* src/mod_muc/mod_muc_log.erl: Spam prevention: The default behaviour

is now to use the nofollow rel attributes for links that are submitted
by users (EJAB-185).
* doc/guide.tex: Likewise.

SVN Revision: 728

ChangeLog

@@ -1,5 +1,10 @@
 2007-02-19  Mickael Remond  <mickael.remond@process-one.net>
 
+	* src/mod_muc/mod_muc_log.erl: Spam prevention: The default behaviour 
+	is now to use the nofollow rel attributes for links that are submitted
+	by users (EJAB-185).
+	* doc/guide.tex: Likewise.
+
 	* src/mod_muc/mod_muc_room.erl: API improvement: Implementation of an
 	event to destroy MUC room from an external application (Thanks to
     Massimiliano Mirra) (EJAB-184).

doc/guide.tex

@@ -2023,6 +2023,11 @@ Options:
   are \term{local} and \term{universal}. With the first value, the local time,
   as reported to Erlang by the operating system, will be used. With the latter,
   GMT/UTC time will be used. The default value is \term{local}.
+\titem{spam\_prevention}\ind{options!spam\_prevention}
+  To prevent spam, the \term{spam_prevention} option adds a special attribute
+  to links that prevent their indexation by search engines. The default value
+  is \term{true}, which mean that nofollow attributes will be added to user
+  submitted links. 
 \titem{top\_link}\ind{options!top\_link}
   With this option you can customize the link on the top right corner of each
   log file. The syntax of this option is \term{\{"URL", "Text"\}}. The default
@@ -2049,6 +2054,7 @@ Examples:
                {dirtype, plain},
                {outdir, "/var/www/muclogs"},
                {timezone, universal},
+               {spam_prevention, true},
                {top_link, {"http://www.jabber.ru", "Jabber.ru"}}
     ]},
     ...

src/mod_muc/mod_muc_log.erl

@@ -38,6 +38,7 @@
 		access,
 		lang,
 		timezone,
+		spam_prevention,
 		top_link}).
 
 %%====================================================================
@@ -98,6 +99,7 @@ init([Host, Opts]) ->
     AccessLog = gen_mod:get_opt(access_log, Opts, muc_admin),
     Timezone = gen_mod:get_opt(timezone, Opts, local),
     Top_link = gen_mod:get_opt(top_link, Opts, {"/", "Home"}),
+    NoFollow = gen_mod:get_opt(spam_prevention, Opts, true),
     Lang = case ejabberd_config:get_local_option({language, Host}) of
 	       undefined ->
 		   "";
@@ -111,6 +113,7 @@ init([Host, Opts]) ->
 		access = AccessLog,
 		lang = Lang,
 		timezone = Timezone,
+		spam_prevention = NoFollow,
 		top_link = Top_link}}.
 
 %%--------------------------------------------------------------------
@@ -261,6 +264,7 @@ add_message_to_log(Nick1, Message, RoomJID, Opts, State) ->
 	   css_file = CSSFile,
 	   lang = Lang,
 	   timezone = Timezone,
+	   spam_prevention = NoFollow,
 	   top_link = TopLink} = State,
     Room = get_room_info(RoomJID, Opts),
 
@@ -319,7 +323,7 @@ add_message_to_log(Nick1, Message, RoomJID, Opts, State) ->
 				 [Nick, ?T("leaves the room")]);
 	       {leave, Reason} ->  
 		   io_lib:format("<font class=\"ml\">~s ~s: ~s</font><br/>", 
-				 [Nick, ?T("leaves the room"), htmlize(Reason)]);
+				 [Nick, ?T("leaves the room"), htmlize(Reason,NoFollow)]);
 	       {kickban, "307", ""} ->  
 		   io_lib:format("<font class=\"mk\">~s ~s</font><br/>", 
 				 [Nick, ?T("has been kicked")]);
@@ -337,7 +341,7 @@ add_message_to_log(Nick1, Message, RoomJID, Opts, State) ->
 				 [OldNick, ?T("is now known as"), Nick]);
 	       {subject, T} ->  
 		   io_lib:format("<font class=\"msc\">~s~s~s</font><br/>", 
-				 [Nick, ?T(" has set the subject to: "), htmlize(T)]);
+				 [Nick, ?T(" has set the subject to: "), htmlize(T,NoFollow)]);
 	       {body, T} ->  
 		   case regexp:first_match(T, "^/me\s") of
 		       {match, _, _} ->
@@ -345,7 +349,7 @@ add_message_to_log(Nick1, Message, RoomJID, Opts, State) ->
 					 [Nick, string:substr(htmlize(T), 5)]);
 		       nomatch ->
 			   io_lib:format("<font class=\"mn\">&lt;~s&gt;</font> ~s<br/>", 
-					 [Nick, htmlize(T)])
+					 [Nick, htmlize(T,NoFollow)])
 		   end
 	   end,
     {Hour, Minute, Second} = Time,
@@ -640,11 +644,19 @@ put_room_config(F, RoomConfig, Lang) ->
     fw(F,   "<div class=\"rcos\" id=\"a~p\" style=\"display: none;\" ><br/>~s</div>", [Now2, RoomConfig]),
     fw(F, "</div>").
 
+%% htmlize
+%% The default behaviour is to ignore the nofollow spam prevention on links
+%% (NoFollow=false)
 htmlize(S1) ->
+    htmlize(S1, false).
+
+%% The NoFollow parameter tell if the spam prevention should be applied to the link found
+%% true means 'apply nofollow on links'.
+htmlize(S1, NoFollow) ->
     S2_list = string:tokens(S1, "\n"),
     lists:foldl(
       fun(Si, Res) -> 
-	      Si2 = htmlize2(Si),
+	      Si2 = htmlize2(Si, NoFollow),
 	      case Res of
 		  "" -> Si2;
 		  _ -> Res ++ "<br/>" ++ Si2
@@ -653,14 +665,21 @@ htmlize(S1) ->
       "",
       S2_list).
 
-htmlize2(S1) ->
+htmlize2(S1, NoFollow) ->
     S2 = element(2, regexp:gsub(S1, "\\&", "\\&amp;")),
     S3 = element(2, regexp:gsub(S2, "<", "\\&lt;")),
     S4 = element(2, regexp:gsub(S3, ">", "\\&gt;")),
-    S5 = element(2, regexp:gsub(S4, "(http|ftp)://.[^ ]*", "<a href=\"&\">&</a>")),
+    S5 = element(2, regexp:gsub(S4, "(http|ftp)://.[^ ]*", link_regexp(NoFollow))),
     %% Remove 'right-to-left override' unicode character 0x202e
     element(2, regexp:gsub(S5, [226,128,174], "[RLO]")).
 
+%% Regexp link
+%% Add the nofollow rel attribute when required
+link_regexp(false) ->
+    "<a href=\"&\">&</a>";
+link_regexp(true) ->
+    "<a href=\"&\" rel=\"nofollow\">&</a>".
+
 get_room_info(RoomJID, Opts) ->
     Title =
 	case lists:keysearch(title, 1, Opts) of