MDEV-19275 Provide SQL service to plugins.

test_sql_service plugin added and employed in test_sql_service.test.

mysql-test/suite/plugins/r/test_sql_service.result

+install plugin test_sql_service soname 'test_sql_service';
+set global test_sql_service_run_test= 1;
+show status like 'test_sql_service%';
+Variable_name	Value
+Test_sql_service_passed	0
+uninstall plugin test_sql_service;
+Warnings:
+Warning	1620	Plugin is busy and will be uninstalled on shutdown

mysql-test/suite/plugins/t/test_sql_service.opt

+--thread_handling='one-thread-per-connection'
+

mysql-test/suite/plugins/t/test_sql_service.test

+
+--source include/not_embedded.inc
+
+if (!$TEST_SQL_SERVICE_SO) {
+  skip No TEST_SQL_SERVICE plugin;
+}
+
+# An unfortunate wait for check-testcase.test to complete disconnect.
+let count_sessions= 1;
+source include/wait_until_count_sessions.inc;
+
+install plugin test_sql_service soname 'test_sql_service';
+
+set global test_sql_service_run_test= 1;
+show status like 'test_sql_service%';
+
+uninstall plugin test_sql_service;
+

plugin/test_sql_service/CMakeLists.txt

+# Copyright (C) 2013 Alexey Botchkov and SkySQL 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
+
+SET(SOURCES test_sql_service.c)
+
+MYSQL_ADD_PLUGIN(test_sql_service  ${SOURCES} MODULE_ONLY RECOMPILE_FOR_EMBEDDED)

plugin/test_sql_service/test_sql_service.c

+/* Copyright (C) 2019, Alexey Botchkov and MariaDB Corporation
+
+   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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
+
+
+#define PLUGIN_VERSION 0x100
+#define PLUGIN_STR_VERSION "1.0.0"
+
+#define _my_thread_var loc_thread_var
+
+#include <my_config.h>
+#include <assert.h>
+#include <my_global.h>
+#include <my_base.h>
+#include <typelib.h>
+//#include <mysql_com.h>  /* for enum enum_server_command */
+#include <mysql/plugin.h>
+#include <mysql/plugin_audit.h>
+//#include <string.h>
+
+
+LEX_STRING * thd_query_string (MYSQL_THD thd);
+unsigned long long thd_query_id(const MYSQL_THD thd);
+size_t thd_query_safe(MYSQL_THD thd, char *buf, size_t buflen);
+const char *thd_user_name(MYSQL_THD thd);
+const char *thd_client_host(MYSQL_THD thd);
+const char *thd_client_ip(MYSQL_THD thd);
+LEX_CSTRING *thd_current_db(MYSQL_THD thd);
+int thd_current_status(MYSQL_THD thd);
+enum enum_server_command thd_current_command(MYSQL_THD thd);
+
+int maria_compare_hostname(const char *wild_host, long wild_ip, long ip_mask,
+                         const char *host, const char *ip);
+void maria_update_hostname(const char **wild_host, long *wild_ip, long *ip_mask,
+                         const char *host);
+
+/* Status variables for SHOW STATUS */
+static long test_passed= 0;
+static struct st_mysql_show_var test_sql_status[]=
+{
+  {"test_sql_service_passed", (char *)&test_passed, SHOW_LONG},
+  {0,0,0}
+};
+
+static my_bool do_test= TRUE;
+static void run_test(MYSQL_THD thd, struct st_mysql_sys_var *var,
+                     void *var_ptr, const void *save);
+static MYSQL_SYSVAR_BOOL(run_test, do_test, PLUGIN_VAR_OPCMDARG,
+           "Perform the test now.", NULL, run_test, FALSE);
+static struct st_mysql_sys_var* test_sql_vars[]=
+{
+  MYSQL_SYSVAR(run_test),
+  NULL
+};
+
+
+extern int execute_sql_command(const char *command,
+                                   char *hosts, char *names, char *filters);
+
+
+
+static int do_tests()
+{
+  char plugins[1024];
+  char names[1024];
+  char dl[2048];
+  int result;
+
+  result= execute_sql_command("select 'plugin', name, dl from mysql.plugin",
+                          plugins, names, dl);
+
+  return result;
+}
+ 
+
+void auditing(MYSQL_THD thd, unsigned int event_class, const void *ev)
+{
+}
+
+
+static void run_test(MYSQL_THD thd  __attribute__((unused)),
+                     struct st_mysql_sys_var *var  __attribute__((unused)),
+                     void *var_ptr  __attribute__((unused)),
+                     const void *save  __attribute__((unused)))
+{
+  test_passed= do_tests();
+}
+
+
+static int init_done= 0;
+
+static int test_sql_service_plugin_init(void *p __attribute__((unused)))
+{
+  init_done= 1;
+  return 0;
+}
+
+
+static int test_sql_service_plugin_deinit(void *p __attribute__((unused)))
+{
+  if (!init_done)
+    return 0;
+
+  return 0;
+}
+
+
+static struct st_mysql_audit maria_descriptor =
+{
+  MYSQL_AUDIT_INTERFACE_VERSION,
+  NULL,
+  auditing,
+  { MYSQL_AUDIT_GENERAL_CLASSMASK |
+    MYSQL_AUDIT_TABLE_CLASSMASK |
+    MYSQL_AUDIT_CONNECTION_CLASSMASK }
+};
+maria_declare_plugin(test_sql_service)
+{
+  MYSQL_AUDIT_PLUGIN,
+  &maria_descriptor,
+  "TEST_SQL_SERVICE",
+  "Alexey Botchkov (MariaDB Corporation)",
+  "Test SQL service",
+  PLUGIN_LICENSE_GPL,
+  test_sql_service_plugin_init,
+  test_sql_service_plugin_deinit,
+  PLUGIN_VERSION,
+  test_sql_status,
+  test_sql_vars,
+  PLUGIN_STR_VERSION,
+  MariaDB_PLUGIN_MATURITY_STABLE
+}
+maria_declare_plugin_end;
+

sql/log.cc

@@ -1355,7 +1355,7 @@ bool LOGGER::slow_log_print(THD *thd, const char *query, size_t query_length,
     my_hrtime_t current_time= { hrtime_from_time(thd->start_time) +
                                 thd->start_time_sec_part + query_utime };
 
-    if (!query)
+    if (!query || thd->get_command() == COM_STMT_PREPARE)
     {
       is_command= TRUE;
       query= command_name[thd->get_command()].str;

sql/sp_head.cc

@@ -1211,6 +1211,7 @@ sp_head::execute(THD *thd, bool merge_da_on_success)
   Query_arena execute_arena(&execute_mem_root, STMT_INITIALIZED_FOR_SP),
               backup_arena;
   query_id_t old_query_id;
+  CSET_STRING old_query;
   TABLE *old_derived_tables;
   TABLE *old_rec_tables;
   LEX *old_lex;
@@ -1291,6 +1292,7 @@ sp_head::execute(THD *thd, bool merge_da_on_success)
     be able properly do close_thread_tables() in instructions.
   */
   old_query_id= thd->query_id;
+  old_query= thd->query_string;
   old_derived_tables= thd->derived_tables;
   thd->derived_tables= 0;
   old_rec_tables= thd->rec_tables;
@@ -1567,6 +1569,7 @@ sp_head::execute(THD *thd, bool merge_da_on_success)
   old_change_list.move_elements_to(thd);
   thd->lex= old_lex;
   thd->set_query_id(old_query_id);
+  thd->set_query_inner(old_query);
   DBUG_ASSERT(!thd->derived_tables);
   thd->derived_tables= old_derived_tables;
   thd->rec_tables= old_rec_tables;

sql/sql_acl.cc

@@ -14679,3 +14679,40 @@ maria_declare_plugin(mysql_password)
   MariaDB_PLUGIN_MATURITY_STABLE                /* Maturity         */
 }
 maria_declare_plugin_end;
+
+
+/*
+  Exporting functions that allow plugins to do server-style
+  host/user matching. Used in server_audit2 plugin.
+*/
+extern "C" int maria_compare_hostname(
+                  const char *wild_host, long wild_ip, long ip_mask,
+                  const char *host, const char *ip)
+{
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
+  acl_host_and_ip h;
+  h.hostname= (char *) wild_host;
+  h.ip= wild_ip;
+  h.ip_mask= ip_mask;
+
+  return compare_hostname(&h, host, ip);
+#else
+  return 0;
+#endif
+}
+
+
+extern "C" void maria_update_hostname(
+                  const char **wild_host, long *wild_ip, long *ip_mask,
+                  const char *host)
+{
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
+  acl_host_and_ip h;
+  update_hostname(&h, host);
+  *wild_host= h.hostname;
+  *wild_ip= h.ip;
+  *ip_mask= h.ip_mask;
+#endif
+}
+
+

sql/sql_prepare.cc

@@ -2618,6 +2618,15 @@ void mysqld_stmt_prepare(THD *thd, const char *packet, uint packet_length)
 
   if (stmt->prepare(packet, packet_length))
   {
+    /*
+       Prepare failed and stmt will be freed.
+       Now we have to save the query_string in the so the
+       audit plugin later gets the meaningful notification.
+    */
+    if (alloc_query(thd, stmt->query_string.str(), stmt->query_string.length()))
+    {
+      thd->set_query(0, 0);
+    }
     /* Statement map deletes statement on erase */
     thd->stmt_map.erase(stmt);
     thd->clear_last_stmt();
@@ -2752,6 +2761,7 @@ bool Lex_prepared_stmt::get_dynamic_sql_string(THD *thd,
 void mysql_sql_stmt_prepare(THD *thd)
 {
   LEX *lex= thd->lex;
+  CSET_STRING orig_query= thd->query_string;
   const LEX_CSTRING *name= &lex->prepared_stmt.name();
   Prepared_statement *stmt;
   LEX_CSTRING query;
@@ -2822,7 +2832,16 @@ void mysql_sql_stmt_prepare(THD *thd)
                                          thd->m_statement_psi,
                                          stmt->name.str, stmt->name.length);
 
-  if (stmt->prepare(query.str, (uint) query.length))
+  bool res= stmt->prepare(query.str, (uint) query.length);
+  /*
+    stmt->prepare() sets thd->query_string with the prepared
+    query, so the audit plugin gets adequate notification with the
+    mysqld_stmt_* set of functions.
+    But here we should restore the original query so it's mentioned in
+    logs properly.
+  */
+  thd->set_query(orig_query);
+  if (res)
   {
     /* Statement map deletes the statement on erase */
     thd->stmt_map.erase(stmt);
@@ -2841,6 +2860,7 @@ void mysql_sql_stmt_prepare(THD *thd)
 void mysql_sql_stmt_execute_immediate(THD *thd)
 {
   LEX *lex= thd->lex;
+  CSET_STRING orig_query= thd->query_string;
   Prepared_statement *stmt;
   LEX_CSTRING query;
   DBUG_ENTER("mysql_sql_stmt_execute_immediate");
@@ -2889,6 +2909,14 @@ void mysql_sql_stmt_execute_immediate(THD *thd)
   thd->free_items();
   thd->free_list= free_list_backup;
 
+  /*
+    stmt->execute_immediately() sets thd->query_string with the executed
+    query, so the audit plugin gets adequate notification with the
+    mysqld_stmt_* set of functions.
+    But here we should restore the original query so it's mentioned in
+    logs properly.
+  */
+  thd->set_query_inner(orig_query);
   stmt->lex->restore_set_statement_var();
   delete stmt;
   DBUG_VOID_RETURN;
@@ -3205,6 +3233,13 @@ static void mysql_stmt_execute_common(THD *thd,
   if (!(stmt= find_prepared_statement(thd, stmt_id)))
   {
     char llbuf[22];
+    /*
+      Did not find the statement with the provided stmt_id.
+      Set thd->query_string with the stmt_id so the
+      audit plugin gets the meaningful notification.
+    */
+    if (alloc_query(thd, llbuf, strlen(llbuf)))
+      thd->set_query(0, 0);
     my_error(ER_UNKNOWN_STMT_HANDLER, MYF(0), static_cast<int>(sizeof(llbuf)),
              llstr(stmt_id, llbuf), "mysqld_stmt_execute");
     DBUG_VOID_RETURN;
@@ -3969,6 +4004,19 @@ bool Prepared_statement::prepare(const char *packet, uint packet_len)
     DBUG_RETURN(TRUE);
   }
 
+  /*
+    We'd like to have thd->query to be set to the actual query
+    after the function ends.
+    This value will be sent to audit plugins later.
+    As the statement is created, the query will be stored
+    in statement's arena. Normally the statement lives longer than
+    the end of this query, so we can just set thd->query_string to
+    be the stmt->query_string.
+    Though errors can result in statement to be freed. These cases
+    should be handled appropriately.
+  */
+  stmt_backup.query_string= thd->query_string;
+
   old_stmt_arena= thd->stmt_arena;
   thd->stmt_arena= this;
 
@@ -4504,6 +4552,15 @@ Prepared_statement::reprepare()
     */
     thd->get_stmt_da()->clear_warning_info(thd->query_id);
   }
+  else
+  {
+    /*
+       Prepare failed and the 'copy' will be freed.
+       Now we have to restore the query_string in the so the
+       audit plugin later gets the meaningful notification.
+    */
+    thd->set_query(query(), query_length());
+  }
   return error;
 }
 
@@ -5127,7 +5184,7 @@ class Protocol_local : public Protocol_text
 
   Protocol_local(THD *thd_arg, ulong prealloc= 0) :
     Protocol_text(thd_arg, prealloc),
-      cur_data(0), first_data(0), data_tail(&first_data)
+      cur_data(0), first_data(0), data_tail(&first_data), alloc(0)
     {}
  
 protected: