Backport from 6.0-codebase.

WL#3771
  "Audit Plugin Interface"
  Implement new plug-in type - AUDIT
  New plug-in: audit_null
    simply increments counter for how many times it was called.

include/Makefile.am:
  wl3771
    add new headers to distribution
include/mysql/plugin.h:
  wl3771
    define new AUDIT plugin type
    Split out fulltext plugin type into its own header
include/mysql/plugin.h.pp:
  wl3771
    no real API change, just re-arranged some code
include/mysql/plugin_audit.h:
  wl3771
    pluggable audit interface
include/mysql/plugin_ftparser.h:
  wl3771
    Split out fulltext plugin type into its own header
libmysqld/CMakeLists.txt:
  wl3771
    add sql_audit.cc to build
libmysqld/Makefile.am:
  wl3771
    add sql_audit.cc to build
plugin/audit_null:
  wl3771
    an example plugin for testing pluggable audit interface
plugin/audit_null/Makefile.am:
  wl3771
    an example plugin for testing pluggable audit interface
plugin/audit_null/audit_null.c:
  wl3771
    an example plugin for testing pluggable audit interface
plugin/audit_null/plug.in:
  wl3771
    an example plugin for testing pluggable audit interface
sql/CMakeLists.txt:
  wl3771
    add sql_audit.cc to build
sql/Makefile.am:
  wl3771
    add sql_audit.cc to build
sql/event_queue.cc:
  wl3771
    release audit resources before waiting
sql/log.cc:
  wl3771
    add general audit call for log
sql/mysqld.cc:
  wl3771
    add audit initialize/finalize
    add general audit call for error
sql/sql_audit.cc:
  wl3771
    pluggable audit interface implementation
sql/sql_audit.h:
  wl3771
    pluggable audit interface implementation
sql/sql_class.cc:
  wl3771
    add thd audit init/deinit calls
sql/sql_class.h:
  wl3771
    add required data structures for audit to THD
sql/sql_connect.cc:
  wl3771
    release audit resources before waiting
sql/sql_insert.cc:
  wl3771
    release audit plugins before waiting
sql/sql_parse.cc:
  wl3771
    add general audit call for results
sql/sql_plugin.cc:
  wl3771
    add declarations for audit plugin type

1 files changed, 448 insertions, 0 deletions

diff --git a/sql/sql_audit.cc b/sql/sql_audit.cc
new file mode 100644
index 00000000000..0e9b5302728
--- /dev/null
+++ b/sql/sql_audit.cc
@@ -0,0 +1,448 @@
+/* Copyright (C) 2007 MySQL AB
+
+   This program 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 of the License.
+
+   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+#include "mysql_priv.h"
+#include "sql_audit.h"
+
+extern int initialize_audit_plugin(st_plugin_int *plugin);
+extern int finalize_audit_plugin(st_plugin_int *plugin);
+
+#ifndef EMBEDDED_LIBRARY
+
+unsigned long mysql_global_audit_mask[MYSQL_AUDIT_CLASS_MASK_SIZE];
+
+static pthread_mutex_t LOCK_audit_mask;
+
+static void event_class_dispatch(THD *thd, const struct mysql_event *event);
+
+
+static inline
+void set_audit_mask(unsigned long *mask, uint event_class)
+{
+  mask[0]= 1;
+  mask[0]<<= event_class;
+}
+
+static inline
+void add_audit_mask(unsigned long *mask, const unsigned long *rhs)
+{
+  mask[0]|= rhs[0];
+}
+
+static inline
+bool check_audit_mask(const unsigned long *lhs,
+                      const unsigned long *rhs)
+{
+  return !(lhs[0] & rhs[0]);
+}
+
+
+typedef void (*audit_handler_t)(THD *thd, uint event_subtype, va_list ap);
+
+/**
+  MYSQL_AUDIT_GENERAL_CLASS handler
+  
+  @param[in] thd
+  @param[in] event_subtype
+  @param[in] error_code
+  @param[in] ap
+  
+*/
+
+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.general_error_code= va_arg(ap, int);
+  event.general_thread_id= thd ? thd->thread_id : 0;
+  event.general_time= va_arg(ap, time_t);
+  event.general_user= va_arg(ap, const char *);
+  event.general_user_length= va_arg(ap, unsigned int);
+  event.general_command= va_arg(ap, const char *);
+  event.general_command_length= va_arg(ap, unsigned int);
+  event.general_query= va_arg(ap, const char *);
+  event.general_query_length= va_arg(ap, unsigned int);
+  event.general_charset= va_arg(ap, struct charset_info_st *);
+  event.general_rows= (unsigned long long) va_arg(ap, ha_rows);
+  event_class_dispatch(thd, (const mysql_event*) &event);
+}
+
+
+static audit_handler_t audit_handlers[] =
+{
+  general_class_handler
+};
+
+static const uint audit_handlers_count=
+  (sizeof(audit_handlers) / sizeof(audit_handler_t));
+
+
+/**
+  Acquire and lock any additional audit plugins as required
+  
+  @param[in] thd
+  @param[in] plugin
+  @param[in] arg
+
+  @retval FALSE Always  
+*/
+
+static my_bool acquire_plugins(THD *thd, plugin_ref plugin, void *arg)
+{
+  uint event_class= *(uint*) arg;
+  unsigned long event_class_mask[MYSQL_AUDIT_CLASS_MASK_SIZE];
+  st_mysql_audit *data= plugin_data(plugin, struct st_mysql_audit *);
+
+  set_audit_mask(event_class_mask, event_class);
+
+  /* Check if this plugin is interested in the event */
+  if (check_audit_mask(data->class_mask, event_class_mask))
+    return 0;
+
+  /*
+    Check if this plugin may already be registered. This will fail to
+    acquire a newly installed plugin on a specific corner case where
+    one or more event classes already in use by the calling thread
+    are an event class of which the audit plugin has interest.
+  */
+  if (!check_audit_mask(data->class_mask, thd->audit_class_mask))
+    return 0;
+  
+  /* Check if we need to initialize the array of acquired plugins */
+  if (unlikely(!thd->audit_class_plugins.buffer))
+  {
+    /* specify some reasonable initialization defaults */
+    my_init_dynamic_array(&thd->audit_class_plugins,
+                          sizeof(plugin_ref), 16, 16);
+  }
+  
+  /* lock the plugin and add it to the list */
+  plugin= my_plugin_lock(NULL, &plugin);
+  insert_dynamic(&thd->audit_class_plugins, (uchar*) &plugin);
+
+  return 0;
+}
+
+
+/**
+  Notify the audit system of an event
+  
+  @param[in] thd
+  @param[in] event_class
+  @param[in] event_subtype
+  @param[in] error_code
+
+*/
+
+void mysql_audit_notify(THD *thd, uint event_class, uint event_subtype, ...)
+{
+  va_list ap;
+  audit_handler_t *handlers= audit_handlers + event_class;
+  unsigned long event_class_mask[MYSQL_AUDIT_CLASS_MASK_SIZE];
+  
+  DBUG_ASSERT(event_class < audit_handlers_count);
+
+  set_audit_mask(event_class_mask, event_class);
+  /*
+    Check to see if we have acquired the audit plugins for the
+    required audit event classes.
+  */
+  if (thd && check_audit_mask(thd->audit_class_mask, event_class_mask))
+  {
+    plugin_foreach(thd, acquire_plugins, MYSQL_AUDIT_PLUGIN, &event_class);
+    add_audit_mask(thd->audit_class_mask, event_class_mask);
+  }
+
+  va_start(ap, event_subtype);  
+  (*handlers)(thd, event_subtype, ap);
+  va_end(ap);
+}
+
+
+/**
+  Release any resources associated with the current thd.
+  
+  @param[in] thd
+
+*/
+
+void mysql_audit_release(THD *thd)
+{
+  plugin_ref *plugins, *plugins_last;
+  
+  if (!thd || !(thd->audit_class_plugins.elements))
+    return;
+  
+  plugins= (plugin_ref*) thd->audit_class_plugins.buffer;
+  plugins_last= plugins + thd->audit_class_plugins.elements;
+  for (; plugins < plugins_last; plugins++)
+  {
+    st_mysql_audit *data= plugin_data(*plugins, struct st_mysql_audit *);
+	
+    /* Check to see if the plugin has a release method */
+    if (!(data->release_thd))
+      continue;
+
+    /* Tell the plugin to release its resources */
+    data->release_thd(thd);
+  }
+
+  /* Now we actually unlock the plugins */  
+  plugin_unlock_list(NULL, (plugin_ref*) thd->audit_class_plugins.buffer,
+                     thd->audit_class_plugins.elements);
+  
+  /* Reset the state of thread values */
+  reset_dynamic(&thd->audit_class_plugins);
+  bzero(thd->audit_class_mask, sizeof(thd->audit_class_mask));
+}
+
+
+/**
+  Initialize thd variables used by Audit
+  
+  @param[in] thd
+
+*/
+
+void mysql_audit_init_thd(THD *thd)
+{
+  bzero(&thd->audit_class_plugins, sizeof(thd->audit_class_plugins));
+  bzero(thd->audit_class_mask, sizeof(thd->audit_class_mask));
+}
+
+
+/**
+  Free thd variables used by Audit
+  
+  @param[in] thd
+  @param[in] plugin
+  @param[in] arg
+
+  @retval FALSE Always  
+*/
+
+void mysql_audit_free_thd(THD *thd)
+{
+  mysql_audit_release(thd);
+  DBUG_ASSERT(thd->audit_class_plugins.elements == 0);
+  delete_dynamic(&thd->audit_class_plugins);
+}
+
+
+/**
+  Initialize Audit global variables
+*/
+
+void mysql_audit_initialize()
+{
+  pthread_mutex_init(&LOCK_audit_mask, MY_MUTEX_INIT_FAST);
+  bzero(mysql_global_audit_mask, sizeof(mysql_global_audit_mask));
+}
+
+
+/**
+  Finalize Audit global variables  
+*/
+
+void mysql_audit_finalize()
+{
+  pthread_mutex_destroy(&LOCK_audit_mask);
+}
+
+
+/**
+  Initialize an Audit plug-in
+  
+  @param[in] plugin
+
+  @retval FALSE  OK
+  @retval TRUE   There was an error.
+*/
+
+int initialize_audit_plugin(st_plugin_int *plugin)
+{
+  st_mysql_audit *data= (st_mysql_audit*) plugin->plugin->info;
+  
+  if (!data->class_mask || !data->event_notify ||
+      !data->class_mask[0])
+  {
+    sql_print_error("Plugin '%s' has invalid data.",
+                    plugin->name.str);
+    return 1;
+  }
+  
+  if (plugin->plugin->init && plugin->plugin->init(NULL))
+  {
+    sql_print_error("Plugin '%s' init function returned error.",
+                    plugin->name.str);
+    return 1;
+  }
+
+  /* Make the interface info more easily accessible */
+  plugin->data= plugin->plugin->info;
+  
+  /* Add the bits the plugin is interested in to the global mask */
+  pthread_mutex_lock(&LOCK_audit_mask);
+  add_audit_mask(mysql_global_audit_mask, data->class_mask);
+  pthread_mutex_unlock(&LOCK_audit_mask);
+
+  return 0;
+}
+
+
+/**
+  Performs a bitwise OR of the installed plugins event class masks
+
+  @param[in] thd
+  @param[in] plugin
+  @param[in] arg
+
+  @retval FALSE  always
+*/
+static my_bool calc_class_mask(THD *thd, plugin_ref plugin, void *arg)
+{
+  st_mysql_audit *data= plugin_data(plugin, struct st_mysql_audit *);
+  if ((data= plugin_data(plugin, struct st_mysql_audit *)))
+    add_audit_mask((unsigned long *) arg, data->class_mask);
+  return 0;
+}
+
+
+/**
+  Finalize an Audit plug-in
+  
+  @param[in] plugin
+
+  @retval FALSE  OK
+  @retval TRUE   There was an error.
+*/
+int finalize_audit_plugin(st_plugin_int *plugin)
+{
+  unsigned long event_class_mask[MYSQL_AUDIT_CLASS_MASK_SIZE];
+  
+  if (plugin->plugin->deinit && plugin->plugin->deinit(NULL))
+  {
+    DBUG_PRINT("warning", ("Plugin '%s' deinit function returned error.",
+                            plugin->name.str));
+    DBUG_EXECUTE("finalize_audit_plugin", return 1; );
+  }
+  
+  plugin->data= NULL;
+  bzero(&event_class_mask, sizeof(event_class_mask));
+
+  /* Iterate through all the installed plugins to create new mask */
+  pthread_mutex_lock(&LOCK_audit_mask);
+  plugin_foreach(current_thd, calc_class_mask, MYSQL_AUDIT_PLUGIN,
+                 &event_class_mask);
+
+  /* Set the global audit mask */
+  bmove(mysql_global_audit_mask, event_class_mask, sizeof(event_class_mask));
+  pthread_mutex_unlock(&LOCK_audit_mask);
+
+  return 0;
+}
+
+
+/**
+  Dispatches an event by invoking the plugin's event_notify method.  
+
+  @param[in] thd
+  @param[in] plugin
+  @param[in] arg
+
+  @retval FALSE  always
+*/
+
+static my_bool plugins_dispatch(THD *thd, plugin_ref plugin, void *arg)
+{
+  const struct mysql_event *event= (const struct mysql_event *) arg;
+  unsigned long event_class_mask[MYSQL_AUDIT_CLASS_MASK_SIZE];
+  st_mysql_audit *data= plugin_data(plugin, struct st_mysql_audit *);
+
+  set_audit_mask(event_class_mask, event->event_class);
+
+  /* Check to see if the plugin is interested in this event */
+  if (check_audit_mask(data->class_mask, event_class_mask))
+    return 0;
+
+  /* Actually notify the plugin */
+  data->event_notify(thd, event);
+
+  return 0;
+}
+
+
+/**
+  Distributes an audit event to plug-ins
+  
+  @param[in] thd
+  @param[in] event
+*/
+
+static void event_class_dispatch(THD *thd, const struct mysql_event *event)
+{
+  /*
+    Check if we are doing a slow global dispatch. This event occurs when
+    thd == NULL as it is not associated with any particular thread.
+  */
+  if (unlikely(!thd))
+  {
+    plugin_foreach(thd, plugins_dispatch, MYSQL_AUDIT_PLUGIN, (void*) event);
+  }
+  else
+  {
+    plugin_ref *plugins, *plugins_last;
+
+    /* Use the cached set of audit plugins */
+    plugins= (plugin_ref*) thd->audit_class_plugins.buffer;
+    plugins_last= plugins + thd->audit_class_plugins.elements;
+
+    for (; plugins < plugins_last; plugins++)
+      plugins_dispatch(thd, *plugins, (void*) event);
+  }
+}
+
+
+#else /* EMBEDDED_LIBRARY */
+
+
+void mysql_audit_initialize()
+{
+}
+
+
+void mysql_audit_finalize()
+{
+}
+
+
+int initialize_audit_plugin(st_plugin_int *plugin)
+{
+  return 1;
+}
+
+
+int finalize_audit_plugin(st_plugin_int *plugin)
+{
+  return 0;
+}
+
+
+void mysql_audit_release(THD *thd)
+{
+}
+
+
+#endif /* EMBEDDED_LIBRARY */