ssl: Improve shutdown logic

Add possibility to downgrade an SSL/TLS connection to a tcp connection,
and give back the socket control to a user process.

Add application setting to be able to change fatal alert shutdown
timeout, also shorten the  default timeout. The fatal alert timeout is
the number of milliseconds between sending of a fatal alert and
closing the connection. Waiting a little while improves the
peers chances to properly receiving the alert so it may
shutdown gracefully.

1 files changed, 18 insertions, 2 deletions

diff --git a/lib/ssl/src/ssl.erl b/lib/ssl/src/ssl.erl
index 120e8b59ed..f611079912 100644
--- a/lib/ssl/src/ssl.erl
+++ b/lib/ssl/src/ssl.erl
@@ -34,7 +34,7 @@
 	 listen/2, transport_accept/1, transport_accept/2,
 	 ssl_accept/1, ssl_accept/2, ssl_accept/3,
 	 controlling_process/2, peername/1, peercert/1, sockname/1,
-	 close/1, shutdown/2, recv/2, recv/3, send/2, getopts/2, setopts/2
+	 close/1, close/2, shutdown/2, recv/2, recv/3, send/2, getopts/2, setopts/2
 	]).
 %% SSL/TLS protocol handling
 -export([cipher_suites/0, cipher_suites/1, suite_definition/1,
@@ -247,11 +247,27 @@ ssl_accept(Socket, SslOptions, Timeout) when is_port(Socket) ->
 %% Description: Close an ssl connection
 %%--------------------------------------------------------------------
 close(#sslsocket{pid = Pid}) when is_pid(Pid) ->
-    ssl_connection:close(Pid);
+    ssl_connection:close(Pid, {close, ?DEFAULT_TIMEOUT});
 close(#sslsocket{pid = {ListenSocket, #config{transport_info={Transport,_, _, _}}}}) ->
     Transport:close(ListenSocket).
 
 %%--------------------------------------------------------------------
+-spec  close(#sslsocket{}, integer() | {pid(), integer()}) -> term().
+%%
+%% Description: Close an ssl connection
+%%--------------------------------------------------------------------
+close(#sslsocket{pid = TLSPid}, 
+      {Pid, Timeout} = DownGrade) when is_pid(TLSPid), 
+				       is_pid(Pid), 
+				       (is_integer(Timeout) andalso Timeout > 0) or (Timeout == infinity) ->
+    ssl_connection:close(TLSPid, {close, DownGrade});
+close(#sslsocket{pid = TLSPid}, Timeout) when is_pid(TLSPid), 
+					      (is_integer(Timeout) andalso Timeout > 0) or (Timeout == infinity) ->
+    ssl_connection:close(TLSPid, {close, Timeout});
+close(#sslsocket{pid = {ListenSocket, #config{transport_info={Transport,_, _, _}}}}, _) ->
+    Transport:close(ListenSocket).
+
+%%--------------------------------------------------------------------
 -spec send(#sslsocket{}, iodata()) -> ok | {error, reason()}.
 %%
 %% Description: Sends data over the ssl connection