Add getCapabilities to filters

Common capabilities are now defined in routing.h. The common
capabilities can be defined using bits 0 - 15.

Router capabilities are defined using bits 16-31 and filter
capabilities (should there ever be such) using bits 32-47.

So, to find out the capabilities of a service you only need to
OR the capabilities of the router and all filters together.

For instance, if a single filter needs statement based routing,
then that is what is done.

include/maxscale/filter.h

@@ -25,6 +25,7 @@
  */
 
 #include <maxscale/cdefs.h>
+#include <maxscale/routing.h>
 #include <maxscale/dcb.h>
 #include <maxscale/session.h>
 #include <maxscale/buffer.h>
@@ -83,6 +84,7 @@ typedef struct filter_object
     int    (*routeQuery)(FILTER *instance, void *fsession, GWBUF *queue);
     int    (*clientReply)(FILTER *instance, void *fsession, GWBUF *queue);
     void   (*diagnostics)(FILTER *instance, void *fsession, DCB *dcb);
+    uint64_t (*getCapabilities)();
 } FILTER_OBJECT;
 
 /**
@@ -90,7 +92,7 @@ typedef struct filter_object
  * is changed these values must be updated in line with the rules in the
  * file modinfo.h.
  */
-#define FILTER_VERSION  {2, 1, 0}
+#define FILTER_VERSION  {2, 2, 0}
 /**
  * The definition of a filter from the configuration file.
  * This is basically the link between a plugin to load and the
@@ -121,6 +123,22 @@ void dprintAllFilters(DCB *);
 void dprintFilter(DCB *, FILTER_DEF *);
 void dListFilters(DCB *);
 
+/**
+ * Specifies capabilities specific for filters. Common capabilities
+ * are defined by @c routing_capability_t.
+ *
+ * @see routing_capability_t
+ *
+ * @note The values of the capabilities here *must* be between 0x000100000000
+ *       and 0x800000000000, that is, bits 32 to 47.
+ */
+
+/*
+typedef enum filter_capability
+{
+} filter_capability_t;
+*/
+
 MXS_END_DECLS
 
 #endif

include/maxscale/router.h

@@ -30,6 +30,7 @@
  */
 
 #include <maxscale/cdefs.h>
+#include <maxscale/routing.h>
 #include <maxscale/service.h>
 #include <maxscale/session.h>
 #include <maxscale/buffer.h>
@@ -93,14 +94,19 @@ typedef struct router_object
 #define ROUTER_VERSION  { 2, 0, 0 }
 
 /**
- * Router capability type. Indicates what kind of input router accepts.
+ * Specifies capabilities specific for routers. Common capabilities
+ * are defined by @c routing_capability_t.
+ *
+ * @see routing_capability_t
+ *
+ * @note The values of the capabilities here *must* be between 0x00010000
+ *       and 0x80000000, that is, bits 16 to 31.
  */
-typedef enum router_capability_t
+typedef enum router_capability
 {
-    RCAP_TYPE_UNDEFINED     = 0x00,
-    RCAP_TYPE_STMT_INPUT    = 0x01, /**< Statement per buffer */
-    RCAP_TYPE_PACKET_INPUT  = 0x02, /**< Data as it was read from DCB */
-    RCAP_TYPE_NO_RSESSION   = 0x04 /**< Router does not use router sessions */
+    RCAP_TYPE_NO_RSESSION   = 0x00010000, /**< Router does not use router sessions */
+    RCAP_TYPE_NO_USERS_INIT = 0x00020000, /**< Prevent the loading of authenticator
+                                             users when the service is started */
 } router_capability_t;
 
 MXS_END_DECLS

include/maxscale/routing.h

@@ -0,0 +1,38 @@
+#pragma once
+/*
+ * Copyright (c) 2016 MariaDB Corporation Ab
+ *
+ * Use of this software is governed by the Business Source License included
+ * in the LICENSE.TXT file and at www.mariadb.com/bsl.
+ *
+ * Change Date: 2019-07-01
+ *
+ * On the date above, in accordance with the Business Source License, use
+ * of this software will be governed by version 2 or later of the General
+ * Public License.
+ */
+
+/**
+ * @file routing.h - Common definitions and declarations for routers and filters.
+ */
+
+#include <maxscale/cdefs.h>
+
+MXS_BEGIN_DECLS
+
+/**
+ * Routing capability type. Indicates what kind of input a router or
+ * a filter accepts.
+ *
+ * @note The values of the capabilities here *must* be between 0x0000
+ *       and 0x8000, that is, bits 0 to 15.
+ */
+typedef enum routing_capability
+{
+    RCAP_TYPE_STMT_INPUT = 0x0001, /**< Statement per buffer. */
+} routing_capability_t;
+
+#define RCAP_TYPE_NONE 0
+
+MXS_END_DECLS
+