Move c2s_preprocessing_hook into mongoose_c2s_hooks

src/c2s/mongoose_c2s.erl

@@ -587,10 +587,11 @@ handle_foreign_packet(StateData = #c2s_data{host_type = HostType, lserver = LSer
 -spec handle_c2s_packet(c2s_data(), c2s_state(), exml:element()) -> fsm_res().
 handle_c2s_packet(StateData = #c2s_data{host_type = HostType}, C2SState, El) ->
     Acc0 = element_to_origin_accum(StateData, El),
-    Acc1 = mongoose_hooks:c2s_preprocessing_hook(HostType, Acc0, StateData),
-    case mongoose_acc:get(hook, result, undefined, Acc1) of
-        drop -> {next_state, session_established, StateData};
-        _ -> do_handle_c2s_packet(StateData, C2SState, Acc1)
+    case mongoose_c2s_hooks:c2s_preprocessing_hook(HostType, Acc0, hook_arg(StateData)) of
+        {ok, Acc1} ->
+            do_handle_c2s_packet(StateData, C2SState, Acc1);
+        {stop, _Acc1} ->
+            {next_state, session_established, StateData}
     end.
 
 -spec do_handle_c2s_packet(c2s_data(), c2s_state(), mongoose_acc:t()) -> fsm_res().

src/c2s/mongoose_c2s_hooks.erl

@@ -10,6 +10,7 @@
 -export_type([hook_fn/0, hook_params/0, hook_result/0]).
 
 %% XML handlers
+-export([c2s_preprocessing_hook/3]).
 -export([user_send_packet/3,
          user_receive_packet/3,
          user_send_message/3,
@@ -30,6 +31,22 @@
          user_socket_closed/3,
          user_socket_error/3]).
 
+%%% @doc Event triggered after a user sends _any_ packet to the server.
+%%% The purpose is to modify, or reject, packets, before they are further processed.
+%%% TODO: this can really be merged into `user_send_packet' with early priority.
+-spec c2s_preprocessing_hook(HostType, Acc, Params) -> Result when
+    HostType :: mongooseim:host_type(),
+    Acc :: mongoose_acc:t(),
+    Params :: hook_params(),
+    Result :: hook_result().
+c2s_preprocessing_hook(HostType, Acc, #{c2s_data := StateData} = Params) ->
+    ParamsWithLegacyArgs = ejabberd_hooks:add_args(Params, [StateData]),
+    {Tag, Acc1} = gen_hook:run_fold(c2s_preprocessing_hook, HostType, Acc, ParamsWithLegacyArgs),
+    case mongoose_acc:get(hook, result, undefined, Acc1) of
+        drop -> {stop, Acc1};
+        _ -> {Tag, Acc1}
+    end.
+
 %%% @doc Event triggered after a user sends _any_ packet to the server.
 %%% Examples of handlers can be metrics, archives, and any other subsystem
 %%% that wants to see all stanzas the user delivers.