Avoid PID collisions

Fixes #1470

diff --git a/src/ejabberd_sm_sql.erl b/src/ejabberd_sm_sql.erl
index d59c3670ad055a87f8f1678b2512b3e22ebf4582..9fc02758830f1f0723fc13ada34a58e96a0b455f 100644 (file)
--- a/src/ejabberd_sm_sql.erl
+++ b/src/ejabberd_sm_sql.erl
@@ -47,7 +47,7 @@
 %%%===================================================================
 -spec init() -> ok | {error, any()}.
 init() ->
-    Node = jlib:atom_to_binary(node()),
+    Node = erlang:atom_to_binary(node(), latin1),
     ?INFO_MSG("Cleaning SQL SM table...", []),
     lists:foldl(
       fun(Host, ok) ->
@@ -68,8 +68,8 @@ set_session(#session{sid = {Now, Pid}, usr = {U, LServer, R},
     InfoS = jlib:term_to_expr(Info),
     PrioS = enc_priority(Priority),
     TS = now_to_timestamp(Now),
-    PidS = list_to_binary(erlang:pid_to_list(Pid)),
-    Node = jlib:atom_to_binary(node(Pid)),
+    PidS = enc_pid(Pid),
+    Node = erlang:atom_to_binary(node(Pid), latin1),
     case ?SQL_UPSERT(LServer, "sm",
                      ["!usec=%(TS)d",
                       "!pid=%(PidS)s",
@@ -89,7 +89,7 @@ delete_session(_LUser, LServer, _LResource, {Now, Pid}) ->
     PidS = list_to_binary(erlang:pid_to_list(Pid)),
     case ejabberd_sql:sql_query(
           LServer,
-          ?SQL("select @(usec)d, @(pid)s, @(username)s,"
+          ?SQL("select @(usec)d, @(pid)s, @(node)s, @(username)s,"
                 " @(resource)s, @(priority)s, @(info)s "
                 "from sm where usec=%(TS)d and pid=%(PidS)s")) of
        {selected, [Row]} ->
@@ -97,7 +97,9 @@ delete_session(_LUser, LServer, _LResource, {Now, Pid}) ->
               LServer,
               ?SQL("delete from sm"
                    " where usec=%(TS)d and pid=%(PidS)s")),
-           {ok, row_to_session(LServer, Row)};
+           try {ok, row_to_session(LServer, Row)}
+           catch _:{node_down, _} -> {error, notfound}
+           end;
        {selected, []} ->
            {error, notfound};
        Err ->
@@ -114,10 +116,15 @@ get_sessions() ->
 get_sessions(LServer) ->
     case ejabberd_sql:sql_query(
           LServer,
-           ?SQL("select @(usec)d, @(pid)s, @(username)s,"
+           ?SQL("select @(usec)d, @(pid)s, @(node)s, @(username)s,"
                 " @(resource)s, @(priority)s, @(info)s from sm")) of
        {selected, Rows} ->
-           [row_to_session(LServer, Row) || Row <- Rows];
+           lists:flatmap(
+             fun(Row) ->
+                     try [row_to_session(LServer, Row)]
+                     catch _:{node_down, _} -> []
+                     end
+             end, Rows);
        Err ->
            ?ERROR_MSG("failed to select from 'sm' table: ~p", [Err]),
            []
@@ -126,11 +133,16 @@ get_sessions(LServer) ->
 get_sessions(LUser, LServer) ->
     case ejabberd_sql:sql_query(
           LServer,
-           ?SQL("select @(usec)d, @(pid)s, @(username)s,"
+           ?SQL("select @(usec)d, @(pid)s, @(node)s, @(username)s,"
                 " @(resource)s, @(priority)s, @(info)s from sm"
                 " where username=%(LUser)s")) of
        {selected, Rows} ->
-           [row_to_session(LServer, Row) || Row <- Rows];
+           lists:flatmap(
+             fun(Row) ->
+                     try [row_to_session(LServer, Row)]
+                     catch _:{node_down, _} -> []
+                     end
+             end, Rows);
        Err ->
            ?ERROR_MSG("failed to select from 'sm' table: ~p", [Err]),
            []
@@ -139,11 +151,16 @@ get_sessions(LUser, LServer) ->
 get_sessions(LUser, LServer, LResource) ->
     case ejabberd_sql:sql_query(
           LServer,
-           ?SQL("select @(usec)d, @(pid)s, @(username)s,"
+           ?SQL("select @(usec)d, @(pid)s, @(node)s, @(username)s,"
                 " @(resource)s, @(priority)s, @(info)s from sm"
                 " where username=%(LUser)s and resource=%(LResource)s")) of
        {selected, Rows} ->
-           [row_to_session(LServer, Row) || Row <- Rows];
+           lists:flatmap(
+             fun(Row) ->
+                     try [row_to_session(LServer, Row)]
+                     catch _:{node_down, _} -> []
+                     end
+             end, Rows);
        Err ->
            ?ERROR_MSG("failed to select from 'sm' table: ~p", [Err]),
            []
@@ -175,12 +192,39 @@ enc_priority(undefined) ->
 enc_priority(Int) when is_integer(Int) ->
     integer_to_binary(Int).
 
-row_to_session(LServer, {USec, PidS, User, Resource, PrioS, InfoS}) ->
+row_to_session(LServer, {USec, PidS, NodeS, User, Resource, PrioS, InfoS}) ->
     Now = timestamp_to_now(USec),
-    Pid = erlang:list_to_pid(binary_to_list(PidS)),
+    Pid = dec_pid(PidS, NodeS),
     Priority = dec_priority(PrioS),
     Info = ejabberd_sql:decode_term(InfoS),
     #session{sid = {Now, Pid}, us = {User, LServer},
             usr = {User, LServer, Resource},
             priority = Priority,
             info = Info}.
+
+-spec enc_pid(pid()) -> binary().
+enc_pid(Pid) ->
+    list_to_binary(erlang:pid_to_list(Pid)).
+
+-spec dec_pid(binary(), binary()) -> pid().
+dec_pid(PidBin, NodeBin) ->
+    PidStr = binary_to_list(PidBin),
+    Pid = erlang:list_to_pid(PidStr),
+    case erlang:binary_to_atom(NodeBin, latin1) of
+       Node when Node == node() ->
+           Pid;
+       Node ->
+           try set_node_id(PidStr, NodeBin)
+           catch _:badarg ->
+                   erlang:error({node_down, Node})
+           end
+    end.
+
+-spec set_node_id(string(), binary()) -> pid().
+set_node_id(PidStr, NodeBin) ->
+    ExtPidStr = erlang:pid_to_list(
+                 binary_to_term(
+                   <<131,103,100,(size(NodeBin)):16,NodeBin/binary,0:72>>)),
+    [H|_] = string:tokens(ExtPidStr, "."),
+    [_|T] = string:tokens(PidStr, "."),
+    erlang:list_to_pid(string:join([H|T], ".")).