X-Git-Url: https://granicus.if.org/sourcecode?a=blobdiff_plain;f=src%2Fbackend%2Futils%2Fmisc%2Fsuperuser.c;h=fdaa99e1f81a8e4ba04ce2b8f32c844a619949bf;hb=ee33b95d9c2ecec170bc517783d7268a4bd0c793;hp=5848b444199aa63c6f20e03cd9201172a74f8fd7;hpb=44fbe20d620d4f2e39aaa9896de4683e55b0d317;p=postgresql

diff --git a/src/backend/utils/misc/superuser.c b/src/backend/utils/misc/superuser.c
index 5848b44419..fdaa99e1f8 100644
--- a/src/backend/utils/misc/superuser.c
+++ b/src/backend/utils/misc/superuser.c
@@ -2,36 +2,45 @@
  *
  * superuser.c
  *	  The superuser() function.  Determines if user has superuser privilege.
- *	  Also, a function to check for the owner (datdba) of a database.
  *
+ * All code should use either of these two functions to find out
+ * whether a given user is a superuser, rather than examining
+ * pg_authid.rolsuper directly, so that the escape hatch built in for
+ * the single-user case works.
  *
- * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
+ *
+ * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/misc/superuser.c,v 1.22 2002/05/20 23:51:43 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/misc/superuser.c,v 1.38 2008/09/09 18:58:08 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
 
-#include "access/heapam.h"
-#include "catalog/catname.h"
-#include "catalog/pg_database.h"
-#include "catalog/pg_shadow.h"
+#include "catalog/pg_authid.h"
+#include "utils/inval.h"
 #include "utils/syscache.h"
 #include "miscadmin.h"
-#include "utils/fmgroids.h"
+
+
+/*
+ * In common cases the same roleid (ie, the session or current ID) will
+ * be queried repeatedly.  So we maintain a simple one-entry cache for
+ * the status of the last requested roleid.  The cache can be flushed
+ * at need by watching for cache update events on pg_authid.
+ */
+static Oid	last_roleid = InvalidOid;	/* InvalidOid == cache not valid */
+static bool last_roleid_is_super = false;
+static bool roleid_callback_registered = false;
+
+static void RoleidCallback(Datum arg, int cacheid, ItemPointer tuplePtr);
 
 
 /*
  * The Postgres user running this command has Postgres superuser privileges
- *
- * All code should use either of these two functions to find out
- * whether a given user is a superuser, rather than evaluating
- * pg_shadow.usesuper directly, so that the escape hatch built in for
- * the single-user case works.
  */
 bool
 superuser(void)
@@ -40,54 +49,61 @@ superuser(void)
 }
 
 
+/*
+ * The specified role has Postgres superuser privileges
+ */
 bool
-superuser_arg(Oid userid)
+superuser_arg(Oid roleid)
 {
-	bool		result = false;
-	HeapTuple	utup;
+	bool		result;
+	HeapTuple	rtup;
+
+	/* Quick out for cache hit */
+	if (OidIsValid(last_roleid) && last_roleid == roleid)
+		return last_roleid_is_super;
 
 	/* Special escape path in case you deleted all your users. */
-	if (!IsUnderPostmaster && userid == BOOTSTRAP_USESYSID)
+	if (!IsUnderPostmaster && roleid == BOOTSTRAP_SUPERUSERID)
 		return true;
 
-	utup = SearchSysCache(SHADOWSYSID,
-						  ObjectIdGetDatum(userid),
+	/* OK, look up the information in pg_authid */
+	rtup = SearchSysCache(AUTHOID,
+						  ObjectIdGetDatum(roleid),
 						  0, 0, 0);
-	if (HeapTupleIsValid(utup))
+	if (HeapTupleIsValid(rtup))
+	{
+		result = ((Form_pg_authid) GETSTRUCT(rtup))->rolsuper;
+		ReleaseSysCache(rtup);
+	}
+	else
+	{
+		/* Report "not superuser" for invalid roleids */
+		result = false;
+	}
+
+	/* If first time through, set up callback for cache flushes */
+	if (!roleid_callback_registered)
 	{
-		result = ((Form_pg_shadow) GETSTRUCT(utup))->usesuper;
-		ReleaseSysCache(utup);
+		CacheRegisterSyscacheCallback(AUTHOID,
+									  RoleidCallback,
+									  (Datum) 0);
+		roleid_callback_registered = true;
 	}
+
+	/* Cache the result for next time */
+	last_roleid = roleid;
+	last_roleid_is_super = result;
+
 	return result;
 }
 
-
 /*
- * The Postgres user running this command is the owner of the specified
- * database.
+ * UseridCallback
+ *		Syscache inval callback function
  */
-bool
-is_dbadmin(Oid dbid)
+static void
+RoleidCallback(Datum arg, int cacheid, ItemPointer tuplePtr)
 {
-	Relation	pg_database;
-	ScanKeyData entry[1];
-	HeapScanDesc scan;
-	HeapTuple	dbtuple;
-	int32		dba;
-
-	/* There's no syscache for pg_database, so must look the hard way */
-	pg_database = heap_openr(DatabaseRelationName, AccessShareLock);
-	ScanKeyEntryInitialize(&entry[0], 0x0,
-						   ObjectIdAttributeNumber, F_OIDEQ,
-						   ObjectIdGetDatum(dbid));
-	scan = heap_beginscan(pg_database, SnapshotNow, 1, entry);
-	dbtuple = heap_getnext(scan, ForwardScanDirection);
-	if (!HeapTupleIsValid(dbtuple))
-		elog(ERROR, "database %u does not exist", dbid);
-	dba = ((Form_pg_database) GETSTRUCT(dbtuple))->datdba;
-	heap_endscan(scan);
-	heap_close(pg_database, AccessShareLock);
-
-	/* XXX some confusion about whether userids are OID or int4 ... */
-	return (GetUserId() == (Oid) dba);
+	/* Invalidate our local cache in case role's superuserness changed */
+	last_roleid = InvalidOid;
 }