Keep Ranch ref in rabbit_reader v1 record

This is used to check if we're over connection limit and avoids
risky attempts to retrieve the ref from socket host/port.

Author: Loïc Hoguin

deps/rabbit/src/rabbit_reader.erl

@@ -66,6 +66,8 @@
 -record(v1, {
           %% parent process
           parent,
+          %% Ranch ref
+          ranch_ref,
           %% socket
           sock,
           %% connection state, see connection record
@@ -168,7 +170,7 @@ init(Parent, HelperSup, Ref) ->
     {ok, Sock} = rabbit_networking:handshake(Ref,
         application:get_env(rabbit, proxy_protocol, false)),
     Deb = sys:debug_options([]),
-    start_connection(Parent, HelperSup, Deb, Sock).
+    start_connection(Parent, HelperSup, Ref, Deb, Sock).
 
 -spec system_continue(_,_,{[binary()], non_neg_integer(), #v1{}}) -> any().
 
@@ -293,10 +295,10 @@ socket_op(Sock, Fun) ->
                            exit(normal)
     end.
 
--spec start_connection(pid(), pid(), any(), rabbit_net:socket()) ->
+-spec start_connection(pid(), pid(), ranch:ref(), any(), rabbit_net:socket()) ->
           no_return().
 
-start_connection(Parent, HelperSup, Deb, Sock) ->
+start_connection(Parent, HelperSup, RanchRef, Deb, Sock) ->
     process_flag(trap_exit, true),
     RealSocket = rabbit_net:unwrap_socket(Sock),
     Name = case rabbit_net:connection_string(Sock, inbound) of
@@ -314,6 +316,7 @@ start_connection(Parent, HelperSup, Deb, Sock) ->
         socket_op(Sock, fun (S) -> rabbit_net:socket_ends(S, inbound) end),
     ?store_proc_name(Name),
     State = #v1{parent              = Parent,
+                ranch_ref           = RanchRef,
                 sock                = RealSocket,
                 connection          = #connection{
                   name               = Name,
@@ -1213,17 +1216,16 @@ handle_method0(#'connection.tune_ok'{frame_max   = FrameMax,
              heartbeater = Heartbeater};
 
 handle_method0(#'connection.open'{virtual_host = VHost},
-               State = #v1{connection_state = opening,
+               State = #v1{ranch_ref        = RanchRef,
+                           connection_state = opening,
                            connection       = Connection = #connection{
                                                 log_name = ConnName,
-                                                host = Addr,
-                                                port = Port,
                                                 user = User = #user{username = Username},
                                                 protocol = Protocol},
                            helper_sup       = SupPid,
                            sock             = Sock,
                            throttle         = Throttle}) ->
-    ok = is_over_node_connection_limit(Addr, Port),
+    ok = is_over_node_connection_limit(RanchRef),
     ok = is_over_vhost_connection_limit(VHost, User),
     ok = is_over_user_connection_limit(User),
     ok = rabbit_access_control:check_vhost_access(User, VHost, {socket, Sock}, #{}),
@@ -1324,13 +1326,12 @@ is_vhost_alive(VHostPath, User) ->
                             [VHostPath, User#user.username, VHostPath])
     end.
 
-is_over_node_connection_limit(Addr, Port) ->
+is_over_node_connection_limit(RanchRef) ->
     Limit = rabbit_misc:get_env(rabbit, connection_max, infinity),
     case Limit of
         infinity -> ok;
         N when is_integer(N) ->
-            Ref = rabbit_networking:ranch_ref(Addr, Port),
-            #{active_connections := ActiveConns} = ranch:info(Ref),
+            #{active_connections := ActiveConns} = ranch:info(RanchRef),
 
             case ActiveConns > Limit of
                 false -> ok;