postgres
diff --git a/‎src/backend/tcop/backend_startup.c
Copy file name to clipboardExpand all lines: src/backend/tcop/backend_startup.c
+23Lines changed: 23 additions & 0 deletions b/‎src/backend/tcop/backend_startup.c
Copy file name to clipboardExpand all lines: src/backend/tcop/backend_startup.c
+23Lines changed: 23 additions & 0 deletions
diff --git a/‎src/backend/utils/misc/guc_tables.c
Copy file name to clipboardExpand all lines: src/backend/utils/misc/guc_tables.c
+11Lines changed: 11 additions & 0 deletions b/‎src/backend/utils/misc/guc_tables.c
Copy file name to clipboardExpand all lines: src/backend/utils/misc/guc_tables.c
+11Lines changed: 11 additions & 0 deletions
@@ -37,6 +37,9 @@
 #include "utils/ps_status.h"
 #include "utils/timeout.h"
 
+/* GUCs */
+bool		Trace_connection_negotiation = false;
+
 static void BackendInitialize(ClientSocket *client_sock, CAC_state cac);
 static int	ProcessStartupPacket(Port *port, bool ssl_done, bool gss_done);
 static void SendNegotiateProtocolVersion(List *unrecognized_protocol_options);
@@ -474,6 +477,16 @@ ProcessStartupPacket(Port *port, bool ssl_done, bool gss_done)
 		SSLok = 'N';			/* No support for SSL */
 #endif
 
+		if (Trace_connection_negotiation)
+		{
+			if (SSLok == 'S')
+				ereport(LOG,
+						(errmsg("SSLRequest accepted")));
+			else
+				ereport(LOG,
+						(errmsg("SSLRequest rejected")));
+		}
+
 retry1:
 		if (send(port->sock, &SSLok, 1, 0) != 1)
 		{
@@ -519,6 +532,16 @@ ProcessStartupPacket(Port *port, bool ssl_done, bool gss_done)
 			GSSok = 'G';
 #endif
 
+		if (Trace_connection_negotiation)
+		{
+			if (GSSok == 'G')
+				ereport(LOG,
+						(errmsg("GSSENCRequest accepted")));
+			else
+				ereport(LOG,
+						(errmsg("GSSENCRequest rejected")));
+		}
+
 		while (send(port->sock, &GSSok, 1, 0) != 1)
 		{
 			if (errno == EINTR)
 
@@ -96,6 +96,7 @@
 
 /* XXX these should appear in other modules' header files */
 extern bool Log_disconnections;
+extern bool Trace_connection_negotiation;
 extern int	CommitDelay;
 extern int	CommitSiblings;
 extern char *default_tablespace;
@@ -1224,6 +1225,16 @@ struct config_bool ConfigureNamesBool[] =
 		false,
 		NULL, NULL, NULL
 	},
+	{
+		{"trace_connection_negotiation", PGC_POSTMASTER, DEVELOPER_OPTIONS,
+			gettext_noop("Log details of pre-authentication connection handshake."),
+			NULL,
+			GUC_NOT_IN_SAMPLE
+		},
+		&Trace_connection_negotiation,
+		false,
+		NULL, NULL, NULL
+	},
 	{
 		{"log_disconnections", PGC_SU_BACKEND, LOGGING_WHAT,
 			gettext_noop("Logs end of a session, including duration."),