From: Dan McGuirk <mcguirk@indirect.com>

Subject: [HACKERS] better access control error messages

This patch replaces the 'no such class or insufficient privilege' with
distinct error messages that tell you whether the table really doesn't
exist or whether access was denied.

Author: scrappy

src/backend/commands/copy.c

@@ -6,7 +6,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.21 1997/01/10 17:46:33 momjian Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.22 1997/03/12 20:47:32 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -102,13 +102,15 @@ DoCopy(char *relname, bool binary, bool oids, bool from, bool pipe,
     Relation rel;
     extern char *UserName;    /* defined in global.c */
     const AclMode required_access = from ? ACL_WR : ACL_RD;
+    int result;
 
     rel = heap_openr(relname);
     if (rel == NULL) elog(WARN, "COPY command failed.  Class %s "
                           "does not exist.", relname);
-    
-    if (!pg_aclcheck(relname, UserName, required_access))
-        elog(WARN, "%s %s", relname, ACL_NO_PRIV_WARNING);
+
+    result = pg_aclcheck(relname, UserName, required_access);
+    if(result != ACLCHECK_OK)
+        elog(WARN, "%s: %s", relname, aclcheck_error_strings[result]);
         /* Above should not return */
     else if (!superuser() && !pipe)
         elog(WARN, "You must have Postgres superuser privilege to do a COPY "

src/backend/executor/execMain.c

@@ -26,7 +26,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.10 1997/01/22 05:26:27 vadim Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.11 1997/03/12 20:47:41 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -289,7 +289,7 @@ ExecCheckPerms(CmdType operation,
     HeapTuple htp;
     List *lp;
     List *qvars, *tvars;
-    int32 ok = 1;
+    int32 ok = 1, aclcheck_result = -1;
     char *opstr;
     NameData rname;
     char *userName;
@@ -317,21 +317,21 @@ ExecCheckPerms(CmdType operation,
 	    if (intMember(resultRelation, qvars) ||
 		intMember(resultRelation, tvars)) {
 		/* result relation is scanned */
-		ok = CHECK(ACL_RD);
+		ok = ((aclcheck_result = CHECK(ACL_RD)) == ACLCHECK_OK);
 		opstr = "read";
 		if (!ok)
 		    break;
 	    }
 	    switch (operation) {
 	    case CMD_INSERT:
-		ok = CHECK(ACL_AP) ||
-		    CHECK(ACL_WR);
+		ok = ((aclcheck_result = CHECK(ACL_AP)) == ACLCHECK_OK) ||
+		     ((aclcheck_result = CHECK(ACL_WR)) == ACLCHECK_OK);
 		opstr = "append";
 		break;
 	    case CMD_NOTIFY: /* what does this mean?? -- jw, 1/6/94 */
 	    case CMD_DELETE:
 	    case CMD_UPDATE:
-		ok = CHECK(ACL_WR);
+		ok = ((aclcheck_result = CHECK(ACL_WR)) == ACLCHECK_OK);
 		opstr = "write";
 		break;
 	    default:
@@ -340,7 +340,7 @@ ExecCheckPerms(CmdType operation,
 	    }
 	} else {
 	    /* XXX NOTIFY?? */
-	    ok = CHECK(ACL_RD);
+	    ok = ((aclcheck_result = CHECK(ACL_RD)) == ACLCHECK_OK);
 	    opstr = "read";
 	}
 	if (!ok)
@@ -352,7 +352,7 @@ ExecCheckPerms(CmdType operation,
 	elog(WARN, "%s on \"%-.*s\": permission denied", opstr, 
 	     NAMEDATALEN, rname.data);
 */	    
-	elog(WARN, "%s %s", rname.data, ACL_NO_PRIV_WARNING);
+	elog(WARN, "%s: %s", rname.data, aclcheck_error_strings[aclcheck_result]);
     }
 }
 

src/backend/parser/parse_query.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/parser/Attic/parse_query.c,v 1.14 1997/02/14 23:02:29 momjian Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/parser/Attic/parse_query.c,v 1.15 1997/03/12 20:47:57 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -133,7 +133,7 @@ addRangeTableEntry(ParseState *pstate,
     relation = heap_openr(relname);
     if (relation == NULL) {
 	elog(WARN,"%s: %s",
-	     relname, ACL_NO_PRIV_WARNING);
+	     relname, aclcheck_error_strings[ACLCHECK_NO_CLASS]);
     }
 
     /*

src/backend/tcop/aclchk.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/tcop/Attic/aclchk.c,v 1.6 1997/01/23 19:33:31 scrappy Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/tcop/Attic/aclchk.c,v 1.7 1997/03/12 20:48:17 scrappy Exp $
  *
  * NOTES
  *    See acl.h.
@@ -17,7 +17,7 @@
 #include <string.h>
 #include "postgres.h"
 
-#include "utils/acl.h"		/* where declarations for this file goes */
+#include "utils/acl.h"		/* where declarations for this file go */
 #include "access/heapam.h"
 #include "access/htup.h"
 #include "access/tupmacs.h"
@@ -55,6 +55,15 @@
 #define	Name_pg_group			"pggroup"
 #endif
 
+/* warning messages, now more explicit. */
+/* should correspond to the order of the ACLCHK_* result codes above. */
+char *aclcheck_error_strings[] = {
+  "No error.",
+  "Permission denied.",
+  "Table does not exist.",
+  "Must be table owner."
+};
+
 #ifdef ACLDEBUG_TRACE
 static
 dumpacl(Acl *acl)
@@ -268,10 +277,10 @@ aclcheck(Acl *acl, AclId id, AclIdType idtype, AclMode mode)
      * the system never creates an empty ACL.
      */
     if (num < 1) {
-#ifdef ACLDEBUG_TRACE
+#ifdef ACLDEBUG_TRACE || 1
 	elog(DEBUG, "aclcheck: zero-length ACL, returning 1");
 #endif
-	return(1);
+	return ACLCHECK_OK;
     }
 
     switch (idtype) {
@@ -284,7 +293,7 @@ aclcheck(Acl *acl, AclId id, AclIdType idtype, AclMode mode)
 		elog(DEBUG, "aclcheck: found %d/%d",
 		     aip->ai_id, aip->ai_mode);
 #endif
-		return((aip->ai_mode & mode) ? 1 : 0);
+		return((aip->ai_mode & mode) ? ACLCHECK_OK : ACLCHECK_NO_PRIV);
 	    }
 	}
 	for (found_group = 0;
@@ -304,7 +313,7 @@ aclcheck(Acl *acl, AclId id, AclIdType idtype, AclMode mode)
 		    elog(DEBUG, "aclcheck: found %d/%d",
 			 aip->ai_id, aip->ai_mode);
 #endif
-		    return(0);
+		    return ACLCHECK_NO_PRIV;
 		}
 #endif
 	    }
@@ -313,7 +322,7 @@ aclcheck(Acl *acl, AclId id, AclIdType idtype, AclMode mode)
 #ifdef ACLDEBUG_TRACE
 	    elog(DEBUG,"aclcheck: all groups ok");
 #endif
-	    return(1);
+	    return ACLCHECK_OK;
 	}
 	break;
     case ACL_IDTYPE_GID:
@@ -329,7 +338,7 @@ aclcheck(Acl *acl, AclId id, AclIdType idtype, AclMode mode)
 		elog(DEBUG, "aclcheck: found %d/%d",
 		     aip->ai_id, aip->ai_mode);
 #endif
-		return((aip->ai_mode & mode) ? 1 : 0);
+		return((aip->ai_mode & mode) ? ACLCHECK_OK : ACLCHECK_NO_PRIV);
 	    }
 	}
 	break;
@@ -343,7 +352,7 @@ aclcheck(Acl *acl, AclId id, AclIdType idtype, AclMode mode)
 #ifdef ACLDEBUG_TRACE
     elog(DEBUG, "aclcheck: using world=%d", aidat->ai_mode);
 #endif
-    return((aidat->ai_mode & mode) ? 1 : 0);
+    return((aidat->ai_mode & mode) ? ACLCHECK_OK : ACLCHECK_NO_PRIV);
 }
 
 int32
@@ -370,7 +379,7 @@ pg_aclcheck(char *relname, char *usename, AclMode mode)
 	   pg_database table, there is still additional permissions checking
 	   in dbcommands.c */
 	if (mode & ACL_AP)
-	    return (1);
+	    return ACLCHECK_OK;
     }
 
     /*
@@ -383,7 +392,7 @@ pg_aclcheck(char *relname, char *usename, AclMode mode)
 	!((Form_pg_user) GETSTRUCT(htp))->usecatupd) {
 	elog(DEBUG, "pg_aclcheck: catalog update to \"%-.*s\": permission denied",
 	     NAMEDATALEN, relname);
-	return(0);
+	return ACLCHECK_NO_PRIV;
     }
 
     /*
@@ -394,7 +403,7 @@ pg_aclcheck(char *relname, char *usename, AclMode mode)
 	elog(DEBUG, "pg_aclcheck: \"%-.*s\" is superuser",
 	     NAMEDATALEN, usename);
 #endif
-	return(1);
+	return ACLCHECK_OK;
     }
 
 #ifndef ACLDEBUG
@@ -403,7 +412,7 @@ pg_aclcheck(char *relname, char *usename, AclMode mode)
     if (!HeapTupleIsValid(htp)) {
 	elog(WARN, "pg_aclcheck: class \"%-.*s\" not found",
 	     NAMEDATALEN, relname);
-	return(1);
+	/* an elog(WARN) kills us, so no need to return anything. */
     }
     if (!heap_attisnull(htp, Anum_pg_class_relacl)) {
 	relation = heap_openr(RelationRelationName);
@@ -436,7 +445,7 @@ pg_aclcheck(char *relname, char *usename, AclMode mode)
 	if (!RelationIsValid(relation)) {
 	    elog(NOTICE, "pg_checkacl: could not open \"%-.*s\"??",
 		 RelationRelationName);
-	    return(1);
+	    return ACLCHECK_NO_CLASS;
 	}
 	fmgr_info(NameEqualRegProcedure,
 		  &relkey[0].sk_func,
@@ -494,8 +503,8 @@ pg_ownercheck(char *usename,
     switch (cacheid) {
     case OPROID:
 	if (!HeapTupleIsValid(htp))
-	    elog(WARN, "pg_ownercheck: operator %d not found",
-		 (int) value);
+	    elog(WARN, "pg_ownercheck: operator %ld not found",
+		 PointerGetDatum(value));
 	owner_id = ((OperatorTupleForm) GETSTRUCT(htp))->oprowner;
 	break;
     case PRONAME:

src/backend/tcop/utility.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.11 1997/01/16 14:56:21 momjian Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.12 1997/03/12 20:48:27 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -381,10 +381,13 @@ ProcessUtility(Node *parsetree,
     case T_RuleStmt:            /* CREATE RULE */
 	{
 	    RuleStmt *stmt = (RuleStmt *)parsetree;
+	    int aclcheck_result;
+
 #ifndef NO_SECURITY
 	    relname = stmt->object->relname;
-	    if (!pg_aclcheck(relname, userName, ACL_RU))
-		elog(WARN, "%s %s", relname, ACL_NO_PRIV_WARNING);	
+	    aclcheck_result = pg_aclcheck(relname, userName, ACL_RU);
+	    if(aclcheck_result != ACLCHECK_OK)
+		elog(WARN, "%s: %s", relname, aclcheck_error_strings[aclcheck_result]);	
 #endif
 	    commandTag = "CREATE";
 	    CHECK_IF_ABORTED();
@@ -423,19 +426,21 @@ ProcessUtility(Node *parsetree,
 			 relname);
 #ifndef NO_SECURITY
 		if (!pg_ownercheck(userName, relname, RELNAME))
-		    elog(WARN, "you do not own class \"%s\"",
-			 relname);
+		    elog(WARN, "%s: %s", relationName, aclcheck_error_strings[ACLCHECK_NOT_OWNER]);
 #endif
 		RemoveIndex(relname);
 		break;
 	    case RULE:
 		{
 		    char *rulename = stmt->name;
+		    int aclcheck_result;
 #ifndef NO_SECURITY
 
 		    relationName = RewriteGetRuleEventRel(rulename);
-		    if (!pg_aclcheck(relationName, userName, ACL_RU))
-			elog(WARN, "%s %s", relationName, ACL_NO_PRIV_WARNING);
+		    aclcheck_result = pg_aclcheck(relationName, userName, ACL_RU);
+		    if(aclcheck_result != ACLCHECK_OK) {
+		        elog(WARN, "%s: %s", relationName, aclcheck_error_strings[aclcheck_result]);
+		    }
 #endif
 		    RemoveRewriteRule(rulename);
 		}
@@ -457,7 +462,7 @@ ProcessUtility(Node *parsetree,
 		    ruleName = MakeRetrieveViewRuleName(viewName);
 		    relationName = RewriteGetRuleEventRel(ruleName);
 		    if (!pg_ownercheck(userName, relationName, RELNAME))
-			elog(WARN, "%s %s", relationName, ACL_NO_PRIV_WARNING);
+			elog(WARN, "%s: %s", relationName, aclcheck_error_strings[ACLCHECK_NOT_OWNER]);
 		    pfree(ruleName);
 #endif
 		    RemoveView(viewName);

src/include/utils/acl.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: acl.h,v 1.4 1996/11/10 03:06:14 momjian Exp $
+ * $Id: acl.h,v 1.5 1997/03/12 20:48:48 scrappy Exp $
  *
  * NOTES
  *    For backward-compatability purposes we have to allow there
@@ -111,10 +111,14 @@ typedef ArrayType IdList;
 #define	ACL_MODE_WR_CHR		'w'
 #define	ACL_MODE_RU_CHR		'R'
 
-/* we use this warning string both for non-existent tables and
-   insufficient privilege so non-privileged users cannot ascertain whether 
-   the class exists or not */
-#define ACL_NO_PRIV_WARNING "Either no such class or insufficient privilege"
+/* result codes for pg_aclcheck */
+#define ACLCHECK_OK               0
+#define ACLCHECK_NO_PRIV          1
+#define ACLCHECK_NO_CLASS         2
+#define ACLCHECK_NOT_OWNER        3
+
+/* warning messages.  set these in aclchk.c. */
+extern char *aclcheck_error_strings[];
 
 /*
  * Enable ACL execution tracing and table dumps