Added mysql_common.c for mysql common routines

First attempt to split MySQL routines in client and backend libraries.
Compiled on Centos but not tested

mysql_protocol.h header file is coming soon.

modules/protocol/mysql_common.c

@@ -0,0 +1,87 @@
+/*
+ * This file is distributed as part of the SkySQL Gateway.  It is free
+ * software: you can redistribute it and/or modify it under the terms of the
+ * GNU General Public License as published by the Free Software Foundation,
+ * version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Copyright SkySQL Ab 2013
+ */
+
+/*
+ * MySQL Protocol common routines for client to gateway and gateway to backend
+ *
+ * Revision History
+ * Date         Who                     Description
+ * 17/06/2013   Massimiliano Pinto      Common MySQL protocol routines
+ */
+
+#include "mysql_protocol.h"
+
+static char *version_str = "V1.0.0";
+
+///////////////////////////////////////
+MySQLProtocol *gw_mysql_init(MySQLProtocol *data) {
+        int rv = -1;
+
+        MySQLProtocol *input = NULL;
+
+        if (input == NULL) {
+                // structure allocation
+                input = calloc(1, sizeof(MySQLProtocol));
+
+                if (input == NULL)
+                        return NULL;
+
+        }
+
+#ifdef MYSQL_CONN_DEBUG
+	fprintf(stderr, "gw_mysql_init() called\n");
+#endif
+
+        return input;
+}
+
+
+//////////////////////////////////////
+// close a connection if opened
+// free data scructure
+//////////////////////////////////////
+void gw_mysql_close(MySQLProtocol **ptr) {
+	MySQLProtocol *conn = *ptr;
+
+	if (*ptr == NULL)
+		return;
+
+#ifdef MYSQL_CONN_DEBUG
+	fprintf(stderr, "Closing MySQL connection %i, [%s]\n", conn->fd, conn->scramble);
+#endif
+
+	if (conn->fd > 0) {
+		//COM_QUIT will not be sent here, but from the caller of this routine!
+#ifdef MYSQL_CONN_DEBUG
+		fprintf(stderr, "mysqlgw_mysql_close() called for %i\n", conn->fd);
+#endif
+		close(conn->fd);
+	} else {
+#ifdef MYSQL_CONN_DEBUG
+		fprintf(stderr, "mysqlgw_mysql_close() called, no socket %i\n", conn->fd);
+#endif
+	}
+
+	free(*ptr);
+
+	*ptr = NULL;
+
+#ifdef MYSQL_CONN_DEBUG
+	fprintf(stderr, "mysqlgw_mysql_close() free(conn) done\n");
+#endif
+}