BUG#47059 - In audit plugin I cannot see the event subclasses,

            e.g.MYSQL_AUDIT_GENERAL_ERROR

General audit API (MYSQL_AUDIT_GENERAL_CLASS) didn't expose event
subclass to plugins.

This patch exposes event subclass to plugins via
struct mysql_event_general::event_subclass.

This change is not compatible with existing general audit plugins.
Audit interface major version has been incremented.

include/mysql/plugin_audit.h

@@ -24,7 +24,7 @@
 
 #define MYSQL_AUDIT_CLASS_MASK_SIZE 1
 
-#define MYSQL_AUDIT_INTERFACE_VERSION 0x0100
+#define MYSQL_AUDIT_INTERFACE_VERSION 0x0200
 
 /*
   The first word in every event class struct indicates the specific
@@ -32,7 +32,7 @@
 */
 struct mysql_event
 {
-  int event_class;
+  unsigned int event_class;
 };
 
 
@@ -52,7 +52,8 @@ struct mysql_event
 
 struct mysql_event_general
 {
-  int event_class;
+  unsigned int event_class;
+  unsigned int event_subclass;
   int general_error_code;
   unsigned long general_thread_id;
   const char *general_user;

plugin/audit_null/audit_null.c

@@ -22,6 +22,9 @@
 #endif
 
 static volatile int number_of_calls; /* for SHOW STATUS, see below */
+static volatile int number_of_calls_general_log;
+static volatile int number_of_calls_general_error;
+static volatile int number_of_calls_general_result;
 
 
 /*
@@ -41,6 +44,9 @@ static volatile int number_of_calls; /* for SHOW STATUS, see below */
 static int audit_null_plugin_init(void *arg __attribute__((unused)))
 {
   number_of_calls= 0;
+  number_of_calls_general_log= 0;
+  number_of_calls_general_error= 0;
+  number_of_calls_general_result= 0;
   return(0);
 }
 
@@ -60,7 +66,6 @@ static int audit_null_plugin_init(void *arg __attribute__((unused)))
 
 static int audit_null_plugin_deinit(void *arg __attribute__((unused)))
 {
-  printf("audit_null was invoked %u times\n", number_of_calls);
   return(0);
 }
 
@@ -76,11 +81,29 @@ static int audit_null_plugin_deinit(void *arg __attribute__((unused)))
 */
 
 static void audit_null_notify(MYSQL_THD thd __attribute__((unused)),
-                              const struct mysql_event *event
-                              __attribute__((unused)))
+                              const struct mysql_event *event)
 {
   /* prone to races, oh well */
   number_of_calls++;
+  if (event->event_class == MYSQL_AUDIT_GENERAL_CLASS)
+  {
+    const struct mysql_event_general *event_general=
+      (const struct mysql_event_general *) event;
+    switch (event_general->event_subclass)
+    {
+    case MYSQL_AUDIT_GENERAL_LOG:
+      number_of_calls_general_log++;
+      break;
+    case MYSQL_AUDIT_GENERAL_ERROR:
+      number_of_calls_general_error++;
+      break;
+    case MYSQL_AUDIT_GENERAL_RESULT:
+      number_of_calls_general_result++;
+      break;
+    default:
+      break;
+    }
+  }
 }
 
 
@@ -90,10 +113,10 @@ static void audit_null_notify(MYSQL_THD thd __attribute__((unused)),
 
 static struct st_mysql_audit audit_null_descriptor=
 {
-  MYSQL_AUDIT_INTERFACE_VERSION,    /* interface version      */
-  NULL,                             /* release_thd function   */
-  audit_null_notify,                /* notify function        */
-  { (unsigned long) -1 }            /* class mask             */
+  MYSQL_AUDIT_INTERFACE_VERSION,                    /* interface version    */
+  NULL,                                             /* release_thd function */
+  audit_null_notify,                                /* notify function      */
+  { (unsigned long) MYSQL_AUDIT_GENERAL_CLASSMASK } /* class mask           */
 };
 
 /*
@@ -102,8 +125,13 @@ static struct st_mysql_audit audit_null_descriptor=
 
 static struct st_mysql_show_var simple_status[]=
 {
-  {"audit_null_called", (char *)&number_of_calls, SHOW_INT},
-  {0,0,0}
+  { "Audit_null_called", (char *) &number_of_calls, SHOW_INT },
+  { "Audit_null_general_log", (char *) &number_of_calls_general_log, SHOW_INT },
+  { "Audit_null_general_error", (char *) &number_of_calls_general_error,
+    SHOW_INT },
+  { "Audit_null_general_result", (char *) &number_of_calls_general_result,
+    SHOW_INT },
+  { 0, 0, 0}
 };
 
 
@@ -121,7 +149,7 @@ mysql_declare_plugin(audit_null)
   PLUGIN_LICENSE_GPL,
   audit_null_plugin_init,     /* init function (when loaded)     */
   audit_null_plugin_deinit,   /* deinit function (when unloaded) */
-  0x0001,                     /* version                         */
+  0x0002,                     /* version                         */
   simple_status,              /* status variables                */
   NULL,                       /* system variables                */
   NULL

sql/sql_audit.cc

@@ -65,6 +65,7 @@ static void general_class_handler(THD *thd, uint event_subtype, va_list ap)
 {
   mysql_event_general event;
   event.event_class= MYSQL_AUDIT_GENERAL_CLASS;
+  event.event_subclass= event_subtype;
   event.general_error_code= va_arg(ap, int);
   event.general_thread_id= thd ? thd->thread_id : 0;
   event.general_time= va_arg(ap, time_t);