Merge pull request #1812 from rabbitmq/max_msg_size

Introduce a configurable limit to message size

1 files changed, 40 insertions, 18 deletions

diff --git a/src/rabbit_channel.erl b/src/rabbit_channel.erl
index d1f3b06528..eeae247193 100644
--- a/src/rabbit_channel.erl
+++ b/src/rabbit_channel.erl
@@ -72,7 +72,7 @@
 -export([get_vhost/1, get_user/1]).
 %% For testing
 -export([build_topic_variable_map/3]).
--export([list_queue_states/1]).
+-export([list_queue_states/1, get_max_message_size/0]).
 
 %% Mgmt HTTP API refactor
 -export([handle_method/5]).
@@ -158,7 +158,9 @@
   delivery_flow,
   interceptor_state,
   queue_states,
-  queue_cleanup_timer
+  queue_cleanup_timer,
+  %% Message content size limit
+  max_message_size
 }).
 
 -define(QUEUE, lqueue).
@@ -441,6 +443,7 @@ init([Channel, ReaderPid, WriterPid, ConnPid, ConnName, Protocol, User, VHost,
                   _ ->
                       Limiter0
               end,
+    MaxMessageSize = get_max_message_size(),
     State = #ch{state                   = starting,
                 protocol                = Protocol,
                 channel                 = Channel,
@@ -473,7 +476,8 @@ init([Channel, ReaderPid, WriterPid, ConnPid, ConnName, Protocol, User, VHost,
                 reply_consumer          = none,
                 delivery_flow           = Flow,
                 interceptor_state       = undefined,
-                queue_states            = #{}},
+                queue_states            = #{},
+                max_message_size        = MaxMessageSize},
     State1 = State#ch{
                interceptor_state = rabbit_channel_interceptor:init(State)},
     State2 = rabbit_event:init_stats_timer(State1, #ch.stats_timer),
@@ -793,6 +797,16 @@ code_change(_OldVsn, State, _Extra) ->
 
 format_message_queue(Opt, MQ) -> rabbit_misc:format_message_queue(Opt, MQ).
 
+-spec get_max_message_size() -> non_neg_integer().
+
+get_max_message_size() ->
+    case application:get_env(rabbit, max_message_size) of
+        {ok, MS} when is_integer(MS) ->
+            erlang:min(MS, ?MAX_MSG_SIZE);
+        _ ->
+            ?MAX_MSG_SIZE
+    end.
+
 %%---------------------------------------------------------------------------
 
 reply(Reply, NewState) -> {reply, Reply, next_state(NewState), hibernate}.
@@ -985,12 +999,19 @@ extract_topic_variable_map_from_amqp_params([{amqp_params, {amqp_params_direct,
 extract_topic_variable_map_from_amqp_params(_) ->
     #{}.
 
-check_msg_size(Content) ->
+check_msg_size(Content, MaxMessageSize) ->
     Size = rabbit_basic:maybe_gc_large_msg(Content),
-    case Size > ?MAX_MSG_SIZE of
-        true  -> precondition_failed("message size ~B larger than max size ~B",
-                                     [Size, ?MAX_MSG_SIZE]);
-        false -> ok
+    case Size of
+        S when S > MaxMessageSize ->
+            ErrorMessage = case MaxMessageSize of
+                ?MAX_MSG_SIZE ->
+                    "message size ~B is larger than max size ~B";
+                _ ->
+                    "message size ~B is larger than configured max size ~B"
+            end,
+            precondition_failed(ErrorMessage,
+                                [Size, MaxMessageSize]);
+        _ -> ok
     end.
 
 check_vhost_queue_limit(#resource{name = QueueName}, VHost) ->
@@ -1164,16 +1185,17 @@ handle_method(#'basic.publish'{immediate = true}, _Content, _State) ->
 handle_method(#'basic.publish'{exchange    = ExchangeNameBin,
                                routing_key = RoutingKey,
                                mandatory   = Mandatory},
-              Content, State = #ch{virtual_host    = VHostPath,
-                                   tx              = Tx,
-                                   channel         = ChannelNum,
-                                   confirm_enabled = ConfirmEnabled,
-                                   trace_state     = TraceState,
-                                   user            = #user{username = Username} = User,
-                                   conn_name       = ConnName,
-                                   delivery_flow   = Flow,
-                                   conn_pid        = ConnPid}) ->
-    check_msg_size(Content),
+              Content, State = #ch{virtual_host     = VHostPath,
+                                   tx               = Tx,
+                                   channel          = ChannelNum,
+                                   confirm_enabled  = ConfirmEnabled,
+                                   trace_state      = TraceState,
+                                   user             = #user{username = Username} = User,
+                                   conn_name        = ConnName,
+                                   delivery_flow    = Flow,
+                                   conn_pid         = ConnPid,
+                                   max_message_size = MaxMessageSize}) ->
+    check_msg_size(Content, MaxMessageSize),
     ExchangeName = rabbit_misc:r(VHostPath, exchange, ExchangeNameBin),
     check_write_permitted(ExchangeName, User),
     Exchange = rabbit_exchange:lookup_or_die(ExchangeName),