diff options
Diffstat (limited to 'lib/inets/src/http_server/mod_responsecontrol.erl')
-rw-r--r-- | lib/inets/src/http_server/mod_responsecontrol.erl | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/lib/inets/src/http_server/mod_responsecontrol.erl b/lib/inets/src/http_server/mod_responsecontrol.erl new file mode 100644 index 0000000000..79e2e1bdba --- /dev/null +++ b/lib/inets/src/http_server/mod_responsecontrol.erl @@ -0,0 +1,303 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2001-2009. All Rights Reserved. +%% +%% 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 online 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. +%% +%% %CopyrightEnd% +%% +%% + +-module(mod_responsecontrol). +-export([do/1]). + +-include("httpd.hrl"). + +do(Info) -> + ?DEBUG("do -> response_control",[]), + case proplists:get_value(status, Info#mod.data) of + %% A status code has been generated! + {_StatusCode, _PhraseArgs, _Reason} -> + {proceed, Info#mod.data}; + %% No status code has been generated! + undefined -> + case proplists:get_value(response, Info#mod.data) of + %% No response has been generated! + undefined -> + case do_responsecontrol(Info) of + continue -> + {proceed, Info#mod.data}; + Response -> + {proceed,[Response | Info#mod.data]} + end; + %% A response has been generated or sent! + _Response -> + {proceed, Info#mod.data} + end + end. + +%%---------------------------------------------------------------------- +%%Control that the request header did not contians any limitations +%%wheather a response shall be createed or not +%%---------------------------------------------------------------------- +do_responsecontrol(Info) -> + ?DEBUG("do_response_control -> Request URI: ~p",[Info#mod.request_uri]), + Path = mod_alias:path(Info#mod.data, Info#mod.config_db, + Info#mod.request_uri), + case file:read_file_info(Path) of + {ok, FileInfo} -> + control(Path, Info, FileInfo); + _ -> + %% The requested asset is not a plain file and then it must + %% be generated everytime its requested + continue + end. + +%%---------------------------------------------------------------------- +%%Control the If-Match, If-None-Match, and If-Modified-Since +%%---------------------------------------------------------------------- + + +%% If a client sends more then one of the if-XXXX fields in a request +%% The standard says it does not specify the behaviuor so I specified it :-) +%% The priority between the fields is +%% 1.If-modified +%% 2.If-Unmodified +%% 3.If-Match +%% 4.If-Nomatch + +%% This means if more than one of the fields are in the request the +%% field with highest priority will be used + +%%If the request is a range request the If-Range field will be the winner. + +control(Path, Info, FileInfo) -> + case control_range(Path, Info, FileInfo) of + undefined -> + case control_Etag(Path, Info, FileInfo) of + undefined -> + case control_modification(Path, Info, FileInfo) of + continue -> + continue; + ReturnValue -> + send_return_value(ReturnValue, FileInfo) + end; + continue -> + continue; + ReturnValue -> + send_return_value(ReturnValue, FileInfo) + end; + Response-> + Response + end. + +%%---------------------------------------------------------------------- +%%If there are both a range and an if-range field control if +%%---------------------------------------------------------------------- +control_range(Path,Info,FileInfo) -> + case proplists:get_value("range", Info#mod.parsed_header) of + undefined-> + undefined; + _Range -> + case proplists:get_value("if-range", Info#mod.parsed_header) of + undefined -> + undefined; + EtagOrDate -> + control_if_range(Path,Info,FileInfo,EtagOrDate) + end + end. + +control_if_range(_Path, Info, FileInfo, EtagOrDate) -> + case httpd_util:convert_request_date(strip_date(EtagOrDate)) of + bad_date -> + FileEtag=httpd_util:create_etag(FileInfo), + case FileEtag of + EtagOrDate -> + continue; + _ -> + {if_range,send_file} + end; + _ErlDate -> + %%We got the date in the request if it is + case control_modification_data(Info, FileInfo#file_info.mtime, + "if-range") of + modified -> + {if_range,send_file}; + _UnmodifiedOrUndefined-> + continue + end + end. + +%%---------------------------------------------------------------------- +%%Controls the values of the If-Match and I-None-Mtch +%%---------------------------------------------------------------------- +control_Etag(Path, Info, FileInfo)-> + FileEtag = httpd_util:create_etag(FileInfo), + %%Control if the E-Tag for the resource matches one of the Etags in + %%the -if-match header field + case control_match(Info, FileInfo, "if-match", FileEtag) of + nomatch -> + %%None of the Etags in the if-match field matched the current + %%Etag for the resource return a 304 + {412, Info, Path}; + match -> + continue; + undefined -> + case control_match(Info, FileInfo, "if-none-match", FileEtag) of + nomatch -> + continue; + match -> + case Info#mod.method of + "GET" -> + {304, Info, Path}; + "HEAD" -> + {304, Info, Path}; + _OtherrequestMethod -> + {412, Info, Path} + end; + undefined -> + undefined + end + end. + +%%---------------------------------------------------------------------- +%%Control if there are any Etags for HeaderField in the request if so +%%Control if they match the Etag for the requested file +%%---------------------------------------------------------------------- +control_match(Info, _FileInfo, HeaderField, FileEtag)-> + case split_etags(proplists:get_value(HeaderField, + Info#mod.parsed_header)) of + undefined-> + undefined; + Etags-> + %%Control that the match any star not is availible + case lists:member("*",Etags) of + true-> + match; + false-> + compare_etags(FileEtag, Etags) + end + end. + +%%---------------------------------------------------------------------- +%%Split the etags from the request +%%---------------------------------------------------------------------- +split_etags(undefined)-> + undefined; +split_etags(Tags) -> + string:tokens(Tags,", "). + +%%---------------------------------------------------------------------- +%%Control if the etag for the file is in the list +%%---------------------------------------------------------------------- +compare_etags(Tag,Etags) -> + case lists:member(Tag,Etags) of + true -> + match; + _ -> + nomatch + end. + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% %% +%%Control if the file is modificated %% +%% %% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +%%---------------------------------------------------------------------- +%%Control the If-Modified-Since and If-Not-Modified-Since header fields +%%---------------------------------------------------------------------- +control_modification(Path,Info,FileInfo)-> + ?DEBUG("control_modification() -> entry",[]), + case control_modification_data(Info, + FileInfo#file_info.mtime, + "if-modified-since") of + modified-> + continue; + unmodified-> + {304, Info, Path}; + undefined -> + case control_modification_data(Info, + FileInfo#file_info.mtime, + "if-unmodified-since") of + modified -> + {412, Info, Path}; + _ContinueUndefined -> + continue + end + end. + +%%---------------------------------------------------------------------- +%%Controls the date from the http-request if-modified-since and +%%if-not-modified-since against the modification data of the +%%File +%%---------------------------------------------------------------------- +%%Info is the record about the request +%%ModificationTime is the time the file was edited last +%%Header Field is the name of the field to control + +control_modification_data(Info, ModificationTime, HeaderField)-> + case strip_date(proplists:get_value(HeaderField, + Info#mod.parsed_header)) of + undefined-> + undefined; + LastModified0 -> + LastModified = calendar:universal_time_to_local_time( + httpd_util:convert_request_date(LastModified0)), + ?DEBUG("control_modification_data() -> " + "~n Request-Field: ~s" + "~n FileLastModified: ~p" + "~n FieldValue: ~p", + [HeaderField, ModificationTime, LastModified]), + FileTime = + calendar:datetime_to_gregorian_seconds(ModificationTime), + FieldTime = calendar:datetime_to_gregorian_seconds(LastModified), + if + FileTime =< FieldTime -> + ?DEBUG("File unmodified~n", []), unmodified; + FileTime >= FieldTime -> + ?DEBUG("File modified~n", []), modified + end + end. + +%% IE4 & NS4 sends an extra '; length=xxxx' string at the end of the If-Modified-Since +%% header, we detect this and ignore it (the RFCs does not mention this). +strip_date(undefined) -> + undefined; +strip_date([]) -> + []; +strip_date([$;,$ | _]) -> + []; +strip_date([C | Rest]) -> + [C | strip_date(Rest)]. + +send_return_value({412,_,_}, _FileInfo)-> + {status,{412,none,"Precondition Failed"}}; + +send_return_value({304,Info,Path}, FileInfo)-> + Suffix = httpd_util:suffix(Path), + MimeType = httpd_util:lookup_mime_default(Info#mod.config_db,Suffix, + "text/plain"), + LastModified = + case (catch httpd_util:rfc1123_date(FileInfo#file_info.mtime)) of + Date when is_list(Date) -> + [{last_modified, Date}]; + _ -> %% This will rarly happen, but could happen + %% if a computer is wrongly configured. + [] + end, + + Header = [{code,304}, + {etag, httpd_util:create_etag(FileInfo)}, + {content_length,"0"}, {mime_type, MimeType} | LastModified], + {response, {response, Header, nobody}}. |