Rest]) -> + bind_path(VRest, Rest); +bind_path(_, _) -> + fail. + +% utilities + + +%% create vhost list from ini +make_vhosts() -> + Vhosts = lists:foldl(fun({Vhost, Path}, Acc) -> + [{parse_vhost(Vhost), split_path(Path)}|Acc] + end, [], couch_config:get("vhosts")), + lists:reverse(lists:usort(Vhosts)). + +parse_vhost(Vhost) -> + case urlsplit_netloc(Vhost, []) of + {[], Path} -> + {make_spec("*", []), '*', Path}; + {HostPort, []} -> + {H, P} = split_host_port(HostPort), + H1 = make_spec(H, []), + {H1, P, []}; + {HostPort, Path} -> + {H, P} = split_host_port(HostPort), + H1 = make_spec(H, []), + {H1, P, string:tokens(Path, "/")} + end. + + +split_host_port(HostAsString) -> + case string:rchr(HostAsString, $:) of + 0 -> + {split_host(HostAsString), '*'}; + N -> + HostPart = string:substr(HostAsString, 1, N-1), + case (catch erlang:list_to_integer(string:substr(HostAsString, + N+1, length(HostAsString)))) of + {'EXIT', _} -> + {split_host(HostAsString), '*'}; + Port -> + {split_host(HostPart), Port} + end + end. + +split_host(HostAsString) -> + string:tokens(HostAsString, "\."). + +split_path(Path) -> + make_spec(string:tokens(Path, "/"), []). + + +make_spec([], Acc) -> + lists:reverse(Acc); +make_spec([""|R], Acc) -> + make_spec(R, Acc); +make_spec(["*"|R], Acc) -> + make_spec(R, [?MATCH_ALL|Acc]); +make_spec([P|R], Acc) -> + P1 = parse_var(P), + make_spec(R, [P1|Acc]). + + +parse_var(P) -> + case P of + ":" ++ Var -> + {bind, Var}; + _ -> P + end. + + +% mochiweb doesn't export it. +urlsplit_netloc("", Acc) -> + {lists:reverse(Acc), ""}; +urlsplit_netloc(Rest=[C | _], Acc) when C =:= $/; C =:= $?; C =:= $# -> + {lists:reverse(Acc), Rest}; +urlsplit_netloc([C | Rest], Acc) -> + urlsplit_netloc(Rest, [C | Acc]). + +make_path(Parts) -> + "/" ++ string:join(Parts,[?SEPARATOR]). |