Expose more information to audit plugin

Summary:
We need some extra info for the shadowing and security logging. This is a
simple first step of info that MariaDB actually also exposes.
Now we would have the `query_id` and the database name for general events.
Making as few changes as possible to accomplish it, so I'm just taking the
information from the TDH and exposing it through `mysql_event_general`
struct and as a argument to disconnect.

Test Plan: I didn't find any proper testing for plugin changes, so I'm trusting Jenkins

Reviewers: tianx, chip, santoshb, jtolmer

Reviewed By: chip

Author: drilibo

Diff for: include/mysql/plugin_audit.h

@@ -25,7 +25,7 @@
 
 #define MYSQL_AUDIT_CLASS_MASK_SIZE 1
 
-#define MYSQL_AUDIT_INTERFACE_VERSION 0x0301
+#define MYSQL_AUDIT_INTERFACE_VERSION 0x0302
 
 
 /*************************************************************************
@@ -63,6 +63,10 @@ struct mysql_event_general
   MYSQL_LEX_STRING general_sql_command;
   MYSQL_LEX_STRING general_external_user;
   MYSQL_LEX_STRING general_ip;
+  /* Added in version 0x302 */
+  long long query_id;
+  const char *database;
+  unsigned int database_length;
 };
 
 

Diff for: include/mysql/plugin_audit.h.pp

@@ -276,6 +276,9 @@
   MYSQL_LEX_STRING general_sql_command;
   MYSQL_LEX_STRING general_external_user;
   MYSQL_LEX_STRING general_ip;
+  long long query_id;
+  const char *database;
+  unsigned int database_length;
 };
 struct mysql_event_connection
 {

Diff for: sql/sql_audit.cc

@@ -87,6 +87,9 @@ static void general_class_handler(THD *thd, uint event_subtype, va_list ap)
   event.general_host= va_arg(ap, MYSQL_LEX_STRING);
   event.general_external_user= va_arg(ap, MYSQL_LEX_STRING);
   event.general_ip= va_arg(ap, MYSQL_LEX_STRING);
+  event.database= va_arg(ap, const char *);
+  event.database_length= va_arg(ap, unsigned int);
+  event.query_id= (unsigned long long) thd->query_id;
   event_class_dispatch(thd, MYSQL_AUDIT_GENERAL_CLASS, &event);
 }
 

Diff for: sql/sql_audit.h

@@ -81,6 +81,8 @@ void mysql_audit_general_log(THD *thd, const char *cmd, uint cmdlen,
     const char *user= user_buff;
     uint userlen= make_user_name(thd, user_buff);
     time_t time= (time_t) thd->start_time.tv_sec;
+    size_t databaselen;
+    const char *database;
 
     if (thd)
     {
@@ -108,21 +110,25 @@ void mysql_audit_general_log(THD *thd, const char *cmd, uint cmdlen,
       external_user.length= thd->security_ctx->get_external_user()->length();
       sql_command.str= (char *) sql_statement_names[thd->lex->sql_command].str;
       sql_command.length= sql_statement_names[thd->lex->sql_command].length;
+      database= thd->db;
+      databaselen= thd->db_length;
     }
     else
     {
       ip= empty;
       host= empty;
       external_user= empty;
       sql_command= empty;
+      database= 0;
+      databaselen= 0;
     }
     const CHARSET_INFO *clientcs= thd ? thd->variables.character_set_client
       : global_system_variables.character_set_client;
 
     mysql_audit_notify(thd, MYSQL_AUDIT_GENERAL_CLASS, MYSQL_AUDIT_GENERAL_LOG,
                        error_code, time, user, userlen, cmd, cmdlen, query.str,
                        query.length, clientcs, rows, sql_command, host,
-                       external_user, ip);
+                       external_user, ip, database, databaselen);
   }
 #endif
 }
@@ -149,14 +155,15 @@ void mysql_audit_general(THD *thd, uint event_subtype,
   {
     time_t time= my_time(0);
     uint msglen= msg ? strlen(msg) : 0;
-    uint userlen;
-    const char *user;
+    uint userlen, databaselen;
+    const char *user, *database;
     char user_buff[MAX_USER_HOST_SIZE];
     CSET_STRING query;
     MYSQL_LEX_STRING ip, host, external_user, sql_command;
     ha_rows rows;
     static MYSQL_LEX_STRING empty= { C_STRING_WITH_LEN("") };
 
+
     if (thd)
     {
       if (!thd->rewritten_query.length())
@@ -178,6 +185,8 @@ void mysql_audit_general(THD *thd, uint event_subtype,
       external_user.length= thd->security_ctx->get_external_user()->length();
       sql_command.str= (char *) sql_statement_names[thd->lex->sql_command].str;
       sql_command.length= sql_statement_names[thd->lex->sql_command].length;
+      database= thd->db;
+      databaselen= thd->db_length;
     }
     else
     {
@@ -188,12 +197,15 @@ void mysql_audit_general(THD *thd, uint event_subtype,
       external_user= empty;
       sql_command= empty;
       rows= 0;
+      database= 0;
+      databaselen= 0;
     }
 
     mysql_audit_notify(thd, MYSQL_AUDIT_GENERAL_CLASS, event_subtype,
                        error_code, time, user, userlen, msg, msglen,
                        query.str(), query.length(), query.charset(), rows,
-                       sql_command, host, external_user, ip);
+                       sql_command, host, external_user, ip, database,
+                       databaselen);
   }
 #endif
 }