Bug#14635: Accept NEW.x as INOUT parameters to stored procedures

from within triggers

Add support for passing NEW.x as INOUT and OUT parameters to stored
procedures.  Passing NEW.x as INOUT parameter requires SELECT and
UPDATE privileges on that column, and passing it as OUT parameter
requires only UPDATE privilege.


mysql-test/r/sp-error.result:
  Update the result for new message.
mysql-test/r/trigger-grant.result:
  Add result for bug#14635.
mysql-test/r/trigger.result:
  Add result for bug#14635.
mysql-test/t/trigger-grant.test:
  Add test case for bug#14635.
mysql-test/t/trigger.test:
  Add test case for bug#14635.
sql/item.cc:
  Add implementations of set_value() and set_required_privilege() methods
  of Settable_routine_parameter interface.
  
  Use Item_trigger_field::want_privilege instead of
  Item_trigger_field::access_type.
  
  Reset privileges on Item_trigger_field::cleanup().
sql/item.h:
  Add interface class Settable_routine_parameter and interface query
  method to Item class.  Item_splocal and Item_trigger_field implement
  this interface.
  
  For Item_trigger_field:
   - add read_only attribute and is_read_only() method.
   - remove access_type and add original_privilege and want_privilege
     instead.
   - add set_value() method.
   - add reset_privilege() method.
sql/item_func.cc:
  Add implementations of set_value() method of Settable_routine_parameter
  interface.
sql/item_func.h:
  Item_func_get_user_var implements Settable_routine_parameter interface.
sql/share/errmsg.txt:
  Update english ER_SP_NOT_VAR_ARG message.
sql/sp_head.cc:
  Use Settable_routine_parameter interface for parameter update.
sql/sql_yacc.yy:
  Set read_only and want_privilege members in Item_trigger_field
  appropriately.  For NEW.x trigger variable used in left-hand-side
  of SET statement the latter is set to UPDATE_ACL, otherwise it is
  set to SELECT_ACL (but see Item_trigger_field::set_required_privilege(),
  where it may be updated to different value).

1 files changed, 93 insertions, 8 deletions

diff --git a/sql/item.h b/sql/item.h
index 24aca4a86d1..617690e1fd9 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -372,6 +372,42 @@ public:
 
 /*************************************************************************/
 
+class sp_rcontext;
+
+
+class Settable_routine_parameter
+{
+public:
+  /*
+    Set required privileges for accessing the parameter.
+
+    SYNOPSIS
+      set_required_privilege()
+        rw        if 'rw' is true then we are going to read and set the
+                  parameter, so SELECT and UPDATE privileges might be
+                  required, otherwise we only reading it and SELECT
+                  privilege might be required.
+  */
+  virtual void set_required_privilege(bool rw) {};
+
+  /*
+    Set parameter value.
+
+    SYNOPSIS
+      set_value()
+        thd       thread handle
+        ctx       context to which parameter belongs (if it is local
+                  variable).
+        it        item which represents new value
+
+    RETURN
+      FALSE if parameter value has been set,
+      TRUE if error has occured.
+  */
+  virtual bool set_value(THD *thd, sp_rcontext *ctx, Item *it)= 0;
+};
+
+
 typedef bool (Item::*Item_processor)(byte *arg);
 typedef Item* (Item::*Item_transformer) (byte *arg);
 typedef void (*Cond_traverser) (const Item *item, void *arg);
@@ -744,6 +780,15 @@ public:
   }
 
   virtual bool is_splocal() { return 0; } /* Needed for error checking */
+
+  /*
+    Return Settable_routine_parameter interface of the Item.  Return 0
+    if this Item is not Settable_routine_parameter.
+  */
+  virtual Settable_routine_parameter *get_settable_routine_parameter()
+  {
+    return 0;
+  }
 };
 
 
@@ -842,7 +887,8 @@ inline bool Item_sp_variable::send(Protocol *protocol, String *str)
   runtime.
 *****************************************************************************/
 
-class Item_splocal :public Item_sp_variable
+class Item_splocal :public Item_sp_variable,
+                    private Settable_routine_parameter
 {
   uint m_var_idx;
 
@@ -880,6 +926,15 @@ public:
 
   inline enum Type type() const;
   inline Item_result result_type() const;
+
+private:
+  bool set_value(THD *thd, sp_rcontext *ctx, Item *it);
+
+public:
+  Settable_routine_parameter *get_settable_routine_parameter()
+  {
+    return this;
+  }
 };
 
 /*****************************************************************************
@@ -2100,14 +2155,13 @@ class Table_triggers_list;
         two Field instances representing either OLD or NEW version of this
         field.
 */
-class Item_trigger_field : public Item_field
+class Item_trigger_field : public Item_field,
+                           private Settable_routine_parameter
 {
 public:
   /* Is this item represents row from NEW or OLD row ? */
   enum row_version_type {OLD_ROW, NEW_ROW};
   row_version_type row_version;
-  /* Is this item used for reading or updating the value? */
-  enum access_types { AT_READ = 0x1, AT_UPDATE = 0x2 };
   /* Next in list of all Item_trigger_field's in trigger */
   Item_trigger_field *next_trg_field;
   /* Index of the field in the TABLE::field array */
@@ -2118,11 +2172,11 @@ public:
   Item_trigger_field(Name_resolution_context *context_arg,
                      row_version_type row_ver_arg,
                      const char *field_name_arg,
-                     access_types access_type_arg)
+                     ulong priv, const bool ro)
     :Item_field(context_arg,
                (const char *)NULL, (const char *)NULL, field_name_arg),
-     row_version(row_ver_arg), field_idx((uint)-1),
-     access_type(access_type_arg), table_grants(NULL)
+     row_version(row_ver_arg), field_idx((uint)-1), original_privilege(priv),
+     want_privilege(priv), table_grants(NULL), read_only (ro)
   {}
   void setup_field(THD *thd, TABLE *table, GRANT_INFO *table_grant_info);
   enum Type type() const { return TRIGGER_FIELD_ITEM; }
@@ -2133,8 +2187,39 @@ public:
   void cleanup();
 
 private:
-  access_types access_type;
+  void set_required_privilege(const bool rw);
+  bool set_value(THD *thd, sp_rcontext *ctx, Item *it);
+
+public:
+  Settable_routine_parameter *get_settable_routine_parameter()
+  {
+    return (read_only ? 0 : this);
+  }
+
+  bool set_value(THD *thd, Item *it)
+  {
+    return set_value(thd, NULL, it);
+  }
+
+private:
+  /*
+    'want_privilege' holds privileges required to perform operation on
+    this trigger field (SELECT_ACL if we are going to read it and
+    UPDATE_ACL if we are going to update it).  It is initialized at
+    parse time but can be updated later if this trigger field is used
+    as OUT or INOUT parameter of stored routine (in this case
+    set_required_privilege() is called to appropriately update
+    want_privilege and cleanup() is responsible for restoring of
+    original want_privilege once parameter's value is updated).
+  */
+  ulong original_privilege;
+  ulong want_privilege;
   GRANT_INFO *table_grants;
+  /*
+    Trigger field is read-only unless it belongs to the NEW row in a
+    BEFORE INSERT of BEFORE UPDATE trigger.
+  */
+  bool read_only;
 };