Introduce a configurable limit to message size.

Add `max_message_size` configuration to configure limit
in bytes.
If message is bigger - channel exception will be thrown.

Default limit is 128MB.
There is still a hard limit of 521MB.

[#161983593]

Author: hairyhum

Makefile

@@ -130,7 +130,9 @@ define PROJECT_ENV
 	    {vhost_restart_strategy, continue},
 	    %% {global, prefetch count}
 	    {default_consumer_prefetch, {false, 0}},
-	    {channel_queue_cleanup_interval, 60000}
+	    {channel_queue_cleanup_interval, 60000},
+	    %% Default max message size is 128 MB
+	    {max_message_size, 134217728}
 	  ]
 endef
 

priv/schema/rabbit.schema

@@ -554,6 +554,9 @@ end}.
 }.
 
 
+{mapping, "msx_message_size", "rabbit.max_message_size",
+    [{datatype, integer}, {validators, ["less_then_512MB"]}]}.
+
 %% Customising Socket Options.
 %%
 %% See (http://www.erlang.org/doc/man/inet.html#setopts-2) for
@@ -1361,6 +1364,11 @@ fun(Size) when is_integer(Size) ->
     Size > 0 andalso Size < 2147483648
 end}.
 
+{validator, "less_then_512MB", "Max message size should be less than 512MB and gre than 0",
+fun(Size) when is_integer(Size) ->
+    Size > 0 andalso Size < 536870912
+end}.
+
 {validator, "less_than_1", "Flooat is not beetween 0 and 1",
 fun(Float) when is_float(Float) ->
     Float > 0 andalso Float < 1

src/rabbit_channel.erl

@@ -990,7 +990,15 @@ check_msg_size(Content) ->
     case Size > ?MAX_MSG_SIZE of
         true  -> precondition_failed("message size ~B larger than max size ~B",
                                      [Size, ?MAX_MSG_SIZE]);
-        false -> ok
+        false ->
+            case application:get_env(rabbit, max_message_size) of
+                {ok, MaxSize} when is_integer(MaxSize) andalso Size > MaxSize ->
+                    precondition_failed("message size ~B larger than"
+                                            " configured max size ~B",
+                                        [Size, MaxSize]);
+
+                _ -> ok
+            end
     end.
 
 check_vhost_queue_limit(#resource{name = QueueName}, VHost) ->

test/unit_inbroker_parallel_SUITE.erl

@@ -58,6 +58,7 @@ groups() ->
           set_disk_free_limit_command,
           set_vm_memory_high_watermark_command,
           topic_matching,
+          max_message_size,
           {queue_max_length, [], [
             {max_length_simple, [], MaxLengthTests},
             {max_length_mirrored, [], MaxLengthTests}]}
@@ -1299,6 +1300,84 @@ sync_mirrors(QName, Config) ->
         _ -> ok
     end.
 
+gen_binary_mb(N) ->
+    B1M = << <<"_">> || _ <- lists:seq(1, 1024 * 1024) >>,
+    << B1M || _ <- lists:seq(1, N) >>.
+
+assert_channel_alive(Ch) ->
+    amqp_channel:call(Ch, #'basic.publish'{routing_key = <<"nope">>},
+                          #amqp_msg{payload = <<"HI">>}).
+
+assert_channel_fail_max_size(Ch, Monitor, ExpectedException) ->
+    receive
+        {'DOWN', Monitor, process, Ch,
+            {shutdown,
+                {server_initiated_close, 406, Exception}}} ->
+            ?assertMatch(Exception, ExpectedException)
+    after 100000 ->
+        error({channel_exception_expected, max_message_size})
+    end.
+
+max_message_size(Config) ->
+    Binary128M = gen_binary_mb(128),
+    {_, Ch} = rabbit_ct_client_helpers:open_connection_and_channel(Config, 0),
+    %% Default message size is 128MB
+    Size128Mb = 1024 * 1024 * 128,
+    Size128Mb = rabbit_ct_broker_helpers:rpc(Config, 0,
+        application, get_env, [rabbit, max_message_size, undefined]),
+
+    Size128Mb = byte_size(Binary128M),
+    %% Binary is whithin the max size limit
+    amqp_channel:call(Ch, #'basic.publish'{routing_key = <<"nope">>}, #amqp_msg{payload = Binary128M}),
+    %% Channel process is alive
+    assert_channel_alive(Ch),
+
+    Monitor = monitor(process, Ch),
+    %% This publish should cause a channel exception
+    BinaryBiggerThan128M = <<"_", Binary128M/binary>>,
+    amqp_channel:call(Ch, #'basic.publish'{routing_key = <<"nope">>}, #amqp_msg{payload = BinaryBiggerThan128M}),
+    ct:pal("Assert channel error 128"),
+    ExpectedException = <<"PRECONDITION_FAILED - message size ",
+                          (integer_to_binary(byte_size(BinaryBiggerThan128M)))/binary,
+                          " larger than configured max size ",
+                          (integer_to_binary(Size128Mb))/binary>>,
+    assert_channel_fail_max_size(Ch, Monitor, ExpectedException),
+
+
+    {_, Ch1} = rabbit_ct_client_helpers:open_connection_and_channel(Config, 0),
+
+    %% Set a bigger message size
+    rabbit_ct_broker_helpers:rpc(Config, 0,
+        application, set_env, [rabbit, max_message_size, 1024 * 1024 * 256]),
+
+    amqp_channel:call(Ch1, #'basic.publish'{routing_key = <<"nope">>}, #amqp_msg{payload = Binary128M}),
+    assert_channel_alive(Ch1),
+
+    amqp_channel:call(Ch1, #'basic.publish'{routing_key = <<"nope">>}, #amqp_msg{payload = BinaryBiggerThan128M}),
+    assert_channel_alive(Ch1),
+
+    %% Set message size above 512MB.
+    %% The actual limit will be 512MB
+    rabbit_ct_broker_helpers:rpc(Config, 0,
+        application, set_env, [rabbit, max_message_size, 1024 * 1024 * 515]),
+
+    Binary512M = << Binary128M/binary, Binary128M/binary,
+                    Binary128M/binary, Binary128M/binary>>,
+
+    BinaryBiggerThan512M = <<"_", Binary512M/binary>>,
+
+    amqp_channel:call(Ch1, #'basic.publish'{routing_key = <<"nope">>}, #amqp_msg{payload = Binary512M}),
+    assert_channel_alive(Ch1),
+
+    Monitor1 = monitor(process, Ch1),
+    amqp_channel:call(Ch1, #'basic.publish'{routing_key = <<"nope">>}, #amqp_msg{payload = BinaryBiggerThan512M}),
+    ct:pal("Assert channel error 512"),
+    ExpectedException1 = <<"PRECONDITION_FAILED - message size ",
+                          (integer_to_binary(byte_size(BinaryBiggerThan512M)))/binary,
+                          " larger than max size ",
+                          (integer_to_binary(byte_size(Binary512M)))/binary>>,
+    assert_channel_fail_max_size(Ch1, Monitor1, ExpectedException1).
+
 %% ---------------------------------------------------------------------------
 %% rabbitmqctl helpers.
 %% ---------------------------------------------------------------------------