Development of mod_register and mod_vcard

Hi,

I am using ejabberd 2.1.4. I have noticed that mod_register does not conform to XEP-0077 (http://xmpp.org/extensions/xep-0077.html) in that it does not respond with the element if a username already exists. I have made the following modifications so that this is possible. I have never even seen Erlang before, let alone programmed in it so there will probably be a better way to accomplish this change...

In ejabberd_c2s.erl:

Add:

    get_attrs_internal({xmlelement, _Name, Attrs, _Els}) ->
        Attrs.

Modify process_unauthenticated_stanza():

    process_unauthenticated_stanza(StateData, El) ->
        case jlib:iq_query_info(El) of
        #iq{} = IQ ->
            Attrs = get_attrs_internal(El),
            From = xml:get_attr_s("from", Attrs),
            Res = ejabberd_hooks:run_fold(c2s_unauthenticated_iq,
                          StateData#state.server,
                          empty,
                          [StateData#state.server, IQ,
                           StateData#state.ip, From]),
            case Res of
            empty ->
                % The only reasonable IQ's here are auth and register IQ's
                % They contain secrets, so don't include subelements to response
                ResIQ = IQ#iq{type = error,
                      sub_el = [?ERR_SERVICE_UNAVAILABLE]},
                Res1 = jlib:replace_from_to(
                     jlib:make_jid("", StateData#state.server, ""),
                     jlib:make_jid("", "", ""),
                     jlib:iq_to_xml(ResIQ)),
                send_element(StateData, jlib:remove_attr("to", Res1));
            _ ->
                send_element(StateData, Res)
            end;
        _ ->
            % Drop any stanza, which isn't IQ stanza
            ok
        end.

Then in mod_register.erl:

Modify -export. Change:

         unauthenticated_iq_register/4,

to:

         unauthenticated_iq_register/5,

Modify unauthenticated_iq_register():

    unauthenticated_iq_register(_Acc,
                    Server, #iq{type = Type, xmlns = ?NS_REGISTER} = IQ, IP, From) ->
        Address = case IP of
             {A, _Port} -> A;
              _ -> undefined
              end,
        FromJid =
            case Type of
                get -> jlib:string_to_jid(From);
                _ -> jlib:make_jid("", "", "")
            end,
        ResIQ = process_iq(FromJid,
                   jlib:make_jid("", Server, ""),
                   IQ,
                   Address),
        Res1 = jlib:replace_from_to(jlib:make_jid("", Server, ""),
                    jlib:make_jid("", "", ""),
                    jlib:iq_to_xml(ResIQ)),
        jlib:remove_attr("to", Res1);

    unauthenticated_iq_register(Acc, _Server, _IQ, _IP, _From) ->
        Acc.

Replace "get" case of process_iq()/4 (to end of function) with:

	get ->
		case From of
		#jid{user = User,
			 lserver = Server} ->
			case ejabberd_auth:is_user_exists(User,Server) of
			true ->
				IQ#iq{type = result,
				  sub_el = [{xmlelement,
						 "query",
						 [{"xmlns", "jabber:iq:register"}],
						 [{xmlelement, "registered", [], []},
						  {xmlelement, "instructions", [],
						   [{xmlcdata,
							translate:translate(
								Lang,
								"Choose a username and password to register with this server")}]},
						  {xmlelement, "username", [], [{xmlcdata,translate:translate(Lang,User)}]},
						  {xmlelement, "password", [], []}]}]};
			false ->
				IQ#iq{type = result,
				  sub_el = [{xmlelement,
						 "query",
						 [{"xmlns", "jabber:iq:register"}],
						 [{xmlelement, "instructions", [],
						   [{xmlcdata,
							translate:translate(
								Lang,
								"Choose a username and password to register with this server")}]},
						  {xmlelement, "username", [], [{xmlcdata,translate:translate(Lang,User)}]},
						  {xmlelement, "password", [], []} ]}]}
			end;
		_ ->
			IQ#iq{type = result,
			  sub_el = [{xmlelement,
					 "query",
					 [{"xmlns", "jabber:iq:register"}],
					 [{xmlelement, "instructions", [],
					   [{xmlcdata,
						translate:translate(
							Lang,
							"Choose a username and password to register with this server")}]},
					  {xmlelement, "username", [], []},
					  {xmlelement, "password", [], []} ]}]}
		end
    end.

My other modification is to make the vCard functionality conform better to XEP-0054 (http://xmpp.org/extensions/xep-0054.html). In particular, examples 3 and 4 in section 3.1 where the vCard does not exist in the server. My modification returns example 3 if the user does not exist in the ejabberd database and example 4 if the user exists, but there is no vCard defined for that user. Previously, the empty "vCard" element would not be returned in either case.

Modify mod_vcard.erl:

Replace function process_sm_iq()/3 with:

	process_sm_iq(From, To, #iq{type = Type, sub_el = SubEl} = IQ) ->
		case Type of
		set ->
			#jid{user = User, lserver = LServer} = From,
			case lists:member(LServer, ?MYHOSTS) of
			true ->
				set_vcard(User, LServer, SubEl),
				IQ#iq{type = result, sub_el = []};
			false ->
				IQ#iq{type = error, sub_el = [SubEl, ?ERR_NOT_ALLOWED]}
			end;
		get ->
			#jid{luser = LUser, lserver = LServer} = To,
			case ejabberd_auth:is_user_exists(LUser,LServer) of
			true ->
				US = {LUser, LServer},
				F = fun() ->
					mnesia:read({vcard, US})
				end,
				Els = case mnesia:transaction(F) of
						{atomic, Rs} ->
							lists:map(
								fun(R) -> R#vcard.vcard end,
								Rs);
						{aborted, _Reason} ->
							[]
				end,
				case Els of
					[] -> IQ#iq{type = result, sub_el = [{xmlelement,"vCard",[{"xmlns","vcard-temp"}],[]}]};
					_  -> IQ#iq{type = result, sub_el = Els}
				end;
			false ->
				Els = [
						{xmlelement,"vCard",[{"xmlns","vcard-temp"}],[]},
						{xmlelement,"error",[{"type","cancel"}],[{xmlelement,"item-not-found",[{"xmlns","urn:ietf:params:xml:ns:xmpp-stanzas"}],[]}]}
					],
				IQ#iq{type = error, sub_el = Els}
			end
		end.

I hope you find these modifications useful.

Cheers, Mike.