Revert d3fd719c5287 (Remove should_offer/1).

5 files changed, 25 insertions, 12 deletions

diff --git a/src/rabbit_auth_mechanism.erl b/src/rabbit_auth_mechanism.erl
index 1d14f9f0b8..897199ee78 100644
--- a/src/rabbit_auth_mechanism.erl
+++ b/src/rabbit_auth_mechanism.erl
@@ -23,6 +23,10 @@ behaviour_info(callbacks) ->
      %% A description.
      {description, 0},
 
+     %% If this mechanism is enabled, should it be offered for a given socket?
+     %% (primarily so EXTERNAL can be SSL-only)
+     {should_offer, 1},
+
      %% Called before authentication starts. Should create a state
      %% object to be passed through all the stages of authentication.
      {init, 1},
diff --git a/src/rabbit_auth_mechanism_amqplain.erl b/src/rabbit_auth_mechanism_amqplain.erl
index 5e422eee89..2168495db8 100644
--- a/src/rabbit_auth_mechanism_amqplain.erl
+++ b/src/rabbit_auth_mechanism_amqplain.erl
@@ -19,7 +19,7 @@
 
 -behaviour(rabbit_auth_mechanism).
 
--export([description/0, init/1, handle_response/2]).
+-export([description/0, should_offer/1, init/1, handle_response/2]).
 
 -include("rabbit_auth_mechanism_spec.hrl").
 
@@ -38,6 +38,9 @@ description() ->
     [{name, <<"AMQPLAIN">>},
      {description, <<"QPid AMQPLAIN mechanism">>}].
 
+should_offer(_Sock) ->
+    true.
+
 init(_Sock) ->
     [].
 
diff --git a/src/rabbit_auth_mechanism_cr_demo.erl b/src/rabbit_auth_mechanism_cr_demo.erl
index 7fd20f8b32..77aa34ea0a 100644
--- a/src/rabbit_auth_mechanism_cr_demo.erl
+++ b/src/rabbit_auth_mechanism_cr_demo.erl
@@ -19,7 +19,7 @@
 
 -behaviour(rabbit_auth_mechanism).
 
--export([description/0, init/1, handle_response/2]).
+-export([description/0, should_offer/1, init/1, handle_response/2]).
 
 -include("rabbit_auth_mechanism_spec.hrl").
 
@@ -43,6 +43,9 @@ description() ->
      {description, <<"RabbitMQ Demo challenge-response authentication "
                      "mechanism">>}].
 
+should_offer(_Sock) ->
+    true.
+
 init(_Sock) ->
     #state{}.
 
diff --git a/src/rabbit_auth_mechanism_plain.erl b/src/rabbit_auth_mechanism_plain.erl
index 1ca07018e4..e2f9bff9c5 100644
--- a/src/rabbit_auth_mechanism_plain.erl
+++ b/src/rabbit_auth_mechanism_plain.erl
@@ -19,7 +19,7 @@
 
 -behaviour(rabbit_auth_mechanism).
 
--export([description/0, init/1, handle_response/2]).
+-export([description/0, should_offer/1, init/1, handle_response/2]).
 
 -include("rabbit_auth_mechanism_spec.hrl").
 
@@ -41,6 +41,9 @@ description() ->
     [{name, <<"PLAIN">>},
      {description, <<"SASL PLAIN authentication mechanism">>}].
 
+should_offer(_Sock) ->
+    true.
+
 init(_Sock) ->
     [].
 
diff --git a/src/rabbit_reader.erl b/src/rabbit_reader.erl
index 3908b64692..29321c601b 100644
--- a/src/rabbit_reader.erl
+++ b/src/rabbit_reader.erl
@@ -564,7 +564,7 @@ start_connection({ProtocolMajor, ProtocolMinor, _ProtocolRevision},
       version_major = ProtocolMajor,
       version_minor = ProtocolMinor,
       server_properties = server_properties(Protocol),
-      mechanisms = auth_mechanisms_binary(),
+      mechanisms = auth_mechanisms_binary(Sock),
       locales = <<"en_US">> },
     ok = send_on_channel0(Sock, Start, Protocol),
     switch_callback(State#v1{connection = Connection#connection{
@@ -616,7 +616,7 @@ handle_method0(#'connection.start_ok'{mechanism = Mechanism,
                State0 = #v1{connection_state = starting,
                             connection       = Connection,
                             sock             = Sock}) ->
-    AuthMechanism = auth_mechanism_to_module(Mechanism),
+    AuthMechanism = auth_mechanism_to_module(Mechanism, Sock),
     Capabilities =
         case rabbit_misc:table_lookup(ClientProperties, <<"capabilities">>) of
             {table, Capabilities1} -> Capabilities1;
@@ -709,14 +709,14 @@ handle_method0(_Method, #v1{connection_state = S}) ->
 send_on_channel0(Sock, Method, Protocol) ->
     ok = rabbit_writer:internal_send_command(Sock, 0, Method, Protocol).
 
-auth_mechanism_to_module(TypeBin) ->
+auth_mechanism_to_module(TypeBin, Sock) ->
     case rabbit_registry:binary_to_type(TypeBin) of
         {error, not_found} ->
             rabbit_misc:protocol_error(
               command_invalid, "unknown authentication mechanism '~s'",
               [TypeBin]);
         T ->
-            case {lists:member(T, auth_mechanisms()),
+            case {lists:member(T, auth_mechanisms(Sock)),
                   rabbit_registry:lookup_module(auth_mechanism, T)} of
                 {true, {ok, Module}} ->
                     Module;
@@ -727,15 +727,15 @@ auth_mechanism_to_module(TypeBin) ->
             end
     end.
 
-auth_mechanisms() ->
+auth_mechanisms(Sock) ->
     {ok, Configured} = application:get_env(auth_mechanisms),
-    [Name || {Name, _Module} <- rabbit_registry:lookup_all(auth_mechanism),
-             lists:member(Name, Configured)].
+    [Name || {Name, Module} <- rabbit_registry:lookup_all(auth_mechanism),
+             Module:should_offer(Sock), lists:member(Name, Configured)].
 
-auth_mechanisms_binary() ->
+auth_mechanisms_binary(Sock) ->
     list_to_binary(
             string:join(
-              [atom_to_list(A) || A <- auth_mechanisms()], " ")).
+              [atom_to_list(A) || A <- auth_mechanisms(Sock)], " ")).
 
 auth_phase(Response,
            State = #v1{auth_mechanism = AuthMechanism,