MDEV-19275 Provide SQL service to plugins.

Protocol_local fixed so it can be used now.
Some Protocol:: methods made virtual so they can adapt.
as well as net_ok and net_send_error functions.
execute_sql_string function is exported to the plugins.
To be changed with the mysql_use_result.

libmysqld/emb_qcache.cc

@@ -491,8 +491,8 @@ int emb_load_querycache_result(THD *thd, Querycache_stream *src)
   *prev_row= NULL;
   data->embedded_info->prev_ptr= prev_row;
 return_ok:
-  net_send_eof(thd, thd->server_status,
-               thd->get_stmt_da()->current_statement_warn_count());
+  thd->protocol->net_send_eof(thd, thd->server_status,
+    thd->get_stmt_da()->current_statement_warn_count());
   DBUG_RETURN(0);
 err:
   DBUG_RETURN(1);

libmysqld/emb_qcache.h

@@ -81,4 +81,3 @@ class Querycache_stream
 uint emb_count_querycache_size(THD *thd);
 int emb_load_querycache_result(THD *thd, Querycache_stream *src);
 void emb_store_querycache_result(Querycache_stream *dst, THD* thd);
-bool net_send_eof(THD *thd, uint server_status, uint total_warn_count);

libmysqld/lib_sql.cc

@@ -1139,7 +1139,7 @@ bool Protocol::send_result_set_metadata(List<Item> *list, uint flags)
 
   for (uint pos= 0 ; (item= it++); pos++)
   {
-    if (prot.store_field_metadata(thd, item, pos))
+    if (prot.store_item_metadata(thd, item, pos))
       goto err;
   }
 
@@ -1254,8 +1254,7 @@ bool Protocol_binary::write()
     @retval FALSE Success
 */
 
-bool
-net_send_ok(THD *thd,
+bool Protocol::net_send_ok(THD *thd,
             uint server_status, uint statement_warn_count,
             ulonglong affected_rows, ulonglong id, const char *message,
             bool, bool)
@@ -1290,16 +1289,16 @@ net_send_ok(THD *thd,
 */
 
 bool
-net_send_eof(THD *thd, uint server_status, uint statement_warn_count)
+Protocol::net_send_eof(THD *thd, uint server_status, uint statement_warn_count)
 {
   bool error= write_eof_packet(thd, server_status, statement_warn_count);
   thd->cur_data= 0;
   return error;
 }
 
 
-bool net_send_error_packet(THD *thd, uint sql_errno, const char *err,
-                           const char *sqlstate)
+bool Protocol::net_send_error_packet(THD *thd, uint sql_errno, const char *err,
+                                     const char *sqlstate)
 {
   uint error;
   char converted_err[MYSQL_ERRMSG_SIZE];

libmysqld/libmysql.c

@@ -1087,11 +1087,6 @@ unsigned int STDCALL mysql_field_count(MYSQL *mysql)
   return mysql->field_count;
 }
 
-my_ulonglong STDCALL mysql_affected_rows(MYSQL *mysql)
-{
-  return mysql->affected_rows;
-}
-
 my_ulonglong STDCALL mysql_insert_id(MYSQL *mysql)
 {
   return mysql->insert_id;

sql-common/client.c

@@ -3735,6 +3735,12 @@ static MYSQL_RES * cli_use_result(MYSQL *mysql)
 }
 
 
+my_ulonglong STDCALL mysql_affected_rows(MYSQL *mysql)
+{
+  return mysql->affected_rows;
+}
+
+
 /**************************************************************************
   Return next row of the query results
 **************************************************************************/

sql/mysqld.cc

@@ -2553,7 +2553,7 @@ void close_connection(THD *thd, uint sql_errno)
 
   if (sql_errno)
   {
-    net_send_error(thd, sql_errno, ER_DEFAULT(sql_errno), NULL);
+    thd->protocol->net_send_error(thd, sql_errno, ER_DEFAULT(sql_errno), NULL);
     thd->print_aborted_warning(lvl, ER_DEFAULT(sql_errno));
   }
   else

sql/protocol.cc

@@ -32,13 +32,6 @@
 #include <stdarg.h>
 
 static const unsigned int PACKET_BUFFER_EXTRA_ALLOC= 1024;
-/* Declared non-static only because of the embedded library. */
-bool net_send_error_packet(THD *, uint, const char *, const char *);
-/* Declared non-static only because of the embedded library. */
-bool net_send_ok(THD *, uint, uint, ulonglong, ulonglong, const char *,
-                 bool, bool);
-/* Declared non-static only because of the embedded library. */
-bool net_send_eof(THD *thd, uint server_status, uint statement_warn_count);
 #ifndef EMBEDDED_LIBRARY
 static bool write_eof_packet(THD *, NET *, uint, uint);
 #endif
@@ -152,11 +145,11 @@ bool Protocol_binary::net_store_data_cs(const uchar *from, size_t length,
     @retval TRUE An error occurred and the message wasn't sent properly
 */
 
-bool net_send_error(THD *thd, uint sql_errno, const char *err,
-                    const char* sqlstate)
+bool Protocol::net_send_error(THD *thd, uint sql_errno, const char *err,
+                              const char* sqlstate)
 {
   bool error;
-  DBUG_ENTER("net_send_error");
+  DBUG_ENTER("Protocol::net_send_error");
 
   DBUG_ASSERT(!thd->spcont);
   DBUG_ASSERT(sql_errno);
@@ -214,19 +207,19 @@ bool net_send_error(THD *thd, uint sql_errno, const char *err,
 
 #ifndef EMBEDDED_LIBRARY
 bool
-net_send_ok(THD *thd,
-            uint server_status, uint statement_warn_count,
-            ulonglong affected_rows, ulonglong id, const char *message,
-            bool is_eof,
-            bool skip_flush)
+Protocol::net_send_ok(THD *thd,
+                      uint server_status, uint statement_warn_count,
+                      ulonglong affected_rows, ulonglong id,
+                      const char *message, bool is_eof,
+                      bool skip_flush)
 {
   NET *net= &thd->net;
   StringBuffer<MYSQL_ERRMSG_SIZE + 10> store;
 
   bool state_changed= false;
 
   bool error= FALSE;
-  DBUG_ENTER("net_send_ok");
+  DBUG_ENTER("Protocol::net_send_ok");
 
   if (! net->vio)	// hack for re-parsing queries
   {
@@ -329,11 +322,11 @@ static uchar eof_buff[1]= { (uchar) 254 };      /* Marker for end of fields */
 */    
 
 bool
-net_send_eof(THD *thd, uint server_status, uint statement_warn_count)
+Protocol::net_send_eof(THD *thd, uint server_status, uint statement_warn_count)
 {
   NET *net= &thd->net;
   bool error= FALSE;
-  DBUG_ENTER("net_send_eof");
+  DBUG_ENTER("Protocol::net_send_eof");
 
   /*
     Check if client understand new format packets (OK instead of EOF)
@@ -420,8 +413,8 @@ static bool write_eof_packet(THD *thd, NET *net,
    @retval TRUE  An error occurred and the messages wasn't sent properly
 */
 
-bool net_send_error_packet(THD *thd, uint sql_errno, const char *err,
-                           const char* sqlstate)
+bool Protocol::net_send_error_packet(THD *thd, uint sql_errno, const char *err,
+                                     const char* sqlstate)
 
 {
   NET *net= &thd->net;
@@ -434,7 +427,7 @@ bool net_send_error_packet(THD *thd, uint sql_errno, const char *err,
   char buff[2+1+SQLSTATE_LENGTH+MYSQL_ERRMSG_SIZE], *pos;
   my_bool ret;
   uint8 save_compress;
-  DBUG_ENTER("send_error_packet");
+  DBUG_ENTER("Protocol::send_error_packet");
 
   if (net->vio == 0)
   {
@@ -963,7 +956,7 @@ bool Protocol::send_result_set_metadata(List<Item> *list, uint flags)
   for (uint pos= 0; (item=it++); pos++)
   {
     prot.prepare_for_resend();
-    if (prot.store_field_metadata(thd, item, pos))
+    if (prot.store_item_metadata(thd, item, pos))
       goto err;
     if (prot.write())
       DBUG_RETURN(1);
@@ -1043,7 +1036,7 @@ bool Protocol::write()
 #endif /* EMBEDDED_LIBRARY */
 
 
-bool Protocol_text::store_field_metadata(THD *thd, Item *item, uint pos)
+bool Protocol_text::store_item_metadata(THD *thd, Item *item, uint pos)
 {
   Send_field field(thd, item);
   return store_field_metadata(thd, field, item->charset_for_protocol(), pos);

sql/protocol.h

@@ -50,14 +50,13 @@ class Protocol
   }
 #endif
   uint field_count;
-#ifndef EMBEDDED_LIBRARY
-  bool net_store_data(const uchar *from, size_t length);
-  bool net_store_data_cs(const uchar *from, size_t length,
-                      CHARSET_INFO *fromcs, CHARSET_INFO *tocs);
-#else
   virtual bool net_store_data(const uchar *from, size_t length);
   virtual bool net_store_data_cs(const uchar *from, size_t length,
                       CHARSET_INFO *fromcs, CHARSET_INFO *tocs);
+  virtual bool net_send_ok(THD *, uint, uint, ulonglong, ulonglong, const char *,
+                           bool, bool);
+  virtual bool net_send_error_packet(THD *, uint, const char *, const char *);
+#ifdef EMBEDDED_LIBRARY
   char **next_field;
   MYSQL_FIELD *next_mysql_field;
   MEM_ROOT *alloc;
@@ -181,6 +180,9 @@ class Protocol
   };
   virtual enum enum_protocol_type type()= 0;
 
+  virtual bool net_send_eof(THD *thd, uint server_status, uint statement_warn_count);
+  bool net_send_error(THD *thd, uint sql_errno, const char *err,
+                      const char* sqlstate);
   void end_statement();
 
   friend int send_answer_1(Protocol *protocol, String *s1, String *s2,
@@ -191,7 +193,7 @@ class Protocol
 
 /** Class used for the old (MySQL 4.0 protocol). */
 
-class Protocol_text final :public Protocol
+class Protocol_text :public Protocol
 {
   StringBuffer<FLOATING_POINT_BUFFER> buffer;
   bool store_numeric_string_aux(const char *from, size_t length);
@@ -226,10 +228,10 @@ class Protocol_text final :public Protocol
 #ifdef EMBEDDED_LIBRARY
   void remove_last_row() override;
 #endif
-  bool store_field_metadata(const THD *thd, const Send_field &field,
-                            CHARSET_INFO *charset_for_protocol,
-                            uint pos);
-  bool store_field_metadata(THD *thd, Item *item, uint pos);
+  virtual bool store_field_metadata(const THD *thd, const Send_field &field,
+                                    CHARSET_INFO *charset_for_protocol,
+                                    uint pos);
+  bool store_item_metadata(THD *thd, Item *item, uint pos);
   bool store_field_metadata_for_list_fields(const THD *thd, Field *field,
                                             const TABLE_LIST *table_list,
                                             uint pos);
@@ -321,8 +323,6 @@ class Protocol_discard final : public Protocol
 
 
 void send_warning(THD *thd, uint sql_errno, const char *err=0);
-bool net_send_error(THD *thd, uint sql_errno, const char *err,
-                    const char* sqlstate);
 void net_send_progress_packet(THD *thd);
 uchar *net_store_data(uchar *to,const uchar *from, size_t length);
 uchar *net_store_data(uchar *to,int32 from);

sql/sql_audit.h

@@ -254,35 +254,36 @@ void mysql_audit_notify_connection_disconnect(THD *thd, int errcode)
 }
 
 static inline
-void mysql_audit_notify_connection_change_user(THD *thd)
+void mysql_audit_notify_connection_change_user(THD *thd,
+                                               const Security_context *old_ctx)
 {
   if (mysql_audit_connection_enabled())
   {
-    const Security_context *sctx= thd->security_ctx;
     mysql_event_connection event;
 
     event.event_subclass= MYSQL_AUDIT_CONNECTION_CHANGE_USER;
     event.status= thd->get_stmt_da()->is_error() ?
                   thd->get_stmt_da()->sql_errno() : 0;
     event.thread_id= (unsigned long)thd->thread_id;
-    event.user= sctx->user;
-    event.user_length= safe_strlen_uint(sctx->user);
-    event.priv_user= sctx->priv_user;
-    event.priv_user_length= strlen_uint(sctx->priv_user);
-    event.external_user= sctx->external_user;
-    event.external_user_length= safe_strlen_uint(sctx->external_user);
-    event.proxy_user= sctx->proxy_user;
-    event.proxy_user_length= strlen_uint(sctx->proxy_user);
-    event.host= sctx->host;
-    event.host_length= safe_strlen_uint(sctx->host);
-    event.ip= sctx->ip;
-    event.ip_length= safe_strlen_uint(sctx->ip);
+    event.user= old_ctx->user;
+    event.user_length= safe_strlen_uint(old_ctx->user);
+    event.priv_user= old_ctx->priv_user;
+    event.priv_user_length= strlen_uint(old_ctx->priv_user);
+    event.external_user= old_ctx->external_user;
+    event.external_user_length= safe_strlen_uint(old_ctx->external_user);
+    event.proxy_user= old_ctx->proxy_user;
+    event.proxy_user_length= strlen_uint(old_ctx->proxy_user);
+    event.host= old_ctx->host;
+    event.host_length= safe_strlen_uint(old_ctx->host);
+    event.ip= old_ctx->ip;
+    event.ip_length= safe_strlen_uint(old_ctx->ip);
     event.database= thd->db;
 
     mysql_audit_notify(thd, MYSQL_AUDIT_CONNECTION_CLASS, &event);
   }
 }
 
+
 static inline
 void mysql_audit_external_lock_ex(THD *thd, my_thread_id thread_id,
     const char *user, const char *host, const char *ip, query_id_t query_id,

sql/sql_class.cc

@@ -348,6 +348,12 @@ void thd_clear_errors(THD *thd)
 }
 
 
+extern "C" unsigned long long thd_query_id(const MYSQL_THD thd)
+{
+  return((unsigned long long)thd->query_id);
+}
+
+
 /**
   Get thread attributes for connection threads
 
@@ -4983,6 +4989,55 @@ extern "C" size_t thd_query_safe(MYSQL_THD thd, char *buf, size_t buflen)
 }
 
 
+extern "C" const char *thd_user_name(MYSQL_THD thd)
+{
+  if (!thd->security_ctx)
+    return 0;
+
+  return thd->security_ctx->user;
+}
+
+
+extern "C" const char *thd_client_host(MYSQL_THD thd)
+{
+  if (!thd->security_ctx)
+    return 0;
+
+  return thd->security_ctx->host;
+}
+
+
+extern "C" const char *thd_client_ip(MYSQL_THD thd)
+{
+  if (!thd->security_ctx)
+    return 0;
+
+  return thd->security_ctx->ip;
+}
+
+
+extern "C" LEX_CSTRING *thd_current_db(MYSQL_THD thd)
+{
+  return &thd->db;
+}
+
+
+extern "C" int thd_current_status(MYSQL_THD thd)
+{
+  Diagnostics_area *da= thd->get_stmt_da();
+  if (!da)
+    return 0;
+
+  return da->is_error() ? da->sql_errno() : 0;
+}
+
+
+extern "C" enum enum_server_command thd_current_command(MYSQL_THD thd)
+{
+  return thd->get_command();
+}
+
+
 extern "C" int thd_slave_thread(const MYSQL_THD thd)
 {
   return(thd->slave_thread);

sql/sql_class.h

@@ -195,7 +195,14 @@ extern char empty_c_string[1];
 extern MYSQL_PLUGIN_IMPORT const char **errmesg;
 
 extern "C" LEX_STRING * thd_query_string (MYSQL_THD thd);
+extern "C" unsigned long long thd_query_id(const MYSQL_THD thd);
 extern "C" size_t thd_query_safe(MYSQL_THD thd, char *buf, size_t buflen);
+extern "C" const char *thd_user_name(MYSQL_THD thd);
+extern "C" const char *thd_client_host(MYSQL_THD thd);
+extern "C" const char *thd_client_ip(MYSQL_THD thd);
+extern "C" LEX_CSTRING *thd_current_db(MYSQL_THD thd);
+extern "C" int thd_current_status(MYSQL_THD thd);
+extern "C" enum enum_server_command thd_current_command(MYSQL_THD thd);
 
 /**
   @class CSET_STRING