From 544a38dd45f6a58d34296c6c768afd086eb2ac70 Mon Sep 17 00:00:00 2001 From: Christopher Lenz Date: Fri, 28 Mar 2008 23:32:19 +0000 Subject: Imported trunk. git-svn-id: https://svn.apache.org/repos/asf/incubator/couchdb/trunk@642432 13f79535-47bb-0310-9956-ffa450edef68 --- src/couch_inets/mod_esi.erl | 432 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 432 insertions(+) create mode 100644 src/couch_inets/mod_esi.erl (limited to 'src/couch_inets/mod_esi.erl') diff --git a/src/couch_inets/mod_esi.erl b/src/couch_inets/mod_esi.erl new file mode 100644 index 00000000..f0e8ae80 --- /dev/null +++ b/src/couch_inets/mod_esi.erl @@ -0,0 +1,432 @@ +%% ``The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved via the world wide web at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% The Initial Developer of the Original Code is Ericsson Utvecklings AB. +%% Portions created by Ericsson are Copyright 1999, Ericsson Utvecklings +%% AB. All Rights Reserved.'' +%% +%% $Id$ +%% +-module(mod_esi). + +%% API +%% Functions provided to help erl scheme alias programmer to +%% Create dynamic webpages that are sent back to the user during +%% Generation +-export([deliver/2]). + +%% Callback API +-export([do/1, load/2]). + +-include("httpd.hrl"). + +-define(VMODULE,"ESI"). +-define(DEFAULT_ERL_TIMEOUT,15000). + +%%%========================================================================= +%%% API +%%%========================================================================= +%%-------------------------------------------------------------------------- +%% deliver(SessionID, Data) -> ok | {error, bad_sessionID} +%% SessionID = pid() +%% Data = string() | io_list() (first call must send a string that +%% contains all header information including "\r\n\r\n", unless there +%% is no header information at all.) +%% +%% Description: Send (Html page generated sofar) to the server +%% request handling process so it can forward it to the client. +%%------------------------------------------------------------------------- +deliver(SessionID, Data) when pid(SessionID) -> + SessionID ! {ok, Data}, + ok; +deliver(_SessionID, _Data) -> + {error, bad_sessionID}. + +%%%========================================================================= +%%% CALLBACK API +%%%========================================================================= +%%-------------------------------------------------------------------------- +%% do(ModData) -> {proceed, OldData} | {proceed, NewData} | {break, NewData} +%% | done +%% ModData = #mod{} +%% +%% Description: See httpd(3) ESWAPI CALLBACK FUNCTIONS +%%------------------------------------------------------------------------- +do(ModData) -> + case httpd_util:key1search(ModData#mod.data, status) of + {_StatusCode, _PhraseArgs, _Reason} -> + {proceed, ModData#mod.data}; + undefined -> + case httpd_util:key1search(ModData#mod.data, response) of + undefined -> + generate_response(ModData); + _Response -> + {proceed, ModData#mod.data} + end + end. +%%-------------------------------------------------------------------------- +%% load(Line, Context) -> eof | ok | {ok, NewContext} | +%% {ok, NewContext, Directive} | +%% {ok, NewContext, DirectiveList} | {error, Reason} +%% Line = string() +%% Context = NewContext = DirectiveList = [Directive] +%% Directive = {DirectiveKey , DirectiveValue} +%% DirectiveKey = DirectiveValue = term() +%% Reason = term() +%% +%% Description: See httpd(3) ESWAPI CALLBACK FUNCTIONS +%%------------------------------------------------------------------------- +load("ErlScriptAlias " ++ ErlScriptAlias, []) -> + case regexp:split(ErlScriptAlias," ") of + {ok, [ErlName | Modules]} -> + {ok, [], {erl_script_alias, {ErlName,Modules}}}; + {ok, _} -> + {error, ?NICE(httpd_conf:clean(ErlScriptAlias) ++ + " is an invalid ErlScriptAlias")} + end; +load("EvalScriptAlias " ++ EvalScriptAlias, []) -> + case regexp:split(EvalScriptAlias, " ") of + {ok, [EvalName|Modules]} -> + {ok, [], {eval_script_alias, {EvalName, Modules}}}; + {ok, _} -> + {error, ?NICE(httpd_conf:clean(EvalScriptAlias) ++ + " is an invalid EvalScriptAlias")} + end; +load("ErlScriptTimeout " ++ Timeout, [])-> + case catch list_to_integer(httpd_conf:clean(Timeout)) of + TimeoutSec when integer(TimeoutSec) -> + {ok, [], {erl_script_timeout, TimeoutSec * 1000}}; + _ -> + {error, ?NICE(httpd_conf:clean(Timeout) ++ + " is an invalid ErlScriptTimeout")} + end; +load("ErlScriptNoCache " ++ CacheArg, [])-> + case catch list_to_atom(httpd_conf:clean(CacheArg)) of + true -> + {ok, [], {erl_script_nocache, true}}; + false -> + {ok, [], {erl_script_nocache, false}}; + _ -> + {error, ?NICE(httpd_conf:clean(CacheArg)++ + " is an invalid ErlScriptNoCache directive")} + end. + +%%%======================================================================== +%%% Internal functions +%%%======================================================================== +generate_response(ModData) -> + case scheme(ModData#mod.request_uri, ModData#mod.config_db) of + {eval, ESIBody, Modules} -> + eval(ModData, ESIBody, Modules); + {erl, ESIBody, Modules} -> + erl(ModData, ESIBody, Modules); + no_scheme -> + {proceed, ModData#mod.data} + end. + +scheme(RequestURI, ConfigDB) -> + case match_script(RequestURI, ConfigDB, erl_script_alias) of + no_match -> + case match_script(RequestURI, ConfigDB, eval_script_alias) of + no_match -> + no_scheme; + {EsiBody, ScriptModules} -> + {eval, EsiBody, ScriptModules} + end; + {EsiBody, ScriptModules} -> + {erl, EsiBody, ScriptModules} + end. + +match_script(RequestURI, ConfigDB, AliasType) -> + case httpd_util:multi_lookup(ConfigDB, AliasType) of + [] -> + no_match; + AliasAndMods -> + match_esi_script(RequestURI, AliasAndMods, AliasType) + end. + +match_esi_script(_, [], _) -> + no_match; +match_esi_script(RequestURI, [{Alias,Modules} | Rest], AliasType) -> + AliasMatchStr = alias_match_str(Alias, AliasType), + case regexp:first_match(RequestURI, AliasMatchStr) of + {match, 1, Length} -> + {string:substr(RequestURI, Length + 1), Modules}; + nomatch -> + match_esi_script(RequestURI, Rest, AliasType) + end. + +alias_match_str(Alias, erl_script_alias) -> + "^" ++ Alias ++ "/"; +alias_match_str(Alias, eval_script_alias) -> + "^" ++ Alias ++ "\\?". + + +%%------------------------ Erl mechanism -------------------------------- + +erl(#mod{method = Method} = ModData, ESIBody, Modules) + when Method == "GET"; Method == "HEAD"-> + case httpd_util:split(ESIBody,":|%3A|/",2) of + {ok, [Module, FuncAndInput]} -> + case httpd_util:split(FuncAndInput,"[\?/]",2) of + {ok, [FunctionName, Input]} -> + generate_webpage(ModData, ESIBody, Modules, + Module, FunctionName, Input, + script_elements(FunctionName, Input)); + {ok, [FunctionName]} -> + generate_webpage(ModData, ESIBody, Modules, + Module, FunctionName, "", + script_elements(FunctionName, "")); + {ok, BadRequest} -> + {proceed,[{status,{400,none, BadRequest}} | + ModData#mod.data]} + end; + {ok, BadRequest} -> + {proceed, [{status,{400, none, BadRequest}} | ModData#mod.data]} + end; + +erl(#mod{method = "POST", entity_body = Body} = ModData, ESIBody, Modules) -> + case httpd_util:split(ESIBody,":|%3A|/",2) of + {ok,[Module, Function]} -> + generate_webpage(ModData, ESIBody, Modules, Module, + Function, Body, [{entity_body, Body}]); + {ok, BadRequest} -> + {proceed,[{status, {400, none, BadRequest}} | ModData#mod.data]} + end. + +generate_webpage(ModData, ESIBody, ["all"], ModuleName, FunctionName, + Input, ScriptElements) -> + generate_webpage(ModData, ESIBody, [ModuleName], ModuleName, + FunctionName, Input, ScriptElements); +generate_webpage(ModData, ESIBody, Modules, ModuleName, FunctionName, + Input, ScriptElements) -> + case lists:member(ModuleName, Modules) of + true -> + Env = httpd_script_env:create_env(esi, ModData, ScriptElements), + Module = list_to_atom(ModuleName), + Function = list_to_atom(FunctionName), + case erl_scheme_webpage_chunk(Module, Function, + Env, Input, ModData) of + {error, erl_scheme_webpage_chunk_undefined} -> + erl_scheme_webpage_whole(Module, Function, Env, Input, + ModData); + ResponseResult -> + ResponseResult + end; + false -> + {proceed, [{status, {403, ModData#mod.request_uri, + ?NICE("Client not authorized to evaluate: " + ++ ESIBody)}} | ModData#mod.data]} + end. + +%% Old API that waits for the dymnamic webpage to be totally generated +%% before anythig is sent back to the client. +erl_scheme_webpage_whole(Module, Function, Env, Input, ModData) -> + case (catch Module:Function(Env, Input)) of + {'EXIT',Reason} -> + {proceed, [{status, {500, none, Reason}} | + ModData#mod.data]}; + Response -> + {Headers, Body} = + httpd_esi:parse_headers(lists:flatten(Response)), + Length = httpd_util:flatlength(Body), + case httpd_esi:handle_headers(Headers) of + {proceed, AbsPath} -> + {proceed, [{real_name, httpd_util:split_path(AbsPath)} + | ModData#mod.data]}; + {ok, NewHeaders, StatusCode} -> + send_headers(ModData, StatusCode, + [{"content-length", + integer_to_list(Length)}| NewHeaders]), + case ModData#mod.method of + "HEAD" -> + {proceed, [{response, {already_sent, 200, 0}} | + ModData#mod.data]}; + _ -> + httpd_response:send_body(ModData, + StatusCode, Body), + {proceed, [{response, {already_sent, 200, + Length}} | + ModData#mod.data]} + end + end + end. + +%% New API that allows the dynamic wepage to be sent back to the client +%% in small chunks at the time during generation. +erl_scheme_webpage_chunk(Mod, Func, Env, Input, ModData) -> + process_flag(trap_exit, true), + Self = self(), + %% Spawn worker that generates the webpage. + %% It would be nicer to use erlang:function_exported/3 but if the + %% Module isn't loaded the function says that it is not loaded + Pid = spawn_link( + fun() -> + case catch Mod:Func(Self, Env, Input) of + {'EXIT',{undef,_}} -> + %% Will force fallback on the old API + exit(erl_scheme_webpage_chunk_undefined); + _ -> + ok + end + end), + + Response = deliver_webpage_chunk(ModData, Pid), + + process_flag(trap_exit,false), + Response. + +deliver_webpage_chunk(#mod{config_db = Db} = ModData, Pid) -> + Timeout = erl_script_timeout(Db), + deliver_webpage_chunk(ModData, Pid, Timeout). + +deliver_webpage_chunk(#mod{config_db = Db} = ModData, Pid, Timeout) -> + case receive_headers(Timeout) of + {error, Reason} -> + %% Happens when webpage generator callback/3 is undefined + {error, Reason}; + {Headers, Body} -> + case httpd_esi:handle_headers(Headers) of + {proceed, AbsPath} -> + {proceed, [{real_name, httpd_util:split_path(AbsPath)} + | ModData#mod.data]}; + {ok, NewHeaders, StatusCode} -> + IsDisableChunkedSend = + httpd_response:is_disable_chunked_send(Db), + case (ModData#mod.http_version =/= "HTTP/1.1") or + (IsDisableChunkedSend) of + true -> + send_headers(ModData, StatusCode, + [{"connection", "close"} | + NewHeaders]); + false -> + send_headers(ModData, StatusCode, + [{"transfer-encoding", + "chunked"} | NewHeaders]) + end, + handle_body(Pid, ModData, Body, Timeout, length(Body), + IsDisableChunkedSend) + end; + timeout -> + send_headers(ModData, {504, "Timeout"},[{"connection", "close"}]), + httpd_socket:close(ModData#mod.socket_type, ModData#mod.socket), + process_flag(trap_exit,false), + {proceed,[{response, {already_sent, 200, 0}} | ModData#mod.data]} + end. + +receive_headers(Timeout) -> + receive + {ok, Chunk} -> + httpd_esi:parse_headers(lists:flatten(Chunk)); + {'EXIT', Pid, erl_scheme_webpage_chunk_undefined} when is_pid(Pid) -> + {error, erl_scheme_webpage_chunk_undefined}; + {'EXIT', Pid, Reason} when is_pid(Pid) -> + exit({mod_esi_linked_process_died, Pid, Reason}) + after Timeout -> + timeout + end. + +send_headers(ModData, StatusCode, HTTPHeaders) -> + ExtraHeaders = httpd_response:cache_headers(ModData), + httpd_response:send_header(ModData, StatusCode, + ExtraHeaders ++ HTTPHeaders). + +handle_body(_, #mod{method = "HEAD"} = ModData, _, _, Size, _) -> + process_flag(trap_exit,false), + {proceed, [{response, {already_sent, 200, Size}} | ModData#mod.data]}; + +handle_body(Pid, ModData, Body, Timeout, Size, IsDisableChunkedSend) -> + httpd_response:send_chunk(ModData, Body, IsDisableChunkedSend), + receive + {ok, Data} -> + handle_body(Pid, ModData, Data, Timeout, Size + length(Data), + IsDisableChunkedSend); + {'EXIT', Pid, normal} when is_pid(Pid) -> + httpd_response:send_final_chunk(ModData, IsDisableChunkedSend), + {proceed, [{response, {already_sent, 200, Size}} | + ModData#mod.data]}; + {'EXIT', Pid, Reason} when is_pid(Pid) -> + exit({mod_esi_linked_process_died, Pid, Reason}) + after Timeout -> + process_flag(trap_exit,false), + {proceed,[{response, {already_sent, 200, Size}} | + ModData#mod.data]} + end. + +erl_script_timeout(Db) -> + httpd_util:lookup(Db, erl_script_timeout, ?DEFAULT_ERL_TIMEOUT). + +script_elements(FuncAndInput, Input) -> + case input_type(FuncAndInput) of + path_info -> + [{path_info, Input}]; + query_string -> + [{query_string, Input}]; + _ -> + [] + end. + +input_type([]) -> + no_input; +input_type([$/|_Rest]) -> + path_info; +input_type([$?|_Rest]) -> + query_string; +input_type([_First|Rest]) -> + input_type(Rest). + +%%------------------------ Eval mechanism -------------------------------- + +eval(#mod{request_uri = ReqUri, method = "POST", + http_version = Version, data = Data}, _ESIBody, _Modules) -> + {proceed,[{status,{501,{"POST", ReqUri, Version}, + ?NICE("Eval mechanism doesn't support method POST")}}| + Data]}; + +eval(#mod{method = Method} = ModData, ESIBody, Modules) + when Method == "GET"; Method == "HEAD" -> + case is_authorized(ESIBody, Modules) of + true -> + case generate_webpage(ESIBody) of + {error, Reason} -> + {proceed, [{status, {500, none, Reason}} | + ModData#mod.data]}; + {ok, Response} -> + {Headers, _} = + httpd_esi:parse_headers(lists:flatten(Response)), + case httpd_esi:handle_headers(Headers) of + {ok, _, StatusCode} -> + {proceed,[{response, {StatusCode, Response}} | + ModData#mod.data]}; + {proceed, AbsPath} -> + {proceed, [{real_name, AbsPath} | + ModData#mod.data]} + end + end; + false -> + {proceed,[{status, + {403, ModData#mod.request_uri, + ?NICE("Client not authorized to evaluate: " + ++ ESIBody)}} | ModData#mod.data]} + end. + +generate_webpage(ESIBody) -> + (catch lib:eval_str(string:concat(ESIBody,". "))). + +is_authorized(_ESIBody, ["all"]) -> + true; +is_authorized(ESIBody, Modules) -> + case regexp:match(ESIBody, "^[^\:(%3A)]*") of + {match, Start, Length} -> + lists:member(string:substr(ESIBody, Start, Length), Modules); + nomatch -> + false + end. -- cgit v1.2.3