%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2016. All Rights Reserved.
%%
%% 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.
%%
%% %CopyrightEnd%
%%
%%
-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, store/2]).
-include("httpd.hrl").
-include("httpd_internal.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 <Data> (Html page generated sofar) to the server
%% request handling process so it can forward it to the client.
%%-------------------------------------------------------------------------
deliver(SessionID, Data) when is_pid(SessionID) ->
SessionID ! {esi_data, 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 proplists:get_value(status, ModData#mod.data) of
{_StatusCode, _PhraseArgs, _Reason} ->
{proceed, ModData#mod.data};
undefined ->
case proplists:get_value(response, ModData#mod.data) 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, []) ->
try re:split(ErlScriptAlias," ", [{return, list}]) of
[ErlName | StrModules] ->
Modules = lists:map(fun(Str) ->
list_to_atom(string:strip(Str))
end, StrModules),
{ok, [], {erl_script_alias, {ErlName, Modules}}}
catch _:_ ->
{error, ?NICE(string:strip(ErlScriptAlias) ++
" is an invalid ErlScriptAlias")}
end;
load("EvalScriptAlias " ++ EvalScriptAlias, []) ->
try re:split(EvalScriptAlias, " ", [{return, list}]) of
[EvalName | StrModules] ->
Modules = lists:map(fun(Str) ->
list_to_atom(string:strip(Str))
end, StrModules),
{ok, [], {eval_script_alias, {EvalName, Modules}}}
catch
_:_ ->
{error, ?NICE(string:strip(EvalScriptAlias) ++
" is an invalid EvalScriptAlias")}
end;
load("ErlScriptTimeout " ++ Timeout, [])->
case catch list_to_integer(string:strip(Timeout)) of
TimeoutSec when is_integer(TimeoutSec) ->
{ok, [], {erl_script_timeout, TimeoutSec * 1000}};
_ ->
{error, ?NICE(string:strip(Timeout) ++
" is an invalid ErlScriptTimeout")}
end;
load("ErlScriptNoCache " ++ CacheArg, [])->
case catch list_to_atom(string:strip(CacheArg)) of
true ->
{ok, [], {erl_script_nocache, true}};
false ->
{ok, [], {erl_script_nocache, false}};
_ ->
{error, ?NICE(string:strip(CacheArg)++
" is an invalid ErlScriptNoCache directive")}
end.
%%--------------------------------------------------------------------------
%% store(Directive, DirectiveList) -> {ok, NewDirective} |
%% {ok, [NewDirective]} |
%% {error, Reason}
%% Directive = {DirectiveKey , DirectiveValue}
%% DirectiveKey = DirectiveValue = term()
%% Reason = term()
%%
%% Description: See httpd(3) ESWAPI CALLBACK FUNCTIONS
%%-------------------------------------------------------------------------
store({erl_script_alias, {Name, [all]}} = Conf, _)
when is_list(Name) ->
{ok, Conf};
store({erl_script_alias, {Name, Modules}} = Conf, _)
when is_list(Name) ->
try httpd_util:modules_validate(Modules) of
ok ->
{ok, Conf}
catch
throw:Error ->
{error, {wrong_type, {erl_script_alias, Error}}}
end;
store({eval_script_alias, {Name, Modules}} = Conf, _)
when is_list(Name)->
try httpd_util:modules_validate(Modules) of
ok ->
{ok, Conf}
catch
throw:Error ->
{error, {wrong_type, {eval_script_alias, Error}}}
end;
store({erl_script_alias, Value}, _) ->
{error, {wrong_type, {erl_script_alias, Value}}};
store({erl_script_timeout, TimeoutSec}, _)
when is_integer(TimeoutSec) andalso (TimeoutSec >= 0) ->
{ok, {erl_script_timeout, TimeoutSec * 1000}};
store({erl_script_timeout, Value}, _) ->
{error, {wrong_type, {erl_script_timeout, Value}}};
store({erl_script_nocache, Value} = Conf, _)
when (Value =:= true) orelse (Value =:= false) ->
{ok, Conf};
store({erl_script_nocache, Value}, _) ->
{error, {wrong_type, {erl_script_nocache, Value}}}.
%%%========================================================================
%%% 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 re:run(RequestURI, AliasMatchStr, [{capture, first}]) of
{match, [{0, 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") orelse (Method =:= "HEAD") orelse (Method =:= "DELETE") ->
case httpd_util:split(ESIBody,":|%3A|/",2) of
{ok, [ModuleName, FuncAndInput]} ->
case httpd_util:split(FuncAndInput,"[\?/]",2) of
{ok, [FunctionName, Input]} ->
generate_webpage(ModData, ESIBody, Modules,
list_to_atom(ModuleName),
FunctionName, Input,
script_elements(FuncAndInput, Input));
{ok, [FunctionName]} ->
generate_webpage(ModData, ESIBody, Modules,
list_to_atom(ModuleName),
FunctionName, "",
script_elements(FuncAndInput, ""));
{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 = "PUT", entity_body = Body} = ModData,
ESIBody, Modules) ->
case httpd_util:split(ESIBody,":|%3A|/",2) of
{ok, [ModuleName, FuncAndInput]} ->
case httpd_util:split(FuncAndInput,"[\?/]",2) of
{ok, [FunctionName, Input]} ->
generate_webpage(ModData, ESIBody, Modules,
list_to_atom(ModuleName),
FunctionName, {Input,Body},
script_elements(FuncAndInput, Input));
{ok, [FunctionName]} ->
generate_webpage(ModData, ESIBody, Modules,
list_to_atom(ModuleName),
FunctionName, {undefined,Body},
script_elements(FuncAndInput, ""));
{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,[ModuleName, Function]} ->
generate_webpage(ModData, ESIBody, Modules,
list_to_atom(ModuleName),
Function, Body, []);
{ok, BadRequest} ->
{proceed,[{status, {400, none, BadRequest}} | ModData#mod.data]}
end;
erl(#mod{request_uri = ReqUri,
method = "PATCH",
http_version = Version,
data = Data}, _ESIBody, _Modules) ->
{proceed, [{status,{501,{"PATCH", ReqUri, Version},
?NICE("Erl mechanism doesn't support method PATCH")}}|
Data]}.
generate_webpage(ModData, ESIBody, [all], Module, FunctionName,
Input, ScriptElements) ->
generate_webpage(ModData, ESIBody, [Module], Module,
FunctionName, Input, ScriptElements);
generate_webpage(ModData, ESIBody, Modules, Module, FunctionName,
Input, ScriptElements) ->
Function = list_to_atom(FunctionName),
case lists:member(Module, Modules) of
true ->
Env = httpd_script_env:create_env(esi, ModData, ScriptElements),
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(Mod, Func, Env, Input, ModData) ->
case (catch Mod:Func(Env, Input)) of
{'EXIT',{undef, _}} ->
{proceed, [{status, {404, ModData#mod.request_uri, "Not found"}}
| ModData#mod.data]};
{'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),
{ok, NewHeaders, StatusCode} = httpd_esi:handle_headers(Headers),
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.
%% 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);
{continue, _} = Continue ->
exit(Continue);
_ ->
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};
{continue, _} = Continue ->
Continue;
{Headers, Body} ->
{ok, NewHeaders, StatusCode} = httpd_esi:handle_headers(Headers),
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);
timeout ->
send_headers(ModData, 504, [{"connection", "close"}]),
httpd_socket:close(ModData#mod.socket_type, ModData#mod.socket),
{proceed,[{response, {already_sent, 200, 0}} | ModData#mod.data]}
end.
receive_headers(Timeout) ->
receive
{esi_data, Chunk} ->
httpd_esi:parse_headers(lists:flatten(Chunk));
{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, {continue, _} = Continue} when is_pid(Pid) ->
Continue;
{'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, erl_script_nocache),
httpd_response:send_header(ModData, StatusCode,
ExtraHeaders ++ HTTPHeaders).
handle_body(_, #mod{method = "HEAD"} = ModData, _, _, Size, _) ->
{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
{esi_data, Data} when is_binary(Data) ->
handle_body(Pid, ModData, Data, Timeout, Size + byte_size(Data),
IsDisableChunkedSend);
{esi_data, Data} ->
handle_body(Pid, ModData, Data, Timeout, Size + length(Data),
IsDisableChunkedSend);
{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) ->
Error = lists:flatten(io_lib:format("mod_esi process failed with reason ~p", [Reason])),
httpd_util:error_log(ModData#mod.config_db, Error),
httpd_response:send_final_chunk(ModData,
[{"Warning", "199 inets server - body maybe incomplete, "
"internal server error"}],
IsDisableChunkedSend),
done
after Timeout ->
kill_esi_delivery_process(Pid),
httpd_response:send_final_chunk(ModData, [{"Warning", "199 inets server - "
"body maybe incomplete, timed out"}],
IsDisableChunkedSend),
done
end.
kill_esi_delivery_process(Pid) ->
exit(Pid, kill),
receive
{'EXIT', Pid, killed} ->
%% Clean message queue
receive
{esi_data, _} ->
ok
after 0 ->
ok
end,
receive
{ok, _} ->
ok
after 0 ->
ok
end
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 = "PUT",
http_version = Version,
data = Data}, _ESIBody, _Modules) ->
{proceed,[{status,{501,{"PUT", ReqUri, Version},
?NICE("Eval mechanism doesn't support method PUT")}}|
Data]};
eval(#mod{request_uri = ReqUri,
method = "DELETE",
http_version = Version,
data = Data}, _ESIBody, _Modules) ->
{proceed,[{status,{501,{"DELETE", ReqUri, Version},
?NICE("Eval mechanism doesn't support method DELETE")}}|
Data]};
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") orelse (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)),
{ok, _, StatusCode} =httpd_esi:handle_headers(Headers),
{proceed,[{response, {StatusCode, Response}} |
ModData#mod.data]}
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 re:run(ESIBody, "^[^\:(%3A)]*", [{capture, first}]) of
{match, [{Start, Length}]} ->
lists:member(list_to_atom(string:substr(ESIBody, Start+1, Length)),
Modules);
nomatch ->
false
end.
