dist_opts in net_kernel

Signed-off-by: Peter M <petermm@gmail.com>

Author: petermm

libs/estdlib/src/net_kernel.erl

@@ -73,8 +73,7 @@
 %% @param Options options for distribution. Supported options are:
 %% - `name_domain' : whether name should be short or long
 %% - `proto_dist' : the module used for distribution (e.g. `socket_dist')
-%% - `dist_listen_min' : defines the min port range for the listener socket.
-%% - `dist_listen_max' : defines the max port range for the listener socket.
+%% - `dist_opts' : a map of options passed through to the dist module's `listen/2'
 %%-----------------------------------------------------------------------------
 -spec start(atom(), map()) -> {ok, pid()}.
 start(Name, Options0) when is_atom(Name) andalso is_map(Options0) ->
@@ -83,31 +82,12 @@ start(Name, Options0) when is_atom(Name) andalso is_map(Options0) ->
             case Key of
                 name_domain when Val =:= shortnames orelse Val =:= longnames -> ok;
                 proto_dist when is_atom(Val) -> ok;
-                dist_listen_min when is_integer(Val) -> ok;
-                dist_listen_max when is_integer(Val) -> ok;
+                dist_opts when is_map(Val) -> ok;
                 _ -> error({invalid_option, Key, Val}, [Name, Options0])
             end
         end,
         Options0
     ),
-    % Check that if one of dist_listen_min and dist_listen_max are configured, both are configured.
-    % And verify dist_listen_max is larger or equal to dist_listen_min.
-    ok =
-        case {maps:is_key(dist_listen_min, Options0), maps:is_key(dist_listen_max, Options0)} of
-            {true, false} ->
-                error(missing_dist_listen_max, [Name, Options0]);
-            {false, true} ->
-                error(missing_dist_listen_min, [Name, Options0]);
-            {true, true} ->
-                Min = maps:get(dist_listen_min, Options0),
-                Max = maps:get(dist_listen_max, Options0),
-                if
-                    Min > Max -> error(invalid_port_range, [Name, Options0]);
-                    true -> ok
-                end;
-            _ ->
-                ok
-        end,
     Options1 = Options0#{name => Name},
     Options2 = split_name(Options1),
     net_kernel_sup:start(Options2);
@@ -211,14 +191,14 @@ init(Options) ->
     process_flag(trap_exit, true),
     LongNames = maps:get(name_domain, Options, longnames) =:= longnames,
     ProtoDist = maps:get(proto_dist, Options, socket_dist),
-    ListenOpts = maps:with([dist_listen_min, dist_listen_max], Options),
+    DistOpts = maps:get(dist_opts, Options, #{}),
     Name = maps:get(name, Options),
     Node = maps:get(node, Options),
     Cookie = crypto:strong_rand_bytes(16),
     TickInterval = (?NET_TICK_TIME * 1000) div ?NET_TICK_INTENSITY,
     Self = self(),
     Ticker = spawn_link(fun() -> ticker(Self, TickInterval) end),
-    case ProtoDist:listen(Name, ListenOpts) of
+    case ProtoDist:listen(Name, DistOpts) of
         {ok, {Listen, _Address, Creation}} ->
             true = erlang:setnode(Node, Creation),
             AcceptPid = ProtoDist:accept(Listen),

libs/estdlib/src/socket_dist.erl

@@ -45,8 +45,13 @@ listen(Name) ->
 listen(Name, Opts) ->
     PortMin = maps:get(dist_listen_min, Opts, 0),
     PortMax = maps:get(dist_listen_max, Opts, 0),
+    validate_port_range(PortMin, PortMax),
     try_listen_port(Name, PortMin, PortMax).
 
+validate_port_range(0, 0) -> ok;
+validate_port_range(Min, Max) when is_integer(Min), is_integer(Max), Min =< Max -> ok;
+validate_port_range(Min, Max) -> error({invalid_port_range, Min, Max}).
+
 try_listen_port(_Name, Port, PortMax) when Port > PortMax ->
     {error, no_port_available};
 try_listen_port(Name, Port, PortMax) ->