improve URI support

This change includes three improvements:

1. Support configuring tls versions through the uri. Previusly this
could only be done in code or by configururing the application
environment.
2. Default the hostname connection property to the URI host if no
hostname query parameter was found.
3. Make sasl=plain implicit if the URI contains a username and password.

[#159650732]

deps/amqp10_client/src/amqp10_client.erl

@@ -347,6 +347,10 @@ parse_uri(Uri) ->
         Err -> Err
     end.
 
+parse_usertoken(U) ->
+    [User, Pass] = string:tokens(U, ":"),
+    {plain, to_binary(User), to_binary(Pass)}.
+
 parse_result({Scheme, UserInfo, Host, Port, "/", Query0}) ->
     Query = lists:foldl(fun (W, Acc) ->
                                 [K, V] = string:tokens(W, "="),
@@ -355,14 +359,15 @@ parse_result({Scheme, UserInfo, Host, Port, "/", Query0}) ->
                         string:tokens(safe_substr(Query0, 2), "&")),
     Sasl = case Query of
                #{"sasl" := "anon"} -> anon;
-               #{"sasl" := "plain"} ->
+               #{"sasl" := "plain"} when length(UserInfo) =:= 0 ->
+                   throw(plain_sasl_missing_userinfo);
+               _ ->
                    case UserInfo of
-                       [] -> throw(plain_sasl_missing_userinfo);
+                       [] ->
+                           none;
                        U ->
-                           [User, Pass] = string:tokens(U, ":"),
-                           {plain, to_binary(User), to_binary(Pass)}
-                   end;
-               _ -> none
+                           parse_usertoken(U)
+                   end
            end,
     Ret0 = maps:fold(fun("idle_time_out", V, Acc) ->
                              Acc#{idle_time_out => list_to_integer(V)};
@@ -374,6 +379,7 @@ parse_result({Scheme, UserInfo, Host, Port, "/", Query0}) ->
                              Acc#{transfer_limit_margin => list_to_integer(V)};
                         (_, _, Acc) -> Acc
                      end, #{address => Host,
+                            hostname => to_binary(Host),
                             port => Port,
                             sasl => Sasl}, Query),
     case Scheme of
@@ -402,6 +408,10 @@ parse_tls_opt("verify", V, Acc)
     [{verify, to_atom(V)} | Acc];
 parse_tls_opt("verify", _V, _Acc) ->
     throw({invalid_option, verify});
+parse_tls_opt("versions", V, Acc) ->
+    Parts = string:split(V, ","),
+    Versions = [try_to_existing_atom(P) || P <- Parts],
+    [{versions, Versions} | Acc];
 parse_tls_opt("fail_if_no_peer_cert", V, Acc)
   when V =:= "true" orelse
        V =:= "false" ->
@@ -418,11 +428,22 @@ parse_tls_opt(_K, _V, Acc) ->
 to_atom(X) when is_list(X) -> list_to_atom(X).
 to_binary(X) when is_list(X) -> list_to_binary(X).
 
+try_to_existing_atom(L) when is_list(L) ->
+    try list_to_existing_atom(L) of
+        A -> A
+    catch
+        _:badarg ->
+            throw({non_existent_atom, L})
+    end.
+
+
 -ifdef(TEST).
 -include_lib("eunit/include/eunit.hrl").
 
 parse_uri_test_() ->
-    [?_assertEqual({ok, #{address => "my_host", port => 9876,
+    [?_assertEqual({ok, #{address => "my_host",
+                          port => 9876,
+                          hostname => <<"my_host">>,
                           sasl => none}}, parse_uri("amqp://my_host:9876")),
      ?_assertEqual({ok, #{address => "my_proxy",
                           port => 9876,
@@ -433,23 +454,38 @@ parse_uri_test_() ->
                           sasl => {plain, <<"fred">>, <<"passw">>}}},
                    parse_uri("amqps://fred:passw@my_proxy:9876?sasl=plain&" ++
                              "hostname=my_host&max_frame_size=512&idle_time_out=60000")),
+     %% make sasl plain implicit when username and password is present
+     ?_assertEqual({ok, #{address => "my_proxy",
+                          port => 9876,
+                          hostname => <<"my_proxy">>,
+                          sasl => {plain, <<"fred">>, <<"passw">>}}},
+                   parse_uri("amqp://fred:passw@my_proxy:9876")),
      ?_assertEqual(
         {ok, #{address => "my_proxy", port => 9876,
+               hostname => <<"my_proxy">>,
                tls_opts => {secure_port, [{cacertfile, "/etc/cacertfile.pem"},
                                           {certfile, "/etc/certfile.pem"},
                                           {fail_if_no_peer_cert, true},
                                           {keyfile, "/etc/keyfile.key"},
                                           {server_name_indication, "frazzle"},
-                                          {verify, verify_none}
+                                          {verify, verify_none},
+                                          {versions, ['tlsv1.1', 'tlsv1.2']}
                                          ]},
                sasl => {plain, <<"fred">>, <<"passw">>}}},
         parse_uri("amqps://fred:passw@my_proxy:9876?sasl=plain"
                   "&cacertfile=/etc/cacertfile.pem&certfile=/etc/certfile.pem"
                   "&keyfile=/etc/keyfile.key&verify=verify_none"
                   "&fail_if_no_peer_cert=true"
-                  "&server_name_indication=frazzle")),
+                  "&server_name_indication=frazzle"
+                  "&versions=tlsv1.1,tlsv1.2")),
+     %% invalid tls version
+     ?_assertEqual({error, {non_existent_atom, "tlsv1.9999999"}},
+                   parse_uri("amqps://fred:passw@my_proxy:9876?sasl=plain&" ++
+                  "versions=tlsv1.1,tlsv1.9999999")),
      ?_assertEqual(
-        {ok, #{address => "my_proxy", port => 9876,
+        {ok, #{address => "my_proxy",
+               port => 9876,
+               hostname => <<"my_proxy">>,
                tls_opts => {secure_port, [{server_name_indication, disable}]},
                sasl => {plain, <<"fred">>, <<"passw">>}}},
         parse_uri("amqps://fred:passw@my_proxy:9876?sasl=plain"