Preserve PID for offline sessions

Don't set the PID to 'undefined' when a session goes offline, as this
looses the information which node created the session table entry.

Fixes #1196.

include/ejabberd_sm.hrl

@@ -1,9 +1,9 @@
 -ifndef(EJABBERD_SM_HRL).
 -define(EJABBERD_SM_HRL, true).
 
--record(session, {sid, usr, us, priority, info}).
+-record(session, {sid, usr, us, priority, info = []}).
 -record(session_counter, {vhost, count}).
--type sid() :: {erlang:timestamp(), pid()} | {erlang:timestamp(), undefined}.
+-type sid() :: {erlang:timestamp(), pid()}.
 -type ip() :: {inet:ip_address(), inet:port_number()} | undefined.
 -type info() :: [{conn, atom()} | {ip, ip()} | {node, atom()}
                  | {oor, boolean()} | {auth_module, atom()}

src/ejabberd_sm.erl

@@ -270,25 +270,28 @@ get_session_pid(User, Server, Resource) ->
 
 -spec set_offline_info(sid(), binary(), binary(), binary(), info()) -> ok.
 
-set_offline_info({Time, _Pid}, User, Server, Resource, Info) ->
-    SID = {Time, undefined},
+set_offline_info(SID, User, Server, Resource, Info) ->
     LUser = jid:nodeprep(User),
     LServer = jid:nameprep(Server),
     LResource = jid:resourceprep(Resource),
-    set_session(SID, LUser, LServer, LResource, undefined, Info).
+    set_session(SID, LUser, LServer, LResource, undefined, [offline | Info]).
 
 -spec get_offline_info(erlang:timestamp(), binary(), binary(),
                        binary()) -> none | info().
 
 get_offline_info(Time, User, Server, Resource) ->
-    SID = {Time, undefined},
     LUser = jid:nodeprep(User),
     LServer = jid:nameprep(Server),
     LResource = jid:resourceprep(Resource),
     Mod = get_sm_backend(LServer),
     case Mod:get_sessions(LUser, LServer, LResource) of
-	[#session{sid = SID, info = Info}] ->
-	    Info;
+	[#session{sid = {Time, _}, info = Info}] ->
+	    case proplists:get_bool(offline, Info) of
+		true ->
+		    Info;
+		false ->
+		    none
+	    end;
 	_ ->
 	    none
     end.
@@ -425,11 +428,12 @@ set_session(SID, User, Server, Resource, Priority, Info) ->
 -spec online([#session{}]) -> [#session{}].
 
 online(Sessions) ->
-    lists:filter(fun(#session{sid = {_, undefined}}) ->
-			 false;
-		    (_) ->
-			 true
-		 end, Sessions).
+    lists:filter(fun is_online/1, Sessions).
+
+-spec is_online(#session{}) -> boolean().
+
+is_online(#session{info = Info}) ->
+    not proplists:get_bool(offline, Info).
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
@@ -678,15 +682,17 @@ check_for_sessions_to_replace(User, Server, Resource) ->
     check_max_sessions(LUser, LServer).
 
 check_existing_resources(LUser, LServer, LResource) ->
-    SIDs = get_resource_sessions(LUser, LServer, LResource),
-    if SIDs == [] -> ok;
+    Mod = get_sm_backend(LServer),
+    Ss = Mod:get_sessions(LUser, LServer, LResource),
+    {OnlineSs, OfflineSs} = lists:partition(fun is_online/1, Ss),
+    lists:foreach(fun(#session{sid = S}) ->
+			  Mod:delete_session(LUser, LServer, LResource, S)
+		  end, OfflineSs),
+    if OnlineSs == [] -> ok;
        true ->
+	   SIDs = [SID || #session{sid = SID} <- OnlineSs],
 	   MaxSID = lists:max(SIDs),
-	   lists:foreach(fun ({_, undefined} = S) ->
-				 Mod = get_sm_backend(LServer),
-				 Mod:delete_session(LUser, LServer, LResource,
-						    S);
-			     ({_, Pid} = S) when S /= MaxSID ->
+	   lists:foreach(fun ({_, Pid} = S) when S /= MaxSID ->
 				 Pid ! replaced;
 			     (_) -> ok
 			 end,

src/mod_admin_extra.erl

@@ -863,12 +863,15 @@ connected_users_vhost(Host) ->
 
 %% Code copied from ejabberd_sm.erl and customized
 dirty_get_sessions_list2() ->
-    mnesia:dirty_select(
-      session,
-      [{#session{usr = '$1', sid = {'$2', '$3'}, priority = '$4', info = '$5',
-		 _ = '_'},
-	[{is_pid, '$3'}],
-	[['$1', {{'$2', '$3'}}, '$4', '$5']]}]).
+    Ss = mnesia:dirty_select(
+	   session,
+	   [{#session{usr = '$1', sid = '$2', priority = '$3', info = '$4',
+		      _ = '_'},
+	     [],
+	     [['$1', '$2', '$3', '$4']]}]),
+    lists:filter(fun([_USR, _SID, _Priority, Info]) ->
+			 not proplists:get_bool(offline, Info)
+		 end, Ss).
 
 %% Make string more print-friendly
 stringize(String) ->
@@ -903,8 +906,8 @@ user_sessions_info(User, Host) ->
 		   {'EXIT', _Reason} ->
 		       [];
 		   Ss ->
-		       lists:filter(fun(#session{sid = {_, Pid}}) ->
-					    is_pid(Pid)
+		       lists:filter(fun(#session{info = Info}) ->
+					    not proplists:get_bool(offline, Info)
 				    end, Ss)
 	       end,
     lists:map(

src/mod_configure.erl

@@ -1917,21 +1917,29 @@ set_form(From, Host, ?NS_ADMINL(<<"end-user-session">>),
     Xmlelement = ?SERRT_POLICY_VIOLATION(Lang, <<"has been kicked">>),
     case JID#jid.lresource of
       <<>> ->
-	  SIDs = mnesia:dirty_select(session,
-				     [{#session{sid = {'$1', '$2'},
-						usr = {LUser, LServer, '_'},
-						_ = '_'},
-				       [{is_pid, '$2'}],
-				       [{{'$1', '$2'}}]}]),
-	  [Pid ! {kick, kicked_by_admin, Xmlelement} || {_, Pid} <- SIDs];
+	  SIs = mnesia:dirty_select(session,
+				    [{#session{usr = {LUser, LServer, '_'},
+					       sid = '$1',
+					       info = '$2',
+					       _ = '_'},
+				      [], [{{'$1', '$2'}}]}]),
+	  Pids = [P || {{_, P}, Info} <- SIs,
+		       not proplists:get_bool(offline, Info)],
+	  lists:foreach(fun(Pid) ->
+				Pid ! {kick, kicked_by_admin, Xmlelement}
+			end, Pids);
       R ->
-	  [{_, Pid}] = mnesia:dirty_select(session,
-					   [{#session{sid = {'$1', '$2'},
-						      usr = {LUser, LServer, R},
-						      _ = '_'},
-					     [{is_pid, '$2'}],
-					     [{{'$1', '$2'}}]}]),
-	  Pid ! {kick, kicked_by_admin, Xmlelement}
+	  [{{_, Pid}, Info}] = mnesia:dirty_select(
+				 session,
+				 [{#session{usr = {LUser, LServer, R},
+					    sid = '$1',
+					    info = '$2',
+					    _ = '_'},
+				   [], [{{'$1', '$2'}}]}]),
+	  case proplists:get_bool(offline, Info) of
+	    true -> ok;
+	    false -> Pid ! {kick, kicked_by_admin, Xmlelement}
+	  end
     end,
     {result, []};
 set_form(From, Host,