src/backend/utils/misc/superuser.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * superuser.c
   4  *        The superuser() function.  Determines if user has superuser privilege.
   5  *        Also, a function to check for the owner (datdba) of a database.
   6  *
   7  *
   8  * Portions Copyright (c) 1996-2004, PostgreSQL Global Development Group
   9  * Portions Copyright (c) 1994, Regents of the University of California
  10  *
  11  *
  12  * IDENTIFICATION
  13  *        $PostgreSQL: pgsql/src/backend/utils/misc/superuser.c,v 1.29 2004/08/29 04:13:00 momjian Exp $
  14  *
  15  *-------------------------------------------------------------------------
  16  */
  17 #include "postgres.h"
  18
  19 #include "access/heapam.h"
  20 #include "catalog/pg_shadow.h"
  21 #include "commands/dbcommands.h"
  22 #include "utils/syscache.h"
  23 #include "miscadmin.h"
  24
  25
  26 /*
  27  * The Postgres user running this command has Postgres superuser privileges
  28  *
  29  * All code should use either of these two functions to find out
  30  * whether a given user is a superuser, rather than evaluating
  31  * pg_shadow.usesuper directly, so that the escape hatch built in for
  32  * the single-user case works.
  33  */
  34 bool
  35 superuser(void)
  36 {
  37         return superuser_arg(GetUserId());
  38 }
  39
  40
  41 bool
  42 superuser_arg(AclId userid)
  43 {
  44         bool            result = false;
  45         HeapTuple       utup;
  46
  47         /* Special escape path in case you deleted all your users. */
  48         if (!IsUnderPostmaster && userid == BOOTSTRAP_USESYSID)
  49                 return true;
  50
  51         utup = SearchSysCache(SHADOWSYSID,
  52                                                   Int32GetDatum(userid),
  53                                                   0, 0, 0);
  54         if (HeapTupleIsValid(utup))
  55         {
  56                 result = ((Form_pg_shadow) GETSTRUCT(utup))->usesuper;
  57                 ReleaseSysCache(utup);
  58         }
  59         return result;
  60 }